WorldWideScience

Sample records for proliferating dispersion sites

  1. Analysis of site-specific dispersion conditions

    International Nuclear Information System (INIS)

    Paesler-Sauer, J.

    1989-03-01

    This report presents an analysis of atmospheric dispersion conditions in the environs of nuclear power stations in the Federal Republic of Germany. The analysis is based on meteorological data measured on the power station sites (KFUe = nuclear reactor remote control records) and by neighbouring stations operated by the German Weather Service. The data are series of hourly mean values of wind and temperature gradient or stability class over the period of one or more years. The aim of the data analysis is to find types of dispersion conditions characterized by the flow field and stratification, and to assess the feasibility of calculating these quantities in the case of an emergency. Influences of terrain structures in the environs of the site are considered. The annual frequencies of types of dispersion situations are assessed, the capability to recognize the dispersion situation from meteorological data measured on the site and the applicability of dispersion models are discussed. (orig.) [de

  2. Catalysis on singly dispersed bimetallic sites

    Science.gov (United States)

    Zhang, Shiran; Nguyen, Luan; Liang, Jin-Xia; Shan, Junjun; Liu, Jingyue; Frenkel, Anatoly I.; Patlolla, Anitha; Huang, Weixin; Li, Jun; Tao, Franklin

    2015-08-01

    A catalytic site typically consists of one or more atoms of a catalyst surface that arrange into a configuration offering a specific electronic structure for adsorbing or dissociating reactant molecules. The catalytic activity of adjacent bimetallic sites of metallic nanoparticles has been studied previously. An isolated bimetallic site supported on a non-metallic surface could exhibit a distinctly different catalytic performance owing to the cationic state of the singly dispersed bimetallic site and the minimized choices of binding configurations of a reactant molecule compared with continuously packed bimetallic sites. Here we report that isolated Rh1Co3 bimetallic sites exhibit a distinctly different catalytic performance in reduction of nitric oxide with carbon monoxide at low temperature, resulting from strong adsorption of two nitric oxide molecules and a nitrous oxide intermediate on Rh1Co3 sites and following a low-barrier pathway dissociation to dinitrogen and an oxygen atom. This observation suggests a method to develop catalysts with high selectivity.

  3. Remediation of sites with dispersed radioactive contamination

    International Nuclear Information System (INIS)

    2004-01-01

    disciplines, including the health sciences, chemistry, physics, geology, microbiology and environmental engineering, is necessary in order to develop technical solutions. It is also necessary to include information on the political, social and economic context. This report describes remediation techniques that are applicable to dispersed radioactive contamination at a variety of sites, including surface soil, the vadose zone, surface water, sediments and groundwater

  4. Dispersion factors - tables and diagrams for the Karlsruhe site

    International Nuclear Information System (INIS)

    Papadopoulos, D.; Baer, M.; Honcu, S.

    1984-02-01

    Dispersion experiments were performed at the Nuclear Research Center for the Karlsruhe site. The evaluation of these experiments allowed to determine the parameters of lateral or vertical atmospheric dispersions. This report is a compilation of tables and diagrams showing the dispersion factors calculated with the help of the dispersion parameters. These dispersion factors are valid for the Karlsruhe site. They have been normalized to 1 m/s wind speed and to 1 g/s (or 1 Bq/s) source strength. (orig.) [de

  5. Site-Specific Atmospheric Dispersion Characteristics of Korean Nuclear Power Plant Sites

    International Nuclear Information System (INIS)

    Han, M. H.; Kim, E. H.; Suh, K. S.; Hwang, W. T.; Choi, Y. G.

    2001-01-01

    Site-specific atmospheric dispersion characteristics have been analyzed. The northwest and the southwest wind prevail on nuclear sites of Korea. The annual isobaric surface averaged for twenty years around Korean peninsula shows that west wind prevails. The prevailing west wind is profitable in the viewpoint of radiation protection because three of four nuclear sites are located in the east side. Large scale field tracer experiments over nuclear sites have been conducted for the purpose of analyzing the atmospheric dispersion characteristics and validating a real-time atmospheric dispersion and dose assessment system FADAS. To analyze the site-specific atmospheric dispersion characteristics is essential for making effective countermeasures against a nuclear emergency

  6. Between-site differences in the scale of dispersal and gene flow in red oak.

    Directory of Open Access Journals (Sweden)

    Emily V Moran

    Full Text Available Nut-bearing trees, including oaks (Quercus spp., are considered to be highly dispersal limited, leading to concerns about their ability to colonize new sites or migrate in response to climate change. However, estimating seed dispersal is challenging in species that are secondarily dispersed by animals, and differences in disperser abundance or behavior could lead to large spatio-temporal variation in dispersal ability. Parentage and dispersal analyses combining genetic and ecological data provide accurate estimates of current dispersal, while spatial genetic structure (SGS can shed light on past patterns of dispersal and establishment.In this study, we estimate seed and pollen dispersal and parentage for two mixed-species red oak populations using a hierarchical bayesian approach. We compare these results to those of a genetic ML parentage model. We also test whether observed patterns of SGS in three size cohorts are consistent with known site history and current dispersal patterns. We find that, while pollen dispersal is extensive at both sites, the scale of seed dispersal differs substantially. Parentage results differ between models due to additional data included in bayesian model and differing genotyping error assumptions, but both indicate between-site dispersal differences. Patterns of SGS in large adults, small adults, and seedlings are consistent with known site history (farmed vs. selectively harvested, and with long-term differences in seed dispersal. This difference is consistent with predator/disperser satiation due to higher acorn production at the low-dispersal site. While this site-to-site variation results in substantial differences in asymptotic spread rates, dispersal for both sites is substantially lower than required to track latitudinal temperature shifts.Animal-dispersed trees can exhibit considerable spatial variation in seed dispersal, although patterns may be surprisingly constant over time. However, even under

  7. Spontaneous dispersion of PdO onto acid sites of zeolites studied by in situ DXAFS

    CERN Document Server

    Okumura, K; Niwa, M; Yokota, S; Kato, K; Tanida, H; Uruga, T

    2003-01-01

    The generation of highly dispersed PdO over zeolite supports was studied using in situ energy-dispersive XAFS (DXAFS) technique. From the comparison with the Na-ZSM-5, it was found that the oxidation as well as the spontaneous dispersion of Pd was promoted through the interaction between PdO and acid sites of H-form zeolites. (author)

  8. Between-Site Differences in the Scale of Dispersal and Gene Flow in Red Oak

    Science.gov (United States)

    Emily V Moran; James S. Clark

    2012-01-01

    Background: Nut-bearing trees, including oaks (Quercus spp.), are considered to be highly dispersal limited, leading to concerns about their ability to colonize new sites or migrate in response to climate change. However, estimating seed dispersal is challenging in species that are secondarily dispersed by animals, and differences in...

  9. Site fidelity, mate fidelity, and breeding dispersal in American kestrels

    Science.gov (United States)

    Steenhof, K.; Peterson, B.E.

    2009-01-01

    We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

  10. Geology, geophysics, and physical properties of the U12n.25 non-proliferation experiment site

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, M.J.; Bradford, R.P.; Hopkins, S.P. [Raytheon Services Nevada, Mercury, NV (United States)] [and others

    1994-12-31

    The Nuclear Non-Proliferation Experiment was conducted in the U12n.25 drift in N-Tunnel at the Nevada Test Site. The geologic characterization of the site was performed by Raytheon Services Nevada geologists in the standard manner used for all underground nuclear weapons-effects tests executed by the Defense Nuclear Agency. The U12n.25 test bed was constructed in zeolitized ash-fall tuff of the Tunnel Beds Tuff, Subunit 4K, 389.0 m below the surface of Rainier Mesa. The structural geology of the site was simple, with the nearest fault plane projected to be 12 m below the mined cavity at closest approach, and an average bedding dip of seven degrees to the northwest. The cavity excavation revealed several small fractures, including one which produced minor amounts of free water during construction. The physical properties of the site were well within the range of experience for the zeolitized tuff of N-Tunnel and no geology-related problems were encountered during construction. The zeolitized tuff of N-Tunnel has been the site of twenty nuclear tests conducted by the Defense Nuclear Agency. The similarities of geologic setting, site geometry, and physical properties allow many comparisons of Non-Proliferation Experiment results with the large nuclear-test data base.

  11. On-site and off-site forensic analysis capabilities for proliferation and terrorism prevention

    International Nuclear Information System (INIS)

    Whipple, R.E.; Nunes, P.J.; Reynolds, J.G.; Alcaraz, A.; Hart, B.R.

    2004-01-01

    Full text: We will present current on-site technologies that can be utilized for the screening of explosives, chemical agents, and environmental contaminants. These techniques must have the capability to detect various hazardous materials at very low levels, since they pose a major challenge for first responders. Specifically, the technology must detect concealed explosives or chemical agents on-site rapidly. Lawrence Livermore National Laboratory (LLNL) is currently developing several different high explosive screening and detection technologies for field use. Two technologies that have demonstrated an ability to screen for explosives at low levels are colorimetric spot tests and thin layer chromatography (TLC). Another technology that has demonstrated usefulness for the on-site analysis of unknowns is portable gas chromatography-mass spectrometry (GC-MS) with solid phase micro-extraction (SPME) sampling. Several examples utilizing these technologies and their usefulness will be presented. In addition to developing on-site screening methods, LLNL is an Organization for the Prohibition of Chemical Weapons (OPCW) designated laboratory and is certified to accept CW suspect samples. Currently, LLNL is expanding its ISO-17025 certification to include nuclear forensics and explosives. These off-site forensic analysis capabilities and certified procedures will support the needs for homeland security. We will highlight some of the ISO-17025 requirements to accredit procedures, handle samples, and reports. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract W-7405-ENG-48

  12. On-site and off-site forensic analysis capabilities for proliferation and terrorism prevention

    International Nuclear Information System (INIS)

    Hart, B.R.; Whipple, R.E.; Nunes, P.J.; Reynolds, J.G.; Alcaraz, A.

    2004-01-01

    We present current on-site technologies that can be utilized for the screening of explosives, chemical agents, and environmental contaminants. These techniques must have the capability to detect various hazardous materials at very low levels, since they pose a major challenge for first responders. Specifically, the technology must detect concealed explosives or chemical agents on-site rapidly. Lawrence Livermore National Laboratory (LLNL) is currently developing several different high explosive screening and detection technologies for field use. Two technologies that have demonstrated an ability to screen for explosives at low levels are colorimetric spot tests and thin layer chromatography (TLC). Another technology that has demonstrated usefulness for the on-site analysis of unknowns is portable gas chromatography-mass spectrometry (GC-MS) with solid phase micro-extraction (SPME) sampling. Several examples utilizing these technologies and their usefulness will be presented. In addition to developing on-site screening methods, LLNL is an Organization for the Prohibition of Chemical Weapons (OPCW) designated laboratory and is certified to accept CW suspect samples. Currently, LLNL is expanding its ISO-17025 certification to include nuclear forensics and explosives. These off-site forensic analysis capabilities and certified procedures will support the needs for homeland security. We will highlight some of the ISO-17025 requirements to accredit procedures, handle samples, and reports. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract W-7405-ENG-48. (author)

  13. Utilization of multimode Love wave dispersion curve inversion for geotechnical site investigation

    International Nuclear Information System (INIS)

    Hamimu, La; Nawawi, Mohd; Safani, Jamhir

    2011-01-01

    Inversion codes based on a modified genetic algorithm (GA) have been developed to invert multimode Love wave dispersion curves. The multimode Love wave dispersion curves were synthesized from the profile representing shear-wave velocity reversal using a full SH (shear horizontal) waveform. In this study, we used a frequency–slowness transform to extract the dispersion curve from the full SH waveform. Dispersion curves overlain in dispersion images were picked manually. These curves were then inverted using the modified GA. To assess the accuracy of the inversion results, differences between the true and inverted shear-wave velocity profile were quantified in terms of shear-wave velocity and thickness errors, E S and E H . Our numerical modeling showed that the inversion of multimode dispersion curves can significantly provide the better assessment of a shear-wave velocity structure, especially with a velocity reversal profile at typical geotechnical site investigations. This approach has been applied on field data acquired at a site in Niigata prefecture, Japan. In these field data, our inversion results show good agreement between the calculated and experimental dispersion curves and accurately detect low velocity layer targets

  14. Atmospheric Dispersion Simulation for Level 3 PSA at Ulchin Nuclear Site using a PUFF model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jun; Han, Seok-Jung; Jeong, Hyojoon; Jang, Seung-Cheol [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    Air dispersion prediction is a key in the level 3 PSA to predict radiation releases into the environment for preparing an effective strategy for an evacuation as a basis of the emergency preparedness. To predict the atmospheric dispersion accurately, the specific conditions of the radiation release location should be considered. There are various level 3 PSA tools and MACSS2 is one of the widely used level 3 PSA tools in many countries including Korea. Due to the characteristics of environmental conditions in Korea, it should be demonstrated that environmental conditions of Korea nuclear sites can be appropriately illustrated by the tool. In Korea, because all nuclear power plants are located on coasts, sea and land breezes might be a significant factor. The objectives of this work is to simulate the atmospheric dispersion for Ulchin nuclear site in Korea using a PUFF model and to generate the data which can be used for the comparison with that of PLUME model. A nuclear site has own atmospheric dispersion characteristics. Especially in Korea, nuclear sites are located at coasts and it is expected that see and land breeze effects are relatively high. In this work, the atmospheric dispersion at Ulchin nuclear site was simulated to evaluate the effect of see and land breezes in four seasons. In the simulation results, it was observed that the wind direction change with time has a large effect on atmospheric dispersion. If the result of a PLUME model is more conservative than most severe case of a PUFF model, then the PLUME model could be used for Korea nuclear sites in terms of safety assessment.

  15. Comparison of the Radionuclides Dispersion at the UAE Barakah Site with that at the ROK Shin-Kori Site - Comparison of the radionuclides dispersion in Barakah site with that in Shin-Kori site

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-yeop; Lee, Kun Jai; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Beeley, Philip A. [Khalifa University of Science, Technology and Research, P.O. Box 127788, Abu Dhabi (United Arab Emirates)

    2014-07-01

    In order to understand the characteristics of atmospheric dispersion of radionuclides in the desert environment of Barakah site in UAE, comparison research with the results of other environments could be an appropriate way to facilitate it. Shin-Kori site is the proper comparison target because same reactor type of APR1400 with that in Barakah site is under construction. Hypothetical accident scenario was considered and accident source term which had been developed in previous research has been applied as releasing source. After reviewing several computation codes, ADMS5 has been selected as an atmospheric dispersion modeling tool which is installing advanced Gaussian plum model and plentiful options. The climate data of both Barakah and Shin-Kori were acquired and the environments of both sites have been simulated considering wind speed, wind direction, temperature, humidity, ground surface roughness and etc. Near field final human doses on the maps have been schematised regarding statistical meteorological data of both sites and dose conversion factors from the publications of ICRP and federal guidance report of EPA. The results of this research are expected to enhance the understanding about differences between two environments which have same reactor type and to improve the comprehension of desert environment of Barakah site as well. Applying different dose conversion factors to Barakah site considering the desert biosphere could be further study to obtain more accurate results. (authors)

  16. Hydrological dispersion of radioactive material in relation to nuclear power plant siting

    International Nuclear Information System (INIS)

    1985-01-01

    This Guide discusses the dispersion of normal and accidental releases of radioactive materials from nuclear power plants into surface water, including the washout of airborne radionuclides, and gives recommendations on information to be collected during the various stages of the siting procedure, a minimum measurement programme and the selection and validation of appropriate mathematical models for predicting dispersion. Guidelines are also provided for the optimal use of models for a specific site situation and for defining the necessary input parameters. Results of existing validation studies are given

  17. Compounding effects on nest-site dispersal of Barn Owls Tyto alba

    DEFF Research Database (Denmark)

    Huffeldt, Nicholas Per; Aggerholm, Iben Næs; Brandtberg, Nathia Hass

    2012-01-01

    of pulli ringed in Denmark (1921-2009; n=590) and glmms to test density, recovery time, ringing date and brood size for their influence on dispersal probability and recovery distance. Results The probability of being recovered >1 km from the nest-site as well as total recovery distances increased steeply...... from 0 to 100 days after ringing, being stable thereafter, and was also impacted by brood size. Owls ringed very early or late in the breeding season were more likely to be recovered nest-site at a recovery time where dispersal seemed to be completed....

  18. Nest-site fidelity and dispersal of Gyrfalcons estimated by noninvasive genetic sampling

    Science.gov (United States)

    Booms, T.L.; Talbot, S.L.; Sage, G.K.; McCaffery, B.J.; McCracken, K.G.; Schempf, P.F.

    2011-01-01

    We used feathers from adult Gyrfalcons (Falco rusticolus) molted in breeding territories and blood samples from nestlings to document nest-site fidelity and dispersal of breeding adults and juveniles at three areas 100- 350 km apart in Yukon Delta National Wildlife Refuge, Alaska, 2003-2007. We used genotypes from seven polymorphic microsatellite loci that provided a mean probability of identity of 0.91 ??10 -5. Breeding Gyrfalcons were highly faithful to study area and territory; we documented no dispersals of breeding birds among study areas and only one dispersal between territories. But their fidelity to nest sites was low; 22% of birds returned to the same nest site the following year. Distance among alternate nests within a territory averaged 750 m and was similar for both sexes. Mean tenure in a territory was 2.8 years, similar for both sexes, and distributed bimodally with peaks at 1 and 4 years. Mean annual turnover rate at the Ingakslugwat Hills (Volcanoes) study area was 20%. We detected three young that established breeding territories at distances ranging from 0 to 254 km from their natal territory, representing 2.5% apparent recruitment. Gyrfalcons in the Askinuk Mountains study area were slightly but statistically significantly differentiated genetically from those in the Volcanoes and Kilbuck Mountain study areas. These data are the first published on the nest-site fidelity, breeding dispersal, and natal dispersal of the Gyrfalcon in North America and demonstrate the utility of noninvasive genetic sampling to greatly improve our understanding of avian dispersal and its underlying mechanisms. ?? The Cooper Ornithological Society 2011.

  19. Plastic pellets as oviposition site and means of dispersal for the ocean-skater insect Halobates.

    Science.gov (United States)

    Majer, A P; Vedolin, M C; Turra, A

    2012-06-01

    Microplastics are omnipresent in the oceans and generally have negative impacts on the biota. However, flotsam may increase the availability of hard substrates, which are considered a limiting resource for some oceanic species, e.g. as oviposition sites for the ocean insect Halobates. This study describes the use of plastic pellets as an oviposition site for Halobates micans and discusses possible effects on its abundance and dispersion. Inspection of egg masses on stranded particles on beaches revealed that a mean of 24% (from 0% to 62%) of the pellets bore eggs (mean of 5 and max. of 48 eggs per pellet). Most eggs (63%) contained embryos, while 37% were empty egg shells. This shows that even small plastic particles are used as oviposition site by H. micans, and that marine litter may have a positive effect over the abundance and dispersion of this species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. An overview of the on-site inspection measurements from the non-proliferation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, J.J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    An on-site inspection (OSI) is an in-person visit to site to collect data and examine evidence in order to determine the source of an ambiguous event detected via remote monitoring systems or other measures. Its purpose is to determine whether the treaty has been violated, to deter violations, and to build confidence. At the time of this writing, it is anticipated that the Comprehensive Test Ban Treaty (CTBT) being developed in the Conference on Disarmament will contain OSI provisions. In an era of testing moratoria, the Non-Proliferation Experiment (NPE) provided a unique opportunity to investigate candidate OSI techniques. On site inspections could occur in three different contexts: after-the-fact inspections based on information from remote monitoring systems; inspections prior to, during, and after large declared chemical explosions (e.g., a large mining explosion); continuous monitoring inspections with unattended sensors at certain agreed-upon sites (e.g., previous test sites). OSI monitoring techniques need to be designed to detect the phenomena and residual effects of nuclear explosions. In the underground case, the primary effects of interest for OSI are the electromagnetic pulse, shock waves, aftershocks, radioactive gas, rubble zone, and apical void. These effects are well known and the basic techniques for their detection well established. We designed our measurement program for the NPE to answer specific issues about these detection technologies. Our measurement program includes the following: zerotime electromagnetic measurements; seismic aftershock survey; before and after electrical soundings; gas tracers introduced into the explosive; before and after multispectral overhead imagery from low-flying aircraft; before and after geological surveys.

  1. Experimental and Numerical Modelling of CO2 Atmospheric Dispersion in Hazardous Gas Emission Sites.

    Science.gov (United States)

    Gasparini, A.; sainz Gracia, A. S.; Grandia, F.; Bruno, J.

    2015-12-01

    Under stable atmospheric conditions and/or in presence of topographic depressions, CO2 concentrations can reach high values resulting in lethal effect to living organisms. The distribution of denser than air gases released from the underground is governed by gravity, turbulence and dispersion. Once emitted, the gas distribution is initially driven by buoyancy and a gas cloud accumulates on the ground (gravitational phase); with time the density gradient becomes less important due to dispersion or mixing and gas distribution is mainly governed by wind and atmospheric turbulence (passive dispersion phase). Natural analogues provide evidences of the impact of CO2 leakage. Dangerous CO2 concentration in atmosphere related to underground emission have been occasionally reported although the conditions favouring the persistence of such a concentration are barely studied.In this work, the dynamics of CO2 in the atmosphere after ground emission is assessed to quantify their potential risk. Two approaches have been followed: (1) direct measurement of air concentration in a natural emission site, where formation of a "CO2 lake" is common and (2) numerical atmospheric modelling. Two sites with different morphology were studied: (a) the Cañada Real site, a flat terrain in the Volcanic Field of Campo de Calatrava (Spain); (b) the Solforata di Pomezia site, a rough terrain in the Alban Hills Volcanic Region (Italy). The comparison between field data and model calculations reveal that numerical dispersion models are capable of predicting the formation of CO2 accumulation over the ground as a consequence of underground gas emission. Therefore, atmospheric modelling could be included as a valuable methodology in the risk assessment of leakage in natural degassing systems and in CCS projects. Conclusions from this work provide clues on whether leakage may be a real risk for humans and under which conditions this risk needs to be included in the risk assessment.

  2. Closure Report for Corrective Action Unit 366: Area 11 Plutonium Valley Dispersion Sites, Nevada National Security Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2013-12-31

    This Closure Report (CR) presents information supporting closure of Corrective Action Unit (CAU) 366, Area 11 Plutonium Valley Dispersion Sites, and provides documentation supporting the completed corrective actions and confirmation that closure objectives for CAU 366 were met. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; the U.S. Department of Energy (DOE), Environmental Management; the U.S. Department of Defense; and DOE, Legacy Management (FFACO, 1996 as amended).

  3. Radioactive dispersion analysis for hypothetical nuclear power plant (NPP) candidate site in Perak state, Malaysia

    Science.gov (United States)

    Shamsuddin, Shazmeen Daniar; Basri, Nor Afifah; Omar, Nurlyana; Koh, Meng-Hock; Ramli, Ahmad Termizi; Saridan Wan Hassan, Wan Muhamad

    2017-10-01

    Malaysia is planning to build a nuclear power plant (NPP) by 2030 to diversify the national electricity supply and resources. Selection of an NPP site must consider various factors, especially nuclear safety consideration to fulfil the nuclear safety objectives. Environmental Risk Assessment Analysis is a part of safety requirements by the International Atomic Energy Agency (IAEA) prior to the NPP commissioning process. Risk Assessments Analysis (RIA) is compulsory for the NPP site evaluation. One of RIA methods are Radioactive Dispersion Analysis using probabilistic risk analysis software. It is also important to perform studies to estimate the impact to the neighbouring population in the case of a nuclear accident at the power plant. In the present work, aimed to study the impact of a hypothetical nuclear accident by simulating the dispersion pattern of radionuclides originated from a candidate site at Manjung, Perak. The work has been performed using the HotSpot Health Physics codes. Two types of radionuclides have been considered namely 137Cs and 131I. In calculations, the initial concentration of radioactive materials of Fukushima Daiichi accident data are used which are 2.06 x 1016 Bq and 1.68 x 1017 Bq respectively for the two radionuclides. The result shows that the dispersion distance obtained from both software are not the same. It shows that 137Cs and 131I can be dispersed as far as 16 km and 80 km away from the site during radiological accident respectively, reaching major towns in Perak. Using HOTSPOT, the estimated total effective dose equivalent (TEDE) for 137Cs and 131I at major towns in Perak such as Lumut and Sitiawan are 1.2 mSv and 9.9 mSv. As for Taiping, Ipoh, Kampar, and Teluk Intan the estimated TEDE is around 0.2 mSv and 1.6 mSv respectively. In conclusion, the dispersion can reach as far as 80 km from the site. However, estimated annual effective dose is not more than 1 mSv limit, which is considered acceptable in the point of view of

  4. Radioactive dispersion analysis for hypothetical nuclear power plant (NPP candidate site in Perak state, Malaysia

    Directory of Open Access Journals (Sweden)

    Shamsuddin Shazmeen Daniar

    2017-01-01

    Full Text Available Malaysia is planning to build a nuclear power plant (NPP by 2030 to diversify the national electricity supply and resources. Selection of an NPP site must consider various factors, especially nuclear safety consideration to fulfil the nuclear safety objectives. Environmental Risk Assessment Analysis is a part of safety requirements by the International Atomic Energy Agency (IAEA prior to the NPP commissioning process. Risk Assessments Analysis (RIA is compulsory for the NPP site evaluation. One of RIA methods are Radioactive Dispersion Analysis using probabilistic risk analysis software. It is also important to perform studies to estimate the impact to the neighbouring population in the case of a nuclear accident at the power plant. In the present work, aimed to study the impact of a hypothetical nuclear accident by simulating the dispersion pattern of radionuclides originated from a candidate site at Manjung, Perak. The work has been performed using the HotSpot Health Physics codes. Two types of radionuclides have been considered namely 137Cs and 131I. In calculations, the initial concentration of radioactive materials of Fukushima Daiichi accident data are used which are 2.06 x 1016 Bq and 1.68 x 1017 Bq respectively for the two radionuclides. The result shows that the dispersion distance obtained from both software are not the same. It shows that 137Cs and 131I can be dispersed as far as 16 km and 80 km away from the site during radiological accident respectively, reaching major towns in Perak. Using HOTSPOT, the estimated total effective dose equivalent (TEDE for 137Cs and 131I at major towns in Perak such as Lumut and Sitiawan are 1.2 mSv and 9.9 mSv. As for Taiping, Ipoh, Kampar, and Teluk Intan the estimated TEDE is around 0.2 mSv and 1.6 mSv respectively. In conclusion, the dispersion can reach as far as 80 km from the site. However, estimated annual effective dose is not more than 1 mSv limit, which is considered acceptable in the point

  5. New radiocarbon dates from the Bapot-1 site in Saipan and Neolithic dispersal by stratified diffusion

    International Nuclear Information System (INIS)

    Clark, G.; Petchey, F.; Winter, O.; Carson, M.; O'Day, P.

    2010-01-01

    The colonisation of the Mariana Islands in Western Micronesia is likely to represent an early ocean dispersal of more than 2000 km. Establishing the date of human arrival in the archipelago is important for modelling Neolithic expansion in Island Southeast Asia and the Pacific, particularly the role of long-distance dispersals. This paper presents new 14 C results and a ΔR estimate from the Bapot-1 site on Saipan Island, which indicate human arrival at ca. 3400-3200 cal. BP. Archaeological chronologies of long-distance dispersal to Western Micronesia and the Lapita expansion (Bismarcks to Samoa) show that the Neolithic dispersal rate was increasing during the period ca. 3400-2900 cal. BP. The range-versus-time relationship is similar to stratified diffusion whereby a period of relatively slow expansion is succeeded by long-distance movement. An increase in new colonies created by long-distance migrants results in accelerating range expansion. (author). Refs., 6 figs., 2 tabs.

  6. Model calculating annual mean atmospheric dispersion factor for coastal site of nuclear power plant

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper describes an atmospheric dispersion field experiment performed on the coastal site of nuclear power plant in the east part of China during 1995 to 1996. The three-dimension joint frequency are obtained by hourly observation of wind and temperature on a 100m high tower; the frequency of the “event day of land and sea breezes” are given by observation of surface wind and land and sea breezes; the diffusion parameters are got from measurements of turbulent and wind tunnel simulation test.A new model calculating the annual mean atmospheric dispersion factor for coastal site of nuclear power plant is developed and established.This model considers not only the effect from mixing release and mixed layer but also the effect from the internal boundary layer and variation of diffusion parameters due to the distance from coast.The comparison between results obtained by the new model and current model shows that the ratio of annual mean atmospheric dispersion factor gained by the new model and the current one is about 2.0.

  7. Modelling and analysis of radionuclide dispersion from PWR on abnormal condition in Bojanegara Serang site

    International Nuclear Information System (INIS)

    Sri Kuntjoro

    2010-01-01

    Additional of electrical power especially Nuclear Power Plant will give radiological consequence sto population and environment due to radioactive release in normal and abnormal condition. In consequence the management of nuclear power plant must supply data and strong argumentation to clarify the safety of nuclear power plant to environment. For that purpose it needs to be carried out an analysis of abnormal condition in nuclear power plant and its radiological consequences to the environment. That analysis is done using abnormal condition simulation model postulated on 1000 MWe nuclear power plant.That simulation model is used also to evaluate environmental potential as site capability in supporting the radiological consequences. Radionuclide transport modeling from reactor core to containment uses EMERALD computer code. Other computer codes are Wind rose, PC-COSYMA and Arc View are used to simulate meteorology condition, radionuclide release to population distribution of food production and consumption and distribution of radiation dose received to population around nuclear power plant. Application of that simulation is carried out to NPP candidate site in Bojanegara-Kramatwatu, Serang Banten peninsula. Using source term data, meteorology data, dispersion data and pathways modeling are resulting radionuclide dispersion model and radiation pathway acceptance at the surrounding nuclear power plant site (Bojanegara-Serang peninsula). The result shows that maximum radiation dose received is lower than dose permitted in accordance with regulatory body (BAPETEN). (author)

  8. Grand LAgrangian Deployment (GLAD): Surface Dispersion Characteristics Near the Deepwater Horizon Oil Spill Site

    Science.gov (United States)

    Ozgokmen, Tamay; Poje, Andrew; Lipphardt, Bruce, Jr.; Haza, Angelique; Haus, Brian; Jacobs, Gregg; Reniers, Ad; Olascoaga, Josefina; Ryan, Edward; Novelli, Guillaume; Kirwan, Albert, Jr.; Griffa, Annalisa; Chen, Shuyi; Hogan, Pat

    2013-04-01

    Initial dispersion, residence time, and advective pathway results obtained from the nearly simultaneous deployment of some 300 surface drifters in the vicinity of the DwH oil spill in the DeSoto Canyon are reported. The goal of the GLAD experiment was to characterize, with unprecedented statistical significance, multi-point and multi-scale dispersion properties of the flow in the region of the DwH spill site including demarcation of the advective pathways between the Canyon and larger-scale flow features in the Gulf. Both the absolute and relative dispersion of surface drifters was quite slow for those drifters initialized within the Missippippi River Outflow. For the initial time period considered, drifter motion was characterized by large amplitude inertial motions, overall strong topographic control, and significant indications of interior control by frontal dynamics on 1-5 km scales. Very limited exchange, either across-shelf or with nearby mesoscale features, was observed and residence times in the Canyon typically exceeded one week with many drifters remaining there for more than 21 days.

  9. Testing the atmospheric dispersion model of CSA N288.1 with site-specific data

    CERN Document Server

    Chouhan, S L

    2001-01-01

    The atmospheric dispersion component of CSA Standard N288. 1, which provides guidelines for calculating derived release limits, has been tested. Long-term average concentrations of tritium in air were predicted using site-specific release rates and meteorological data and compared with measured concentrations at 43 monitoring sites at all CANDU stations in Canada. The predictions correlate well with the observations but were found to be conservative, overestimating by about 50% on average. The model overpredicted 84% of the time, with the highest prediction lying a factor of 5.5 above the corresponding observation. The model underpredicted the remaining 16% of the time, with the lowest prediction about one-half of the corresponding measurement. Possible explanations for this bias are discussed but no single reason appears capable of accounting for the discrepancy. Rather, the tendency to overprediction seems to result from the cumulative effects of a number of small conservatisms in the model. The model predi...

  10. Testing the atmospheric dispersion model of CSA N288.1 with site-specific data

    International Nuclear Information System (INIS)

    Chouhan, S.L.; Davis, P.A.

    2001-01-01

    The atmospheric dispersion component of CSA Standard N288. 1, which provides guidelines for calculating derived release limits, has been tested. Long-term average concentrations of tritium in air were predicted using site-specific release rates and meteorological data and compared with measured concentrations at 43 monitoring sites at all CANDU stations in Canada. The predictions correlate well with the observations but were found to be conservative, overestimating by about 50% on average. The model overpredicted 84% of the time, with the highest prediction lying a factor of 5.5 above the corresponding observation. The model underpredicted the remaining 16% of the time, with the lowest prediction about one-half of the corresponding measurement. Possible explanations for this bias are discussed but no single reason appears capable of accounting for the discrepancy. Rather, the tendency to overprediction seems to result from the cumulative effects of a number of small conservatisms in the model. The model predictions were slightly better when site-specific meteorological data were used in the calculations in place of the default data of N288.1. Some large discrepancies between predictions and observations at specific monitoring sites suggest that it is the measurements rather than the model that are at fault. The testing has therefore provided a check on the observations as well as on the model. Recommendations on model use and data collection are made to improve the level of agreement between predictions and observations in the future. (author)

  11. Seismic velocity site characterization of 10 Arizona strong-motion recording stations by spectral analysis of surface wave dispersion

    Science.gov (United States)

    Kayen, Robert E.; Carkin, Brad A.; Corbett, Skye C.

    2017-10-19

    Vertical one-dimensional shear wave velocity (VS) profiles are presented for strong-motion sites in Arizona for a suite of stations surrounding the Palo Verde Nuclear Generating Station. The purpose of the study is to determine the detailed site velocity profile, the average velocity in the upper 30 meters of the profile (VS30), the average velocity for the entire profile (VSZ), and the National Earthquake Hazards Reduction Program (NEHRP) site classification. The VS profiles are estimated using a non-invasive continuous-sine-wave method for gathering the dispersion characteristics of surface waves. Shear wave velocity profiles were inverted from the averaged dispersion curves using three independent methods for comparison, and the root-mean-square combined coefficient of variation (COV) of the dispersion and inversion calculations are estimated for each site.

  12. Dispersal of radioactivity by wildlife from contaminated sites in a forested landscape

    Energy Technology Data Exchange (ETDEWEB)

    Garten, C.T. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

    1995-12-31

    Oak Ridge National Laboratory (ORNL) is located within the Valley and Ridge Physiographic Province of eastern Tennessee (USA). Wildlife populations have access to some radioactively contaminated sites at ORNL. Contaminated animals or animal nests within the Laboratory`s boundaries have been found to contain {sup 90}Sr or {sup 137}Cs on the order of 10{sup -2}-10{sup 4} Bq g{sup -1} and trace amounts of other radionuclides (including transuranic elements). Animals that are capable of flight and animals with behaviour patterns or developmental life stages involving contact with sediments in radioactive ponds, like benthic invertebrates, present the greatest potential for dispersal of radioactivity. The emigration of frogs and turtles from waste ponds also presents a potential for dispersal of radioactivity but over distances < 5 km. Mud-dauber wasps (Hymenoptera) and swallows (Hirundinidae) may transport radioactive mud for nest building, but also over relatively short distances (0.2-1 km). Movement by small mammals is limited by several factors, including physical barriers and smaller home ranges. Larger animals, like white-tailed deer (Odocoileus virginianus) are potential vectors of radioactivity due to their greater body size, longer life expectancy, and larger home range. Larger animals contain greater amounts of total radioactivity than smaller animals, but tissue concentrations of {sup 137}Cs generally decline with body size. (author).

  13. Dispersal of radioactivity by wildlife from contaminated sites in a forested landscape

    International Nuclear Information System (INIS)

    Garten, C.T. Jr.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) is located within the Ridge and Valley physiographic province of eastern Tennessee (USA). This area is characterized by deciduous forests dominated by hardwood and mixed mesophytic tree species. Wildlife populations have access to some radioactively contaminated sites at ORNL, and contaminated animals or animal nests within the Laboratory's boundaries have been found to contain on the order of 10 -12 to 10 -6 Ci/g of 90 Sr or 137 Cs, and trace amounts of other radionuclides (including transuranic elements). Theoretical calculations indicate that nanocurie levels of 90 Sr in bone can arise from relatively small amounts (1%) of contaminated browse vegetation in a deer's diet. Measures that have been undertaken at ORNL to curtail the dispersal of radioactivity by animals are briefly reviewed

  14. Modeling emissions and dispersion of contaminants from cleanup activities at a mixed waste site to estimate air impacts and risks

    International Nuclear Information System (INIS)

    Chang, Y.S.; Menlove, S.

    1993-09-01

    The transport and dispersion of contaminants via the air pathway is a major concern during cleanup of contaminated sites. Impacts to air quality and human health during cleanup were evaluated for the Weldon Spring site by using site-specific information for source areas, activities, and receptor locations. In order to ensure protection of human health and the environment, results are being used to focus on those cleanup activities for which release controls should be emphasized

  15. Studies of tritium dispersion around and close to the buildings on the JET site

    International Nuclear Information System (INIS)

    Caldwell-Nichols, C.J.

    1995-01-01

    The dispersion of gases released to the environment at significant distances from the release point can be predicted using propriety computer codes. However during and after the Preliminary Tritium Experiment 1,2 (PTE) at JET in 1991 comparatively high levels of tritium were measured around the buildings and also there was measurable uptake of tritium in the site cooling water. Better assessment of likely tritium concentrations resulting from discharges is required to determine if tritium would tend to concentrate close to the buildings due to the complex air flow patterns around them. Three methods have been considered, namely computational studies, wind tunnel testing and tracer release experiments. A graduated approach has been adopted as each method has its limitations, tracer experiments being particularly expensive. Computational studies indicate that under worst case conditions the maximum ground level concentrations (Bq/m.) per unit stack release rate (Bq/s) is 1.0E-4 but more generally less. The results are presented noting the limitations of this approach. To aid understanding and verify some of the results, wind tunnel tests on a model of the JET site have been undertaken and the results discussed. The need for tracer release studies is considered. 3 refs., 6 figs

  16. Recreational use in dispersed public lands measured using social media data and on-site counts.

    Science.gov (United States)

    Fisher, David M; Wood, Spencer A; White, Eric M; Blahna, Dale J; Lange, Sarah; Weinberg, Alex; Tomco, Michael; Lia, Emilia

    2018-09-15

    Outdoor recreation is one of many important benefits provided by public lands. Data on recreational use are critical for informing management of recreation resources, however, managers often lack actionable information on visitor use for large protected areas that lack controlled access points. The purpose of this study is to explore the potential for social media data (e.g., geotagged images shared on Flickr and trip reports shared on a hiking forum) to provide land managers with useful measures of recreational use to dispersed areas, and to provide lessons learned from comparing several more traditional counting methods. First, we measure daily and monthly visitation rates to individual trails within the Mount Baker-Snoqualmie National Forest (MBSNF) in western Washington. At 15 trailheads, we compare counts of hikers from infrared sensors, timelapse cameras, and manual on-site counts, to counts based on the number of shared geotagged images and trip reports from those locations. Second, we measure visitation rates to each National Forest System (NFS) unit across the US and compare annual measurements derived from the number of geotagged images to estimates from the US Forest Service National Visitor Use Monitoring Program. At both the NFS unit and the individual-trail scales, we found strong correlations between traditional measures of recreational use and measures based on user-generated content shared on the internet. For national forests in every region of the country, correlations between official Forest Service statistics and geotagged images ranged between 55% and 95%. For individual trails within the MBSNF, monthly visitor counts from on-site measurements were strongly correlated with counts from geotagged images (79%) and trip reports (91%). The convenient, cost-efficient and timely nature of collecting and analyzing user-generated data could allow land managers to monitor use over different seasons of the year and at sites and scales never previously

  17. Post-test geologic observations made at the non-proliferation experiment site, N-tunnel, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, D.R.; Bradford, R.P.; Hopkins, S.P. [Raytheon Services Nevada, Mercury, NV (United States)] [and others

    1994-12-31

    Qualitative evaluations of damage resulting from an underground explosion can provide valuable information concerning the size of the charge, as well as the location of a clandestine detonation. However, caution must be exercised during the appraisal because the effects of an explosion are a function of many factors in addition to yield. Construction techniques, the physical properties of the surrounding rock, and the depth of burial are all important considerations when evaluating the effects of an underground detonation. Raytheon Services Nevada geologists documented underground and surface effects of the Non-Proliferation Experiment, as they have for all recent underground weapons-effects tests conducted by the Defense Nuclear Agency. Underground, the extent of the visible damage decreased rapidly from severe at the closest inspection point 100 m from the Working Point, to insignificant 300 m from the Working Point. The severity of damage correlates in some instances with the orientation of the drift with respect to the shock-wave propagation direction. No evidence of the Non-Proliferation explosion was visible on the mesa surface 389 m above the Working Point the day after the explosion.

  18. New concepts for small power reactors without on-site refuelling for non-proliferation

    International Nuclear Information System (INIS)

    Brown, N.W.; Hasberger, J.A.

    2000-01-01

    The report discusses the preliminary requirements and a technical approach for developing small reactors and the rationale for selecting them. It then discusses the four nuclear system technologies and how they might proceed to meet the requirements. Brief discussions are provided on the approaches to stimulating the appropriate international and industrial participation necessary to finance development of a design with improved proliferation resistance that is useful to the developing countries. (author)

  19. Increased cell proliferation in spleen and lymph nodes peripheral to contact allergen application site

    International Nuclear Information System (INIS)

    Chipinda, Itai; Anderson, Stacey E.; Butterworth, Leon F.; Beezhold, Donald; Siegel, Paul D.

    2009-01-01

    The local lymph node assay (LLNA) is widely used to identify chemicals that are contact sensitizers. The assay involves dosing mice with the chemical on both ears and pooling the superficial parotid lymph nodes for assessment of lymphocyte proliferation as a marker of sensitization. The present study explored potential reduction in animal usage by dosing one ear with the allergen and the other with vehicle-only. The respective draining lymph nodes were processed separately for tritiated thymidine ( 3 H-TdR) incorporation. Cell proliferation in proper axillary and renal nodes, as well as in the spleen was also assessed. Cross-contamination of the chemicals from the dosed ears to other parts of the body via preening was prevented by dosing restrained animals and washing off the residual chemical with saline after 4 h. Dosing the left ear with 0.02% oxazolone (OX) on unrestrained animals resulted in marked cell proliferation in its draining lymph node (stimulation index, SI = 12.8) and in the lymph node draining the contra-lateral vehicle-dosed ear (SI = 6), as well as the proper axillary lymph nodes (SI = 3.3). Increased 3 H-TdR incorporation was not observed in the renal lymph nodes (SI = 1.1). Similar stimulation of cells was observed in the lymph node draining the ear contra-lateral to the 30% hexylcinnamaldehyde (HCA)-dosed ear. Increased proliferative activity was observed in contra-lateral draining lymph nodes of restrained mice demonstrating that these results cannot be attributed to cross-contamination of adjacent skin. A significant increase in proliferation of splenocytes was also observed. It is concluded that dermal application of a contact allergen, as exemplified by OX and HCA, may induce cell proliferation in the neighboring lymph nodes and spleen indicative of hapten and/or haptenated proteins diffusing through the skin to peripheral nodes and the blood to produce systemic sensitization. It is also possible that lymphatic capillaries may communicate

  20. Site restoration: Estimation of attributable costs from plutonium-dispersal accidents

    International Nuclear Information System (INIS)

    Chanin, D.I.; Murfin, W.B.

    1996-05-01

    A nuclear weapons accident is an extremely unlikely event due to the extensive care taken in operations. However, under some hypothetical accident conditions, plutonium might be dispersed to the environment. This would result in costs being incurred by the government to remediate the site and compensate for losses. This study is a multi-disciplinary evaluation of the potential scope of the post-accident response that includes technical factors, current and proposed legal requirements and constraints, as well as social/political factors that could influence decision making. The study provides parameters that can be used to assess economic costs for accidents postulated to occur in urban areas, Midwest farmland, Western rangeland, and forest. Per-area remediation costs have been estimated, using industry-standard methods, for both expedited and extended remediation. Expedited remediation costs have been evaluated for highways, airports, and urban areas. Extended remediation costs have been evaluated for all land uses except highways and airports. The inclusion of cost estimates in risk assessments, together with the conventional estimation of doses and health effects, allows a fuller understanding of the post-accident environment. The insights obtained can be used to minimize economic risks by evaluation of operational and design alternatives, and through development of improved capabilities for accident response

  1. Atmospheric dispersion experiments over complex terrain in a spanish valley site (Guardo-90)

    International Nuclear Information System (INIS)

    Ibarra, J.I.

    1991-01-01

    An intensive field experimental campaign was conducted in Spain to quantify atmospheric diffusion within a deep, steep-walled valley in rough, mountainous terrain. The program has been sponsored by the spanish companies of electricity and is intended to validate existing plume models and to provide the scientific basis for future model development. The atmospheric dispersion and transport processes in a 40x40 km domain were studied in order to evaluate SO 2 and SF 6 releases from an existing 185 m chimney and ground level sources in a complex terrain valley site. Emphasis was placed on the local mesoscale flows and light wind stable conditions. Although the measuring program was intensified during daytime for dual tracking of SO 2 /SF 6 from an elevated source, nighttime experiments were conducted for mountain-valley flows characterization. Two principle objectives were pursued: impaction of plumes upon elevated terrain, and diffusion of gases within the valley versus diffusion over flat, open terrain. Artificial smoke flows visualizations provided qualitative information: quantitative diffusion measurements were obtained using sulfur hexafluoride gas with analysis by highly sensitive electron capture gas chromatographs systems. Fourteen 2 hours gaseous tracer releases were conducted

  2. Site restoration: Estimation of attributable costs from plutonium-dispersal accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chanin, D.I.; Murfin, W.B. [Technadyne Engineering Consultants, Inc., Albuquerque, NM (United States)

    1996-05-01

    A nuclear weapons accident is an extremely unlikely event due to the extensive care taken in operations. However, under some hypothetical accident conditions, plutonium might be dispersed to the environment. This would result in costs being incurred by the government to remediate the site and compensate for losses. This study is a multi-disciplinary evaluation of the potential scope of the post-accident response that includes technical factors, current and proposed legal requirements and constraints, as well as social/political factors that could influence decision making. The study provides parameters that can be used to assess economic costs for accidents postulated to occur in urban areas, Midwest farmland, Western rangeland, and forest. Per-area remediation costs have been estimated, using industry-standard methods, for both expedited and extended remediation. Expedited remediation costs have been evaluated for highways, airports, and urban areas. Extended remediation costs have been evaluated for all land uses except highways and airports. The inclusion of cost estimates in risk assessments, together with the conventional estimation of doses and health effects, allows a fuller understanding of the post-accident environment. The insights obtained can be used to minimize economic risks by evaluation of operational and design alternatives, and through development of improved capabilities for accident response.

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

    International Nuclear Information System (INIS)

    Savolainen, Ilkka

    1980-01-01

    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)

  4. Atmospheric dispersion and deposition of 131I released from the Hanford Site

    International Nuclear Information System (INIS)

    Ramsdell, J.V. Jr.; Simonen, C.A.; Burk, K.W.; Stage, S.A.

    1996-01-01

    Approximately 2.6 x 10 4 TBq (700,000 Ci) of 131 I were released to the air from reactor fuel processing plants on the Hanford Site in southcentral Washington State from December 1944 through December 1949. The Hanford Environmental Dose Reconstruction Project developed a suite of codes to estimate the doses that might have resulted from these releases. The Regional Atmospheric Transport Code for Hanford Emission Tracking (RATCHET) computer code is part of this suite. The RATCHET code implements a Lagrangian-trajectory, Gaussian-puff dispersion model that uses hourly meterological and release rate data to estimate daily time-integrated air concentrations and surface contamination for use, in dose estimates. In this model, iodine is treated as a mixture of three species (inorganic gases, organic gases, and particles). Model deposition parameters are functions of the mixture and meterological conditions. A resistance model is used to calculate dry deposition velocities. Equilibrium between concentrations in the precipitation and the air near the ground is assumed in calculating wet deposition of gases, and irreversible washout of the particles is assumed. RATCHET explicitly treats the uncertainties in model parameters and meteorological conditions. Uncertainties in 131 I release rates and partitioning among the nominal species are treated by varying model input. The results of 100 model runs for December 1944 through December 1949 indicate that monthly average air concentrations and deposition have uncertainties ranging from a factor of two near the center of the time-integrated plume to more than an order of magnitude near the edge. These results indicate that ∼10% of the 131 I released to the atmosphere decayed during transit in the study area, ∼56% was deposited within the study area, and the remaining 34% was transported out of the study area while still in the air

  5. Special proliferative sites are not needed for seeding and proliferation of transfused bone marrow cells in normal syngeneic mice

    International Nuclear Information System (INIS)

    Brecher, G.; Ansell, J.D.; Micklem, H.S.; Tjio, J.H.; Cronkite, E.P.

    1982-01-01

    The widely held view that transfused bone marrow cells will not proliferate in normal mice, not exposed to irradiation or other forms of bone marrow ablation, was reinvestigated. Forty million bone marrow cells from male donors were given to female recipients on each of 5 consecutive days, 5 to 10 times the number customarily used in the past. When the recipients were examined 2-13 weeks after the last transfusion, donor cells were found to average 16-25% of total marrow cells. Similar percentages of donor cells were found when variants of the enzyme phosphoglycerate kinase determined electrophoretically were used for identification of donor and recipient cells. Evidence is presented that the proportion of donor cells is compatible with a nonlinear dependence on the number of cells transfused over the range tested - i.e., 20-200 million bone marrow cells injected intravenously. Special proliferative sites thus do not appear to be required

  6. Issues in clustered nuclear siting: a comparison of a hypothetical nuclear energy center in New Jersey with dispersed nuclear siting

    International Nuclear Information System (INIS)

    Meier, P.M.; Morell, D.

    1976-09-01

    The report is an analysis of a hypothetical nuclear energy center (NEC) conducted in support of the recently completed study by the Nuclear Regulatory Commission, mandated by the Congress in the Energy Reorganization Act of 1974. The intent of the analysis of the hypothetical, or ''surrogate'', site was to inject a local and regional perspective into the assessment of technical, environmental, institutional, and socioeconomic issues which could be adequately addressed only by reference to a specific site. The hypothetical NEC site in Ocean County, New Jersey, was chosen to illustrate the problems and impacts of potential energy centers in coastal and near-coastal sites in relatively close proximity to large metropolitan areas. Earlier studies of hypothetical energy centers on the Mississippi River at River Bend, La., and on the Columbia River near Hanford, Washington, were also re-examined for their relevance to this new study effort. Neither Ocean County, nor any of the other surrogate sites, have been considered for actual construction of an NEC, nor does their selection for study purposes imply any judgement of desirability. Indeed, the major finding of the report presented is that Ocean County is a relatively poor location for an energy center, and this may well be true of many coastal locations similar to the Jersey shore. The objective in selecting surrogate sites, then, was not to find the best locations, but to select sites that would illustrate the broadest range of potential public policy and siting issues

  7. Dispersal of the emerald ash borer, Agrilus planipennis, in newly-colonized sites

    Science.gov (United States)

    Rodrigo J. Mercader; Andrew M. Siegert; Andrew M. Liebhold; Deborah G. McCullough

    2009-01-01

    Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive forest insect pest threatening more than 8 billion ash (Fraxinus spp.) trees in North America. Development of effective survey methods and strategies to slow the spread of A. planipennis requires an understanding of dispersal...

  8. The effects of site, supplemental food, and age on survivorship of Carolina Chickadees and implications for dispersal through- riparian corridors

    Science.gov (United States)

    Doherty, P.F.; Grubb, T.G.

    2000-01-01

    Few studies have examined survivorship of animals in forest fragments differing in size, and none has used appropriate mark-recapture analysis techniques taking into account probability of recapture. Using Program MARK, a flexible mark-recapture software package, we estimated annual survival rates of Carolina Chickadees over a 5-yr period in a fragmented landscape in Ohio. The probability of survival was related to site (riparian woodland or woodlot area) and increased with the presence of supplemental food. While there was little evidence for an age difference in apparent survival in woodlots, young birds appeared to survive less well in forested river corridors. This last result was quite likely due, at least in part, to age-specific dispersal, suggesting that river corridors function as important dispersal routes for young birds.

  9. NKS NordRisk II: Atlas of long-range atmospheric dispersion and deposition of radionuclides from selected risk sites in the Northern Hemisphere

    DEFF Research Database (Denmark)

    Smith Korsholm, Ulrik; Astrup, Poul; Lauritzen, Bent

    The present atlas has been developed within the NKS/NordRisk-II project "Nuclear risk from atmospheric dispersion in Northern Europe". The atlas describes risks from hypothetical long-range dispersion and deposition of radionuclides from 16 nuclear risk sites on the Northern Hemisphere...... spanning the climate variability associated with the North Atlantic Oscillation, and corresponding time evolution of the ensemble mean atmospheric dispersion....

  10. The non-proliferation experiment and gas sampling as an on-site inspection activity: A progress report

    International Nuclear Information System (INIS)

    Carrigan, C.R.

    1994-03-01

    The Non-proliferation Experiment (NPE) is contributing to the development of gas sampling methods and models that may be incorporated into future on-site inspection (OSI) activities. Surface gas sampling and analysis, motivated by nuclear test containment studies, have already demonstrated the tendency for the gaseous products of an underground nuclear test to flow hundreds of meters to the surface over periods ranging from days to months. Even in the presence of a uniform sinusoidal pressure variation, there will be a net flow of cavity gas toward the surface. To test this barometric pumping effect at Rainier Mesa, gas bottles containing sulfur hexaflouride and 3 He were added to the pre-detonation cavity for the 1 kt chemical explosives test. Pre-detonation measurements of the background levels of both gases were obtained at selected sites on top of the mesa. The background levels of both tracers were found to be at or below mass spectrographic/gas chromatographic sensitivity thresholds in the parts-per-trillion range. Post-detonation, gas chromatographic analyses of samples taken during barometric pressure lows from the sampling sites on the mesa indicate the presence of significant levels (300--600 ppt) of sulfur hexaflouride. However, mass spectrographic analyses of gas samples taken to date do not show the presence of 3 He. To explain these observations, several possibilities are being explored through additional sampling/analysis and numerical modeling. For the NPE, the detonation point was approximately 400 m beneath the surface of Rainier Mesa and the event did not produce significant fracturing or subsidence on the surface of the mesa. Thus, the NPE may ultimately represent an extreme, but useful example for the application and tuning of cavity gas detection techniques

  11. Enhanced air dispersion modelling at a typical Chinese nuclear power plant site: Coupling RIMPUFF with two advanced diagnostic wind models.

    Science.gov (United States)

    Liu, Yun; Li, Hong; Sun, Sida; Fang, Sheng

    2017-09-01

    An enhanced air dispersion modelling scheme is proposed to cope with the building layout and complex terrain of a typical Chinese nuclear power plant (NPP) site. In this modelling, the California Meteorological Model (CALMET) and the Stationary Wind Fit and Turbulence (SWIFT) are coupled with the Risø Mesoscale PUFF model (RIMPUFF) for refined wind field calculation. The near-field diffusion coefficient correction scheme of the Atmospheric Relative Concentrations in the Building Wakes Computer Code (ARCON96) is adopted to characterize dispersion in building arrays. The proposed method is evaluated by a wind tunnel experiment that replicates the typical Chinese NPP site. For both wind speed/direction and air concentration, the enhanced modelling predictions agree well with the observations. The fraction of the predictions within a factor of 2 and 5 of observations exceeds 55% and 82% respectively in the building area and the complex terrain area. This demonstrates the feasibility of the new enhanced modelling for typical Chinese NPP sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Comparison between dispersed nuclear power plants and a nuclear energy center at a hypothetical site on Kentucky Lake, Tennessee. Volume I. Summary

    International Nuclear Information System (INIS)

    Burwell, C.C.; Reister, D.B.; Rosemarin, C.S.; Sisman, O.; Suffern, J.S.

    1976-05-01

    A brief summary is presented of the surrogate site concept used to compare the Nuclear Energy Center (NEC) concept with the present method of dispersed siting of nuclear power plants. Included are data on power transmission, environmental considerations, and a discussion of a site selection methodology

  13. Experimental and numerical study of atmospheric turbulence and dispersion in stable conditions and in near field at a complex site

    International Nuclear Information System (INIS)

    Wei, Xiao

    2016-01-01

    An experimental program has been designed in order to study pollutants dispersion at a complex site with a focus on stable conditions, which are still challenging for numerical modelling. This experimental program is being conducted at the SIRTA site in a southern suburb of Paris and consists in measuring, in near field, the turbulence and the pollutants dispersion. The aim of this program is to characterize the fine structure of turbulence and associated dispersion through high temporal and spatial resolution measurements. Then, these measurements allow to validate and improve the performance of CFD simulation for turbulence and dispersion in a heterogeneous field. The instrumental set up includes 12 ultrasonic anemometers measuring continuously wind velocity and temperature at 10 Hz, and 6 photo-ionization detectors (PIDs) measuring gas concentration at 50 Hz during tracer tests. Intensive observations periods (IOPs) with gas releases have been performed since March 2012. First of all, a detailed study of flow on the site is made, because it must be characterised and properly simulated before attempting to simulate the pollutants dispersion. This study is based on two years of continuous measurements and on measurements performed during IOPs. Turbulence strong anisotropy in the surface layer is characterized by calculating variances, integral length scales and power spectra of the three wind velocity components. Propagation of turbulent structures between sensors has been characterized with velocity correlations. Energy spectra show several slopes in different frequency regions. Also, data analyses show impact of terrain heterogeneity on the measurements. The forest to the north of the experimental field modifies wind velocity and direction for a large northerly sector. It induces a strong directional wind shear and a wind deceleration below the forest height. Numerical simulations are carried out using the CFD code, Code-Saturne, in RANS mode with a standard k

  14. Experimental and numerical study of atmospheric turbulence and dispersion in stable conditions and in near field at a complex site

    International Nuclear Information System (INIS)

    Wei, Xiao

    2016-01-01

    An experimental program has been designed in order to study pollutants dispersion at a complex site with a focus on stable conditions, which are still challenging for numerical modelling. This experimental program is being conducted at the SIRTA site in a southern suburb of Paris and consists in measuring, in near field, the turbulence and the pollutants dispersion. The aim of this program is to characterize the fine structure of turbulence and associated dispersion through high temporal and spatial resolution measurements. Then, these measurements allow to validate and improve the performance of CFD simulation for turbulence and dispersion in a heterogeneous field. The instrumental set up includes 12 ultrasonic anemometers measuring continuously wind velocity and temperature at 10 Hz, and 6 photo-ionization detectors (PIDs) measuring gas concentration at 50 Hz during tracer tests. Intensive observations periods (IOPs) with gas releases have been performed since March 2012.First of all, a detailed study of flow on the site is made, because it must be characterised and properly simulated before attempting to simulate the pollutants dispersion. This study is based on two years of continuous measurements and on measurements performed during IOPs. Turbulence strong anisotropy in the surface layer is characterized by calculating variances, integral length scales and power spectra of the three wind velocity components. Propagation of turbulent structures between sensors has been characterized with velocity correlations. Energy spectra show several slopes in different frequency regions. Also, data analyses show impact of terrain heterogeneity on the measurements. The forest to the north of experimental field modifies wind velocity and direction for a large northerly sector. It induces a strong directional wind shear and a wind deceleration below the forest height. Numerical simulations are carried out using the CFD code Code-Saturne in RANS mode with a standard κ

  15. Corrective Action Investigation Plan for Corrective Action Unit 366: Area 11 Plutonium Valley Dispersion Sites, Nevada National Security Site, Nevada

    International Nuclear Information System (INIS)

    Matthews, Patrick

    2011-01-01

    Corrective Action Unit 366 comprises the six corrective action sites (CASs) listed below: (1) 11-08-01, Contaminated Waste Dump No.1; (2) 11-08-02, Contaminated Waste Dump No.2; (3) 11-23-01, Radioactively Contaminated Area A; (4) 11-23-02, Radioactively Contaminated Area B; (5) 11-23-03, Radioactively Contaminated Area C; and (6) 11-23-04, Radioactively Contaminated Area D. These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed July 6, 2011, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 366. The presence and nature of contamination at CAU 366 will be evaluated based on information collected from a field investigation. Radiological contamination will be evaluated based on a comparison of the total effective dose (TED) at sample locations to the dose-based final action level (FAL). The TED will be calculated by summing the estimates of internal and external dose. Results from the analysis of soil samples collected from sample plots will be used to calculate internal radiological dose. Thermoluminescent dosimeters placed at each sample location will be used to measure external radiological dose. Based on historical documentation of the releases

  16. EFFAIR: a computer program for estimating the dispersion of atmospheric emissions from a nuclear site

    International Nuclear Information System (INIS)

    Dormuth, K.W.; Lyon, R.B.

    1978-11-01

    Analysis of the transport of material through the turbulent atmospheric boundary layer is an important part of environmental impact assessments for nuclear plants. Although this is a complex phenomenon, practical estimates of ground level concentrations downwind of release are usually obtained using a simple Gaussian formula whose coefficients are obtained from empirical correlations. Based on this formula, the computer program EFFAIR has been written to provide a flexible tool for atmospheric dispersion calculations. It is considered appropriate for calculating dilution factors at distances of 10 2 to 10 4 metres from an effluent source if reflection from the inversion lid is negligible in that range. (author)

  17. Simultaneous pore enlargement and introduction of highly dispersed Fe active sites in MSNs for enhanced catalytic activity

    International Nuclear Information System (INIS)

    Gu Jinlou; Dong Xu; Elangovan, S.P.; Li Yongsheng; Zhao Wenru; Iijima, Toshio; Yamazaki, Yasuo; Shi Jianlin

    2012-01-01

    An effective post-hydrothermal treatment strategy has been developed to dope highly dispersed iron catalytical centers into the framework of mesoporous silica, to keep the particle size in nanometric scale, and in the meanwhile, to expand the pore size of the synthesized mesoporous silica nanoparticles (MSNs). Characterization techniques such as XRD, BET, SEM and TEM support that the synthesized samples are long period ordered with particles size about 100 nm and a relatively large pore size of ca. 3.5 nm. UV–vis, XPS and EPR measurements demonstrate that the introduced iron active centers are highly dispersed in a coordinatively unsaturated status. NH 3 -TPD verifies that the acid amount of iron-doped MSNs is quite high. The synthesized nanocatalysts show an excellent catalytic performance for benzylation of benzene by benzyl chloride, and they present relatively higher yield and selectivity to diphenylmethane with a lower iron content and much shorter reaction time. - Graphical abstract: Uniform MSNs with iron active centers and large pore size have been prepared by a newly developed strategy, which demonstrates enhanced catalytic performance for benzylation of benzene by benzyl chloride. Highlights: ► Iron species were introduced into the framework of mesoporous silica nanoparticles with uniform dispersion. ► The pore sizes of the synthesized nanocatalysts were expanded. ► The acidic site quantities were quite high and the acidic centers were accessible. ► The nanocatalysts presented higher yield and selectivity to diphenylmethane with significantly lower Fe content.

  18. Closure Report for Corrective Action Unit 568: Area 3 Plutonium Dispersion Sites Nevada National Security Site, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick [Navarro, Las Vegas, NV (United States)

    2017-06-01

    The purpose of this CR is to provide documentation and justification that no further corrective action is needed for the closure of CAU 568 based on the implementation of corrective actions. This includes a description of closure activities that were performed and an evaluation of the verification data. The CAP (NNSA/NFO, 2016a) and ROTC-1 (NNSA/NFO, 2016c) provide information relating to the selection of CAAs and the reasoning behind their selection. The CADD (NNSA/NFO, 2015) identifies the release sites that require additional corrective action and presents information supporting the selection of CAAs.

  19. Radioactive cesium isotope ratios as a tool for determining dispersal and re-dispersal mechanisms downwind from the Nevada Nuclear Security Site.

    Science.gov (United States)

    Snyder, Darin C; Delmore, James E; Tranter, Troy; Mann, Nick R; Abbott, Michael L; Olson, John E

    2012-08-01

    Fractionation of the two longer-lived radioactive cesium isotopes ((135)Cs and (137)Cs) produced by above ground nuclear tests have been measured and used to clarify the dispersal mechanisms of cesium deposited in the area between the Nevada Nuclear Security Site and Lake Mead in the southwestern United States. Fractionation of these isotopes is due to the 135-decay chain requiring several days to completely decay to (135)Cs, and the 137-decay chain less than one hour decay to (137)Cs. Since the Cs precursors are gases, iodine and xenon, the (135)Cs plume was deposited farther downwind than the (137)Cs plume. Sediment core samples were obtained from the Las Vegas arm of Lake Mead, sub-sampled and analyzed for (135)Cs/(137)Cs ratios by thermal ionization mass spectrometry. The layers proved to have nearly identical highly fractionated isotope ratios. This information is consistent with a model where the cesium was initially deposited onto the land area draining into Lake Mead and the composite from all of the above ground shots subsequently washed onto Lake Mead by high intensity rain and wind storms producing a layering of Cs activity, where each layer is a portion of the composite. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Corrective Action Decision Document for Corrective Action Unit 366: Area 11 Plutonium Valley Dispersion Sites Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Matthews

    2012-09-01

    CAU 366 comprises six corrective action sites (CASs): • 11-08-01, Contaminated Waste Dump #1 • 11-08-02, Contaminated Waste Dump #2 • 11-23-01, Radioactively Contaminated Area A • 11-23-02, Radioactively Contaminated Area B • 11-23-03, Radioactively Contaminated Area C • 11-23-04, Radioactively Contaminated Area D The purpose of this CADD is to identify and provide the rationale for the recommendation of corrective action alternatives (CAA) for the six CASs within CAU 366. Corrective action investigation (CAI) activities were performed from October 12, 2011, to May 14, 2012, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 366: Area 11 Plutonium Valley Dispersion Sites.

  1. Should high-level nuclear waste be disposed of at geographically dispersed sites?

    International Nuclear Information System (INIS)

    Bassett, G.W. Jr.

    1992-01-01

    Consideration of the technical feasibility of Yucca Mountain in Nevada as the site for a high-level nuclear waste repository has led to an intense debate regarding the economic, social, and political impacts of the repository. Impediments to the siting process mean that the nuclear waste problem is being resolved by adhering to the status quo, in which nuclear waste is stored at scattered sites near major population centers. To assess the merits of alternative siting strategies--including both the permanent repository and the status quo- we consider the variables that would be included in a model designed to select (1) the optimal number of disposal facilities, (2) the types of facilities (e.g., permanent repository or monitored retrievable facility), and (3) the geographic location of storage sites. The objective function in the model is an all-inclusive measure of social cost. The intent of the exercise is not to demonstrate the superiority of any single disposal strategy; uncertainties preclude a conclusive proof of optimality for any of the disposal options. Instead, we want to assess the sensitivity of a variety of proposed solutions to variations in the physical, economic, political, and social variables that influence a siting strategy

  2. A comparison of models to assess the atmospheric dispersion of resuspended radionuclides on the Nevada Test Site

    International Nuclear Information System (INIS)

    Green, J.R.; Eckart, R.E.

    1994-11-01

    A study of computer codes was made to determine the suitability of their use for modeling radionuclide dispersion from attachment to fugitive dust at the GMX safety shot area of the Nevada Test site. Two codes, the Industrial Source Complex 2 Long Term Model (ISCLT2) and the Fugitive Dust Model (FDM), were subsequently chosen to model the GMX site. Dose calculations were performed using the output values generated by the computer codes. The concentration values produced by the two codes were within a factor of two of each other and were not significantly different. The FDM, however, was felt to be a more useful code for use in calculating doses caused by attachment to fugitive dust

  3. Speciation dynamics of metals in dispersion of nanoparticles with discrete distribution of charged binding sites.

    Science.gov (United States)

    Polyakov, Pavel D; Duval, Jérôme F L

    2014-02-07

    We report a comprehensive theory to evaluate the kinetics of complex formation between metal ions and charged spherical nanoparticles. The latter consist of an ion-impermeable core surrounded by a soft shell layer characterized by a discrete axisymmetric 2D distribution of charged sites that bind metal ions. The theory explicitly integrates the conductive diffusion of metal ions from bulk solution toward the respective locations of the reactive sites within the particle shell volume. The kinetic constant k for outer-sphere nanoparticle-metal association is obtained from the sum of the contributions stemming from all reactive sites, each evaluated from the corresponding incoming flux of metal ions derived from steady-state Poisson-Nernst-Planck equations. Illustrations are provided to capture the basic intertwined impacts of particle size, overall particle charge, spatial heterogeneity in site distribution, type of particle (hard, core-shell or porous) and concentration of the background electrolyte on k. As a limit, k converges with predictions from previously reported analytical expressions derived for porous particles with low and high charge density, cases that correspond to coulombic and mean-field (smeared-out) electrostatic treatments, respectively. The conditions underlying the applicability of these latter approaches are rigorously identified in terms of (i) the extent of overlap between electric double layers around charged neighbouring sites, and (ii) the magnitude of the intraparticulate metal concentration gradient. For the first time, the proposed theory integrates the differentiated impact of the local potential around the charged binding sites amidst the overall particle field, together with that of the so-far discarded intraparticulate flux of metal ions.

  4. Nuclear Energy Center: upper St. Lawrence region. Part I. Siting. Part II. Fort Drum surrogate site, description and impact assessment. Part III. Dispersed sites impact assessment and comparison with the NEC

    Energy Technology Data Exchange (ETDEWEB)

    Merry, P.A.; Luner, C.; Hong, S.W.; Canham, H.O.; Boggs, J.F.; McCool, T.P.

    1976-12-01

    This report is one of many supporting documents used by the Nuclear Regulatory commission in the preparation of the Nuclear Energy Center Site Survey (NECSS) mandated by Congress. While the overall study focuses on the feasibility and practicability of nuclear energy centers (NECs), this report is directed towards choosing a suitable surrogate site in the upper St. Lawrence region of New York State, assessing the probable impacts associated with construction and operation of the NEC, and comparing these impacts with those associated with small dispersed nuclear power stations. The upper St. Lawrence region is surveyed to identify a specific site that might be suitable for a surrogate NEC. Several assumptions about the basic design of an NEC are delineated, and a general overview of the characteristics of the region is given. The Fort Drum Military Reservation is chosen as a suitable surrogate site. Fort Drum and the surrounding area are described in terms of land use and population patterns, terrestrial and aquatic ecology, water use and quality, meteorology, institutional framework, and socioeconomic structure. The impacts associated with NEC development are assessed. Then the impacts associated with smaller dispersed nuclear power stations located throughout New York State are assessed and compared with the impacts associated with the NEC. Finally, the impacts due to development of the transmission line networks associated with the NEC and with the dispersed power stations are assessed and compared.

  5. Post-fledging dispersal of king penguins (Aptenodytes patagonicus from two breeding sites in the South Atlantic.

    Directory of Open Access Journals (Sweden)

    Klemens Pütz

    Full Text Available Most studies concerning the foraging ecology of marine vertebrates are limited to breeding adults, although other life history stages might comprise half the total population. For penguins, little is known about juvenile dispersal, a period when individuals may be susceptible to increased mortality given their naïve foraging behaviour. Therefore, we used satellite telemetry to study king penguin fledglings (n = 18 from two sites in the Southwest Atlantic in December 2007. The two sites differed with respect to climate and proximity to the Antarctic Polar Front (APF, a key oceanographic feature generally thought to be important for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice. Three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. Derived tracking parameters describing their migratory behaviour showed no significant differences between sites. Nevertheless, generalized linear habitat modelling revealed that juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of chlorophyll. Our results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adaptations to the environment around their prospective breeding site.

  6. Post-fledging dispersal of king penguins (Aptenodytes patagonicus) from two breeding sites in the South Atlantic.

    Science.gov (United States)

    Pütz, Klemens; Trathan, Phil N; Pedrana, Julieta; Collins, Martin A; Poncet, Sally; Lüthi, Benno

    2014-01-01

    Most studies concerning the foraging ecology of marine vertebrates are limited to breeding adults, although other life history stages might comprise half the total population. For penguins, little is known about juvenile dispersal, a period when individuals may be susceptible to increased mortality given their naïve foraging behaviour. Therefore, we used satellite telemetry to study king penguin fledglings (n = 18) from two sites in the Southwest Atlantic in December 2007. The two sites differed with respect to climate and proximity to the Antarctic Polar Front (APF), a key oceanographic feature generally thought to be important for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia) migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice. Three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. Derived tracking parameters describing their migratory behaviour showed no significant differences between sites. Nevertheless, generalized linear habitat modelling revealed that juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of chlorophyll. Our results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adaptations to the environment around their prospective breeding site.

  7. NKS NordRisk II: Atlas of long-range atmospheric dispersion and deposition of radionuclides from selected risk sites in the Northern Hemisphere

    International Nuclear Information System (INIS)

    Smith Korsholm, U.; Havskov Soerensen, J.; Astrup, P.; Lauritzen, B.

    2011-04-01

    The present atlas has been developed within the NKS/NordRisk-II project 'Nuclear risk from atmospheric dispersion in Northern Europe'. The atlas describes risks from hypothetical long-range dispersion and deposition of radionuclides from 16 nuclear risk sites on the Northern Hemisphere. The atmospheric dispersion model calculations cover a period of 30 days following each release to ensure almost complete deposition of the dispersed material. The atlas contains maps showing the total deposition and time-integrated air concentration of Cs-137 and I-131 based on three years of meteorological data spanning the climate variability associated with the North Atlantic Oscillation, and corresponding time evolution of the ensemble mean atmospheric dispersion. (Author)

  8. NKS NordRisk II: Atlas of long-range atmospheric dispersion and deposition of radionuclides from selected risk sites in the Northern Hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Smith Korsholm, U.; Havskov Soerensen, J. (Danish Meteorological Institute (DMI), Copenhagen (Denmark)); Astrup, P.; Lauritzen, B. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy. Radiation Research Div., Roskilde (Denmark))

    2011-04-15

    The present atlas has been developed within the NKS/NordRisk-II project 'Nuclear risk from atmospheric dispersion in Northern Europe'. The atlas describes risks from hypothetical long-range dispersion and deposition of radionuclides from 16 nuclear risk sites on the Northern Hemisphere. The atmospheric dispersion model calculations cover a period of 30 days following each release to ensure almost complete deposition of the dispersed material. The atlas contains maps showing the total deposition and time-integrated air concentration of Cs-137 and I-131 based on three years of meteorological data spanning the climate variability associated with the North Atlantic Oscillation, and corresponding time evolution of the ensemble mean atmospheric dispersion. (Author)

  9. The field tracer test study of atmospheric dispersion in Fujian Huian Nuclear Power Plant site

    International Nuclear Information System (INIS)

    Hu Erbang; Xin Cuntian; Yan Jiangyu; Ren Zhiqiang; Xuan Yiren; Jia Peirong

    2003-01-01

    The SF 6 tracer tests and its main results completed in site of Fujian Huian Nuclear Power Plant during summer, 2002, are described. A total of 15 times of SF 6 tracer tests were done in the July, in which the time of atmospheric stability B, C, D, E is respectively 3, 2, 9, 1 based on ΔT-U method and the time of B, D, E is respectively 1, 11, 3 based on ΔT method. About 50 samples were collected in each SF 6 tracer tests, the maximum of sample distance from the tower in which the SF 6 tracer was released is about 15 km. The values of p y , p z , q y , q z in the formula of diffusion parameters is determined. Finally the above diffusion parameters are compared with P-G curve, Briggs diffusion parameters and those obtained from turbulence observation and wind tunnel simulation test done in the past time. (authors)

  10. Aspects of benthic decapod diversity and distribution from rocky nearshore habitat at geographically widely dispersed sites.

    Directory of Open Access Journals (Sweden)

    Gerhard Pohle

    Full Text Available Relationships of diversity, distribution and abundance of benthic decapods in intertidal and shallow subtidal waters to 10 m depth are explored based on data obtained using a standardized protocol of globally-distributed samples. Results indicate that decapod species richness overall is low within the nearshore, typically ranging from one to six taxa per site (mean = 4.5. Regionally the Gulf of Alaska decapod crustacean community structure was distinguishable by depth, multivariate analysis indicating increasing change with depth, where assemblages of the high and mid tide, low tide and 1 m, and 5 and 10 m strata formed three distinct groups. Univariate analysis showed species richness increasing from the high intertidal zone to 1 m subtidally, with distinct depth preferences among the 23 species. A similar depth trend but with peak richness at 5 m was observed when all global data were combined. Analysis of latitudinal trends, confined by data limitations, was equivocal on a global scale. While significant latitudinal differences existed in community structure among ecoregions, a semi-linear trend in changing community structure from the Arctic to lower latitudes did not hold when including tropical results. Among boreal regions the Canadian Atlantic was relatively species poor compared to the Gulf of Alaska, whereas the Caribbean and Sea of Japan appeared to be species hot spots. While species poor, samples from the Canadian Atlantic were the most diverse at the higher infraordinal level. Linking 11 environmental variables available for all sites to the best fit family-based biotic pattern showed a significant relationship, with the single best explanatory variable being the level of organic pollution and the best combination overall being organic pollution and primary productivity. While data limitations restrict conclusions in a global context, results are seen as a first-cut contribution useful in generating discussion and more in

  11. NKS NordRisk. Atlas of long-range atmospheric dispersion and deposition of radionuclides from selected risk sites in the Northern Hemisphere

    International Nuclear Information System (INIS)

    Havskov Soerensen, J.; Baklanov, A.; Mahura, A.; Lauritzen, Bent; Mikkelsen, Torben

    2008-07-01

    Within the NKS NordRisk project, 'Nuclear risk from atmospheric dispersion in Northern Europe', the NKS NordRisk Atlas has been developed. The atlas describes risks from hypothetical long-range atmospheric dispersion and deposition of radionuclides from selected nuclear risk sites in the Northern Hemisphere. A number of case studies of long-term long-range atmospheric transport and deposition of radionuclides has been developed, based on two years of meteorological data. Radionuclide concentrations in air and radionuclide depositions have been evaluated and examples of long-term averages of the dispersion and deposition and of the variability around these mean values are provided. (au)

  12. NKS NordRisk. Atlas of long-range atmospheric dispersion and deposition of radionuclides from selected risk sites in the Northern Hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Havskov Soerensen, J.; Baklanov, A.; Mahura, A. (Danish Meteorological Institute, Copenhagen (Denmark)); Lauritzen, Bent; Mikkelsen, Torben (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark))

    2008-07-15

    Within the NKS NordRisk project, 'Nuclear risk from atmospheric dispersion in Northern Europe', the NKS NordRisk Atlas has been developed. The atlas describes risks from hypothetical long-range atmospheric dispersion and deposition of radionuclides from selected nuclear risk sites in the Northern Hemisphere. A number of case studies of long-term long-range atmospheric transport and deposition of radionuclides has been developed, based on two years of meteorological data. Radionuclide concentrations in air and radionuclide depositions have been evaluated and examples of long-term averages of the dispersion and deposition and of the variability around these mean values are provided. (au)

  13. 14C-dopamine microinjected into the brain-stem of the rat: dispersion kinetics, site content and functional dose

    International Nuclear Information System (INIS)

    Myers, R.D.; Hoch, D.B.

    1978-01-01

    A morphological analysis was undertaken of both the dispersion characteristics and tissue content of dopamine (DA) microinjected acutely into the brain-stem of the anesthetized rat. 14C-DA, with a specific activity of 56-62 mCi/mMol, was infused unilaterally into the pars compacta of the substantia nigra in one of four test volumes: 0.5, 1.0, 4.0 or 8.0 microliters. The concentration of the 14C-DA solution was 1.0 microCi/microliter, equivalent to 3.01 micrograms/microliters, which was delivered at an injection rate of 1.0 microliter per 45 sec. At an interval of either one min or 15 min following the microinjection, the rat's brain was removed rapidly from its calvarium, flash frozen and then cut in the coronal plane on a freezing microtome in 500 micron slabs. After each of the respective serial slabs was mounted on glass, the Eik Nes-Brizzee trochar technique for the discrete removal of tissue samples was used to obtain 0.5 mm dia. cylindrical plugs of meso-diencephalic tissue at distances from the site of injection ranging from 0.5 to 2.5 mm, center to center. Each sample plug was subsequently solubilized and 14C-DA activity quantitated by liquid scintillation spectrometry. The results show that regardless of volume, the spatial patterning of the microinjected solution assumes a tear-drop or pear shape, not a sphere. Further, as the volume of the injection is increased from 0.5 to 8.0 microliters, the magnitude of the dispersion of 14C-DA is enhanced throughout the surrounding parenchyma, but not in a linear fashion

  14. Abstracts of 3. International scientific-practical conference 'Semipalatinsk Test Site. Radiation Legacy and Non-proliferation Issues'

    International Nuclear Information System (INIS)

    2008-01-01

    The Conference gathered representatives of more than 25 countries and international organizations. In the Conference among with actual problems of current environment conditions in Kazakhstan, perspective trends in the field of radiation protection, radio-ecological and radiobiological research and issues of international co-operation in support of non-proliferation regime, other advanced scientific projects were considered [ru

  15. Corrective Action Decision Document for Corrective Action Unit 568. Area 3 Plutonium Dispersion Sites, Nevada National Security Site, Nevada Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick [Nevada Field Ofice, Las Vegas, NV (United States). National Nuclear Security Administration

    2015-08-01

    The purpose of this Corrective Action Decision Document is to identify and provide the rationale for the recommendation of corrective action alternatives (CAAs) for the 14 CASs within CAU 568. Corrective action investigation (CAI) activities were performed from April 2014 through May 2015, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 568: Area 3 Plutonium Dispersion Sites, Nevada National Security Site, Nevada; and in accordance with the Soils Activity Quality Assurance Plan, which establishes requirements, technical planning, and general quality practices. The purpose of the CAI was to fulfill data needs as defined during the DQO process. The CAU 568 dataset of investigation results was evaluated based on a data quality assessment. This assessment demonstrated that the dataset is complete and acceptable for use in fulfilling the DQO data needs. Based on the evaluation of analytical data from the CAI, review of future and current operations at the 14 CASs, and the detailed and comparative analysis of the potential CAAs, the following corrective actions are recommended for CAU 568: • No further action is the preferred corrective action for CASs 03-23-17, 03-23-22, 03-23-26. • Closure in place is the preferred corrective action for CAS 03-23-19; 03-45-01; the SE DCBs at CASs 03-23-20, 03-23-23, 03-23-31, 03-23-32, 03-23-33, and 03-23-34; and the Pascal-BHCA at CAS 03-23-31. • Clean closure is the preferred corrective action for CASs 03-08-04, 03-23-30, and 03-26-04; and the four well head covers at CASs 03-23-20, 03-23-23, 03-23-31, and 03-23-33.

  16. Dispersal of estradiol-17 beta from the site of injection in the pectoral muscles of Japanese quail

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, G.A.

    1985-09-01

    Exogenous estrogens, if given in sufficient quantity, stimulate vitellogenesis in the males of vitellogenic species. In the present study, ethanolic solutions of estradiol-17 beta (E2), labeled with 16-alpha-( SVI)iodoestradiol (( SVI)E2) or sodium iodide (Na SVI), were injected into the pectoral muscles of male Japanese quail. The rate of dispersal of the estradiol from the site of injection was measured in vivo during 4 days. The curves of radioactivity appeared to be diphasic. The dose percentages forming the second phase of these curves and the half-time for the second phase were: for 16 mumol E2 (( SVI)E2 label)/100 g body weight, 84.6% and 27.6 hr; for 6 pmol ( SVI)E2/100 g, 20.0% and 17.2 hr; for 16 mumol E2 (Na SVI label)/100 g, 6.7% and 99.0 hr, and for Na SVI, 6.1% and 83.1 hr. Thus, in male quail the estradiol-induced stimulation of vitellogenesis apparently resulted from a continuing hormonal pressure on the liver during the period of study and not from a rapid flow of E2 to the liver shortly after injection.

  17. Fissile material proliferation risk

    International Nuclear Information System (INIS)

    Dreicer, J.S.; Rutherford, D.A.

    1996-01-01

    The proliferation risk of a facility depends on the material attractiveness, level of safeguards, and physical protection applied to the material in conjunction with an assessment of the impact of the socioeconomic circumstances and threat environment. Proliferation risk is a complementary extension of proliferation resistance. The authors believe a better determination of nuclear proliferation can be achieved by establishing the proliferation risk for facilities that contain nuclear material. Developing a method that incorporates the socioeconomic circumstances and threat environment inherent to each country enables a global proliferation assessment. To effectively reduce the nuclear danger, a broadly based set of criteria is needed that provides the capability to relatively assess a wide range of nuclear related sites and facilities in different countries and still ensure a global decrease in proliferation risk for fissile material (plutonium and highly enriched uranium)

  18. THE INTERPLAY BETWEEN GEOCHEMICAL REACTIONS AND ADVECTION-DISPERSION IN CONTAMINANT TRANSPORT AT A URANIUM MILL TAILINGS SITE

    Science.gov (United States)

    It is well known that the fate and transport of contaminants in the subsurface are controlled by complex processes including advection, dispersion-diffusion, and chemical reactions. However, the interplay between the physical transport processes and chemical reactions, and their...

  19. Dispersal and life span spectra in plant communities : a key to safe site dynamics, species coexistence and conservation

    NARCIS (Netherlands)

    Strykstra, RJ; Bekker, RM; Van Andel, J

    Dispersal and life span of individual plant species within five plant communities were assessed to obtain a characterization of these communities in this respect. Such a characterization is important in the context of restoration and maintenance. The most frequent species of five communities were

  20. Dispersion of radioactive material in air and water and consideration of population distribution in site evaluation for nuclear power plants. Safety guide

    International Nuclear Information System (INIS)

    2002-01-01

    The IAEA issues Safety Requirements and Safety Guides pertaining to nuclear power plants and activities in the field of nuclear energy, on the basis of its Safety Fundamentals publication on The Safety of Nuclear Installations. The present Safety Guide, which supplements the Code on the Safety of Nuclear Power Plants: Siting, concerns the effects of a nuclear power plant on the surrounding region and the consideration of population distribution in the siting of a plant. This Safety Guide makes recommendations on how to meet the requirements of the Code on the Safety of Nuclear Power Plants: Siting, on the basis of knowledge of the mechanisms for the dispersion of effluents discharged into the atmosphere and into surface water and groundwater. Relevant site characteristics and safety considerations are discussed. Population distribution, the projected population growth rate, particular geographical features, the capabilities of local transport networks and communications networks, industry and agriculture in the region, and recreational and institutional activities in the region should be considered in assessing the feasibility of developing an emergency response plan. In the selection of a site for a facility using radioactive material, such as a nuclear power plant, account should be taken of any local features that might be affected by the facility and of the feasibility of off-site intervention, including emergency response and protective actions. This is in addition to the evaluation of any features of the site itself that might affect the safety of the facility. This Safety Guide recommends methods for the assessment of regional and local characteristics. This Safety Guide supersedes four earlier IAEA Safety Guides, namely: Atmospheric Dispersion in Nuclear Power Plant Siting (Safety Series No. 50-SG-S3 (1980)); Site Selection and Evaluation for Nuclear Power Plants with Respect to Population Distribution (Safety Series No. 50-SG-S4 (1980)); Hydrological

  1. Dispersion of radioactive material in air and water and consideration of population distribution in site evaluation for nuclear power plants. Safety guide

    International Nuclear Information System (INIS)

    2004-01-01

    The IAEA issues Safety Requirements and Safety Guides pertaining to nuclear power plants and activities in the field of nuclear energy, on the basis of its Safety Fundamentals publication on The Safety of Nuclear Installations. The present Safety Guide, which supplements the Code on the Safety of Nuclear Power Plants: Siting, concerns the effects of a nuclear power plant on the surrounding region and the consideration of population distribution in the siting of a plant. This Safety Guide makes recommendations on how to meet the requirements of the Code on the Safety of Nuclear Power Plants: Siting, on the basis of knowledge of the mechanisms for the dispersion of effluents discharged into the atmosphere and into surface water and groundwater. Relevant site characteristics and safety considerations are discussed. Population distribution, the projected population growth rate, particular geographical features, the capabilities of local transport networks and communications networks, industry and agriculture in the region, and recreational and institutional activities in the region should be considered in assessing the feasibility of developing an emergency response plan. In the selection of a site for a facility using radioactive material, such as a nuclear power plant, account should be taken of any local features that might be affected by the facility and of the feasibility of off-site intervention, including emergency response and protective actions. This is in addition to the evaluation of any features of the site itself that might affect the safety of the facility. This Safety Guide recommends methods for the assessment of regional and local characteristics. This Safety Guide supersedes four earlier IAEA Safety Guides, namely: Atmospheric Dispersion in Nuclear Power Plant Siting (Safety Series No. 50-SG-S3 (1980)). Site Selection and Evaluation for Nuclear Power Plants with Respect to Population Distribution (Safety Series No. 50-SG-S4 (1980)). Hydrological

  2. Characterization of Roman glass tesserae from the Coriglia excavation site (Italy) via energy-dispersive X-ray fluorescence spectrometry and Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Donais, Mary Kate; Sparks, Andrew; Redente, Monica [Saint Anselm College, Department of Chemistry, Manchester, NH (United States); Pevenage, Jolien van; Moens, Luc; Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, Ghent (Belgium); George, David B. [Saint Anselm College, Department of Classics, Manchester, NH (United States); Vandenabeele, Peter [Ghent University, Department of Archaeology, Ghent (Belgium)

    2016-12-15

    The combined use of handheld energy-dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and micro-energy-dispersive X-ray fluorescence spectrometry permitted the characterization of Roman glass tesserae excavation from the Coriglia (Italy) archeological site. Analyses of ten different glass colors were conducted as spot analyses on intact samples and as both spot analyses and line scans on select cross-sectioned samples. The elemental and molecular information gained from these spectral measurements allowed for the qualitative chemical characterization of the bulk glass, decolorants, opacifiers, and coloring agents. The use of an antimony opacifier in many of the samples supports the late Imperial phasing as determined through numismatic, fresco, ceramics, and architectural evidence. And dealinization of the exterior glass layers caused by the burial environment was confirmed. (orig.)

  3. A first possible chameleon from the late Miocene of India (the hominoid site of Haritalyangar): a tentative evidence for an Asian dispersal of chameleons.

    Science.gov (United States)

    Sankhyan, Anek R; Čerňanský, Andrej

    2016-12-01

    Miocene rare fossils from India, tentatively attributed to chameleons, are described for the first time. The material consists of a fragment of the left squamosal and an element interpreted as a posterodorsal process of the parietal. The specimens come from a late Miocene site of the Nagri Formation (Middle Siwaliks, ~ 9 Mya) at Haritalyangar, North India. This material presents a possible evidence for a chameleon dispersal to Asia. Based on molecular data, the dispersion of an Asian chamaeleonid lineage from Africa to Arabia/Asia is dated at approximately 13 Mya and its diversification in situ at around 6-8 Mya. However, till now, no Miocene-age fossil record has been described to support crown chamaeleonid presence in this area. The material described herein is very fragmented. If correctly allocated, the Haritalyangar chameleons show the oldest known occurrence of this clade in India, at least approximately 9 Mya ago.

  4. A comparison between dispersed nuclear power plants and a nuclear energy center at a hypothetical site on Kentucky Lake, Tennessee. Vol. III. Environmental considerations

    International Nuclear Information System (INIS)

    Fitzpatrick, F.C.; Gray, D.D.; Hyndman, J.R.; Sisman, O.; Suffern, J.S.; Tyrrell, P.A.; West, D.C.

    1976-02-01

    The thermal, ecological, and social impacts of a 40-reactor NEC are compared to impacts from four 10-reactor NECs and ten 4-reactor power plants. The comparison was made for surrogate sites in western Tennessee. The surrogate site for the 40-reactor NEC is located on Kentucky Lake. A layout is postulated for ten clusters of four reactors each with 2.5-mile spacing between clusters. The plants use natural-draft cooling towers. A transmission system is proposed for delivering the power (48,000 MW) to five load centers. Comparable transmission systems are proposed for the 10-reactor NECs and the 4-reactor dispersed sites delivering power to the same load centers.

  5. A study on atmospheric dispersion around Kalpakkam coastal site using a non-hydrostatic model and comparison with field data

    International Nuclear Information System (INIS)

    Jamima, P.; Lakshminarasimhan, J.; Venkatesan, R.

    2002-01-01

    Study of the sea breeze characteristics and Thermal Internal Boundary Layer (TIBL) is very important to understand the dispersion characteristics of air pollutants near coastal area. In the present paper, dispersion characteristics near Kalpakkam coastal area are studied and discussed by simulating sea breeze characteristics and TIBL using a non-hydrostatic mesoscale model in its two dimensional form. The model is run with surface physics, simplified radiation physics and turbulent kinetic energy (TKE) closure scheme for diffusion. A joint meteorological field experiment was carried out by IITM-Pune at Kalpakkam by deploying state of art sensors and tether balloon systems for observing the height profiles of meteorological parameters. The data taken from the field experiment is used here to compare the simulations. Results shows that the onset of sea breeze is one hour before as observed from the field experiment. Slight difference is also seen in wind speed and temperature. Spatial variation of the dispersion pattern could be understood from the simulated TKE profile. From the study, it is shown that the model gives only a over all picture of the real scenario and successful simulations require the inclusion of more atmospheric dynamics such as microphysics, cumulus parameterization and atmospheric radiation. (author)

  6. Experimental study of a model and parameters calculating annual mean atmospheric dispersion factor for a nuclear power plant to be build in coastal site

    International Nuclear Information System (INIS)

    Hu Erbang; Chen Jiayi; Zhang Maoshuan; Gao Zhanrong; Yao Rentai; Jia Peirong; Qiao Qingdang

    1999-01-01

    The author tries to develop a new model calculating annual mean atmospheric dispersion factor for a nuclear power plant to be build in coastal site based on field experiments. This model considers not only the difference between shore ward and off-shore but also the comprehensive effect of following factors: mixed layer and thermal internal boundary layer, mixing release and variation of diffusion parameters due to the distance from coast and so on. The various parameters needed in the model are obtained from the field atmospheric experiments done on the NPP site during 1995∼1996. There dimension joint frequency is got from wind and temperature measurements at 4 heights of a tower of 100 m; diffusion parameters shore ward and off-shore from turbulent measurement and wind tunnel simulation test; the parameters relative to sea and land breeze and thermal internal boundary layer are obtained from tests with low altitude radiosonde and lost balloon at 3 sites during two periods of Summer and Winter. Finally a comparison of the results given by this model and commonly used model provided by relative guides is done. The comparison shows that about 1 times under estimation is found for the maximum of annual mean atmospheric dispersion factor in common model because the effect from thermal internal boundary layer and other factors are neglected

  7. Sleeping sites and latrines of spider monkeys in continuous and fragmented rainforests: implications for seed dispersal and forest regeneration.

    Directory of Open Access Journals (Sweden)

    Arturo González-Zamora

    Full Text Available Spider monkeys (Ateles geoffroyi use sites composed of one or more trees for sleeping (sleeping sites and sleeping trees, respectively. Beneath these sites/trees they deposit copious amounts of dung in latrines. This behavior results in a clumped deposition pattern of seeds and nutrients that directly impacts the regeneration of tropical forests. Therefore, information on the density and spatial distribution of sleeping sites and latrines, and the characteristics (i.e., composition and structure of sleeping trees are needed to improve our understanding of the ecological significance of spider monkeys in influencing forest composition. Moreover, since primate populations are increasingly forced to inhabit fragmented landscapes, it is important to assess if these characteristics differ between continuous and fragmented forests. We assessed this novel information from eight independent spider monkey communities in the Lacandona rainforest, Mexico: four continuous forest sites and four forest fragments. Both the density of sleeping sites and latrines did not differ between forest conditions. Latrines were uniformly distributed across sleeping sites, but the spatial distribution of sleeping sites within the areas was highly variable, being particularly clumped in forest fragments. In fact, the average inter-latrine distances were almost double in continuous forest than in fragments. Latrines were located beneath only a few tree species, and these trees were larger in diameter in continuous than fragmented forests. Because latrines may represent hotspots of seedling recruitment, our results have important ecological and conservation implications. The variation in the spatial distribution of sleeping sites across the forest indicates that spider monkeys likely create a complex seed deposition pattern in space and time. However, the use of a very few tree species for sleeping could contribute to the establishment of specific vegetation associations

  8. Sleeping sites and latrines of spider monkeys in continuous and fragmented rainforests: implications for seed dispersal and forest regeneration.

    Science.gov (United States)

    González-Zamora, Arturo; Arroyo-Rodríguez, Víctor; Oyama, Ken; Sork, Victoria; Chapman, Colin A; Stoner, Kathryn E

    2012-01-01

    Spider monkeys (Ateles geoffroyi) use sites composed of one or more trees for sleeping (sleeping sites and sleeping trees, respectively). Beneath these sites/trees they deposit copious amounts of dung in latrines. This behavior results in a clumped deposition pattern of seeds and nutrients that directly impacts the regeneration of tropical forests. Therefore, information on the density and spatial distribution of sleeping sites and latrines, and the characteristics (i.e., composition and structure) of sleeping trees are needed to improve our understanding of the ecological significance of spider monkeys in influencing forest composition. Moreover, since primate populations are increasingly forced to inhabit fragmented landscapes, it is important to assess if these characteristics differ between continuous and fragmented forests. We assessed this novel information from eight independent spider monkey communities in the Lacandona rainforest, Mexico: four continuous forest sites and four forest fragments. Both the density of sleeping sites and latrines did not differ between forest conditions. Latrines were uniformly distributed across sleeping sites, but the spatial distribution of sleeping sites within the areas was highly variable, being particularly clumped in forest fragments. In fact, the average inter-latrine distances were almost double in continuous forest than in fragments. Latrines were located beneath only a few tree species, and these trees were larger in diameter in continuous than fragmented forests. Because latrines may represent hotspots of seedling recruitment, our results have important ecological and conservation implications. The variation in the spatial distribution of sleeping sites across the forest indicates that spider monkeys likely create a complex seed deposition pattern in space and time. However, the use of a very few tree species for sleeping could contribute to the establishment of specific vegetation associations typical of the

  9. Corrective Action Investigation Plan for Corrective Action Unit 571: Area 9 Yucca Flat Plutonium Dispersion Sites, Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Bernadine; Matthews, Patrick

    2013-07-01

    CAU 571 is a grouping of sites where there has been a suspected release of contamination associated with nuclear testing. This document describes the planned investigation of CAU 571, which comprises the following corrective action sites (CASs): • 09-23-03, Atmospheric Test Site S-9F • 09-23-04, Atmospheric Test Site T9-C • 09-23-12, Atmospheric Test Site S-9E • 09-23-13, Atmospheric Test Site T-9D • 09-45-01, Windrows Crater These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the investigation report. The sites will be investigated based on the data quality objectives (DQOs) developed on March 6, 2013, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (now the Nevada Field Office). The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 571. The site investigation process will also be conducted in accordance with the Soils Activity Quality Assurance Plan, which establishes requirements, technical planning, and general quality practices to be applied to this activity. The potential contamination sources associated with CAU 571 CASs are from nuclear testing activities. The DQO process resulted in an assumption that total effective dose (TED) within a default contamination boundary exceeds the final action level (FAL) and requires corrective action. The presence and nature of contamination outside the default

  10. Corrective Action Investigation Plan for Corrective Action Unit 568: Area 3 Plutonium Dispersion Sites Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick

    2014-01-01

    CAU 568 is a grouping of sites where there has been a suspected release of contamination associated with nuclear testing. This document describes the planned investigation of CAU 568, which comprises the following corrective action sites (CASs): • 03-23-17, S-3I Contamination Area • 03-23-19, T-3U Contamination Area • 03-23-20, Otero Contamination Area • 03-23-22, Platypus Contamination Area • 03-23-23, San Juan Contamination Area • 03-23-26, Shrew/Wolverine Contamination Area These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the investigation report.

  11. Comparison between dispersed nuclear power plants and a nuclear energy center at a hypothetical site on Kentucky Lake, Tennessee. Vol. IV. A site selection methodology

    International Nuclear Information System (INIS)

    Rosemarin, C.S.; Yaffee, S.L.

    1976-09-01

    A methodology has been developed for selecting suitable sites for development as nuclear energy centers. First, the forty-eight contiguous states were screened on the basis of four variables: (1) seismic stability; (2) distance from projected population centers; (3) adequate water supply; and (4) noninterference with scenic and reserved lands. After location of a surrogate area in north central Tennessee, further screening was performed using 22 variables to find a suitable 75-sq-mile surrogate site within this 1500-sq-mile area. A computer method for screening the surrogate area is presented, and the use of the data for the 22 variables is illustrated

  12. Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

    International Nuclear Information System (INIS)

    Winterle, Bret

    2001-01-01

    Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

  13. Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

    Energy Technology Data Exchange (ETDEWEB)

    Winterle, Bret

    2001-07-01

    Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

  14. Corrective Action Investigation Plan for Corrective Action Unit 366: Area 11 Plutonium Valley Dispersion Sites, Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Matthews

    2011-09-01

    Corrective Action Unit 366 comprises the six corrective action sites (CASs) listed below: (1) 11-08-01, Contaminated Waste Dump No.1; (2) 11-08-02, Contaminated Waste Dump No.2; (3) 11-23-01, Radioactively Contaminated Area A; (4) 11-23-02, Radioactively Contaminated Area B; (5) 11-23-03, Radioactively Contaminated Area C; and (6) 11-23-04, Radioactively Contaminated Area D. These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed July 6, 2011, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 366. The presence and nature of contamination at CAU 366 will be evaluated based on information collected from a field investigation. Radiological contamination will be evaluated based on a comparison of the total effective dose (TED) at sample locations to the dose-based final action level (FAL). The TED will be calculated by summing the estimates of internal and external dose. Results from the analysis of soil samples collected from sample plots will be used to calculate internal radiological dose. Thermoluminescent dosimeters placed at each sample location will be used to measure external radiological dose. Based on historical documentation of the releases

  15. A Tracer Experiment to Understand Dispersion Characteristics at a Nuclear Power Plant Site-Focusing on the Comparison with Predictive Results using Reg. Guide 1.145 model

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyojoon; Kim, Eunhan; Jeong, Haesun; Hwang, Wontae; Han, Moonhee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    There remains disagreement regarding the application of a Gaussian plume model in PAVAN, as it relates to the complicated geographical features of a coastal area. Therefore, this study was performed in order to figure out the characteristics of the PAVAN program that was developed based on the equations of Gaussian Plume Model, which reflected the actual measured concentration of radioactive materials released to the air. It also evaluated the appropriateness of using a Gaussian plume model for assessing the environmental impact of radiation from a nuclear power plant. In order to analyze the dispersion characteristics of radioactive materials released into the air from the Wolsong nuclear power plant, SF{sub 6} gas was released from the site at night for one hour under stable atmospheric conditions disadvantageous to dilute a tracer gas in this study. The measured concentrations were compared with theoretical estimates derived from meteorological data observed during the experiment period to evaluate the prediction capabilities of the Gaussian plume model. This study conducted a tracer dispersion experiment at the site of Wolsong Nuclear Power Plant site in Korea to analyze the atmospheric dispersion characteristics of radioactive materials. It compared the experimental value with the calculated value using the Gaussian Plume Model as suggested in Reg. 1.145, based on the meteorological data observed in the experiment time period, and evaluated the conservative estimate of the calculated value. In the area where the calculated value is relatively high, the calculated value tends to show higher than the experimental value, which confirmed the conservative manner of the estimating of the calculated value using the Gaussian Plume Model. The short-term exposure of radiation to a human body caused by a nuclear accident would be higher in the area where the atmospheric concentration of radiation is high. Therefore, it is a sufficiently conservative manner to use the

  16. A Tracer Experiment to Understand Dispersion Characteristics at a Nuclear Power Plant Site-Focusing on the Comparison with Predictive Results using Reg. Guide 1.145 model

    International Nuclear Information System (INIS)

    Jeong, Hyojoon; Kim, Eunhan; Jeong, Haesun; Hwang, Wontae; Han, Moonhee

    2014-01-01

    There remains disagreement regarding the application of a Gaussian plume model in PAVAN, as it relates to the complicated geographical features of a coastal area. Therefore, this study was performed in order to figure out the characteristics of the PAVAN program that was developed based on the equations of Gaussian Plume Model, which reflected the actual measured concentration of radioactive materials released to the air. It also evaluated the appropriateness of using a Gaussian plume model for assessing the environmental impact of radiation from a nuclear power plant. In order to analyze the dispersion characteristics of radioactive materials released into the air from the Wolsong nuclear power plant, SF 6 gas was released from the site at night for one hour under stable atmospheric conditions disadvantageous to dilute a tracer gas in this study. The measured concentrations were compared with theoretical estimates derived from meteorological data observed during the experiment period to evaluate the prediction capabilities of the Gaussian plume model. This study conducted a tracer dispersion experiment at the site of Wolsong Nuclear Power Plant site in Korea to analyze the atmospheric dispersion characteristics of radioactive materials. It compared the experimental value with the calculated value using the Gaussian Plume Model as suggested in Reg. 1.145, based on the meteorological data observed in the experiment time period, and evaluated the conservative estimate of the calculated value. In the area where the calculated value is relatively high, the calculated value tends to show higher than the experimental value, which confirmed the conservative manner of the estimating of the calculated value using the Gaussian Plume Model. The short-term exposure of radiation to a human body caused by a nuclear accident would be higher in the area where the atmospheric concentration of radiation is high. Therefore, it is a sufficiently conservative manner to use the Gaussian

  17. [Influence of pacing site on myocardial transmural dispersion of repolarization in intact normal and dilated cardiomyopathy dogs].

    Science.gov (United States)

    Bai, Rong; Pu, Jun; Liu, Nian; Lu, Jia-Gao; Zhou, Qiang; Ruan, Yan-Fei; Niu, Hui-Yan; Wang, Lin

    2003-12-25

    In order to verify the hypothesis that left ventricular epicardial (LV-Epi) pacing and biventricular (BiV) pacing unavoidably influence the myocardial electrophysiological characters and may result in high risk of malignant ventricular arrhythmia, we calculated, in both normal mongrel dogs and dog models with rapid-right-ventricular-pacing induced dilated cardiomyopathy congestive heart failure (DCM-CHF), the monophasic action potential duration (MAPD) and the transmural dispersion of repolarization (TDR) in intracardiac electrogram together with the QT interval and T(peak)-T(end) (T(p(-T(e)) interval in surface electrocardiogram (ECG) during LV-Epi and BiV pacing, compared with those during right ventricular endocardial (RV-Endo) pacing. To prepare the DCM-CHF dog model, rapid right ventricular pacing (250 bpm) was performed for 23.6+/-2.57 days to the dog. All the normal and DCM-CHF dogs were given radio frequency catheter ablation (RFCA) to His bundle with the guide of X-ray fluoroscopy. After the RFCA procedures, the animals were under the situation of complete atrioventricular block so that the canine heart rates could be voluntarily controlled in the following experiments. After a thoracotomy, ECG and monophasic action potentials (MAP) of subendocardial, subepicardial and mid-layer myocardium were recorded synchronously in 8 normal and 5 DCM-CHF dogs during pacing from endocardium of RV apex (RV-Endo), epicardium of LV anterior wall (LV-Epi) and simultaneously both of the above (biventricular, BiV), the later was similar to the ventricular resynchronization therapy to congestive heart failure patients in clinic. The Tp-Te) meant the interval from the peak to the end of T wave, which was a representative index of TDR in surface ECG. The TDR was defined as the difference between the longest and the shortest MAPD of subendocardial, subepicardial and mid-layer myocardium. Our results showed that in normal dogs, pacing participating of LV (LV-Epi, BiV) prolonged

  18. Proliferation risks

    International Nuclear Information System (INIS)

    Carchon, R.

    1998-09-01

    The report gives an overview of different aspects related to safeguards of fissile materials. Existing treaties including the Non-Proliferation Treaty, and the Tlatelolco and the Rarotonga Treaties are discussed. An overview of safeguards systems for the control of fissile materials as well as the role of various authorities is given. An overall overview of proliferation risks, the physical protection of fissile materials and the trade in fissile materials is given. Finally, the status in problem countries and de facto nuclear weapon states is discussed

  19. Corrective Action Plan for Corrective Action Unit 568: Area 3 Plutonium Dispersion Sites Nevada National Security Site, Nevada, Revision 0 with ROTC 1

    International Nuclear Information System (INIS)

    Matthews, Patrick; Burmeister, Mark

    2016-01-01

    The purpose of this CAP is to provide the plan for implementation of the recommended corrective action alternatives (CAAs) for CAU 568. Site characterization activities were performed in 2014, and the results are presented in Appendix A of the CAU 568 CADD. The CAAs were recommended in the CADD. The scope of work required to implement the recommended CAAs of closure in place and clean closure at 11 of the 14 CASs includes the following: The installation of physical barriers over the nine safety experiment ground zeroes to cover contamination at CASs 03-23-20 (Otero), 03-23-23 (San Juan and Pascal-C), 03-23-31 (Pascal-B, Luna, Colfax), 03-23-32 (Pascal-A), 03-23-33 (Valencia), and 03-23-34 (Chipmunk); the characterization and removal of three soil and debris piles at CAS 03-08-04, and one HCA soil pile at CAS 03-23-30; the removal of three steel well head covers (PSM) from CASs 03-23-20 (Otero), 03-23-31 (Luna), and 03-23-33 (Valencia); the removal of soil and lead PSM from two locations at CAS 03-26-04; Implementation of FFACO use restrictions at nine safety experiment ground zeroes at CASs 03-23-20, 03-23-23, 03-23-31, 03-23-32, 03-23-33, and 03-23-34; the steel well head cover at CAS 03-23-23; the areas meeting HCA conditions at CASs 03-23-19 and 03-23-31; and the Boomer crater area at CAS 03-45-01. The FFACO use restriction boundaries will be presented in the CAU 568 closure report.

  20. Corrective Action Plan for Corrective Action Unit 568: Area 3 Plutonium Dispersion Sites Nevada National Security Site, Nevada, Revision 0 with ROTC 1

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick [Navarro Nevada Environmental Services, NV (United States); Burmeister, Mark [Navarro Nevada Environmental Services, NV (United States)

    2016-05-01

    The purpose of this CAP is to provide the plan for implementation of the recommended corrective action alternatives (CAAs) for CAU 568. Site characterization activities were performed in 2014, and the results are presented in Appendix A of the CAU 568 CADD. The CAAs were recommended in the CADD. The scope of work required to implement the recommended CAAs of closure in place and clean closure at 11 of the 14 CASs includes the following: The installation of physical barriers over the nine safety experiment ground zeroes to cover contamination at CASs 03-23-20 (Otero), 03-23-23 (San Juan and Pascal-C), 03-23-31 (Pascal-B, Luna, Colfax), 03-23-32 (Pascal-A), 03-23-33 (Valencia), and 03-23-34 (Chipmunk); the characterization and removal of three soil and debris piles at CAS 03-08-04, and one HCA soil pile at CAS 03-23-30; the removal of three steel well head covers (PSM) from CASs 03-23-20 (Otero), 03-23-31 (Luna), and 03-23-33 (Valencia); the removal of soil and lead PSM from two locations at CAS 03-26-04; Implementation of FFACO use restrictions at nine safety experiment ground zeroes at CASs 03-23-20, 03-23-23, 03-23-31, 03-23-32, 03-23-33, and 03-23-34; the steel well head cover at CAS 03-23-23; the areas meeting HCA conditions at CASs 03-23-19 and 03-23-31; and the Boomer crater area at CAS 03-45-01. The FFACO use restriction boundaries will be presented in the CAU 568 closure report.

  1. Conserving archaeological sites as biological and historical resources in the Gulf of Mexico: the effects of crude oil and dispersant on the biodiversity and corrosion potential of shipwreck bacterial biofilms

    Science.gov (United States)

    Salerno, J. L.; Little, B.; Lee, J.; Ray, R.; Hamdan, L. J.

    2016-02-01

    There are more than 2,000 documented shipwrecks in the Gulf of Mexico. Historic shipwrecks are invaluable cultural resources, but also serve as artificial reefs, enhancing biodiversity in the deep sea. Oil and gas-related activities have the potential to impact shipwreck sites. An estimated 30% of the oil from the Deepwater Horizon spill was deposited in the deep-sea, in areas that contain shipwrecks. We conducted field and laboratory experiments to determine if crude oil, dispersed oil, and/or dispersant affect the community composition, metabolic function, and/or corrosion potential of microorganisms inhabiting shipwrecks. Platforms containing carbon steel coupons (CSC) (n = 34 per platform) were placed at impacted and non-impacted shipwrecks or into four experimental microcosm tanks. After a 2-week acclimation period, tanks were treated with crude oil and/or dispersant or received no treatment. CSC and seawater (SW) samples for bacterial genetic analysis were collected bi-weekly (at 16 wks for field samples). Proteobacteria dominated field and lab CSC bacterial communities (77-97% of sequences). Field CSC bacterial communities differed at each wreck site (P = 0.001), with oil-impacted sites differing from control sites. Lab CSC bacterial communities differed between all treatment groups (P = 0.005) and changed over the course of the experiment (P = 0.001). CSC bacterial species richness, diversity, and dominance increased with time across all treatments indicating the recruitment and establishment of microbial biofilms on CSCs. SW bacterial communities differed between treatment groups (P = 0.001), with the dispersant treatment being most dissimilar from all other treatments (P < 0.01), and changed over time (P = 0.001). Oil- and oil/dispersant-treated CSCs exhibited higher corrosion compared to dispersant and control treatments. These findings indicate that exposure to oil and/or dispersant may alter bacterial community composition and corrosion potential.

  2. Nuclear proliferation

    International Nuclear Information System (INIS)

    Stencel, S.

    1978-01-01

    The terms and reactions to President Carter's nuclear policy, culminating in the 1978 Nuclear Non-Proliferation Act, are reviewed and analyzed. The new law increases restrictions on nuclear exports, encourages continued use of light water reactors in preference to plutonium-fueled reactors, and emphasizes technical solutions to proliferation problems. Critics of the law point out that it will hurt U.S. trade unfairly, that other countries do not have as many fuel options as the U.S. has, and that nuclear sales have as many political and economic as technical solutions. Compromise areas include new international safety guidelines, the possibility of an international nuclear fuel bank, and a willingness to consider each case on its merits. 21 references

  3. Preventing proliferation

    International Nuclear Information System (INIS)

    Rathjens, G.

    1983-01-01

    Challenging the argument that nuclear proliferation may be stabilizing, the author cites the Israeli attack on Iraq as evidence that emergent nuclear states may be moved to attack their adversaries.The larger the number of decision makers who can unleash nuclear weapons, the greater the liklihood of their use. Several reasons are cited for nations to seek nuclear capability: the accelerated spread of technology, the deterioration in US-Soviet relations and strength relative to their nations, the high cost of conventional weapons, and a loss of confidence in the international safeguards system. The imposition of constraints, such as a Comprehensive Test Ban Treaty, on nuclear trade and technology transfer are likely to have a high cost. The US position on this issue is likely to be determined by the balance of power with the Soviet Union. 5 references

  4. Seed dispersal in fens

    Science.gov (United States)

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  5. Centrifuge-less dispersive liquid-liquid microextraction base on the solidification of switchable solvent for rapid on-site extraction of four pyrethroid insecticides in water samples.

    Science.gov (United States)

    Hu, Lu; Wang, Huazi; Qian, Heng; Liu, Chaoran; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang; Xu, Donghui

    2016-11-11

    An on-site dispersive liquid liquid microextraction base on the solidification of switchable solvent has been developed as a simple, rapid and eco-friendly sample extraction method for the fast determination of pyrethroid insecticides in aqueous samples using high-performance liquid chromatography with ultraviolet detection. In this extraction method, medium-chain saturated fatty acids (n≥10), which can rapidly solidify at low temperatures (centrifugation. The microextraction process was performed in a 10mL syringe and the pretreatment process could thus be finished in 5min. No external energy resources were required in this method, which makes it a potential method for on-site extraction. The optimal experimental parameters were as follows: 350μL of decanoic acid (1mol/L) was used as the extraction solvent, 150μL of sulfuric acid (2mol/L) was used to decrease the pH of the samples, no salt was added, and the temperature of the samples was in the range of 20-40°C. Finally, the sample was cooled in an ice bath for three minutes. Under these optimal conditions, good responses for four pyrethroid insecticides were obtained in the concentration ranges of 1-500μg/L, with coefficients of determination greater than 0.9993. The recoveries of the four pyrethroid insecticides ranged from 84.7 to 95.3%, with relative standard deviations ranging from 1.6 to 4.6%. The limits of detection based on a signal-to-noise ratio of 3 were in the range of 0.24-0.68μg/L, and the enrichment factors were in the range of 121-136. The results demonstrate that this method was successfully applied to determine pyrethroid insecticides in real water samples. No centrifugation or any special apparatus are required, make this a promising method for rapid field-sampling procedures. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Hydrodynamic disperser

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, A.I.; Chernov, V.S.; Prokopov, L.I.; Proselkov, Yu.M.; Tikhonov, Yu.P.

    1980-01-15

    A hydrodynamic disperser is suggested which contains a housing, slit nozzles installed on a circular base arranged opposite from each other, resonators secured opposite the nozzle and outlet sleeve. In order to improve the effectiveness of dispersion by throttling the flow, each resonator is made in the form of a crimped plate with crimpings that decrease in height in a direction towards the nozzle.

  7. Proliferating Cell Nuclear Antigen-dependent Rapid Recruitment of Cdt1 and CRL4Cdt2 at DNA-damaged Sites after UV Irradiation in HeLa Cells*

    Science.gov (United States)

    Ishii, Takashi; Shiomi, Yasushi; Takami, Toshihiro; Murakami, Yusuke; Ohnishi, Naho; Nishitani, Hideo

    2010-01-01

    The licensing factor Cdt1 is degraded by CRL4Cdt2 ubiquitin ligase dependent on proliferating cell nuclear antigen (PCNA) during S phase and when DNA damage is induced in G1 phase. Association of both Cdt2 and PCNA with chromatin was observed in S phase and after UV irradiation. Here we used a micropore UV irradiation assay to examine Cdt2 accumulation at cyclobutane pyrimidine dimer-containing DNA-damaged sites in the process of Cdt1 degradation in HeLa cells. Cdt2, present in the nucleus throughout the cell cycle, accumulated rapidly at damaged DNA sites during G1 phase. The recruitment of Cdt2 is dependent on prior PCNA chromatin binding because Cdt2 association was prevented when PCNA was silenced. Cdt1 was also recruited to damaged sites soon after UV irradiation through its PIP-box. As Cdt1 was degraded, the Cdt2 signal at damaged sites was reduced, but PCNA, cyclobutane pyrimidine dimer, and XPA (xeroderma pigmentosum, complementation group A) signals remained at the same levels. These findings suggest that Cdt1 degradation following UV irradiation occurs rapidly at damaged sites due to PCNA chromatin loading and the recruitment of Cdt1 and CRL4Cdt2, before DNA damage repair is completed. PMID:20929861

  8. Catalyst Architecture for Stable Single Atom Dispersion Enables Site-Specific Spectroscopic and Reactivity Measurements of CO Adsorbed to Pt Atoms, Oxidized Pt Clusters, and Metallic Pt Clusters on TiO2.

    Science.gov (United States)

    DeRita, Leo; Dai, Sheng; Lopez-Zepeda, Kimberly; Pham, Nicholas; Graham, George W; Pan, Xiaoqing; Christopher, Phillip

    2017-10-11

    Oxide-supported precious metal nanoparticles are widely used industrial catalysts. Due to expense and rarity, developing synthetic protocols that reduce precious metal nanoparticle size and stabilize dispersed species is essential. Supported atomically dispersed, single precious metal atoms represent the most efficient metal utilization geometry, although debate regarding the catalytic activity of supported single precious atom species has arisen from difficulty in synthesizing homogeneous and stable single atom dispersions, and a lack of site-specific characterization approaches. We propose a catalyst architecture and characterization approach to overcome these limitations, by depositing ∼1 precious metal atom per support particle and characterizing structures by correlating scanning transmission electron microscopy imaging and CO probe molecule infrared spectroscopy. This is demonstrated for Pt supported on anatase TiO 2 . In these structures, isolated Pt atoms, Pt iso , remain stable through various conditions, and spectroscopic evidence suggests Pt iso species exist in homogeneous local environments. Comparing Pt iso to ∼1 nm preoxidized (Pt ox ) and prereduced (Pt metal ) Pt clusters on TiO 2 , we identify unique spectroscopic signatures of CO bound to each site and find CO adsorption energy is ordered: Pt iso ≪ Pt metal atoms bonded to TiO 2 and that Pt iso exhibits optimal reactivity because every atom is exposed for catalysis and forms an interfacial site with TiO 2 . This approach should be generally useful for studying the behavior of supported precious metal atoms.

  9. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  10. Definition of global dispersion coefficients

    International Nuclear Information System (INIS)

    Naff, R.L.

    1983-10-01

    For estimation of a global longitudinal dispersivity at the Gorleben site, data available primarily consist of suites of geophysical logs from wells penetrating the Quaternary aquifer. A length scale for the principle aquifer at Gorleben is to be found. Samples are to be taken separately to estimate the variance in hydraulic conductivity (Taylor Analysis, Fickian dispersion process). (DG)

  11. Implementations of the hydrological dispersion models of RODOS for assessment of off-site nuclear impacts caused by non energy production sources

    International Nuclear Information System (INIS)

    Zheleznyak, M.; Maderich, V.; Onishi, Y.

    2003-01-01

    Full text: The main aim of the Hydrological Dispersion Module (HDM) of the RODOS - the real-time on-line decision support system for nuclear emergency management in Europe, is the prediction of the dispersion of radionuclides in aquatic systems following atmospheric fallout. HDM provides also the supplementary possibility to simulate the transport of radionuclide in aquatic systems following a direct release of radioactivity into the surface waters. The hydrological model chain of RODOS was developed to simulate processes, such as runoff of radionuclides from watersheds following deposition from the atmosphere (RETRACE model), transport of radionuclides in river systems (1-D model RIVTOX), the radionuclide behaviour in lakes and reservoirs (radioecological box model LAKECO, 2-D lateral-longitudinal model COASTOX), river floodplains (COASTOX), estuaries and seas ( 3-D model THREETOX). The output from the HDM is transferred into the aquatic food chain and dose model FDMA (part of RODOS) to assess the main exposure pathways. The RODOS system was developed to support the offsite nuclear emergency management in a case of the accidents at the acting nuclear power plants. However the models, integrated into the RODOS are more generic and therefore ones can be applied for management of nuclear emergencies caused also by other sources. Three case studies are considered in this presentation for analyses of such possibilities. Case study 1: the simulations of hypothetical nuclear releases from the nuclear submarine 'Kursk' sunken on August the 12 th 2000 in the Barents Sea were carried out to show the ability of cope with RODOS-HDM model THREETOX the emergency situations an the board of ships with nuclear engines. 'Kursk' contains two pressurized-water nuclear reactors OK-650b of 190 MW. The submarine was salvaged in 2002. Two scenarios of 137 Cs releases - the permanent leakage of 1 TBq/year of and an instantaneous leakage of 4500 TBq have been simulated for the period of

  12. Energy dispersive X-ray fluorescence analysis of ancient coins: The case of Greek silver drachmae from the Emporion site in Spain

    International Nuclear Information System (INIS)

    Pitarch, A.; Queralt, I.

    2010-01-01

    Greek colonizers arrived at the Iberian Peninsula at the beginning of the sixth century B.C. and founded a small colony known as Emporion in north-east Spain. By the fifth century B.C., this colony became a small polis with a well-organized administrative structure. In this context, the necessity of coinage was a fact and the first coins were minted. Some of these coins were characterized by using energy dispersive X-ray fluorescence equipment. The analytical study focused on the elemental characterization of the coins minted from the fourth century to the first century B.C. and their compositional evolution during this period. The investigation has pointed out a very high fineness of the alloys throughout the time, with an average silver content around 98.32%, and the feasibility of energy dispersive X-ray fluorescence as a screening tool for the characterization of the alloys.

  13. Spatially-Explicit Assessments of Genetic Biodiversity and Dispersal in Gopher Tortoises for Evaluation of Habitat Fragmentation at DoD Sites

    Science.gov (United States)

    2008-10-01

    crocodilian population genetics questions. J. Herpetology . 35: 541-544. Diemer JE. 1992. Home range and movements of the tortoise Gopherus...polyphemus in northern Florida. Journal of Herpetology 26:158–162 Diffendorfer JE. 1998. Testing models of source-sink dynamics and balanced dispersal...associated with tortoise (Gopherus polyphemus) burrows in four habitats in south-central Florida. Journal of Herpetology 25:477-481. Luikart G, Cornuet J-M

  14. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  15. Dispersal and disturbance as factors limiting the distribution of rare plant species at the Savannah River Site and the Carolina Sandhills National Wildlife Refuge.

    Energy Technology Data Exchange (ETDEWEB)

    Primack, Richard; Walker, Joan.

    2003-12-10

    An experiment was conducted to identify effective methods of creating new populations of herbaceous species in managed upland longleaf pine forest at two locations in the Fall-line Sandhills of South Carolina. We included thirteen species and a variety of site treatments. All sites were burned and lightly raked prior to planting. Sowing seeds on untreated or fertilized treatments resulted in the lowest establishment of all treatments. Digging the planting area to remove belowground plant structures and using hardware cloth cages to exclude potential mammalian seed predators and herbivores led to increased establishment of target species. Establishment was higher using seedling transplants compared to seeds. Success rate was highly variable among sites so population establishment efforts should try to incorporate many sites initially to find the sites that give the greatest chance of success, or increase efforts to carefully identify species, habitat requirements and screen potential sites accordingly. Some species showed very low rates of success despite the variety of methods used; for such species additional work is required on their basic ecology, in particular germination biology and site requirements, as part of a restoration project. The overall low rate of establishment success emphasizes the need to protect and manage existing populations of uncommon Sandhills species, and to recognize that establishing large, long-term, reproducing populations of such species will be difficult.

  16. Comparison between dispersed nuclear power plants and a nuclear energy center at a hypothetical site on Kentucky Lake, Tennessee. Volume II. Transmission of power

    International Nuclear Information System (INIS)

    Reister, D.B.; Zelby, L.W.

    1976-05-01

    A comparison is made among power transmission systems required to serve a single set of load center demands from four modes of siting the generating facilities: a single generation site with an ultimate generation capacity of 48,000 MW; four generation sites each with a generation capacity of 12,000 MW; 10 generation sites each with a generation capacity of 4,800 MW; and a system that resulted when the existing utility plan for future generation was logically expanded. The time period for the study is from the year 1985 to the year 2020, when the full 48,000 MW of new capacity from the single large nuclear energy center is on-line. The load centers served are Huntsville, Alabama; Evansville, Indiana; Paducah, Kentucky; and Chattanooga, Nashville, and Memphis, Tennessee. Generation sites are real locations but are hypothetical in terms of miles of transmission lines, the product of the amount of power transmitted and the distance transmitted (GW-miles), and cost

  17. Proliferating cell nuclear antigen (PCNA): a new marker to study human colonic cell proliferation.

    OpenAIRE

    Kubben, F J; Peeters-Haesevoets, A; Engels, L G; Baeten, C G; Schutte, B; Arends, J W; Stockbrügger, R W; Blijham, G H

    1994-01-01

    Immunohistochemistry of the S phase related proliferating cell nuclear antigen (PCNA) was studied as an alternative to ex-vivo bromodeoxyuridine (BrdU) immunohistochemistry for assessment of human colonic cell proliferation. From 16 subjects without colonic disease biopsy specimens were collected from five different sites along the colorectum and processed for BrdU and PCNA immunohistochemistry. The mean proliferation index of PCNA was significantly higher at 133% of the value obtained with B...

  18. The threat of proliferation

    International Nuclear Information System (INIS)

    Palme, Olof.

    1986-01-01

    The paper on the threat of proliferation, is a keynote speech delivered to the Colloquium on Nuclear War, Nuclear Proliferation and their Consequences, Geneva, 1985. Topics discussed in the address include: nuclear weapons, nuclear war, terrorists, Non-Proliferation Treaty, nuclear disarmament, and leadership in world affairs. (UK)

  19. Use of isotope ratios to assess sources of Pb and Zn dispersed in the environment during mining and ore processing within the Orlovka-Spokoinoe mining site (Russia)

    International Nuclear Information System (INIS)

    Dolgopolova, A.; Weiss, D.J.; Seltmann, R.; Kober, B.; Mason, T.F.D.; Coles, B.; Stanley, C.J.

    2006-01-01

    Element concentrations, element ratios and Pb and Zn isotope data are reported for different geologic samples (barren and ore-bearing granites and host rocks), technogenic products (ore concentrates and tailings) and biologic samples (lichens and birch leaves) from the Orlovka-Spokoinoe mining district, Eastern Transbaikalia, Russia, with the aim to trace the sources of Pb and Zn at a local level within the mining site. Lichens and birch leaves were used as receptors of contamination within the mining site. Pb/Zr and Zn/Zr values indicated Pb and Zn enrichment relative to host rocks. Zn isotope data of 15 geologic and 11 lichen samples showed different Zn isotopic signatures with the total range for the geologic suite of -0.4 per mille to +1.2 per mille and for lichens of +0.4 per mille to +1.4 per mille in δ 66 Zn relative to Lyon JMC Zn standard. The source of isotopically heavy Zn within the Orlovka-Spokoinoe mining site could be potentially associated with long-range atmospheric aerosols that also contributed Pb to the studied mining site. Our results demonstrated that Zn isotopes might be used as new tools for Zn source assessment

  20. Dispersion strengthening

    International Nuclear Information System (INIS)

    Scattergood, R.O.; Das, E.S.P.

    1976-01-01

    Using digital computer-based methods, models for dispersion strengthening can now be developed which take into account many of the important effects that have been neglected in the past. In particular, the self interaction of a dislocation can be treated, and a computer simulation method was developed to determine the flow stress of a random distribution of circular, impenetrable obstacles, taking into account all such interactions. The flow stress values depended on the obstacle sizes and spacings, over and above the usual 1/L dependence where L is the average obstacle spacing. From an analysis of the results, it was found that the main effects of the self interactions can be captured in a line tension analogue in which the obstacles appear to be penetrable

  1. Influence of mercury ore roasting sites from 16th and 17th century on the mercury dispersion in surroundings of Idrija

    Directory of Open Access Journals (Sweden)

    Mateja Gosar

    2006-06-01

    Full Text Available In the first decade of mercury mining in Idrija the ore was roasted in piles. After that the ore was roasted for 150 years, until 1652, in earthen vessels at various sites in the woods around Idrija. Up to present 21 localities of ancient roasting sites were established.From the roasting areas Frbej‘ene trate, lying on a wide dolomitic terrace on the left side of the road from Idrija to ^ekovnik, 3 soil profiles are discussed. In all three profiles in the upper, organic matter rich soil horizon very high mercury contents (from 3 to 4,000mg/kg were found. In two profiles the contents rapidly decrease with depth, to about 10- times lower values already at 0.5 m. Below that, the mercury contents decrease slowly, to reach at the 1.3 m depth a few mg/kg metal. In the third profile the upper humic layer is followed downward by an additional humic layer containing very abundant pottery fragments. In this layer the maximum mercury contents were determined, 7.474 mg/kg Hg. The underlying loamy soil contains between 1000 and 2000 mg/kg mercury. Pšenk is one of the larger localities of roasting vessels fragments. It is located at Lačna voda brook below Hlev{e, above its confluence with the Padar ravine. The most abundant pottery remains are found in the upper western margin of the area, just below the way to Hleviše. The considered geochemical profile P{enk contains at the top a 45 cm thick humic layer with 4,000 to 5,000 mg/kg mercury. Deeper the contents fall to around 100 mg/kg mercury. The alculations result in an estimated amount of 1.4 t mercury still present at the P{enk locality, and in about 40 t of mercury on all roasting sites described up to present.The determined mercury contents in soils at old roasting sites are very high, and they surpass all hitherto described localities at Idrija and in the surroundings.

  2. Mineralogy of the clay fraction of soils from the moray cusco archaeological site: a study by energy dispersive X-ray fluorescence, X-ray diffractometry and Mössbauer spectroscopy

    International Nuclear Information System (INIS)

    Cerón Loayza, María L.; Bravo Cabrejos, Jorge A.; Mejía Santillán, Mirian E.

    2011-01-01

    The purpose of this work is to report the advances in the elemental and structural characterization of the clay fraction of soils from the terraces of the Moray Archaeological site, located 38 km north of the city of Cusco, Cusco Region. One sample was collected from each of the twelve terraces of this site and its clay fraction was separated by sedimentation. Previously the pH of the raw samples was measured resulting that all of the samples were from alkaline to strongly alkaline. Energy dispersive X-ray fluorescence (EDXRF) was used for the elemental characterization, and X-ray diffractometry (XRD) and transmission Mössbauer spectroscopy (TMS), using the γ 14.4 keV nuclear resonance transition in 57 Fe, were used for the structural characterization of the clays and clay minerals present in each sample. The EDXRF analyses of all the samples show the presence of relatively high concentrations of sulfur in some of the samples and relatively high concentrations of calcium in all of the samples, which may be related to the high alkalinity of the samples. By XRD it is observed the presence of quartz, calcite, gypsum, cronstedtite, 2:1 phyllosilicates, and iron oxides. The mineralogical analysis of Fe by TMS shows that it is present in the form of hematite and occupying Fe 2 +  and Fe 3 +  sites in phyllosilicates, cronstedtite, and other minerals not yet identified.

  3. Mineralogy of the clay fraction of soils from the moray cusco archaeological site: a study by energy dispersive X-ray fluorescence, X-ray diffractometry and Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ceron Loayza, Maria L., E-mail: malucelo@hotmail.com; Bravo Cabrejos, Jorge A.; Mejia Santillan, Mirian E. [Universidad Nacional Mayor de San Marcos, Laboratorio de Analisis de Suelos, Laboratorio de Espectroscopia Moessbauer, Facultad de Ciencias Fisicas (Peru)

    2011-11-15

    The purpose of this work is to report the advances in the elemental and structural characterization of the clay fraction of soils from the terraces of the Moray Archaeological site, located 38 km north of the city of Cusco, Cusco Region. One sample was collected from each of the twelve terraces of this site and its clay fraction was separated by sedimentation. Previously the pH of the raw samples was measured resulting that all of the samples were from alkaline to strongly alkaline. Energy dispersive X-ray fluorescence (EDXRF) was used for the elemental characterization, and X-ray diffractometry (XRD) and transmission Moessbauer spectroscopy (TMS), using the {gamma} 14.4 keV nuclear resonance transition in {sup 57}Fe, were used for the structural characterization of the clays and clay minerals present in each sample. The EDXRF analyses of all the samples show the presence of relatively high concentrations of sulfur in some of the samples and relatively high concentrations of calcium in all of the samples, which may be related to the high alkalinity of the samples. By XRD it is observed the presence of quartz, calcite, gypsum, cronstedtite, 2:1 phyllosilicates, and iron oxides. The mineralogical analysis of Fe by TMS shows that it is present in the form of hematite and occupying Fe{sup 2 + } and Fe{sup 3 + } sites in phyllosilicates, cronstedtite, and other minerals not yet identified.

  4. Dispersal Timing: Emigration of Insects Living in Patchy Environments.

    Directory of Open Access Journals (Sweden)

    Milica Lakovic

    Full Text Available Dispersal is a life-history trait affecting dynamics and persistence of populations; it evolves under various known selective pressures. Theoretical studies on dispersal typically assume 'natal dispersal', where individuals emigrate right after birth. But emigration may also occur during a later moment within a reproductive season ('breeding dispersal'. For example, some female butterflies first deposit eggs in their natal patch before migrating to other site(s to continue egg-laying there. How breeding compared to natal dispersal influences the evolution of dispersal has not been explored. To close this gap we used an individual-based simulation approach to analyze (i the evolution of timing of breeding dispersal in annual organisms, (ii its influence on dispersal (compared to natal dispersal. Furthermore, we tested (iii its performance in direct evolutionary contest with individuals following a natal dispersal strategy. Our results show that evolution should typically result in lower dispersal under breeding dispersal, especially when costs of dispersal are low and population size is small. By distributing offspring evenly across two patches, breeding dispersal allows reducing direct sibling competition in the next generation whereas natal dispersal can only reduce trans-generational kin competition by producing highly dispersive offspring in each generation. The added benefit of breeding dispersal is most prominent in patches with small population sizes. Finally, the evolutionary contests show that a breeding dispersal strategy would universally out-compete natal dispersal.

  5. Proliferation: myth or reality?

    International Nuclear Information System (INIS)

    2005-01-01

    This article analyzes the proliferation approach, its technical condition and political motivation, and the share between the myth (political deception, assumptions and extrapolations) and the reality of proliferation. Its appreciation is complicated by the irrational behaviour of some political actors and by the significant loss of the non-use taboo. The control of technologies is an important element for proliferation slowing down but an efficient and autonomous intelligence system remains indispensable. (J.S.)

  6. Hydrodynamic dispersion

    International Nuclear Information System (INIS)

    Pryce, M.H.L.

    1985-01-01

    A dominant mechanism contributing to hydrodynamic dispersion in fluid flow through rocks is variation of travel speeds within the channels carrying the fluid, whether these be interstices between grains, in granular rocks, or cracks in fractured crystalline rocks. The complex interconnections of the channels ensure a mixing of those parts of the fluid which travel more slowly and those which travel faster. On a macroscopic scale this can be treated statistically in terms of the distribution of times taken by a particle of fluid to move from one surface of constant hydraulic potential to another, lower, potential. The distributions in the individual channels are such that very long travel times make a very important contribution. Indeed, while the mean travel time is related to distance by a well-defined transport speed, the mean square is effectively infinite. This results in an asymmetrical plume which differs markedly from a gaussian shape. The distribution of microscopic travel times is related to the distribution of apertures in the interstices, or in the microcracks, which in turn are affected in a complex way by the stresses acting on the rock matrix

  7. Director's series on proliferation

    International Nuclear Information System (INIS)

    Bailey, K.C.; Price, M.E.

    1995-01-01

    This is an occasional publication of essays on the topics of nuclear, chemical, biological, and missile proliferation. The views represented are those of the author's. Essay topics include: Nuclear Proliferation: Myth and Reality; Problems of Enforcing Compliance with Arms Control Agreements; The Unreliability of the Russian Officer Corps: Reluctant Domestic Warriors; and Russia's Nuclear Legacy

  8. Proliferation Networks and Financing

    International Nuclear Information System (INIS)

    Gruselle, Bruno

    2007-01-01

    The objective of this study is to propose practical solutions aimed at completing and strengthening the existing arrangement for the control of nuclear proliferation through a control of financial as well as material or immaterial flows. In a first part, the author proposes a systemic analysis of networks of suppliers and demanders. He notably evokes the Khan's network and the Iraqi acquisition network during the 1993-2001 period. He also proposes a modelling of proliferation networks (supplier networks and acquisition networks) and of their interactions. In a second part, the author examines possible means and policies aimed at neutralising proliferation networks: organisation, adaptation and improvement of intelligence tools in front of proliferation networks, and means, limitations and perspectives of network neutralisation. He also briefly addresses the possibility of military action to contain proliferation flows

  9. Catchment Dispersion Mechanisms in an Urban Context

    Science.gov (United States)

    Gironas, J. A.; Mejia, A.; Rossel, F.; Rinaldo, A.; Rodriguez, F.

    2014-12-01

    Dispersion mechanisms have been examined in-depth in natural catchments in previous studies. However, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. Thus, these features can modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. This model computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment (France) as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further studies with other catchments are needed to assess whether the latter is a general feature of urban drainage networks.

  10. Peruvians Dispersed

    DEFF Research Database (Denmark)

    Pærregaard, Karsten

    This book presents a comparative study of Peruvian transnational migration to the United States, Spain, Japan and Argentina. It applies a multi-sited ethnographic fieldwork approach to study is the multicultural life-world of Peruvians and the economic, social, political and ritual relations...... that link them together in a diasporic network across national boundaries and tie them to their country of origin.  The book has three aims: 1) to examine how Peruvians create networks and design strategies to cope with the mechanisms of inclusion and exclusion that mediate their incorporation......).  Analytically, the study operates on two levels.  On the one hand, it draws on ethnographic data gathered in particular localities in the United States, Spain, Japan and Argentina to analyze a variety of issues such as livelihoods, family networks, religious institutions, migrant organizations, identity...

  11. Seed dispersal in fens

    NARCIS (Netherlands)

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and

  12. Non-proliferation

    International Nuclear Information System (INIS)

    Manley, I.T.

    1981-01-01

    Proliferation is a problem that can only be solved when the political problems which lead countries to contemplate, the possession of nuclear weapons are solved; in the meantime it can only be managed. Non-proliferation policy has to deal both with the political and the technical aspects of proliferation. It must seek to buy time by addressing the reasons why nations feel the political need to construct nuclear weapons, as well as delaying the moment when such nations feel capable of doing so. The subject is examined and proposals made. (author)

  13. Getting serious about proliferation

    International Nuclear Information System (INIS)

    Leventhal, P.

    1984-01-01

    The US needs to give a higher priority to nuclear non-proliferation, but Reagan's policies assume that proliferation is inevitable and that it is more important to be a reliable supplier than to cause trade frictions by trading only with those nations which sign the non-proliferation treaty (NPT). This undercuts US leadership and the intent of the agreement. Several bills now before Congress could help to restore US leadership by tightening export restrictions and the use of plutonium from the US

  14. Modeling of atmospheric dispersion of radionuclides

    International Nuclear Information System (INIS)

    Baklouti, Nada

    2010-01-01

    This work is a prediction of atmospheric dispersion of radionuclide from a chronic rejection of the nuclear power generating plant that can be located in one of the Tunisian sites: Skhira or Bizerte. Also it contains a study of acute rejection 'Chernobyl accident' which was the reference for the validation of GENII the code of modeling of atmospheric dispersion.

  15. Nuclear proliferation and terrorism

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This section of the book, Part III, has two chapters (9 and 10). Chapter 9, Nuclear Power and Proliferation of Nuclear Weapons, is disucssed under these subjects: nuclear nonproliferation: origins and status; requirements for nuclear weapons manufacture; current nuclear programs and proliferation capabilities; encouraging decisions to forego weapons; arms control; safeguards; attitudes and expectations. Chapter 10, Nuclear Terrorism, discusses these areas: theft of nuclear materials; attacks on nuclear reactors; responding to nuclear terrorism; security and civil liberties

  16. Nuclear non-proliferation

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    DOE's nuclear non-proliferation responsibilities are defined by the provisions of the Atomic Energy Act of 1954, as amended, and of the Nuclear Non-Proliferation Act of 1978 (NNPA). The Department's major responsibilities in this area are to: (1) provide technical assistance to the Department of State in negotiating agreements for civil cooperation in the peaceful uses of nuclear energy with other countries and international organizations; (2) join with other agencies to reach executive branch judgments with respect to the issuance of export licenses by the Nuclear Regulatory Commission; (3) be responsible for processing subsequent arrangements with other agencies as required by the Nuclear Non-Proliferation Act; (4) control the distribution of special nuclear materials, components, equipment, and nuclear technology exports; (5) participate in bilateral and multilateral cooperation with foreign governments and organizations to promote the peaceful uses of nuclear energy; and (6) act as a primary technical resource with respect to US participation in the International Atomic Energy Agency

  17. Dynamics of nuclear proliferation

    International Nuclear Information System (INIS)

    Meyer, S.M.

    1984-01-01

    This book looks beyond policy disputes to make a systematic examination of the assumptions and contending hypotheses that constitute contemporary thinking on nuclear proliferation. Rather than determine who is right or wrong, the intent is to develop a better picture by using the various schools of thought as analytic windows. A better understanding of how the process operates should offer better guidance for predicting future nuclear proliferation and, ultimately, for controlling it. Separate chapters deal with the contending views, the technological and motivational bases of nuclear proliferation, the presence of a technological imperative, testing the motivational hypothesis, the dynamics of the process, and forecasting. Four appendices present historical decisions, the technical model, cost-estimating procedures, and procedures for estimating nuclear propensities. 288 references, 17 figures, 26 tables

  18. Proliferation resistance modeling

    International Nuclear Information System (INIS)

    Bari, R.; Peterson, P.; Roglans, J.; Mladineo, S.; Nuclear Engineering Division; BNL; Univ. of California at Berkely; PNNL

    2004-01-01

    The National Nuclear Security Administration is developing methods for nonproliferation assessments. A working group on Nonproliferation Assessment Methodology (NPAM) assembled a toolbox of methods for various applications in the nonproliferation arena. One application of this methodology is to the evaluation of the proliferation resistance of Generation IV nuclear energy systems. This paper first summarizes the key results of the NPAM program and then provides results obtained thus far in the ongoing application, which is co-sponsored by the DOE Office of Nuclear Energy Science and Technology. In NPAM, a top-level measure of proliferation resistance for a fuel cycle system is developed from a hierarchy of metrics. The problem is decomposed into: metrics to be computed, barriers to proliferation, and a finite set of threats. The analyst models the process undertaken by the proliferant to overcome barriers to proliferation and evaluates the outcomes. In addition to proliferation resistance (PR) evaluation, the application also addresses physical protection (PP) evaluation against sabotage and theft. The Generation IV goal for future nuclear energy systems is to assure that they are very unattractive and the least desirable route for diversion or theft of weapons-usable materials, and provide increased physical protection against terrorism. An Expert Group, addressing this application, has identified six high-level measures for the PR goals (six measures have also been identified for the PP goals). Combined together, the complete set of measures provides information for program policy makers and system designers to compare specific system design features and integral system characteristics and to make choices among alternative options. The Group has developed a framework for a phased evaluation approach to analyzing PR and PP of system characteristics and to quantifying metrics and measures. This approach allows evaluations to become more detailed and representative

  19. Estimate of dispersion in an unsaturated aquifer

    Science.gov (United States)

    Stephenson, D.; De Jesus, A. S. M.

    1985-10-01

    The Nuclear Development Corporation of South Africa (Pty) Ltd. (NUCOR) is constructing a low-level radioactive waste disposal site near Springbok in Namaqualand, an arid region to the west of South Africa. A groundwater model was developed which required site-specific data and this work describes procedures developed to assess the dispersivity of the soil in the vicinity of the proposed site. Preliminary laboratory tests, carried out using a sodium chloride solution, indicated the order of magnitude of the dispersivity for saturated soil at various levels. This enabled site tests to be designed. The site tests were done by injecting a pulse of scandium-46 into a hole and monitoring the displacement of the radioactive cloud as it moved down under gravity and spread laterally. A mathematical model was developed to predict the behaviour of the cloud and calibration of the model yielded vertical and horizontal dispersivities. The dispersion of radioactivity at the cloud front was assumed to occur in unsaturated medium while the continuously injected water behind the radioactivity was assumed to disperse in a saturated medium. Thus monitoring the concentration of both yielded approximate values for the effective dispersivities in unsaturated and saturated media.

  20. The G8 global partnership against proliferation

    International Nuclear Information System (INIS)

    Devaux, O.

    2003-01-01

    Launched in 2002, the G8 global partnership against the proliferation of massive destruction weapons will contribute up to 20 billion dollars to the dismantling of the nuclear and chemical weapons of the former USSR (20000 nuclear warheads stored in 123 sites, 1350 tons of weapon grade plutonium and enriched uranium, 40000 tons of chemical agents, 190 decommissioned nuclear submarines etc..). This partnership, which has entered its realization phase, inaugurates a new cooperation with the Russian Federation. I could be used tomorrow in other regions of the world and become an instrument of the international community for the fight against proliferation. (J.S.)

  1. Dispersion of radioactive materials in air and water

    International Nuclear Information System (INIS)

    Tolksdorf, P.; Meurin, G.

    1976-01-01

    A review of current analytical methods for treating the dispersion of radioactive material in air and water is given. It is shown that suitable calculational models, based on experiments, exist for the dispersion in air. By contrast, the analysis of the dispersion of radioactive material in water still depends on the evaluation of experiments with site-specific models. (orig.) [de

  2. Cell Proliferation in Neuroblastoma

    Science.gov (United States)

    Stafman, Laura L.; Beierle, Elizabeth A.

    2016-01-01

    Neuroblastoma, the most common extracranial solid tumor of childhood, continues to carry a dismal prognosis for children diagnosed with advanced stage or relapsed disease. This review focuses upon factors responsible for cell proliferation in neuroblastoma including transcription factors, kinases, and regulators of the cell cycle. Novel therapeutic strategies directed toward these targets in neuroblastoma are discussed. PMID:26771642

  3. Controlling nuclear proliferation

    International Nuclear Information System (INIS)

    Sweet, W.

    1981-01-01

    Nuclear non-proliferation policy depends on the 1968 Non-Proliferation Treaty, in which countries promise not to acquire nuclear weapons in exchange for open access to peaceful nuclear technology, and a system of international safeguards that are imposed on exported nuclear equipment and facilities operated by parties to the treaty. Critics have feared all along that non-nuclear countries might circumvent or exploit the system to obtain nuclear weapons and that the Atoms for Peace plan would spread the very technology it sought to control. The nuclear weapons states would like everyone else to believe that atomic bombs are undesirable, but they continue to rely on the bombs for their own defense. Israel's raid on Iraq's nuclear reactor focused world attention on the proliferation problem and helped to broaden and sterengthen its prospects. It also highlighted the weakness that there are no effective sanctions against violators. Until the international community can ageee on enforcement measures powerful enough to prevent nuclear proliferation, individual countries may be tempted to follow Israel's example, 19 references

  4. Clock synchronization and dispersion

    International Nuclear Information System (INIS)

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Wong, Franco N C

    2002-01-01

    We present a method to defeat effects of dispersion of timing signals when synchronizing clocks. It is based on the recently proposed 'conveyor belt synchronization' scheme and on the quantum dispersion cancellation effect

  5. Dispersing powders in liquids

    CERN Document Server

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  6. The non-proliferation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, W.J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    On September 22, 1993, the Department of Energy detonated more than 1.2 million kg of blasting agent in a tunnel in Rainier Mesa at the Nevada Test Site. The resulting explosion generated seismic, electromagnetic, and air pressure signals that were recorded on instruments deployed at distances ranging from a few meters to hundreds and, in some cases, thousands of kilometers. More than 12 organizations made measurements before, during, and after the explosions. The explosion and its associated experiments are known as the Non-Proliferation Experiment (NPE). Analyses of the measurements made during the NPE and comparisons with similar measurements made on previous nearly nuclear explosions and on a co-located smaller explosion detonated at the same site are providing basic phenomenological insights into what is potentially one of the comprehensive Test Ban Treaty (CTBT)-distinguishing between nuclear explosions and some of the many conventional explosions that occur each year. The NPE is also providing information on the use of chemical explosions to develop empirical discriminants in regions where no nuclear explosions have been recorded. In another verification application, several NPE projects are examining the utility of on-site, pre-shot, shot-time, and post-shot measurements of gas seepage, seismic activity, and other observables as a means of identifying the source of signals that appear like nuclear explosions at regional distances. Two related activities are being considered. First, challenge on-site inspections, conducted after an event has occurred, may be able to use the characteristics of phenomena that persist after the explosion to detect and identify the source of the signals that appeared ambiguous or explosion-like to remote sensors. Second, cooperative, on-site measurements made at the time of a pre-nounced conventional explosion may provide assurance that a nuclear explosion did not occur as part of or in place of the pre-announced explosion.

  7. Dispersal of Engineered Male Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Winskill, Peter; Carvalho, Danilo O; Capurro, Margareth L; Alphey, Luke; Donnelly, Christl A; McKemey, Andrew R

    2015-11-01

    Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of 'genetically sterile' male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed. The dispersal ability of released 'genetically sterile' male Aedes aegypti at a field site in Brazil has been estimated. Dispersal kernels embedded within a generalized linear model framework were used to analyse data collected from three large scale mark release recapture studies. The methodology has been applied to previously published dispersal data to compare the dispersal ability of 'genetically sterile' male Aedes aegypti in contrasting environments. We parameterised dispersal kernels and estimated the mean distance travelled for insects in Brazil: 52.8 m (95% CI: 49.9 m, 56.8 m) and Malaysia: 58.0 m (95% CI: 51.1 m, 71.0 m). Our results provide specific, detailed estimates of the dispersal characteristics of released 'genetically sterile' male Aedes aegypti in the field. The comparative analysis indicates that despite differing environments and recapture rates, key features of the insects' dispersal kernels are conserved across the two studies. The results can be used to inform both risk assessments and release programmes using 'genetically sterile' male Aedes aegypti.

  8. Theory of dispersive microlenses

    Science.gov (United States)

    Herman, B.; Gal, George

    1993-01-01

    A dispersive microlens is a miniature optical element which simultaneously focuses and disperses light. Arrays of dispersive mircolenses have potential applications in multicolor focal planes. They have a 100 percent optical fill factor and can focus light down to detectors of diffraction spot size, freeing up areas on the focal plane for on-chip analog signal processing. Use of dispersive microlenses allows inband color separation within a pixel and perfect scene registration. A dual-color separation has the potential for temperature discrimination. We discuss the design of dispersive microlenses and present sample results for efficient designs.

  9. Nuclear non-proliferation

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This patent describes the treaty on the non-proliferation of nuclear weapons which is the corner-stone of an international non-proliferation regime which has grown to embrace the overwhelming majority of countries in the world in the period since the Treaty. The other elements of the regime include, first of all, the safeguards system of IAEA-which operates to prevent the diversion of nuclear materials to military or other prohibited activities and must be accepted by all non-nuclear-weapon parties to the Treaty and, secondly, the Antarctic Treaty, the Treaty for the Prohibition of Nuclear Weapons in Latin America (Treaty of Tlatelolco) and the south Pacific Nuclear Free zone Treaty (Treaty of Rarotonga)-which serve to extend the regime geographically. The last two Treaties require safeguards agreements with IAEA. In addition, the Treaty of Tlatelolco contains provisions establishing the agency for the Prohibition of Nuclear Weapons in Latin America and the Caribbean to ensure compliance

  10. Proliferation in cycle

    Energy Technology Data Exchange (ETDEWEB)

    Piao Yunsong [College of Physical Sciences, Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: yspiao@gucas.ac.cn

    2009-06-15

    In the contracting phase with w{approx_equal}0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w{approx_equal}0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

  11. Proliferation in cycle

    International Nuclear Information System (INIS)

    Piao Yunsong

    2009-01-01

    In the contracting phase with w≅0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w≅0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

  12. Global proliferation concerns

    International Nuclear Information System (INIS)

    Simpkins, R.

    1978-01-01

    The Non-Proliferation Treaty and the IAGA Safeguards System are discussed. President Carter's program to defer commercial reprocessing and recycle, to restructure the breeder program, to develop alternative fuel cycles, to increase US uranium enrichment capability, to provide fuel assurance for consumer nations, to continue the embargo of sensitive technology and equipment and to develop the International Nuclear Fuel Cycle Evaluation Program is outlined

  13. Fused silica thermal conductivity dispersion at high temperature

    International Nuclear Information System (INIS)

    Bouchut, P.; Decruppe, D.; Delrive, L.

    2004-01-01

    A continuous CO 2 laser is focused to locally anneal small fused silica spots. A noncontact radiometry diagnostic enables us to follow surface temperature variation that occurs from site to site. A 'steady state' dispersion of surface temperature is observed across our sample. We show that nonhomogeneous silica thermal conductivity, above 1000 K is responsible for this temperature dispersion

  14. Proliferation after the Iraq war

    International Nuclear Information System (INIS)

    Daguzan, J.F.

    2004-09-01

    This article uses the Iraq war major event to analyze the approach used by the US to fight against proliferation. It questions the decision and analysis process which has led to the US-British intervention and analyzes the consequences of the war on the proliferation of other countries and on the expected perspectives. Finally, the future of proliferation itself is questioned: do we have to fear more threat or is the virtuous circle of non-proliferation well started? (J.S.)

  15. Intracellular Na+ regulation of Na+ pump sites in cultured vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Allen, J.C.; Navran, S.S.; Seidel, C.L.; Dennison, D.K.; Amann, J.M.; Jemelka, S.K.

    1989-01-01

    Enzymatically dispersed cells from canine saphenous vein and femoral artery were grown in fetal calf serum and studied at day 0 (freshly dispersed) through confluence in primary culture. Intracellular Na levels (Nai), but not intracellular K (Ki), were increased after 24 h in culture and then decreased to a steady state by 4 days. Na+ pump site number [( 3 H] ouabain binding) increased through day 3 and remained elevated. Nai was still elevated at 2 days when the Na+ pump site number began to increase. Total pump turnover (maximum ouabain-inhibited 86 Rb uptake) reflected the increase in Na+ pump site number. These key events precede the observed increases in both protein production and cellular proliferation. If the same cells are maintained in defined medium, without fetal calf serum, Nai, Ki, and the number of [ 3 H]ouabain binding sites do not change with time. These data are consistent with the suggestion that the initial mitogenic response of vascular smooth muscle cells to fetal calf serum involves an increased Na+ influx, and a Nai accumulation, caused by low Na+ pump density. The synthesis of new pump sites effects a decrease in the accumulated Nai, which may be related to cell proliferation

  16. Can we predict nuclear proliferation

    International Nuclear Information System (INIS)

    Tertrais, Bruno

    2011-01-01

    The author aims at improving nuclear proliferation prediction capacities, i.e. the capacities to identify countries susceptible to acquire nuclear weapons, to interpret sensitive activities, and to assess nuclear program modalities. He first proposes a retrospective assessment of counter-proliferation actions since 1945. Then, based on academic studies, he analyzes what causes and motivates proliferation, with notably the possibility of existence of a chain phenomenon (mechanisms driving from one program to another). He makes recommendations for a global approach to proliferation prediction, and proposes proliferation indices and indicators

  17. Non-proliferation

    International Nuclear Information System (INIS)

    Deiseroth, D.; Gustafsson, S.

    1993-01-01

    The issue of Nuclear Non Proliferation has been moved to a leading place on the contemporary international security agenda. What about the situation of nuclear weapons and nuclear technology in Russia, Kazakhstan, Ukraine and Belorussia? Why did the IAEA-inspectors totally failed to discover any sign of Iraq's clandestine nuclear-weapon programme before the Gulf War? Do the NATO and their nuclear power states violate Art. VI of the Non-Proliferation-Treaty (NPT), because they are - despite the end of the cold war - not willing to renounce of the ''option of the first use of nuclear weapons''? Does the NPT establish a form of nuclear apartheid? What will be the situation if the NPT-Extension-Conference in 1995 will be unable to obtain a majority of the parties for any one extension proposal? Do we need a new international nuclear control agency with severe powers, a sort of nuclear Interpol? The Colloquium ''Saving NPT and abolishing Nuclear Weapons'', held in Stockholm in September 1992, organized by the Swedish and the German Sections of IALANA, tried to analyse some of the raised issues. (orig.) [de

  18. Non Proliferation of Nuclear

    International Nuclear Information System (INIS)

    Bambang S Irawan

    2004-01-01

    Non-Proliferation Treaty of Nuclear Weapons is the international community's efforts to maintain the security of the world, in order to prevent the spread of nuclear technology and the use of nuclear weapons, promoting cooperation for the use of nuclear peaceful purposes, build mutual trust (Confidence Building Measures) as well as to achieve the ultimate goal of disarmament overall (General and Complete Disarmament). Addressing the post-WTC tragedy, 11 September 2001, the Indonesian government should set up a National Measures (National Action Plan), among others formed the National Security Council and NBC Counter Proliferation Unit, or the National Authority for Nuclear Treaty, preparing national legislation, to prevent the abuse nuclear materials for terrorist acts, prevent Illicit Trafficking of Nuclear materials, developed a National Preparedness and Emergency Response Management in the event of a nuclear accident or attack by the use of nuclear terrorism. Importance of a National Action Plan meant the existence of a national commitment in the context of compliance with treaties and conventions which have been ratified relating to safety, security, safeguards towards a general and complete disarmament, to safeguard national security and maintain peace (safeguards) international

  19. Initiatives for proliferation prevention

    International Nuclear Information System (INIS)

    1997-04-01

    Preventing the proliferation of weapons of mass destruction is a central part of US national security policy. A principal instrument of the Department of Energy's (DOE's) program for securing weapons of mass destruction technology and expertise and removing incentives for scientists, engineers and technicians in the newly independent states (NIS) of the former Soviet Union to go to rogue countries or assist terrorist groups is the Initiatives for Proliferation Prevention (IPP). IPP was initiated pursuant to the 1994 Foreign Operations Appropriations Act. IPP is a nonproliferation program with a commercialization strategy. IPP seeks to enhance US national security and to achieve nonproliferation objectives by engaging scientists, engineers and technicians from former NIS weapons institutes; redirecting their activities in cooperatively-developed, commercially viable non-weapons related projects. These projects lead to commercial and economic benefits for both the NIS and the US IPP projects are funded in Russian, Ukraine, Kazakhstan and Belarus. This booklet offers an overview of the IPP program as well as a sampling of some of the projects which are currently underway

  20. Uncertainties in Nuclear Proliferation Modeling

    International Nuclear Information System (INIS)

    Kim, Chul Min; Yim, Man-Sung; Park, Hyeon Seok

    2015-01-01

    There have been various efforts in the research community to understand the determinants of nuclear proliferation and develop quantitative tools to predict nuclear proliferation events. Such systematic approaches have shown the possibility to provide warning for the international community to prevent nuclear proliferation activities. However, there are still large debates for the robustness of the actual effect of determinants and projection results. Some studies have shown that several factors can cause uncertainties in previous quantitative nuclear proliferation modeling works. This paper analyzes the uncertainties in the past approaches and suggests future works in the view of proliferation history, analysis methods, and variable selection. The research community still lacks the knowledge for the source of uncertainty in current models. Fundamental problems in modeling will remain even other advanced modeling method is developed. Before starting to develop fancy model based on the time dependent proliferation determinants' hypothesis, using graph theory, etc., it is important to analyze the uncertainty of current model to solve the fundamental problems of nuclear proliferation modeling. The uncertainty from different proliferation history coding is small. Serious problems are from limited analysis methods and correlation among the variables. Problems in regression analysis and survival analysis cause huge uncertainties when using the same dataset, which decreases the robustness of the result. Inaccurate variables for nuclear proliferation also increase the uncertainty. To overcome these problems, further quantitative research should focus on analyzing the knowledge suggested on the qualitative nuclear proliferation studies

  1. Proliferation: myth or reality?; La proliferation: mythe ou realite?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This article analyzes the proliferation approach, its technical condition and political motivation, and the share between the myth (political deception, assumptions and extrapolations) and the reality of proliferation. Its appreciation is complicated by the irrational behaviour of some political actors and by the significant loss of the non-use taboo. The control of technologies is an important element for proliferation slowing down but an efficient and autonomous intelligence system remains indispensable. (J.S.)

  2. Dispersal of forest insects

    Science.gov (United States)

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  3. Improved new generation dispersants

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The use of dispersants to combat oil spills has attracted controversy over the years, and there has been a number of accusations of the chemicals involved doing more harm than good. A new study by the International Petroleum Industry Environmental Conservation Association discusses the positive and the negatives of dispersant use to be considered when drawing up spill contingency plans. (author)

  4. The nuclear proliferation

    International Nuclear Information System (INIS)

    Gere, F.

    1995-04-01

    In this book is detailed the beginning of nuclear military power, with the first bomb of Hiroshima, the different ways of getting uranium 235 and plutonium 239, and how the first countries (Usa, Ussr, China, United kingdom, France) got nuclear weapons. Then the most important part is reviewed with the details of non-proliferation treaty and the creation of IAEA to promote civilian nuclear power in the world and to control the use of plutonium and uranium in nuclear power plants. The cases of countries who reached the atom mastery, such Israel, South Africa, Pakistan, Iraq, North Korea, Argentina, Brazil, Iran, Algeria, Taiwan and the reasons which they wanted nuclear weapon for or why they gave up, are exposed

  5. Dispersal and metapopulation stability

    Directory of Open Access Journals (Sweden)

    Shaopeng Wang

    2015-10-01

    Full Text Available Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.

  6. Romania non-proliferation policy

    International Nuclear Information System (INIS)

    Biro, Lucian; Grama, Viviana

    2001-01-01

    Full text: Non-proliferation concept in Romania is based on the Treaty on the Non-proliferation of Nuclear Weapons, which was ratified in 1970. According to the Article III of the Treaty, Romania ratified in 1972, the Agreement between Romania and IAEA for the application of Safeguards in connection with the Treaty on the Non-proliferation of Nuclear Weapons. In 2000 Romania ratified the Additional Protocol to contribute through increased transparency, to confidence that no undeclared nuclear activities are concealed within the declared programme or make use of elements of that programme. Under the Additional Protocol Romania understands to increase the transparency of its nuclear activities lengthways fuel cycle. Romania has a strong legal framework to control nuclear material and nuclear activities. The Law 111/1996, republished is the Law on the safe deployment of nuclear activities. CNCAN issued National Regulations for Safeguards and Physical Protection. Prospecting for uranium in Romania was initiated in 1950. Between 1962 and 1978 all the uranium ore production was stockpiled at the mine sites. In 1978 the Feldioara Powder Plant was commissioned, since then both ore stockpiles and ore exploited have been processed to uranium chemical concentrates. The Powder Plant Feldioara was conceived and built following the necessity of milling and processing the uranium ore to UO 2 , in concordance with the national nuclear programme in order to produce electric energy from nuclear fuel. The Nuclear Fuel Plant has capability to manufacture CANDU-6 nuclear fuel. Nuclear Fuel Plant consists of two Production areas, the Quality Assurance and Engineering Departments. There are two Production Departments: Pelleting area including granulation, pressing, sintering, pellet grinding, uranium recycling and Assembling area including components fabrication, beryllium coating, brazing, graphite coating, fuel element and bundle assembly welding. Romania's Strategy for Energy Sector

  7. Study on evaluation methods for Rayleigh wave dispersion characteristic

    Science.gov (United States)

    Shi, L.; Tao, X.; Kayen, R.; Shi, H.; Yan, S.

    2005-01-01

    The evaluation of Rayleigh wave dispersion characteristic is the key step for detecting S-wave velocity structure. By comparing the dispersion curves directly with the spectra analysis of surface waves (SASW) method, rather than comparing the S-wave velocity structure, the validity and precision of microtremor-array method (MAM) can be evaluated more objectively. The results from the China - US joint surface wave investigation in 26 sites in Tangshan, China, show that the MAM has the same precision with SASW method in 83% of the 26 sites. The MAM is valid for Rayleigh wave dispersion characteristic testing and has great application potentiality for site S-wave velocity structure detection.

  8. Spatial characterization of catchment dispersion mechanisms in an urban context

    Science.gov (United States)

    Rossel, Florian; Gironás, Jorge; Mejía, Alfonso; Rinaldo, Andrea; Rodriguez, Fabrice

    2014-12-01

    Previous studies have examined in-depth the dispersion mechanisms in natural catchments. In contrast, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. This has the ability to modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. The U-McIUH computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment in France as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion in the catchment, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further study with other catchments is needed to asses if the latter is a general feature of urban drainage networks.

  9. A costal dispersion model

    International Nuclear Information System (INIS)

    Rahm, L.; Nyberg, L.; Gidhagen, L.

    1990-01-01

    A dispersion model to be used off costal waters has been developed. The model has been applied to describe the migration of radionuclides in the Baltic sea. A summary of the results is presented here. (K.A.E)

  10. Wave-equation dispersion inversion

    KAUST Repository

    Li, Jing; Feng, Zongcai; Schuster, Gerard T.

    2016-01-01

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained

  11. Reactimeter dispersion equation

    OpenAIRE

    A.G. Yuferov

    2016-01-01

    The aim of this work is to derive and analyze a reactimeter metrological model in the form of the dispersion equation which connects reactimeter input/output signal dispersions with superimposed random noise at the inlet. It is proposed to standardize the reactimeter equation form, presenting the main reactimeter computing unit by a convolution equation. Hence, the reactimeter metrological characteristics are completely determined by this unit hardware function which represents a transient re...

  12. Fickian dispersion is anomalous

    Science.gov (United States)

    Cushman, John H.; O'Malley, Dan

    2015-12-01

    The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

  13. Nuclear proliferation: linkages and solutions

    International Nuclear Information System (INIS)

    Quester, G.H.

    1979-01-01

    Nuclear proliferation must be periodically re-examined as a moral as well as a practical foreign policy dilemma. The question is asked whether proliferation precludes a safe and peaceful world, or if a halt to proliferation is adequate without other arms control. The moral dilemma in foreign policy arises over the need to make practical choices which often serve one goal while sacrificing another. The ramifications of nuclear proliferation are examined and the conclusions reached that it is not an acceptable option. It is also decided that, because general disarmament steps will be more difficult to achieve, the world may have to accept a small number of nuclear arsenals as the price of state sovereignties. A high priority for making the effort to prevent proliferation is advised. 8 references

  14. Thorium cycles and proliferation

    International Nuclear Information System (INIS)

    Lovins, A.B.

    1979-01-01

    This paper analyzes several prevalent misconceptions about nuclear fuel cycles that breed fissile uranium-233 from thorium. Its main conclusions are: U-233, despite the gamma radioactivity of associated isotopes, is a rather attractive material for making fission bombs, and is a credible material for subnational as well as national groups to use for this purpose; (2) pure thorium cycles, which in effect merely substitute U-233 for Pu, would take many decades and much U to establish, and offer no significant safeguards advantage over Pu, cycles; (3) denatured Th-U cycles, which dilute the U-233 with inert U-238 to a level not directly usable in bombs, are not an effective safeguard even against subnational bomb-making; (4) several other features of mixed Th-U cycles are rather unattractive from a safeguards point of view; (5) thus, Th cycles of any kind are not a technical fix for proliferation (national or subnational) and, though probably more safeguardable than Pu cycles, are less so than once-through U cycles that entail no reprocessing; (6) while thorium cycles have some potential technical advantages, including flexibility, they cannot provide major savings in nuclear fuel resources compared to simpler ways of saving neutrons and U; and (7) while advocates of nuclear power may find Th cycles worth exploring, such cycles do not differ fundamentally from U cycles in any of the respects--including safeguards and fuel resources--that are relevant to the broader nuclear debate, and should not be euphorically embraced as if they did

  15. Theoretical Approaches to Nuclear Proliferation

    Directory of Open Access Journals (Sweden)

    Konstantin S. Tarasov

    2015-01-01

    Full Text Available This article analyses discussions between representatives of three schools in the theory of international relations - realism, liberalism and constructivism - on the driving factors of nuclear proliferation. The paper examines major theoretical approaches, outlined in the studies of Russian and foreign scientists, to the causes of nuclear weapons development, while unveiling their advantages and limitations. Much of the article has been devoted to alternative approaches, particularly, the role of mathematical modeling in assessing proliferation risks. The analysis also reveals a variety of different approaches to nuclear weapons acquisition, as well as the absence of a comprehensive proliferation theory. Based on the research results the study uncovers major factors both favoring and impeding nuclear proliferation. The author shows that the lack of consensus between realists, liberals and constructivists on the nature of proliferation led a number of scientists to an attempt to explain nuclear rationale by drawing from the insights of more than one school in the theory of IR. Detailed study of the proliferation puzzle contributes to a greater understating of contemporary international realities, helps to identify mechanisms that are most likely to deter states from obtaining nuclear weapons and is of the outmost importance in predicting short- and long-term security environment. Furthermore, analysis of the existing scientific literature on nuclear proliferation helps to determine future research agenda of the subject at hand.

  16. Nuclear non proliferation and disarmament

    International Nuclear Information System (INIS)

    2000-01-01

    In the framework of the publication of a document on the ''weapons mastership, disarmament and non proliferation: the french action'', by the ministry of Foreign Affairs and the ministry of Defense, the French Documentation organization presents a whole document. This document describes and details the following topics: the conference on the treaty of non proliferation of nuclear weapons, the France, Usa and Non Governmental Organizations position, the threats of the proliferation, the french actions towards the disarmament, the disarmament in the world, a chronology and some bibliographic resources. (A.L.B.)

  17. International proliferation on nuclear weapons

    International Nuclear Information System (INIS)

    Hill, J.

    1977-01-01

    The subject is dealt with under the following headings: introduction; routes to proliferation (preparation of U 235 , Pu 239 , U 233 ); nuclear power fuel cycles and proliferation; the fast reactor fuel cycle; security aspects of the existing fuel cycle; the IAEA and the nuclear non-proliferation treaty. It is concluded that 'the basis for sound international control exists, and taken together with the further technical steps which will be taken to make the existing fuel cycles more robust against the diversion of materials by terrorists and the abuse of civil nuclear power programmes by governments, we have good reason to proceed now with the orderly exploitation of ...nuclear energy...'. (U.K.)

  18. Cell proliferation is necessary for the regeneration of oral structures in the anthozoan cnidarian Nematostella vectensis

    Directory of Open Access Journals (Sweden)

    Passamaneck Yale J

    2012-12-01

    Full Text Available Abstract Background The contribution of cell proliferation to regeneration varies greatly between different metazoan models. Planarians rely on pluripotent neoblasts and amphibian limb regeneration depends upon formation of a proliferative blastema, while regeneration in Hydra can occur in the absence of cell proliferation. Recently, the cnidarian Nematostella vectensis has shown potential as a model for studies of regeneration because of the ability to conduct comparative studies of patterning during embryonic development, asexual reproduction, and regeneration. The present study investigates the pattern of cell proliferation during the regeneration of oral structures and the role of cell proliferation in this process. Results In intact polyps, cell proliferation is observed in both ectodermal and endodermal tissues throughout the entire oral-aboral axis, including in the tentacles and physa. Following bisection, there is initially little change in proliferation at the wound site of the aboral fragment, however, beginning 18 to 24 hours after amputation there is a dramatic increase in cell proliferation at the wound site in the aboral fragment. This elevated level of proliferation is maintained throughout the course or regeneration of oral structures, including the tentacles, the mouth, and the pharynx. Treatments with the cell proliferation inhibitors hydroxyurea and nocodazole demonstrate that cell proliferation is indispensable for the regeneration of oral structures. Although inhibition of regeneration by nocodazole was generally irreversible, secondary amputation reinitiates cell proliferation and regeneration. Conclusions The study has found that high levels of cell proliferation characterize the regeneration of oral structures in Nematostella, and that this cell proliferation is necessary for the proper progression of regeneration. Thus, while cell proliferation contributes to regeneration of oral structures in both Nematostella and

  19. Reliability benefits of dispersed wind resource development

    International Nuclear Information System (INIS)

    Milligan, M.; Artig, R.

    1998-05-01

    Generating capacity that is available during the utility peak period is worth more than off-peak capacity. Wind power from a single location might not be available during enough of the peak period to provide sufficient value. However, if the wind power plant is developed over geographically disperse locations, the timing and availability of wind power from these multiple sources could provide a better match with the utility's peak load than a single site. There are other issues that arise when considering disperse wind plant development. Singular development can result in economies of scale and might reduce the costs of obtaining multiple permits and multiple interconnections. However, disperse development can result in cost efficiencies if interconnection can be accomplished at lower voltages or at locations closer to load centers. Several wind plants are in various stages of planning or development in the US. Although some of these are small-scale demonstration projects, significant wind capacity has been developed in Minnesota, with additional developments planned in Wyoming, Iowa and Texas. As these and other projects are planned and developed, there is a need to perform analysis of the value of geographically disperse sites on the reliability of the overall wind plant.This paper uses a production-cost/reliability model to analyze the reliability of several wind sites in the state of Minnesota. The analysis finds that the use of a model with traditional reliability measures does not produce consistent, robust results. An approach based on fuzzy set theory is applied in this paper, with improved results. Using such a model, the authors find that system reliability can be optimized with a mix of disperse wind sites

  20. Coping with power dispersion?

    DEFF Research Database (Denmark)

    2014-01-01

    The last decades have witnessed a significant shift in policy competences away from central governments in Europe. The reallocation of competences spans over three dimensions: upwards; sideways; and downwards. This collection takes the dispersion of powers as a starting point and seeks to assess...... how the actors involved cope with the new configurations. In this introduction, we discuss the conceptualization of power dispersion and highlight the ways in which the contributions add to this research agenda. We then outline some general conclusions and end by indicating future avenues of research....... Taken together, the collection contributes some answers to the challenge of defining and measuring – in a comparative way – the control and co-ordination mechanisms which power dispersion generates. It also explores the tension between political actors' quest for autonomy and the acknowledgement...

  1. Energy dispersive X-ray fluorescence spectroscopy/Monte Carlo simulation approach for the non-destructive analysis of corrosion patina-bearing alloys in archaeological bronzes: The case of the bowl from the Fareleira 3 site (Vidigueira, South Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Bottaini, C. [Hercules Laboratory, University of Évora, Palacio do Vimioso, Largo Marquês de Marialva 8, 7000-809 Évora (Portugal); Mirão, J. [Hercules Laboratory, University of Évora, Palacio do Vimioso, Largo Marquês de Marialva 8, 7000-809 Évora (Portugal); Évora Geophysics Centre, Rua Romão Ramalho 59, 7000 Évora (Portugal); Figuereido, M. [Archaeologist — Monte da Capelinha, Apartado 54, 7005, São Miguel de Machede, Évora (Portugal); Candeias, A. [Hercules Laboratory, University of Évora, Palacio do Vimioso, Largo Marquês de Marialva 8, 7000-809 Évora (Portugal); Évora Chemistry Centre, Rua Romão Ramalho 59, 7000 Évora (Portugal); Brunetti, A. [Department of Political Science and Communication, University of Sassari, Via Piandanna 2, 07100 Sassari (Italy); Schiavon, N., E-mail: schiavon@uevora.pt [Hercules Laboratory, University of Évora, Palacio do Vimioso, Largo Marquês de Marialva 8, 7000-809 Évora (Portugal); Évora Geophysics Centre, Rua Romão Ramalho 59, 7000 Évora (Portugal)

    2015-01-01

    Energy dispersive X-ray fluorescence (EDXRF) is a well-known technique for non-destructive and in situ analysis of archaeological artifacts both in terms of the qualitative and quantitative elemental composition because of its rapidity and non-destructiveness. In this study EDXRF and realistic Monte Carlo simulation using the X-ray Monte Carlo (XRMC) code package have been combined to characterize a Cu-based bowl from the Iron Age burial from Fareleira 3 (Southern Portugal). The artifact displays a multilayered structure made up of three distinct layers: a) alloy substrate; b) green oxidized corrosion patina; and c) brownish carbonate soil-derived crust. To assess the reliability of Monte Carlo simulation in reproducing the composition of the bulk metal of the objects without recurring to potentially damaging patina's and crust's removal, portable EDXRF analysis was performed on cleaned and patina/crust coated areas of the artifact. Patina has been characterized by micro X-ray Diffractometry (μXRD) and Back-Scattered Scanning Electron Microscopy + Energy Dispersive Spectroscopy (BSEM + EDS). Results indicate that the EDXRF/Monte Carlo protocol is well suited when a two-layered model is considered, whereas in areas where the patina + crust surface coating is too thick, X-rays from the alloy substrate are not able to exit the sample. - Highlights: • EDXRF/Monte Carlo simulation is used to characterize an archeological alloy. • EDXRF analysis was performed on cleaned and patina coated areas of the artifact. • EDXRF/Montes Carlo protocol is well suited when a two-layered model is considered. • When the patina is too thick, X-rays from substrate are unable to exit the sample.

  2. Non-proliferation and nuclear data

    International Nuclear Information System (INIS)

    Sowerby, M.G.

    1978-01-01

    A review is made of the problem of the proliferation of nuclear weapons with particular emphasis on proliferation and nuclear power. Some indications of the nuclear data requirements associated with methods of reducing proliferation risks are presented

  3. Intermittent pressure decreases human keratinocyte proliferation in vitro.

    Science.gov (United States)

    Nasca, Maria R; Shih, Alan T; West, Dennis P; Martinez, Wanda M; Micali, Giuseppe; Landsman, Adam S

    2007-01-01

    The aim of this study was to investigate the correlation between pressure changes and keratinocyte proliferation by determining whether keratinocytes exposed to altered mechanical pressures would proliferate at different rates compared to control cells not subjected to pressure changes. Tissue culture flasks of human keratinocytes plated at an approximate density of 15,000 cells/cm(2) undergoing an intermittent cyclic pressure of 362 mm Hg at a frequency of 2.28 or 5.16 cycles/min (0.038 or 0.086 Hz) for 8 h were compared to control flasks grown at ambient room pressure. An in-line pressure transducer was used to monitor and adjust pressure within the cell chambers, using a solenoid valve. A thymidine incorporation assay assessed the amount of cell proliferation in each set of experiments. Differences in proliferation between keratinocytes subjected to cyclic pressure changes and control cells were found to be statistically significant (p < 0.05) in 4 out of 5 proliferation assays. Also, a higher frequency of pressure changes consistently generated a reduced proliferation rate compared to that seen in cells exposed to a lower frequency of pressure changes. These data indicate that keratinocytes undergoing intermittent pressure changes exhibit decreased proliferation rates compared to controls. Furthermore, an increased frequency rate seems to have a greater effect on proliferation than low-frequency rate pressure changes, suggesting that the stress caused by frequently changed pressure may play a greater role in reducing keratinocyte proliferation than the actual magnitude of load applied to the cells. Our results support the current treatment protocol of reducing speed and duration of walking on the site of the wound to promote healing of foot ulcers. (c) 2007 S. Karger AG, Basel.

  4. In vitro proliferation of adult human beta-cells.

    Directory of Open Access Journals (Sweden)

    Sabine Rutti

    Full Text Available A decrease in functional beta-cell mass is a key feature of type 2 diabetes. Glucagon-like peptide 1 (GLP-1 analogues induce proliferation of rodent beta-cells. However, the proliferative capacity of human beta-cells and its modulation by GLP-1 analogues remain to be fully investigated. We therefore sought to quantify adult human beta-cell proliferation in vitro and whether this is affected by the GLP-1 analogue liraglutide.Human islets from 7 adult cadaveric organ donors were dispersed into single cells. Beta-cells were purified by FACS. Non-sorted cells and the beta-cell enriched ("beta-cells" population were plated on extracellular matrix from rat (804G and human bladder carcinoma cells (HTB9 or bovine corneal endothelial ECM (BCEC. Cells were maintained in culture+/-liraglutide for 4 days in the presence of BrdU.Rare human beta-cell proliferation could be observed either in the purified beta-cell population (0.051±0.020%; 22 beta-cells proliferating out of 84'283 beta-cells counted or in the non-sorted cell population (0.055±0.011%; 104 proliferating beta-cells out of 232'826 beta-cells counted, independently of the matrix or the culture conditions. Liraglutide increased human beta-cell proliferation on BCEC in the non-sorted cell population (0.082±0.034% proliferating beta-cells vs. 0.017±0.008% in control, p<0.05.These results indicate that adult human beta-cell proliferation can occur in vitro but remains an extremely rare event with these donors and particular culture conditions. Liraglutide increases beta-cell proliferation only in the non-sorted cell population and only on BCEC. However, it cannot be excluded that human beta-cells may proliferate to a greater extent in situ in response to natural stimuli.

  5. Nuclear risk from atmospheric dispersion in Northern Europe - Summary Report

    DEFF Research Database (Denmark)

    Lauritzen, Bent

    The objective of the NordRisk II project has been to derive practical means for assessing the risks from long-range atmospheric dispersion of radioac-tive materials. An atlas over different atmospheric dispersion and deposi-tion scenarios has been developed using historical numerical weather pre......-diction (NWP) model data. The NWP model data covers three years span-ning the climate variability associated with the North Atlantic Oscillation, and the atlas considers radioactive releases from 16 release sites in and near the Nordic countries. A statistical analysis of the long-range disper......-sion and deposition patterns is undertaken to quantify the mean dispersion and deposition as well as the variability. Preliminary analyses show that the large-scale atmospheric dispersion and deposition is near-isotropic, irrespective of the release site and detailed climatology, and allows for a simple...

  6. Feasibility of using Ohmsett for dispersant testing and research

    International Nuclear Information System (INIS)

    Ross, S.L.; Buist, I.A.; Potter, S.G.; Belore, R.C.

    2000-01-01

    Laboratory dispersant testing proved to be of limited value for the prediction of actual dispersant effectiveness in spill situations. Variables such as oil type, weathered state, dispersant type, dispersant-to-oil ratio application method etc. were difficult to reproduce. A feasibility study was conducted at the Ohmsett facility in Leonardo, New Jersey to determine if the site was suitable for dispersant effectiveness testing. The study consisted of four phases: (1) interfacial tension laboratory tests, (2) turbidity tests, (3) the determination of the efficiency of filtering materials at the facility and alternative filtering materials, and (3) full-scale testing. Results indicated that dispersant in the water after the tests affected the interfacial tension of oils used in other tests following this one. Noticeable dispersion of floating oil occurred only after the concentration of dispersant in the water reached 400 ppm, making it possible to conduct consecutive experiments without having to worry about residual dispersant in the tank. The filtering of water to remove the dispersed oil was only required after several experiments had taken place on a given day. Evidently, it was only possible to have an underwater view of the dispersant testing during the first test of a series. The use of cellulose to aid the filtering at the facility removed most of the dispersed oil. The use of activated carbon resulted in a high degree of efficiency for the removal of dissolved dispersant. The testing of dispersant at Ohmsett proved possible as long as the design and implementation phases of the testing program respected the limitations stipulated above. 3 refs., 3 tabs., 3 figs

  7. Interface, a dispersed architecture

    NARCIS (Netherlands)

    Vissers, C.A.

    1976-01-01

    Past and current specification techniques use timing diagrams and written text to describe the phenomenology of an interface. This paper treats an interface as the architecture of a number of processes, which are dispersed over the related system parts and the message path. This approach yields a

  8. Psychorheology of food dispersions

    Czech Academy of Sciences Publication Activity Database

    Štern, Petr; Panovská, Z.; Pokorný, J.

    2010-01-01

    Roč. 58, č. 1 (2010), s. 29-35 ISSN 0042-790X R&D Projects: GA AV ČR IAA2060404 Institutional research plan: CEZ:AV0Z20600510 Keywords : psychorheology * food dispersions * tomato ketchup * rheology * sensory analysis Subject RIV: BK - Fluid Dynamics Impact factor: 0.553, year: 2010

  9. Dispersal of sticky particles

    Science.gov (United States)

    Reddy, Ramana; Kumar, Sanjeev

    2007-12-01

    In this paper, we show through simulations that when sticky particles are broken continually, particles are dispersed into fine dust only if they are present in a narrow range of volume fractions. The upper limit of this range is 0.20 in the 2D and 0.10 in the 3D space. An increase in the dimensionality of space reduces the upper limit nearly by a factor of two. This scaling holds for dispersal of particles in hyperdimensional space of dimensions up to ten, the maximum dimension studied in this work. The maximum values of volume fractions obtained are significantly lower than those required for close packing and random packing of discs in 2D and spheres in 3D space. These values are also smaller than those required for critical phenomena of cluster percolation. The results obtained are attributed to merger cascades of sticky particles, triggered by breakup events. A simple theory that incorporates this cascade is developed to quantitatively explain the observed scaling of the upper limit with the dimensionality of space. The theory also captures the dynamics of the dispersal process in the corresponding range of particle volume fractions. The theory suggests that cascades of order one and two predominantly decide the upper limit for complete dispersal of particles.

  10. Infrasonic measurements of the Non-Proliferation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, R.W.; Noel, S.; Meadows, W. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    Two infrasonic arrays were operated for the Non-Proliferation Experiment (NPE). The arrays were located at the Nevada Test Site and at St. George, UT. The results were consistent with experience on underground tests, and therefore close to underground nuclear tests of similar size.

  11. Estimating plume dispersion: a comparison of several sigma schemes

    International Nuclear Information System (INIS)

    Irwin, J.S.

    1983-01-01

    The lateral and vertical Gaussian plume dispersion parameters are estimated and compared with field tracer data collected at 11 sites. The dispersion parameter schemes used in this analysis include Cramer's scheme, suggested for tall stack dispersion estimates, Draxler's scheme, suggested for elevated and surface releases, Pasquill's scheme, suggested for interim use in dispersion estimates, and the Pasquill--Gifford scheme using Turner's technique for assigning stability categories. The schemes suggested by Cramer, Draxler and Pasquill estimate the dispersion parameters using onsite measurements of the vertical and lateral wind-velocity variances at the effective release height. The performances of these schemes in estimating the dispersion parameters are compared with that of the Pasquill--Gifford scheme, using the Prairie Grass and Karlsruhe data. For these two experiments, the estimates of the dispersion parameters using Draxler's scheme correlate better with the measurements than did estimates using the Pasquill--Gifford scheme. Comparison of the dispersion parameter estimates with the measurement suggests that Draxler's scheme for characterizing the dispersion results in the smallest mean fractional error in the estimated dispersion parameters and the smallest variance of the fractional errors

  12. Mars Exploration Rovers Landing Dispersion Analysis

    Science.gov (United States)

    Knocke, Philip C.; Wawrzyniak, Geoffrey G.; Kennedy, Brian M.; Desai, Prasun N.; Parker, TImothy J.; Golombek, Matthew P.; Duxbury, Thomas C.; Kass, David M.

    2004-01-01

    Landing dispersion estimates for the Mars Exploration Rover missions were key elements in the site targeting process and in the evaluation of landing risk. This paper addresses the process and results of the landing dispersion analyses performed for both Spirit and Opportunity. The several contributors to landing dispersions (navigation and atmospheric uncertainties, spacecraft modeling, winds, and margins) are discussed, as are the analysis tools used. JPL's MarsLS program, a MATLAB-based landing dispersion visualization and statistical analysis tool, was used to calculate the probability of landing within hazardous areas. By convolving this with the probability of landing within flight system limits (in-spec landing) for each hazard area, a single overall measure of landing risk was calculated for each landing ellipse. In-spec probability contours were also generated, allowing a more synoptic view of site risks, illustrating the sensitivity to changes in landing location, and quantifying the possible consequences of anomalies such as incomplete maneuvers. Data and products required to support these analyses are described, including the landing footprints calculated by NASA Langley's POST program and JPL's AEPL program, cartographically registered base maps and hazard maps, and flight system estimates of in-spec landing probabilities for each hazard terrain type. Various factors encountered during operations, including evolving navigation estimates and changing atmospheric models, are discussed and final landing points are compared with approach estimates.

  13. Future non-proliferation challenges

    International Nuclear Information System (INIS)

    Yelchenko, Volodymyr

    2008-01-01

    Having chaired the Second Session of the Preparatory Committee Mr. Volodymyr Yelchenko noted that the NPT States parties reaffirmed the important role of the Treaty as the cornerstone of the global non-proliferation regime. They stressed that non-compliance with the Treaty provisions by States parties undermined non-proliferation and placed emphasis on the mutually reinforcing nature of disarmament and non-proliferation, and due respect for the right of States parties to the peaceful use of nuclear energy in conformity with the treaty. They reaffirmed the importance of promoting the peaceful uses of nuclear energy and international nuclear cooperation for peaceful purposes in ways consistent with the non-proliferation goal of the Treaty. The universality aspect was brought to the front with the lack of progress in this area. States parties called upon India, Israel and Pakistan to accede to the Treaty as non-nuclear-weapons states, promptly and without conditions and to bring into force comprehensive safeguards agreements, together with Additional Protocols, for ensuring non-proliferation. There is concern that non-States actors could gain access to weapons of mass destruction. One of the underlying themes at the Second Prepcom was the total elimination of nuclear weapons as the only absolute guarantee against their proliferation. Negative consequences to nuclear non-proliferation were also mentioned in the context of the abrogation of the Anti-Ballistic Missile Treaty and the development of missile defense systems, with the risk of a new arms race on Earth and in outer space. The importance of the immediate commencement of negotiations in the Conference of Disarmament on a treaty concerning fissile material for nuclear weapons or other nuclear explosive devices and the urgent conclusion of such a treaty as a beneficial step towards non-proliferation was stressed. The NPT states parties reaffirmed the role of the IAEA as the sole competent authority responsible for

  14. Malignant proliferating trichilemmal tumour presenting early in life: An uncommon feature

    Directory of Open Access Journals (Sweden)

    Shalinee Rao

    2011-01-01

    Full Text Available Malignant proliferating trichilemmal tumour is a rare cutaneous malignant neoplasm usually occurring in elderly women. We present a case of malignant trichilemmal tumour in a young lady of 26 years of age with a previous history of proliferating trichilemmal tumour at the same site.

  15. Dispersed flow film boiling

    International Nuclear Information System (INIS)

    Andreani, M.; Yadigaroglu, G.

    1989-12-01

    Dispersed flow film boiling is the heat transfer regime that occurs at high void fractions in a heated channel. The way this transfer mode is modelled in the NRC computer codes (RELAP5 and TRAC) and the validity of the assumption and empirical correlations used is discussed. An extensive review of the theoretical and experimental work related with heat transfer to highly dispersed mixtures reveals the basic deficiencies of these models: the investigation refers mostly to the typical conditions of low rate bottom reflooding, since the simulation of this physical situation by the computer codes has often showed poor results. The alternative models that are available in the literature are reviewed, and their merits and limits are highlighted. The modification that could improve the physics of the models implemented in the codes are identified. (author) 13 figs., 123 refs

  16. Working document dispersion models

    International Nuclear Information System (INIS)

    Dop, H. van

    1988-01-01

    This report is a summary of the most important results from June 1985 of the collaboration of the RIVM (Dutch National Institute for Public Health and Environment Hygiene) and KNMI (Royal Dutch Meteorologic Institute) on the domain of dispersion models. It contains a short description of the actual SO x /NO x -model. Furthermore it contains recommendations for modifications of some numerical-mathematical aspects and an impulse to a more complete description of chemical processes in the atmosphere and the (wet) deposition process. A separate chapter is devoted to the preparation of meteorologic data which are relevant for dispersion as well as atmospheric chemistry and deposition. This report serves as working document for the final formulation of a acidifying- and oxidant-model. (H.W.). 69 refs.; 51 figs.; 13 tabs.; 3 schemes

  17. Spatially Dispersed Employee Recovery

    DEFF Research Database (Denmark)

    Hvass, Kristian Anders; Torfadóttir, Embla

    2014-01-01

    Employee recovery addresses either employee well-being or management's practices in aiding employees in recovering themselves following a service failure. This paper surveys the cabin crew at a small, European, low-cost carrier and investigates employees' perceptions of management practices to aid...... personnel achieve service recovery. Employee recovery within service research often focuses on front-line employees that work in a fixed location, however a contribution to the field is made by investigating the recovery of spatially dispersed personnel, such as operational personnel in the transport sector......, who have a work place away from a fixed or central location and have minimal management contact. Results suggest that the support employees receive from management, such as recognition, information sharing, training, and strategic awareness are all important for spatially dispersed front...

  18. Heat dispersion in rivers

    International Nuclear Information System (INIS)

    Shaw, T.L.

    1974-01-01

    One of the tasks of the Sonderforschungsbereich 80 is to study the dispersion of heat discharged into rivers and other bodies of water and to develop methods which permit prediction of detrimental effects caused by the heated discharges. In order to help the SFB 80 to specify this task, Dr. Shaw, lecturer of Civil Engineering at the Bristol University, conducted a literature survey on heat-dispersion studies during the two months which he spent as a visiting research fellow with the SFB 80 at the University of Karlsruhe in the summer of 1973. The following report is the outcome of this survey. It gives Dr. Shaw's assessment of the present state of knowledge - based almost exclusively on literature in the English language - and compares this with the knowledge required by river planners. The apparent discrepancy leads to suggestions for future research. Selected references as well as a representative bibliography can be found at the end of the report. (orig.) [de

  19. Nuclear proliferation and safeguards. Summary

    International Nuclear Information System (INIS)

    1982-03-01

    This comprehensive analysis of the technological, economic, and political factors affecting the potential spread of nuclear weapons proved useful in the congressional debate which culminated in the Nuclear Non-Proliferation Act of 1978. The report was subsequently published commercially and has been a frequently cited reference in the literature on proliferation and nuclear power. Despite developments since 1977, the information in the OTA report is still useful to those wishing to obtain an indepth understanding of the issues. Included is an analysis of why a nation might want nuclear weapons development program and the various sources of nuclear material are discussed. The control of proliferation is considered as well as its relation to the nuclear industry

  20. Domestic Politics and Nuclear Proliferation

    International Nuclear Information System (INIS)

    Kim, Chul Min; Yim, Man Sung

    2016-01-01

    The external security threat is known as the most important factor of nuclear weapons program, the domestic politics situation can also affect the nuclear proliferation decision of a country. For example, when a leader wants nuclear weapons as an ultimate weapon, the domestic politics situation can determine the effectiveness of the weapons program of a country. This study analyzes the current knowledge of the relationship between domestic politics and nuclear proliferation and suggests the main challenges of the quantitative models trying to calculate nuclear proliferation risk of countries. The domestic politics status is one of the most important indicators of nuclear program. However, some variables have never been used in quantitative analyses; for example, number of veto players and the public opinion on nuclear weapons; despite they are considered to be important in various qualitative studies. Future studies should focus on how should they be coded and how can they be linked with existing domestic politics variables

  1. Domestic Politics and Nuclear Proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chul Min; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The external security threat is known as the most important factor of nuclear weapons program, the domestic politics situation can also affect the nuclear proliferation decision of a country. For example, when a leader wants nuclear weapons as an ultimate weapon, the domestic politics situation can determine the effectiveness of the weapons program of a country. This study analyzes the current knowledge of the relationship between domestic politics and nuclear proliferation and suggests the main challenges of the quantitative models trying to calculate nuclear proliferation risk of countries. The domestic politics status is one of the most important indicators of nuclear program. However, some variables have never been used in quantitative analyses; for example, number of veto players and the public opinion on nuclear weapons; despite they are considered to be important in various qualitative studies. Future studies should focus on how should they be coded and how can they be linked with existing domestic politics variables.

  2. Taylor dispersion of nanoparticles

    Science.gov (United States)

    Balog, Sandor; Urban, Dominic A.; Milosevic, Ana M.; Crippa, Federica; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2017-08-01

    The ability to detect and accurately characterize particles is required by many fields of nanotechnology, including materials science, nanotoxicology, and nanomedicine. Among the most relevant physicochemical properties of nanoparticles, size and the related surface-to-volume ratio are fundamental ones. Taylor dispersion combines three independent phenomena to determine particle size: optical extinction, translational diffusion, and sheer-enhanced dispersion of nanoparticles subjected to a steady laminar flow. The interplay of these defines the apparent size. Considering that particles in fact are never truly uniform nor monodisperse, we rigorously address particle polydispersity and calculate the apparent particle size measured by Taylor dispersion analysis. We conducted case studies addressing aqueous suspensions of model particles and large-scale-produced "industrial" particles of both academic and commercial interest of various core materials and sizes, ranging from 15 to 100 nm. A comparison with particle sizes determined by transmission electron microscopy confirms that our approach is model-independent, non-parametric, and of general validity that provides an accurate account of size polydispersity—independently on the shape of the size distribution and without any assumption required a priori.

  3. Ultracentrifuge and non-proliferation

    International Nuclear Information System (INIS)

    Voortman, A.J.

    1977-01-01

    The author states that there is no meaningful difference, from the point of view of proliferation between peaceful, civil, scientific application of nuclear fission, and the use of it in nuclear weapons. The proliferation of the nuclear technology for weapons appeared and appears to be closely connected with the spread of peaceful applications of nuclear technology. In connection with this, he discusses the Ultracentrifuge plant at Almelo (Netherlands) and the supply of nuclear technology by West-Germany especially to Brazil. Further the changed American policy and the possibility of an American/Russian deal to prevent the spread of the nuclear enrichment technology is discussed

  4. Nozzle for electric dispersion reactor

    Science.gov (United States)

    Sisson, W.G.; Basaran, O.A.; Harris, M.T.

    1995-11-07

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

  5. Larval fish dispersal in a coral-reef seascape

    KAUST Repository

    Almany, Glenn R.

    2017-05-23

    Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km2) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13–19 km, with 90% of settlement occurring within 31–43 km. Mean dispersal distances were considerably greater (43–64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

  6. Larval fish dispersal in a coral-reef seascape

    KAUST Repository

    Almany, Glenn R.; Planes, Serge; Thorrold, Simon R.; Berumen, Michael L.; Bode, Michael; Saenz Agudelo, Pablo; Bonin, Mary C.; Frisch, Ashley J.; Harrison, Hugo B.; Messmer, Vanessa; Nanninga, Gerrit B.; Priest, Mark; Srinivasan, Maya; Sinclair-Taylor, Tane; Williamson, David H.; Jones, Geoffrey P.

    2017-01-01

    Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km2) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13–19 km, with 90% of settlement occurring within 31–43 km. Mean dispersal distances were considerably greater (43–64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

  7. Dispersant field testing : a review of procedures and considerations

    International Nuclear Information System (INIS)

    Fingas, M.F.

    2004-01-01

    The effectiveness of a dispersant is defined by the amount of oil that the dispersant puts into the water column compared to the amount of oil that was initially spilled. Effectiveness is generally determined visually in plumes of dispersed oil that are visible from ships and aircraft. This paper describes 25 specific issues and technical concerns regarding field testing of dispersant effectiveness. Recent field tests were reviewed and literature that relates to testing procedures was sited. The 25 factors that are important for the appropriate outcome of dispersant field experiments include: mass balance; proper controls; analytical method; differential plume movement; time lag and length of time followed; mathematics of calculation and integration; lower and upper limits of analytical methods; use of remote sensing; thickness measurement; behaviour of oil with surfactant content; surfactant stripping; tracking surface oil and dispersed oil; recovering surface oil; visibility of oil from the surface; background levels of hydrocarbons; fluorescence of dispersant; herding; emulsion breaking; application success; heterogeneity of slick and plume; deposition measurements; true analytical standards; effect of wind on dispersant and slick; dispersant run-off; and weathering of the oil. It was concluded that the most important factors are the ability to determine mass balance, use proper controls, analytical methods and to avoid procedures that give incorrect results. 34 refs., 4 tabs., 1 fig

  8. Proliferating macrophages prevail in atherosclerosis.

    Science.gov (United States)

    Randolph, Gwendalyn J

    2013-09-01

    Macrophages accumulate in atherosclerotic lesions during the inflammation that is part of atherosclerosis development and progression. A new study in mice indicates that the accumulation of macrophages in atherosclerotic plaques depends on local macrophage proliferation rather than the recruitment of circulating monocytes.

  9. Nuclear Proliferation Technology Trends Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zentner, Michael D.; Coles, Garill A.; Talbert, Robert J.

    2005-10-04

    A process is underway to develop mature, integrated methodologies to address nonproliferation issues. A variety of methodologies (both qualitative and quantitative) are being considered. All have one thing in common, a need for a consistent set of proliferation related data that can be used as a basis for application. One approach to providing a basis for predicting and evaluating future proliferation events is to understand past proliferation events, that is, the different paths that have actually been taken to acquire or attempt to acquire special nuclear material. In order to provide this information, this report describing previous material acquisition activities (obtained from open source material) has been prepared. This report describes how, based on an evaluation of historical trends in nuclear technology development, conclusions can be reached concerning: (1) The length of time it takes to acquire a technology; (2) The length of time it takes for production of special nuclear material to begin; and (3) The type of approaches taken for acquiring the technology. In addition to examining time constants, the report is intended to provide information that could be used to support the use of the different non-proliferation analysis methodologies. Accordingly, each section includes: (1) Technology description; (2) Technology origin; (3) Basic theory; (4) Important components/materials; (5) Technology development; (6) Technological difficulties involved in use; (7) Changes/improvements in technology; (8) Countries that have used/attempted to use the technology; (9) Technology Information; (10) Acquisition approaches; (11) Time constants for technology development; and (12) Required Concurrent Technologies.

  10. Tracer dispersion - experiment and CFD

    International Nuclear Information System (INIS)

    Zitny, R.

    2004-01-01

    Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

  11. High density dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.

    1996-01-01

    A fuel development campaign that results in an aluminum plate-type fuel of unlimited LEU burnup capability with an uranium loading of 9 grams per cm 3 of meat should be considered an unqualified success. The current worldwide approved and accepted highest loading is 4.8 g cm -3 with U 3 Si 2 as fuel. High-density uranium compounds offer no real density advantage over U 3 Si 2 and have less desirable fabrication and performance characteristics as well. Of the higher-density compounds, U 3 Si has approximately a 30% higher uranium density but the density of the U 6 X compounds would yield the factor 1.5 needed to achieve 9 g cm -3 uranium loading. Unfortunately, irradiation tests proved these peritectic compounds have poor swelling behavior. It is for this reason that the authors are turning to uranium alloys. The reason pure uranium was not seriously considered as a dispersion fuel is mainly due to its high rate of growth and swelling at low temperatures. This problem was solved at least for relatively low burnup application in non-dispersion fuel elements with small additions of Si, Fe, and Al. This so called adjusted uranium has nearly the same density as pure α-uranium and it seems prudent to reconsider this alloy as a dispersant. Further modifications of uranium metal to achieve higher burnup swelling stability involve stabilization of the cubic γ phase at low temperatures where normally α phase exists. Several low neutron capture cross section elements such as Zr, Nb, Ti and Mo accomplish this in various degrees. The challenge is to produce a suitable form of fuel powder and develop a plate fabrication procedure, as well as obtain high burnup capability through irradiation testing

  12. Intelligent hand-portable proliferation sensing system

    International Nuclear Information System (INIS)

    Dieckman, S.L.; Bostrom, G.A.; Waterfield, L.G.; Jendrzejczyk, J.A.; Ahuja, S.; Raptis, A.C.

    1997-01-01

    Argonne National Laboratory, with support from DOE's Office of Nonproliferation and National Security, is currently developing an intelligent hand-portable sensor system. This system is designed specifically to support the intelligence community with the task of in-field sensing of nuclear proliferation and related activities. Based upon pulsed laser photo-ionization time-of-flight mass spectrometry technology, this novel sensing system is capable of quickly providing a molecular or atomic analysis of specimens. The system is capable of analyzing virtually any gas phase molecule, or molecule that can be induced into the gas phase by (for example) sample heating. This system has the unique advantages of providing unprecedented portability, excellent sensitivity, tremendous fieldability, and a high performance/cost ratio. The system will be capable of operating in a highly automated manner for on-site inspections, and easily modified for other applications such as perimeter monitoring aboard a plane or drone. The paper describes the sensing system

  13. Dispersal of Beauveria bassiana by the activity of nettle insects.

    Science.gov (United States)

    Meyling, Nicolai V; Pell, Judith K; Eilenberg, Jørgen

    2006-10-01

    Recent studies have shown that the entomopathogenic fungus Beauveria bassiana occurs naturally on the phylloplanes of several plants, including nettles. Insects could, by their activity, be contributing to this inoculum by dispersing it from other sites. The potential of nettle aphids Microlophium carnosum and their predator Anthocoris nemorum to disperse conidia of B. bassiana from soil to nettles and from sporulating cadavers in the nettle canopy was investigated in laboratory experiments. In petri dish assays, aphids showed potential to distribute B. bassiana from soil to nettle leaves. Predators dispersed inoculum from both soil and cadavers to nettle leaves in petri dishes. In microcosms, aphids did not disperse B. bassiana from the soil or from cadavers confined in the canopy, but A. nemorum were able to transfer inoculum from soil into the nettle canopy and to distribute conidia from cryptic cadavers. In some instances, infections were initiated in aphids and predators as a consequence of dispersal.

  14. Spurious dispersion effects at FLASH

    International Nuclear Information System (INIS)

    Prat, Eduard

    2009-07-01

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  15. Spurious dispersion effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Prat, Eduard

    2009-07-15

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  16. Dispersion stability of thermal nanofluids

    Directory of Open Access Journals (Sweden)

    Fan Yu

    2017-10-01

    Full Text Available Thermal nanofluids, the engineered fluids with dispersed functional nanoparticles, have exhibited extraordinary thermophysical properties and added functionalities, and thus have enabled a broad range of important applications. The poor dispersion stability of thermal nanofluids, however, has been considered as a long-existing issue that limits their further development and practical application. This review overviews the recent efforts and progresses in improving the dispersion stability of thermal nanofluids such as mechanistic understanding of dispersion behavior of nanofluids, examples of both water-based and oil-based nanofluids, strategies to stabilize nanofluids, and characterization techniques for dispersion behavior of nanofluids. Finally, on-going research needs, and possible solutions to research challenges and future research directions in exploring stably dispersed thermal nanofluids are discussed. Keywords: Thermal nanofluids, Dispersion, Aggregation, Electrostatic stabilization, Steric stabilization

  17. Phonon dispersion in vanadium

    International Nuclear Information System (INIS)

    Ivanov, A.S.; Rumiantsev, A.Yu.

    1999-01-01

    Complete text of publication follows. Phonon dispersion curves in Vanadium metal are investigated by neutron inelastic scattering using three-axis spectrometers. Due to extremely low coherent scattering amplitude of neutrons in natural isotope mixture of vanadium the phonon frequencies could be determined in the energy range below about 15 meV. Several phonon groups were measured with the polarised neutron scattering set-up. It is demonstrated that the intensity of coherent inelastic scattering observed in the non-spin-flip channel vanishes in the spin-flip channel. The phonon density of states is measured on a single crystal keeping the momentum transfer equal to a vector of reciprocal lattice where the coherent inelastic scattering is suppressed. Phonon dispersion curves in vanadium, as measured by neutron and earlier by X-ray scattering, are described in frames of a charge-fluctuation model involving monopolar and dipolar degrees of freedom. The model parameters are compared for different transition metals with body-centred cubic-structure. (author)

  18. Dispersion and current measurements

    International Nuclear Information System (INIS)

    Boelskifte, S.

    1986-04-01

    A model for the simulation of particle movements in water should incorporate the mutual distance dependent correlation. As long as reliable data are given accessible a model can be created of the dispersion in a given area from a statistical description of turbulence. Current measurements have been performed in an area north of the Swedish nuclear power plant Barsebaeck, and statistical time series analysis have made it possible to estimate multivariate autoregressive moving-average (ARMA) models for these data using the Box-Jenkins method. The correlation structure for the area has been investigated in detail. Transport and dispersion models for the marine environment are used in estimating doses to the population from the aquatic food chain. Some of these models are described with special emphasis on the time and length scales they cover. Furthermore, to illustrate the background of the simulation model, short introductuions are given to health physics, time series analysis, and turbulence theory. Analysis of the simulation model shows the relative importance of the different parameters. The model can be expanded to conditional simulation, where the current measurements are used directly to simulate the movement of one of the particles. Results from the model are also compared to results from a sampling of bioindicators (Fucus vesiculosus) along the Danish coast. The reliability of bioindicators in this kind of experiment is discussed. (author)

  19. Quantum optical rotatory dispersion

    Science.gov (United States)

    Tischler, Nora; Krenn, Mario; Fickler, Robert; Vidal, Xavier; Zeilinger, Anton; Molina-Terriza, Gabriel

    2016-01-01

    The phenomenon of molecular optical activity manifests itself as the rotation of the plane of linear polarization when light passes through chiral media. Measurements of optical activity and its wavelength dependence, that is, optical rotatory dispersion, can reveal information about intricate properties of molecules, such as the three-dimensional arrangement of atoms comprising a molecule. Given a limited probe power, quantum metrology offers the possibility of outperforming classical measurements. This has particular appeal when samples may be damaged by high power, which is a potential concern for chiroptical studies. We present the first experiment in which multiwavelength polarization-entangled photon pairs are used to measure the optical activity and optical rotatory dispersion exhibited by a solution of chiral molecules. Our work paves the way for quantum-enhanced measurements of chirality, with potential applications in chemistry, biology, materials science, and the pharmaceutical industry. The scheme that we use for probing wavelength dependence not only allows one to surpass the information extracted per photon in a classical measurement but also can be used for more general differential measurements. PMID:27713928

  20. A Dictyostelium chalone uses G proteins to regulate proliferation

    Directory of Open Access Journals (Sweden)

    Hanson Nana E

    2009-07-01

    Full Text Available Abstract Background Several studies have shown that organ size, and the proliferation of tumor metastases, may be regulated by negative feedback loops in which autocrine secreted factors called chalones inhibit proliferation. However, very little is known about chalones, and how cells sense them. We previously identified two secreted proteins, AprA and CfaD, which act as chalones in Dictyostelium. Cells lacking AprA or CfaD proliferate faster than wild-type cells, and adding recombinant AprA or CfaD to cells slows their proliferation. Results We show here that cells lacking the G protein components Galpha8, Galpha9, and Gbeta proliferate faster than wild-type cells despite secreting normal or high levels of AprA and CfaD. Compared with wild-type cells, the proliferation of galpha8-, galpha9- and gbeta- cells are only weakly inhibited by recombinant AprA (rAprA. Like AprA and CfaD, Galpha8 and Gbeta inhibit cell proliferation but not cell growth (the rate of increase in mass and protein per nucleus, whereas Galpha9 inhibits both proliferation and growth. galpha8- cells show normal cell-surface binding of rAprA, whereas galpha9- and gbeta- cells have fewer cell-surface rAprA binding sites, suggesting that Galpha9 and Gbeta regulate the synthesis or processing of the AprA receptor. Like other ligands that activate G proteins, rAprA induces the binding of [3H]GTP to membranes, and GTPgammaS inhibits the binding of rAprA to membranes. Both AprA-induced [3H]GTP binding and the GTPgammaS inhibition of rAprA binding require Galpha8 and Gbeta but not Galpha9. Like aprA- cells, galpha8- cells have reduced spore viability. Conclusion This study shows that Galpha8 and Gbeta are part of the signal transduction pathway used by AprA to inhibit proliferation but not growth in Dictyostelium, whereas Galpha9 is part of a differealnt pathway that regulates both proliferation and growth, and that a chalone signal transduction pathway uses G proteins.

  1. A Dictyostelium chalone uses G proteins to regulate proliferation.

    Science.gov (United States)

    Bakthavatsalam, Deenadayalan; Choe, Jonathan M; Hanson, Nana E; Gomer, Richard H

    2009-07-27

    Several studies have shown that organ size, and the proliferation of tumor metastases, may be regulated by negative feedback loops in which autocrine secreted factors called chalones inhibit proliferation. However, very little is known about chalones, and how cells sense them. We previously identified two secreted proteins, AprA and CfaD, which act as chalones in Dictyostelium. Cells lacking AprA or CfaD proliferate faster than wild-type cells, and adding recombinant AprA or CfaD to cells slows their proliferation. We show here that cells lacking the G protein components Galpha8, Galpha9, and Gbeta proliferate faster than wild-type cells despite secreting normal or high levels of AprA and CfaD. Compared with wild-type cells, the proliferation of galpha8-, galpha9- and gbeta- cells are only weakly inhibited by recombinant AprA (rAprA). Like AprA and CfaD, Galpha8 and Gbeta inhibit cell proliferation but not cell growth (the rate of increase in mass and protein per nucleus), whereas Galpha9 inhibits both proliferation and growth. galpha8- cells show normal cell-surface binding of rAprA, whereas galpha9- and gbeta- cells have fewer cell-surface rAprA binding sites, suggesting that Galpha9 and Gbeta regulate the synthesis or processing of the AprA receptor. Like other ligands that activate G proteins, rAprA induces the binding of [3H]GTP to membranes, and GTPgammaS inhibits the binding of rAprA to membranes. Both AprA-induced [3H]GTP binding and the GTPgammaS inhibition of rAprA binding require Galpha8 and Gbeta but not Galpha9. Like aprA- cells, galpha8- cells have reduced spore viability. This study shows that Galpha8 and Gbeta are part of the signal transduction pathway used by AprA to inhibit proliferation but not growth in Dictyostelium, whereas Galpha9 is part of a differealnt pathway that regulates both proliferation and growth, and that a chalone signal transduction pathway uses G proteins.

  2. Powder diffraction studies using anomalous dispersion

    International Nuclear Information System (INIS)

    Cox, D.E.; Wilkinson, A.P.

    1993-01-01

    With the increasing availability and accessibility of high resolution powder diffractometers at many synchrotron radiation sources throughout the world, there is rapidly-growing interest in the exploitation of anomalous dispersion techniques for structural studies of polycrystalline materials. In conjunction with the Rietveld profile method for structure refinement, such studies are especially useful for the determination of the site distributions of two or more atoms which are near neighbors in the periodic table, or atoms which are distributed among partially occupied sites. Additionally, it is possible to (1) determine the mean-square displacements associated with different kinds of atoms distributed over a single set of sites, (2) distinguish between different oxidation states and coordination geometries of a particular atom in a compound and (3) to determine f' for a wide range of atomic species as a function of energy in the vicinity of an absorption edge. Experimental methods for making anomalous dispersion measurements are described in some detail, including data collection strategies, data analysis and correlation problems, possible systematic errors, and the accuracy of the results. Recent work in the field is reviewed, including cation site-distribution studies (e.g. doped high T c superconductors, ternary alloys, FeCo 2 (PO 4 ) 3 , FeNi 2 BO 5 ), oxidation-state contrast (e.g. YBa 2 Cu 3 O 6+x , Eu 3 O 4 , GaCl 2 , Fe 2 PO 5 ), and the effect of coordination geometry (e.g. Y 3 Ga 5 O l2 )

  3. International nuclear proliferation: multilateral diplomacy and regional aspects

    Energy Technology Data Exchange (ETDEWEB)

    Kapur, A.

    1979-01-01

    Confidential interviews with about 200 officials at 18 nuclear research sites around the world form the background for this discussion of the proliferation issues as they affect the Nuclear Non-Proliferation Treaty (NPT). Critics of the NPT cite its narrow focus on horizontal proliferation and its failures in the areas of vertical proliferation, nuclear technology transfers, heavy-water-reactor systems, and safeguards. The international negotiations necessary to resolve these issues and the difficulty of reaching a global consensus indicate a need to restructure the U.S. decision process before diplomacy can progress. The book discusses the history and nature of proliferation and its relationship to multinational diplomacy; the problems of permanent and workable safeguards; and regional political ramifications in the creeping dependencies of South Asia, apartheid in South Africa, militarization in Japan, and the nuclearization of Brazil and Argentina. The analysis concludes that central issues were not settled by the NPT and that U.S. failures to speak without consulting allies may mean that a bilateral rather than multinational approach should be tried. 105 references, 5 figures, 12 tables. (DCK)

  4. Overview of clustered nuclear siting and its technical aspects

    International Nuclear Information System (INIS)

    Meier, P.M.

    1976-09-01

    In recent years there has been growing discussion over the ability of new siting approaches to redress the increasing problems of nuclear plant location. This debate has focused largely on three alternatives to the conventional siting of nuclear reactors; floating offshore plants; underground siting; and nuclear energy centers (NECs) consisting of up to 40 reactors at a single site, and, possibly, including fuel cycle facilities within their perimeter. Congressional interest in energy centers, especially in view of concern over the proliferation of nuclear reactors throughout the country, and with the special problems of safeguards over fuel reprocessing and the use of plutonium as a reactor fuel, resulted in a mandate to the Nuclear Regulatory Commission to make a comprehensive analysis of the energy center concept. A common finding of all of the studies of the nuclear energy center concept thus far is that there appear to be no technical considerations that would clearly preclude energy centers. With the one significant exception regarding the meteorological impacts of the concentration of heat and moisture releases to the atmosphere, engineering solutions would appear to be quite adequate to address any difficulties of environmental impact, electrical systems management, water supply or construction management, and to keep the overall physical environmental impact of an energy center not significantly different to that of an equivalent number of dispersed reactors

  5. A single hole tracer test to determine longitudinal dispersion

    International Nuclear Information System (INIS)

    Noy, D.J.; Holmes, D.C.

    1986-03-01

    The paper concerns a single hole tracer test to determine longitudinal dispersion, which is an important parameter in assessing the suitability of a site for radioactive waste disposal. The theory, equipment and procedure for measuring longitudinal dispersion in a single borehole is described. Results are presented for field trials conducted in an aquifer, where the technique produced good results. The measured value of longitudinal dispersion, from a single hole test, relates only to a limited volume of rock immediately adjacent to the borehole. (U.K.)

  6. Metapopulation extinction risk: dispersal's duplicity.

    Science.gov (United States)

    Higgins, Kevin

    2009-09-01

    Metapopulation extinction risk is the probability that all local populations are simultaneously extinct during a fixed time frame. Dispersal may reduce a metapopulation's extinction risk by raising its average per-capita growth rate. By contrast, dispersal may raise a metapopulation's extinction risk by reducing its average population density. Which effect prevails is controlled by habitat fragmentation. Dispersal in mildly fragmented habitat reduces a metapopulation's extinction risk by raising its average per-capita growth rate without causing any appreciable drop in its average population density. By contrast, dispersal in severely fragmented habitat raises a metapopulation's extinction risk because the rise in its average per-capita growth rate is more than offset by the decline in its average population density. The metapopulation model used here shows several other interesting phenomena. Dispersal in sufficiently fragmented habitat reduces a metapopulation's extinction risk to that of a constant environment. Dispersal between habitat fragments reduces a metapopulation's extinction risk insofar as local environments are asynchronous. Grouped dispersal raises the effective habitat fragmentation level. Dispersal search barriers raise metapopulation extinction risk. Nonuniform dispersal may reduce the effective fraction of suitable habitat fragments below the extinction threshold. Nonuniform dispersal may make demographic stochasticity a more potent metapopulation extinction force than environmental stochasticity.

  7. Non proliferation of nuclear weapons?

    International Nuclear Information System (INIS)

    Le Guelte, Georges

    2015-10-01

    After having evoked the behaviour of nuclear countries regarding the development of nuclear weapons and uranium procurement, or nuclear programmes after the Second World War until nowadays, the author presents the non proliferation Treaty (NPT) as a construction at the service of super-powers. He comments and discusses the role of the IAEA control system and its evolutions: a control limited to declared installations, an export control with the spectre of plutonium, a control system thwarted by some technological innovations, information systems coming in, and an additional protocol related to the application of guarantees. He comments the evolution of the context from a bipolar world to a world without pole which raises the issue of how to have commitments respected: description of the role and practice of non proliferation during the Cold War, after the Cold War, and in a world without governance

  8. Proliferation Vulnerability Red Team report

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, J.P.; Barnard, R.W.; Bennett, D.E. [and others

    1996-10-01

    This report is the product of a four-month independent technical assessment of potential proliferation vulnerabilities associated with the plutonium disposition alternatives currently under review by DOE/MD. The scope of this MD-chartered/Sandia-led study was limited to technical considerations that could reduce proliferation resistance during various stages of the disposition processes below the Stored Weapon/Spent Fuel standards. Both overt and covert threats from host nation and unauthorized parties were considered. The results of this study will be integrated with complementary work by others into an overall Nonproliferation and Arms Control Assessment in support of a Secretarial Record of Decision later this year for disposition of surplus U.S. weapons plutonium.

  9. Nuclear power and weapons proliferation

    International Nuclear Information System (INIS)

    Greenwood, T.; Rathjens, C.W.; Ruina, J.

    1977-01-01

    The relationship between nuclear weapons development and nuclear electric power is examined. A brief description of nuclear weapons design is first given. This is then followed by a discussion of various aspects of nuclear power technology and of how they affect a nuclear weapon programme. These include fuel cycles, chemical reprocessing of spent fuel, uranium enrichment, and the control of dissemination of nuclear technology. In conclusion there is a discussion of possible political and institutional controls for limiting nuclear proliferation. (U.K.)

  10. CBRN and proliferation in Asia

    International Nuclear Information System (INIS)

    Brisset, Jean-Vincent

    2015-01-01

    The author proposes a brief overview of the history, evolution and status of military nuclear weapons and programmes as well as bacteriologic and chemical weapons (nuclear weapons, ballistic missile, and position with respect with the Conventions on chemical and bacteriologic weapons) in Asian countries (China, Japan, India, Pakistan, North Korea). In a second part, he discusses issues related to exports and possible proliferation from these countries

  11. Broadening our approaches to studying dispersal in raptors

    Science.gov (United States)

    Morrison, J.L.; Wood, P.B.

    2009-01-01

    Dispersal is a behavioral process having consequences for individual fitness and population dynamics. Recent advances in technology have spawned new theoretical examinations and empirical studies of the dispersal process in birds, providing opportunities for examining how this information may be applied to studies of the dispersal process in raptors. Many raptors are the focus of conservation efforts; thus, reliable data on all aspects of a species' population dynamics, including dispersal distances, movement rates, and mortality rates of dispersers, are required for population viability analyses that are increasingly used to inform management. Here, we address emerging issues and novel approaches used in the study of avian dispersal, and provide suggestions to consider when developing and implementing studies of dispersal in raptors. Clarifying study objectives is essential for selection of an appropriate methodology and sample size needed to obtain accurate estimates of movement distances and rates. Identifying an appropriate study-area size will allow investigators to avoid underestimating population connectivity and important population parameters. Because nomadic individuals of some species use temporary settling areas or home ranges before breeding, identification of these areas is critical for conservation efforts focusing on habitats other than breeding sites. Study designs for investigating raptor dispersal also should include analysis of environmental and social factors influencing dispersal, to improve our understanding of condition-dependent dispersal strategies. Finally, we propose a terminology for use in describing the variety of movements associated with dispersal behavior in raptors, and we suggest this terminology could be used consistently to facilitate comparisons among studies. ?? 2009 The Raptor Research Foundation, Inc.

  12. Atmospheric tracer experiments for regional dispersion studies

    International Nuclear Information System (INIS)

    Heffter, J.L.; Ferber, G.J.

    1980-01-01

    Tracer experiments are being conducted to verify atmospheric transport and dispersion calculations at distances from tens to hundreds of km from pollutant sources. In one study, a 2 1/2 year sampling program has been carried out at 13 sites located 30 to 140 km from a source of 85 Kr at the Savannah River Plant in South Carolina. Average weekly concentrations as well as twice-daily concentrations were obtained. Sampling data and meteorological data, including surface, tower, and rawinsonde observations are available on magnetic tape for model verification studies. Some verification results for the Air Resources Laboratories Atmospheric Transort and Dispersion Model (ARL-ATAD) are shown for averaging periods from one week to two years

  13. Neural control of colonic cell proliferation.

    Science.gov (United States)

    Tutton, P J; Barkla, D H

    1980-03-15

    The mitotic rate in rat colonic crypts and in dimethylhydrazine-induced colonic carcinomas was measured using a stathmokinetic technique. In sympathectomized animals cell proliferation was retarded in the crypts but not in the tumors, whereas in animals treated with Metaraminol, a drug which releases norepinephrine from nerve terminals, crypt cell but not tumor cell proliferation was accelerated. Blockade of alpha-adrenoceptors also inhibited crypt cell proliferation. However, stimulation of beta-adrenoceptors inhibited and blockade of beta-adrenoceptors accelerated tumor cell proliferation without influencing crypt cell proliferation. Injection of either serotonin or histamine stimulated tumor but not crypt cell proliferation and blockade or serotonin receptors or histamine H2-receptors inhibited tumor cell proliferation. It is postulated that cell proliferation in the colonic crypts, like that in the jejunal crypts, is under both endocrine and autonomic neural control whereas colonic tumor cell division is subject to endocrine regulation alone.

  14. Relativistic plasma dispersion functions

    International Nuclear Information System (INIS)

    Robinson, P.A.

    1986-01-01

    The known properties of plasma dispersion functions (PDF's) for waves in weakly relativistic, magnetized, thermal plasmas are reviewed and a large number of new results are presented. The PDF's required for the description of waves with small wave number perpendicular to the magnetic field (Dnestrovskii and Shkarofsky functions) are considered in detail; these functions also arise in certain quantum electrodynamical calculations involving strongly magnetized plasmas. Series, asymptotic series, recursion relations, integral forms, derivatives, differential equations, and approximations for these functions are discussed as are their analytic properties and connections with standard transcendental functions. In addition a more general class of PDF's relevant to waves of arbitrary perpendicular wave number is introduced and a range of properties of these functions are derived

  15. Dispersion of contaminants in saturated porous media

    International Nuclear Information System (INIS)

    Moltyaner, G.L.; Poisson, J.M.

    1987-10-01

    The main objective of this paper is to outline the experimental and theoretical investigations performed in an attempt to validate the applicability of finite element based numerical models for the prediction of the behaviour of a conservative tracer at the Twin Lake aquifer, Chalk River Nuclear Laboratories, Chalk River, Ontario. The essential point is that the 3/4 of a million data points obtained at the Twin Lake site from a 40 m natural gradient tracer test provide a unique opportunity for quantifying the system variability and for testing finite element models of the dispersion process. The subject of this discussion is the advection-dispersion model of contaminant transport - its equation and solution by the Galerkin finite element method. The report gives a brief description of the experimental data and the methods for the estimation of transport parameters. Scales of averaging associated with the conceptual formulation of the dispersion process, measurement of process variables, parameter estimation and the numerical models are discussed. The compatibility between the scales is emphasized as a major requirement for predictive modelling. The developed finite element model of the radioiodine transport describes the overall behaviour of the tracer plume but lacks the capability to simulate the fingerlike spreading of the plume due to the fact that the grid does not have an adequately fine space discretization. Unfortunately, a refinement of the grid spacing is limited by the size of the site computer memory. For the advection-dominated transport, as that encountered at the Twin Lake aquifer, the failure to satisfy fine mesh requirement causes numerical dispersion. In general, it was concluded that the conventional finite element model may produce accurate simulation of the tracer cloud provided that the adequately fine space discretization of the grid compatible with the support scale of measurements and the adequately fine time discretization are made. This

  16. Statistical Thermodynamics of Disperse Systems

    DEFF Research Database (Denmark)

    Shapiro, Alexander

    1996-01-01

    Principles of statistical physics are applied for the description of thermodynamic equilibrium in disperse systems. The cells of disperse systems are shown to possess a number of non-standard thermodynamic parameters. A random distribution of these parameters in the system is determined....... On the basis of this distribution, it is established that the disperse system has an additional degree of freedom called the macro-entropy. A large set of bounded ideal disperse systems allows exact evaluation of thermodynamic characteristics. The theory developed is applied to the description of equilibrium...

  17. Geometry of physical dispersion relations

    International Nuclear Information System (INIS)

    Raetzel, Dennis; Rivera, Sergio; Schuller, Frederic P.

    2011-01-01

    To serve as a dispersion relation, a cotangent bundle function must satisfy three simple algebraic properties. These conditions are derived from the inescapable physical requirements that local matter field dynamics must be predictive and allow for an observer-independent notion of positive energy. Possible modifications of the standard relativistic dispersion relation are thereby severely restricted. For instance, the dispersion relations associated with popular deformations of Maxwell theory by Gambini-Pullin or Myers-Pospelov are not admissible. Dispersion relations passing the simple algebraic checks derived here correspond to physically admissible Finslerian refinements of Lorentzian geometry.

  18. Methods for estimating on-site ambient air concentrations at disposal sites

    International Nuclear Information System (INIS)

    Hwang, S.T.

    1987-01-01

    Currently, Gaussian type dispersion modeling and point source approximation are combined to estimate the ambient air concentrations of pollutants dispersed downwind of an areawide emission source, using the approach of virtual point source approximation. This Gaussian dispersion modeling becomes less accurate as the receptor comes closer to the source, and becomes inapplicable for the estimation of on-site ambient air concentrations at disposal sites. Partial differential equations are solved with appropriate boundary conditions for use in estimating the on-site concentrations in the ambient air impacted by emissions from an area source such as land disposal sites. Two variations of solution techniques are presented, and their predictions are compared

  19. Dispersion bias, dispersion effect, and the aerosol-cloud conundrum

    International Nuclear Information System (INIS)

    Liu Yangang; Daum, Peter H; Guo Huan; Peng Yiran

    2008-01-01

    This work examines the influences of relative dispersion (the ratio of the standard deviation to the mean radius of the cloud droplet size distribution) on cloud albedo and cloud radiative forcing, derives an analytical formulation that accounts explicitly for the contribution from droplet concentration and relative dispersion, and presents a new approach to parameterize relative dispersion in climate models. It is shown that inadequate representation of relative dispersion in climate models leads to an overestimation of cloud albedo, resulting in a negative bias of global mean shortwave cloud radiative forcing that can be comparable to the warming caused by doubling CO 2 in magnitude, and that this dispersion bias is likely near its maximum for ambient clouds. Relative dispersion is empirically expressed as a function of the quotient between cloud liquid water content and droplet concentration (i.e., water per droplet), yielding an analytical formulation for the first aerosol indirect effect. Further analysis of the new expression reveals that the dispersion effect not only offsets the cooling from the Twomey effect, but is also proportional to the Twomey effect in magnitude. These results suggest that unrealistic representation of relative dispersion in cloud parameterization in general, and evaluation of aerosol indirect effects in particular, is at least in part responsible for several outstanding puzzles of the aerosol-cloud conundrum: for example, overestimation of cloud radiative cooling by climate models compared to satellite observations; large uncertainty and discrepancy in estimates of the aerosol indirect effect; and the lack of interhemispheric difference in cloud albedo.

  20. Nuclear Proliferation: A Historical Overview

    Science.gov (United States)

    2008-03-01

    Soviet Union in 1991, Kazakhstan inherited approximately 1,410 nuclear warheads and the Semipalatinsk nuclear weapons test site . This placed Kazakhstan...Soviet Union, Kazakhstan inherited approximately 1,410 nuclear warheads and the Semipalatinsk nuclear weapons test site . See Mark D. Skootsky, “An...construction of a nuclear test site . This development moved Brazil into the Modest Weapons Potential category. In 1979 the Pilot Uranium Enrichment Plant

  1. The European dimension in non-proliferation

    International Nuclear Information System (INIS)

    Krause, J.

    1996-01-01

    Europe was for decades the focal point of efforts to prevent or constrain nuclear proliferation and the first region in which non-proliferation efforts failed. Paper deals with current proliferation problems in Europe, namely, diversion of weapons, diversion from dismantling, production over-capacity, security concerns. Legal instruments against proliferation in Europe described here include development of international norms; instruments of security assurance and cooperation; disarmament assistance; fissile material management; assistance in creating export control systems; improving and harmonizing export controls for dual-purpose items. Problems in implementing non-proliferation instruments are described separately

  2. The international nuclear non-proliferation system

    International Nuclear Information System (INIS)

    Simpson, J.; McGrew, T.

    1985-01-01

    This volume focuses upon the issues raised at this Conference, and attempts to address the international diplomatic, political and trading, rather than technical, questions which surround nuclear non-proliferation policies. It does so by bringing together chapters contributed by participants in non-proliferation diplomacy, those with experience in shaping International Atomic Energy Agency and national policies and academic observers of non-proliferation activities and the international nuclear industry. An analysis is provided of past non-proliferation policies and activities and current issues, and an attempt is made to offer ideas for new initiatives which may sustain the non-proliferation system in the future

  3. Nanoparticles for cells proliferation enhancement

    International Nuclear Information System (INIS)

    Popa, V.; Braniste, F.; Tiginyanu, I.M.; Lisii, C.; Nacu, V.

    2013-01-01

    The potential of semiconductor nanoparticles as stimulator for avian mesenchyme stem cells proliferation enhancement is demonstrated. The effect is related to nanoparticles polarization due to external ultrasound field resulting in local electrical stimulation. Our preliminary results demonstrates that the number of cells have been increased by 23 % ±2%) in cell cultures under the action of external ultrasound stimulation. Morphological analysis and viability shows no differences between the control group and the group studied. These results suggest the possibility for tissue regeneration enhancement by remote stimulation of implanted semiconductor nanoparticles. (authors)

  4. The USA and proliferation in Northeast Asia

    International Nuclear Information System (INIS)

    Weeks, S.B.

    1995-01-01

    United States policy on proliferation in Northeast Asia poses a test of balance between general US global non-proliferation goals and specific US regional security goals for Northeast Asia. US policy on proliferation in Northeast Asia further poses a test of priorities for US bilateral relations with the key Northeast Asian states, as non-proliferation and regional security goals must be weighed against other (e.g., economic, human rights) declared US policy goals. The result is a US policy equation for Northeast Asia proliferation that is considerably more complex in execution than might be expected from the simple statement of the US goal to avoid nuclear proliferation in Northeast Asia. The question of security assurances - both negative and positive - may be closely related to US policies to avoid proliferation in Northeast Asia

  5. Fissile material disposition and proliferation risk

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, J.S.; Rutherford, D.A. [Los Alamos National Lab., NM (United States). NIS Div.

    1996-05-01

    The proliferation risk of a facility is dependent on the material attractiveness, level of safeguards, and physical protection applied to the material in conjunction with an assessment of the impact of the socioeconomic circumstances and threat environment. Proliferation risk is a complementary extension of proliferation resistance. The authors believe a better determination of nuclear material proliferation can be achieved by establishing the proliferation risk for facilities that contain nuclear material. Developing a method that incorporates the socioeconomic circumstances and threat environment inherent to each country enables a global proliferation assessment. In order to effectively reduce the nuclear danger, a broadly based set of criteria is needed that provides the capability to relatively assess a wide range of disposition options/facilities in different countries and still ensure a global decrease in proliferation risk for plutonium.

  6. Fissile material disposition and proliferation risk

    International Nuclear Information System (INIS)

    Dreicer, J.S.; Rutherford, D.A.

    1996-01-01

    The proliferation risk of a facility is dependent on the material attractiveness, level of safeguards, and physical protection applied to the material in conjunction with an assessment of the impact of the socioeconomic circumstances and threat environment. Proliferation risk is a complementary extension of proliferation resistance. The authors believe a better determination of nuclear material proliferation can be achieved by establishing the proliferation risk for facilities that contain nuclear material. Developing a method that incorporates the socioeconomic circumstances and threat environment inherent to each country enables a global proliferation assessment. In order to effectively reduce the nuclear danger, a broadly based set of criteria is needed that provides the capability to relatively assess a wide range of disposition options/facilities in different countries and still ensure a global decrease in proliferation risk for plutonium

  7. Modeling pollutant dispersion within a tornadic thunderstorm

    Energy Technology Data Exchange (ETDEWEB)

    Pepper, D W

    1982-01-01

    A three-dimensional numerical model has been developed to calculate ground-level air concentration and deposition of particles entrained in a tornadic thunderstorm. The rotational characteristics of the tornadic storm are within the larger mesoscale flow of the storm system and transported with the vortex. Turbulence exchange coefficients are based on empirical values. The quasi-Lagrangian method of moments is used to model the transport of concentration within a grid cell volume. Results indicate that updrafts and downdrafts, coupled with scavenging of particles by precipitation, account for most of the material being deposited closer to the site than anticipated. Approximately 5% of the pollutant is dispersed into the stratosphere.

  8. Auroral electron time dispersion

    International Nuclear Information System (INIS)

    Kletzing, C.A.

    1989-01-01

    A sounding rocket flight was launched from Greenland in 1985 to study high latitude, early morning auroral physics. The payload was instrumented with electron and ion detectors, AC and DC electric field experiments, a plasma density experiment, and a magnetometer to measure the ambient field. The rocket was launched during disturbed conditions, when the polar cap was in a contracted state with visible aurora overhead. The electron data contained numerous signatures indicative of time-of-flight energy dispersion characterized by a coherent structure in which lower energy electrons arrived at the rocket after higher energy electrons. A model was constructed to explain this phenomena by the sudden application of a region of parallel electric field along a length of magnetic field line above the rocket. The model incorporates detector response and uses an altitudinal density profile based on auroral zone measurements. Three types of potential structures were tried: linear, quadratic and cubic. Of the three it was found that the cubic (electric field growing in a quadratic manner moving up the field line) produced the best fit to the data. The potential region was found to be approximately 1-2 R e in extent with the lower edge 3000-4000 km away from the rocket. The background electron temperature in the model which produced the best fit to the data was of the order of 15 eV

  9. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the

  10. Progress in urban dispersion studies

    DEFF Research Database (Denmark)

    Batchvarova, E.; Gryning, Sven-Erik

    2006-01-01

    The present Study addresses recent achievements in better representation Of the urban area structure in meteorology and dispersion parameterisations. The setup and Main Outcome of several recent dispersion experiments in Urban areas and their use in model validation are discussed. The maximum con...

  11. Nest-mediated seed dispersal

    Science.gov (United States)

    Robert J. Warren; Jason P. Love; Mark A. Bradford

    2017-01-01

    Many plant seeds travel on the wind and through animal ingestion or adhesion; however, an overlooked dispersal mode may lurk within those dispersal modes. Viable seeds may remain attached or embedded within materials birds gather for nest building. Our objective was to determine if birds inadvertently transport seeds when they forage for plant materials to...

  12. Regulation of proliferation of embryonic heart mesenchyme: Role of transforming growth factor-beta 1 and the interstitial matrix

    International Nuclear Information System (INIS)

    Choy, M.; Armstrong, M.T.; Armstrong, P.B.

    1990-01-01

    Proliferation of atrioventricular cushion mesenchyme of the embryonic avian heart maintained in three-dimensional aggregate culture is stimulated by interaction with the interstitial matrix. Chicken serum or transforming growth factor-beta 1, which stimulates proliferation, induces matrix deposition in regions of the aggregate showing high labeling indices with tritiated thymidine. Dispersed heart mesenchyme interstitial matrix introduced into serum-free culture is incorporated into the aggregate and stimulates cellular proliferation similar to serum or transforming growth factor-beta 1. Proliferation is reversibly inhibited by the peptide Gly-Arg-Gly-Asp-Ser-Pro. It is suggested that transforming growth factor-beta 1 stimulates the production of interstitial matrix and that a sufficient stimulus for proliferation in this system is the presence of the matrix, which acts as the adhesive support for cellular anchorage

  13. Non-proliferation and disarmament

    International Nuclear Information System (INIS)

    Ritter von Wagner, A.

    1993-01-01

    In 1995 the Conference on the prolongation of the Non-Proliferation Treaty will take place. Will it be extended for a long term, indefinitely or only for a fixed period? The Federal Government of Germany advocates an unlimited extension of the Non-Proliferation Treaty. Others have different ideas alleging that the Treaty is imperfect and discriminating. It is a thorn in the side of many States, in particular of the Third World, which no longer want to put up with being treated as second-class states. One argument which is considered especially embarrassing by developing countries as a visible expression of such discrimination, are the nuclear tests which are still carried out by nuclear weapon states. Is the political situation still such that one needs those weapons? Strategists gradually find it difficult to argument; over and over again they claim that an abandonment of nuclear weapons would make the world unsafer. But development has gradually passed over them. Nevertheless, one finds it hard to throw overboard considerations which for years have determined one's thinking. (orig./HSCH) [de

  14. Gas Centrifuges and Nuclear Proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Albright, David

    2004-09-15

    Gas centrifuges have been an ideal enrichment method for a wide variety of countries. Many countries have built gas centrifuges to make enriched uranium for peaceful nuclear purposes. Other countries have secretly sought centrifuges to make highly enriched uranium for nuclear weapons. In more recent times, several countries have secretly sought or built gas centrifuges in regions of tension. The main countries that have been of interest in the last two decades have been Pakistan, Iraq, Iran, and North Korea. Currently, most attention is focused on Iran, Pakistan, and North Korea. These states did not have the indigenous abilities to make gas centrifuges, focusing instead on illicit and questionable foreign procurement. The presentation covered the following main sections: Spread of centrifuges through illicit procurement; Role of export controls in stopping proliferation; Increasing the transparency of gas centrifuge programs in non-nuclear weapon states; and, Verified dismantlement of gas centrifuge programs. Gas centrifuges are important providers of low enriched uranium for civil nuclear power reactors. They also pose special nuclear proliferation risks. We all have special responsibilities to prevent the spread of gas centrifuges into regions of tension and to mitigate the consequences of their spread into the Middle East, South Asia, and North Asia.

  15. Temporal variations in atmospheric dispersion at Hanford

    International Nuclear Information System (INIS)

    Ramsdell, J.V.; Burk, K.W.

    1990-01-01

    Climatological data are frequently used to estimate atmospheric dispersion factors for historical periods and for future releases for which adequate meteorological data are unavailable. This practice routinely leads to questions concerning the representativeness of data used. The work described here was performed to provide a basis for answering these questions at the U.S. Department of Energy's Hanford Site in eastern Washington. Atmospheric transport and diffusion near Hanford have been examined using a Lagrangian puff dispersion model and hourly meteorological data from the Hanford Meteorological Station and a network of 24 surface wind stations for a 5-yr period. Average normalized monthly concentrations were computed at 2.5-km intervals on a 31 by 31 grid from January 1983 through 1987, assuming an elevated release in the 200-East Area. Monthly average concentrations were used to determine 5-yr mean pattern and monthly mean patterns and the interannual variability about each pattern. Intra-annual and diurnal variations in dispersion factors are examined for six locations near Hanford

  16. UFOMOD - atmospheric dispersion and deposition

    International Nuclear Information System (INIS)

    Panitz, H.J.; Matzerath, C.; Paesler-Sauer, J.

    1989-10-01

    The report gives an introduction into the modelling of atmospheric dispersion and deposition which has been implemented in the new program system UFOMOD for assessing the consequences after nuclear accidents. According to the new structure of UFOMOD, different trajectory models with ranges of validity near to the site and at far distances are applied. Emphasis is laid on the description of the segmented plume model MUSEMET and its affilated submodels, being the removal of activity from the cloud by dry and wet deposition, and special effects like plume rise and the behaviour of plumes released into building wakes. In addition, the evaluation of γ-dose correction factors to take account of the finite extent of the radioactive plume in the near range (up to about 20 km) are described. Only brief introductions are given into the principles of the other models available: the puff model RIMPUFF, the long-range puff model MESOS, and the special straight-line Gaussian model ISOLA which are used if low-level long-duration releases are considered. To define starting times of weather sequences and the probabilities of occurrence of these sequences, it is convenient to perform stratified sampling. Therefore, the preprocessing program package METSAM has been developed to perform for generic ACAs a random sampling of weather sequences out off a population of classified weather conditions. The sampling procedure and a detailed input/output (I/O) description is presented and an additional appendix, respectively. A general overview on the I/O structure of MUSEMET as well as a brief user guide to run the KfK version of the MESOS code are also given in the appendix. (orig.) [de

  17. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    Science.gov (United States)

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  18. Thermal behavior analysis of U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

  19. Thermal behavior analysis of U-Mo/Al dispersion fuel

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu

    2004-01-01

    According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

  20. Wave-equation dispersion inversion

    KAUST Repository

    Li, Jing

    2016-12-08

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained from Rayleigh waves recorded by vertical-component geophones. Similar to wave-equation traveltime tomography, the complicated surface wave arrivals in traces are skeletonized as simpler data, namely the picked dispersion curves in the phase-velocity and frequency domains. Solutions to the elastic wave equation and an iterative optimization method are then used to invert these curves for 2-D or 3-D S-wave velocity models. This procedure, denoted as wave-equation dispersion inversion (WD), does not require the assumption of a layered model and is significantly less prone to the cycle-skipping problems of full waveform inversion. The synthetic and field data examples demonstrate that WD can approximately reconstruct the S-wave velocity distributions in laterally heterogeneous media if the dispersion curves can be identified and picked. The WD method is easily extended to anisotropic data and the inversion of dispersion curves associated with Love waves.

  1. Evaluation of hovercraft for dispersant application

    Energy Technology Data Exchange (ETDEWEB)

    Dickens, D; Belore, R; Buist, I; Humphrey, B

    1988-01-01

    A series of field trials were carried out in Vancouver, Canada in July and August 1986 to determine whether or not hovercraft should be considered for dispersant application. Questions are: the ability of the hovercraft to ''fly'' over an oil slick at high speed without displacing the oil out of the path, the potential for using the hovercraft to impart vertical mixing energy into the water column to aid in the dispersant process and, the ability to mount a suitable spray boom and obtain a uniform spray pattern across the swath width. The field trials and subsequent interpretation of results provide positive answers to the first and second question. The question of mixing energy requires some qualification. The hovercraft contributes considerable mixing energy to the immediate water surface through air entrainment but this effect is short lived and there does not appear to be significant long term vertical mixing in the hovercraft wake. Recommendations are made for operating procedures and boom mounting which should ensure a uniform drop size and dose rate across a swath up to 18 m. The cushion air escaping from around the craft perimeter is not an important factor in adversly affecting the dispersant spray pattern. Depending on the type of machine available, hovcercraft have the capability of treating up to a 1km/sup 2/ slick between loads, at average speeds in the 15 to 25 knot range. The inherent advantages of high transit speed to the site (up to 45 Knots), amphibious operation (i.e. not draft limited) and lack of ceiling or visibility restrictions provide hovercarft with unique capabilities in the dispersant application role. Two patents relating to the process have been abstracted. Appendix B gives the sprecifications of two different models of hovercrafts. 14 refs., 29 figs., 6 tabs.

  2. Dispersion Decay and Scattering Theory

    CERN Document Server

    Komech, Alexander

    2012-01-01

    A simplified, yet rigorous treatment of scattering theory methods and their applications Dispersion Decay and Scattering Theory provides thorough, easy-to-understand guidance on the application of scattering theory methods to modern problems in mathematics, quantum physics, and mathematical physics. Introducing spectral methods with applications to dispersion time-decay and scattering theory, this book presents, for the first time, the Agmon-Jensen-Kato spectral theory for the Schr?dinger equation, extending the theory to the Klein-Gordon equation. The dispersion decay plays a crucial role i

  3. Velocity Dispersions Across Bulge Types

    International Nuclear Information System (INIS)

    Fabricius, Maximilian; Bender, Ralf; Hopp, Ulrich; Saglia, Roberto; Drory, Niv; Fisher, David

    2010-01-01

    We present first results from a long-slit spectroscopic survey of bulge kinematics in local spiral galaxies. Our optical spectra were obtained at the Hobby-Eberly Telescope with the LRS spectrograph and have a velocity resolution of 45 km/s (σ*), which allows us to resolve the velocity dispersions in the bulge regions of most objects in our sample. We find that the velocity dispersion profiles in morphological classical bulge galaxies are always centrally peaked while the velocity dispersion of morphologically disk-like bulges stays relatively flat towards the center--once strongly barred galaxies are discarded.

  4. Proliferation resistance fuel cycle technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. S.; Ko, W. I

    1999-02-01

    The issues of dual use in nuclear technology are analysed for nuclear fuel cycle with special focus on uranium enrichment and spent fuel reprocessing which are considered as the most sensitive components in terms of vulnerability to diversion. Technical alternatives to mitigrate the vulnerability, as has been analysed in depth during the NASAP and INFCE era in the late seventies, are reviewed to characterize the DUPIC fuel cycle alternative. On the other hand, the new realities in nuclear energy including the disposition of weapon materials as a legacy of cold war are recast in an angle of nuclear proliferation resistance and safeguards with a discussion on the concept of spent fuel standard concept and its compliance with the DUPIC fuel cycle technology. (author)

  5. Missile proliferation and missile defense

    International Nuclear Information System (INIS)

    Zarif, M. Javad

    2002-01-01

    The global security environment is becoming increasingly volatile and dangerous. A new arms race is looming in the horizon ... [Missiles have] become the strong weapon of the poor and the discriminated against who find themselves vulnerable to outside threat. They believe missiles may prove instrumental in deterring the enemy from beginning a full scale war ... the engagement of all states at the United Nations in the issue of missiles, through the panel of governmental experts, and the new idea of exploring the subject in the Conference on Disarmament do provide a dim light at the end of the tunnel. ... Efforts at non-proliferation of missiles are more likely to succeed when viewed as an integral part of a global and comprehensive negotiation and progress in other areas of disarmament. (author)

  6. Attenuation and velocity dispersion in the exploration seismic frequency band

    Science.gov (United States)

    Sun, Langqiu

    the well logs; the models' parameters are adjusted by fitting the synthetic data to the observed data. In this way, seismic attenuation and velocity dispersion provide new insight into petrophysics properties at the Mallik and McArthur River sites. Potentially, observations of attenuation and velocity dispersion in the exploration seismic frequency band can improve the deconvolution process for vibrator data, Q-compensation, near-surface analysis, and first break picking for seismic data.

  7. Dispersion of effluents in the atmosphere; Dispersion des effluents dans l`atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-12-31

    This conference day was organized by the `convection` section of the French association of thermal engineers with the support of the environment and energy mastery agency (ADEME). This book of proceedings contains 10 papers entitled: `physical modeling of atmospheric dispersion in wind tunnels. Some industrial examples`; `modeling of the noxious effects of a fire on the environment of an industrial site: importance of thermal engineering related hypotheses`; `atmospheric diffusion of a noxious cloud: fast evaluation method of safety areas around refrigerating installations that use ammonia`; `modeling of atmospheric flows in urban areas in order to study the dispersion of pollutants`; `use of a dispersion parameter to characterize the evolution of a diffusion process downstream of a linear source of passive contaminant placed inside a turbulent boundary layer`; `elements of reflexion around the development of an analytical methodology applied to the elaboration of measurement strategies of air quality in ambient and outdoor atmospheres around industrial sites`; `state-of-the-art about treatment techniques for VOC-rich gaseous effluents`; `characteristics of the time variation of the atmospheric pollution in the Paris region and visualization of its space distribution`; `mass-spectrometry for the measurement of atmospheric pollutants`; `volume variations in natural convection turbulence`. (J.S.)

  8. Dispersion of effluents in the atmosphere; Dispersion des effluents dans l`atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This conference day was organized by the `convection` section of the French association of thermal engineers with the support of the environment and energy mastery agency (ADEME). This book of proceedings contains 10 papers entitled: `physical modeling of atmospheric dispersion in wind tunnels. Some industrial examples`; `modeling of the noxious effects of a fire on the environment of an industrial site: importance of thermal engineering related hypotheses`; `atmospheric diffusion of a noxious cloud: fast evaluation method of safety areas around refrigerating installations that use ammonia`; `modeling of atmospheric flows in urban areas in order to study the dispersion of pollutants`; `use of a dispersion parameter to characterize the evolution of a diffusion process downstream of a linear source of passive contaminant placed inside a turbulent boundary layer`; `elements of reflexion around the development of an analytical methodology applied to the elaboration of measurement strategies of air quality in ambient and outdoor atmospheres around industrial sites`; `state-of-the-art about treatment techniques for VOC-rich gaseous effluents`; `characteristics of the time variation of the atmospheric pollution in the Paris region and visualization of its space distribution`; `mass-spectrometry for the measurement of atmospheric pollutants`; `volume variations in natural convection turbulence`. (J.S.)

  9. Social environment affects juvenile dispersal in great tits (Parus major)

    NARCIS (Netherlands)

    Nicolaus, Marion; Michler, Stephanie P. M.; Jalvingh, Kirsten M.; Ubels, Richard; van der Velde, Marco; Komdeur, Jan; Both, Christiaan; Tinbergen, Joost M.; Wilson, Ken

    1. Habitat selection can affect individual fitness, and therefore, individuals are expected to assess habitat quality of potential breeding sites before settlement. 2. We investigated the role of social environment on juvenile dispersal behaviour in the great tit (Parus major). Two main

  10. Characterization of non point source pollutants and their dispersion ...

    African Journals Online (AJOL)

    EJIRO

    landing site in Uganda. N. Banadda. Agricultural and Bio-Systems Engineering Department, Makerere University, P. O. Box 7062, Kampala, Uganda. E-mail: banadda@agric.mak.ac.ug. Fax: +256-414-53.16.41. Accepted 5 January, 2011. The aim of this research is to characterize non point pollutants and their dispersion in ...

  11. Scale-Dependent Solute Dispersion in Variably Saturated Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Z. F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bott, Yi-Ju [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-29

    This work was performed to support performance assessment (PA) calculations for the Integrated Disposal Facility (IDF) at the Hanford Site. PA calculations require defensible estimates of physical, hydraulic, and transport parameters to simulate subsurface water flow and contaminant transport in both the near- and far-field environments. Dispersivity is one of the required transport parameters.

  12. China's position on nuclear non-proliferation

    International Nuclear Information System (INIS)

    Qian Jiadong.

    1986-01-01

    The paper discusses China's position on nuclear non-proliferation, in view of the fact that China does not subscribe to the Non-Proliferation Treaty (NPT). China refuses to accede to the NPT because it considers the treaty to be discriminatory, and reasons are given for this point of view. However its stand for nuclear disarmament and disapproval of nuclear proliferation are declared. Nuclear arms race, prevention of nuclear war, and nuclear disarmament are also considered. (UK)

  13. Nuclear power and nuclear-weapons proliferation

    International Nuclear Information System (INIS)

    Moniz, E.J.; Neff, T.L.

    1978-01-01

    Concern over the risk of nuclear proliferation has led to extensive reexamination of the technical, economic, and political assumptions underlying both national and international nuclear policies. An attempt is made in the present article to clarify the basic technical and political issues. The connections between various fuel cycles and their possible proliferation risks are discussed. As the resolution of the existing differing views on proliferation risks will be largely a political process, solutions to the problem are not proposed

  14. Nuclear energy and nuclear weapons proliferation

    International Nuclear Information System (INIS)

    1989-01-01

    A summary of the report dispatched in the middle of 1978 by the Atlantic Council of United States, organized by North American citizens, is presented. The report considers the relation between the production of nucleoelectric energy and the capacity of proliferation of nuclear weapons. The factors which affect the grade of proliferation risk represented by the use of nuclear energy in the world comparing this risk with the proliferation risks independently of nuclear energy, are examined. (M.C.K.) [pt

  15. What Causes Animals to Disperse?

    Indian Academy of Sciences (India)

    research involving animal behaviour and ecology for a very long time. ... shall examine two different types of dispersals that occur, try to understand the ... finally look at some practical methods through which the phe- ..... further qualitative or.

  16. The handbook of nuclear non-proliferation

    International Nuclear Information System (INIS)

    Yang, M. H.; Lee, B. W.; Oh, K. B.; Lee, H. M.; Ko, H. S.; Ryu, J. S.; Lee, K. S.

    2003-07-01

    This report analyzed international non-proliferation regime preventing from spread of nuclear weapon. This report took review from the historical background of non-proliferation regime to the recent changes and current status. It is here divided into multilateral and bilateral regime. First of all, this report dealt four multilateral treaties concluded for international non-proliferation such as NPT, NWFZ, CTBT and others. And international organization and regimes concerned with non-proliferation are also analyzed focused on UN, IAEA, ZC and NSG, regional safeguards system and international conferences. In addition, this report reviewed the nuclear cooperation agreement related with Korea which is a important tool for bilateral regime

  17. Strengthening the non proliferation regime: French views

    International Nuclear Information System (INIS)

    Delaune, P.

    2013-01-01

    3 main issues can be identified in the French policy concerning the backing of non proliferation: 1) responding resolutely to proliferation crises, 2) reinforcing substantive efforts to prevent and impede proliferation, and 3) strengthening the non-proliferation regime. The first issue is very important because combating proliferation is vital to the security of all. Concerning the second issue, France attaches particular importance to strengthening specific measures to prevent and check proliferation. Let me mention a few proposals that we put forward: exports need to be controlled more effectively, proliferation activities have to be criminalized, or the development of proliferation-resistant technologies should be supported. Concerning the third issue it means the strengthening of the non-proliferation regime, France proposes several means: -) aiming at the universalization of the additional protocol; -) ensuring that the Agency continues to have sufficient human, financial and technical resources to fulfill its verification mission effectively; -) encouraging the IAEA to make full use of the authority available to it; -) enhancing the use of information relevant to the delivery of the IAEA mandate; and -) sharing more accurate information concerning the breaches of commitments that happen. The paper is followed by the slides of the presentation. (A.C.)

  18. Intelligence and Nuclear Proliferation: Lessons Learned

    International Nuclear Information System (INIS)

    Hansen, Keith A.

    2011-09-01

    Intelligence agencies play a fundamental role in the prevention of nuclear proliferation, as they help to understand other countries' intentions and assess their technical capabilities and the nature of their nuclear activities. The challenges in this area remain, however, formidable. Past experiences and the discoveries of Iraq's WMD programs, of North Korean nuclear weapon program, and of Iranian activities, have put into question the ability of intelligence to monitor small, clandestine proliferation activities from either states or non-state entities. This Proliferation Paper analyzes the complex challenges intelligence faces and the various roles it plays in supporting national and international nuclear non-proliferation efforts, and reviews its track record. In an effort to shed light on the role and contribution of intelligence in national and international efforts to halt, if not prevent, further nuclear weapon proliferation, this paper first analyzes the challenges intelligence faces in monitoring small, clandestine proliferation activities and the role it plays in supporting non-proliferation efforts. It then reviews the intelligence track record in monitoring proliferation including the lessons learned from Iraq. Finally, it addresses whether it is possible for intelligence to accurately monitor future clandestine proliferation efforts. (author)

  19. Birefringent dispersive FDTD subgridding scheme

    OpenAIRE

    De Deckere, B; Van Londersele, Arne; De Zutter, Daniël; Vande Ginste, Dries

    2016-01-01

    A novel 2D finite difference time domain (FDTD) subgridding method is proposed, only subject to the Courant limit of the coarse grid. By making mu or epsilon inside the subgrid dispersive, unconditional stability is induced at the cost of a sparse, implicit set of update equations. By only adding dispersion along preferential directions, it is possible to dramatically reduce the rank of the matrix equation that needs to be solved.

  20. Dispersion engineering for integrated nanophotonics

    CERN Document Server

    Vanbésien, Olivier

    2014-01-01

    This book shows how dispersion engineering in two dimensional dielectric photonic crystals can provide new effects for the precise control of light propagation for integrated nanophotonics.Dispersion engineering in regular and graded photonic crystals to promote anomalous refraction effects is studied from the concepts to experimental demonstration via nanofabrication considerations. Self collimation, ultra and negative refraction, second harmonic generation, mirage and invisibility effects which lead to an unprecedented control of light propagation at the (sub-)wavelength scale for the

  1. Dispersion coefficients for coastal regions

    International Nuclear Information System (INIS)

    MacRae, B.L.; Kaleel, R.J.; Shearer, D.L.

    1983-03-01

    The Nuclear Regulatory Commission (NRC) has undertaken an extensive atmospheric dispersion research and measurement program from which it is intended will emerge improved predictive techniques for employment in licensing decisions and for emergency planning and response. Through this program the NRC has conducted field measurement programs over a wide range of geographic and topographic locations, and are using the acquired tracer and meteorological measurements to evaluate existing dispersion models and prediction techniques, and to develop new techniques when necessary

  2. Commercial Satellite Imagery Analysis for Countering Nuclear Proliferation

    Science.gov (United States)

    Albright, David; Burkhard, Sarah; Lach, Allison

    2018-05-01

    High-resolution commercial satellite imagery from a growing number of private satellite companies allows nongovernmental analysts to better understand secret or opaque nuclear programs of countries in unstable or tense regions, called proliferant states. They include North Korea, Iran, India, Pakistan, and Israel. By using imagery to make these countries’ aims and capabilities more transparent, nongovernmental groups like the Institute for Science and International Security have affected the policies of governments and the course of public debate. Satellite imagery work has also strengthened the efforts of the International Atomic Energy Agency, thereby helping this key international agency build its case to mount inspections of suspect sites and activities. This work has improved assessments of the nuclear capabilities of proliferant states. Several case studies provide insight into the use of commercial satellite imagery as a key tool to educate policy makers and affect policy.

  3. Solitary excitations in discrete two-dimensional nonlinear Schrodinger models with dispersive dipole-dipole interactions

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Gaididei, Yuri Borisovich; Johansson, M.

    1998-01-01

    The dynamics of discrete two-dimensional nonlinear Schrodinger models with long-range dispersive interactions is investigated. In particular, we focus on the cases where the dispersion arises from a dipole-dipole interaction, assuming the dipole moments at each lattice site to be aligned either...

  4. The role of animal seed dispersal in accelerating native forest regeneration on degraded tropical lands.

    Science.gov (United States)

    J.M. Wunderle Jr.

    1997-01-01

    this paper reviews the characteristicas of animal seed dispersal. relevant to tropical forest restoration efforts and discusses their managment implication. In many tropical regions seed dispersal by animals is the predominant form of dissemination of propagules and has a potential to facilitate recolonization of native vegetation on degraded sites.

  5. Brexit, Euratom and nuclear proliferation

    International Nuclear Information System (INIS)

    Soedersten, Anna

    2016-01-01

    One of the issues absent from the academic (and public) debate on the United Kingdom's (UK) referendum vote to withdraw from the European Union (EU) (commonly referred to as 'Brexit') is what will happen to the UK's membership in the European Atomic Energy Community (Euratom). The Euratom Treaty was signed in Rome in 1957, together with the European Economic Community (EEC) Treaty. It was concluded for an unlimited period and it establishes a Community that has a separate legal personality from the EU. Thus, the EU and Euratom form two separate, although closely linked entities. Euratom's principal mission is related to the economy, tasked with 'creating the conditions necessary for the speedy establishment and growth of nuclear industries'; in other words, to promote the nuclear industry. This reflects the high expectations for nuclear energy in the 1950's. Some even believed that the development of nuclear energy would trigger an industrial revolution; however, Euratom only came to play a minor role in the European integration process. Despite this, the Euratom Treaty has remained, almost unchanged, since its adoption and is still frequently applied, although it is unclear to what extent it has boosted the nuclear industry. This article has a two-fold purpose. The first purpose is to address the constitutional issue of 'partial membership'. All EU member states are also members of Euratom. It has always been assumed that with membership in the EU also comes a membership in Euratom. But, what about withdrawal? What are the arguments for 'partial membership'? The second purpose of this article is to shed light on some implications of Brexit as it relates to Euratom. The most serious consequences are perhaps found in the area of nuclear non-proliferation. The United Kingdom is one of two nuclear weapon states in the EU (France being the other one). Withdrawal from Euratom means withdrawal from its control system, the system of so-called nuclear safeguards. Under

  6. Proliferation after the Iraq war; La proliferation apres la guerre d'Irak

    Energy Technology Data Exchange (ETDEWEB)

    Daguzan, J.F

    2004-09-15

    This article uses the Iraq war major event to analyze the approach used by the US to fight against proliferation. It questions the decision and analysis process which has led to the US-British intervention and analyzes the consequences of the war on the proliferation of other countries and on the expected perspectives. Finally, the future of proliferation itself is questioned: do we have to fear more threat or is the virtuous circle of non-proliferation well started? (J.S.)

  7. The challenges of nuclear proliferation

    International Nuclear Information System (INIS)

    Le Guelte, Georges

    2015-01-01

    The author of this article first outlines that the Non Proliferation Treaty (NPT) is a tool of domination used by nuclear powers: they can keep and even develop their own nuclear arsenal, while other countries who sign this treaty commit themselves not to try to acquire nuclear weapons. The USA and USSR kept on persuading various countries to sign this treaty, but eventually let some countries develop their military nuclear programme (Israel, Pakistan, or India). He evokes technical difficulties in the application of the Treaty, notably for the control of centrifugation activities. He outlines that the USA have now a dominant position with respect to this Treaty and its application, but that the Treaty remains a major safety element for the world. He evokes more recent and negative evolutions: the withdrawal of North Korea from the Treaty, the destruction of an Iraqi nuclear reactor by Israel (i.e. the destruction of a nuclear installation belonging to a country who signed the NPT by a country who did not sign it). He proposes an overview of the Iranian issue (history of the Iranian nuclear programme, of the nuclear crisis, of the still going on negotiations), and describes what could be the worst possible scenario

  8. North Korea: a mercenary proliferator?

    International Nuclear Information System (INIS)

    Hemez, Remy

    2015-01-01

    After having recalled that North Korea possesses a rather advanced ballistic programme which has been started in the 1970 with the Chinese support, that North Korea is the fourth world producer of ballistic missiles, the author outlines that this country has become a major proliferator as it exports this production to different States and non-State actors. He recalls the long history of relationships between North Korea and terrorist organisations (even during the Cold War), comments the current and major support of North Korea to Hamas and Hezbollah in Gaza and in Lebanon. These relationships are then related with those these both organisations have with Syria and Iran who are in fact the relays between them and North Korea. The author explains why Hamas and Hezbollah must buy their weapons to such a far country: Iran is submitted to international sanctions, Iran and Syria want to avoid being banned from the international community for selling weapon to a terrorist (or so-said) organisation, and prices are rather competitive. If North Korea is also submitted to international sanctions, weapon smuggling seems to be institutional in this country. The author finally briefly evokes the issue of chemical weapons: North Korea possesses few thousand tonnes of these weapons, and could export them to non-state organisations

  9. Director`s series on proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, K.C.; Price, M.E. [eds.

    1995-11-17

    This is an occasional publication of essays on the topics of nuclear, chemical, biological, and missile proliferation. The views represented are those of the author`s. Essay topics include: Nuclear Proliferation: Myth and Reality; Problems of Enforcing Compliance with Arms Control Agreements; The Unreliability of the Russian Officer Corps: Reluctant Domestic Warriors; and Russia`s Nuclear Legacy.

  10. Proliferation resistance of small modular reactors fuels

    Energy Technology Data Exchange (ETDEWEB)

    Polidoro, F.; Parozzi, F. [RSE - Ricerca sul Sistema Energetico,Via Rubattino 54, 20134, Milano (Italy); Fassnacht, F.; Kuett, M.; Englert, M. [IANUS, Darmstadt University of Technology, Alexanderstr. 35, D-64283 Darmstadt (Germany)

    2013-07-01

    In this paper the proliferation resistance of different types of Small Modular Reactors (SMRs) has been examined and classified with criteria available in the literature. In the first part of the study, the level of proliferation attractiveness of traditional low-enriched UO{sub 2} and MOX fuels to be used in SMRs based on pressurized water technology has been analyzed. On the basis of numerical simulations both cores show significant proliferation risks. Although the MOX core is less proliferation prone in comparison to the UO{sub 2} core, it still can be highly attractive for diversion or undeclared production of nuclear material. In the second part of the paper, calculations to assess the proliferation attractiveness of fuel in typical small sodium cooled fast reactor show that proliferation risks from spent fuel cannot be neglected. The core contains a highly attractive plutonium composition during the whole life cycle. Despite some aspects of the design like the sealed core that enables easy detection of unauthorized withdrawal of fissile material and enhances proliferation resistance, in case of open Non-Proliferation Treaty break-out, weapon-grade plutonium in sufficient quantities could be extracted from the reactor core.

  11. Regional-scale input of dispersed and discrete volcanic ash to the Izu-Bonin and Mariana subduction zones

    Science.gov (United States)

    Scudder, Rachel P.; Murray, Richard W.; Schindlbeck, Julie C.; Kutterolf, Steffen; Hauff, Folkmar; McKinley, Claire C.

    2014-11-01

    We have geochemically and statistically characterized bulk marine sediment and ash layers at Ocean Drilling Program Site 1149 (Izu-Bonin Arc) and Deep Sea Drilling Project Site 52 (Mariana Arc), and have quantified that multiple dispersed ash sources collectively comprise ˜30-35% of the hemipelagic sediment mass entering the Izu-Bonin-Mariana subduction system. Multivariate statistical analyses indicate that the bulk sediment at Site 1149 is a mixture of Chinese Loess, a second compositionally distinct eolian source, a dispersed mafic ash, and a dispersed felsic ash. We interpret the source of these ashes as, respectively, being basalt from the Izu-Bonin Front Arc (IBFA) and rhyolite from the Honshu Arc. Sr-, Nd-, and Pb isotopic analyses of the bulk sediment are consistent with the chemical/statistical-based interpretations. Comparison of the mass accumulation rate of the dispersed ash component to discrete ash layer parameters (thickness, sedimentation rate, and number of layers) suggests that eruption frequency, rather than eruption size, drives the dispersed ash record. At Site 52, the geochemistry and statistical modeling indicates that Chinese Loess, IBFA, dispersed BNN (boninite from Izu-Bonin), and a dispersed felsic ash of unknown origin are the sources. At Site 1149, the ash layers and the dispersed ash are compositionally coupled, whereas at Site 52 they are decoupled in that there are no boninite layers, yet boninite is dispersed within the sediment. Changes in the volcanic and eolian inputs through time indicate strong arc-related and climate-related controls.

  12. Pollutant dispersion studies - An update on the problems in Indian coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.

    Pollutant dispersion problems along the Indian coastal waters are characterisEd. by site-specificity, as a result of seasonal and physiographic variabilities. Presence of large rivers, estuaries and backwaters add to the problems of waste disposal...

  13. A Stochastic Model for the Landing Dispersion of Hazard Detection and Avoidance Capable Flight Systems

    Science.gov (United States)

    Witte, L.

    2014-06-01

    To support landing site assessments for HDA-capable flight systems and to facilitate trade studies between the potential HDA architectures versus the yielded probability of safe landing a stochastic landing dispersion model has been developed.

  14. Atmospherically dispersed radiocarbon at the Chalk River Laboratories

    International Nuclear Information System (INIS)

    Milton, G.M.; Brown, R.M.; Repta, C.J.W.; Selkirk, C.J.

    1996-01-01

    A small percentage of the total radiocarbon produced by the NRX and NRU experimental reactors at the Chalk River Laboratories has been vented from the main reactor stack and atmospherically dispersed across the site. Surveys conducted in 1982-83 and 1993-94 have shown that atmospheric levels more than 50 m from the stack are never greater than 600 Bq.kg -1 carbon above the natural background level, falling to near-global atmospheric levels at the site boundaries roughly 7 km away. A dispersion factor > 1.2 x 10 6 m 3 .s -1 at ∼ 0.75 km distance from the point of emission is calculated on the basis of recent in-stack monitoring. Analysis of growth rings in on-site trees has provided an opportunity to search for correlations of 14 C output summer power production and/or moderator losses. (author). 16 refs., 14 tabs., 11 figs

  15. Dispersive regime of the Jaynes–Cummings and Rabi lattice

    International Nuclear Information System (INIS)

    Zhu, Guanyu; Koch, Jens; Schmidt, Sebastian

    2013-01-01

    Photon-based strongly correlated lattice models like the Jaynes–Cummings and Rabi lattices differ from their more conventional relatives like the Bose–Hubbard model by the presence of an additional tunable parameter: the frequency detuning between the pseudo-spin degree of freedom and the harmonic mode frequency on each site. Whenever this detuning is large compared to relevant coupling strengths, the system is said to be in the dispersive regime. The physics of this regime is well-understood at the level of a single Jaynes–Cummings or Rabi site. Here, we extend the theoretical description of the dispersive regime to lattices with many sites, for both strong and ultra-strong coupling. We discuss the nature and spatial range of the resulting qubit–qubit and photon–photon coupling, demonstrate the emergence of photon-pairing and squeezing and illustrate our results by exact diagonalization of the Rabi dimer. (paper)

  16. Atmospheric dispersion of radioactive materials

    International Nuclear Information System (INIS)

    Chino, Masamichi

    1988-01-01

    The report describes currently available techniques for predicting the dispersion of accidentally released radioactive materials and techniques for visualization using computer graphics. A simulation study is also made on the dispersion of radioactive materials released from the Chernobyl plant. The simplest models include the Gauss plume model and the puff model, which cannot serve to analyze the effects of the topography, vertical wind shear, temperature inversion layer, etc. Numerical analysis methods using advection and dispersion equations are widely adopted for detailed evaluation of dispersion in an emergency. An objective analysis model or a hydrodynamical model is often used to calculate the air currents which are required to determine the advection. A small system based on the puff model is widely adopted in Europe, where the topography is considered to have only simple effects. A more sophisticated large-sized system is required in nuclear facilities located in an area with more complex topographic features. An emergency system for dispersion calculation should be equipped with a graphic display to serve for quick understanding of the radioactivity distribution. (Nogami, K.)

  17. Micromixer based on Taylor dispersion

    International Nuclear Information System (INIS)

    Yang, H; Nguyen, N-T; Huang, X

    2006-01-01

    This paper reports an analytical model, the fabrication and the characterization of a polymeric micromixer based on Taylor dispersion. Due to the distributed velocity field over the channel cross section, the effective dispersion in axial direction in a microchannel is much stronger than the pure molecular diffusion. In our work, squential segmentation was used in the micromixer for improving mixing in a microchannel. The micromixer was designed and fabricated based on lamination of five 100-μm-thick polymer sheets. Rubber valve seats were embedded between the forth and the fifth layers. The polymer layers were machined using a CO 2 laser. The lamination of the five layers was carried out by a commercial hot laminator (Aurora LM-450HC). External solenoid actuators are used for closing the valves at the mixer inlets. The experimental results confirm the effect of Taylor dispersion. Mixing ratio can be adjusted by pulse width modulation of the control signal of the solenoids

  18. Improving IUE High Dispersion Extraction

    Science.gov (United States)

    Lawton, Patricia J.; VanSteenberg, M. E.; Massa, D.

    2007-01-01

    We present a different method to extract high dispersion International Ultraviolet Explorer (IUE) spectra from the New Spectral Image Processing System (NEWSIPS) geometrically and photometrically corrected (SI HI) images of the echellogram. The new algorithm corrects many of the deficiencies that exist in the NEWSIPS high dispersion (SIHI) spectra . Specifically, it does a much better job of accounting for the overlap of the higher echelle orders, it eliminates a significant time dependency in the extracted spectra (which can be traced to the background model used in the NEWSIPS extractions), and it can extract spectra from echellogram images that are more highly distorted than the NEWSIPS extraction routines can handle. Together, these improvements yield a set of IUE high dispersion spectra whose scientific integrity is sign ificantly better than the NEWSIPS products. This work has been supported by NASA ADP grants.

  19. STELLAR MASS DEPENDENT DISK DISPERSAL

    International Nuclear Information System (INIS)

    Kennedy, Grant M.; Kenyon, Scott J.

    2009-01-01

    We use published optical spectral and infrared (IR) excess data from nine young clusters and associations to study the stellar mass dependent dispersal of circumstellar disks. All clusters older than ∼3 Myr show a decrease in disk fraction with increasing stellar mass for solar to higher mass stars. This result is significant at about the 1σ level in each cluster. For the complete set of clusters we reject the null hypothesis-that solar and intermediate-mass stars lose their disks at the same rate-with 95%-99.9% confidence. To interpret this behavior, we investigate the impact of grain growth, binary companions, and photoevaporation on the evolution of disk signatures. Changes in grain growth timescales at fixed disk temperature may explain why early-type stars with IR excesses appear to evolve faster than their later-type counterparts. Little evidence that binary companions affect disk evolution suggests that photoevaporation is the more likely mechanism for disk dispersal. A simple photoevaporation model provides a good fit to the observed disk fractions for solar and intermediate-mass stars. Although the current mass-dependent disk dispersal signal is not strong, larger and more complete samples of clusters with ages of 3-5 Myr can improve the significance and provide better tests of theoretical models. In addition, the orbits of extra-solar planets can constrain models of disk dispersal and migration. We suggest that the signature of stellar mass dependent disk dispersal due to photoevaporation may be present in the orbits of observed extra-solar planets. Planets orbiting hosts more massive than ∼1.6 M sun may have larger orbits because the disks in which they formed were dispersed before they could migrate.

  20. A critical review on the scaling theory of dispersion

    Science.gov (United States)

    Zech, Alraune; Mai, Juliane; Attinger, Sabine; Dietrich, Peter; Teutsch, Georg; Fiori, Aldo; Rubin, Yoram

    2014-05-01

    The phenomenon of dispersive mixing of solutes in aquifers is subject of research since decades. The characterization of dispersivity at a particular field site is a prerequisite to predict the movement and spreading of a contaminant plume. Experimental investigations have shown, that field-scale dispersivities vary over orders of magnitude, which apparently depends on the scale of measurement. Gelhar et al. [1992] and Schulze-Makuch [2005] have reviewed a large number of transport experiments reported in the literature. Based on that data Schulze-Makuch [2005] performed a trend analysis of longitudinal dispersivity, fostering the empirical relationship of a power law between dispersivities and the scale of measurement without an upper bound. The goal of our study is to critically revisit not only the data used for the trend analysis but the power-law scale dependence of longitudinal dispersivity (e.g. Neuman [1990], Xu and Eckstein [1995]). Our particular focus is on the reported dispersivities of large amount (larger than 100m) and large measurement scales (in the order of kilometers). We aim to evaluate current theories of transport against a critical "mass" of field experiments and to bracket the conditions of their applicability. We further aim to evaluate the adequacy of the field sampling techniques that were employed from the perspective of more than 30 years development in modeling and field characterization. Given the tremendous progress in field data acquisition techniques and new insights gained, it is reasonable to expect that interpretations of past experiments may be flawed due to the limitations or inadequacy of field sampling techniques. Gelhar, L.W., C. Welty, and K.R. Rehfeldt, 1992, A critical review of data on field-scale dispersion in aquifers, Water Resources Research 28, No. 7: 1955-1974. Schulze-Makuch, D., 2005, Longitudinal dispersivity data and implications for scaling behavior, Ground Water, Vol. 43, No. 3, 443-456. Neuman, S.P., 1990

  1. Dispersion of multi-walled carbon nanotubes in biocompatible dispersants

    International Nuclear Information System (INIS)

    Piret, J.-P.; Detriche, S.; Vigneron, R.; Vankoningsloo, S.; Rolin, S.; Mejia Mendoza, J. H.; Masereel, B.; Lucas, S.; Delhalle, J.; Luizi, F.; Saout, C.; Toussaint, O.

    2010-01-01

    Owing to their phenomenal electrical and mechanical properties, carbon nanotubes (CNT) have been an area of intense research since their discovery in 1991. Different applications for these nanoparticles have been proposed, among others, in electronics and optics but also in the medical field. In parallel, emerging studies have suggested potential toxic effects of CNT while others did not, generating some conflicting outcomes. These discrepancies could be, in part, due to different suspension approaches used and to the agglomeration state of CNT in solution. In this study, we described a standardized protocol to obtain stable CNT suspensions, using two biocompatible dispersants (Pluronic F108 and hydroxypropylcellulose) and to estimate the concentration of CNT in solution. CNT appear to be greatly individualized in these two dispersants with no detection of remaining bundles or agglomerates after sonication and centrifugation. Moreover, CNT remained perfectly dispersed when added to culture medium used for in vitro cell experiments. We also showed that Pluronic F108 is a better dispersant than hydroxypropylcellulose. In conclusion, we have developed a standardized protocol using biocompatible surfactants to obtain reproducible and stable multi-walled carbon nanotubes suspensions which can be used for in vitro or in vivo toxicological studies.

  2. Evidence for an association between post-fledging dispersal and microsatellite multilocus heterozygosity in a large population of greater flamingos.

    Directory of Open Access Journals (Sweden)

    Mark A F Gillingham

    Full Text Available Dispersal can be divided into three stages: departure, transience and settlement. Despite the fact that theoretical studies have emphasized the importance of heterozygosity on dispersal strategies, empirical evidence of its effect on different stages of dispersal is lacking. Here, using multi-event capture-mark-recapture models, we show a negative association between microsatellite multilocus heterozygosity (MLH; 10 loci; n = 1023 and post-fledging dispersal propensity for greater flamingos, Phoenicopterus roseus, born in southern France. We propose that the negative effects of inbreeding depression affects competitive ability and therefore more homozygous individuals are more likely to disperse because they are less able to compete within the highly saturated natal site. Finally, a model with the effect of MLH on propensity of post-fledgling dispersers to disperse to the long-distance sites of Africa was equivalent to the null model, suggesting that MLH had low to no effect on dispersal distance. Variations in individual genetic quality thus result in context-dependent heterogeneity in dispersal strategies at each stage of dispersal. Our results have important implications on fitness since sites visited early in life are known to influence site selection later on in life and future survival.

  3. Hematopoietic stem cell migration and proliferation after Partial body irradiation

    International Nuclear Information System (INIS)

    Murata, Takashi; Utsumi, Makoto; Hotta, Tomomitsu; Yamada, Hideo

    1983-01-01

    Stem cell migration in hematopoietic recovery after partial body irradiation was investigated with special emphasis on the comparative roles of the bone marrow and the spleen. The number of CFU-S in circulation declined rapidly and reached zero within a day after irradiation, thereafter it increased gradually. This finding suggests the presence of two different phases of stem cell migration. One is a rapid migrating phase in which stem cells are released rapidly within a day after irradiation, and the other is a slow migrating phase. The result of split doses of local body irradiation experiments implicated a role for the spleen distinct from that of the bone marrow in the preferential distribution of stem cells early after irradiation. The cell kinetic study showed that the proliferation of CFU-S occurred actively in irradiated bone marrow and the spleens as compared to that in unirradiated control. But on Day 7 and on Day 10 after irradiation, the proliferation of CFU-S in shielded bone marrow did not occur as actively as those in irradiated areas. The results of our present studies suggest that the spleen is not only the storage pools of migrating stem cells but also the main site of active proliferation of CFU-S in the early period of hematopoietic regeneration. (author)

  4. Atypical IgG4+ Plasmacytic Proliferations and Lymphomas: Characterization of 11 Cases.

    Science.gov (United States)

    Bledsoe, Jacob R; Wallace, Zachary S; Deshpande, Vikram; Richter, Joshua R; Klapman, Jason; Cowan, Andrew; Stone, John H; Ferry, Judith A

    2017-09-01

    To report the clinicopathologic features of monotypic immunoglobulin G4+ (IgG4+) lymphoid and plasmacytic proliferations. Cases were identified from the pathology files. Pathology and clinical materials were reviewed. Eleven cases of monotypic IgG4+ proliferations were identified at nodal, orbital, or salivary sites. Six cases (three men, three women; age, 57-94 years) met criteria for lymphoma or plasma cell neoplasia. Most contained frequent Mott cells. Five cases (three men, two women; age, 40-80 years) had restricted proliferations of atypical/monotypic IgG4+ plasma cells in a background of reactive lymphoid hyperplasia or inflammation. Monotypic IgG4+ proliferations include lymphomas, plasmacytic neoplasms, and a previously uncharacterized group of proliferations not meeting criteria for conventional hematolymphoid neoplasia. Distinct features included prominent Mott cells and/or monotypic plasma cells within follicles. The proliferations were infrequently associated with IgG4-related disease (IgG4-RD). Our findings raise questions regarding the relationship between clonal IgG4+ proliferations, reactive/inflammatory processes, and IgG4-RD. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  5. The effect of cerium valence states at cerium oxide nanoparticle surfaces on cell proliferation

    KAUST Repository

    Naganuma, Tamaki

    2014-05-01

    Understanding and controlling cell proliferation on biomaterial surfaces is critical for scaffold/artificial-niche design in tissue engineering. The mechanism by which underlying integrin ligates with functionalized biomaterials to induce cell proliferation is still not completely understood. In this study, poly-l-lactide (PL) scaffold surfaces were functionalized using layers of cerium oxide nanoparticles (CNPs), which have recently attracted attention for use in therapeutic application due to their catalytic ability of Ce4+ and Ce3+ sites. To isolate the influence of Ce valance states of CNPs on cell proliferation, human mesenchymal stem cells (hMSCs) and osteoblast-like cells (MG63) were cultured on the PL/CNP surfaces with dominant Ce4+ and Ce3+ regions. Despite cell type (hMSCs and MG63 cells), different surface features of Ce4+ and Ce3+ regions clearly promoted and inhibited cell spreading, migration and adhesion behavior, resulting in rapid and slow cell proliferation, respectively. Cell proliferation results of various modified CNPs with different surface charge and hydrophobicity/hydrophilicity, indicate that Ce valence states closely correlated with the specific cell morphologies and cell-material interactions that trigger cell proliferation. This finding suggests that the cell-material interactions, which influence cell proliferation, may be controlled by introduction of metal elements with different valence states onto the biomaterial surface. © 2014 Elsevier Ltd.

  6. Framework of Comprehensive Proliferation Resistance Evaluation Methodology

    International Nuclear Information System (INIS)

    Kim, Min Su; Jo, Seong Youn; Kim, Min Soo; Kim, Jae San; Lee, Hyun Kyung

    2007-01-01

    Civilian nuclear programs can be used as a pretext to acquire technologies, materials, equipment for military weapon programs. Consequently, international society has a strong incentive to develop a nuclear system more proliferation resistant to assure that the civilian nuclear energy system is an unattractive and least desirable route for diversion of weapon usable material. The First step developing a more proliferation resistant nuclear energy system is to develop a systematic and standardized evaluation methodology to ensure that any future nuclear energy system satisfies the proliferation resistance goals. Many attempts to develop systematic evaluation methodology have been proposed and many systems for assessing proliferation resistance have been previously studied. However, a comprehensive proliferation resistance evaluation can not be achieved by simply applying one method since complicated proliferation resistance characteristics, including inherent features and extrinsic features, should be completely evaluated. Therefore, it is necessary to develop one incorporated evaluation methodology to make up for weak points of each evaluation method. The objective of this study is to provide a framework of comprehensive proliferation resistance evaluation methodology by incorporating two generally used evaluation methods, attribute and scenario analysis

  7. Nuclear proliferation: prospects, problems, and proposals

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This issue of the ANNALS addresses itself to three aspects of nuclear proliferation: the prospect that new nuclear powers will come on the scene, the problems that their arrival may create, and ways of coping with those problems. In an introductory paper, ''Quo Vadimus,'' Joseph I. Coffey investigates the pros and cons of proliferation, concluding that it is not a question of whether there will be nuclear proliferation, but in what countries. Part I, Where We Are, contains five papers preceded by introductory comments by Joseph I. Coffey. The papers and their authors are: Why States Go--and Don't Go--Nuclear, William Epstein; How States Can ''Go Nuclear,'' Frank C. Barnaby; What Happens If. . .Terrorists, Revolutionaries, and Nuclear Weapons, David Kreiger; Safeguards Against Diversion of Nuclear Material: An Overview, Ryukichi Imai; and Reducing the Incentives to Proliferation, George H. Quester. Part II, And Where We May Go, again includes some introductory remarks by Joseph I. Coffey. The seven succeeding papers are: Nth Powers of the Future, Ashok Kapur; Nuclear Proliferation and World Politics, Lewis A. Dunn; Arms Control in a Nuclear Armed World, Colin Gray; The United Nations, the Superpowers, and Proliferation, Abraham Bargman; Proliferation and the Future: Destruction or Transformation, Frederick C. Thayer; Decision Making in a Nuclear Armed World, Michael Brenner; and The United States in a World of Nuclear Powers, Michael Nacht. This special report is concluded with a glossary

  8. Which future for nuclear counter-proliferation?

    International Nuclear Information System (INIS)

    Duval, M.

    2010-01-01

    Dealing with the case of nuclear weapons possessed by nuclear states (but not eventually by terrorists), the author first identifies the constants of counter-proliferation: it is linked to interest conflicts between those who try to preserve their monopoly and those who try to acquire a new weapon either because of a threat or for reasons of regional prestige, the evolution from use to deterrence, the appearance of new actors after the USA and Russia, the role of nuclear tactical weapons, and the future of Russian weapons and know-how. He presents the international counter-proliferation context: the Non Proliferation Treaty (NPT), the IAEA and its controls, the Nuclear Supplier Group (NSG), the nuclear-free zones, the Comprehensive Test Ban Treaty (CTBT), the Missile Technology Control Regime (MTCR). He describes how and why proliferation occurs: uranium enrichment and plutonium technology, political reasons in different parts of the world. Then, he gives an overview of the proliferation status by commenting the cases of Israel, Iraq, India, Pakistan, North Korea, and Iran. He discusses the future of proliferation (involved countries, existence of a nuclear black market) and of counter-proliferation as far as Middle-East and North Korea are concerned. He tries finally to anticipate the consequences for nuclear deterrence strategy, and more particularly for Europe and France

  9. Harmine stimulates proliferation of human neural progenitors

    Directory of Open Access Journals (Sweden)

    Vanja Dakic

    2016-12-01

    Full Text Available Harmine is the β-carboline alkaloid with the highest concentration in the psychotropic plant decoction Ayahuasca. In rodents, classical antidepressants reverse the symptoms of depression by stimulating neuronal proliferation. It has been shown that Ayahuasca presents antidepressant effects in patients with depressive disorder. In the present study, we investigated the effects of harmine in cell cultures containing human neural progenitor cells (hNPCs, 97% nestin-positive derived from pluripotent stem cells. After 4 days of treatment, the pool of proliferating hNPCs increased by 71.5%. Harmine has been reported as a potent inhibitor of the dual specificity tyrosine-phosphorylation-regulated kinase (DYRK1A, which regulates cell proliferation and brain development. We tested the effect of analogs of harmine, an inhibitor of DYRK1A (INDY, and an irreversible selective inhibitor of monoamine oxidase (MAO but not DYRK1A (pargyline. INDY but not pargyline induced proliferation of hNPCs similarly to harmine, suggesting that inhibition of DYRK1A is a possible mechanism to explain harmine effects upon the proliferation of hNPCs. Our findings show that harmine enhances proliferation of hNPCs and suggest that inhibition of DYRK1A may explain its effects upon proliferation in vitro and antidepressant effects in vivo.

  10. Wastewater effluent dispersal in Southern California Bays

    KAUST Repository

    Uchiyama, Yusuke; Idica, Eileen Y.; McWilliams, James C.; Stolzenbach, Keith D.

    2014-01-01

    The dispersal and dilution of urban wastewater effluents from offshore, subsurface outfalls is simulated with a comprehensive circulation model with downscaling in nested grid configurations for San Pedro and Santa Monica Bays in Southern California during Fall of 2006. The circulation is comprised of mean persistent currents, mesoscale and submesoscale eddies, and tides. Effluent volume inflow rates at Huntington Beach and Hyperion are specified, and both their present outfall locations and alternative nearshore diversion sites are assessed. The effluent tracer concentration fields are highly intermittent mainly due to eddy currents, and their probability distribution functions have long tails of high concentration. The dilution rate is controlled by submesoscale stirring and straining in tracer filaments. The dominant dispersal pattern is alongshore in both directions, approximately along isobaths, over distances of more than 10. km before dilution takes over. The current outfall locations mostly keep the effluent below the surface and away from the shore, as intended, but the nearshore diversions do not. © 2014 Elsevier Ltd.

  11. Wastewater effluent dispersal in Southern California Bays

    KAUST Repository

    Uchiyama, Yusuke

    2014-03-01

    The dispersal and dilution of urban wastewater effluents from offshore, subsurface outfalls is simulated with a comprehensive circulation model with downscaling in nested grid configurations for San Pedro and Santa Monica Bays in Southern California during Fall of 2006. The circulation is comprised of mean persistent currents, mesoscale and submesoscale eddies, and tides. Effluent volume inflow rates at Huntington Beach and Hyperion are specified, and both their present outfall locations and alternative nearshore diversion sites are assessed. The effluent tracer concentration fields are highly intermittent mainly due to eddy currents, and their probability distribution functions have long tails of high concentration. The dilution rate is controlled by submesoscale stirring and straining in tracer filaments. The dominant dispersal pattern is alongshore in both directions, approximately along isobaths, over distances of more than 10. km before dilution takes over. The current outfall locations mostly keep the effluent below the surface and away from the shore, as intended, but the nearshore diversions do not. © 2014 Elsevier Ltd.

  12. Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*

    Science.gov (United States)

    Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

    2014-01-01

    In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies. PMID:24599687

  13. Non-proliferation and multinational enterprises

    International Nuclear Information System (INIS)

    1979-04-01

    The paper supplements CC/WG.2/9 in presenting the Japanese delegation's contribution in the areas of non-proliferation and multi-national enterprises. The paper questions whether multinational enrichment enterprises would constitute a significant non-proliferation factor, noting that the nature of the venture might create a potential for the dissemination of sensitive information. The paper also argues that a multi-national venture which was not economically competitive (with national facilities) would have questionable viability. The conclusion is that non-proliferation advantages, if any, would be a result, not an objective of such a venture

  14. Comparative analysis of proliferation resistance assessment methodologies

    International Nuclear Information System (INIS)

    Takaki, Naoyuki; Kikuchi, Masahiro; Inoue, Naoko; Osabe, Takeshi

    2005-01-01

    Comparative analysis of the methodologies was performed based on the discussions in the international workshop on 'Assessment Methodology of Proliferation Resistance for Future Nuclear Energy Systems' held in Tokyo, on March 2005. Through the workshop and succeeding considerations, it is clarified that the proliferation resistance assessment methodologies are affected by the broader nuclear options being pursued and also by the political situations of the state. Even the definition of proliferation resistance, despite the commonality of fundamental issues, derives from perceived threat and implementation circumstances inherent to the larger programs. Deep recognitions of the 'difference' among communities would help us to make further essential and progressed discussion with harmonization. (author)

  15. Dispersion of radioactively contamination turtles on the SRP: research and reconnaissance

    International Nuclear Information System (INIS)

    Lamb, T.; Taylor, B.; Gibbons, J.W.

    1986-01-01

    Although SREL continued long-term studies on turtles during 1986, much research effort centered on contaminated turtle dispersion. The problem of radionuclide contamination in turtles and their dispersal through aquatic sites on and off the Savannah River Plant (SRP) was approached along three fronts. The first involved site reconnaissance, where aquatic habitats, adjacent to contaminated areas on the SRP were identified and surveyed for contaminated turtles. The second approach involved the development of a dispersal model. Third, mitochondrial DNA analysis was conducted to assess genetic differentiation between turtle populations inhabiting either side of the Savannah River near SRP. 1 figures, 2 tables

  16. Atmospheric dispersion of radionuclides released by a nuclear plant

    International Nuclear Information System (INIS)

    Barboza, A.A.

    1989-01-01

    A numerical model has been developed to simulate the atmospheric dispersion of radionuclides released by a nuclear plant operating under normal conditions. The model, based on gaussian plume representation, accouts for and evaluates several factors which affect the concentraction of effluents in the atmosphere, such as: ressuspension, deposition, radioactive decay, energy and type of the radiation emitted, among others. The concentraction of effluents in the atmosphere is calculated for a uniform mesh of points around the plant, allowing the equivalent doses to be then evaluated. Simulations of the atmosphere dispersion of radioactive plumes of Cs 137 and Ar 41 have been performed assuming a constant rate of release, as expected from the normal operation of a nuclear plant. Finally, this work analyzes the equivalent doses at ground level due to the dispersion of Cs 137 and Ar 41 , accumulated over one year and determines the isodose curves for a hypothetical site. (author) [pt

  17. A newly developed dispersal metric indicates the succession of benthic invertebrates in restored rivers.

    Science.gov (United States)

    Li, Fengqing; Sundermann, Andrea; Stoll, Stefan; Haase, Peter

    2016-11-01

    Dispersal capacity plays a fundamental role in the riverine benthic invertebrate colonization of new habitats that emerges following flash floods or restoration. However, an appropriate measure of dispersal capacity for benthic invertebrates is still lacking. The dispersal of benthic invertebrates occurs mainly during the aquatic (larval) and aerial (adult) life stages, and the dispersal of each stage can be further subdivided into active and passive modes. Based on these four possible dispersal modes, we first developed a metric (which is very similar to the well-known and widely used saprobic index) to estimate the dispersal capacity for 802 benthic invertebrate taxa by incorporating a weight for each mode. Second, we tested this metric using benthic invertebrate community data from a) 23 large restored river sites with substantial improvements of river bottom habitats dating back 1 to 10years, b) 23 unrestored sites very close to the restored sites, and c) 298 adjacent surrounding sites (mean±standard deviation: 13.0±9.5 per site) within a distance of up to 5km for each restored site in the low mountain and lowland areas of Germany. We hypothesize that our metric will reflect the temporal succession process of benthic invertebrate communities colonizing the restored sites, whereas no temporal changes are expected in the unrestored and surrounding sites. By applying our metric to these three river treatment categories, we found that the average dispersal capacity of benthic invertebrate communities in the restored sites significantly decreased in the early years following restoration, whereas there were no changes in either the unrestored or the surrounding sites. After all taxa had been divided into quartiles representing weak to strong dispersers, this pattern became even more obvious; strong dispersers colonized the restored sites during the first year after restoration and then significantly decreased over time, whereas weak dispersers continued to increase

  18. DIMO, a plant dispersal model

    NARCIS (Netherlands)

    Wamelink, G.W.W.; Jochem, R.; Greft, van der J.G.M.; Franke, J.; Malinowska, A.H.; Geertsema, W.; Prins, A.H.; Ozinga, W.A.; Hoek, van der D.C.J.; Grashof-Bokdam, C.J.

    2014-01-01

    Due to human activities many natural habitats have become isolated. As a result the dispersal of many plant species is hampered. Isolated populations may become extinct and have a lower probability to become reestablished in a natural way. Moreover, plant species may be forced to migrate to new

  19. A generalized advection dispersion equation

    Indian Academy of Sciences (India)

    This paper examines a possible effect of uncertainties, variability or heterogeneity of any dynamic system when being included in its evolution rule; the notion is illustrated with the advection dispersion equation, which describes the groundwater pollution model. An uncertain derivative is defined; some properties of.

  20. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances. We ensured exogenous va...

  1. Statistical description of turbulent dispersion

    NARCIS (Netherlands)

    Brouwers, J.J.H.

    2012-01-01

    We derive a comprehensive statistical model for dispersion of passive or almost passive admixture particles such as fine particulate matter, aerosols, smoke and fumes, in turbulent flow. The model rests on the Markov limit for particle velocity. It is in accordance with the asymptotic structure of

  2. Magnetic exciton dispersion in praseodymium

    DEFF Research Database (Denmark)

    Rainford, B. D.; Houmann, Jens Christian Gylden

    1971-01-01

    Measurements of the dispersion of magnetic excitons have been made in a single crystal of praseodymium metal using inelastic neutron scattering. A preliminary analysis of the data yields the first detailed information about the exchange interactions and the crystal field splittings in the light...... rare-earth metals....

  3. On Dispersion in Visual Photoreceptors

    NARCIS (Netherlands)

    Stavenga, D.G.; Barneveld, H.H. van

    1975-01-01

    An idealized visual pigment absorbance spectrum is used together with a Kramers-Kronig dispersion relation to calculate the contribution of the visual pigment to the refractive index of the fly photoreceptor. It appears that an absorption coefficient of 0.010 µm-1 results in a refractive index

  4. Dispersal in Mastomys natalensis mice

    DEFF Research Database (Denmark)

    Van Hooft, Pim; Cosson, J F; Vibe-Petersen, Solveig

    2008-01-01

    Mastomys natalensis is the major pest rodent in sub-Saharan Africa. In this study, population genetic techniques were used to gain new insights into its dispersal behaviour, a critical parameter in pest management. Using 11 microsatellites, 272 individuals from a 300 ha area in Tanzania were geno...

  5. Site Features

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of various site features from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times...

  6. Canada's nuclear non-proliferation policy

    International Nuclear Information System (INIS)

    1982-05-01

    Canada's non-proliferation safeguards policy has two objectives: 1) to promote a more effective and comprehensive international non-proliferation regime; and 2) to ensure that Canadian nuclear exports will not be used for any nuclear explosive purpose. By emphasizing the key role of the Non-Proliferation Treaty, promoting reliance upon and improvements in the IAEA safeguards system, treating nuclear weapon and non-weapon states alike, and working for new approaches covering reprocessing, Canada promotes attainment of the first objective. The second is served through the network of bilateral nuclear agreements that Canada has put into place with its partners. The Canadian objective in post-INFCE forums is to persuade the international community to devise a more effective and comprehensive non-proliferation regime into which Canada and other suppliers may subsume their national requirements

  7. Handbook for nuclear non-proliferation

    International Nuclear Information System (INIS)

    Lee, Byung Wook; Oh, Keun Bae; Lee, Kwang Seok; Lee, Dong Jin; Ko, Han Seok.

    1997-05-01

    This book analyzed international non-proliferation regime preventing from spread of nuclear weapon. This book took review from the historical background of non-proliferation regime to the recent changes and status. The regime, here, is divided into multilateral and bilateral regime. First of all, this book reports four multilateral treaties concluded for non-proliferation such as NPT, NWFZ, CTBT and others. Secondly, international organization and regimes concerned with non-proliferation are analyzed with emphasis of UN, IAEA, ZC and NSG, Regional Safeguards System and international conference. Finally, this book report the current circumstances of nuclear cooperation agreement related with Korea which is an important means for bilateral regime. (author). 13 tabs., 2 figs

  8. Nuclear experts and nuclear weapons proliferation

    International Nuclear Information System (INIS)

    Mueller, H.

    1979-01-01

    In Germany the issue of nuclear weapons proliferation has attracted scant attention. Most potential nuclear weapon states are important trade partners of the FRG and, since further proliferation of nuclear weapons could worsen conflicts involving these, it should be in the FRG's interest to limit proliferation. The security of the FRG is also dependent on the common interest of the great powers to avoid nuclear war. The contradictory positions of Usa and the USSR on nuclear weapons policy regarding themselves and non-nuclear weapon states encourages less developed countries to see nuclear weaponry as useful. The NPT and IAEA safeguards have only limited inhibiting effect. The nuclear export policy of the FRG has been dominated by short term economic advantage, neglecting the negative long term effects of decreased political stability. The FRG should formulate a policy based on self-restraint, positive stimuli and extension of controls, using its economic strength to deter proliferation. (JIW)

  9. Handbook for nuclear non-proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Wook; Oh, Keun Bae; Lee, Kwang Seok; Lee, Dong Jin; Ko, Han Seok

    1997-05-01

    This book analyzed international non-proliferation regime preventing from spread of nuclear weapon. This book took review from the historical background of non-proliferation regime to the recent changes and status. The regime, here, is divided into multilateral and bilateral regime. First of all, this book reports four multilateral treaties concluded for non-proliferation such as NPT, NWFZ, CTBT and others. Secondly, international organization and regimes concerned with non-proliferation are analyzed with emphasis of UN, IAEA, ZC and NSG, Regional Safeguards System and international conference. Finally, this book report the current circumstances of nuclear cooperation agreement related with Korea which is an important means for bilateral regime. (author). 13 tabs., 2 figs.

  10. The future of non-proliferation

    International Nuclear Information System (INIS)

    Gere, F.

    2000-01-01

    This paper comprises two parts. The first part makes a status of the non-proliferation policy: problems of ratification of Start 2 and CTBT treaties, nuclear tests in India and Pakistan in May 1998 etc. The second part makes a prospective reflexion on the evolution of the position of nuclearized countries at the 2015-2030 vista: role of Asia, nuclear perception, evolution of the US perception of non-proliferation, military strategy and European unification. (J.S.)

  11. Nuclear power and the proliferation issue

    International Nuclear Information System (INIS)

    Marshall, W.

    1978-02-01

    The purpose of the lecture is to discuss nuclear proliferation, analyse which problems are real and which are a misapprehension, and to suggest a way forward which retains the benefits of nuclear power while providing a more certain protection against undesirable proliferation. After an introductory section the lecture continues under the following headings: plutonium production and accessibility; the use of plutonium; fast reactor fuel; the interim period; conclusions. (U.K.)

  12. Panel on nuclear export and proliferation

    International Nuclear Information System (INIS)

    Kimel, W.R.

    1977-01-01

    Summaries of six panelists' remarks make the following points: one cannot suppress nuclear weapons by suppressing nuclear power; a proliferated world would be extremely dangerous; US supports IAEA safeguards; plutonium shouldn't be recycled in power reactors; and the problem of nonproliferation is a social and institutional problem, not a technological one. Viewographs showing the semantics of proliferation, ways to get nuclear weapons materials, etc. are included

  13. Energy efficiency and proliferation assessment factors

    International Nuclear Information System (INIS)

    1979-02-01

    The objective of INFCE is to evaluate the nuclear fuel cycles from the point of view of their ability to satisfy the worldwide nuclear energy needs, while minimizing the proliferation risks. Accordingly, the different working groups have to take into consideration as well the energy-efficiency and the proliferation-resistance of these nuclear fuel cycles. The present working paper is aimed at suggesting the main assessment factors which should be taken into consideration

  14. Russia and proliferation in Northeast Asia

    International Nuclear Information System (INIS)

    Ignatov, A.I.

    1995-01-01

    For Russia, security, including non-proliferation, in Northeast Asia means in particular the maintenance of stability. Progress in arms control and non-proliferation may enhance regional stability. A common regional approach is proposed. Russia recognizes the US alliances with Japan and republic of Korea and is searching for a new cooperation framework in the region, namely further development of relations with China and reasonable rapprochement with Japan

  15. 3’UTR Shortening Potentiates MicroRNA-Based Repression of Pro-differentiation Genes in Proliferating Human Cells

    Science.gov (United States)

    Hoffman, Yonit; Bublik, Debora Rosa; P. Ugalde, Alejandro; Elkon, Ran; Biniashvili, Tammy; Agami, Reuven; Oren, Moshe; Pilpel, Yitzhak

    2016-01-01

    Most mammalian genes often feature alternative polyadenylation (APA) sites and hence diverse 3’UTR lengths. Proliferating cells were reported to favor APA sites that result in shorter 3’UTRs. One consequence of such shortening is escape of mRNAs from targeting by microRNAs (miRNAs) whose binding sites are eliminated. Such a mechanism might provide proliferation-related genes with an expression gain during normal or cancerous proliferation. Notably, miRNA sites tend to be more active when located near both ends of the 3’UTR compared to those located more centrally. Accordingly, miRNA sites located near the center of the full 3’UTR might become more active upon 3'UTR shortening. To address this conjecture we performed 3' sequencing to determine the 3' ends of all human UTRs in several cell lines. Remarkably, we found that conserved miRNA binding sites are preferentially enriched immediately upstream to APA sites, and this enrichment is more prominent in pro-differentiation/anti-proliferative genes. Binding sites of the miR17-92 cluster, upregulated in rapidly proliferating cells, are particularly enriched just upstream to APA sites, presumably conferring stronger inhibitory activity upon shortening. Thus 3’UTR shortening appears not only to enable escape from inhibition of growth promoting genes but also to potentiate repression of anti-proliferative genes. PMID:26908102

  16. 3'UTR Shortening Potentiates MicroRNA-Based Repression of Pro-differentiation Genes in Proliferating Human Cells.

    Directory of Open Access Journals (Sweden)

    Yonit Hoffman

    2016-02-01

    Full Text Available Most mammalian genes often feature alternative polyadenylation (APA sites and hence diverse 3'UTR lengths. Proliferating cells were reported to favor APA sites that result in shorter 3'UTRs. One consequence of such shortening is escape of mRNAs from targeting by microRNAs (miRNAs whose binding sites are eliminated. Such a mechanism might provide proliferation-related genes with an expression gain during normal or cancerous proliferation. Notably, miRNA sites tend to be more active when located near both ends of the 3'UTR compared to those located more centrally. Accordingly, miRNA sites located near the center of the full 3'UTR might become more active upon 3'UTR shortening. To address this conjecture we performed 3' sequencing to determine the 3' ends of all human UTRs in several cell lines. Remarkably, we found that conserved miRNA binding sites are preferentially enriched immediately upstream to APA sites, and this enrichment is more prominent in pro-differentiation/anti-proliferative genes. Binding sites of the miR17-92 cluster, upregulated in rapidly proliferating cells, are particularly enriched just upstream to APA sites, presumably conferring stronger inhibitory activity upon shortening. Thus 3'UTR shortening appears not only to enable escape from inhibition of growth promoting genes but also to potentiate repression of anti-proliferative genes.

  17. Noninvasive Assessment of Tumor Cell Proliferation in Animal Models

    Directory of Open Access Journals (Sweden)

    Matthias Edinger

    1999-10-01

    Full Text Available Revealing the mechanisms of neoplastic disease and enhancing our ability to intervene in these processes requires an increased understanding of cellular and molecular changes as they occur in intact living animal models. We have begun to address these needs by developing a method of labeling tumor cells through constitutive expression of an optical reporter gene, noninvasively monitoring cellular proliferation in vivo using a sensitive photon detection system. A stable line of HeLa cells that expressed a modified firefly luciferase gene was generated, proliferation of these cells in irradiated severe combined immunodeficiency (SCID mice was monitored. Tumor cells were introduced into animals via subcutaneous, intraperitoneal and intravenous inoculation and whole body images, that revealed tumor location and growth kinetics, were obtained. The number of photons that were emitted from the labeled tumor cells and transmitted through murine tissues was sufficient to detect 1×103 cells in the peritoneal cavity, 1×104 cells at subcutaneous sites and 1×106 circulating cells immediately following injection. The kinetics of cell proliferation, as measured by photon emission, was exponential in the peritoneal cavity and at subcutaneous sites. Intravenous inoculation resulted in detectable colonies of tumor cells in animals receiving more than 1×103 cells. Our demonstrated ability to detect small numbers of tumor cells in living animals noninvasively suggests that therapies designed to treat minimal disease states, as occur early in the disease course and after elimination of the tumor mass, may be monitored using this approach. Moreover, it may be possible to monitor micrometastases and evaluate the molecular steps in the metastatic process. Spatiotemporal analyses of neoplasia will improve the predictability of animal models of human disease as study groups can be followed over time, this method will accelerate development of novel therapeutic

  18. Managing Proliferation Issues with Iran

    International Nuclear Information System (INIS)

    Nelson, C. Richard; Saltiel, David H.

    2002-01-01

    particular, will continue to play a vital role in determining the extent to which Iran is able to pursue WMD options. Without a fundamental change in the regional security environment, however, there is little reason to expect changes in Iranian WMD and missile policies, and the United States, acting alone and short of war, cannot prevent Iran from ultimately developing WMD and delivery systems. Furthermore, U.S. policies that take a tougher line with Russia, China and North Korea are not likely to lead to more restraint among these potential sources of WMD and missile technology. In the absence of engagement with Iran, unilateral U.S. economic sanctions will remain the principal, if flawed, U.S. policy tool for seeking to prevent Iran from acquiring WMD. The rationale is that by discouraging trade and investment, particularly in Iran's energy sector, the government of Iran will have less revenue to pursue proliferation. Without broad international support for economic isolation, however, such an effort may hinder Iran's WMD programs, though it cannot block them. Finally, options are needed to deal with major failures in nonproliferation efforts. These options include measures to deter Iranian use of WMD, to defend against their use if deterrence fails, and to destroy Iranian WMD capabilities should the need arise

  19. Strengthening the nuclear non-proliferation regime

    International Nuclear Information System (INIS)

    Carlson, J.

    2003-01-01

    Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

  20. Supporting non proliferation and global security efforts

    International Nuclear Information System (INIS)

    Pochon, E.

    2013-01-01

    CEA contributes as a major actor of France's action against nuclear proliferation and to the strengthening of nuclear security at national level as European and International levels, in particular through the support of the IAEA activities in nuclear non proliferation with the French Support Programme for the IAEA safeguards system and security with the contribution to the IAEA Nuclear Security Plan and cooperation projects with the European Commission. The CEA is a French government funded technological research organization, organized around 5 branches: Nuclear Energy, Technological Researches, Defence (DAM), Material Sciences and Life Sciences. Within the scope of its activities, CEA covers most of the research areas and techniques in nuclear non-proliferation and security. The CEA is also the advisor of the French Government on nuclear policy. Treaty monitoring and the development and implementation of non proliferation and global security programs is an important mission of DAM which rely on nuclear weapons manufacture and past testing experience. The programmes on non proliferation and global security carried out to fulfil DAM's mission cover the following areas: development of monitoring and detection methods and equipments, country profiles and nuclear stockpiles assessment, arms control instruments, proliferation resistance of nuclear fuel cycle, monitoring of nuclear tests, operation and maintenance of national detection capabilities and contribution to CTBT verification systems. (A.C.)

  1. Site decontamination

    International Nuclear Information System (INIS)

    Bicker, A.E.

    1981-01-01

    Among the several DOE sites that have been radiologically decontaminated under the auspices of the Nevada Operations Office are three whose physical characteristics are unique. These are the Tatum Dome Test Site (TDTS) near Hattiesburg, Mississippi; a location of mountainous terrain (Pahute Mesa) on the Nevada Test Site; and the GNOME site near Carlsbad, New Mexico. In each case the contamination, the terrain, and the climate conditions were different. This presentation includes a brief description of each site, the methods used to perform radiological surveys, the logistics required to support the decontamination (including health physics and sample analysis), and the specific techniques used to reduce or remove the contamination

  2. Dispersion modeling by kinematic simulation: Cloud dispersion model

    International Nuclear Information System (INIS)

    Fung, J C H; Perkins, R J

    2008-01-01

    A new technique has been developed to compute mean and fluctuating concentrations in complex turbulent flows (tidal current near a coast and deep ocean). An initial distribution of material is discretized into any small clouds which are advected by a combination of the mean flow and large scale turbulence. The turbulence can be simulated either by kinematic simulation (KS) or direct numerical simulation. The clouds also diffuse relative to their centroids; the statistics for this are obtained from a separate calculation of the growth of individual clouds in small scale turbulence, generated by KS. The ensemble of discrete clouds is periodically re-discretized, to limit the size of the small clouds and prevent overlapping. The model is illustrated with simulations of dispersion in uniform flow, and the results are compared with analytic, steady state solutions. The aim of this study is to understand how pollutants disperses in a turbulent flow through a numerical simulation of fluid particle motion in a random flow field generated by Fourier modes. Although this homogeneous turbulent is rather a 'simple' flow, it represents a building block toward understanding pollutant dispersion in more complex flow. The results presented here are preliminary in nature, but we expect that similar qualitative results should be observed in a genuine turbulent flow.

  3. Nuclear power plant site evaluation using site population-meterology factor

    International Nuclear Information System (INIS)

    Rho, B.H.; Kang, C.H.

    1982-01-01

    In this paper, as a site evaluation technique, SPNF(Site Population Neteorology Factor) which is modified from SPF(Site Population Factor) of the USNRC model, is defined from site population and meteorology data in order to consider the radiological impacts to the population at large from the atmospheric dispersion of the radioactive effluents released during routine plant operation as well as accidental conditions. The SPMF model proved its propriety from the comparison of SPMF and SPF for Kori site. The relative suitability of Korean sites to the U.S. sites have been also examined using SPF. (Author)

  4. UV curable aqueous dispersions for wood coatings

    International Nuclear Information System (INIS)

    Peeters, S.; Bleus, J.P.; Wang, Z.J.; Arceneaux, J. A.; Hall, J.

    1999-01-01

    In this paper the characterisation of aqueous dispersions of UV curable resins is described. Two types of dispersions were used: dispersions that are tacky after water evaporation and tack - free before cure dispersions. The physical and rheological properties of these products have been determined and the performance of these dispersions in various formulations, especially for wood applications has been studied. With these dispersions, it is possible to produce coatings having a good cure speed, good surface hardness and good solvent -, chemical - and water resistance

  5. Laser control of natural disperse systems

    Science.gov (United States)

    Vlasova, Olga L.; Bezrukova, Alexandra G.

    2003-10-01

    Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

  6. Nanomechanical IR spectroscopy for fast analysis of liquid-dispersed engineered nanomaterials

    OpenAIRE

    Andersen, Alina Joukainen; Yamada, Shoko; Ek, Pramod Kumar; Andresen, Thomas Lars; Boisen, Anja; Schmid, Silvan

    2016-01-01

    The proliferated use of engineered nanomaterials (ENMs), e.g. in nanomedicine, calls for novel techniques allowing for fast and sensitive analysis of minute samples. Here we present nanomechanical IR spectroscopy (NAM-IR) for chemical analysis of picograms of ENMs. ENMs are nebulized directly from dispersion and efficiently collected on nanomechanical string resonators through a non-diffusion limited sampling method. Even very small amounts of sample can convert absorbed IR light into a measu...

  7. Nanocomposites from Stable Dispersions of Carbon Nanotubes in Polymeric Matrices Using Dispersion Interaction

    Science.gov (United States)

    Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Kang, Jin Ho (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor)

    2016-01-01

    Stable dispersions of carbon nanotubes (CNTs) in polymeric matrices include CNTs dispersed in a host polymer or copolymer whose monomers have delocalized electron orbitals, so that a dispersion interaction results between the host polymer or copolymer and the CNTs dispersed therein. Nanocomposite products, which are presented in bulk, or when fabricated as a film, fiber, foam, coating, adhesive, paste, or molding, are prepared by standard means from the present stable dispersions of CNTs in polymeric matrices, employing dispersion interactions, as presented hereinabove.

  8. Site organization and site arrangement

    International Nuclear Information System (INIS)

    Boissonnet, B.; Macqueron, J.F.

    1976-01-01

    The present paper deals with criteria for the choice of a production unit or power plant site, the organization and development of a site in terms of its particular characteristics and takes into account personnel considerations in site organizations as well as the problem of integrating the architecture into the environment. (RW) [de

  9. Nuclear arbitration: Interpreting non-proliferation agreements

    International Nuclear Information System (INIS)

    Tzeng, Peter

    2015-01-01

    At the core of the nuclear non-proliferation regime lie international agreements. These agreements include, inter alia, the Nuclear Non-proliferation Treaty, nuclear co-operation agreements and nuclear export control agreements.1 States, however, do not always comply with their obligations under these agreements. In response, commentators have proposed various enforcement mechanisms to promote compliance. The inconvenient truth, however, is that states are generally unwilling to consent to enforcement mechanisms concerning issues as critical to national security as nuclear non-proliferation.3 This article suggests an alternative solution to the non-compliance problem: interpretation mechanisms. Although an interpretation mechanism does not have the teeth of an enforcement mechanism, it can induce compliance by providing an authoritative interpretation of a legal obligation. Interpretation mechanisms would help solve the non-compliance problem because, as this article shows, in many cases of alleged non-compliance with a non-proliferation agreement, the fundamental problem has been the lack of an authoritative interpretation of the agreement, not the lack of an enforcement mechanism. Specifically, this article proposes arbitration as the proper interpretation mechanism for non-proliferation agreements. It advocates the establishment of a 'Nuclear Arbitration Centre' as an independent branch of the International Atomic Energy Agency (IAEA), and recommends the gradual introduction of arbitration clauses into the texts of non-proliferation agreements. Section I begins with a discussion of international agreements in general and the importance of interpretation and enforcement mechanisms. Section II then discusses nuclear non-proliferation agreements and their lack of interpretation and enforcement mechanisms. Section III examines seven case studies of alleged non-compliance with non-proliferation agreements in order to show that the main problem in many cases

  10. Transverse dispersion in heterogeneous fractures

    International Nuclear Information System (INIS)

    Dershowitz, Bill; Shuttle, Dawn; Klise, Kate; Outters, Nils; Hermanson, Jan

    2004-12-01

    This report evaluates the significance of transverse dispersion processes for solute transport in a single fracture. Transverse dispersion is a potentially significant process because it increases the fracture surface area available for sorptive and diffusive properties, and has the potential to transport solute between what would otherwise be distinctive, streamline pathways. Transverse dispersion processes are generally ignored in one-dimensional repository performance assessment approaches. This report provides an initial assessment of the magnitude of transverse dispersion effect in a single heterogeneous fracture on repository safety assessment. This study builds on a previous report which considered the network effects on transport dispersion including streamline routing and mixing at fracture intersections. The project uses FracMan software. This platform has been extensively used by SKB in other projects. FracMan software is designed to generate and analyze DFN's as well as to compute fluid flow in DFN's with the MAFIC Finite element method (FEM) code. Solute transport was modeled using the particle tracking inside MAFIC, the 2-D Laplace Transform Galerkin inside PAWorks/LTG, and the 1-D Laplace Transform approach designed to replicate FARF31 inside GoldSim.The study reported here focuses on a single, 20-meter scale discrete fracture, with simplified boundary conditions intended to represent the position of this fracture within a fracture network. The range of assumptions made regarding fracture heterogeneity were as follows: Base case, Heterogeneous fracture, geostatistical field, correlation length 0.01 m. Case 1a, Homogeneous fracture, transmissivity = 10 -7 m 2 /s. Case 1b, Heterogeneous fracture, non-channeled geostatistical field correlation length 5 m. Case 1c, Heterogeneous fracture, channeled, anisotropic geostatistical field. Case 1d, Heterogeneous fracture, fracture intersection zone (FIZ) permeability enhanced. Case 5, Simple channelized

  11. Ontogenetic behavior and dispersal of Sacramento River white sturgeon, Acipenser transmontanus, with a note on body color

    Science.gov (United States)

    Kynard, B.; Parker, E.

    2005-01-01

    We studied Sacramento River white sturgeon, Acipenser transmontanus, in the laboratory to develop a conceptual model of ontogenetic behavior and provide insight into probable behavior of wild sturgeon. After hatching, free embryos initiated a low intensity, brief downstream dispersal during which fish swam near the bottom and were photonegative. The weak, short dispersal style and behavior of white sturgeon free embryos contrasts greatly with the intense, long dispersal style and behavior (photopositive and swimming far above the bottom) of dispersing free embryos of other sturgeon species. If spawned eggs are concentrated within a few kilometers downstream of a spawning site, the adaptive significance of the free embryo dispersal is likely to move fish away from the egg deposition site to avoid predation and reduce fish density prior to feeding. Larvae foraged on the open bottom, swam innate fish dispersal and post-dispersal rearing habitat, which is now highly altered by damming and reservoirs. Sacramento River white sturgeon has a two-step downstream dispersal by the free embryo and juvenile life intervals. Diel activity of all life intervals peaked at night, whether fish were dispersing or foraging. Nocturnal behavior is likely a response to predation, which occurs during both activities. An intense black-tail body color was present on foraging larvae, but was weak or absent on the two life intervals that disperse. Black-tail color may be an adaptation for avoiding predation, signaling among aggregated larvae, or both, but not for dispersal. ?? Springer 2005.

  12. Procedure for preparation of dispersions

    International Nuclear Information System (INIS)

    1978-01-01

    Procedure for the preparation of a water based dispersion of cerium oxide, characterised in that a suspension of cerium (IV) hydroxide is formed with an acid, where the acid is in the state of a disaggregation of aggregated crystalline cerium hydroxide, the suspension being preheated for a specified time and to a specified temperature, so that the pH value becomes constant, and whereby the quantity of acid in the suspension is such that the constant pH value is lower than 5.4, so that a conditioned suspension may be obtained, and water may be mixed with the conditioned suspension for making a water based dispersion of cerium oxide. (G.C.)

  13. Stochastic models for atmospheric dispersion

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager

    2003-01-01

    Simple stochastic differential equation models have been applied by several researchers to describe the dispersion of tracer particles in the planetary atmospheric boundary layer and to form the basis for computer simulations of particle paths. To obtain the drift coefficient, empirical vertical...... positions close to the boundaries. Different rules have been suggested in the literature with justifications based on simulation studies. Herein the relevant stochastic differential equation model is formulated in a particular way. The formulation is based on the marginal transformation of the position...... velocity distributions that depend on height above the ground both with respect to standard deviation and skewness are substituted into the stationary Fokker/Planck equation. The particle position distribution is taken to be uniform *the well/mixed condition( and also a given dispersion coefficient...

  14. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 (student) teams start up and manage real companies under identical circumstances for one year. We...... ensured exogenous variation in otherwise random team composition by assigning students to teams based on their measured cognitive abilities. Each team performs a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of business teams first...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub- teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  15. Magnetic effects in anomalous dispersion

    International Nuclear Information System (INIS)

    Blume, M.

    1992-01-01

    Spectacular enhancements of magnetic x-ray scattering have been predicted and observed experimentally. These effects are the result of resonant phenomena closely related to anomalous dispersion, and they are strongest at near-edge resonances. The theory of these resonances will be developed with particular attention to the symmetry properties of the scatterer. While the phenomena to be discussed concern magnetic properties the transitions are electric dipole or electric quadrupole in character and represent a subset of the usual anomalous dispersion phenomena. The polarization dependence of the scattering is also considered, and the polarization dependence for magnetic effects is related to that for charge scattering and to Templeton type anisotropic polarization phenomena. It has been found that the strongest effects occur in rare-earths and in actinides for M shell edges. In addition to the scattering properties the theory is applicable to ''forward scattering'' properties such as the Faraday effect and circular dichroism

  16. Faraday anomalous dispersion optical tuners

    Science.gov (United States)

    Wanninger, P.; Valdez, E. C.; Shay, T. M.

    1992-01-01

    Common methods for frequency stabilizing diode lasers systems employ gratings, etalons, optical electric double feedback, atomic resonance, and a Faraday cell with low magnetic field. Our method, the Faraday Anomalous Dispersion Optical Transmitter (FADOT) laser locking, is much simpler than other schemes. The FADOT uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. This method is vibration insensitive, thermal expansion effects are minimal, and the system has a frequency pull in range of 443.2 GHz (9A). Our technique is based on the Faraday anomalous dispersion optical filter. This method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters. We present the first theoretical model for the FADOT and compare the calculations to our experimental results.

  17. Dispersed Fringe Sensing Analysis - DFSA

    Science.gov (United States)

    Sigrist, Norbert; Shi, Fang; Redding, David C.; Basinger, Scott A.; Ohara, Catherine M.; Seo, Byoung-Joon; Bikkannavar, Siddarayappa A.; Spechler, Joshua A.

    2012-01-01

    Dispersed Fringe Sensing (DFS) is a technique for measuring and phasing segmented telescope mirrors using a dispersed broadband light image. DFS is capable of breaking the monochromatic light ambiguity, measuring absolute piston errors between segments of large segmented primary mirrors to tens of nanometers accuracy over a range of 100 micrometers or more. The DFSA software tool analyzes DFS images to extract DFS encoded segment piston errors, which can be used to measure piston distances between primary mirror segments of ground and space telescopes. This information is necessary to control mirror segments to establish a smooth, continuous primary figure needed to achieve high optical quality. The DFSA tool is versatile, allowing precise piston measurements from a variety of different optical configurations. DFSA technology may be used for measuring wavefront pistons from sub-apertures defined by adjacent segments (such as Keck Telescope), or from separated sub-apertures used for testing large optical systems (such as sub-aperture wavefront testing for large primary mirrors using auto-collimating flats). An experimental demonstration of the coarse-phasing technology with verification of DFSA was performed at the Keck Telescope. DFSA includes image processing, wavelength and source spectral calibration, fringe extraction line determination, dispersed fringe analysis, and wavefront piston sign determination. The code is robust against internal optical system aberrations and against spectral variations of the source. In addition to the DFSA tool, the software package contains a simple but sophisticated MATLAB model to generate dispersed fringe images of optical system configurations in order to quickly estimate the coarse phasing performance given the optical and operational design requirements. Combining MATLAB (a high-level language and interactive environment developed by MathWorks), MACOS (JPL s software package for Modeling and Analysis for Controlled Optical

  18. Hydrodynamic dispersion within porous biofilms

    KAUST Repository

    Davit, Y.

    2013-01-23

    Many microorganisms live within surface-associated consortia, termed biofilms, that can form intricate porous structures interspersed with a network of fluid channels. In such systems, transport phenomena, including flow and advection, regulate various aspects of cell behavior by controlling nutrient supply, evacuation of waste products, and permeation of antimicrobial agents. This study presents multiscale analysis of solute transport in these porous biofilms. We start our analysis with a channel-scale description of mass transport and use the method of volume averaging to derive a set of homogenized equations at the biofilm-scale in the case where the width of the channels is significantly smaller than the thickness of the biofilm. We show that solute transport may be described via two coupled partial differential equations or telegrapher\\'s equations for the averaged concentrations. These models are particularly relevant for chemicals, such as some antimicrobial agents, that penetrate cell clusters very slowly. In most cases, especially for nutrients, solute penetration is faster, and transport can be described via an advection-dispersion equation. In this simpler case, the effective diffusion is characterized by a second-order tensor whose components depend on (1) the topology of the channels\\' network; (2) the solute\\'s diffusion coefficients in the fluid and the cell clusters; (3) hydrodynamic dispersion effects; and (4) an additional dispersion term intrinsic to the two-phase configuration. Although solute transport in biofilms is commonly thought to be diffusion dominated, this analysis shows that hydrodynamic dispersion effects may significantly contribute to transport. © 2013 American Physical Society.

  19. Dispersion of Bed Load Particles

    OpenAIRE

    SAWAI, Kenji

    1987-01-01

    The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...

  20. Faraday anomalous dispersion optical filters

    Science.gov (United States)

    Shay, T. M.; Yin, B.; Alvarez, L. S.

    1993-01-01

    The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

  1. Dispersive stresses in wind farms

    Science.gov (United States)

    Segalini, Antonio; Braunbehrens, Robert; Hyvarinen, Ann

    2017-11-01

    One of the most famous models of wind farms is provided by the assumption that the farm can be approximated as a horizontally-homogeneous forest canopy with vertically-varying force intensity. By means of this approximation, the flow-motion equations become drastically simpler, as many of the three-dimensional effects are gone. However, the application of the horizontal average operator to the RANS equations leads to the appearance of new transport terms (called dispersive stresses) originating from the horizontal (small-scale) variation of the mean velocity field. Since these terms are related to the individual turbine signature, they are expected to vanish outside the roughness sublayer, providing a definition for the latter. In the present work, an assessment of the dispersive stresses is performed by means of a wake-model approach and through the linearised code ORFEUS developed at KTH. Both approaches are very fast and enable the characterization of a large number of wind-farm layouts. The dispersive stress tensor and its effect on the turbulence closure models are investigated, providing guidelines for those simulations where it is impossible to resolve the farm at a turbine scale due to grid requirements (as, for instance, mesoscale simulations).

  2. Improving practical atmospheric dispersion models

    International Nuclear Information System (INIS)

    Hunt, J.C.R.; Hudson, B.; Thomson, D.J.

    1992-01-01

    The new generation of practical atmospheric dispersion model (for short range ≤ 30 km) are based on dispersion science and boundary layer meteorology which have widespread international acceptance. In addition, recent improvements in computer skills and the widespread availability of small powerful computers make it possible to have new regulatory models which are more complex than the previous generation which were based on charts and simple formulae. This paper describes the basis of these models and how they have developed. Such models are needed to satisfy the urgent public demand for sound, justifiable and consistent environmental decisions. For example, it is preferable that the same models are used to simulate dispersion in different industries; in many countries at present different models are used for emissions from nuclear and fossil fuel power stations. The models should not be so simple as to be suspect but neither should they be too complex for widespread use; for example, at public inquiries in Germany, where simple models are mandatory, it is becoming usual to cite the results from highly complex computational models because the simple models are not credible. This paper is written in a schematic style with an emphasis on tables and diagrams. (au) (22 refs.)

  3. Dispersion relations in loop calculations

    International Nuclear Information System (INIS)

    Kniehl, B.A.

    1996-01-01

    These lecture notes give a pedagogical introduction to the use of dispersion relations in loop calculations. We first derive dispersion relations which allow us to recover the real part of a physical amplitude from the knowledge of its absorptive part along the branch cut. In perturbative calculations, the latter may be constructed by means of Cutkosky's rule, which is briefly discussed. For illustration, we apply this procedure at one loop to the photon vacuum-polarization function induced by leptons as well as to the γf anti-f vertex form factor generated by the exchange of a massive vector boson between the two fermion legs. We also show how the hadronic contribution to the photon vacuum polarization may be extracted from the total cross section of hadron production in e + e - annihilation measured as a function of energy. Finally, we outline the application of dispersive techniques at the two-loop level, considering as an example the bosonic decay width of a high-mass Higgs boson. (author)

  4. High seed dispersal ability of Pinus canariensis in stands of contrasting density inferred from genotypic data

    Directory of Open Access Journals (Sweden)

    Unai López de Heredia

    2015-04-01

    Full Text Available Aim of the study: Models that combine parentage analysis from molecular data with spatial information of seeds and seedlings provide a framework to describe and identify the factors involved in seed dispersal and recruitment of forest species. In the present study we used a spatially explicit method (the gene shadow model in order to assess primary and effective dispersal in Pinus canariensis. Area of study: Pinus canariensis is endemic to the Canary Islands (Spain. Sampling sites were a high density forest in southern slopes of Tenerife and a low density stand in South Gran Canaria. Materials and methods: We fitted models based on parentage analysis from seeds and seedlings collected in two sites with contrasting stand density, and then compared the resulting dispersal distributions. Main results: The results showed that: 1 P. canariensis has a remarkable dispersal ability compared to other pine species; 2 there is no discordance between primary and effective dispersals, suggesting limited secondary dispersal by animals and lack of Janzen-Connell effect; and 3 low stand densities enhance the extent of seed dispersal, which was higher in the low density stand. Research highlights: The efficient dispersal mechanism of P. canariensis by wind inferred by the gene shadow model is congruent with indirect measures of gene flow, and has utility in reconstructing past demographic events and in predicting future distribution ranges for the species.

  5. Site operations

    International Nuclear Information System (INIS)

    House, W.B.; Ebenhack, D.G.

    1989-01-01

    This chapter is a discussion of the management and operations practices used at the Barnwell Waste Management Facility in Barnwell, SC. The following topics are discussed: (1) Waste receiving and inspection, including manifest and certificates of compliance, radiological surveys, disposition of nonconforming items, and decontamination and disposition of secondary waste streams; (2) Waste disposal, including Title 10 CFR 61 requirements, disposal area evaluations, shipment offloading, container emplacement, and radiation protection; (3) Trench closure, including trench backfilling, trench capping, and permanent markers; (4) Site maintenance and stabilization, including trench maintenance, surface water management, and site closure activities; (5) Site monitoring programs, including operational monitoring, and environmental monitoring program; (6) Personnel training and qualifications, including basic training program, safety training program, special skills training, and physical qualifications; (7) Records management, including waste records, personnel training records, personnel dosimetry records, site monitoring records, trench qualification and construction records, and site drawings and stabilization records; (8) Site security; (9) Emergency response plans; and (10) Quality assurance

  6. Roles of survival and dispersal in reintroduction success of Griffon vulture (Gyps fulvus).

    Science.gov (United States)

    Le Gouar, Pascaline; Robert, Alexandre; Choisy, Jean-Pierre; Henriquet, Sylvain; Lecuyer, Philippe; Tessier, Christian; Sarrazin, François

    2008-06-01

    The success of reintroduction programs greatly depends on the amount of mortality and dispersal of the released individuals. Although local environmental pressures are likely to play an important role in these processes, they have rarely been investigated because of the lack of spatial replicates of reintroduction. In the present study, we analyzed a 25-year data set encompassing 272 individuals released in five reintroduction programs of Griffon Vultures (Gyps fulvus) in France to examine the respective roles of survival and dispersal in program successes and failures. We use recent developments in multi-strata capture-recapture models to take into account tag loss in survival estimates and to consider and estimate dispersal among release areas. We also examined the effects of sex, age, time, area, and release status on survival, and we tested whether dispersal patterns among release areas were consistent with habitat selection theories. Results indicated that the survival of released adults was reduced during the first year after release, with no difference between sexes. Taking into account local observations only, we found that early survival rates varied across sites. However when we distinguished dispersal from mortality, early survival rates became equal across release sites. It thus appears that among reintroduction programs difference in failure and success was due to differential dispersal among release sites. We revealed asymmetrical patterns of dispersal due to conspecific attraction: dispersers selected the closest and the largest population. We showed that mortality can be homogeneous from one program to another while, on the contrary, dispersal is highly dependent on the matrix of established populations. Dispersal behavior is thus of major interest for metapopulation restoration and should be taken into account in planning reintroduction designs.

  7. Chromatic Dispersion Estimation in Digital Coherent Receivers

    DEFF Research Database (Denmark)

    Soriano, Ruben Andres; Hauske, Fabian N.; Guerrero Gonzalez, Neil

    2011-01-01

    Polarization-diverse coherent demodulation allows to compensate large values of accumulated linear distortion by digital signal processing. In particular, in uncompensated links without optical dispersion compensation, the parameter of the residual chromatic dispersion (CD) is vital to set...

  8. Effects of nonlocal dispersive interactions on self-trapping excitations

    DEFF Research Database (Denmark)

    Gaididei, Yu.B.; Mingaleev, S.F.; Christiansen, Peter Leth

    1997-01-01

    -site and intersite states. It is shown that for s sufficiently large all features of the model are qualitatively the same as in the NLS model with a nearest-neighbor interaction. For s less than some critical value s(cr), there is an interval of bistability where two stable stationary states exist at each excitation...... number N = Sigma(n)\\psi(n)\\(2). For cubic nonlinearity the bistability of on-site solitons may occur for dipole-dipole dispersive interaction (s = 3), while s(cr) for intersite solitons is close to 2.1. For increasing degree of nonlinearity sigma, s(cr) increases. The long-distance behavior...

  9. Extensive dispersal of Roanoke logperch (Percina rex) inferred from genetic marker data

    Science.gov (United States)

    Roberts, James H.; Angermeier, Paul; Hallerman, Eric M.

    2016-01-01

    The dispersal ecology of most stream fishes is poorly characterised, complicating conservation efforts for these species. We used microsatellite DNA marker data to characterise dispersal patterns and effective population size (Ne) for a population of Roanoke logperchPercina rex, an endangered darter (Percidae). Juveniles and candidate parents were sampled for 2 years at sites throughout the Roanoke River watershed. Dispersal was inferred via genetic assignment tests (ATs), pedigree reconstruction (PR) and estimation of lifetime dispersal distance under a genetic isolation-by-distance model. Estimates of Ne varied from 105 to 1218 individuals, depending on the estimation method. Based on PR, polygamy was frequent in parents of both sexes, with individuals spawning with an average of 2.4 mates. The sample contained 61 half-sibling pairs, but only one parent–offspring pair and no full-sib pairs, which limited our ability to discriminate natal dispersal of juveniles from breeding dispersal of their parents between spawning events. Nonetheless, all methods indicated extensive dispersal. The AT indicated unrestricted dispersal among sites ≤15 km apart, while siblings inferred by the PR were captured an average of 14 km and up to 55 km apart. Model-based estimates of median lifetime dispersal distance (6–24 km, depending on assumptions) bracketed AT and PR estimates, indicating that widely dispersed individuals do, on average, contribute to gene flow. Extensive dispersal of P. rex suggests that darters and other small benthic stream fishes may be unexpectedly mobile. Monitoring and management activities for such populations should encompass entire watersheds to fully capture population dynamics.

  10. Statistical Physics of Colloidal Dispersions.

    Science.gov (United States)

    Canessa, E.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis is concerned with the equilibrium statistical mechanics of colloidal dispersions which represent useful model systems for the study of condensed matter physics; namely, charge stabilized colloidal dispersions and polymer stabilized colloidal dispersions. A one-component macroparticle approach is adopted in order to treat the macroscopic and microscopic properties of these systems in a simple and comprehensive manner. The thesis opens with the description of the nature of the colloidal state before reviewing some basic definitions and theory in Chapter II. In Chapter III a variational theory of phase equilibria based on the Gibbs-Bogolyobov inequality is applied to sterically stabilized colloidal dispersions. Hard spheres are chosen as the reference system for the disordered phases while an Einstein model is used for the ordered phases. The new choice of pair potential, taken for mathematical convenience, is a superposition of two Yukawa functions. By matching a double Yukawa potential to the van der Waals attractive potential at different temperatures and introducing a purely temperature dependent coefficient to the repulsive part, a rich variety of observed phase separation phenomena is qualitatively described. The behaviour of the potential is found to be consistent with a small decrease of the polymer layer thickness with increasing temperature. Using the same concept of a collapse transition the non-monotonic second virial coefficient is also explained and quantified. It is shown that a reduction of the effective macroparticle diameter with increasing temperature can only be partially examined from the point of view of a (binary-) polymer solution theory. This chapter concludes with the description of the observed, reversible, depletion flocculation behaviour. This is accomplished by using the variational formalism and by invoking the double Yukawa potential to allow

  11. Measuring dispersal as distance-dependent recruitment rates: testing the performance of DDRR on simulated data.

    NARCIS (Netherlands)

    Van Noordwijk, A.J.

    2011-01-01

    Dispersal is an important process in ecology, but its measurement is difficult. In particular, natal dispersal— the net movement between site of birth and site of first reproduction—is important, since it determines population structure. Using simulated data, I study the claim that measuring

  12. Dispersion properties of photonic crystal fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Dridi, Kim

    1998-01-01

    Approximate dispersion and bending properties of all-silica two-dimensional photonic crystal fibres are characterised by the combination of an effective-index model and classical analysis tools for optical fibres. We believe for the first time to have predicted the dispersion properties of photonic...... crystal fibres. The results strongly indicate that these fibres have potential applications as dispersion managing components...

  13. Dispersion of coupled mode-gap cavities

    NARCIS (Netherlands)

    Lian, Jin; Sokolov, Sergei; Yuce, E.; Combrie, S.; de Rossi, A.; Mosk, Allard

    2015-01-01

    The dispersion of a coupled resonator optical waveguide made of photonic crystal mode-gap cavities is pronouncedly asymmetric. This asymmetry cannot be explained by the standard tight binding model. We show that the fundamental cause of the asymmetric dispersion is the inherent dispersive cavity

  14. Characterization of finite spaces having dispersion points

    International Nuclear Information System (INIS)

    Al-Bsoul, A. T

    1997-01-01

    In this paper we shall characterize the finite spaces having dispersion points. Also, we prove that the dispersion point of a finite space with a dispersion points fixed under all non constant continuous functions which answers the question raised by J. C obb and W. Voxman in 1980 affirmatively for finite space. Some open problems are given. (author). 16 refs

  15. Non-proliferation policy of the Republic of Kazakhstan

    International Nuclear Information System (INIS)

    Shkol'nik, V.S.; Zhantikin, T.M.

    1997-01-01

    The present abstract reveals the aspects of Kazakstan's non-proliferation policy. After acquiring independence in Kazakstan there remained a huge nuclear inheritance of the USSR. Kazakstan had to determine its policy regarding nuclear stuff. One of the most important test sites of the former USSR - Semipalatinsk test site - was closed. The Republic signed the Lisbon Protocols to the Treaty between the USSR and USA on the reduction and limitation of strategic and offensive arms. On December 13, 1993, Kazakstan and the IAEA concluded the IAEA Safeguards Agreement. All nuclear weapons were removed from Kazakstan territory, work resulting in military nuclear power use was terminated. A wide program on conversion of the former military research infrastructure is being performed with the support of some foreign countries. For instance Kazakstan / USA jointly work on withdrawing highly enriched nuclear materials from Ulba Metallurgical Plant to the USA enterprises for processing ('Sapphere'). Another conversion activity is liquidation of the former testing holes at Semipalatinsk test site. In relation to this there appeared an agreement between U.S. Department of defence and Ministry of Sciences and New Technologies of the Republic of Kazakstan (October, 3, 1995). A sensitive information is present at the area of the former test site. The traditional IAEA safeguards are used to nuclear facilities and nuclear materials

  16. Directed seed dispersal of Piper by Carollia perspicillata and its effect on understory plant diversity and folivory.

    Science.gov (United States)

    Salazar, Diego; Kelm, Detlev H; Salazar, Diego

    2013-11-01

    Directed dispersal occurs when seeds are differentially deposited to sites where offspring survivorship is higher than at randomly chosen sites. Traditionally, characteristics of the dispersal target sites that could increase survivorship of the dispersed plants are thought to be intrinsic to the sites. If directed dispersal is constant over extended periods of time, however, it is likely that nonrandom patterns of dispersal could modify the ecological characteristics of the target site in ways that could increase survivorship and fitness of the dispersed plants. Here we report patterns of Piper diversity (richness, equitability, and similarity) and Piper folivory within plots near natural or artificial roosts of Carollia perspicillata vs. similar plots without bat roosts. Plots with bat roosts, both natural and artificial, had significantly higher Piper species diversity. Additionally, we found that plots with a higher Piper species diversity showed less specialist folivory, higher generalist folivory, and lower total herbivore leaf damage than plots with low Piper diversity. Finally, plots with bat roosts also showed less specialist folivory, lower generalist folivory, and lower total folivory when compared to plots without roosts. We propose that long-lasting nonrandom patterns of seed dispersal can change the local ecological characteristics of target sites via changes in plant diversity, and that these changes are likely to reduce the local rates of folivory and, therefore, increase seed and adult plant survivorship.

  17. Breeding Dispersal by Birds in a Dynamic Urban Ecosystem.

    Science.gov (United States)

    Marzluff, John M; DeLap, Jack H; Oleyar, M David; Whittaker, Kara A; Gardner, Beth

    2016-01-01

    Changes in land cover during urbanization profoundly affect the diversity of bird communities, but the demographic mechanisms affecting diversity are poorly known. We advance such understanding by documenting how urbanization influences breeding dispersal-the annual movement of territorial adults-of six songbird species in the Seattle, WA, USA metropolitan area. We color-banded adults and mapped the centers of their annual breeding activities from 2000-2010 to obtain 504 consecutive movements by 337 adults. By comparing movements, annual reproduction, and mate fidelity among 10 developed, 5 reserved, and 11 changing (areas cleared and developed during our study) landscapes, we determined that adaptive breeding dispersal of sensitive forest species (Swainson's Thrush and Pacific wren), which involves shifting territory and mate after reproductive failure, was constrained by development. In changing lands, sensitive forest specialists dispersed from active development to nearby forested areas, but in so doing suffered low annual reproduction. Species tolerant of suburban lands (song sparrow, spotted towhee, dark-eyed junco, and Bewick's wren) dispersed adaptively in changing landscapes. Site fidelity ranged from 0% (Pacific wren in changing landscape) to 83% (Bewick's wren in forest reserve). Mate fidelity ranged from 25% (dark-eyed junco) to 100% (Bewick's wren). Variation in fidelity to mate and territory was consistent with theories positing an influence of territory quality, asynchronous return from migration, prior productivity, and reproductive benefits of retaining a familiar territory. Costly breeding dispersal, as well as reduced reproductive success and lowered survival cause some birds to decline in the face of urbanization. In contrast, the ability of species that utilize edges and early successional habitats to breed successfully, disperse to improve reproductive success after failure, and survive throughout the urban ecosystem enables them to maintain

  18. Breeding Dispersal by Birds in a Dynamic Urban Ecosystem.

    Directory of Open Access Journals (Sweden)

    John M Marzluff

    Full Text Available Changes in land cover during urbanization profoundly affect the diversity of bird communities, but the demographic mechanisms affecting diversity are poorly known. We advance such understanding by documenting how urbanization influences breeding dispersal-the annual movement of territorial adults-of six songbird species in the Seattle, WA, USA metropolitan area. We color-banded adults and mapped the centers of their annual breeding activities from 2000-2010 to obtain 504 consecutive movements by 337 adults. By comparing movements, annual reproduction, and mate fidelity among 10 developed, 5 reserved, and 11 changing (areas cleared and developed during our study landscapes, we determined that adaptive breeding dispersal of sensitive forest species (Swainson's Thrush and Pacific wren, which involves shifting territory and mate after reproductive failure, was constrained by development. In changing lands, sensitive forest specialists dispersed from active development to nearby forested areas, but in so doing suffered low annual reproduction. Species tolerant of suburban lands (song sparrow, spotted towhee, dark-eyed junco, and Bewick's wren dispersed adaptively in changing landscapes. Site fidelity ranged from 0% (Pacific wren in changing landscape to 83% (Bewick's wren in forest reserve. Mate fidelity ranged from 25% (dark-eyed junco to 100% (Bewick's wren. Variation in fidelity to mate and territory was consistent with theories positing an influence of territory quality, asynchronous return from migration, prior productivity, and reproductive benefits of retaining a familiar territory. Costly breeding dispersal, as well as reduced reproductive success and lowered survival cause some birds to decline in the face of urbanization. In contrast, the ability of species that utilize edges and early successional habitats to breed successfully, disperse to improve reproductive success after failure, and survive throughout the urban ecosystem enables them

  19. The US proliferation security initiative (PSI)

    International Nuclear Information System (INIS)

    Gregoire, B.

    2004-01-01

    The proliferation security initiative (PSI), launched by President Bush on May 31, 2003, aims at intercepting any transfer of mass destruction weapons, of their vectors and related equipments, towards or coming from countries or organizations suspected to have a proliferation activity. This initiative, which involves coercive means to fight against proliferation, raises international lawfulness and legal questions, the answers of which are today under construction. This article analyzes the place of the European Union in the PSI, the action means (optimization of existing means, cooperation between intelligence and interception services), and the PSI stakes (lawfulness with respect to the international law, bilateral agreements, draft boarding agreement, sustain of the United Nations, widening of the partnership and of the field of action). (J.S.)

  20. Proliferation resistance assessment of thermal recycle systems

    International Nuclear Information System (INIS)

    1979-02-01

    This paper examines the major proliferation aspects of thermal recycle systems and the extent to which technical or institutional measures could increase the difficulty or detectability of misuse of the system by would-be proliferators. It does this by examining the various activities necessary to acquire weapons-usable material using a series of assessment factors; resources required, time required, detectability. It is concluded that resistance to proliferation could be improved substantially by collecting reprocessing, conversion and fuel fabrication plants under multi national control and instituting new measures to protect fresh MOX fuel. Resistance to theft at sub-national level could be improved by co-location of sensitive facilities high levels of physical protection at plants and during transportation and possibly by adding a radiation barrier to MOX prior to shipment

  1. Israel's position on non-proliferation

    International Nuclear Information System (INIS)

    Marom, R.

    1986-01-01

    Israel maintained that the complex international system and worldwide political tension created a situation in which comprehensive plans of disarmament could not produce any positive result. The deadlock in the field of general and complete disarmament has brought Israel to the realization that one possible way to alleviate the stalemate could be progress by stages through partial measures of disarmament. Israel's position on non-proliferation indicates that the establishment of a nuclear-weapon-free-zone (NWFZ), as it relates to the Middle-East, could serve as a credible alternative to the unilateral adherence to the Non-Proliferation of Nuclear Weapon (NPT) and an effective measure of non-proliferation in the region. (Author)

  2. Director`s series on proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, K.C. [ed.

    1993-09-07

    Two essays are included in this booklet. Their titles are ``The Dynamics of the NPT Extension Decision`` and ``North Korea`s Nuclear Gambit.`` The first paper discusses the conference to be held in 1995 to review the Nuclear Non-Proliferation Treaty (NPT) which will decide whether the treaty shall continue in force indefinitely, or shall be extended for an additional fixed period or periods. Topics relevant to this discussion are: Arms control issues, the nuclear test ban, the limited test ban treaty, the French nuclear testing moratorium, former Soviet nuclear weapons, Iraq, North Korea, nuclear-weapon-free zones, security, controls on nuclear weapon materials, peaceful uses of nuclear energy, safeguards, politics, and organizational and procedural issues. The second paper examines short, medium, and long term issues entailed in Korea`s nuclear proliferation. Topics considered include: Korean unification, North Korean politics, the nuclear issue as leverage, and the Nuclear Non- Proliferation Treaty.

  3. The economics of proliferation and counterproliferation

    International Nuclear Information System (INIS)

    Murray, B.L.; Hallenbeck, R.A.; Gill, J.M.

    1993-01-01

    On June 2, 1993, the fourth meeting of the seminar series on open-quotes Proliferation of Ballistic Missiles and Weapons of Mass Destruction and Implications for Regional Stabilityclose quotes was held at SAIC in McLean, Virginia. This series is sponsored by the Arms Control and Disarmament Agency and is cosponsored by the Ballistic Missile Defense Organization, the Defense Nuclear Agency, the Department of Energy, and the Office of the Secretary of Defense for International Security Policy. The June seminar, open-quotes The Economics of Proliferation and Counterproliferation,close quotes discussed how economic issues and interests affect proliferation judgments. Seminar participants also examined three economic tools for advancing counterproliferation objectives: Economic Development Assistance, Export Controls, and Economic open-quotes Burdensharingclose quotes and Conversion Assistance

  4. Nuclear dilemma: power, proliferation, and development

    International Nuclear Information System (INIS)

    Miller, M.

    1979-01-01

    Debate over President Carter's nuclear energy policy centers on how to develop nuclear power for civilian use and prevent the proliferation of nuclear materials for weapons. Both supporters and opponents of nuclear energy have been critical of Carter's policies because each side fails to see the linkage between the two concerns as codified in the 1978 Non-Proliferation Act. The author uses a dialogue format to illustrate the arguments for resisting proliferation and recognizing nuclear energy as an appropriate technology. The consequences of a nuclear moratorium are explored along with implications for foreign policy. U.S. leadership in developing energy technologies that can meet a broad range of appropriate applications, combined with leadership in building appropriate political frameworks, is needed if nuclear energy is to make a positive contribution toward world peace and acceptable living standards. 8 references

  5. Nuclear exports and non-proliferation

    International Nuclear Information System (INIS)

    Courteix, Simone.

    1978-01-01

    Increased preoccupation in present times with the risk of proliferation of nuclear weapons is reflected in the multiplication of international agreements such as the Non-proliferation Treaty and in the strengthening of consultations between industrialised countries (London Club). After analysing the IAEA safeguards system under the Non-proliferation Treaty and its shortcomings both technically and otherwise, the author considers how this situation can be remedied in the light of the London Agreements and in view of the position of the main countries concerned. The annex to the book contains the texts of many international agreements and relevant national regulations as well as nuclear policy statements. It also includes a detailed bibliograaphy. (NEA) [fr

  6. Nuclear power and nuclear weapon proliferation

    International Nuclear Information System (INIS)

    Apold, A.

    1978-01-01

    The theme of Dr. Marshall's lecture was that it is, from the viewpoint of prevention of proliferation of nuclear weapons,preferable to use plutonium as a fuel in FBR reactors rather than store it in what, in effect, would be plutonium mines. The true threat of proliferation lies in uranium enrichment. The FBR reactor is misunderstood and the US policy is not against breeders as such. Safeguards against the misuse of plutonium by leaving a residue of radioactivity after reprocessing is quite feasible, despite certain practical problems and extra costs. Weapon proliferation is subject to political objectives and intentions. Definite proposals are, (a) a limited number of reprocessing centres, (b) an accelerated development of FBR reactors, (c) a new FBR fuel cycle, (d) stop storage of spent thermal reactor fuel, (e) reinforced safeguards. (JIW)

  7. Dedifferentiation and proliferation of mammalian cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Yiqiang Zhang

    2010-09-01

    Full Text Available It has long been thought that mammalian cardiomyocytes are terminally-differentiated and unable to proliferate. However, myocytes in more primitive animals such as zebrafish are able to dedifferentiate and proliferate to regenerate amputated cardiac muscle.Here we test the hypothesis that mature mammalian cardiomyocytes retain substantial cellular plasticity, including the ability to dedifferentiate, proliferate, and acquire progenitor cell phenotypes. Two complementary methods were used: 1 cardiomyocyte purification from rat hearts, and 2 genetic fate mapping in cardiac explants from bi-transgenic mice. Cardiomyocytes isolated from rodent hearts were purified by multiple centrifugation and Percoll gradient separation steps, and the purity verified by immunostaining and RT-PCR. Within days in culture, purified cardiomyocytes lost their characteristic electrophysiological properties and striations, flattened and began to divide, as confirmed by proliferation markers and BrdU incorporation. Many dedifferentiated cardiomyocytes went on to express the stem cell antigen c-kit, and the early cardiac transcription factors GATA4 and Nkx2.5. Underlying these changes, inhibitory cell cycle molecules were suppressed in myocyte-derived cells (MDCs, while microRNAs known to orchestrate proliferation and pluripotency increased dramatically. Some, but not all, MDCs self-organized into spheres and re-differentiated into myocytes and endothelial cells in vitro. Cell fate tracking of cardiomyocytes from 4-OH-Tamoxifen-treated double-transgenic MerCreMer/ZEG mouse hearts revealed that green fluorescent protein (GFP continues to be expressed in dedifferentiated cardiomyocytes, two-thirds of which were also c-kit(+.Contradicting the prevailing view that they are terminally-differentiated, postnatal mammalian cardiomyocytes are instead capable of substantial plasticity. Dedifferentiation of myocytes facilitates proliferation and confers a degree of stemness

  8. Nuclear war nuclear proliferation and their consequences

    International Nuclear Information System (INIS)

    Aga Khan, Sadruddin

    1986-01-01

    The paper concerns the proceedings of a conference hosted by the Groupe de Bellerive to explore and discuss the implications for humanity of nuclear war, nuclear proliferation and their consequences, Geneva 1985. The conference was divided into five sessions, headed by the subject titles: the nuclear non-proliferation treaty (NPT) and its future, the spread of nuclear weapons among nations, global effects of a nuclear war, the nuclear arms race and arms control, the NPT and its future. Twenty eight papers were presented in the five sessions. (UK)

  9. Director`s series on proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, K.C.; Price, M.E. [eds.

    1994-12-27

    The Director`s Series on Proliferation is an occasional publication of essays on the topics of nuclear, chemical, biological, and missile proliferation. The seven papers presented in this issue cover the following topics: Should the Treaty on the Nonproliferation of Nuclear Weapons (NPT) be amended?; NPT extension - Legal and procedural issues; An Indonesian view of NPT review conference issues; The treaty of Tlatelolco and the NPT - Tools for peace and development; Perspectives on cut-off, weapons dismantlement, and security assurances; Belarus and NPT challenges; A perspective on the chemical weapons convention - Lessons learned from the preparatory commission.

  10. Proliferation risks; Proliferatierisico's

    Energy Technology Data Exchange (ETDEWEB)

    Carchon, R

    1998-09-01

    The report gives an overview of different aspects related to safeguards of fissile materials. Existing treaties including the Non-Proliferation Treaty, and the Tlatelolco and the Rarotonga Treaties are discussed. An overview of safeguards systems for the control of fissile materials as well as the role of various authorities is given. An overall overview of proliferation risks, the physical protection of fissile materials and the trade in fissile materials is given. Finally, the status in problem countries and de facto nuclear weapon states is discussed.

  11. Proliferation resistance criteria for fissile material disposition

    International Nuclear Information System (INIS)

    Close, D.A.; Fearey, B.L.; Markin, J.T.; Rutherford, D.A.; Duggan, R.A.; Jaeger, C.D.; Mangan, D.L.; Moya, R.W.; Moore, L.R.; Strait, R.S.

    1995-04-01

    The 1994 National Academy of Sciences study open-quotes Management and Disposition of Excess Weapons Plutoniumclose quotes defined options for reducing the national and international proliferation risks of materials declared excess to the nuclear weapons program. This report proposes criteria for assessing the proliferation resistance of these options. The criteria are general, encompassing all stages of the disposition process from storage through intermediate processing to final disposition including the facilities, processing technologies and materials, the level of safeguards for these materials, and the national/subnational threat to the materials

  12. United States non-proliferation policy

    International Nuclear Information System (INIS)

    Scheinman, L.

    1978-01-01

    U.S. non-proliferation policy is aimed at slowing the spread of nuclear weapons capabilities, managing the destabilizing effects of nuclear technology for energy purposes, and fostering international standards and institutions to deal responsibly with global nuclear development. These goals assume that nuclear technology has not already precluded social control and recognize the social benefits offered by peaceful uses of atomic energy. Non-proliferation policies recognize that the motivation for possessing nuclear weapons is a more-difficult problem than technical ability and will concentrate on reducing those incentives through international agreements and safeguards and by maintaining the separation of commercial nuclear fuel cycles and military uses

  13. Functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores.

    Science.gov (United States)

    Bueno, Rafael S; Guevara, Roger; Ribeiro, Milton C; Culot, Laurence; Bufalo, Felipe S; Galetti, Mauro

    2013-01-01

    Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.

  14. On the relative contributions of wind vs. animals to seed dispersal of four Sierra Nevada pines.

    Science.gov (United States)

    Vander Wall, Stephen B

    2008-07-01

    Selective pressures that influence the form of seed dispersal syndromes are poorly understood. Morphology of plant propagules is often used to infer the means of dispersal, but morphology can be misleading. Several species of pines, for example, have winged seeds adapted for wind dispersal but owe much of their establishment to scatter-hoarding animals. Here the relative importance of wind vs. animal dispersal is assessed for four species of pines of the eastern Sierra Nevada that have winged seeds but differed in seed size: lodgepole pine (Pinus contorta murrayana, 8 mg); ponderosa pine (Pinus ponderosa ponderosa, 56 mg); Jeffrey pine (Pinus jeffreyi, 160 mg); and sugar pine (Pinus lambertiana, 231 mg). Pre-dispersal seed mortality eliminated much of the ponderosa pine seed crop (66%), but had much less effect on Jeffrey pine (32% of seeds destroyed), lodgepole pine (29%), and sugar pine (7%). When cones opened most filled seeds were dispersed by wind. Animals removed > 99% of wind-dispersed Jeffrey and sugar pine seeds from the ground within 60 days, but animals gathered only 93% of lodgepole pine seeds and 38% of ponderosa pine seeds during the same period. Animals gathered and scatter hoarded radioactively labeled ponderosa, Jeffrey, and sugar pine seeds, making a total of 2103 caches over three years of study. Only three lodgepole pine caches were found. Caches typically contained 1-4 seeds buried 5-20 mm deep, depths suitable for seedling emergence. Although Jeffrey and sugar pine seeds are initially wind dispersed, nearly all seedlings arise from animal caches. Lodgepole pine is almost exclusively wind dispersed, with animals acting as seed predators. Animals treated ponderosa pine in an intermediate fashion. Two-phased dispersal of large, winged pine seeds appears adaptive; initial wind dispersal helps to minimize pre-dispersal seed mortality whereas scatter hoarding by animals places seeds in sites with a higher probability of seedling establishment.

  15. Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores

    Science.gov (United States)

    Bueno, Rafael S.; Guevara, Roger; Ribeiro, Milton C.; Culot, Laurence; Bufalo, Felipe S.; Galetti, Mauro

    2013-01-01

    Background Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. Methodology/Principal Findings We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Conclusions/Significance Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers. PMID

  16. Functional redundancy and complementarities of seed dispersal by the last neotropical megafrugivores.

    Directory of Open Access Journals (Sweden)

    Rafael S Bueno

    Full Text Available Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris and muriquis (Brachyteles arachnoides are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest.We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest.Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.

  17. Normal-dispersion microresonator Kerr frequency combs

    Directory of Open Access Journals (Sweden)

    Xue Xiaoxiao

    2016-06-01

    Full Text Available Optical microresonator-based Kerr frequency comb generation has developed into a hot research area in the past decade. Microresonator combs are promising for portable applications due to their potential for chip-level integration and low power consumption. According to the group velocity dispersion of the microresonator employed, research in this field may be classified into two categories: the anomalous dispersion regime and the normal dispersion regime. In this paper, we discuss the physics of Kerr comb generation in the normal dispersion regime and review recent experimental advances. The potential advantages and future directions of normal dispersion combs are also discussed.

  18. Comparative Study on Atmospheric Dispersion Module of Level 3 PSA

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Dahye; Jang, Misuk; Kang, Hyun Sik; Kim, Seoung Rae [NESS, Daejeon (Korea, Republic of)

    2016-10-15

    Some regulation documents such as Regulatory Guides and NUREG publications from the U.S. Nuclear Regulatory Commission (NRC) have influences on domestic radiation environmental analyses. As renewal versions of NUREG-0800 and NUREG-1555 have issued lately, the assessment for Severe Accident (SA) with Probabilistic Safety Assessment (PSA) should be added to Safety Analysis Report (SAR) and Radiation Environmental Report (RER). Because these reports are the required documents for obtaining the construction permit and operating license, it is important to understand the PSA methodology and it needs to improve the site-specific input data of L3PSA codes for SA. First, our review focuses on the atmospheric dispersion and deposition related input data of L3PSA code in this paper. Then we will continue to review the improvements of other input data. Two atmospheric dispersion models, which are PAVAN developed for design basis accident and ATMOS of MACCS2 code developed for SA, were reviewed in this paper. L3PSA deals with the effects of severe accidents and basically includes the evaluation of both short- and long-term effects. Therefore, both the deposition effects and nuclide information(type, amount, and chemical characteristics of released radionuclide) would be considered as the input parameters of atmospheric dispersion model for L3PSA. Additionally, the meteorological data would be sampled randomly to meet the purpose of probabilistic method. However, the sampling method would be selected according to analysis purpose. After review, ATMOS module and its input data are suitably developed for the atmospheric dispersion analysis of L3PSA. However, ATMOS module was developed using the site-specific terrain and environment characteristics. For the domestic application, it needs to study the input data reflecting the Korean terrain and environment characteristics. It would be also continuously improved in response to the time- and site-specific changes of weather

  19. Dispersed publication of editorial research

    DEFF Research Database (Denmark)

    Rosenberg, Jacob; Pommergaard, Hans-Christian; Vinther, Siri

    2015-01-01

    INTRODUCTION: There seems to be no dedicated journals available for publication of editorial research in the biomedical sciences; that is research into editorial or publication process issues involving the scientific approach to writing, reviewing, editing and publishing. It is unknown where papers...... journals with a median of one article per journal (range: 1-17). CONCLUSION: The publication of papers on editorial research seems to be dispersed. In order to increase the visibility of this research field, it may be reasonable to establish well-defined platforms such as dedicated journals or journal...

  20. A nonlocal inhomogeneous dispersal process

    Science.gov (United States)

    Cortázar, C.; Coville, J.; Elgueta, M.; Martínez, S.

    This article in devoted to the study of the nonlocal dispersal equation u(x,t)=∫R J({x-y}/{g(y)}){u(y,t)}/{g(y)} dy-u(x,t) in R×[0,∞), and its stationary counterpart. We prove global existence for the initial value problem, and under suitable hypothesis on g and J, we prove that positive bounded stationary solutions exist. We also analyze the asymptotic behavior of the finite mass solutions as t→∞, showing that they converge locally to zero.

  1. Taylor dispersion on a fractal

    International Nuclear Information System (INIS)

    Mazo, R.M.

    1998-01-01

    Taylor dispersion is the greatly enhanced diffusion in the direction of a fluid flow caused by ordinary diffusion in directions orthogonal to the flow. It is essential that the system be bounded in space in the directions orthogonal to the flow. We investigate the situation where the medium through which the flow occurs has fractal properties so that diffusion in the orthogonal directions is anomalous and non-Fickian. The effective diffusion in the flow direction remains normal; its width grows proportionally with the time. However, the proportionality constant depends on the fractal dimension of the medium as well as its walk dimension. (author)

  2. Rebamipide delivered by brushite cement enhances osteoblast and macrophage proliferation.

    Directory of Open Access Journals (Sweden)

    Michael Pujari-Palmer

    Full Text Available Many of the bioactive agents capable of stimulating osseous regeneration, such as bone morphogenetic protein-2 (BMP-2 or prostaglandin E2 (PGE2, are limited by rapid degradation, a short bioactive half-life at the target site in vivo, or are prohibitively expensive to obtain in large quantities. Rebamipide, an amino acid modified hydroxylquinoline, can alter the expression of key mediators of bone anabolism, cyclo-oxygenase 2 (COX-2, BMP-2 and vascular endothelial growth factor (VEGF, in diverse cell types such as mucosal and endothelial cells or chondrocytes. The present study investigates whether Rebamipide enhances proliferation and differentiation of osteoblasts when delivered from brushite cement. The reactive oxygen species (ROS quenching ability of Rebampide was tested in macrophages as a measure of bioactivity following drug release incubation times, up to 14 days. Rebamipide release from brushite occurs via non-fickian diffusion, with a rapid linear release of 9.70% ± 0.37% of drug per day for the first 5 days, and an average of 0.5%-1% per day thereafter for 30 days. Rebamipide slows the initial and final cement setting time by up to 3 and 1 minute, respectively, but does not significantly reduce the mechanical strength below 4% (weight percentage. Pre-osteoblast proliferation increases by 24% upon exposure to 0.4 uM Rebamipide, and by up to 73% when Rebamipide is delivered via brushite cement. Low doses of Rebamipide do not adversely affect peak alkaline phosphatase activity in differentiating pre-osteoblasts. Rebamipide weakly stimulates proliferation in macrophages at low concentrations (118 ± 7.4% at 1 uM, and quenches ROS by 40-60%. This is the first investigation of Rebamipide in osteoblasts.

  3. Angiotensin Converting Enzyme Regulates Cell Proliferation and Migration.

    Directory of Open Access Journals (Sweden)

    Erika Costa de Alvarenga

    Full Text Available The angiotensin-I converting enzyme (ACE plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II. More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet.Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration.We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC, and experimental results in CHO cells, demonstrated that the β3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5 showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein.ACE activation regulates melanoma cell proliferation and migration.

  4. Extragalactic dispersion measures of fast radio bursts

    International Nuclear Information System (INIS)

    Xu, Jun; Han, J. L.

    2015-01-01

    Fast radio bursts show large dispersion measures, much larger than the Galactic dispersion measure foreground. Therefore, they evidently have an extragalactic origin. We investigate possible contributions to the dispersion measure from host galaxies. We simulate the spatial distribution of fast radio bursts and calculate the dispersion measures along the sightlines from fast radio bursts to the edge of host galaxies by using the scaled NE2001 model for thermal electron density distributions. We find that contributions to the dispersion measure of fast radio bursts from the host galaxy follow a skew Gaussian distribution. The peak and the width at half maximum of the dispersion measure distribution increase with the inclination angle of a spiral galaxy, to large values when the inclination angle is over 70°. The largest dispersion measure produced by an edge-on spiral galaxy can reach a few thousand pc cm −3 , while the dispersion measures from dwarf galaxies and elliptical galaxies have a maximum of only a few tens of pc cm −3 . Notice, however, that additional dispersion measures of tens to hundreds of pc cm −3 can be produced by high density clumps in host galaxies. Simulations that include dispersion measure contributions from the Large Magellanic Cloud and the Andromeda Galaxy are shown as examples to demonstrate how to extract the dispersion measure from the intergalactic medium. (paper)

  5. Unusually high dispersion of nitrogen-doped carbon nanotubes in DNA solution.

    Science.gov (United States)

    Kim, Jin Hee; Kataoka, Masakazu; Fujisawa, Kazunori; Tojo, Tomohiro; Muramatsu, Hiroyuki; Vega-Díaz, Sofía M; Tristán-López, F; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S

    2011-12-08

    The dispersibility in a DNA solution of bundled multiwalled carbon nanotubes (MWCNTs), having different chemical functional groups on the CNT sidewall, was investigated by optical spectroscopy. We observed that the dispersibility of nitrogen (N)-doped MWCNTs was significantly higher than that of pure MWCNTs and MWCNTs synthesized in the presence of ethanol. This result is supported by the larger amount of adsorbed DNA on N-doped MWCNTs, as well as by the higher binding energy established between nucleobases and the N-doped CNTs. Pure MWCNTs are dispersed in DNA solution via van der Waals and hydrophobic interactions; in contrast, the nitrogenated sites within N-doped MWCNTs provided additional sites for interactions that are important to disperse nanotubes in DNA solutions. © 2011 American Chemical Society

  6. Experimental study on thermal dispersion in and near the surf zone

    International Nuclear Information System (INIS)

    Komori, Shuzo; Tanaka, Hiroyoshi; Wada, Akira

    1978-01-01

    The site of Fukushima No. 1 Nuclear Power Station of Tokyo Electric Power Company was selected, and first, irregular waves with the typical wave spectra (in usual time and in storm time) in the sea region of the site were reproduced in the hydraulic model, then the characteristics of thermal dispersion and the velocityfield of warmed water (its discharge is 25.3 m 3 /sec.) in and near the surf zone under the action of those irregular waves were discussed. Finally, the similarity was investigated between the dispersion phenomenon in the hydraulic model and that in the prototype by comparing the experimental results of the dispersion range of warmed water with the results of field measurements. It may be concluded that the enveloped range of thermal dispersion in prototype can be predicted fairly correctly under almost the same discharge condition as this experiment if the prototype conditions of waves and currents are considered carefully and reproduced in a hydraulic model. (Kobatake, H.)

  7. Implementation of meso-scale radioactive dispersion model for GPU

    Energy Technology Data Exchange (ETDEWEB)

    Sunarko [National Nuclear Energy Agency of Indonesia (BATAN), Jakarta (Indonesia). Nuclear Energy Assessment Center; Suud, Zaki [Bandung Institute of Technology (ITB), Bandung (Indonesia). Physics Dept.

    2017-05-15

    Lagrangian Particle Dispersion Method (LPDM) is applied to model atmospheric dispersion of radioactive material in a meso-scale of a few tens of kilometers for site study purpose. Empirical relationships are used to determine the dispersion coefficient for various atmospheric stabilities. Diagnostic 3-D wind-field is solved based on data from one meteorological station using mass-conservation principle. Particles representing radioactive pollutant are dispersed in the wind-field as a point source. Time-integrated air concentration is calculated using kernel density estimator (KDE) in the lowest layer of the atmosphere. Parallel code is developed for GTX-660Ti GPU with a total of 1 344 scalar processors using CUDA. A test of 1-hour release discovers that linear speedup is achieved starting at 28 800 particles-per-hour (pph) up to about 20 x at 14 4000 pph. Another test simulating 6-hour release with 36 000 pph resulted in a speedup of about 60 x. Statistical analysis reveals that resulting grid doses are nearly identical in both CPU and GPU versions of the code.

  8. Which future for nuclear counter-proliferation?; Quel avenir pour la contre-proliferation nucleaire?

    Energy Technology Data Exchange (ETDEWEB)

    Duval, M.

    2010-07-15

    Dealing with the case of nuclear weapons possessed by nuclear states (but not eventually by terrorists), the author first identifies the constants of counter-proliferation: it is linked to interest conflicts between those who try to preserve their monopoly and those who try to acquire a new weapon either because of a threat or for reasons of regional prestige, the evolution from use to deterrence, the appearance of new actors after the USA and Russia, the role of nuclear tactical weapons, and the future of Russian weapons and know-how. He presents the international counter-proliferation context: the Non Proliferation Treaty (NPT), the IAEA and its controls, the Nuclear Supplier Group (NSG), the nuclear-free zones, the Comprehensive Test Ban Treaty (CTBT), the Missile Technology Control Regime (MTCR). He describes how and why proliferation occurs: uranium enrichment and plutonium technology, political reasons in different parts of the world. Then, he gives an overview of the proliferation status by commenting the cases of Israel, Iraq, India, Pakistan, North Korea, and Iran. He discusses the future of proliferation (involved countries, existence of a nuclear black market) and of counter-proliferation as far as Middle-East and North Korea are concerned. He tries finally to anticipate the consequences for nuclear deterrence strategy, and more particularly for Europe and France

  9. Introduction to nonlinear dispersive equations

    CERN Document Server

    Linares, Felipe

    2015-01-01

    This textbook introduces the well-posedness theory for initial-value problems of nonlinear, dispersive partial differential equations, with special focus on two key models, the Korteweg–de Vries equation and the nonlinear Schrödinger equation. A concise and self-contained treatment of background material (the Fourier transform, interpolation theory, Sobolev spaces, and the linear Schrödinger equation) prepares the reader to understand the main topics covered: the initial-value problem for the nonlinear Schrödinger equation and the generalized Korteweg–de Vries equation, properties of their solutions, and a survey of general classes of nonlinear dispersive equations of physical and mathematical significance. Each chapter ends with an expert account of recent developments and open problems, as well as exercises. The final chapter gives a detailed exposition of local well-posedness for the nonlinear Schrödinger equation, taking the reader to the forefront of recent research. The second edition of Introdu...

  10. Dispersivity in heterogeneous permeable media

    International Nuclear Information System (INIS)

    Chesnut, D.A.

    1994-01-01

    When one fluid displaces another through a one-dimensional porous medium, the composition changes from pure displacing fluid at the inlet to pure displaced fluid some distance downstream. The distance over which an arbitrary percentage of this change occurs is defined as the mixing zone length, which increases with increasing average distance traveled by the displacement front. For continuous injection, the mixing zone size can be determined from a breakthrough curve as the time required for the effluent displacing fluid concentration to change from, say, 10% to 90%. In classical dispersion theory, the mixing zone grows in proportion to the square root of the mean distance traveled, or, equivalently, to the square root of the mean breakthrough time. In a multi-dimensional heterogeneous medium, especially at field scales, the size of the mixing zone grows almost linearly with mean distance or travel time. If an observed breakthrough curve is forced to fit the, clinical theory, the resulting effective dispersivity, instead of being constant, also increases almost linearly with the spatial or temporal scale of the problem. This occurs because the heterogeneity in flow properties creates a corresponding velocity distribution along the different flow pathways from the inlet to the outlet of the system. Mixing occurs mostly at the outlet, or wherever the fluid is sampled, rather than within the medium. In this paper, we consider the effects. of this behavior on radionuclide or other contaminant migration

  11. Dispersivity in heterogeneous permeable media

    International Nuclear Information System (INIS)

    Chesnut, D.A.

    1994-01-01

    When one fluid displaces another through a one-dimensional porous medium, the composition changes from pure displacing fluid at the inlet to pure displaced fluid some distance downstream. The distance over which an arbitrary percentage (typically 80%) of this change occurs is defined as the mixing zone length, which increases with increasing average distance traveled by the displacement front. Alternatively, for continuous injection, the mixing zone size can be determined from a breakthrough curve as the time required for the effluent displacing fluid concentration to change from, say, 10% to 90%. In classical dispersion theory, the mixing zone grows in proportion to the square root of the mean distance traveled, or, equivalently, to the square root of the mean breakthrough time. In a multi-dimensional heterogeneous medium, especially at field scales, the size of the mixing zone grows almost linearly with mean distance or travel time. If an observed breakthrough curve is forced to fit the classical theory, the resulting effective dispersivity, instead of being constant, also increases almost linearly with the spatial or temporal scale of the problem. This occurs because the heterogeneity in flow properties creates a corresponding velocity distribution along the different flow pathways from the inlet to the outlet of the system. Mixing occurs mostly at the outlet, or wherever the fluid is sampled, rather than within the medium. In this paper, we consider the effects of this behavior on radionuclide or other contaminant migration

  12. Superfund Sites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This layer represents active Superfund Sites published by the Environmental Protection Agency (EPA). These data were extracted from the Superfund Enterprise...

  13. Site development

    International Nuclear Information System (INIS)

    Noack, J.

    1975-01-01

    The subject of this paper is a general view over all necessary considerations to develop the site after it has been chosen and before starting with the construction of a nuclear power plant. (orig./RW) [de

  14. Site selection

    International Nuclear Information System (INIS)

    Olsen, C.W.

    1983-07-01

    The conditions and criteria for selecting a site for a nuclear weapons test at the Nevada Test Site are summarized. Factors considered are: (1) scheduling of drill rigs, (2) scheduling of site preparation (dirt work, auger hole, surface casing, cementing), (3) schedule of event (when are drill hole data needed), (4) depth range of proposed W.P., (5) geologic structure (faults, Pz contact, etc.), (6) stratigraphy (alluvium, location of Grouse Canyon Tuff, etc.), (7) material properties (particularly montmorillonite and CO 2 content), (8) water table depth, (9) potential drilling problems (caving), (10) adjacent collapse craters and chimneys, (11) adjacent expended but uncollapsed sites, (12) adjacent post-shot or other small diameter holes, (13) adjacent stockpile emplacement holes, (14) adjacent planned events (including LANL), (15) projected needs of Test Program for various DOB's and operational separations, and (16) optimal use of NTS real estate

  15. Stochastic cellular automata model of cell migration, proliferation and differentiation: validation with in vitro cultures of muscle satellite cells.

    Science.gov (United States)

    Garijo, N; Manzano, R; Osta, R; Perez, M A

    2012-12-07

    Cell migration and proliferation has been modelled in the literature as a process similar to diffusion. However, using diffusion models to simulate the proliferation and migration of cells tends to create a homogeneous distribution in the cell density that does not correlate to empirical observations. In fact, the mechanism of cell dispersal is not diffusion. Cells disperse by crawling or proliferation, or are transported in a moving fluid. The use of cellular automata, particle models or cell-based models can overcome this limitation. This paper presents a stochastic cellular automata model to simulate the proliferation, migration and differentiation of cells. These processes are considered as completely stochastic as well as discrete. The model developed was applied to predict the behaviour of in vitro cell cultures performed with adult muscle satellite cells. Moreover, non homogeneous distribution of cells has been observed inside the culture well and, using the above mentioned stochastic cellular automata model, we have been able to predict this heterogeneous cell distribution and compute accurate quantitative results. Differentiation was also incorporated into the computational simulation. The results predicted the myotube formation that typically occurs with adult muscle satellite cells. In conclusion, we have shown how a stochastic cellular automata model can be implemented and is capable of reproducing the in vitro behaviour of adult muscle satellite cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 7-Piperazinethylchrysin inhibits melanoma cell proliferation by ...

    African Journals Online (AJOL)

    In B16F10 and A375 cells, treatment with PEC caused the inhibition ... Conclusion: PEC inhibited melanoma cell proliferation, apparently by blocking the cell cycle at G0/G1 .... all statistical analyses. .... Financial support from the Department of.

  17. Limiting Future Proliferation and Security Risks

    International Nuclear Information System (INIS)

    Bari, R.

    2011-01-01

    A major new technical tool for evaluation of proliferation and security risks has emerged over the past decade as part the activities of the Generation IV International Forum. The tool has been developed by a consensus group from participating countries and organizations and is termed the Proliferation Resistance and Physical Protection (PR and PP) Evaluation Methodology. The methodology defines a set of challenges, analyzes system response to these challenges, and assesses outcomes. The challenges are the threats posed by potential actors (proliferant states or sub-national adversaries). It is of paramount importance in an evaluation to establish the objectives, capabilities, resources, and strategies of the adversary as well as the design and protection contexts. Technical and institutional characteristics are both used to evaluate the response of the system and to determine its resistance against proliferation threats and robustness against sabotage and terrorism threats. The outcomes of the system response are expressed in terms of a set of measures, which thereby define the PR and PP characteristics of the system. This paper summarizes results of applications of the methodology to nuclear energy systems including reprocessing facilities and large and small modular reactors. The use of the methodology in the design phase a facility will be discussed as it applies to future safeguards concepts.

  18. Does programmed CTL proliferation optimize virus control?

    DEFF Research Database (Denmark)

    Wodarz, Dominik; Thomsen, Allan Randrup

    2005-01-01

    CD8 T-cell or cytotoxic T-lymphocyte responses develop through an antigen-independent proliferation and differentiation program. This is in contrast to the previous thinking, which was that continuous antigenic stimulation was required. This Opinion discusses why nature has chosen the proliferati...

  19. Canada's nuclear non-proliferation policy

    International Nuclear Information System (INIS)

    1985-01-01

    Canada's non-proliferation and safeguards policy has two objectives: 1) to promote the emergence of a more effective and comprehensive international non-proliferation regime; and 2) to assure the Canadian people and the international community that Canadian nuclear exports will not be used for any nuclear explosive purpose. By emphasizing the key role of the NPT, by promoting reliance upon and improvements in the IAEA safeguards system, by treating nuclear weapon and non-nuclear weapon states alike regarding Canadian nuclear exports, by working for new approaches covering the sensitive phases (e.g. reprocessing) of the nuclear fuel cycle, Canada's policy promotes attainment of the first objective. The latter objective is served through the network of bilateral nuclear agreements that Canada has put into place with its nuclear partners. Those agreements provide assurance that Canada's nuclear exports are used solely for legitimate, peaceful, nuclear energy production purposes. At the same time, Canada, having formulated its non-proliferation and safeguards policy during the period 1945 to 1980, has recognized that it has gone as far as it can on its own in this field and that from this point on any further changes should be made on the basis of international agreement. The Canadian objective in post-INFCE forums such as the Committee on Assurances of Supply is to exert Canada's best efforts to persuade the international community to devise a more effective and comprehensive international non-proliferation regime into which Canada and other suppliers might subsume their national requirements

  20. Luteoloside Inhibits Proliferation of Human Chronic Myeloid ...

    African Journals Online (AJOL)

    Purpose: To investigate the effects of luteoloside on the proliferation of human chronic ..... Zhang N, Wang D, Zhu Y, Wang J, Lin H. Inhibition ... Han X. Protection of Luteolin-7-O-Glucoside Against ... Hwang YJ, Lee EJ, Kim HR, Hwang KA.

  1. Arsenic and urinary bladder cell proliferation

    International Nuclear Information System (INIS)

    Luster, Michael I.; Simeonova, Petia P.

    2004-01-01

    Epidemiologic studies have demonstrated that a close association exists between the elevated levels of arsenic in drinking water and the incidence of certain cancers, including transitional cell carcinomas of the urinary bladder. We have employed in vitro and in vivo models to examine the effects of sodium arsenite on the urinary bladder epithelium. Mice exposed to 0.01% sodium arsenite in drinking water demonstrated hyperproliferation of the bladder uroepithelium within 4 weeks after initiating treatment. This occurred in the absence of amorphous precipitates and was accompanied by the accumulation of trivalent arsenite (iAs 3+ ), and to a lesser extent dimethylarsenic (DMA), arsenate (iAs 5+ ), and monomethylarsenic (MMA) in bladder tissue. In contrast to the bladder, urinary secretion was primarily in the form of DMA and MMA. Arsenic-induced cell proliferation in the bladder epithelium was correlated with activation of the MAP kinase pathway, leading to extracellular signal-regulated kinase (ERK) kinase activity, AP-1 activation, and expression of AP-1-associated genes involved in cell proliferation. Activation of the MAP kinase pathway involved both epidermal growth factor (EGF) receptor-dependent and -independent events, the latter involving Src activation. Studies summarized in this review suggest that arsenic accumulates in urinary bladder epithelium causing activation of specific signaling pathways that lead to chronic increased cell proliferation. This may play a non-epigenetic role in carcinogenesis by increasing the proliferation of initiated cells or increasing the mutational rate

  2. Non-proliferation and nuclear disarmament

    International Nuclear Information System (INIS)

    Shea, M.

    2000-01-01

    Fissionable materials are common to all nuclear weapons and controls on the production, storage, processing and use of fissionable materials provides one means to address non-proliferation and disarmament. In this article, the relevance of such controls is examined and the current situation and future prospects are assessed. (authors)

  3. Nuclear Society and non-proliferation problems

    International Nuclear Information System (INIS)

    Gagarinskij, A.Ya.; Kushnarev, S.V.; Ponomarev-Stepnoj, N.N.; Sukhoruchkin, V.K.; Khromov, V.V.; Shmelev, V.M.

    1997-01-01

    In the USSR Nuclear Society in 1991 the special working group on the problems of nuclear weapons non-proliferation and nuclear materials control, uniting the experts of different types (nuclear physicists, lawyers, teachers), was created. This group became the mechanism of the practical Nuclear Society activity realization in this sphere. Three milestones of the innovative activity can be specified. First Milestone. In January 1992 the Central Nuclear Society Board (of the International Public Nuclear Society Association) published a special appeal to the First Leaders of all countries - former USSR republics. This address paid a special attention to the unity of the USSR power-industrial complex, and numerous problems arisen while separating this complex, including nuclear weapons non-proliferation problems, were indicated as well. Second Milestone. In 1992 and 1993 the Nuclear Society experts issued two selection 'Nuclear Non-proliferation and Control Problems' including reviewing basic papers. In addition, materials on non-proliferation and control are published regularly in the organs. Third Milestone.In 1993 - 1997 some special scientific and technical events (conferences, workshops, meetings) allowing to analyze the joint international projects and contracts outcomes, and establish new contacts between the specialists of NIS, Baltic states and others, have been hold

  4. EMP at the Non-Proliferation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J. [AWE, Aldermaston (United Kingdom)

    1994-12-31

    This experiment presented an opportunity to field customized equipment designed to detect and record electromagnetic pulse (EMP) emanations from an explosion over a wide frequency range. Any data recorded could be used in conjunction with the seismic methods to further non-proliferation studies. No EMP emanations were detectable from the four sensors deployed outside the tunnel confines.

  5. Some remarks on rockbursts and nuclear proliferation

    Energy Technology Data Exchange (ETDEWEB)

    McGarr, A. [Geological Survey, Menlo Park, CA (United States)

    1994-12-31

    This report describes problems associated with non-proliferation verification. Issues are described which can arise in the course of monitoring test ban treaties, with an example of an occurrence in South Africa. A problem for most situations appears to be the seismic source.

  6. Luteoloside Inhibits Proliferation of Human Chronic Myeloid ...

    African Journals Online (AJOL)

    Purpose: To investigate the effects of luteoloside on the proliferation of human chronic myeloid leukemia K562 cells and whether luteoloside induces cell cycle arrest and apoptosis in K562 cells. Methods: Luteoloside's cytotoxicity was assessed using a cell counting kit. Cell cycle distribution was analysed by flow cytometry ...

  7. Thalidomide increases human keratinocyte migration and proliferation.

    Science.gov (United States)

    Nasca, M R; O'Toole, E A; Palicharla, P; West, D P; Woodley, D T

    1999-11-01

    Thalidomide is reported to have therapeutic utility in the treatment of pyoderma gangrenosum, Behçet's disease, aphthous ulcers, and skin wounds. We investigated the effect of thalidomide on human keratinocyte proliferation and migration, two early and critical events in the re-epithelialization of skin wounds. Thalidomide at concentrations less than 1 microM did not affect keratinocyte viability. Using a thymidine incorporation assay, we found that thalidomide, at therapeutic concentrations, induced more than a 2. 5-fold increase in the proliferative potential of the cells. Keratinocyte migration was assessed by two independent motility assays: a colloidal gold assay and an in vitro scratch assay. At optimal concentrations, thalidomide increased keratinocyte migration on a collagen matrix more than 2-fold in the colloidal gold assay and more than 3-fold in the scratch assay over control. Although pro-migratory, thalidomide did not alter the level of metalloproteinase-9 secreted into culture medium. Thalidomide did, however, induce a 2-4-fold increase in keratinocyte-derived interleukin-8, a pro-migratory cellular autocrine factor. Human keratinocyte migration and proliferation are essential for re-epithelialization of skin wounds. Interleukin-8 increases human keratinocyte migration and proliferation and is chemotactic for keratinocytes. Therefore, thalidomide may modulate keratinocyte proliferation and motility by a chemokine-dependent pathway.

  8. A global-scale dispersion analysis of iodine-129 from nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Nishizawa, Masato; Suzuki, Takashi; Nagai, Haruyasu; Togawa, Orihiko

    2010-01-01

    A three-dimensional global chemical transport model, MOZART-2, is applied to investigate the global-sale dispersion of Iodine-129 from nuclear fuel reprocessing plants. The concentration and deposition of 129 I obtained by MOZART-2 are dispersed all over the Northern Hemisphere. The emission of 129 I to the atmosphere is thus important in considering the transport of 129 I to remote sites. (author)

  9. Physical modelling of flow and dispersion over complex terrain

    Science.gov (United States)

    Cermak, J. E.

    1984-09-01

    Atmospheric motion and dispersion over topography characterized by irregular (or regular) hill-valley or mountain-valley distributions are strongly dependent upon three general sets of variables. These are variables that describe topographic geometry, synoptic-scale winds and surface-air temperature distributions. In addition, pollutant concentration distributions also depend upon location and physical characteristics of the pollutant source. Overall fluid-flow complexity and variability from site to site have stimulated the development and use of physical modelling for determination of flow and dispersion in many wind-engineering applications. Models with length scales as small as 1:12,000 have been placed in boundary-layer wind tunnels to study flows in which forced convection by synoptic winds is of primary significance. Flows driven primarily by forces arising from temperature differences (gravitational or free convection) have been investigated by small-scale physical models placed in an isolated space (gravitational convection chamber). Similarity criteria and facilities for both forced and gravitational-convection flow studies are discussed. Forced-convection modelling is illustrated by application to dispersion of air pollutants by unstable flow near a paper mill in the state of Maryland and by stable flow over Point Arguello, California. Gravitational-convection modelling is demonstrated by a study of drainage flow and pollutant transport from a proposed mining operation in the Rocky Mountains of Colorado. Other studies in which field data are available for comparison with model data are reviewed.

  10. Nuclear non proliferation and disarmament; Non-proliferation nucleaire et desarmement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    In the framework of the publication of a document on the ''weapons mastership, disarmament and non proliferation: the french action'', by the ministry of Foreign Affairs and the ministry of Defense, the French Documentation organization presents a whole document. This document describes and details the following topics: the conference on the treaty of non proliferation of nuclear weapons, the France, Usa and Non Governmental Organizations position, the threats of the proliferation, the french actions towards the disarmament, the disarmament in the world, a chronology and some bibliographic resources. (A.L.B.)

  11. Proliferation: does the peaceful use of nuclear energy have to lead to proliferation of nuclear weapons

    International Nuclear Information System (INIS)

    Muench, E.; Stein, G.

    The question of whether the proliferation of nuclear weapons is promoted by an increasing use of peaceful nuclear energy can be answered with a well-founded no. Even a regional renouncing of the peaceful use of nuclear energy would not reduce the worldwide problem of nuclear weapons' proliferation. Therefore, joint efforts must be aimed at promoting trust between peoples in the nuclear sphere and the political reasons for the proliferation of nuclear weapons must be reduced in order also to promote international harmony

  12. Does interdependence alleviate proliferation risks in Asia?

    International Nuclear Information System (INIS)

    Yoshida, Osamu

    1997-01-01

    As the extension Conference of the Non-Proliferation Treaty ended with its unlimited extension without any modification of the treaty obligation of the nuclear-weapon states to nuclear disarmament, the prospect of the regime to incorporate those suspected nuclear powers in Asia, namely India, Pakistan and Israel, has become dark. In this paper the problem of proliferation risk centred in India is analysed. It is well known that India was the first to criticize the Non-Proliferation Treaty regime as highly discriminating between the five nuclear haves and the rest. As was always the case, India's point is logically persuasive and consistent. However, it is also true that the logical or legal point of view does not always solve the problem. Therefore, we look at the regional and international political constellation in which any assertion has to be constructed. At present there is very little possibility that this region will become nuclear-free. This is because the horizontal proliferation, that has seemingly taken place here, is the result of a 'nuclear chain reaction', starting with a minor nuclear-weapon state, China. However, the economic upsurge in the region now throws the nuclear chain-reactions into the background. It has come to a standstill and the future of nuclear proliferation here will have to be decided by global nuclear disarmament, as there is no motivation on the side of the two Asian giants to agree on the reduction in their nuclear arsenals, though under American pressure, another suspected nuclear power, Pakistan, may have to give up its nuclear development plan

  13. Nuclear proliferation: present, past and future

    International Nuclear Information System (INIS)

    Alonso, M.; Zaleski, P.

    1993-01-01

    Since the end of WW II one of the more, if not the most, serious concerns of all people in the world has been to preserve this planet avoiding a nuclear war. On the positive side, in spite of the huge arsenal of strategic and tactical nuclear weapons (NW) accumulated over the years by the US and the former SU and the innumerable military conflicts we have witnessed since WW II, no NW have been used again. But this should not be a great consolation: the fact that countries have refrained from using NW does not necessarily mean that it will always be that way. As long as countries try to solve their differences by the use of force the danger of a nuclear confrontation remains, and nuclear disarmament and proliferation should cotinue to be a serious concern. This concern has profound political, social and ethical components that have been analyzed extensively and profusely. The purpose of this paper is more limited: to provide an overview of the national and international efforts to minimize the risk of a nuclear war by regulating, restricting and containing the development and possession of NW. This is what has become know as the nuclear non-proliferation regime. Any nuclear non-proliferation regime must have two essential goals: achieving nuclear disarmament by the NWS (and thereby eliminating vertical proliferation). To make a regime effective it must rely on international agreements, a system of safeguards coupled with inspection and verification procedures, and above all on the good faith of all nations involved. It should be stated from the very beginning that nuclear non-proliferation efforts, like all disarmament efforts, are essentially of political nature, albeit having an important scientific and technological component. They are effective only to the extent that countries really renounce NW and are prepared to severely sanction those who do not. (Author) 31 refs

  14. Proliferation resistance assessment of pyro processing

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, E. H.; Ko, W. I.; Kim, H. D. [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    In 2002, world experts gathered and defined the term proliferation resistance as 'the characteristic of a nuclear energy system that impedes the diversion or undeclared production of nuclear material, or misuse of technology, by State in order to acquire nuclear weapons or other nuclear explosive devices.' The same report also defines the following terms: Intrinsic barriers (technical features) of proliferation resistance are features that result from the technical design of nuclear energy systems, including those that facilitate the implementation of extrinsic measures. Extrinsic barriers (institutional measures) of proliferation resistance are features that result from the decisions and undertakings of states related to nuclear energy system. Intrinsic barriers are further divided into material barriers.the 'intrinsic, or inherent, qualities of materials that reduce the inherent desirability or attractiveness of the material as an explosive' and technical barriers. The 'intrinsic technical lements of the fuel cycle, its facilities, processes, and equipment that serve to make it difficult to gain access to materials and/or to use or misuse facilities to obtain weapons usable materials.' Material barriers include isotopic, chemical, radiological, mass and bulk, and detectability, whereas technical barriers include facility unattractiveness, accessibility, available fissile mass, detectability of and time required for diversion, and skills, expertise, and knowledge. Assessing the proliferation resistance of pyro processing is meaningful only when compared with other processes. This paper attempts to discuss the features of pyro processing by comparing it with direct disposal and aqueous separation processes from a proliferation resistance viewpoint.

  15. Flow time, flow velocity and longitudinal dispersion in Moselle and Weser rivers; Fliesszeit, Fliessgeschwindigkeit und Longitudinale Dispersion in Mosel und Weser

    Energy Technology Data Exchange (ETDEWEB)

    Krause, W.J.; Krinitzky, T.; Cremer, M. [Bundesanstalt fuer Gewaesserkunde (BfG), Koblenz (Germany)

    2003-07-01

    Since 1980, the Federal Institute of Hydrology has performed dispersion investigations with tritium as a tracer on Federal Waterways. The aim was to establish dispersion prognoses, i.e. forecasts of the longitudinal dispersion of concentrations of noxious substances in the water column. Characteristic parameters like discharge-relevant flow velocities, dispersion and elimination constants of emittent sites and selected river sections will be determined. They will serve as basis for a mathematical model permitting to forecast discharge-relevant flow velocities, expected impact times, concentration maxima and the duration of critical concentration increases. In the following, the results obtained at the Moselle river and the investigations carried out on the Weser river will be shortly described. (orig.)

  16. Diverse FGF receptor signaling controls astrocyte specification and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyungjun [School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Song, Mi-Ryoung, E-mail: msong@gist.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Bioimaging Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2010-05-07

    During CNS development, pluripotency neuronal progenitor cells give rise in succession to neurons and glia. Fibroblast growth factor-2 (FGF-2), a major signal that maintains neural progenitors in the undifferentiated state, is also thought to influence the transition from neurogenesis to gliogenesis. Here we present evidence that FGF receptors and underlying signaling pathways transmit the FGF-2 signals that regulate astrocyte specification aside from its mitogenic activity. Application of FGF-2 to cortical progenitors suppressed neurogenesis whereas treatment with an FGFR antagonist in vitro promoted neurogenesis. Introduction of chimeric FGFRs with mutated tyrosine residues into cortical progenitors and drug treatments to specifically block individual downstream signaling pathways revealed that the overall activity of FGFR rather than individual autophosphorylation sites is important for delivering signals for glial specification. In contrast, a signal for cell proliferation by FGFR was mainly delivered by MAPK pathway. Together our findings indicate that FGFR activity promotes astrocyte specification in the developing CNS.

  17. Lessons learned from the non-proliferation experiment

    Energy Technology Data Exchange (ETDEWEB)

    McWilliam, C.; Curtis, S. [DOE, Las Vegas, NV (United States)

    1994-12-31

    The Department of Energy sponsored Non-Proliferation Experiment (formerly known as the Chemical Kiloton) involved the detonation of blasting agent approximately equivalent to one kiloton of energy release on the Nevada Test Site in an effort to determine if (and if so, which) discriminators exist between conventional and nuclear detonations of similar yield. Coordination among hundreds of scientists from at least fifteen different organizations were required to design the experiments necessary to collect and interpret data from this unique and complex event. Stakeholders and members of the Group of Scientific Experts of the Conference on Disarmament observed the progress of the experiment first hand. The experiment was a success in that a vast majority of the expected data was collected and shared quickly and efficiently throughout the international scientific community. The management of the project was discussed among the major co-sponsoring organizations and the significant {open_quotes}lessons learned{close_quotes} are presented.

  18. Diverse FGF receptor signaling controls astrocyte specification and proliferation

    International Nuclear Information System (INIS)

    Kang, Kyungjun; Song, Mi-Ryoung

    2010-01-01

    During CNS development, pluripotency neuronal progenitor cells give rise in succession to neurons and glia. Fibroblast growth factor-2 (FGF-2), a major signal that maintains neural progenitors in the undifferentiated state, is also thought to influence the transition from neurogenesis to gliogenesis. Here we present evidence that FGF receptors and underlying signaling pathways transmit the FGF-2 signals that regulate astrocyte specification aside from its mitogenic activity. Application of FGF-2 to cortical progenitors suppressed neurogenesis whereas treatment with an FGFR antagonist in vitro promoted neurogenesis. Introduction of chimeric FGFRs with mutated tyrosine residues into cortical progenitors and drug treatments to specifically block individual downstream signaling pathways revealed that the overall activity of FGFR rather than individual autophosphorylation sites is important for delivering signals for glial specification. In contrast, a signal for cell proliferation by FGFR was mainly delivered by MAPK pathway. Together our findings indicate that FGFR activity promotes astrocyte specification in the developing CNS.

  19. Radiocarbon dispersion around Canadian nuclear facilities

    International Nuclear Information System (INIS)

    Milton, G.M.; Kramer, S.J.; Brown, R.M.; Repta, C.J.W.; King, K.J.; Rao, R.R.

    1995-01-01

    Canadian deuterium uranium (CANDU) pressurized heavy-water reactors produce 14 C by neutron activation of trace quantities of nitrogen in annular gas and reactor components ( 14 N(n,p) 14 C), and from 17 O in the heavy water moderator by ( 17 O(n,α) 14 C). The radiocarbon produced in the moderator is removed on ion exchange resins incorporated in the water purification systems; however, a much smaller gaseous portion is vented from reactor stacks at activity levels considerably below 1% of permissible derived emission limits. Early measurements of the carbon speciation indicated that >90% of the 14 C emitted was in the form of CO 2 .We conducted surveys of the atmospheric dispersion of 14 CO 2 at the Chalk River Laboratories and at the Pickering Nuclear Generating Station. We analyzed air, vegetation, soils and tree rings to add to the historical record of 14 C emissions at these sites, and to gain an understanding of the relative importance of the various carbon pools that act as sources/sinks within the total 14 C budget. Better model parameters than those currently available for calculating the dose to the critical group can be obtained in this manner. Global dose estimates may require the development of techniques for estimating emissions occurring outside the growing season. (author)

  20. A laboratory dispersant effectiveness test which reflects dispersant efficiency in the field

    International Nuclear Information System (INIS)

    Lunel, T.; Wood, P.

    1996-01-01

    Oil dispersion efficiencies of surfactants, from laboratory dispersion tests and field data were compared and calibrated. Data from an oil spill, where dispersants were used as a major part of the response, was analysed. The data was accumulated through the monitoring of the dispersant operation of the Sea Empress spill incident, in which Forties Blend oil was spilled at sea. This detailed data set was used to calibrate existing laboratory dispersant tests, and to devise a new International Dispersant Effectiveness Test. The objective was to create a comprehensive guide to decision making on whether and when to start a dispersant spraying operation. The dispersion efficiencies obtained from the laboratory dispersant tests were compared with field data. Flume tests produced the highest percentage of dispersed oil for all the dispersal tests. However, it was emphasised that the total percentage of oil dispersed should not be the only measure of dispersant effectiveness, since it does not distinguish between the contribution of natural and chemically enhanced dispersion. 9 refs., 1 tab., 9 figs

  1. Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus).

    Science.gov (United States)

    Moore, Jennifer A; Draheim, Hope M; Etter, Dwayne; Winterstein, Scott; Scribner, Kim T

    2014-01-01

    Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540) from three generations of black bears (Ursus americanus) harvested in a large (47,739 km2), geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337). We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed) but a small proportion (21%) of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km) were comparable to male dispersal distances (59.0±3.2 km). Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1) intensive harvest promotes restricted dispersal, or 2) high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.

  2. Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus.

    Directory of Open Access Journals (Sweden)

    Jennifer A Moore

    Full Text Available Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540 from three generations of black bears (Ursus americanus harvested in a large (47,739 km2, geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337. We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed but a small proportion (21% of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km were comparable to male dispersal distances (59.0±3.2 km. Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1 intensive harvest promotes restricted dispersal, or 2 high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.

  3. Pollen Forecast and Dispersion Modelling

    Science.gov (United States)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  4. Tomography with energy dispersive diffraction

    Science.gov (United States)

    Stock, S. R.; Okasinski, J. S.; Woods, R.; Baldwin, J.; Madden, T.; Quaranta, O.; Rumaiz, A.; Kuczewski, T.; Mead, J.; Krings, T.; Siddons, P.; Miceli, A.; Almer, J. D.

    2017-09-01

    X-ray diffraction can be used as the signal for tomographic reconstruction and provides a cross-sectional map of the crystallographic phases and related quantities. Diffraction tomography has been developed over the last decade using monochromatic x-radiation and an area detector. This paper reports tomographic reconstruction with polychromatic radiation and an energy sensitive detector array. The energy dispersive diffraction (EDD) geometry, the instrumentation and the reconstruction process are described and related to the expected resolution. Results of EDD tomography are presented for two samples containing hydroxyapatite (hAp). The first is a 3D-printed sample with an elliptical crosssection and contains synthetic hAp. The second is a human second metacarpal bone from the Roman-era cemetery at Ancaster, UK and contains bio-hAp which may have been altered by diagenesis. Reconstructions with different diffraction peaks are compared. Prospects for future EDD tomography are also discussed.

  5. Which future for the nuclear counter-proliferation?; Quel avenir pour la contre-proliferation nucleaire?

    Energy Technology Data Exchange (ETDEWEB)

    Duval, M

    2004-10-01

    After a recall of the permanent data about proliferation and of the safeguards implemented by the international community, the author demonstrates that proliferation has moved towards Asia where a real 'black market' has been created. Then he analyzes the consequences of this change on the future of nuclear deterrent. Finally, he expresses his nostalgia in front of this drift and worries about the future uselessness of the means devoted to this 'pacifying' strategy. (J.S.)

  6. Determination of dispersity of crushed granite

    International Nuclear Information System (INIS)

    Liu Dejun; Fan Xianhua; Zhang Yingjie; Yao Jun; Zhou Duo; Wang Yong

    2004-01-01

    The experimental crushed granite column breakthrough curves, using 99 Tc as spike tracer and 3 H as invariant tracer, are analyzed by different linear regression techniques. Dispersity of crushed granite and retardation factor of 99 TcO 4 - on the crushed granite are determined simultaneously by one linear regression technique. Dispersity of crushed granite is also obtained with 3 H as invariant tracer by the other linear regression technique. The dispersities found by spike source and invariant source methods are compared. The experimental results show that the dispersity found by spike source method is close to that found by invariant source method. It indicates that dispersity is only the characteristic of dispersion medium

  7. Determination of dispersity of crushed granite

    International Nuclear Information System (INIS)

    Liu, D.J.; Fan, X.H.

    2005-01-01

    Experimental crushed granite column breakthrough curves, using 99 Tc as spike tracer and 3 H as invariant tracer, were analyzed by different linear regression techniques. Dispersity of crushed granite and the retardation factor of 99 TcO 4 - on the crushed granite were determined simultaneously by one linear regression. Dispersity of crushed granite was also obtained with 3 H as invariant tracer by the other linear regression. The dispersities found by spike source and invariant source methods are compared. Experimental results show that the dispersity found by the spike source method is close to that found by the invariant source method. This indicates that dispersity is only a characteristic of the dispersion medium. (author)

  8. Integrating individual movement behaviour into dispersal functions.

    Science.gov (United States)

    Heinz, Simone K; Wissel, Christian; Conradt, Larissa; Frank, Karin

    2007-04-21

    Dispersal functions are an important tool for integrating dispersal into complex models of population and metapopulation dynamics. Most approaches in the literature are very simple, with the dispersal functions containing only one or two parameters which summarise all the effects of movement behaviour as for example different movement patterns or different perceptual abilities. The summarising nature of these parameters makes assessing the effect of one particular behavioural aspect difficult. We present a way of integrating movement behavioural parameters into a particular dispersal function in a simple way. Using a spatial individual-based simulation model for simulating different movement behaviours, we derive fitting functions for the functional relationship between the parameters of the dispersal function and several details of movement behaviour. This is done for three different movement patterns (loops, Archimedean spirals, random walk). Additionally, we provide measures which characterise the shape of the dispersal function and are interpretable in terms of landscape connectivity. This allows an ecological interpretation of the relationships found.

  9. Single-particle dispersion in compressible turbulence

    Science.gov (United States)

    Zhang, Qingqing; Xiao, Zuoli

    2018-04-01

    Single-particle dispersion statistics in compressible box turbulence are studied using direct numerical simulation. Focus is placed on the detailed discussion of effects of the particle Stokes number and turbulent Mach number, as well as the forcing type. When solenoidal forcing is adopted, it is found that the single-particle dispersion undergoes a transition from the ballistic regime at short times to the diffusive regime at long times, in agreement with Taylor's particle dispersion argument. The strongest dispersion of heavy particles is announced when the Stokes number is of order 1, which is similar to the scenario in incompressible turbulence. The dispersion tends to be suppressed as the Mach number increases. When hybrid solenoidal and compressive forcing at a ratio of 1/2 is employed, the flow field shows apparent anisotropic property, characterized by the appearance of large shock wave structures. Accordingly, the single-particle dispersion shows extremely different behavior from the solenoidal forcing case.

  10. Site development

    International Nuclear Information System (INIS)

    Gaynor, R.K.

    1989-01-01

    Development of a low-level radioactive waste land disposal facility is little different than any industrial development of similar scope. Consideration must be made for normal business and operations management, security, facility maintenance, traffic control and necessary amenities for personnel. The item specific to the low-level waste site is the handling of radioactive waste materials and the regulatory and environmental protection procedures that must be planned for and accomodated in the site design and development. Each of these elements and the facility as a whole must be designed to be compatible with local land use plans, available transportation and support services, and the social and economic goals of the local community. Plans should also be made for quality control and orderly construction. This chapter deals with those aspects of the facility, its design and construction which are integral parts to the overall performance of the site

  11. Dispersal and individual quality in a long lived species

    Science.gov (United States)

    Cam, E.; Monnat, J.-Y.; Royle, J. Andrew

    2004-01-01

    The idea of differences in individual quality has been put forward in numerous long-term studies in long-lived species to explain differences in lifetime production among individuals. Despite the important role of individual heterogeneity in vital rates in demography, population dynamics and life history theory, the idea of 'individual quality' is elusive. It is sometimes assumed to be a static or dynamic individual characteristic. When considered as a dynamic trait, it is sometimes assumed to vary deterministically or stochastically, or to be confounded with the characteristics of the habitat. We addressed heterogeneity in reproductive performance among individuals established in higher-quality habitat in a long-lived seabird species. We used approaches to statistical inference based on individual random effects permitting quantification of heterogeneity in populations and assessment of individual variation from the population mean. We found evidence of heterogeneity in breeding probability, not success probability. We assessed the influence of dispersal on individual reproductive potential. Dispersal is likely to be destabilizing in species with high site and mate fidelity. We detected heterogeneity after dispersal, not before. Individuals may perform well regardless of quality before destabilization, including those that recruited in higher-quality habitat by chance, but only higher-quality individuals may be able to overcome the consequences of dispersal. Importantly, results differed when accounting for individual heterogeneity (an increase in mean breeding probability when individuals dispersed), or not (a decrease in mean breeding probability). In the latter case, the decrease in mean breeding probability may result from a substantial decrease in breeding probability in a few individuals and a slight increase in others. In other words, the pattern observed at the population mean level may not reflect what happens in the majority of individuals.

  12. Proliferation of group II introns in the chloroplast genome of the green alga Oedocladium carolinianum (Chlorophyceae

    Directory of Open Access Journals (Sweden)

    Jean-Simon Brouard

    2016-10-01

    longer and dispersed repeats are more abundant, but a smaller fraction of the Oedocladium genome is occupied by introns. Six additional group II introns are present, five of which lack ORFs and carry highly similar sequences to that of the ORF-less IIA intron shared with Oedogonium. Secondary structure analysis of the group IIA introns disclosed marked differences in the exon-binding sites; however, each intron showed perfect or nearly perfect base pairing interactions with its target site. Discussion Our results suggest that chloroplast genes rearrange more slowly in the Oedogoniales than in the Chaetophorales and raise questions as to what was the nature of the foreign coding sequences in the IR of the common ancestor of the Oedogoniales. They provide the first evidence for intragenomic proliferation of group IIA introns in the Viridiplantae, revealing that intron spread in the Oedocladium lineage likely occurred by retrohoming after sequence divergence of the exon-binding sites.

  13. Functionalization of surfactant wrapped graphenenanosheets with alkylazides for enhanced dispersibility

    Science.gov (United States)

    Vadukumpully, Sajini; Gupta, Jhinuk; Zhang, Yongping; Xu, Guo Qin; Valiyaveettil, Suresh

    2011-01-01

    A facile and simple approach for the covalent functionalization of surfactant wrapped graphene sheets is described. The approach involves functionalization of dispersible graphene sheets with various alkylazides and 11-azidoundecanoic acid proved the best azide for enhanced dispersibility. The functionalization was confirmed by infrared spectroscopy and scanning tunneling microscopy. The free carboxylic acidgroups can bind to gold nanoparticles, which were introduced as markers for the reactive sites. The interaction between gold nanoparticles and the graphene sheets was followed by UV-vis spectroscopy. The gold nanoparticle-graphene composite was characterized by transmission electron microscopy and atomic force microscopy, demonstrating the uniform distribution of gold nanoparticles all over the surface. Our results open the possibility to control the functionalization on graphene in the construction of composite nanomaterials.A facile and simple approach for the covalent functionalization of surfactant wrapped graphene sheets is described. The approach involves functionalization of dispersible graphene sheets with various alkylazides and 11-azidoundecanoic acid proved the best azide for enhanced dispersibility. The functionalization was confirmed by infrared spectroscopy and scanning tunneling microscopy. The free carboxylic acidgroups can bind to gold nanoparticles, which were introduced as markers for the reactive sites. The interaction between gold nanoparticles and the graphene sheets was followed by UV-vis spectroscopy. The gold nanoparticle-graphene composite was characterized by transmission electron microscopy and atomic force microscopy, demonstrating the uniform distribution of gold nanoparticles all over the surface. Our results open the possibility to control the functionalization on graphene in the construction of composite nanomaterials. Electronic Supplementary Information (ESI) available: Synthesis and characterization details of dodecylazide

  14. Site Practice

    DEFF Research Database (Denmark)

    Wahedi, Haseebullah

    2016-01-01

    different practices in the construction phase. The research is based on an ethnographic study of a case in Denmark. The empirical data were collected through direct observations and semi-structured interviews with site managers, contract managers, foremen and craftsmen. Findings revealed...... that the construction phase comprises several communities and practices, leading to various uses of the drawings. The results indicated that the craftsmen used drawings to position themselves in the correct location, and that the site managers and contract managers used them as management tools and legal documents...

  15. Membranes as separators of dispersed emulsion phases

    OpenAIRE

    Lefferts, A.G.

    1997-01-01

    The reuse or discharge of industrial waste waters, containing small fractions of dispersed oil, requires a purification treatment for which membranes can be used. If only little oil is present, removal of the dispersed phase might be preferable to the more commonly applied removal of the continuous phase. For this purpose dispersed phase separators can be applied, which combine the features of conventional coalescers and membrane filtration. The membrane surface promotes coalescence ...

  16. Formulation of disperse systems science and technology

    CERN Document Server

    Tadros, Tharwat F

    2014-01-01

    This book presents comprehensively the science and technology behind the formulation of disperse systems like emulsions, suspensions, foams and others. Starting with a general introduction, the book covers a broad range of topics like the role of different classes of surfactants, stability of disperse systems, formulation of different dispersions, evaluation of formulations and many more. Many examples are included, too. Written by the experienced author and editor Tharwart Tadros, this book is indispensable for every scientist working in the field.

  17. Key factors for UV curable pigment dispersions

    International Nuclear Information System (INIS)

    Magny, B.; Pezron, E.; Ciceron, P.H.; Askienazy, A.

    1999-01-01

    UV oligomers with good pigment dispersion are needed to allow good formulation flexibility and possibility to apply thinner films. Pigment dispersion mainly depends on three phenomena: the wetting of agglomerates, the breakage of agglomerates by mechanical stress and the stabilization of smaller agglomerates and primary particles against flocculation. It has been shown that oligomers with low viscosity and low surface tension induce a good pigment wetting. Examples of monomers and oligomers for good pigment dispersion are given

  18. Liquid agents for dispersion of hard alloys

    International Nuclear Information System (INIS)

    Putintseva, M.N.

    2006-01-01

    Effects of dispersant properties on granulometric, chemical, and phase composition of the products of WC hard alloy electroerosion are considered. It is established that an increase of liquid dispersant permittivity results in enhanced powder dispersity, and an increase of boiling temperature and kinematic viscosity of a hydrocarbon liquid promotes a carbon loss from WC and intensifies pyrolysis of the liquid.On electroerosion of WC base hard alloy in oil a powder particle consists of b-WC+W 2 C phases, in kerosine - of a-WC+b-WC, in distilled water - of W+W 2 C. The viscosity of liquid dispersants practically has no effect on powder particle size [ru

  19. Effectiveness of dispersants on thick oil slicks

    International Nuclear Information System (INIS)

    Ross, S.; Belore, R.

    1993-01-01

    Experiments were conducted to determine the relationship between dispersant effectiveness and oil slick thickness, and thereby determine the optimum time for applying dispersant onto spilled oil at sea. Tests were completed at a lab-scale level by varying the three parameters of oil type, dispersant application, and oil thickness. The tests were intended to be comparative only. The primary oils used were Alberta sweet mix blend and Hibernia B-27 crude. The dispersant, Corexit 9527, was applied either premixed with the oil, dropwise in one application, or dropwise in multiple applications to simulate a multi-hit aircraft operation. The apparatus used in the experiment was an oscillating hoop tank, with oil-containing rings used to obtain and maintain uniform slick thickness. The results indicate that the effectiveness potential of a chemical dispersant does not decrease as slick thickness increases. In fact, results of the tests involving Hibernia oil suggest that oils that tend to herd easily would be treated more effectively if dispersant were applied when the oil was relatively thick (1 mm or greater) to avoid herding problems. The oil slicks premixed with dispersant did not disperse well in the thick oil tests, not because of dispersant-oil interaction problems but because of reduced mixing energy. 6 refs., 4 figs., 1 tab

  20. Modelling airborne dispersion of coarse particulate material

    International Nuclear Information System (INIS)

    Apsley, D.D.

    1989-03-01

    Methods of modelling the airborne dispersion and deposition of coarse particulates are presented, with the emphasis on the heavy particles identified as possible constituents of releases from damaged AGR fuel. The first part of this report establishes the physical characteristics of the irradiated particulate in airborne emissions from AGR stations. The second part is less specific and describes procedures for extending current dispersion/deposition models to incorporate a coarse particulate component: the adjustment to plume spread parameters, dispersion from elevated sources and dispersion in conjunction with building effects and plume rise. (author)

  1. Entrapped Sediments as a Source of Phosphorus in Epilithic Cyanobacterial Proliferations in Low Nutrient Rivers

    Science.gov (United States)

    Wood, Susanna A.; Depree, Craig; Brown, Logan; McAllister, Tara; Hawes, Ian

    2015-01-01

    Proliferations of the benthic mat-forming cyanobacteria Phormidium have been reported in rivers worldwide. Phormidium commonly produces natural toxins which pose a health risk to animal and humans. Recent field studies in New Zealand identified that sites with Phormidium proliferations consistently have low concentrations of water column dissolved reactive phosphorus (DRP). Unlike other river periphyton, Phormidium mats are thick and cohesive, with water and fine sediment trapped in a mucilaginous matrix. We hypothesized that daytime photosynthetic activity would elevate pH inside the mats, and/or night time respiration would reduce dissolved oxygen. Either condition could be sufficient to facilitate desorption of phosphates from sediment incorporated within mats, thus allowing Phormidium to utilize it for growth. Using microelectrodes, optodes and pulse amplitude modulation fluorometry we demonstrated that photosynthetic activity results in elevated pH (>9) during daytime, and that night-time respiration causes oxygen depletion (river water and this, together with elevated concentrations of elements, including iron, suggest phosphorus release from entrapped sediment. Sequential extraction of phosphorus from trapped sediment was used to investigate the role of sediment at sites on the Mangatainoka River (New Zealand) with and without Phormidium proliferations. Deposition of fine sediment (sediment can provide a source of phosphorus to support Phormidium growth and proliferation. PMID:26479491

  2. Cell proliferation and ageing in mouse colon

    International Nuclear Information System (INIS)

    Hamilton, E.; Franks, L.M.

    1980-01-01

    Cell kinetic parameters in the descending colon of unirradiated mice, 3-30-months-old were compared with those in mice irradiated repeatedly from the age of 6 or 24 months. The latter animals were given 1250 rad local X-irradiation to the colon every 6 weeks. Dose-survival curves showed the colon crypts of 6 and 24-months-old mice were similarly radiosensitive. In unirradiated mice the number of crypts per colon section decreased significantly at 30 months, but no significant age-related changes were seen in crypt size or labelling index (LI). Cell proliferation returned to control levels within 6 weeks of each X-ray dose and remained at this level for 20 weeks after the final dose. Later, cell proliferation in the irradiated colon fell significantly below control. A total of 6 or 7 doses each of 1250 rad produced only 1 colon carcinoma amongst 50 mice kept until they died. (author)

  3. Ki67 and proliferation in breast cancer.

    Science.gov (United States)

    Pathmanathan, Nirmala; Balleine, Rosemary L

    2013-06-01

    New approaches to the prognostic assessment of breast cancer have come from molecular profiling studies. A major feature of this work has been to emphasise the importance of cancer cell proliferation as a key discriminative indicator of recurrence risk for oestrogen receptor positive breast cancer in particular. Mitotic count scoring, as a component of histopathological grade, has long formed part of a routine evaluation of breast cancer biology. However, there is an increasingly compelling case to include a specific proliferation score in breast cancer pathology reports based on expression of the cell cycle regulated protein Ki67. Immunohistochemical staining for Ki67 is a widely available and economical test with good tolerance of pre-analytical variations and staining conditions. However, there is currently no evidence based protocol established to derive a reliable and informative Ki67 score for routine clinical use. In this circumstance, pathologists must establish a standardised framework for scoring Ki67 and communicating results to a multidisciplinary team.

  4. Wp specific methylation of highly proliferated LCLs

    International Nuclear Information System (INIS)

    Park, Jung-Hoon; Jeon, Jae-Pil; Shim, Sung-Mi; Nam, Hye-Young; Kim, Joon-Woo; Han, Bok-Ghee; Lee, Suman

    2007-01-01

    The epigenetic regulation of viral genes may be important for the life cycle of EBV. We determined the methylation status of three viral promoters (Wp, Cp, Qp) from EBV B-lymphoblastoid cell lines (LCLs) by pyrosequencing. Our pyrosequencing data showed that the CpG region of Wp was methylated, but the others were not. Interestingly, Wp methylation was increased with proliferation of LCLs. Wp methylation was as high as 74.9% in late-passage LCLs, but 25.6% in early-passage LCLs. From two Burkitt's lymphoma cell lines, Wp specific hypermethylation was also found (>80%). Interestingly, the expression of EBNA2 gene which located directly next to Wp was associated with its methylation. Our data suggested that Wp specific methylation may be important for the indicator of the proliferation status of LCLs, and the epigenetic viral gene regulation of EBNA2 gene by Wp should be further defined possibly with other biological processes

  5. HTGR strategy for reduced proliferation potential

    International Nuclear Information System (INIS)

    Stewart, H.B.; Dahlberg, R.C.

    1978-01-01

    The HTGR stratregy for reduced proliferation potential is one aspect of a potential broader nuclear strategy aimed primarily toward a transition nuclear period between today's uranium-consumption reactors and the long-range balanced system of breeder and advanced near-breeder reactors. In particular, the normal commerce of U-233 could be made acceptable by: (a) dependence on the gamma radiation from U-232 daughter products, (b) enhancement of that radioactivity by incomplete fission-product decontamination of the bred-fuel, or (c) denaturing of the U-233 with U-238. These approaches would, of course, supplement institutional initiatives to improve proliferation resistance such as the collocation of facilities and the establishment of secure energy centers. 6 refs

  6. Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

    Science.gov (United States)

    Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

    2015-08-24

    Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Risk assessment of alternative proliferation routes

    International Nuclear Information System (INIS)

    Ahmed, S.; Husseiny, A.A.

    1982-01-01

    Multi-Attribute Decision Theory is applied to rank II alternative routes to nuclear proliferation in order of difficulty in acquiring nuclear weapons by nonnuclear countries. The method is based on reducing the various variables affecting the decision to a single function providing a measure for the proliferation route. The results indicate that the most difficult route to obtain atomic weapons is through nuclear power reactors, specifically the liquid-metal fast breeder reactor, heavy water Canada deuterium uranium reactor, and light water reactors such as boiling water and pressurized water reactors. The easiest routes are supercritical centrifuge isotope separation, laser isotope separation, and research reactor. However, nonnuclear routes available that result in substantial damage to life and property are easier than any nuclear route

  8. Polymeric dispersants for control of steam generator fouling

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; Klimas, S.J.; Lepine, L.; Turner, C.W.

    1999-05-01

    Fouling of steam generators by corrosion products from the feedtrain leads to loss of heat-transfer efficiency, disturbances in thermalhydraulics, and potential corrosion problems resulting from the development of sites for localized accumulation of aggressive chemicals. This report summarizes studies of the use of polymeric dispersants for the control of fouling, which were conducted at the Chalk River Laboratories. High-temperature settling studies on magnetite suspensions were performed to screen available generic dispersants, and the dispersants were ranked in terms of their dispersion efficiency; polyacrylic acid (PAA) and the phosphonate, HEDP, were ranked as the most efficient. Polyacrylic acid was considered more suitable than HEDP for nuclear steam generators, and more emphasis was given to the former in these studies. The dispersants had no effect on the particle deposition rates under single-phase forced-convective flow, but did reduce the deposition rates under flow-boiling conditions. The extent to which the deposition rates were reduced increased in proportion to the dispersant concentration. Preliminary corrosion tests indicated that pitting or general corrosion of steam generator tube materials in the presence of PAA was negligible. Corrosion of carbon steel, although higher in a magnetite-packed crevice under heat flux than in bulk water, was lower in the presence of PAA than in its absence. Some impurities (e.g., sulphate, sodium) were observed in commercially available PAA products at small, though significant concentrations, making these products unacceptable for use in nuclear plants. However, the PAA could be purified by ion exchange. Preliminary experiments, to assess the thermal stability of PAA at steam generator operating temperature, showed the polymer to break down in deaerated solutions and under argon cover to give hydrogen and carbon dioxide as the two major products in the gas phase and variable concentrations of acetate and formate

  9. Site selection

    CERN Multimedia

    CERN PhotoLab

    1968-01-01

    To help resolve the problem of site selection for the proposed 300 GeV machine, the Council selected "three wise men" (left to right, J H Bannier of the Netherlands, A Chavanne of Switzerland and L K Boggild of Denmark).

  10. Site Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A

    2001-04-01

    The objectives, the programme, and the achievements of the Site Restoration Department of SCK-CEN in 2000 are summarised. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and activities related to the management of decommissioning projects. The department provides consultancy and services to external organisations.

  11. Site Restoration

    International Nuclear Information System (INIS)

    Noynaert, L.; Bruggeman, A.; Cornelissen, R.; Massaut, V.; Rahier, A.

    2001-01-01

    The objectives, the programme, and the achievements of the Site Restoration Department of SCK-CEN in 2000 are summarised. Main activities include the decommissioning of the BR3 PWR-reactor as well as other clean-up activities, projects on waste minimisation and activities related to the management of decommissioning projects. The department provides consultancy and services to external organisations

  12. IAEA safeguards and non-proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Harry, R J.S.

    1995-02-01

    An overview is given of efforts to contain the nuclear weapons proliferation during half a century of man-controlled nuclear fission. An initial policy of denial did not work, a following period of cooperation needed a gradual strengthening of international assurances on the peaceful character of the flourishing use of nuclear techniques for power generation and of other applications. The focus of the nuclear weapon proliferation concern changed from the highly developed states to developing states. The Non-Proliferation Treaty laid the basis for a unique system of voluntarily accepted international inspections to verify the peaceful use of nuclear energy. The IAEA got the task to implement this `Full Scope Safeguards` on all nuclear material and all nuclear activities in the non-nuclear weapon states. Thanks to the structure of the IAEA, in which both proponent and states with a critical attitude take part in the decision making process on the IAEA execution of its tasks, a balanced, and widely acceptable system emerged. International developments necessitated additional improvements of the non-proliferation system. The increase of strength of sub-national groups triggered international cooperation on physical protection, about a quarter of a century ago. More recently, it appeared that NPT states with assumed nuclear weapon ambitions operated in the margins between the interpretation of IAEA safeguards and the spirit and purpose of NPT. Improvements of the IAEA safeguards and a stronger cooperation between states, including the constraints which exporting states have imposed on nuclear supplies, strengthen the safeguards system. The important reductions in the two largest nuclear weapon arsenals lead, together with the delay in the fast breeder implementation, to large stockpiles of nuclear weapon usable materials. Also in this areas new internationally credible assurances have to be obtained, that these materials will never return to nuclear weapon applications.

  13. Non-proliferation efforts in South Asia

    International Nuclear Information System (INIS)

    Chellaney, B.

    1994-01-01

    Southern Asia is one of the most volatile regions in the world because of inter-State and intra-State conflicts. Security in the region highly depends on the rival capabilities of the involved states, Pakistan, India, China. Increased Confidence building and nuclear transparency are becoming more significant issues in attaining stability in the region, although non-proliferation efforts in this region have attained little headway

  14. IAEA safeguards and non-proliferation

    International Nuclear Information System (INIS)

    Harry, R.J.S.

    1995-02-01

    An overview is given of the efforts to contain the nuclear weapons proliferation during half a century of man-controlled nuclear fission. An initial policy of denial did not work, a following period of cooperation needed a gradual strengthening of international assurances on the exclusively peaceful character of the flourishing use of nuclear techniques for power generation and of other applications. The focus of the nuclear weapon proliferation concern changed from the highly developed states to developing states. The Non-Proliferation Treaty laid the basis for a unique system of voluntarily accepted international inspections to verify the peaceful use of nuclear energy. The IAEA got the task to implement this 'Full Scope Safeguards' on all nuclear material and all nuclear activities in the non-nuclear weapon states. Thanks to the structure of the IAEA, in which both proponent and states with a critical attitude take part in the decision making process on the IAEA execution of its tasks, a balanced, and widely acceptable system emerged. International developments necessitated additional improvements of the non-proliferation system. The increase of strength of sub-national groups triggered international cooperation on physical protection, about a quarter of a century ago. More recently, it appeared that NPT states with assumed nuclear weapon ambitions operated in the margins between the interpretation of IAEA safeguards and the spirit and purpose of NPT. Improvements of the IAEA safeguards and a stronger cooperation between states, including the constraints which exporting states have imposed on nuclear supplies, strengthen the safeguards system. The important reductions in the two largest nuclear weapon arsenals lead, together with the delay in the fast breeder implementation, to large stockpiles of nuclear weapon usable materials. Also in this areas new internationally credible assurances have to be obtained, that these materials will never return to nuclear

  15. Note: How Does Product Proliferation Affect Responsiveness?

    OpenAIRE

    Diwakar Gupta; Mandyam M. Srinivasan

    1998-01-01

    In this note we consider some strategies that a manufacturing firm may use to deal with an increase in the variety of products it offers. We indicate how alternate strategies for dealing with product proliferation impact the firm's responsiveness, measured in terms of average production lead time and average work-in-process inventory. Focusing on the make-to-order environment and using queueing models, we derive conditions under which an increase in product variety can improve both individual...

  16. Security Guarantees and Nuclear Non-Proliferation

    International Nuclear Information System (INIS)

    Bruno Tertrais

    2011-01-01

    The purpose of this paper is to discuss the value of 'security guarantees', that is, positive security assurances that include a formal or informal defense commitment, in preventing nuclear proliferation. It demonstrates that such guarantees have proven to be a very effective instrument in preventing States from going nuclear. It would thus seem logical to reinforce or extend them. However, this path is fraught with obstacles and dilemmas

  17. Security Guarantees and Nuclear Non-Proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Bruno Tertrais

    2011-07-01

    The purpose of this paper is to discuss the value of 'security guarantees', that is, positive security assurances that include a formal or informal defense commitment, in preventing nuclear proliferation. It demonstrates that such guarantees have proven to be a very effective instrument in preventing States from going nuclear. It would thus seem logical to reinforce or extend them. However, this path is fraught with obstacles and dilemmas

  18. Plutonium Proliferation: The Achilles Heel of Disarmament

    International Nuclear Information System (INIS)

    Leventhal, Paul

    2001-01-01

    Plutonium is a byproduct of nuclear fission, and it is produced at the rate of about 70 metric tons a year in the world's nuclear power reactors. Concerns about civilian plutonium ran high in the 1970s and prompted enactment of the Nuclear Non-Proliferation Act of 1978 to give the United States a veto over separating plutonium from U.S.-supplied uranium fuel. Over the years, however, so-called reactor-grade plutonium has become the orphan issue of nuclear non-proliferation, largely as a consequence of pressures from plutonium-separating countries. The demise of the fast breeder reactor and the reluctance of utilities to introduce plutonium fuel in light-water reactors have resulted in large surpluses of civilian, weapons-usable plutonium, which now approach in size the 250 tons of military plutonium in the world. Yet reprocessing of spent fuel for recovery and use of plutonium proceeds apace outside the United States and threatens to overwhelm safeguards and security measures for keeping this material out of the hands of nations and terrorists for weapons. A number of historical and current developments are reviewed to demonstrate that plutonium commerce is undercutting efforts both to stop the spread of nuclear weapons and to work toward eliminating existing nuclear arsenals. These developments include the breakdown of U.S. anti-plutonium policy, the production of nuclear weapons by India with Atoms-for-Peace plutonium, the U.S.-Russian plan to introduce excess military plutonium as fuel in civilian power reactors, the failure to include civilian plutonium and bomb-grade uranium in the proposed Fissile Material Cutoff Treaty, and the perception of emerging proliferation threats as the rationale for development of a ballistic missile defense system. Finally, immobilization of separated plutonium in high-level waste is explored as a proliferation-resistant and disarmament-friendly solution for eliminating excess stocks of civilian and military plutonium.

  19. Director`s series on proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, K.C.; Price, M.E. [eds.

    1994-10-17

    This series is an occasional publication of essays on the topics of nuclear, chemical, biological, and missile proliferation. Essays contained in this document include: Key issues on NPT renewal and extension, Africa and nuclear nonproliferation, Kenya`s views on the NPT, Prospects for establishing a zone free of weapons of mass destruction in the middle east, effects of a special nuclear weapon materials cut-off convention, and The UK view of NPT renewal.

  20. Proliferation resistance assessment of nuclear systems

    International Nuclear Information System (INIS)

    1978-09-01

    The paper focuses on examining the degree to which nuclear systems could be used to acquire nuclear weapons material. It establishes a framework for proliferation resistance assessment and illustrates its applicability through an analysis of reference systems for once-through cycles, breeder cycles and thermal recycle. On a more tentative basis, the approach is applied to various alternative technical and institutional measures. This paper was also submitted to Working Groups 5 and 8

  1. Proliferation Persuasion. Coercive Bargaining with Nuclear Technology

    Energy Technology Data Exchange (ETDEWEB)

    Volpe, Tristan A. [George Washington Univ., Washington, DC (United States)

    2015-08-31

    Why do states wait for prolonged periods of time with the technical capacity to produce nuclear weapons? Only a handful of countries have ever acquired the sensitive nuclear fuel cycle technology needed to produce fissile material for nuclear weapons. Yet the enduring trend over the last five decades is for these states to delay or forgo exercising the nuclear weapons option provided by uranium enrichment or plutonium reprocessing capabilities. I show that states pause at this threshold stage because they use nuclear technology to bargain for concessions from both allies and adversaries. But when does nuclear latency offer bargaining benefits? My central argument is that challengers must surmount a dilemma to make coercive diplomacy work: the more they threaten to proliferate, the harder it becomes to reassure others that compliance will be rewarded with nuclear restraint. I identify a range of mechanisms able to solve this credibility problem, from arms control over breakout capacity to third party mediation and confidence building measures. Since each step towards the bomb raises the costs of implementing these policies, a state hits a sweet spot when it first acquires enrichment and/or reprocessing (ENR) technology. Subsequent increases in proliferation capability generate diminishing returns at the bargaining table for two reasons: the state must go to greater lengths to make a credible nonproliferation promise, and nuclear programs exhibit considerable path dependency as they mature over time. Contrary to the conventional wisdom about power in world politics, less nuclear latency thereby yields more coercive threat advantages. I marshal new primary source evidence from archives and interviews to identify episodes in the historical record when states made clear decisions to use ENR technology as a bargaining chip, and employ this theory of proliferation persuasion to explain how Japan, North Korea, and Iran succeeded and failed to barter concessions from the

  2. Sovereignty and non-proliferation policy

    International Nuclear Information System (INIS)

    Kimminich, O.

    1990-01-01

    The Non-Proliferation Treaty seems to violate the fundamental principle of the quality of the states. However, if interpreted in the light of the latest developments of the international law, it is possible to justify the discriminations which it imposes on the non-nuclear states. A crucial point is the implementation of article VI by the nuclear states. If the latter procrastinate in nuclear disarmament the whole NPT-regime will collapse. (orig.) [de

  3. INFCE and US non-proliferation policy

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, W H [Library of Congress, Washington, DC (USA)

    1980-12-01

    The International Fuel Cycle Evaluation (INFCE), which published its final reports in February 1980 produced a massive international effort of a kind never before seen. Over a period of two years its eight working groups held 61 meetings involving 519 experts from 46 countries and five international organizations. This article outlines the background and structure of INFCE and discusses how its recommendations diverge from US non-proliferation policy.

  4. Enhancement by Enlargement: The Proliferation Security Initiative

    Science.gov (United States)

    2008-01-01

    Minister Mahathir Mohammad. In any event, Malaysia’s expressions of common interest with the United States in cooperative efforts to combat terrorism...instances 10 The sharp change in the current Malaysian government’s stance toward cooperation with the United States from that of the preceding, Mahathir ...preceding prime minister, Mahathir , Malaysia was implicated in the proliferation network of Pakistan’s A. Q. Khan. As part of that network

  5. DISPERSION OF GLYPHOSATE IN SOILS UNDERGOING EROSION

    Directory of Open Access Journals (Sweden)

    Gorana Todorovic Rampazzo

    2010-08-01

    Full Text Available Different physical, chemical and biological processes influence the behaviour of organic contaminants in soils. A better understanding of the organic pollutant behaviour in soils would improve the environmental protection. One possible way for better attenuation of the risk of pollution in agriculture can be achieved through ta better-specified pesticide management based on the adaptation of the pesticide type and application rates to the specific environmental characteristics of the area of application. Nowadays, one of the actually most applied herbicide world wide is glyphosate. Glyphosate is highly water soluble and traces have been found in surface and groundwater systems. For a better understanding of the natural influence of erosion processes on glyphosate behaviour and dispersion under heavy rain conditions after application in the field, two erosion simulation experiments were conducted on two different locations in Austria with completely different soil types in September 2008. The results of the experiments showed that under normal practical conditions (e.g. no rainfall is expected immediatly after application, the potential adsorption capacity of the Kirchberg soil (Stagnic Cambisol, with about 16.000 ppm Fe-oxides is confirmed compared to the low adsorption Chernosem soil (about 8.000 ppm pedogenic Fe-oxides.  Considering the enormous difference in the run-off amounts between the two sites Pixendorf and Kirchberg soils it can be concluded how important the soil structural conditions and vegetation type and cover are for the risks of erosion and, as a consequence, pollution of neighbouring waters. In the rainfall experiments under comparable simulation conditions, the amount of run-off was about 10 times higher at Kirchberg, owing to its better infiltration rate, than at the Pixendorf site. Moreover, the total loss of glyphosate (NT+CT through run-off at the Kirchberg site was more than double that at Pixendorf, which confirms the

  6. Future technology challenges in non-proliferation

    International Nuclear Information System (INIS)

    Richardson, J.H.

    2004-01-01

    Radiation detection technologies are an important tool in the prevention of proliferation. A variety of new developments have enabled enhanced performance in terms of energy resolution, spatial resolution, predictive modeling and simulation, active interrogation, and ease of operation and deployment in the field. For example, various gamma ray imaging approaches are being explored to combine spatial resolution with background suppression in order to enhance sensitivity at reasonable standoff distances and acquisition times. New materials and approaches are being developed in order to provide adequate energy resolution in field use without the necessity for liquid nitrogen. Finally, different detectors combined into distributed networks offer promise for detection and tracking of radioactive materials. As the world moves into the 21st century, the possibility of greater reliance on nuclear energy will impose additional technical requirements to prevent proliferation. In addition to proliferation resistant reactors, a careful examination of the various possible fuel cycles from cradle to grave will provide additional technical and nonproliferation challenges in the areas of conversion, enrichment, transportation, recycling and waste disposal. Radiation detection technology and information management have a prominent role in any future global regime for nonproliferation beyond the current Advanced Protocol. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. (author)

  7. NSAIDs and Cell Proliferation in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Raj Ettarh

    2010-06-01

    Full Text Available Colon cancer is common worldwide and accounts for significant morbidity and mortality in patients. Fortunately, epidemiological studies have demonstrated that continuous therapy with NSAIDs offers real promise of chemoprevention and adjunct therapy for colon cancer patients. Tumour growth is the result of complex regulation that determines the balance between cell proliferation and cell death. How NSAIDs affect this balance is important for understanding and improving treatment strategies and drug effectiveness. NSAIDs inhibit proliferation and impair the growth of colon cancer cell lines when tested in culture in vitro and many NSAIDs also prevent tumorigenesis and reduce tumour growth in animal models and in patients, but the relationship to inhibition of tumour cell proliferation is less convincing, principally due to gaps in the available data. High concentrations of NSAIDs are required in vitro to achieve cancer cell inhibition and growth retardation at varying time-points following treatment. However, the results from studies with colon cancer cell xenografts are promising and, together with better comparative data on anti-proliferative NSAID concentrations and doses (for in vitro and in vivo administration, could provide more information to improve our understanding of the relationships between these agents, dose and dosing regimen, and cellular environment.

  8. Elements of safety and non proliferation

    International Nuclear Information System (INIS)

    Jalouneix, Jean; Aurelle, Jacques; Funk, Pierre; Ladsous, David; Bon Nguyen, Romuald; Goue, Georges; Lefevre, Odile

    2015-01-01

    This book on nuclear safety and non proliferation is based on knowledge and expertise of the IRSN. The first chapter addresses the safety of nuclear materials, of their installations and of their transportations. It proposes some contextual elements, presents the general guidelines of the French nuclear safety arrangement, the approach to take risks into account, the involved governmental and public bodies, the legal framework, and the protection and control arrangement (in terms of planning of safety-related activities, in terms of operator obligations, in terms of exercises and management crisis). The second part addresses the safety of radioactive sources: context (peculiarity, losses and thefts), international framework (source categories, Euratom directive), and the French organisation. The third chapter addresses nuclear non proliferation: historical background (creation and role of the IAEA and of the EAEC, definitions), principle of statements, inspection process, and French organisation (legal framework, governmental bodies, the IRSN). The last chapter addresses the issue of chemical non proliferation: historical background, international context (Convention on chemical weapons, organisation for their ban), and the French organisation

  9. Proliferation networks: between Sopranos and Supermarket

    International Nuclear Information System (INIS)

    Schlumberger, Guillaume; Gruselle, Bruno

    2006-01-01

    One success in the struggle against proliferation during the last decade has been that Western countries have reinforced mechanisms for control over exports of goods and technologies intended for the perfection of weapons of mass destruction. These new constraints have probably resulted in the appearance of a genuine proliferation economy, partly underground, organized around contacts between acquisition and sales networks, searching to exploit weaknesses in existing control systems to obtain wanted goods and technologies. This phenomenon is particularly worrying, because the level of technical skills attained by some suppliers is sufficiently high to guarantee that their customers will have a functional product satisfying their demand. Apart from systematic exploitation of vulnerabilities in export control systems, the capacity of these networks of suppliers to conduct their operations is reinforced by access to technologies and globalization of the market and financial tools. This article is the first of a series of two and explores the operation of these proliferation networks. The second article will be dedicated to an analysis of existing tools or other tools that can be implemented to combat them. (authors)

  10. Uranium dependence and the proliferation problem

    International Nuclear Information System (INIS)

    Jacoby, H.D.

    1977-01-01

    A 20-year ''breathing space'' of adequate uranium supplies is felt to warrant delaying breeder technology until the threat of proliferation can be met with adequate internationally controlled stockpiles and marketing. Although a shift to breeder reactors developed as concern grew over the possibility of depleted uranium reserves, U.S. policy has now reversed this trend in favor of nuclear systems with a lower risk of proliferation. A review of uranium dependence analyzes the fuel cycle, current and projected reserves, reliable enrichment services, and international effects of proliferation and market disruptions. Uranium supply forecasts are more positive now because overstated reactor buildup projections led utilities to order more fuel than they will need until the late 1980s. These surpluses of light-water reactor fuel could be stockpiled at a cost of $20 billion, felt to be a relatively modest figure in terms of the total cost of nuclear power. A stockpile able to meet demand levels could offer the security of domestic supplies with trade opportunities and would retain levels of exploration and extraction. Several strategies for managing stockpiles are possible, but international control is seen as the best way to maintain reliable prices and uniform supply policies for all nations

  11. The motivations of proliferating countries. Final report

    International Nuclear Information System (INIS)

    Archambault, Jean-Claude; Daguzan, Jean-Francois; Pasco, Xavier; Sitt, Bernard

    2006-01-01

    This report is based on previous works made by the GSPP group (GSPP stands for geographic-social-psychological-political) which defined conceptual backgrounds for a new approach to nuclear proliferation, notably by introducing an associated method, the GSPP method, which is used in this study. Thus, this report first presents the GSPP method through its application to the analysis of the decision dynamics in the case of a proliferating State, a discussion of the seven determining factors (national resources, history and strategic context, type of political regime, leader's history and personal typology, international dependencies and alliances, elites and mediators, public opinions), a discussion of the interactions between these factors, an application of the first determining factor, and an application of the GSPP method to the case of biological and chemical proliferation. In the next part, the authors propose sheets which report the application of the method to different countries (Iran, Israel, Iraq, Algeria, Libya, China, India, Pakistan, North and South Korea, Taiwan, Japan, Australia, Indonesia, South Africa). The content and the exploitation of these sheets is then discussed, and the authors address the perspective of development of a GSPP model, notably by using the Maslowe pyramid. They propose an application of this model to the case of Iran

  12. Nuclear non-proliferation: failures and prospects

    International Nuclear Information System (INIS)

    Imai, R.; Press, R.

    1980-01-01

    The objective of this paper is to examine the evolution of combined political and technical attempts to achieve worldwide acceptance of a commitment to non-proliferation, to note failures to date, and to identify essential factors to be satisfied if greater and necessary success is to be achieved in the immediate future. For this it is necessary to separate the realism and unrealism so often involved in discussing the concept of non-proliferation, as defined above, particularly if treated as a moral principle rather than as part of a general security issue reflecting shifts in regional and global stability. The political nature of the non-proliferation problem is underlined by the fact that whereas five nuclear weapon states are currently accepted, any threatened increase in that number is discouraged by every possible peaceful means. This fact combines political acceptance of an existing international situation with a belief that any addition to the present number must lead to international instability. Success in preventing additions may be more readily achieved through political understanding and perhaps some compromises, in particular cases, rather than through seeking a universal solution to a generalized problem

  13. Nuclear power and nuclear weapons proliferation

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    An appropriate non-proliferation treaty should not discriminate among the non-weapon states, but should seek a cooperative approach with all countries seeking nuclear power and willing to accept international safeguards. Near-term proliferation problems, represented by nations already on the threshold of weapon capability, should not be confused with the long-term problem of world-wide nuclear development. The first can be handled with incentives and disincentives imposed on specific countries, while the latter involves the distribution of plutonium on the basis of alternative fuel cycles. To retain world leadership, U.S. efforts along these lines should be to encourage a dialogue between suppliers and recipients and to coordinate the economic and security issues of its own non-proliferation and foreign policies. One option is a U.S. commitment to a multinational fuel storage and reprocessing facility. Technical evaluation and demonstration of alternative fuel cycles to reach an international consensus would be a parallel activity

  14. Laser enrichment: a new path to proliferation

    International Nuclear Information System (INIS)

    Casper, B.M.

    1977-01-01

    The use of lasers to obtain enriched uranium is an easier and cheaper method than methods currently in use. The immediate concern is that it could promote easy access to nuclear weapons by countries that do not presently have them. Mr. Casper feels that the U.S. government is working against itself; while the State Department is seeking to block one path to proliferation, ERDA laboratories are developing new technology that could open another. The proliferation implications have not been factored in a serious way into the decisions to proceed with this research. It is also clear that the United States does not now have a comprehensive policy that deals with all potentially important paths to proliferation, including laser enrichment. Mr. Casper states that there is still time to stop and consider whether laser enrichment should be developed, in light of its broader consequences. But this will not happen if the decisions are left exclusively in the hands of those promoting the technology, the author says. It is just this sort of situation that prompted the creation of several government institutions to provide independent assessments of new technologies. The Office of Technology Assessment, the Nuclear Regulatory Commission, and the Arms Control and Disarmament Agency all have the authority to intervene. Laser enrichment provides a good test of these institutions and of the viability of the concept of technology assessment. The status, benefits and risks, and the policy needed on laser research are discussed

  15. The Non-Proliferation Treaty increases security

    International Nuclear Information System (INIS)

    Kahiluoto, K.

    1995-01-01

    Extension of the Nuclear Non-Proliferation Treaty indefinitely was a historic decision. The Treaty is the most extensive international agreement on security policy to date; now its obligations have become a permanent part of international justice. Moreover, the NPT represents a political and moral obligation. Through the NPT, the international community has made a permanent commitment to restrict the proliferation of nuclear weapons. Increasing pressures will be applied to the few countries still outside the NPT, making it more likely that these countries will eventually change their views. The likelihood of regional bans on nuclear weapons in the Middle East and in Asia, too, will increase. The Treaty promotes the establishment of new nuclear-free zones. The nuclear-free zone in Latin America - the countries covered by the Tlatelolco Treaty - is already very close to its full implementation. Finland is firmly committed to the obligations of the Non-Proliferation Treaty. The NPT Conference of 1995 was among the first international meetings in which Finland participated, and took an active role, as a Member State of the European Union. (orig.)

  16. TWEAK induces liver progenitor cell proliferation

    Science.gov (United States)

    Jakubowski, Aniela; Ambrose, Christine; Parr, Michael; Lincecum, John M.; Wang, Monica Z.; Zheng, Timothy S.; Browning, Beth; Michaelson, Jennifer S.; Baestcher, Manfred; Wang, Bruce; Bissell, D. Montgomery; Burkly, Linda C.

    2005-01-01

    Progenitor (“oval”) cell expansion accompanies many forms of liver injury, including alcohol toxicity and submassive parenchymal necrosis as well as experimental injury models featuring blocked hepatocyte replication. Oval cells can potentially become either hepatocytes or biliary epithelial cells and may be critical to liver regeneration, particularly when hepatocyte replication is impaired. The regulation of oval cell proliferation is incompletely understood. Herein we present evidence that a TNF family member called TWEAK (TNF-like weak inducer of apoptosis) stimulates oval cell proliferation in mouse liver through its receptor Fn14. TWEAK has no effect on mature hepatocytes and thus appears to be selective for oval cells. Transgenic mice overexpressing TWEAK in hepatocytes exhibit periportal oval cell hyperplasia. A similar phenotype was obtained in adult wild-type mice, but not Fn14-null mice, by administering TWEAK-expressing adenovirus. Oval cell expansion induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) was significantly reduced in Fn14-null mice as well as in adult wild-type mice with a blocking anti-TWEAK mAb. Importantly, TWEAK stimulated the proliferation of an oval cell culture model. Finally, we show increased Fn14 expression in chronic hepatitis C and other human liver diseases relative to its expression in normal liver, which suggests a role for the TWEAK/Fn14 pathway in human liver injury. We conclude that TWEAK has a selective mitogenic effect for liver oval cells that distinguishes it from other previously described growth factors. PMID:16110324

  17. GPNMB promotes proliferation of developing eosinophils.

    Science.gov (United States)

    Hwang, Sae Mi; Kang, Jin Hyun; Kim, Bo Kyum; Uhm, Tae Gi; Kim, Hye Jeong; Lee, Hyune-Hwan; Binas, Bert; Chung, Il Yup

    2017-08-01

    Glycoprotein non-metastatic melanoma protein B (GPNMB) is a type I transmembrane protein that is expressed in a wide variety of cell types, including haematopoietic lineages. We previously demonstrated that GPNMB is one of the most highly expressed genes at an early and intermediate stage of eosinophil development. We herein examined GPNMB expression and its possible functional effect using cord blood (CB) CD34+ haematopoietic stem cells differentiating toward eosinophils during a 24-day culture period. Western blot and confocal microscopy analyses showed that GPNMB reached its highest levels at day 12 with most GPNMB-positive cells also expressing major basic protein 1 (MBP1), an eosinophil granule protein. GPNMB declined thereafter, but was still present at an appreciable level at day 24, the time when CB eosinophils most abundantly expressed MBP1 and were thus considered fully differentiated. When the developing CB cells were cultured in the presence of a blocking anti-GPNMB antibody, cell proliferation was significantly reduced. In agreement, ectopic expression of GPNMB in heterologous cells resulted in a significant increase in cell proliferation, while small interfering RNA of GPNMB inhibited the GPNMB-mediated proliferation. Thus, GPNMB is expressed in a temporal manner during eosinophil development and delivers a proliferative signal upon activation. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  18. MicroRNA let-7b regulates neural stem cell proliferation and differentiation by targeting nuclear receptor TLX signaling.

    Science.gov (United States)

    Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Lang, Ming-Fei; Yang, Su; Li, Wendong; Shi, Yanhong

    2010-02-02

    Neural stem cell self-renewal and differentiation is orchestrated by precise control of gene expression involving nuclear receptor TLX. Let-7b, a member of the let-7 microRNA family, is expressed in mammalian brains and exhibits increased expression during neural differentiation. However, the role of let-7b in neural stem cell proliferation and differentiation remains unknown. Here we show that let-7b regulates neural stem cell proliferation and differentiation by targeting the stem cell regulator TLX and the cell cycle regulator cyclin D1. Overexpression of let-7b led to reduced neural stem cell proliferation and increased neural differentiation, whereas antisense knockdown of let-7b resulted in enhanced proliferation of neural stem cells. Moreover, in utero electroporation of let-7b to embryonic mouse brains led to reduced cell cycle progression in neural stem cells. Introducing an expression vector of Tlx or cyclin D1 that lacks the let-7b recognition site rescued let-7b-induced proliferation deficiency, suggesting that both TLX and cyclin D1 are important targets for let-7b-mediated regulation of neural stem cell proliferation. Let-7b, by targeting TLX and cyclin D1, establishes an efficient strategy to control neural stem cell proliferation and differentiation.

  19. Bioavailability as a tool in site management

    NARCIS (Netherlands)

    Harmsen, J.; Naidu, R.

    2013-01-01

    Bioavailability can form the basis for describing potential risks that contaminants pose to the environment and human health, and for determining remedial options to reduce risks of contaminant dispersal and toxicity. In assessments of polluted sites, methods to measure bioavailability can lead to a

  20. The Asian countries and the non-proliferation treaty prorogation

    International Nuclear Information System (INIS)

    Hoffmann, N.

    1995-01-01

    This work deals with the non-proliferation treaty prorogation of Asia. The position of the asian countries under the old non-proliferation treaty is given. It includes the 1968 non-proliferation treaty signatories, the calling in question again and the criticisms revealed by the asian countries. The positions and the open forecasts expressed on the non-proliferation treaty prorogation and the article on the elimination of the nuclear weapons are also given. (O.L.)