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1

Artificial radioactivity in Lough Foyle  

International Nuclear Information System (INIS)

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

2

Artificial radioactivity in Carlingford Lough, Ireland  

International Nuclear Information System (INIS)

The routine discharges of low-level liquid waste from the British Nuclear Fuels reprocessing plant at Sellafield in Cumbria have resulted in enhanced concentrations of artificial radioactivity in the Irish marine environment, particularly along the north-east coast. During 1990 a detailed study of levels of artificial radioactivity in Carlingford, Lough, a sea Lough in which a significant number of commercial shellfish producers are located, was carried out. The aim of this study was to determine whether radioactivity concentrations in environmental materials from the Lough were enhanced above those found elsewhere along the north-east coast. The study concluded that concentrations in the Lough were broadly similar to those measured elsewhere along this coast. In 1994, the discharge authorisations for Sellafield were revised, resulting in increased discharges of some radionuclides including technetium-99. In October 1997 a follow-up to the original study was carried out by the RPII and the EHS to determine the current concentrations of artificial radioactivity in the Lough and to assess the effects of Sellafield discharges on the region following the revision of the certificate of authorisation

3

Artificial radioactivity of the Black Sea  

International Nuclear Information System (INIS)

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

4

Principle of natural and artificial radioactive series equivalency  

International Nuclear Information System (INIS)

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

5

Monitoring artificial radioactivity in the Nordic countries  

International Nuclear Information System (INIS)

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

6

16. Analysis of artificial radioactive materials  

International Nuclear Information System (INIS)

The methods of artificial radionuclide determination and identification are reviewed and characterized. The analyses and separation techniques of fission products and transuranium elements are discussed in more detail. (M.D.)

7

Natural and Artificial Radioactivity in Drinkingwater in Malaga, Spain  

International Nuclear Information System (INIS)

The measurement of radioactivity in drinking water permits us to determine the exposure of the population to radiation from the habitual consumption of water. An intensive study of the water supply in the city of Malaga during 2002-2010 has been carried out in order to determine the gross alpha and gross beta activities and natural and artificial radionuclides present in drinking water. A database on natural and artificial radioactivity in water was created. The results indicated that a high percentage of the water sample contains a total gross alpha and beta concentration of less than 0.10 Bq/L and 1 Bq/L, respectively. The main objectives were: (1) to analyse gross alpha and gross beta activities and to know the statistical distributions; (2) to study the levels of natural and artificial radionuclides; (3) to determine a possible mathematical correlation between the radionuclides and several factors. (author)

8

Natural and artificial radioactivity levels in sediments in Algiers bay  

International Nuclear Information System (INIS)

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

9

Natural and artificial radioactivity levels in sediments in Algiers bay  

Energy Technology Data Exchange (ETDEWEB)

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

Benamar, M.A.; Zerrouki, A.; Idiri, Z.; Tobbeche, S. [Centre de Developpement des Techniques Nucleaires, Alger-Gare (Algeria)

1997-08-01

10

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

11

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.)

12

Natural and artificial radioactivity in the Svalbard glaciers  

International Nuclear Information System (INIS)

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

13

Sociological aspects of artificially induced abortion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Not every pregnancy is planned and artificially induced abortion is an answer to unwanted pregnancy. It is not easy for women to find themselves in a situation when they must decide whether to terminate the pregnancy or not, distressed, they are on their own and desperate. They find a whole list of various reasons speaking in favour of artificially induced abortion. Slovenian law is positively oriented towards promoting motherhood but women's decisions are quite often based on social factors....

Vrabl, Amanda

2013-01-01

14

Artificial radioactivity in the environmental samples as IAEA reference materials  

International Nuclear Information System (INIS)

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

15

Level of natural and artificial radioactivity in Algeria.  

Science.gov (United States)

A national environmental sampling program was carried out during 1993 to determine natural and artificial radionuclides contents in the (0-15 cm) upper layer of the soil. The main objective was to establish a radioactive reference level in the whole territory, since 131I, 134Cs and 137Cs were detected in most of the analysed samples collected right after the Chernobyl accident (May 1986). Soil samples were analysed by direct counting by gamma-ray spectrometry. In addition, terrestrial gamma-ray dose rates in air have been measured out of doors throughout Algeria. In each of the 48 administrative divisions of the country selected sites were chosen to collect soil samples and measure gamma-ray dose rates. The gamma-emitting radionuclides resulting from the radioactive decay of 238U and 232Th, 40K and 137Cs were detected in most of the analysed samples. Radioactivity concentrations in Bq kg-1 dry mass in soil samples of 226Ra, 214Pb, 214Bi, 212Pb, 228Ac, 40K and 137Cs range between (5-176), (2-107), (3-65), (2-97), (3-144), (36-1405) and (0.3-41) respectively. In addition, six selected soil samples were analysed to determine plutonium isotopes contents. Radioactivity concentrations in Bq kg-1 dry mass of 238Pu and 239 + 240Pu vary between (0.012-0.013) and (0.24-0.61) respectively. The dose rates in air measured over the whole country were found to range between 20 and 133 nGy h-1. Presence of 137Cs has been clearly observed. An approach has been made to determine its origin, considering the global fallout, the Chernobyl accident and the French nuclear bomb tests in the 60s as the main potential sources. It is concluded that Algeria has indeed been affected by the Chernobyl accident. PMID:9570102

Baggoura, B; Noureddine, A; Benkrid, M

1998-07-01

16

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)

17

Studies of induced radioactivity at the AGS  

International Nuclear Information System (INIS)

With the goals of higher proton intensities, along with the many modes the AGS now runs and those being commissioned to run, we have begun detailed studies of the beam induced radioactivity in the AGS

18

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)

19

Natural and induced radioactivity in food  

International Nuclear Information System (INIS)

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

20

Multiprotocol-induced plasticity in artificial synapses  

Science.gov (United States)

We suggest a `universal' electrical circuit for the realization of an artificial synapse that exhibits long-term plasticity induced by different protocols. The long-term plasticity of the artificial synapse is basically attributed to the nonvolatile resistance change of the bipolar resistive switch in the circuit. The synaptic behaviour realized by the circuit is termed `universal' inasmuch as (i) the shape of the action potential is not required to vary so as to implement different plasticity-induction behaviours, activity-dependent plasticity (ADP) and spike-timing-dependent plasticity (STDP), (ii) the behaviours satisfy several essential features of a biological chemical synapse including firing-rate and spike-timing encoding and unidirectional synaptic transmission, and (iii) both excitatory and inhibitory synapses can be realized using the same circuit but different diode polarity in the circuit. The feasibility of the suggested circuit as an artificial synapse is demonstrated by conducting circuit calculations and the calculation results are introduced in comparison with biological chemical synapses.We suggest a `universal' electrical circuit for the realization of an artificial synapse that exhibits long-term plasticity induced by different protocols. The long-term plasticity of the artificial synapse is basically attributed to the nonvolatile resistance change of the bipolar resistive switch in the circuit. The synaptic behaviour realized by the circuit is termed `universal' inasmuch as (i) the shape of the action potential is not required to vary so as to implement different plasticity-induction behaviours, activity-dependent plasticity (ADP) and spike-timing-dependent plasticity (STDP), (ii) the behaviours satisfy several essential features of a biological chemical synapse including firing-rate and spike-timing encoding and unidirectional synaptic transmission, and (iii) both excitatory and inhibitory synapses can be realized using the same circuit but different diode polarity in the circuit. The feasibility of the suggested circuit as an artificial synapse is demonstrated by conducting circuit calculations and the calculation results are introduced in comparison with biological chemical synapses. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03405h

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

2014-11-01

 
 
 
 
21

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

22

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)

23

Linear accelerator therapeutic dose - induced radioactivity dependence  

International Nuclear Information System (INIS)

Full text: Radiotherapy with the use of linear medical accelerators is widely applied method in oncological treatment. Patient's irradiation is carried out with the use of primary electron as well as secondary X-ray radiation, particularly high - energy beams above 10 MeV. From physical point of view probability of nuclear reactions during emission of these beams could not be neglected. This means that therapeutic beams induce additional radioactivity and contribute to neutron flux production (via photo- and electronuclear reactions (?,n) and (e,e'n) respectively), which occur mainly in accelerator head. Those effects generally are undesired in this kind of treatment. Neutron capture reaction contributes to induced activity too. Although therapeutic beam interactions are limited to irradiation field, neutron flux is significant over the whole therapeutic room. Therefore induced activity occurs also outside the accelerator beam. The distance from isocentre larger, the contribution of photonuclear reactions is smaller and simple capture reactions become dominant, as neutrons are reaching resonance and thermal energies (cross sections of (n,?) reactions are larger for slow neutrons than for fast ones). All objects inside therapeutic room may emit gamma radiation as a result of inducing radioactivity, including patient's body. In this paper we discuss the dependence between therapeutic dose and activity induced in mammal bones. This activity leads to gamma ray emission is activity leads to gamma ray emission registered by the high purity germanium detector as well as the scintillation probe. Results of investigations presented here are focused on activation effects which occur during emission of 15 MV and 20 MV therapeutic X-ray beams. The purpose is to describe how therapeutic conditions (the dose and time of irradiation) influence induced radioactivity. Preliminary studies of time scale of studied phenomenon (decay rate, calculation of half - life and identification of main isotopes involved in this dynamic process) is given. Correlation between therapeutic dose and activity inside the patient's body induced during high - energy beam irradiation could be useful for in vivo dose dosimetry

24

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)

25

Radioactivity induced in gamma-ray spectrometers  

Science.gov (United States)

A review is given of the data and methods used in the prediction of radioactivity induced in spaceborne gamma-ray spectrometers by the space radiation environment. The large masses of current and future detectors requires the application of particle transport codes and results from such codes are presented for scintillator detectors. Calculations and irradiation data are also presented for germanium and bismuth germanate and future requirements are outlined.

Dyer, C. S.; Truscott, P. R.; Hammond, N. D. A.; Comber, C.

1989-05-01

26

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

27

Dating of artificial radioactivity in sediments of the river Yenisei  

International Nuclear Information System (INIS)

For many years the Mining and Chemical Combine was producing weapon-grade plutonium in three nuclear plants on the banks of the river Yenisei south of the city Krasnoyarsk, Siberia. Artificial radionuclides were found in sediments of the river in close distance to the plants as well as over the whole length of the river up to the icy Kara-Sea. In order to reconstruct the discharge into the river and to understand migration processes dating of the activity in undisturbed sediment cores had to be done. Due to vertical advection of water through the sediments the age of sediment layers and the age of the activity therein have to be distinguished. The following methods of dating have been analyzed: The Pb-210 gamma-spectrometric method which showed to be not applicable, the Eu-152/Eu-154 ratio, the Po-210 alpha-spectrometric method, and modelling of the vertical distribution of activity in the sediment. Furthermore, ICP-MS analyses of Np, Am and Pu isotopes have been used to perform dating analyses. The results of the different methods are compared in order to ensure a proper understanding of the history of the activity and of the processes within the sediment. (author)

28

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

International Nuclear Information System (INIS)

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

29

Estimation of absorbed gamma dose in air due to natural and artificial radioactivity of soil  

International Nuclear Information System (INIS)

This Ph. D. thesis is devoted to the measurements of air absorbed gamma doses due to natural and artificial radioactivity in soil. It contains four chapters, conclusions, acknowledge, and a reference list. The first chapter presents problems related to the measurement of natural and artificial radioactivity coming from soil contamination due to nuclear explosions or nuclear accidents. The natural and artificial radionuclides which usually contaminate the soil are reviewed. The chapter two presents the original contribution of the author in the field of the methods of soil sampling and NaI(Tl) gamma spectrometry analysis of radioactive samples. Also the results of the measurements carried out in 10 counties in Romania are here reported. The natural radionuclides measured were Ra-226, Th-232, and K-40, while the artificial radionuclides were Cs-137 and Cs-134. In the third chapter the radioactivity levels are reported as absorbed air gamma doses due to presence of 137 Cs and 134 Cs in soil. Also here the effective dose equivalents estimated for the population of the 10 counties are presented. In the chapter four a discussion is given concerning the dose levels measured following the Chernobyl nuclear accident as function of time elapsed from the accident and of depth of soil sampling and of soil type. It is shown that the dose levels which affected the population in the studied zones are within the values of radioprotection standards in Romania. Thf radioprotection standards in Romania. These data were used as input to solve the problem of the biological effects of low doses on the population health. (M.I.C.). 42 Figs., 54+15 Tabs., 216 Refs, 1 App

30

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 applicat...

Kharissova, Oxana V.; Me?ndez-rojas, Miguel A.; Kharisov, Boris I.; Ubaldo Ortiz Méndez; Perla Elizondo Martínez

2014-01-01

31

Artificial intelligence methods applied for quantitative analysis of natural radioactive sources  

International Nuclear Information System (INIS)

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

32

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

International Nuclear Information System (INIS)

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

33

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

34

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

International Nuclear Information System (INIS)

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

35

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)

36

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)

37

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

International Nuclear Information System (INIS)

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

38

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

Science.gov (United States)

Environmental biomonitoring has demonstrated that organisms such as crustaceans, fish and mushrooms are useful to evaluate and monitor both ecosystem contamination and quality. Particularly, some mushroom species have a high capacity to retain radionuclides and some toxic elements from the soil and the air. The potential of mushrooms to accumulate radionuclides in their fruit-bodies has been well documented. However, there are no studies that determine natural and artificial radionuclide composition in edible mushrooms, in Brazil. Artificial ((137)Cs) and natural radioactivity ((40)K, (22)(6)Ra, (2)(28)Ra) were determined in 17 mushroom samples from 3 commercialized edible mushroom species. The edible mushrooms collected were Agaricus sp., Pleurotus sp. and Lentinula sp. species. The activity measurements were carried out by gamma spectrometry. The levels of (137)Cs varied from 1.45 ± 0.04 to 10.6 ± 0.3 Bq kg(-1), (40)K levels varied from 461 ± 2 to 1535 ± 10 Bq kg(-1), (2)(26)Ra levels varied from 14 ± 3 to 66 ± 12 Bq kg(-1) and (228)Ra levels varied from 6.2 ± 0.2 to 54.2 ± 1.7 Bq kg(-1). (137)Cs levels in Brazilian mushrooms are in accordance with the radioactive fallout in the Southern Hemisphere. The artificial and natural activities determined in this study were found to be below the maximum permissible levels as established by national legislation. Thus, these mushroom species can be normally consumed by the population without any apparent risks to human health. PMID:22765964

de Castro, L P; Maihara, V A; Silva, P S C; Figueira, R C L

2012-11-01

39

Artificial magnetic field induced by an evanescent wave.  

Science.gov (United States)

Cold atomic gases are perfect laboratories for realization of quantum simulators. In order to simulate solid state systems in the presence of magnetic fields special effort has to be made because atoms are charge neutral. There are different methods for realization of artificial magnetic fields, that is the creation of specific conditions so that the motion of neutral particles mimics the dynamics of charged particles in an effective magnetic field. Here, we consider adiabatic motion of atoms in the presence of an evanescent wave. Theoretical description of the adiabatic motion involves artificial vector and scalar potentials related to the Berry phases. Due to the large gradient of the evanescent field amplitude, the potentials can be strong enough to induce measurable effects in cold atomic gases. We show that the resulting artificial magnetic field is able to induce vortices in a Bose-Einstein condensate trapped close to a surface of a prism where the evanescent wave is created. We also analyze motion of an atomic cloud released from a magneto-optical trap that falls down on the surface of the prism. The artificial magnetic field is able to reflect falling atoms that can be observed experimentally. PMID:25567430

Mochol, Ma?gorzata; Sacha, Krzysztof

2015-01-01

40

Determination of natural and artificial radioactivity in soil at North Lebanon province  

International Nuclear Information System (INIS)

The concentrations of natural and artificial radionuclides at 57 sampling locations along the North Province of Lebanon are reported. The samples were collected from uncultivated areas in a region not previously reported. The samples were analyzed by gamma spectrometers with High Purity Germanium detectors of 30% and 40% relative efficiency. The activity concentrations of primordial naturally occurring radionuclides of 238U, 232Th, and 40K varied between 4–73 Bq kg?1, 5–50 Bq kg?1, and 57–554 Bq kg?1 respectively. The surface activity concentrations due to the presence of these radionuclides were calculated and Kriging-geostatistical method was used to plot the obtained data on the Lebanese radioactive map. The results for 238U, 232Th, and 40K ranged from 0.2 kBq m?2 to 9 kBq m?2, from 0.2 kBq m?2 to 3 kBq m?2, and from 3 kBq m?2 to 29 kBq m?2 respectively. For the anthropogenic radionuclides, the activity concentrations of 137Cs founded in soil ranged from 2 Bq kg?1 to 113 Bq kg?1, and the surface activity concentration from 0.1 kBq m?2 to 5 kBq m?2. The total absorbed gamma dose rates in air from natural and artificial radionuclides in these locations were calculated. The minimum value was 6 nGy h?1 and the highest one was 135 nGy h?1 with an average of 55 nGy h?1 in which the natural terrestrial radiation contributes in 99% and the artificial radionuclides mainly 137Cs contributes only in 1%. The total effective dose calculated varied in the range of 7 ?Sv y?1 and 166 ?Sv y?1 while the average value was 69 ?Sv y?1 which is below the permissible limit 1000 ?Sv y?1

 
 
 
 
41

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

42

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)

43

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

44

Avalanches and disorder-induced criticality in artificial spin ices  

Science.gov (United States)

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

Chern, Gia-Wei; Reichhardt, C.; Olson Reichhardt, C. J.

2014-06-01

45

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

46

Radioactive implant induced X-ray emission  

Science.gov (United States)

Two approaches with X-ray excitation sources directly inside a sample have been examined: mixing a sample in solution with a radioisotope or bombardment of a solid specimen with a radioactive ion beam. The radioisotopes used weere 3H, 35S, 125I, with detection limits of, for example, 20 ?g/g for Ag excited by a 125I implant of ˜75 kBq; 100 ?g/g for Ti excited by a 3H implant of ˜7 MBq. For comparable detection limits, the source strengths required are ˜10 3 less than that needed with external sources. The elemental coverage and the capabilities for simultaneous multielement detection are similar to "conventional" XES. In the beam implant mode, the spot size and energy of the beam provide for spatially resolved in situ X-ray excitation at a desired location inside a solid.

Joyce, J. R.; Sanni, A. O.; Schweikert, E. A.

47

Radioactive implant induced X-ray emission  

International Nuclear Information System (INIS)

Two approaches with X-ray excitation sources directly inside a sample have been examined: mixing a sample in solution with a radioisotope or bombardment of a solid specimen with a radioactive ion beam. The radioisotopes used were 3H, 35S, 125I, with detections limits of, for example, 20 ?g/g for Ag excited by a 125I implant of approx. equal to 75 kBq; 100 ?g/g for Ti excited by a 3H implant of approx. equal to 7 MBq. For comparable detection limits, the source strengths required are approx. equal to 103 less than that needed with external sources. The elemtal coverage and the capabilities for simultaneous multielement detection are similar to 'conventional' XES. In the beam implant mode, the spot size and energy of the beam provide for spatially resolved in situ X-ray excitation at a desired location inside a solid. (orig.)

48

Linear accelerator therapeutic dose-induced radioactivity dependence  

International Nuclear Information System (INIS)

Dependence between therapeutic dose and activity induced in mammal bones is discussed. This activity leads to gamma ray emission registered by HPGe detector and scintillation probe. Presented results are focused on activation which occurs during emission of 15 and 20 MV photon beams. The purpose is to describe how therapeutic conditions (dose, time of irradiation) influence the induced radioactivity. Preliminary studies of decay rate, calculation of half-life and identification of isotopes involved in this dynamic process are given.

49

Applicability of artificial intelligence to reservoir induced earthquakes  

Science.gov (United States)

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

Samui, Pijush; Kim, Dookie

2014-06-01

50

studies on the fixation of chemical and radioactive contaminants by natural and artificial compounds  

International Nuclear Information System (INIS)

the main objective of the work presented in this is to study the adsorption of U(VI), Cr(VI) and Gd (lll) from aqueous medium using modified sorel's cement as artificial adsorbents. the thesis is classified into three chapters; namely ,introduction ,experimental and results and discussion. the first chapter,introduction,includes chemical and radioactive contaminant, some aspects of the properties and aqueous chemistry of uranium, chromium and gadolinium . the separation of different pollutant and their methods of separation based on the types of adsorbents, and the theoretical background of adsorption isotherms, kinetics and ion diffusion as well as literature survey which is related to the present work are given.the second chapter, experimental,contains the different materials employed, their chemical purity, and a detailed description for instruments used are given.the third chapter.results and discussionincludes the experimental results obtained and their interpretation .this chapter is classified into three main parts; namely, characterization, equilibrium and kinetic investigations

51

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.)

52

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

International Nuclear Information System (INIS)

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

53

Studying the induced radioactivity of a varian clinac 2100C/D accelerator  

International Nuclear Information System (INIS)

Objective: To Study the influences of dose, time, distance and irradiation mode on induced radioactivity by measuring a Varian Clinac 2100C/D accelerator. Methods: The induced radioactivity was measured in different dose, time, distance and irradiation mode by using of 450P model dosemeter. The results was analysed. Results: The induced radioactivity is direct ratio with dose, inverse ratio with time and distance. In different irradiation mode, the induced radioactivity is different. Conclusion: The induced radioactivity level of accelerator is related with dose, time, distance and irradiation mode. (authors)

54

Artificial radioactivity in environmental media (air, rainwater, soil, vegetation) in Austria after the Fukushima nuclear accident.  

Science.gov (United States)

Several environmental media in Austria were monitored for artificial radionuclides released during the Fukushima nuclear accident. Air (up to 1.2 mBq/m(3) particulate (131)I) and rainwater (up to 5.2 Bq/L (131)I) proved to be the media best suited for the environmental monitoring, allowing also a temporal resolution of the activity levels. Significant regional differences in the wet deposition of (131)I with rain could be observed within the city of Vienna during the arrival of the contaminated air masses. Forward-trajectory analysis supported the hypothesis that the contaminated air masses coming from the northwest changed direction to northeast over Northern Austria, leading to a strong activity concentration gradient over Vienna. In the course of the environmental monitoring of the Fukushima releases, this phenomenon-significant differences of (131)I activity concentrations in rainwater on a narrow local scale (8.1 km)-appears to be unique. Vegetation (grass) was contaminated with (131)I and/or (137)Cs at a low level. Soil (up to 22 Bq/kg (137)Cs) was only affected by previous releases (nuclear weapon tests, Chernobyl). Here, also significant local differences can be observed due to different deposition rates during the Chernobyl accident. The effective ecological half-lives of (137)Cs in soil were calculated for four locations in Austria. They range from 7 to 30 years. No Austrian sample investigated herein exceeded the detection limit for (134)Cs; hence, the Fukushima nuclear accident did not contribute significantly to the total radiocesium inventory in Austrian environmental media. The levels of detected radioactivity were of no concern for public health. PMID:22961486

Steinhauser, Georg; Merz, Stefan; Hainz, Dieter; Sterba, Johannes H

2013-04-01

55

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

2002-08-01

56

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)

57

Radioactive targets for neutron-induced cross section measurements  

Energy Technology Data Exchange (ETDEWEB)

Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high detection efficiency of DANCE, combined with the high TOF-neutron flux available at the Lujan Center provides a versatile tool for measuring many important cross section data using radioactive and isotopically enriched targets of about 1 milligram. Another powerful instrument is the Lead-slowing down spectrometer (LSDS), which will enable the measurement of neutron-induced fission cross-section of U-235m and other short-lived actinides in a energy range from 1-200 keV with sample sizes down to 10 nanograms. Due to the short half-life of the U-235m isomer (T{sub 1/2} = 26 minutes), the samples must be rapidly and repeatedly extracted from its {sup 239}Pu parent. Since {sup 239}Pu is itself highly fissile, the separation must not only be rapid, but must also be of very high purity (the Pu must be removed from the U with a decontamination factor >10{sup 12}). Once extracted and purified, the {sup 235m}U isomer would be electrodeposited on solar cells as a fission detector and placed within the LSDS for direct (n,f) cross section measurements. The production of radioactive targets of a few milligrams will be described as well as the containment for safe handling of these targets at the Lujan Center at LANSCE. To avoid any contamination, the targets are electrochemically fixed onto thin Ti foils and two foils are placed back to back to contain the radioactive material within. This target sandwich is placed in a cylinder made of aluminum with thin translucent windows made of Kapton. Actinides targets, such as {sup 234,235,236,238}U, {sup 237}Np, and {sup 239}Pu are prepared by electrodeposition or molecular plating techniques. Target thicknesses of 1-2 mg/cm{sup 2} with sizes of 1 cm{sup 2} or more have been made. Other targets will be fabricated from separation of irradiated isotopically enriched targets, such as {sup 155}Eu from {sup 154}Sm,{sup 171}Tm from {sup 170}Er, and {sup 147}Pm from {sup 146}Nd, which has been irradiated in the high flux reactor at ILL, Grenoble. A radioactive sample isotope separator (RSIS) is in the process of being commissioned for the preparation of other radioactive targets. A brief summary of these experiments and the radioactive target preparation technique will be given.

Kronenberg, A. (Andreas); Bond, E. M. (Evelyn M.); Glover, S. E. (Samuel E.); Rundberg, R. S. (Robert S.); Vieira, D. J. (David J.); Esch, E. I. (Ernst-Ingo); Reifarth, R. (Rene); Ullmann, J. L. (John L.); Haight, Robert C.; Rochmann, D. (Dimitri)

2004-01-01

58

Orofacial tumours induced in rats with radioactive cerium chloride  

International Nuclear Information System (INIS)

Fifty nine 6 week-old Sprague Dawley male rats were inoculated near the left angle of the mandibular bone with radioactive colloidal cerium. Fifty three rats presented orofacial tumours: forty-two single tumours and 11 double tumours. The survival time of animals with tumours ranged between 262 to 501 days after inoculation of cerium. Six rats died without tumours. Squamous cell carcinomas (SCC) and bone and soft tissue (BSTS) sarcomas were the predominant histological types (respectively 42 SCC and 14 (BSTS). Other types of tumours were also observed: 3 salivary adenocarcinomas, 3 tumours with double differrentiation, one ganglioneuroblastoma and one odontosarcoma. Double tumours were found in rats which had a significantly greater mean survival time, suggesting that the probability of double tumours increases with time. No correlation was found between the mean initial radioactivity and histological type of tumours, mean survival time, locoregional extension or presence of metastases. In general, the low incidence of metastases (17.3%) contrasted with a large locoregional extension. Only one out of five osteosarcomas of the mandible presented lung metastases, a low rate when compared to osteogenic osteosarcomas of the leg induced in rats by radioactive cerium (60-80% of metastases). The mean labelling index determined by autoradiographic study one hour after injection of 5.5 ?/g of tritiated thymidine was 23.7% +- 6.4% and 27.8% +- 6.8% respectively, for SCC and BS7.8% +- 6.8% respectively, for SCC and BSTS). These radio-induced tumours may constitute an interesting experimental model for human orofacial tumours

59

Induced radioactivity of the IHEP proton synchrotron beam extraction equipment  

International Nuclear Information System (INIS)

The measurement results of induced radioactivity of the beam extraction equipment during 1972-1978 are presented. All the values are given to the moment of the accelerator stop. The experimental data permits to predict further possible variations of the induced radioactivity levels of the equipment. Given are the measures required for reduction of the accelerator equipment irradiation, which are the following: 1) compensation of residual distortion of a closed beam orbit in the course of the induction system operation; 2) limitation of the intensity of drop on the internal targets up to the 11 protons per target level over a cycle; 3) putting into operation the program control system for the duration of a current pulse of a linear accelerator to minimize the beam residues at the 70 GeV energy during physical experiments; 4) construction of the system of beam interception and cutting-off to ensure effective energy suppression of uncontrolled beam residues and localization of their radiation effect; 5) extraction of a high-energy beam out of the accelerator during the experiments (e.g., into the neutrino channel for apparatus adjusting) instead of its dropping on the interceptor-target; 6) beam orbit controlling in the case of multiturn injection into the accelerator

60

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)

 
 
 
 
61

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

62

Using radioactivity  

International Nuclear Information System (INIS)

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

63

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

International Nuclear Information System (INIS)

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

64

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)

65

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

International Nuclear Information System (INIS)

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

66

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)

67

Very low levels of artificial radioactivity in the environment in 2009  

International Nuclear Information System (INIS)

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.)

68

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

International Nuclear Information System (INIS)

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

69

Anthrax toxin-induced rupture of artificial lipid bilayer membranes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

2013-01-01

70

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

71

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

Science.gov (United States)

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

Faghihi, R; Mehdizadeh, S; Sina, S

2011-04-01

72

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)

73

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.)

74

Radioactivity  

International Nuclear Information System (INIS)

In this chapter the phenomenon of radioactivity is explained. The various decay modes, rate and time of decay, the unit system - old and new, non-natural and produced radionuclides and daughter products are discussed. (G.H.)

75

Radioactivity  

International Nuclear Information System (INIS)

Tables are presented of trends in annual emissions of radioactive gaseous effluents at sites of civil establishments in the U.K. Trends in the discharge to surface and coastal water sites in the U.K. and trends in the radioactivity of solid wastes dumped in the N.E. Atlantic and in the volume and activity level of wastes disposed at sites in the U.K. are presented. Tables of radioactivity in samples of fish and shellfish at selected sites are presented. Radioactivity from global fallout and the annual mean ratio of 90Sr to calcium, and concentrations of 137Cs in milk are given. Trends in estimated collective doses from the consumption of fish and shellfish in the U.K. and Europe are presented. (U.K.)

76

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

International Nuclear Information System (INIS)

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

77

Artificial magnetic field induced by an evanescent wave  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cold atomic gases are perfect laboratories for realization of quantum simulators. In order to simulate solid state systems in the presence of magnetic fields special effort has to be made because atoms are charge neutral. There are different methods for realization of artificial magnetic fields, that is the creation of specific conditions so that the motion of neutral particles mimics the dynamics of charged particles in an effective magnetic field. Here, we consider adiabat...

Mochol, Malgorzata; Sacha, Krzysztof

2013-01-01

78

Measurement of neutron-induced 152Eu radioactivity in Nagasaki  

International Nuclear Information System (INIS)

Induced radioactivity from neutrons released at the time of the bomb (ATB) still remains near the hypocenter in Hiroshima and Nagasaki. Data useful for estimating neutron fluence and air tissue kerma of neutrons ATB will be obtained by measuring 152Eu remaining in rocks of river embankments near the hypocenter. Samples were collected from stone embankments on both sides of rivers within a radius of 1000 m from the hypocenter in Hiroshima and Nagasaki. The samples were collected from 13 sites in Hiroshima and 76 sites in Nagasaki and were mainly from depths to 10 mm from the surface; however, some samples were collected from depths of 300-465 mm to check the neutron energy. Each sample was dried, pulverized, and placed in a plastic container, and the gamma ray spectrum was analyzed using a Ge(Li) semiconductor detector. As the level of 152Eu produced in rocks is dependent on the Eu content, its content was quantitated by the activation analysis method using the nuclear reactor at Kyoto University. Since the value of the Eu content of the rocks had a relatively wide variation, measurements were conducted on all samples. The spatial distribution, which showed the relation between the value of 152Eu activity on the surface of the rocks and the slant distance, was obtained and the relaxation length was calculated. The depth distribution of 152Eu activity in rocks was obtained for three different cases located at the hypocenter. (fferent cases located at the hypocenter. (author)

79

Host treatments affecting artificial pulmonary metastases; interpretation of loss of radioactivity labelled cells from lungs  

International Nuclear Information System (INIS)

The effect was examined of various host treatments (Corynebacterium parvum injection, immunization, thoracic irradiation, cyclophosphamide injection and anticoagulation) on both lung colony formation and lung clearance of radioactive cells after i.v. injection of tumour cells. The non-immunogenic KHT tumour in C3H/Km mice, and the immunogenic EMT6 tumour in BALB/c/Ka mice were used. For all pretreatments except immunization, the curve loss of radioactivity from the lungs had an initial steep portion representing intravascular death of the tumour cells, followed 1-2 days after tumour-cell injection by a shallow exponential curve which likely represented spontaneous death of tumour cells in the perivascular tissues. Essentially all the injected tumour cells lodged initially in the lungs, and this was unaffected by the different host treatments. Except for specific immunization, cell death in the perivascular tissues was also unaffected by host treatment. However, the survival of the tumour cells during the 24 h after injection was extremely dependent on the particular host pretreatment. The results indicated that host treatments such as C. parvum injection or anticoagulation can markedly affect the number of blood-borne pulmonary metastases, but are only effective if given before the tumour cells arrive in the lung vasculature. (author)

80

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

International Nuclear Information System (INIS)

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

 
 
 
 
81

Radioactivity  

International Nuclear Information System (INIS)

Over 75% of the annual radiation dose received by the average person in the UK comes from natural radioactivity and about 20% is due to medical irradiation. Other radioactive sources which amount to about 0.1% of the total dose are discussed. These include 1) world-wide fallout from weapon testing with data on the annual mean ratios of strontium-90 to calcium and concentrations of caesium-137 in milk since 1958; 2) atmospheric discharges of low level radioactive waste with data on the annual mean concentrations of strontium-90 and caesium-137 in milk from farms near Sellafield, Harwell, Winfrith and Dounreay since 1972; and 3) liquid discharges of low level radioactive waste with data on the principal exposure pathways and trends in estimates of public radiation exposure since 1975 for various discharge sites belonging to BNFL, UKAEA, CEGB AND SSEB. Reference is also made to additional tables of data on radioactive emissions, concentrations and exposure in the UK which are available from the Dept. of the Environment. (U.K.)

82

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

International Nuclear Information System (INIS)

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

83

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

84

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

85

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

International Nuclear Information System (INIS)

This paper presents results on the concentration of 137Cs, 90Sr, 3H in water samples from 5 locations in NW Black Sea collected in 1999. In sediment samples, 137Cs, and Pu were determined as well as some major and minor elements by X-ray fluorescence. For the surface water samples, 137Cs concentration varied between (26.3 ± 3.4) mBq/l and (41.2 ± 5.6) mBq/l. The concentration of 90Sr was of about 11 mBq/l. The concentration of tritium was low between 24 and 7 T.U. Higher radioactive concentrations in sediment were found in the samples collected from the stations located close to Danube river. For 137Cs values up to (128 ± 6) Bq/kg were found, in agreement to results for NW Black Sea in previous years. The measured concentrations of 239+240Pu, 238Pu radioisotopes are within the range of the values reported in earlier research for the Western Black Sea and Bulgarian Black Sea Coast. (author)

86

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

International Nuclear Information System (INIS)

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

87

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

International Nuclear Information System (INIS)

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

88

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

89

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 xto 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.

90

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

91

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

92

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

93

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

94

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.)

95

Radioactivity  

International Nuclear Information System (INIS)

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

96

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

International Nuclear Information System (INIS)

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

97

Radioactivity and radiation protection  

International Nuclear Information System (INIS)

The volume covers the following issues: chemical elements and their smallest particles; nuclear reactions and radioactivity; energy of radiation particles and gamma quanta; interactions between radiation and matter; radiation measurement and measuring units; radiation effects on living cells; radionuclides in the human body; natural radiation sources - natural radiation exposure; artificial radiation sources - civilization-induced radiation exposure; radiation protection measures against external radiation effects; radiation protection measures against internal radiation effects; radiation protection for persons within a nuclear power plant.

98

Inhibition of artificially induced cough in man by bronchodilators.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

1. The antitussive properties of bronchodilators were evaluated in a total of 47 normal volunteers. 2. Cough was induced by inhalation of ultrasonically nebulized solutions of distilled water and hypotonic saline. 3. Inhaled fenoterol hydrobromide (360 micrograms; 20 volunteers) and inhaled ipratropium bromide (72 micrograms; 14 volunteers) both significantly reduced couch compared with placebo (P less than 0.01). Oral salbutamol sulphate (4 mg; 11 volunteers) and oral pirenzepine hydrochlori...

Lowry, R.; Higenbottam, T.; Johnson, T.; Godden, D.

1987-01-01

99

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)

100

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Lee, S.; Evangelista, D. G.

2006-01-01

 
 
 
 
101

Artificial UV-B induced changes in pigmentation of marine diatom Coscinodiscus gigas.  

Science.gov (United States)

In vitro studies in marine diatom Coscinodiscus gigas revealed that artificial UV-B radiation (313 nm) at a dose level of 0.4W m(-2) for a continuous period of 3 hours in a UV treatment chamber caused disbursement of chromatophores from their normal loci and resulted in clumping / aggregation of chromatophores exhibiting a phenomenon called UV-B induced syntrophism. It is also understood that such clumping could cause only insignificant reduction in photosynthetic oxygen release. PMID:17915774

Yogamoorthi, A

2007-04-01

102

Inducing ovulation and artificial insemination in the European brown hare (Lepus europaeus Pallas, 1778).  

Science.gov (United States)

The aim of the study was to show whether it is possible to induce ovulation in the hare by GnRH analogue administration and to carry out an effective artificial insemination (AI). The research was carried out during the breeding and non-breeding season. During the breeding season, plasma progesterone concentrations increased on the 4th day after intramuscular injection of GnRH analogue (buserelin), indicating induced ovulation and corpus luteum development. Prostaglandin F(2)alpha (dinoprost) was an effective luteolytic agent on day 9. During the non-breeding season, the GnRH analogue injection does not cause an increase of progesterone. The 17beta-estradiol concentrations during the breeding and non-breeding season were similar. It was shown that after GnRH analogue administration and artificial insemination with semen diluted in Tris buffer extender 80% females delivered live young (39-43 days after artificial insemination), which proves the effectiveness of inducing ovulation in the hare by means of hormonal stimulation. PMID:18555621

Kozdrowski, Roland; Siemieniuch, Marta

2009-06-01

103

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

104

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

International Nuclear Information System (INIS)

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

105

Effect of etching on the laser-induced damage properties of artificial defects under 1064-nm laser irradiation  

Science.gov (United States)

The cracks and scratches inevitably generated by previous grinding and polishing significantly lower the ability of laser resistance of optical substrates. In this study, the artificial indentations, scratches, and structural defects imbedded with metal nanoparticles are fabricated. The laser-induced damage characteristics of such defects in different types and sizes are investigated qualitatively and quantitatively under 1064-nm laser irradiation. Moreover, the etching effect on improving the laser-induced damage threshold (LIDT) of artificial defects under different etching conditions is analyzed. LIDT is then evaluated according to the etching depth and the morphologies of artificial defects.

Lu, Menglei; Ma, Bin; Zhan, Guangda; Jiao, Hongfei; Cheng, Xinbin

2014-12-01

106

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)

107

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

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

Nachtrodt, Frederik

2013-01-01

108

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

International Nuclear Information System (INIS)

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

109

Minimizing abdominal wall damage during high-intensity focused ultrasound ablation by inducing artificial ascites.  

Science.gov (United States)

High-intensity focused ultrasound (HIFU) is becoming an important tool for tumor treatment [especially hepatocellular carcinoma (HCC)] in Asian countries. A HIFU system provides unique advantages of low invasiveness and absence of nonradiation. However, if the target HCC is close to the proximal surface of the liver, HIFU may overheat diaphragm, abdominal wall or skin. To avoid this complication, a method using artificial ascites in the abdominal cavity to separate the liver from the peritoneum, and to serve as a heat sink to cool overlying structures and thereby avoid inducing permanent damage was proposed. Target tissue that was 10 mm below the liver surface was ablated in 12 New Zealand white rabbits: 6 in the experimental group and 6 in the control group. Artificial ascites was established in the experimental group by injecting normal saline into the abdominal cavity until the pressure reached 150 mm H2O. Artificial ascites not only reduced the probability and extent of thermal damage to intervening structures, but also had no adverse affect on the efficacy of HIFU ablation. PMID:18647009

Wu, Chih-Ching; Chen, Wen-Shiang; Ho, Ming-Chih; Huang, Kai-Wen; Chen, Chiung-Nien; Yen, Jia-Yush; Lee, Po-Huang

2008-07-01

110

Five new eudesmane-type sesquiterpenoids from Chinese agarwood induced by artificial holing.  

Science.gov (United States)

Five new eudesmane-type sesquiterpenoids (1-5), along with six known ones (6-11), were isolated from Chinese agarwood induced by artificial holing originating from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae). The structures of the new sesquiterpenoids were established by spectroscopic methods including UV, IR, MS, 1D, and 2D NMR. Compounds 1, 3, 6 and 7 exhibited antibacterial activities against both Staphylococcus aureus and Ralstonia solanacearum, and compound 5 only showed an inhibitory activity towards S. aureus. Compounds 1, 6, 7 and 10 showed weak acetylcholinesterase inhibitory activity. PMID:25447164

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

2015-01-01

111

Induced radioactivity in tissues caused by high energy protons  

International Nuclear Information System (INIS)

Theoretical and experimental investigations were performed to study the induced activity in biological objects with the identification of nuclides, the definition of their contribution to the absorbed dose and of the levels of internal and external irradiation from activation of ?- and ?-radiation with the local effect of a proton beam at 1000 MeV. Research was conducted using a medical proton beam at 100 MeV on the synchrocyclotron at the Institute of Nuclear Physics, Academy of Sciences of the USSR, Leningrad. Contribution of induced activity does not exceed 0.1 % of the absorbed dose of proton radiation. The level of external irradiation from the fission of ?-active nuclides in the tissue should be taken into account by the staff who are brought into direct contact with an irradiated biological object in the first 30 min after the accelerator is switched off. Eye protection should be specially envisaged

112

Radioactive contamination screening with laser-induced fluorescence  

Energy Technology Data Exchange (ETDEWEB)

The ability to induce, detect and discriminate fluorescence of uranium oxides makes available new capabilities for screening the surface of large complex facilities for uranium. This paper will present the results of field tests evaluate laser-induced fluorescence (LIF) as a contamination screening tool and report on the progress to produce a field portable instrument for uranium surveys on exposed surfaces. The principal effect is to illuminate the surface of an object or an area with a remotely-located light source, and to evaluate the re-radiated emission energy. A gated intensified CCD camera was used with ultraviolet (UV) laser excitation to discriminate the phosphorescent (persistent) green uranium emission from the prompt background fluorescence which results from excitation of plants, concrete, soils, and other background materials.

Sheely, R. [Oak Ridge K-25 Site, TN (United States); Di Benedetto, J. [EG and G Energy Measurements, Inc., Goleta, CA (United States). Santa Barbara Operations

1994-06-01

113

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.)

114

Nuclear reactions and subsequent radioactive decays 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 isotopes available in nature, including the following: 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, radioactivity induced by irradiation of a neutron flux of 1x1015 n/cm2 sec for 4 months, and reference for the cross section. The mass number dependences of (n,2n), (n,p) and (n,?) reaction cross sections by 14-MeV neutrons are given in figures to show general trends of the cross sections. (auth.)

115

Time and energy resolved runaway measurements in TFR from induced radioactivity  

International Nuclear Information System (INIS)

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

116

De novo generation of satellite DNA-based artificial chromosomes by induced large-scale amplification.  

Science.gov (United States)

Mammalian artificial chromosomes (MACs) are engineered chromosomes with defined genetic content that can function as non-integrating vectors with large carrying capacity and stability. The large carrying capacity allows the engineering of MACs with multiple copies of the same transgene, gene complexes, and to include regulatory elements necessary for the regulated expression of transgene(s). In recent years, different approaches have been explored to generate MACs (Vos Curr Opin Genet Dev 8:351-359, 1998; Danielle et al. Trends Biotech 23:573-583, 2005; Duncan and Hadlaczky Curr Opin Biotech 18:420-424, 2007): (1) the de novo formation by centromere seeding, the "bottom-up" approach, (2) the truncation of natural chromosomes or the modification of naturally occurring minichromosomes, the "top-down" approach, and (3) the in vivo "inductive" approach. Satellite DNA-based artificial chromosomes (SATACs) generated by the in vivo "inductive" method have the potential to become an efficient tool in diverse gene technology applications such as cellular protein manufacturing (Kennard et al. BioPharm Int 20:52-59, 2007; Kennard et al. Biotechnol Bioeng 104:526-539, 2009; Kennard et al. Biotechnol Bioeng 104:540-553, 2009), transgenic animal production (Telenius et al. Chromosome Res 7:3-7, 1999; Co et al. Chromosome Res 8:183-191, 2000; Monteith et al. Methods Mol Biol 240:227-242, 2003), and ultimately a safe vector for gene therapy (Vanderbyl et al. Stem Cells 22:324-333, 2004; Vanderbyl et al. Exp Hematol 33:1470-1476, 2005; Katona et al. Cell. Mol. Life Sci 65:3830-3838, 2008). A detailed protocol for the de novo generation of satellite DNA-based artificial chromosomes (SATACs) via induced large-scale amplification is presented. PMID:21431723

Csonka, Erika

2011-01-01

117

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

Science.gov (United States)

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

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

2015-01-01

118

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

Science.gov (United States)

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%.

Lee, S.; Evangelista, D. G.

2006-07-01

119

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

120

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

 
 
 
 
121

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

Science.gov (United States)

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

Miyahara, Makoto

2007-01-01

122

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

123

Generation of induced pluripotent stem cells by using a mammalian artificial chromosome expression system.  

Science.gov (United States)

Direct reprogramming of mouse fibroblasts into induced pluripotent stem cells (iPS) was achieved recently by overexpression of four transcription factors encoded by retroviral vectors. Most of the virus vectors, however, may cause insertional mutagenesis in the host genome and may also induce tumor formation. Therefore, it is very important to discover novel and safer, non-viral reprogramming methods. Here we describe the reprogramming of somatic cells into iPS cells by a novel protein-based technique. Engineered Oct4, Sox2 and Klf4 transcription factors carrying an N-terminal Flag-tag and a C-terminal polyarginine tail were synthesized by a recently described mammalian artificial chromosome expression system (ACEs). This system is suitable for the high-level production of recombinant proteins in mammalian tissue culture cells. Recombinant proteins produced in this system contain all the post-translational modifications essential for the stability and the authentic function of the proteins. The engineered Oct4, Sox2 and Klf4 proteins efficiently induced the reprogramming of mouse embryonic fibroblasts by means of protein transduction. This novel method allows for the generation of iPS cells, which may be suitable for therapeutic applications in the future. PMID:25194736

Tóth, Anna; Fodor, Katalin; Blazsó, P; Cserpán, I; Praznovszky, Tünde; Tubak, V; Udvardy, A; Hadlaczky, Gy; Katona, R L

2014-09-01

124

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

125

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

Science.gov (United States)

The future installation of the Large Hadron Collider in the tunnel formerly housing the Large Electron Positron collider (LEP) required the dismantling of the latter after 11-year operation. As required by the French legislation, an extensive theoretical study was conducted before decommissioning to establish the possible activation paths both in the accelerator and in the four experiments (L3, ALEPH, OPAL and DELPHI) installed around the ring. The aim was to define which areas may contain activated material and which ones would be completely free of activation. The four major sources of activation in LEP, i.e., distributed and localized beam losses, synchrotron radiation and the super-conducting RF cavities, were investigated. Conversion coefficients from unit lost beam power to induced specific activity were established for a number of materials. A similar study was conducted for the four experiments, evaluating the four potential sources of induced radioactivity, namely e +e - annihilation events, two-photon events, e +e - Bhabha scattering events and beam-related radiation, i.e., synchrotron radiation and off-momentum beam particles. Decommissioning started early in 2001 and was completed by February 2002. Every single piece removed from the machine tunnel and experimental areas was double-checked for induced radioactivity, with complementary gamma-spectrometry measurements performed on samples of the various materials. The measurements have to a large extent confirmed the predictions. The overall intent of this paper is to provide data and computational guidelines for assessing induced radioactivity in high-energy electron accelerators, which could be of use in future decommissioning.

Silari, Marco; Ulrici, Luisa

2004-07-01

126

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

International Nuclear Information System (INIS)

The future installation of the Large Hadron Collider in the tunnel formerly housing the Large Electron Positron collider (LEP) required the dismantling of the latter after 11-year operation. As required by the French legislation, an extensive theoretical study was conducted before decommissioning to establish the possible activation paths both in the accelerator and in the four experiments (L3, ALEPH, OPAL and DELPHI) installed around the ring. The aim was to define which areas may contain activated material and which ones would be completely free of activation. The four major sources of activation in LEP, i.e., distributed and localized beam losses, synchrotron radiation and the super-conducting RF cavities, were investigated. Conversion coefficients from unit lost beam power to induced specific activity were established for a number of materials. A similar study was conducted for the four experiments, evaluating the four potential sources of induced radioactivity, namely e+e- annihilation events, two-photon events, e+e- Bhabha scattering events and beam-related radiation, i.e., synchrotron radiation and off-momentum beam particles. Decommissioning started early in 2001 and was completed by February 2002. Every single piece removed from the machine tunnel and experimental areas was double-checked for induced radioactivity, with complementary gamma-spectrometry measurements performed on samples of the various materials. The on samples of the various materials. The measurements have to a large extent confirmed the predictions. The overall intent of this paper is to provide data and computational guidelines for assessing induced radioactivity in high-energy electron accelerators, which could be of use in future decommissioning

127

Experimental study on induced radioactivity in boron-doped low activation concrete for DT fusion reactors  

International Nuclear Information System (INIS)

In order to investigate applicability of the boron-doped low activation concrete to the DT nuclear fusion reactor, DT neutron irradiation tests were performed together with the standard sample using the FNS facility at JAERI. Radioactivities induced in the specimens were measured during 1 h - 100 d cooling time after 12 h irradiation. From radioactivities detected in the specimens, the effective dose rate was calculated. Dose rates are reduced drastically in the boron-doped low activation concrete compared with those in a standard sample except in the case of a short period of cooling 7 - 10 d after a short period of irradiation less than 20 d. It is concluded that the boron-doped low activation concrete used in the present study is highly useful as a shielding material. (author)

128

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

129

Surface gamma dose rates from thick sources, and danger parameters for radioactivity induced by accelerator radiation  

International Nuclear Information System (INIS)

This paper examines dosimetric and practical aspects of the induced radioactivity danger parameter (Barbier, 1969), as used for calculating gamma radiation dose rates near to objects that have been exposed to high energy radiation. A simplified method of calculation, based on energy balance in infinite homogenous media, is proposed. This method requires no ''build-up factor'' to account for secondary photons, and provides adequate approximations in many applications. Where necessary, correction factors can be applied, to take account of source material and surface effects: these have been computed by a Monte Carlo program for C, water, Al, Fe and Pb. Variations of dose rate with source thickness have also been calculated. These results can also be applied generally to the calculation of surface gamma dose rates from uniformly radioactive objects

130

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

International Nuclear Information System (INIS)

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

131

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

International Nuclear Information System (INIS)

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

132

Study of Natural and Artificial Radioactivity of Sinai Soils and Analysis of Uranium in Contaminated Samples by Uranyl Nitrate Solution  

International Nuclear Information System (INIS)

Sinai Peninsula covers an area of approximately 61000 km2 and is separated geographically from Egypt by the Suez canal and the gulf of Suez. It is located in the north east of Egypt, between the arms of the red sea. Twenty eight samples were collected from Rafah at North to EI Naqab at south for measuring the natural radioactivity 238U, 232Th, 40K and also 137Cs as man made radioactivity using HPGe detector and its components. The radium equivalent and the gamma radiation hazard index (I?) were also calculated. Total uranium content for nine samples was determined using laser fluorimetry. The 235U/238U ratio with different concentration of uranyl nitrate solution was also determined by nondestructive gamma assay. The count rate isotopic ratios of 235U/ 238U at different gamma transitions were found to be straight line with increase of uranium concentration from 50 to 900 ppm. The soil samples which were contaminated with different concentrations of uranyl nitrate (1-500 ppm) found that uranium could be detected in these samples at a threshold concentration of 50 ppm

133

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

International Nuclear Information System (INIS)

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

134

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

135

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

136

Environmental radioactivity measurements  

International Nuclear Information System (INIS)

In our surroundings there exist both natural and artificial radioactive materials. The analysis or measurements of such environmental radioactivities are important not only in geochemistry but also in grasping radioactive contamination of the environment and the influences of radiation on the human body. Before the measurements, chemical forms and dissolved states of the radioactive materials in the environment need to be known. A review is made of the papers etc. published mostly since 1977, concerning environmental radioactivity measurements: pretreatment and collection of radioactive nuclides; measurements of artificial radioactive nuclides (radiocobalt, radiostrontium and radiocesium, radioiodine, transuranium elements, etc.); measurements of natural radioactive nuclides (uranium and thorium isotopes, radium isotopes, etc.); environmental radioactivity measurements manual. (Mori, K.)

137

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

138

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.))

139

Calculation of radioactivity induced in gamma-ray spectrometers during spaceflight  

International Nuclear Information System (INIS)

Radioactivity induced in detector materials by cosmic rays, trapped protons and secondary neutrons is a major source of background in gamma-ray astronomy and remote sensing spectroscopy of the moon and the planets. A calculation scheme for assessing this component has been developed based on semi-empirical cross-sections and stochastic calculations of energy-loss spectra of radioactive nuclides. In addition, predictive methods are available based on experimental data obtained from monoenergetic proton beam irradiations of scintillators at energies of 155, 600, 800 MeV and 6 GeV. Application of these methods to in-flight results from scintillator detectors carried on lightweight OSO spacecraft, for which trapped protons of 20-200 MeV dominate, shows that the induced radiactivity at lower photon energies can be well explained by spallation interactions of primary protons in the central crystal detector elements. The contributions to the induced activity due to collimators, materials surrounding the detector, and the spacecraft become increasingly important at higher proton energies. For such detectors carried on the Apollo missions, the more energetic (> 300 MeV) cosmic-ray flux dominates. The library of isotopes presently used can predict only about half the induced radiactivity, and corrections for missing radionuclides must be based on the experimental irradiation results. Results from crystals returned to Earth from Apollo 17 and Apollo-Soyuz show that, for heavy sp7 and Apollo-Soyuz show that, for heavy spacecraft, secondary neutrons can significantly enchance the background. Preliminary estimates have been made of the important gamma-ray line features to be expected from cosmic-ray and trapped proton induced spallation products in germanium detectors. (orig.)

140

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

International Nuclear Information System (INIS)

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

 
 
 
 
141

Ability of use of radiation monitoring networks on detection of natural and artificial radioactivity in the environment  

International Nuclear Information System (INIS)

In the paper there are analysed and compared regional and local early warning radiation monitoring systems. The second generation of early warning systems comprises at least one air filter unit in order to enrich airborne radioactivity, in addition to the traditional dose rate measurement. Two possible implementations of these devices are the systems with moving filter band(s) and with static filter(s), respectively. Model systems are compared and evaluated by virtue of their response to two critical cases: the appearance of an instantaneous contaminant originating from the vicinity of the device and the slow bild-up of and a contaminant arriving from a long distance. Structure and components of sampling, data acquisition and data evaluation procedures are compared according to the requirements of early warning systems. (author)

142

Artificial radioactive contamination of sediments along the Romanian sector of the Danube river and the Black Sea coast  

International Nuclear Information System (INIS)

The concentrations of 90Sr, 238Pu, 239,240Pu and 241Am were determined in 12 sediment samples, collected from the bed of the Romanian sector of the Danube river and the Black Sea coast during 1996-1997. The samples were dissolved using a microwave digestion technique which left the refractory part of the samples undissolved. Part of the samples were also dissolved totally by alkaline fusion. The results obtained after radiochemical separations and measurement of the radionuclides by the two dissolution methods were compared recommending the optimum method. The radioactive contamination of the investigated sector in 1996-1997 is compared with the results obtained for the same locations in 1994-1995 reported in previous papers. (author)

143

Results of concentration measurements of artificial radioactive aerosols in the lower atmosphere; Resultats des mesures de concentration, dans la basse atmosphere, des aerosols radioactifs artificiels  

Energy Technology Data Exchange (ETDEWEB)

This report gives the results of the measurements of artificial gross-{beta}-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) [French] Ce rapport contient les resultats des mesures de radioactivite {beta} globale d'origine artificielle des aerosols dans la basse atmosphere, effectuees conjointement par le Service d'Electronique Physique du Departement d'Electronique et le Laboratoire de Physique de l'Atmosphere de la Faculte des Sciences de Paris. Les mesures ont commence en septembre 1956 et ont ete poursuivies dans un nombre croissant de stations, tant en France que dans le reste du monde. Le present rapport s'arrete a la fin aout 1961, c'est-a-dire au moment de la reprise des essais nucleaires. Apres avoir rappele la constitution et les proprietes des aerosols radioactifs presents dans l'atmosphere, les auteurs indiquent les methodes de mesure utilisees, evaluent leur precision et discutent les differents aspects des resultats de leurs mesures. (auteurs)

Ardouin, B.; Jehanno, C.; Labeyrie, J.; Lambert, G.; Tanaevsky, O.; Vassy, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

144

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

CERN Document Server

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

Silari, Marco

2004-01-01

145

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)

146

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

Directory of Open Access Journals (Sweden)

Full Text Available The activity concentration of natural and fallout radionuclides in the soil at some selected Thanas around the TRIGA Mark-II Research Reactor at Atomic Energy Research Establishment (AERE, Savar, Dhaka were measured by using a high purity germanium detector (HPGe. The study revealed that only natural radionuclides were present in the samples and no trace of any artificial radionuclide was found. The average activity concentration of 238U, 232Th and 40K were found to be 37.8 ± 5.6 Bq.kg-1, 58.2 ± 11.0 Bq.kg-1 and 790.8 ± 153.4 Bq.kg-1 respectively. The radium equivalent activity (Req, absorbed dose rate (D, external radiation hazard index (Hex and internal radiation hazard index (Hin were also calculated to find out the probable radiological hazard of the natural radioactivity.

Shawpan C. Sarkar

2011-12-01

147

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

148

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

149

STUDY OF THE RADIOACTIVITY INDUCED IN AIR BY A 15-MEV PROTON BEAM.  

Science.gov (United States)

Radioactivity induced by a 15-MeV proton beam extracted into air was studied at the beam transport line of the 18-MeV cyclotron at the Bern University Hospital (Inselspital). The produced radioactivity was calculated and measured by means of proportional counters located at the main exhaust of the laboratory. These devices were designed for precise assessment of air contamination for radiation protection purposes. The main produced isotopes were (11)C, (13)N and (14)O. Both measurements and calculations correspond to two different irradiation conditions. In the former, protons were allowed to travel for their full range in air. In the latter, they were stopped at the distance of 1.5 m by a beam dump. Radioactivity was measured continuously in the exhausted air starting from 2 min after the end of irradiation. For this reason, the short-lived (14)O isotope gave a negligible contribution to the measured activity. Good agreement was found between the measurements and the calculations within the estimated uncertainties. Currents in the range of 120-370 nA were extracted in air for 10-30 s producing activities of 9-22 MBq of (11)C and (13)N. The total activities for (11)C and (13)N per beam current and irradiation time for the former and the latter irradiation conditions were measured to be (3.60 ± 0.48) × 10(-3) MBq (nA s)(-1) and (2.89 ± 0.37) × 10(-3) MBq (nA s)(-1), respectively. PMID:24982259

Braccini, S; Ereditato, A; Nesteruk, K P; Scampoli, P; Zihlmann, K

2014-06-30

150

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

151

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.)

152

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)

153

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

154

Filtration and ventilation of induced radioactive gases at the ETL linac  

International Nuclear Information System (INIS)

The facilities of filtration and ventilation of induced radioactive gases were installed in the ETL linac building in 1980. The yield estimation of 15O, 13N, O3 and NOX described here was done for the design of the facilities used for filtration and ventilation of these gases. At the pulsed injection for the storage ring and at the measurement of electron energy spectra, a few part of the electron beam is scattered and spilled from the vacuum beam duct and yields most of them in the accelerator room. Even at the most serious conditions, no cooling time enables reducing their density less than a level of the legally permissible density except of the axiliary shielding area near the target in each experimental room. (author)

155

Radioactivity and radiation protection; Radioaktivitaet und Strahlenschutz  

Energy Technology Data Exchange (ETDEWEB)

The volume covers the following issues: chemical elements and their smallest particles; nuclear reactions and radioactivity; energy of radiation particles and gamma quanta; interactions between radiation and matter; radiation measurement and measuring units; radiation effects on living cells; radionuclides in the human body; natural radiation sources - natural radiation exposure; artificial radiation sources - civilization-induced radiation exposure; radiation protection measures against external radiation effects; radiation protection measures against internal radiation effects; radiation protection for persons within a nuclear power plant.

Volkmer, Martin

2007-04-15

156

Chromosome damage induced by artificial seed aging in barley : 3. Behavior of chromosomal aberrations during plant growth.  

Science.gov (United States)

Barley (Hordeum vulgare L. 'Himalaya') seeds were artificially aged under two storage conditions (32 °C/12% moisture content (m.c.) and 38 °C/18% m.c.) to study the behavior of induced chromosomal aberrations during plant growth. The frequencies of aberrant anaphases at first mitosis in root tips were correlated with loss of germinability. However, after 3 and 5 weeks' growth, aberration frequency declined. In plants grown from artificially aged seeds, the frequency of aberrant anaphases appeared to be stabilized at about 1% after 5 weeks' growth, in spite of the large differences in the frequencies at first mitosis. This suggests that because of their genetic imbalance, cells with chromosomal aberrations induced by seed aging were being excluded during plant growth. Meiotic chromosome configurations at MI were normal (7 II) in all plants studied, although a few precocious separations were found. Meiotic aberrations were found at AI-TI, AII-TII and the tetrad stages in the pollen mother cells of plants grown from the control and artificially aged seeds. However, there were no clear differences among the control and the two aging treatments. It was obvious that some cells with meiotic chromosomal aberrations were lost between the AI-TI and AII-TII stages, and still more between the AII-TII and tetrad stages. The frequency of tetrads with micronuclei in plants produced from artificially aged seeds was the same as in the control. The plants grown from artificially aged seeds showed high pollen fertility (95.2 to 97.0%) and seed fertility (90.1 to 97.2%) which was comparable to the control values (97.4 and 97.9%) respectively, indicating no special effects of seed aging. Anaphase cells of the first mitosis in the next (A2) generation were analyzed to study the transmission of chromosomal aberrations through mitotic and meiotic cell divisions in the A1 generation. Aberrant anaphases in the progeny from the artificially aged seeds were not higher than those of the control progeny. This indicates that the chromosomal aberrations induced by seed aging are not transmitted to the next generation. PMID:24258542

Murata, M; Tsuchiya, T; Roos, E E

1984-01-01

157

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

Energy Technology Data Exchange (ETDEWEB)

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 10{sup 13} 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)

Kasugai, Y.; Takada, H.; Nakashima, H. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

2001-03-01

158

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 harbbeach 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)

159

Effectiveness of centrifuge-induced artificial gravity with ergometric exercise as a countermeasure during simulated microgravity exposure in humans  

Science.gov (United States)

To test the effectiveness of centrifuge-induced artificial gravity with ergometric exercise, 12 healthy young men (20.7±1.9yr) were exposed to simulated microgravity for 14 days of -6? head-down bedrest. Half the subjects were randomly selected and loaded 1.2 G artificial gravity with 60 W (four out of six subjects) or 40 W (two out of six subjects) of ergometric workload on days 1,2,3,5,7,9,11,12,13,14 (CM group). The rest of the subjects served as the control. Anti-G score, defined as the G-load×running time to the endpoint, was significantly elongated by the load of the centrifuge-ergometer. Plasma volume loss was suppressed ( -5.0±2.4 vs. -16.4±1.9%), and fluid volume shift was prevented by the countermeasure load. Elevated heart rate and muscle sympathetic nerve activity after bedrest were counteracted, and exaggerated response to head-up tilt was also suppressed. Centrifuge-induced artificial gravity with exercise is effective in preventing cardiovascular deconditioning due to microgravity exposure, however, an effective and appropriate regimen (magnitude of G-load and exercise workload) should be determined in future studies.

Iwase, Satoshi

2005-07-01

160

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

Science.gov (United States)

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

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

2012-12-01

 
 
 
 
161

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

162

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)

163

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

164

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

Science.gov (United States)

The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (P<0.0001). In a nutshell, ozone enhanced the remineralizing potential of nanohydroxyapatite, and laser induced fluorescence was found to be effective in assessing the surface mineral changes in enamel. Ozone can be considered an effective agent in reversing the initial enamel caries there by preventing the tooth from entering into the repetitive restorative cycle.

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

2014-02-01

165

Calculations of the production rate of radioactive nuclear beam induced by 70 MeV protons on 72Ge target  

International Nuclear Information System (INIS)

Under the condition of the calculated relative cross sections in good agreement with the experimental data, the production rate (s-1·?A-1) of the main radioactive nuclei induced by 70 MeV protons on 72Ge and its compound Zr5Ge3 targets are calculated by nuclear reaction model code SPEC. The calculated production rates of 72As and 71As are 2-3 times higher than the evaluated values abroad

166

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)

167

Damage detection on railway bridges using Artificial Neural Network and train induced vibrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A damage detection approach based on Artificial Neural Network (ANN), using the statistics of structural dynamic responses as the damage index, is proposed in this study for Structural Health Monitoring (SHM). Based on the sensitivity analysis, the feasibility of using the changes of variances and covariance of dynamic responses of railway bridges under moving trains as the indices for damage detection is evaluated.   A FE Model of a one-span simply supported beam bridge is built, considerin...

Shu, Jiangpeng; Zhang, Ziye

2012-01-01

168

Natural radioactivity contents in tobacco and radiation dose induced from smoking  

International Nuclear Information System (INIS)

One of the causative factors for cancer-inducing mechanisms in humans is radioactive elements present in tobacco leaves used in the manufacture of cigarettes. Smoking of tobacco and its products increases the internal intake and radiation dose due to naturally occurring radionuclides that are considered to be one of the most significant causes of lung cancer. In this work, different commercial types of cigarettes, cigar and moassel were collected from market. Naturally occurring radionuclides 226Ra and 214Bi (238U series), 228Ac and 228Ra (232Th series), 40K and man-made 137Cs were measured in tobacco using gamma-ray spectrometer. Results show that the average concentrations of 238U, 232Th and 40K were 4.564, 3.940 and 1289.53 Bq kg-1, respectively. This reflects their origin from the soil by root uptake and fertilisers used in the cultivation of tobacco plants. Concentration of 137Cs was 0.348 Bq kg-1 due to root uptake or deposition onto the leaf foliage. For smokers, the annual effective dose due to inhalation of 238U varied from 49.35 to 139.40 ?Sv-1 (average 104.27 ?Sv y-1), while of 232Th from 23.86 to 111.06 ?Sv y -1 (average 65.52 ?Sv y-1). The annual effective dose resulting from 137Cs was varied from 10.96 to 24.01 nSv y-1 (ave10.96 to 24.01 nSv y-1 (average 19.41 nSv y-1). (authors)

169

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.)

170

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

International Nuclear Information System (INIS)

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

171

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-06-10

172

Results 2005 of the surveillance of the artificial radioactivity levels of aquatic ecosystems in the basin of Seine-Normandy. Riviere 2005  

International Nuclear Information System (INIS)

Set up in 2004 by the A.C.R.O. the citizens network of radioecological surveillance, information and evaluation (R.I.V.I.E.R.E.) aims at making a follow-up of the radioactive contamination of the aquatic ecosystems on the scale of the Seine-Normandy pond: from Nogent-on-Seine to La Hague and from the Mont-Saint-Michel to the Treport. The peculiarity of this network, which also makes its strength is to associate strictly all those who wish to appropriate the knowledge of the radioactivity levels around to them. With R.I.V.I.E.R.E., the citizen is at the same moment an author and an actor of the surveillance of his environment as his information. An approach defended by the A.C.R.O. since about 20 years and which has no equivalent anywhere else. This project has four main objectives: to know the levels and the tendencies of the present radioactivity in the main aquatic ecosystems of the Seine-Normandy widened pond, and so feed a data base including more than 3000 analysis (limited to the gamma radioactivity and to the tritium); to allow the citizens who put a lot to appropriate the knowledge and the indispensable references to understand the radioactivity of their environment; to establish a support in the public information about the radioactivity in environment; to supply data to the national network of measures of the radioactivity in environment, network established by decree recently and in charge of the evaluation of the public exposure. (N.C.)

173

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

174

Amyloid-?-Induced Ion Flux in Artificial Lipid Bilayers and Neuronal Cells: Resolving a Controversy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Understanding the pathogenicity of amyloid-beta (A?) peptides constitutes a major goal in research on Alzheimer’s disease (AD). One hypothesis entails that A? peptides induce uncontrolled, neurotoxic ion flux through cellular membranes. The exact biophysical mechanism of this ion flux is, however, a subject of an ongoing controversy which has attenuated progress toward understanding the importance of A?-induced ion flux in AD. The work presented here addresses two prevalent controversies...

Capone, Ricardo; Quiroz, Felipe Garcia; Prangkio, Panchika; Saluja, Inderjeet; Sauer, Anna M.; Bautista, Mahealani R.; Turner, Raymond S.; Yang, Jerry; Mayer, Michael

2009-01-01

175

A Calculation of the radioactivity induced in PWR cluster control rods with the origin and casmo codes  

International Nuclear Information System (INIS)

The radioactivity induced in PWR cluster control rods during reactor operation has been calculated using the computer programme ORIGEN. Neutron fluxes and spectrum conditions as well as the strongly shielded cross sections for the absorber materials Ag, In and Cd have been obtained by running the cell and assembly code CASMO for a couple of typical cases. The results show that Ag-110m, Fe-55 and Co-60 give the largest activity contributions in the interval 1-10 years after the end of irradiation, and Ni-63 and Cd-113m in a longer time perspective. (author)

176

Comparison of thermally induced and naturally occurring water-borne leakages from hard rock depositories for radioactive waste  

International Nuclear Information System (INIS)

The relative importance of thermally induced and naturally occurring flows of water as causes of leakage from hard rock depositories for radioactive wastes is assessed. Separate analyses are presented for involatile, high level waste from reprocessing of fuel and for plutonium contaminated waste from fabrication of fuel. The effects of varying the quantities of wastes, pre-burial storage and the shapes and depths of depositories are considered. It is concluded that for representative values of these variables, thermal flow will remain the major cause of leakage for long times after the burial of both types of waste. (Auth.)

177

5. Chemistry of radioactive elements  

International Nuclear Information System (INIS)

A review is given of the individual radioactive elements and artificial cisuranium and transuranium elements. The discovery, isotopes, chemical characteristics and compounds are shown for each. (M.D.)

178

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 ion (LOD) of 2.3 mg dm-3 of Cu and a mean squared error (MSE) of 0.5 for the predictions

179

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

Science.gov (United States)

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

Rieder, Karl-Heinz; Meyer, Gerhard; Moresco, Francesca; Morgenstern, Karina; Hla, Saw-Wai; Repp, Jascha; Alemani, Micol; Grill, Leonhard; Gross, Leo; Mehlhorn, Michael; Gawronski, Heiko; Simic-Milosevich, Violeta; Henzl, Jörg; Braun, Kai F.; Foelsch, Stefan; Bartels, Ludwig

2005-01-01

180

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

 
 
 
 
181

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

182

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

183

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-01-15

184

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

185

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

186

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

187

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

International Nuclear Information System (INIS)

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

188

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

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

L. J. Baddeley

189

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

Directory of Open Access Journals (Sweden)

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

R. Napoli

1998-06-01

190

Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence? / Miocardiopatia dilatada induzida por estimulação cardíaca artificial: mito ou realidade sustentada pelas evidências?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A estimulação cardíaca artificial (ECA) é o tratamento mais seguro e eficaz para a bradicardia sintomática irreversível. Nas indicações propícias, pode trazer grande benefício clínico. Contudo, as evidências mostram que a ação da ECA geraria, em alguns casos, efeitos deletérios à estrutura e fisiolo [...] gia cardíacas. Este potencial efeito negativo da ECA convencional poderia ser mais acentuado principalmente em pacientes com comprometimento prévio da função ventricular esquerda e, sobretudo, quando o eletrodo é colocado em posição apical do ventrículo direito (VD). Intrigante é, contudo, que após quase 6 décadas de ECA do VD, apenas uma reduzida parcela de pacientes apresenta esta condição clinicamente manifesta. Os determinantes do surgimento ou não da cardiopatia por ECA não estão totalmente esclarecidos. Ainda é motivo de debate a existência de uma relação de causalidade entre o padrão de BRE artificial secundário à ativação antifisiológica ventricular, alterações da dinâmica contrátil ventricular, e condições clínicas (disfunção sistólica prévia, cardiopatia estrutural preexistente, tempo desde o implante) ou elétricas (duração do intervalo QRS, dose percentual de estimulação ventricular). Esta revisão aborda dados contemporâneos sobre esta nova entidade e discute alternativas de como utilizar a ECA neste contexto, com ênfase na terapia de ressincronização cardíaca. Abstract in english 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 vent [...] ricular 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.

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

2014-09-01

191

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

192

Artificially induced polyploidization in Humulus lupulus L. and its effect on morphological and chemical traits.  

Science.gov (United States)

Chemically induced polyploids were obtained by the colchicine treatment of shoot tips of Humulus lupulus L. 'Sybilla'. Flow cytometry revealed that most of the treatments resulted in the production of tetraploids. The highest number of tetraploids was obtained when explants were immersed in 0.05% colchicine for 48 h. A field experiment was conducted to compare diploid and tetraploid plants and assess the effect of genome polyploidization on the morphological and chemical characteristics. Tetraploids showed significant differences in relation to diploids. They had thinner and shorter shoots. The influence of chromosome doubling was also reflected in the length, width and area of leaves. The length of female flowers in the tetraploids was significantly shorter than that observed in diploids. Tetraploids produced a diverse number of lupuline glands that were almost twice as large as those observed in diploids. The most distinct effect of genome polyploidization was a significant increase in the weight of cones and spindles. Contents of major chemical constituents of hop cones was little affected by ploidy level. Total essential oils were significantly lower than those in diploids. However there was a significant increase in the proportion of humulene, caryophyllene and farnesene, oils desired by the brewing industry. PMID:24399911

Trojak-Goluch, Anna; Skomra, Urszula

2013-12-01

193

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)

194

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

195

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.ding materials.

196

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)

197

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

Science.gov (United States)

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

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

2014-09-19

198

Gamma-Radiation Induced Grafted Membranes Used in Radioactive Waste Treatment  

International Nuclear Information System (INIS)

Acrylamide monomer (AAm) was grafted onto poly(vinyl chloride) (PVC) films using gamma-radiation to produce high performance functional membrane which can be employed as ion-exchanger. The preparation and characterization of the synthetic membrane are investigated. In order to elucidate the possible application of this prepared membrane, some selected properties such as swelling behavior, electrical conductivity and mechanical properties were studied. In addition, thermal properties are studied using thermogravimetric analysis (TGA), differential scanning calorimeter (DSC) and the change in polymer morphology by XRD technique. The selectivity of such membrane towards different radionuclides is also investigated. On the bases of these investigations, the applicability of the prepared membranes is determined and discussed. The prepared PVC-g-PAAm has a great tendency to remove 60Co from a radioactive liquid waste containing both 60Co and 137Cs

199

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)

200

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

 
 
 
 
201

Induced structural radioactivity inventory analysis of the base case aqueous ATW reactor concept  

International Nuclear Information System (INIS)

The purpose of the Los Alamos National Laboratory Accelerator Transmutation of Nuclear Waste (ATW) project is the substantial reduction in volume of this country's long-lived high-level radioactive waste in a safe and energy efficient manner. An evaluation of the Accelerator Transmutation of Nuclear Waste concept has four aspects; material balance, energy balance, performance and cost. An evaluation of the material balance compares the amount of long-lived high-level waste transmuted with the amount and type of waste created in the process. One component of the material balance is the activation of structural materials over the lifetime of the transmutation reactor. An activation analysis has been performed on four structure regions of the reaction vessel: the tungsten target; the lead target and annulus; the Zircalloy and aluminum tubing carrying the actinide slurry and; the stainless steel tank

202

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)

203

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

Science.gov (United States)

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

Lokier, Stephen; Krieg Dosier, Ginger

2013-04-01

204

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

205

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)

206

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

International Nuclear Information System (INIS)

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

207

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)

208

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

209

Induced radioactivity in a patient-specific collimator used in proton therapy  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the activation of a patient-specific collimator, calculating dose rates, total activities and activities per unit mass of the mixture of radionuclides generated by proton irradiation in the energy range 100-250 MeV. Monte Carlo simulations were first performed for a generic case, using an approximate geometry and on the basis of assumptions on beam intensity and irradiation profile. A collimator used for a prostate cancer treatment was obtained from the MD Anderson Cancer Center (MDACC), Houston, USA, from which a number of samples were cut and analyzed by gamma spectrometry. The results of the gamma spectrometry are compared with the results of Monte Carlo simulations performed using geometrical and irradiation data specific to the unit. The assumptions made for the simulations and their impact on the results are discussed. Dose rate measurements performed in a low-background area at CERN and routine radiation protection measurements at the MDACC are also reported. It is shown that it should generally be possible to demonstrate that the material can be regarded as non-radioactive after allowing a sufficient decay-time, typically of the order of a few months.

Cesana, Alessandra [Politecnico di Milano, Department of Energy, Via Ponzio 34/3, 20133 Milano (Italy); Mauro, Egidio [CERN, 1211 Geneva 23 (Switzerland); Silari, Marco, E-mail: marco.silari@cern.c [CERN, 1211 Geneva 23 (Switzerland)

2010-07-01

210

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

211

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

International Nuclear Information System (INIS)

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

212

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

213

Transmutation and induced radioactivity of W in the armor and first wall of fusion reactors  

International Nuclear Information System (INIS)

The transmutation and induced activity of W in the armor and first wall of a fusion reactor were calculated for various blanket compositions, taking account of multiple step reactions. Neutron spectra calculated with ANISN showed that the flux of low energy neutrons at both armor and first wall using water coolant is fairly high compared to liquid Li, He gas and FliBe coolants. About 4% of W transmutes to Re for the W armor of all blankets after 10 MWy/m2 irradiation and is not affected by the difference in blanket composition. On the other hand. W in the first wall substantially transmutes to Re followed by Os for the water cooled blanket. For the longer irradiation. W was predicted to transmute to Os base alloy. The induced activity of the W armor is hardly influenced by the neutron spectrum. The formation of 186mRe and 186Re controlling the induced activity of the armor for long cooling times is not significant from the viewpoint of the safety level. (orig.)

214

gamma radiation -induced preparation of some resins for the separation of radioactive isotopes  

International Nuclear Information System (INIS)

organic resins have many applications not only in the industrial and environmental fields but also in the nuclear field, this may be returned to its high measured capacity, high selectivity, low solubility and high chemical radiation stability. in this work, gamma radiation was used in the preparation of p(AM-AA-DMAEM) and p(AM-AA)-EDTANa2 using template polymerization technique in the presence of N,N'-methylene-diacrylamide (DAM) as a crosslinked. characterization of the prepared polymeric resins was studied by using infrared spectra to determine all function groups in the obtained polymeric materials . p(AM-AA-DMAEM)and p(AM-AA)-EDTANa2, were used for the sorption of Ga(lll), Cu(ll),Ni(ll) and Zn(ll) in aqueous solution as single component system. the effect pf ph, weight of resins, metal ion concentrations and contact time on the sorption of these metal ions were studied. also, p(AM-AA-DMAEM)and p(AM-AA)-EDTANa2 were used for the separation of these metal ions were studied. also,p( AM-AA-DMAEM)and p(AM-AA)-EDTANa2 were used for the separation of Ga(lll), from Cu (ll), Ni (ll), and Zn(ll) in aqueous media. the effect pf ph, contact time and the weight of the resin on the separation were studied using batch technique. chromatographic separation of Ga(lll) from Cu(ll), Ni (ll), and Zn (ll) onto p(AM-AA-DMAEM)and p(AM-AA)-EDTANa2 was also studied. the effect of flow rate, breakthrough curves, stability test of resireakthrough curves, stability test of resins, and cyclic properties of the resins were studied in details. batch experiments for testing the capability of polymeric resins for the sorption of radioactive isotope (72Ga) that produced from the reactor were studied

215

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

216

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

CERN Document Server

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

Rokni, S H; Gwise, T; Liu, J C; Roesler, S

2002-01-01

217

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

218

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

219

Artificial heart  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Nishta, B. V.

2006-01-01

220

An experimental investigation of radioactivity induced by ions associated with the operation of pulsed power accelerators  

International Nuclear Information System (INIS)

Energetic light ion beams are being studied in Sandia National Laboratories' Particle Beam Fusion Accelerator 11 (PBFA II) for the purpose of studying the physics of applied B-diodes with the hope that these beams can be applied to inertial confinement fusion. These beams induce nuclear reactions both in the diode itself and in the materials surrounding the diode. A series of experiments was conducted wherein samples of metals typically used in the diode/gas cell region of PBFA II were exposed to ion beams at energies expected to be achieved in PBFA II. The metals studied were aluminum alloys 2024 and 6061, brass, copper, inconel alloys 625 and 718, Stainless Steel 304, tantalum, titanium, and tungsten. The ion beams studied consisted of protons at energies of 6, 12, and 19 MeV, Lithium-7 at energies of 10, 15, 20, and 30 MeV; Lithium-6 at 30 MeV; and Boron-10 and Boron-11 at 30 MeV. The induced activity of each sample was measured as a function of time with an ion chamber and was used to estimate the rate at which the initial short-lived activity of the sample decayed. In addition, the activity of each sample was periodically measured with a Geiger counter in contact with the irradiated surface of the sample, was normalized to the total amount of energy incident on the sample, and was used as a basis to compare the amount of activity generated per mega-joule of energy for each sample. Additionally, gamma-ray spectra of the activated samples were collected using a gertivated samples were collected using a germanium detector, and these spectra were analyzed qualitatively to identify the long-lived radioisotopes present in the sample. Future work will also be discussed

 
 
 
 
221

Henry Becquerel, Pierre and Marie Curie and radioactivity: background, circumstances and implication of the founder discoveries  

International Nuclear Information System (INIS)

After Roentgen's X-rays discovery in 1895, Henry Becquerel discovers a proper radiation of uranium. Then, Pierre and Marie Curie discover polonium and radium. They establish that some atoms may produce spontaneously energy under radiations form which may lead to induce radioactivity. The essential interpretation was done by Rutherford with the distinction of alpha, beta and gamma radiations, and the atomic model of Rutherford-Bohr. The first transmutations under radiations effects lead to the neutrons discovery by Bothe and Becker, Irene Curie and Frederic Joliot, and to the interpretation by Chadwick, the artificial radioactivity of phosphorous by I. Curie and F. Joliot, and to the fission. (A.B.). 7 photos

222

Radioactive surveillance in peruvian foods  

International Nuclear Information System (INIS)

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

223

Processing semblances induced through inter-postsynaptic functional LINKs, presumed biological parallels of K-lines proposed for building artificial intelligence  

Directory of Open Access Journals (Sweden)

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

KunjumonIVadakkan

2011-07-01

224

Artificial intelligence  

CERN Document Server

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

Ennals, J R

2014-01-01

225

Experimental studies on the neutron emission spectrum and induced radioactivity of the sup 7 Li(d,n) reaction in the 20-40 MeV region  

CERN Document Server

To improve the data accuracy of the neutron emission spectrum of the sup 7 Li(d,n) reaction and the radioactivity ( sup 7 Be, sup 3 H, etc.) accumulated in the sup 7 Li target in IFMIF, we have measured the neutron emission spectrum and the radioactivity of sup 7 Be induced in the lithium target for 25 MeV deuterons at the Tohoku University AVF cyclotron (K=110) facility. Neutron spectra were measured with the time-of-flight (TOF) method at four laboratory angles by using a beam swinger system and a well collimated TOF channel. Induced radioactivity was measured by detecting the gamma-rays from sup 7 Be with a pure Ge detector. Experimental results are compared with other experimental data. The present result of neutron emission spectra are in qualitative agreement with other experimental data but that of sup 7 Be production was much larger than expected by the recent codes. Measurement will be extended to several incident energies up to 40 MeV.

Baba, M; Hagiwara, M; Sugimoto, M; Miura, T; Kawata, N; Yamadera, A; Orihara, H

2002-01-01

226

Radioactive contamination of the environment  

International Nuclear Information System (INIS)

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

227

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

228

Isolation and Characterization of BoHV-1 from Seropositive Cows after Inducing Artificial Stress in West Bengal, India  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Infectious Bovine Rhinotracheitis (BoHV-1) is the most important emerging disease of cattle in India. With an aim to reactivate BoHV-1 from latently infected sero-positive cattle for molecular characteristics of the isolates prevalent in tropical and sub-tropical countries like India and further epidemiological investigations on IBR infections this study had been conducted. Artificial stress with dexamethasone at the dose rate of 0.1 mg kg-1 body weight for 5 consecutive days was i...

Amaresh Chatterjee; Ujjwal Biswas; Biplab Pal; Dhruba Chakraborty; Chanchal Guha; Tapabrata Saha; Patricia Koenig; Martin Beer

2013-01-01

229

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

230

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

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

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

233

Radioactive wastes  

International Nuclear Information System (INIS)

The chapter presents the problems of the radioactive waste in Brazil and the discussion on the final disposal related to nuclear production raising and solution for temporary systems of radioactive wastes

234

Reproductive failure experimentally induced in sows via artificial insemination with semen spiked with porcine circovirus type 2.  

Science.gov (United States)

Porcine circovirus type 2 (PCV2) is associated with reproductive failure in female pigs. However, the association of PCV2-positive semen in the pathogenesis has not been elucidated. The objectives of this study were to determine whether semen spiked with PCV2 causes infection in PCV2-naïve, mature female pigs and whether delivery of PCV2 via artificial insemination causes reproductive failure or fetal infection. Nine sows were randomly allocated into 3 groups of 3 sows each and artificially inseminated with PCV2 DNA-negative semen (group 1), PCV2 DNA-negative semen spiked with PCV2a (group 2), or PCV2b (group 3). All sows in groups 2 and 3 developed PCV2 viremia 7 to 14 days after insemination. None of the group 2 sows became pregnant, whereas all group 3 sows (3/3) farrowed at the expected date. At parturition, presuckle serum samples were collected, and live-born piglets, stillborn fetuses, and mummified fetuses were necropsied. All live-born piglets (n = 8) in group 3 were PCV2 viremic at birth. Stillborn fetuses (n = 2) had gross lesions of congestive heart failure. Mummified fetuses (n = 25) varied in crown-rump length from 7 to 27 cm, indicating fetal death between 42 and 105 days of gestation. PCV2 antigen was detected in the myocardium by immunohistochemistry of 7/8 (88%) live-born piglets, 2/2 (100%) of the stillborn fetuses, and 25/25 (100%) of the mummified fetuses. In addition, 4/25 mummified fetuses had PCV2 antigen associated with smooth muscle cells and fibroblasts. The results of this study indicate that intrauterine administration of PCV2 causes reproductive failure in naïve sows. PMID:19276045

Madson, D M; Patterson, A R; Ramamoorthy, S; Pal, N; Meng, X J; Opriessnig, T

2009-07-01

235

Risk methodology for geologic disposal of radioactive waste: a distribution-free approach to inducing rank correlation among input variables for simulation studies  

International Nuclear Information System (INIS)

A method for inducing a desired rank correlation matrix on a multivariate input random variable is introduced in this paper. This method is simple to use, is distribution free, preserves the exact form of the marginal distributions on the input variables, and may be used with any type of sampling scheme for which correlation of input variables is a meaningful concept. A small simulation study provides an estimate of the bias and variability involved in the method. Input variables used in a model for study of geologic disposal of radioactive waste provide an example of the usefulness of this procedure

236

Artificial Intelligence  

CERN Document Server

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

Warwick, Kevin

2011-01-01

237

Radioactive battery  

International Nuclear Information System (INIS)

A radioactive battery is described that is comprised of a container housing an electrolyte, two electrodes immersed in the electrolyte and insoluble radioactive material disposed adjacent one electrode. Insoluble radioactive material of different intensity of radioactivity may be disposed adjacent the second electrode. If hydrobromic acid is used as the electrolyte, Br2 will be generated by the radioactivity and is reduced at the cathode: Br2 + 2e = 2 Br-. At the anode Br- is oxidized: 2Br- = Br2 + 2e. (U.S.)

238

Preliminary analysis of the induced structural radioactivity inventory of the base-case aqueous accelerator transmutation of waste reactor concept  

International Nuclear Information System (INIS)

The purpose of the Los Alamos National Laboratory Accelerator Transmutation of (Nuclear) Waste (ATW) project is the substantial reduction in volume of long-lived high-level radioactive waste of the US in a safe and energy-efficient manner. An evaluation of the ATW concept has four aspects: material balance, energy balance, performance, and cost. An evaluation of the material balance compares the amount of long-lived high-level waste transmuted with the amount and type, of waste created in the process. One component of the material balance is the activation of structural materials over the lifetime of the transmutation reactor. A preliminary radioactivity and radioactive mass balance analysis has been performed on four structure regions of the reaction chamber: the tungsten target, the lead annulus, six tubing materials carrying the actinide slurry, and five reaction vessel structural materials. The amount of radioactive material remaining after a 100-yr cooling period for the base-case ATW was found to be 338 kg of radionuclides. The bulk of this material (313 kg) was generated in the zirconium-niobium (Zr-Nb) actinide tubing material. Replacement of the Zr-Nb tubing material with one of the alternative tubing materials analyzed would significantly reduce the short- and long-term radioactive mass produced. The alternative vessel material Al-6061 alloys, Tenelon, HT-9, and 2 1/4 Cr-1 Mo and the alternative actinide tubing materials Al-6061 alloy, carbon-carbon matrix, ials Al-6061 alloy, carbon-carbon matrix, silicon carbide, and Ti-6 Al-4 V qualify for shallow land burial. Alternative disposal options for the base-case structural material Type 304L stainless steel and the actinide tubing material Zr-Nb will need to be considered as neither qualifies for shallow land burial

239

Artificial photosynthesis  

Directory of Open Access Journals (Sweden)

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

Andrew C. Benniston

2008-12-01

240

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)

 
 
 
 
241

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)

242

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

243

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

244

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 times more likely (P/AI 35 vs. 21%; Ptimes more likely to get pregnant than cows with peak milk yields greater than 55kg (P/AI 37 vs. 28%; Pinseminated 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

245

PBPK model for radioactive iodide and perchlorate kinetics and perchlorate-induced inhibition of iodide uptake in humans.  

Science.gov (United States)

Detection of perchlorate (ClO4-) in several drinking water sources across the U.S. has lead to public concern over health effects from chronic low-level exposures. Perchlorate inhibits thyroid iodide (I-) uptake at the sodium (Na+)-iodide (I-) symporter (NIS), thereby disrupting the initial stage of thyroid hormone synthesis. A physiologically based pharmacokinetic (PBPK) model was developed to describe the kinetics and distribution of both radioactive I- and cold ClO4- in healthy adult humans and simulates the subsequent inhibition of thyroid uptake of radioactive I- by ClO4-. The model successfully predicts the measured levels of serum and urinary ClO4- from drinking water exposures, ranging from 0.007 to 12 mg ClO4-/kg/day, as well as the subsequent inhibition of thyroid 131I- uptake. Thyroid iodine, as well as total, free, and protein-bound radioactive I- in serum from various tracer studies, are also successfully simulated. This model's parameters, in conjunction with corresponding model parameters established for the male, gestational, and lactating rat, can be used to estimate parameters in a pregnant or lactating human, that have not been or cannot be easily measured to extrapolate dose metrics and correlate observed effects in perchlorate toxicity studies to other human life stages. For example, by applying the adult male rat:adult human ratios of model parameters to those parameters established for the gestational and lactating rat, we can derive a reasonable estimate of corresponding parameters for a gestating or lactating human female. Although thyroid hormones and their regulatory feedback are not incorporated in the model structure, the model's successful prediction of free and bound radioactive I- and perchlorate's interaction with free radioactive I- provide a basis for extending the structure to address the complex hypothalamic-pituitary-thyroid feedback system. In this paper, bound radioactive I- refers to I- incorporated into thyroid hormones or iodinated proteins, which may or may not be bound to plasma proteins. PMID:15509666

Merrill, Elaine A; Clewell, Rebecca A; Robinson, Peter J; Jarabek, Annie M; Gearhart, Jeffery M; Sterner, Teresa R; Fisher, Jeffrey W

2005-01-01

246

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)

247

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

Directory of Open Access Journals (Sweden)

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

C. Bes

2013-07-01

248

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

249

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

250

Artificial blood  

Digital Repository Infrastructure Vision for European Research (DRIVER)

#Blood substitutes have been developed for almost a century. The various type of artificial blood was continuously available on the market. The theme of this report is to identify the best substitute in emergency situation for some patients and science students. The definition of best is given; thus, as the vital part of the report, the comparison between them is described and discussed. Modified hemoglobin, bovine-based hemoglobin and PFCs are three basic types. In terms of the perfor...

Umit Yasar; Pinar Yilgor Huri; Nurten Dikmen

2006-01-01

251

Radioactive Material  

CERN Multimedia

The Radiation Protection Group of the Safety Commission is responsible for shipping of radioactive material from CERN to any external institute or organisation. The RP group is equally responsible for the reception of radioactive material shipped to any of the CERN sites. Anyone who needs to ship from or import into CERN radioactive material must contact the Radioactive Shipping Service of the RP group in advance. Instructions are available at: http://cern.ch/rp-shipping or in the Radiation Protection Procedure PRP13: https://edms.cern.ch/document/346823 Radiation Protection Group

2004-01-01

252

Radioactive materials and radioactive waste  

International Nuclear Information System (INIS)

This article is about nuclear waste and the NIMBY (Not In My Back Yard) attitude of the public. The fear of nuclear materials and radioactivity is examined, working from the radioactivity in an average garden which contains 0.8 kg potassium-40, 6 kg of thorium and 2 kg of uranium in the top metre of soil. From this we receive a radiation dose all the time. Background radiation also comes from cosmic radiation, radioactive gases, mainly radon and the food and drink we consume. As well as natural radioactivity we receive doses from man-made sources such as X-rays, and the nuclear industry. The risks of radioactivity depend on the material itself and the pathway by which the radioactivity could reach you. The risk is shown to be very small with radiation effects from the nuclear industry only a small fraction of natural radiation effects, even including accidents and leakages. (UK)

253

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

International Nuclear Information System (INIS)

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

254

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

255

Environmental radioactivity annual report 1988  

International Nuclear Information System (INIS)

Artificial radioactivity in the environment in New Zealand and Rarotonga during 1988 continued to be at a trace level only, typical of recent years. Average levels were: total beta activity in air, 0.08 mBq/m3; strontium-90 deposition, 0.1 MBq/km2; caesium-137 in milk, 0.18 Bq/gK; strontium-90 in milk, 0.041 Bq/gCa. No artificial radionuclides were detected on high-volume air filters. Total beta activity deposition at Hokitika was higher than usual at 336 MBq/km2, and this is thought to be due to heavy deposition of natural radioactivity during heavy spring rains. Strontium-90 deposition was the lowest since measurements began in 1960, and was virtually undetectable. The report includes monitoring data for natural beryllium-7 including plots of variations in atmospheric concentration during 1987 and 1988. (author). 9 refs., 9 figs., 2 tabs

256

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.)

257

The effect of artificially induced hyperglycemia on the radiation response of the Lewis lung and EMT6 tumor models  

International Nuclear Information System (INIS)

The effect of hyperglycemia, induced by administration of glucose, on the radiation response of the Lewis lung and EMT6 tumor models has been evaluated. Neither acute (single i.p. injection of 8mg/glucose) nor chronic (multiple i.p. injections of 6mg/g glucose plus glucose in the water bottles) administrations of glucose increased the radiation response of either tumor. A combination of a single i.p. injection of glucose and a reduction of the O2 content of the inspired gas to 10 per cent did by itself reduce cell survival by 55-75% in the EMT6 and 80-90% in the Lewis lung carcinoma. However, this treatment had little effect on the shape of the radiation dose-response curve, and simply gave rise to a parallel shift of the survival curve, indicating that this treatment had little or no specificity for hypoxic cells. (author)

258

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.

259

Ambient radioactivity levels and radiation doses. Annual report 2010  

International Nuclear Information System (INIS)

The annual report 2010 on ambient radioactivity levels and radiation doses covers the following topics in two parts: Part (A) General information: (I) Natural environmental radioactivity. (II) Artificial radioactivity in the environment. (III) Occupational radiation exposure. (IV) Radiation exposures from medical applications. (V) The handling of radioactive materials and sources of ionizing radiation. (VI) Non-ionizing radiation. Part (B) Current data and their evaluation: (I) Natural environmental radioactivity. (II) Artificial radioactivity in the environment. (III) Occupational radiation exposure. (IV) Radiation exposures from medical applications. (V) The handling of radioactive materials and sources of ionizing radiation. (VI) Non-ionizing radiation (electromagnetic fields, optical radiation). The Annex covers explanation on terms, physical units, glossary, list of abbreviations, radiation protection laws, regulations etc. and a list of selected radionuclides.

260

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

 
 
 
 
261

Transmutation of radioactive wastes: how and why?  

International Nuclear Information System (INIS)

After having evoked the natural or spontaneous transmutation of natural or artificial radioactive atoms, the author describes how this transmutation is technically obtained, indicates the two main families of atoms present in a used nuclear fuel and for which transmutation is to be investigated (long-lived fission residues or products, and transuranium elements) and of which the behaviour in neutron fluxes must be explored. He discusses the industrial means required for artificial transmutation. He discusses the interest of performing such a transmutation

262

Effect of photoperiod on endocrine profiles and vitellogenin expression in European eels Anguilla anguilla during artificially induced ovarian development.  

Science.gov (United States)

The aim of this work was to determine the effects of dark and light conditions on the E2, testosterone and thyroid hormones levels and on the gene expression levels (vitellogenin 1, vitellogenin 2, and estradiol receptor one) in European eels (Anguilla anguilla) during ovarian development induced by increasing doses of carp pituitary extracts (CPEs). The subjects were divided into 2 groups: 14-hour light:10-hour dark (Light Group) and 24-hour darkness (Dark Group). All the eels received intramuscular injections with CPE at a dosage of 10 mg/kg body weight (BW) once a week for the first 3 weeks, 20 mg/kg BW fourth-sixth week, 30 mg/kg BW seventh-ninth week, and 40 mg/kg up to the end of the experiment (13th week). Vitellogenin and estradiol receptor expression levels did not show significant differences between the two housing conditions whereas in both groups vitellogenin mRNA increased starting from first CPE injection. Testosterone and 17-beta estradiol plasma levels were significantly greater in the Dark Group compared with the Light Group starting from the ninth and the 13th week, respectively. These results suggest that darkness could be a useful variable for standardizing gonadal maturation in eels kept in captivity. PMID:25459031

Parmeggiani, A; Govoni, N; Zannoni, A; Di Biase, A; Sirri, R; Forni, M; Mandelli, M; Mordenti, O

2015-03-01

263

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

264

Radioactivity: A stocktaking of misconceptions and misunderstandings  

International Nuclear Information System (INIS)

Ignorance about the nature of radioactivity contributed to confusions and misunderstandings of the processes involved in the Chernobyl reactor accident. People do not discriminate between natural and artificial radioactivity and explain the actual hazard, health hazards, enhanced susceptibility to cancer and leukaemia and contamination of food by merely quoting measured values, half lives and small doses which does not help the confusion or misconceptions. The author discusses some principal ways how to remedy this situation. (DG)

265

Environmental radioactivity annual report 1994  

International Nuclear Information System (INIS)

During 1994 artificial radioactivity in the environment in New Zealand and Rarotonga continued to be at trace level only, typical of recent years. There has been no significant change in artificial radioactivity status of the environment. Atmospheric and deposited radioactivity was monitored at Kaitaia, Hokitika and Rarotonga and milk radioactivity was monitored in Auckland, Taranaki and Westland. Average levels measured were: total beta activity in air, 0.13 mBq/m3; 90Sr deposition, 0.2 ± 0.2 Bq/m2; 137Cs in milk, 0.08 Bq/g K; 90Sr in milk, 0.02 Bq/g Ca. Total beta activity depositions at Hokitika and Rarotonga were 213 Bq/m2 and 174 Bq/m2 respectively. Annual total 210Pb depositions at Kaitaia, Hokitika and Rarotonga were 44, 124 Bq/m2 respectively. No artificial radionuclides were detected by gamma spectroscopic analysis of high-volume air filters during 1994, with weekly sampling periods. Annual average atmospheric 137Cs concentrations, assessed by analysis of yearly air filter aggregates, at the New Zealand and Rarotonga monitoring sites were 0.04 ± 0.02 and 0.03 ± 0.02 ?Bq/m3 respectively. Average atmospheric concentrations of natural 7Be and 210Pb were 3.1 and 0.07 mBq/m3 respectively. The report includes data on trends in atmospheric radioactivity levels since 1987. (author). 8 refs., 5 tabs., nce 1987. (author). 8 refs., 5 tabs., 3 figs

266

Exotic radioactivity  

International Nuclear Information System (INIS)

Since the discovery of natural radioactivity by Becquerel, various radioactive decay modes were found: leptonic decay (?+, ?- and electron capture decay) and hadronic decay (? decay, proton emission decay and fragmentation). The exotic radioactivities take place between fission and ? decay or proton emission. The author presents the different steps of the discovery of 14C emission decay of 223Ra. Two mechanisms are proposed to interpret this heavy ion emission: 14C cluster preformation in 223Ra nucleus or superasymmetry fission of 223Ra nucleus. Experiments performed with SOLENO, a magnetic spectrometer are presented

267

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)

268

Rock radioactivity  

International Nuclear Information System (INIS)

Natural radioactivity of rocks penetrated by the well was studied both on cores and in situ. Core measurements were aimed at determining concentrations of naturally radioactive elements (NRE) such a uranium, thorium and potassium. The methods used are as follows: gamma-spectrometry; scintillation gamma-spectrometry; instrumental neutron-activation analysis for uranium and thorium, X-ray spectral and X-ray fluorescence analyses, delayed neutron technique. Mean NRE concentrations were determined for the rock types identified by petrochemical methods. Rock radioactivity in situ was derived from gamma-log readings. The log was run in both the integral (GL) and the spectral (SGL) modifications

269

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.)

270

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)

271

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 ...

272

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

273

Measurement of radioactivity in steel  

International Nuclear Information System (INIS)

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

274

Enhanced biological effect induced by a radioactive 9C-ion beam at the depths around its Bragg peak  

International Nuclear Information System (INIS)

To explore the potential of double irradiation source, radioactive 9C-ion beam, in tumor therapy, a comparative study on the surviving effect of human salivary gland cells at different penetration depths between 9C and 12C-ion beams has been carried out. The 9C-ion beam came out more efficient in cell killing at the depths around its Bragg peak than the 12C beam, especially at the distal side of the Bragg peak. Compared to the 12C beam, an increase in RBE by a factor of up to 2.13 has been observed at the depths distal to the Bragg peak of the 9C beam. The 9C beam showed an enhanced biological effect at the penetration depths around its Bragg peak, corresponding to the stopping region of the incident 9C-ions and where the delayed low-energy particles were emitted. Further analysis revealed that cell lethality by the emitted particles from the stopping 9C-ions is responsible for the excessive biological effect at the penetration depths around the Bragg peak of the 9C beam

275

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

Energy Technology Data Exchange (ETDEWEB)

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 {sup 7}Li and {sup 19}F 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 10{sup 9} 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 ({sup 19}Ne decays), then 135Bq decaying with a half-life of 53.22 days ({sup 7}Be decays).

Swift, D C; McNaney, J M

2009-01-30

276

Induced radioactive nuclides of 10-MeV radiotherapy accelerators detected by using a portable Hp-Ge survey meter  

International Nuclear Information System (INIS)

The radioactivation of linear accelerator components for radiation therapy is interest for radiation protection in general, and particularly, when decommissioning these structures. The energy spectra of gamma rays emitted from the heads of two accelerator models, EXL-15SP and Clinac iX, after 10-MeV X-ray irradiation, were measured using a high-purity germanium semiconductor survey meter. After spectrum analyses, activities of 24Na, 28Al, 54Mn, 56Mn, 57Ni, 58Co, 60Co, 64Cu, 65Zn, 122Sb, 124Sb, 181W, 187W, 196Au, and 198Au were detected. One centimetre deep dose-equivalent rate of the heads of the linear accelerator was measured using the survey meter. The dose rate decreased to ?10 % of its initial rate after 1 week. Long-term activations were few, the radioactivity level was low, and a cooling time of several days was effective for reducing dose rate to an acceptable level for decommissioning. (authors)

277

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

278

Environmental radioactivity in New Zealand and Rarotonga : annual report 2010  

International Nuclear Information System (INIS)

The atmosphere was monitored for radioactivity at Kaitaia, Rarotonga and Chatham Islands; deposited radioactivity was monitored at Hokitika (through rainwater testing); and radioactivity in milk was monitored in the Waikato, Taranaki and Westland regions. Any artificial radioactivity continued to be at levels which are below detection thresholds in many cases and significantly below levels which would give rise to health concerns. This continues the trend of recent years, and confirms there has been no significant change in the radioactivity status of the environment. (author). 6 refs., 2 tabs.

279

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

International Nuclear Information System (INIS)

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

280

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

 
 
 
 
281

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

282

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

283

Artificial Sperm  

Directory of Open Access Journals (Sweden)

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

Nolte J

2013-01-01

284

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

285

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)

286

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

CERN Multimedia

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

287

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

288

Oxidation-induced geochemical changes in trench leachates from the Maxey Flats low-level radioactive waste disposal site  

International Nuclear Information System (INIS)

A knowledge of extra-trench processes related to oxidation-induced geochemical changes that are likely to occur when iron-rich, anoxic trench waters encounter an oxidizing environment along a redox gradient is essential for modeling radionuclide transport at low-level waste (LLW) disposal sites. The results of laboratory oxidation experiments on several trench leachates from the Maxey Flats site show that, upon oxidation, a series of geochemical changes were initiated that resulted in a drastically different solute geochemistry, involving oxidation of ferrous iron and subsequent precipitation of ferric oxyhydroxide, changes in alkalinity and acidity, a drastic increase in redox potential (Eh), and generally relatively little change in the concentrations of 60Co, 137Cs, and 85Sr in solution. The observations made in this study have important geochemical implications for the modeling of LLW sites in that the source term as an input parameter cannot be assumed to be constant, both spatially and temporally. The acid-generating potential and buffering capacity of an anoxic source term are important geochemical controls that maintain a balance between acidity and alkalinity and largely determine the nature and extent of oxidation-induced geochemical changes likely to occur along a redox gradient. The presence of organic chelating agents can alter the source term geochemistry to such an extent that authigenic ferric oxyhydroxide, which represthigenic ferric oxyhydroxide, which represents a geochemical discontinuity at the redox interface along leachate migration paths, proves to be a relatively ineffective sink for radionuclides

289

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

290

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

291

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

292

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

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

An experimental investigation of radioactivity induced by ions associated with the operation of pulsed-power accelerators  

Science.gov (United States)

Energetic light ion beams are being studied in Sandia National Laboratories' Particle Beam Fusion Accelerator II (PBFA II) for the purpose of studying the physics of applied B-diodes with the hope that these beams can be applied to inertial confinement fusion. These beams induce nuclear reactions both in the diode itself and in the materials surrounding the diode. A series of experiments was conducted wherein samples of metals typically used in the diode/gas cell region of PBFA II were exposed to ion beams at energies expected to be achieved in PBFA II. The metals studied were aluminum alloys 2024 and 6061, brass, copper, Inconel alloys 625 and 718, Stainless Steel 304, tantalum, titanium, and tungsten. The ion beams studied consisted of protons at energies of 6, 12, and 19 MeV; deuterons at 6 MeV; Lithium-7 at energies of 10, 15, 20, and 30 MeV; Lithium-6 at 30 MeV; and Boron-10 and Boron-11 at 30 MeV. The induced activity of each sample was measured as a function of time with an ion chamber and was used to estimate the rate at which the initial short-lived activity of the sample decayed. In addition, the activity of each sample was periodically measured with a Geiger counter in contact with the irradiated surface of the sample, was normalized to the total amount of energy incident on the sample, and was used as a basis to compare the amount of activity generated per mega-joule of energy for each sample. Additionally, gamma-ray spectra of the activated samples were collected using a germanium detector, and these spectra were analyzed qualitatively to identify the long-lived radioisotopes present in the sample.

Vosburg, S. K.; Ruiz, C. L.; Cooper, G. W.; Schmidlapp, F. A.

1993-03-01

295

Radioactivity and treatment of radioactive wastes  

International Nuclear Information System (INIS)

In this chapter (10) of the text-book treatment of radioactive wastes is described. This chapter consist of the following sections: (1) Radioactivity; (2) Effect of ionizing radiation on organism; (3) Nuclear fuel cycle; (4) Nuclear energetics - the present state and perspectives of development (in this section types of nuclear reactors are reviewed); (5) Radioactive wastes, treatment of radioactive wastes; (6) Review of legislative of the Slovak Republic about treatment of radioactive wastes and health protection at work with radioactive materials

296

Radioactivity and treatment of radioactive wastes  

International Nuclear Information System (INIS)

In this chapter (10) of the text-book treatment of radioactive wastes is described. This chapter consist of following sections: (1) Radioactivity; (2) Effect of ionizing radiation on organism; (3) Nuclear fuel cycle; (4) Nuclear energetics - present state and perspectives of development (in this section types of nuclear reactors are reviewed); (5) Radioactive wastes, treatment of radioactive wastes; (6) Review of legislative of the Slovak Republic about treatment of radioactive wastes and health protection at work with radioactive materials

297

Very low level radioactive material  

International Nuclear Information System (INIS)

Man's environment contains naturally occurring radionuclides and doses from exposures to these radionuclides mostly cannot be avoided. Consequently, almost everything may be considered as very low level radioactive material. In practical terms, management and the selection of different routes for low level material is confined to material which was subject to industrial processing or which is under a system of radiological control. Natural radionuclides with concentrations reaching reporting or notification levels will be discussed below; nevertheless, the main body of this paper will be devoted to material, mainly of artificial origin, which is in the system involving notification, registration and licensing of practices and sources. It includes material managed in the nuclear sector and sources containing artificially produced radionuclides used in hospitals, and in industry. Radioactive materials emit ionising radiations which are harmful to man and his environment. National and international regulations provide the frame for the system of radiation protection. Nevertheless, concentrations, quantities or types of radionuclide may be such, that the material presents a very low hazard, and may therefore be removed from regulatory control, as it would be a waste of time and effort to continue supervision. These materials are said to be exempted from regulatory control. Material exempted in a particular country is no longer distinguishable from ''ordinary'' material antinguishable from ''ordinary'' material and may be moved from country to country. Unfortunately, criteria for exempting radioactive materials differ strongly between countries and free trade. Therefore there is a necessity for an international approach to be developed for exemption levels

298

Microscopic artificial swimmers  

Science.gov (United States)

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

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

2005-10-01

299

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.

2004-04-01

300

Disposal of radioactive wastes  

International Nuclear Information System (INIS)

This book provides information on the origin, characteristics and methods of processing of radioactive wastes, as well as the philosophy and practice of their storage and disposal. Chapters are devoted to the following topics: radioactive wastes, characteristics of radioactive wastes, processing liquid and solid radioactive wastes, processing wastes from spent fuel reprocessing, processing gaseous radioactive wastes, fixation of radioactive concentrates, solidification of high-level radioactive wastes, use of radioactive wastes as raw material, radioactive waste disposal, transport of radioactive wastes and economic problems of radioactive wastes disposal. (C.F.)

 
 
 
 
301

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

302

HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they f...

Ivana Vukanac; Aleksandar Kandic; Mirjana Duraševic; Bojan Seslak

2012-01-01

303

Radioactive wastes  

International Nuclear Information System (INIS)

This paper is part of the Annual Literature Review issue of Water Environment Research. The review attempts to provide a concise summary of important water-related environmental science and engineering literature of the past year, of which 40 separate topics are discussed. On the topic of radioactive wastes, the present paper deals with the following aspects: national programs; waste repositories; mixed wastes; waste processing and decommissioning; environmental occurrence and transport of radionuclides; and remedial actions and treatment. 178 refs

304

Coupled electron transfers in artificial photosynthesis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Light-induced charge separation in molecular assemblies has been widely investigated in the context of artificial photosynthesis. Important progress has been made in the fundamental understanding of electron and energy transfer and in stabilizing charge separation by multi-step electron transfer. In the Swedish Consortium for Artificial Photosynthesis, we build on principles from the natural enzyme photosystem II and Fe-hydrogenases. An important theme in this biomimetic effort is that of cou...

Hammarstro?m, Leif; Styring, Stenbjörn

2008-01-01

305

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

306

A Light Driven Artificial Goldfish  

Science.gov (United States)

Liquid crystalline elastomers (LCEs) undergo large and rapid shape changes when illuminated by light. We have immersed an azo-dye doped LCE in a fluid and alternately illuminate either side of the LCE with light to create an artificial goldfish of sorts. These light induced deformations allow the LCE to interact with a fluid environment in novel ways. We use a fluid flow visualization technique to attempt to understand the dynamics of these interactions. We describe our experimental setup, the LCE drive scheme used, and our observations of induced motion in both the LCE sample and the surrounding fluid.

Neal, J.; Finkelmann, H.; Palffy-Muhoray, P.; Shelley, M.; Toth-Katona, T.

2005-03-01

307

Environmental radioactivity annual report 1993  

International Nuclear Information System (INIS)

During 1993 artificial radioactivity in the environment in New Zealand and Rarotonga continued to be at trace level only, typical of recent years. There has been no significant change in artificial radioactivity status of the environment since 1992. Atmospheric and deposited radioactivity was monitored at Kaitaia, Hokitika and Rarotonga and milk radioactivity was monitored in Auckland, Taranaki and Westland. Average levels measured were: total beta activity in air, 0.15 mBq/m3; 90Sr deposition, 0.1 Bq/km2; 137Cs in milk, 0.15 Bq/g K; 90Sr in milk, 0.02 Bq/g Ca. Total beta activity depositions at Hokitika and Rarotonga were 172 Bq/m2 and 334 Bq/m2 respectively. Annual total 210Pb depositions at Kaitaia, Hokitika and Rarotonga were 48, 115, 33 Bq/m2 respectively. No artificial radionuclides were detected by gamma spectroscopic analysis of high-volume air filters during 1993, with weekly sampling periods. Annual average atmospheric 137Cs concentrations, assessed by analysis of yearly air filter aggregates, at Kaitaia, Hokitika and Rarotonga were 0.02, 0.05 and 3 respectively. Average atmospheric concentrations of natural 7Be and 210Pb were 2.9 mBq/m3 and 0.05 mBq/m3 respectively. Atmospheric beta activity was found to be made up of contributions from cosmogenic radionuclides (60%), 210genic radionuclides (60%), 210Pb/210Bi (25%) and natural radionuclides in suspended dust (15%). A study of trends in atmospheric 137Cs concentrations, derived from analyses of yearly aggregates of air filters for the period 1986-1993, indicated that fission products from the Chernobyl reactor did not reach detectable levels in New Zealand, confirming earlier projections and indications. Fallout 210Pb and 210Po in diet contribute estimated annual average effective annual average effective dose commitments of 4.5 and 2.3 ?Sv respectively, compared to the total dose commitment of 90Sr and 137Cs, of about 2 ?Sv/y. The report includes data on trends in atmospheric radioactivity levels since 1987. (author). 15 refs., 7 tabs., 4 figs

308

Radioactive nuclides in the living environment  

International Nuclear Information System (INIS)

There are several radioactive nuclides in the living environment, such as those existing since the creation of the earth, those coming from experimental nuclear explosions, and radiations of the cosmic rays. A lesson on these radioactive nuclides was considered useful for understanding the place of nuclear technology, and have been made on the title of 'Radioactive Nuclides in the Living Environment' in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. When the curriculum of the general course was modified in 1993, the lesson was left in a changed form. Thus, the textbook of the lesson is presented in this report. The contents are natural and artificial radioactive nuclides in the living environment and where they have come from etc. (author)

309

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

310

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

311

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)

Disposal of nuclear waste in deep geological formations is expected to induce thermal fluxes for hundreds of years with maximum temperature reaching about 100-150 deg. C in the nearfield argillaceous environment. The long-term behavior of clays subjected to such thermal gradients needs to be perfectly understood in safety assessment considerations. In this respect, a Toarcian argillaceous unit thermally disturbed by the intrusion of a 1.1-m wide basaltic dike at the Perthus pass (Herault, France), was studied in detail as a natural analogue. The thermal imprint induced by the dike was evaluated by a mineralogical, chemical and K-Ar study of the <2 ?m clay fraction of shale samples collected at increasing distance from the basalt. The data suggest that the mineral composition of the shales was not significantly disturbed when the temperature was below 100-150 deg. C. Closer to the dike at 150-300 deg. C, changes such as progressive dissolution of chlorite and kaolinite, increased content of the mixed layers illite-smectite with more illite layers, complete decalcification and subsequent increased content of quartz, were found. At the eastern contact with the dike, the mineral and chemical compositions of both the shales and the basalt suggest water-rock interactions subsequent to the intrusion with precipitation of palagonite and renewed but discrete deposition of carbonate. A pencil cleavage developed in the shales during the dike emplacement probably favored water cdike 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

312

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  

Energy Technology Data Exchange (ETDEWEB)

Disposal of nuclear waste in deep geological formations is expected to induce thermal fluxes for hundreds of years with maximum temperature reaching about 100-150 deg. C in the nearfield argillaceous environment. The long-term behavior of clays subjected to such thermal gradients needs to be perfectly understood in safety assessment considerations. In this respect, a Toarcian argillaceous unit thermally disturbed by the intrusion of a 1.1-m wide basaltic dike at the Perthus pass (Herault, France), was studied in detail as a natural analogue. The thermal imprint induced by the dike was evaluated by a mineralogical, chemical and K-Ar study of the <2 {mu}m clay fraction of shale samples collected at increasing distance from the basalt. The data suggest that the mineral composition of the shales was not significantly disturbed when the temperature was below 100-150 deg. C. Closer to the dike at 150-300 deg. C, changes such as progressive dissolution of chlorite and kaolinite, increased content of the mixed layers illite-smectite with more illite layers, complete decalcification and subsequent increased content of quartz, were found. At the eastern contact with the dike, the mineral and chemical compositions of both the shales and the basalt suggest water-rock interactions subsequent to the intrusion with precipitation of palagonite and renewed but discrete deposition of carbonate. A pencil cleavage developed in the shales during the 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.

Techer, Isabelle [Laboratoire de Geochimie Isotopique, UMR 6635 CNRS CEREGE/CUFR Nimes/Universite Aix-Marseille 3, Parc Scientifique et Technique Georges Besse, 150 rue G. Besse, 30035 Nimes (France)]. E-mail: techer@forpro.org; Rousset, Davy [Centre de Geochimie de la Surface, UMR 7517, 1 rue Blessig, 67084 Strasbourg (France); Clauer, Norbert [Centre de Geochimie de la Surface, UMR 7517, 1 rue Blessig, 67084 Strasbourg (France); Lancelot, Joel [Laboratoire de Geochimie Isotopique, UMR 6635 CNRS CEREGE/CUFR Nimes/Universite Aix-Marseille 3, Parc Scientifique et Technique Georges Besse, 150 rue G. Besse, 30035 Nimes (France); Boisson, Jean-Yves [Institut de Radioprotection et de Surete Nucleaire, BP 17, 92262 Fontenay aux Roses (France)

2006-02-15

313

Radioactive substances  

International Nuclear Information System (INIS)

This paper deals with the use and particularly the disposal of radioactive substances in laboratories, under the headings: introduction (general comments; classification of radionuclides; units; records); sealed sources; natural U, Th and K; materials with very short half-lives; contaminated clothing (disposables; re-usable items); low activity solid waste (collection; disposal into normal refuse; disposal to landfill waste sites; incineration; disposal to sewers); moderate-activity solid materials; liquids (washing-up water from sinks and handbasins; sluices and latrines; other aqueous liquids; solvent-based waste; liquid scintillation wastes); gases and vapours; biological materials; spillages and decontamination. (U.K.)

314

A methodology for environmental radioactivity monitoring  

International Nuclear Information System (INIS)

A research programme has been carried out aimed at ascertaining in the Po River (Northern Italy) the combinations 'environmental unit/detectable element' more effective for radioecological monitoring purposes. S.M.O.D. (sedimentable mineral-organic detritus) in artificial banks was recognized as very interesting combination. S.M.O.D. has shown an accumulation ability for various natural and artificial radionuclides. It was thus possible to ascertain levels of radioactivity even under condition not readily detectable with the matrices usually used for radiation protection monitoring. 6 refs.; 4 figs.; 2 tabs

315

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

316

Uranium and radioactivity  

International Nuclear Information System (INIS)

The article gives results of investigations on uranium content and the proportion of induced and natural radioactivity in wines of different vines and regions. The ecological chain of ground, vine, grape, grape-juice, and wine is described, and the author shows that 14C and T measurements can be used to determine the age of wines with the aim of detecting adulterated vintages and blends of different years. The 14C and T content also indicates a direct connection with nuclear explosions. (RB/AK)

317

Radioactive wastes  

International Nuclear Information System (INIS)

A review is presented on the environmental behavior of radioactive wastes. The management of high-level wastes and waste disposal methods were discussed. Some topics included were ore processing, coagulation, absorption and ion exchange, fixation, ground disposal, flotation, evaporation, transmutation and extraterrestrial disposal. Reports were given of the 226Ra, 224Ra and tritium activity in hot springs, 90Sr concentrations in the groundwater and in White Oak Creek, radionuclide content of algae, grasses and plankton, radionuclides in the Danube River, Hudson River, Pacific Ocean, Atlantic Ocean, Lake Michigan, Columbia River and other surface waters. Analysis showed that 239Pu was scavenged from Lake Michigan water by phytoplankton and algae by a concentration factor of up to 10,000. Benthic invertebrates and fish showed higher 239Pu concentrations than did their pelagic counterparts. Concentration factors are also given for 234Th, 60Co, Fe and Mr in marine organisms. Two models for predicting the impact of radioactivity in the food chain on man were mentioned. In an accidental release from a light-water power reactor to the ocean, the most important radionuclides discharged were found to be 90Sr, 137Cs, 239Pu and activation products 65Zr, 59Fe, and 95Zr

318

Cluster Radioactivity  

Science.gov (United States)

One of the rare examples of phenomena predicted before experimental discovery, offers the opportunity to introduce fission theory based on the asymmetric two center shell model. The valleys within the potential energy surfaces are due to the shell effects and are clearly showing why cluster radioactivity was mostly detected in parent nuclei leading to a doubly magic lead daughter. Saddle point shapes can be determined by solving an integro-differential equation. Nuclear dynamics allows us to calculate the half-lives. The following cluster decay modes (or heavy particle radioactivities) have been experimentally confirmed: 14C, 20O, 23F, 22,24-26Ne, 28,30Mg, 32,34Si with half-lives in good agreement with predicted values within our analytical superasymmetric fission model. The preformation probability is calculated as the internal barrier penetrability. An universal curve is described and used as an alternative for the estimation of the half-lives. The macroscopic-microscopic method was extended to investigate two-alpha accompanied fission and true ternary fission. The methods developed in nuclear physics are also adapted to study the stability of deposited atomic clusters on the planar surfaces.

Poenaru, Dorin N.; Greiner, Walter

319

Artificial ferroelectricity in perovskite superlattices  

Science.gov (United States)

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

Tsurumi, Takaaki; Harigai, Takakiyo; Tanaka, Daisuke; Nam, Song-Min; Kakemoto, Hirofumi; Wada, Satoshi; Saito, Keisuke

2004-11-01

320

Radioactivity of some alpha, beta and gamma emitting radionuclides in surface marine sediments of different bays in Algeria  

International Nuclear Information System (INIS)

Samples of surface (0-15) cm marine sediments of different grain sizes, namely sand, muddy and fine sand, were collected in the western, central and east coast of Algeria, to measure concentrations of natural and artificial radioactivity. The aim of this study is to detect any radioactive contamination, its origin and also to determine the uptake of radioactivity by marine surface sediments

 
 
 
 
321

Radioactive Substances Act 1993  

...Open sources are radioactive materials that...apply to keep or use open sources, download application form RSA1o...defined as being a “radioactive source containing radioactive material where the...

322

Radioactive waste management in radioactive installations  

International Nuclear Information System (INIS)

It is presented a norm to establish general criteria and basic requirements related to radioactive waste management. The norm is applied to radioactive installations subject to licensing process by Brazilian Nuclear Energy Commission-CNEN. (Author)

323

Artificial pinning centres in YBCO thin films induced by substrate decoration with gas-phase-prepared Y2O3 nanoparticles  

International Nuclear Information System (INIS)

Y2O3 nanoparticles prepared by an inert gas phase condensation process were used to introduce artificial pinning centres in YBa2Cu3O7-? thin films. The areal density of the particles was varied between 120 and 4200 particles ?m-2 without changing the mean particle diameter of approximately 9 nm. Y2O3 particles were deposited on TiO2 terminated SrTiO3 (100) single-crystal substrates with areal densities up to 1654 particles ?m-2 and subsequently covered with YBa2Cu3O7-? by off-axis pulsed laser deposition (PLD). The areal density of the room temperature deposited particles is not changed by the substrate heating during PLD although their height on the substrate decreases. An influence on Jc is demonstrated for particle densities above 1588 particles ?m-2, indicating that the substrate decoration with Y2O3 nanoparticles from the gas phase affects the formation of artificial pinning centres in the YBa2Cu3O7-? films and can be applied to further study of the effect of particle size and areal density on defect formation in YBa2Cu3O7-?

324

Artificial pinning centres in YBCO thin films induced by substrate decoration with gas-phase-prepared Y{sub 2}O{sub 3} nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

Y{sub 2}O{sub 3} nanoparticles prepared by an inert gas phase condensation process were used to introduce artificial pinning centres in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films. The areal density of the particles was varied between 120 and 4200 particles {mu}m{sup -2} without changing the mean particle diameter of approximately 9 nm. Y{sub 2}O{sub 3} particles were deposited on TiO{sub 2} terminated SrTiO{sub 3} (100) single-crystal substrates with areal densities up to 1654 particles {mu}m{sup -2} and subsequently covered with YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} by off-axis pulsed laser deposition (PLD). The areal density of the room temperature deposited particles is not changed by the substrate heating during PLD although their height on the substrate decreases. An influence on J{sub c} is demonstrated for particle densities above 1588 particles {mu}m{sup -2}, indicating that the substrate decoration with Y{sub 2}O{sub 3} nanoparticles from the gas phase affects the formation of artificial pinning centres in the YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} films and can be applied to further study of the effect of particle size and areal density on defect formation in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}.

Sparing, M [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany); Backen, E [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany); Freudenberg, T [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany); Huehne, R [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany); Rellinghaus, B [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany); Schultz, L [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany); Holzapfel, B [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany)

2007-09-15

325

Environmental radioactivity and radiation doses in Switzerland 1992  

International Nuclear Information System (INIS)

This report summarises the 1992 results of the environmental radioactivity monitoring programme together with interpretation and outcoming radiation exposure of the Swiss population. The surveillance programme includes radioactivity of air, rain, surface water, soil, vegetation, food, etc. as well as natural radioactivity, exposure by radon in dwellings, radioactivity released to the environment by nuclear installations and other enterprises processing radioisotopes and further radiation sources. In 1992, Swiss nuclear power stations and industrial plants licensed to process radionuclides respected their limits for radioactivity release to the environment, and no inadmissible concentrations or ambient doses have been detected in the surroundings. The mean radiation exposure of the public amounted, as in the previous years, to approximately 4.6 mSv per year. Thereof 2.2 mSv derived from natural radon in dwellings whereas the total artificial radioactivity without that from medical applications yielded less than 0.2 mSv per year. (author) figs., tabs., refs

326

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

327

HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT  

Directory of Open Access Journals (Sweden)

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

Ivana Vukanac

2012-09-01

328

Complex assessment of ecological safety in regard to radioactive contamination induced by activities for decommissioning and liquidation of uranium ore mining and processing sites  

International Nuclear Information System (INIS)

Activities for decommissioning of uranium ore mining or processing sites as well as post-decommissioning safe isolation from the biosphere of remaining radioactive wastes have to be planned and performed on the basis of laws and regulations defining maximum permissible radioactivity levels and risks for the environment and the population in the area. For this purpose, remaining amounts of tailings and other wastes are buried under isolating material, the last layer consisting of soil for recultivation of the area. The paper discusses several projects for decommissioning, safe containment and/or rehabilitation and rededication of abandoned mines or processing sites. (orig./CB)

329

Radioactivity in the Great Lakes.  

Science.gov (United States)

Studies of radioactivity in the Laurentian Great Lakes are reviewed to evaluate the impact of radionuclide dissemination on the world's foremost freshwater aquatic ecosystem. The status of radiologically-degraded areas is also reported. Significant amounts of radioactivity are stored in the basin, which has numerous nuclear reactors as well as uranium mine waste areas. The prevailing low levels of artificially-produced radionuclides, arising largely from previous fallout inputs, provide very little radiation dose to the area residents consuming lake water. The interlake transport of radionuclides is adequately described by existing models, though some refinement of the source term is needed. Revised estimates of fallout over each lake are given, but no data are available to estimate drainage basin contributions. Only limited information is available on the dispersal of radioactive pollutants. The influence of chemical parameters on radionuclide cycling has been extensively investigated in Lake Michigan and, to a lesser degree, in Lake Ontario. The need for developing a radiological objective for fish becomes apparent from an assessment of the very few data collected thus far on the biological and dosimetric aspects. Several research and monitoring needs are also identified. PMID:2063188

Joshi, S R

1991-03-01

330

Comparison of cross-sectional hardness and transverse microradiography of artificial carious enamel lesions induced by different demineralising solutions and gels.  

Science.gov (United States)

The aims of this study were: (1) to correlate surface (SH) and cross-sectional hardness (CSH) with microradiographic parameters of artificial enamel lesions; (2) to compare lesions prepared by different protocols. Fifty bovine enamel specimens were allocated by stratified randomisation according to their initial SH values to five groups and lesions produced by different methods: MC gel (methylcellulose gel/lactic acid, pH 4.6, 14 days); PA gel (polyacrylic acid/lactic acid/hydroxyapatite, pH 4.8, 16 h); MHDP (undersaturated lactate buffer/methyl diphosphonate, pH 5.0, 6 days); buffer (undersaturated acetate buffer/fluoride, pH 5.0, 16 h), and pH cycling (7 days). SH of the lesions (SH(1)) was measured. The specimens were longitudinally sectioned and transverse microradiography (TMR) and CSH measured at 10- to 220-microm depth from the surface. Overall, there was a medium correlation but non-linear and variable relationship between mineral content and radicalCSH. radicalSH(1) was weakly to moderately correlated with surface layer properties, weakly correlated with lesion depth but uncorrelated with integrated mineral loss. MHDP lesions showed the highest subsurface mineral loss, followed by pH cycling, buffer, PA gel and MC gel lesions. The conclusions were: (1) CSH, as an alternative to TMR, does not estimate mineral content very accurately, but gives information about mechanical properties of lesions; (2) SH should not be used to analyse lesions; (3) artificial caries lesions produced by the protocols differ, especially considering the method of analysis. PMID:20016178

Magalhães, A C; Moron, B M; Comar, L P; Wiegand, A; Buchalla, W; Buzalaf, M A R

2009-01-01

331

Environmental radioactivity  

International Nuclear Information System (INIS)

Outline summary of a report prepared under contract to the DOE: Research Priorities and UK Estuaries: An Overview identifying Research Requirements. Topics considered include the study of radionuclides released into the NE Irish Sea from BNFL, Sellafields, differences in the isotopic composition of stable lead in various sediments, the concentration and distribution of 'hot particles' derived from BNFL in the Irish Sea and adjacent areas, together with attempts to separate hot particles from sediments, and the composition and properties of marine surfaces in relation to uptake and loss of radionuclides, particularly in relation to the common mussel, Mytilus edulis. The problem of the presence of transuranic radionuclides in the bottom sediments of the NE Irish Sea is considered. Profiles of radioactivity are being developed at the shelf-break in order to determine the transfer of radionuclides from the sea surface to the deep sea and to coastal waters; organisms examined include phytoplankton, zooplankton and crustacea (shrimps). Organisms such as Acantharia have been examined to determine transfer of elements and radionuclides to skeletal structures eg Sr, Ba and Si. (U.K.)

332

A study of marine zoo-benthos of OM attouyour (systematic, ecology and radioactivity)  

International Nuclear Information System (INIS)

This study introduces a survey of marine zoo-Benthos found in the littoral zone of Om Attouyour. Measuring natural and artificial radioactivity. Likewise, artificial radionuclides levels and Hg, Pb, Cd, Zn, and Cu concentrations were low or within the range measured for similar samples in other coasts of the Mediterranean. (author)

333

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)

334

Monitoring of radioactivity in the marine environment  

International Nuclear Information System (INIS)

The necessity of radioactivity monitoring in the marine environment was imposed by the increasing development of nuclear power and its world-wide use in many different segments of economic and social life. Both natural and artificial radioactivity play an important role in marine ecology and human health. In this respect three major facts continue to prevail in Romania. The fallout, the presence of the Danube river and the expectations for future energy production. Spatial and temporal monitoring of marine radioactivity along the Romanian Black Sea shore has been systematically performed in the Romanian Marine Research Institute in close co-operation with the Institute of Meteorology and Hydrology since 1981. Marine emerged and submerged sediments, coastal and offshore sea water, macroalgae, in vertebrates and fish off the Danube mouths and/or along the coast are monitored for natural and artificial radioactivity by means of beta gross measurements and gamma spectrometry. Concentrations of radionuclides as K-40, Cs-134, Cs-137 in abiotic and biotic samples, environmental distributions coefficients and concentrations factors (CF), as well as experimentally-derived CFs in marine biota as radioecological bioindicators are assessed and stored for a national data base. (author) 3 tabs., 18 refs

335

Disposal of radioactive wastes  

International Nuclear Information System (INIS)

Radioactive waste management and disposal requirements options available are discussed. The possibility of beneficial utilization of radioactive wastes is covered. Methods of interim storage of transuranium wastes are listed. Methods of shipment of low-level and high-level radioactive wastes are presented. Various methods of radioactive waste disposal are discussed

336

Environmental radioactivity in Switzerland  

International Nuclear Information System (INIS)

The current report contains a summary of the radioactivity monitoring results carried out in Switzerland during the year 1991 and the resultant radiation dosages thus ascertained. The report embraces natural radioactivity, radioactivity in foodstuffs, radiation exposure from radon within buildings and the effects of radioactivity emanating from nuclear power plants and other production facilities as well as from other sources of radiation. figs., tabs

337

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.)

338

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)

339

Radioactive pollution  

International Nuclear Information System (INIS)

The widely published claims that the public health effects resulting from routine emissions are between 0.01 and 0.1 serious health effects per gigawattyear, and hence are at least a thousand times smaller than those resulting from air pollution by the burning of coal, cannot be true, for two reasons. The authors of these claims have ignored at least two of the more important isotopes, radon-222 and carbon-14, which are presently released to the environment, and thus contribute greatly to the health impact of nuclear energy. The health effects calculated in the earlier work cover only those which occur during the year in which the energy is generated. This means, figuratively speaking, that the authors have confused an annual installment payment with the full cost. This is unacceptable. The contribution to the health impact of nuclear energy arising from the single isotopic species radon-222 emanating from the mill tailings is estimated to 400 lung cancer deaths/GW(e)y, larger even than the most pessimistic estimates of the health impact of energy from coal through atmospheric pollution. We have no assurance that other long-lived isotopes do not contribute comparable amounts to the health impact of nuclear energy. The discussion of the health impact of radon-222 raises the fundamental moral question--how far into the future our responsibility extends. If such a long-termresponsibility is rejected, then we must at least try to predict the environmental buildup of radiopredict the environmental buildup of radioactive pollutants, in order to avoid unacceptable and irreversible levels of radiation dose rate. The potential health consequences from long-lived radioisotopes seem to have been largely ignored so far, and should be explored in detail

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 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

 
 
 
 
341

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

342

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 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.

Jun, J. S.; Kim, K. S. [Taejon Radiation Monitoring Station, Daejeon (Korea, Republic of)

1998-01-15

343

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

344

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 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

345

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)

346

Radioactive characterization of sand samples from Failaka Island in Kuwait  

International Nuclear Information System (INIS)

Sand samples were collected from Failaka Island in the state of Kuwait for radioactive characterization. The activity concentrations of both natural and artificial radionuclides were determined using gamma (?)-ray spectrometry. From the measured ?-spectra, radioactivity concentrations were determined for Uranium-238 (238U), Thorium-232 (232Th), Radium-226 (226Ra), Potassium-40 (40K), and Cesium-137 (137Cs). To evaluate the radiological hazard of the natural radioactivity on Failaka Island, the radium equivalent activity, the representative level index, the external hazard index, the internal hazard index, the absorbed dose, and the effective dose rate were calculated and compared with international approved values. (author)

347

Artificial muscle: facts and fiction.  

Science.gov (United States)

Mechanical devices are sought to support insufficient or paralysed striated muscles including the failing heart. Nickel-titanium alloys (nitinol) present the following two properties: (i) super-elasticity, and (ii) the potential to assume different crystal structures depending on temperature and/or stress. Starting from the martensite state nitinol is able to resume the austenite form (state of low potential energy and high entropy) even against an external resistance. This one-way shape change is deployed in self-expanding vascular stents. Heating induces the force generating transformation from martensite to the austenite state while cooling induces relaxation back to the martensite state. This two-way shape change oscillating between the two states may be used in cyclically contracting support devices of silicon-coated nitinol wires. Such a contractile device sutured to the right atrium has been tested in vitro in a bench model and in vivo in sheep. The contraction properties of natural muscles, specifically of the myocardium, and the tight correlation with ATP production by oxidative phosphorylation in the mitochondria is briefly outlined. Force development by the nitinol device cannot be smoothly regulated as in natural muscle. Its mechanical impact is forced onto the natural muscle regardless of the actual condition with regard to metabolism and Ca2+-homeostasis. The development of artificial muscle on the basis of nitinol wires is still in its infancy. The nitinol artificial muscle will have to prove its viability in the various clinical settings. PMID:22183715

Schaub, Marcus C

2011-01-01

348

On the modification of nuclear chronometry methods in astrophysics and geophysics induced by excited states of alpha radioactive nuclei and gamma emission  

International Nuclear Information System (INIS)

In practically all methods of nuclear chronometry known till now, were the lifetimes of only fundamental states for decaying ?-radioactive nuclei usually taken into account. But in the processes of nuclear synthesis in stars and under the influence of the constant cosmic radiation on the surfaces of planets, also the excited ?-radioactive nuclei appear. Between them, there are the states with the excited ?-particles inside the parent nuclei. They have much smaller lifetimes relative to the Geiger and Nutall law. And inside the large masses of stellar, terrestrial and meteoric substances, the transitions between different excited radioactive nuclei are accompanied by infinite chains of the ?-radiations with the subsequent ?-absorptions, the further ?-radiations etc. We must describe the ?-decay evolution, considering such excited states and multiple ?-radiations and ?-absorptions inside stars and also under the influence of the cosmic radiation on the earth surface. We present the quantum-mechanical approach, which is based on the generalized Krylov–Fock theorem. Some simple estimations are presented. They give rise to the conclusion that the usual (non-corrected) "nuclear clocks" do not really indicate the realistic values but the upper limits of the durations of the ?-decay stellar and planet processes. (author)

349

Environmental radioactivity in New Zealand and Rarotonga : annual report 2006  

International Nuclear Information System (INIS)

Artificial radioactivity in the environment in New Zealand and Rarotonga monitored during 2006 continued to be at trace levels only, typical of recent years during which there has been no significant change in the radioactivity status of the environment. Atmospheric radioactivity was monitored at Kaitaia, Rarotonga and Chatham Islands; deposited radioactivity was monitored at Hokitika; and radioactivity in milk was monitored in the Waikato, Taranaki and Westland regions. The annual total beta concentration in deposition in Hokitika was 409 ± 29 Bq/m2. The annual average levels of caesium-137 (137Cs) in milk powder were: 137Cs in milk in Waikato = 0.75 ± 0.29 Bq/kg; 137Cs in milk in Taranaki = 0.98 ± 0.33 Bq/kg; 137Cs in milk in Westland = 0.47 ± 0.25 Bq/kg. (author). 6 refs., 2 tabs

350

Experimental studies on utilization of argonless artificial air  

International Nuclear Information System (INIS)

The radioactive argon produced in nuclear reactors causes environmental pollution. One of the substantial methods to reduce radioactive argon is the utilization of the artificial air with low argon content in reactor rooms. The artificial air close to natural air is obtainable by mixing commercial oxygen and nitrogen, however, there are some technical problems to be solved before it is solved. A small scale facility supplying artificial air was manufactured for trial, in order to find the optimum condition of controlling the mixing and to develop the continuous measurement method for the argon concentration in artificial air. In this study, the following facts have been found. For providing with the argonless artificial air close to natural air, the mixing of the gases evaporating from commercial liquid oxygen and nitrogen can be safely controlled. For the mixing control covering the wide range of flow rate, it is necessary to set up an auxiliary line in low flow range, in addition to the ordinary main line. The method of controlling the flow ratio of oxygen and nitrogen is not suitable to the control in low flow range. The oxygen concentration control method detecting it continuously is applicable to the control of whole flow range. The argon concentration is measured with an X-ray emission spectrometer. (Kako, I.)

351

Natural and artificial radioactivity in soils of forests  

International Nuclear Information System (INIS)

Levels of 222 Rn, 40 K, 235 U, 226 Ra and 137 Cs were studied in soils of a forest zone located at 3000 m altitude in the central portion of Mexico. the radon concentrations in different soil horizons were determined with solid state nuclear track detectors and the concentrations of 40 K, 235 U, 226 Ra and 137 Cs in soil samples were measured with a gamma spectrometer at low level coupled to a High purity Ge detector. The results indicate differences of a magnitude order in the radon concentrations inside the studied area. The levels of 40 K, 235 U, 226 Ra and 137 Cs are discussed as function of the perturbation grade of the soil and atmospheric pollution. (Author)

352

Artificial Hydration and Nutrition  

Science.gov (United States)

... should talk with the doctor about the patient's medical condition and risks and benefits of giving artificial hydration ... Care Trainer's Guide, Module 11, withholding, withdrawing therapy. In: Emanuel LL, von Gunten CJ, Ferris FD. ...

353

Intelligence: Real or artificial?  

Science.gov (United States)

Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally referred to behavior-environment relations and not to inferred internal structures and processes. It is concluded that if workers in artificial intelligence are to succeed in their general goal, then they must design machines that are adaptive, that is, that can learn. Thus, artificial intelligence researchers must discard their essentialist model of natural intelligence and adopt a selectionist model instead. Such a strategic change should lead them to the science of behavior analysis. PMID:22477051

Schlinger, Henry D.

1992-01-01

354

Introduction to artificial intelligence  

Science.gov (United States)

This paper presents an introductory view of Artificial Intelligence (AI). In addition to defining AI, it discusses the foundations on which it rests, research in the field, and current and potential applications.

Cheeseman, P.; Gevarter, W.

1986-01-01

355

Artificial Intelligence in Games  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Based on the recent surge in interest in the both academic and games industry in character- based artificial intelligence. Although the games are mainly related with entertainments, but with this there are other serious applications of gaming, including military training, educational games, driving training, medical training and games that reflect social consciousness or advocate for a cause. Artificial intelligence in games is a concept of taking game applications beyond the lim...

Raju; Nitin Sikka; Sanjeev Kumar; Rahul Gupta

2012-01-01

356

Artificial black holes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study black holes for the linear hyperbolic equations describing the wave propagation in the moving medium. Such black holes are called artificial since the Lorentz metric associated with the hyperbolic equation does not necessary satisfies the Einstein equations. Artificial black holes also arise when we consider perturbations of the Einstein equations. In this paper we review author's results of [E2] and [E3] on the existence and the stability of black holes for the sta...

Eskin, Gregory

2011-01-01

357

Physics of Artificial Gravity  

Science.gov (United States)

This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.

Bukley, Angie; Paloski, William; Clement, Gilles

2006-01-01

358

Principles of artificial intelligence  

CERN Document Server

A classic introduction to artificial intelligence intended to bridge the gap between theory and practice, Principles of Artificial Intelligence describes fundamental AI ideas that underlie applications such as natural language processing, automatic programming, robotics, machine vision, automatic theorem proving, and intelligent data retrieval. Rather than focusing on the subject matter of the applications, the book is organized around general computational concepts involving the kinds of data structures used, the types of operations performed on the data structures, and the properties of th

Nilsson, Nils J

2014-01-01

359

Artificial intelligence in medicine.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of ...

Ramesh, A. N.; Kambhampati, C.; Monson, J. R. T.; Drew, P. J.

2004-01-01

360

Artificial skin. Jinko hifu  

Energy Technology Data Exchange (ETDEWEB)

In order to restore the human skin wounds, the transplantation is only one measure. The transplantation can take only when own skin is used, and there is no successful example by using other person's skin. When the own skin is not sufficient due to the too vast damage, the artificial skin, which can be regenerated as it is, is required. The artificial skin is said to be the most difficult organ among the artificial organs, even though its function is quite simple. Although there are the pig skin, the collagen membrane and the synthetic materials such as the polyurethane and so forth, as the materials similar to the artificial skin, they cover the wounds just until the cuticle is formed. Recently there is a cultivated skin. Firstly the normal skin with a size of the stamp is cut off, and then the cuticle cells are taken to pieces and cultivated, and consequently it is possible to increase the area by several 10 times. In addition, there is also a trial to make the artificial skin synthetically. Its upper layer is composed of the silicon, and the lower layer is the collagen membrane with a sponge structure. The silicon, membrane can be said to be an ideal artificial skin, because it detaches naturally. The chitin, which has recently appeared as the wound protection material, is also the promising material. 3 figs.

Kifune, K. (Unitika Ltd., Osaka (Japan))

1993-06-15

 
 
 
 
361

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)

362

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

363

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

364

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 ...

365

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

366

Radioactive waste management  

International Nuclear Information System (INIS)

This booklet is a publication by International Atomic Energy Agency for general awareness of citizens and policy-makers to clarify their concept of nuclear wastes. In a very simple way it tells what is radioactivity, radiations and radioactive wastes. It further hints on various medial and industrial uses of radiations. It discusses about different types of radioactive wastes and radioactive waste management. Status of nuclear power plants in Central and Eastern European countries are also discussed

367

Leakage of natural radioactivity  

International Nuclear Information System (INIS)

Migration naturally occurring radioactive substances leached by water out of Australian uranium deposits is being investigated by scientists from the Australian Atomic Energy Commission. These investigations help predict the long-term consequences of leaching of material from underground repositories of radioactive wastes from nuclear power stations. Rates of migration of naturally radioactive substances provide yardsticks by which to access the migration rates of man-made radioactive substances

368

Environmental radioactivity in Switzerland  

International Nuclear Information System (INIS)

The current report contains a summary of the radioactivity monitoring results carried out in Switzerland during the years 1989 and 1990 and the resultant radiation dosages thus ascertained. The report embraces natural radioactivity, radioactivity in foodstuffs, radiation exposure from radon within buildings and the effects of radioactivity emanating from nuclear power plants and other production facilities as well as from other sources of radiation. refs., figs., tabs

369

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

370

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

371

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)

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

Packaging radioactive wastes  

International Nuclear Information System (INIS)

This paper provides information on the packaging of radioactive wastes for which disposal routes are not presently available. It is the first of a series of Radioactive Waste Management Papers planned to provide information and assistance to those concerned with production of radioactive waste. (author)

374

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)

375

Aspects of radioactive waste management  

International Nuclear Information System (INIS)

The origin and types of radioactive waste, the objective and the fundamental principles of radioactive waste management and the classification of radioactive waste are presented. Problems of the radioactive waste management are analyzed. (authors)

376

Characterization and comparison of insulin resistance induced by Cushing Syndrome or diestrus against healthy control dogs as determined by euglycemic- hyperinsulinemic glucose clamp profile glucose infusion rate using an artificial pancreas apparatus.  

Science.gov (United States)

Euglycemic-hyperinsulinemic glucose clamp (EHGC) method is a gold standard for assessing insulin resistance in humans. However, this method has yet to be commonly used with dogs, due to the requirement of frequent blood sampling for glucose measurement and adjusting glucose infusion rate (GIR). The purpose of this study was to evaluate insulin resistance, induced either by Cushing Syndrome (CS) or diestrus in dogs, as determined by GIR by EHGC, using an artificial pancreas apparatus. Twenty animals were used in this study with ten (7 females and 3 males) serving as healthy controls, four (3 females, 1 male) diagnosed with CS, and six (all females) undergoing diestrus. A higher GIR value indicates increased insulin sensitivity and lower insulin resistance. GIR of healthy control animals was determined to be within a reference range of [10.6-21.3] with a median of 15.2 mg/kg/min. In comparison, the CS group had a median of 5.4 mg/kg/min; whereas the diestrus group exhibited a median of 8.9 mg/kg/min. Insulin resistant animals suffering from CS and undergoing diestrus demonstrated reductions of 65 and 40% in GIR, respectively; thus indicating differences in degree of insulin insensitivity can be discerned using the EHGC method. PMID:22785565

Fukuta, Hiroko; Mori, Akihiro; Urumuhan, Nazarbek; Lee, Peter; Oda, Hitomi; Saeki, Kaori; Kurishima, Miyuki; Nozawa, Satoshi; Mizutani, Hisashi; Mishina, Suguru; Arai, Toshiro; Sako, Toshinori

2012-11-01

377

Artificial Intelligence in Games  

Directory of Open Access Journals (Sweden)

Full Text Available Based on the recent surge in interest in the both academic and games industry in character- based artificial intelligence. Although the games are mainly related with entertainments, but with this there are other serious applications of gaming, including military training, educational games, driving training, medical training and games that reflect social consciousness or advocate for a cause. Artificial intelligence in games is a concept of taking game applications beyond the limits of interactive gaming. Such system learn about the player’s behaviours during game play and beyond the pre-programmed set provides and interactively develop and provide a best experience to the players.General Terms The main aim of our research is to develop such artificial intelligence techniques that can have a substantial impact in the game industry. In the following research paper we are going to study about Case Based Reasoning (CBR, automatic behaviour adjustment for believing characters, drama management and user modelling for interactive stories and strategic behaviour planning for real time strategy games. We include problems in adopting artificial intelligence in games and some algorithms for respective games. Future aspect of artificial intelligence in games is also mentioned in the paper.

Raju

2012-11-01

378

Experiments with radioactivity  

International Nuclear Information System (INIS)

The booklet describing experiments with radioactivity includes the following chapters: (1) radiation alarm (2) What is radioactivity? (3) Radioactive decay (4) Half-time (5) Alpha decay (6) Beta decay (6) Gamma decay (8) Neutron radiation (9) Measurement of radioactive radiation (1) Radiation and living tissue (11) Safety measures (12) Radiation protection during experiments (13) Radioactive sources (14) Experiments with a cloud chamber (15) Construction of a Geiger counter (16) Transistor radiation detector (17) Scintillation counter (18) Geiger counter with glow lamp with external power supply (19) Geiger counter with glow lamp with battery power supply (20) Technical dictionary.

379

Geoscientific evaluation of radioactive waste isolation in Japan  

International Nuclear Information System (INIS)

Japan has been hit by several kinds of calamities related to geologic events, and the recurrence of such events is still a possibility in most parts of the country. Accordingly, it would be difficult to find a favorable site for the permanent storage of radioactive waste, but the author believes that a site suitable for retrievable storage could possibly be found. In this region of a high degree of faulting and relatively large groundwater flows, it is necessary to satisfy the following factors to derive a favorable area for radioactive waste isolation: (a) areas with little or no volcanic or recent tectonic activity, such as active faults or active volcanoes; (b-1) geologic formations with little or no flowing groundwater; and (b-2) formations where all or most of the groundwater is easily controlled by artificial drainage. Some of the Neogene argillaceous sediments may be favorable because they satisfy the factor (b-1). Some Neogene argillaceous sediments have fewer faults and fractures; this is because tectonically induced stress has been absorbed by the plasticity of the rocks. Generally, the argillaceous sediments in the region contain water, but most of the water is bound by clay minerals contained in the rocks and is not free to migrate. Palaeozoic calcareous formations potentially satisfy the factor (b-2). In several areas of the region, dry limestone mines exist in these formations. The groundwater in limestones would have to be gathered into a drainage syste have to be gathered into a drainage system below the repository by draining either natural fractures or cave systems

380

Artificial intelligence in nanotechnology.  

Science.gov (United States)

During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines. PMID:24121558

Sacha, G M; Varona, P

2013-11-15

 
 
 
 
381

Artificial intelligence in nanotechnology  

International Nuclear Information System (INIS)

During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines. (topical review)

382

A survey of radioactive levels of agricultural products in Saitama prefecture  

Energy Technology Data Exchange (ETDEWEB)

Past atmospheric nuclear testing which have been conducted frequently, have caused environmental pollution due to the diffusion of radioactive substances into the atmosphere and from the radioactive fallout. The environmental pollution from nuclear testing into the atmosphere has resulted in the radioactive contamination in agricultural products and has continued for a long time. The radioactive contamination of agricultural products occurs through air, water and soil which were contaminated by radioactive fallout. In this paper, for the purpose of analyzing the extent of the radioactive contamination levels in the agricultural products of Saitama Prefecture, spinach, green soybeans, dried shiitake and welsh onion, were selected among products, as the amount of the harvest is abundant in all of Japan. Radioactivity concentration was investigated by gamma-ray spectrometry and radiochemical analysis. The radioactivity concentrations of artificial radioactive nuclides, cesium-137 ({sup 137}Cs) and strontium-90 ({sup 90}Sr), were detected in the range which is considered to be the result of radioactive fallout. Moreover, in order to examine the effect on radioactivity concentrations in agricultural products by culinary processing, the raw agricultural products were boiled, and their radioactivity concentrations were compared with the raw produce. The radioactivity concentrations in the boiled were lower than those in the raw produce. (author)

Motegi, Misako; Miyake, Sadaaki; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Inst. of Public health, Saitama (Japan)

1997-09-01

383

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

384

Artificial intelligence executive summary  

International Nuclear Information System (INIS)

Artificial intelligence (AI) is a high technology field that can be used to provide problem solving diagnosis, guidance and for support resolution of problems. It is not a stand alone discipline, but can also be applied to develop data bases for retention of the expertise that is required for its own knowledge base. This provides a way to retain knowledge that otherwise may be lost. Artificial Intelligence Methodology can provide an automated construction management decision support system, thereby restoring the manager's emphasis to project management

385

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

386

Rutherford, Radioactivity, and the Atomic Nucleus  

CERN Document Server

Modern atomic and nuclear physics took its start in the early part of the twentieth century, to a large extent based upon experimental investigations of radioactive phenomena. Foremost among the pioneers of the new kind of physics was Ernest Rutherford, who made fundamental contributions to the structure of matter for more than three decades and, in addition, founded important research schools in Manchester and Cambridge. This paper reviews the most important aspects of Rutherford's scientific work in the period from about 1900 to 1920, and it also refers to some of his last experiments of the 1930s. The emphasis is on his theory of radioactive disintegration (1902), the discovery of the atomic nucleus (1911), and the first artificially produced element transformation (1919). Following the transmutation experiments, Rutherford developed elaborate models of the atomic nucleus, but these turned out to be unsuccessful. Other subjects could be included, but the three mentioned are undoubtedly those of the greates...

Kragh, Helge

2012-01-01

387

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.)

388

Influence of inducing luteal regression before a modified fixed-time artificial insemination protocol in postpartum beef cows on pregnancy success.  

Science.gov (United States)

Most fixed-time insemination protocols utilize an injection of GnRH at the beginning of the protocol to initiate a new follicular wave. However, the ability of GnRH to initiate a new follicular wave is dependent on the stage of the estrous cycle. We hypothesized that administering PGF(2?) 3 d before initiating a fixed-time AI protocol would improve synchrony of follicular waves and result in greater pregnancy success. Therefore, our objective was to determine whether inducing luteal regression 3 d before a fixed-time AI protocol would improve control of follicular turnover and pregnancy success to fixed-time AI. Multiparous crossbred cows at 3 locations (n = 108, 296, and 97) were randomly assigned to 1 of 2 treatments: 1) PGF(2?) [25 mg; intramuscularly (i.m.)] on d -9, GnRH (100 ?g; i.m.) and insertion of a controlled internal drug-releasing device (CIDR) on d -6, PGF(2?) (25 mg; i.m.) and CIDR removal with PGF(2?) (25 mg; i.m.) at CIDR removal on d 0 (PG-CIDR) or 2) GnRH (100 ?g; i.m.) and insertion of a CIDR on d -5 and CIDR removal with PGF(2?) (25 mg; i.m.) at CIDR removal and 4 to 6 h after CIDR removal (5-d CIDR). Cows were time-inseminated between 66 and 72 h (PG-CIDR) or 70 to 74 h (5-d CIDR) after CIDR removal, and GnRH was administered at the time of fixed-time AI. At location 1, ovulatory response to the first injection of GnRH was determined by ultrasonography at the time of GnRH and 48 h after GnRH administration. Among cows with follicles ?10 mm in diameter, more (P = 0.03) PG-CIDR-treated cows ovulated after the initial GnRH injection (88%, 43/49) compared with the 5-d CIDR-treated cows (68%, 34/50). Pregnancy outcome was not influenced by location (P = 0.96), age of the animal (P = 1.0), cycling status (P = 0.99), BCS (P = 1.0), or any 2-way interactions (P ? 0.13). However, pregnancy success was influenced by synchronization protocol (P = 0.04). Pregnancy outcome was greater (P = 0.04) for the PG-CIDR protocol (64%) compared with the 5-d CIDR protocol (55%). In summary, control of follicular turnover was improved by inducing luteal regression 3 d before initiation of a fixed-time AI protocol, and pregnancy success was improved with the PG-CIDR protocol compared with the 5-d protocol. PMID:21948605

Perry, G A; Perry, B L; Krantz, J H; Rodgers, J

2012-02-01

389

National policy and experience with the management of radioactive wastes from non-fuel cycle activities in the Czech Republic  

International Nuclear Information System (INIS)

Research, production, and application of radioisotopes in many fields of science, industry, agriculture, medicine, education, etc. proceeded in the former Czechoslovak Republic (CSFR) since the mid-fifties. These activities resulted in a great accumulation of relatively large volumes and activities of radioactive wastes. Therefore, in 1959 the Czechoslovak government appointed the Institute for Research, Production, and Application of Radioisotopes (IRPAR), now NYCOM, to be the central authority for collection and disposal of these radioactive wastes. In 1972 these responsibilities were defined in more detail by the decree of the Ministry of Health of the Czech Republic No. 59/1972 on the protection of public health against the effects of ionizing radiation. From the very beginning the services for collection, transport, and disposal provided by IRPAR (NYCOM) were based on the concept of waste concentration and their safe disposal in well-controlled facilities. The aim of disposal is to guarantee that man and his environment will not suffer, neither at present nor in the future, from these wastes. This aim is achieved by isolation of radioactive wastes from the human environment by a system of multiple barriers for a sufficiently long period of time to allow activity to decay below acceptable limits. The disposal of radioactive wastes in the central repositories started in 1959, when the first repository located near the village Hostim in the Beroun District was put ige Hostim in the Beroun District was put in operation. The operational period of this repository was ended in 1963 and it was closed in 1965. At present, there are other two repositories in operation. The repository Richard serves for disposal of wastes containing artificial radionuclides, i.e., nuclides with induced radioactivity and fission products. The repository Bratrstvi serves for disposal of naturally occurring radionuclides, i.e., nuclides of uranium and thorium and their daughter products. (author). 2 refs, 2 figs

390

Regions with increased natural radioactivity. Pt. 3  

International Nuclear Information System (INIS)

The goals pursued by the investigation on hand were: 1. to get a survey of natural radioactivity in the Fichtelgebirge; 2. to find and describe locally restricted areas of high natural radioactivity (abnormal radiation, hot spots); this will be a starting point 3. for the assessment of possible increased radiation exposure and of the state of health of a restricted number of persons. Furthermore, there are also 4. underground data for the eventual stipulation of maximum permissible values for natural radioactivity. 5. The situation in the Fichtelgebirge shall be compared with that of the monazite sand-stone areas in India. The highest gamma dose rates measured in locally restricted areas were: 1. granite road pavement: 24 ?R/h; 2. granite quarries (35 ?R/h); 3. caves below granite rock (40 to 70 ?R/h); 4. slag brick pavement on market place and main street of Marktredwitz (53.4 ?R/h) (part of which removed already); 5. uranium abnormalities on a farmer's field (80-100 ?R/h) (0.6 m below the surface: 1.500 ?R/h); this may be considered an uranium deposit with a content in uranium of up to 0.3%; 6. over 100 ?R/h in front of an uranium ore mine in the uranium prospection drift (rest of the drift in the granite no more than 29.3+-3.3 ?R/h). The resulting maximum conceivable radiation exposure is assessed. The question whether there is a necessity for setting tolerance limit values for natural radioactivity is raised again; the magnitude in comparison with limit values for artificial radioactivity in radioactive controlled areas is pointed out. (orig./HP)

391

Environmental radioactivity surveillance programme 1997 and 1998  

International Nuclear Information System (INIS)

This report presents the results of the terrestrial monitoring programme carried out by the Radiological Protection Institute of Ireland (RPII) during 1997 and 1998. The principal objective of this programme is to assess the exposure to the Irish population arising from radioactivity in the Irish terrestrial environment. The programme also fulfils Irish obligations under Article 35 of the EURATOM Treaty whereby each Member State of the European Union is required to monitor continuously levels of radioactivity in the environment, thus ensuring compliance with basic safety standards. No abnormal readings were observed during this reporting period for gamma dose rate, radioactivity in airborne particulates or radioactivity in rainwater. The measured concentrations of strontium-90 in milk and caesium-137 in air and milk were consistent with global fallout levels at these latitudes. Atmospheric concentrations of krypton-85, which is released into the atmosphere as a result of nuclear fuel reprocessing, reflected the gradual build up of this radionuclide in the troposphere of the northern hemisphere with corresponding increases in skin and effective dose. However, none of the increases observed were of significance from a radiological safety point of view. Drinking water supplies showed a significant variation in gross alpha activity concentrations. Supplies with levels exceeding the 100 mBq/l screening level were investigated further. The results of these investigations indicated that these supplies were in compliance with the WHO guidelines pertaining to radioactivity in drinking water. The levels of artificial radioactivity recorded during this reporting period in air, rainwater, drinking water and milk continue to be insignificant from a radiological safety point of view and do not pose a significant risk to human health.(author)

392

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

393

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.)

394

Potentiated clinoptilolite: artificially enhanced aluminosilicate reduces symptoms associated with endoscopically negative gastroesophageal reflux disease and nonsteroidal anti-inflammatory drug induced gastritis  

Directory of Open Access Journals (Sweden)

Full Text Available Wilna Potgieter, Caroline Selma Samuels, Jacques Renè SnymanDepartment of Pharmacology, School of Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, Gauteng, South AfricaPurpose: The cation exchanger, a potentiated clinoptilolite (Absorbatox™ 2.4D, is a synthetically enhanced aluminosilicate. The aim of this study was to evaluate the possible benefits of a potentiated clinoptilolite as a gastroprotective agent in reducing the severity of clinical symptoms and signs associated with 1 endoscopically negative gastroesophageal reflux disease (ENGORD and 2 nonsteroidal anti-inflammatory drug (NSAID medication.Methods and patients: Two randomized, double-blind, placebo-controlled, pilot studies, the ENGORD and NSAID studies, were conducted. After initial negative gastroscopy, a total of 25 patients suffering from ENGORD were randomized to receive either placebo capsules or 750 mg Absorbatox twice daily for 14 days. The NSAID study recruited 23 healthy patients who received orally either 1,500 mg Absorbatox or placebo three times daily, plus 500 mg naproxen twice daily. Patients underwent gastroscopic evaluation of their stomach linings prior to and on day 14 of the study. Gastric biopsies were obtained and evaluated via the upgraded Sydney system, whereas visible gastric events and status of the gastric mucosa were evaluated via a 0–3 rating scale. During both studies, patients recorded gastric symptoms in a daily symptom diary.Results: In the ENGORD study, patients who received the potentiated clinoptilolite reported a significant reduction (P?0.05 in severity of symptoms including reduction in heartburn (44%, discomfort (54%, and pain (56%. Symptom-free days improved by 41% compared to the group who received placebo (not significant. This was over and above the benefits seen with the proton pump inhibitor. In the NSAID study, the reduction in gastric symptom severity was echoed in the group who received the potentiated clinoptilolite. Treatment with the potentiated clinoptilolite resulted in significant prevention (P?0.05 of mucosal erosion severity as graded by the gastroenterologist.Conclusion: Absorbatox is a nonabsorbable aluminosilicate with potential gastroprotective benefits as it protected against ENGORD symptoms and NSAID-induced gastric events. The exact mechanism of action is not clear but may be due to its binding to hydrogen ions and biologically active amines and nitrates.Keywords: cation exchanger, gastro-protective agent, endoscopy, zeolite

Potgieter W

2014-07-01

395

Artificial intelligence within AFSC  

Science.gov (United States)

Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

Gersh, Mark A.

1990-01-01

396

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

397

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

398

Artificial Disc Replacement  

Science.gov (United States)

... of an FDA-approved study. There are also disc replacements designed for use in the cervical spine (the neck). These devices have only been used a relatively short time, and several are currently undergoing evaluation in FDA-approved trials in the United States. Who needs an artificial disc?

399

Argumentation in Artificial Intelligence  

CERN Document Server

Examines the intersection between two fields of inquiry, including Argumentation Theory and Artificial Intelligence. This book presents an overview of key concepts in argumentation theory and of formal models of argumentation in AI. It offers a review of the foundational issues in argumentation and formal argument modeling.

Simari, Guillermo

2009-01-01

400

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

 
 
 
 
401

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

402

Preparation of radioactive tracer for studying sediment movement  

International Nuclear Information System (INIS)

In order to study the movement of sediment in harbours, estuaries and streams, artificial sediment in the form of glass is prepared. A preselected nuclide is added to the glass during its manufacture. The density and size distribution of the glass particles is method with that of the natural sediment. The activation of the artificial sediment in a reactor changes the nuclide into a radioactive isotope thereby tagging it and making it possible to trace its movement with suitable radiation detector. The method of tracer preparation is described with special reference to sadiment movement studies at Karachi harbour. (authors)

403

Radioactivity and its measurement  

CERN Document Server

Begins with a description of the discovery of radioactivity and the historic research of such pioneers as the Curies and Rutherford. After a discussion of the interactions of &agr;, &bgr; and &ggr; rays with matter, the energetics of the different modes of nuclear disintegration are considered in relation to the Einstein mass-energy relationship as applied to radioactive transformations. Radiation detectors and radioactivity measurements are also discussed

Mann, W B; Garfinkel, S B

2013-01-01

404

Disposal of radioactive wastes  

International Nuclear Information System (INIS)

The meeting which was organized by Bundesamt fuer Strahlenschutz and took place on November 25 and 26, 1991 in Berlin informed the plant owners liable to delivery, the nuclear waste conditioners, and the nuclear licensing and supervisory boards in the five new provinces of unified Germany on the disposal of radioactive wastes. Emphasis was placed on the radioactive waste acceptance requirements, waste package quality control, safety aspects relevant to the Morsleben repository, and on the conditioning and intermediate storage of radioactive wastes. (BBR)

405

Radioactive Branching Using Dice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dice rolling (Emeric,1997) is a useful pedagogical tool (Arthur & Ian,2012; Todd, Clifton, Ingrid, Zdravko,2006)) to introduce students to the concepts and essential features of radioactivity. It can be extended to explain radioactive branching. In the process, the students learn about half life, decay constant and activity of a radioactive substance. Terms like stochastic processes, probability of decay, statistical fluctuations, and mutually exclusive processes; becomes clear in this pr...

Sarmistha Sahu

2012-01-01

406

Drainage of radioactive areas  

International Nuclear Information System (INIS)

This Code of Practice covers all the drainage systems which may occur in the radioactive classified area of an establishment, namely surface water, foul, process and radioactive drainage. It also deals with final discharge lines. The Code of Practice concentrates on those aspects of drainage which require particular attention because the systems are in or from radioactive areas and typical illustrations are given in appendices. The Code makes references to sources of information on conventional aspects of drainage design. (author)

407

Radioactive Branching Using Dice  

Directory of Open Access Journals (Sweden)

Full Text Available Dice rolling (Emeric,1997 is a useful pedagogical tool (Arthur & Ian,2012; Todd, Clifton, Ingrid, Zdravko,2006 to introduce students to the concepts and essential features of radioactivity. It can be extended to explain radioactive branching. In the process, the students learn about half life, decay constant and activity of a radioactive substance. Terms like stochastic processes, probability of decay, statistical fluctuations, and mutually exclusive processes; becomes clear in this process.

Sarmistha Sahu

2012-09-01

408

Radioactive Waste Management Basis  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this Radioactive Waste Managemen