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1

Artificial radioactivity is fifty: 1934-1984  

International Nuclear Information System (INIS)

This book has been published on the occasion of the fiftieth anniversary celebration of the artificial radioactivity discovery; contributions from men who have been near the Joliot at the beginning of the artificial radioactivity, or whose work have been marked by this discovery are gathered in this book. Subjects have been choosed very freely by the authors; that explains their great diversity. The reader will find precious memories from direct witnesses of this great time; he will find also descriptions of the following works; he will even find audacious dreams on matter utilization possibilities, which may rise to-morrow

2

Artificial radioactivity is fifty: 1934-1984  

Energy Technology Data Exchange (ETDEWEB)

This book has been published on the occasion of the fiftieth anniversary celebration of the artificial radioactivity discovery; contributions from men who have been near the Joliot at the beginning of the artificial radioactivity, or whose work have been marked by this discovery are gathered in this book. Subjects have been chosen very freely by the authors; that explains their great diversity. The reader will find precious memories from direct witnesses of this great time; he will also find descriptions of the following works; he will even find audacious dreams on matter utilization possibilities, which may rise tomorrow.

Amaldi, E.; Biquard, P.; Goldstein, L.

1984-01-01

3

Natural and artificial radioactivity in Great Bratislava  

International Nuclear Information System (INIS)

[en] The results of the aviation measurement of the gamma-radiation are presented in the form of the maps of iso-lines of the concentration of the natural radioactive elements (potassium, uranium, thorium) and artificial radionuclides (cesium-137, cesium-134). From the obtained dates the maps of dose rate of the gamma-radiation in the air are calculated, of the dose equivalent rate and the map of the fraction of the dose equivalent rate from the natural elements potassium, uranium, thorium. The natural radioactivity of the minerals in the Great Bratislava region, especially for the extreme low values of the contain of the thorium, does not amount the average values of the radioactivity of the Earth crust. The area activity of cesium-137 are in the range 2 - 10 kBq.m-2 and cesium-134 is 1 - 2.5 kBq.m-2. From the point of view of the summary level of the external irradiation from the Earth surface the measured zone as relative even is evaluated, in the range 10-100 nSv.h-1. The total average level of the dose rate of the external irradiation of man (inclusively from the cosmic radiation 40-50 nSv.h-1) in the conditions of Bratislava is 100 nSv.h-1. The contribution of external component of the irradiation is 40-100 nSv.h-1 (0.1-0.3 mSv.y-1). The dose equivalent commitment of internal component from the cesium-137 is for the all age category of the population under the level negligible risk 0.01 mSv.y-1[sk] Vysledky leteckeho merania ziarenia gama su prezentovane vo forme map izolinii koncentracie prirodnych radioaktivnych prvkov (K, U, Th) i umelych radionuklidov (Cs-137, Cs-134). Zo ziskanych udajov su vypocitane mapy davkoveho prikonu ziarenia gama vo vzduchu, prikonu davkoveho ekvivalentu a mapa podielu davkoveho ekvivalentu z prirodnych prvkov K, U, Th. Prirodna radioaktivita hornin v oblasti Velkej Bratislavy, zvlast pre extremne nizke hodnoty obsahu toria, nedosahuje ani priemernych hodnot radioaktivity zemskej kory. Plosne aktivty Cs-137 su v rozsahu 2 az 10 kBq.m-2 a Cs-134 je 1 az 2.5 kBq.m-2. Z hladiska sumarnej urovne externeho oziarenia zo zemskeho povrchu sa hodnoti merana oblast za relativne rovnomernu, v rozsahu 10-100 nSv.h-1. Celkova priemerna uroven prikonu externeho oziarenia cloveka (vratane kozmickeho 40-50 nSv.h-1) v podmienkach Bratislavy je 100 nSv.h-1. Prispevok externej zlozky oziarenia je 40-100 nSv.h-1 (0.1-0.3 mSv.y-1). Uvazok internej zlozky z Cs-137 je pre vsetky vekove kategorie obyvatelstva pod urovnou zanedbatelneho rizika 0.01 mSv.y-1

1997-01-01

4

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.)

1981-01-01

5

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)

2011-04-01

6

Radioactive contamination of natural and artificial materials  

International Nuclear Information System (INIS)

The gamma radiation of different materials was measured in an underground low-background chamber with extraordinary background characteristics. The excellent background conditions of the measurements enabled investigators to see the alpha-particle peaks of the internal radioactive contamination of NaI(Tl) detectors, which were especially made for these measurements. The sensitivity limit of the installation was determined by the internal contamination of the NaI(Tl) detectors alone. Any radiation background, except for three substances, tungsten, copper, and brass, could be registered

1978-04-28

7

Natural and Artificial Radioactivity in Drinking Water in Malaga, Spain  

International Nuclear Information System (INIS)

Water has a vast importance for numerous human activities, so that securing supplies of drinking water of a standard quality is becoming more and more difficult. The measurement of radioactivity in drinking water permits us to determine the exposure of the population to radiation from the habitual consumption of water. The occurrence of radionuclides in drinking water gives rise to internal exposure of humans, directly on the decay of radionuclides taken into the body through ingestion and inhalation and indirectly when they are incorporated as part of the food-chain The measurement of radioactivity in drinking water permits us to determine the exposure of population to radiation from the habitual consumption of water. An intensive study of the water supply in the city of Malaga during 2002-2010 has been carried out in order to determine the gross alpha activities, gross beta activities and natural and artificial radionuclides present in drinking water. A data base on natural and artificial radioactivity in water was produced. The results indicated that a high percentage of the water sample contains a total gross alpha and beta less than 0.10 Bq/l and 1 Bq/l respectively. The main objectives were: 1) to analyses gross alpha and gross beta activities and to know the statistical distributions. 2) to study the levels of natural and artificial radionuclides 3) to determine a possible mathematical correlation between the radionuclides and several factors.

2011-04-01

8

Resuspension of radioactivity induced  

International Nuclear Information System (INIS)

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

1975-01-01

9

Natural and artificial radioactivity in coastal regions of UK  

International Nuclear Information System (INIS)

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

1991-01-01

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

1979-01-01

11

Medical imaging was boosted by the discovery of artificial radioactivity  

International Nuclear Information System (INIS)

[en] 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.)

2002-01-01

12

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

International Nuclear Information System (INIS)

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

1994-01-01

13

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

Energy Technology Data Exchange (ETDEWEB)

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

Baeza, A.; Miro, C.; Paniagua, J.M. [Univ. of Extremadura, Caceres (Spain); Navarro, E.; Rodriguez, M.J.; Sanchez, F. [Univ. of Valencia (Spain)

1994-01-01

14

Radioactivity of natural and artificial building materials - a comparative study.  

UK PubMed Central (United Kingdom)

Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point to the limitations of the internal hazard considerations based on only measured (226)Ra activity concentrations without direct radon measurements. Our data are compared to those obtained in other countries and they provide a good basis to expand the database of radioactivity of building materials and gives information about the safety and situation of the building material industry in this central region of Europe.

Szabó Z; Völgyesi P; Nagy HÉ; Szabó C; Kis Z; Csorba O

2013-04-01

15

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 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)

1998-01-01

16

Level of natural and artificial radioactivity in Algeria.  

UK PubMed Central (United Kingdom)

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.

Baggoura B; Noureddine A; Benkrid M

1998-07-01

17

Natural and artificial radioactivity determination of some medicinal plants  

International Nuclear Information System (INIS)

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

2010-01-01

18

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)

1989-01-01

19

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)

1991-01-01

20

Natural and artificial radioactivity determination of some medicinal plants  

Energy Technology Data Exchange (ETDEWEB)

Several medicinal plants used in Italy were analysed to determine natural and artificial radioactivity in those parts (leaves, fruits, seeds, roots, peduncles, flowers, barks, berries, thallus) used generally as remedies. The radionuclides were determined by alpha ({sup 238}U, {sup 210}Po) and gamma ({sup 214}Pb-Bi, {sup 210}Pb, {sup 40}K and {sup 137}Cs) spectrometry. {sup 238}U ranged between <0.1 and 7.32 Bq kg{sub dry}{sup -1}; {sup 210}Po between <0.1 and 30.3 Bq kg{sub dry}{sup -1}; {sup 214}Pb-{sup 214}Bi between <0.3 and 16.6 Bq kg{sub dry}{sup -1}; {sup 210}Pb between <3 and 58.3 Bq kg{sub dry}{sup -1}; {sup 40}K between 66.2 and 3582.0 Bq kg{sub dry}{sup -1}; {sup 137}Cs between <0.3 and 10.7 Bq kg{sub dry}{sup -1}. The percentage of {sup 210}Po extraction in infusion and decoction was also determined; the arithmetical mean value of percentage of {sup 210}Po extraction resulted 20.7 {+-} 7.5.

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

2010-09-15

 
 
 
 
21

Nuclear chemistry fifty years after the discovery of artificial radioactivity  

International Nuclear Information System (INIS)

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

1984-01-01

22

Modeling of the radioactive contamination of the Techa river by artificial neural networks  

International Nuclear Information System (INIS)

This study examines the applicability of using artificial neural network in modeling radioactive contamination features for the Techa River. A multi layer perceptron trained with error back propagation algorithm was used to model processes of filtration of radioactive isotopes from the Techa Reservoirs to the Techa River and their migration in the river system. (authors)

2006-01-01

23

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

2002-01-01

24

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

International Nuclear Information System (INIS)

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

1996-01-01

25

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

International Nuclear Information System (INIS)

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

1962-01-01

26

NATURAL AND ARTIFICIAL RADIOACTIVITY IN IMPORTED FISHERY PRODUCTS  

Directory of Open Access Journals (Sweden)

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

M.C. Campagna; A. Nardoni; R. Cavallina

2013-01-01

27

NATURAL AND ARTIFICIAL RADIOACTIVITY IN IMPORTED FISHERY PRODUCTS  

Directory of Open Access Journals (Sweden)

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

M.C. Campagna; A. Nardoni; R. Cavallina

2010-01-01

28

Evolution of artificial radioactivity in Channel sediments, 1971-1975  

International Nuclear Information System (INIS)

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

1976-01-01

29

Induced radioactivity due to high energy radiation  

International Nuclear Information System (INIS)

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

1975-08-28

30

Artificial radioactivity of Finnish vegetables in the 2000s.  

UK PubMed Central (United Kingdom)

A survey on long-lived artificial radionuclides (137)Cs and (90)Sr in vegetables produced in Finland was carried out in 2009-2010. The mean (137)Cs concentrations of all the outdoor vegetables were well below 0.5 Bq kg(-1), ranging from <0.01 to 8.15 Bq kg(-1) (fresh weight). The highest (137)Cs contents were found in potato and root vegetables. The uneven distribution of the (137)Cs deposition after the Chernobyl accident in 1986 was still seen in the (137)Cs contents of outdoor vegetables. The (137)Cs contents of greenhouse vegetables varied from <0.01 to 9.3 Bq kg(-1), and the highest concentrations were found in organic lettuce grown in peat pots. The concentrations of (90)Sr in the vegetables varied from 0.0087 to 0.17 Bq kg(-1) fresh weight. The mean effective dose resulting from (137)Cs and (90)Sr in vegetables in 2009-2010 was <0.3 µSv a(-1) and poses no health risk to the consumers.

Kostiainen E; Turtiainen T

2013-01-01

31

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)

2004-01-01

32

Dating of artificial radioactivity in sediments of the river Yenisei  

Energy Technology Data Exchange (ETDEWEB)

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)

Klemt, E.; Parliachenka, A.; Spasova, Y.; Zibold, G. [University of Applied Sciences, Fachhochschule Ravensburg-Weingarten (Germany); Rollin, S.; Burger, M. [Spiez Laboratory, CH-3700 Spiez, Schweiz (Switzerland)

2004-07-01

33

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.

2012-01-01

34

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

International Nuclear Information System (INIS)

[en] In the present work, the enhancement of radioactivity due to rainfall in the Aegean Sea using floating measuring systems was observed and quantified. The data were acquired with a NaI underwater detection system, which was installed on a floating measuring system at a depth of 3 m. The results of natural and artificial radioactivity are discussed taking into account the rainfall intensity and wind direction. The activity concentration of 214Bi increased up to (991±102) Bq/m3 after strong rainfall in the North Aegean Sea in winter (humid period) with east wind direction. On other hand, the maximum activity concentration reached the level of (110±10) Bq/m3 in summer (dry period) during south winds

2008-01-01

35

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

Science.gov (United States)

In the present work, the enhancement of radioactivity due to rainfall in the Aegean Sea using floating measuring systems was observed and quantified. The data were acquired with a NaI underwater detection system, which was installed on a floating measuring system at a depth of 3m. The results of natural and artificial radioactivity are discussed taking into account the rainfall intensity and wind direction. The activity concentration of (214)Bi increased up to (991+/-102)Bq/m(3) after strong rainfall in the North Aegean Sea in winter (humid period) with east wind direction. On other hand, the maximum activity concentration reached the level of (110+/-10)Bq/m(3) in summer (dry period) during south winds. PMID:18495486

Tsabaris, C

2008-04-12

36

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

Energy Technology Data Exchange (ETDEWEB)

In the present work, the enhancement of radioactivity due to rainfall in the Aegean Sea using floating measuring systems was observed and quantified. The data were acquired with a NaI underwater detection system, which was installed on a floating measuring system at a depth of 3 m. The results of natural and artificial radioactivity are discussed taking into account the rainfall intensity and wind direction. The activity concentration of {sup 214}Bi increased up to (991{+-}102) Bq/m{sup 3} after strong rainfall in the North Aegean Sea in winter (humid period) with east wind direction. On other hand, the maximum activity concentration reached the level of (110{+-}10) Bq/m{sup 3} in summer (dry period) during south winds.

Tsabaris, C. [Hellenic Centre for Marine Research, P.O. Box 712, Anavyssos, Gr-19013 (Greece)], E-mail: tsabaris@ath.hcmr.gr

2008-11-15

37

Radioactivities induced in some LDEF samples  

Science.gov (United States)

Radioactivities induced in several Long Duration Exposure Facilities (LDEF) samples were measured by low-level counting at Los Alamos and elsewhere. These radionuclides have activities similar to those observed in meteorites and lunar samples. Some trends were observed in these measurements in terms of profiles in trunnion layers and as a function of radionuclide half-life. Several existing computer codes were used to model the production by the protons trapped in the Earth's radiation belts and by the galactic cosmic rays of some of these radionuclides, Mn-54 and Co-57 in steel, Sc-46 in titanium, and Na-22 in alloys of titanium and aluminum. Production rates were also calculated for radionuclides possibly implanted in LDEF, Be-7, Be-10, and C-14. Enhanced concentrations of induced isotopes in the surfaces of trunnion sections relative to their concentrations in the center are caused by the lower-energy protons in the trapped radiation. Secondary neutrons made by high-energy trapped protons and by galactic cosmic rays produce much of the observed radioactivities, especially deep in an object. Comparisons of the observed to calculated activities of several radionuclides with different half-lives indicate that the flux of trapped protons at LDEF decreased significantly at the end of the mission.

Reedy, Robert C.; Moss, Calvin E.; Bobias, S. George; Masarik, Jozef

1993-04-01

38

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)

2005-01-01

39

Radioactively induced noise in gas-sampling uranium calorimeters  

International Nuclear Information System (INIS)

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

1982-01-01

40

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

International Nuclear Information System (INIS)

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

2005-01-01

 
 
 
 
41

Metaphase and anaphase in the artificially induced monopolar spindle.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

By using monopolar spindles artificially induced in sea urchin embryos, we examined whether or not the presence of two opposing poles was an indispensable condition for keeping chromosomes at a fixed distance from the pole at metaphase and for the anaphase chromosome movement. Chromosomes were stain...

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

42

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

International Nuclear Information System (INIS)

[en] Detection of pulmonary aspiration of gastric contents by radioactive measurements of bronchial material was performed in 13 artificially ventilated infants (14 studies) after ingestion of 99m-technetium sulfure colloide. 10/13 had strong clinical suspicion of recurrent pulmonary aspiration. 10 out of 14 examinations were positive (71%). This technique is more sensitive than scintigraphic methods described in literature and particularly adapted to these patients[fr] La recherche de fausses routes tracheales par comptages bronchiques lors de reflux gastro-oesophagiens a ete effectuee chez 13 nourrissons en ventilation assistee (14 examens) apres ingestion de colloides techneties. 10/13 avaient une symptomatologie evocatrice de fausses routes. 10 des 14 examens pratiques etaient positifs (71% des cas). Cette technique est plus sensible que les methodes d'imagerie decrites dans la litterature et est particulierement adaptee a ce type de patients

1989-01-01

43

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

International Nuclear Information System (INIS)

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

2011-01-01

44

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)

1969-01-01

45

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

Energy Technology Data Exchange (ETDEWEB)

The mathematical techniques are becoming more important to solve geometry and standard identification problems. The gamma spectrometry of radioactive waste drums would be a complex solution problem. The main difficulty is the detectors calibration for this geometry; the waste is not homogeneously distributed inside the drums, therefore there are many possible combinations between the activity and the position of these radionuclides inside the drums, making the preparation of calibration standards impracticable. This work describes the development of a methodology to estimate the activity of a 200 L radioactive waste drum, as well as a mapping of the waste distribution, using Artificial Neural Network. The neural network data set entry obtaining was based on the possible detection efficiency combination with 10 sources activities varying from 0 to 74 x 10{sup 3} Bq. The set up consists of a 200 L drum divided in 5 layers. Ten detectors were positioned all the way through a parallel line to the drum axis, from 15 cm of its surface. The Cesium -137 radionuclide source was used. The 50 efficiency obtained values (10 detectors and 5 layers), combined with the 10 source intensities resulted in a 100,000 lines for 15 columns matrix, with all the possible combinations of source intensity and the Cs-137 position in the 5 layers of the drum. This archive was divided in 2 parts to compose the set of training: input and target files. The MatLab 7.0 module of neural networks was used for training. The net architecture has 10 neurons in the input layer, 18 in the hidden layer and 5 in the output layer. The training algorithm was the 'traincgb' and after 300 'epoch s' the medium square error was 0.00108172. This methodology allows knowing the detection positions answers in a heterogeneous distribution of radionuclides inside a 200 L waste drum; in consequence it is possible to estimate the total activity of the drum in the training neural network limits. The results accuracy depends on the way that the waste drum is divided and to the amount of intensities that it is interpolated between the minimum and maximum limits. The use of the Artificial Neural Networks associated to Monte Carlo Method showed to be efficient in the isotopic characterization of radioactive waste drums. (authors)

Potiens, J.R.A.J.; Hiromoto, G. [Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil)

2006-07-01

46

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

UK PubMed Central (United Kingdom)

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

El Samad O; Baydoun R; Nsouli B; Darwish T

2013-03-01

47

Induced radioactivity in the ESRF storage ring.  

UK PubMed Central (United Kingdom)

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

Berkvens P

2005-01-01

48

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

49

ATP synthesis in chromatophores driven by artificially induced ion gradients.  

UK PubMed Central (United Kingdom)

An electrochemical potential difference for protons (delta mu H+) across the membrane of bacterial chromatophores was induced by an artificially generated pH difference (delta pH) and a K+/valinomycin diffusion potential, delta phi. The initial rate of ATP synthesis was measured with a rapid-mixing quenched-flow apparatus in the time range between 70 ms and 30 s after the acid-base transition. The rate of ATP synthesis depends exponentially on delta pH. Increasing diffusion potentials shift the delta pH dependency to lower delta pH values. Diffusion potentials were calculated from the Goldman equation. Using estimated permeability coefficients, the rate of ATP synthesis depends only on the electrochemical potential difference of protons irrespective of the relative contribution of delta pH and delta phi.

Turina P; Melandri BA; Gräber P

1991-02-01

50

ATP synthesis in chromatophores driven by artificially induced ion gradients.  

Science.gov (United States)

An electrochemical potential difference for protons (delta mu H+) across the membrane of bacterial chromatophores was induced by an artificially generated pH difference (delta pH) and a K+/valinomycin diffusion potential, delta phi. The initial rate of ATP synthesis was measured with a rapid-mixing quenched-flow apparatus in the time range between 70 ms and 30 s after the acid-base transition. The rate of ATP synthesis depends exponentially on delta pH. Increasing diffusion potentials shift the delta pH dependency to lower delta pH values. Diffusion potentials were calculated from the Goldman equation. Using estimated permeability coefficients, the rate of ATP synthesis depends only on the electrochemical potential difference of protons irrespective of the relative contribution of delta pH and delta phi. PMID:2001702

Turina, P; Melandri, B A; Gräber, P

1991-02-26

51

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

International Nuclear Information System (INIS)

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

1999-01-01

52

Induced radioactivity in Bevatron concrete radiation shielding blocks  

International Nuclear Information System (INIS)

The Bevatron accelerated protons up to 6.2 GeV and heavy ions up to 2.1 GeV/amu. It operated from 1954 to 1993. Radioactivity was induced in some concrete radiation shielding blocks by prompt radiation. Prompt radiation is primarily neutrons and protons that were generated by the Bevatron's primary beam interactions with targets and other materials. The goal was to identify the gamma-ray emitting nuclides (t1/2 > 0.5 yr) that could be present in the concrete blocks and estimate the depth at which the maximum radioactivity presently occurs. It is shown that the majority of radioactivity was produced via thermal neutron capture by trace elements present in concrete. The depth of maximum thermal neutron flux, in theory, corresponds with the depth of maximum induced activity. To estimate the depth at which maximum activity occurs in the concrete blocks, the LAHET Code System was used to calculate the depth of maximum thermal neutron flux. The primary beam interactions that generate the neutrons are also modeled by the LAHET Code System

1994-01-01

53

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

International Nuclear Information System (INIS)

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

2000-01-01

54

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

International Nuclear Information System (INIS)

[en] 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 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)

1988-01-01

55

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)

1963-01-01

56

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

Directory of Open Access Journals (Sweden)

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

Junaid Ali Khan; Muhammad Asif Zahoor Raja

2013-01-01

57

Induced radioactivity in and around high-energy particle accelerators  

International Nuclear Information System (INIS)

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

2011-01-01

58

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)

1979-01-01

59

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

International Nuclear Information System (INIS)

[en] 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

1985-01-01

60

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

International Nuclear Information System (INIS)

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

1994-01-01

 
 
 
 
61

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

International Nuclear Information System (INIS)

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

1975-01-01

62

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.)

2002-01-01

63

Anthrax toxin-induced rupture of artificial lipid bilayer membranes.  

UK PubMed Central (United Kingdom)

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 BJ; Panchal RG; Bavari S; Nguyen TL; Gussio R; Ribot W; Friedlander A; Chabot D; Reiner JE; Robertson JW; Balijepalli A; Halverson KM; Kasianowicz JJ

2013-08-01

64

Anthrax toxin-induced rupture of artificial lipid bilayer membranes.  

Science.gov (United States)

We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm. PMID:23947891

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

2013-08-14

65

Anthrax toxin-induced rupture of artificial lipid bilayer membranes  

Science.gov (United States)

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

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

2013-08-01

66

Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy  

International Nuclear Information System (INIS)

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

2010-01-01

67

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

68

Muon-induced production of radioactive isotopes in scintillation detectors  

CERN Multimedia

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

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

2000-01-01

69

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)

2008-01-01

70

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

71

Destabilization of artificial biomembrane induced by the penetration of tryptophan  

International Nuclear Information System (INIS)

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

2011-03-15

72

Low-energy radioactive ion beam induced nuclear reactions  

International Nuclear Information System (INIS)

Low-energy post-accelerated radioactive ion beams have been used to study nuclear reactions addressing important nuclear structure and nuclear astrophysics questions. A high-granularity, large-solid-angle silicon strip detector array has been used to account for the low reaction products' yields. First experiments using a 6He beam on thin 12C targets show the feasibility of direct reaction studies with good angular resolution and a detection limit in access of 0.1 mb sr-1 cross sections. The measurement of the six ?-decay channel in a 13N-induced reaction on a 11B target shows the capabilities of this experimental technique even for sophisticated reaction studies. The study of stellar properties in ground-based experiments, in particular break-out reactions from the hot-CNO, i.e. 15O(?, ?)19Ne, can be pursued using these beams. Experiments are being performed to study these reactions by measurement of d(18Ne, p)19Ne*(?)15O and ?(18Ne, p), which might provide an alternative breakout route. (author)

1998-01-01

73

Spatial Heterogeneity of Artificial Reefs Functioning according to Wind-Induced Lagrangian Circulation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the scope of the program "Récifs Prado" for artificial reef immersion in the Bay of Marseilles (southern France), we adapted the fine resolution (100 m) of the 3D numerical model POM (Princeton Ocean Model) to compute the typical patterns of the wind induced circulation within the bay. In additio...

Pradal, Marie-Aude; Millet, Bertrand

74

Radioactivity  

Energy Technology Data Exchange (ETDEWEB)

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).

1989-04-01

75

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; Guo-Qin Ge

2013-01-01

76

Products of an Artificially Induced Hydrothermal System at Yucca Mountain  

Energy Technology Data Exchange (ETDEWEB)

Studies of mineral deposition in the recent geologic past at Yucca Mountain, Nevada, address competing hypotheses of hydrothermal alteration and deposition from percolating groundwater. The secondary minerals being studied are calcite-opal deposits in fractures and lithophysal cavities of ash-flow tuffs exposed in the Exploratory Studies Facility (ESF), a 7.7-km tunnel excavated by the Yucca Mountain Site Characterization Project within Yucca Mountain. An underground field test in the ESF provided information about the minerals deposited by a short-lived artificial hydrothermal system and an opportunity for comparison of test products with the natural secondary minerals. The heating phase lasted nine months, followed by a nine-month cooling period. Natural pore fluids were the only source of water during the thermal test. Condensation and reflux of water driven away from the heater produced fluid flow in certain fractures and intersecting boreholes. The mineralogic products of the thermal test are calcite-gypsum aggregates of less than 4-micrometer crystals and amorphous silica as glassy scale less than 0.2 mm thick and as mounds of tubules with diameters less than 0.7 micrometers. The minute crystal sizes of calcite and gypsum from the field test are very different from the predominantly coarser calcite crystals (up to cm scale) in natural secondary-mineral deposits at the site. The complex micrometer-scale textures of the amorphous silica differ from the simple forms of opal spherules and coatings in the natural deposits, even though some natural spherules are as small as 1 micrometer. These differences suggest that the natural minerals, especially if they were of hydrothermal origin, may have developed coarser or simpler forms during subsequent episodes of dissolution and redeposition. The presence of gypsum among the test products and its absence from the natural secondary-mineral assemblage may indicate a higher degree of evaporation during the test than during the deposition of natural calcite-opal deposits.

S. Levy

2000-08-07

77

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

Energy Technology Data Exchange (ETDEWEB)

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

Furuta, M.; Katayama, T.; Ito, N.; Mizohata, A.; Toratani, H.; Takeda, A. (Osaka Prefectural Radiation Research Inst. (Japan))

1990-01-01

78

Virus-induced gene silencing using artificial miRNAs in Nicotiana benthamiana.  

Science.gov (United States)

Virus-induced gene silencing using artificial microRNAs (MIR VIGS) is a newly developed technique for plant reverse genetic studies. Traditional virus-induced gene silencing (VIGS) assays introduce a large gene fragment, which is expressed and then converted into small RNAs by the endogenous siRNA-based gene silencing machinery of the plant host. By contrast, MIR VIGS uses well-designed miRNAs to induce RNA-mediated silencing of the target gene. Using a single artificial miRNA can provide greater specificity by reducing off-target effects. Here, we describe a detailed protocol for MIR VIGS in Nicotiana benthamiana using a modified Cabbage leaf curl virus (CaLCuV)-based vector. PMID:23386298

Tang, Yang; Lai, Yizhen; Liu, Yule

2013-01-01

79

Virus-induced gene silencing using artificial miRNAs in Nicotiana benthamiana.  

UK PubMed Central (United Kingdom)

Virus-induced gene silencing using artificial microRNAs (MIR VIGS) is a newly developed technique for plant reverse genetic studies. Traditional virus-induced gene silencing (VIGS) assays introduce a large gene fragment, which is expressed and then converted into small RNAs by the endogenous siRNA-based gene silencing machinery of the plant host. By contrast, MIR VIGS uses well-designed miRNAs to induce RNA-mediated silencing of the target gene. Using a single artificial miRNA can provide greater specificity by reducing off-target effects. Here, we describe a detailed protocol for MIR VIGS in Nicotiana benthamiana using a modified Cabbage leaf curl virus (CaLCuV)-based vector.

Tang Y; Lai Y; Liu Y

2013-01-01

80

Data for estimating radioactivity induced by high protons  

International Nuclear Information System (INIS)

[en] Suitable for practical use nuclear physical constants for the radioactivity estimates obtained by the complete approximation of radionuclide production cross sections in proton-nucleus interactions are presented. 6 refs.; 8 tabs

1989-01-01

 
 
 
 
81

Radioactivity in spruces  

Energy Technology Data Exchange (ETDEWEB)

Some specimens of spruces have been examined by gamma spectroscopy for their amount of natural and induced radioactivity. Besides the natural radionuclides K-40 and Be-7, several gamma-ray emitters of the natural decay chains have been detected, and Cs-137. The activity concentration of the latter, artificial radionuclide, has been found to be very low in comparison with the concentration of all the natural gamma emitters measured.

Huebner, A.; Jordine, W.; Wolf, A.

1986-06-07

82

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

2009-01-01

83

The ends and means of artificially induced targeted protein degradation.  

UK PubMed Central (United Kingdom)

Studies on knockout mutants and conditional mutants are invaluable to biological research and have been used extensively to probe the intricacies of biological systems through loss of function associated with attenuation of a particular protein. Besides, RNAi technology has been developed in recent years to further aid the process of scientific inquiry. Even though, the methods, dealing with DNA and RNA have met with great success, are not without their shortcomings. In order to overcome the inadequacies of existing methods, a host of new techniques, aimed at knockdowns at the protein rather than the nucleic acid level, have been devised. Essentially, these methods can achieve rapid degradation of cellular pools of a target protein in response to an inducible signal coupled with dose-dependent modulation and exquisite temporal control, features which are absent from techniques involving manipulations at the DNA or RNA level. This review aims to provide a broad overview of a gamut of these methods, while highlighting the strengths and weaknesses of each one. Last two decades of advances presented here in the field of targeted protein degradation serve as a beacon to further research and are likely to find applications in the areas of medicine and allied fields of biology.

Prabha CR; Mukherjee S; Raman R; Kulkarni S

2012-12-01

84

Induced radioactivity of building and structural materials in the 680 MeV synchrotron hall  

International Nuclear Information System (INIS)

[en] The residual radioactivity induced by scattered neutrons in iron, concrete, copper and aluminium has been measured in the hall of the 680 MeV proton accelerator. Radioisotopic composition in these materials has been determined using a Ge(Li) gamma spectrometer. The neutron flux density in sampling points has been measured with activation detectors. The relation between the dose rate due to gamma radiation of the residual radioactivity and the nutron flux density has been obtained

1975-01-01

85

Measurements of induced radioactivity in electron- and photon-irradiated beef  

International Nuclear Information System (INIS)

Samples of beef were irradiated with electrons of approx. 10-and 13.5- MeV energies or with 60Co ?-ray photons (1.17 and 1.33 MeV). Induced radioactivity was measured with a ?-ray spectrometer, consisting of a Ge(Li) detector and a multichannel analyzer. No induced radioactivity could be detected in the photon-irradiated samples; also for 10-MeV electrons the activity was below the detection limit. The irradiation by 13.5-MeV electrons, however, resulted in measurable radioactivity and the amount of 13N-activity was in agreement with previously calculated values. These measurements confirm previous conclusions that irradiation of food with electrons at 10 MeV or even at 13.5 Mev does not constitute any health risk due to radioactivity. Part of the induced radioactivity from 13.5-MeV electron irradiation is due to neutron capture, and the results suggest that several neutron sources contribute to the measured radioactivity. (author).

1987-01-01

86

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

International Nuclear Information System (INIS)

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

1988-01-01

87

Radioactivity. Centenary of radioactivity discovery  

International Nuclear Information System (INIS)

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

1997-01-01

88

Studies of muon-induced radioactivity at NuMI  

CERN Document Server

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

Boehnlein, David J

2012-01-01

89

Studies of muon-induced radioactivity at NuMI  

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-12-01

90

Artificial niche substrates for embryonic and induced pluripotent stem cell cultures.  

UK PubMed Central (United Kingdom)

Stem cells possess the ability to self-renew and differentiate into other cell types. In vivo, stem cells reside in their own anatomic niches in a defined physiological environment, from which they are released to differentiate into a required cell type when deemed appropriate. While a resident within the niche, the stem cell receives signals that in turn maintain the cell in a pluripotent state. In addition, the niche also provides nourishment to the cell. Physically, the niche also serves to anchor the cell via various ECM components and cell-adhesion molecules. Therefore, in vitro models that replicate the in vivo niche will lead to a better understanding of stem cell fate and turnover. In turn, this will help inform attempts to culture stem cells in vitro on artificial niche-like substrates. In this review, we have highlighted recent studies describing artificial niche-like substrates used to culture embryonic and induced pluripotent stem cells in vitro.

Joddar B; Ito Y

2013-05-01

91

Fusion probability for neutron-rich radioactive Sn induced reactions  

Energy Technology Data Exchange (ETDEWEB)

Evaporation residue cross sections for $^{124,126,127,128}$Sn+$^{64}$Ni and $^{132}$Sn+$^{58}$Ni have been measured to study the effects of neutron excess in neutron-rich radioactive nuclei on fusion. For the reactions with $^{64}$Ni, the fusion probability does not decrease with increasing neutron excess in Sn, contrary to the result of the stable beam Sn+Zr measurement. A comparison of the reduced evaporation residue cross sections for $^{126}$Sn+$^{64}$Ni and $^{132}$Sn+$^{58}$Ni, which make the same compound nucleus, shows that the fusion probability is indistinguishable for reactions involving the same atomic elements but different isotope combinations.

Liang, J Felix [ORNL; Gross, Carl J [ORNL; Kohley, Zachary W [ORNL; Shapira, Dan [ORNL; Varner Jr, Robert L [ORNL; Allmond, James M [ORNL; Caraley, Anne L [State University of New York, Oswego; Lagergren, Karin B [ORNL; Mueller, Paul Edward [ORNL

2012-01-01

92

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-10-26

93

Prediction of radiation induced hardening of reactor pressure vessel steels using artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we use an artificial neural network approach to obtain predictions of neutron irradiation induced hardening, more precisely of the change in the yield stress, for reactor pressure vessel steels of pressurized water nuclear reactors. Different training algorithms are proposed and compared, with the goal of identifying the best procedure to follow depending on the needs of the user. The numerical importance of some input variables is also studied. Very accurate numerical regressions are obtained, by taking only four input variables into account: neutron fluence, irradiation temperature, and chemical composition (Cu and Ni content). Accurate extrapolations in term of neutron fluence are obtained.

Castin, N., E-mail: ncastin@sckcen.b [Studie Centrum voor Kerneenergie - Centre d' Etudes de l' energie Nucleaire (SCK-CEN), NMS unit, Boeretang 200, B2400, Mol (Belgium); Universite Libre de Bruxelles (ULB), Physique des Solides Irradies et des Nanostructures (PSIN), Boulevard du Triomphe CP234, 1050 Brussels (Belgium); Malerba, L.; Chaouadi, R. [Studie Centrum voor Kerneenergie - Centre d' Etudes de l' energie Nucleaire (SCK-CEN), NMS unit, Boeretang 200, B2400, Mol (Belgium)

2011-01-01

94

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

Energy Technology Data Exchange (ETDEWEB)

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, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne and {sup 40}Ar 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)

Tanaka, Susumu; Fukuda, Mitsuhiro; Nishimura, Koichi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Watanabe, Hiromasa; Yamano, Naoki

1997-05-01

95

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

International Nuclear Information System (INIS)

[en] 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)

1997-01-01

96

Radioactive isotope and isomer separation with using light induced drift effect  

International Nuclear Information System (INIS)

The isotope separation with using light induced drift (LID) is discussed. The basic theoretical characteristics of the method are deduced: separation simultaneously with an arbitrary high enrichment and without significant losses; separation productivity up to 100 ?g/h. These characteristics are sufficient and very convenient for separation of expensive radioactive isotopes and isomers which are applied in medicine and science. The first experimental separation of the radioactive isotopes (22,24Na) by using the LID effect is reported. 13 refs.; 5 figs.

1991-01-01

97

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

98

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

International Nuclear Information System (INIS)

[en] 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)

2005-01-01

99

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 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)

2004-01-01

100

Diclofenac-enriched artificial sediment induces oxidative stress in Hyalella azteca.  

UK PubMed Central (United Kingdom)

Diclofenac is a nonsteroidal anti-inflammatory drug widely used in Mexico where it is sold over the counter. It enters water bodies through municipal and industrial discharges, posing a risk to water systems and aquatic organisms. Diclofenac-enriched artificial sediment was used to evaluate the toxicity of this pharmaceutical on the sentinel species Hyalella azteca, using oxidative stress biomarkers in order to determine if the set of tests used in this study is a suitable early damage biomarker. The median lethal concentration (72-h LC(50)) was determined and oxidative stress was evaluated using lipid peroxidation, protein carbonyl content to evaluate oxidized protein content, and the activity of superoxide dismutase, catalase, and glutathione peroxidase. All biomarkers were significantly altered. Diclofenac induces oxidative stress in H. azteca and the set of tests used (lipid peroxidation, protein carbonyl content, antioxidant enzyme activities) constitutes an adequate early damage biomarker for evaluating the toxicity of this pharmaceutical group in aquatic species.

Oviedo-Gómez DG; Galar-Martínez M; García-Medina S; Razo-Estrada C; Gómez-Oliván LM

2010-01-01

 
 
 
 
101

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

International Nuclear Information System (INIS)

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

1984-01-01

102

Nuclear reactions and subsequent radioactive decays induced by 14-MeV neutrons  

International Nuclear Information System (INIS)

[en] 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.)

1976-01-01

103

Time and energy resolved runaway measurements in TFR from induced radioactivity  

Energy Technology Data Exchange (ETDEWEB)

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.

1983-09-01

104

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

International Nuclear Information System (INIS)

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

2008-06-15

105

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

Directory of Open Access Journals (Sweden)

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

Fábio Pandini; Fernando Irajá Félix de Carvalho; José Fernandes Barbosa Neto

1997-01-01

106

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

107

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

International Nuclear Information System (INIS)

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

2001-01-01

108

[Classification of plastics with laser-induced breakdown spectroscopy based on principal component analysis and artificial neural network model].  

UK PubMed Central (United Kingdom)

The classification of seven kinds of plastic (ABS, PET, PP, PS, PVC, HDPE and PMMA) with the laser-induced breakdown spectroscopy based on artificial neural network model was investigated in the present paper. One hundred seventy LIBS spectra for each type of plastic were collected. Firstly, all 1 190 plastics LIBS spectra were studied with principal component analysis. The first five principal components (PC) totally explain 78.4% of the original spectrum information. Therefore, the scores of five PCs of 130 LIBS spectra for each kind of plastic were chosen as the training set to build a back-propagation artificial network model. And the other 40 LIBS spectra of each sample were used as the testing set for the trained model. The classification accuracy was 97.5%. Experimental results demonstrate that plastics can be classified by using principal component analysis and artificial neural network (BP) method.

Wang QQ; Huang ZW; Liu K; Li WJ; Yan JX

2012-12-01

109

[Classification of plastics with laser-induced breakdown spectroscopy based on principal component analysis and artificial neural network model].  

Science.gov (United States)

The classification of seven kinds of plastic (ABS, PET, PP, PS, PVC, HDPE and PMMA) with the laser-induced breakdown spectroscopy based on artificial neural network model was investigated in the present paper. One hundred seventy LIBS spectra for each type of plastic were collected. Firstly, all 1 190 plastics LIBS spectra were studied with principal component analysis. The first five principal components (PC) totally explain 78.4% of the original spectrum information. Therefore, the scores of five PCs of 130 LIBS spectra for each kind of plastic were chosen as the training set to build a back-propagation artificial network model. And the other 40 LIBS spectra of each sample were used as the testing set for the trained model. The classification accuracy was 97.5%. Experimental results demonstrate that plastics can be classified by using principal component analysis and artificial neural network (BP) method. PMID:23427530

Wang, Qian-Qian; Huang, Zhi-Wen; Liu, Kai; Li, Wen-Jiang; Yan, Ji-Xiang

2012-12-01

110

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

1988-01-01

111

Environmental radioactivity. Measurement and monitoring; Umweltradioaktivitaet. Messung und Ueberwachung  

Energy Technology Data Exchange (ETDEWEB)

The contribution on environmental radioactivity covers the following issues: natural and artificial radioactivity; continuous monitoring of radioactivity; monitoring authorities and measurement; radioactivity in the living environment; radioactivity in food and feeding stuff; radioactivity of game meat and wild-growing mushrooms; radioactivity in mines; radioactivity in the research center Rossendorf.

NONE

2009-11-15

112

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

International Nuclear Information System (INIS)

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

2011-01-01

113

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

International Nuclear Information System (INIS)

[en] 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 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

1980-01-01

114

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1983-01-01

115

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

CERN Multimedia

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

Cesa, A

2013-01-01

116

Increase in cerebral blood flow as a predictor of hyperbaric oxygen-induced convulsion in artificially ventilated rats.  

Directory of Open Access Journals (Sweden)

Full Text Available In spontaneously breathing rats, a transient increase in cerebral blood flow (CBF) has been shown to be a predictor of hyperbaric oxygen (HBO)-induced convulsion. In the present study, we evaluated whether artificially ventilated animals also show an increase in CBF prior to the onset of HBO-induced convulsion. Rats were ventilated with 100% oxygen in 5 atmospheres. CBF, blood pressure, and an electroencephalogram were monitored continuously. Convulsion was observed at 41 +/- 12 min after the initiation of HBO treatment. A single abrupt increase in CBF, reaching 223 +/- 39% of the control level, was observed at 29 +/- 13 min after the initiation of HBO exposure and lasted until the onset of convulsion 12 +/- 2 min later. The time of the increase in CBF correlated strongly with the onset of convulsion (r = 0.99, P < 0.001). Further, the logistic regression curve demonstrated a close relationship between the duration of increased CBF and percentage of epileptiform electrical-discharge incidence (r = 0.92, P < 0.006). The durations of increased CBF causing convulsion in 10%, 50%, and 90% of the rats were 8.4 min, 11.7 min, and 15.1 min, respectively. These results indicate that an increase in CBF is a predictor of HBO-induced convulsion in artificially ventilated rats. The increase in CBF may be involved in the pathogenesis of HBO-induced convulsion.

Kurasako T; Takeda Y; Hirakawa M

2000-01-01

117

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

Energy Technology Data Exchange (ETDEWEB)

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 {sup 19}Ne, {sup 14,15}O, {sup 20,21}Na, {sup 17,18}F 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 {mu}-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{sup +15} is the present goal. (orig.).

D`Auria, J.M. [Simon Fraser Univ., Burnaby, BC (Canada); Buchmann, L. [TRIUMF, Vancouver, B.C. V6T 2A3 (Canada); Hutcheon, D. [TRIUMF, Vancouver, B.C. V6T 2A3 (Canada); Lipnik, P. [Simon Fraser Univ., Burnaby, BC (Canada); Hunter, D. [Simon Fraser Univ., Burnaby, BC (Canada); Rogers, J. [TRIUMF, Vancouver, B.C. V6T 2A3 (Canada); Helmer, R. [TRIUMF, Vancouver, B.C. V6T 2A3 (Canada); Giesen, U. [University of Alberta, Edmonton, Alta. T6G 2N5 (Canada); Olin, A. [TRIUMF, Vancouver, B.C. V6T 2A3 (Canada); Bricault, P. [TRIUMF, Vancouver, B.C. V6T 2A3 (Canada)

1997-08-04

118

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

Energy Technology Data Exchange (ETDEWEB)

The measurement of low energy fusion reactions of importance to nuclear astrophysics scenarios are a prime objective of the physics program of the new ISAC facility, located at TRIUMF in Vancouver, Canada. Intense radioactive beams of {sup 19}Ne, {sup 14,15}O, {sup 20,21}Na, {sup 17,18}F 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 experimental configuration will be a new Recoil 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 Electro-Magnetic Separator (EMS) employing Wien filters. The recoiling reaction products will then be detected using either a Si {mu}-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{sup +15} is the present goal. (orig.). 15 refs.

D`Auria, J.M.; Lipnik, P.; Hunter, D. [Simon Fraser Univ., Burnaby, BC (Canada); Buchmann, L.; Hutcheon, D.; Rogers, J.; Helmer, R.; Olin, A.; Bricault, P. [TRIUMF, Vancouver, BC (Canada); Giesen, U. [Alberta Univ., Edmonton, AB (Canada); Bateman, N. [Simon Fraser Univ., Burnaby, BC (Canada)]|[TRIUMF, Vancouver, BC (Canada)

1997-04-01

119

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

120

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

International Nuclear Information System (INIS)

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

1997-01-01

 
 
 
 
121

Filtration and ventilation of induced radioactive gases at the ETL linac  

International Nuclear Information System (INIS)

[en] 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)

1987-01-01

122

Detection of pion-induced radioactivity by autoradiography and positron emission tomography (PET)  

International Nuclear Information System (INIS)

[en] An autoradiographic technique incorporating a new imaging system was used to detect pion-induced radioactivity in Plexiglass and the results were compared with aluminium activation and PET imaging. The activity distribution in the region of the pion-stopping peak was similar in all three cases. Another large signal in the entrance region due to in-flight interactions [12C(?-,?-n)11C] was detected by autoradiography and by PET but was not reflected in the aluminium activation measurements. This new technique is capable of defining the stopping region in phantoms with a better resolution than PET scanning and is useful as a complementary technique to other methods of pion dosimetry

1989-01-01

123

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.

N.A.T. Carvalho; F.S. Vannucci; R. Amaral; P.S. Baruselli

2010-01-01

124

OXYTOCIN-INDUCED CERVICAL DILATION AND CERVICAL MANIPULATION IN SHEEP: EFFECTS ON LAPAROSCOPIC ARTIFICIAL INSEMINATION  

Science.gov (United States)

Difficulty of cervical penetration during transcervical artificial insemination (TAI), limits its use in sheep. Trauma of cervical manipulation (CM) may explain low fertility after TAI. We investigated effects of cervical dilation using exogenous oxytocin (OT) to facilitate TAI and its effect on rep...

125

Radioactive ion beams produced by neutron-induced fission at ISOLDE  

CERN Multimedia

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

126

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

International Nuclear Information System (INIS)

[en] 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)

1987-01-01

127

Giant cross-kerr effect for propagating microwaves induced by an artificial atom.  

UK PubMed Central (United Kingdom)

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

Hoi IC; Kockum AF; Palomaki T; Stace TM; Fan B; Tornberg L; Sathyamoorthy SR; Johansson G; Delsing P; Wilson CM

2013-08-01

128

Giant cross-kerr effect for propagating microwaves induced by an artificial atom.  

Science.gov (United States)

We investigate the effective interaction between two microwave fields, mediated by a transmon-type superconducting artificial atom which is strongly coupled to a coplanar transmission line. The interaction between the fields and atom produces an effective cross-Kerr coupling. We demonstrate average cross-Kerr phase shifts of up to 20 degrees per photon with both coherent microwave fields at the single-photon level. Our results provide an important step toward quantum applications with propagating microwave photons. PMID:23952397

Hoi, Io-Chun; Kockum, Anton F; Palomaki, Tauno; Stace, Thomas M; Fan, Bixuan; Tornberg, Lars; Sathyamoorthy, Sankar R; Johansson, Göran; Delsing, Per; Wilson, C M

2013-08-02

129

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-07-01

130

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

International Nuclear Information System (INIS)

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

2006-01-01

131

Artificial vision.  

UK PubMed Central (United Kingdom)

A number treatment options are emerging for patients with retinal degenerative disease, including gene therapy, trophic factor therapy, visual cycle inhibitors (e.g., for patients with Stargardt disease and allied conditions), and cell transplantation. A radically different approach, which will augment but not replace these options, is termed neural prosthetics ("artificial vision"). Although rewiring of inner retinal circuits and inner retinal neuronal degeneration occur in association with photoreceptor degeneration in retinitis pigmentosa (RP), it is possible to create visually useful percepts by stimulating retinal ganglion cells electrically. This fact has lead to the development of techniques to induce photosensitivity in cells that are not light sensitive normally as well as to the development of the bionic retina. Advances in artificial vision continue at a robust pace. These advances are based on the use of molecular engineering and nanotechnology to render cells light-sensitive, to target ion channels to the appropriate cell type (e.g., bipolar cell) and/or cell region (e.g., dendritic tree vs. soma), and on sophisticated image processing algorithms that take advantage of our knowledge of signal processing in the retina. Combined with advances in gene therapy, pathway-based therapy, and cell-based therapy, "artificial vision" technologies create a powerful armamentarium with which ophthalmologists will be able to treat blindness in patients who have a variety of degenerative retinal diseases.

Zarbin M; Montemagno C; Leary J; Ritch R

2011-09-01

132

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

International Nuclear Information System (INIS)

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

2008-01-01

133

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

134

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

Energy Technology Data Exchange (ETDEWEB)

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

Konno, Osamu; Masumoto, Kazuyoshi; Yagi, Masuo (Tohoku Univ., Sendai (Japan). Lab. of Nuclear Science); Fujikawa, Shin-ichiro

1984-01-01

135

Prediction of the brain temperature from other body temperatures in hypothermia induced rats by using artificial neural networks.  

UK PubMed Central (United Kingdom)

In this study, a microcontroller based temperature controlled hypothermia induction system is realized. The novelty of the experimental system is in using a thermoelectric Peltier cooler to bring the body temperature to hypothermic levels. The right and left ear, rectum, and brain temperatures of a rat are measured with this system. Then, an artificial neural network (ANN) is trained using temperature data to predict brain temperature from other body temperatures. It is shown that the system has the capability to predict the brain temperature with low error from rectum temperature measurements. The results from this empirical prototype also show that it is possible to use the system on humans to induce local hypothermia safely, where an interior temperature probe in the scalp is eliminated.

Demirel H; Gökta? HH; Erkal B; Ciylan B

2012-07-01

136

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-06-15

137

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.)

1981-01-01

138

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

139

Preliminary examination of induced radioactivity in pepper by 10 MeV electron irradiation; Measurement of. beta. -ray with liquid scintillation counter  

Energy Technology Data Exchange (ETDEWEB)

{beta}-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).

Katayama, Tadashi; Furuta, Masakazu; Sibata, Setsuko; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan)); Takeda, Atsuhiko

1991-10-01

140

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

International Nuclear Information System (INIS)

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

2005-01-01

 
 
 
 
141

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

International Nuclear Information System (INIS)

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

2009-01-01

142

Radioactivity and radiation protection  

International Nuclear Information System (INIS)

The book on radioactivity and radiation protection includes the following chapters: chemical elements and their smallest particles; nuclear transformations and radioactivity; energy of radiation particles and gamma quanta; interactions of 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 - civilizing radiation exposure; radiation protection measures against external radiation effects; protection measures in nuclear power plants for radioactive materials retention; radiation protection for persons in a nuclear power plant.

2012-01-01

143

Dynamics of presynaptic protein recruitment induced by local presentation of artificial adhesive contacts.  

UK PubMed Central (United Kingdom)

In this study, we introduce a novel approach to induce and observe the formation of presynaptic compartments in axons through a combination of atomic force microscopy (AFM) and fluorescence microscopy. First, we use a poly-D-lysine-coated bead attached to an AFM tip to induce the recruitment of two synaptic proteins, bassoon and synaptophysin, and measure their absolute arrival times to the presynaptic department. We find that bassoon arrives before synaptophysin. Second, we observe the formation of very long (several 10s of ?m), structured, protein-containing membranous strings as the AFM tip was withdrawn from the axon. It is conceivable that these strings might be a novel mechanism by which new neurites or branch points along existing neurites may be generated in situ.

Suarez F; Thostrup P; Colman D; Grutter P

2013-01-01

144

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

International Nuclear Information System (INIS)

Radioactivities of residual neutron-induced radionuclides of Co-60 and Eu-152 in rocks exposed by Nagasaki Atomic Bomb were determined. Samples were obtained from the surface to 2 cm in depth of rocks. Each sample was pulverized and placed in a plastic container, and gamma-ray spectrum was measured with a pure germanium semiconductor detector. To determine the amount of natural element of cobalt and europium contained in each sample, the neutron activation method was performed by the reactor of the Research Reactor Institute, Kyoto University (KUR). The radioactivities of Co-60 and Eu-152 were evaluated as per 1 mg natural element at the time of Atomic Bomb. The results show that the radioactivities of Co-60 and Eu-152 in rocks were decreased with increasing slant distance. The Co-60 activity was 6.88±2.13 Bq/mgCo and the Eu-152 activity was 75.9±8.79 Bq/mgEu at 510 m from the epicenter. When we compared the activity of Eu-152 calculated by Loewe with our data, we found a divergence between them as the distance from the epicenter increases. (author).

1989-01-26

145

Radioactivity induced in apollo 11 lunar surface material by solar flare protons.  

UK PubMed Central (United Kingdom)

Comparison of values of the specific radioactivities reported for lunar surface material from the Apollo 11 mission with analogous data for stone meteorites suggests that energetic particles from the solar flare of 12 April 1969 may have produced most of the cobalt-56 observed.

Heydegger HR; Turkevich A

1970-05-01

146

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 induced in BoHV-1 sero-positive cows. Then isolation from nasal swabs was attempted in Madin Darby Bovine Kidney (MDBK) cell line to find out the prevalent strain in India. The virus was isolated from all the three cows. All the three isolates were typed as BoHV-1.2 (Strain India 4, India 5 and India 6). The reactivation obtained in this study with dexamethasone suggests the usefulness of BoHV-1 cow latency model for epidemiological investigations on BoHV-1 infections in tropical and sub-tropical countries like India, Pakistan etc.

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

2013-01-01

147

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.

C. Del Negro; E. Armadillo; E. Bozzo; L. Cafarella; A. Meloni; R. Napoli; A. Zirizzotti

1998-01-01

148

Radioactive contamination of the Guatemalan marine environment  

International Nuclear Information System (INIS)

As part of the IAEA TC project GUA/2/005 'Radioactivity and Contamination of the Marine Environment in Guatemala', concentrations of artificial and natural radionuclides have been determined in marine water and sediments, giving important information to establish the base line of the natural radioactivity and the radioactive contamination in this area that not have been studying

1999-01-01

149

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

International Nuclear Information System (INIS)

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

2001-01-01

150

Differential behaviour of two cyanobacterium species to UV radiation. Artificial UV radiation induces phycoerythrin synthesis.  

UK PubMed Central (United Kingdom)

Altitude is an important factor contributing to the local UV-B climate. In the European Alps solar UV-B increases approximately 21% 1000 m-1. A Nostoc muscorum (UTEX 389) originating from Scotland and a Nostoc sp. isolated from a highland lake (Yanaqocha) located 3980 m above sea level (Cusco, Perú) have been used in a study where the tolerance to UV radiation (UVR) stress of both species was determined. Following irradiation doses of 15 kJ UV (UV-A plus UV-B, equivalent to approximately 6 h exposure to unfiltered solar light at noon for a standard midlatitude region with normal ozone concentration), the viability of Nostoc sp. is 30% compared to 3% for Nostoc muscorum. UV-B induces the reduction of the number of phycobilisomes per cell, phycobilisome disassembly and/or degradation as well as phycobilisome uncoupling. Following UV exposure, phycoerythrin (PE) fluorescence emission increases dramatically in both species, indicating accumulation of PE in the phycobilisome rods. The detected increase in PE due to UVR is confirmed using a monoclonal antibody anti-PE.

Aráoz R; Shelton M; Lebert M; Häder DP

1998-07-01

151

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

1984-01-01

152

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

Directory of Open Access Journals (Sweden)

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

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

2000-01-01

153

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

Scientific Electronic Library Online (English)

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

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

2000-10-01

154

Light-induced multistep oxidation of dinuclear manganese complexes for artificial photosynthesis.  

Science.gov (United States)

Two dinuclear manganese complexes, [Mn(2)BPMP(mu-OAc)(2)].ClO(4) (1, where BPMP is the anion of 2,6-bis([N,N-di(2-pyridinemethyl)amino]methyl)-4-methylphenol) and [Mn(2)L(mu-OAc)(2)].ClO(4) (2, where L is the trianion of 2,6-bis([N-(2-hydroxy-3,5-di-tert-butylbenzyl)-N-(2-pyridinemethyl)amino]methyl)-4-methylphenol), undergo several oxidations by laser flash photolysis, using ruthenium(II)-tris-bipyridine (tris(2,2-bipyridyl)dichloro-ruthenium(II) hexahydrate) as photo-sensitizer and penta-amminechlorocobalt(III) chloride as external electron acceptor. In both complexes stepwise electron transfer was observed. In 1, four Mn-valence states from the initial Mn(2)(II,II) to the Mn(2)(III,IV) state are available. In 2, three oxidation steps are possible from the initial Mn(2)(III,III)state. The last step is accomplished in the Mn(2)(IV,IV) state, which results in a phenolate radical. For the first time we provide firm spectral evidence for formation of the first intermediate state, Mn(2)(II,III), in 1 during the stepwise light-induced oxidation. Observation of Mn(2)(II,III) is dependent on conditions that sustain the mu-acetato bridges in the complex, i.e., by forming Mn(2)(II,III) in dry acetonitrile, or by addition of high concentrations of acetate in aqueous solutions. We maintain that the presence of water is necessary for the transition to higher oxidation states, e.g., Mn(2)(III,III) and Mn(2)(III,IV) in 1, due to a bridging ligand exchange reaction which takes place in the Mn(2)(II,III) state in water solution. Water is also found to be necessary for reaching the Mn(2)(IV,IV) state in 2, which explains why this state was not reached by electrolysis in our earlier work (Eur. J. Inorg. Chem (2002) 2965). In 2, the extra coordinating oxygen atoms facilitate the stabilization of higher Mn valence states than in 1, resulting in formation of a stable Mn(2)(IV,IV) without disintegration of 2. In addition, further oxidation of 2, led to the formation of a phenolate radical (g = 2.0046) due to ligand oxidation. Its spectral width (8 mT) and very fast relaxation at 15 K indicates that this radical is magnetically coupled to the Mn(2)(IV,IV) center. PMID:15134919

Huang, Ping; Högblom, Joakim; Anderlund, Magnus F; Sun, Licheng; Magnuson, Ann; Styring, Stenbjörn

2004-05-01

155

Artificial nose  

UK PubMed Central (United Kingdom)

The utility model relates to the field of medical apparatuses, and discloses an artificial nose which comprises a first air-vent and a second air-vent, wherein a cavity is located between the first air-vent and the second air-vent, and is characterized in that the cavity is provided with a filtering device with humidification indication. The utility model can directly indicate the use state of the artificial nose, and prompts to change the artificial nose in proper time, thereby not only preventing disadvantage affects to the health of patients as the artificial nose is used overtime, but also preventing waste as the use time limit is insufficient.

YUNFEI CAO; XUEFEI ZHOU

156

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

157

Measurement and analysis of radioactivity induced in yttrium and lead in fusion peak neutron field  

Energy Technology Data Exchange (ETDEWEB)

Yttrium is an element in oxide dispersion strengthened (ODS) steels to be used as structural material at high neutron doses and temperatures. Lead acts as a neutron multiplier and coolant in breeding blanket concepts such as the EU test blanket modules (TBM) with Pb-17Li. Samples of pure Y and Pb were irradiated with D-T fusion neutrons. The radioactivity following irradiation was determined several times during decay by {gamma}-spectroscopy. The results were analysed with the European Activation System. Ratios of calculated-to-experimental values for individual activities are discussed in connection with the expected activation performance of the materials in fusion power plant conditions.

Seidel, K. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, D-01062 Dresden (Germany)]. E-mail: seidel@physik.phy.tu-dresden.de; Eichin, R. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, D-01062 Dresden (Germany); Forrest, R.A. [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Freiesleben, H. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, D-01062 Dresden (Germany); Unholzer, S. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, D-01062 Dresden (Germany)

2005-11-15

158

Combined autoradiography and formaldehyde-induced fluorescence methods for localization of radioactively labeled substances in relation to monoamine neurons.  

UK PubMed Central (United Kingdom)

A combined technique of formaldehyde-induced fluorescence (FIF) and autoradiography is described for the localization of radioactively labeled substances in relation to monoamine neurons. This method permits the simultaneous visualization of 3H-labeled steroid hormone or drug uptake sites and fluorescing monoamine neural elements (cell bodies, fiber projections, terminals) in the same tissue section. Thin frozen sections cut in a cryostat are freeze-dried, exposed to formaldehyde vapor at 80 degrees C, and carried through dry-mount autoradiography processing steps before fluorescence microscopy screening. Subsequent histological staining of sections and light microscopy are employed for conventional autoradiogram screening. With this procedure, 3H-estradiol and 3H-dihydrotestosterone are localized in various catecholamine (CA) neurons in the diencephalon and lower brain stem of the rat. Also, catecholaminergic as well as noncatecholaminergic sex steroid target neurons are seen to be innervated by CA terminals in various rat brain regions.

Grant LD; Stumpf WE

1981-01-01

159

Combined autoradiography and formaldehyde-induced fluorescence methods for localization of radioactively labeled substances in relation to monoamine neurons.  

Science.gov (United States)

A combined technique of formaldehyde-induced fluorescence (FIF) and autoradiography is described for the localization of radioactively labeled substances in relation to monoamine neurons. This method permits the simultaneous visualization of 3H-labeled steroid hormone or drug uptake sites and fluorescing monoamine neural elements (cell bodies, fiber projections, terminals) in the same tissue section. Thin frozen sections cut in a cryostat are freeze-dried, exposed to formaldehyde vapor at 80 degrees C, and carried through dry-mount autoradiography processing steps before fluorescence microscopy screening. Subsequent histological staining of sections and light microscopy are employed for conventional autoradiogram screening. With this procedure, 3H-estradiol and 3H-dihydrotestosterone are localized in various catecholamine (CA) neurons in the diencephalon and lower brain stem of the rat. Also, catecholaminergic as well as noncatecholaminergic sex steroid target neurons are seen to be innervated by CA terminals in various rat brain regions. PMID:7053241

Grant, L D; Stumpf, W E

1981-01-01

160

Study on the induced release limits of radioactive effluents to the environment for the HANARO facilities  

International Nuclear Information System (INIS)

[en] The research reactor HANARO and its related facilities have been in operation in the KAERI (Korea Atomic Energy Research Institute) site since 1995. So much operational experiences have been accumulated and experimental data have been collected for last 10 years. Amendment of the existing derived release limits for the HANARO stack monitors is necessary because the domestic laws related to the radiation protection were revised to cope with the introduction of the International Commission on Radiological Protection's new recommendations (ICRP-60) and actual data through operation. The new release limits have been estimated by considering the gaseous radioactive effluents of the HANARO and the conservative meteorological conditions. It will meet the domestic laws in most conditions, if the HANARO is operated under the alarm set points with the new release limits. The results may be applied to the HANARO facilities hereafter

2005-01-01

 
 
 
 
161

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

1993-01-01

162

Design of experiment for studying (?,p) reaction induced by 22Mg radioactive beam  

International Nuclear Information System (INIS)

This paper shows the feasibility of experiment of 22Mg(?,p)2'5Al reaction in environment of X-rays burst with temperature in GK, where the pure radioactive beams 22Mg approximately 0.29-1.24 MeV/u (lab) with temperature T9 = 1-3 (GK), are created by primary reaction 3He(20Ne, 22Mg)n reaction and online filtered by CRIB. The projectile 22Mg bombards to secondary target filled with Helium gas. The experiment is designed by using thick target method to scan resonance states above alpha threshold and inverse kinetics technique. We can measure experimental cross section, and thus, reaction rate of 22Mg(?,p)25Al reaction, which is useful for explanation of anomaly in astronomy, as well as resonance states of 26Si can be determined from this experiment. (author)

2011-01-01

163

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.

2001-01-01

164

Artificial urushi.  

Science.gov (United States)

A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity. PMID:11763444

Kobayashi, S; Uyama, H; Ikeda, R

2001-11-19

165

Artificial urushi.  

UK PubMed Central (United Kingdom)

A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity.

Kobayashi S; Uyama H; Ikeda R

2001-11-01

166

ARTIFICIAL REEF  

UK PubMed Central (United Kingdom)

An artificial reef consists of a cylindrical core (1) having means for receiving substantially radially outward-projecting elements (3) in the form of hollow or solid sections in the form of rods or tubes.

MEISINGSET Sverre

167

ARTIFICIAL ENZYMES  

UK PubMed Central (United Kingdom)

The present invention is directed to the use of artificial polymers in the mimetization of enzymatic active sites and the carrying-out of catalysis using these artificial enzymes. Further, as used herein, an artificial enzyme refers more generally to a polymer-based scaffold for presenting specific chemically active atoms optimally for reactions, not just those that mimic natural enzymes. Various polymers can be used for this mimetization, including polyimides, polyurea, polyurethane, polyacrylic acid, and polylactic acid, as well as other polymers having properties and functionality that enable integration with natural and artificial amino acids, other molecules having nucleophilic and electrophilic groups (akin to the amine and carboxyl functionalities, respectively, of amino acids), as well as other molecules contributing unique chemical abilities not usually associated with the orthogonal functions inherent in most amino acids, i.e., amines, carboxyls, formamides, hydroxyls, mercaptyls and saturated hydrocarbons.

BENTLEY PAUL; SUZARA VINCENT

168

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 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)

2007-01-01

169

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

170

Radioactivity monitoring  

International Nuclear Information System (INIS)

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

1982-05-26

171

Radioactivity [includes radioactivity levels  

International Nuclear Information System (INIS)

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

1988-01-01

172

Radioactivity (includes radioactivity levels)  

Energy Technology Data Exchange (ETDEWEB)

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

1989-01-01

173

Radioactivity and food  

Energy Technology Data Exchange (ETDEWEB)

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

Olszyna-Marzys, A.E. (Laboratorio Unificado de Control de Alimentos y Medicamentos (LUCAM) (Guatemala))

1990-03-01

174

Timescale of natural annealing in radioactive minerals affects retardation of radiation-damage-induced leaching  

Energy Technology Data Exchange (ETDEWEB)

The paper concerns natural annealing and radiation-damage-induced leaching in solidified nuclear materials. Results are presented of radioisotope measurements on ancient uranium- and thorium-rich materials, which indicate that 'self-annealing' strikingly reduces the rate of dissolution. An annealing time of 15 k yr is estimated. The results also suggest a localized submicroscopic loss of order. Finally the data infers that minerals in which such annealing occurs could be suitable for nuclear waste-storage media.

Eyal, Y. (General Electric Co., Schenectady, NY (USA). Corporate Research and Development Center; Technion-Israel Inst. of Tech., Haifa. Dept. of Nuclear Engineering); Fleischer, R.L. (General Electric Co., Schenectady, NY (USA). Corporate Research and Development Center)

1985-04-11

175

Timescale of natural annealing in radioactive minerals affects retardation of radiation-damage-induced leaching  

International Nuclear Information System (INIS)

The paper concerns natural annealing and radiation-damage-induced leaching in solidified nuclear materials. Results are presented of radioisotope measurements on ancient uranium- and thorium-rich materials, which indicate that 'self-annealing' strikingly reduces the rate of dissolution. An annealing time of 15 k yr is estimated. The results also suggest a localized submicroscopic loss of order. Finally the data infers that minerals in which such annealing occurs could be suitable for nuclear waste-storage media. (U.K.)

1985-04-11

176

Artificial radioactive tracers: a tool for oceanography  

International Nuclear Information System (INIS)

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

1993-01-01

177

IV. Neutron radiation and artificial radioactivity  

International Nuclear Information System (INIS)

The history is described of the discovery of the neutron and the characteristic is given of the interaction of neutrons with matter during the passage of neutron radiation. In the irradiation of different elements with neutrons reactions take place (n,gamma), (n,p) and (n,alpha) and the transmutation of elements. The transmutation takes place also during reactions (alpha,n) (alpha,p), (p,gamma) and (d,p). The fission of 238U and 235U is described and fission reaction is defined. The effects of the atom bomb are described. The principle is briefly explained of reactors and a diagrammatic section is made of the nuclear reactor. Generator systems serve the production of short-lived radioisotopes. The properties are given of radioisotopes 3H, 14C, 24Na, 32P, 35S, 51Cr, 59Fe, 60Co, sup(99m)Tc, radioiodine, 137Cs and 198Au and their uses in medicine. (E.S.).

1984-01-01

178

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

DEFF Research Database (Denmark)

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

Toftmann, B.; Schou, JØrgen

1999-01-01

179

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

CERN Multimedia

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

180

Artificial noses.  

UK PubMed Central (United Kingdom)

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

Stitzel SE; Aernecke MJ; Walt DR

2011-08-01

 
 
 
 
181

Characteristics of geothermal heat extraction from an artificial reservoir crack surrounded by thermally induced secondary-crack network  

Energy Technology Data Exchange (ETDEWEB)

Geothermal heat extraction system of high-temperature rock mass, using artificially formed cracks in porous mass, has been proposed and studied as one of positive extraction methods. The authors examined the behavior of geothermal fluid in the underground system by using numerical simulation, considering the secondary crack network which extends from the artificial crack surfaces into the rock mass. Numerical simulation was performed by using a model consisting of three parts, a discrete crack model for the artificial reservoir crack, a double porosity model for the region of the secondary crack network, and a porous media model for the region outside the secondary crack network. The results of the simulation show that the temperature at the outlet is highly depends on the permeability of the secondary crack network in the direction parallel to the main reservoir crack. The area of the region of intense temperature drop increases with the permeability of the secondary crack network. The temperature at the outlet is also sensitive to the width of the region of the secondary crack network. The wider the width of the secondary crack network, the higher the temperature at the outlet. 21 refs., 11 figs.

Hayashi, Kazuo; Kagawa, Hiroaki (Tohoku Univ., Sendai (Japan); Olympus Optical Co., Ltd., Tokyo (Japan))

1989-01-25

182

Radioactive decay  

International Nuclear Information System (INIS)

A comprehensive study of the radioactive decay which plays a significant role in most chemical applications of isotopes is presented. First the kinetics, then the different kinds and mechanisms of radioactive processes are dealt with (disintegration of radioactive mixtures, branching decays, radioactive equilibrium, isotope dating techniques, alpha, beta, and photon and neutron decay, electron capture, spontaneous fission, isomeric transitions, etc.).

1987-01-01

183

Induced radioactivity due to high energy charged particle beam in view of radiation control  

International Nuclear Information System (INIS)

[en] Practically coping with the design, construction, and operation control of large accelerators includes many problems, though safety calculations and measurements are reported recently regarding shielding and induced radiation. The radiation intensity obtained from the reaction of high speed particles on target nuclides is generally proportional to the product of the number of atoms of the target, the flux density of irradiated particles and activation cross-section, and is obtained by multiplying the factors for the time elapsed ''in operation'' and ''after shut down'' to the above product. The report describes the outline of the dominant causes of producing fast neutrons, the produced nuclides and their intensity level and energy due to charged particles, the thermalization of fast neutrons, the induced activity due to fast neutrons and neutron relase by high energy electron beam. It is important from the stand-point of radiation control to know and measure in advance the activity produced during the operation of and the residual activity after the shut down of a high energy accelerator itself and in an irradiation laboratory, and further to grasp the variation of these radiation level with time. Approximately four conditions prescribing the radiation level are described on the basis of present knowledge. (Wakatsuki, Y.)

1975-08-28

184

Artificial Intelligence  

CERN Multimedia

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

185

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

1979-01-01

186

EAGLE GUIDE. Radioactivity from A to Z; EAGLE-GUIDE. Radioaktivitaet von A bis Z  

Energy Technology Data Exchange (ETDEWEB)

The booklet on radioactivity is a lexicon-type compendium of definitions, fundamental terms and information on radioactivity. Radioactive processes occur in the sun and on earth, live is dependent on these processes. Human beings are exposed to cosmic radiation, radiation from natural radioactive nuclides and artificial radiation sources. There is almost no possibility to protect oneself from natural radioactivity. The protection from artificial radioactivity can be reached by appropriate protection measures. Artificial radiation sources will certainly by part of mankind in the future, in nuclear medicine, radiation therapy and for research purposes. The booklet is aimed to provide information to everybody as a basis to be able to discuss the respective topics.

Stolz, Werner

2011-07-01

187

In-beam PET measurements of {beta}{sup +} radioactivity induced by proton beams  

Energy Technology Data Exchange (ETDEWEB)

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

Parodi, K.; Enghardt, W. [Forschungszentrum Rossendorf, Dresden (Germany); Haberer, T. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)

2002-01-07

188

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

UK PubMed Central (United Kingdom)

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

Parodi K; Enghardt W; Haberer T

2002-01-01

189

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., 3 figs

190

Using Gold Nanoparticles as Artificial Defects in Thin Films: What Have We Learned About Laser-Induced Damage Driven by Localized Absorbers?  

Energy Technology Data Exchange (ETDEWEB)

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

Papernov, S.; Schmid, A.W.

2007-03-14

191

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

International Nuclear Information System (INIS)

[en] 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

1997-01-01

192

Artificial nose  

UK PubMed Central (United Kingdom)

The invention belongs to a medical appliance especially relates to an artificial nose suitable for critical patients having tracheotomy operation. The artificial nose comprises a respiratory tube with tracheae jack. The respiratory tube is connected to a breather tank. The tracheae jack is axial perpendicular arranged in the middle of the respiratory tube. Air outlet and inlet with unidirectional inlet valve flap and outlet valve flap. The air inlet of the respiratory tube is connected with the breather tank through gas-supply pipe. The breather tank is provided an oxygen transfer opening at the bottom. The invention can moisten and clean the suction air for patient with medication through atomization, which can avoid self aleopation, and realize adjustable quantity of respiratory oxygen and keep wet.

WU DI

193

Artificial heart  

Energy Technology Data Exchange (ETDEWEB)

Super-pure plutonium-238 could use heat produced during fission to power an implanted artificial heart. Three model hearts have worked for some time. Concern that excess heat would make the procedure unsafe for humans has broadened the search for another energy source, such as electrohydraulic drive or an external power battery. A back pack approach may provide an interim solution until materials are developed which can withstand heart activity and be small enough for implantation.

1984-10-18

194

Artificial foliage  

UK PubMed Central (United Kingdom)

An artificial foliage structure with wire cores embedded in its leafy parts causing these parts to "spring back" upon removal of compressive loading acting thereupon. These wire cores may be made of hard, springy steel such as piano wire or small diameter spring wire. Thicker, woody limbs and branches have embedded therein heavier wire cores that are sufficiently soft to be given a set solely by manually applied bending force.

PITMAN DAVID B

195

Radioactive source  

International Nuclear Information System (INIS)

A radioactive layer in a radioactive source is sealed by the application of a sealing layer on the radioactive layer. The sealing layer can consist of a film of oxide of titanium, tin, zirconium, aluminum, or chromium. Preferably, the sealing layer is pure titanium dioxide. The radioactive layer is embedded in a finish enamel which, in turn, is on a priming enamel which surrounds a substrate

1976-01-01

196

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

International Nuclear Information System (INIS)

[en] To improve the data accuracy of the neutron emission spectrum of the 7Li(d,n) reaction and the radioactivity (7Be, 3H, etc.) accumulated in the 7Li target in IFMIF, we have measured the neutron emission spectrum and the radioactivity of 7Be 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 7Be 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 7Be production was much larger than expected by the recent codes. Measurement will be extended to several incident energies up to 40 MeV

2002-01-01

197

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 Multimedia

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

198

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

Energy Technology Data Exchange (ETDEWEB)

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. E-mail: babam@cyric.tohoku.ac.jp; Aoki, T.; Hagiwara, M.; Sugimoto, M.; Miura, T.; Kawata, N.; Yamadera, A.; Orihara, H

2002-12-01

199

Prediction of neutron induced radioactivity in the concrete walls of a PET cyclotron vault room with MCNPX.  

UK PubMed Central (United Kingdom)

PURPOSE: The authors want to assess the relevance of the neutron activation of the concrete vault of the PET cyclotron at CIMES (Universidad de Malaga) by predicting specific activities of the main activation products in the vault and their variation profiles as a function of penetration depth into concrete at present and after 10 yr of cyclotron operation. METHODS: The dual proton cyclotron is used for PET isotopes production, mainly 18F. During the years 2006 and 2008, the using rate has been 1 h/day at single beam (40 microA). From January 2008, using rate is 4 h/day at dual beam (80 microA). The energy of the cyclotron proton beam is 18 MeV. Four point locations were chosen on the walls of the cyclotron room to assess neutron induced activity concentrations. In each wall point location, neutron induced radionuclide specific activity was assessed from the wall surface to a depth of 120 cm within concrete. Simulations were carried out with the Monte Carlo based radiation transport code MCNPX (v2.6.0). RESULTS: According to MCNPX calculations, activity depth profiles of activation products studied, except 54Mn, have a maximum at variable depths from the wall surface never beyond 12 cm. 54Mn activity decreases exponentially in all the studied depth ranges within wall concrete. The activity of 152Eu, 154Eu, 60CO, 134Cs, 46Sc, and 65Zn decreases exponentially beyond a 30 cm depth into concrete. 54Mn activity presents the faster decrease within a concrete vault with an attenuation length of 21 cm. According to MCNPX estimations, present activity in the cyclotron vault is mostly due to 46Sc and 60Co, with highest specific activity near the vault surface of 146 +/- 16 and 50 +/- 4.6 Bq/kg, respectively. 46Sc and 60Co activity measurements near the surface wall present an acceptable match with the estimation within the uncertainties, but measured activities of the other radionuclides are quite over the MCNPX estimations. The calculations after 10 yr of cyclotron operation predict a slight increase for short half-life radionuclides (46Sc, 54Mn, and 65Zn). However, long half-life neutron induced radionuclides importantly increase their activities, especially 60Co and 152Eu. These radionuclides and 46Sc give the main contribution to the wall activity in a 10 yr period. Estimated highest 46Sc and 60Co activities in 10 yr of cyclotron operation are in acceptable agreement with published measurements, but MCNPX calculated activities are lower than the measurements for the rest of the radionuclides. CONCLUSIONS: MCNPX estimates acceptably present activity levels of 46Sc and 60Co as confirmed by activity measurements, but underestimates activity for the rest of the neutron induced radionuclides in the wall. Activity measurements have revealed the inhomogeneity of wall concrete atomic composition since large differences in activity values were found in two near wall surface locations with similar neutron flux. Such inhomogeneity cannot be modeled with the program that considers the material composition homogeneous. Highest specific activities estimated in a 10 yr operation are under exemption limits and therefore the cyclotron vault can be discarded as radioactive waste.

Martínez-Serrano JJ; Díez de los Ríos A

2010-11-01

200

Radioactivity in Tatras  

International Nuclear Information System (INIS)

In our study we compared the amount of radioactive isotopes of elements of rock samples from the peaks of the High Tatras and tarns with samples of the rocks from the Low Tatras. We determined the natural radioisotopes 40K, 226Ra, 232Th, but also artificial isotope 137Cs. We found in the study during the measurements that the highest values of natural radionuclides among the measured samples are in the samples from the Low Tatras. However, there is fourfold less artificial radionuclide 137Cs than in the High Tatras. We also found elevated levels of natural radionuclides in the Tatras's tarns compared to the relatively close shields. This finding is also true for 226Ra in Vrbicke pleso in the Low Tatras, but also in the High Tatras for 226Ra and 232Th in Velke zabie pleso. (authors)

2012-01-01

 
 
 
 
201

Ambient radioactivity levels and radiation doses. Annual report 2009; Umweltradioaktivitaet und Strahlenbelastung. Jahresbericht 2009  

Energy Technology Data Exchange (ETDEWEB)

The annual report on environmental radioactivity and radiation exposure 2009 consists of two parts. Part A: General information: natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposures from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. Part B includes current data and their evaluation for natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposures from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation.

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

2010-12-15

202

Artificial nose  

UK PubMed Central (United Kingdom)

The utility model relates to an artificial nose, which is composed of an air hole, an inner filtering tube, an outer cannula, a sealing ring and an air connection opening. One end of the outer cannula adopts a whole-opening form, and the other end adopts a closed form. A circular air hole is arranged at the closed end of the outer cannula. The inner filtering tube which is penetrated from top to bottom is arranged in the center of the outer cannula, the inner filtering tube is a circular pipe on the body of which a breathing hole is arranged, the air connection opening is arranged at the tail end of the inner filtering tube, and the sealing ring which can not generate the air leakage phenomenon from the outer cannula and the inner filtering tube is arranged in the intercalated layer at the tail end of the filtering tube and the outer cannula. The medical gauze used for filtering is arranged between both the intercalated layers of the outer cannula and the inner filtering tube in the sealing ring. When being used, the moistening treatment is required to be performed to the medical gauze used for filtering. When the artificial nose of the utility model is used, the air absorbed is filtered through the moistened cotton yarn, the bacteria dust with big granule can be blocked, and the humidity of the absorbed air can be increased. The manufacturing process of the artificial nose is simple, the use is convenient, and during the using process, the humiture is feasible.

YAQIONG ZHANG; GUILAN DAI; ZHIHUA SUN

203

Artificial reef  

UK PubMed Central (United Kingdom)

An artificial reef of lightweight construction employs a dome-shaped, thin-walled enclosure of plastic material having apertures therein to permit acquatic life to enter and exit. The enclosure has a circular perimeter that is provided with a circumferential trough integrally formed with the enclosure. At a staging area adjacent the installation site, concrete ballast is poured into the trough to form a perimetrical weight which holds the reef in position on the desired underwater surface. The construction allows the reef to be installed from the surface of the water by releasing it over the site and permitting it to parachute downwardly through the water until it comes to rest.

VAN DOREN DAVID A

204

Artificial graphites  

International Nuclear Information System (INIS)

Artificial graphites are obtained by agglomeration of carbon powders with an organic binder, then by carbonisation at 10000C and graphitization at 28000C. After description of the processes and products, we show how the properties of the various materials lead to the various uses. Using graphite enables us to solve some problems, but it is not sufficient to satisfy all the need of the application. New carbonaceous material open application range. Finally, if some products are becoming obsolete, other ones are being developed in new applications.

1984-01-01

205

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

Science.gov (United States)

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

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

2013-01-01

206

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-31

207

Response to artificial drying until drought-induced death in different elevation populations of a high-mountain plant.  

UK PubMed Central (United Kingdom)

Climate change is imposing warmer and more arid conditions on high-mountain Mediterranean pastures. The severity of these conditions is more intense in lower elevation populations and may be critical for their survival. In this context, we asked whether local adaptation plays an important role in the response of these populations to climate change, and if so, what mechanisms are involved. Previous works, involving reciprocal sowings suggested the existence of local adaptation in lower elevation populations of Silene ciliata, a perennial representative of high-mountain Mediterranean pastures. To determine if this local advantage is due to better adaptation to more intense water stress conditions, an experiment was conducted in which S. ciliata plants from three populations located at different elevations (Low, Intermediate and High) were subjected to severe artificial water stress. Results showed that plants from the Low population had greater tolerance to water stress than plants from the High population in the earliest stages of water shortage. Furthermore, responses of proteins to specific antibodies related to drought were evaluated. Two representative late-embryogenesis abundant (LEA) proteins known to play a role in water stress tolerance were expressed throughout the drought treatment in plants from the three populations, with some pattern differences among individuals within populations. This study detected slight evidence of local adaptation to water stress in populations from different elevations.

García-Fernández A; Iriondo JM; Bartels D; Escudero A

2013-01-01

208

ARTIFICIAL REEF  

UK PubMed Central (United Kingdom)

FIELD: agriculture. ^ SUBSTANCE: invention relates to fishery immediately dealing with design of artificial reefs serving to stimulate bioproductivity of benthal biocenoses additionally it is to utilised in construction of hydraulic engineering structures. The artificial reef is assembled of structural elements that have a recess in the central part of their upper bases connected to each other, the elements form shelters for hydrocoles. The innovation consists in the structural element being shaped as an isosceles trapezoid with the wall section increasing by a factor of 1.5-2.0 towards the lower base the element has two additional recesses arranged in the upper and the lower bases different sides of the centre with the recess height being equal to 1/2 of the element height, the width exceeding the lower base thickness by 10-15 cm the elements are connected by way of the lower recess of one element being inserted in the upper recess of another one. ^ EFFECT: improvement of the reef stability, reliability and strength as well as reduction of its assembly process labour intensity. ^ 3 cl, 4 dwg

SHEVCHENKO VLADIMIR NIKOLAEVICH; SAENKO ELENA MIKHAJLOVNA

209

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)

2008-01-01

210

Effects of photo-induced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on physical properties of cross-linked polyethylene in artificial hip joints.  

UK PubMed Central (United Kingdom)

Osteolysis caused by wear particles from polyethylene in the artificial hip joints is a serious issue. We have used photo-induced radical graft polymerization to graft 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer onto the surface of cross-linked polyethylene (CLPE-g-MPC) in order to reduce friction and wear at the bearing surface of the joint. The physical and mechanical properties of CLPE and CLPE-g-MPC were not significantly different, expect that the friction coefficient of untreated CLPE cups was 0.0075, compared with 0.0009 for CLPE-g-MPC cup, an 88% reduction. After 3.0 x 10(6) cycles in the hip joint simulator test, we could not observe any wear of CLPE-g-MPC cups. We concluded that the advantage of photo-induced radical graft polymerization technique was that the grafted MPC polymer gave a high lubricity only on the surface and has no effect on the bulk properties of the CLPE substrate.

Kyomoto M; Moro T; Konno T; Takadama H; Kawaguchi H; Takatori Y; Nakamura K; Yamawaki N; Ishihara K

2007-09-01

211

Evidence for swelling-induced adenosine and adenine nucleotide release in rat cerebral cortex exposed to monocarboxylate-containing or hypotonic artificial cerebrospinal fluids.  

UK PubMed Central (United Kingdom)

Recent reports have described a swelling-induced release of adenosine triphosphate (ATP) from a variety of non-nervous system cell types, which may be involved in the regulatory volume decrease (RVD) response. The present study examined the effects of swelling induced by applications of hypotonic or monocarboxylic acid containing artificial cerebrospinal fluid (aCSF) on the release of adenosine nucleotides and adenosine from the in vivo rat cerebral cortex using a cortical cup technique. Hypotonic aCSF (25mM NaCl) elicited a significant increase in adenosine, but not adenine nucleotide, release. Applications of sodium L-lactate, pyruvate, or acetate (all 20mM) evoked increases in adenine nucleotides but not adenosine. D-Lactate (20mM) enhanced adenosine and ATP release. Inhibition of the plasma membrane monocarboxylate transporter with cyano-4-hydroxycinnamate (4-CIN, 2mM) blocked the effects of L-lactate on purine release. These in vivo results demonstrate that osmoregulatory processes in cortical cells evoke an efflux of adenine nucleotides and/or adenosine. In that these purines activate a variety of receptors, it is possible that they may function as autocrine or paracrine signaling agents, facilitating volume regulation and enhancing local blood flow.

Phillis JW; O'Regan MH

2002-06-01

212

Artificial Neural Network Modeling of Healthy Risk Level Induced by Aircraft Pollutant Impacts around Soekarno Hatta International Airport  

Directory of Open Access Journals (Sweden)

Full Text Available Aircraft pollutant emissions are an important part of sources of pollution that directly or indirectly affect human health and ecosystems. This research suggests an Artificial Neural Network model to determine the healthy risk level around Soekarno Hatta International Airport-Cengkareng Indonesia. This ANN modeling is a flexible method, which enables to recognize highly complex non-linear correlations. The network was trained with real measurement data and updated with new measurements, enhancing its quality and making it the ideal method for this research. Measurements of aircraft pollutant emissions are carried out with the aim to be used as input data and to validate the developed model. The obtained results concerned the improved ANN architecture model based on pollutant emissions as input variables. ANN model processes variables—hidden layers—and gives an output variable corresponding to a healthy risk level. This model is characterized by a 4-10-1 scheme. Based on ANN criteria, the best validation performance is achieved at epoch 28 from 34 epochs with the Mean Squared Error (MSE) of 9 × 10-3. The correlation between targets and outputs is confirmed. It validated a close relationship between targets and outputs. The network output errors value approaches zero. Further research is needed with the aim to enlarge the scheme of the ANN model by increasing its input variables. This is one of the major key defining environmental capacities of an airport that should be applied by Indonesian airport authorities. These would institute policies to manage or reduce pollutant emissions considering population and income growth to be socially positive.

Salah Khardi; Jermanto Setia Kurniawan; Irwan Katili; Setyo Moersidik

2013-01-01

213

Changes induced in Biomphalaria glabrata (Say, 1818) following trials for artificial stimulation of its internal defense system  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Biomphalaria glabrata can react through different pathways to Schistosoma mansoni miracidium penetration, according to the degree of resistance/susceptibility presented by different snail strains, which is a genetically determined character, resistance being the dominant feature. However, it has been observed that previous susceptible snail strain may change its reactive behavior along the course of infection, exhibiting later a pattern of cercarial shedding and histopato (more) pathological picture compatible with high resistance. Such observation suggests the possibility of B. glabrata to develop a sort of adaptative immunity face a schistosome infection. To explore on this aspect, the present investigation looked for the behavior of S. mansoni infection in B. glabrata previously subjected to different means of artificial stimulation of its internal defense system. Snails previously inoculated with irradiated miracídia (Group I); treated with S. mansoni antigens (Group II) or with a non-related parasite antigen (Group III) were challenged with 20 viable S. mansoni miracidia, and later looked for cercarial shedding and histopathologic changes at different times from exposition. Nodules of hemocyte accumulations were found at the site of antigen injection. These nodules resembled solid granulomas, and were larger and more frequent in snails injected with S. mansoni products as compared to those injected with Capillaria hepatica. However, the presence of such granulomas did not avoid the S. mansoni challenge infection from developing in a similar way as that seen in controls. The data are indicative that hemocytes are able to proliferate locally when stimulated, such capacity also remaining localized, not being shared by the population of hemocytes located elsewhere within the snail body.

Azevedo, Carine Machado; Borges, Claudia Cunha; Andrade, Zilton A

2006-10-01

214

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; W.-C. Liu; M.-H. Hsu

2012-01-01

215

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

216

Inflatable artificial sphincter  

Science.gov (United States)

Artificial sphincter (AUS) - urinary ... and you will not feel pain. An artificial sphincter has three parts: A cuff, which fits around ... Lower belly (men and women) Once the artificial sphincter is in place, you will use the pump ...

217

ARTIFICIAL REEF  

UK PubMed Central (United Kingdom)

A polygonal fish reef is provided, which promotes the breeding and the growth of macroalgae by supplying nutrient to the artificial fish reef. A polygonal fish reef comprises: a main structure(10) of which the whole outlook is formed in a polygon and in which a declined part(12) of which the side inclines at the predetermined angle and a nutrient receiving portion(14) are formed a frame(20) which is formed in the same shape as the nutrient receiving portion formed in the center of the main structure and in which a vertical pillar(22) and a horizontal pillar(24) are welded and an inclined plate(30) which is welded to the edge of the frame at the predetermined angle and is fixed.

KIM BYOUNG SUB; KANG JO HAE; CHOI MIN HO

218

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)

1992-01-01

219

Radioactive materials and radioactive waste  

Energy Technology Data Exchange (ETDEWEB)

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).

Marshall, Walter

1992-01-01

220

Biological artificial fluid-induced non-lamellar phases in glyceryl monooleate: the kinetics pathway and its digestive process by bile salts.  

Science.gov (United States)

Abstract Background: The cubic (Q(II)) phase is a promising sustained-release system. However, its rigid gel-like propensity is highly viscous, which makes it difficult to handle in pharmaceutical applications. To circumvent this problem, a less viscous lamellar (L(?)) phase that could spontaneously transform to Q(II) phase by the introduction of water or biological artificial fluid can be used. However, the kinetics pathway of phase transition, susceptibility to digestive processes and impact of the transition on drug release are not yet well understood. Method: We investigated various biological artificial fluid-induced L(?) to inverse Q(II) phase transition over time in glyceryl monooleate (GMO) by water penetration scan and light polarizing microscopy. To reveal the structure stability, fluorescence spectroscopy studies were conducted using pyrene as a probe. Furthermore, the release mechanism of pyrene as a lipophilic drug model in the spontaneously formed Q(II) was investigated. Result: Although hexagonal (H(II)) mesophases occurred when phosphate buffered saline (PBS) 7.4, 0.1?M HCl or sodium taurocholate (NaTC) solutions were introduced to GMO at room temperature, they disappear with the exception of 0.1?M HCl at 37?°C. Compared with 25?°C, L(?) to Q(II) phase transition was in a faster rate as almost completely transforms were observed after 2?h post-immersion. The spontaneously formed mesophases were stable over 24?h immersions in PBS or pancreatic lipase solutions as proven by the extremely low fluorescence signal, however they were digestible by bile salts. This result indicated that digestion by bile salts was the major pathway instead of digestion by lipases. Moreover, pyrene fluorescence spectroscopy confirmed that the digestion by bile salts induced the formation of GMO-bile salt mixed micelles whose performance depended on the bile salt concentrations. This dependence influenced the drug release from the spontaneously formed Q(II) phase. Conclusion: All the results concluded that temperature, pH and ionic strength tendencies for the formation of non-lamellar structures greatly influenced the self-assembly process, thereby affecting the final mesophase structure. The results of this study are important to understand the lamellar to non-lamellar lipid-phase transitions and their possible pharmaceutical applications. PMID:23350691

Zhou, Yanyan; Wang, Qifang; Wang, Yan; Xu, Hui; Yuan, Bo; Li, Sanming; Liu, Hongzhuo

2013-01-25

 
 
 
 
221

Biological artificial fluid-induced non-lamellar phases in glyceryl monooleate: the kinetics pathway and its digestive process by bile salts.  

UK PubMed Central (United Kingdom)

Abstract Background: The cubic (Q(II)) phase is a promising sustained-release system. However, its rigid gel-like propensity is highly viscous, which makes it difficult to handle in pharmaceutical applications. To circumvent this problem, a less viscous lamellar (L(?)) phase that could spontaneously transform to Q(II) phase by the introduction of water or biological artificial fluid can be used. However, the kinetics pathway of phase transition, susceptibility to digestive processes and impact of the transition on drug release are not yet well understood. Method: We investigated various biological artificial fluid-induced L(?) to inverse Q(II) phase transition over time in glyceryl monooleate (GMO) by water penetration scan and light polarizing microscopy. To reveal the structure stability, fluorescence spectroscopy studies were conducted using pyrene as a probe. Furthermore, the release mechanism of pyrene as a lipophilic drug model in the spontaneously formed Q(II) was investigated. Result: Although hexagonal (H(II)) mesophases occurred when phosphate buffered saline (PBS) 7.4, 0.1?M HCl or sodium taurocholate (NaTC) solutions were introduced to GMO at room temperature, they disappear with the exception of 0.1?M HCl at 37?°C. Compared with 25?°C, L(?) to Q(II) phase transition was in a faster rate as almost completely transforms were observed after 2?h post-immersion. The spontaneously formed mesophases were stable over 24?h immersions in PBS or pancreatic lipase solutions as proven by the extremely low fluorescence signal, however they were digestible by bile salts. This result indicated that digestion by bile salts was the major pathway instead of digestion by lipases. Moreover, pyrene fluorescence spectroscopy confirmed that the digestion by bile salts induced the formation of GMO-bile salt mixed micelles whose performance depended on the bile salt concentrations. This dependence influenced the drug release from the spontaneously formed Q(II) phase. Conclusion: All the results concluded that temperature, pH and ionic strength tendencies for the formation of non-lamellar structures greatly influenced the self-assembly process, thereby affecting the final mesophase structure. The results of this study are important to understand the lamellar to non-lamellar lipid-phase transitions and their possible pharmaceutical applications.

Zhou Y; Wang Q; Wang Y; Xu H; Yuan B; Li S; Liu H

2013-01-01

222

Elemental analysis of topaz from northern areas of Pakistan and assessment of induced radioactivity level after neutron irradiation for color induction  

International Nuclear Information System (INIS)

To study the impurity elements, which render color-induced topaz long lived radionuclides, three samples of topaz, from three different cities of the Northern Pakistan (Baltistan, Gilgit and Mardan) were analyzed using k 0 instrumental neutron activation analysis (k0-INAA). The samples were irradiated in Pakistan Research Reactor-1 (PARR-1) and PARR-2 at Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad. The method was validated by analyzing IAEA-S7 reference material. In three samples a total of 22 trace level impurity elements were quantified. Among impurities, 10 elements including As, Ce, Ga, Ge, La, Na, Sb, Sc, U and Zn were common in topaz of all the three places. The storage time has been calculated for each sample required to bring the induced radioactivity down to permissible level given by US National Regulatory Commission. (author)

2011-01-01

223

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)

1980-01-01

224

Measurement of the radioactivity induced in the soil around the decay volume of neutrino beam line at KEK  

Energy Technology Data Exchange (ETDEWEB)

The Decay Volume of neutrino beam line of 12 GeV proton synchrotron at KEK was constructed underground on the KEK site. Then the soil around the Decay Volume were slightly activated. The radioactive concentrations of radionuclides were measured for the soil around the Decay Volume. Various long-lived radionuclides (Be-7, Na-22, Sc-46, Sc-47, V-48, Cr-51, Mn-52, Mn-54, Fe-59 and Co-60) were observed in soil samples by {gamma}-ray spectra measurement, and H-3 was also detected by liquid scintillation counting. The maximum total radioactive concentration was 0.38 Bq/g, which was about 60% of the estimated value before the operation started. (author)

Miura, T.; Suzuki, T.; Numajiri, M. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Ishihama, S. [Tokyo Nuclear Services Co., Ltd., Tokyo (Japan)

2002-06-01

225

Clostridium perfringens epsilon toxin induces a rapid change of cell membrane permeability to ions and forms channels in artificial lipid bilayers.  

UK PubMed Central (United Kingdom)

Epsilon toxin is a potent toxin produced by Clostridium perfringens types B and D, which are responsible for a rapidly fatal enterotoxemia in animals. One of the main properties of epsilon toxin is the production of edema. We have previously found that epsilon toxin causes a rapid swelling of Madin-Darby canine kidney cells and that the toxin does not enter the cytosol and remains associated with the cell membrane by forming a large complex (Petit, L., Gibert, M., Gillet, D., Laurent-Winter, C., Boquet, P., and Popoff, M. R. (1997) J. Bacteriol. 179, 6480-6487). Here, we report that epsilon toxin induced in Madin-Darby canine kidney cells a rapid decrease of intracellular K(+), and an increase of Cl(-) and Na(+), whereas the increase of Ca(2+) occurred later. The entry of propidium iodide that was correlated with the loss of cell viability monitored by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test indicates that epsilon toxin formed large pores. In artificial lipid bilayers, epsilon toxin caused current steps with a single-channel conductance of 60 pS in 100 mm KCl, which represented general diffusion pores. The channels were slightly selective for anions, but cations could also penetrate. Epsilon toxin formed wide and water-filled channels permeable to hydrophilic solutes up to a molecular mass of at least 1 kDa, which probably represents the basic mechanism of toxin action on target cells.

Petit L; Maier E; Gibert M; Popoff MR; Benz R

2001-05-01

226

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

Directory of Open Access Journals (Sweden)

Full Text Available HF radar backscatter which has been artificially-induced by a high power RF facility such as the EISCAT heater at Tromsø has been demonstrated to provide ionospheric electric field data of unprecedented temporal resolution and accuracy. Here such data are used to investigate ULF wave processes observed by the CUTLASS HF radars. Within a short period of time during a single four hour experiment three distinct wave types are observed with differing periods, and latitudinal and longitudinal phase evolution. Combining information from the three waves allows them to be divided into those with a large-scale nature, driven externally to the magnetosphere, and those with small azimuthal scale lengths, driven by wave-particle interactions. Furthermore, the nature of the wave-particle interactions for two distinct small-scale waves is revealed, with one wave interpreted as being driven by a drift resonance process and the other by a drift-bounce resonance interaction. Both of these mechanisms with m ? -35 and proton energies of 35–45 keV appear to be viable wave energy sources in the postnoon sector.Key words. Ionosphere (active experiments; wave-particle interactions) – Magnetospheric physics (MHD waves and in-stabilities).

T. K. Yeoman; D. M. Wright

0000-01-01

227

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

2011-01-01

228

Four decades of opposing natural and human-induced artificial selection acting on Windermere pike (Esox lucius).  

Science.gov (United States)

The ability of natural selection to drive local adaptation has been appreciated ever since Darwin. Whether human impacts can impede the adaptive process has received less attention. We tested this hypothesis by quantifying natural selection and harvest selection acting on a freshwater fish (pike) over four decades. Across the time series, directional natural selection tended to favour large individuals whereas the fishery targeted large individuals. Moreover, non-linear natural selection tended to favour intermediate sized fish whereas the fishery targeted intermediate sized fish because the smallest and largest individuals were often not captured. Thus, our results unequivocally demonstrate that natural selection and fishery selection often acted in opposite directions within this natural system. Moreover, the two selective factors combined to produce reduced fitness overall and stronger stabilizing selection relative to natural selection acting alone. The long-term ramifications of such human-induced modifications to adaptive landscapes are currently unknown and certainly warrant further investigation. PMID:17498150

Carlson, Stephanie M; Edeline, Eric; Asbjørn Vøllestad, L; Haugen, Thrond O; Winfield, Ian J; Fletcher, Janice M; Ben James, J; Stenseth, Nils Chr

2007-06-01

229

Protection of metallurgical production from radioactive contamination  

International Nuclear Information System (INIS)

[en] Systems to detect any ionising radiation source in scrap are routinely installed at the input to metallurgical plants. Tracking by means of hand instruments enables removing various radioactive materials from scrap. Materials can be contaminated by natural radionuclides (e.g. materials of the NORM type) and by artificial radionuclides (e.g. 60Co in steel products). If radioactivity is detected, the material is disposed of in compliance with applicable legislation

2010-07-01

230

Radioactive waste management  

International Nuclear Information System (INIS)

In this chapter the radioactive waste management is presented. This chapter consists of the following parts: Radioactive decay and radioactivity; Effect of ionizing radiation on human body; Establishment of radioactive wastes and their categorization; Radioactive waste management (Ways of dealing with radioactive waste and Storage and permanent disposal of radioactive waste; Nuclear fuel cycle and production of radioactive waste.

2010-01-01

231

HIV-1 reverse transcriptase artificially targeted for proteasomal degradation induces a mixed Th1/Th2-type immune response.  

UK PubMed Central (United Kingdom)

Targeting of a DNA vaccine encoded protein for degradation via the proteasome is attempted since it may enhance the immunogenicity of the vaccine. We have fused HIV-1 reverse transcriptase (RT) to mouse ornithine decarboxylase (ODC), a protein rapidly degraded by proteasome in an ubiquitine-independent fashion, to enhance the introduction of RT into the MHC class I pathway. We also designed a fusion of RT with two short signals from the C-terminus of ODC (ODCsig) representing a minimal proteasome-targeting moiety of ODC (PEST signal). Fusion to ODC or ODC signal domain led to a marked enhancement of RT degradation. Plasmids encoding RT-ODC and RT-ODCsig chimera were used to immunize BALB/c mice. The administration of the plasmids was not associated with autoimmune disease. Moreover, mice receiving RT-ODCsig gene mounted a mixed Th1/Th2 response characterized by the in vitro secretion of IFN-gamma, IL-2, TNF-alpha, IL-4, and IL-10 upon stimulation of splenocytes with RT protein or RT derived peptides. Serum titers of 10(2) to 10(3) were observed in more than 50% of animals in that group, whereas fewer animals mounted an anti-RT response in the RT-ODC gene immunized group. Chimeras of the type described here can, therefore, be used in vaccinations aiming to induce HIV-1 RT-specific immune response.

Starodubova ES; Boberg A; Litvina M; Morozov A; Petrakova NV; Timofeev A; Latyshev O; Tunitskaya V; Wahren B; Isaguliants MG; Karpov VL

2008-09-01

232

Radioactivity Calculations  

Science.gov (United States)

Three problems in radioactive buildup and decay are presented and solved. Matrix algebra is used to solve the second problem. The third problem deals with flux depression and is solved by the use of differential equations. (LC)

Onega, Ronald J.

1969-01-01

233

Radioactivity Monitoring of the Irish Environment 2008  

International Nuclear Information System (INIS)

[en] 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. Radioacti

234

Handling radioactivity  

Energy Technology Data Exchange (ETDEWEB)

The aim of this book is to present an overall view in a descriptive and essentially nonmathematical way of the practicalities of handling radioactivity. It is hoped that the material will be particularly helpful to those entering the nuclear field for the first time and to those working in related areas whose responsibilities require them to have a general knowledge of the subject of radioactivity handling and its vocabulary.

Stewart, D.C.

1988-01-01

235

Radioactive pollution  

International Nuclear Information System (INIS)

In the wake of the Chernobyl reactor accident on April 26, 1986, many individual values for radioactivity in the air, in foodstuffs and in the soil were measured and published. Prof. Dr. Rolf Steiner, Wiesbaden, the author of this paper, evaluated the host of data - mostly official pollution data -, drew conclusions regarding the radioactivity actually released at Chernobyl, and used the data to test the calculation model adotped by the Radiation Protection Ordinance. (orig./RB)

1987-01-01

236

The radioactivity of the sea  

International Nuclear Information System (INIS)

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

1990-01-01

237

The radioactivity of the sea  

Energy Technology Data Exchange (ETDEWEB)

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

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

1990-08-01

238

Artificially lipid-anchored proteins can elicit clustering-induced intracellular signaling events in Jurkat T-lymphocytes independent of lipid raft association.  

Science.gov (United States)

We have incorporated artificial lipid-anchored streptavidin conjugates with fully saturated or polyunsaturated lipid anchors into the plasma membranes of Jurkat T-lymphocytes to assess previous conclusions that the activation of signaling processes induced in these cells by clustering of endogenous glycosylphosphatidylinositol-anchored proteins or ganglioside GM1 depends specifically on the association of these membrane components with lipid rafts. Lipid-anchored streptavidin conjugates could be incorporated into Jurkat or other mammalian cell surfaces by inserting biotinylated phosphatidylethanolamine-polyethyleneglycols (PE-PEGs) and subsequently binding streptavidin to the cell-incorporated PE-PEGs. Saturated dipalmitoyl-PE-PEG-streptavidin conjugates prepared in this manner partitioned substantially into the detergent-insoluble membrane fraction isolated from Jurkat or fibroblast cells, whereas polyunsaturated dilinoleoyl-PE-PEG-anchored conjugates were wholly excluded from this fraction, consistent with the differences in the affinities of the two types of lipid anchors for liquid-ordered membrane domains. Remarkably, however, antibody-mediated cross-linking of either dipalmitoyl- or dilinoleoyl-PE-PEG-anchored streptavidin conjugates in Jurkat cells induced elevation of cytoplasmic calcium levels and tyrosine phosphorylation of the scaf-folding protein linker of T-cell activation in a manner similar to that observed upon cross-linking of endogenous CD59 or ganglioside GM1. The amplitude of the cross-linking-stimulated elevation of cytoplasmic calcium moreover showed an essentially identical dependence on the level of incorporated streptavidin conjugate for either type of lipid anchor. Confocal fluorescence microscopy revealed that PE-PEG-streptavidin conjugates with saturated versus polyunsaturated anchors showed very similar surface distributions vis à vis GM1 or CD59 under conditions where one or both species were cross-linked. These results indicate that cross-linking of diverse proteins anchored only to the outer leaflet of the plasma membrane can induce activation of Jurkat T-cell-signaling responses, but they appear to contradict previous suggestions that this phenomenon rests specifically on the association of such species with lipid rafts. PMID:15817446

Wang, Tian-yun; Leventis, Rania; Silvius, John R

2005-04-07

239

Artificially lipid-anchored proteins can elicit clustering-induced intracellular signaling events in Jurkat T-lymphocytes independent of lipid raft association.  

UK PubMed Central (United Kingdom)

We have incorporated artificial lipid-anchored streptavidin conjugates with fully saturated or polyunsaturated lipid anchors into the plasma membranes of Jurkat T-lymphocytes to assess previous conclusions that the activation of signaling processes induced in these cells by clustering of endogenous glycosylphosphatidylinositol-anchored proteins or ganglioside GM1 depends specifically on the association of these membrane components with lipid rafts. Lipid-anchored streptavidin conjugates could be incorporated into Jurkat or other mammalian cell surfaces by inserting biotinylated phosphatidylethanolamine-polyethyleneglycols (PE-PEGs) and subsequently binding streptavidin to the cell-incorporated PE-PEGs. Saturated dipalmitoyl-PE-PEG-streptavidin conjugates prepared in this manner partitioned substantially into the detergent-insoluble membrane fraction isolated from Jurkat or fibroblast cells, whereas polyunsaturated dilinoleoyl-PE-PEG-anchored conjugates were wholly excluded from this fraction, consistent with the differences in the affinities of the two types of lipid anchors for liquid-ordered membrane domains. Remarkably, however, antibody-mediated cross-linking of either dipalmitoyl- or dilinoleoyl-PE-PEG-anchored streptavidin conjugates in Jurkat cells induced elevation of cytoplasmic calcium levels and tyrosine phosphorylation of the scaf-folding protein linker of T-cell activation in a manner similar to that observed upon cross-linking of endogenous CD59 or ganglioside GM1. The amplitude of the cross-linking-stimulated elevation of cytoplasmic calcium moreover showed an essentially identical dependence on the level of incorporated streptavidin conjugate for either type of lipid anchor. Confocal fluorescence microscopy revealed that PE-PEG-streptavidin conjugates with saturated versus polyunsaturated anchors showed very similar surface distributions vis à vis GM1 or CD59 under conditions where one or both species were cross-linked. These results indicate that cross-linking of diverse proteins anchored only to the outer leaflet of the plasma membrane can induce activation of Jurkat T-cell-signaling responses, but they appear to contradict previous suggestions that this phenomenon rests specifically on the association of such species with lipid rafts.

Wang TY; Leventis R; Silvius JR

2005-06-01

240

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

 
 
 
 
241

Thermal neutron induced charged particle reactions in radioactive targets of /sup 37/Ar, /sup 109/Cd, /sup 125/Xe, /sup 127/Xe, and /sup 132/Cs  

CERN Document Server

Thermal neutron induced charged particle reactions in a radioactive target of /sup 37/Ar have been studied. Upper limits of the cross- sections for the (n, alpha ) reaction in radioactive targets of /sup 109/Cd, /sup 125,127/Xe, and /sup 132/Cs have been obtained. The isotopically pure targets were produced at the ISOLDE facility at CERN and irradiated with thermal neutrons at the high flux reactor of the Institute Laue-Langevin in Grenoble. Charged particles from (n, p) and (n, alpha ) reactions in /sup 37/Ar were observed with cross-sections of 69+or-14 b and 1970+or-330b, respectively. The Q-values for these reactions were determined to be 1600+or-12 keV and 4630+or-7 keV, in agreement with existing mass data. The branching ratio Gamma /sub alpha // Gamma /sub p/ of the /sup 37/Ar capturing state was found to be 28.5+or-2.7. An upper limit of the cross-section for the (n, gamma alpha ) reaction in /sup 37/Ar was obtained. (18 refs).

Asghar, M; Hagberg, E; Jonson, B; Tidemand-Petersson, P

1978-01-01

242

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.

2011-01-01

243

Radioactivity of dates in Saudi Arabia  

Energy Technology Data Exchange (ETDEWEB)

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

Nasser Al-Mohawes; Pao-Shan Weng

1984-06-01

244

Environmental radioactivity surveillance programme 1990 - 1993  

International Nuclear Information System (INIS)

[en] 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

1995-01-01

245

Alternatives of applications in the information taking with artificial radioactive tools in the mature fields of the South region; Alternativas de aplicaciones en la toma de informacion con herramientas radiactivas artificiales en los campos maduros de la region Sur  

Energy Technology Data Exchange (ETDEWEB)

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)

Fuentes, J.L

2005-07-01

246

History of radioactivity  

International Nuclear Information System (INIS)

[en] 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)

1981-01-01

247

Proceedings: Artificial Reef Conference. Artificial Reefs Around the World.  

Science.gov (United States)

The section, Artificial Reefs Around the World, includes the following articles 'Artificial Reefs in France', 'Some Problems that may be Faced in the Construction of an Artificial Reef', 'Historical Review of Artificial Reef Activities in Japan', and 'A B...

W. H. Clark

1974-01-01

248

Radioactive waste  

Energy Technology Data Exchange (ETDEWEB)

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

Alvarez, R.; Mukhijani, A.

1988-08-01

249

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

International Nuclear Information System (INIS)

[en] 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

1989-01-01

250

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

International Nuclear Information System (INIS)

[en] 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)

2005-01-01

251

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 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 ± (more) 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) - control 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 - (more) 135) h, respectively, been reduced (P

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

2004-04-01

252

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

253

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

International Nuclear Information System (INIS)

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

2009-01-01

254

Radioactive techniques for corrosion monitoring  

International Nuclear Information System (INIS)

In-situ corrosion rate measurements by utilizing induced radioactivity in metal have been used widely in corrosion research. The corrosion rate is monitored continuously by radiation counters placed at a convenient location outside the test equipment, taking advantage of the ability of gamma rays to penetrate metals. The corrosion rate is determined by loss of radioactivity due to removal of radioactive metal by the corrosive reactions. The measurements are fully non-destructive, very accurate and easy to interpret. The report describes the experience with these types of corrosion rate measurements for research and industrial applications, the instrumentation, available isotopes and safety precautions.

1989-01-01

255

Reconstruction of two victims' posturing based on the induced radioactivities in their bones in the criticality accident in Tokai-Mura, Japan.  

Science.gov (United States)

On 30 September 1999, three workers were severely exposed to neutrons and gamma rays in a criticality accident that occurred at a uranium conversion facility in Tokai-mura, Ibaraki Prefecture, Japan. Radiochemical analyses of 32P and 45Ca induced by neutrons in bone matrix were carried out after the deaths of two of the victims. It was found that more than several million becquerels of both nuclides had been produced in their body skeletons. Results showed non-homogeneous distributions of neutron fluence in the bodies, from which it could be deduced how both workers were positioned relative to the fission source during exposure, i.e., at the moment of the first nuclear excursion. For the victim who died first, the activities in the central part of his body were more than those of his extremities. Also, in the central part of his body, the right side showed more activities than the left side. As for the second man, the activities indicated rather uniform exposure to neutrons to the whole body although the geometrical distribution of the activity varied enough to assume his orientation. Such information on the geometrical distribution of neutron-induced radioactivities in the skeleton can be used to reconstruct the posturing of the victims, which is necessary to estimate their apparent absorbed doses. PMID:12075680

Miyamoto, Kiriko; Watanabe, Yoshihito; Yukawa, Masae; Takeda, Hiroshi; Nishimura, Yoshikazu; Ishigure, Nobuhito; Hirama, Toshiyasu; Akashi, Makoto

2002-07-01

256

Reconstruction of two victims' posturing based on the induced radioactivities in their bones in the criticality accident in Tokai-Mura, Japan.  

UK PubMed Central (United Kingdom)

On 30 September 1999, three workers were severely exposed to neutrons and gamma rays in a criticality accident that occurred at a uranium conversion facility in Tokai-mura, Ibaraki Prefecture, Japan. Radiochemical analyses of 32P and 45Ca induced by neutrons in bone matrix were carried out after the deaths of two of the victims. It was found that more than several million becquerels of both nuclides had been produced in their body skeletons. Results showed non-homogeneous distributions of neutron fluence in the bodies, from which it could be deduced how both workers were positioned relative to the fission source during exposure, i.e., at the moment of the first nuclear excursion. For the victim who died first, the activities in the central part of his body were more than those of his extremities. Also, in the central part of his body, the right side showed more activities than the left side. As for the second man, the activities indicated rather uniform exposure to neutrons to the whole body although the geometrical distribution of the activity varied enough to assume his orientation. Such information on the geometrical distribution of neutron-induced radioactivities in the skeleton can be used to reconstruct the posturing of the victims, which is necessary to estimate their apparent absorbed doses.

Miyamoto K; Watanabe Y; Yukawa M; Takeda H; Nishimura Y; Ishigure N; Hirama T; Akashi M

2002-07-01

257

ARTIFICIAL REEF AND ARTIFICIAL REEF COMPLEX  

UK PubMed Central (United Kingdom)

PURPOSE: An artificial fish reef and an artificial fish reef composite are provided to enhance stability against external force and to minimize sinking thereof. CONSTITUTION: An artificial fish reef comprises a main body(110) and a plurality of grooves(117) formed in the main body. Both sides of the main body are able to be divided into four protrusions which are formed in an X-shape and a central part formed in the center of the protrusions. A plurality of grooves are formed in the outer circumference of the main body in order to connect the sides of the main body.

YUN CHI WOONG

258

Radioactivity and foods  

Energy Technology Data Exchange (ETDEWEB)

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

Olszyna-Marzys, A.E. (Unified Lab. of Food and Drug Control, Guatemala City (Guatemala))

1991-01-01

259

Radioactivity; Die Radioaktivitaet  

Energy Technology Data Exchange (ETDEWEB)

The following topics are dealt with: The radioactive substances, the ionization of gases, measuring methods, the physical nature of radiations, radiation effects, the continuous production of radioactive matter, radioactive emanations, excited radioactivity, theory of transmutation series, the transmutation products of uranium, thorium, and actinium, the transmutation products of radium, the energy development, radioactive processes, atmospheric activity, the radioactivity as general property of matter. (HSI)

Rutherford, E.

2007-07-01

260

Cloning of the Koi Herpesvirus Genome as an Infectious Bacterial Artificial Chromosome Demonstrates That Disruption of the Thymidine Kinase Locus Induces Partial Attenuation in Cyprinus carpio koi?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial chromosome (BAC) clone that can be used to produce KHV recombinant strains. This goal was achieved ...

Costes, B.; Fournier, G.; Michel, B.; Delforge, C.; Raj, V. Stalin; Dewals, B.; Gillet, L.; Drion, P.; Body, A.; Schynts, F.

 
 
 
 
261

Cohort study on radioactive iodine-induced hypothyroidism: implications for graves' ophthalmopathy and optimal timing for thyroid hormone assessment.  

UK PubMed Central (United Kingdom)

BACKGROUND: Graves' ophthalmopathy (GO) develops or worsens in up to one-third of patients treated with radioactive iodine (RAI) for Graves' hyperthyroidism. We sought to identify the prevalence of development or worsening of GO in patients treated with RAI for Graves' hyperthyroidism and to identify the risk factors associated with that outcome. METHODS: We identified a retrospective cohort of consecutive patients treated with RAI at Mayo Clinic (Rochester, MN) between 2005 and 2006. We assessed their medical records for evidence of hypothyroidism and development or worsening of GO in the year after therapy. Hypothyroidism was defined as thyrotropin >3.0?mIU/L or free thyroxine <0.8?ng/dL. RESULTS: We identified 291 consecutive patients who received RAI therapy during the study period, with 195 out of 291 having complete follow-up data for a one-year period. GO was present in 46 out of 195 patients (23.6%) at baseline. After RAI treatment, GO developed or worsened in 25 out of 195 patients (12.8%) and it was associated with hypothyroidism at first follow-up (p=0.011) with an odds ratio (OR) of 3.3 [95% confidence interval (CI) 1.3-8.7]. More smokers than nonsmokers developed new or worse GO (17.7% vs. 11.8%), but that difference did not reach statistical significance (p=0.35). Preexisting GO (24% of patients) was associated with a higher risk for negative GO outcome compared with patients who had no GO at baseline (11%; p=0.021). Both development of hypothyroidism by the first visit after RAI therapy (OR 3.6) and preexistent GO (OR 2.8) remained significant in a multivariate analysis. Development of hypothyroidism was more likely in patients with longer duration to first follow-up (p<0.001). By 6-8 weeks after RAI treatment, the prevalence of hypothyroidism was ?40%, while that of hyperthyroidism was only 20%. CONCLUSIONS: The presence of hypothyroidism at the first assessment of thyroid function after RAI administration is a strong predictor for adverse GO outcome. This risk is highest in patients with preexisting GO. We suggest that in order to prevent clinical hypothyroidism and the associated risk for GO, the optimal time for first measurement of fT4 is before 6 weeks after RAI therapy.

Stan MN; Durski JM; Brito JP; Bhagra S; Thapa P; Bahn RS

2013-05-01

262

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

1967-01-01

263

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%), 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

1994-01-01

264

Artificial cognition architectures  

CERN Multimedia

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

265

Hydroxyapatite coating enhances polyethylene terephthalate artificial ligament graft osseointegration in the bone tunnel  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proxim...

Li, Hong; Ge, Yunsheng; Wu, Yang; Jiang, Jia; Gao, Kai; Zhang, Pengyun; Wu, Lingxiang; Chen, Shiyi

266

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

267

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

268

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

269

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 installa-tion. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally oc-curring 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 pre-sented in this paper.

Ivana Vukanac; Aleksandar Kandi?; Mirjana ?uraševi?; Bojan Šešlak

2012-01-01

270

A ARTIFICIAL JOINTS AND A METHOD FOR MODIFYING SURFACES OF A ARTIFICIAL JOINTS  

UK PubMed Central (United Kingdom)

An artificial joint and the surface modification of the artificial joint are provided, in which the titanium coating layer is formed even after the titanium coating layer is formed on the surface of the Ti alloy. An artificial joint in which the oxide film inducing the micro-arc oxidation is formed comprises: a Ti alloy(1) a titanium coating layer(2) which is applied on the Ti alloy and is formed in order to prevent the elution of the composition of the Ti alloy an oxide film(3) of the porosity formed in the titanium coating layer by the micro-arc oxidation.

SUN DOO HOON; KIM YONG SIK

271

Artificial Reefs Feasibility Study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Marine Institute commissioned this study to review the current status of artificial reefs world-wide with a view to determining the feasibility of the development of a sea angling initiative based on the deployment and exploitation of artificial reefs. The study, conducted by the Coastal Resourc...

O'Leary, E; Hubbard, T; O'Leary, D

272

Fifth generation (artificial intelligence)  

Energy Technology Data Exchange (ETDEWEB)

The paper explains the concept of artificial intelligence and gives a number of examples of systems with this ability. The author concludes, that an international race in the scientific field is already taking place and that there are already signs of commercial rivalry. The Japanese government aims to create a fifth generation of computer systems with artificial intelligence during the '80s.

Guntram, U.

1983-11-01

273

Nonstationary artificial black holes  

CERN Multimedia

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

Eskin, Gregory

2013-01-01

274

Environmental radioactivity and radiation exposure  

International Nuclear Information System (INIS)

[en] 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.)

1980-01-01

275

Radioactive patient  

International Nuclear Information System (INIS)

Patients containing diagnostic or therapeutic amounts of radionuclides present exposure problems for medical and technical personnel. It is essential that personnel be aware of the magnitude of exposure expected and the methods available for its reduction. The design of a nuclear medicine facility should consider patients as sources of exposure. The size of imaging areas may be increased to reduce exposure to attending personnel. Patients containing radioactivity should be segregated from other patients and their families. Hospitalized patients given therapeutic amounts of radionuclides represent sources of exposure and contamination to personnel providing care. The use of disposable materials and the monitoring of these materials for contamination will reduce contamination of the hospital environment. Adequate instruction of personnel is essential to programs using therapeutic amounts of radionuclides so that patients are not made to feel isolated because of the form of treatment they are receiving.

1986-01-01

276

Radioactive colloids  

International Nuclear Information System (INIS)

Different techniques for the characterization of radioactive colloids, used in nuclear medicine, have been evaluated and compared. Several radioactive colloids have been characterized in vitro and in vivo and tested experimentally. Colloid biokinetics following interstitial or intravenous injection were evaluated with a scintillation camera technique. Lymphoscintigraphy with a Tc-99-labelled antimony sulphur colloid was performed in 32 patients with malignant melanoma in order to evaluate the technique. Based on the biokinetic results, absorbed doses in tissues and organs were calculated. The function of the reticuloendothelial system has been evaluated in rats after inoculation with tumour cells. Microfiltration and photon correlation spectroscopy were found to be suitable in determining activity-size and particle size distributions, respectively. Maximal lymph node uptake following subcutaneous injection was found to correspond to a colloid particle size between 10 and 50 nm. Lymphoscintigraphy was found to be useful in the study of lymphatic drainage from the primary tumour site in patients with malignant melanoma on the trunk. Quantitative analysis of ilio-inguinal lymph node uptake in patients with malignant melanoma on the lower extremities was, however, found to be of no value for the detection of metastatic disease in lymph nodes. High absorbed doses may be received in lymph nodes (up to 1 mGy/MBq) and at the injection site (about 10 mGy/MBq). In an experimental study it was found that the relative colloid uptake in bone marrow and spleen depended on the total number of intravenously injected particles. This may considerably affect the absorbed dose in these organs. (author)

1987-01-01

277

Ambient radioactivity levels and radiation doses. Annual report 2010; Umweltradioaktivitaet und Strahlenbelastung. Jahresbericht 2010  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-04-15

278

Model of radioactive background of solid environmental subjects  

Energy Technology Data Exchange (ETDEWEB)

Environmental subjects are complicated technologically influenced systems with multi-levelled spatial and temporary inhomogeneity of radionuclides distribution. Their radioactive background is a sum of a number of natural and techno-genic factors: natural radioactivity, nuclear weapon testing, using nuclear technologies in industries, etc. Correct determination of radioactive background is in fact a basis for accepting just juridic, economic and social decisions. A general procedure of computation of upper borders of radioactive background of environmental subjects is offered. It is proved to work in application to soil as a triple system consisting of sand, clay and organic matter. There is a reason to believe that it works as well for all environmental subjects with components of significantly different radioactivity. The procedure is modelling of confident interval of background radioactivity which is based upon the different ability of various components of environmental subject to accumulate natural and artificial radionuclides. (author)

Gablin, V.; Verbova, L.; Sobolev, A. [Moscow Scientific-Industrial Association Radon 2/14, Moscow (Russian Federation)

2004-07-01

279

Model of radioactive background of solid environmental subjects  

International Nuclear Information System (INIS)

[en] Environmental subjects are complicated technologically influenced systems with multi-levelled spatial and temporary inhomogeneity of radionuclides distribution. Their radioactive background is a sum of a number of natural and techno-genic factors: natural radioactivity, nuclear weapon testing, using nuclear technologies in industries, etc. Correct determination of radioactive background is in fact a basis for accepting just juridic, economic and social decisions. A general procedure of computation of upper borders of radioactive background of environmental subjects is offered. It is proved to work in application to soil as a triple system consisting of sand, clay and organic matter. There is a reason to believe that it works as well for all environmental subjects with components of significantly different radioactivity. The procedure is modelling of confident interval of background radioactivity which is based upon the different ability of various components of environmental subject to accumulate natural and artificial radionuclides. (author)

2004-01-01

280

From meandering to straight grain boundaries: Improving the structures of artificially-induced grain boundaries in superconducting YBa{sub 2}Cu{sub 3}O{sub y} bicrystals  

Energy Technology Data Exchange (ETDEWEB)

This paper presents several key aspects of the successful approach to preparing artificially-induced [001] tilt YBa{sub 2}Cu{sub 3}O{sub y} (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.

Zhang, X.F.; Todt, V.R.; Miller, D.J.

1997-08-01

 
 
 
 
281

Artificial Coral Reefs  

Science.gov (United States)

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

Sohmer, Rachel.

282

Radiation protection. Radioactivity and health  

International Nuclear Information System (INIS)

[en] 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./HP)[de] Die vorliegende Broschuere macht den Versuch, den Zusammenhang zwischen Radioaktivitaet und Gesundheit auch fuer den Nicht-Fachmann verstaendlich darzustellen. Nach einer kurzen Behandlung der Grundbegriffe der Radioaktivitaet befasst sie sich mit den natuerlichen und kuenstlichen Strahlenexpositionen, denen der Mensch im Industriezeitalter ausgesetzt ist. Die damit verbundenen Wirkungen auf den Menschen werden eingehend in bezug auf somatische und genetische Strahleneffekte behandelt. Die Erlaeuterung der radiooekologischen Zusammenhaenge, beginnend bei den radioaktiven Ableitungen aus kerntechnischen Anlagen bis zur Ermittlung der Strahlenexposition des Menschen, wird ergaenzt durch die Beschreibung der strahlenmedizinischen Risikobeziehungen. Die Ausfuehrungen sollen die Ergebnisse langjaehriger Forschungsarbeiten zur Beantwortung der Frage der strahlenbiologischen Risiken in verstaendlicher Form widerspiegeln und zur sachlichen Information ueber dieses so ausserordentlich bedeutsame Gebiet beitragen. (orig./HP)

1985-01-01

283

Radioactivity in the Great Lakes.  

UK PubMed Central (United Kingdom)

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.

Joshi SR

1991-03-01

284

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.).

1985-01-01

285

Artificial Sweeteners and Cancer  

Science.gov (United States)

... used instead of sucrose (table sugar) to sweeten foods and beverages. Because artificial sweeteners are many times sweeter than ... the FDA in 1988 for use in specific food and beverage categories, and was later approved as a general ...

286

Artificial Hydration and Nutrition  

Science.gov (United States)

... the fluid under the skin. This is called hypodermoclysis, or subcutaneous fluid replacement. Another method of artificial ... a family member or another caregiver can do hypodermoclysis at home after a doctor or nurse shows ...

287

Introduction to artificial intelligence  

Energy Technology Data Exchange (ETDEWEB)

The author discusses the development of artificial intelligence (AI). He explains the basic elements of AI: Heuristic search, knowledge representation, AI languages and tools, Natural Language Processing, computer vision, expert systems and problem solving and planning.

Gevarter, W.B.

1987-09-01

288

Artificial life down under.  

Science.gov (United States)

For many years, Australian researchers have been contributing to the areas of artificial life and complex adaptive systems. This report highlights some of the Australian-based activities in these areas. PMID:16053577

Abbass, Hussein A

2005-01-01

289

Latex bead-based artificial antigen-presenting cells induce tumor-specific CTL responses in the native T-cell repertoires and inhibit tumor growth.  

UK PubMed Central (United Kingdom)

Cell-free artificial antigen-presenting cells (aAPCs) were generated by coupling H-2K(b)/TRP2 tetramers together with anti-CD28 and anti-4-1BB antibodies onto cell-sized latex beads and injected intravenously and subcutaneously into naïve mice and antigen-primed mice (B6, H-2K(b)). Vigorous tumor antigen-specific CTL responses in the native T-cell repertoire in each mouse model were elicited as evaluated by measuring surface CD69 and CD25, intracellular IFN-?, tetramer staining and cytolysis of melanoma cells. Furthermore, the aAPCs efficiently inhibited subcutaneous tumor growth and markedly delayed tumor progression in tumor-bearing mice. These data suggest that bead-based aAPCs represent a potential strategy for the active immunotherapy of cancers or persistent infections.

Shen C; Cheng K; Miao S; Wang W; He Y; Meng F; Zhang J

2013-02-01

290

Monitoring of radioactivity in the marine environment  

International Nuclear Information System (INIS)

[en] 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

1992-01-01

291

Radioactive monitoring of the marine environment  

International Nuclear Information System (INIS)

[en] 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)

1991-01-01

292

Fragrant artificial flower apparatus  

UK PubMed Central (United Kingdom)

A fragrant artificial flower display has one or more artificial flowers extending out of the interior of a vessel and one or more fragrant gel-coated rods connected to the stems of the flowers by a clip. The clips support the rods above the bottom of the vessel so that they are closer to the open top of the vessel to better release fragrance into the surrounding air, even when the vessel is tall and the rods are short.

RYAN LYN; PESU MAXINE

293

Artificial muscle: facts and fiction.  

UK PubMed Central (United Kingdom)

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.

Schaub MC

2011-01-01

294

Heidegger and artificial intelligence  

Energy Technology Data Exchange (ETDEWEB)

The discipline of Artificial Intelligence, in its quest for machine intelligence, showed great promise as long as its areas of application were limited to problems of a scientific and situation neutral nature. The attempts to move beyond these problems to a full simulation of man's intelligence has faltered and slowed it progress, largely because of the inability of Artificial Intelligence to deal with human characteristic, such as feelings, goals, and desires. This dissertation takes the position that an impasse has resulted because Artificial Intelligence has never been properly defined as a science: its objects and methods have never been identified. The following study undertakes to provide such a definition, i.e., the required ground for Artificial Intelligence. The procedure and methods employed in this study are based on Heidegger's philosophy and techniques of analysis as developed in Being and Time. Results of this study show that both the discipline of Artificial Intelligence and the concerns of Heidegger in Being and Time have the same object; fundamental ontology. The application of Heidegger's conclusions concerning fundamental ontology unites the various aspects of Artificial Intelligence and provides the articulation which shows the parts of this discipline and how they are related.

Diaz, G.

1987-01-01

295

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

296

Radioactivity in the environment  

International Nuclear Information System (INIS)

This chapter discusses various aspects of radioactivity in the environment. After giving basic information on radiation and radioactivity, other topics discussed include biological effects of radiation, natural radioactivity, medical applications of radioactivity, pollution from nuclear weapons explosions, pollution from electric power generation plants and other nuclear reactors and pollution from non-nuclear processes. (U.K.).

1990-01-01

297

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 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

1976-01-01

298

Radioactive waste management  

International Nuclear Information System (INIS)

Radioactive waste generated from utilization of radioisotopes and each step of the nuclear fuel cycle and decommissioning of nuclear facilities are presented. On the safe management of radioactive waste management, international safety standards are established such as ''The Principles of Radioactive Waste Management (IAEA)'' and The Joint Convention on the Safety of Radioactive Waste Management. Basic steps of radioactive waste management consist of treatment, conditioning and disposal. Disposal is the final step of radioactive waste management and its safety is confirmed by safety assessment in the licensing process. Safety assessment means evaluation of radiation dose rate caused by radioactive materials contained in disposed radioactive waste. The results of the safety assessment are compared with dose limits. The key issues of radioactive waste disposal are establishment of long term national strategies and regulations for safe management of radioactive waste, siting of repository, continuity of management activities and financial bases for long term, and security of human resources. (Author).

2007-06-20

299

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.)

1981-01-01

300

Natural and artificial radioactivity in soils of forests  

International Nuclear Information System (INIS)

[en] 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)

2001-01-01

 
 
 
 
301

Decrease of deposited artificial radioactivity in urban environments  

International Nuclear Information System (INIS)

[en] The behavior of cesium during the first three years after deposition was investigated with in-situ gamma spectrometry at 48 measuring sites. An evaluation method was developed which allowed determination of retention on asphalt surfaces, the effective depth profile in soils covered with grass, and time factor developments of the gamma dose rate. Two months after deposition, the gamma dose rate on grassy soils amounts to 60% of the dose rate for smooth large-scale surfaces with identical deposition, but without weathering or soil migration. After 3 years this ratio lies at 35%. On asphalt surfaces, however, there was after 2 months only a dose rate of 20% of the dose rate on smooth surfaces without weathering; after 3 years it was only 4%. Environment factors were defined which determined the ratio of dose rates on measuring areas to dose rates on large grassy surfaces. The environment factors are the smaller, the bigger the proportion of asphalt. They are constant as regards the time factor, or they decrease gradually after deposition. Results were approximated analytically. The investigation of tiles showed that there was an activity retention of 30-60% on roofs in Munich following wet deposition of cesium. After 2 years it was still 10-25%. (orig./HP)[de] Das Verhalten von Caesium in den ersten drei Jahren nach der Ablagerung wurde fuer 48 Messplaetze mittels in-situ ?-Spektrometrie untersucht. Dazu wurde ein Auswerteverfahren entwickelt, das die Bestimmung der Rueckhaltung auf befestigten Oberflaechen, der effektiven Tiefenprofile in Wiesenboeden und der zeitlichen Entwicklung von ?-Dosisleistung erlaubt. 2 Monate nach der Ablagerung betraegt die ?-Dosisleistung auf Wiesen 60% der ?-Dosisleistung ueber einer glatten, unendlich ausgedehnten Flaeche mit derselben Deposition aber ohne Abwitterung oder Einwandern in den Erdboden. Dieses Verhaeltnis liegt nach 3 Jahren bei 35%. Demgegenueber wurde auf befestigten Plaetzen nach 2 Monaten nur eine ?-Dosisleistung in Hoehe von 20% der ?-Dosisleistung ueber eine glatte Flaeche ohne Abwittern gefunden, nach 3 Jahren waren es nur noch 4%. Es wurden Umgebungsfaktoren definiert, die das Verhaeltnis der ?-Dosisleistung an den Messplaetzen zur ?-Dosisleistung ueber grossen Wiesenflaechen angeben. Die Umgebungsfaktoren sind umso kleiner, je groesser der Anteil befestigter Flaechen an einem Messplatz ist. Sie sind zeitlich konstant oder nehmen mit der Zeit nach der Ablagerung ab. Alle Ergebnisse wurden analytisch approximiert. Die Untersuchung von Dachziegeln ergab, dass bei der nassen Ablagerung des Caesiums in Muenchen auf den Daechern 30-60% der Aktivitaet zurueckgehalten wurden. Nach 2 Jahren waren es immerhin noch 10-25%. (orig./HP)

1990-01-01

302

Risk analysis of radioactive waste disposal in salt deposits, app. 1  

International Nuclear Information System (INIS)

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

1975-09-03

303

Application of biotechnology to the problem of the disposal of radioactive wastes  

Energy Technology Data Exchange (ETDEWEB)

Artificial biological systems are proposed for use in the treatment of low- and intermediate-level radioactive wastes. The microbial conversion of organic and inorganic substances under continuous conditions, involving the turnover of matter, will allow a significant reduction in volume of radioactive wastes. Such specialised systems can act as a biogeochemical barrier for radionuclide transport. 14 refs.

Belyi, A.V.; Gurevich, Yu.L.; Pustoshilov, P.P.; Sadovsky, M.G. [Laboratory of the Ecological Biotechnology, Institute of Biophysics of Siberian Division of Russian Academy of Sciences, Krasnoyarsk (Russian Federation)

1998-07-01

304

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

2000-01-01

305

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

2003-01-01

306

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)

1998-01-01

307

Six-year experiences in the environmental radioactivity monitoring in Taiwan  

International Nuclear Information System (INIS)

An islandwide network for environmental radioactivity monitoring established in 1974 is described with reference to (1) measurement of radioactive fallout from nuclear testings, (2) environmental monitoring for nuclear power plants and a radioactive waste disposal site, (3) a site specially designated by the government, and (4) installations involving radiation. Naturally occurring and artificial radionuclides are equally emphasized. All significant results are reported and discussed. (H.K.)

1980-03-14

308

Radioactivity of wood ash  

International Nuclear Information System (INIS)

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

2000-01-01

309

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

2013-10-11

310

Artificial intelligence in nanotechnology.  

UK PubMed Central (United Kingdom)

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.

Sacha GM; Varona P

2013-11-01

311

Artificial recharge of groundwater  

Energy Technology Data Exchange (ETDEWEB)

The vast underground reservoirs formed by aquifers constitute invaluable water supply sources as well as water storage facilities. Because natural replenishment of the supply occurs very slowly, continued excessive exploitation of it causes groundwater levels to decline with time. If not corrected this leads to an eventual depletion of a valuable natural resource. To prevent mining and groundwater pollution, the artificial recharge of groundwater basins is becoming increasingly important in groundwater management as a way to increase this natural supply of water. Artificial recharge can reduce, stop, and even reverse declining levels of groundwater. In addition, it can protect underground freshwater in coastal aquifers against salt-water intrusion from the ocean, and can be used to store surface and reclaimed water for future use. This book is a treatise of the artificial recharge of groundwater, with particular emphasis on recharge with reclaimed municipal wastewater.

Asano, T.

1985-01-01

312

Artificial leg embedding device and artificial leg  

UK PubMed Central (United Kingdom)

An artificial leg embedding device comprises an upper plate and a lower plate. The upper plate comprises a front leg segment obliquely extending and a rear leg segment transversely extending from the tail end of the front leg segment. The lower plate comprises a connecting segment fixed on the bottom surface of the front leg segment of the upper plate and a heel segment obliquely extending downwards from the connecting segment. A bending position at the joint of the connecting segment of the lower plate and the heel segment and a bending position at the joint of the front leg segment of the upper leg and the rear leg segment are totally sealed. Through deformation of the upper plate and the lower plate, weight loaded on the upper plate and the lower plate and counteraction force from the ground are absorbed and users feel more comfortable when walking. Further, the artificial leg embedding device can achieve functions of simple components, increasing durability and being manufactured conveniently according to personal requirements.

JIANYOU CHEN

313

How is the water molecule activated on metalloporphyrins? Oxygenation of substrates induced through one-photon/two-electron conversion in artificial photosynthesis by visible light.  

UK PubMed Central (United Kingdom)

The reaction mechanism of the highly efficient (phi = 0.60), selective photochemical epoxidation of alkenes sensitized by CO-coordinated tetra(2,4,6-trimethyl)phenylporphyrinatoruthenium(II) (Ru(II)TMP(CO)), with water acting both as an electron and oxygen atom donor, was investigated. The steady-state light irradiation of the reaction mixture indicated the formation of the Ru(II)TMP (CO) cation radical under neutral conditions, which was effectively trapped by an hydroxide ion to regenerate the starting sensitizer. By means of a laser flash photolysis experiment, the formation of the cation radical as the primary process from the triplet excited state of Ru(II)TMP(CO) was clearly observed. Four kinds of transients were detected in completely different ranges of the delay time: the excited triplet state of Ru(II)TMP(CO) [delay time region <20 micros], the cation radical of Ru(II)TMP(CO)(CH3CN) [20-50 micros], the hydroxyl-coordinated Intermediate [I] [50-200 micros], and the cyclohexane-attached Intermediate [II] [200 micros-8 ms]. A reaction mechanism was revealed that involves RuTMP(CO) cation radical formation from the triplet excited state of the sensitizer, followed by attack of an hydroxide ion to form an hydroxyl-coordinated Ru-porphyrin (Intermediate [I]) and subsequent reaction with cyclohexene to form Intermediate [II]. The kinetics for each step of the successive processes was carefully analyzed and their rate constants were determined. The two-electron oxidation of water by one-photon irradiation, as revealed in the photochemical epoxidation, is proposed to be one of the more promising candidates to get through the bottleneck of water oxidation in artificial photosynthesis.

Shimada T; Kumagai A; Funyu S; Takagi S; Masui D; Nabetani Y; Tachibana H; Tryk DA; Inoue H

2012-01-01

314

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

Science.gov (United States)

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

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

2009-01-01

315

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

UK PubMed Central (United Kingdom)

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

Redon CE; Dickey JS; Bonner WM; Sedelnikova OA

2009-01-01

316

How is the water molecule activated on metalloporphyrins? Oxygenation of substrates induced through one-photon/two-electron conversion in artificial photosynthesis by visible light.  

Science.gov (United States)

The reaction mechanism of the highly efficient (phi = 0.60), selective photochemical epoxidation of alkenes sensitized by CO-coordinated tetra(2,4,6-trimethyl)phenylporphyrinatoruthenium(II) (Ru(II)TMP(CO)), with water acting both as an electron and oxygen atom donor, was investigated. The steady-state light irradiation of the reaction mixture indicated the formation of the Ru(II)TMP (CO) cation radical under neutral conditions, which was effectively trapped by an hydroxide ion to regenerate the starting sensitizer. By means of a laser flash photolysis experiment, the formation of the cation radical as the primary process from the triplet excited state of Ru(II)TMP(CO) was clearly observed. Four kinds of transients were detected in completely different ranges of the delay time: the excited triplet state of Ru(II)TMP(CO) [delay time region <20 micros], the cation radical of Ru(II)TMP(CO)(CH3CN) [20-50 micros], the hydroxyl-coordinated Intermediate [I] [50-200 micros], and the cyclohexane-attached Intermediate [II] [200 micros-8 ms]. A reaction mechanism was revealed that involves RuTMP(CO) cation radical formation from the triplet excited state of the sensitizer, followed by attack of an hydroxide ion to form an hydroxyl-coordinated Ru-porphyrin (Intermediate [I]) and subsequent reaction with cyclohexene to form Intermediate [II]. The kinetics for each step of the successive processes was carefully analyzed and their rate constants were determined. The two-electron oxidation of water by one-photon irradiation, as revealed in the photochemical epoxidation, is proposed to be one of the more promising candidates to get through the bottleneck of water oxidation in artificial photosynthesis. PMID:22470972

Shimada, Tetsuya; Kumagai, Akihiro; Funyu, Shigeaki; Takagi, Shinsuke; Masui, Dai; Nabetani, Yu; Tachibana, Hiroshi; Tryk, Donald A; Inoue, Haruo

2012-01-01

317

Realizing artificial photosynthesis.  

UK PubMed Central (United Kingdom)

Artificial photosynthesis comprises the design of systems for converting solar energy into useful forms based on the fundamental science underlying natural photosynthesis. There are many approaches to this problem. In this report, the emphasis is on molecule-based systems for photochemical production of fuels using sunlight. A few examples of typical components of artificial photosynthetic systems including antennas, reaction centres, catalysts for fuel production and water oxidation, and units for photoprotection and photoregulation are presented in order to illustrate the current state of the field and point out challenges yet to be fully addressed.

Gust D; Moore TA; Moore AL

2012-01-01

318

Artificial business brain  

Energy Technology Data Exchange (ETDEWEB)

Researchers at Kingston Polytechnic are putting artificial intelligence into low-cost commercial systems. The research team is working on producing a machine that will work like the human mind, by combining pattern recognition with a cybernetic idea called connectivity. The company reliability engineering is to launch an accounting software package and a reliability prediction package which will offer small businesses the benefits of artificial intelligence, running on the Apple IIE, for about >800. Instead of storing data, the program stores a knowledge base of unrelated rules which the machine can use to perform functions. This means a computer can be taught in the same way that a human clerk can be taught.

Murphy, J.

1984-04-26

319

BIODEGRADABLE ARTIFICIAL REEF  

UK PubMed Central (United Kingdom)

PURPOSE: A biodegradable artificial fish reef is provided to neutralize the toxicity of cement and to be utilized as a food source of microorganism. CONSTITUTION: A biodegradable artificial fish reef includes biodegradable pellets made of one or more inorganic minerals 10-30 weight% selected from a group consisting of poly lactic acid 40-50 weight%, polybutylene succinate 30-40 weight%, diatomite, vermiculite, perlite, and paracel. The biodegradable pellet is compounded at the temperature of 160-170 deg.C and includes slag ball or bottom ash.

JANG CHUL JOONG

320

Artificial black holes  

CERN Multimedia

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 stationary wave equations in two space dimensions, and in the axisymmetric case.

Eskin, Gregory

2011-01-01

 
 
 
 
321

Realizing artificial photosynthesis.  

Science.gov (United States)

Artificial photosynthesis comprises the design of systems for converting solar energy into useful forms based on the fundamental science underlying natural photosynthesis. There are many approaches to this problem. In this report, the emphasis is on molecule-based systems for photochemical production of fuels using sunlight. A few examples of typical components of artificial photosynthetic systems including antennas, reaction centres, catalysts for fuel production and water oxidation, and units for photoprotection and photoregulation are presented in order to illustrate the current state of the field and point out challenges yet to be fully addressed. PMID:22470964

Gust, Devens; Moore, Thomas A; Moore, Ana L

2012-01-01

322

Equine artificial insemination.  

UK PubMed Central (United Kingdom)

Artificial insemination is an effective technique for improving utilization of the stallion while maintaining normal conception rates in the mare. However, procedures for collection, evaluation, and insemination of semen must be followed carefully to achieve good results. Techniques for preservation of equine semen in the liquid or frozen state could potentially allow for more widespread use of genetically superior stallions. Further acceptance of artificial insemination and the use of cooled or frozen transported semen by breed registries is needed before this will occur. More work is needed to perfect methods of semen preservation, even though semen from some stallions can be cooled or frozen quite successfully at the present time.

Yates DJ; Whitacre MD

1988-08-01

323

SYMPTOMATIC HERPES, A SEQUELA OF ARTIFICIALLY INDUCED FEVER : INCIDENCE AND CLINICAL ASPECTS; RECOVERY OF A VIRUS FROM HERPETIC VESICLES, AND COMPARISON WITH A KNOWN STRAIN OF HERPES VIRUS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

1. Symptomatic herpes occurred in 190 (46.2 per cent) of 411 patients treated with fever induced by physical methods. 2. Herpes recurred in only 7, or 5.3 per cent, of 131 patients given subsequent fever treatments, suggesting that some immunity develops with the first attack. 3. An acute encephali...

Warren, Stafford L.; Carpenter, Charles M.; Boak, Ruth A.

324

Giant radioactive halos: indicators of unknown radioactivity?  

Science.gov (United States)

A new group of giant radioactive halos has been found with radii in excess of anything previously discovered. Since alternate explanations for these giant halos are inconclusive at present, the possibility is considered that they originate with unknown alpha radioactivity, either from isomers of known elements or from superheavy elements. PMID:17791843

Gentry, R V

1970-08-14

325

Giant radioactive halos: indicators of unknown radioactivity?  

UK PubMed Central (United Kingdom)

A new group of giant radioactive halos has been found with radii in excess of anything previously discovered. Since alternate explanations for these giant halos are inconclusive at present, the possibility is considered that they originate with unknown alpha radioactivity, either from isomers of known elements or from superheavy elements.

Gentry RV

1970-08-01

326

Artificial intelligence and automation  

CERN Document Server

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

Bourbakis, NG

1998-01-01

327

Argumentation in Artificial Intelligence  

CERN Multimedia

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

328

ATE applications of artificial intelligence  

Energy Technology Data Exchange (ETDEWEB)

Artificial intelligence technologies have been investigated by the Naval Air Engineering Center for potential applications to ATE. It was found that artificial intelligence is capable of accumulating knowledge from expert technicians and expanding on the knowledge of optimum ATE support.

Kunert, J.

1982-01-01

329

Radioactive waste management  

International Nuclear Information System (INIS)

[en] 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

1994-01-01

330

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.

1998-01-01

331

Radioactive waste transportation  

International Nuclear Information System (INIS)

Problems of radioactive materials transportation compromising a part of nuclear fuel cycle are reviewed. Safety of transportation is defined as the basic concept of controlling radioactive materials transport. Principal international safety standard, data of the IAEA conference on the problems of controlling radioactive materials transport are discussed. Comprehensive analysis of controlling problems and technical questions as well as line of attack on the development of radioactive materials transportation are presented. Waste transport in Sweden is discussed

2004-01-01

332

Production of radioactive stents  

International Nuclear Information System (INIS)

In the last years radioactive stents proved to inhibit neointima formation. This report describes the actual status of producing such radioactive stents. Different methods of radioactive Stent production are considered. The ion beam implantation of P-32 applied at the Research Center Karlsruhe will be described in more detail. (orig.)

2000-01-01

333

Understanding radioactive waste  

International Nuclear Information System (INIS)

[en] This book discusses the sources and health effects of radioactive wastes. It reveals the techniques to concentrate and immobilize radioactivity and examines the merits of various disposal ideas. The book, which is designed for the lay reader, explains the basic science of atoms,nuclear particles,radioactivity, radiation and health effects

1989-01-01

334

Radioactive materials in California  

International Nuclear Information System (INIS)

[en] This draft report covers: radioactive materials at fixed facilities, nuclear power plants and radioactive wastes, environmental surveillance and radiation monitoring, and decommissioning and decontamination of radioactive facilities. Licensing, hazards, problem areas, etc. are covered, and recommendations are given for these problem areas

1978-01-01

335

Philosophical and Psychological Problems of Artificial Intelligence.  

Science.gov (United States)

The following topics are discussed: Artificial intelligence as a scientific direction; Heuristic search theory and the psychology of intelligence; Prospects for improving artificial intelligence; Artificial intelligence and materialism; Artificial intelli...

O. K. Tikhomirov

1975-01-01

336

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.

2012-01-01

337

Artificial insemination in dromedary camels.  

Science.gov (United States)

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

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

2012-10-25

338

Artificial insemination in dromedary camels.  

UK PubMed Central (United Kingdom)

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

Skidmore JA; Morton KM; Billah M

2013-01-01

339

Acoustic cavitation structures produced by artificial implants of nuclei.  

UK PubMed Central (United Kingdom)

High-density controllable bubble structures are produced in the vicinity of radiating surface by artificially implant nuclei. Two kinds of typical cavitation structures produced by artificially implant nuclei are investigated. The focusing action and the physical origin of jet-induced cone-like bubble structure are analyzed. The sonochemical activity of cavitation structures is measured by using the standard method of potassium iodide dosimetry. The controllability of cavitation bubble cluster in the acoustic field is also discussed in this work.

Bai L; Deng J; Li C; Xu D; Xu W

2014-01-01

340

Spatially Resolved Artificial Chemistry  

DEFF Research Database (Denmark)

Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction. It reviews calibration procedures, outlines the computational algorithms, and summarizes examplary applications. Four different platforms for BD and DPD simulations are presented that differ in their focus, features, and complexity.

Fellermann, Harold

2009-01-01

 
 
 
 
341

Simple artificial nose  

UK PubMed Central (United Kingdom)

The utility model belongs to the medical apparatus field, in particular a simple artificial nose for tracheotomy patient which includes a pair of injection syringe, a gas barrel casing tube, an oxygen uptake pipe and a securing strap. The simple artificial nose has characteristic that: the injection syringe is extracted the pintle, a hatch is cut off on a middle part, the hatch diameter is a collar extension diameter of the gas barrel casing tube, and the casing tube is equipped with a securing strapes, the oxygen uptake pipe enters from a mamilla point of the injection syringe. The improved injection syringe processes continuous gas flue humidification to the tracheotomy patient using continuous oxygen absorption, an opened air flue formed by tracheotomy changes into a closed air flue which makes phlegm moist to eliminate easily, reaches aims of keeping respiratory tract smoothly, reducing infection contamination and increasing oxygen therapy, the injection syringe has advantages of low cost, simple operation and convenient replacement.

JUNYING GUO; LITING DONG

342

Artificially structured magnetic materials  

Energy Technology Data Exchange (ETDEWEB)

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

Falco, C.M.

1990-09-28

343

ARTIFICIAL PERIODONTAL MEMBRANE  

UK PubMed Central (United Kingdom)

FIELD: medicine. ^ SUBSTANCE: invention refers to the area of medicine and is intended for creating an artificial periodontal membrane. The implant shall be fixed. Fractal structure nano-particles and nano-particles of metal or intermetallic compound similar to the dental implant material as well as fractal structure-oriented silver particles distributed in a strap are used as the periodontal membrane basis. The strap is a gel composition made of the patient's blood autoplasm, nano- particles of the relative metal or intermetallic compound and colloidal silver. ^ EFFECT: invention enables making an artificial periodontal membrane that would replace the missing periodontal membrane, provides for complete implant's plantation and removes the negative response of soft jaw tissues. ^ 1 dwg

BORISENKO NIKOLAJ IVANOVICH; GIZATULLIN RAMIL MIKHAJLOVICH

344

Artificial intelligence at CSM  

Energy Technology Data Exchange (ETDEWEB)

The recent developments in artificial intelligence have been cited as being the most significant technological advancement in computer science in the twentieth century. Machines that can mimic human reasoning will have a great impact upon our civilization. The way we think, learn, and work will be changed in a profound way. It is for these reasons that the Colorado School of Mines, in order to maintain its reputation of quality engineering education, has entered the AI field. CSM presently is evaluating artificial intelligence for applications in the mineral industries; decision support systems, process control, machine vision, data acquisition and analysis, etc. Future plans are to move AI out of the research laboratories and into the curriculum. An understanding of the concepts and unlimited power of the application of AI will enhance the engineering methods of Mines graduates. 6 references.

Braun, G.; Jones, J.E.

1985-08-01

345

The oceanic geochemistry of artificial radionuclides: The SEEP Project  

International Nuclear Information System (INIS)

[en] Radionuclides have been and continue to be introduced to the marine environment in various ways. The atmospheric testing of nuclear weapons in the 1960s resulting in global fallout has been the major contributor of artificial radionuclides to the environment. Nuclear power plants have produced a large quantity of radioactive wastes which are presently being stored on land. The United States, amongst other countries (e.g., England, France, Japan), was seriously investigating the possibility of disposing of these radioactive wastes in the ocean. Clearly it is important to study and to understand the oceanographic behavior of radioactive substances. The DOE sponsored SEEP (Shelf Edge Exchange Processes) research; discussed here, is a detailed study into the biogeochemistry of radionuclides in the shelf and slope environment. The questions asked by this research (see below) pertain directly to problems arising from the introduction of radionuclides into the oceans from energy-related industries (e.g. nuclear power plants, waste disposal)

1991-01-01

346

Artificial rumen leaven  

UK PubMed Central (United Kingdom)

The artificial rumen fermenting agent consists of rumen microbe 50-80 wt%, basidiomycetes colony 10-30 wt% lactic acid bacteria 5-30 wt% and saccharomycete 5-10 wt%. It has the advantages of decomposing cellulose, hemicellulose, lignin, etc. in stalk feed easily to raise the nutritive value, raise volatile fatty acid content, protein content and coarse fat content raised feed utilization rate and improved feed palatability.

YUN ZHAOXUE

347

Artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

This volume provides an introduction to the exciting field of artificial neural networks and their potential role in the emerging field of neurocomputing. Although the genesis of this subject can be traced back to the 1940s, the present interest is largely due to the recent developments in theoretical models, technologies, and algorithms. This volume is devoted to introductory and theoretical concepts, and the emphasis is on network architectures, learning, associative memories, with a glimpse of the application areas and implementation experiences.

Vemuri, V.

1988-01-01

348

Artificially structured materials  

International Nuclear Information System (INIS)

Artificially structured materials, including superlattices, multilayers, amorphous alloys, quasicrystals, metastable crystalline alloys, granular metals, have been extensively studied in recent years. These man-made solids contain intricate structures and extra degree of freedom, which can be exploited for fundamental studies and tailoring properties. We present some examples of a wide range of phenomena exhibited by these materials as revealed by Moessbauer spectroscopy and other techniques. (orig.)

1990-01-01

349

Antithrombotic artificial organs  

International Nuclear Information System (INIS)

A new antithrombotic material useful for making artificial organs (artificial blood vessel, artificial heart, etc.) can be prepared by graft-polymerizing an acrylic ester (methyl methacrylate, methyl acrylate, ethyl acrylate, etc.) with a synthetic fiber (teflon, etc.). The graft-polymerization can be carried out by means of gamma radiation with cobalt 60 (dose rate 2.6x103 r/min., total dose 8x104 to 3.5x105 r). A graft ratio of 5 to 80% is attainable. In one example, a tubular sample made of teflon fiber having an inner diameter of 5 to 10 mm was immersed into methyl methacrylate in an ampoule in the absence of air and exposed to cobalt 60 gamma ray at the dose rate of 3.18x103 rad/min. After extraction with acetone, the sample was dried. The total dose was 3.5x105 rad and the graft ratio was ca. 25%. The sample was transplanted to vena cava of dog. No formation of thrombus was observed by autopsy (4 months after the transplantation). In control (teflon tube not graft-polymerized) thrombus was observed by autopsy 7 days after the transplantation. (Kaichi, S.).

1971-01-01

350

Molecular characterization of three GnRH receptor paralogs in the European eel, Anguilla anguilla: tissue-distribution and changes in transcript abundance during artificially induced sexual development.  

UK PubMed Central (United Kingdom)

Gonadotropin-releasing hormone receptor (GnRH-R) activation stimulates synthesis and release of gonadotropins in the vertebrate pituitary and also mediates other processes both in the brain and in peripheral tissues. To better understand the differential function of multiple GnRH-R paralogs, three GnRH-R genes (gnrhr1a, 1b, and 2) were isolated and characterized in the European eel. All three gnrhr genes were expressed in the brain and pituitary of pre-pubertal eels, and also in several peripheral tissues, notably gills and kidneys. During hormonally induced sexual maturation, pituitary expression of gnrhr1a (female) and gnrhr2 (male and female) was up-regulated in parallel with gonad development. In the brain, a clear regulation during maturation was seen only for gnrhr2 in the midbrain, with highest levels recorded during early vitellogenesis. These data suggest that GnRH-R2 is the likely hypophysiotropic GnRH-R in male eel, while both GnRH-R1a and GnRH-R2 seems to play this role in female eels.

Peñaranda DS; Mazzeo I; Hildahl J; Gallego V; Nourizadeh-Lillabadi R; Pérez L; Asturiano JF; Weltzien FA

2013-04-01

351

The use of ?CT and ESEM in the study of the osmosis-induced water uptake by Eurobitum bituminized radioactive waste.  

UK PubMed Central (United Kingdom)

Laboratory water uptake tests are performed at the Belgian Nuclear Research Centre SCK•CEN to obtain insight into the hydromechanical behavior of Eurobitum bituminized radioactive waste under geological disposal conditions. Small nonradioactive and radioactive Eurobitum samples are hydrated in restricted swelling conditions (i.e., nearly constant volume conditions and constant stress conditions). Microfocus X-ray computer tomography (?CT) proves to be a very suitable technique to follow up the ingress of water in the samples. ?CT analyses demonstrate that, under the studied hydration conditions, the water uptake by Eurobitum samples is a diffusion controlled process. A characterization of the partially leached samples with environmental scanning electron microscopy (ESEM) shows that the hydration of salt crystals and the subsequent dilution of the salt solution result in an increase in pore size that is limited to a few tens of ?m in restricted swelling conditions. The ?CT and ESEM analyses allow improvement in the understanding of water uptake by Eurobitum in restricted swelling conditions. In this article we discuss the ?CT and ESEM analyses of nonradioactive Eurobitum samples that were hydrated for 2 to 4 years at a constant stress of 1, 22, 33, and 44 bar or in nearly constant volume conditions.

Mariën A; Valcke E; Bleyen N; Van Geet M; Wevers M

2012-10-01

352

The use of ?CT and ESEM in the study of the osmosis-induced water uptake by Eurobitum bituminized radioactive waste.  

Science.gov (United States)

Laboratory water uptake tests are performed at the Belgian Nuclear Research Centre SCK•CEN to obtain insight into the hydromechanical behavior of Eurobitum bituminized radioactive waste under geological disposal conditions. Small nonradioactive and radioactive Eurobitum samples are hydrated in restricted swelling conditions (i.e., nearly constant volume conditions and constant stress conditions). Microfocus X-ray computer tomography (?CT) proves to be a very suitable technique to follow up the ingress of water in the samples. ?CT analyses demonstrate that, under the studied hydration conditions, the water uptake by Eurobitum samples is a diffusion controlled process. A characterization of the partially leached samples with environmental scanning electron microscopy (ESEM) shows that the hydration of salt crystals and the subsequent dilution of the salt solution result in an increase in pore size that is limited to a few tens of ?m in restricted swelling conditions. The ?CT and ESEM analyses allow improvement in the understanding of water uptake by Eurobitum in restricted swelling conditions. In this article we discuss the ?CT and ESEM analyses of nonradioactive Eurobitum samples that were hydrated for 2 to 4 years at a constant stress of 1, 22, 33, and 44 bar or in nearly constant volume conditions. PMID:23046634

Mariën, An; Valcke, Elie; Bleyen, Nele; Van Geet, Maarten; Wevers, Martine

2012-10-09

353

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)

1999-01-01

354

Studies on fluctuation of natural radioactivity in the environment of nuclear energy facilities  

International Nuclear Information System (INIS)

[en] Extremely small amounts of radioactive substances released from nuclear energy facilities to the environment show different trends according to the natural and social conditions. These often coincide with natural radioactivity in the environment. Therefore, to evaluate the effects on the environment, the situations of both natural and artificial radioactivities must be grasped. The following matters are described: space radiation doses measured by TLD and the fluctuation, total ? radioactivity in environmental samples and the fluctuation, fluctuation of 40K, 214Bi and 208Tl in environmental samples, and stable elements in environmental samples. (Mori, K.)

1977-01-01

355

Survey monitoring of environmental radioactivity in Daegu area  

Energy Technology Data Exchange (ETDEWEB)

The objectives of the project are to monitor an abnormal radiation level in Taegu and Kyungpook region, and to enhance our ability to prepare for the radiological emergency situation by establishing the radioactivity monitoring system in Taegu and Kyungpook region. Gross beta activities were measured and gamma radionuclides were analysed for the environmental samples of air-borned dust. precipitation. fallout and drinking water collected in Taegu radioactivity monitoring center. and gamma exposure rates were also measured. To establish the basic data base on the environmental radioactivity, gamma radionuclide analyses were carried out for the samples of soil, drinking water, grain, vegetable, milk, and fish which were obtained from 31 different areas, and the spatial gamma exposure rates from 61 different points were also measured in Taegu and Kyungpook region. In conclusion, it didn't appear any evidence for newly pollution of artificial radioactivity in Taegu and Kyungpook region.

Kang, H. D.; Lee, S. Y. [Kyungpook National Univ., Daegu (Korea, Republic of)

1998-01-15

356

Measurement of environmental radioactivity in Toki district  

International Nuclear Information System (INIS)

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

1981-01-01

357

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

1982-03-11

358

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

359

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)

1983-01-01

360

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).

1992-01-01

 
 
 
 
361

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

2012-01-01

362

Learning more about radioactivity  

International Nuclear Information System (INIS)

This digest brochure explains what radioactivity is, where it comes from, how it is measured, what are its effects on the body and the way to protect it against these effects, the uses of radioactivity (In the medical field, In industry, In the food industry, and In the cultural world). It ends with some examples of irradiation levels, of natural radioactivity and with the distribution in France of various sources of exposure. (J.S.)

2008-01-01

363

Radioactive wastes and discharges  

Energy Technology Data Exchange (ETDEWEB)

The guide sets out the radiation safety requirements and limits for the treatment of radioactive waste. They shall be observed when discharging radioactive substances into the atmosphere or sewer system, or when delivering solid, low-activity waste to a landfill site without a separate waste treatment plan. The guide does not apply to the radioactive waste resulting from the utilisation of nuclear energy or natural resources.

NONE

2000-07-01

364

Radioactive Plumes Monitoring Simulator  

International Nuclear Information System (INIS)

The Airborne Radiation Monitoring System (ARMS) monitors air or ground radioactive contamination. The contamination source can be a radioactive plume or an area contaminated with radionuclides. The system is based on two major parts, an airborne unit carried by a helicopter and a ground station carried by a truck. The system enables real time measurement and analysis of radioactive plumes as well as post flight processing. The Radioactive Plumes Monitoring Simulator purpose is to create a virtual space where the trained operators experience full radiation field conditions, without real radiation hazard. The ARMS is based on a flying platform and hence the simulator allows a significant reduction of flight time costs.

1999-12-20

365

Radioactive waste management  

International Nuclear Information System (INIS)

This document discusses the international radioactive waste management programmes which are becoming increasingly more important with decommission of nuclear reactors. Quality assurance during waste handling, transport, processing and disposal is very important. Site selection for radioactive waste disposal is another very important criteria. Safeguard and safety analysis of any step of waste management is important. IAEA realizes the importance of international cooperation for sharing the information and technical information. It started region cooperation projects, coordinated research programmes etc. It has published three Safety Guides and one Safety Practice covering all aspects of radioactive waste management and Radioactive Waste Safety Standards (RADWASS) programme. 4 figs, 9 tabs.

1995-01-01

366

Radioactive Waste Management Basis  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

Perkins, B K

2009-06-03

367

Radioactive waste management  

International Nuclear Information System (INIS)

[en] Radioactive waste management involves two fundamental approaches: the radioactive materials can be either released or discharged to the environment, or they must be confined and isolated from the biosphere until the noxious radionuclides have decayed to innocuous concentrations. Releases of radioactivity to the environment generally occur as liquid or gaseous discharges (effluents) from nuclear facilities. The amount of radioactivity which can be released is based on allowable exposures to population groups and is controlled by national regulations and guidelines, usually based on recommendations of the International Committee on Radiation Protection. There are very few instances where radioactive effluents from nuclear facilities can be released without some form of control or treatment to remove excessive radioactivity. Most of the radioactive wastes arising from the operation of nuclear fuel cycle facilities require processing to concentrate the radioactive elements into a smaller volume which can be more conveniently handled, thereby permitting the release or disposal of the bulk of the processed material. Radioactive waste management involves the use of normal industrial operations and techniques adapted to cope with the barriers needed to protect the workers and operations from excessive radiation and contact with the radionuclides. Consequently, very often the equipment and its operating procedures become rather sophisticated to permit operation and maintenance behind the protective barriers. Actually, most research and development activities involving technology for the management of radioactive wastes are concerned with adapting normal industrial operations or laboratory techniques to the handling of radioactive materials. It is the consensus amongst those involved with, or knowledgeable about, radioactive waste management, that technology and flow schemes have now been developed to the extent that they are workable. The basic knowledge required to collect, treat, package and store safely all nuclear fuel cycle wastes of concern is available. Furthermore, in many cases, optional technology exists for different situations or economic optimization. Consequently, from a technical standpoint, it seems that lack of appropriate methods and technology for handling the radioactive waste need not become a bottleneck for the implementation of nuclear power. On the other hand, some of the required radioactive waste management technology still remains in its developmental stage. Much remains to be done in working out the engineering and design details, satisfying appropriate regulatory requirements, and adapting the technology to actual operating conditions and controls. These last remarks apply principally to those radioactive wastes arising from the reprocessing of irradiated fuel which essentially contain all the radioactive products of nuclear fission

1976-01-01

368

Radioactive waste in perspective  

CERN Document Server

Large volumes of hazardous wastes are produced each year, however only a small proportion of them are radioactive. While disposal options for hazardous wastes are generally well established, some types of hazardous waste face issues similar to those for radioactive waste and also require long-term disposal arrangements. The objective of this NEA study is to put the management of radioactive waste into perspective, firstly by contrasting features of radioactive and hazardous wastes, together with their management policies and strategies, and secondly by examining the specific case of the wastes

2010-01-01

369

Controlling radioactive waste  

International Nuclear Information System (INIS)

The guideline of the Ministry for Environmental Protection for controlling radioactive waste with a negligible development of heat defines in detail what data are relevant to the control of radioactive waste and should be followed up on and included in a system of documentation. By introducing the AVK (product control system for tracing the course of waste disposal) the operators of German nuclear power plants have taken the requirements of this guideline into account. In particular, possibilities for determining the degree of radioactivity of radioactive waste, which the BMU-guidelines call for, were put into practice by means of the programming technology of the product control system's module MOPRO. (orig.).

1991-05-23

370

Management of radioactive wastes  

Energy Technology Data Exchange (ETDEWEB)

The basic philosophy in the management of all radioactive wastes in India has been to concentrate and contain as much activity as possible and to discharge to the environment only such of those streams that have radioactivity contents much below the nationally and internationally accepted levels. Radioactive waste management programmes followed at various nuclear facilities in operation and those formulated for nuclear facilities under construction are described. Methods of treatment of solid, liquid and gaseous radioactive wastes which are currently practised in India are outlined.

Balu, K.; Bhatia, S.C. (Bhabha Atomic Research Centre, Bombay (India). Waste Management Operations Section)

1981-08-01

371

Radioactive materials and environment  

International Nuclear Information System (INIS)

[en] Radioactive materials are very widely used in medicine, industry, agriculture and scientific and industrial research besides their use as nuclear weapons. The radiation energy emitted from radioactive materials into the environment has severe hazards. Because of their unique characteristics, the contamination caused by them is not comparable to other commonly known pollutions. This paper deals with various salient features of the radioactive materials, their frequent applications, the degree of hazards due to contamination in the environment and the essential safety measures to be taken in handling and disposing of the radioactive materials. (auth.)

1979-01-01

372

Radioactive materials and environment  

International Nuclear Information System (INIS)

[en] Radioactive materials are very widely used in medicine, industry, agriculture and scientific and industrial research besides their use as nuclear weapons. The radiation energy emitted from radioactive materials into the environment has severe hazards. Because of their unique characteristics, the contamination caused by them is not comparable to other commonly known pollutions. This paper deals with various salient features of the radioactive materials, their numerous applications, the deqree of hazards due to contamination in the environment and the essential safety measures to be taken in handling and disposing of the radioactive materials. (auth.)

1979-01-01

373

Environmental radioactivity in New Zealand and Rarotonga : annual report 1999  

International Nuclear Information System (INIS)

During 1998, artificial radioactivity in the environment in New Zealand and Rarotonga 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, Hokitika and Rarotonga; deposited radioactivity was monitored at Hokitika; and milk radioactivity was monitored in the Waikato, Taranaki and Westland regions. Average levels measured were: total beta activity in air, 0.1 mBq per cubic m; 90Sr deposition, 0.1 +/- 0.2 Bq per square m; 137Cs in milk, 0.1 Bq/g K; 90Sr in milk, 0.02 Bq/g Ca. Total beta activity deposition at Hokitika was 216 Bq per square m. Annual total 210Pb and 7Be depositions at Hokitika were 134 and 6410 Bq per square m respectively. No artificial radionuclides, except 137Cs, were detected by gamma spectroscopic analysis of high-volume air filters during 1998, with weekly sampling periods. The annual-average atmospheric 137Cs concentration in the region, assessed by analysis of yearly air-filter aggregates, was 0.04 micro Bq per cubic m. Average atmospheric concentrations of natural 7Be and 210Pb were 3.7 mBq per cubic m and 0.07 mBq per cubic m respectively. (author). 9 refs., 3 figs., 5 tabs

2000-01-01

374

Environmental radioactivity in New Zealand and Rarotonga : annual report 1995  

International Nuclear Information System (INIS)

During 1995 artificial radioactivity in the environment in New Zealand and Rarotonga 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 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, 0.09 mBq/m3; 90Sr deposition, 0.2 + or - 0.2 Bq/m2; 137Cs in milk, 0.08 Bq/g K; 90Sr in milk, 0.03 Bq/m2 and 180 Bq/m2 respectively. Annual total 210Pb and 7Be depositions at Hokitika were 136 and 6550 Bq/m2 respectively. No artificial radionuclides were detected by gamma spectroscopic analysis of high-volume air filters during 1995, with weekly sampling periods. The annual-average atmospheric 137Cs concentration, assessed by analysis of yearly air-filter aggregates, was 0.03 + or - 0.01 ?Bq/m3 in New Zealand, and 3 and 0.07 mBq/m3 respectively. The report includes data and comment on trends in atmospheric radioactivity levels since 1987. (author). 9 refs., 5 tabs.,3 figs

375

Environmental radioactivity in Turkey, 2007  

International Nuclear Information System (INIS)

In this report, the activity concentrations of natural and artificial radionuclides, gross alpha/beta activities and air gamma dose rates in the environmental and food samples provided from Turkey's seven geographical regions within the environmental radioactivity monitoring program in 2007 are presented. The activity concentrations of the natural (238U, 232Th, 226Ra, 4:0K and 7Be) and artificial (137Cs, 134Cs, 90Sr, 238-239+240Pu, 241Am) radionuclides and gross alpha/beta activities in the samples were measured by using the gamma spectrometry, the alpha spectrometry, the liquid scintillation counter and the gross alpha /beta counting system. Results show that 137Cs and 90Sr radionuclides originating from the Chernobyl Nuclear Reactor accident in 1986 exist in some of samples even in low levels. The mean activity concentrations of 238U, 232Th, 226Ra and 40K in the studied surface soil samples were found as 32.1 Bq kg-1, 35.0 Bq kg-1, 29.0 Bq kg-1 and 446.7 Bq kg-1, respectively, while the mean activity concentrations of the fission product 137Cs was found as 18.4 Bq kg-1. While the activity concentrations of 238U, 232Th and 226Ra in the analyzed food samples are lower than the minimum detectable activity (MDA), 134Cs and 7Be radionuclides are not observed. The mean activity concentrations of 137Cs and 90Sr radionuclides are 0.24 Bq L-1 and 0.05 Bq L-1, respectively. (Includes 4 tables and 7 figures)

2009-01-01

376

Artificial mismatch hybridization  

Energy Technology Data Exchange (ETDEWEB)

An improved nucleic acid hybridization process is provided which employs a modified oligonucleotide and improves the ability to discriminate a control nucleic acid target from a variant nucleic acid target containing a sequence variation. The modified probe contains at least one artificial mismatch relative to the control nucleic acid target in addition to any mismatch(es) arising from the sequence variation. The invention has direct and advantageous application to numerous existing hybridization methods, including, applications that employ, for example, the Polymerase Chain Reaction, allele-specific nucleic acid sequencing methods, and diagnostic hybridization methods.

Guo, Zhen (Madison, WI); Smith, Lloyd M. (Madison, WI)

1998-01-01

377

Artificial reef structure  

UK PubMed Central (United Kingdom)

An artificial reef device comprising an axle rod supporting a plurality of buoyant reef bodies rotatably mounted on the axle rod. The axle rod and buoyant sections are suspended at a desired level above a water bottom by anchors attached to anchor lines further attached to the axle rod. A plurality of distally projecting rods is mounted on the buoyant reef bodies. The distally projecting rods are mounted in a manner such that the buoyant reef bodies rotate independently of each other on the axle rod without interference from the distally projecting rods. Some of the projecting rods may be hollow to receive soluble fish attractant for disbursement through the hollow rods.

BRIGNAC CHARLES

378

Radioactive waste management in Ghana  

International Nuclear Information System (INIS)

Radioactive materials have been used in Ghana for more than four decades. They are used in medicine, industries, and for research and teaching purposes. Due to the numerous social and economic benefits derived from the use of radioactive materials there has been a noticeable growth in the use of radioactive materials in Ghana. The radioactive waste produced must be managed. The National Radioactive Waste Management Centre was therefore established to carry out radioactive waste safety operations in Ghana. This paper highlights radioactive waste management strategies being adopted by the National Radioactive Waste Management Centre to manage radioactive waste anticipated and in existence. (author)

2005-01-01

379

Gross alpha radioactivity of drinking water in Venezuela  

Energy Technology Data Exchange (ETDEWEB)

Bottled mineral water is consumed by a large population in Venezuela. The alpha emitters concentration was measured in samples of bottled water and water springs collected near the surface. Approximately 30% of the total mineral water suppliers was monitored. a database on natural and artificial radioactivity in drinking water was produced. Results indicate that 54% of the waters sampled contain a total alpha radioactivity of less than 0.185 Bql{sup -1} and only 12% above 0.37 Bql{sup -1}. Our results revealed a total annual dose of 2.3 mSv year{sup -1}. (author).

Sajo-Bohus, L.; Gomez, J.; Greaves, E.D. [Universidad Simon Bolivar, Caracas (Venezuela). Dept. de Quimica; Capote, T. [Universidad Centro Occidental Lisandro Alvarado (Venezuela); Herrera, O. [Ministerior de Sanidad y Asistencia Social, Caracas (Venezuela); Salazar, V. [Ministerio del Ambiente y los Recursos Naturales Renovables, Caracas (Venezuela); Smith, A. [National Air and Radiation Environmental Lab., Montgomery, AL (United States)

1997-07-01

380

Radioactive accumulation in alga samples from Romanian Black Sea coast  

International Nuclear Information System (INIS)

The natural and artificial radioactivity of the brown alga Cystoseira barbata samples collected on the Romanian Black Sea coast in 1996 in reported. The results on 137Cs were obtained through gamma-spectrometry, on 90Sr by beta-counting of the 90Y oxalate precipitated after strontium separation, on 226Ra by the emanation method, while the concentrations of U, Th, Pu and Am isotopes were obtained through radiochemical separations using tracers followed by alpha-spectrometry counting of the stainless steel discs after electrodeposition. These results add further evidence that Cystoseira barbata may be used as a bioindicator for radioactive contamination of the coastal waters. (author)

1999-01-01

 
 
 
 
381

[Artificial neural networks in Neurosciences].  

UK PubMed Central (United Kingdom)

This article shows that artificial neural networks are used for confirming the relationships between physiological and cognitive changes. Specifically, we explore the influence of a decrease of neurotransmitters on the behaviour of old people in recognition tasks. This artificial neural network recognizes learned patterns. When we change the threshold of activation in some units, the artificial neural network simulates the experimental results of old people in recognition tasks. However, the main contributions of this paper are the design of an artificial neural network and its operation inspired by the nervous system and the way the inputs are coded and the process of orthogonalization of patterns.

Porras Chavarino C; Salinas Martínez de Lecea JM

2011-11-01

382

PRCESS OF MANUFACTURING ARTIFICIAL EATTING  

UK PubMed Central (United Kingdom)

A manufacturing method of the artificial bait is provided, which remarkably can reduce the water pollution and makes effective fishing possible. A manufacturing method of the maggot artificial bait includes: mixing the maggot fragrance powder, the maggot powder 40~90 wt.%, the polyvinyl chloride(PVC) resin 2~20 wt.%, the jelly component 2~20 wt.%, the gelatin 2~20 wt.%, and antiseptic 2~5 wt.% and extrusion molding the mixture in the artificial bait(10) of the worm shape. Wrinkles are formed in the core region of the artificial bait of the worm shape.

SHIN JI HOON

383

Radioactivity of household water in Finland  

International Nuclear Information System (INIS)

A nationwide study on artificial and natural radioactivity in household water has been under way in Finland since the 1960s. The occurrence of artificial radionuclides in the surface water of drainage basins has been monitored extensively. The proportion of household water derived from surface waters in Finland is currently 48 %, but its usage is decreasing whereas that of groundwater is increasing at an annual rate of 1 - 2 %. The natural radioactivity of household water has been studied in almost all of the waters distributed by public waterworks and in 5400 private ground water wells. The downward trend in 90Sr, 137Cs and 3H concentrations in surface water continued from the middle 1960s until the Chernobyl accident. After the accident ten different radionuclides were detected in surface waters, but only 137Cs made a minor contribution the radiation dose. The maximum effective dose via ingestion of water was about 0.001 mSv in 1986, and considerably lower in the following years.

1991-01-01

384

Radioactivity values in the river Elbe  

International Nuclear Information System (INIS)

[en] The largest portion of artificially produced radionuclides that currently gets into the river Elbe still stems from the fallout of supra-terrestrial atom bomb tests carried through decades ago in part. On the basis of a longitudinal profile of the Elbe from Schnackenburg to the Elbe estuary, no measurable increases were ascertained in the course of the systematic investigations pointing to artificial radionuclides of regional origin. This is also true of the nuclear power plants situated on the river Elbe. The amounts of radioactive nuclides, accurately known from emission measurements, which are discharged with sewage water from the Stade and Brunsbuettel nuclear power plants and reach the Elbe are so slight that they result in no measurable increase in radioactive nuclide levels in the Elbe. This is confirmed by the theoretical calculation. (orig./PW)[de] Der derzeit mengenmaessig bedeutendste Eintrag kuenstlicher Radionuklide erfolgt immer noch durch den Fallout der teils Jahrzehnte zurueckliegenden oberirdischen Kernwaffenversuche. Im Laengsprofil der Elbe von Schnackenburg bis zur Elbmuendung wurden im Rahmen der systematischen Untersuchungen keine messbaren Aufstockungen festgestellt, die auf regionale Eintraege kuenstlicher Radionuklide hinweisen. Dies gilt auch fuer die an der Elbe gelegenen Kernkraftwerke. Der aus der Emissionsmessung genau bekannte Eintrag kuenstlicher Radionuklide mit dem Abwasser aus den Kernkraftwerken Stade und Brunsbuettel ist so gering, dass er zu keiner messbaren Aufstockung in der Elbe fuehrt. Dies wird auch durch die theoretische Berechnung der Aufstockung bestaetigt. (orig./PW)

1987-01-01

385

Artificial photosynthesis. Jinko kogosei  

Energy Technology Data Exchange (ETDEWEB)

The artificial photosynthesis (carbon dioxide reduction) which is to realize the photosynthetic function of chlorophyte is a difficult technical problem and, however, taken notice of as one of measures (lowering in carbon dioxide production) against the global heating. Then, the photoreducing reaction of carbon dioxide which is a basic research, necessary for the realization of artificial photosynthesis, was completed in study. Four kinds of catalyst, effective on the multi-electron reducing reaction of carbon dioxide light, were found out, ie, semiconductor catalyst, metallic colloid catalyst, enzyme and metallic complex catalyst. In the reaction system (semiconductor catalyst and metallic colloid catalyst) having a heterogeneous interface, water being effective as electron donator, methane and other high reduction products are obtained, though the reaction is low in effect. While in metallic complex and other homogeneous systems, though there are systems, high in reaction, systems of which the electronic source is water are problematic in design and discovery. The foregoing being about the present status, the discovery of combined system, utilizing characteristics of different catalytic systems, may be also one of the future research problems. 20 refs., 11 figs., 3 tabs.

Ibusuki, Takashi (National Research Inst. for Pollution and Resources, Tsukuba (Japan))

1990-01-01

386

Stress and radioactive waste management  

International Nuclear Information System (INIS)

In the Supreme Court case ''People Against Nuclear Energy (PANE) vs Metropolitan Edison,'' one of the conclusions was that the Nuclear Regulatory Commission did not have to consider psychological distress, community cohesiveness and sense of well-being in the supplement to the Environmental Impact Statement (EIS) covering the restart of Three Mile Island (TMI). This decision was based on the assumption that the intention of the National Environmental Policy Act (NEPA) is to focus on the physical environment, and the casual chain between psychological distress and adverse health effects is tenuous. In this paper the authors summarize the literature on the relationship between environmentally-induced stress and its effects on health. They present the results of a new survey research project in which levels of stress were evaluated in West Chicago, Illinois, a community in which radioactive wastes have been present for many years. Explanatory social variables are brought into the evaluation in which stress is evaluated as a function of proximity to the radioactive waste site. In addition, stress is discussed in the context of attitudes on nuclear power, environmental group participation, and knowledge about the health effects associated with radioactive waste. The paper ends with a discussion of the portion of the Supreme Court decision in which psychological distress, community stability, cohesiveness and sense of well being are excluded as variables to address in EISs

1987-01-01

387

Treatment of radioactive wastes  

International Nuclear Information System (INIS)

[en] This report is a review of some waste management activities including sources, system of collection and treatment of radioactive wastes. The report also includes methods and options used for treatment of liquid and solid radioactive wastes. (author). 26 refs., 5 figs., 6 tabs

1992-01-01

388

New forms of radioactivity  

International Nuclear Information System (INIS)

In the last decade progress in the production and study of nuclei far from stability have led to several discoveries in the field of nuclear decay modes. Recent results for proton radioactivity, multiple ?-delayed particle emission and ?-delayed triton emission are described. The recent discovery of 14C radioactivity from the natural radioelement 223Ra and further developments are also described

1985-01-01

389

Radioactive waste disposal package  

Energy Technology Data Exchange (ETDEWEB)

A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

Lampe, Robert F. (Bethel Park, PA)

1986-01-01

390

Sealed radioactive sources toolkit  

International Nuclear Information System (INIS)

The IAEA has developed a Sealed Radioactive Sources Toolkit to provide information to key groups about the safety and security of sealed radioactive sources. The key groups addressed are officials in government agencies, medical users, industrial users and the scrap metal industry. The general public may also benefit from an understanding of the fundamentals of radiation safety

2005-01-01

391

Radioactivity in agriculture  

International Nuclear Information System (INIS)

Discusses briefly the effect of radioactivity on the soil, vegetation and fruit with numerical data on concentration of various radioactive substances and depth of penetration in the soil. The information is based on data by the Seibersdorf Research Centre in association with Chernobyl. (P.G.R.)

1986-01-01

392

Biodegradation of radioactive animals.  

UK PubMed Central (United Kingdom)

The two most common disposal alternatives for animals contaminated with radioactive materials are incineration and burial. For most of the country burial has entailed shipping the carcasses to a commercial disposal facility at Barnwell, South Carolina, where it was landfilled along with other solid radioactive waste. Unfortunately, since 30 June 1994, this facility accepts waste generated by the states of the Southeast Compact only. Therefore, burial is no longer an option for most of the country's generators and incineration is an option only for those institutions which have, or have access to, an incinerator that is permitted to burn radioactive materials and that accepts animal carcasses with de minimis levels of radioactive contaminants. Many institutions, especially those in congested urban areas where the public does not support incineration, do not have viable outlets for radioactive animal carcasses. Interim, on-site storage poses problems of its own. Biodegradation of animal carcasses with dermestid beetles is an inexpensive approach to this waste management problem.

Party N; Party E; Wilkerson A; Gershey EL

1995-06-01

393

Radioactive waste processing method  

International Nuclear Information System (INIS)

[en] Large sized radioactive wastes generated from radioactive material processing facilities are solidified stably. The radioactive wastes are cut, in the facility where they are generated, into a size containable to a large scaled processing container. They are stored in a large sized processing vessel equipped with casters. The large sized processing vessel is transported to a waste processing facility. A solidifying material is packed in the large scaled processing vessel. A lid is fixed to the large sized processing vessel. The large scaled processing vessel covered with the lid is stored. According to this method, large sized radioactive wastes generated upon reconstruction and dismantling of radioactive material processing facilities can be processed efficiently and safely at a low cost. (I.S.)

1996-02-29

394

Monitoring of radioactivity in the environs of Finnish nuclear power stations in 1987. Supplement 5 to annual report STUK-A-74.  

Science.gov (United States)

Results of the environmental programmes for monitoring radioactive contamination around Finnish nuclear power plants in 1987 are reported. Fallout from the Chernobyl accident, which took place in April 1986, was still dominating the artificial radiation s...

K. L. Sjoeblom S. Klemola E. Ilus H. Arvela L. Blomqvist

1989-01-01

395

Fusion Reactor Radioactive Waste Management.  

Science.gov (United States)

Quantities and compositions of non-tritium radioactive waste are estimated for some current conceptual fusion reactor designs, and disposal of large amounts of radioactive waste appears necessary. Although the initial radioactivity of fusion reactor and f...

J. D. Kaser A. K. Postma D. J. Bradley

1976-01-01

396

Radioactivity in drinking water. From basics to practice  

International Nuclear Information System (INIS)

Radioactive material of natural and artificial origin contributes to the radiation exposure of the public. In this paper the current scientific and legal basics are given to show comprehensively the evaluation methods and limitation of public radiation exposure. The implementation of concepts and methods into the radiation protection practice with consideration of the experience in Austria is demonstrated. International developments give an outlook on future solutions of this specific environmental related radiation protection problem. (orig.)

2009-01-01

397

Artificially disordered birefringent optical fibers.  

UK PubMed Central (United Kingdom)

We develop and experimentally verify a theory of evolution of polarization in artificially-disordered multi-mode optical fibers. Starting with a microscopic model of photo-induced index change, we obtain the first and second order statistics of the dielectric tensor in a Ge-doped fiber, where a volume disorder is intentionally inscribed via UV radiation transmitted through a diffuser. A hybrid coupled-power & coupled-mode theory is developed to describe the transient process of de-polarization of light launched into such a fiber. After certain characteristic distance, the power is predicted to be equally distributed over all co-propagating modes of the fiber regardless of their polarization. Polarization-resolved experiments, confirm the predicted evolution of the state of polarization. Complete mode mixing in a segment of fiber as short as ? 10cm after 3.6dB insertion loss is experimentally observed. Equal excitation of all modes in such a multi-mode fiber creates the conditions to maximize the information capacity of the system under e.g. multiple-input-multiple-output (MIMO) transmission setup.

Herath S; Puente NP; Chaikina EI; Yamilov A

2012-02-01

398

Radioactivity and drinking water supply. Pt. 7  

International Nuclear Information System (INIS)

[en] To estimate the effects of radiation exposure to man by environmental radioactivity a dose analysis is to be undertaken considering the various exposure pathways and the activity-to-dose ratios. These estimations showed that the artificial radioactivity before and even after the Chernobyl accident is only a fraction of the whole natural radiation dose. For the critical examination a risk evaluation is needed. The additional radiation exposure as a consequence of the Chernobyl accident in the first year amounts only to 10 to 50 percent and in the life time dose (50 years) only to 1 percent of the background radiation dose. Therefore the additional radiation exposure of the whole population by this accident via drinking water may be neglected. Nevertheless a local overload of the water path with natural or artificial radioactivity has to be controlled and the group of persons concerned has to be protected. (orig.)[de] Zur Beurteilung der Strahlenbelastung des Menschen durch die Umweltradioaktivitaet muss eine Expositionsanalyse unter Beruecksichtigung der verschiedenen Expositionspfade und der Aktivitaets-Dosis-Beziehungen vorgenommen werden. Diese zeigt, dass die zusaetzliche Strahlenbelastung durch die kuenstliche Umweltradioaktivitaet vor und auch nach Tschernobyl nur einen Bruchteil der gesamten Strahlenbelastung ausmacht. Zur Bewertung dieses Anteils muss eine Risikoanalyse vorgenommen werden. Angesichts der Tatsache, dass die gesamte zusaetzliche Strahlenbelastung als Folge des Tschernobylunfalls im ersten Jahr in der Groessenordnung von 10% bis maximal 50% (in Sueddeutschland) und in der 50-Jahres-Folgedosis nur etwa 1% der natuerlichen Strahlenbelastung des Menschen betraegt, ist die zusaetzliche Strahlenbelastung ueber den Trinkwasserpfad fuer die Gesamtbevoelkerung mit Sicherheit zu vernachlaessigen. Dies schliesst nicht aus, dass oertlich uebermaessige Belastungen des Wasserpfads mit natuerlicher oder kuenstlicher Radioaktivitaet beachtet und die betroffenen Personengruppen geschuetzt werden muessen. (orig.)

1987-01-01

399

Artificial selenoenzymes: designed and redesigned.  

UK PubMed Central (United Kingdom)

Enzymes, highly evolved machinery developed by nature, catalyse reactions with formidable efficiency and specificity under mild conditions. Considerable efforts have been devoted for several decades on the development of enzyme-like catalysts with tailored properties by rationally manipulating natural and artificially synthesized host molecules. One of the great challenges is to design artificial systems with catalytic efficiencies and specificities rivalling natural components. Although most of the designed artificial enzymes present mild rate promotion, the high efficiency and specificity rivalling natural ones by artificially designed system appears. In this tutorial review, we recount the methods and strategies of design and redesign of artificial selenoenzymes on synthesized and natural hosts, with emphasis on construction of the active sites of antioxidative glutathione peroxidase (GPx) by the concept of synergy between recognition and catalysis (66 references).

Huang X; Liu X; Luo Q; Liu J; Shen J

2011-03-01

400

Conservative smoothing versus artificial viscosity  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-08-01

 
 
 
 
401

Few-electron artificial atoms  

International Nuclear Information System (INIS)

[en] Artificial atoms. i.e., bound systems of excess electrons confined in semiconductor quantum dots, are studied by the variational and Hartree-Fock methods. The confinement potential is assumed to have the form of a spherical potential well of finite depth, which provides a theoretical model for electron states in a spherical semiconductor nanocrystal embedded in an insulating matrix. For the two- and three-electron artificial atoms, we have applied the variational method and obtained the binding of both the ground states and excited states. The Hartree-Fock method has been applied to the N-electron artificial atoms with N = 1,...., 20. It is shown that the shells of the artificial atoms are filled by electrons in the same manner like those of the natural atoms. In particular, Hund's rule is fulfilled. The radial probability density calculated for artificial atoms is different from that for natural atoms. Refs. 14, figs. 4 (author)

1999-01-01

402

Artificial resuspension studies  

International Nuclear Information System (INIS)

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

1990-01-01

403

Artificial Immune Systems (2010)  

CERN Document Server

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

Greensmith, Julie; Aickelin, Uwe

2010-01-01

404

ARTIFICIAL ANTERIOR CHAMBER SYSTEM  

UK PubMed Central (United Kingdom)

A microkeratome cutting head includes a head structure, an applanation plate, and a stromal plate. The head structure may include a blade cavity for receiving a blade and a blade opening through which the blade extends. The blade is configured for creating a corneal flap at a corneal flap thickness. The applanation plate is disposed at an elevation above the stromal plate plane. The elevation difference is approximately equal to the corneal flap thickness. An artificial anterior chamber (AAC) system is used to hold the donor eye for interfacing with the microkeratome. The AAC system includes an optional pressure valve and pressure gauge in a closed loop system for the user or surgeon to control line pressure applied to the donor eye during the procedure.

ROSS RODNEY L; DENNEWILL JAMES R

405

Artificial Intelligence (AI)  

Science.gov (United States)

The science and engineering of Artificial Intelligence has come a long way since 1950, when scientists began to explore the link between human intelligence and machines. Since then, computer scientists have made advances in creating machines that can engage in human-like behaviors, mimic human thought, understand speech, and beat the best human chessplayer. Applications are far and wide, from military technology to personal cell phones. This Topic In Depth reviews some of the past accomplishments, current research and future challenges in AI.John McCarthy from the Computer Science Department at Stanford University has posted this article answering some common questions people have about Artificial Intelligence, including the implications of this work for the meaning of intelligence. (1). This next website (part of a ThinkQuest website competition) gives a history of AI among other interesting tidbits about different approaches and applications (2). The Turing Test Page elaborates on Alan Turing's conditions for considering a machine to be intelligent, which he outlined in a 1950 article that is also available from this website (3). The Singularity Institute describes itsambitious plan to develop "real AI" (4 ). The New Scientist highlights some applications for AI which range from the traditional to new wave (5 ). On a lighter note, this webpage by IBM is dedicated to Deep Blue and the event that captured the attention of chess and computer fans -- the rematch between the supercomputer, Deep Blue, and Kasparov (6 ). Ai Research has made their HAL Nursery available to the public -- a collection of "Virtual Children" you can interact with online. (7).

406

Environmental radioactivity surveillance programme. 1999 and 2000  

International Nuclear Information System (INIS)

The Radiological Protection Institute of Ireland continued to monitor levels of radioactivity in air, drinking water and foodstuffs in 1999 and 2000 and the results are presented in this report, the sixth in a series dealing with the terrestrial environment. Radioactivity is present in the terrestrial environment due to natural processes, the testing of nuclear weapons in the atmosphere, accidents such as the Chernobyl accident and the routine discharge of radionuclides from nuclear installations. The Institute monitored airborne radioactivity at ten stations throughout the country. One site was equipped to detect the presence of krypton-85, a radionuclide which is released into the environment primarily as a result of the reprocessing of nuclear fuel at installations such as Sellafield in the UK and La Hague in France. Both in 1999 and 2000, levels of radionuclides in airborne particulates were low and consistent with measurements in previous years. Public water supplies are sampled from each county at least every four years with supplies to certain major population centres sampled annually. Water supplies from eleven counties were sampled between 1999 and 2000 and all of the waters tested were found to be within legal requirements for water quality from a radiological point of view. The levels of artificial radioactivity in milk and other foodstuffs such as milk products, baby foods, beef, lamb, poultry and vegetables continued to be very low in 1999 and 2000 and, for the majority of samples, below the detection limits. External gamma dose rates were monitored continuously at twelve locations around the country. The dose rate was recorded every twenty minutes and the readings transmitted automatically to the Institute's computer database at Clonskeagh (Dublin). No abnormally high levels were observed at any of the twelve stations in either 1999 or 2000. The data presented in this report demonstrate that the levels of artificial radioactivity in the Irish terrestrial environment, including foodstuffs, remain extremely low and do not pose a significant risk to health. Nonetheless, the Radiological Protection Institute of Ireland remains vigilant and will continue to monitor the exposure of people living in Ireland to all relevant sources of ionising radiation. (author)

2002-01-01

407

Environmental radioactivity surveillance programme 1999 and 2000  

International Nuclear Information System (INIS)

[en] The Radiological Protection Institute of Ireland continued to monitor levels of radioactivity in air, drinking water and foodstuffs in 1999 and 2000 and the results are presented in this report, the sixth in a series dealing with the terrestrial environment. Radioactivity is present in the terrestrial environment due to natural processes, the testing of nuclear weapons in the atmosphere, accidents such as the Chernobyl accident and the routine discharge of radionuclides from nuclear installations. The Institute monitored airborne radioactivity at ten stations throughout the country. One site was equipped to detect the presence of krypton-85, a radionuclide which is released into the environment primarily as a result of the reprocessing of nuclear fuel at installations such as Sellafield in the UK and La Hague in France. Both in 1999 and 2000, levels of radionuclides in airborne particulates were low and consistent with measurements in previous years. Public water supplies are sampled from each county at least every four years with supplies to certain major population centres sampled annually. Water supplies from eleven counties were sampled between 1999 and 2000 and all of the waters tested were found to be within legal requirements for water quality from a radiological point of view. The levels of artificial radioactivity in milk and other foodstuffs such as milk products, baby foods, beef, lamb, poultry and vegetables continued to be very low in 1999 and 2000 and, for the majority of samples, below the detection limits. External gamma dose rates were monitored continuously at twelve locations around the country. The dose rate was recorded every twenty minutes and the readings transmitted automatically to the Institute's computer database at Clonskeagh (Dublin). No abnormally high levels were observed at any of the twelve stations in either 1999 or 2000. The data presented in this report demonstrate that the levels of artificial radioactivity in the Irish terrestrial environment, including foodstuffs, remain extremely low and do not pose a significant risk to health. Nonetheless, the Radiological Protection Institute of Ireland remains vigilant and will continue to monitor the exposure of people living in Ireland to all relevant sources of ionising radiation

1997-08-01

408

Living with radioactivity  

International Nuclear Information System (INIS)

[en] In the first part physical aspects of radioactivity are out-lined. Included are maps of natural radioactivity burden over Europe - to be considered when planning vacations - and meteorological maps of Europe after the Chernobyl accident, to illustrate transport of radionuclei through the atmosphere. The second part is concerned with the biological effects of radioactivity including radiotherapy and radiation illness. The third part gives advice on provisions for and acting in the case, of a radiation accident. 20 refs., 13 figs., 9 tabs. (qui)

1986-01-01

409

Radioactivity and environment  

International Nuclear Information System (INIS)

[en] The year 1996 is going to be the anniversary year for the nuclear energy. the centenary of the radioactivity discovery by the physician Henri Becquerel, anniversary of forty years of the putting into operation of the first french nuclear power plant (G1 at Marcoule), anniversary of thirty years of french nuclear tests in Polynesia, without forgetting the ten candles for the Chernobyl disaster. Here is an inquiry to answer to some questions such what is radioactivity, where does it come from, what is dangerous, what is not dangerous. The first article tells us the history of radioactivity discovery until the super Phenix reactor. (N.C.)

1996-01-01

410

Radioactivity; La radioactivite  

Energy Technology Data Exchange (ETDEWEB)

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.)

NONE

2002-07-01

411

Radioactive waste disposal  

International Nuclear Information System (INIS)

The current disposal concept for radioactive waste in the FRG was discussed in the framework of this seminar. In addition to this concept for the treatment of radioactive waste also the volume of this waste is indicated. The present state of the two repositories 'Konrad' and 'Gorleben' is explained, as well as the requirements on waste packages for transportation, intermediate and ultimate storage. The final part discusses the conditioning of this radioactive waste and the control of the barrels as regards the observance of the requirements. (orig.)

1988-01-01

412

Simulating and detecting artificial magnetic fields in trapped atoms  

CERN Multimedia

A Bose-Einstein condensate exhibiting a nontrivial phase induces an artificial magnetic field in immersed impurity atoms trapped in a stationary, ring-shaped optical lattice. We present an effective Hamiltonian for the impurities for two condensate setups: the condensate in a rotating ring and in an excited rotational state in a stationary ring. We use Bogoliubov theory to derive analytical formulas for the induced artificial magnetic field and the hopping amplitude in the limit of low condensate temperature where the impurity dynamics is coherent. As methods for observing the artificial magnetic field we discuss time of flight imaging and mass current measurements. Moreover, we compare the analytical results of the effective model to numerical results of a corresponding two-species Bose-Hubbard model. We also study numerically the clustering properties of the impurities and the quantum chaotic behavior of the two-species Bose-Hubbard model.

Rosenkranz, Matthias; Jaksch, Dieter; 10.1103/PhysRevA.81.013607

2010-01-01

413

Radiation protection. Radioactivity and health. 3. ed.  

International Nuclear Information System (INIS)

[en] 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.)[de] Die vorliegende Broschuere macht den Versuch, den Zusammenhang zwischen Radioaktivitaet und Gesundheit auch fuer den Nicht-Fachmann verstaendlich darzustellen. Nach einer kurzen Behandlung der Grundbegriffe der Radioaktivitaet befasst sie sich mit den natuerlichen und kuenstlichen Strahlenexpositionen, denen der Mensch im Industriezeitalter ausgesetzt ist. Die damit verbundenen Wirkungen auf den Menschen werden eingehend in Bezug auf somatische und genetische Strahleneffekte behandelt. Die Erlaeuterung der radiooekologischen Zusammenhaenge, beginnend bei den radioaktiven Ableitungen aus kerntechnischen Anlagen bis zur Ermittlung der Strahlenexposition des Menschen, wird ergaenzt durch die Beschreibung der strahlenmedizinischen Risikobeziehungen. Die Ausfuehrungen sollen die Ergebnisse langjaehriger Forschungsarbeiten zur Beantwortung der Frage der strahlenbiologischen Risiken in verstaendlicher Form widerspiegeln und zur sachlichen Information ueber dieses so ausserordentlich bedeutsame Gebiet beitragen. (orig.)

1986-01-01