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1

Artificial radioactivity in Carlingford Lough  

International Nuclear Information System (INIS)

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

2

Resuspension of radioactivity induced  

International Nuclear Information System (INIS)

Airborne particulates from burning fields outside the Hanford reservation were sampled with an aircraft-mounted air filter. Radioactivity concentrations in air samples collected from the smoke plume were compared to concentrations in ambient background air samples. Airborne concentrations of 7Be and 95Zr-Nb in the smoke were 1.2 to 4.6 times ambient background levels. (U.S.)

3

Induced radioactivity in LDEF components  

Science.gov (United States)

A systematic study of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is being carried out in order to gather information about the low earth orbit radiation environment and its effects on materials. The large mass of the LDEF spacecraft, its stabilized configuration, and long mission duration have presented an opportunity to determine space radiation-induced radioactivities with a precision not possible before. Data presented include preliminary activities for steel and aluminum structural samples, and activation subexperiment foils. Effects seen in the data show a clear indication of the trapped proton anisotropy in the South Atlantic Anomaly and suggest contributions from different sources of external radiation fluxes.

Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

1992-01-01

4

Natural and Artificial Radioactivity in Drinking Water in Malaga, Spain  

International Nuclear Information System (INIS)

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 radionucli

5

Modelling of artificial radioactivity migration in environment: a survey  

International Nuclear Information System (INIS)

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

6

Medical imaging was boosted by the discovery of artificial radioactivity  

International Nuclear Information System (INIS)

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.)

7

Radioactivity of natural and artificial building materials – a comparative study  

International Nuclear Information System (INIS)

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

8

Artificial radioactivity on the coasts of Northern Ireland  

International Nuclear Information System (INIS)

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)

9

Problem of Induced Radioactivity in Food Products  

International Nuclear Information System (INIS)

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 (?, ?')-reactions. In this range the 107Ag(?, ?') 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 ((?, ?') reactions the possibility of (?, 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 ?Ci/g food). Factors which determine the maximum permissible retermine the maximum permissible radiation energy and dose are discussed. (author)

10

Natural and artificial radioactivity determination of some medicinal plants  

Energy Technology Data Exchange (ETDEWEB)

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 ({sup 238}U, {sup 210}Po) and gamma ({sup 214}Pb-Bi, {sup 210}Pb, {sup 40}K and {sup 137}Cs) spectrometry. {sup 238}U ranged between <0.1 and 7.32 Bq kg{sub dry}{sup -1}; {sup 210}Po between <0.1 and 30.3 Bq kg{sub dry}{sup -1}; {sup 214}Pb-{sup 214}Bi between <0.3 and 16.6 Bq kg{sub dry}{sup -1}; {sup 210}Pb between <3 and 58.3 Bq kg{sub dry}{sup -1}; {sup 40}K between 66.2 and 3582.0 Bq kg{sub dry}{sup -1}; {sup 137}Cs between <0.3 and 10.7 Bq kg{sub dry}{sup -1}. The percentage of {sup 210}Po extraction in infusion and decoction was also determined; the arithmetical mean value of percentage of {sup 210}Po extraction resulted 20.7 {+-} 7.5.

Desideri, Donatella, E-mail: donatella.desideri@uniurb.i [Institute of General Chemistry, Urbino University ' Carlo Bo' , Piazza Rinascimento 6, 61029 Urbino (Italy); Meli, Maria Assunta; Roselli, Carla [Institute of General Chemistry, Urbino University ' Carlo Bo' , Piazza Rinascimento 6, 61029 Urbino (Italy)

2010-09-15

11

Artificial radioactivity in tide washed pastures in south west Scotland  

International Nuclear Information System (INIS)

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 ?Sv which is less than 6% of the ICRP principal dose limit of 1 mSv. (author)

12

Daily measurements of natural and artificial radioactivity in 1962  

International Nuclear Information System (INIS)

Daily numerical results of measures concerning ? 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 ??curie/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

Daily measurements of natural and artificial radioactivity in 1960  

International Nuclear Information System (INIS)

Daily numerical results of measures concerning ? 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 ??curie / 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)

14

Radioactivity induced by high-energy protons  

International Nuclear Information System (INIS)

Comparison of calculated and experimental data on induced radioactivity yields for comparatively light materials (7Be, 22Na, 24Na), produced in marble, cement and graphite under irradiation by 12 GeV protons, is conducted to increase the accuracy of forecasting the radiation situation at high-energy proton acceleration. Precision of the data, obtained is evaluated using various approximations

15

Investigations on natural and artificial radioactivity in Dobrogea  

International Nuclear Information System (INIS)

To evaluate potential impact of radioactive emissions of Cernavoda NPP on the environment, preliminary investigations on the radioactivity in the area and surroundings were carried out. Consequently the concentration of H-3 was determined in vine (leaves and sap) and viticulture products (grapes and wine) and the concentrations of K-40, Cs-137 and Sr-90 were measured in soil, surface water and aquatic sediments. The corresponding specific activities are generally characteristic for areas less contaminated by Chernobyl nuclear accident (except the northern area of Dobrogea where the Chernobyl fallout has produced a rather high contamination of the environment). For tritium, the results show values fitted in the range of natural background. (author)

16

Natural and artificial alpha radioactivity of platinum isotopes  

Energy Technology Data Exchange (ETDEWEB)

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 {sup 176}Pt to the excited level of {sup 172}Os, and the rare, quite recently observed, case of the natural alpha decay of {sup 190}Pt to the first excited level of {sup 186}Os. Comparison with other alpha decay half-life estimates for the naturally occurring platinum isotopes has also been presented.

Tavares, O A P; Medeiros, E L, E-mail: emil@cbpf.br [Centro Brasileiro de Pesquisas Fisicas-CBPF/MCT, Rua Dr Xavier Sigaud 150, 22290-180 Rio de Janeiro-RJ (Brazil)

2011-10-15

17

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

International Nuclear Information System (INIS)

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)

18

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

International Nuclear Information System (INIS)

In order to check radioactivity of beta-emmitters produced by (?, 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? 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 ?-activities were detected. From the amount of observed radioactivities of ?-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)

19

Evolution of artificial radioactivity in Channel sediments, 1971-1975  

International Nuclear Information System (INIS)

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 28?m 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

20

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

International Nuclear Information System (INIS)

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

 
 
 
 
21

Phonon-induced artificial magnetic fields  

CERN Document Server

We investigate the effect of a rotating Bose-Einstein condensate on a system of immersed impurity atoms trapped by an optical lattice. We analytically show that for a one-dimensional, ring-shaped setup the coupling of the impurities to the Bogoliubov phonons of the condensate leads to a non-trivial phase in the impurity hopping. The presence of this phase can be tested by observing a drift in the transport properties of the impurities. These results are quantitatively confirmed by a numerically exact simulation of a two-mode Bose-Hubbard model. We also give analytical expressions for the occurring phase terms for a two-dimensional setup. The phase realises an artificial magnetic field and can for instance be used for the simulation of the quantum Hall effect using atoms in an optical lattice.

Klein, Alexander

2008-01-01

22

Radioactively induced noise in gas-sampling uranium calorimeters  

International Nuclear Information System (INIS)

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 ?-particles from the uranium must be stopped before entering the sensing volume of gas-uranium calorimeters

23

Electromagnetically induced transparency on a single artificial atom  

CERN Document Server

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 controllability of individual artificial atoms and a possibility to manipulate the atomic states. The system can be used as a switchable mirror of microwaves and opens a good perspective for its applications in photonic quantum information processing and other fields.

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

2010-01-01

24

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

International Nuclear Information System (INIS)

This report gives the results of the measurements of artificial gross-?-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)

25

Artificial neural network application in isotopic characterization of radioactive waste drums  

International Nuclear Information System (INIS)

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)

26

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

27

Metaphase and anaphase in the artificially induced monopolar spindle.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

By using monopolar spindles artificially induced in sea urchin embryos, we examined whether or not the presence of two opposing poles was an indispensable condition for keeping chromosomes at a fixed distance from the pole at metaphase and for the anaphase chromosome movement. Chromosomes were stained with Hoechst dye 33342 and their behavior was followed in the monopolar and the control bipolar spindles. In the monopolar spindle, chromosomes were first arranged on a curved metaphase plate an...

Ito, K.; Masuda, M.; Fujiwara, K.; Hayashi, H.; Sato, H.

1994-01-01

28

Study on radioactivity and negative ion originated from a thoron artificial hot spring  

International Nuclear Information System (INIS)

To elucidate the various characteristic and their availabilities of the radioactivity and negative air ion originated from an artificial thoron hot spring, we simulated a hot spring, we simulated a hot spring condition using a monazite powder and measured the negative air ions and radioactivities in the condition. In the result, the radioactivity of the thorium series nuclide (208Tl) in monazite was 5.3 times of that of the uranium series nuclide (214Bi). For the pH(3.5-12.5) dependence of the leaching nuclides from monazite in water, the thorium series nuclides (228Ac, 212Pb) were well leached on the strong acid side because the monazite includes the rare earth element (REE) which was high ionization tendency and was substituted by the radioactive nuclide. On the other side, the uranium series nuclides (214Bi, 214Pb) leached in water were not detected because the specific activities of the uranium series nuclide are lower relative to those of the thorium series nuclide. Moreover, there were many negative air ions originated from monazite in the place within 10 cm away from the monazite surface. This is suggested that most negative ions exist within the range of the radiated ? rays. Negative air ions increased with increasing atmospheric relative humidity (35-60%). This is suggested that negative air ions stably existed in the hydration type such as O2-bar(H2O)n. Furthe>-bar(H2O)n. Furthermore, for the hydrous rate dependence of the negative air ions originated from monazite, the negative air ions without supernatant fluid were larger than those with supernatant fluid, because ? rays ionized water on the surface of monazite. (author)

29

Table of nuclear reactions and subsequent radioactive dacays induced by 14-MeV neutrons  

International Nuclear Information System (INIS)

Compilation of the data on nuclear reactions and subsequent radioactive decays induced by 14-MeV neutrons is presented in tabular form for most of the isotopes available in nature and for some of the artificially-produced isotopes, including the following items: Nuclide (isotopic abundance), type of nuclear reaction, reaction Q-value, reaction product, type of decay, decay Q-value, half-life of reaction product, decay product, maximum reaction cross section, neutron energy for maximum cross section, reaction cross section for 14 MeV neutrons, saturated radioactivity induced by irradiation of a neutron flux of 1 n/cm2sec for a mol of atoms, and reference for the cross section. The mass number dependence of (n, ?), (n, 2n), (n, p), (n, d), (n, t), (n, 3He) and (n, ?) reaction cross sections for 14-MeV neutrons is given in figures to show general trends of the cross sections

30

Monitoring induced denitrification in an artificial aquifer recharge system.  

Science.gov (United States)

As demands on groundwater increase, artificial recharge is becoming a common method for enhancing groundwater supply. The Llobregat River is a strategic water supply resource to the Barcelona metropolitan area (Catalonia, NE Spain). Aquifer overexploitation has leaded to both a decrease of groundwater level and seawater intrusion, with the consequent deterioration of water quality. In the middle section of the aquifer, in Sant Vicenç del Horts, decantation and infiltration ponds recharged by water from the Llobregat River (highly affected from wastewater treatment plant effluents), were installed in 2007, in the framework of the ENSAT Life+ project. At the bottom of the infiltration pond, a vegetal compost layer was installed to promote the growth of bacteria, to induce denitrification and to create favourable conditions for contaminant biodegradation. This layer consists on a mixture of compost, aquifer material, clay and iron oxide. Understanding the fate of contaminants, such as nitrate, during artificial aquifer recharge is required to evaluate the impact of artificial recharge in groundwater quality. In order to distinguish the source of nitrate and to evaluate the capability of the organic reactive layer to induce denitrification, a multi-isotopic approach coupled with hydrogeochemical data was performed. Groundwater samples, as well as river samples, were sampled during artificial and natural recharge periods. The isotopic analysis included: ?15N and ?18O of dissolved nitrate, ?34S and ?18O of dissolved sulphate, ?13C of dissolved inorganic carbon, and ?2H and ?18O of water. Dissolved nitrate isotopic composition (?15NNO3 from +9 to +21 o and ?18ONO3 from +3 to +16 ) demonstrated that heterotrophic denitrification induced by the reactive layer was taking place during the artificial recharge periods. An approximation to the extent of nitrate attenuation was calculated, showing a range between 95 and 99% or between 35 and 45%, by using the extreme literature ?N values of -4o and -22o respectively (Aravena and Robertson, 1998; Pauwels et al., 2000). Ongoing denitrification batch experiments will allow us to determine the specific nitrogen and oxygen isotopic fractionation induced by the organic reactive layer, in order to estimate more precisely the extent of denitrification during artificial aquifer recharge. These results confirmed that the reactive layer induces denitrification in the recharge ponds area, proving the usefulness of an isotopic approach to characterize water quality improvement occurring during artificial aquifer recharge. References 1. Aravena, R., Robertson, W.D., 1998. Use of multiple isotope tracers to evaluate denitrification in ground water: Study of nitrate from a large-flux septic system plume. Ground Water, 36(6): 975-982. 2. Pauwels, H., J.C., Kloppmann, W., 2000. Denitrification and mixing in a schist aquifer: Influence on water chemistry and isotopes. Chemical Geology, 168(3-4): 307-324. Acknowledgment This study was supported by the projects CGL2011-29975-C04-01 from the Spanish Government, 2009SGR-00103 from the Catalan Government and ENPI/2011/280-008 from the European Commission. Please fill in your abstract text.

Grau-Martinez, Alba; Torrentó, Clara; Folch, Albert; Domènech, Cristina; Otero, Neus; Soler, Albert

2014-05-01

31

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

Science.gov (United States)

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 ?-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

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

2014-01-01

32

Artificial neural networks modeling of radioactive contamination of the Techa river  

International Nuclear Information System (INIS)

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

33

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

International Nuclear Information System (INIS)

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)

34

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

International Nuclear Information System (INIS)

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 ?-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

35

Simulation of induced radioactivity for Heavy Ion Medical Machine  

CERN Document Server

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.

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

2013-01-01

36

Radioactivity  

International Nuclear Information System (INIS)

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.)

37

Induced radioactivity in the ESRF storage ring.  

Science.gov (United States)

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

Berkvens, P

2005-01-01

38

Emissions induced by the process of radioactive remnants conditioning  

International Nuclear Information System (INIS)

The techniques applied in the Decontamination Dept., HDB, for conditioning radioactive primary and secondary waste induce emission of radiological and chemical pollutants. The paper explains the current common practice of emission monitoring and presents data of the plant-specific release of pollutants via the gaseous and liquid effluents pathway. Practice has shown that there have been no problems at all in keeping the emissions from operation below the regulatory maximum acceptable limits. The amounts released are so small that the effects on the environment remain at minimum level. Thus pollutant emission is not a factor restricting the processing of radioactive remnants or primary waste, even if high-level radioactive inventories are involved, if conditioning systems are designed and constructed in line with the appropriate operating data accumulated so far, and if emssion control is made a prime goal in the planning, control and monitoring of procedures and processes. (orig.)

39

Metaphase and anaphase in the artificially induced monopolar spindle.  

Science.gov (United States)

By using monopolar spindles artificially induced in sea urchin embryos, we examined whether or not the presence of two opposing poles was an indispensable condition for keeping chromosomes at a fixed distance from the pole at metaphase and for the anaphase chromosome movement. Chromosomes were stained with Hoechst dye 33342 and their behavior was followed in the monopolar and the control bipolar spindles. In the monopolar spindle, chromosomes were first arranged on a curved metaphase plate and then spread on a part of the imaginary surface of a sphere whose center was the monopole. The estimated chromosome-to-pole distance was similar to that of bipolar spindles at metaphase and remained fixed until chromosomes started to move toward the pole. The average duration of metaphase in the monopolar spindle was 6 times longer than that in the bipolar spindle. The poleward movement of chromosomes in the monopolar spindle was similar to the anaphase A (chromosome-to-pole movement) in the bipolar spindle with respect to the velocity, duration, distance, and synchronization of migration. These results show that even half of the normal spindle has capacities for the arrangement of chromosomes at metaphase and for the anaphase A chromosome movement. Based on these results, we were able to exclude some existing theories of metaphase, such as the one based on the balance of forces between the two poles. PMID:8171013

Ito, K; Masuda, M; Fujiwara, K; Hayashi, H; Sato, H

1994-04-26

40

Prediction of radiation induced liver disease using artificial neural networks  

International Nuclear Information System (INIS)

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)

 
 
 
 
41

Artificial sweeteners induce glucose intolerance by altering the gut microbiota.  

Science.gov (United States)

Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage. PMID:25231862

Suez, Jotham; Korem, Tal; Zeevi, David; Zilberman-Schapira, Gili; Thaiss, Christoph A; Maza, Ori; Israeli, David; Zmora, Niv; Gilad, Shlomit; Weinberger, Adina; Kuperman, Yael; Harmelin, Alon; Kolodkin-Gal, Ilana; Shapiro, Hagit; Halpern, Zamir; Segal, Eran; Elinav, Eran

2014-10-01

42

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

Science.gov (United States)

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 “inducedradioactivity 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.

Kolar, Z. I.

1999-01-01

43

Radioactive-induced tumors by phosphorus-32 as colloidal compound  

International Nuclear Information System (INIS)

Chromic colloidal phosphate labeled with 32P, which has been proposed for the treatment of several articular diseases, was injected intra-articularly in the knee joint of adult Wistar rats. After a 270 days minimum latent period, tumors began to appear in the injected zone, to a 70% frequency. Ten lung metastases were detected. In five cases, squamous cell carcinomas were induced in the injected area. The relevance of a sound evaluation of the risk involved in treatments with radioactive isotopes, is discussed

44

The induced radioactivity danger parameter for gamma radiation  

International Nuclear Information System (INIS)

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)

45

Anthrax toxin-induced rupture of artificial lipid bilayer membranes  

Science.gov (United States)

We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm.

Nablo, Brian J.; Panchal, Rekha G.; Bavari, Sina; Nguyen, Tam L.; Gussio, Rick; Ribot, Wil; Friedlander, Art; Chabot, Donald; Reiner, Joseph E.; Robertson, Joseph W. F.; Balijepalli, Arvind; Halverson, Kelly M.; Kasianowicz, John J.

2013-08-01

46

The content of natural radioactive elements and artificial radioisotopes in Moldova's soils  

International Nuclear Information System (INIS)

The results of multiyear investigations of natural radionuclide (U-238, Th-232, Ra-226, K-40) and artificial isotopes (Sr-90, Cs-137, I-131) content on soil and plants are presented. Six anomalous polluted areas were detected after Chernobyl nuclear power plant accident. (authors)

47

Induced radioactivity in and around high-energy particle accelerators  

International Nuclear Information System (INIS)

Particle accelerators and their surroundings are locations of residual radioactivity production that is induced by the interaction of high-energy particles with matter. This paper gives an overview of the principles of activation caused at proton accelerators, which are the main machines operated at Conseil Europeen pour la Recherche Nucleaire. It describes the parameters defining radio-nuclide production caused by beam losses. The second part of the paper concentrates on the analytic calculation of activation and the Monte Carlo approach as it is implemented in the FLUKA code. Techniques used to obtain, on the one hand, estimates of radioactivity in Becquerel and, on the other hand, residual dose rates caused by the activated material are discussed. The last part of the paper focuses on experiments that allow for benchmarking FLUKA activation calculations and on simulations used to predict activation in and around high-energy proton machines. In that respect, the paper addresses the residual dose rate that will be induced by proton-proton collisions at an energy of two times 7 TeV in and around the Compact Muon Solenoid (CMS) detector. Besides activation of solid materials, the air activation expected in the CMS cavern caused by this beam operation is also discussed. (authors)

48

Induced radioactivity in and around high-energy particle accelerators.  

Science.gov (United States)

Particle accelerators and their surroundings are locations of residual radioactivity production that is induced by the interaction of high-energy particles with matter. This paper gives an overview of the principles of activation caused at proton accelerators, which are the main machines operated at Conseil Européen pour la Recherche Nucléaire. It describes the parameters defining radio-nuclide production caused by beam losses. The second part of the paper concentrates on the analytic calculation of activation and the Monte Carlo approach as it is implemented in the FLUKA code. Techniques used to obtain, on the one hand, estimates of radioactivity in Becquerel and, on the other hand, residual dose rates caused by the activated material are discussed. The last part of the paper focuses on experiments that allow for benchmarking FLUKA activation calculations and on simulations used to predict activation in and around high-energy proton machines. In that respect, the paper addresses the residual dose rate that will be induced by proton-proton collisions at an energy of two times 7 TeV in and around the Compact Muon Solenoid (CMS) detector. Besides activation of solid materials, the air activation expected in the CMS cavern caused by this beam operation is also discussed. PMID:21697180

Vincke, Helmut; Theis, Chris; Roesler, Stefan

2011-07-01

49

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

International Nuclear Information System (INIS)

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)

50

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

International Nuclear Information System (INIS)

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)

51

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

Energy Technology Data Exchange (ETDEWEB)

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).

Davies, A.N.; Singer, J. (Saint Thomas' Hospital, London (United Kingdom). South East London Radiotherapy Dept.)

1994-08-01

52

Measurement of natural radioactivity and radiation hazards for some natural and artificial building materials available in Romania  

International Nuclear Information System (INIS)

As building materials are known to be the second source regarding high radon concentrations, it is very important to determine the amounts of natural radionuclides from every building material in use. In the present study the most frequently used Romanian natural (sand, gypsum, limestone) and artificial (portland cement, lime, clinker, electrofilter powder, fly ash, cement-lime plaster mortar, cement plaster mortar) building materials were analyzed. The absorbed dose rate and the annual effective dose equivalent rate for people living in dwelling buildings made of these building materials under investigation were also calculated. The analysis was performed with gamma-ray spectrometry, with two hyper-pure germanium detectors. The activity concentrations of natural radionuclides were in the ranges: 5.2-511.8 Bq kg-21 for 226Ra; 0.6-92.6 Bq kg-1 for 232Th and -1 for 40K, respectively. The radium equivalent activity in the fifty-one (51) samples varied from 9 to 603 Bq kg-1. By calculating all the radioactivity indices (Raeq, Hext, I?, Iyr) it was found that all the building materials under investigation can be used to erect dwelling buildings. Except for sample SA6, SA7 and SA11 among the natural building materials and sample SG1, SG2, FAH1, CLM1, CM1 among the artificial building materials that are considered hazardous materials when are used in large quantities. (author)

53

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

International Nuclear Information System (INIS)

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 ?-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)

54

Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2010-06-15

55

NATURAL AND ARTIFICIAL RADIOACTIVITY IN BULGARIAN SOILS ALONG THE DANUBE RIVER  

Directory of Open Access Journals (Sweden)

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.

I YORDANOVA

2005-07-01

56

Natural and artificial radioactivity distribution In soil of Fars province (IR)  

International Nuclear Information System (INIS)

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 40K, 137Cs, 232Th and 238U 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. (authors)

57

A Transport Model for Nuclear Reactions Induced by Radioactive Beams  

CERN Document Server

Major ingredients of an isospin and momentum dependent transport model for nuclear reactions induced by radioactive beams are outlined. Within the IBUU04 version of this model we study several experimental probes of the equation of state of neutron-rich matter, especially the density dependence of the nuclear symmetry energy. Comparing with the recent experimental data from NSCL/MSU on isospin diffusion, we found a nuclear symmetry energy of $% E_{sym}(\\rho )\\approx 31.6(\\rho /\\rho_{0})^{1.05}$ at subnormal densities. Predictions on several observables sensitive to the density dependence of the symmetry energy at supranormal densities accessible at GSI and the planned Rare Isotope Accelerator (RIA) are also made.

Li, B A; Das, C B; Das-Gupta, S; Gale, C; Ko, C M; Yong, G C; Zuo, W; Li, Bao-An; Chen, Lie-Wen; Das, Champak B.; Gupta, Subal Das; Gale, Charles; Ko, Che Ming; Yong, Gao-Chan; Zuo, Wei

2005-01-01

58

Destabilization of artificial biomembrane induced by the penetration of tryptophan  

International Nuclear Information System (INIS)

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. ?-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 ? and 3.573 x 10-8 F to 1.391 x 106 ? 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.

59

Destabilization of artificial biomembrane induced by the penetration of tryptophan  

Energy Technology Data Exchange (ETDEWEB)

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.

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

60

Destabilization of artificial biomembrane induced by the penetration of tryptophan  

Science.gov (United States)

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. ?-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 × 10 -3 mol L -1, the limiting molecular area of lecithin increased from 110.5 to 138.5 Å 2, 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 × 10 6 ? and 3.573 × 10 -8 F to 1.391 × 10 6 ? and 3.340 × 10 -8 F when the concentration of tryptophan increased from 0 to 2 × 10 -3 mol L -1. Correspondingly, the breakdown voltage of s-BLM decreased from 2.51 to 1.72 V.

Chen, Liuhua; Gan, Lihua; Liu, Mingxian; Fan, Rong; Xu, Zijie; Hao, Zhixian; Chen, Longwu

2011-03-01

 
 
 
 
61

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

62

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

International Nuclear Information System (INIS)

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

63

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

International Nuclear Information System (INIS)

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)

64

Comparative experimental analysis of the effect caused by artificial and real induced damage in composite laminates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the results of an extensive experimental campaign aimed to examine the effect upon the vibration response and on the residual load-bearing capacity caused by both: isolated artificially induced interlaminar damage and low-velocity impact induced damage in composite laminates. The experimental programme included modal testing, drop-weight impact testing, ultrasonic inspection, transverse quasi-static loading testing and compression testing conducted on a set of 72 carbon fi...

Pe?rez Marti?nez, Marco Antonio; Gil Espert, Llui?s; Sa?nchez Romero, Montserrat; Oller Marti?nez, Sergio Horacio

2014-01-01

65

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 invento...

Li, Y.; Chen, G.; Tang, C.; Zhou, G.; Zheng, L.

2012-01-01

66

Electromagnetically Induced Transparency Using a Artificial Molecule in Circuit Quantum Electrodynamics  

Directory of Open Access Journals (Sweden)

Full Text Available 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 susceptibility for the artificial system via the density matrix formalism. The complex susceptibility has additional dependence on the qubit parameters and hence can be tuned to a certain extent.

Hai-Chao Li

2013-06-01

67

Scoping estimates of the LDEF satellite induced radioactivity  

Science.gov (United States)

The Long Duration Exposure Facility (LDEF) satellite was recovered after almost six years in space. It was well-instrumented with ionizing radiation dosimeters, including thermoluminescent dosimeters, plastic nuclear track detectors, and a variety of metal foil samples for measuring nuclear activation products. The extensive LDEF radiation measurements provide the type of radiation environments and effects data needed to evaluate and help resolve uncertainties in present radiation models and calculational methods. A calculational program was established to aid in LDEF data interpretation and to utilize LDEF data for assessing the accuracy of current models. A summary of the calculational approach is presented. The purpose of the reported calculations is to obtain a general indication of: (1) the importance of different space radiation sources (trapped, galactic, and albedo protons, and albedo neutrons); (2) the importance of secondary particles; and (3) the spatial dependence of the radiation environments and effects expected within the spacecraft. The calculational method uses the High Energy Transport Code (HETC) to estimate the importance of different sources and secondary particles in terms of fluence, absorbed dose in tissue and silicon, and induced radioactivity as a function of depth in aluminum.

Armstrong, Tony W.; Colborn, B. L.

1990-01-01

68

Radioactivity  

International Nuclear Information System (INIS)

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.)

69

The possibilities and limits of monitoring of artificial radioactivity of seawater by measuring the gross radiation at permanent measuring stations at sea  

International Nuclear Information System (INIS)

A radiological measuring network is operated in the Heligoland Bay and the western Baltic. The monitoring equipment is installed on lightships and on Heligoland. Radon decomposition products are found to a depth of 15 m in the water. The artificial radioactivity in the range of 0.1-10 p Ci/l found in the sea is monitored by flux counters as it varies with time. (DG)

70

Study of genetic effects in plants induced by natural radioactivity in southwest France  

International Nuclear Information System (INIS)

Southwest France has a number of radioactive areas with an average background rate ranging between 1 and 30 ?rads/h. Reference response curves were established for the ?1+/?1 ?2+/?2 system of tobacco in the artificially radioactive site of the French Atomic Energy Commission at Cadarache (137Cs); the response was found to be linear between 10 ?rads/h (background) and 1 rad/h. The response of the system, together with that of the waxy system in Barley, was then studied over natural uranous sites in the Permian Basin of Lodeve (Herault) and the area of Lagravette

71

Evaluation of radioactivity induced by patient-specific devices in proton therapy  

Energy Technology Data Exchange (ETDEWEB)

Estimating the radioactivity induced by patient-specific devices installed near the patient skin is important, because patients are directly exposed during the treatment. This study evaluated the radioactivity induced by a brass collimator and a PMMA range compensator in a proton beam and identified the radionuclides produced by nuclear interactions with the proton beam and with the patient-specific devices. The total dose rate depended on the radionuclides, which had short decay times and 1 hour later their activities reach about one-fiftieth of the initial values in the cases of both PMMA and brass. Although the radioactivity induced by proton therapy can affect patients during the radiotherapy, the total radiation dose is much smaller than the prescribed dose for cancer treatment, and the treatment time is very short. Therefore, the radioactivity induced by patient-specific devices should be negligible.

Lee, Sang Hoon; Cho, Sung Koo; You, Seung Hoon; Shin, Dong Ho; Park, Sung Yong; Lee, Se Byeong [National Cancer Center, Goyang (Korea, Republic of); Kwak, Jung Won [Asan Medical Center, Seoul (Korea, Republic of); Woo, Jong Kwan [Jeju National University, Jeju (Korea, Republic of); Kim, Dae Hyun [Catholic University, Seoul (Korea, Republic of)

2012-01-15

72

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

Science.gov (United States)

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.

Smith, Mark; Logar, John; Vrain, Olivier

2014-12-01

73

Artificial Vaginocervical Stimulation Induces a Conditioned Place Preference in Female Rats  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Female rats express a conditioned place preference (CPP) for a context paired with mating. During a mating encounter, the female rat is exposed to several different types of stimuli, including, but not limited to, vaginocervical stimulation and social contact. The present experiment tested the hypothesis that two components of the mating interaction, vaginocervical stimulation or social contact, each induce a CPP in female rats. During conditioning rats received nonpaced mating, artificial va...

Meerts, Sarah H.; Clark, Ann S.

2009-01-01

74

Laboratory Observations of Wave-Induced Radial Transport within an "Artificial Radiation Belt"  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Wave-induced radial transport of energetic electrons has been observed in a laboratory terrella. In the experiment, electron-cyclotron-resonance heating (ECRH) is used to create a localized population of trapped energetic electrons (1 keV < Eh < 50 keV) within a low-density discharge which we refer to as an "artificial radiation belt." As the intensity of the radiation belt increases, quasiperiodic bursts of drift-resonant fluctuations, ? ? ?dh, are excited. The frequency spectrum of this...

Mauel, M.

1997-01-01

75

Radioactivity of Tobacco Leaves and Radiation Dose Induced from Smoking  

Directory of Open Access Journals (Sweden)

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 ?Sv/y (average 79.7 ?Sv/y, while for 228Ra from 19.3 to 116.0 ?Sv/y (average 67.1 ?Sv/y and for 210Pb from 47.0 to 134.9 ?Sv/y (average 104.7 ?Sv/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 ?Sv/y (average 251.5 ?Sv/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.

Constantin Papastefanou

2009-02-01

76

Evaluation of induced radioactivity in 10 MeV electron-irradiated spices  

International Nuclear Information System (INIS)

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.)

77

Evaluation of induced radioactivity in 10 MeV electron-irradiated spices  

Energy Technology Data Exchange (ETDEWEB)

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.).

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

78

Sunlight-induced pyrimidine dimers in human skin fibroblasts in comparison with dimerization after artificial UV-irradiation  

International Nuclear Information System (INIS)

We compared artificial UV-sources such as germicidal- or sun-lamps with summer noon sunlight in Switzerland for selective efficiency in the induction of pyrimidine dimers in the DNA of human cells. In our studies we determined cytosine-thymine (C-T) as well as thymine-thymine dimer densities (T-T) by high pressure liquid chromatography in cultures of xeroderma pigmentosum cells of group A. Using far-UV light from a germicidal lamp, we found a rate of formation per Jm-2 for C-T and T-T of 0.0019% and 0.0024%, respectively, of the total thymine radioactivity in hydrolysates of [3H]thymidine labeled cells. After irradiation with an unfiltered sunlamp, we measured a rate of formation of 0.0005% per Jm-2 both for C-T and T-T, based on the sunlamp emission of 297 ± 4 nm wavelength. Utilization of Kodacel- or Mylar-filters lowered the rate of dimerization by a factor of 2 and 60, respectively. One hour of irradiation with noon summer sunlight induced 0.038 ± 0.012% C-T and 0.036 ± 0.011% T-T. This extent of dimer production is equivalent to 15 Jm-2 of far-UV exposure at 254 nm. (author)

79

Induced-radioactivity in J-PARC spallation neutron source  

International Nuclear Information System (INIS)

Radioactivity estimation was performed on a MW-class spallation neutron source by using the DCHAIN-SP code system to design facility from both safety and maintenance points of view. Remote handling procedures and shielding parameters were considered based on the estimation. The results are reflected on the design of J-PARC neutron source facility. (author)

80

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

International Nuclear Information System (INIS)

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)

 
 
 
 
81

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

International Nuclear Information System (INIS)

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

82

Studies of Muon-Induced Radioactivity at NuMI  

International Nuclear Information System (INIS)

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.

83

Studies of muon-induced radioactivity at NuMI  

Energy Technology Data Exchange (ETDEWEB)

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.

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

84

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

85

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

International Nuclear Information System (INIS)

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

86

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

International Nuclear Information System (INIS)

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.)

87

Induced radioactivity and residual dose rates in the LHC experiments  

International Nuclear Information System (INIS)

The Large Hadron Collider (LHC) at CERN started beam operations in 2008 and has clearly outperformed initial expectations. At the two biggest LHC experiments, ATLAS and CMS, the delivered integrated luminosity (which refers to the number of inelastic interactions during a certain time interval) for 2011 has been exceeded by a factor of almost 6 compared with its initial goal given at the beginning of 2010. LHCb and ALICE are operating already at their nominal luminosities and even above. Consequently, radiation levels in the LHC experiments are increasing. Further, the amount of radioactive material inside the experiments is becoming larger. Predictions of the expected residual dose rate during accesses are necessary in order to plan and co-ordinate work activities inside the experimental caverns. The Monte-Carlo particle transport code FLUKA was used to assess the expected prompt and residual dose rates at the LHC experiments. Further, the code was used to calculate the amount of material which would become radioactive and therefore requires special treatment and alertness when being handled, modified, stored or shipped. Estimates of radiation levels are presented and compared with the first measurements. An outlook of the expected radiation levels after several additional years of LHC operation is also given. (authors)

88

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

International Nuclear Information System (INIS)

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 ?-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)

89

IRACM : A code system to calculate induced radioactivity produced by ions and neutrons  

International Nuclear Information System (INIS)

It is essential to estimate of radioactivity induced in accelerator components and samples bombarded by energetic ion beams and the secondary neutrons of high-energy accelerator facilities in order to reduce the amount of radioactive wastes and to minimize radiation exposure to personnel. A computer code system IRACM has been developed to estimate product nuclides and induced radioactivity in various radiation environments of accelerator facilities. Nuclide transmutation with incident particles of neutron, proton, deuteron, alpha, 12C, 14N, 16O, 20Ne and 40Ar can be computed for arbitrary multi-layer target system in a one-dimensional geometry. The code system consists of calculation modules and libraries including activation cross sections, decay data and photon emission data. The system can be executed in both FACOM-M780 mainframe and DEC workstations. (author)

90

Radioactivity induced by cosmic radiation in the Saint Severin meteorite  

International Nuclear Information System (INIS)

On 27 June 1966 at 2.40 p.m. G.M.T., a stone meteorite (chondrite) fell close to Saint Severin (Charente, France). Eight fragments were found with respective masses of 113 kg, 57.6 kg, 46 kg, 27.2 kg, 19.9 kg, 5.2 kg, 2.7 kg and 0.35 kg. They are distributed with good approximation along a straight line in the east-west direction over a distance of about 10 km. Low-activity gamma spectrometry measurements (NaI(Tl) scintillator 10 cm x 8 cm) were commenced on the 113 kg fragment only 60 hours after it fell, allowing the detection of short-lived radioactive cosmonuclides. The following nuclides were found: 24Na, 5'2Mn, 48V, 56Co + 58Co, 46Sc, 54Mn, 22Na, 60Co, 26A1 and 40K. (author)

91

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  

International Nuclear Information System (INIS)

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)

92

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

Directory of Open Access Journals (Sweden)

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%.

S. Lee

2006-01-01

93

Bluelight-induced, flavin-mediated transport of redox equivalents across artificial bilayer membranes  

International Nuclear Information System (INIS)

This paper continues studies of physico-chemical properties of vesicle-bound flavins. Based on previous results, an advanced model system was designed in order to study the mechanisms underlying bluelight-induced redox transport across artificial membranes. The lumen of single-shelled vesicles was charged with cytochrome c, and amphiphilic flavin (AF1 3, AF1 10) was bound to the membrane. Upon bluelight irradiation redox equivalents are translocated from exogeneous 1e-(EDTA)-and 2e-(BH3CN-) donors across the membrane finally reducing the trapped cytochrome c both under aerobic and anaerobic conditions. The mechanisms involved are explored and evidence for the involvement of various redox states of oxygen, dihydroflavin and flavosemiquinone is presented

94

Artificially-induced organelles are optimal targets for optical trapping experiments in living cells.  

Science.gov (United States)

Optical trapping supplies information on the structural, kinetic or rheological properties of inner constituents of the cell. However, the application of significant forces to intracellular objects is notoriously difficult due to a combination of factors, such as the small difference between the refractive indices of the target structures and the cytoplasm. Here we discuss the possibility of artificially inducing the formation of spherical organelles in the endoplasmic reticulum, which would contain densely packed engineered proteins, to be used as optimized targets for optical trapping experiments. The high index of refraction and large size of our organelles provide a firm grip for optical trapping and thereby allow us to exert large forces easily within safe irradiation limits. This has clear advantages over alternative probes, such as subcellular organelles or internalized synthetic beads. PMID:25071944

López-Quesada, C; Fontaine, A-S; Farré, A; Joseph, M; Selva, J; Egea, G; Ludevid, M D; Martín-Badosa, E; Montes-Usategui, M

2014-07-01

95

Induced radioactivity of LDEF materials and structural components  

Science.gov (United States)

We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEO) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design.

Harmon, B. A.; Laird, C. E.; Fishman, G. J.; Parnell, T. A.; Camp, D. C.; Frederick, C. E.; Hurley, D. L.; Lindstrom, D. J.; Moss, C. E.; Reedy, R. C.; Reeves, J. H.; Smith, A. R.; Winn, W. G.; Benton, E. V.

1996-01-01

96

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

Energy Technology Data Exchange (ETDEWEB)

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

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

97

Comparison of the performances of nanosecond and femtosecond Laser Induced Breakdown Spectroscopy for depth profiling of an artificially corroded bronze  

Science.gov (United States)

Single Pulse Laser Induced Breakdown Spectroscopy (SP-LIBS), performed by nanosecond and femtosecond laser sources has been applied to the study of the depth profiling of the artificially obtained patina of a bronze sample. The results show improved performances of femtosecond LIBS compared to nanosecond one. The differences found in the analyses are related to the different laser-matter interaction processes induced by the different time duration of the laser pulses.

De Bonis, A.; De Filippo, B.; Galasso, A.; Santagata, A.; Smaldone, A.; Teghil, R.

2014-05-01

98

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

Directory of Open Access Journals (Sweden)

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%.

Y. Li

2012-08-01

99

Alginate bead fabrication and encapsulation of living cells under centrifugally induced artificial gravity conditions.  

Science.gov (United States)

This study presents a novel method for the direct, centrifugally induced fabrication of small, Ca2+-hardened alginate beads at polymer-tube micronozzles. The bead diameter can arbitrarily be adjusted between 180-800 microm by the nozzle geometry and spinning frequencies between 5-28 Hz. The size distribution of the main peak features a CV of 7-16%, only. Up to 600 beads per second and channel are issued from the micronozzle through an air gap towards the curing agent contained in a standard lab tube ('Eppi'). Several tubes can be mounted on a 'flying bucket' rotor where they align horizontally under rotation and return to a vertical position as soon as the rotor is at rest. The centrifugally induced, ultra-high artificial gravity conditions (up to 180 g) even allow the micro-encapsulation of alginate solutions displaying viscosities up to 50 Pa s, i.e. approximately 50,000 times the viscosity of water! With this low cost technology for microencapsulation, HN25 and PC12 cells have successfully been encapsulated while maintaining vitality. PMID:18465307

Haeberle, Stefan; Naegele, Lars; Burger, Robert; von Stetten, Felix; Zengerle, Roland; Ducrée, Jens

2008-06-01

100

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

Science.gov (United States)

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%.

Li, Y.; Chen, G.; Tang, C.; Zhou, G.; Zheng, L.

2012-08-01

 
 
 
 
101

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

International Nuclear Information System (INIS)

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

102

Decay radioactivity induced in plasma-facing materials by deutrium-tritium neutrons  

International Nuclear Information System (INIS)

Deuterium-tritium (D-T) neutron-induced radioactivity constitutes one of the foremost issues in fusion reactor design. Designers have been using radioactivity codes and associated nuclear data libraries for nucleonic designs of fusion reactors. However, in the past, there was hardly any experimental validation of these codes/libraries. An elaborate, experimental program was initiated in 1988 under a U.S. Department of Energy/Japan Atomic Energy Research Institute collaborative program to validate the radioactivity codes/libraries. As many as 14 neutron energy spectra were covered for a number of materials. The analyses of the isotopic activities of the irradiated materials using the activation cross-section libraries of four leading radioactivity codes, i.e., ACT4/THIDA-1, REAC-3. DKR-ICF; and RACC, have shown large discrepancies among the calculations on one hand and between the calculations and the measurements, on the other. Vanadium, Co, Ni, Zn, Zr, Mo, In, Sn, and W each count the largest number of discrepant isotopic activities. In addition to providing detailed results of the status of predictability of individual isotopic activities using the ACT4, REAC-3, DKR-ICF, and RACC activation cross-section libraries, safety factors cum quality factors characterizing each library are presented and discussed. The related issues of confidence level and associated uncertainty are also highlighted. 37 refs., 112 figs., 24 tabs

103

2-(2-Phenylethyl)chromone derivatives from Chinese agarwood induced by artificial holing.  

Science.gov (United States)

Three new 2-(2-phenylethyl)chromone derivatives (1-3), together with thirteen known ones (4-16), were isolated from the EtOAc extract of Chinese agarwood induced by artificial holing, originating from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae). The chemical structures of the new compounds were identified by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). Compounds 1, 6, 15 and 16 exhibited inhibitory effects on Staphylococcus aureus, and compounds 15 and 16 showed inhibitory effects on Ralstonia solanacearum. Compounds 1-3, 7, 9, 11, 12, 15 and 16 exhibited acetylcholinesterase inhibitory activity. A possible biogenetic pathway of compounds 1-16 was proposed to show the relationships between diepoxy-tetrahydro-2-(2-phenylethyl)chromones, epoxy-tetrahydro-2-(2-phenylethyl) chromones, tetrahydro-2-(2-phenylethyl)chromones, and 2-(2-phenylethyl)chromones of the flidersia type, the four main types of 2-(2-phenylethyl)chromones found in agarwood, on the basis of their appearances in different stage of agarwood formation. PMID:25068202

Li, Wei; Cai, Cai-Hong; Dong, Wen-Hua; Guo, Zhi-Kai; Wang, Hao; Mei, Wen-Li; Dai, Hao-Fu

2014-10-01

104

BH3-based Fusion Artificial Peptide Induces Apoptosis and Targets Human Colon Cancer  

Science.gov (United States)

Dysregulation of apoptosis is a pilot event before cancer development and plays important roles for cancer to develop resistance to chemical therapeutics. So exploring strategies to recovery the apoptosis balance is a charming and long-endeavored aim in the attempts to conquer cancers. The present study shows an exciting potency of a fusion peptide to inhibit and target to cancer cells, which is composed of BH3 (Bcl-2 Homology 3) effector domain from PUMA (p53 upregulated modulator of apoptosis) and targeting domain of trans-activator of transcription (TAT) and DV3. The in vitro results demonstrated cancer growth inhibition by the fusion peptide in colon cancer cells, as well as in lung adenocarcinoma cell line and breast carcinoma cell line of human origin. But the viability of HEK293, a noncancerous cell line, was not affected, indicating the cancer specificity of the fusion peptide. Apoptosis activation was induced by the peptide through the mitochondria pathway. In vivo studies displayed its tumor inhibiting ability by intratumoral injection. When the fusion peptide was administered systematically by tail vein, the peptide targeted the established tumors in nude mice. No other organs were significantly involved. The fusion peptide is an artificially designed molecule worthy of further evaluation and development. PMID:19352325

Liu, Yongjun; Li, Yunfeng; Wang, Haijuan; Yu, Jing; Lin, Hongwei; Xu, Dongkui; Wang, Yang; Liang, Ailing; Liang, Xiao; Zhang, Xueyan; Fu, Ming; Qian, Haili; Lin, Chen

2009-01-01

105

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

Science.gov (United States)

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.

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

2014-09-01

106

Evaluation of transmutation and low induced radioactivity and requirements for candidate structural materials  

International Nuclear Information System (INIS)

The effects of fusion neutron spectrum and fluence on the evaluation of transmutation and induced radioactivity of candidate reduced and/or low activation materials such as 9Cr-2W ferritic steel, V-5Cr-5Ti and SiCf/SiC composite have been examined by simulation calculations using structural models based on ITER design. The transmutations from W to Re and Os in the ferritic steel and from V to Cr in the V alloy were predicted to considerably occur depending on thermal neutron fluxes mainly determined by the composition of blanket/shields while induced radioactivity decay behaviours are not appreciably affected by the spectrum change of fusion neutrons. The acceptable concentrations of impurities such as Mo, Nb and Tb for waste disposal and hands-on recycling have been more restricted with increasing fluence because of the accumulation of nuclides controlling the radioactivity. In the effort of manufacturing high-purity materials, fused-salt electrolysis for vanadium and chemical vapor infiltration for SiCf/SiC composite have been shown to be potential processes to obtain purified materials satisfying the low activation criteria. (orig.)

107

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

108

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

International Nuclear Information System (INIS)

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)

109

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

International Nuclear Information System (INIS)

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,?)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

110

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

International Nuclear Information System (INIS)

Injection into a thick shale formation of intermediate-level radioactive wastes (specific activity of less than 6 x 103 ?Ci/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 e 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

111

A study of assessment on site-choosing of NPPs about human induced outside external artificial events based on multiple objective fuzzy optimal selections  

International Nuclear Information System (INIS)

According to 'AD101/04-Siting of NPPs on Human Induced Outside Artificial External Events', the article evaluates the plane air crash, explosion, release of dangerous liquid quantitatively, then get several site of NPP compared, in advantage of multiple objective fuzzy optimal selection, come to a decision about the sorting of superiority of site from the standpoint of outside artificial human induced events. (authors)

112

High energy proton-induced radioactivity in HgI2 crystals  

International Nuclear Information System (INIS)

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.))

113

Dependence of neutron-induced radioactivity in fusion reactors on geometric design parameters  

International Nuclear Information System (INIS)

Although the neutron-induced activation in a fusion reactor is a non-linear problem whose solution requires the use of neutron transport codes and neutron activation and decay codes, a number of simple arguments can be made which give useful scaling laws for the total radioactivity in a fusion reactor. Because these laws rely heavily on assumptions of linearity and the smallness of second-order effects, we have compared them to the results of computer experiments designed to investigate their validity over the range of operating parameters typical of fusion reactors

114

Dependence of neutron-induced radioactivity in fusion reactors on geometric design parameters  

Energy Technology Data Exchange (ETDEWEB)

Although the neutron-induced activation in a fusion reactor is a non-linear problem whose solution requires the use of neutron transport codes and neutron activation and decay codes, a number of simple arguments can be made which give useful scaling laws for the total radioactivity in a fusion reactor. Because these laws rely heavily on assumptions of linearity and the smallness of second-order effects, we have compared them to the results of computer experiments designed to investigate their validity over the range of operating parameters typical of fusion reactors.

Lasche, G.P.; Blink, J.A.

1983-01-01

115

Benchmark studies of induced radioactivity and remanent dose rates produced in LHC materials  

International Nuclear Information System (INIS)

Samples of materials that will be used for elements of the LHC machine as well as for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy Reference Field facility. The materials included various types of steel, copper, titanium, concrete and marble as well as light materials such as carbon composites and boron nitride. Emphasis was put on an accurate recording of the irradiation conditions, such as irradiation profile and intensity, and on a detailed determination of the elemental composition of the samples. After the irradiation, the specific activity induced in the samples as well as the remanent dose rate were measured at different cooling times ranging from about 20 minutes to two months. Furthermore, the irradiation experiment was simulated using the FLUKA Monte Carlo code and specific activities. In addition, dose rates were calculated. The latter was based on a new method simulating the production of various isotopes and the electromagnetic cascade induced by radioactive decay at a certain cooling time. In general, solid agreement was found, which engenders confidence in the predictive power of the applied codes and tools for the estimation of the radioactive nuclide inventory of the LHC machine as well as the calculation of remanent doses to personnel during interventions. (authors)

116

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

CERN Document Server

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...

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

2014-01-01

117

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

International Nuclear Information System (INIS)

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)

118

A study of the stability of an artificial beach and of the transport of fine sediments in suspension using radioactive tracers  

International Nuclear Information System (INIS)

The paper describes two applications of radioactive tracers in dynamic sedimentology in the light of experiments carried out in Singapore, between 1981 and 1982, along the new beaches reclaimed from the sea. The first part deals with the properties of transfer of a silt sediment suspension by the west tide. The tracer used was 198Au-labelled silt. Successive determinations were made of the trajectory, average velocity, variation in time of the vertical and horizontal dispersion, and dilution and settling of sediments released into the sea by point and instantaneous injection, after which the data were extrapolated to continuous release. The second part is devoted to a study of the stability of the artificial beaches forming the new coastline, using for the purpose 192Ir-labelled glass tracer of the same grain size as the sediments in situ. The results are presented in the form of isoactivity curves and transport diagrams. They can be used to determine the axis and average velocity of transport and the dispersion parameters (dimensions of the patch, change in the centre of gravity and quartiles). The thickness and rate of bed-load transport are then calculated by the 'method of count-rate balance'. Each part has a section on 'methodology', in which the tracer technique is reviewed (principle, labelling, release and detection) and a section where the results are analysed. The study has shown the hazards of beach pollution and the silting-up of harbour installations through the discharge of sediments into the sea as well as the hazard of erosion at the edges of the new coastline by the north-east and south-west monsoons. (author)

119

Use of GnRH to induce an accessory corpus luteum in buffaloes fixed time artificially inseminated  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to induce an accessory corpus luteum (CL in buffaloes fixed time artificially inseminated. Two hundred and forty buffaloes received the treatment sequence GnRH/PGF2?/GnRH after which were inseminated artificially. Six days after the insemination, the animals were divided in two groups (G1 = Control and G2 = GnRH and received 0 ?g or 25 ?g of GnRH to induce an accessory CL. After twenty four days (D40, pregnancy diagnosis was performed by ultrasonography and 79 buffalo (G1, n = 39; G2, n = 40 were randomly selected to verify the ovary status by ultrasound. Fifty three pregnant buffaloes (G1, n = 32; G2, n = 21 were followed to verify the birth rate. Data were analyzed by Chi-square test. The conception rate, the accessory CL rate and the birth rate were higher in G2 than in G1 (P<0.05. The use of GnRH to induce an accessory CL in buffaloes increased the conception and birth rates. Thus, the increase of the cost of Ovsynch protocol with the thirty dose of GnRH is rewarded by the increment on conception and birth rates and reduction of days open.

P.S. Baruselli

2010-02-01

120

A facility for studying radiative capture reactions induced with radioactive beams at ISAC  

International Nuclear Information System (INIS)

The measurement of low energy fusion reactions of importance to nuclear astrophysics scenarios are a prime objective of the physics program of thenew ISAC facility, located at TRIUMF in Vancouver, Canada. Intense radioactive beams of 19Ne, 14,15O, 20,21Na, 17,18F and other low Z species with energies in the range of 0.15 to 1.5 MeV/mass unit will be available to measure cross sections and resonance strengths of alpha and proton induced reactions. An important component of the experimentalconfiguration will be a new reaction product detection facility (RPDF) consisting of a windowless gas target, surrounded by a gamma array, while the recoils are separated from the intense radioactive beam using a recoil mass spectrometer (RMS). The RMS will be based on a Wien filter. The recoiling reaction products will then be detected using either a Si ?-strip array or a gas filled detector. Using these devices along with coincidence requirements and time of flight conditions a background reduction factor of the order of 10+15 is the present goal. (orig.)

 
 
 
 
121

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

CERN Document Server

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 ...

Herrera-Martínez, Adonai

122

Radiological considerations on multi-MW targets Part I Induced radioactivity  

CERN Document Server

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...

Agosteo, S; Silari, M; 10.1016/j.nima.2005.02.018

2005-01-01

123

Induced radioactivity in sludge subjected to gamma treatment using spent nuclear fuel  

International Nuclear Information System (INIS)

Reference is made to an earlier study of the possible use of ?-radiation from spent nuclear fuel elements during their residence in decay pool, or in temporary storage ponds, for the sterilisation of sludges. Calculations reported in the present paper make it clear that this use of spent elements does not carry the risk of generating radioactive sludge, since the maximum ?-energy (5 MeV) is well below the 10 MeV required to produce nuclear reactions. In addition, the extent of sludge activation induced by neutron flux was not such as to cause significant radioactive pollution, even on the most pessimistic estimate, since the Ci/t values for thermal and fast neutrons in dry, digested and raw sludge were 3.0, 5.6 and 91.3 x 10-6, and 2.4, 55.0 and 3.9 x 10-9 respectively. These are lower than the maximum values permitted in ordinary substances and foodstuffs. (author)

124

The radioactivity  

International Nuclear Information System (INIS)

This work deals with the radioactivity. Natural or artificial, the radioactivity is the sign that the matter gets settled. But radioactivity can destroy the more complex matter structure too. In the first part is described how the matter gets settled and is stabilized. Then is recalled the progressive creation of the matter during the universe cooling. The radiation effects on the diverse organization levels of the matter are measured: the physical alteration of matter, the perturbation of the chemical bonds, the maladjustment and sometimes the death of biological cells. In the second part, the role that the radioactivity has taken in the science and in its uses all along this century is explained. (O.M.). 9 refs., 10 figs., 1 tab

125

Comparison Between Predictions & Observations of Induced Radioactive Background in Interplanetary Missions  

Science.gov (United States)

Radioactivity induced in detector materials and their immediate surroundings is the major source of discrete-line, gamma-ray background and an important source of continuum background in the performance of remote-sensing, gamma-ray spectroscopy of planetary bodies. In interplanetary space the dominant sources of particles are cosmic rays and their secondaries arising from interactions with the spacecraft and the surface of the target body. In addition, certain future gamma-ray astronomy missions, such as INTEGRAL, are to be located so as to perform their observations in interplanetary space rather than in the traditional low earth orbits. Such location removes contributions from the earth's atmosphere and inner radiation belt at the expense of increased exposure to cosmic rays and solar particle events. Accurate prediction of the activation of key materials by cosmic rays is of the utmost importance for detector design and data interpretation.

Dyer, Clivea; Truscott, Peter; Evans, Howard; Evans, Larry; Trombka, Jacob

1997-01-01

126

Measurement of induced radioactivity in a spallation neutron field of a mercury target for GeV-proton bombardment  

International Nuclear Information System (INIS)

An integral experiment on radioactivity induced in spallation neutron fields was carried out under the ASTE (AGS-Spallation Target Experiment) collaboration using AGS (Alternative Gradient Synchrotron) at BNL (Brookhaven National Laboratory). The spallation neutrons were produced by bombarding a mercury target with protons of 1.6, 12 and 24 GeV. The number of protons was 3 - 4 x 1013 for each irradiation. The irradiated materials were titanium, nickel, cobalt, yttrium, and bismuth, and placed on the cylindrical surface of the mercury target at the distance of 15 - 16 cm from the beam-incident-surface of the target. Disintegration rates of induced radioactivities were measured at several cooling-time ranging from hours to months. The principal nuclides contributing to the radioactivity were pointed out for each material. The experimental results for bismuth were compared with the calculations with DCAHIN-SP code. (author)

127

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

International Nuclear Information System (INIS)

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.)

128

First observations of SPEAR-induced artificial backscatter from CUTLASS and the EISCAT Svalbard radars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Results are presented from the first two active experimental campaigns undertaken by the new SPEAR (Space Plasma Exploration by Active Radar) high-power system that has recently become operational on Spitzbergen, in the Svalbard archipelago. SPEAR's high-power beam was used to excite artificial enhancements in the backscatter detected by the ESR (EISCAT Svalbard Radar) parallel to the geomagnetic field, as well as coherent backscatter detected by both of the CUTLASS (Co-operative UK Twin...

Robinson, T. R.; Yeoman, T. K.; Dhillon, R. S.; Lester, M.; Thomas, E. C.; Thornhill, J. D.; Wright, D. M.; Eyken, A. P.; Mccrea, I. W.

2006-01-01

129

Radioactive ion beams produced by neutron-induced fission at ISOLDE  

CERN Document Server

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...

Catherall, R; Gilardoni, S S; Köster, U

2003-01-01

130

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

International Nuclear Information System (INIS)

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 ?m 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 ?m location on tissue section was pre-irradiated with 1-10 3He2+ particles (5 MeV; LET 75 keV/?m) 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)

131

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

International Nuclear Information System (INIS)

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)

132

Two Electromagnetically Induced Transparency Windows and Cross-Phase Modulation with Four-Level Superconducting Artificial Atoms  

Science.gov (United States)

Superconducting circuit quantum electrodynamics (SCQED) employs microwave transmission lines coupled to artificial atoms, which are typical two-level and recently three-level for electromagnetically induced transparency (EIT). We propose SCQED with a four-level tripod-configuration artificial atom to enable cross-phase modulation between two traveling-wave microwave fields. Our master-equation analysis for three driving fields (``signal,'' ``probe'' and ``coupling'') demonstrates the existence of two distinct EIT transparency windows in the spectral-response profile as a function of coupling and weak fields strength. We provide the first theoretical analysis of this unexpected second window and show its advantages over the known first EIT window. Specifically we show that this second EIT window provides both the signal and probe fields with identical response functions provided that their Rabi frequencies and detunings are the same. Exploiting the second window with judiciously chosen external flux and energy detuning result in low absorption, excellent group velocity matching, and high nonlinearity, thereby enabling strong cross-phase modulation for SCQED.

Alotaibi, Hessa; Sanders, Barry

2013-03-01

133

Effect of centrifuge-induced artificial gravity and ergometric exercise on cardiovascular deconditioning, myatrophy, and osteoporosis induced by a -6 degrees head-down bedrest.  

Science.gov (United States)

We have reported that centrifuge-induced artificial gravity with ergometric exercise could reduce developing cardiovascular deconditioning in humans. In the present study, we examined this load could prevent the myatrophy and osteoporosis induced by head-down bedrest for 20 days. Subjects were ten healthy male volunteers with informed consent. They were requested to lie down at -6 degrees for 20 days, and evaluation for cardiovascular deconditioning, myatrophy, and osteoporosis. As the result, high G-load with low intensity exercise suppressed the orthostatic intolerance and increase in serum osteoporotic marker, whereas low G-load with high intensity ergometric exercise maintained the maximal oxygen intake, heart dimension, and prevented myatrophy. The combination of high/low G-load with low/high intensity exercise will determine the optimal protocol for prevention of cardiovascular deconditioning, myatrophy, and osteoporosis. PMID:16240530

Iwase, Satoshi; Takada, Hiroki; Watanabe, Yoriko; Ishida, Koji; Akima, Hiroshi; Katayama, Keisho; Iwase, Mitsunori; Hirayanagi, Kaname; Shiozawa, Tomoki; Hamaoka, Takafumi; Masuo, Yoshihisa; Custaud, Marc-Antoine

2004-07-01

134

Influence of falling time of dust particle on cosmic-ray induced radioactivities in the cosmic dusts  

International Nuclear Information System (INIS)

The calculation of the production rates of nuclides induced by cosmic-rays in the cosmic dusts has been done considering the falling time of dust particle. The results show that the production rate of radioactive nuclides with half-life shorter than 105 years due to the solar cosmic-rays is almost equal to that estimated under the assumption of the radioactive equilibrium at the earth orbit as often done so far, but for radioactive nuclides with half-life longer than 1x106 years the dust dynamic should be considered in the calculation. Furthermore, the calculation shows that, for the nuclide whose excitation function has no peak in the low energy region such as 10Be, the contribution of the galactic cosmic rays in the isotope production becomes very important, contrary to the ordinary expectation. (auth.)

135

Characteristics of radioactivities induced in aluminum alloys and the effects due to those major and minor components  

International Nuclear Information System (INIS)

In order to search the usefulness of aluminum alloys as a material for an accelerator and its surrounding apparatus, the characteristics of radioactivities induced in several aluminum alloys (AA 1230, AA 2219, JIS 5052, AA 6063 and AA 7079) and stainless steel (SUS 304) irradiated for a long time with high energy bremsstrahlung have been studied fundamentally and compared with each other. After the concentrations of major alloying elements and impurities in the above samples were determined by means of photon-activation, proton-activation and emission spectrochemical analyses, they were irradiated with 30 and 200 MeV bremsstrahlung. As the results, it was proved that the intensities of radioactivities induced in the aluminum alloys are greatly affected by those major and minor components, but are remarkably lower than that in the stainless steel. (author)

136

Interactive system for calculating the isotope composition and induced radioactivity of irradiated materials on nuclear power facilities  

International Nuclear Information System (INIS)

An interactive system for calculations of the isotope composition and induced radioactivity of irradiated materials in projected nuclear power facilities is described. The proposed system includes preparation of data for calculations, computational module, and intuitively clear graphical interface. Application of the system is illustrated by calculations of the activity of nuclides formed upon irradiation of a lead-bismuth target in an accelerator with the beam current varying in the course of exposure

137

Isospin dependence of nucleon emission and radial flow in heavy-ion collisions induced by high energy radioactive beams  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Using an isospin- and momentum-dependent transport model we study the emission of free nucleons and the nuclear radial flow in central heavy-ion collisions induced by high energy radioactive beams. The midrapidity neutron/proton ratio and its transverse momentum dependence are found very sensitive to the high density behavior of nuclear symmetry energy. The nuclear radial flow, however, depends only weakly on the symmetry energy.

Li, Bao-an; Yong, Gao-chan; Zuo, Wei

2004-01-01

138

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

Science.gov (United States)

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. PMID:25372916

Ferrari, Andrés Di Leoni; Borges, Anibal Pires; Albuquerque, Luciano Cabral; Sussenbach, Carolina Pelzer; Rosa, Priscila Raupp da; Piantá, Ricardo Medeiros; Wiehe, Mario; Goldani, Marco Antônio

2014-09-01

139

First observations of SPEAR-induced artificial backscatter from CUTLASS and the EISCAT Svalbard radars  

Directory of Open Access Journals (Sweden)

Full Text Available Results are presented from the first two active experimental campaigns undertaken by the new SPEAR (Space Plasma Exploration by Active Radar high-power system that has recently become operational on Spitzbergen, in the Svalbard archipelago. SPEAR's high-power beam was used to excite artificial enhancements in the backscatter detected by the ESR (EISCAT Svalbard Radar parallel to the geomagnetic field, as well as coherent backscatter detected by both of the CUTLASS (Co-operative UK Twin Located Auroral Sounding System coherent radars, in directions orthogonal to the geomagnetic field. The ESR detected both enhanced ion-lines as well as enhanced plasma-lines, that were sustained for the whole period when SPEAR was transmitting ordinary mode radio waves, at frequencies below the maximum F-region plasma frequency. On a number of occasions, coherent backscatter was also observed in one or in both of the CUTLASS radars, in beams that intersected the heated volume. Although the levels of enhanced backscatter varied considerably in time, it appeared that ion-line, plasma-line and coherent backscatter were all excited simultaneously, in contrast to what has typically been reported at Tromsø, during EISCAT heater operations. A description of the technical and operational aspects of the new SPEAR system is also included.

T. R. Robinson

2006-03-01

140

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

International Nuclear Information System (INIS)

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)

 
 
 
 
141

Evaluation of potential induced radioactivity in medical products as a function of electron energy in electron beam sterilization  

Energy Technology Data Exchange (ETDEWEB)

Commercial sterilization of medical devices may be performed using electron beam irradiators at various electron energies. The potential for activating components of the devices has been discussed, with current standards stating that electron energy greater than 10 MeV requires assessment of potential induced radioactivity. This paper evaluates the potential for induced activity in medical products sterilized in electron beam as a function of the electron maximum energy. Monte Carlo simulation of a surrogate medical device was used to calculate photon and neutron fields resulting from electron irradiation, which were used to calculate concentrations for several radionuclides. The experiments confirmed that 10 MeV is a conservative assumption for limiting induced radioactivity. However, under the conditions as evaluated, which is a limited total quantity of metal in the material being irradiated and absent a limited number of elements; the amount of induced activity at 12 MeV could also be considered insignificant. The comparison of the sum-of-fractions to the US Nuclear Regulatory Commission exempt concentration limits is less than unity for all energies below 12.1 MeV, which suggests that there is minimal probability of significant induced activity at energies above the 10 MeV upper energy limit. - Highlights: > This study estimates induced radioactivity for electron irradiation as a function of energy. > MCNPX was used to model systems from 8 MeV up to 13 MeV. > Under conditions given, energies up to 12 MeV may create insignificant activation. > Measured concentrations were within a factor of two of those calculated. > Depth dose profiles show good agreement with the model.

Smith, Mark A., E-mail: msmith@sterigenics.com [Sterigenics International, 10811 Withers Cove Park Drive, Charlotte, NC 28211 (United States); Nuclear Engineering Teaching Laboratory, University of Texas at Austin, Austin, TX (United States)

2012-01-15

142

Evaluation of potential induced radioactivity in medical products as a function of electron energy in electron beam sterilization  

International Nuclear Information System (INIS)

Commercial sterilization of medical devices may be performed using electron beam irradiators at various electron energies. The potential for activating components of the devices has been discussed, with current standards stating that electron energy greater than 10 MeV requires assessment of potential induced radioactivity. This paper evaluates the potential for induced activity in medical products sterilized in electron beam as a function of the electron maximum energy. Monte Carlo simulation of a surrogate medical device was used to calculate photon and neutron fields resulting from electron irradiation, which were used to calculate concentrations for several radionuclides. The experiments confirmed that 10 MeV is a conservative assumption for limiting induced radioactivity. However, under the conditions as evaluated, which is a limited total quantity of metal in the material being irradiated and absent a limited number of elements; the amount of induced activity at 12 MeV could also be considered insignificant. The comparison of the sum-of-fractions to the US Nuclear Regulatory Commission exempt concentration limits is less than unity for all energies below 12.1 MeV, which suggests that there is minimal probability of significant induced activity at energies above the 10 MeV upper energy limit. - Highlights: ? This study estimates induced radioactivity for electron irradiation as a function of energy. ? MCNPX was used to model systems from 8 MeV up to 13 MeV. del systems from 8 MeV up to 13 MeV. ? Under conditions given, energies up to 12 MeV may create insignificant activation. ? Measured concentrations were within a factor of two of those calculated. ? Depth dose profiles show good agreement with the model.

143

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

International Nuclear Information System (INIS)

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

144

A Novel Approach for Blast-Induced Flyrock Prediction Based on Imperialist Competitive Algorithm and Artificial Neural Network  

Science.gov (United States)

Flyrock is one of the major disturbances induced by blasting which may cause severe damage to nearby structures. This phenomenon has to be precisely predicted and subsequently controlled through the changing in the blast design to minimize potential risk of blasting. The scope of this study is to predict flyrock induced by blasting through a novel approach based on the combination of imperialist competitive algorithm (ICA) and artificial neural network (ANN). For this purpose, the parameters of 113 blasting operations were accurately recorded and flyrock distances were measured for each operation. By applying the sensitivity analysis, maximum charge per delay and powder factor were determined as the most influential parameters on flyrock. In the light of this analysis, two new empirical predictors were developed to predict flyrock distance. For a comparison purpose, a predeveloped backpropagation (BP) ANN was developed and the results were compared with those of the proposed ICA-ANN model and empirical predictors. The results clearly showed the superiority of the proposed ICA-ANN model in comparison with the proposed BP-ANN model and empirical approaches. PMID:25147856

Marto, Aminaton; Jahed Armaghani, Danial; Tonnizam Mohamad, Edy; Makhtar, Ahmad Mahir

2014-01-01

145

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

International Nuclear Information System (INIS)

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

146

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

International Nuclear Information System (INIS)

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

147

Induced radioactivity in the air of the 300 GeV proton accelerator at CERN  

International Nuclear Information System (INIS)

This contribution investigates the formation of radioactive elements which may be produced by the interaction of high-energy particles, thermal neutrons and gamma particles on the one hand, and the components of air within the tunnel of the 300 GeV proton accelerator on the other. The radioactive element concentration in the air at the outlet of the air conditioning system and the dispersion in the atmosphere has been calculated. It is shown that 13N, 15O, 11C, and 41Ar are the radioactive products occuring in calculable concentrations. The concentrations are below the maximum permissible values. (orig.)

148

Radioactive ion beams produced by neutron-induced fission at ISOLDE  

Energy Technology Data Exchange (ETDEWEB)

The production rates of neutron-rich fission products for the next-generation radioactive beam facility EURISOL [EU-RTD Project EURISOL (HPRI-CT-1999-50001)] 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 [E. Kugler, Hyperfine Interact. 129 (2000) 23], 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 UC{sub 2}/graphite and ThO{sub 2} targets with tungsten and tantalum converters, are presented. To gain further knowledge for the design of a dedicated target as required by the TARGISOL project [EU-RTD Project TARGISOL (HPRI-CT-2001-50033)], the results are compared to simulations, using the MARS [N.V. Mokhov, S.I. Striganov, A. Van Ginneken, S.G. Mashnik, A.J. Sierk, J. Ranft, MARS code developments, in: 4th Workshop on Simulating Accelerator Radiation Environments, SARE-4, Knoxville, USA, 14-15.9.1998, FERMILAB-PUB-98-379, nucl-th/9812038; N.V. Mokhov, The Mars Code System User's Guide, Fermilab-FN-628, 1995; N.V. Mokhov, MARS Code Developments, Benchmarking and Applications, Fermilab-Conf-00-066, 2000; O.E. Krivosheev, N.V. Mokhov, A New MARS and its Applications, Fermilab-Conf-98/43, 1998] code interfaced with MCNP [J.S. Hendrics, MCNP4C LANL Memo X-5; JSH-2000-3; J.F. Briemesteir (Ed.), MCNP - A General Montecarlo N-Particle Transport Code, Version 4C, LA-13709-M] libraries, of the neutron flux from the converters interacting with the actinide targets.

Catherall, R. E-mail: richard.catherall@cern.ch; Lettry, J.; Gilardoni, S.; Koester, U

2003-05-01

149

Radioactive ion beams produced by neutron-induced fission at ISOLDE  

International Nuclear Information System (INIS)

The production rates of neutron-rich fission products for the next-generation radioactive beam facility EURISOL [EU-RTD Project EURISOL (HPRI-CT-1999-50001)] 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 [E. Kugler, Hyperfine Interact. 129 (2000) 23], 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 and tantalum converters, are presented. To gain further knowledge for the design of a dedicated target as required by the TARGISOL project [EU-RTD Project TARGISOL (HPRI-CT-2001-50033)], the results are compared to simulations, using the MARS [N.V. Mokhov, S.I. Striganov, A. Van Ginneken, S.G. Mashnik, A.J. Sierk, J. Ranft, MARS code developments, in: 4k, J. Ranft, MARS code developments, in: 4th Workshop on Simulating Accelerator Radiation Environments, SARE-4, Knoxville, USA, 14-15.9.1998, FERMILAB-PUB-98-379, nucl-th/9812038; N.V. Mokhov, The Mars Code System User's Guide, Fermilab-FN-628, 1995; N.V. Mokhov, MARS Code Developments, Benchmarking and Applications, Fermilab-Conf-00-066, 2000; O.E. Krivosheev, N.V. Mokhov, A New MARS and its Applications, Fermilab-Conf-98/43, 1998] code interfaced with MCNP [J.S. Hendrics, MCNP4C LANL Memo X-5; JSH-2000-3; J.F. Briemesteir (Ed.), MCNP - A General Montecarlo N-Particle Transport Code, Version 4C, LA-13709-M] libraries, of the neutron flux from the converters interacting with the actinide targets

150

Partitioning of Sr2+ into Calcite Precipitates Induced by Bacterial Ureolysis in Artificial Groundwater.  

Science.gov (United States)

A suite of experiments were performed to investigate the partitioning of Sr2+ (to mimic the radionuclide 90Sr) between calcite and groundwater, in response to the hydrolysis of urea by B. pasteurii under simulated in-situ aquifer conditions. Three duplicate experiments were performed at 25° C over 8 days in microcosms inoculated with B. pasteurii ATCC 11859 and containing an artificial groundwater (AGW). The AGW composition was based upon the aqueous chemistry of the metal and radionuclide contaminated Snake River Plain Aquifer, Idaho,USA. Microcosms also contained 25 mM urea, and 1 mM of Sr as a contaminant treatment. Control experiments were run with non urea hydrolyzing bacteria, B. subtillus. Control experiments exhibited little change in pH, and dissolved ammonium and Ca2+ concentrations. Conversely during experiments inoculated with B. pasteurii, ammonium production increased asymptotically, peaking two days into the experiment when approximately all urea had been hydrolyzed. The production of ammonium and bicarbonate from urea hydrolysis caused an asymptotic increase in pH from 6.5 to 9.1 one day into the experiment. Dissolved Ca2+ and Sr2+ decreased asymptotically from the beginning of the experiment, and was accompanied by the development of solid precipitates identified as calcite by X-Ray diffraction. This caused an asymptotic decrease in the saturation state of calcite (S) after one day of the experiment. Specific rate constants were derived for calcite precipitation and critical saturation state from the time course data following a second-order chemical affinity based law. Calcite precipitation rate is fundamentally controlled by, and exhibits a positive association with S. Mass balance indicates the percentage of total Sr (dissolved and in calcite) incorporated into the calcite precipitate increases rapidly to 59 % after two days of the experiment, and increases less rapidly thereafter to a maximum of 67 %. Corresponding measured distribution coefficients (DMe) exhibit a positive association with S and calcite precipitation rates. Therefore DMe is greatest after one day of the experiment (DMe maximum = 0.39), which corresponds to the highest S and calcite precipitation rate, and decreases thereafter (DMe minimum = 0.16) as S and calcite precipitation rate decreases. Therefore the extent of Sr incorporation into calcite precipitates resulting from the hydrolysis of urea by B. pasteurii appears to be a primary function of precipitation rate, which is controlled by S. The median DMe determined by this study (0.22) is greater than previously published coefficients for Sr in calcite by up to an order of magnitude. This demonstrates the potential of calcite precipitation by bacterial ureolysis as a remediation strategy for 90Sr in calcite saturated aquifers.

Mitchell, A. C.; Ferris, F. G.; Mancini, A.; Litwin, Y.

2003-12-01

151

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  

Energy Technology Data Exchange (ETDEWEB)

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)

Gensdarmes, F

2000-07-01

152

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

International Nuclear Information System (INIS)

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, eithons. 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 of

153

Analysis of micro-composition of biological tissue by means of induced radioactivity  

Energy Technology Data Exchange (ETDEWEB)

The use of radioactive isotopes as tracers promises a wealth of information regarding the biochemical role of most elements and their components. Usually a radioactive sample of the element to be studied is administered to the plant or animal in a convenient form, and its distribution and rate of exchange are determined in later assays. This technique has, however, certain limitations, two of which will be discussed here: (1) radioactive isotopes are not generally useful for measurements of the concentration of elements in the body or its parts. They can be used only to give a measure of the rate of exchange of the elements and (2) the use of radioactive isotopes for tracer experiments requires that the radiation dose delivered to the tissue should be small in order not to disturb normal biological function.

Tobias, C.A.; Dunn, R.W.

1948-05-24

154

Assessment of Artificially Induced Pressure Sores Using a Modified Fractal Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, a guinea pig model has been developed for generation and monitoring of pressure sores. A system with pressure sensors and a suitable feedback was used for inducing pressure sores. High-frequency ultrasound images were taken from the wound site after tissue was released from the applied pressure for a 21 days period. Fractal properties of the selected windows were calculated, which leads to proposing a Modified Fractal Signature (MFS. The MFS proved to be an efficient measure for assessing the pressure sores. Exploiting the proposed idea, the progression of necrotic tissue could be studied. It is shown that this measure is also capable of evaluating the healing process of pressure sores.

S. Moghimi

2009-01-01

155

Expression of androgen receptor mRNA in the ovary of Japanese eel, Anguilla japonica, during artificially induced ovarian development.  

Science.gov (United States)

In order to elucidate how androgens may mediate their effects on ovarian growth, we investigated the mRNA levels of two subtypes of androgen receptor (ara and arb) in the ovary of feminized Japanese eel (Anguilla japonica) during artificially induced ovarian development by quantitative real-time reverse transcriptase polymerase chain reaction and in situ hybridization. Ara mRNA levels were high from the late oil droplet stage to the late vitellogenic stage, whereas arb mRNA levels were high from the late oil droplet stage to the midvitellogenic stage. Both ar mRNAs were predominantly observed in the follicle cells and the epithelial cells of the ovigerous lamellae in all stages. In the oil droplet stage, oogonia exhibited intense signals for ar mRNAs. There was no obvious difference in localization pattern between ara and arb in all ovaries examined, irrespective of maturational stage. It was difficult to identify the follicle cell types that were positive for ar mRNA during ovarian development. Only in post-ovulatory follicles could theca and granulosa cells be clearly identified, and ar signals were observed in both layers. The predominant localization of ar mRNA in the follicle cells suggests that androgens play important roles in oocyte growth by acting on these cells in this species. We have shown the expression profile and localization of ar mRNA during ovarian development for the first time in an oviparous vertebrate. PMID:20553719

Tosaka, Ryota; Todo, Takashi; Kazeto, Yukinori; Mark Lokman, P; Ijiri, Shigeho; Adachi, Shinji; Yamauchi, Kohei

2010-09-15

156

Radioactive contamination of the biosphere  

International Nuclear Information System (INIS)

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

157

Artificial piezoelectric grass for energy harvesting from turbulence-induced vibration  

International Nuclear Information System (INIS)

The primary objective of this research is to develop a deploy-and-forget energy harvesting device for use in low-velocity, highly turbulent fluid flow environments i.e. streams or ventilation systems. The work presented here focuses on a novel, lightweight, highly robust, energy harvester design referred to as piezoelectric grass. This biologically inspired design consists of an array of cantilevers, each constructed with piezoelectric material. When exposed to proper turbulent flow conditions, these cantilevers experience vigorous vibrations. Preliminary results have shown that a small array of piezoelectric grass was able to produce up to 1.0 mW per cantilever in high-intensity turbulent flow having a mean velocity of 11.5 m s?1. According to the literature, this is among the highest output achieved using similar harvesting methods. A distributed parameter model for energy harvesting from turbulence-induced vibration will be introduced and experimentally validated. This model is generalized for the case of a single cantilever in turbulent cross-flow. Two high-sensitivity pressure probes were needed to perform spectral measurements within various turbulent flows. The design and performance of these probes along with calibration and measurement techniques will be discussed. (paper)

158

Artificial piezoelectric grass for energy harvesting from turbulence-induced vibration  

Science.gov (United States)

The primary objective of this research is to develop a deploy-and-forget energy harvesting device for use in low-velocity, highly turbulent fluid flow environments i.e. streams or ventilation systems. The work presented here focuses on a novel, lightweight, highly robust, energy harvester design referred to as piezoelectric grass. This biologically inspired design consists of an array of cantilevers, each constructed with piezoelectric material. When exposed to proper turbulent flow conditions, these cantilevers experience vigorous vibrations. Preliminary results have shown that a small array of piezoelectric grass was able to produce up to 1.0 mW per cantilever in high-intensity turbulent flow having a mean velocity of 11.5 m s-1. According to the literature, this is among the highest output achieved using similar harvesting methods. A distributed parameter model for energy harvesting from turbulence-induced vibration will be introduced and experimentally validated. This model is generalized for the case of a single cantilever in turbulent cross-flow. Two high-sensitivity pressure probes were needed to perform spectral measurements within various turbulent flows. The design and performance of these probes along with calibration and measurement techniques will be discussed.

Hobeck, J. D.; Inman, D. J.

2012-10-01

159

Urease-induced calcification of segmented polymer hydrogels - a step towards artificial biomineralization.  

Science.gov (United States)

Natural organic/inorganic composites, such as nacre, bones and teeth, are perfectly designed materials with exceptional mechanical properties. Numerous approaches have been taken to synthetically prepare such composites. The presented work describes a new way of mineralizing bulk materials on a large scale following the approach of bioinduced mineralization. To this end, a series of polymer conetworks with entrapped urease were prepared. After polymerization, the entrapped urease shows high enzymatic activity. The bioactive polymer conetworks were then treated with an aqueous mixture of urea and CaCl2. The urease-induced calcification indeed allows formation of carbonate crystals exclusively within the hydrogel even at room temperature. The influence of network composition, degree of cross-linking, immobilized urease concentration and temperature of calcification were investigated. By varying these parameters, spherical, monolithic clusters, as well as bar-like nanocrystals with different aspect ratios in spherical or dendritic arrays, are formed. The grown nanocrystals improve the stiffness of the starting material by up to 700-fold, provided that the microstructure shows a dense construction without pores and strong interaction between crystals and network. The process has the potential to generate a new class of hybrid materials that would be available on the macroscopic scale for use in lightweight design and medicine. PMID:24887285

Rauner, Nicolas; Meuris, Monika; Dech, Stephan; Godde, Julia; Tiller, Joerg C

2014-09-01

160

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages  

Energy Technology Data Exchange (ETDEWEB)

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modi (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek-Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.

Brai, Maria; Gennaro, Gaetano [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze Ed.18, 90128 Palermo (Italy); Schillaci, Tiziano, E-mail: tschillaci@unipa.i [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze Ed.18, 90128 Palermo (Italy); Tranchina, Luigi [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze Ed.18, 90128 Palermo (Italy)

2009-10-15

 
 
 
 
161

Sounding of HF heating-induced artificial ionospheric disturbances by navigational satellite radio transmissions  

Science.gov (United States)

During experiments carried out in 2009-2011 the midlatitude ionosphere was modified by powerful HF pulses from the Sura heating facility located near Nizhny Novgorod (Russia) and operated by the Radio Physical Research Institute. GPS/GLONASS and Parus/Tsikada satellite radio transmissions responding to the heating-induced disturbances in electron density were analyzed. The variations in the total electron content (TEC), which are proportional to the reduced phase of navigational signals, were studied for various schemes of radiation of the heating wave. The variations in TEC (their amplitudes and temporal behavior) caused by HF heating are identified in several examples. The TEC spectra contain frequency components corresponding to the modulation periods of the heating wave. For the first time, the spatial structure of the wave disturbances generated in the ionosphere by high-power radio waves radiated by the Sura heating facility with a square wave modulation of the effective radiated power at a frequency lower than or of the order of the Brunt-Vaisala frequency of the neutral atmosphere is imaged using the method of low-orbital radio tomography and GPS/GLONASS data.

Kunitsyn, V. E.; Andreeva, E. S.; Frolov, V. L.; Komrakov, G. P.; Nazarenko, M. O.; Padokhin, A. M.

2012-01-01

162

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages  

International Nuclear Information System (INIS)

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modi (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek-Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.

163

A Novel Method to Detect Pressure-Induced Sensor Attenuations (PISA) in an Artificial Pancreas.  

Science.gov (United States)

Continuous glucose monitors (CGMs) provide real-time interstitial glucose concentrations that are essential for automated treatment of individuals with type 1 diabetes. Miscalibration, noise spikes, dropouts, or pressure applied to the site (e.g., lying on the site while sleeping) can cause inaccurate glucose signals, which could lead to inappropriate insulin dosing decisions. These studies focus on the problem of pressure-induced sensor attenuations (PISAs) that occur overnight and can cause undesirable pump shut-offs in a predictive low glucose suspend system. The algorithm presented here uses real-time CGM readings without knowledge of meals, insulin doses, activity, sensor recalibrations, or fingerstick measurements. The real-time PISA detection technique was tested on outpatient "in-home" data from a predictive low-glucose suspend trial with over 1125 nights of data. A total of 178 sets were created by using different parameters for the PISA detection algorithm to illustrate its range of available performance. The tracings were reviewed via a web-based analysis tool by an engineer with an extensive expertise on analyzing clinical datasets and ~3% of the CGM readings were marked as PISA events which were used as the gold standard. It is shown that 88.34% of the PISAs were successfully detected by the algorithm, and the percentage of false detections could be reduced to 1.70% by altering the algorithm parameters. Use of the proposed PISA detection method can result in a significant decrease in undesirable pump suspensions overnight, and may lead to lower overnight mean glucose levels while still achieving a low risk of hypoglycemia. PMID:25316716

Baysal, Nihat; Cameron, Fraser; Buckingham, Bruce A; Wilson, Darrell M; Chase, H Peter; Maahs, David M; Bequette, B Wayne

2014-11-01

164

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  

International Nuclear Information System (INIS)

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

165

Very low levels of artificial radioactivity in the environment in 2009; Des niveaux de radioactivite artificielle qui restent tres faibles dans l'environnement en 2009 (IRSN)  

Energy Technology Data Exchange (ETDEWEB)

The 2009 edition of the annual state of the environment in France concerning radioactivity shows very low levels of radioactivity that are consistent with previous measurements. The radiological survey of 3 particular areas (Val de Loire, south-west of France and Rhone valley) has been made through several measurement campaigns that have involved for each area the recovery of between 100 to 200 samples in the different segments of the environment. This radiological state will be a standard for the area concerned. The 2009 edition reports also the radiological surveys of 3 ancient industrial sites: detection of Thorium 232 on the site of the Orflam-Plast company at Pargny-sur-Saulx (Marne department), detection of Carbon 14 around the ancient laboratory of the Isotopchim company near Forcalquier (Alpes de Haute Provence department) and radium contamination on the ancient site of the Satchi company at Charvet (Seine Saint-Denis department). (A.C.)

Anon.

2011-01-15

166

Artificial Limbs  

Science.gov (United States)

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

167

Can a radioactive implant induced x-ray emission (RIXE) technique be used to in vivo measurement of heavy elements  

International Nuclear Information System (INIS)

A radioactive implant induced x-ray emission (RIXE) technique was examined for the in vivo determination of heavy elements. By the use of 67Ga, 99mTc, 123I, 133Xe and 201Tl implant excitation sources, the excitation efficiency and x-ray attenuation were measured to reveal the potential pairs of source-heavy element of interest for in vivo elemental analysis by the RIXE technique. Detection limits for the RIXE in vivo analysis were evaluated according to Currie's criterion. Four pairs, 99mTc - Pb, 201Tl - I, 133Xe - Cd and 123I -Cd are potential. (author) 16 refs.; 5 figs.; 2 tabs

168

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

International Nuclear Information System (INIS)

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 6.88±2.13 Bq/mgCo and the Eu-152 activity was 75.9±8.79 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)

169

Artificial graphite  

International Nuclear Information System (INIS)

Data on the structure, mechanical, chemical and physical properties of artificial graphites are systematized. Problems on preparation of artificial graphite and effect of manufacturing factors on its properties are described. Fields of artificial graphite implementation, in particular reactor engineering, are pointed out. Specific behaviour of graphite in operation is described

170

Indução à ovulação pelo uso de LHRH análogo e fertilização artificial em rã-touro (Rana catesbeiana) / Spawning inducing by analog LHRH and artificial fertilization of bullfrog (Rana catesbeiana)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho teve por objetivo aperfeiçoar a técnica de reprodução induzida existente para rã-touro, com o intuito de aumentar a taxa de fecundidade e viabilizar seu uso pelo produtor. As doses hormonais para a indução da ovulação e espermiação seguiram as propostas de FALCON e CULLEY (1995) e ALON [...] SO (1997); entretanto, a técnica de fertilização artificial foi adaptada da metodologia para reprodução artificial de peixes com ovos não-aderentes (WOYNAROVICH e HORVÁTH, 1983). A técnica proposta apresenta as seguintes etapas: I) sincronização da ovulação e da espermiação, por meio de hormônio liberador de gonadotropina ((Des-Gli10, D-His(Bzl)6, Pro-NHEt9)-LHRH)); II) extração dos óvulos de cada fêmea (1 a 2 minutos); III) fertilização dos óvulos (2 minutos) com líquido espermático diluído em 100 mL de água; IV) hidratação dos ovos em 10 a 20 litros de água; e V) incubação dos ovos em quadros de tela de 1x 0,70 m, com malha de 1 mm. As taxas de fertilização obtidas com as modificações propostas foram superiores a 60%. Ressalta-se ainda que a técnica propiciou a obtenção, a partir de um mesmo animal, de várias desovas, sendo que cada fêmea pode ovular em intervalos de, aproximadamente, 45 dias. Abstract in english The objective of this study was to improve the artificial fertilization techniques for bullfrog, to increase the fertilization rate and become their use accessible for frog producers. Hormone dosages for inducing ovulation and spermiation followed those proposed by FALCON and CULLEY (1995) and ALONS [...] O (1997); however, the artificial fertilization technique was adapted from the available methodology for artificial reproduction of fish with non-adhering eggs (WOYNAROVICH e HORVÁTH, 1983). The proposed technique consists of the following steps: I) synchronization of ovulation and spermiation through gonadotropin releasing hormone ((Des-Gli10, D-His(Bzl)6, Pro-NHEt9)-LHRH)); II) complete ovule extrusion in every female (1 to 2 minutes); III) ovule fertilization (2 minutes) with sperm diluted in 100 mL water; IV) ova hydration in 10 - 20 L water; V) ova incubation in screen frames, measuring 1,0 x 0,7 m, with 1 mm screen size. Fertilization rate obtained with the proposed modifications stayed above 60 %. It should also be emphasized that the proposed techniques allowed to obtain several spawns from the same frog, and each female was able to ovulate, approximately, every 45 days.

Claudio Angelo, Agostinho; Francisco Stefano, Wechsler; Paulo Eduardo de Oliveira, Nictheroy; Daniela Felipe, Pinheiro.

1261-12-01

171

Induced formation and maturation of acetylcholine receptor clusters in a defined 3D bio-artificial muscle.  

Science.gov (United States)

Dysfunction of the neuromuscular junction is involved in a wide range of muscular diseases. The development of neuromuscular junction through which skeletal muscle is innervated requires the functional modulation of acetylcholine receptor (AchR) clustering on myofibers. However, studies on AchR clustering in vitro are mostly done on monolayer muscle cell culture, which lacks a three-dimensional (3D) structure, a prominent limitation of the two-dimensional (2D) system. To enable a better understanding on the structure-function correlation underlying skeletal muscle innervation, a muscle system with a well-defined geometry mimicking the in vivo muscular setting is needed. Here, we report a 3D bio-artificial muscle (BAM) bioengineered from green fluorescent protein-transduced C3H murine myoblasts as a novel in vitro tissue-based model for muscle innervation studies. Our cell biological and molecular analysis showed that this BAM is structurally similar to in vivo muscle tissue and can reach the perinatal differentiation stage, higher than does 2D culture. Effective clustering and morphological maturation of AchRs on BAMs induced by agrin and laminin indicate the functional activity and plasticity of this BAM system toward innervation. Taken together, our results show that the BAM provides a favorable 3D environment that at least partially recapitulates real physiological skeletal muscle with regard to innervation. With a convenience of fabrication and manipulation, this 3D in vitro system offers a novel model for studying mechanisms underlying skeletal muscle innervation and testing therapeutic strategies for relevant nervous and muscular diseases. PMID:23371342

Wang, Lin; Shansky, Janet; Vandenburgh, Herman

2013-12-01

172

Induced Radioactivity and Waste Classification of Reactor Zone Components of the Chernobyl Nuclear Power Plant Unit 1 After Final Shutdown  

International Nuclear Information System (INIS)

The dismantlement of the reactor core materials and surrounding structural components is a major technical concern for those planning closure and decontamination and decommissioning of the Chernobyl Nuclear Power Plant (NPP). Specific issues include when and how dismantlement should be accomplished and what the radwaste classification of the dismantled system would be at the time it is disassembled. Whereas radiation levels and residual radiological characteristics of the majority of the plant systems are directly measured using standard radiation survey and radiochemical analysis techniques, actual measurements of reactor zone materials are not practical due to high radiation levels and inaccessibility. For these reasons, neutron transport analysis was used to estimate induced radioactivity and radiation levels in the Chernobyl NPP Unit 1 reactor core materials and structures.Analysis results suggest that the optimum period of safe storage is 90 to 100 yr for the Unit 1 reactor. For all of the reactor components except the fuel channel pipes (or pressure tubes), this will provide sufficient decay time to allow unlimited worker access during dismantlement, minimize the need for expensive remote dismantlement, and allow for the dismantled reactor components to be classified as low- or medium-level radioactive waste. The fuel channel pipes will remain classified as high-activity waste requiring remote dismantlement for hundreds of years due to the high concentration of of years due to the high concentration of induced 63Ni in the Zircaloy pipes

173

Radioactivity in the environment  

International Nuclear Information System (INIS)

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

174

Characterization and comparison of seismic signals emitted during field scale sheer box experiments and artificially induced landslides  

Science.gov (United States)

The identification and detection of landslide induced seismic signals, recorded by deployed seismometers on active landslides has been the subject of many studies. The most commonly faced problem is the uncertainty in identifying which of the recorded signals are representing a movement or a failure in the landslide's body. In this paper we present two novel experimental campaigns; 1) field scale laboratory experiments of a 65cm diameter sheer box, 2) artificially induced failure of two, two-meter high vertical soil slopes. Using a field scale sheer box we recorded seismic signals emitted during soil slippage events, a phenomenon observed at a landslide's failure plain. This was implemented by displacing, a few centimeters at a time (1-10cm), a concrete cylinder filled with soil along a corridor free from vegetation. The field scale sheer box methodology allows control over a large number of parameters that affect a landslide. For example, it is possible to control soil saturation thus simulating different rain events or control the stress field on the soil's slippage surface simulating displacement events at different depths. More than 40 displacement events were induced under four different loading conditions between 472kg to 829kg. All soil slippage events were recorded above the levels of background seismic noise. Repetition of the methodology under the same experimental conditions resulted in similar seismic signals allowing us to define a 'characteristic seismic response' for soils. In the second experimental campaign, two controlled landslides were experimentally induced by increasing the vertical load on top of a 2m soil scarp. We were able to detect from 1 to 10 centimeter wide crack propagations and displacements, and approximately 20x20x10cm to 100x50x20cm block failure events based on microseismic recordings, field notes, video recordings and displacement measurements of the landslide's crown that failed during the experiments. Direct correlation between these visual recordings with seismic signals produced unique frequency patterns. Scanning all seismic data searching for these patterns allowed for detection of displacement events within the recordings that were not observed visually and were likely located within the landslide's mass. Both experimental campaigns were recorded by short period 3D seismic sensors. In order to validate the signals emitted using the sheer box methodology we compared them to the small displacement events recorded in the landslide experiments in the frequency domain by calculating their power spectral densities. Our results show close similarity between the two, validating the field scale lab experiment as a tool for preliminary understanding of the expected seismicity of an active landslide. Our study demonstrates the potential of microseismic motoring for detecting small soil displacements and soil block failures above ambient noise levels, as part of an active landslide monitoring campaign. Future research will use these results to design a monitoring network based on the threshold for event detection, which is a function of the displacement rate and the source-to-receiver distance. To our knowledge these are the first controlled field experiments that can allow validation and calibration of seismic monitoring for landslide detection.

Yfantis, Georgios; Martinez Carvajal, Hernan Eduardo; Pytharouli, Stella; Lunn, Rebecca

2014-05-01

175

Alloy development for fast induced radioactivity decay for fusion reactor applications  

International Nuclear Information System (INIS)

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

176

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

International Nuclear Information System (INIS)

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)

177

Ambient radioactivity levels and radiation doses. Annual report 2012  

International Nuclear Information System (INIS)

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.

178

Measurement and analysis of radioactivity induced in CuCrZr by D-T neutrons  

International Nuclear Information System (INIS)

CuCrZr is used in high heat flux components of ITER and other fusion reactor designs. A CuCrZr alloy of the European Fusion Technology Programme was irradiated with D-T neutrons, and the ?-activities of all nuclides which are relevant up to the recycling limit of the material were measured. The results were analysed with the European Activation System (versions EASY-2001 and EASY-2003). The calculated total activation property of the material was validated within 10%. The long-term radioactivity was estimated to be well below the hands-on limit with an uncertainty of 19%

179

Radiation-induced chromosomal aberrations in simulated internal contamination with radioactive caesium  

International Nuclear Information System (INIS)

Human blood samples were treated with various amounts of dissolved 137Cs and incubated for one hour, then washed with culture medium. The doses received by lymphocytes were calculated and the cells were cultivated for chromosomal aberration assay. It was found that the unstable forms of chromosomal aberrations, taken separately or collectively, were distributed in a non-Poisson manner among the irradiated cells. The data were fitted to the linear and linear quadratic models. In accidents involving internal contamination with radioactive caesium, this approach may be used for dose assessment as an adjunct to physical measurements by whole-body counter and bioassay. (author)

180

A fast method for the calculation of electron number density and temperature in laser-induced breakdown spectroscopy plasmas using artificial neural networks  

Science.gov (United States)

A fast and precise method for the determination of electron temperature and electron number density in laser-induced plasmas is presented. The method is based on the use of a simple artificial neural network (ANN), trained on a suitable set of laser-induced breakdown spectroscopy spectra. The training procedure is quite fast; once the ANN is set, the determination of plasma temperature and electron number density is almost instantaneous, allowing the possibility of measuring these parameters, with good precision, in real time. A direct application of this new method could be the characterization of plasmas generated during pulsed laser deposition process of thin films and nanoparticles generation. The plasma electronic parameters will help to tune the energies involved in the stoichiometry and crystallization control of those nanostructured materials. As an example, the characteristics of the plasma induced by a Nd:YAG laser on a pure titanium target are determined, at different laser fluences.

Borges, Fábio O.; Cavalcanti, Gildo H.; Gomes, Gabriela C.; Palleschi, Vincenzo; Mello, Alexandre

2014-10-01

 
 
 
 
181

An active artificial cornea with the function of inducing new corneal tissue generation in vivo-a new approach to corneal tissue engineering  

International Nuclear Information System (INIS)

An active artificial cornea which can perform the function of inducing new cornea generation in vivo but does not need culture cells in vitro and which has similar optical and mechanical properties to those of the human cornea was constructed. An animal keratoplasty experiment using the artificial cornea as the implant showed that the animals' corneas could keep smooth surface and clear stroma postoperatively, and that the repopulation of the host's keratocytes, the degradation of the implant and new corneal tissue generation were completed at 5-6 months after surgery. Such an artificial cornea has several advantages over other corneal equivalents constructed in the typical way of tissue engineering: in having similar mechanical and optical properties to those of the human cornea and with no exogenetic cells, it can be used universally in different implantation surgeries without immunoreaction; it is easy to prepare and process into different shapes and sizes on a large scale, and suitable for long-distance transportation and long-term storage. All these characteristics make it a new approach to cornea tissue engineering having potential in many clinical applications

182

An active artificial cornea with the function of inducing new corneal tissue generation in vivo-a new approach to corneal tissue engineering  

Energy Technology Data Exchange (ETDEWEB)

An active artificial cornea which can perform the function of inducing new cornea generation in vivo but does not need culture cells in vitro and which has similar optical and mechanical properties to those of the human cornea was constructed. An animal keratoplasty experiment using the artificial cornea as the implant showed that the animals' corneas could keep smooth surface and clear stroma postoperatively, and that the repopulation of the host's keratocytes, the degradation of the implant and new corneal tissue generation were completed at 5-6 months after surgery. Such an artificial cornea has several advantages over other corneal equivalents constructed in the typical way of tissue engineering: in having similar mechanical and optical properties to those of the human cornea and with no exogenetic cells, it can be used universally in different implantation surgeries without immunoreaction; it is easy to prepare and process into different shapes and sizes on a large scale, and suitable for long-distance transportation and long-term storage. All these characteristics make it a new approach to cornea tissue engineering having potential in many clinical applications.

Huang Yaoxiong; Li Qinhua [Institute of Biomedical Engineering, Ji Nan University, Guang Zhou (China)

2007-09-15

183

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)  

International Nuclear Information System (INIS)

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)

184

31P NMR characterization of terminal phosphates induced on DNA by the artificial nuclease 'Mn-TMPyP/KHSO5' in comparison with DNases I and II.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Phosphorus-31 NMR has been applied to the characterization of terminal phosphates on fragments of calf thymus DNA induced by three different nuclease systems: DNase I, DNase II and the artificial nuclease 'Mn-TMPyP/KHSO5'. In this last case, the oxidative damage to deoxyribose leads to two monophosphates esters (at the 3' and 5' ends) on both sides of the cleavage site. This method constitutes a promising approach to visualise the phosphate termini generated in DNA or RNA cleavage by cytotoxi...

Gasmi, G.; Pasdeloup, M.; Pratviel, G.; Pitie?, M.; Bernadou, J.; Meunier, B.

1991-01-01

185

Artificial blood  

Directory of Open Access Journals (Sweden)

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.

Sarkar Suman

2008-01-01

186

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)  

Energy Technology Data Exchange (ETDEWEB)

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)

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

1969-07-01

187

Induced radioactivity in the target station and decay tunnel from a 4MW proton beam  

CERN Document Server

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. A first 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 has been performed by the Monte Carlo hadronic cascade code FLUKA. The aim is 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. This paper discusses the first results of such calculations.

Agosteo, S; Otto, T; Silari, Marco

2003-01-01

188

Tide induced mathematical model for coastal radioactive discharges and its application  

International Nuclear Information System (INIS)

A mathematical model has been developed to evaluate spatial and temporal distribution of radionuclide concentration from a continous discharge of radioactive liquid effluents into the Tarapur coastal waters, taking into consideration tidal effects and seasonal variation of ocean currents. It is found that all the nuclides studied except 131I, attain steady state concentration more or less at the same time interval after continuous discharge, depending on the distance along the coast. Further, the confinement of radionuclides parallel to the coast is significant. Limiting discharge rates (LDR) for some typical radionuclides have also been computed using a radiological model. The calculations show the the LDR values vary from 7 to 50,000 Ci.d-1, the lowest and highest being for 239Pu and 134Cs respectively. (author)

189

Radioactive waste disposal in granite  

International Nuclear Information System (INIS)

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)

190

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

Directory of Open Access Journals (Sweden)

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 «?» 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 (? > 0.9 and age (? > 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.

Shevchenko ?. A.

2014-03-01

191

Benchmark Studies of Induced Radioactivity Produced in LHC Materials, Pt I: Remanent Dose Rates  

Energy Technology Data Exchange (ETDEWEB)

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 analyzed 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.

Brugger, M.; Mayer, S.; Roesler, S.; Ulrici, L.; /CERN; Khater, H.; Prinz, A.; Vincke, H.; /SLAC

2006-04-12

192

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

Science.gov (United States)

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. PMID:16604585

Brugger, M; Khater, H; Mayer, S; Prinz, A; Roesler, S; Ulrici, L; Vincke, H

2005-01-01

193

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

International Nuclear Information System (INIS)

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)

194

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

International Nuclear Information System (INIS)

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 sea 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)

195

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 consider...

-b Chen, W.; -c Liu, W.; -h Hsu, M.

2012-01-01

196

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

DEFF Research Database (Denmark)

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 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.

Schou, JØrgen; Larsen, N.B.

1999-01-01

197

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

International Nuclear Information System (INIS)

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

198

Viability study of using the Laser-Induced Breakdown Spectroscopy technique for radioactive waste detection at IPEN-CNEN/SP, Brazil  

International Nuclear Information System (INIS)

this work a viability study to apply the Laser-Induced Breakdown Spectroscopy (LIBS) technique for radioactive waste characterization was developed using a high power q-switched Nd:YAG rod-Laser, operating at 1064 nm with 9 ns of pulse-width and pulse-to-pulse energy around 10 to 20 mJ. When applied in a non-radioactive deionized water sample, our methodology exhibits a good potential to spectroscopy detection of Hydrogen species with resolution around 0.035 nm at full width at half maximum (FWHM). (author)

199

Viability study of using the Laser-Induced Breakdown Spectroscopy technique for radioactive waste detection at IPEN-CNEN/SP, Brazil  

Energy Technology Data Exchange (ETDEWEB)

this work a viability study to apply the Laser-Induced Breakdown Spectroscopy (LIBS) technique for radioactive waste characterization was developed using a high power q-switched Nd:YAG rod-Laser, operating at 1064 nm with 9 ns of pulse-width and pulse-to-pulse energy around 10 to 20 mJ. When applied in a non-radioactive deionized water sample, our methodology exhibits a good potential to spectroscopy detection of Hydrogen species with resolution around 0.035 nm at full width at half maximum (FWHM). (author)

Tunes, Matheus A.; Schon, Claudio G., E-mail: matheus.tunes@ctmsp.mar.mil.br [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Engenharia Metalugica e de Materiais. Escola Politecnica; Wetter, Niklaus U., E-mail: nuwetter@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

200

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

International Nuclear Information System (INIS)

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

 
 
 
 
201

Radiation induced change in the affinity of a plastic resin to chlorine contained in artificial tap water  

International Nuclear Information System (INIS)

?-Radiation curing of a polyacetal resin was attempted in order to eliminate the unsuitable property for the joints of tap water pipes. In the case of non-irradiated resin, almost all available chlorine (AC) contained in usual tap water disappeared. ?-Irradiation of the resin showed an indirect effect on eliminating such a property; that is, a decrease in the amount of AC from artificial tap water (test solution) showed a decrease to JIS (Japan Industrial Standards) level of requirement at certain absorption doses. However, it was also found that the decrease in the amount of AC from the test solution increased with time after ?-irradiation. (author)

202

Inhibition of BmNPV replication in silkworm cells using inducible and regulated artificial microRNA precursors targeting the essential viral gene lef-11.  

Science.gov (United States)

Bombyx mori nucleopolyhedrovirus (BmNPV) is a major silkworm pathogen, causing substantial economic losses to the sericulture industry annually. We demonstrate a novel anti-BmNPV system expressing mature artificial microRNAs (amiRNAs) targeting the viral lef-11 gene. The mature amiRNAs inhibited the lef-11 gene in silkworm BmN-SWU1 cells. Antiviral assays demonstrated that mature amiRNAs silenced the gene and inhibited BmNPV proliferation efficiently. As constitutive overexpression of mature amiRNAs may induce acute cellular toxicity, we further developed a novel virus-induced amiRNA expression system. The amiRNA cassette is regulated by a baculovirus-induced fusion promoter. This baculovirus-induced RNA interference system is strictly regulated by virus infection, which functions in a negative feedback loop to activate the expression of mature amiRNAs against lef-11 and subsequently control inhibition of BmNPV replication. Our study advances the use of a regulatable amiRNA cassette as a safe and effective tool for research of basic insect biology and antiviral application. PMID:24486953

Zhang, Jun; He, Qian; Zhang, Chun-Dong; Chen, Xiang-Yun; Chen, Xue-Mei; Dong, Zhan-Qi; Li, Na; Kuang, Xiu-Xiu; Cao, Ming-Ya; Lu, Cheng; Pan, Min-Hui

2014-04-01

203

Artificial Blood  

Directory of Open Access Journals (Sweden)

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

Umit Yasar

2012-04-01

204

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

International Nuclear Information System (INIS)

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

205

In-beam PET measurements of beta+ radioactivity induced by proton beams.  

Science.gov (United States)

Our first in-beam PET measurements of the beta+ activation induced by proton irradiation are presented. Monoenergetic proton beams in the energy and intensity range suited for the treatment of deep-seated tumours were delivered by the synchrotron of the Gesellschaft für Schwerionenforschung Darmstadt (GSI). They were stopped in PMMA blocks placed in the centre of the field of view of the positron camera that is installed in the heavy ion tumour treatment facility at GSI. The beta+ activity signal was found to be three times larger than that produced by carbon ions at the same range and applied physical dose. The reconstructed spatial beta+ activity distributions were analysed and compared with the production of positron emitters predicted by a calculation based on experimental cross-sections and on the proton flux given by the FLUKA Monte Carlo code. The shape of the depth-activity profiles was well reproduced by the model and the correlation with the proton range and the depth-dose distributions was carefully investigated. Despite the non-trivial range determination from the beta+ activity distribution in the proton case, our experimental investigation supports the feasibility of an in situ proton therapy monitoring by means of in-beam PET, as already clinically implemented for the monitoring of carbon ion therapy at GSI Darmstadt. PMID:11814225

Parodi, K; Enghardt, W; Haberer, T

2002-01-01

206

Use of artificial tracers in hydrology  

International Nuclear Information System (INIS)

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

207

Immunostimulatory response induced by supplementation of Ficus benghalensis root powder, in the artificial feed the Indian freshwater murrel, Channa punctatus.  

Science.gov (United States)

Methanol extract from the dried aerial root of Ficus benghalensis, was used to evaluate antibacterial activity on the bacterial strains of Aeromonas hydrophila and Escherichia coli, by disc diffusion method. In order to study, if there is any immunostimulatory response of F. benghalensis, immunized fish were fed with supplementary artificial feed containing 5% F. benghalensis dried root powder. There was no marked difference in the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in control and treated fish, suggesting that the supplementary feed had no adverse effect on liver or kidney. Serum lysozyme, tissue super oxide dismutase (SOD), percentage phagocytosis, phagocytotic index, nitric oxide (NO), total serum protein and immunoglobulin increased significantly in the treated fish compared to control fish. Serum immunoglobulin levels were estimated by development of a sandwich ELISA, and levels were found to increase with successive immunizations of BSA. PMID:22789713

Verma, Vipin Kumar; Rani, Kumari Vandana; Sehgal, Neeta; Prakash, Om

2012-09-01

208

Analysis of induced-radioactivity using DCHAIN-SP for Pb and Hg at a mercury target irradiated by 2.8 and 24 GeV protons  

International Nuclear Information System (INIS)

The high energy particle induced radioactivity calculation code system consisting PHITS, MCNP4C and DCHAIN-SP 2001 was validated for mercury and lead samples by the experimental activation data obtained using AGS (Alternative Gradient Synchrotrons) accelerator at Brookhaven National Laboratory. As a result, we found that the calculation is consistent with the experimental data within a factor of 2 on the average. Mass yield curves of the spallation reactions were approximately deduced using the experimental activation data. (author)

209

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

International Nuclear Information System (INIS)

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

210

Artificial receptors.  

Science.gov (United States)

Herein I will provide a brief overview of artificial receptors with emphasis on molecularly imprinted polymers (MIPs) and their applications. Alternative techniques to produce artificial receptors such as in silico designed and modelled polymers as well as different receptors designed using libraries of more or less natural composition will also be mentioned. Examples of these include aptamers and bio-nanocomposites. The physical presentation of the receptors is important and may depend on the application. Block polymerization of MIPs and grinding to particles of suitable size used to be the preferred technique, but today beaded materials can be produced in sizes down to nanobeads and also nanofibers can be used to increase available surface area and thereby capacity. For sensor applications it may be attractive to include the artificial receptors in surface coatings or in membrane structures. Different composite designs can be used to provide additional desirable properties. MIPs and other artificial receptors are gaining rapidly increasing attention in very shifting application areas and an attempt to provide a systematic account for current applications has been made with examples from separation, solid-phase extraction, analysis, carbohydrate specific experiments, and MIPs-directed synthesis. PMID:17985098

Danielsson, Bengt

2008-01-01

211

Artificial Sweeteners  

Science.gov (United States)

This Science Update, from Science NetLinks, features an interview with Purdue University psychologist Susie Swithers about new research suggesting that artificial sweeteners may promote overeating. Science Updates are audio interviews with scientists and are accompanied by a set of questions as well as links to related Science NetLink lessons and other related resources.

Science Update;

2004-08-02

212

Radioactivity and food  

International Nuclear Information System (INIS)

Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.15 references

213

Radioactivity monitoring  

International Nuclear Information System (INIS)

The radioactivity of a radioactive fluid, e.g. in a nuclear reactor, is monitored, in the presence of background radiation, without interruption of radioactivity detection by performing successive measurements on two different volumes (CH1, CH2) of the radioactive fluid, the background being eliminated by subtraction. In the first measurement, the radioactive fluid is present in both chambers CH1, CH2. In the second measurement, the radioactive fluid is present in chamber CH2 and a non-radioactive fluid is present in chamber CH1. The radioactivity is monitored using a single detector DET. (author)

214

The effect of Amaranth oil on monolayers of artificial lipids and hepatocyte plasma membranes with adrenalin-induced stress.  

Science.gov (United States)

In this paper the oil from seeds of Amaranthus cruentus L. (AmO) was shown to be an efficient modulator of the physical chemical properties of artificial lipid and rat hepatocyte plasma membranes. AmO improved the membrane stability, their stress resistance and the adsorption of neurotensin to plasma membranes with the distinct biphasic interactions being observed even after adrenalin stress exposure. The analysis of pro-/antioxidant balance in rat blood revealed a mild prooxidant activity after AmO intake, which was accompanied by accumulation of oxidative destruction products in plasma membranes. This prooxidant action of AmO was corroborated in vitro in an adrenalin autooxidation model. On the other hand, the observed improved resistance to adrenalin stress in AmO supplemented rats was associated with an antioxidant response in blood and plasma membrane studies. The AmO effects can be attributed to the modulation of the metabolic pathways involved into oxygen and free radical homeostasis. PMID:24206699

Yelisyeyeva, O P; Semen, K O; Ostrovska, G V; Kaminskyy, D V; Sirota, T V; Zarkovic, N; Mazur, D; Lutsyk, O D; Rybalchenko, K; Bast, A

2014-03-15

215

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

International Nuclear Information System (INIS)

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)

216

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

International Nuclear Information System (INIS)

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)

217

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  

Energy Technology Data Exchange (ETDEWEB)

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

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

218

Artificial Wormhole  

CERN Document Server

It is shown that recently reported result by the OPERA Collaboration (arXive:1109.4897) of an early arrival time of muon neutrinos with respect to the speed of light in vacuum does not violate standard physical laws. We show that vacuum polarization effects in intensive external fields may form a wormhole-like object. The simplest theory of such an effect is presented and basic principles of formation of an artificial wormhole are also considered.

Kirillov, A A

2012-01-01

219

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

Science.gov (United States)

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.

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

2012-12-01

220

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

W.-B. Chen

2012-12-01

 
 
 
 
221

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

Science.gov (United States)

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 100?g of GnRH on day 0. CIDR removal and PGF(2?) (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

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

2012-10-01

222

Fecundación Artificial  

Directory of Open Access Journals (Sweden)

Full Text Available Por Fecundación artificial se entiende, la fecundación de una hembra sin el servicio directo del macho, es decir la introducción al aparato genital femenino, del esperma que se ha recogido por medios artificiales. Esta fecundación, practicada en debidas condiciones, tiene el mismo efecto de la fecundación natural, con las ventajas que veremos más adelante. La fecundación artificial permite explotar un reproductor a su máximum de capacidad, ya que se considera, para no hacer cálculos alegres, que un servicio de un caballo puede servir, diluido, por lo menos para cuatro yeguas, según los autores americanos, y para 10 a 15, según otros autores. El toro y el carnero pueden dar esperma suficiente en un servicio para fecundar de 10 a 12 hembras, según,los americanos, y según otros autores, hasta para 40. Los investigadores rusos han podido fecundar hasta 60 vacas con un solo servicio y han logrado con reproductores valiosos, fecundar 10.263 vacas por toro, a pesar de que éstos sólo han servido, durante un periodo de monta de sólo dos meses. Estos mismos han logrado fecundar artificialmente 2.733 ovejas con un solo carnero, y 1.403 con otro Los investigadores americanos han contado 22 servicios a un carnero vigoroso en un periodo de ocho horas, y durante este tiempo produjo esperma suficiente para haber fecundado 200 ovejas artificialmente. La fecundación artificial sirve para evitar la trasmisión de enfermedades que se contagian por el coito, tales como la durina, enfermedad ésta producida por un tripanosoma que por fortuna no existe entre nosotros. A las estaciones de monta llevan con frecuencia hembras afectadas de enfermedades como la vaginitis granulosa de la vaca, que se contagia al toro y de éste a otras hembras. Como el control sanitario de toda hembra llevada al servicio de un reproductor de estas estaciones de monta no siempre puede efectuarse por dificultades de distinta índole, mediante la fecundación artificial se evita el contagio de los reproductores y la consiguiente propagación. Mediante la fecundación artificial se puede efectuar el servicio a distancia, sin el costo y riesgo del transporte del macho o de la hembra.

Ochoa. Fidel

1939-10-01

223

Potential hazard due to induced radioactivity secondary to radiotherapy: the report of task group 136 of the American Association of Physicists in Medicine.  

Science.gov (United States)

External-beam radiation therapy mostly uses high-energy photons (x-rays) produced by medical accelerators, but many facilities now use proton beams, and a few use fast-neutron beams. High-energy photons offer several advantages over lower-energy photons in terms of better dose distributions for deep-seated tumors, lower skin dose, less sensitivity to tissue heterogeneities, etc. However, for beams operating at or above 10 MV, some of the materials in the accelerator room and the radiotherapy patient become radioactive due primarily to photonuclear reactions and neutron capture, exposing therapy staff and patients to unwanted radiation dose. Some recent advances in radiotherapy technology require treatments using a higher number of monitor units and monitor-unit rates for the same delivered dose, and compared to the conventional treatment techniques and fractionation schemes, the activation dose to personnel can be substantially higher. Radiotherapy treatments with proton and neutron beams all result in activated materials in the treatment room. In this report, the authors review critically the published literature on radiation exposures from induced radioactivity in radiotherapy. They conclude that the additional exposure to the patient due to induced radioactivity is negligible compared to the overall radiation exposure as a part of the treatment. The additional exposure to the staff due to induced activity from photon beams is small at an estimated level of about 1 to 2 mSv y. This is well below the allowed occupational exposure limits. Therefore, the potential hazard to staff from induced radioactivity in the use of high-energy x-rays is considered to be low, and no specific actions are considered necessary or mandatory. However, in the spirit of the "As Low as Reasonably Achievable (ALARA)" program, some reasonable steps are recommended that can be taken to reduce this small exposure to an even lower level. The dose reduction strategies suggested should be followed only if these actions are considered reasonable and practical in the individual clinics. Therapists working with proton beam and neutron beam units handle treatment devices that do become radioactive, and they should wear extremity monitors and make handling apertures and boluses their last task upon entering the room following treatment. Personnel doses from neutron-beam units can approach regulatory limits depending on the number of patients and beams, and strategies to reduce doses should be followed. PMID:25271934

Thomadsen, Bruce; Nath, Ravinder; Bateman, Fred B; Farr, Jonathan; Glisson, Cal; Islam, Mohammad K; LaFrance, Terry; Moore, Mary E; George Xu, X; Yudelev, Mark

2014-11-01

224

Geochemical ways of artificial radionuclide migration in biosphere  

International Nuclear Information System (INIS)

The collection contains abstracts of papers concerning aspects of distribution, forms and migration of artificial radionuclides in biosphere, simulation of their behaviour in separate components and systems. Methods of radioactivity monitoring in biosphere are discussed

225

Ambient radioactivity levels and radiation doses. Annual report 2012; Umweltradioaktivitaet und Strahlenbelastung. Jahresbreicht 2012  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2014-06-15

226

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

227

Customs control of radioactive materials  

International Nuclear Information System (INIS)

Customs officers take part in the combat against illicit traffic od radioactive materials by means of different regulations dealing with nuclear materials, artificial radiation sources or radioactive wastes. The capability of customs officers is frequently incomplete and difficult to apply due to incompatibility of the intervention basis. In case of contaminated materials, it seems that the customs is not authorised directly and can only perform incidental control. In order to fulfil better its mission of fighting against illicit traffic of radioactive materials customs established partnership with CEA which actually includes practical and theoretical training meant to augment the capabilities of customs officers

228

Environmental radioactivity and radiation load  

International Nuclear Information System (INIS)

The section on environmental radioactivity and radiation load explains radiological terms and units, deals further with recommendations and limiting values for radiation doses, measuring programmes and measuring networks, natural radiation loads, radiation load from artificial sources, source strengths and incidence of some radionuclides in the biosphere, radioactive substances in the air near the soil, in precipitations, in the soil, in vegetation, in food and in water, radioactive wastes, and particular incidents - aspects of radiation protection relevant to the environment. A great many tables and figures illustrate the report. (HSCH)

229

Induced radioactivity and influence of materials selection in deuterium-deuterium and deuterium-tritium fusion reactors  

International Nuclear Information System (INIS)

The radioactivity, biological hazard potential, and afterheat levels in the deuterium-deuterium (D-D) fuel cycle fusion reactor, SATYR, have been evaluated for two types of structural materials: ferritic steel (HT-9) and sintered aluminum product. Results are compared to the corresponding levels in the deuterium-tritium (D-T) fuel cycle systems, STARFIRE and WITAMIR-I, both during operation and after plant decomissioning. The influence of blanket replacements on the radioactivity levels has been considered in the comparative analysis. It has been found that the long-term radioactivity level (100 to 1000 yr after plant shutdown) in the ferritic steel blanket of the SATYR design is somewhat higher, by a factor of 2 to 6, than that found for a D-T reactor system employing the same structural alloy. The high levels are attributed to the softer spectrum and the larger structure volume fraction encountered in the D-D machines. However, the levels during plant operation ( about30 yr) are comparable. Isotopic tailoring and elemental substitution in alloys to reduce the long-term radioactivity levels in the SATYR design are discussed. It is found that three orders of magnitude reduction in radioactivity levels can be achieved by isotopically tailoring the molybdenum in the ferritic steel to 100% 97Mo. The elemental substitution of vanadium for nickel and molybdenum in ferritic steels is shown to reduce long-term radioactivity levels by four orders of magnitude. These low levels at long times after shutdown are below those found for blankets using aluminum alloy structure. The results make clear that elemental composition should be a primary consideration in alloy formulation if the goal of a low radioactivity level in fusion reactor radwaste is to be achieved

230

[Artificial blood].  

Science.gov (United States)

To prepare for shortage of blood components and to avoid side effects such as blood borne infectious disease, blood substitutes such as artificial red cell (artificial oxygen carrier) and artificial platelet are being developed. As for oxygen carriers, there are several candidates such as perfluorochemicals, modified hemoglobins and liposome encapsulated hemoglobins and albuimin heme. Perfluorochemicals have limited oxygen carrying capacity and oxygen inhalation is mandatory when they are used. Modified hemoglobins such as intermolecular or intramolecular cross linked hemoglobins have side effect to cause hypertension by scavenging nitro oxide (NO) which is produced by endothelial cells, because the size of these hemoglobins are small enough to go to the adjacent place near endothelial surface. Hemoglobin vesicles (HbV) in which hemoglobins are encapsulated in liposome is most possible candidate for oxygen carrier. Usefulness and safety of the HbV is evidenced by animal shock model or exchange transfusion model and they are now being prepared for clinical trials as red blood substitutes or oxygen therapeutics. Albumin heme in which recombinant human serum albumin incorporating synthetic heme is thought an ideal resuscitation fluid as this material has colloid oncotic pressure. Short time storage and viral infection are serious concern in platelet transfusion therapy for bleeding thrombocytopenic patients. Adhesion of the platelet to the collagen surface and aggregation at the bleeding sites to plug holes in blood vessels, and to facilitate the function of the remaining platelets is a starting point in developing platelet substitutes and several platelet substitutes have been proposed on this theory. PMID:15696696

Kobayashi, Koichi

2005-01-01

231

Environmental radioactivity and drinking water supply. Pt. 4  

International Nuclear Information System (INIS)

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)

232

ULF waves with drift resonance and drift-bounce resonance energy sources as observed in artificially-induced HF radar backscatter  

Directory of Open Access Journals (Sweden)

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 been demonstrated to provide ionospheric electric field data of unprecedented temporal resolution and accuracy. Here such data are used to investigate ULF wave processes observed by the CUTLASS HF radars. Within a short period of time during a single four hour experiment three distinct wave types are observed with differing periods, and latitudinal and longitudinal phase evolution. Combining information from the three waves allows them to be divided into those with a large-scale nature, driven externally to the magnetosphere, and those with small azimuthal scale lengths, driven by wave-particle interactions. Furthermore, the nature of the wave-particle interactions for two distinct small-scale waves is revealed, with one wave interpreted as being driven by a drift resonance process and the other by a drift-bounce resonance interaction. Both of these mechanisms with m ? -35 and proton energies of 35–45 keV appear to be viable wave energy sources in the postnoon sector.

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

T. K. Yeoman

233

Structural, Kinetic, and Docking Studies of Artificial Imine Reductases Based on Biotin-Streptavidin Technology: An Induced Lock-and-Key Hypothesis.  

Science.gov (United States)

An artificial imine reductase results upon incorporation of a biotinylated Cp*Ir moiety (Cp* = C5Me5(-)) within homotetrameric streptavidin (Sav) (referred to as Cp*Ir(Biot-p-L)Cl] ? Sav). Mutation of S112 reveals a marked effect of the Ir/streptavidin ratio on both the saturation kinetics as well as the enantioselectivity for the production of salsolidine. For [Cp*Ir(Biot-p-L)Cl] ? S112A Sav, both the reaction rate and the selectivity (up to 96% ee (R)-salsolidine, kcat 14-4 min(-1) vs [Ir], KM 65-370 mM) decrease upon fully saturating all biotin binding sites (the ee varying between 96% ee and 45% ee R). In contrast, for [Cp*Ir(Biot-p-L)Cl] ? S112K Sav, both the rate and the selectivity remain nearly constant upon varying the Ir/streptavidin ratio [up to 78% ee (S)-salsolidine, kcat 2.6 min(-1), KM 95 mM]. X-ray analysis complemented with docking studies highlight a marked preference of the S112A and S112K Sav mutants for the SIr and RIr enantiomeric forms of the cofactor, respectively. Combining both docking and saturation kinetic studies led to the formulation of an enantioselection mechanism relying on an "induced lock-and-key" hypothesis: the host protein dictates the configuration of the biotinylated Ir-cofactor which, in turn, by and large determines the enantioselectivity of the imine reductase. PMID:25317660

Robles, Victor Muñoz; Dürrenberger, Marc; Heinisch, Tillmann; Lledós, Agustí; Schirmer, Tilman; Ward, Thomas R; Maréchal, Jean-Didier

2014-11-01

234

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

Energy Technology Data Exchange (ETDEWEB)

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: Black-Right-Pointing-Pointer We use statistical techniques for identification of archeological materials. Black-Right-Pointing-Pointer Input data for LDA and ANN are PC scores counted from stand-off LIBS spectra. Black-Right-Pointing-Pointer The method used for identification of archeological materials provides good results. Black-Right-Pointing-Pointer After recording more spectra we can get useful tool for rapid analysis in situ.

Vitkova, Gabriela [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Novotny, Karel, E-mail: codl@sci.muni.cz [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Prokes, Lubomir [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Hrdlicka, Ales [Central European Institute of Technology, CEITEC MU, Masaryk University (Czech Republic); Kaiser, Jozef [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Novotny, Jan [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Malina, Radomir; Prochazka, David [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic)

2012-07-15

235

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

International Nuclear Information System (INIS)

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

236

Measurements of D-T neutron induced radioactivity in plasma-facing materials and their role in qualification of activation cross-section libraries and codes  

International Nuclear Information System (INIS)

The D-T neutron-induced radioactivity constitutes one of the foremost issues in fusion reactor design. The validation of activation cross-sections and decay data libraries is one of the important requirements for validating ITER design from safety and waste disposal viewpoints. An elaborate, experimental program was initiated in 1988, under USDOE-JAERI collaborative program, to validate the radioactivity codes/libraries. The measurements of decay-? spectra from irradiated, high purity samples of Al, Si, Ti, V, Cr, Mn-Cu alloy, Fe, Co, Ni, Cu, stainless steel 316 (AISI 316), Zn, Zr, Nb, Mo, In, Sn, Ta, W, and Pb, among others, were conducted under D-T neutron fluences varying from 1.6 x 1010ncm-2 to 6.1 x 1013ncm-2. As many as 14 neutron energy spectra were covered for a number of materials. The analysis of isotopic activities of the irradiated materials using activation cross-section libraries of four leading radioactivity codes, i.e. ACT4/THIDA-2, REAC-3, DKR-ICF, and RACC, has shown large discrepancies among the calculations, on the one hand, and between the calculations and the measurements, on the other. A discussion is also presented on definition and obtention of safety cum quality factors for various activation libraries. (orig.)

237

Airborne measurement of radioactivity  

International Nuclear Information System (INIS)

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.)

238

Total Artificial Heart  

Science.gov (United States)

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

239

Permanently Attached Artificial Limb.  

Science.gov (United States)

The patent application is for a permanently attached artificial limb comprising an endoprosthesis in combination with an artificial tendon attachment. The artificial tendon attachment permits the use of existing skeletal muscles to power external articula...

C. W. Hall

1977-01-01

240

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

International Nuclear Information System (INIS)

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.)

 
 
 
 
241

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

International Nuclear Information System (INIS)

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)

242

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

243

Artificial Economy  

Directory of Open Access Journals (Sweden)

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.

Alexandru JIVAN

2011-08-01

244

The artificial heart  

...The artificial heart topic moment artificial heart IOP physics A patient heading home after being given an artificial heart has made news headlines. ...Careers Policy Resources You are here Resources Topic of the moment Archive Artificial heart Topic of the moment Archive Antimatter The Apollo programme Archeology ...Fiction to fact Fuel cells Geolocation Graphene The career of Stephen Hawking Artificial heart Herschel Space Observatory Higgs boson Metamaterials Meteor and asteroid impacts ...sport Television Transit of Venus Volcanic ash Weights and measures cryptography The artificial heart A patient heading home after being given an artificial heart ...

245

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

Science.gov (United States)

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.

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

246

3. International symposium 'Radiation protection'. Radioactively contaminated sites - environmental radioactivity  

International Nuclear Information System (INIS)

National and international experts lecture on their national programs for the registration and clean-up of sites contaminated by uranium mining. A survey of the situations in the USA, Canada and Germany is given. The new collimated in-situ gamma spectrometry measurement technique intended to be used for registration of contaminated surfaces is presented. Natural and artificial radioactivity as well as the radioactivity of anthropogenically changed materials are considered. The dose relevance of these radiation sources is discussed. The state of the much discussed consideration of natural radiation sources in legislation on radiation protection is presented. (DG)

247

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

International Nuclear Information System (INIS)

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)

248

Nanobiocatalytic assemblies for artificial photosynthesis.  

Science.gov (United States)

Natural photosynthesis, a solar-to-chemical energy conversion process, occurs through a series of photo-induced electron transfer reactions in nanoscale architectures that contain light-harvesting complexes, protein-metal clusters, and many redox biocatalysts. Artificial photosynthesis in nanobiocatalytic assemblies aims to reconstruct man-made photosensitizers, electron mediators, electron donors, and redox enzymes for solar synthesis of valuable chemicals through visible light-driven cofactor regeneration. The key requirement in the design of biocatalyzed artificial photosynthetic process is an efficient and forward electron transfer between each photosynthetic component. This review describes basic principles in combining redox biocatalysis with photocatalysis, and highlights recent research outcomes in the development of nanobiocatalytic assemblies that can mimic natural photosystems I and II, respectively. Current issues in biocatalyzed artificial photosynthesis and future perspectives will be briefly discussed. PMID:24832068

Kim, Jae Hong; Nam, Dong Heon; Park, Chan Beum

2014-08-01

249

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

Directory of Open Access Journals (Sweden)

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.

Van So Le

2011-01-01

250

Radioactivity and food preservation  

International Nuclear Information System (INIS)

In food irradiation, electrons or electromagnetic radiation are used to destroy microorganisms and insects or to prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undesirable changes or induced radioactivity are produced in the irradiated food

251

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

252

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  

International Nuclear Information System (INIS)

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)

253

Radioactivity; La radioactivite  

Energy Technology Data Exchange (ETDEWEB)

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.)

NONE

1998-08-01

254

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

Science.gov (United States)

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.

El Haddad, J.; Bruyère, D.; Ismaël, A.; Gallou, G.; Laperche, V.; Michel, K.; Canioni, L.; Bousquet, B.

2014-07-01

255

Environmental radioactivity and radiation exposure  

International Nuclear Information System (INIS)

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.)

256

Ambient radioactivity levels and radiation doses. Annual report 2011  

International Nuclear Information System (INIS)

The annual report 2011 on ambient radioactivity levels and radiation doses covers the following issues: Part A: Natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposure 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 exposure, radiation exposure from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. The Appendix includes Explanations of terms, radiation doses and related units, external and internal radiation exposure, stochastic and deterministic radiation effects, genetic radiation effects, induction of malignant neoplasm, risk assessment, physical units and glossary, laws, ordinances, guidelines, recommendations and other regulations concerning radiation protection, list of selected radionuclides.

257

Única ou dupla inseminação artificial em tempo fixo em porcas com ovulações induzidas pelo Hormônio Luteinizante / Single or double artificial insemination in fixed time in sows with ovulation induced by Luteinizing Hormon  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Duzentas e cinqüenta e quatro matrizes Camborough 22 (PIC®), foram divididas em 3 tratamentos: T 1 (n=60) - 600 UI de eCG após desmama e 5 mg de LH, 72 h após eCG , com única inseminação artificial (IA) (24 h após LH); T 2 (n=95) - mesmo tratamento hormonal do T1, com 2 IA (24 e 32 h após LH); T 3 ( [...] n=99) - grupo controle sem tratamento hormonal, com 3 IA. As médias de intervalo desmame-estro (IDE) em T1, T2 e T3 foram de 87,4 ± 3,0 (87 a 111), 87 ± 0 (87) e 99,9 ± 13,6 (63 a 135) horas, respectivamente, sendo reduzidas (P horas, respectivamente para T1, T2 e T3, sendo menor (P Abstract in english Two hundred fifty four sows Camborough 22 (PIC®), were divided in 3 treatments: T 1 (n=60) - 600 UI of eCG after weaning and 5 mg of LH, after 72 h, with single artificial insemination (AI) (24 h after LH); T 2 (n=95) - same hormonal treatment of T1, with 2 AI (24 and 32 h after LH); T 3 (n=99) - co [...] ntrol group, with 3 AI. The averages of weaning-to-estrus interval (WEI) in T1, T2 and T3 were of 87,4 ± 3,0 (87 - 111), 87 ± 0 (87) and 99,9 ± 13,6 (63 - 135) h, respectively, been reduced (P

Paulo Henrique, Candini; Aníbal de Sant' Anna, Moretti; Eraldo Luis, Zanella; Paulo Roberto Souza da, Silveira; Carlos Henrique Cabral, Viana; Isabel, Santos.

258

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)  

Energy Technology Data Exchange (ETDEWEB)

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)

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

1963-11-15

259

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

International Nuclear Information System (INIS)

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)

260

Radioactivity Monitoring of the Irish Environment 2008  

International Nuclear Information System (INIS)

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 level

 
 
 
 
261

Forest decline, natural and technically generated radioactivity  

International Nuclear Information System (INIS)

The question investigated is whether the radioactive rare gases emanating from nuclear plants are causative or participate in the triggering of forest disease. For one thing, a chemical reaction could be responsible for such an effect exerted by these artificial radioactive effluents. However, a calculation shows the concentration of radionuclides, respectively, in this case, their decomposition products, to be by many orders of magnitude smaller than other constituents in air; so a chemical reaction of this kind may be excluded. For the other part, rare gases might contribute to forest damage by their radioactive decomposition and late physical, chemical, and biological effects. In this connection, a detailed analysis is made of the comparability of natural radioactivity with radioactivity generated by nuclear plants. A possible contribution towards the total stress situation of forests (chemical air pollution, natural radioactivity, artificially produced radioactive rare gases, weather conditions and conditions arising from forest management and the like) would amount to a proportion smaller than 1/1000 considering natural radioactivity as a possible stress factor only. (orig.)

262

Cluster radioactivity  

International Nuclear Information System (INIS)

The phenomenon of spontaneous emission of nuclei intermediate in mass between alpha particles and fission fragments is known as cluster radioactivity (CR) or exotic radioactivity. The process of emission of clusters heavier than alpha particles is called cluster decay or exotic decay. This process is not accompanied by emission of neutron. The CR phenomenon was first predicted in 1980 by Sandulescu et al on the basis of quantum mechanical fragmentation theory (QMFT). Theoretical model-1. Alpha-decay like models 2. Fission like models will be discussed in this talk. And also it is associated with present scenario cluster radioactivity exhibited by some isotopes of Gadolinium (Gd), Z=64. (author)

263

Predicted neutron yield and radioactivity for laser-induced (p,n) reactions in LiF  

International Nuclear Information System (INIS)

Design calculations are presented for a pulsed neutron source comprising polychromatic protons accelerated from a metal foil by a short-pulse laser, and a LiF converter in which (p,n) reactions occur. Although the proton pulse is directional, neutrons are predicted to be emitted relatively isotropically. The neutron spectrum was predicted to be similar to the proton spectrum, but with more neutrons of low energy in the opposite direction to the incident protons. The angular dependence of spectrum and intensity was predicted. The (p,n) reactions generate unstable nuclei which decay predominantly by positron emission to the original 7Li and 19F isotopes. For the initial planned experiments using a converter 1mm thick, we predict that 0.1% of the protons will undergo a (p,n) reaction, producing 109 neutrons. Ignoring the unreacted protons, neutrons, and prompt gamma emission as excited nuclear states decay, residual positron radioactivity (and production of pairs of 511 keV annihilation photons) is initially 4.2MBq decaying with a half-life of 17.22 s for 6 mins (19Ne decays), then 135Bq decaying with a half-life of 53.22 days (7Be decays)

264

Artificiality in Social Sciences  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This text provides with an introduction to the modern approach of artificiality and simulation in social sciences. It presents the relationship between complexity and artificiality, before introducing the field of artificial societies which greatly benefited from the computer power fast increase, gifting social sciences with formalization and experimentation tools previously owned by "hard" sciences alone. It shows that as "a new way of doing social sciences", artificial societies should undo...

Rennard, Jean-philippe

2006-01-01

265

Radioactivity Monitoring of the Irish Environment 2009  

International Nuclear Information System (INIS)

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 y

266

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  

International Nuclear Information System (INIS)

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

267

Radioactive Iodine  

Science.gov (United States)

... muscles, and other organs working normally. Why is iodine used in some thyroid gland treatment? Iodine is ... it is concentrated as iodide. What is radioactive iodine (rai)? Iodine, in the form of iodide, is ...

268

Risk analysis of radioactive waste disposal in salt deposits  

International Nuclear Information System (INIS)

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

269

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  

International Nuclear Information System (INIS)

roup 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

270

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

Energy Technology Data Exchange (ETDEWEB)

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)

NONE

1996-12-01

271

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

Energy Technology Data Exchange (ETDEWEB)

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)

NONE

1996-05-01

272

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

International Nuclear Information System (INIS)

Highlights: ? Proton, deuteron, 3He and ?-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.

273

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

Science.gov (United States)

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

Paleos, Constantinos M; Pantos, A

2014-05-20

274

Environmental radioactivity surveillance programme 1990 - 1993  

International Nuclear Information System (INIS)

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

275

Radioactivity of dates in Saudi Arabia  

Energy Technology Data Exchange (ETDEWEB)

Samples of dates from three regions of Saudi Arabia were measured for the radioactivity of both natural and artificial origins. The results were compared with gross ..beta.. and /sup 187/Cs activity of coffee beans produced in different countries. No significant activity in date samples was detected.

Nasser Al-Mohawes; Pao-Shan Weng

1984-06-01

276

Teaching concepts in the field of radioactivity and nuclear energy  

International Nuclear Information System (INIS)

This issue of 'Naturwissenschaften im Unterricht', dealing with the subjects of physics and chemistry, gives an account of the fundamentals of radioactivity, nuclear fission, controlled nuclear fission, nuclear power plants, dosimetry, safety engineering, shielding measures to prevent the release of radioactive substances, pressure engineering, emergency core cooling systems, waste disposal and natural and artificial environmental radioactivity. Teachers will find helpful hints as to the method of instruction and the explanation of problems. (DG)

277

Wear measurement using radioactive tracer technique based on proton, deuteron and {alpha}-particle induced nuclear reactions on molybdenum  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Proton, deuteron, {sup 3}He and {alpha}-particle activation of Mo. Black-Right-Pointing-Pointer TLA (thin layer activation). Black-Right-Pointing-Pointer Wear measurement. Black-Right-Pointing-Pointer Integral production yields. Black-Right-Pointing-Pointer 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 {sup 93,94g,94m,95g,95m,96,99m}Tc, {sup 90,93m,99}Mo, {sup 90,91m,92m,95m,95g,96}Nb and {sup 88,89}Zr were measured up to 50 MeV deuteron energy Tarkanyi et al., 2012 [1], {sup 93m,93g,94m,94g,95m,95g,96g,99m}Tc, {sup 90,93m,99}Mo, {sup 90,92m,95m,95g,96}Nb and {sup 88,89}Zr were measured up to 40 MeV proton energy Tarkanyi et al., 2012 [2] and {sup 93m,93g,94m,94g,95m,95g,96g,99m}Tc, {sup 93m,99}Mo, {sup 90}Nb, {sup 94,95,97,103}Ru and {sup 88}Zr were measured up to 40 MeV alpha energy Ditroi et al., 2012 [3] by using the stacked foil technique and activation method. The results for {sup 3}He 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 {sup 95m,96}Tc, {sup 91m,92m,95m,95g}Nb, {sup 99}Mo, {sup 103,97}Ru and {sup 88}Zr 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.

Ditroi, F., E-mail: ditroi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary); Tarkanyi, F.; Takacs, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary)

2012-11-01

278

New radioactivities  

International Nuclear Information System (INIS)

Radioactivities emerge as ambassadors from a distant world, the nucleus of an atom. The nucleus sends forth a flash of energy; a couple of protons, a few neutrons or other particles. Each of these ambassadors carries a particular message. Most often they announce the decay of a nucleus from an energetic, unstable state to a less energetic, more stable state to a less energetic, more stable one. Radioactivities also reveal subtle clues about nuclear structure. By piecing these clues together, investigators have created detailed models of the nucleus. The models not only account for most nuclear phenomena but also predict many new types of radioactivities. Until the 1980's it appeared as though the nuclear fragments from radioactive processes came in roughly three sizes: four, 100 or 200 nucleons. In the four-nucleon range is the alpha particle, or helium nucleus. If an alpha particle emerges from an atom, it leaves behind a nucleus composed of approximately 200 nucleons. In the 100-nucleon range are the fragments from fission, a process in which a heavy nucleus splits roughly in half. The restricted range of sizes raised an intriguing question: Why did a nucleus not emit a fragment composed of other quantities of nucleons--why not 14 or 24? Today it is known that a nucleus can indeed eject a fragment of this size or any other. These new radioactivities form when a large number of nucleons within the nucleus spontaneously rearrange themselves in certain configurations

279

History of radioactivity  

International Nuclear Information System (INIS)

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 ?-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)

280

Mechanism of glucan-induced agglutination in Streptococcus mutans. I. Binding of radioactive glucan to whole cells of S. mutans OMZ-176.  

Science.gov (United States)

The binding of radioactive glucan to Streptococcus mutans cells, which are agglutinated by dextrans, was examined. The glucan was synthesized from sucrose by extracellular glucosyltransferases from S. mutans FA-1 and was highly branched at C-3 and C-6 of D-glucose residues, containing 17% of a (1 leads to 3)inter-chain residues. Binding of glucan to whole cells of S. mutans OMZ-176, which were agglutinated by addition of glucan or Dextran T2000, was irreversible and followed saturation type kinetics; saturation was achieved at approximately 110 ng of glucan per ml. About 14 ng of glucan were bound per mg of the cells at the saturated concentration. The heated cells of this organism, however, had a relatively low ability of glucan-binding, compared with the freshly prepared and lyophilized cells. Binding to the heated cells was entirely of a non-saturation type. Binding of Dextran T2000 or T10 was determined by competition between the labeled glucan and unlabeled Dextrans for the binding site(s). Both Dextrans and glucan from S. mutans FA-1 were bound to the same site(s). Other organisms, which did not undergo glucan- and Dextran-induced agglutination, had a relatively lower ability of glucan-binding than S. mutans, which was agglutinated. PMID:36546

Suginaka, H; Ebisu, S; Kotani, S

1978-01-01

 
 
 
 
281

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

International Nuclear Information System (INIS)

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.)

282

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

International Nuclear Information System (INIS)

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

283

Radioecological observations in the trace-measurement and dosimetric evaluation of radioactive traces in the air  

International Nuclear Information System (INIS)

The following topics are dealt with: Weekly measurement of 137Cs and 40K, long-time measurement series, natural radioactive nuclides, artificial radioactive nuclides, 85Kr, 133Xe, 90Sr, 137Cs, and 238-240Pu, the radioecology of 129I, dosimetric evaluation of radioactive traces in air. (HSI)

284

Optimization of beam and target combinations for hybrid reactor systems and for the fission-induced production of radioactive beams  

International Nuclear Information System (INIS)

This thesis work consists of two parts: a) theoretical, and b) experimental. We combine and use the high energy transport code LAHET, the low energy transport code MCNP, and the activation code CINDER. Our benchmarking calculations show that LAHET neglects the Coulomb dissociation for deuterons. By adding this missing term, we obtain a good agreement with the available data. We also conclude that LAHET describes well the data for isotope production yields if the ORNL fission model is employed for nuclei with Z>90. The 'default' RAL fission model gives too broad isotopic distributions and fails to reproduce the data in absolute value. We examine different combinations of beams, beam energies, spallation target and multiplying medium materials in order to optimize the neutron production, energy amplification and isotope production via neutron induced fissions. We show that the (d,xn) reactions could bring a number of important advantages when compared to the (p,xn) reactions. We conclude that the use of deuterons instead of protons should result in higher primary beam intensities, lower costs of the system and facilitate radioprotection problems. Within the SPIRAL Phase-II project at GANIL, we propose d(100 MeV)+Be?xn+U as an optimum combination for the production of neutron rich nuclei in the mass region 75?A?160. However, the production of tritium gas in the target-converter should be considered carefully. The use of heavier metal targets-converters may cause moetal targets-converters may cause more severe problems of radioprotection.Our experimental work is closely related to the theoretical investigations. We measure the complete proton spectra for 1.00 and 200 MeV deuteron induced reactions on 8 thin targets (Be, C, Al, Ni, Nb, Ta,, Pb and U) and in the angular region 8 deg C ? ?p ? 120 deg C. The experiments were carried at LNS (Saclay, France) and at NAC (Faure, South Africa). Good quality data (within 10% in absolute value and with 4-8 MeV energy threshold) support our improved LAHET physics modelling for (d,xp) and, consequently, for (d,xn) reactions. (author)

285

Environmental radioactivity  

International Nuclear Information System (INIS)

The theme of the nineteenth annual meeting of the National Council on Radiation Protection was Environmental Radioactivity. Papers were presented on the role of the environment and of natural and man-made sources within it, assessments of radioactivity at test sites in the Marshall Islands and at Three Mile Island, environmental modeling, long-lived radionuclide problems, waste disposal and criteria for dose limits. Reports were presented from active scientific committees of the NCRP including those on 1) Neutron Contamination from Medical Electron Accelerators, 2) Thyroid Cancer Risk, and 3) Priorities for Dose Reduction. Seventeen papers were entered into the Energy Data Base

286

Radioactivity Monitoring of the Irish Environment 2006  

International Nuclear Information System (INIS)

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

287

Study of proton-induced reactions in a radioactive 129I target at Ep=660 MeV  

International Nuclear Information System (INIS)

Two NaI (85% 129I and 15% 127I) targets were exposed to a beam of 660-MeV protons. Cross sections for formation of 76 residual nuclei were obtained by the induced activity method. The results are compared with other experimental data on 127I and theoretical calculations by eleven models contained in the codes LAHET3 (using the Bertini+Dresner, ISABEL+Dresner, INCL+Dresner, and INCL+ABLA options), CASCADE, CEM95, CEM2K, LAQGSM+GEM2, CEM2k+GEM2, LAQGSM+GEMINI, and CEM2k+GEMINI. Most of the models describe spallation products with masses close to the target reasonably well while the reliability of the codes differs greatly in the deep spallation and fission/fragmentation regions. The difficulties in describing products with A=40-80 by all of the codes tested here except for CEM2k+GEMINI and LAQGSM+GEMINI is related to the neglect of fission (and fragmentation) processes for targets as light as 129I. (orig.)

288

Study of proton induced reactions in a radioactive 129I target at Ep = 660 MeV  

International Nuclear Information System (INIS)

Two NaI (85% 129I and 15% 127I) targets were exposed to a beam of 660-MeV protons. Cross sections for formation of 76 residual nuclei were obtained by the induced activity method. The results are compared with other experimental data on 127I and theoretical calculations by eleven models contained fin the codes LAHET3 (using the Bertini+Dresner, ISABEL+Dresner, INCL-Dresner, and INCL-ABLA options), CASCADE, CEM95, CEM2K, LAQGSM+GEM2, LAQGSM+GEMINI, and CEM2k+GEMINI. Most of the models describe spallation products with masses close to the target reasonably well while the reliability of the codes differs greatly in the deep spallation and fission/fragmentation regions. The difficulties in describing products with A = 40-80 by all of the codes tested here except for CEM2k+GEMINI and LAQGSM+GEMINI is related to the neglect of fission (and fragmentation) processes for targets as light as 129I.

289

Study of Proton Induced Reactions in a Radioactive 129-I Target at Ep=660 MeV  

CERN Document Server

Two NaI (85% 129-I and 15% 127-I) targets were exposed to a beam of 660-MeV protons. Cross sections for formation of 76 residual nuclei were obtained by the induced activity method. The results are compared with other experimental data on 127-I and theoretical calculations by eleven models contained in the codes LAHET3 (using the Bertini+Dresner, ISABEL+Dresner, INCL+Dresner, and INCL+ABLA options), CASCADE, CEM95, CEM2K, LAQGSM+GEM2, CEM2k+GEM2, LAQGSM+GEMINI, and CEM2k+GEMINI. Most of the models describe spallation products with masses close to the target reasonably well while the reliability of the codes differs greatly in the deep spallation and fission/fragmentation regions. The difficulties in describing products with A=40-80 by all of the codes tested here except for CEM2k+GEMINI and LAQGSM+GEMINI is related to the neglect of fission (and fragmentation) processes for targets as light as 129-I.

Pronskikh, V S; Balabekyan, A R; Barashenkov, V S; Dzhelepov, V P; Gustov, S A; Filinova, V P; Kalinnikov, V G; Krivopustov, M I; Mirokhin, I V; Solnyshkin, A A; Stegailov, V I; Tsoupko-Sitnikov, V M; Mrazek, J; Brandt, R; Westmeier, W; Odoj, R; Mashnik, S G; Sierk, A J; Prael, R E; Gudima, K K; Baznat, M I

2004-01-01

290

Radioactivity of some dried fruits  

International Nuclear Information System (INIS)

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

291

Artificial cognition architectures  

CERN Document Server

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

Crowder, James A; Friess, Shelli A

2013-01-01

292

Levels of glucose, serum albumin and somatic cells before and during early stages of acute clinical mastitis artificially induced in cows by means of human strains of group-B streptococci (GBS) administered intracisternally.  

Science.gov (United States)

The investigation was performed on 3 cows, sampled repeatedly before and during the initial 48 h of artificially induced, acute, clinical mastitis. The results of the investigation both augment and support those of earlier work on the levels and significant correlations of glucose, serum albumin and somatic cells in normal and abnormal secretions monitored before and after the usual milking of healthy lactating cows had been suspended. During acute mastitis, udder secretions from artificially infected quarters showed highly significant escalations of somatic cell counts which coincided with equally significant increases of a high and intermediate level of serum albumin values in both the infected and non-infected quarters. Corresponding glucose values fluctuated from 0,07-0, 22 and 0,18-0, 32 mM in the former and latter quarters respectively. The selective and elevated transfer of serum albumin in otherwise unaffected quarters of acutely mastitic udders suggests rather specific collateral vascular and epithelial changes of unknown nature and magnitude. The data indicate that marked fluctuations of glucose may occur within and between quarters of individual and different cows respectively. Such variations could significantly affect phagocytosis and killing of bacteria challenging the intramammary leucocytic udder barrier before and particularly during manifestation of mastitis. Hence, udder health, although dependent on specific natural defence mechanisms such as the leucocytes and related systems in milk, may depend even more significantly on the supplies of glucose to and within the bovine mammary gland. PMID:7312308

Giesecke, W H; Van den Heever, L W

1981-06-01

293

Radioactive Decay  

Science.gov (United States)

Created by William Barker and David Smith for the Connected Curriculum Project, this module develops a mathematical model for decay of radioactive substances, and a technique for deciding whether quantitative data fits the model or not. This is one within a much larger set of learning modules hosted by Duke University.

Barker, William; Smith, David

2010-06-28

294

Radioactivity Monitoring of the Irish Environment 2007  

International Nuclear Information System (INIS)

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 he

295

Radioactivity and foods  

International Nuclear Information System (INIS)

The purpose of this article is to describe and contrast two relationships between radiation and food on the one hand, beneficial preservation of food by controlled exposure to ionizing radiation; and, on the other, contamination of food by accidental incorporation of radioactive nuclides within the food itself. In food irradiation, electrons or electromagnetic radiation is used to destroy microorganisms and insects or prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undesirable changes or induced radioactivity is produced in the irradiated food. An altogether different situation is presented by exposure of food animals and farming areas to radioactive materials, as occurred after the major Soviet nuclear reactor accident at Chernobyl. This article furnishes the basic information needed to understand the nature of food contamination associated with that event and describes the work of international organizations seeking to establish appropriate safe limits for levels of radioactivity in foods

296

Enhanced extrinsic magnetoresistance in La2/3Sr1/3MnO3 artificial grain boundaries induced by ion implantation  

International Nuclear Information System (INIS)

The resistance of polycrystalline divalent-ion-doped LaMnO3 has been shown to be highly sensitive to low magnetic fields. To enable direct study of the properties of isolated grain boundaries, we developed a new method to form artificial boundaries in manganite thin films. Metal slits about 70nm in width were printed by 30KV focused Ga ion beam nanolithography on a 4?mLa2/3Sr1/3MnO3 bridge, and the materials in these slits were then irradiated by accelerated H2+ ions. Using this method, magnetoresistance (MR) >8% and >16% were, respectively, obtained at 150 and at 10K in a magnetic field of 1T. This technique is very promising in terms of its simplicity and flexibility of fabrication and has the potential for high-density integration

297

Artificial extracellular matrix composed of collagen I and highly sulfated hyaluronan interferes with TGF?(1) signaling and prevents TGF?(1)-induced myofibroblast differentiation.  

Science.gov (United States)

Sulfated glycosaminoglycans are promising components for functional biomaterials since sulfate groups modulate the binding of growth factors and thereby influence wound healing. Here, we have investigated the influence of an artificial extracellular matrix (aECM) consisting of collagen I (coll) and hyaluronan (HA) or highly sulfated HA (hsHA) on dermal fibroblasts (dFb) with respect to their differentiation into myofibroblasts (MFb). Fibroblasts were cultured on aECM in the presence of aECM-adsorbed or soluble transforming growth factor ?1 (TGF?1). The synthesis of ?-smooth muscle actin (?SMA), collagen and the ED-A splice variant of fibronectin (ED-A FN) were analyzed at the mRNA and protein levels. Furthermore, we investigated the bioactivity and signal transduction of TGF?1 in the presence of aECM and finally made interaction studies of soluble HA or hsHA with TGF?1. Artificial ECM composed of coll and hsHA prevents TGF?1-stimulated ?SMA, collagen and ED-A FN expression. Our data suggest an impaired TGF?1 bioactivity and downstream signaling in the presence of aECM containing hsHA, shown by massively reduced Smad2/3 translocation to the nucleus. These data are explained by in silico docking experiments demonstrating the occupation of the TGF?-receptor I binding site by hsHA. Possibly, HA sulfation has a strong impact on TGF?1-driven differentiation of dFb and thus could be used to modulate the properties of biomaterials. PMID:23602877

van der Smissen, Anja; Samsonov, Sergey; Hintze, Vera; Scharnweber, Dieter; Moeller, Stephanie; Schnabelrauch, Matthias; Pisabarro, M Teresa; Anderegg, Ulf

2013-08-01

298

Nonstationary artificial black holes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study the existence of artificial non-stationary spherically symmetric black holes. We give examples of the appearance of black holes and of disappearance of white holes. We also discuss the relation between the apparent and the event horizons for the case of artificial black holes.

Eskin, Gregory

2013-01-01

299

Radioactive waste management  

International Nuclear Information System (INIS)

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

300

Radioactive alchemy  

Energy Technology Data Exchange (ETDEWEB)

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.)

Anon.

2014-07-15

 
 
 
 
301

The puzzling units of radioactivity  

International Nuclear Information System (INIS)

The authors review the different units used in radioprotection and dosimetry: Becquerel (Bq), Gray (Gy) and Sievert (Sv). Their definitions and their domains of use are clarified. 2 examples are given: Cs137, an artificial nuclide released in nuclear accidents and uranium and its decay products that contribute to natural radioactivity. It is recalled that each year the Rhone river carries 100 tonnes of natural uranium that comes mostly from rainwater runoff and yet an incident at the Tricastin plant that led to the release of 74 kg of uranium in the environment for 2 days triggered a large anxiety among the population. (A.C.)

302

Secondary component of radioactive nuclides  

International Nuclear Information System (INIS)

Noticeable increase of artificial radionuclides because of the transportation of wind lifted radioactive particles from highly polluted regions in Belarus and Ukraine has been observed in Lithuania. Data on caesium radioisotopes concentration fluctuations in 1987 and 1992 are presented. Broader description of the increase (up to 300 ?Bq/m3) of 137 Cs concentration in the air in Vilnius in 1992 due to the transportation of the products of fires in peat-bog and forests in Belarus in autumn of 1992 is given. (author)

303

The natural radioactivity of the biosphere  

International Nuclear Information System (INIS)

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

304

Radioactivity in Hocking River Basin  

International Nuclear Information System (INIS)

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

305

Artificial Coral Reefs  

Science.gov (United States)

Coral reefs are among the most diverse ecosystems on the planet...and the most threatened. Artificial reefs may help stem the loss of these valuable and beautiful habitats, with shipwrecks, old subway cars, and other structures taking the place of living coral or rocky outcrops. The following Web sites introduce artificial reefs, reef ecology, and some ongoing efforts to establish reef communities in the U.S. and beyond. PBS's NATURE offers a fascinating look at the artificial reefs created by the thousands of shipwrecks and downed planes from World War II that riddle the South Pacific (1). This is the companion Web site to the documentary War Wrecks of the Coral Seas, and it includes some great multimedia features. The next site comes from the National Oceanic and Atmospheric Administration and contains an excellent photo gallery of coral ecosystems around the world (2). The collection includes six pages of artificial reef photos taken in the Pacific. The following site comes from the online companion to the BBC's acclaimed documentary series The Blue Planet. Based on the episode The Web of Life, this site offers a fun, multimedia challenge for learning about and testing one's knowledge of coral reefs (3). The site includes a section on artificial reefs (click on Take it Further). Next, an August 2001 segment from National Public Radio's All Things Considered explores efforts to create artificial reefs using decommissioned New York City subway cars -- a project of Delaware's Department of Natural Resources and Environmental Control in the Division of Fish and Wildlife (4). Likewise, the non-profit group Artificial Reefs of the Keys is working to bring a de-commissioned military ship to the Florida Keys (5). The New Jersey Scuba Diver Web site provides an excellent introduction to artificial reef ecology; focused on reefs in New Jersey, of course. The mini-tutorial comes courtesy of William Figly, Principal Fisheries Biologist for the New Jersey Artificial Reef Program (6). The Fall 2001 issue of California Wild, the magazine of the California Academy of Sciences, addresses the benefits and concerns of off shore oil rigs becoming artificial reefs (7). Finally, visitors will find dozens of news articles and Web links related to artificial reefs in this entry, a page from the New England Artificial Reef Society Web site (8).

Sohmer, Rachel.

306

Radioactive dating  

International Nuclear Information System (INIS)

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)

307

?-H2AX as a biomarker of DNA damage induced by ionizing radiation in human peripheral blood lymphocytes and artificial skin  

Science.gov (United States)

Ionizing radiation (IR) exposure is inevitable in our modern society and can lead to a variety of deleterious effects including cancer and birth defects. A reliable, reproducible and sensitive assessment of exposure to IR and the individual response to that exposure would provide much needed information for the optimal treatment of each donor examined. We have developed a diagnostic test for IR exposure based on detection of the phosphorylated form of variant histone H2AX (?-H2AX), which occurs specifically at sites of DNA double-strand breaks (DSBs). The cell responds to a nascent DSB through the phosphorylation of thousands of H2AX molecules flanking the damaged site. This highly amplified response can be visualized as a ?-H2AX focus in the chromatin that can be detected in situ with the appropriate antibody. Here we assess the usability of ?-H2AX focus formation as a possible biodosimeter for human exposure to IR using peripheral blood lymphocytes irradiated ex vivo and three-dimensional artificial models of human skin biopsies. In both systems, the tissues were exposed to 0.2-5 Gy, doses of IR that might be realistically encountered in various scenarios such as cancer radiotherapies or accidental exposure to radiation. Since the ?-H2AX response is maximal 30 min after exposure and declines over a period of hours as the cells repair the damage, we examined the time limitations of the useful detectability of ?-H2AX foci. We report that a linear response proportional to the initial radiation dose was obtained 48 and 24 h after exposure in blood samples and skin cells respectively. Thus, detection of ?-H2AX formation to monitor DNA damage in minimally invasive blood and skin tests could be useful tools to determine radiation dose exposure and analyze its effects on humans.

Redon, Christophe E.; Dickey, Jennifer S.; Bonner, William M.; Sedelnikova, Olga A.

2009-04-01

308

Artificial Left Ventricle  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Ranjbar, Saeed; Meybodi, Tohid Emami; Meybodi, Mahmood Emami

2014-01-01

309

Radioactivity values in the river Elbe  

International Nuclear Information System (INIS)

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)

310

Ambient radioactivity levels and radiation doses. Annual report 2011; Umweltradioaktivitaet und Strahlenbelastung. Jahresbericht 2011  

Energy Technology Data Exchange (ETDEWEB)

The annual report 2011 on ambient radioactivity levels and radiation doses covers the following issues: Part A: Natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposure 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 exposure, radiation exposure from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. The Appendix includes Explanations of terms, radiation doses and related units, external and internal radiation exposure, stochastic and deterministic radiation effects, genetic radiation effects, induction of malignant neoplasm, risk assessment, physical units and glossary, laws, ordinances, guidelines, recommendations and other regulations concerning radiation protection, list of selected radionuclides.

Bernhard-Stroel, Claudia; Hachenburger, Claudia; Trugenberger-Schnabel, Angela; Peter, Josef (comps.) [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

2013-07-15

311

Pregnancy rate in lactating Bos indicus cows subjected to fixed-time artificial insemination and treated with different follicular growth inducers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The objective of this experiment was to evaluate the effects of replacing eCG with FSH or FSH/LH on the diameter of ovulatory follicles (DOF) and the pregnancy rates (PR) of lactating Bos indicus cows subjected to a synchronization of ovulation protocol and fixed-time artificial insemination (FTAI) [...] based on progesterone, estradiol benzoate (EB), PGF2?, and estradiol cypionate (EC). On day 0, primiparous and multiparous Nellore cows (n = 329) at 68 days postpartum were body condition scored (BCS) and received a P4 implant (PRIMER 1.0 g P4) plus 2 mg EB intramuscularly (IM). At day 8, the implant was removed, and 250 ?g cloprostenol were injected IM along with 0.5 mg EC. At the time of implant removal, the animals were divided into one of four treatments: cows received (G1) 1 mL of saline solution IM (Control; n = 80); (G2) 300 IU eCG IM (ECG300; n = 84); (G3) 15 mg FSH IM (Folltropin; n = 82); and (G4) 30 IU FSH/LH IM (Pluset; n = 83); all cows were subjected to FTAI 48-54 h after implant removal (day 10). Transrectal ultrasonography was performed to measure the DOF to FTAI and to estimate the pregnancy rate on day 35. A statistical analysis examined the effects of the treatment, technician, semen, BCS, calf age and parity on PR to FTAI. There was no significant difference in PR and DOF among the treatment groups (G1, 41.3%, 13.1 mm; G2, 46.4%, 14.5 mm; G3, 46.3%, 14.2 mm; and G4, 48.2%, 14.3 mm), but PR was higher in multiparous than in primiparous cows. Commercial FSH solutions (Pluset or Folltropin) do not promote increases in PR or DOF of lactating Nellore cows and are equal to eCG in promoting growth in preovulatory follicles and elevating the PR in Nellore cows with a moderate BCS subjected to a progesterone-based FTAI protocol with EC.

Ériklis, Nogueira; Dayanna Schiavi do Nascimento, Batista; Luiz Carlos Cesar da, Costa Filho; Alexandre Menezes, Dias; Juliana Corrêa Borges, Silva; Luís Carlos Vinhas, Ítavo.

2014-07-01

312

Artificial photosynthesis for solar water-splitting  

Science.gov (United States)

Hydrogen generated from solar-driven water-splitting has the potential to be a clean, sustainable and abundant energy source. Inspired by natural photosynthesis, artificial solar water-splitting devices are now being designed and tested. Recent developments based on molecular and/or nanostructure designs have led to advances in our understanding of light-induced charge separation and subsequent catalytic water oxidation and reduction reactions. Here we review some of the recent progress towards developing artificial photosynthetic devices, together with their analogies to biological photosynthesis, including technologies that focus on the development of visible-light active hetero-nanostructures and require an understanding of the underlying interfacial carrier dynamics. Finally, we propose a vision for a future sustainable hydrogen fuel community based on artificial photosynthesis.

Tachibana, Yasuhiro; Vayssieres, Lionel; Durrant, James R.

2012-08-01

313

Radioactive colloids  

International Nuclear Information System (INIS)

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)

314

An Assessment of Radioactivity of Selected Industrial Waste  

International Nuclear Information System (INIS)

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

315

Radiation-induced evolution of gas in neutral and alkaline aqueous solutions of sodium nitrate and sodium acetate simulating liquid radioactive wastes  

International Nuclear Information System (INIS)

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

316

Generalised Derived Limits for Selected Artificial Radionuclides in Foodstruffs  

International Nuclear Information System (INIS)

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

317

Radioactive Substances in Metallurgical Waste  

International Nuclear Information System (INIS)

Modern steel making technology in electric arc furnaces today is inconceivable without the use of steel scrap. In addition to radioactive elements 137Cs and 60Co which have so far been found in steel scrap, polluting thus both steel and steel products, 226Ra, 192Ir, 241Am, 232Th, and 90Sr are most represented. During the technological process the named radionuclides are distributed across heat, slag and dust, depending on their chemical and physical properties. Radionuclides which end up in the heat, slag, or dust, act radio-actively for a long period of time, depending on the duration of semi-decomposition of each single isotope. Due to the potential presence of radioactive elements in metallurgical scrap (steel scrap, EAF (electric arc furnace) slag, EAF dust) and in other materials from the EAF process, the process of their identification has been initiated. Gamma-spectrometric analysis (Canberra spectrometric system with Ge-detector) was applied on samples from the steel mill at Sisak Steelworks and from the Felis Foundry in Sisak. The presence of natural isotopes 40K, 226Ra, 232Th and 238U as well as of the artificial isotope 137Cs was established.(author)

318

Environmental radioactivity and radiation exposure  

International Nuclear Information System (INIS)

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.)

319

Decrease of deposited artificial radioactivity in urban environments  

International Nuclear Information System (INIS)

The behavior of cesium during the first three years after deposition was investigated with in-situ gamma spectrometry at 48 measuring sites. An evaluation method was developed which allowed determination of retention on asphalt surfaces, the effective depth profile in soils covered with grass, and time factor developments of the gamma dose rate. Two months after deposition, the gamma dose rate on grassy soils amounts to 60% of the dose rate for smooth large-scale surfaces with identical deposition, but without weathering or soil migration. After 3 years this ratio lies at 35%. On asphalt surfaces, however, there was after 2 months only a dose rate of 20% of the dose rate on smooth surfaces without weathering; after 3 years it was only 4%. Environment factors were defined which determined the ratio of dose rates on measuring areas to dose rates on large grassy surfaces. The environment factors are the smaller, the bigger the proportion of asphalt. They are constant as regards the time factor, or they decrease gradually after deposition. Results were approximated analytically. The investigation of tiles showed that there was an activity retention of 30-60% on roofs in Munich following wet deposition of cesium. After 2 years it was still 10-25%. (orig./HP)

320

Artificial Heart Design Challenge  

Science.gov (United States)

Students are presented with a hypothetical scenario in which they are biomedical engineers asked to design artificial hearts. Using the engineering design process as a guide, the challenge is established and students brainstorm to list everything they might need to know about the heart in order to create a complete mechanical replacement (size, how it functions, path of blood etc.). They conduct research to learn the information and organize it through various activities. They research artificial heart models that have already been used and rate their performance in clinical trials. Finally, they analyze the data to identify the artificial heart features and properties they think work best and document their findings in essay form.

Bio-Inspired Technology and Systems (BITS) RET,

 
 
 
 
321

Radioactive monitoring of the marine environment  

International Nuclear Information System (INIS)

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)

322

Radioactive decontamination  

International Nuclear Information System (INIS)

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.)

323

Radioactivity of the Treated Topaz  

International Nuclear Information System (INIS)

Raw topaz stone samples are subjected to irradiation by neutrons from the Egyptian second research reactor and by gamma (?) rays from a gamma source. Changes in the color of the stones are observed. Irradiation induces radionuclides, resulting to radioactivity. Therefore, some time is required for the radioactivity level of stones to fall to exempted value; hence, radioactivity of the stones after irradiation has to be followed and monitored till their release from the reactor. Storage time might be several months to several years. The decay rates of isotopes created by irradiation depend on the individual isotope. Neutron-irradiated topaz treated in a nuclear reactor facility can present a potential health hazard, if not properly controlled. A special license is required for transportation and distribution of such treated gem stones, because radiation exposures associated. Experience gained in management of irradiated topaz shall be reviewed

324

Radiation protection. Radioactivity and health. 3. ed.  

International Nuclear Information System (INIS)

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.)

325

Radioactivity and Nuclear Issues in Science Fiction  

International Nuclear Information System (INIS)

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)

326

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages. A comparison with micro-X-ray fluorescence analysis  

Science.gov (United States)

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modì (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek-Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.

Brai, Maria; Gennaro, Gaetano; Schillaci, Tiziano; Tranchina, Luigi

2009-10-01

327

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.  

Science.gov (United States)

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

Peñaranda, David S; Mazzeo, Ilaria; Hildahl, Jon; Gallego, Victor; Nourizadeh-Lillabadi, Rasoul; Pérez, Luz; Asturiano, Juan F; Weltzien, Finn-Arne

2013-04-30

328

Artificial Left Ventricle  

CERN Document Server

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...

Ranjbar, Saeed; Meybodi, Mahmood Emami

2014-01-01

329

Artificial limb connection  

Science.gov (United States)

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.

Owens, L. J.

1974-01-01

330

Artificial Gravity Research Plan  

Science.gov (United States)

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.

Gilbert, Charlene

2014-01-01

331

Observations of artificial satellites  

Directory of Open Access Journals (Sweden)

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.

A. MAMMANO

1964-06-01

332

Database in Artificial Intelligence.  

Science.gov (United States)

Describes a specialist bibliographic database of literature in the field of artificial intelligence created by the Turing Institute (Glasgow, Scotland) using the BRS/Search information retrieval software. The subscription method for end-users--i.e., annual fee entitles user to unlimited access to database, document provision, and printed awareness…

Wilkinson, Julia

1986-01-01

333

Artificial recharge of groundwater  

Science.gov (United States)

The Task Committee on Guidelines for Artificial Recharge of Groundwater, of the American Society of Civil Engineers' (ASCE) Irrigation and Drainage Division, sponsored an International Symposium on Artificial Recharge of Groundwater at the Inn-at-the-Park Hotel in Anaheim, Calif., August 23-27, 1988. Cosponsors were the U.S. Geological Survey, California Department of Water Resources, University of California Water Resources Center, Metropolitan Water District of Southern California, with cooperation from the U.S. Bureau of Reclamation, International Association of Hydrological Sciences, American Water Resources Association, U.S. Agency for International Development, World Bank, United Nations Department of Technical Cooperation for Development, and a number of local and state organizations.Because of the worldwide interest in artificial recharge and the need to develop efficient recharge facilities, the Anaheim symposium brought together an interdisciplinary group of engineers and scientists to provide a forum for many professional disciplines to exchange experiences and findings related to various types of artificial recharge; learn from both successful and unsuccessful case histories; promote technology transfer between the various disciplines; provide an education resource for communication with those who are not water scientists, such as planners, lawyers, regulators, and the public in general; and indicate directions by which cities or other entities can save funds by having reasonable technical guidelines for implementation of a recharge project.

334

Artificial intelligence and automation  

CERN Document Server

Covering artificial intelligence and automation, these contributions discuss: the evolution of AI tools; an SPN knowledge representation scheme; software engineering using AI; the impact of AI in VLSI design automation; incremental adaptation as a method to improve reactive behaviour; and more.

Bourbakis, NG

1998-01-01

335

Medicare Coverage: Orthotics & Artificial Limbs  

Science.gov (United States)

... covered? Search Medicare.gov for covered items Orthotics & artificial limbs How often is it covered? Medicare Part B ( ... go to a supplier that’s enrolled in Medicare Artificial limbs and eyes Arm, leg, back, and neck braces ...

336

Survey monitoring of environmental radioactivity in Daejeon area  

International Nuclear Information System (INIS)

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

337

Measurements of radioactive dusts at high altitude. Special investigation  

International Nuclear Information System (INIS)

For the nuclear explosion test conducted by North Korea on October 9 in 2006, the radioactive nuclides etc. contained in the airborne dust collected at high altitude by the Japan Air Self-Defence Force in the spatial investigation were measured. The artificial radioactive nuclides such as caesium and radioactive gas (gaseous radioiodine) were not detected. In addition, from the results of the gross beta activity measurement at high altitude in our country, it was shown that there is no appreciable difference between the activity levels of this period and those of usual periods. (author)

338

Survey monitoring of environmental radioactivity in Daejeon area  

Energy Technology Data Exchange (ETDEWEB)

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 2002. 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.

Jun, Jae Shik; Noh, Hyung Ah [Daejon Radiation Monitoring Station, Daejeon (Korea, Republic of)

2003-12-15

339

Survey monitoring of environmental radioactivity in Daejeon area  

Energy Technology Data Exchange (ETDEWEB)

Systematic understanding of the distribution of environmental radioactivity and radiation level in Taejon, 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 Taejon Radiation Monitoring Station in 2000. In conclusion, the natural environmental radiation level in Taejon 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.

Jun, Jae Shik.; Noh, Hyung Ah [Taejon Radiation Monitoring Station, Daejeon (Korea, Republic of)

2000-12-15

340

Survey monitoring of environmental radioactivity in Daejeon area  

Energy Technology Data Exchange (ETDEWEB)

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.

Jun, Jae Sik; Noh, Hyung Ah [Daejon Radiation Monitoring Station, Daejeon (Korea, Republic of)

2001-12-15

 
 
 
 
341

Survey monitoring of environmental radioactivity in Daejeon area  

International Nuclear Information System (INIS)

Systematic understanding of the distribution of environmental radioactivity and radiation level in Taejon, 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 Taejon Radiation Monitoring Station in 2000. In conclusion, the natural environmental radiation level in Taejon 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

342

Survey monitoring of environmental radioactivity in Daejeon area  

International Nuclear Information System (INIS)

Systematic understanding of the distribution of environmental radioactivity and radiation level in Taejon, 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 Taejon Radiation Monitoring Station in 1998. In conclusion, the natural environmental radiation level in Taejon 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

343

Survey monitoring of environmental radioactivity in Daejeon area  

Energy Technology Data Exchange (ETDEWEB)

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 2002. 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.

Jun, Jae Shik; Noh, Hyung Ah [Daejon Radiation Monitoring Station, Daejeon (Korea, Republic of)

2002-12-15

344

Artificial insemination in dromedary camels.  

Science.gov (United States)

Artificial insemination (AI) is an important technique in all domestic species to ensure rapid genetic progress. The use of AI has been reported in camelids although insemination trials are rare. This could be because of the difficulties involved in collecting as well as handling the semen due to the gelatinous nature of the seminal plasma. In addition, as all camelids are induced ovulators, the females need to be induced to ovulate before being inseminated. This paper discusses the different methods for collection of camel semen and describes how the semen concentration and morphology are analyzed. It also examines the use of different buffers for liquid storage of fresh and chilled semen, the ideal number of live sperm to inseminate and whether pregnancy rates are improved if the animal is inseminated at the tip of the uterine horn verses in the uterine body. Various methods to induce ovulation in the female camels are also described as well as the timing of insemination in relation to ovulation. Results show that collection of semen is best achieved using an artificial vagina, and the highest pregnancy rates are obtained if a minimum of 150×10(6) live spermatozoa (diluted in Green Buffer, lactose (11%), or I.N.R.A. 96) are inseminated into the body of the uterus 24h after the GnRH injection, given to the female camel to induce ovulation. Deep freezing of camel semen is proving to be a great challenge but the use of various freezing protocols, different diluents and different packaging methods (straws verses pellets) will be discussed. Preliminary results indicate that Green and Clear Buffer for Camel Semen is the best diluent to use for freezing dromedary semen and that freezing in pellets rather than straws result in higher post-thaw motility. Preservation of semen by deep-freezing is very important in camelids as it prevents the need to transport animals between farms and it extends the reproductive life span of the male, therefore further work needs to be carried out to improve the fertility of frozen/thawed camel spermatozoa. PMID:23153625

Skidmore, J A; Morton, K M; Billah, M

2013-01-10

345

Radio-ecological aspects in artificial groundwater recharge  

International Nuclear Information System (INIS)

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

346

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

International Nuclear Information System (INIS)

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

347

Thermal fluctuations in artificial spin ice.  

Science.gov (United States)

Artificial spin ice systems have been proposed as a playground for the study of monopole-like magnetic excitations, similar to those observed in pyrochlore spin ice materials. Currents of magnetic monopole excitations have been observed, demonstrating the possibility for the realization of magnetic-charge-based circuitry. Artificial spin ice systems that support thermal fluctuations can serve as an ideal setting for observing dynamical effects such as monopole propagation and as a potential medium for magnetricity investigations. Here, we report on the transition from a frozen to a dynamic state in artificial spin ice with a square lattice. Magnetic imaging is used to determine the magnetic state of the islands in thermal equilibrium. The temperature-induced onset of magnetic fluctuations and excitation populations are shown to depend on the lattice spacing and related interaction strength between islands. The excitations are described by Boltzmann distributions with their factors in the frozen state relating to the blocking temperatures of the array. Our results provide insight into the design of thermal artificial spin ice arrays where the magnetic charge density and response to external fields can be studied in thermal equilibrium. PMID:24908258

Kapaklis, Vassilios; Arnalds, Unnar B; Farhan, Alan; Chopdekar, Rajesh V; Balan, Ana; Scholl, Andreas; Heyderman, Laura J; Hjörvarsson, Björgvin

2014-07-01

348

Decomposition of water and production of H2 using semiconductor-photocatalytic effect induced by gamma ray from high radioactive waste  

International Nuclear Information System (INIS)

The technology of the radiolytic decomposition of water leading to hydrogen production was demonstrated to explore a new field in the utilization of radiation and radioactive elements. The technology used consisted of a photoassisted catalytic method which has been generally investigated for photocatalysis using a semiconductor and light in an electrochemical study. In our study, gamma radiation from Co-60 was used instead of light, and a significant amount of evolved hydrogen was detected. Our preliminary experiments proved the possibility of converting the energy ionizing radiation (gamma radiation) into chemical energy (hydrogen) using a semiconductor-photocatalytic effect. (author)

349

Radioactivity of wood ash  

International Nuclear Information System (INIS)

STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg-1, in decreasing order: 137Cs, 40K, 90Sr, 210Pb,226Ra, 232Th, 134Cs, 235U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and 210Pb was hardly detectable. The NH4Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

350

Artificial structures on Mars  

Science.gov (United States)

Approximately 70,000 images of the surface of Mars at a resolution of up to 1.4 meters per pixel, taken by the Mars Global Surveyor spacecraft, are now in public archives. Approximately 1% of those images show features that can be broadly described as `special shapes', `tracks, trails, and possible vegetation', `spots, stripes, and tubes', `artistic imagery', and `patterns and symbols'. Rather than optical illusions and tricks of light and shadow, most of these have the character that, if photographed on Earth, no one would doubt that they were the products of large biology and intelligence. In a few cases, relationships, context, and fulfillment of a priori predictions provide objective evidence of artificiality that is exempt from the influence of experimenter biases. Only controlled test results can be trusted because biases are strong and operate both for and against artificiality.

Van Flandern, T.

2002-05-01

351

Spatially Resolved Artificial Chemistry  

DEFF Research Database (Denmark)

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. It reviews calibration procedures, outlines the computational algorithms, and summarizes examplary applications. Four different platforms for BD and DPD simulations are presented that differ in their focus, features, and complexity.

Fellermann, Harold

2009-01-01

352

Artificially structured magnetic materials  

Energy Technology Data Exchange (ETDEWEB)

This document reports the progress made during the first six months of the current three-year DOE grant on Artificially Structured Magnetic Materials.'' However, because some of the results of our previous three-year DOE grant on Artificially Structured Superconductors'' continue to emerge, both topics are addressed in this Progress Report. This report describes progress with DOE funding during the current calendar year; description of the research to be conducted during the remaining six months of the current grant year; a description of the status of the graduate students working on this research; lists of the invited talks, seminars and colloquia, of other recognition of our research, and of the publications crediting DOE sponsorship; and a summary of current and pending federal support. Since the research proposed to be conducted during the next 2 1/2 years is described in detail in our DOE proposal, it is only briefly reviewed here.

Falco, C.M.

1990-09-28

353

Ethical Artificial Intelligence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This book-length article combines several peer reviewed papers and new material to analyze the issues of ethical artificial intelligence (AI). The behavior of future AI systems can be described by mathematical equations, which are adapted to analyze possible unintended AI behaviors and ways that AI designs can avoid them. This article also discusses how future AI will differ from current AI, the politics of AI, and the ultimate use of AI to help understand the nature of the ...

Hibbard, Bill

2014-01-01

354

Whither Artificial Reproduction?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Artificial reproduction now offers sub fertile couples a number of options which raise scientific and ethical questions. This article discusses the Canadian and British experiences in formulating regulations and legislation in this important field. Current work on mammalian embryo research foretells the direction which human research will take. This article stresses the need for family physicians' participation in the ethical decisions that accompany these new developments.

Percival-smith, Robin

1985-01-01

355

Essentials of artificial intelligence  

CERN Document Server

Since its publication, Essentials of Artificial Intelligence has beenadopted at numerous universities and colleges offering introductory AIcourses at the graduate and undergraduate levels. Based on the author'scourse at Stanford University, the book is an integrated, cohesiveintroduction to the field. The author has a fresh, entertaining writingstyle that combines clear presentations with humor and AI anecdotes. At thesame time, as an active AI researcher, he presents the materialauthoritatively and with insight that reflects a contemporary, first hand

Ginsberg, Matt

1993-01-01

356

Artificial Neural Network  

Directory of Open Access Journals (Sweden)

Full Text Available An artificial neural network is an information-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information.The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons working in unison to solve specific problems.Ann’s, like people, learn by example.

Kapil Nahar

2012-12-01

357

Artificial gravity Mars spaceship  

Science.gov (United States)

Experience gained in the study of artificial gravity for a manned trip to Mars is reviewed, and a snowflake-configured interplanetary vehicle cluster of habitat modules, descent vehicles, and propulsion systems is presented. An evolutionary design is described which permits sequential upgrading from five to nine crew members, an increase of landers from one to as many a three per mission, and an orderly, phased incorporation of advanced technologies as they become available.

Clark, Benton C.

1989-01-01

358

The SEPAC artificial aurora  

DEFF Research Database (Denmark)

The Space Experiments with Particle Accelerators (SEPAC) and the Atmospheric Emission Photometric Imager (AEPI) were flown on the ATLAS-1 shuttle mission in the spring of 1992. In a series of artificial aurora experiments, SEPAC injected electron beam pulses (6.25 keV, 1.2 A) into the Earth's upper atmosphere while the AEPI camera recorded optical emissions in white light continuum and 4278 Angstrom. The intensity, overall size, and structure of the artificial auroras have been compared to results from a two-stream code which models collisional and transport properties of natural and artificial electron beams. Using the curvature of the magnetic field to resolve the altitude dependence of observed optical emissions, it is found that the beam reaches 110-130 km altitude and excites emissions at intensities that are consistent with model calculations (1 kR). However, it is also concluded that the near-field intensity (5 kR) exceeds model estimates by one order of magnitude. It is argued that this unexpected enhancement is caused by emissions generated within the first 10's of kilometers of the Orbiter by suprathermal electron fluxes at levels that are orders of magnitude larger than predicted by the purely collisional model. It is suggested that the enhanced flux is due to wave-particle interactions heating the ambient plasma.

Neubert, Torsten; Burch, J. L.

1995-01-01

359

Radioactivity measurements as tool for physics dissemination  

International Nuclear Information System (INIS)

In general people associate environmental radioactivity with the artificial radioactivity and knows very little about natural radioactivity. Thus there is a critical need to improve nuclear physics public education. From 2005 in Italy two programs were promoted from Ministry of Education and University and National Institute of Nuclear Physics (INFN) for scientific dissemination in the field of environmental radioactivity. High school students in many Italian regions were involved in particular in indoor radon measurements. With this program students acquired awareness about the risks of inhalation of radon and its progeny and at the same time contributed to carry out radon monitoring, participating to all the experimental phases, from detectors set-up to data analysis. In particular we report about the activities carried out at Catania University and INFN division regarding a survey in the eastern Sicily. The overall monitoring, spanned over a period of 5 years, was carried out using passive nuclear track detection technique, through CR-39 dosimeters. In total about 500 detectors were placed in dwellings and schools in 57 locations. The investigated area have shown medium-high indoor radon concentrations, higher than the Italian average (70 Bq/m3). From the evaluation of the participating teachers and students, this kind of activities represents a successful strategy to enhance dissemination of physics, in particular in radioactivity topics. (author)

360

Radioactive iodine uptake  

Science.gov (United States)

Iodine uptake test; RAIU ... to swallow a liquid or capsule containing radioactive iodine. After a certain period of time (usually 4 ... have: Diarrhea (may decrease absorption of the radioactive iodine) Had recent CT scans using intravenous or oral ...

 
 
 
 
361

Radioactivity in consumer products  

Energy Technology Data Exchange (ETDEWEB)

Papers presented at the conference dealt with regulations and standards; general and biological risks; radioluminous materials; mining, agricultural, and construction materials containing radioactivity; and various products containing radioactive sources.

Moghissi, A.A.; Paras, P.; Carter, M.W.; Barker, R.F. (eds.)

1978-08-01

362

Radioactivity and geophysics  

International Nuclear Information System (INIS)

The paper recalls a few steps of the introduction of radioactivity in geophysics and astrophysics: contribution of radioelements to energy balance of the Earth, age of the Earth based on radioactive disintegration and the discovery of cosmic radiations

363

Radioactive situation in Kyrgyzstan: problems and perspectives  

International Nuclear Information System (INIS)

One of the major problems of the environment contamination in Kyrgyzstan is the development of radioactive and toxic pollution caused by nuclear tests, technogene accidents which took place in neighboring countries, and breach of safe storage and destruction of uranium and hazardous waste tailings. Long-term nuclear tests in various areas of the world and the accident at the NPP have caused the origin of stratospheric deposit of artificial radionuclides, the fallout of which have led to radioactive pollution of the biosphere. Maximum fallout have been observed in the latitudinal zone of 40-60 degrees and in the mountainous regions. As a result of many years of research the main sources of radioactive contamination have been established. It is shown that stratospheric or tropospheric and local fallout have permanently exposed the territory of Kyrgyzstan to the pollution by radionuclides. A brief description of radioactive contamination of the environment in Kyrgyzstan from remote external sources and atmospheric mechanisms of its transfer delineated on the basis of long-term observation of geophysical and atmospheric parameters and regular radiation monitoring have been presented. The investigated mechanisms can be used to interpret the sharp increase of the radioactive background and to estimate the risk to the environment and human health. Some methodological questions about the influence of geophysical conditions on the territorial distribution of contamination have bee considered. The tropospheric mechanism of contamination transfer for different seasons of year has been suggested. The uranium tailings located in mountain regions near densely populated areas and and groundwater basins are the internal sources of radioactive contamination in Kyrgyzstan. Waste products of uranium production present a real treat for the environment and public health. The problem of environment security in connection with destruction of uranium tailings has been discussed. Till now there has not been conducted assessment of radioactive contamination consequences to the environment and human health in this region. The impact of ionization radiation on people health has been presented

364

Radioactivity in the northern seas of europe  

International Nuclear Information System (INIS)

The recent accidents with nuclear powered Russian submarines, such as the Kursk and the K-159, that took place in the Arctic Seas, give rise to high concerns of the public and the media about the radioactive contamination of marine ecosystems and radiological safety of the European population. Those accidents were preceded by decades of discharges of radioactive liquid effluents into coastal seas of Europe and the dumping of packed radioactive waste into the North Atlantic. Being Portugal one country with high consumption rate of seafood caught in its own coastal waters as well as in far seas including the Ar tic seas, the investigation of the radioactive contamination of fish was investigated. Analysis of fish from the Sea of Labrador, Sea of Iceland and Barents Sea, has shown that gamma-emitting radionuclides of artificial origin are in general not detected. The only gamma emitting radionuclide present is Cs-137, in concentrations not higher than 0.3 Bq/kg. This radionuclide originates in the deposition of radioactive fallout following nuclear weapon tests performed in the fifties and sixties. Radionuclides in fish from northern regions and in fish from the Portuguese coast generally are present in concentrations lower than those currently reported for fish from the Irish Sea and the Baltic Sea, impacted with the discharges of radioactive waste from Sellafield and the deposition of fallout from Chernobyl, respectively. Nevertheless, the potential for future accidenttheless, the potential for future accidents and the radioactive waste dumped into the North Atlantic may in the future modify this scenario and potentially increase the currently very low radionuclide concentration in fish included in the Portuguese diet. Therefore, the research and radiological surveillance must be maintained in order to monitor the radiological risk and to ensure the quality of food available to consumers. (author)

365

Management of radioactive waste  

International Nuclear Information System (INIS)

The document gives an overview of of different aspects of radioactive waste management in Belgium. The document discusses the radioactive waste inventory in Belgium, the treatment and conditioning of radioactive waste as well as activities related to the characterisation of different waste forms. A separate chapter is dedicated to research and development regarding deep geological disposal of radioactive waste. In the Belgian waste management programme, particular emphasis is on studies for disposal in clay. Main results of these studies are highlighted and discussed

366

Radioactive consumer products  

Energy Technology Data Exchange (ETDEWEB)

Present situation of utilizing the radioactive consumer products and exposure dose were reviewed with published data. Practically, consumer products are divided into three categories, (1) radioactive nuclides intentionally incorporated into radioluminous dye, ionization chambers for smoke detector, eliminator of static electricity, and glow lamp (2) natural radioactive nuclides contained in false teeth, porcelain, glass, and gas mantle (3) natural radioactive nuclides accumulated as industrial waste at the consumption of coal, petroleum, and natural gas or in fertilizer and materials for construction.

Sato, O. (Tokyo Univ. (Japan). Inst. of Industrial Science)

1981-07-01

367

Monitoring radioactive materials  

International Nuclear Information System (INIS)

Afterheat being released from a radioactive storage system is measured and monitored. Changes in heat release with respect to time is related to expected radioactive decay processes of the confined radioactive materials. Material leakage from storage is detected and defined by deviations from the normal expected heat release-time function being monitored. Such deviations or lack of deviations, as the case may be, provide the desired accountability of the radioactive materials (author)

368

Radioactive consumer products  

International Nuclear Information System (INIS)

Present situation of utilizing the radioactive consumer products and exposure dose were reviewed with published data. Practically, consumer products are divided into three categories, (1) radioactive nuclides intentionally incorporated into radioluminous dye, ionization chambers for smoke detector, eliminator of static electricity, and glow lamp (2) natural radioactive nuclides contained in false teeth, porcelain, glass, and gas mantle (3) natural radioactive nuclides accumulated as industrial waste at the consumption of coal, petroleum, and natural gas or in fertilizer and materials for construction. (Nakanishi, T.)

369

Chemical and isotopic characterization of water-rock interactions in shales induced by the intrusion of a basaltic dike: A natural analogue for radioactive waste disposal  

International Nuclear Information System (INIS)

dike emplacement probably favored water circulation along the contact. Strontium isotopic data suggest that the fluids of probable meteoric origin, reacted with Bathonian and Bajocian limestones before entering the underlying Toarcian shales. By analogy with deep geological radioactive waste repositories, the results report discrete mineralogical variations of the clays when subjected to temperatures of 100-150 deg. C that are expected in deep storage conditions. Beyond 150 deg. C, significant mineralogical changes may alter the physical and chemical properties of the shales, especially of the clay fraction. Also, the development of structural discontinuities in the so-called thermally disturbed zone might be of importance as these discontinuities might become zones for preferential fluid circulation. Finally, the study emphasizes the use of Rb-Sr and K-Ar isotopic systems as tracers of local circulating fluids related to low-grade thermal imprints

370

Radioactivity. Pt. 1  

International Nuclear Information System (INIS)

This bibliographic list offers a selection of literature references on the subjects radioactivity, radiation protection, and medical measures in the event of disaster. The subject radioactivity is subdivided according to basic literature, nuclear energy utilization, nuclear weapons, natural radiation, and radioactivity in ecological systems. (DG)

371

Radioactive waste management  

International Nuclear Information System (INIS)

A survey of the problems inherent in the mangement of radioactive wastes is presented. Aspects covered include the management of spent fuel and of the radioactive wastes which arise from its treatment, the decommissioning of nuclear facilities and the transport of radioactive materials. The present state of relevant technology and the options for the future are reviewed

372

Transport of radioactive materials  

International Nuclear Information System (INIS)

This ninth chapter presents de CNEN-NE--5.01 norm 'Transport of radioactive material'; the specifications of the radioactive materials for transport; the tests of the packages; the requests for controlling the transport and the responsibilities during the transport of radioactive material

373

A scenario for a genetically controlled fission of artificial vesicles.  

DEFF Research Database (Denmark)

Artificial vesicles have been used for decades as model systems of biological cells to investigate scientific questions in simulacra. In recent years, the significance of artificial vesicles further increased because they represent ideal candidates to become the building block of a de novo construction of a cell in a bottom-up manner. Numerous efforts to build an artificial cell that bridge the living and non-living world will most presumably represent one of the main goals of science in the 21st century. It was shown that artificial genetic programs and the required cellular machinery can be incorporated into vesicles, and therefore allow the synthesis of a large number of proteins (Noireaux et al. 2005). However, vesicle fission remains one of the upcoming challenges in the artificial cell project (Noireaux et al. 2011). So far, vesicle fission is implemented by applying mechanical stress to vesicles (Hanczyc et al. 2003). In the present work, we developed a scenario how a genetically controlled fission of vesicles may be achieved by the synthesis of a special class of viral proteins within artificial vesicles. Because the authors already have a lot of experience in the water-in-oil emulsion transfer method to prepare vesicles, the base for the development of a protocol to induce fission in artificial cell may be available.

Bönzli, Eva; Hadorn, Maik

374

Artificial Gravity: Effects on Bone Turnover  

Science.gov (United States)

The impact of microgravity on the human body is a significant concern for space travelers. Since mechanical loading is a main reason for bone loss, artificial gravity might be an effective countermeasure to the effects of microgravity. In a 21-day 6 head-down tilt bed rest (HDBR) pilot study carried out by NASA, USA, the utility of artificial gravity (AG) as a countermeasure to immobilization-induced bone loss was tested. Blood and urine were collected before, during, and after bed rest for bone marker determinations. Bone mineral density was determined by DXA and pQCT before and after bed rest. Urinary excretion of bone resorption markers (n-telopeptide and helical peptide) were increased from pre-bed rest, but there was no difference between the control and the AG group. The same was true for serum c-telopeptide measurements. Bone formation markers were affected by bed rest and artificial gravity. While bone-specific alkaline phosphatase tended to be lower in the AG group during bed rest (p = 0.08), PINP, another bone formation marker, was significantly lower in AG subjects than CN before and during bed rest. PINP was lower during bed rest in both groups. For comparison, artificial gravity combined with ergometric exercise was tested in a 14-day HDBR study carried out in Japan (Iwase et al. J Grav Physiol 2004). In that study, an exercise regime combined with AG was able to significantly mitigate the bed rest-induced increase in the bone resorption marker deoxypyridinoline. While further study is required to more clearly differentiate bone and muscle effects, these initial data demonstrate the potential effectiveness of short-radius, intermittent AG as a countermeasure to the bone deconditioning that occurs during bed rest and spaceflight. Future studies will need to optimize not only the AG prescription (intensity and duration), but will likely need to include the use of exercise or other combined treatments.

Heer, M.; Zwart, S /R.; Baecker, N.; Smith, S. M.

2007-01-01

375

CT staging of lung cancer: the role of artificial pneumothorax  

International Nuclear Information System (INIS)

To determine the role of artificially induced pneumothorax in the evaluation of the chest wall and mediastinal invasion in patients with peripheral bronchogenic carcinoma. CT scans of 22 patients obtained after induced pneumothorax were evaluated. All patients had peripheral lung mass abutting the pleura on a routine CT scan. Room air of 200-400ml was introduced through intrathoracic negative pressure initially, followed by pressure injection through the 18 gauge long bevelled needle under fluoroscopic control. Conclusively, CT with artificial pneumothorax added more information than conventional CT in the evaluation of the chest wall or mediastinal invasion by lung cancer without notable risk

376

Mind, brain and artificial intelligence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Artificial intelligence is one of the disciplines, which along with philosophy, psychology, linguistics, neuroscience, and anthropology forms interdisciplinary field of cognitive science. The aim of artificial intelligence is to create a thinking machine that had feelings and consciousness. This diploma thesis is divided into four chapters. The first chapter contains a definition and overview of the history of artificial intelligence. The second chapter focuses on the symbolic hypothesis and ...

Podbevs?ek, Z?iva

2014-01-01

377

Applicability of nonresonant artificial diamagnetics  

Science.gov (United States)

Artificial diamagnetics are prominent for achieving extraordinarily strong diamagnetism in a wide frequency range. However, as far as the magnetic fields outside the artificial medium are concerned, bulk conductors show a very similar pattern. The question arises whether the complicated internal structure of artificial diamagnetics can, to this end, be replaced by a simpler object. We show that for an electrically small body, internal structuring is likely to make the effective diamagnetic response weaker than that of a simple conducting object.

Jelinek, L.; Lapine, M.; McPhedran, R. C.

2014-09-01

378

Structural and dielectric properties of perovskite-type artificial superlattices  

International Nuclear Information System (INIS)

BaTiO3/SrTiO3, SrZrO3/SrTiO3 and BaTiO3/BaZrO3 artificial superlattices were fabricated by the molecular beam epitaxy process. X-ray diffraction (XRD) reciprocal space mapping measurement was performed using high-resolution XRD. In all artificial superlattices, the superlattices with the 10-periodic structure showed the clear satellite peaks in the XRD pattern and were mostly distorted in the direction of film thickness. Superlattices with the 10-periodic structure showed a high dielectric permittivity of ? r = 33,000 or artificially induced ferroelectricity. It was clarified that the anisotropic lattice distortion introduced by the strains due to the lattice mismatch was the origin of the unique dielectric characteristics of artificial superlattices

379

GeneSys: Hydraulic and thermal characterisation of an artificially induced fracture and implications for its geothermal utilisation; GeneSys: Hydraulische und thermische Charakterisierung des kuenstlich erzeugten Risses und Implikationen fuer dessen geothermische Nutzung  

Energy Technology Data Exchange (ETDEWEB)

Horstberg Z1 is an exploratory well used by Geozentrum Hanover for investigating new geothermal concepts. The investigations focused on the applicability of the water frac technology to dense sedimentary rock in the context of the GeneSys project (Jung et al., 2004). An artificially induced fracture was investigated with a view to its potential for geothermal heat supply. The contribution presents results of hydraulic test evaluations which are indicative of the fracture characteristics. Further, it is investigated which natural supporting mechanism prevents full closure of the fracture after pressure relief. Finally, the thermal characteristics of the fracture are investigated in cyclic tests with the aid of model calculations, in which the central element is the long-term thermal response to cyclic loading with cold water and recirculation of hot water out of the fracture. (orig.) [German] Die Bohrung Horstberg Z1 dient dem Geozentrum Hannover als Forchungsbohrung fuer die geothermische Energiegewinnung. Hier sollen neue Methoden zur Erdwaermegewinnung untersucht und insbesondere Einbohrlochkonzepte getestet werden. Im Zentrum der Untersuchungen steht die Anwendbarkeit der Wasserfrac-Technik auf dichte Sedimentgesteine. Die Untersuchungen an der Bohrung Horstberg Z1 stehen im engen Zusammenhang mit dem GeneSys-Projekt (Jung. et al., 2004). Aufbauend auf den Erfahrungen an der Bohrung Horstberg Z1 sollen hier entwickelte Konzepte auf den Standort Hannover uebertragen und fuer die geothermische Waermeversorgung des Geozentrums umgesetzt werden. An der Bohrung Horstberg Z1 wurden im Herbst 2003 massive Wasserfrac-Tests im Buntsandstein (Detfurth- und Volpriehausen-Formation) durchgefuehrt. Die groesseren Fracoperationen fanden im Detfurth-Sandstein, ueber eine Perforationsstrecke von 3787-3791 m statt. Es wurden hier 2 Fracoperationen mit einer Fliessrate von jeweils 50 l/s und insgesamt ca. 20.000 m{sup 3} Frischwasser ausgefuehrt. Hierdurch konnte ein grossflaechiger kuenstlicher Riss erzeugt werden, der interessante hydraulische und thermische Eigenschaften aufweist. Ueber Ablauf und wesentliche Ergebnisse der bisherigen Untersuchungen an der Bohrung Horstberg Z1 wird bereits in dem Beitrag von Orzol et al. (Das Geothermieprojekt GeneSys - Ergebnisse von massiven Wasserfractests im Buntsandstein des Norddeutschen Beckens) in diesem Band berichtet. Die nachfolgende Darstellung knuepft inhaltlich unmittelbar an diesen Beitrag an. Es werden Ergebnisse von hydraulischen Testauswertungen praesentiert, die Rueckschluss auf die Eigenschaften des Risses zulassen. Weiterhin wird der Frage nachgegangen, welcher natuerliche Stuetzmechanismus ein vollstaendiges Schliessen des Risses nach Druckentlastung verhindert. Schliesslich wird das thermische Verhalten des Risses in zyklischen Tests mit Hilfe von Modellrechnungen untersucht. Im Zentrum dieser Modellrechnungen steht das thermische Langzeitverhalten bei zyklischer Beladung mit Kaltwasser und Rueckfoerderung von Heisswasser aus dem Riss. (orig.)

Tischner, T.; Jatho, R.; Kehrer, P. (GGA Institut, Hannover); Sulzbacher, H.; Jung, R.; Orzol, J. [BGR Hannover (Germany)

2004-12-01

380

Packaging of radioactive materials  

International Nuclear Information System (INIS)

The standard describes the packaging rules of radioactive materials (except for fissile materials, spent fuel elements and bulk radioactive materials) for two groups. Type 'A' packaging assures that the radioactive materials should not go loose or spread out in case of an accident. Type 'B' contains additional, more strickt requirements concerning shielding etc. The packaging rules for radioactive materials of unusual shapes are also reported, including qualifications and inspection regulations of packaging regarding radioactive materials of both usual and unusual shape. The latter involves dissolution testing and qualification techniques. The data required in the certificates for the authorities are summarized. (Sz.J.)

 
 
 
 
381

Air conditioner for radioactive material handling facility  

International Nuclear Information System (INIS)

An air conditioner intakes open-air from an open-air intake port to remove sands and sea salt particles by air filters. Then, natural and artificial radioactive particles of less than 1 ?m are removed by high performance particulate filters. After controlling the temperature by an air heater or an air cooler, air is sent to each of chambers in a facility under pressure elevation by a blower. In this case, glass fibers are used as the filter material for the high performance particulate filter, which has a performance of more than 99.97% for the particles of 0.3 ?m grain size. Since this can sufficiently remove the natural radioactive materials intruded from the outside, a detection limit value in each of the chambers of the facility can be set 10-13 to 10-14 ?ci/cm3 in respect of radiation control. Accordingly, radiation control can be conducted smoothly and appropriately. (I.N.)

382

Radioactivity Monitoring of the Irish Environment 2010-2011  

International Nuclear Information System (INIS)

This report presents the results of the environmental radioactivity monitoring programme carried out by the Radiological Protection Institute of Ireland RPII during 2010 and 2011. The RPII has routinely monitored levels of radioactivity in the Irish 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 to ensure it remains relevant and continues to focus on the most important sources of radioactivity in the environment. The data presented in this report confirm that while the levels of artificial radioactivity in the Irish environment are detectable, they are low. They do not pose a significant risk to the human health of the Irish population. Trace amounts of radioactive isotopes consistent with the Fukushima nuclear accident were detected in air, rainwater and milk samples during the period March to May 2011. These increases in levels of radioactivity were not of concern from a public health point of view. For the remainder of the reporting period, activity concentrations of radionuclides in airborne particles 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 were found to be in compliance with the total indicative dose defined in national and EU legislation. The doses incurred by the Irish public in 2010 and 2011 as a result of artificial radioactivity in the marine environment are small when compared to dose limits or to natural radiation doses received by the Irish public. The doses to the most exposed individuals, members of the oyster and mussel farmers critical group, were approximately 0.02 per cent and 0.05 per cent of the annual dose limit of 1000 microsieverts for members of the public from practices involving controllable sources of radiation in 2010 and 2011 respectively. The increase in 2011 can be attributed to changes in sampling protocol and analytical method. These doses represent a small fraction of the average annual dose to a person in Ireland from all sources of radioactivity of 3950 microsieverts. 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

383

Induced radioactivity in air-estimation of ventilation rates at the vault and experimental areas of the proposed K-500 superconducting cyclotron, Calcutta  

International Nuclear Information System (INIS)

Guidelines are given for the necessary ventilation rates in vault and experimental areas from radiological safety point of view, for the proposed K-500 super-conducting cyclotron at Calcutta. A method is presented for estimating the amount of short lived radioisotopes like 13N and 15O taking the (n,2n) mode of productions. Considering the operating conditions of K-500 machine for the production of maximum neutron flux (300 MeV, 50pnA Li beam on Ta target) the energy differential neutron flux and the energy differential production cross section of 13N and 15O have been generated using ALICE-91 computer code. The differential cross sections have been folded with radial neutron flux distribution and then integrated over the entire volume of the cyclotron vault, to obtain the total production of the two radioactive gases. The DAC values have been obtained by considering the immersion dose in a semi-infinite hemispherical cloud. Natural decay and removal due to ventilation have been considered to get the recommended ventilation rates. (author)

384

Helium 3 precipitation in AISI 316L stainless steel induced by radioactive decay of tritium: Microstructural study of helium bubble precipitation  

Science.gov (United States)

This article deals with the study of the influence of thermomechanical heat treatments, aging conditions (temperature and time), and helium concentration on helium bubble precipitation in a 316L austenitic steel. Helium was generated by the radioactive decay of tritium (tritium trick). Helium bubbles impede the grain growth in 316L steel aged at 1373 K and also the recrystal-lization reaction at this temperature if cold working is performed prior to aging. Transmission electron microscopy (TEM) observations indicated a weak helium precipitation at 1073 and 1223 K, presumably due to the presence of trapping sites for tritium, and no bubble growth after aging up to 100 hours. Precipitation sites are mainly dislocations in the matrix at 1073 K and grain boundaries and individual dislocations in the matrix at 1223 K. The large bubble size (50 nm) observed at 1373 K, even for short aging times (0.083 hour), can partly be attributed to bubble dragging by dislocations toward the grain boundaries. Cold deformation prior to aging leads to a larger bubble size due to growth enhancement during recrystallization. Decreasing the helium content leads to a smaller helium bubble size and density. Tritium trapping at helium bubbles may favor helium 3 accumulation on defects such as grain boundaries, as observed by tritium autoradiography.

Brass, A. M.; Chanfreau, A.; Chene, J.

1994-10-01

385

Charge distributions and coagulation of radioactive aerosols  

International Nuclear Information System (INIS)

The self-charging of radioactive aerosols will be reduced by background ions, such as those produced by radioactive gases. The sources of these background ions and their production rates are specified for a reactor containment atmosphere during a possible nuclear accident. Previous theory is extended to calculate the charging of a polydisperse radioactive aerosol. Gaussian approximations to charge distributions on an aerosol of a given size, and are shown to give a good representation of the exact numerical charge distributions of a Cs aerosol at normal temperatures, and also for highly radioactive aerosol containing 131I in a containment atmosphere. Extensive calculations are performed for charged-induced modifications to Brownian coagulation rates between steady-state size distribution of these radioactive aerosols, and also between small-sized radioactive aerosol and larger (non-radioactive) aerosol. The results show considerable enhancements of the coagulation rates between large and small-sized aerosol, but also a strong suppression of coagulation between large particles. Rate modifications calculated using the Gaussian approximations are generally close to the exact values. Time-dependent calculations for a monodisperse ?-decaying aerosol reveal enhancements in coagulation rates even when the average charge on the aerosol is positive. Our results are relevant to behaviour in a dusty plasma. (author)

386

UK strategy for radioactive discharges. 2001-2020  

International Nuclear Information System (INIS)

At the 1998 Ministerial meeting of the Oslo and Paris (OSPAR) Commission, contracting parties to the 1992 Convention for the Protection of the Marine Environment of the North East Atlantic agreed a Strategy with regard to Radioactive Substances. This is reproduced at Annex 1. The Strategy was endorsed in a Ministerial Declaration, signed by the UK and all other OSPAR contracting parties. The objective of the Strategy is to prevent pollution of the maritime area (as defined under the convention) from ionising radiation, through progressive and substantial reductions of discharges, emissions and losses of radioactive substances. The ultimate aim is to achieve concentrations in the environment near background levels for naturally occurring radioactive substances and close to zero for artificial radioactive substances

387

Radioactivity survey data in Japan, no. 55  

International Nuclear Information System (INIS)

Gamma-ray spectrometry with Ge (Li) detectors was applied to all samples. Artificial radionuclides such as Cs-137, Mn-54 and Co-60 were identified, and their concentrations were determined. Samples were cultured fish, caught fish and marine sediment. The important species were selected in consideration of their importance as ecological indicators and natural resources. The indicator species were selected in consideration of their significant characteristics of accumulating the radionuclides. The treatment of fish and sediment for the measurement is described. The radioactivity of the samples was measured with Ge (Li) detectors for 20 to 24 hours. Radioactive background was measured for 40 to 48 hours at intervals of one week. The radionuclides were identified by analyzing the observed gamma-ray spectra. The corresponding peak area of each radionuclide was calculated, and radioactive background was subtracted. The amounts of the radioactive nuclides were estimated from these net peak areas by correcting them with the counting efficiency of the detectors, sample geometry and others. Besides the detectors, a pulse height analyzer and data output equipments were used. The criteria for the precision of measurement are defined, and the results of analysis are reported for the samples collected from December, 1978, to February, 1980. This report was drawn up by the National Institute of Radiological Sciences. (Kako, I.)

388

Radioactive contamination of wood and its products  

International Nuclear Information System (INIS)

This paper presents research on radioactive contamination of the three most common kinds of wood in Croatia -- beech, oak and fir as well as acorn. Gamma-spectrometric measurements carried out on the samples of bark and wood of beech, oak, fir and acorn have shown radioactivity contents ranging from 1.6±0.1 to 37.3±0.5 Bq/kg from deposited 137Cs, whose concentrations in the soil of Croatia have increased after the Chernobyl accident. Measurements have also shown the radioactivity originating from 40K and 214Bi, which are part of the natural composition of the soil. The distribution of the radionuclides in wood has been discussed, as well as the impact of radioactive contamination of wood by the artificial radionuclide 137Cs upon the forest ecosystem. According to the corresponding model, it has been calculated that a 10 h daily stay in a typical family house increases the annual radiation dose of the population, due to the deposited 137Cs in the structure or furniture, by 343 ?Sv

389

Measurement of environmental radioactivity in Toki district  

International Nuclear Information System (INIS)

When the Institute of Plasma Physics, Nagoya University, expressed the hope to move into Toki district, the environmental problems accompanying the movement were discussed. The effect of the radioactivity leaking from the nuclear facility on human bodies must be far smaller than that of natural radiation, and for the purpose, the amount and fluctuation range of the natural radiation in the district must be known. The initial objectives of this cooperative research were to study on environmental radiation and to make a Geiger counter for the measurement. In 1981, a scintillation counter will be completed, and using a multi-channel pulse height analyzer, the nuclides which are the source of environmental radiation emission will be identified, and the tritium in natural water will be detected. Thus, the evaluation of environmental radiation can be carried out, and the situation before the movement of the research facility can be grasped. In this paper, the natural radioactivity in earth, atmosphere and water and cosmic ray, artificial radioactivity, and environmental radiation exposure dose are reported. Also, the manufacture of a GM counter measuring instrument and the measurements of cosmic ray background, typical earth samples and environmental radioactivity with the GM counter are reported. The related data are attached. (Kako, I.)

390

Generalized Adaptive Artificial Neural Networks  

Science.gov (United States)

Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

Tawel, Raoul

1993-01-01

391

The radioactive inventory of a decommissioned magnox power station structure. 1. Measurements of neutron induced activity in samples from the reactor island  

International Nuclear Information System (INIS)

This report is the first of a series which, together, aim to produce an accurate assessment of neutron induced activation levels in the fixed structural components of a reactor of the steel pressure vessel Magnox type. It describes the measurements made of induced activation, necessary in order to establish credibility in the complex calculations described in the subsequent reports. The report also attempts systematically to assess the potential contributions to the dose and disposal problem from all isotopes with a half-life in excess of 5 years. This is necessary in order to ensure that no isotope has been overlooked which could limit any part of the plan for the decommissioning of a Magnox reactor. In addition the report aims to determine concentrations, in each major material type, of trace elements which lead to the isotopes limiting in decommissioning. (author)

392

Molecular artificial photosynthesis.  

Science.gov (United States)

The replacement of fossil fuels by a clean and renewable energy source is one of the most urgent and challenging issues our society is facing today, which is why intense research has been devoted to this topic recently. Nature has been using sunlight as the primary energy input to oxidise water and generate carbohydrates (solar fuel) for over a billion years. Inspired, but not constrained, by nature, artificial systems can be designed to capture light and oxidise water and reduce protons or other organic compounds to generate useful chemical fuels. This tutorial review covers the primary topics that need to be understood and mastered in order to come up with practical solutions for the generation of solar fuels. These topics are: the fundamentals of light capturing and conversion, water oxidation catalysis, proton and CO2 reduction catalysis and the combination of all of these for the construction of complete cells for the generation of solar fuels. PMID:24473472

Berardi, Serena; Drouet, Samuel; Francàs, Laia; Gimbert-Suriñach, Carolina; Guttentag, Miguel; Richmond, Craig; Stoll, Thibaut; Llobet, Antoni

2014-10-20

393

Artificial sweeteners - a review.  

Science.gov (United States)

Now a days sugar free food are very much popular because of their less calorie content. So food industry uses various artificial sweeteners which are low in calorie content instead of high calorie sugar. U.S. Food and Drug Administration has approved aspartame, acesulfame-k, neotame, cyclamate and alitame for use as per acceptable daily intake (ADI) value. But till date, breakdown products of these sweeteners have controversial health and metabolic effects. On the other hand, rare sugars are monosaccharides and have no known health effects because it does not metabolize in our body, but shows same sweet taste and bulk property as sugar. Rare sugars have no such ADI value and are mainly produced by using bioreactor and so inspite of high demand, rare sugars cannot be produced in the desired quantities. PMID:24741154

Chattopadhyay, Sanchari; Raychaudhuri, Utpal; Chakraborty, Runu

2014-04-01

394

Artificial resuspension studies  

International Nuclear Information System (INIS)

Artificial resuspension studies on a range of Taranaki and other major trial site soils were performed by use of a mechanical dust-raising apparatus. A cascade impactor was used to analyse airborne dust in terms of mass and 241Am activities for particle sizes less than 7 ?m. Plutonium and americium activities were found to be enhanced in the respirable fraction. Reported enhancement factors (defined as the ratio of activity concentration of the respirable fraction to that of the total soil) ranged from 3.7 to 32.5 for Taranaki soils with an average value of 6 appearing reasonable for general application in outer (plume) areas. Values close to unity were measured at major trial sites , One Tree and Tadje. Results of some experiments where uncontamined dust was raised by activities such as walking and driving over dusty ground are also presented. 7 refs., 9 tabs., 4 figs

395

A programmable artificial retina  

International Nuclear Information System (INIS)

An artificial retina is a device that intimately associates an imager with processing facilities on a monolithic circuit. Yet, except for simple environments and applications, analog hardware will not suffice to process and compact the raw image flow from the photosensitive array. To solve this output problem, an on-chip array of bare Boolean processors with halftoning facilities might be used, providing versatility from programmability. By setting the pixel memory size to 3 b, the authors have demonstrated both the technological practicality and the computational efficiency of this programmable Boolean retina concept. Using semi-static shifting structures together with some interaction circuitry, a minimal retina Boolean processor can be built with less than 30 transistors and controlled by as few as 6 global clock signals. The successful design, integration, and test of such a 65x76 Boolean retina on a 50-mm2 CMOS 2-?m circuit are presented

396

Artificial Immune Systems (2010)  

CERN Document Server

The human immune system has numerous properties that make it ripe for exploitation in the computational domain, such as robustness and fault tolerance, and many different algorithms, collectively termed Artificial Immune Systems (AIS), have been inspired by it. Two generations of AIS are currently in use, with the first generation relying on simplified immune models and the second generation utilising interdisciplinary collaboration to develop a deeper understanding of the immune system and hence produce more complex models. Both generations of algorithms have been successfully applied to a variety of problems, including anomaly detection, pattern recognition, optimisation and robotics. In this chapter an overview of AIS is presented, its evolution is discussed, and it is shown that the diversification of the field is linked to the diversity of the immune system itself, leading to a number of algorithms as opposed to one archetypal system. Two case studies are also presented to help provide insight into the m...

Greensmith, Julie; Aickelin, Uwe

2010-01-01

397

Helium 3 precipitation in AISI 316L stainless steel induced by radioactive decay of tritium: Microstructural study of helium bubble precipitation  

International Nuclear Information System (INIS)

The development of the thermonuclear technology has given rise to a renewed interest in the study of the behavior of helium in metals. A great amount of work is still required for the understanding of the role of helium on the mechanical properties of structural materials for fusion technology, especially austenitic stainless steels. This article deals with the study of the influence of thermomechanical heat treatments, aging conditions (temperature and time), and helium concentration of helium bubble precipitation in a 316L austenitic steel. Helium was generated by the radioactive decay of tritium (tritium trick). Helium bubbles impede the grain growth in 316L steel aged at 1,373 K and also the recrystallization reaction at this temperature if cold working is performed prior to aging. Transmission electron microscopy (TEM) observations indicated a weak helium precipitation at 1,073 and 1,223 K, presumably due to the presence of trapping sites for tritium, and no bubble growth after aging up to 100 hours. Precipitation sites are mainly dislocations in the matrix at 1,073 K and grain boundaries and individual dislocations in the matrix at 1,223 K. The large bubble size (50 nm) observed at 1,373 K, even for short aging times (0.083), can partly be attributed to bubble dragging by dislocations toward the grain boundaries. Cold deformation prior to aging leads to a larger bubble size due to growth enhancement during recrystallization. Decreasing the helium content leads tion. Decreasing the helium content leads to a smaller helium bubble size and density. Tritium trapping at helium bubbles may favor helium 3 accumulation on defects such as grain boundaries, as observed by tritium autoradiography

398

Conservative smoothing versus artificial viscosity  

Energy Technology Data Exchange (ETDEWEB)

This report was stimulated by some recent investigations of S.P.H. (Smoothed Particle Hydrodynamics method). Solid dynamics computations with S.P.H. show symptoms of instabilities which are not eliminated by artificial viscosities. Both analysis and experiment indicate that conservative smoothing eliminates the instabilities in S.P.H. computations which artificial viscosities cannot. Questions were raised as to whether conservative smoothing might smear solutions more than artificial viscosity. Conservative smoothing, properly used, can produce more accurate solutions than the von Neumann-Richtmyer-Landshoff artificial viscosity which has been the standard for many years. The authors illustrate this using the vNR scheme on a test problem with known exact solution involving a shock collision in an ideal gas. They show that the norms of the errors with conservative smoothing are significantly smaller than the norms of the errors with artificial viscosity.

Guenther, C.; Hicks, D.L. [Michigan Technological Univ., Houghton, MI (United States); Swegle, J.W. [Sandia National Labs., Albuquerque, NM (United States). Solid and Structural Mechanics Dept.

1994-08-01

399

ORNL radioactive waste operations  

International Nuclear Information System (INIS)

Since its beginning in 1943, ORNL has generated large amounts of solid, liquid, and gaseous radioactive waste material as a by-product of the basic research and development work carried out at the laboratory. The waste system at ORNL has been continually modified and updated to keep pace with the changing release requirements for radioactive wastes. Major upgrading projects are currently in progress. The operating record of ORNL waste operation has been excellent over many years. Recent surveillance of radioactivity in the Oak Ridge environs indicates that atmospheric concentrations of radioactivity were not significantly different from other areas in East Tennesseee. Concentrations of radioactivity in the Clinch River and in fish collected from the river were less than 4% of the permissible concentration and intake guides for individuals in the offsite environment. While some radioactivity was released to the environment from plant operations, the concentrations in all of the media sampled were well below established standards

400

ORNL radioactive waste operations  

Energy Technology Data Exchange (ETDEWEB)

Since its beginning in 1943, ORNL has generated large amounts of solid, liquid, and gaseous radioactive waste material as a by-product of the basic research and development work carried out at the laboratory. The waste system at ORNL has been continually modified and updated to keep pace with the changing release requirements for radioactive wastes. Major upgrading projects are currently in progress. The operating record of ORNL waste operation has been excellent over many years. Recent surveillance of radioactivity in the Oak Ridge environs indicates that atmospheric concentrations of radioactivity were not significantly different from other areas in East Tennesseee. Concentrations of radioactivity in the Clinch River and in fish collected from the river were less than 4% of the permissible concentration and intake guides for individuals in the offsite environment. While some radioactivity was released to the environment from plant operations, the concentrations in all of the media sampled were well below established standards.

Sease, J.D.; King, E.M.; Coobs, J.H.; Row, T.H.

1982-01-01