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Sample records for radioactive tracer study

  1. Acupuncture meridians demythified. A study using the radioactive tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Simon, J.; Esquerre, J.P.; Guiraud, R.; Guiraud, G.; Lazorthes, Y.

    1988-07-01

    Radioactive trajectories can be visualized by injecting a radioactive tracer, technetium 99 m, at the site of acupuncture points. To determine the exact nature of these trajectories we performed several experiments on healthy volunteers, and our results may be summarized as follows. The target organs of technetium 99 m, and notably the thyroid gland, were always visualized. The circulating radioactivity, visible on scintiscans and confirmed by venous blood counts, was not negligible. The radioactive trajectories we observed were often divided at their starting point and did not extend along the whole length of the acupuncture meridians they might have made visible. The radioactive trajectories disappeared after venous blockade to reappear when the blockade was lifted. Finally, the radioactive trajectories obtained were very similar after injection at the acupuncture point and at a control point. These findings indicate a lymphatic and venous drainage of the radioactive tracer at the site of injection followed by transportation through the veins, rather than visualization of acupuncture meridians as suggested by some authors.

  2. Hydrodynamics of a commercial scale CFB boiler-study with radioactive tracer particles

    DEFF Research Database (Denmark)

    Lin, Weigang; Hansen, Peter F.B.; Dam-Johansen, Kim

    1999-01-01

    This paper presents the experimental results with radioactive tracer particles in an 80 MWth circulating fluidized-bed boiler. Batches of gamma-ray emitting tracer particles were injected into the standpipe. The response curves of the impulse injection were measured by a set of successive...

  3. Study of solid and liquid behavior in large copper flotation cells (130 m2 using radioactive tracers

    Directory of Open Access Journals (Sweden)

    Yianatos J.

    2013-05-01

    Full Text Available The behavior of the solid and liquid phases, in large flotation cells, was characterized by means of the radioactive tracer technique. The use of radioactive tracers enabled the identification of the Residence Time Distribution, of floatable and non-floatable solid, from continuous (on-line measuring at the output streams of the flotation cells. For this study, the proper radioactive tracers were selected and applied in order to characterize the different phases; i.e. for liquid phase Br-82 as Ammonium Bromide, for floatable solid recovered in the concentrate Cu-64, and for non-floatable solid in three particle size classes (coarse: >150 μm, intermediate: 45 μm, and fine: <45 μm, Na-24. The experimental results confirmed the strong effect of particle size on the Residence Time Distribution, and mean residence time of solids in larger flotation cells, and consequently in flotation hydrodynamics. From a hydrodynamic point of view, the experimental data confirmed that a single mechanical flotation cells, of large size, can deviate significantly from perfect mixing. The experimental work was developed in a 130 m3 industrial flotation cell of the rougher circuit at El Teniente Division, Codelco-Chile.

  4. Study of solid and liquid behavior in large copper flotation cells (130 m2) using radioactive tracers

    Science.gov (United States)

    Díaz, F.; Jiménez, O.; Yianatos, J.; Contreras, F.

    2013-05-01

    The behavior of the solid and liquid phases, in large flotation cells, was characterized by means of the radioactive tracer technique. The use of radioactive tracers enabled the identification of the Residence Time Distribution, of floatable and non-floatable solid, from continuous (on-line) measuring at the output streams of the flotation cells. For this study, the proper radioactive tracers were selected and applied in order to characterize the different phases; i.e. for liquid phase Br-82 as Ammonium Bromide, for floatable solid recovered in the concentrate Cu-64, and for non-floatable solid in three particle size classes (coarse: >150 μm, intermediate: 45 μm, and fine: flotation cells, and consequently in flotation hydrodynamics. From a hydrodynamic point of view, the experimental data confirmed that a single mechanical flotation cells, of large size, can deviate significantly from perfect mixing. The experimental work was developed in a 130 m3 industrial flotation cell of the rougher circuit at El Teniente Division, Codelco-Chile.

  5. Sodium mobility in a mini-catchment studied with radioactive tracers and artificial precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Christophersen, N.; Seip, H.M.; Qvenild, C.; Tollan, O.

    1982-01-01

    A natural 98 sq m mini-catchment was watered with artificial precipitation at an intensity of 5 mm per hour, 8 hours per day, 5 days per week for several weeks starting August 19, 1980. The tracers were administered on September 3. After 6 days an estimated 84% of the tritiated water and 45% of the Na/sup 2//sub 4/ were recovered in runoff. Na ions were fairly mobile but were delayed with respect to water movement. Some of the remaining Na/sup 24/ ions remained in stagnant zones or took part in isotopic exchange, leaving less than half of the non-radioactive Na ions available for ion exchange with ions such as H/sup +/ in the soil. Mean monthly Na ions in precipitation falling on this section of Norway averaged 15 microequivalents per liter from 1977 to 1980. The 10 microequivalents per liter Na available for ion exchange was of minor importance compared with the 50 microequivalents per liter of H..mu.. in runoff. 23 references, 3 figures, 1 table.

  6. The medical applications of radioactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.G.

    1947-12-31

    This report provides a broad yet in depth overview of the use of radioactive materials as tracers in medicine and biology for the period of 1935--1947. Particular attention is paid to is of radio-sodium, radio-iodine, radio-iron, radio-phosphorus, radio-strontium, and fission products. The main thrust of this paper is human rather than animal work and focuses in work that has been published.

  7. Beach sediments drift study by means of radioactive tracers; L'etude du transport littoral par la methode des traceurs radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Hours, R. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

    1959-07-01

    The present state of the sediments drift studies by means of radioactive tracers is exposed. Various processes of labelling, immersion and detection, used in France and other countries, are reviewed. A more extended analysis of some aspects of the problem by the same authors can be found in 'La Houille Blanche', number 3, may-june 1959 (Rapport C.E.A. number 1269). (author) [French] L'etude du transport littoral des sediments et galets par la methode des traceurs radioactifs est en plein developpement. Le present rapport precise l'etat actuel de la question. Les techniques de marquage, d'immersion et de detection utilisees en France et a l'etranger sont decrites; une analyse plus detaillee de certains aspects de la question est presentee par les memes auteurs dans 'La Houille Blanche', numero 3, mai-juin 1959 (Rapport C.E.A. numero 1269). (auteur)

  8. Radioactive tracer study of Cs{sup +}, Co{sup 2+}, and Eu{sup 3+} sorption on shungite III of the Zazhogino Site

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, R.A.; Kalinin, A.I.; Bondarenko, V.V. [St. Petersburg State Univ. (Russian Federation)

    1995-03-01

    Sorption characteristics of shungite III of the Zazhogino site with respect to Cs{sup +}, Co{sup 2+}, and Eu{sup 3+} cations have been studied by the radioactive tracer method. It was found that the kinetics of the sorption is slow and the equilibrium is attained in about 7 days. At pH 5, the distribution coefficients of Cs{sup +}, Co{sup 2+}, and Eu{sup 3+} are 35, 47, and 660, respectively. The dependence of the distribution coefficients on the pH of aqueous solution was determined. The exchange capacity for Eu{sup 3+} at pH 6 is 36 {mu}eq g{sup -1}. The modification of shungite by treating with toluene or hydrofluoric acid significantly improves its sorption properties.

  9. Radioactive tracers in industry and in environment; Les traceurs radioactifs dans l`industrie et l`environnement

    Energy Technology Data Exchange (ETDEWEB)

    Burgun, G.; Laizier, J. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. des Applications et de la Metrologie des Rayonnements Ionisants

    1996-12-31

    Radioactive tracers are used to localize, identify and follow chemical species, particulates or living organisms. These tracers are easy to detect and can have the same physical, hydrodynamical or chemical behaviour as the mass of matter to follow. This digest paper gives an overview of the main radioactive tracer techniques used in the domains of chemical, processes and mechanical engineering, in hydrogeology, pollutants migration studies, dynamical sedimentology and agronomy. (J.S.).

  10. A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2009-07-01

    The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

  11. Study of the source-detector system geometry using the MCNP-X code in the flowrate measurement with radioactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Avilan Puertas, Eddie, E-mail: epuertas@nuclear.ufrj.br [Universidad Central de Venezuela (UCV), Facultad de Ingenieria, Departamento de Fisica Aplicada, Caracas (Venezuela, Bolivarian Republic of); Braz, Delson, E-mail: delson@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Brandao, Luis E.; Salgado, Cesar M., E-mail: brandao@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The use radioactive tracers for flow rate measurement is applied to a great variety of situations, however the accuracy of the technique is highly dependent of the adequate choice of the experimental measurement conditions. To measure flow rate of fluids in ducts partially filled, is necessary to measure the fluid flow velocity and the fluid height. The flow velocity can be measured with the cross correlation function and the fluid level, with a fluid level meter system. One of the error factors when measuring flow rate, is on the correct setting of the source-detector of the fluid level meter system. The goal of the present work is to establish by mean of MCNP-X code simulations the experimental parameters to measure the fluid level. The experimental tests will be realized in a flow rate system of 10 mm of diameter of acrylic tube for water and oil as fluids. The radioactive tracer to be used is the {sup 82}Br and for the detection will be employed two 1″ NaI(Tl) scintillator detectors, shielded with collimators of 0.5 cm and 1 cm of circular aperture diameter. (author)

  12. Neuroreceptor quantitation in vivo by the steady-state principle using constant infusion or bolus injection of radioactive tracers

    DEFF Research Database (Denmark)

    Lassen, N A

    1992-01-01

    different modes of tracer administration can be used. If the tracer is also infused at a constant rate for a long time, then the occupancy of receptor sites by the cold ligand can be calculated by measuring the equilibrium tracer concentrations in brain and plasma. If the tracer is administered...... sites not occupied by the "cold" ligand is measured by using trace amounts of a radioactive ligand binding to the same receptor. A minimum of two studies at different occupanies must be performed. In this presentation it is proposed to make the second study at essentially zero receptor occupancy...... by administering the tracer alone. The pair of tracer studies, the one without and the other with infusion of cold ligand, allows calculation of the cold ligand's equilibrium dissociation constant Kd. In the special case when tracer and cold ligands are chemically identical, then Bmax can also be calculated. Two...

  13. A study on the piston ring wear in automotive engine Seat 1500 CA by means of radioactive tracer technique; Estudio del desgaste de segmentos en motor Seat 1500 CA mediante trazadores radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Val Cob, M. del; Chul, Y.; Fuentes Figuera de Vargas, J.

    1971-07-01

    The iron side wear in the chromium-plated top compression ring has been a matter of interest for the engine makers and it has been required by them to investigate the wear characteristics of the chromium-plated piston ring. Meanwhile, Bureau of Nuclear Energy in Spain (Junta de Energia Nuclear) and Seat Car Manufacturing Company (Sociedad Espanola de Automoviles de Turismo) agreed to study the wear characteristics of chromium-plated piston ring of type CA gasoline engine for Seat 1500 car by means of radioactive tracer technique. (Author) 9 refs.

  14. Exotic tracers for atmospheric studies

    Energy Technology Data Exchange (ETDEWEB)

    Lovelock, J.E. (Brazzos Ltd., Launceston (UK)); Ferber, G.J. (National Oceanic and Atmospheric Administration, Silver Spring, MD (USA). Air Resources Lab.)

    1982-01-01

    Tracer materials can be injected into the atmosphere to study transport and dispersion processes and to validate air pollution model calculations. Tracers should be inert, non-toxic and harmless to the environment. Tracers for long-range experiments, where dilution is very great, must be measurable at extremely low concentrations, well below the parts per trillion level. Compounds suitable for long-range tracer work are rare and efforts should be made to reserve them for meteorological studies, barring them from commercial uses which would increase atmospheric background concentrations. The use of these exotic tracers, including certain perfluorocarbons and isotopically labelled methanes, should be coordinated within the meteorological community to minimize interferences and maximise research benefits.

  15. Exotic tracers for atmospheric studies

    Science.gov (United States)

    Lovelock, James E.; Ferber, Gilbert J.

    Tracer materials can be injected into the atmosphere to study transport and dispersion processes and to validate air pollution model calculations. Tracers should be inert, non-toxic and harmless to the environment. Tracers for long-range experiments, where dilution is very great, must be measurable at extremely low concentrations, well below the parts per trillion level. Compounds suitable for long-range tracer work are rare and efforts should be made to reserve them for meteorological studies, barring them from commercial uses which would increase atmospheric background concentrations. The use of these exotic tracers, including certain perfluorocarbons and isotopically labelled methanes, should be coordinated within the meteorological community to minimize interferences and maximize research benefits.

  16. Uptake of HNO3 to deliquescent sea-salt particles: a study using the short-lived radioactive isotope tracer 13N

    Directory of Open Access Journals (Sweden)

    C. Guimbaud

    2002-01-01

    Full Text Available The uptake of HNO3 to deliquescent airborne sea-salt particles (RH = 55%, P = 760 torr, T = 300 K at concentrations from 2 to 575 ppbv is measured in an aerosol flow tube using 13N as a tracer. Small particles ( 70 nm diameter are used in order to minimize the effect of diffusion in the gas phase on the mass transfer. Below 100 ppbv, an uptake coefficient (gupt of 0.50 ± 0.20 is derived. At higher concentrations, the uptake coefficient decreases along with the consumption of aerosol chloride. Data interpretation is further supported by using the North American Aerosol Inorganics Model (AIM, which predicts the aqueous phase activities of ions and the gas-phase partial pressures of H2O, HNO3, and HCl at equilibrium for the NaCl/HNO3/H2O system. These simulations show that the low concentration data are obtained far from equilibrium, which implies that the uptake coefficient derived is equal to the mass accommodation coefficient under these conditions. The observed uptake coefficient can serve as input to modeling studies of atmospheric sea-salt aerosol chemistry. The main sea-salt aerosol burden in the marine atmosphere is represented by coarse mode particles (> 1 µm diameter. This implies that diffusion in the gas-phase is the limiting step to HNO3 uptake until the sea-salt has been completely processed.

  17. Semianalytical Solutions of Radioactive or Reactive Tracer Transport in Layered Fractured Media

    Energy Technology Data Exchange (ETDEWEB)

    G.J. Moridis; G. S. Bodvarsson

    2001-10-01

    In this paper, semianalytical solutions are developed for the problem of transport of radioactive or reactive tracers (solutes or colloids) through a layered system of heterogeneous fractured media with misaligned fractures. The tracer transport equations in the matrix account for (a) diffusion, (b) surface diffusion (for solutes only), (c) mass transfer between the mobile and immobile water fractions, (d) linear kinetic or equilibrium physical, chemical, or combined solute sorption or colloid filtration, and (e) radioactive decay or first order chemical reactions. Any number of radioactive decay daughter products (or products of a linear, first-order reaction chain) can be tracked. The tracer-transport equations in the fractures account for the same processes, in addition to advection and hydrodynamic dispersion. Additionally, the colloid transport equations account for straining and velocity adjustments related to the colloidal size. The solutions, which are analytical in the Laplace space, are numerically inverted to provide the solution in time and can accommodate any number of fractured and/or porous layers. The solutions are verified using analytical solutions for limiting cases of solute and colloid transport through fractured and porous media. The effect of important parameters on the transport of {sup 3}H, {sup 237}Np and {sup 239}Pu (and its daughters) is investigated in several test problems involving layered geological systems of varying complexity. {sup 239}Pu colloid transport problems in multilayered systems indicate significant colloid accumulations at straining interfaces but much faster transport of the colloid than the corresponding strongly sorbing solute species.

  18. Semianalytical solutions of radioactive or reactive tracer transport in layered fractured media

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Bodvarsson, G.S.

    2001-10-10

    In this paper, semianalytical solutions are developed for the problem of transport of radioactive or reactive tracers (solutes or colloids) through a layered system of heterogeneous fractured media with misaligned fractures. The tracer transport equations in the matrix account for (a) diffusion, (b) surface diffusion (for solutes only), (c) mass transfer between the mobile and immobile water fractions, (d) linear kinetic or equilibrium physical, chemical, or combined solute sorption or colloid filtration, and (e) radioactive decay or first order chemical reactions. Any number of radioactive decay daughter products (or products of a linear, first-order reaction chain) can be tracked. The tracer-transport equations in the fractures account for the same processes, in addition to advection and hydrodynamic dispersion. Additionally, the colloid transport equations account for straining and velocity adjustments related to the colloidal size. The solutions, which are analytical in the Laplace space, are numerically inverted to provide the solution in time and can accommodate any number of fractured and/or porous layers. The solutions are verified using analytical solutions for limiting cases of solute and colloid transport through fractured and porous media. The effect of important parameters on the transport of {sup 3}H, {sup 237}Np and {sup 239}Pu (and its daughters) is investigated in several test problems involving layered geological systems of varying complexity. {sup 239}Pu colloid transport problems in multilayered systems indicate significant colloid accumulations at straining interfaces but much faster transport of the colloid than the corresponding strongly sorbing solute species.

  19. A thalium-doped sodium iodide well counter for radioactive tracer applications with naturally-abundant 40K

    Science.gov (United States)

    Parker, Andrew J.; Boxall, Colin; Joyce, Malcolm J.; Schotanus, Paul

    2013-09-01

    The use of a thallium-doped sodium-iodide well-type scintillation detector for the assay of the low-activity radioisotope 40K, in open-source potassium chloride aqueous solutions, is described. The hazards, safety concerns and radiowaste generation associated with using open-source radioactive isotopes can present significant difficulties, the use of hot cells and escalated costs in radioanalytical laboratory research. A solution to this is the use of low-hazard alternatives that mimic the migration and dispersion characteristics of notable fission products (in this case 137Cs). The use of NaI(Tl) as a detection medium for naturally-abundant levels of 40K in a range of media is widespread, but the use of 40K as a radioactive tracer has not been reported. The use of such low-activity sources is often complicated by the ability to detect them efficiently. In this paper a scintillator detector designed to detect the naturally-abundant 40K present in potassium chloride in tracer applications is described. Examples of the use of potassium chloride as a tracer are given in the context of ion exchange and electrochemical migration studies, and comparisons in performance are drawn from literature with hyper pure germanium semiconductor detectors, which are more commonly utilised detectors in high-resolution counting applications.

  20. Introduction to the physics of molecular imaging with radioactive tracers in small animals.

    Science.gov (United States)

    King, Michael A; Pretorius, P Hendrik; Farncombe, Troy; Beekman, Freek J

    2002-01-01

    Recent advances have greatly enhanced the three-dimensional (3D) imaging of radioactive tracers in living animals. this article introduces the physics of imaging behind the imaging methods. The article first discusses the selection of the radiation emitted from the tracer and then the process of tomographic reconstruction or how 3D images are made from imaging around the outside of the animal. The technique of single photon emission computed tomography (SPECT) in which the detection of one X-ray or gamma ray at a time is employed for image formation is then described. Finally, positron emission tomography (PET) which relies on the simultaneous detection of the pair of gamma-rays formed when the positron annihilates is presented.

  1. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  2. Collection and processing of information in biological kinetics studies with radioactive tracers; Collecte et traitement de l'information dans les etudes de cinetique biologique avec traceurs radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Remy, J.; Lafuma, J. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    The authors present an automatic method for the collection and treatment of information in biological kinetics experiments using radioactive tracers. The recording are made without any time constant on magnetic tape. The information recorded is sampled by a 400 channel multi-scale analyzer and transferred to punched cards. The digital analysis is done by an I.B.M. computer. The method is illustrated by an example: the hepatic fixation of colloidal gold in the pig. Its advantages and requirements are discussed. In the appendix are given the FORTRAN texts for two programmes used in treating the example presented. (authors) [French] Les auteurs presentent une methode automatique de collecte et de traitement de l'information dans les experiences de cinetique biologique utilisant les traceurs radioactifs. Les enregistrements sont realises sans constante de temps sur bande magnetique. L'information enregistree fait l'objet d'un echantillonnage a l'aide d'un analyseur a 400 canaux en mode multi-echelle puis est transferee sur cartes perforees. L'exploitation digitale est confiee a un ordinateur I.B.M.. La methode est illustree par un exemple d'etude de la fixation hepatique de l'or colloidal chez le porc. Ses avantages et ses exigences sont discutes. En annexe figurent les textes en FORTRAN de deux programmes utilises pour le traitement de l'exemple cite. (auteurs)

  3. Comparison of radioactive tracer tin colloid and phytate for sentinel node biopsy in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yagata, Hiroshi; Suzuki, Masato; Nagashima, Takashi; Kasagawa, Takahiro; Sakakibara, Masahiro; Oshida, Keiko; Sangai, Takafumi; Nakano, S.; Miyazaki, Masaru [Chiba Univ. (Japan). Graduate School of Medicine

    2002-10-01

    Eighty-four consecutive sentinel node biopsies were performed using dye and radioactive tracer (tin colloid for 42 tumors and phytate for 42 tumors). They had subdermal injection on the morning of surgery or the afternoon before surgery. Maximum RI count of each sentinel node was recorded and classified {<=}5 counts per second (cps), 5-20, or 20<. In injection on the afternoon before surgery, 19 tumors had {<=}5 cps and 2 had 20 cps< in 24 of tin colloid, whereas 1 had {<=}5 cps and 18 had 20 cps< in 22 of phytate. In injection on the morning of surgery, 9 had {<=}5 and 20 had 20< in 18 of tin colloid, whereas 1 had {<=}5 and 18 had 20< in 20 of phytate. The injection of phytate tended to have higher RI count than tin colloid. Phytate is superior to tin colloid for sentinel node biopsy in breast cancer. (author)

  4. Analysis of the hydrodynamics of continuous flux systems using radioactive tracers

    CERN Document Server

    Vela, C R

    1996-01-01

    The hydrodynamic behaviour of a flux in a system can be determined through the knowledge and correct interpretation of age distributions of flux elements in a system, which can be obtained with the stimulus-response experimental method. This research attempts to emphasize the relevance of system analysis, as well as the use of radioactive tracers to determine residence time distributions when population balance models are used for such analysis. Hydrodynamics of a flux, water, is analyzed using different systems: i) piston flux system; ii) agitated tank system; iii) two agitated tank system in parallel; iv) two and four agitated tank system in series; and v) a complex system. Different age distributions are determined, as well as the presence of short circuits of different magnitude when system agitation speed is changed. Age distribution curves were built using I-131 radioisotope as tracer, injecting it into the flux inlet of the systems. A Minekin gamma radiation detector was used at the outlet of such syst...

  5. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    Science.gov (United States)

    Kristiansen, N. I.; Stohl, A.; Olivié, D. J. L.; Croft, B.; Søvde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; Zhang, K.; Tsigaridis, K.; Bergman, T.; Evangeliou, N.; Wang, H.; Ma, P.-L.; Easter, R. C.; Rasch, P. J.; Liu, X.; Pitari, G.; Di Genova, G.; Zhao, S. Y.; Balkanski, Y.; Bauer, S. E.; Faluvegi, G. S.; Kokkola, H.; Martin, R. V.; Pierce, J. R.; Schulz, M.; Shindell, D.; Tost, H.; Zhang, H.

    2016-03-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs) and xenon-133 (133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  6. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    Directory of Open Access Journals (Sweden)

    N. I. Kristiansen

    2015-09-01

    Full Text Available Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs and xenon-133 (133Xe were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM sulphate aerosols were the main carriers for the cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulphate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulphate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulphate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 37Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between two and nine weeks after the start of the

  7. Steady state reach-scale theory for radioactive tracer concentration in a simple channel/floodplain system

    Science.gov (United States)

    Lauer, J. Wesley; Willenbring, Jane

    2010-11-01

    A steady state analytical model is presented for reach-scale variation in the concentration of a decaying radioactive tracer associated with sediment particles that regularly pass through an off-channel floodplain. The floodplain is represented as a series of well-mixed sediment reservoirs that continually exchange sediment with the channel. The model allows for tributary input and valley-wide aggradation or degradation. Tracer concentration depends on the upstream boundary concentration, the tracer and sediment load, floodplain geometry, and the rates of in-floodplain tracer production and/or decay. The theory predicts relatively modest down-channel change in the concentration of long-lived isotopes but implies that significant change may occur for (1) tracers with a short-enough half-life (such as 14C) or (2) floodplains with sediment residence times that are large enough for cosmogenic production or meteoric fallout to increase tracer concentration in the down-valley direction. The profiles are shown to be strongly dependent on the grain size distributions of both the sediment load and the floodplain. The results imply that down-channel 14C profiles have the potential to constrain Holocene bed material loads in systems with sufficient storage. The theory concisely describes the general importance of a floodplain for modifying in situ produced cosmogenic tracer concentration and can also characterize floodplain importance for fallout radioisotopes (i.e., 10Be, 210Pb, or 7Be) or organic 14C.

  8. Combined Methylene Blue Dye andRadioactive Tracer Technique for Sentinel Lymph Node Localization in Early Breast Cancer

    Directory of Open Access Journals (Sweden)

    Abdolrasoul Talei

    2010-10-01

    Full Text Available Background: Sentinel lymph node biopsy is a technique used to identify the axillary node most likely to contain tumor cells that have metastasized from a primarycarcinoma of the breast. This technique provides accurate staging with fewer complications than axillary dissection and may result in decreased costs. We designed the present study to determine the accuracy and success rate of a combined blue dyeand radioactive tracer technique in sentinel node localization. Methods: This prospective study included 70 patients with early stage (tumor>5cm; T1, T2 operable breast cancer and nonpalpable axillary lymphadenopathy seen between 2005 and 2009. Patients underwent sentinel lymph node localization using 4mL of blue dye combined with radioactive colloid. After identification and removal of the sentinel node(s, the axilla was checked for any residual radioactivity. A sentinelnode was defined as any node that was hot, hot and blue or only blue.Results:The sentinel node was identified in 66 patients with a detection rate of 94.2%,and a mean of 1.5 sentinel nodes were identified and harvested (range of 1-4. In 23cases, the sentinel lymph node contained metastatic disease on pathological assessment.There was no pathological evidence of any metastases in the sentinel node in the remaining 43 patients. All sentinel lymph nodes were located in level I of the axillary region. In four patients, no sentinel lymph node was found, so axillary dissection was performed. The sensitivity of the procedure in predicting further axillary disease was 95.6% with a specificity of 97.6%.Conclusion: The present study describes the blue dye and radioisotope localization technique as successful in identifying the sentinel lymph node in early-stage breast cancer patients.

  9. Evaluation of oil/water separators units in industrial effluents using radioactive tracers; Avaliacao de unidades para separacao de fase aquosa/organica em efluentes industriais pelo metodo de tracadores radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Luis E.B. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos]. E-mail: brandao@ien.gov.br; Nobrega, Armi Wanderley da [Instituto Nacional de Controle da Qualidade na Saude (INCQS/FIOCRUZ), Rio de Janeiro, RJ (Brazil)]. E-mail: armi@incqs.gov.br; Oliveira, Rene L. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2005-07-01

    In this work is presented a methodology to study and evaluate with radioactive tracers oil/water separators in industrial sewage treatment plants. These units are present, mainly in the petrochemical industry, make possible to remove residues of organic phase present in the effluent and allow to reusing the water in other operations. As radioactive tracers we use {sup 82} Br for the aqueous phase and {sup 123} I for organic phase and two radioactive detectors (NaI 2x2'') register the displacement of the tracers in the unit. With this methodology was possible to analyze the response of the unit in various experimental situations and identify problems in its operation which interfere in the final quality of the effluent treatment. (author)

  10. Tracking different freshwater plumes at the Bay of Biscay scale by using a dissolved radioactive tracer: tritium (HTO)

    Science.gov (United States)

    Oms, Pierre-Emmanuel; Bailly du Bois, Pascal; Dumas, Franck; Lazure, Pascal; Morillon, Mehdi; Solier, Luc; Voiseux, Claire; Le Corre, Cédric; Maire, Donovan

    2017-04-01

    New measurements of a radioactive tracer (tritium) on the whole continental shelf of the Bay of Biscay during several oceanographic campaigns between 2008 and 2016 allow comparison with results of the plume dispersion from the regional circulation model, MARS3D (Lazure and Dumas, 2008). Seaward dispersion of freshwater in the Bay of Biscay is highly variable in time and depends on many processes like tide, wind, freshwater runoff or water mass stratification. Until now salinity was a useful tracer to describe dispersion of freshwater, but the complexity to account for these different sources require an additional conservative tracer. Tritium (3H) is a radionuclide tracer released as HTO in the Bay of Biscay by nuclear power plant through two French rivers, Loire and Gironde. Tritium inflow from Loire and Gironde are well known thanks to plants operator data and an effort of daily measurements. Indeed an automated and daily integrated sampling system is deployed in the Loire River and the Gironde Estuary. These plumes are clearly detectable over the continental shelf despite very low tritium concentrations (0.05 - 0.5 Bq/L, 0.5 - 5 TU). In order to determine such low tritium concentrations in the Bay of Biscay, we use a mass spectrometer to measure the 3He (gas) produced by radioactive disintegration of tritium after 3He ingrowth (1 - 6 months). The aim of this work is to describes and quantify the dispersion processes occurring in the continental shelf according to seasons. Thanks to assessments of the model dispersion compared to in-situ measurements, quantification of the residential time of freshwater in the continental shelf as well as quantification of their transfer from continental shelf to abyssal plain is possible. The 3H/S ratio will allow an estimation of respective inputs from Loire and Gironde in the bay.

  11. Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern

    Energy Technology Data Exchange (ETDEWEB)

    Russow, R.; Knappe, S. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung

    1999-02-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden

  12. Tracer studies of nitrogen assimilation in yeast.

    Science.gov (United States)

    ABRAMS, R; HAMMARSTEN, E

    1949-01-01

    By using N(15) as a tracer the assimilation of ammonia by the yeast, Torulopsis utilis, has been studied. It has been shown that: 1. There was no measurable incorporation of N in the protein or polynucleotide purine of carbon-starved yeast. 2. When ammonia is added to nitrogen-starved yeast there is a long lag period before division begins during which the yeast rapidly synthesizes protein, this process being accompanied by a turnover of polynucleotide purine. There was no significant dilution of the N(15)H(4) (+) of the medium by ordinary NH(4) (+). 3. When yeast containing N(15) is allowed to divide and grow in ordinary ammonia, the total amount of N(15) in the yeast remains constant. The dicarboxylic amino acids are most diluted, while arginine and nucleic acid guanine are not diluted at all.

  13. Groundwater surface water interaction study using natural isotopes tracer

    Science.gov (United States)

    Yoon, Yoon Yeol; Kim, Yong Chul; Cho, Soo Young; Lee, Kil Yong

    2015-04-01

    Tritium and stable isotopes are a component of the water molecule, they are the most conservative tracer for groundwater study. And also, radon is natural radioactive nuclide and well dissolved in groundwater. Therefore, these isotopes are used natural tracer for the study of surface water and groundwater interaction of water curtain greenhouse area. The study area used groundwater as a water curtain for warming tool of greenhouse during the winter, and is associated with issues of groundwater shortage while being subject to groundwater-river water interaction. During the winter time, these interactions were studied by using Rn-222, stable isotopes and H-3. These interaction was monitored in multi depth well and linear direction well of groundwater flow. And dam effect was also compared. Samples were collected monthly from October 2013 to April 2014. Radon and tritium were analyzed using Quantulus low background liquid scintillation counter and stable isotopes were analyzed using an IRIS (Isotope Ratio Infrared Spectroscopy ; L2120-i, Picarro). During the winter time, radon concentration was varied from 0.07 Bq/L to 8.9 Bq/L and different interaction was showed between dam. Surface water intrusion was severe at February and restored April when greenhouse warming was ended. The stable isotope results showed different trend with depth and ranged from -9.16 ‰ to -7.24 ‰ for δ 18O value, while the δD value was ranged from -57.86 ‰ to -50.98 ‰. The groundwater age as dated by H-3 was ranged 0.23 Bq/L - 0.59 Bq/L with an average value of 0.37 Bq/L.

  14. Use of thorium as tracer on study of groundwater of Botucatu sandstone

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Paulo Augusto d' A.; Menezes, Maria Angela B.C. de; Moreira, Rubens Martins; Reis Junior, Aluisio Souza; Kastner, Geraldo Frederico, E-mail: paap@cdtn.br, E-mail: menezes@cdtn.br, E-mail: rubens@cdtn.br, E-mail: reisas@cdtn.br, E-mail: gfk@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Thorium in some mineral compounds is very difficult to be dissolved in aqueous medium. To study the mobility of thorium in water, one alternative is to complex this element with EDTA, becoming possible to follow the behavior of thorium this medium. This way, in groundwater with low natural radioactivity and low {sup 232}Th activity, thorium can be used as a tracer. This paper describes the application of the complex Th-EDTA as a tracer applying the solution trough a sandstone sample made by rock from Botucatu Sandstone. The objective was to simulate the flow of groundwater inside the original rock aiming at future use of rare-earth elements complexed with EDTA as tracer. Alpha spectrometry technique was used to determine {sup 232}Th in the water samples with {sup 230}Th as inner-standard. (author)

  15. TRACER STUDY OF RTU GRADUATES: AN ANALYSIS

    Directory of Open Access Journals (Sweden)

    Thelma L. Ramirez

    2014-01-01

    Full Text Available This paper aimed to determine if the field of specialization in the different colleges of RTU graduates and their academic-acquired skills and competencies are related to their present occupations. A modified Graduate Tracer Study (GTS instrument was utilized to gather the quantitative data. Out of 500 questionnaires administered, there were 250 graduates returned answered questionnaires representing the three Colleges: Education, Arts and Sciences, Business and Entrepreneurial Technology. A face to face interview was also conducted in order to support the gathered data. The SPSS was used to generate results from the acquired quantitative data using the frequency counts, percentage and the Chi-square goodness of fit test. The findings revealed that the graduates claimed that their knowledge, academic-acquired skills and competencies contributed greatly in their job performance. The Chi-square goodness of fit proved that there is a significant relationship between the graduates’ fields of specialization and their occupations after graduation. Likewise, the academic-acquired skills and competencies of the graduates are relevant to their chosen occupations. The results further proved that RTU produces marketable and appropriately trained graduates with the majority landing in course-related jobs within a short period after graduation. The study also indicates that the RTU graduates possess the skills and competencies necessary to succeed in this competitive world. However eexpansion of tie-ups with private business entities is made to at least maintain the high employability level of the graduates.

  16. National Biomedical Tracer Facility: Project definition study

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R.; Peterson, E. [Los Alamos National Lab., NM (United States); Smith, P. [Smith (P.A.) Concepts and Designs (United States)

    1995-05-31

    The Los Alamos National Laboratory is an ideal institution and New Mexico is an ideal location for siting the National Biomedical Tracer Facility (NBTF). The essence of the Los Alamos proposal is the development of two complementary irradiation facilities that combined with our existing radiochemical processing hot cell facilities and waste handling and disposal facilities provide a low cost alternative to other proposals that seek to satisfy the objectives of the NBTF. We propose the construction of a 30 MeV cyclotron facility at the site of the radiochemical facilities, and the construction of a 100 MeV target station at LAMPF to satisfy the requirements and objectives of the NBTF. We do not require any modifications to our existing radiochemical processing hot cell facilities or our waste treatment and disposal facilities to accomplish the objectives of the NBTF. The total capital cost for the facility defined by the project definition study is $15.2 M. This cost estimate includes $9.9 M for the cyclotron and associated facility, $2.0 M for the 100 MeV target station at LAMPF, and $3.3 M for design.

  17. Sistem Pre Kompilasi Data Tracer Studi Online Ditjen Belmawa Ristekdikti (Studi Kasus: Politeknik Harapan Bersama

    Directory of Open Access Journals (Sweden)

    Very Kurnia Bakti

    2017-01-01

    Full Text Available Tracer studi merupakan salah satu upaya yang diharapkan dapat menyediakan informasi untuk mengevaluasi hasil pendidikan di Politeknik Harapan Bersama dari kuisioner yang diberikan kepada alumni. Kegiatan tracer studi ini sudah dilaksanakan secara online, namun masih terdapat kendala pada bagian sistem yang digunakan saat ini, hal tersebut menyebabkan Politeknik Harapan Bersama tidak dapat melaporkan / mengunggah hasil tracer studi kepada Ditjen Belmawa Ristekdikti, dimana form kuisioner dan data export tracer studi yang dihasilkan berbeda dengan kebutuhan seperti yang tercantum pada surat edaran No. 313/B/SE/2016 tentang pelaksanaan tracer studi di tingkat perguruan tinggi. Mengingat pentingnya tracer studi sebagai umpan balik bagi Politeknik Harapan Bersama, maka perlu solusi untuk mengatasi kekurangan sistem ini. Dengan merubah sistem yang ada dengan sistem tracer studi yang baru merupakan solusi yang tepat dalam permasalahan ini. Sistem tracer studi yang baru mampu menghasilkan data tracer studi alumni dan pengisian form kuisioner sesuai dengan standar Ditjen Belmawa Ristekdikti yang dapat diunggah sistem tracer studi ristekdikti.

  18. Evaluation of urban and industrial wastewater treatment plants using radioactive tracers; Otimizacao de unidades de tratamento de aguas residuais urbanas e industriais empregando-se tracadores radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Luis Eduardo Barreira

    2001-07-01

    A methodology for studies and evaluation of sewage treatment plants with radioactive tracers is presented.. Radioisotopes as {sup 82} Br ( for the liquid phase), {sup 110m} Ag and {sup 140} La, (for the solid phase) was used to evaluate sewage flow rates, mixing pattern in equalization tank and test effluent treatment units. The tracer was injected in the unit (instantaneously or in a constant rate with a pump) and NaI-scintillation detectors measured the output signal. The Fortran program TRACADORES was developed to analyze the response function of the units in form of residence times distribution curves (RTD), which represents the probability of an element of the material to interact with the unit, and calculate the mean residence time {gamma}, the central moment of this distribution function. This fundamental parameter characterizes the tank and serves as a quantitative evaluation for its performance. With the radiotracer techniques was possible to identify dead zone, channeling, internal circulation of the solid phase inside the tanks. The technique represents a guideline for redesign a imperfect unit and eliminate the problem. (author)

  19. The use tracer radioactive in the station of treatment residual of in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Damera, A.; Ramos, K. [Center of Attention to the Nuclear Activity, City of Camaguey (Cuba); Ferreira, A.; Magalhaes, A. [Centro of Development of Nuclear Technology, Mines Gerais (Brazil); Derivet, M. [Cuban Institute of Sugar Investigations, Havana (Cuba)

    2001-07-01

    The industry of the petroleum comes being in you finish them decades, an user of the Nuclear Techniques, overalls starting from the II World War, when sources radioactive and new techniques passed the investigators' disposition and technicians of the civil sector. Due to the amplification of activities in some of the technical and economic characteristics of this industry the possibilities of application of the nuclear techniques are proportionally bigger and more important than in many other sectors of the economy. This work was carried out in the Station of Treatment of Residual Industrial (ETDI) in PETROBRAS (Brazil). The ETDI has the function of receiving, to store and to try the you discard liquids and gassy coming from diverse points of the refinery avoiding this way the contamination of the environment. The work consisted on the determination of the time of residence inside the flocculators and the floats, for it was used it the nuclear technique of radioactive radiotracer, concretely the Technetium 99 m. This has a great economic and environmental importance, because when obtaining the time of real.. residence experimentally in the flocculators and the floats, you can compare with those obtained theoretically and to influence on the system, optimizing their operation. (authors)

  20. Ensemble-based simultaneous emission estimates and improved forecast of radioactive pollution from nuclear power plant accidents: application to ETEX tracer experiment.

    Science.gov (United States)

    Zhang, X L; Li, Q B; Su, G F; Yuan, M Q

    2015-04-01

    The accidental release of radioactive materials from nuclear power plant leads to radioactive pollution. We apply an augmented ensemble Kalman filter (EnKF) with a chemical transport model to jointly estimate the emissions of Perfluoromethylcyclohexane (PMCH), a tracer substitute for radionuclides, from a point source during the European Tracer Experiment, and to improve the forecast of its dispersion downwind. We perturb wind fields to account for meteorological uncertainties. We expand the state vector of PMCH concentrations through continuously adding an a priori emission rate for each succeeding assimilation cycle. We adopt a time-correlated red noise to simulate the temporal emission fluctuation. The improved EnKF system rapidly updates (and reduces) the excessively large initial first-guess emissions, thereby significantly improves subsequent forecasts (r = 0.83, p 80% average reduction of the normalized mean square error).

  1. National Biomedical Tracer Facility. Project definition study

    Energy Technology Data Exchange (ETDEWEB)

    Schafer, R.

    1995-02-14

    We request a $25 million government-guaranteed, interest-free loan to be repaid over a 30-year period for construction and initial operations of a cyclotron-based National Biomedical Tracer Facility (NBTF) in North Central Texas. The NBTF will be co-located with a linear accelerator-based commercial radioisotope production facility, funded by the private sector at approximately $28 million. In addition, research radioisotope production by the NBTF will be coordinated through an association with an existing U.S. nuclear reactor center that will produce research and commercial radioisotopes through neutron reactions. The combined facilities will provide the full range of technology for radioisotope production and research: fast neutrons, thermal neutrons, and particle beams (H{sup -}, H{sup +}, and D{sup +}). The proposed NBTF facility includes an 80 MeV, 1 mA H{sup -} cyclotron that will produce proton-induced (neutron deficient) research isotopes.

  2. Nucleon transfer studies with radioactive beams

    CERN Document Server

    Catford, W N

    2002-01-01

    The potential of nucleon transfer experiments using radioactive beams is described, and set in the context of the new experimental challenges and the first reported experiments. Particular attention is paid to the requirements imposed on experiments by studying reactions in inverse kinematics on very light targets.

  3. Boundary integral method application in the transportation modeling of radioactive tracers in porous ways; Aplicacao do metodo da integral de contorno na modelagem do transporte de tracadores radioativos em meios porosos

    Energy Technology Data Exchange (ETDEWEB)

    Ferroni, Jose Geraldo

    1996-03-01

    This work describes a method for estimating the effluent concentrations of radioactive tracers in production wells, considering well to well injection tests and piston-like displacements of fluids in the reservoir. The model for tracer transportation takes into account effects of convection and hydrodynamic dispersion. (author)

  4. Tracer Studies In A Laboratory Beach Subjected To Waves

    Science.gov (United States)

    This work investigated the washout of dissolved nutrients from beaches due to waves by conducting tracer studies in a laboratory beach facility. The effects of waves were studied in the case where the beach was subjected to the tide, and that in which no tidal action was present...

  5. Tracer Studies In A Laboratory Beach Subjected To Waves

    Science.gov (United States)

    This work investigated the washout of dissolved nutrients from beaches due to waves by conducting tracer studies in a laboratory beach facility. The effects of waves were studied in the case where the beach was subjected to the tide, and that in which no tidal action was present...

  6. STRATEGIES FOR QUANTIFYING PET IMAGING DATA FROM TRACER STUDIES OF BRAIN RECEPTORS AND ENZYMES.

    Energy Technology Data Exchange (ETDEWEB)

    Logan, J.

    2001-04-02

    A description of some of the methods used in neuroreceptor imaging to distinguish changes in receptor availability has been presented in this chapter. It is necessary to look beyond regional uptake of the tracer since uptake generally is affected by factors other than the number of receptors for which the tracer has affinity. An exception is the infusion method producing an equilibrium state. The techniques vary in complexity some requiring arterial blood measurements of unmetabolized tracer and multiple time uptake data. Others require only a few plasma and uptake measurements and those based on a reference region require no plasma measurements. We have outlined some of the limitations of the different methods. Laruelle (1999) has pointed out that test/retest studies to which various methods can be applied are crucial in determining the optimal method for a particular study. The choice of method will also depend upon the application. In a clinical setting, methods not involving arterial blood sampling are generally preferred. In the future techniques for externally measuring arterial plasma radioactivity with only a few blood samples for metabolite correction will extend the modeling options of clinical PET. Also since parametric images can provide information beyond that of ROI analysis, improved techniques for generating such images will be important, particularly for ligands requiring more than a one-compartment model. Techniques such as the wavelet transform proposed by Turkheimer et al. (2000) may prove to be important in reducing noise and improving quantitation.

  7. Future radioactive liquid waste streams study

    Energy Technology Data Exchange (ETDEWEB)

    Rey, A.S.

    1993-11-01

    This study provides design planning information for the Radioactive Liquid Waste Treatment Facility (RLWTF). Predictions of estimated quantities of Radioactive Liquid Waste (RLW) and radioactivity levels of RLW to be generated are provided. This information will help assure that the new treatment facility is designed with the capacity to treat generated RLW during the years of operation. The proposed startup date for the RLWTF is estimated to be between 2002 and 2005, and the life span of the facility is estimated to be 40 years. The policies and requirements driving the replacement of the current RLW treatment facility are reviewed. Historical and current status of RLW generation at Los Alamos National Laboratory are provided. Laboratory Managers were interviewed to obtain their insights into future RLW activities at Los Alamos that might affect the amount of RLW generated at the Lab. Interviews, trends, and investigation data are analyzed and used to create scenarios. These scenarios form the basis for the predictions of future RLW generation and the level of RLW treatment capacity which will be needed at LANL.

  8. A Study Plan for Determining Recharge Rates at the Hanford Site Using Environmental Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E. M.; Szecsody, J. E.; Phillips, S. J.

    1991-02-01

    . Seven study sites on the Hanford Site have been selected, in two primary soil types that are believed to represent the extremes in recharge, the Quincy sand and the Warden silt loam. An additional background study site upwind of the Hanford facilities has been chosen at the Yakima Firing Center. Study sites at Hanford were chosen close to micrometeorology stations on downwind transects from the operational facilities. Initial testing will be done on sites that lack perennial vegetation. Six tracer techniques (total chlortde, {sup 36}Cl, {sup 3}H, nitrate, {sup 129}I, and {sup 99}Tc) will be tested on at least one site in the Quincy sand, one site in the Warden si~ loam, and the background site, to determine which combination of tracers wortks best for a given soil type. In subsequent years, additional sites will be investigated to determine the effect of vegetation on recharge estimates and on the performance of individual tracers. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial vartability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other and sites operated by the U.S. Department of Energy as well as at low-level radioactive waste disposal sites.

  9. Studies of Tracer Dispersion and Fluid Flow in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Rage, T.

    1996-12-31

    This doctoral thesis explores the connection between the topology of a porous medium and its macroscopic transport properties and is based on computerized simulation. In porous media, both diffusion and convection contribute to the dispersion of a tracer and their combined effect is emphasized. The governing equations are solved numerically, using finite differences and Monte Carlo technique. The influence of finite Reynolds number on the outcome of echo-experiments is discussed. Comparing experiments and simulations it is found that nonlinear inertial forces lead to a visible deformation of a returned tracer at surprisingly small Reynolds numbers. In a study of tracer dispersion and fluid flow in periodic arrays of discs it is demonstrated that the mechanisms of mechanical dispersion in periodic media and in natural (non-periodic) porous media are essentially different. Measurements of the percolation probability distribution of a sandstone sample is presented. Local porosity theory predicts that this simple geometric function of a porous medium is of dominant importance for its macroscopic transport properties. It is demonstrated that many aspects of transport through fractures can be studied by using simple but realistic models and readily available computer resources. An example may be the transport of hydrocarbon fluids from the source rock to a reservoir. 165 refs., 44 figs., 1 table

  10. Radioisotope tracer study in a sludge hygienization research irradiator (SHRI).

    Science.gov (United States)

    Pant, H J; Thýn, J; Zitný, R; Bhatt, B C

    2001-01-01

    A radioisotope tracer study has been carried out in a batch type sludge hygienization research irradiator with flow from top to bottom, the objective being to measure flow rate, circulation and mixing times and to investigate the hydrodynamic behaviour of the irradiator for identifying the cause(s) of malfunction. A stimulus-response technique with NH4(82)Br as a tracer was used to measure the above parameters. Experiments were carried out at three different flow rates, i.e 1.0, 0.64 and 0.33 m3/min. Three combined models based on a set of differential equations are proposed and used to simulate the measured tracer concentration curves. The obtained parameters were used to estimate dead volume and analyse hydrodynamic behaviour of the irradiator. The nonlinear regression problem of model parameter estimation was solved using the Marquardt-Levenberg method. The measured flow rate was found to be in good agreement with the values shown by the flow meter. The circulation times were found to be half of the mixing times. A simple approach for estimation of dose based on a known vertical dose-rate profile inside the irradiator is presented. About one-fourth of the volume of the irradiator was found to be dead at lower flow rates and this decreased with increase in flow rate. At higher flow rates, a semi stagnant volume was found with slow exchange of flow between the active and dead volumes.

  11. Radioisotope tracer study in a sludge hygienization research irradiator (SHRI)

    Energy Technology Data Exchange (ETDEWEB)

    Pant, H.J. E-mail: hjpant@aspsara.barc.ernet.in; Thyn, J.; Zitny, R.; Bhatt, B.C

    2001-01-15

    A radioisotope tracer study has been carried out in a batch type sludge hygienization research irradiator with flow from top to bottom, the objective being to measure flow rate, circulation and mixing times and to investigate the hydrodynamic behaviour of the irradiator for identifying the cause(s) of malfunction. A stimulus-response technique with NH{sup 82}{sub 4}Br as a tracer was used to measure the above parameters. Experiments were carried out at three different flow rates, i.e 1.0, 0.64 and 0.33 m{sup 3}/min. Three combined models based on a set of differential equations are proposed and used to simulate the measured tracer concentration curves. The obtained parameters were used to estimate dead volume and analyse hydrodynamic behaviour of the irradiator. The nonlinear regression problem of model parameter estimation was solved using the Marquardt-Levenberg method. The measured flow rate was found to be in good agreement with the values shown by the flow meter. The circulation times were found to be half of the mixing times. A simple approach for estimation of dose based on a known vertical dose-rate profile inside the irradiator is presented. About one-fourth of the volume of the irradiator was found to be dead at lower flow rates and this decreased with increase in flow rate. At higher flow rates, a semi stagnant volume was found with slow exchange of flow between the active and dead volumes.

  12. Failure in the detection of the sentinel lymph node with a combined technique of radioactive tracer and blue dye in a patient with cancer of the vulva and a single positive lymph node

    NARCIS (Netherlands)

    Fons, G; ter Rahe, B; Sloof, G; de Hullu, J; van der Velden, J

    Background. In early stage vulvar cancer, the sentinel lymph node procedure with a radioactive tracer appears to be a promising new diagnostic tool to predict lymph node status. No detection failures have been published so far in vulvar cancer. We recently experienced failure in the detection of the

  13. Surface and Interface Studies with Radioactive Ions

    CERN Multimedia

    Weber, A

    2002-01-01

    Investigations on the atomic scale of magnetic surfaces and magnetic multilayers were performed by Perturbed Angular Correlation (PAC) spectroscopy. The unique combination of the Booster ISOLDE facility equipped with a UHV beamline and the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN) is ideally suited for such microscopic studies. Main advantages are the choice of problem-oriented radioactive probes and the purity of mass-separated beams. The following results were obtained: $\\,$i) Magnetic hyperfine fields (B$_{hf}$) of Se on Fe, Co, Ni surfaces were determined. The results prompted a theoretical study on the B$_{hf}$ values of the 4sp-elements in adatom position on Ni and Fe, confirming our results and predicting unexpected behaviour for the other elements. $\\,$ii) Exemplarily we have determined B$_{hf}$ values of $^{111}$Cd at many different adsorption sites on Ni surfaces. We found a strong dependence on the coordination number of the probes. With decreasing coordination nu...

  14. Radioactive fuel cask railcar humping study

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, L.T. (comp.)

    1978-01-01

    The response of two radioactive shipping casks due to railroad humping shocks was calculated using a spring-mass model. The two railcars for these casks had different coupling mechanisms and different tiedown arrangements. Humping tests had been performed on one of the railcars (ATMX-600) and the resulting shock spectra was used to adjust the spring-mass model to get matching results. One car (designed for cask shipment) was equipped with Freightmaster E-15 end of car coupler and had about /sup 1///sub 8/ in. free travel of the cask skid relative to the car. The other car (ATMX-600), equipped with Miner RF-333 draft gear, was designed for nuclear weapon shipment and adapted to nuclear waste shipment by fastening the casks to the floor. Both car frames were built by the same manufacturer and are very similar. The response of the casks was put in shock spectra format and a parametric study was performed with various cask weights. Additional studies were done on the effects of fastening the loose cask, and using the Freightmaster end of car coupler on the ATMX car. Half-sine response spectra were overlaid to include the natural frequency of the cask tiedown. The resulting shock amplitude was plotted against the cask weight for each car. The results show a constant acceleration level for all the weights on the car with hydraulic end-of-car coupler which results from constant force at that impact velocity. The cask acceleration can be reduced by fastening it to the car, rather than allowing it to move freely through some small space. This study also shows that the cask response can be optimized on railcars without hydraulic draft gear by adjusting the tiedown stiffness to keep the tiedown frequency different than car frequencies.

  15. Measurement and simulation of the turbulent dispersion of a radioactive tracer in a two-phase flow system

    Energy Technology Data Exchange (ETDEWEB)

    Hensel, F.; Rohde, U.

    1998-10-01

    The turbulent dispersion of a radiotracer in an experimental setup with a natural convection liquid-gaseous flow was investigated. A liquid-gaseous bubbly flow was generated in a narrow tank by injection of pressurized air into water or by catalytic disintegration of H{sub 2}O{sub 2}. Turbulent Prandtl numbers for gas and tracer dispersion were varied. In the case of higher gas superficial velocities (J{sub gas}{approx}5-15 mm/s), a reasonable agreement was achieved between calculated and measured tracer transport velocity and dispersion coefficient values. A nearly linear correlation between j{sub gas} and D was found in agreement with other authors. The calculation results contribute to a better understanding of the phenomena and interpretation of the measurement results as well as to the validation of the CFD code for turbulent two-phase flow applications. Further investigations are necessary to improve the agreement in the cases of H{sub 2}O{sub 2} disintegration and low gas superficial velocities. (orig.)

  16. Tracer tests in geothermal resource management

    Directory of Open Access Journals (Sweden)

    Axelsson G.

    2013-05-01

    Full Text Available Geothermal reinjection involves injecting energy-depleted fluid back into geothermal systems, providing an effective mode of waste-water disposal as well as supplementary fluid recharge. Cooling of production boreholes is one of the main disadvantages associated with reinjection, however. Tracer testing is an important tool for reinjection studies because tracer tests actually have a predictive power since tracer transport is orders of magnitude faster than cold-front advancement around reinjection boreholes. A simple and efficient method of tracer test interpretation, assuming specific flow channels connecting reinjection and production boreholes, is available. It simulates tracer return profiles and estimates properties of the flow channels, which are consequently used for predicting the production borehole cooling. Numerous examples are available worldwide on the successful application of tracer tests in geothermal management, many involving the application of this interpretation technique. Tracer tests are also used for general subsurface hydrological studies in geothermal systems and for flow rate measurements in two-phase geothermal pipelines. The tracers most commonly used in geothermal applications are fluorescent dyes, chemical substances and radioactive isotopes. New temperature-resistant tracers have also been introduced and high-tech tracers are being considered.

  17. Count rate balance method of measuring sediment transport of sand beds by radioactive tracers; Methode du bilan des taux de comptage d'indicateurs radioactifs pour la determination du debit de charriage des lits sableux

    Energy Technology Data Exchange (ETDEWEB)

    Sauzay, G. [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1967-11-01

    Radioactive tracers are applied to the direct measurement of the sediment transport rate of sand beds. The theoretical measurement formula is derived: the variation of the count rate balance is inverse of that of the transport thickness. Simultaneously the representativeness of the tracer is critically studied. The minimum quantity of tracer which has to be injected in order to obtain a correct statistical definition of count rate given by a low number of grains 'seen' by the detector is then studied. A field experiment was made and has let to study the technological conditions for applying this method: only the treatment of results is new, the experiment itself is carried out with conventional techniques applied with great care. (author) [French] Les indicateurs radioactifs sont appliques a la mesure directe du debit de charriage des lits sableux. On etablit la formule theorique de mesure: le bilan des taux de comptage varie en sens inverse de l'epaisseur de charriage. Parallelement on fait une etude critique de la representativite de l'indicateur, puis on determine la quantite minimale de traceur qu'il faut immerger pour que les taux de comptage fournis pour un faible nombre de grains 'vus' par le detecteur aient une definition statistique correcte. Une experience de terrain a permis d'etudier les conditions technologiques de cette methode: seul le depouillement des resultats est nouveau. L'experimentation in-situ se fait suivant les procedes classiques avec un tres grand soin. (auteur)

  18. Radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Baratta, E.J. [Winchester Engineering and Analytical Center, Winchester, MA (United States)

    1997-01-01

    Cesium-134 and -137 in Foods, Gamma-Ray Spectrophotometric Methods. The method entitled {open_quotes}Cs-134 and Cs-137 in Foods, Gamma-Ray Spectrophotometric Method{close_quotes} has been adopted official first action, with minor revisions. Iodine 131: The method {open_quotes}Iodine-131 in Milk, Radiochemical Separation Method{close_quotes} has been accepted by the Committee on Residues and Related Topics and has been recommended to the Methods Committee for adoption first action. Search is continuing for a new Associated Referee. Plutonium-239: The Associate Referee is doing a literature search for a method for the determination of plutonium in foods. When one is selected, she will prepared a protocol for a collaborative study and submit it for approval. Radium-228: Search is ongoing for a new Associate Referee. When one is appointed, a method should be selected and tested. Strontium-89 and -90: The Associate Referee is investigating methods using resin discs and/or resin columns for these radionuclides. These methods are now being used in analyses for strontium-89 and -90 in water. She will now attempt to apply it to milk. If successful, she will prepare a protocol for a collaborative study and submit it for approval. Tritium: Search is continuing for a new Associate Referee for this topic.

  19. Reintegration of child soldiers in Burundi: a tracer study.

    Science.gov (United States)

    Jordans, Mark J D; Komproe, Ivan H; Tol, Wietse A; Ndayisaba, Aline; Nisabwe, Theodora; Kohrt, Brandon A

    2012-10-25

    Substantial attention and resources are aimed at the reintegration of child soldiers, yet rigorous evaluations are rare. This tracer study was conducted among former child soldiers (N=452) and never-recruited peers (N=191) who participated in an economic support program in Burundi. Socio-economic outcome indicators were measured retrospectively for the period before receiving support (T1; 2005-06); immediately afterwards (T2; 2006-07); and at present (T3; 2010). Participants also rated present functional impairment and mental health indicators. Participants reported improvement on all indicators, especially economic opportunity and social integration. At present no difference existed between both groups on any of the outcome indicators. Socio-economic functioning was negatively related with depression- and, health complaints and positively with intervention satisfaction. The present study demonstrates promising reintegration trajectories of former child soldiers after participating in a support program.

  20. Reintegration of child soldiers in Burundi: a tracer study

    Directory of Open Access Journals (Sweden)

    Jordans Mark JD

    2012-10-01

    Full Text Available Abstract Background Substantial attention and resources are aimed at the reintegration of child soldiers, yet rigorous evaluations are rare. Methods This tracer study was conducted among former child soldiers (N=452 and never-recruited peers (N=191 who participated in an economic support program in Burundi. Socio-economic outcome indicators were measured retrospectively for the period before receiving support (T1; 2005–06; immediately afterwards (T2; 2006–07; and at present (T3; 2010. Participants also rated present functional impairment and mental health indicators. Results Participants reported improvement on all indicators, especially economic opportunity and social integration. At present no difference existed between both groups on any of the outcome indicators. Socio-economic functioning was negatively related with depression- and, health complaints and positively with intervention satisfaction. Conclusion The present study demonstrates promising reintegration trajectories of former child soldiers after participating in a support program.

  1. Reintegration of child soldiers in Burundi: a tracer study

    Science.gov (United States)

    2012-01-01

    Background Substantial attention and resources are aimed at the reintegration of child soldiers, yet rigorous evaluations are rare. Methods This tracer study was conducted among former child soldiers (N=452) and never-recruited peers (N=191) who participated in an economic support program in Burundi. Socio-economic outcome indicators were measured retrospectively for the period before receiving support (T1; 2005–06); immediately afterwards (T2; 2006–07); and at present (T3; 2010). Participants also rated present functional impairment and mental health indicators. Results Participants reported improvement on all indicators, especially economic opportunity and social integration. At present no difference existed between both groups on any of the outcome indicators. Socio-economic functioning was negatively related with depression- and, health complaints and positively with intervention satisfaction. Conclusion The present study demonstrates promising reintegration trajectories of former child soldiers after participating in a support program. PMID:23095403

  2. Radioactive labeling of a natural assemblage of marine sedimentary bacteria and microalgae for trophic studies: An autoradiographic study.

    Science.gov (United States)

    Carman, K R

    1990-05-01

    Autoradiography was used to examine critical questions for trophic studies concerning the uptake of radioactive tracers by a natural assemblage of sedimentary microorganisms. Labeled organic substrates ([(3)H]-acetate and [(3)H]-thymidine) were taken up only by heterotrophic bacteria, and [(14)C]-bicarbonate was taken up only by microalgae. Only approximately 2% of the bacterial assemblage took up detectable quantities of either [(3)H]-acetate or [(3)H]-thymidine, regardless of whether labeled substrates were delivered to sediments via slurries or by injection with a microliter syringe. Significantly more diatoms were labeled when [(14)C]-bicarbonate was delivered to sediments by the injection method (75%) as compared to the slurry method (50%). These results indicate that radio-active tracers can be used in natural sediments to selectively label potential microbial food of invertebrate grazers. Only a small proportion of bacteria, however, may actually use a labeled substrate, which introduces a large uncertainty into the conversion of radioactivity in grazers to the number of bacteria consumed. Finally, the use of disruptive methods (e.g., slurries) to deliver labels to sediments does not increase the proportion of microorganisms that become labeled. Thus, given the variety of artifacts that may be associated with the use of sediment slurries, it is probably advisable to use nondisruptive methods to deliver substrates to sediments.

  3. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain Site Characterization Study; Progress report, June 1--December 31, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Stetzenbach, K.J.

    1990-12-31

    Ground water tracers are solutes dissolved in or carried by ground water to delineate flow pathways. Tracers provide information on direction and speed of water movement and that of contaminants that might be conveyed by the water. Tracers can also be used to measure effective porosity, hydraulic conductivity, dispersivity and solute distribution coefficients. For most applications tracers should be conservative, that is, move at the same rate as the water and not sorb to aquifer materials. Tracers must have a number of properties to be functional. Regardless of the desired properties, the chemical and physical behavior of a tracer in ground water and the porous medium under study must be understood. Good estimates of tracer behavior can be obtained from laboratory studies. Studies in this proposal will address tracer properties with analytical method development, static sorption and degradation studies and column transport studies, Mutagenicity tests will be performed on promising candidates. The tracers that will be used for these experiments are fluorinated organic acids and other organic compounds that have the chemical and biological stability necessary to be effective in the Yucca Mountain environment. Special emphasis will be placed on compounds that fluoresce or have very large ultraviolet absorption coefficients for very high analytical sensitivity.

  4. A parameter identifiability study of two chalk tracer tests

    Directory of Open Access Journals (Sweden)

    S. A. Mathias

    2006-08-01

    Full Text Available As with most fractured rock formations, Chalk is highly heterogeneous. Therefore, meaningful estimates of model parameters must be obtained at a scale comparable with the process of concern. These are frequently obtained by calibrating an appropriate model to observed concentration-time data from radially convergent tracer tests (RCTT. Arguably, an appropriate model should consider radially convergent dispersion (RCD and Fickian matrix diffusion. Such a model requires the estimation of at least four parameters. A question arises as to whether or not this level of model complexity is supported by the information contained within the calibration data. Generally modellers have not answered this question due to the calibration techniques employed. A dual-porosity model with RCD was calibrated to two tracer test datasets from different UK Chalk aquifers. A multivariate sensitivity analysis, which assumed only a priori upper and lower bounds for each model parameter, was undertaken. Rather than looking at measures of uncertainty, the shape of the multivariate objective function surface was used to determine whether a parameter was identifiable. Non-identifiable parameters were then removed and the procedure was repeated until all remaining parameters were identifiable.

    It was found that the single fracture model (SFM (which ignores mechanical dispersion obtained the best mass recovery, excellent model performance and best parameter identifiability in both the tests studied. However, there was no objective evidence suggesting that mechanical dispersion was negligible. Moreover, the SFM (with just two parameters was found to be good at approximating the Single Fracture Dispersion Model SFDM (with three parameters when different, and potentially erroneous parameters, were used. Overall, this study emphasises the importance of adequate temporal sampling of breakthrough curve data prior to peak concentrations, to ensure adequate characterisation of

  5. Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas; Deteccion de fugas por radiotrazado en ducto marino para transporte de gas LP

    Energy Technology Data Exchange (ETDEWEB)

    Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e mail: efrp@nuclear.inin.mx

    2008-07-01

    In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO{sub 3}){sub 3} 6H{sub 2}O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

  6. Evaluation of a radioactive and fluorescent hybrid tracer for sentinel lymph node biopsy in head and neck malignancies: prospective randomized clinical trial to compare ICG-{sup 99m}Tc-nanocolloid hybrid tracer versus {sup 99m}Tc-nanocolloid

    Energy Technology Data Exchange (ETDEWEB)

    Stoffels, Ingo; Leyh, Julia; Schadendorf, Dirk; Klode, Joachim [University Hospital Essen University of Duisburg-Essen, Department of Dermatology, Venerology and Allergology, Essen (Germany); University Duisburg-Essen, West German Cancer Center, Essen (Germany); German Cancer Consortium (DKTK), Essen (Germany); Poeppel, Thorsten [University Hospital Essen University of Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany)

    2015-10-15

    There is some controversy about the value of sentinel lymph node excision (SLNE) in patients with head and neck malignancies. The gold standard for detection and targeted extirpation of the SLN is lymphoscintigraphy with {sup 99m}Tc-nanocolloid. The purpose of this prospective randomized study was to analyse the feasibility and clinical benefit of a hybrid tracer comprising the near-infrared (NIR) fluorescent indocyanine green (ICG) and {sup 99m}Tc-nanocolloid (ICG-{sup 99m}Tc-nanocolloid) in direct comparison with standard {sup 99m}Tc-nanocolloid for guiding SLNE in patients with head and neck cutaneous malignancies. We analysed the data from 40 clinically lymph node-negative patients with melanoma, high-risk cutaneous squamous cell carcinoma, Merkel cell carcinoma or sweat gland carcinoma who underwent SLNE with ICG-{sup 99m}Tc-nanocolloid (cohort A) or with the standard {sup 99m}Tc-nanocolloid (cohort B). Overall SLNs were identified preoperatively in all 20 patients (100 %) in cohort A and in 18 of 20 patients (90 %) in cohort B. The SLN basin was detected preoperatively in 18 patients (90 %) in cohort A and also in 18 patients (90 %) in cohort B. SLNs were identified intraoperatively in all 20 patients (100 %) in cohort A and in 19 patients (95 %) in cohort B (p = 0.487). Metastatic SLNs were detected in 9 patients (22.5 %), 3 (15.0 %) in cohort A and 6 (30.0 %) in cohort B (p = 0.228). The hybrid tracer ICG-{sup 99m}Tc-nanocolloid is an innovative imaging tracer, reliably and readily providing additional information for the detection and excision of SLN in the head and neck region. Therefore, SLNE with combined radioactive and NIR fluorescence guidance is an attractive option for improving the SLN detection rate in patients with cutaneous head and neck malignancies. (orig.)

  7. PENGEMBANGAN SISTEM TRACER STUDY ONLINE BERBASIS WEBSITE DI STMIK AMIKOM YOGYAKARTA

    Directory of Open Access Journals (Sweden)

    Alfie Nur Rahmi

    2014-06-01

    Full Text Available Tracer study is a mechanism that is performed by various parties to keep track of alumni in order to measure the relevance of the purpose and process of education with the current condition of the alumni. In addition, the results of a tracer study was also used as a condition of completeness of accreditation by Badan Akreditasi Nasional Perguruan Tinggi (BAN - PT . Tracer studies can be done in 2 ways , namely tracer manually and online. STMIK AMIKOM Yogyakarta is one of the colleges that have done online with tracer studies utilizing tracer system online at the alumni web pages since 2010. Yet in reality, the system utilization online tracer deemed not optimal in terms of both alumni and the AMIKOM . Based on the analysis of the old system using PIECES analysis, showed some problems and flaws in the old system . The results of this study are expected to prototype a new system able to answer the problems and deficiencies in the old system so that it can optimize the function and use of the online tracer system by the alumni and the AMIKOM.

  8. Simultaneous Analyses and Applications of Multiple Fluorobenzoate and Halide Tracers in Hydrologic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Q; Moran, J E

    2004-01-22

    An analytical method that employs ion chromatography has been developed to more fully exploit the use of fluorobenzoic acids (FBAs) and halides as hydrologic tracers. In a single run, this reliable, sensitive, and robust method can simultaneously separate and quantify halides (fluoride, chloride, bromide, and iodide) and up to seven FBAs from other common groundwater constituents (e.g., nitrate and sulfate). The usefulness of this ion chromatographic (IC) analytical method is demonstrated in both field and laboratory tracer experiments. Field experiments in unsaturated tuff featuring fractures or a fault show that this efficient and cost-effective method helps achieve the objectives of tracer studies that use multiple FBAs and/or diffusivity tracers (simultaneous use of one or more FBA and halide). The field study examines the hydrologic response of fractures and the matrix to different flow rates and the contribution of matrix diffusion in chemical transport. Laboratory tracer experiments with eight geologic media from across the United States--mostly from Department of Energy facilities where groundwater contamination is prevalent and where subsurface characterization employing tracers has been ongoing or is in need--reveal several insights about tracer transport behavior: (1) Bromide and FBAs are not always transported conservatively. (2) The delayed transport of these anionic tracers is likely related to geologic media characteristics, such as organic matter, pH, iron oxide content, and clay mineralogy. (3) Any use of iodine as a hydrologic tracer should take into account the different sorption behaviors of iodide and iodate and the possible conversion of iodine's initial chemical form. (4) The transport behavior of potential FBA and halide tracers under relevant geochemical conditions should be evaluated before beginning ambitious, large-scale field tracer experiments.

  9. Simultaneous Analyses and Applications of Multiple Fluorobenzoate and Halide Tracers in Hydrologic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Q; Moran, J E

    2004-01-22

    An analytical method that employs ion chromatography has been developed to more fully exploit the use of fluorobenzoic acids (FBAs) and halides as hydrologic tracers. In a single run, this reliable, sensitive, and robust method can simultaneously separate and quantify halides (fluoride, chloride, bromide, and iodide) and up to seven FBAs from other common groundwater constituents (e.g., nitrate and sulfate). The usefulness of this ion chromatographic (IC) analytical method is demonstrated in both field and laboratory tracer experiments. Field experiments in unsaturated tuff featuring fractures or a fault show that this efficient and cost-effective method helps achieve the objectives of tracer studies that use multiple FBAs and/or diffusivity tracers (simultaneous use of one or more FBA and halide). The field study examines the hydrologic response of fractures and the matrix to different flow rates and the contribution of matrix diffusion in chemical transport. Laboratory tracer experiments with eight geologic media from across the United States--mostly from Department of Energy facilities where groundwater contamination is prevalent and where subsurface characterization employing tracers has been ongoing or is in need--reveal several insights about tracer transport behavior: (1) Bromide and FBAs are not always transported conservatively. (2) The delayed transport of these anionic tracers is likely related to geologic media characteristics, such as organic matter, pH, iron oxide content, and clay mineralogy. (3) Any use of iodine as a hydrologic tracer should take into account the different sorption behaviors of iodide and iodate and the possible conversion of iodine's initial chemical form. (4) The transport behavior of potential FBA and halide tracers under relevant geochemical conditions should be evaluated before beginning ambitious, large-scale field tracer experiments.

  10. Project definition study for the National Biomedical Tracer Facility

    Energy Technology Data Exchange (ETDEWEB)

    Roozen, K.

    1995-02-15

    The University of Alabama at Birmingham (UAB) has conducted a study of the proposed National Biomedical Tracer Facility (NBTF). In collaboration with General Atomics, RUST International, Coleman Research Corporation (CRC), IsoMed, Ernst and Young and the advisory committees, they have examined the issues relevant to the NBTF in terms of facility design, operating philosophy, and a business plan. They have utilized resources within UAB, CRC and Chem-Nuclear to develop recommendations on environmental, safety and health issues. The Institute of Medicine Panel`s Report on Isotopes for Medicine and the Life Sciences took the results of prior workshops further in developing recommendations for the mission of the NBTF. The IOM panel recommends that the NBTF accelerator have the capacity to accelerate protons to 80 MeV and a minimum of 750 microamperes of current. The panel declined to recommend a cyclotron or a linac. They emphasized a clear focus on research and development for isotope production including target design, separation chemistry and generator development. The facility needs to emphasize education and training in its mission. The facility must focus on radionuclide production for the research and clinical communities. The formation of a public-private partnership resembling the TRIUMF-Nordion model was encouraged. An advisory panel should assist with the NBTF operations and prioritization.

  11. Environmental Tracers

    Directory of Open Access Journals (Sweden)

    Trevor Elliot

    2014-10-01

    Full Text Available Environmental tracers continue to provide an important tool for understanding the source, flow and mixing dynamics of water resource systems through their imprint on the system or their sensitivity to alteration within it. However, 60 years or so after the first isotopic tracer studies were applied to hydrology, the use of isotopes and other environmental tracers are still not routinely necessarily applied in hydrogeological and water resources investigations where appropriate. There is therefore a continuing need to promote their use for developing sustainable management policies for the protection of water resources and the aquatic environment. This Special Issue focuses on the robustness or fitness-for-purpose of the application and use of environmental tracers in addressing problems and opportunities scientifically, to promote their wider use and to address substantive issues of vulnerability, sustainability, and uncertainty in (groundwater resources systems and their management.

  12. Study on Radioecology and Tracer of Iodine-129

    Energy Technology Data Exchange (ETDEWEB)

    Xiaolin, Hou [Riso National Laboratory, NUK, DK, Roskilde (Denmark)

    2004-07-01

    Iodine-129 (15.7 Ma) is a naturally occurring radioisotope of iodine. The ratio of {sup 129}I/{sup 127}I was estimated to be {approx} 10{sup -12} in the ocean and 10{sup -11} in the territorial environment in pre-nuclear era, releases from nuclear weapon tests have increased this ratio to {approx} 10{sup -10}. However, a large amount of iodine-129 was released from various nuclear facilities, and the greatest releases of {sup 129}I are from two European reprocessing plants, especially in recent years. By 1998, 2600 Kg and 220 Kg {sup 129}I have been discharged to the marine environment and atmosphere from La Hague (France) and Sellafield reprocessing plants, respectively. This amount is tens times larger than the total {sup 129}I inventory in the pre-nuclear ocean and weapon test releases. Although there is no significant radiation risk for the human health at present level of {sup 129}I, the continuously increasing production and release of {sup 129}I make the accumulation of {sup 129}I in the environment, immigration, cycle and long term radioecological risk should be give more attention due to its long half-life, high accumulation in human thyroid and high mobility. Iodine is a conservative element in the ocean, the large amount of iodine-129 discharged to the marine system can therefore be used as a oceanographic tracer to study the physical dispersion, mixing and circulative processes of water mass in the ocean. In Riso national laboratory, a radiochemical neutron activation analysis method was developed, using this method the radioecology and tracer of iodine-129 was studied. Some representative works are presented below. (1) Evaluation of radiation exposure of humans to iodine-129. The human and animal thyroids collected from different places, such as Tianjin in China, Gemol in Belarus, Ribe in Denmark, human urine in Denmark, seafood in China were analysed for iodine-129 concentration and {sup 129}I/{sup 127}I ratio, the exposure level were compared with

  13. Artificial ultra-fine aerosol tracers for highway transect studies

    Science.gov (United States)

    Cahill, Thomas A.; Barnes, David E.; Wuest, Leann; Gribble, David; Buscho, David; Miller, Roger S.; De la Croix, Camille

    2016-07-01

    The persistent evidence of health impacts of roadway aerosols requires extensive information for urban planning to avoid putting populations at risk, especially in-fill projects. The required information must cover both highway aerosol sources as well as transport into residential areas under a variety of roadway configurations, traffic conditions, downwind vegetation, and meteorology. Such studies are difficult and expensive to do, but were easier in the past when there was a robust fine aerosol tracer uniquely tied to traffic - lead. In this report we propose and test a modern alternative, highway safety flare aerosols. Roadway safety flares on vehicles in traffic can provide very fine and ultra-fine aerosols of unique composition that can be detected quantitatively far downwind of roadways due to a lack of upwind interferences. The collection method uses inexpensive portable aerosol collection hardware and x-ray analysis protocols. The time required for each transect is typically 1 h. Side by side tests showed precision at ± 4%. We have evaluated this technique both by aerosol removal in vegetation in a wind tunnel and by tracking aerosols downwind of freeways as a function of season, highway configuration and vegetation coverage. The results show that sound walls for at-grade freeways cause freeway pollution to extend much farther downwind than standard models predict. The elevated or fill section freeway on a berm projected essentially undiluted roadway aerosols at distances well beyond 325 m, deep into residential neighborhoods. Canopy vegetation with roughly 70% cover reduced very fine and ultra-fine aerosols by up to a factor of 2 at distances up to 200 m downwind.

  14. Tracer-level radioactive pilot-scale test of in situ vitrification for the stabilization of contaminated soil sites at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, B.P.; Jacobs, G.K.; Naney, M.T. (Oak Ridge National Lab., TN (United States)); Dunbar, N.W. (New Mexico Bureau of Mines and Mineral Resources, Socorro, NM (United States)); Tixier, J.S.; Powell, T.D. (Pacific Northwest Lab., Richland, WA (United States))

    1992-11-01

    A field demonstration of in situ vitrification (ISV) was completed in May 1991, and produced approximately 12 Mg of melted earthen materials containing 12.7 mCi of radioactivity within 500 g of sludge in amodel of an old seepage trench waste disposal unit. Past waste disposal operations at Oak Ridge National Laboratory have left several contaminated seepage sites. In planning for remediation of such sites, ISV technology has been identified as a leading candidate because of the high risks associated with any retrieval option and because of the usual high quality of vitreous waste form. Major isotopes placed in the test trench were [sup 137]Cs and [sup 90]Sr, with lesser amounts of [sup 6O]Co, [sup 241]Am, and [sup 239,240]Pu. A total of 29 MWh of electrical power was delivered to the ground over a 5-day period producing a melt depth of 8.5 ft. During melting, 2.4% of the [sup 137]Cs volatilized from the melt into an off-gas containment hood and was captured quantitatively on a high efficiency particulate air filter. No volatilization of [sup 90]Sr, [sup 241]Am, or [sup 239,240]Pu was detected and > 99.993% retention of these isotopes in the melt was estimated. The use of added rare earth tracers (Ce, La, and Nd), as surrogates for transuranic isotopes, led to estimated melt retentions of >99.9995% during the test. The molten material, composed of the native soil and dolomitic limestone used for filling the test trench, reached a processing temperature of 1500[degrees]C. Standardized leaching procedures using Product Consistency Testing indicated that the ISV product has excellent characteristics relative to other vitreous nuclear waste forms.

  15. Radioisotope tracer studies in the NASA Skylab ethothermic brazing experiment M-552

    Science.gov (United States)

    Braski, D. N.; Adair, H. L.; Kobisk, E. H.

    1974-01-01

    The first use of radioisotope tracer for mapping flow patterns during brazing of metal components in a space environment (near-zero gravity) proved successful. A nickel ferrule was brazed to a nickel tube with Lithobraze BT (71.8% Ag, 28% Cu, 0.2% Li) which contained a trace amount of radioactive Ag-110. Mapping of the flow of the braze alloy in the annulus formed between the tube and the concentric ferrule was determined by counting the radiation intensity as a function of position in the braze joint. Significant information concerning the thermal history of the braze was determined.

  16. Technetium-99m labelled heparin: potential value as a tracer of heparin activity in pharmacokinetic and biodistribution studies

    Energy Technology Data Exchange (ETDEWEB)

    Perdrisot, R.; Barbu, M.; Bok, B.; Berthelot, J.L.; Mazoyer, B.; Colas-Linhart, N. (Laboratoire de Biophysique des Traceurs, Faculte 10-Bichat, 75 - Paris (France))

    1984-01-01

    Pharmacokinetics and biodistribution of 99m Technetium (sup(99m)Tc) labelled heparin were studied to assess its value as a tracer of heparin kinetics in comparison with unlabelled heparin. In vitro, the stability and labelling efficiency (98%) of the labelled drug were excellent and elution was minimal. In vivo, after I.V. infusion of the drug, there was no difference in the same animal between anticoagulant activity measurements and radioactive countings, both displaying a plasmatic biexponential pattern (T/sub 1/=2.9 minutes, T/sub 2/=76 minutes). Biodistribution studies showed primarily liver, spleen and kidney accumulation, with no thyroid uptake. The advantages of this technetium labelling may therefore be used for the heparin drug in various experimental and pathological situations even in humans.

  17. Study on CYCIAE-100 radiation field and residual radioactivity

    Institute of Scientific and Technical Information of China (English)

    BI Yuan-Jie; ZHANG Tian-Jue; JIA Xian-Lu; ZHOU Zheng-He; WANG Feng; WEI Su-Min; ZHONG Jun-Qing; TANG Chuan-Xiang

    2009-01-01

    The accelerators should be properly designed to make the radiation field produced by beam loss ual radiation field.The induced radioactivity in accelerator components is the dominant source of occupational radiation exposure if the accelerator is well shielded.The source of radiation is the beam loss when cyclotron is operating.In this paper,the radiation field for CYCIAE-100 is calculated using Monte Carlo method and the radioactive contamination near stripping foil is studied.A method to reduce the dose equivalent rate of maintenance staff is also given.

  18. Study of two different radioactive sources for prostate brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Neves, Lucio; Perini, Ana Paula [Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG (Brazil); Souza Santos, William de; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear, IPENCNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil); Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA (Brazil)

    2015-07-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a {sup 192}Ir and a {sup 125}I radioactive sources. The {sup 192}Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The {sup 125}I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of {sup 125}I and one of {sup 192}Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the {sup 192}Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the {sup 125}I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  19. Air pollution tracer studies in the lower atmosphere. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The bibliography contains citations concerning the use of tracers to study lower atmospheric air pollution movements. Citations discuss project descriptions and results, techniques, and tracer materials. Tracer movement from nuclear power plants, industrial stacks, and urban areas is discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  20. Basic study on behaviors of radioactive and toxic inorganic elements in environment, and environmental assessment for geological disposal of high-level radioactive wastes. Outline of the prize-winning study of the 12th Osaka Nuclear Science Corporation Prize

    Energy Technology Data Exchange (ETDEWEB)

    Fujikawa, Yoko; Kudo, Akira [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1999-01-01

    This study was made aiming to establish geological disposal technology for high-level radioactive wastes generated in nuclear power plant. A basic study for the technology was made using various radioactive materials containing Pu, U, Cs, Se, etc. as a tracer. First, adsorption mechanisms of various nuclides in ground water such as Cs, Co, Se, etc. onto rocks were investigated by indoor experiment. A certain correlation between the apparent adsorption rate of a nuclide onto rocks and diffusion coefficient into micropores in rocks was demonstrated both theoretically and experimentally. To estimate the radionuclide migration during more than one thousand years based on the results from indoor experiments is difficult, so that construction of a mathematical model was attempted to make numerical simulation. Thus,it was suggested that the properties of underground barrier are considerably related to the adsorption rates of nuclides and also diffusion coefficients into micropores. In addition, the effects of soil microorganisms and organic compounds on the behaviors of radioactive nuclides in soil ecosphere were investigated by extra-low level analysis of long-life radioactivities. More than 10% of Pu derived from Atomic Bomb at Nagasaki were found to be strongly bound to organic compounds in soils, showing that the element is extremely reactive with organic substances. (M.N.)

  1. Study of resonant reactions with radioactive ion beams

    CERN Document Server

    Galindo-Uribarri, A; Chavez, E; Gomez-Del Campo, J; Gross, C J; Huerta, A; Liang, J F; Ortiz, M E; Padilla, E; Pascual, S; Paul, S D; Shapira, D; Stracener, D W; Varner, R L

    2000-01-01

    A fast and efficient method to study (p,p) and (p,alpha) resonances with radioactive beams in inverse kinematics is described. It is based on the use of thick targets and large area double-sided silicon strip detectors (DSSDs) to detect the recoiling light-charged particles and to determine precisely their scattering angle. The first nuclear physics experiments with the technique have been performed recently at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge with stable beams of sup 1 sup 7 O and radioactive beams of sup 1 sup 7 F. The high-quality resonance measurements obtained demonstrate the capabilities of the technique. Pure sup 1 sup 7 F beams from HRIBF were produced by fully stripping the ions and separating the interfering and more abundant sup 1 sup 7 O ions by the beam transport system. The removal of interfering isobars is one of the various common challenges to both accelerator mass spectrometry (AMS) and radioactive ion beam (RIB) production. Experiments done with RIBs will ben...

  2. Glass mixing theory and tracer study results from the SF-10 run

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, B.W.; Routt, K.R.

    1988-08-01

    A general, partial differential equation governing glass mixing in the Slurry Fed Ceramic Melter (SFCM) was derived and a solution obtained based upon certain simplifying assumptions. Tracer studies were then conducted in the SFCM during the SF-10 run to test the theory and characterize glass mixing in this melter. Analysis of the tracer data shows that glass mixing in the SFCM can be explained by use of a model of two, well-mixed tanks in series.

  3. Studies on the Extraction of Gold(I) Cyanide by Quaternary Ammonium Salt Using 198Au as Tracer

    Institute of Scientific and Technical Information of China (English)

    ZHANGTianxi; CHENJing; 等

    2002-01-01

    The solvent extraction of KAu(CN)2 from alkaline solution by quaternary ammonium salts (trialkylmethylammonium chloride or cetyltrimethylammonium bromide) waw investigated by means of 198Au radioactive tracer method. Various parameters,such as the gold (I) concentration in aqueous phase,the modiffer,emulsifiation at the interface of two phases, and phase ratio used in the extraction of gold (I) were studied. The results demonstrate that almost all gold (I) in the aqueous phase was practically extracted into the organic phase. The water content in the organic phase decreased significantly with increase of gold (I) concentration using long chain alcohol as modifier,in contrast with the system with tributyl phosphate (TBP) as modifier. Emulsification at the interface of two phases decreases with an increase of modifier concentration in the organic phase or with the addition of a small amount of lysozyme into the aqueous phase. The method with 198Au tracer can be directly used to determine the Au(I) concentration both in aqueous and organic phases, which is especially suitable for the low concentration of Au(I).

  4. Using biofuel tracers to study alternative combustion regimes

    Science.gov (United States)

    Mack, J. H.; Flowers, D. L.; Buchholz, B. A.; Dibble, R. W.

    2007-06-01

    Interest in the use of alternative fuels and engines is increasing as the price of petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of the new passenger car market. Unfortunately, lower CO2 emissions are countered with higher nitrogen oxides (NOx) and particulate matter (PM) emissions and higher noise. Adding oxygenated compounds to the fuel helps reduce PM emissions. However, relying on fuel alone to reduce PM is unrealistic due to economic constraints and difficult due to the emerging PM standards. Keeping peak combustion temperature below 1700 K inhibits NOx formation. Altering the combustion regime to burn at temperatures below the NOx threshold and accept a wide variety of fuels seems like a promising alternative for future engines. Homogeneous charge compression ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the fuel-air mixture by the piston. HCCI is rapid and relatively cool, producing little NOx and PM. Unfortunately, it is hard to control since HCCI is initiated by temperature and pressure instead of a spark or direct fuel injection. We investigate biofuel HCCI combustion, and use intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to improve our combustion modeling.

  5. Urban Dispersion Program MSG05 Field Study: Summary of Tracer and Meteorological Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2006-08-09

    The Urban Dispersion Program is a multi-year project, funded by the U.S. Department of Homeland Security, to better understand the flow and dispersion of airborne contaminants through and around the deep street canyons of New York City. The first tracer and meteorological field study was a limited study conducted during March 2005 near the Madison Square Garden in midtown Manhattan. Six safe, inert, gaseous perfluorocarbon tracers were released simultaneously at five street-level locations during two experimental days. In addition to collecting tracer data, meteorological data were also collected. Brookhaven National Laboratory conducted the bulk of the tracer and meteorological field efforts with Pacific Northwest National Laboratory and Stevens Institute of Technology assisting by measuring the vertical profile of winds. The Environmental Protection Agency worked with Brookhaven National Laboratory in accomplishing the personal exposure component of the study. This report presents some results from this analysis. In general, different release locations showed vastly different plume footprints for tracer materials, and the situation was made very complex with upwind and/or crosswind transport of tracer near street-level for the different release locations. Overall wind speeds and directions upwind and over the city were generally constant throughout each of the two experimental periods.

  6. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Axel

    2008-06-27

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies.

  7. Radioactive Lysine in Protein Metabolism Studies

    Science.gov (United States)

    Miller, L. L.; Bale, W. F.; Yuile, C. L.; Masters, R. E.; Tishkoff, G. H.; Whipple,, G. H.

    1950-01-09

    Studies of incorporation of DL-lysine in various body proteins of the dog; the time course of labeled blood proteins; and apparent rate of disappearance of labeled plasma proteins for comparison of behavior of the plasma albumin and globulin fractions; shows more rapid turn over of globulin fraction.

  8. Digital signal processing for radioactive decay studies

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Madurga, M.; Paulauskas, S. V. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Ackermann, D.; Heinz, S.; Hessberger, F. P.; Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64220, Darmstadt (Germany); Grzywacz, R. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Miernik, K.; Rykaczewski, K. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Tan, H. [XIA LLC, Hayward, CA 94544 (United States)

    2011-11-30

    The use of digital acquisition system has been instrumental in the investigation of proton and alpha emitting nuclei. Recent developments extend the sensitivity and breadth of the application. The digital signal processing capabilities, used predominately by UT/ORNL for decay studies, include digitizers with decreased dead time, increased sampling rates, and new innovative firmware. Digital techniques and these improvements are furthermore applicable to a range of detector systems. Improvements in experimental sensitivity for alpha and beta-delayed neutron emitters measurements as well as the next generation of superheavy experiments are discussed.

  9. Radioactive geochronometry from the treatise on geochemistry

    CERN Document Server

    Holland, H D

    2011-01-01

    The history of Earth in the Solar System has been unraveled using natural radioactivity. The sources of this radioactivity are the original creation of the elements and the subsequent bombardment of objects, including Earth, in the Solar System by cosmic rays. Both radioactive and radiogenic nuclides are harnessed to arrive at ages of various events and processes on Earth. This collection of chapters from the "Treatise on Geochemistry" displays the range of radioactive geochronometric studies that have been addressed by researchers in various fields of Earth science. These range from the age of Earth and the Solar System to the dating of the history of Earth that assists us in defining the major events in Earth history. In addition, the use of radioactive geochronometry in describing rates of Earth surface processes, including the climate history recorded in ocean sediments and the patterns of circulation of the fluid Earth, has extended the range of utility of radioactive isotopes as chronometric and tracer ...

  10. A novel electrophilic synthesis and evaluation of medium specific radioactivity (1R,2S)-4-[{sup 18}F]fluorometaraminol, a tracer for the assessment of cardiac sympathetic nerve integrity with PET

    Energy Technology Data Exchange (ETDEWEB)

    Eskola, Olli E-mail: olesko@utu.fi; Groenroos, Tove; Bergman, Joergen; Haaparanta, Merja; Marjamaeki, Paeivi; Lehikoinen, Pertti; Forsback, Sarita; Langer, Oliver; Hinnen, Francoise; Dolle, Frederic; Halldin, Christer; Solin, Olof

    2004-01-01

    (1R,2S)-4-[{sup 18}F]fluorometaraminol (4-[{sup 18}F]FMR), a tracer for cardiac sympathetic innervation, was synthesized by electrophilic aromatic substitution. A trimethylstannyl precursor, protected with tert-butoxycarbonyl protecting groups, was radiofluorinated with high specific radioactivity [{sup 18}F]F{sub 2}. Specific radioactivity of 4-[{sup 18}F]FMR, in average 11.8 {+-}3.3 GBq/{mu}mol, was improved 40-800-fold in comparison to the previous electrophilic fluorinations. The biodistribution of 4-[{sup 18}F]FMR in rat was in accordance with the known distribution of sympathetic innervation. 4-[{sup 18}F]FMR showed no metabolic degradation in left ventricle of rat heart, where the uptake was high, rapid and specific.

  11. Radioactivity Confinement Studies Within the SEAL Program

    Science.gov (United States)

    Collén, Jan; Matsugu, Ron; Natalizio, Antonio; Shen, Kecheng

    1997-09-01

    In the framework of the European SEAL program, investigations have been performed with the aim of optimizing the second confinement function and plant layout with respect to normal operation as well as abnormal operation, including accident conditions. This has been done for two conceptual fusion reactor designs: one using water as the coolant and the other using helium. The starting point of these investigations was the SEAFP project design. For the water-cooled reactor design the studies were focused on design options such as pressure suppression spray system, pressure suppression pool with closed containment or with venting to gravel bed filter and stack, and separate expansion volume optionally operated with a vacuum and equipped with spray system. Similar analyses were performed for the helium-cooled reactor design. The analyses were focused on design options comprising a single, large confinement volume or a vent duct connected to an expansion volume operated at vacuum in comparison with the SEAFP Model 1. The thermal-hydraulic analyses performed with the MELCOR code provide an integrated assessment of the cooling loop and confinement system dynamics.

  12. A study of environmental radioactivity measurements for Cankiri, Turkey.

    Science.gov (United States)

    Kapdan, Enis; Taskin, Halim; Kam, Erol; Osmanlioglu, A Erdal; Karahan, Gursel; Bozkurt, Ahmet

    2012-07-01

    This study is the first to assess the level of background radiation for the Cankiri province of Turkey. Indoor air radon concentrations were determined using Columbia Resin-39 nuclear track detectors and the average (222)Rn activity was found to be 44 Bq m(-3) (equivalent to an annual effective dose of 1.1 mSv). Measurements of gamma doses in outdoor air were performed using a portable plastic scintillation detector and the average gamma absorbed dose rate was found to be 8 μR h(-1) (corresponding to an annual effective dose of 87.7 μSv). Radionuclide activity concentrations in soil samples were measured through gamma-ray spectrometry and the average activities were determined as 17.7, 22.3, 357 and 4.1 Bq kg(-1) for the radionuclides (238)U, (232)Th, (40)K and (137)Cs, respectively. The average annual effective dose from the natural radioactivity sources ((238)U series, (232)Th series and (40)K) was calculated to be 44.4 μSv. Radioactivity levels of drinking water samples were carried out using a low-background proportional counter and the average gross alpha and beta activities were obtained as 0.25 and 0.26 Bq l(-1), respectively (equivalent to an annual effective dose of 184 μSv). The average radon concentrations in indoor air and the average radionuclide activities in soil were found to be lower than most Turkish cities while higher levels of outdoor gamma dose rate and water radioactivity were observed. The results of this study showed that the region's background radioactivity level differs considerably from the reported data for Turkish cities.

  13. Study on a Cosmic-ray-produced Silicon-32 as a Tracer for Ocean Processes

    Directory of Open Access Journals (Sweden)

    ZHOU Peng

    2015-01-01

    Full Text Available The isotope silicon-32, with a half-life of approximately 150 years, is a cosmic-ray-produced radioactive nuclide in the atmosphere. Due to its single source and the relatively constant production rate, silicon-32 with its chemical and biological characteristics like the other stable silicon isotopes always has been seen as an ideal clock and tracer which has the potential to fill the dating time-gap and to understand marine from 50 to 1 000 years geochemical-geophysical processes, e.g. the seawater mixing process in offshore and ocean, the geochemistry and cycle of silica in estuary and ocean, the particles mixing process in the deep sea bed, as well as the estimation of the sediment deposition rate and the establishment of the time-sequence to reflect the past marine environmental changes.

  14. Tracer monitoring of enhanced oil recovery projects

    Directory of Open Access Journals (Sweden)

    Kleven R.

    2013-05-01

    Full Text Available In enhanced oil recovery (EOR, chemicals are injected into the oil reservoir, either to increase macroscopic sweep efficiency, or to reduce remaining oil saturation in swept zones. Tracers can be used to identify reservoirs that are specifically suited for EOR operations. Injection of a selection of partitioning tracers, combined with frequent sample analysis of produced fluids, provides information suited for estimation of residual oil saturation. Tracers can also be used to evaluate and optimize the application of EOR chemicals in the reservoir. Suitable tracers will follow the EOR chemicals and assist in evaluation of retention, degradation or trapping. In addition to field applications, tracers also have a large potential as a tool to perform mechanistic studies of EOR chemicals in laboratory experiments. By labelling EOR chemicals with radioactive isotopes of elements such as H, C and S, detailed studies of transport mechanisms can be carried out. Co-injection of labelled compounds in dynamic flooding experiments in porous media will give information about retention or separation of the unique compounds constituting the chemical formulation. Separation of such compounds may be detrimental to obtaining the EOR effect expected. The paper gives new information of specific methods, and discusses current status for use of tracers in EOR operations.

  15. Tracer studies of anodic films formed on aluminium in malonic and oxalic acids

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Vergara, S.J. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom)], E-mail: s.garcia-vergara@manchester.ac.uk; Skeldon, P.; Thompson, G.E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom); Habakaki, H. [Graduate School of Engineering, Hokkaido University, N13-W8, Sapporo 060-8628 (Japan)

    2007-12-30

    Using a tungsten-containing layer, incorporated into sputtering-deposited aluminium, as a tracer, the growth of porous anodic films in malonic and oxalic acid electrolytes has been investigated using transmission electron microscopy, Rutherford backscattering spectroscopy and nuclear reaction analysis. Comparisons were also made with films formed in phosphoric acid electrolyte, which have been studied previously. The findings reveal a distortion of the tracer layer within the barrier region of the porous films, evident as a lagging of the tracer beneath the pores relative to that in the adjacent cell wall region. Further, the films are significantly thicker than the layer of metal consumed during anodizing and display smooth-sided pores. The anodizing behaviours are consistent with a major role for field-assisted flow of film material within the barrier layer in the development of the pores.

  16. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Progress report, October 1, 1994--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Stetzenbach, K.; Farnham, I.

    1994-12-31

    The bromide anion has been used extensively as a tracer for mapping the flow of groundwater. It has proven to be both a safe and reliable groundwater tracer. The goal in this study is to find several tracing compounds with characteristics similar to the bromide anion to be used in multiple well tracing tests. Four groups of fluorinated organic acids were selected as candidates for groundwater tracers. These groups include fluorinated benzoic acids (FBA), fluorinated salicylic acids (FSA), fluorinated toluic acids (FTA), and fluorinated cinnamic acids (FCA). These compounds have been shown to move readily with the flow of water and do not adsorb to soil. They are also non-toxic. In this study, the retention of the fluorinated organic acids on to a soil column is compared to that of the bromide ion. The time required for the elution of each analyte from the soil column is measured using a UV-Vis detector. The soils consist of the light, medium, and dark tuffs used in the batch study. The work performed during this quarter consists of the continuation of the batch studies for the fluorinated benzoic acids and column studies for several potential tracer compounds.

  17. A study on the treatment of radioactive slurry liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Gyeong Hwan; Jung, K. J.; Baik, S. T.; Chung, U. S.; Lee, K. W.; Park, S. K.; Lee, D. G.; Kim, H. R

    2001-01-01

    The aim of this study is to offer the advanced technology of the RSLW treatment during the Decontamination and Decommission(D and D) work of the TRIGA research reactors. Basis concept of the RSLW treatment and relating the equipment were investigated in this year of the project. The experimental equipments such as the rotary vacuum filtration equipment and the centrifuge equipment are designed and developed in order to treat the RSLW considering the minimization of the effective dose for operator and the protection of the diffusion by of the radioactive material.

  18. Environmental radionuclides tracers and timers of terrestrial processes

    CERN Document Server

    Froehlich, Klaus

    2009-01-01

    The book presents a state-of-the-art summary of knowledge on the use of radionuclides to study processes and systems in the continental part of the Earth's environment. It is conceived as a companion to the two volumes of this series, which deal with isotopes as tracers in the marine environment (Livingston, Marine Radioactivity) and with the radioecology of natural and man-made terrestrial systems (Shaw, Radioactivity in Terrestrial Ecosystems). Although the book focuses on natural and anthropogenic radionuclides (radioactive isotopes), it also refers to stable environmental isotopes, which i

  19. [Studies on percutaneous absorption of ruyi jinhuang san patcher with radioisotope tracer].

    Science.gov (United States)

    Zhao, H W; Shen, Z; Zhou, B; Lin, X; Ye, M

    1993-04-01

    Berberine is one of the active ingredients in Ruyi Jinhuang San Patcher. With 3H-berberine as the tracer, a radio-labelled method was used for determining percutaneous rate and drug concentration of berberine in plasma in vivo and in vitro. A study on the percutaneous rate of different technological plasters and various animal skins was also carried out.

  20. Technical Secondary Schools and the Labour Market: Some Results from a Tracer Study in Kenya.

    Science.gov (United States)

    Narman, Anders

    1988-01-01

    Reports tracer studies of Kenyan youths leaving technical school to determine their success at obtaining gainful employment. Almost 43% were neither in formal schooling nor training, nor employed a year after leaving, although technical skills were seen as useful, particularly in private life. (DP)

  1. Obtention of the cation exchange capacity of a natural kaolinite with radioactive tracers; Obtencion de la capacidad de intercambio cationico de una kaolinita natural con trazadores radioactivos

    Energy Technology Data Exchange (ETDEWEB)

    Uribe I, A.; Badillo A, V.E. [Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: Adrya81@hotmail.com

    2005-07-01

    One of the more used techniques for the elimination of the heavy metals present in water systems is to use adsorbent mineral phases like zeolites and clays, among others. The clays are able to exchange easily the fixed ions in the external surface of its crystals or well the ions present in the interlaminar spaces of the structures, for other existent ones in the encircling aqueous solutions for that the Cation exchange capacity (CIC) is defined as the sum of all the cations exchange that a mineral can possess independent to the physicochemical conditions. The CIC is equal to the measure of the total of negative charges of the mineral by mass of the solid (meq/g). In this investigation work, the value of the CIC equal to 2.5 meq/100 g is obtained, of a natural kaolinite from the State of Hidalgo studying the retention of the sodium in the kaolinite with the aid of the radioactive isotope {sup 24} Na and of the selective electrodes technique, making vary the pH value. So is experimentally demonstrated that the CIC is an intrinsic property of the mineral independent of the pH value of the solution and of the charges origin. (Author)

  2. Study of the movement of materials in rotary kilns with aid of radioactive tracers

    Directory of Open Access Journals (Sweden)

    Grasland, G.

    1966-09-01

    Full Text Available Not availableEl cemento portland se compone, esencialmente, de silicatos cálcicos. Se obtiene por cocción en un horno rotativo de una mezcla apropiada de caliza y arcilla. Las temperaturas alcanzadas en el curso de esta operación son del orden de 1.500 °C. Por esta razón, la marcha de los materiales en el horno se hace difícilmente accesible a los métodos habituales de experimentación; no se puede apenas más que observar el resultado final, o, por medidas indirectas, tratar de dar unas explicaciones más o menos convincentes. Los trazadores radiactivos permiten paliar esta laguna; es lo que precisamente se ha hecho en las experiencias que señalaremos a continuación, realizadas hace tiempo ya por M. Rabot en colaboración con el C.E.A.

  3. The study on recycle scheme of the metallic radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Shin, J. I.; Jung, K. J.; Paik, S. T.; Chung, U. S.; Park, J. H.; Park, S. K.; Hwang, D. S.; Lee, D. G.; Kim, H. R

    2002-01-01

    It was understood that regulation criteria for material release varied with countries and that international standards were not setup. But, most advanced countries are continuously studying on the recycling of metallic wastes for the purpose of the reuse of resources and disposal cost reduction. Practically, the advanced countries make a lot of cost profits compared with disposal as their metallic wastes are recycled and reused through technology like melting. The reasonable international standards are also expected to be set in the near future because of the aggressive cooperation between international agencies such as IAEA and NEA toward recycling these wastes. In our case, the recycle criteria for radioactive waste containing radioactive nuclide with long half-life such as Cs-137(half-life: 30y) and Co-60(half-life: 5.26y) including others, which are generated from the nuclear fission or dismantling of nuclear facilities, are not yet established. Therefore, it is required that the recommendation and legalization of the regulatory criteria be carried out for the recycle and reuse of metallic wastes to be generated from the dismantling of domestic nuclear facilities in the future.

  4. A state space transformation can yield identifiable models for tracer kinetic studies with enrichment data.

    Science.gov (United States)

    Ramakrishnan, Rajasekhar; Ramakrishnan, Janak D

    2010-11-01

    Tracer studies are analyzed almost universally by multicompartmental models where the state variables are tracer amounts or activities in the different pools. The model parameters are rate constants, defined naturally by expressing fluxes as fractions of the source pools. We consider an alternative state space with tracer enrichments or specific activities as the state variables, with the rate constants redefined by expressing fluxes as fractions of the destination pools. Although the redefinition may seem unphysiological, the commonly computed fractional synthetic rate actually expresses synthetic flux as a fraction of the product mass (destination pool). We show that, for a variety of structures, provided the structure is linear and stationary, the model in the enrichment state space has fewer parameters than that in the activities state space, and is hence better both to study identifiability and to estimate parameters. The superiority of enrichment modeling is shown for structures where activity model unidentifiability is caused by multiple exit pathways; on the other hand, with a single exit pathway but with multiple untraced entry pathways, activity modeling is shown to be superior. With the present-day emphasis on mass isotopes, the tracer in human studies is often of a precursor, labeling most or all entry pathways. It is shown that for these tracer studies, models in the activities state space are always unidentifiable when there are multiple exit pathways, even if the enrichment in every pool is observed; on the other hand, the corresponding models in the enrichment state space have fewer parameters and are more often identifiable. Our results suggest that studies with labeled precursors are modeled best with enrichments.

  5. Use of tracers for mud filtrate and completion fluid invasion studies

    Energy Technology Data Exchange (ETDEWEB)

    Kleven, Reidun [Statoil DDB, Bergen (Norway); Dahl, John Blessum; Bjoernstad, Tor; Qvenild, Carsten; Tollan, Odd [Institutt for energiteknikk, Kjeller (Norway)

    1996-09-30

    The objectives of this work are (1): to study sorption/desorption of mud filtrate ions near the wellbore region by using water sampled with a formation tester equipment (FTE); (2) to study sorption/desorption of ions in the mud filtrate and the completion fluid by monitoring the ionic composition of produced water; (3) to determine the fraction of mud filtrate and completion fluid water in produced water; and (4) develop a suitable and safe tracer method. A tracer method was developed to measure sorption/desorption of various ions infiltrating the reservoir during drilling and completion of a well. Tritiated water (HTO) was used to tag the mud filtrate and bromide ion (Br{sup -}) to tag the completion fluid. The measurements are based on analysis of FTE and produced water samples. The ionic concentrations observed are compared with corresponding `no sorption/desorption` concentration values determined theoretically. Special attention is paid to the `tracer diagram` of an open well, because a `no sorption/desorption curve` can be expressed in a straight line in a linear coordinate system. Observed deviations from these curves show that sorption/desorption processes have taken place. The tracer method presented was useful to determine the distribution of ions in the pore-water/sedimentary rock system near the wellbore

  6. Field studies of transport and dispersion of atmospheric tracers in nocturnal drainage flows

    Energy Technology Data Exchange (ETDEWEB)

    Gudiksen, P.H.; Ferber, G.J.; Fowler, M.M.; Eberhard, W.L.; Fosberg, M.A.; Knuth, W.R.

    1984-01-01

    A series of tracer experiments were carried out as part of the Atmospheric Studies in Complex Terrain (ASCOT) program to evaluate pollutant transport and dispersion characteristics of nocturnal drainage flows within a valley in northern California. The results indicate that the degree of interaction of the drainage flows with the larger scale regional flows are strongly dependent on how well the shallow drainage flows are shielded by the surrounding topography from the external environment. For the valley under study, the drainage flows from about mid-slope elevations and below were generally decoupled from the externally generated flows; as evidenced by the similarity of the surface tracer distribution produced during widely varying regional flow conditions. However, tracers released immediately above the drainage flows near the ridge top did reveal considerable mixing between the transition layer flows and the underlying surface drainage flows. Likewise, the transport and dispersion of the tracers at elevated heights within the valley basin were extremely dependent on the influences of the regional scale flows on the valley circulation. The dispersion rates associated with the transition layer flows were dependent on topographic constraints but were appreciably higher than those reported for homogeneous flat terrain situations.

  7. Isotope pattern deconvolution as rising tool for isotope tracer studies in environmental research

    Science.gov (United States)

    Irrgeher, Johanna; Zitek, Andreas; Prohaska, Thomas

    2014-05-01

    During the last decade stable isotope tracers have emerged as versatile tool in ecological research. Besides 'intrinsic' isotope tracers caused by the natural variation of isotopes, the intentional introduction of 'extrinsic' enriched stable isotope tracers into biological systems has gained significant interest. Hereby the induced change in the natural isotopic composition of an element allows amongst others for studying the fate and fluxes of metals, trace elements and species in organisms or provides an intrinsic marker or tag of particular biological samples. Due to the shoreless potential of this methodology, the number of publications dealing with applications of isotope (double) spikes as tracers to address research questions in 'real world systems' is constantly increasing. However, some isotope systems like the natural Sr isotopic system, although potentially very powerful for this type of application, are still rarely used, mainly because their adequate measurement/determination poses major analytical challenges; as e.g. Sr is available in significant amounts in natural samples. In addition, biological systems underlie complex processes such as metabolism, adsorption/desorption or oxidation/reduction. As a consequence, classic evaluation approaches such as the isotope dilution mass spectrometry equation are often not applicable because of the unknown amount of tracer finally present in the sample. Isotope pattern deconvolution (IPD), based on multiple linear regression, serves as simplified alternative data processing strategy to double spike isotope dilution calculations. The outstanding advantage of this mathematical tool lies in the possibility of deconvolving the isotope pattern in a spiked sample without knowing the quantities of enriched isotope tracer being incorporated into the natural sample matrix as well as the degree of impurities and species-interconversion (e.g. from sample preparation). Here, the potential of IPD for environmental tracer

  8. Measurement of Kr-85 and Xe-133 as undisturbed tracers for the representing of atmospheric transport after disposal of radioactivity from nuclear facilities; Messungen von Kr-85 und Xe-133 als ungestoerte Tracer zur Darstellung atmosphaerischer Transportvorgaenge nach Freisetzung von Radioaktivitaet aus kerntechnischen Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Frank, G.; Steinkopff, T. [Deutscher Wetterdienst (Germany); Salvamoser, J. [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen (IGU), Woerthsee (Germany)

    2016-07-01

    The Deutscher Wetterdienst (DWD, German Meteorological Service) operates since 1996 a sampling and measurement device for the radioactive rare gases Kr-85 and Xe-133 in Offenbach. These measurements are embedded in the German Measurement and Information System for Monitoring Environmental Radioactivity (Integriertes Mess- und Informationssystem zur Ueberwachung der Radioaktivitaet in der Umwelt, IMIS) [1]. In addition to these measurements the DWD is sampling rare gases in Potsdam and since 2014 in Trier in cooperation with the Bundesamt fuer Strahlenschutz (Federal Office for Radiation Protection, BfS). In the frame of the Global Atmosphere Watch (GAW)-program of the WMO the DWD operated a sampling station at the Zugspitze (Schneefernerhaus) from 1999 to 2005. This location at the Zugspitze is well suited for the observation of long distance transport of Kr-85 in the higher atmosphere. The DWD in Offenbach operates a complex analytical system for the measurement of Kr-85 and Xe-133 since 1998. This system consists of sampling with first enrichment, second enrichment, gas chromatographic separation and preparation of Krypton and Xenon and measurement of Kr-85 and Xe-133. Using the example Fukushima, it is shown, that the radioactive rare gases Kr-85 and Xe-133 are well undisturbed tracers for atmospheric transport in case of a nuclear accident or routine nuclear reprocessing plants. Measurements of Xe-133, I-131, Cs-137 and Kr-85 are correlated with source and atmospheric transport to the sampling sites at Offenbach and Potsdam.

  9. Studies of colossal magnetoresistive oxides with radioactive isotopes

    CERN Document Server

    CERN. Geneva. ISOLDE and Neutron Time-of-Flight Experiments Committee; Amaral, V S; Araújo, J P; Butz, T; Correia, J G; Dubourdieu, C; Habermeier, H U; Lourenço, A A; Marques, J G; Da Silva, M F A; Senateur, J P; Soares, J C; Sousa, J B; Suryan, R; Tokura, Y; Tavares, P B; Tomioka, Y; Tröger, W; Vantomme, A; Vieira, J M; Wahl, U; Weiss, F P; INTC

    2000-01-01

    We propose to study Colossal Magnetoresistive (CMR) oxides with several nuclear techniques, which use radioactive elements at ISOLDE. Our aim is to provide local and element selective information on some of the doping mechanisms that rule electronic interactions and magnetoresistance, in a complementary way to the use of conventional characterisation techniques. Three main topics are proposed: \\\\ \\\\ a) Studies of local [charge and] structural modifications in antiferromagnetic LaMnO$_{3+ \\delta}$ and La$_{1-x}$R$_{x}$MnO$_{3}$ with R=Ca and Cd, doped ferromagnetic systems with competing interactions: - research on the lattice site and electronic characterisation of the doping element. \\\\ \\\\ b) Studies of self doped La$_{x}$R$_{1-x}$MnO$_{3+\\delta}$ systems, with oxygen and cation non-stoichiometry: -learning the role of defects in the optimisation of magnetoresistive properties. \\\\ \\\\ c) Probing the disorder and quenched random field effects in the vicinity of the charge or orbital Ordered/Ferromagnetic phase...

  10. Studies of Colossal Magnetoresistive Oxides with Radioactive Isotopes

    CERN Multimedia

    2002-01-01

    We propose to study Colossal Magnetoresistive (CMR) oxides with several nuclear techniques, which use radioactive elements at ISOLDE. Our aim is to provide local and element selective information on some of the doping mechanisms that rule electronic interactions and magneto- resistance, in a complementary way to the use of conventional characterisation techniques. Three main topics are proposed: \\\\ \\\\ a) Studies of local [charge and] structural modifications in antiferromagnetic LaMnO$_{3+\\delta}$ and La$_{1-x}$R$_{x}$MnO$_{3}$ with R=Ca and Cd, doped ferromagnetic systems with competing interactions: - research on the lattice site and electronic characterisation of the doping element. \\\\ \\\\ b) Studies of self doped La$_{x}$R$_{1-x}$MnO$_{3+\\delta}$ systems, with oxygen and cation non- stoichiometry: - learning the role of defects in the optimisation of magnetoresestive properties. \\\\ \\\\ c) Probing the disorder and quenched random field effects in the vicinity of the charge or orbital Ordered/Ferromagnetic p...

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

    Science.gov (United States)

    Szabó, Zs; Völgyesi, P; Nagy, H É; Szabó, Cs; Kis, Z; Csorba, O

    2013-04-01

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point

  12. Preliminary study of radioactive waste disposal in the vadose zone

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

    To investigate the characteristics of the vadose zone with respect to radioactive waste disposal, the mechanics of unsaturated flow in arid regions and the geohydrology of four areas with a deep water table were studied. The studies indicated that (1) arid sites with a water table deeper than 200 m can be found in at least three distinct geologic settings in the western United States, (2) the physics of unsaturated flow in soils and rock with interstitial porosity at low water contents, particularly under thermal gradients, is not yet completely understood, and (3) under certain conditions unsaturated flow can be so slow that analytic modeling of an unflawed repository is unnecessary to prove effective containment.

  13. Giant-resonance studies with radioactive beams : Perspectives

    NARCIS (Netherlands)

    Harakeh, M.N.

    First-generation radioactive ion-beam facilities have already been in operation for some time. Advanced facilities that will deliver high-intensity radioactive nuclear beams ranging in energy from below the Coulomb barrier to up to several hundred MeV per nucleon (MeV/u) are either starting

  14. Direct reaction experimental studies with beams of radioactive tin ions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K. L., E-mail: kgrzywac@utk.edu; Ayres, A.; Bey, A.; Burcher, S.; Cartegni, L.; Cerizza, G. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Ahn, S. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Allmond, J. M.; Beene, J. R.; Galindo-Uribarri, A.; Liang, J. F.; Nesaraja, C. D.; Pain, S. D.; Radford, D. C.; Schmitt, K. T.; Smith, M. S.; Stracener, D. W.; Varner, R. L. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Bardayan, D. W. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Baugher, T. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903 (United States); and others

    2015-10-15

    The tin chain of isotopes provides a unique region in which to investigate the evolution of single-particle structure, spreading from N = 50 at {sup 100}Sn, through 10 stable isotopes and the N = 82 shell closure at {sup 132}Sn out into the r-process path. Direct reactions performed on radioactive ion beams are sensitive spectroscopic tools for studying exotic nuclei. Here we present one experiment knocking out neutrons from tin isotopes that are already neutron deficient and two reactions that add a neutron to neutron-rich {sup 130}Sn. Both techniques rely on selective particle identification and the measurement of γ rays in coincidence with charged ions. We present the goals of the two experiments and the particle identification for the channels of interest. The final results will be presented in future publications.

  15. Direct Reaction Experimental Studies with Beams of Radioactive Tin Ions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K. L. [University of Tennessee, Knoxville (UTK); Ahn, S.H. [University of Tennessee, Knoxville (UTK); Allmond, James M [ORNL; Ayres, A. [University of Tennessee, Knoxville (UTK); Bardayan, Daniel W [ORNL; Baugher, T. [Michigan State University, East Lansing; Bazin, D. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL); Beene, James R [ORNL; Berryman, J. S. [Michigan State University, East Lansing; Bey, A. [University of Tennessee, Knoxville (UTK); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Cartegni, L. [University of Tennessee, Knoxville (UTK); Chae, K. Y. [University of Tennessee, Knoxville (UTK)/Sungkyunkwan University, Korea; Cizewski, J. A. [Rutgers University; Gade, A. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL); Galindo-Uribarri, Alfredo {nmn} [ORNL; Garcia-Ruiz, R.F. [Instituut voor Kernen Stralingsfysica, KU Leuven, B-3001, Leuven, Belgium; Grzywacz, Robert Kazimierz [ORNL; Howard, Meredith E [ORNL; Kozub, R. L. [Tennessee Technological University (TTU); Liang, J Felix [ORNL; Manning, Brett M [ORNL; Matos, M. [Louisiana State University; McDaniel, S. [Michigan State University, East Lansing; Miller, D. [University of Tennessee, Knoxville (UTK); Nesaraja, Caroline D [ORNL; O' Malley, Patrick [Rutgers University; Padgett, S [University of Tennessee, Knoxville (UTK); Padilla-Rodal, Elizabeth [Universidad Nacional Autonoma de Mexico (UNAM); Pain, Steven D [ORNL; Pittman, S. T. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Radford, David C [ORNL; Ratkiewicz, Andrew J [ORNL; Schmitt, Kyle [ORNL; Smith, Michael Scott [ORNL; Stracener, Daniel W [ORNL; Stroberg, S. [Michigan State University, East Lansing; Tostevin, Jeffrey A [ORNL; Varner Jr, Robert L [ORNL; Weisshaar, D. [Michigan State University, East Lansing; Wimmer, K. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL)/Central Michigan University; Winkler, R. [Michigan State University, East Lansing

    2015-01-01

    The tin chain of isotopes provides a unique region in which to investigate the evolution of single-particle structure, spreading from N = 50 at Sn-100, through 10 stable isotopes and the N = 82 shell closure at Sn-132 out into the r-process path. Direct reactions performed on radioactive ion beams are sensitive spectroscopic tools for studying exotic nuclei. Here we present one experiment knocking out neutrons from tin isotopes that are already neutron deficient and two reactions that add a neutron to neutron-rich Sn-130. Both techniques rely on selective particle identification and the measurement of gamma rays in coincidence with charged ions. We present the goals of the two experiments and the particle identification for the channels of interest. The final results will be presented in future publications.

  16. RP process studies with radioactive beams at ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E. [Argonne National Lab., Physics Div., Argonne, IL (United States)

    1998-06-01

    Reactions of interest to nuclear astrophysics have been studied with radioactive beams at the ATLAS accelerator. Using a modified ISOL technique, beams of {sup 18}F(T{sub 1/2}=110 min) and {sup 56}Ni(T{sub 1/2}=6.1 d) have been produced. The reactions {sup 18}F(p,{alpha}){sup 15}O, {sup 18}F(p,{gamma}){sup 19}Ne, and {sup 56}Ni(d,p){sup 57}Ni have been investigated. The results indicate that the {sup 18}F(p,{gamma}) route is a small contributor to the breakout from the hot CNO cycle into the rp process, while the {sup 56}Ni(p,{gamma}){sup 57}Cu rate is about ten times larger than previously assumed. (orig.)

  17. TRACER STUDY FK UNAND 2008 : PERSEPSI ALUMNI TERHADAP PELAKSANAAN PENDIDIKAN KEDOKTERAN DI FAKULTAS KEDOKTERAN UNIVERSITAS ANDALAS

    Directory of Open Access Journals (Sweden)

    Yulistini Yulistini

    2010-09-01

    Full Text Available AbstrakTracer Study adalah penelitian yang menghimpun informasi tentang sebaran para alumni dan berbagai masukan yang dapat membantu pengembangan kurikulum dan proses pembelajaran di Fakultas Kedokteran Universitas Andalas (FK Unand.Penelitian tracer study di FK Unand 2008 menggunakan pendekatan kuantitatif dengan metode deskriptif analitik. Respondennya adalah alumni FK Unand yang dipilih secara purposive random sampling, yaitu berdasarkan keikutsertaan kegia-tan ilmiah dan kegiatan lainnya di FK Unand tahun 2008.Hasil penelitian menunjukkan persentase responden yang puas dan tidak puas terhadap pelayanan akademik sebanyak 55,5% dan 45,5% dari 124 responden. 61,9% responden merasa puas terhadap pendidikan preklinik dan 50,4% merasa puas terhadap pendidikan klinik. Untuk penilaian kompetensi berdasarkan persepsi responden menunjukkan 66,7% merasa kompeten saat menyelesaikan pendidikan. Uji bivariant menunjukkan hubungan bermakna antara kepuasan terhadap pendidikan preklinik dan klinik, tahun masuk dan jenis kelamin terhadap kompetensi (p<0.05.Kesimpulan adalah sebagian besar responden merasa puas terhadap pelayanan akademik dan pendidikan preklinik. Persentase ketidakpuasan terhadap pen-didikan klinik hanya sedikit lebih tinggi dari pada yang puas. Terdapat hubungan yang bermakna antara kepuasan terhadap pendidikan preklinik, klinik, tahun masuk, dan gender terhadap persepsi responden terhadap kompetensi mereka.Kata kunci :tracer study, alumni, tahun masuk, pre klinik, klinik, kompetensiAbstractTracer Study is a research that gather information about the distribution of the alumni and the various inputs that may help the development of curriculum and learning process in the Faculty of medicine Andalas University (FK Unand Tracer studies FK Unand 2008 using a quantitative approach with a descriptiveARTIKEL PENELITIAN168analytical method. Respondents are FK Unand’s graduates that selected by purposively random sampling, who followed FK Unand

  18. Study for reducing radioactive solid waste at ITER decommissioning period

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Shinichi; Araki, Masanori; Ohmori, Junji; Ohno, Isamu; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2002-11-01

    It is one of the foremost goals for ITER to demonstrate the attractiveness with regard to safety and environmental potential. This implies that the radioactive materials and waste at decommissioning phase should carefully be treated with prescribed regulations. As possible activities during the Coordinated Technical Activity (CTA), the authors have performed a feasibility study for searching the possibility of effective reduction in the activated level as reasonably achievable as possible by taking account of minimum material changes while keeping original design concept and structure. Major induced activation in ITER comes from activated nickel and cobalt so that it is effective for the major structural components to minimize their material contents. Employing less Ni and Co steel in place of high-Ni austenitic stainless steel for blanket shield block, vacuum vessel shield material and TF coil casing has been considered as one of the effective plans to reduce the activated materials at the decommissioning phase. In this study, two less-Ni austenitic stainless steels are evaluated; one is high-Mn austenitic stainless steel JK2 which is developing for jacket material of ITER CS coil and the other is SS204L/ASTM-XM-11 which is also high-Mn steel specified in the popular standards such as American Society of Testing and Material (ASTM). Based on the material changes, activation analyses have been performed to investigate the possibility of reducing radioactive wastes. As a most impressive result, at 40 years after the termination some of main components such as a TF coil casing will reach to the clearance level which is specified by IAEA, and most components will be categorized into extremely low level waste except for limited components. These results will give the appropriate short decommissioning period that is assumed to start at 100 years after the termination in the original design. (author)

  19. Fallout Radionuclides as Tracers in Southern Alps Sediment Studies

    Science.gov (United States)

    Carey, A. E.; Karanovic, Z.; Dibb, J. E.

    2005-12-01

    The primary geologic processes shaping the landscape are physical and chemical weathering and the transport of solids by erosion. As part of our studies on the coupling between physical erosion and chemical weathering, we have determined depositional and erosional processes in New Zealand's tectonically active, rapidly uplifting Southern Alps, specifically focusing on the Hokitika River watershed. The South Island watersheds we are studying are subject to extreme orographic precipitation (as high as 7-12 m annually) and high landslide frequency, but have modest topography due to the rapid erosion. In concert with our studies of chemical weathering and physical erosion, we have used the atmospherically-delivered radionuclides of 7Be, 137Cs and 210Pbexcess to determine the relative magnitude of particle residence time in the high elevation Cropp and Whitcombe subwatersheds and the rates of sedimentation. One- and two-box modeling with 7Be and 210Pbexcess was used to determine soil and sediment residence times. Residence time of fine suspended particles is short and particles can travel the length of the river during a single storm, probably due to the short duration, high-intensity rainfalls which produce rapidly moving, steep flood waves. The readily detected peak of 137Cs activity in Cropp terrace and Hokitika gorge soils yielded sedimentation rates of 0.06-0.12 cm yr-1. At the Cropp terrace, inventory models of 210Pbexcess yield soil accumulation rates significantly less than those determined using the 137Cs activity peak. We attribute the differences to overestimation of 210Pbexcess in surface soils and to contrasting fallout fluxes, geochemical behavior and radionuclide contents of sedimenting materials. Total inventories of 210Pbexcess in soils greatly exceed the expected direct atmospheric deposition, suggesting that lateral transport of this nuclide occurs within the watershed. At the Hokitika gorge, all nuclides studied yielded similar sedimentation rates

  20. A tracer study in an Alaskan gravel beach and its implications on the persistence of the Exxon Valdez oil.

    Science.gov (United States)

    Li, Hailong; Boufadel, Michel C

    2011-06-01

    Despite great efforts including bioremediation, the 1989 Exxon Valdez oil spills persist in many gravel beaches in Prince William Sound, Alaska, USA. To explore this mystery, a lithium tracer study was conducted along two transects on one of these beaches. The tracer injections and transports were successfully simulated using the 2-dimensional numerical model MARUN. The tracer stayed much longer in the oil-persisting, right transect (facing landwand) than in the clean, left transect. If the tracer is approximately regarded as oils, oils in the upper layer would have more opportunities to enter the lower layer in the right transect than in the left one. This may qualitatively explain the oil persistence within the right transect. When the tracer is regarded as nutrients, the long stay of nutrients within the right transect implies that the oil persistence along the right transect was not due to the lack of nutrients during the bioremediation.

  1. A Mathematical Modeling Study of Tracer Mixing in a Continuous Casting Tundish

    Science.gov (United States)

    Chen, Chao; Jonsson, Lage Tord Ingemar; Tilliander, Anders; Cheng, Guoguang; Jönsson, Pär Göran

    2015-02-01

    A mathematical model based on a water model was developed to study the tracer mixing in a single strand tundish. The mixing behavior of black ink and KCl solution was simulated by a mixed composition fluid model, and the data were validated by water modeling results. In addition, a model that solves the scalar transport equation (STE) without any physical properties of the tracer was studied and the results were compared to predictions using the density-coupled model. Furthermore, the mixing behaviors of different amounts of KCl tracers were investigated. Before the model was established, KCl tracer properties such as the KCl molecule diffusion (KMD), the water molecule self-diffusion (WSD) in KCl solution, and the KCl solution viscosity (KV) were evaluated. The RTD curve of 250 mL KCl for the KMD case was closer to the water modeling results than that of the case implemented with only density. Moreover, the ensemble average deviation of the RTD curves of the cases implemented with KMD + WSD, KMD + KV, and KMD + WSD + KV to the KMD case is less than 0.7 pct. Thus, the water self-diffusion and KV were neglected, while the KCl density and KMD were implemented in the current study. The flow pattern of black ink was similar to the STE result i.e., the fluid flowed upwards toward the top surface and formed a large circulating flow at the outlet nozzle. The flow behavior of the 100, 150, and 250 mL KCl cases exhibited a strong tendency to sink to the tundish bottom, and subsequently flow through the holes in the dam. Thereafter, it propagated toward the outlet nozzle. Regarding the KCl tracer amount, the tracer concentration propagated to the outlet nozzle much faster for the larger amount case than for the smaller amount cases. However, the flow pattern for the 50 mL KCl case was somewhat different. The fluid propagated to the top surface which acted like black ink during the initial injection, and subsequently the fluid flowed throughout the holes at a much slower pace

  2. National Biomedical Tracer Facility (NBTF). Project definition study: Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Lagunas-Solar, M.C.

    1995-02-15

    This report describes a five-year plan for the construction and commissioning of a reliable and versatile NBTF facility for the production of high-quality, high-yield radioisotopes for research, biomedical, and industrial applications. The report is organized in nine sections providing, in consecutive order, responses to the nine questions posed by the U.S. Department of Energy in its solicitation for the NBTF Project Definition Study. In order to preserve direct correspondence (e.g., Sec. 3 = 3rd item), this Introduction is numbered {open_quotes}0.{close_quotes} Accelerator and facility designs are covered in Section 1 (Accelerator Design) and Section 2 (Facility Design). Preliminary estimates of capital costs are detailed in Section 3 (Design and Construction Costs). Full licensing requirements, including federal, state, and local ordinances, are discussed in Section 4 (Permits). A plan for the management of hazardous materials to be generated by NBTF is presented in Section 5 (Waste Management). An evaluation of NBTF`s economic viability and its potential market impact is detailed in Section 6(Business Plan), and is complemented by the plans in Section 7 (Operating Plan) and Section 8 (Radioisotope Plan). Finally, a plan for NBTF`s research, education, and outreach programs is presented in Section 9 (Research and Education Programs).

  3. Environmental Radioactivity Study in Surface Sediments of Guacanayabo Gulf (Cuba)

    Science.gov (United States)

    Reyes, H.; López-Pino, N.; Rizo, O. Díaz; Bernal, J. L.; D'Alessandro, K.; Padilla, F.; Corrales, Y.; Casanova, O. A.; Gelen, A.; Martínez, Y.; Aguilar, J.; Arado, J. O.; Maidana, N. L.

    2009-06-01

    Sediment samples have been collected in the Guacanayabo gulf located in the southeast Cuba, to determinate the radioactivity levels of 210Pb, 234Th, 214Pb, 137Cs, 232Th and 40K using Low-Background Gamma Spectrometry and to evaluate its impact in the habitat of important marine species for fishery industry. The obtained results show the lowest radioactivity levels determined in Cuban marine environments. The species capture declination in the last years is not originated by radioactive pollution of the zone.

  4. Study About Origin of Radioactive Cesium in Wild Mushroom in Japan

    OpenAIRE

    鎌田, 素之; 角田, 光淳

    2016-01-01

    Radioactive cesium, released from the Fukushima I nuclear power plant that destroyed by Great East Japan Earthquake, has been detected from various agricultural products. Especially, wild mushrooms are known to assimilate radioactive cesium and other heavy metals. In this study, we focused on the concentration of radioactive cesium in wild mushrooms in Japan, calculated the ratio of 134Cs/137Cs and discussed on their origin whether they were released from the Fukushima I nuclear power plant o...

  5. Solute movement in drained fen peat: a field tracer study in a Somerset (UK) wetland

    Science.gov (United States)

    Baird, Andrew J.; Gaffney, Simon W.

    2000-10-01

    Little is known about solute transport in peats, despite the obvious importance of solute transport on eco-hydrological processes in both managed and natural peatlands. To address this lack of knowledge, we investigated solute transport processes in an agricultural fen peat using a conservative KBr tracer. The main aim of the study was to elucidate solute transport behaviour in general in this peat, with a more specific aim of investigating whether preferential or bypassing flow occurred. The tracer moved through the peat more rapidly than expected, and the pattern of movement showed clear evidence of plot-scale bypassing flow. The data also provide evidence that bypassing flow occurs in pores at smaller scales. The implications of this study for management of wetland pastures in the Somerset Moors in south-west England are discussed.

  6. Joint DOE/NRC field study of tracer migration in the unsaturated zone

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, J.; Polzer, W.; Essington, E.; Cokal, E.; Lane, L.; Lopez, E.; Stallings, E.; Walker, R.

    1986-03-01

    The results of a joint DOE/NRC field experiment to evaluate leaching and transport of solutes in a sandy silt backfill used for shallow land burial operations at Los Alamos are presented for steady-state and unsteady-state flow conditions. The migration of iodide, bromide, and lithium through the backfill material is studied as functions of depth and time and they are compared with one another. The bromide and iodide tracer data are used to estimate the diffusion coefficient, the tortuosity factor, and dispersivity. These values are used to calculate effective dispersion coefficients for subsequent analyses of the retardation factor and the distribution coefficient for lithium using least squares procedures. The results of the tracer migration study are discussed relative to challenges facing the waste management community, and chemical transport modeling opportunities are presented for a modeling workshop to be held in FY86.

  7. Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

    Science.gov (United States)

    Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

    2017-06-01

    Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

  8. Report on the treatability study for inerting small quantities of radioactive explosives and explosive components

    Energy Technology Data Exchange (ETDEWEB)

    Loyola, V.M.; Reber, S.D.

    1996-02-01

    As a result of Sandia`s radiation hardening testing on a variety of its explosive components, radioactive waste streams were generated and have to be disposed of as radioactive waste. Due to the combined hazards of explosives and radioactivity, Sandia`s Radioactive and Mixed Waste Management organization did not have a mechanism for disposal of these waste streams. This report documents the study done to provide a method for the removal of the explosive hazard from those waste streams. The report includes the design of the equipment used, procedures followed, results from waste stream analog tests and the results from the actual explosive inerting tests on radioactive samples. As a result of the inerting treatment, the waste streams were rendered non-explosive and, thus, manageable through normal radioactive waste disposal channels.

  9. Field studies of streamflow generation using natural and injected tracers on Bickford and Walker Branch Watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Genereux, D.; Hemond, H. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Civil Engineering; Mulholland, P. [Oak Ridge National Lab., TN (United States)

    1992-05-01

    Field studies of streamflow generation were undertaken on two forested watersheds, the West Road subcatchment of Bickford Watershed in central Massachusetts and the West Fork of Walker Branch Watershed in eastern Tennessee. A major component of the research was development of a two-stage methodology for the use of naturally-occurring {sup 222}Rn as a tracer. The first of the two stages was solving a mass-balance equation for {sup 222}Rn around a stream reach of interest in order to calculate Rn{sub q}, the {sup 222}Rn content of the lateral inflow to the reach; a conservative tracer (chloride) and a volatile tracer (propane) were injected into the study stream to account for lateral inflow to, and volatilization from, the study reach. The second stage involved quantitative comparison of Rn{sub q} to the measured {sup 222}Rn concentrations of different subsurface waters in order to assess how important these waters were in contributing lateral inflow to the stream reach.

  10. Application of tracer packet technique for multielemental uptake studies on the inorganic ion exchanger zirconium vanadate

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Kamalika; Basu, S.; Ramaswami, A.; Lahiri, Susanta E-mail: slahiri@hp1.saha.ernet.in

    2003-09-01

    The conception of tracer packet was first started with the irradiation of a thick cobalt target with {sup 16}O, {sup 7}Li and {sup 12}C beams, consecutively. This produced carrier-free radiotracers of Mn, Cu, Zn, Ga, Ge, As and Se. These elements are adjacent members in the periodic table and are of nutritional importance. Another 'tracer packet', which was subsequently designed, was of heavy and toxic metals. A gold target irradiated with medium energy {sup 7}Li and {sup 12}C produced {sup 197}Hg, {sup 200}Tl, {sup 200}Pb, {sup 204}Bi, {sup 204}Po. The uptake of these elements has been studied using two different ion exchangers, one of inorganic origin and the other of chelating type.

  11. Study of radioactive impurities in neutron transmutation doped germanium

    Energy Technology Data Exchange (ETDEWEB)

    Mathimalar, S.; Dokania, N.; Singh, V. [India-based Neutrino Observatory, Tata Institute of Fundamental Research, Mumbai 400 005 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Nanal, V., E-mail: nanal@tifr.res.in [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India); Pillay, R.G. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India); Shrivastava, A. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Jagadeesan, K.C.; Thakare, S.V. [Isotope Production and Applications Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2015-02-21

    A program to develop low temperature (mK) sensors with neutron transmutation doped Ge for rare event studies with a cryogenic bolometer has been initiated. For this purpose, semiconductor grade Ge wafers are irradiated with thermal neutron flux from Dhruva reactor at Bhabha Atomic Research Centre (BARC), Mumbai. Spectroscopic studies of irradiated samples have revealed that the environment of the capsule used for irradiating the sample leads to significant levels of {sup 65}Zn, {sup 110m}Ag and {sup 182}Ta impurities, which can be reduced by chemical etching of approximately ∼50μm thick surface layer. From measurements of the etched samples in the low background counting setup, activity due to trace impurities of {sup 123}Sb in bulk Ge is estimated to be ∼1Bq/g after irradiation. These estimates indicate that in order to use the NTD Ge sensors for rare event studies, a cooldown period of ∼2 years would be necessary to reduce the radioactive background to ≤1mBq/g.

  12. Recent direct reaction experimental studies with radioactive tin beams

    CERN Document Server

    Jones, K L; Allmond, J M; Ayres, A; Bardayan, D W; Baugher, T; Bazin, D; Berryman, J S; Bey, A; Bingham, C; Cartegni, L; Cerizza, G; Chae, K Y; Cizewski, J A; Gade, A; Galindo-Uribarri, A; Garcia-Ruiz, R F; Grzywacz, R; Howard, M E; Kozub, R L; Liang, J F; Manning, B; Matos, M; McDaniel, S; Miller, D; Nesaraja, C D; O'Malley, P D; Padgett, S; Padilla-Rodal, E; Pain, S D; Pittman, S T; Radford, D C; Ratkiewicz, A; Schmitt, K T; Shore, A; Smith, M S; Stracener, D W; Stroberg, S R; Tostevin, J; Varner, R L; Weisshaar, D; Wimmer, K; Winkler, R

    2015-01-01

    Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine (ISOL) method. Some of the most interesting regions to study with direct reactions are close to the magic numbers where changes in shell structure can be tracked. These changes can impact the final abundances of explosive nucleosynthesis. The structure of the chain of tin isotopes is strongly influenced by the Z=50 proton shell closure, as well as the neutron shell closures lying in the neutron-rich, N=82, and neutron-deficient, N=50, regions. Here we present two examples of direct reactions on exotic tin isotopes. The first uses a one-neutron transfer reaction and a low-energy reaccelerated ISOL beam to study states in 131Sn from across the N=82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient 106,108Sn...

  13. A study on the safety of radioactive waste incineration facilities

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. C. [Yonsei Univ., Seoul (Korea, Republic of); Park, W. J.; Lee, B. S.; Lee, S. H. [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1994-12-15

    The main scope of the project is the selection of some considerable items in design criteria of radioactive waste incineration facilities not only for the protection of workers and residents during operation but also for the safe disposal of ashes after incineration. The technological and regulational status on incineration technologies in domestic and foreign is surveyed and analyzed for providing such basic items which must be contained in the guideline for safe and appropriate design, construction and operation of the facilities. The contents of the project are summarized as follows; surveying the status on incineration technologies for both radioactive and non-radioactive wastes in domestic and foreign, surveying and analysing same related technical standards and regulations in domestic and foreign, picking out main considerable items and proposing a direction of further research.

  14. A study on the safety of radioactive waste incineration facilities

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. C. [Yonsei Univ., Seoul (Korea, Republic of); Park, W. J.; Lee, B. S.; Lee, S. H. [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1994-12-15

    The main scope of the project is the selection of some considerable items in design criteria of radioactive waste incineration facilities not only for the protection of workers and residents during operation but also for the safe disposal of ashes after incineration. The technological and regulational status on incineration technologies in domestic and foreign is surveyed and analyzed for providing such basic items which must be contained in the guideline for safe and appropriate design, construction and operation of the facilities. The contents of the project are summarized as follows; surveying the status on incineration technologies for both radioactive and non-radioactive wastes in domestic and foreign, surveying and analysing same related technical standards and regulations in domestic and foreign, picking out main considerable items and proposing a direction of further research.

  15. Non Destructive Application of Radioactive Tracer Technique for Characterization of Industrial Grade Anion Exchange Resins Indio GS-300 and Indion-860

    Energy Technology Data Exchange (ETDEWEB)

    Singare, P. U. [Bhavan' s College, Mumbai (India)

    2014-02-15

    The paper deals with the application of radio isotopic non-destructive technique in the characterization of two industrial grade anion exchange resins Indion GS-300 and Indion-860. For the characterization of the two resins, {sup 131}I and {sup 82}Br were used as tracer isotopes to trace the kinetics of iodide and bromide ion-isotopic exchange reactions. It was observed that the values of specific reaction rate (min{sup -1}), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log K{sub d} were calculated as 0.328, 0.577, 0.189 and 19.7 respectively for Indion GS-300 resin, which was higher than the respective values of 0.180, 0.386, 0.070 and 17.0 calculated for Indion-860 resins when measured under identical experimental conditions. Also at a constant temperature of 40.0 .deg. C, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 75.16 % to 78.36 % for Indion GS-300 resins, which was higher than the increases from 49.65 % to 52.36 % compared to that obtained for Indion-860 resins. The overall results indicate that under identical experimental conditions, Indion GS-300 resins show superior performance over Indion-860 resins.

  16. Neonatal Respiratory Diseases in the Newborn Infant: Novel Insights from Stable Isotope Tracer Studies.

    Science.gov (United States)

    Carnielli, Virgilio P; Giorgetti, Chiara; Simonato, Manuela; Vedovelli, Luca; Cogo, Paola

    2016-01-01

    Respiratory distress syndrome is a common problem in preterm infants and the etiology is multifactorial. Lung underdevelopment, lung hypoplasia, abnormal lung water metabolism, inflammation, and pulmonary surfactant deficiency or disfunction play a variable role in the pathogenesis of respiratory distress syndrome. High-quality exogenous surfactant replacement studies and studies on surfactant metabolism are available; however, the contribution of surfactant deficiency, alteration or dysfunction in selected neonatal lung conditions is not fully understood. In this article, we describe a series of studies made by applying stable isotope tracers to the study of surfactant metabolism and lung water. In a first set of studies, which we call 'endogenous studies', using stable isotope-labelled intravenous surfactant precursors, we showed the feasibility of measuring surfactant synthesis and kinetics in infants using several metabolic precursors including plasma glucose, plasma fatty acids and body water. In a second set of studies, named 'exogenous studies', using stable isotope-labelled phosphatidylcholine tracer given endotracheally, we could estimate surfactant disaturated phosphatidylcholine pool size and half-life. Very recent studies are focusing on lung water and on the endogenous biosynthesis of the surfactant-specific proteins. Information obtained from these studies in infants will help to better tailor exogenous surfactant treatment in neonatal lung diseases.

  17. Study on HTR-PM Radioactive Waste Minimization Strategy

    Institute of Scientific and Technical Information of China (English)

    JIANG; Zi-ying; ZHANG; Yan-qi; WEN; Bao-yin; LI; Hong; LIAO; Hai-tao

    2015-01-01

    The high temperature gas-cooled reactor pebble bed module(HTR-PM)in constructionhas the characteristics of the fourth generation reactors and it is different both the reactor structure and the radioactive wastes generation from the PWR NPPs in operation at present in China.

  18. Study on induced radioactivity of China Spallation Neutron Source

    Institute of Scientific and Technical Information of China (English)

    吴青彪; 王庆斌; 吴靖民; 马忠剑

    2011-01-01

    China Spallation Neutron Source (CSNS) is the first High Energy Intense Proton Accelerator planned to be constructed in China during the State Eleventh Five-Year Plan period, whose induced radioactivity is very important for occupational disease hazard as

  19. Studies of Bone Metabolism with the Aid of Radioactive Strontium

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.C.; Copp, D.H., M.D.

    1948-04-01

    The kinetics of skeletal uptake and urinary excretion of radiostrontium were studied during the critieal first hour following intraperitoneal injection of a carrier-free dose. These experiments not only provided valuable data con.cerning the metabolism and fixation of this important fission product, but, because of the close similarity of strontium and calcium, also gave basic information on the process of calcification. Three groups of rats were compared: normal mature adults, young growing normal animals, and young rachitic rats. In all groups, the blood radioactive strontium rose to a maximum in 10-15 minutes, and then declined as the strontium continued to deposit in the skeleton or to be excreted in the urine. Muscle and skin strontium curves followed those of blood quite closely, suggesting a rapid equilibrium between their extracellular fluid and blood plasma. In all groups there was a continous uptake of strontium by the skeleton. In the adults, this was almost constant, suggesting uptek e by absorption and exchange with the calcium of the bone mineral. In the young rats, both normal and rachitic, the very rapid initial rate of uptake of radio-strontium tapered off sharply with time, indicating that some of this radio-element was coming back from the bone into the blood stream. This suggested a rapid labile combination of strontiunl in these animals, which, since it also occured in the rachitic group in which normal calcification is inhibited, probably associated with the protein osteoid matrix present in both. A hypothetical calcification mechanism was suggested by these findings. Urinary excretion and renal clearance of strontium was constant in all three groups, but the clearance was almost ten times as great in the rachitic as in the normal young and adult rats. This would seem to indicate a direct effect of rickets on the renal mechanism of radiostrontium (and calcium) excretion.

  20. Study on Transfer of Ni in Soil—Plant System Using 63Ni Tracer Method

    Institute of Scientific and Technical Information of China (English)

    TUCONG

    1996-01-01

    A study was carried out on the transfer of native and added Ni towards plant both in different soils and at different time by using 63 Ni tracer technique.The transfer of added Ni in soil was greater than native Ni and declined as time increased.The mobility was greater for soluble plus exchangeable fraction of soil Ni but very smaller for residual and Fe/Mn oxide bound fractions.These indicated that Ni was more mobile and more harmful in soils with a low pH and /or low content of Fe/Mn oxides.

  1. Marine Biogenic Minerals Hold Clues About Changes in Ocean Chemistry and Climate: Some Important Lessons Learned from Studies of Stable and Radioactive Isotopes of Be and Al

    Directory of Open Access Journals (Sweden)

    Devendra Lal

    2002-01-01

    Full Text Available The elements Be and Al exhibit very short residence time in ocean waters, and therefore serve as useful tracers for the study of biogeochemical processes in seawater. A unique feature of these tracers is that nuclear interactions of cosmic rays in the atmosphere produce appreciable amounts of two radioactive isotopes, 10Be (with a half-life of 1.5 my and 26Al (with a half-life of 0.7 my, which are introduced in the hydrosphere, cryosphere, and lithosphere via precipitation. Thus, these elements are labeled by their respective radioactive isotopes, which help quantitative tagging of their biogeochemical cycles. Finally, as we report here, several marine organisms incorporate them in their skeletal shells in certain fixed proportions to their concentrations in the seawater, so that it seems possible to study changes in the ocean chemistry and climate over the past several million years. We summarize here the recent discovery by Dong et al.[9] of significant enrichments of intrinsic Be and Al in marine foraminiferal calcite and coral aragonite, and of Al in opal (radiolarians and aragonite (corals, which should make it possible to determine 10Be/Be and 26Al/Al in oceans in the past. We also summarize their measured 10Be/9Be in foraminiferal calcite in Pacific Ocean cores, which reveal that the concentrations and ratios of the stable and cosmogenic isotopes of Be and Al have varied significantly in the past 30 ky. The implications of these results are discussed.

  2. Radioactivity; La radioactivite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

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

  3. Modelling seasonal variations of natural radioactivity in soils: A case study in southern Italy

    Indian Academy of Sciences (India)

    Ilaria Guagliardi; Natalia Rovella; Carmine Apollaro; Andrea Bloise; Rosanna De Rosa; Fabio Scarciglia; Gabriele Buttafuoco

    2016-12-01

    The activity of natural radionuclides in soil has become an environmental concern for local public and national authorities because of the harmful effects of radiation exposure on human health. In this context, modelling and mapping the activity of natural radionuclides in soil is an important research topic. The study was aimed to model, in a spatial sense, the soil radioactivity in an urban and peri-urban soils area in southern Italy to analyse the seasonal influence on soil radioactivity. Measures of gamma radiation naturally emitted through the decay of radioactive isotopes (potassium, uranium and thorium) were analysed using a geostatistical approach to map the spatial distribution of soil radioactivity. The activity of three radionuclides was measured at 181 locations using a high-resolution γ-ray spectrometry. To take into account the influence of season, the measurements were carried out in summer and in winter. Activity data were analysed by using a geostatistical approach and zones of relatively high or low radioactivity were delineated. Among the main processes which influence natural radioactivity such as geology, geochemical, pedological, and ecological processes, results of this study showed a prominent control of radio-emission measurements by seasonal changes. Low natural radioactivity levels were measured in December associated with winter weather and moist soil conditions (due to high rainfall and low temperature), and higher activity values in July, when the soil was dry and no precipitations occurred.

  4. Modelling seasonal variations of natural radioactivity in soils: A case study in southern Italy

    Science.gov (United States)

    Guagliardi, Ilaria; Rovella, Natalia; Apollaro, Carmine; Bloise, Andrea; Rosa, Rosanna De; Scarciglia, Fabio; Buttafuoco, Gabriele

    2016-12-01

    The activity of natural radionuclides in soil has become an environmental concern for local public and national authorities because of the harmful effects of radiation exposure on human health. In this context, modelling and mapping the activity of natural radionuclides in soil is an important research topic. The study was aimed to model, in a spatial sense, the soil radioactivity in an urban and peri-urban soils area in southern Italy to analyse the seasonal influence on soil radioactivity. Measures of gamma radiation naturally emitted through the decay of radioactive isotopes (potassium, uranium and thorium) were analysed using a geostatistical approach to map the spatial distribution of soil radioactivity. The activity of three radionuclides was measured at 181 locations using a high-resolution ?-ray spectrometry. To take into account the influence of season, the measurements were carried out in summer and in winter. Activity data were analysed by using a geostatistical approach and zones of relatively high or low radioactivity were delineated. Among the main processes which influence natural radioactivity such as geology, geochemical, pedological, and ecological processes, results of this study showed a prominent control of radio-emission measurements by seasonal changes. Low natural radioactivity levels were measured in December associated with winter weather and moist soil conditions (due to high rainfall and low temperature), and higher activity values in July, when the soil was dry and no precipitations occurred.

  5. Blood flow in rabbit osteotomies studied with radioactive microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Aalto, K. (Department of Surgery, Aurora Hospital, Nordenskioeldinkatu, Helsinki, Finland); Slaetis, P. (Department of Orthopaedic Surgery and Traumatology, Surgical Hospital, University Central Hospital, Helsinki, Finland)

    1984-01-01

    Arterial embolisation with radioactive microspheres was used to measure the proportion of cardiac output to the skeleton and the tibiofibular bone both in unoperated rabbits and in rabbits after tibial osteotomy and subsequent external fixation. The mean uptake of the intact tibiofibula was 0.11 per cent of the cardiac output and, correspondingly, 0.21 per cent after the osteotomy. Maximal uptake occurred 18 days after the operation which was accompanied by a slight decrease in overall skeletal circulation.

  6. Recent progress of {sup 10}Be tracer studies in Chinese loess

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weijian, E-mail: weijian@loess.llqg.ac.cn [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061 (China); Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry and Application, Xi’an AMS Center, Xi' an 710061 (China); Joint Center for Global Change Studies, Beijing 100875 (China); Xie, Xingjun [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061 (China); Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry and Application, Xi’an AMS Center, Xi' an 710061 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Beck, Warren [NSF-Arizona AMS Facility, University of Arizona, Tucson, AZ 85721 (United States); Kong, Xianghui; Xian, Feng; Du, Yajuan; Wu, Zhenkun [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061 (China); Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry and Application, Xi’an AMS Center, Xi' an 710061 (China)

    2015-10-15

    Studies of cosmogenic {sup 10}Be in Chinese loess began about twenty-five years ago and since then a number of research groups worldwide have contributed to a firm understanding of the production, transport, deposition and storage of {sup 10}Be in loess. The essential characteristics that make {sup 10}Be a useful isotopic tracer in loess, include: (1) dominant atmospheric production directly linked to the intensity of the Earth’s magnetic field; (2) climate-dependent deposition; and (3) subsequent immobility, so that as {sup 10}Be accumulates in a loess profile its stratigraphic integrity is preserved. This fact, combined with very high deposition rates in loess on the Chinese Loess Plateau, makes {sup 10}Be an especially valuable continental archive of paleoclimate and paleomagnetism, complementing marine and ice-core records. Here we provide in particular the most recent progress of {sup 10}Be tracer studies in Chinese loess, including the determination of the correct age of the Brunhes–Matuyama polarity reversal at 780 ± 3 ka B.P., in accord with marine and ice records, and quantitative reconstruction of 130-ka paleoprecipitation using {sup 10}Be from Chinese loess profiles.

  7. Studies on the preparation of low-carrier Se-73,75 tracers for in vivo examinations; Untersuchungen zur Darstellung traegerarm 73,75Se-markierter Tracer fuer in vivo Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Helfer, Andreas

    2013-04-03

    With the growing importance of positron emission tomography (PET) for in vivo imaging in diagnostic medicine there is great interest of developing new labelling methods for the positron emitter selenium-73. As attractive application an examination of a no-carrier-added (n.c.a.) preparation of the analogous tracer Sulindac Selenid and of the selenium containing compound Ebselen was examined with {sup 73,75}Se. First of all a labelling strategy for Sulindac Selenid based on a protected precursor was developed. This precursor should further be transformed into the corresponding standard compound for chomatographic identification of the n.c.a. product. This, however, was not possible. An alternative synthesis method also did not result in a product. Thus, a radioactive labelling in case of Sulindac Selenid was not indicated in spite of a successful synthesis of a precursor. The preparation of Ebselen was performed as earlier described by a sequential one-pot synthesis with a yield of 46 %. An adaption of the reaction parameters to a radiosynthesis with {sup 75}Se failed on the n.c.a. state and also after adding carrier to the reaction mixture. The desired product could, however, be prepared in a copper catalysed one-pot radiosynthesis for the first time under carrier-added conditions. Here, optimized conditions resulted in radiochemical yields of 60 ± 18 %. A no-carrier-added product could finally be achieved using sulphur as nonisotopic carrier in the reaction mixture. After optimisation of reaction parameters n.c.a. [{sup 75}Se]Ebselen could be synthesized with radiochemical yields of 55 ± 7 % within 4 h. Furthermore the desired product could be separated by RHPL-chromatography from its co-produced sulfur-analogue. After transferring the conditions to radiosyntheses with the positron emitter {sup 73}Se, n.c.a. [{sup 73}Se]Ebselen could be achieved with a radiochemical yield of 22 ± 1 % and can now be used as a potential radiotracer in preclinical evaluation

  8. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  9. Tracer Experimental Study of the Main Conveying Conduits of CCl4 Pollutant in the Qiligou Water Supply Resource

    Institute of Scientific and Technical Information of China (English)

    PEI Zong-ping; HAN Bao-ping; LIU Han-hu; LIANG Zhi; ZHOU Dong-lai; ZHU Xue-qiang

    2007-01-01

    The Ordovician karst groundwater in the Qiligou basin is an important water supply source. This groundwater has been seriously contaminated in recent years by CCl4 from a pesticide plant located in the recharge area. The highest concentration of CCl4 in the groundwater is 3909.2 μg/L. Large scale tracer experiments were carried out to study the conveying conduits for CCl4 in the basin on May 1-6, 2005. Nontoxic, edible glucose was used as a tracer and it was detected by spectrophotometric techniques. Well X-61, located near the pesticide plant in the southern recharge area of the basin, was employed for injecting the tracer. Ten wells widely located in the groundwater runoff area were used as observing and sampling wells. The results show that the migration of the pollutants is controlled by the water hydrodynamic field and by the development of karst conduits. The tracer did not enter the up-drainage wells, X-49 and X-47, near the injection point because the water levels at these wells are higher than at the injection point. The adjacent well X-62 is close to the injection site, but the tracer reached the well after eleven hours. Wells X-43, X-59, X-58, YY-1 and X-57, located in the syncline axis runoff area, are respectively 2.5, 3.5, 4.33, 4.38 and 5.44 kilometers from the injection site. The time for initial appearance of tracer was 4, 4, 2, 6 and 4 hours, respectively. The maximum runoff velocity (well X-58) is over two kilometers per hour, indicating that the karst conduits are well developed along the syncline basin axis. These conduits are the main conveying conduits for groundwater and CCl4. Closer wells were not necessarily the first to receive tracer. This shows the inhomogeneity in karst development which causes complex runoff, and pollutant migration, patterns.

  10. Electroweak Decay Studies of Highly Charged Radioactive Ions with TITAN at TRIUMF

    CERN Document Server

    Leach, K G; Klawitter, R; Leistenschneider, E; Lennarz, A; Brunner, T; Frekers, D; Andreiou, C; Kwiatkowski, A A; Dilling, J

    2016-01-01

    Several modes of electroweak radioactive decay require an interaction between the nucleus and bound electrons within the constituent atom. Thus, the probabilities of the respective decays are not only influenced by the structure of the initial and final states in the nucleus, but can also depend strongly on the atomic charge. Conditions suitable for the partial or complete ionization of these rare isotopes occur naturally in hot, dense astrophysical environments, but can also be artificially generated in the laboratory to selectively block certain radioactive decay modes. Direct experimental studies on such scenarios are extremely difficult due to the laboratory conditions required to generate and store radioactive ions at high charge states. A new electron-beam ion trap (EBIT) decay setup with the TITAN experiment at TRIUMF has successfully demonstrated such techniques for performing spectroscopy on the radioactive decay of highly charged ions.

  11. A Preliminary Study on the Measurement of Sediment Concentration in Hill-Slope Runoff with an Electrolyte Tracer

    Directory of Open Access Journals (Sweden)

    Xiaonan Shi Fan Zhang

    2012-01-01

    Full Text Available Sediment concentration in hill-slope runoff is an important index for soil erosion. Developing a reliable and portable measuring system of sediment concentration is a core issue for soil and water conservation study, especially for the Tibetan Plateau under unfavorable climate and terrain conditions for field investigation. Challenges include uneven distribution of sediment across a runoff section as well as difficulty in detecting a wide range of particle sizes. An electrolyte tracer, with the advantage of uniform distribution and its widely used electric-conductivity sensor, can avoid the problems of direct measurement of sediment. A new measurement method of sediment concentration in runoff with an electrolyte tracer is proposed based on a premise that sediment concentration is closely correlated with hydrodynamic dispersion coefficient of solute in runoff. In this study, an experiment system of hill-slope runoff with an electrolyte tracer and sediments is first designed. Second, two model parameters in the advective-dispersive equation of solute transport, flow velocity and diffusion coefficient, are inversely estimated by calibrating the observed concentrations of an electrolyte tracer. And third, the relationship between sediment concentrations and hydrodynamic dispersion coefficients are defined through specified regression. As a result, a measurement system of sediment concentration in hill-slope runoff with an electrolyte tracer is primarily established by integrating the relationship of variables, experiment system, and model theory.

  12. Evaluation of the ERP dispersion model using Darlington tracer-study data. Report No. 90-200-K

    Energy Technology Data Exchange (ETDEWEB)

    Wright, S.C.

    1990-01-01

    In this study, site-boundary atmospheric dilution factors calculated by the atmospheric dispersion model used in the ERP (Emergency Response Planning) computer code were compared to data collected during the Darlington tracer study. The purpose of this comparison was to obtain estimates of model uncertainty under a variety of conditions. This report provides background on ERP, the ERP dispersion model and the Darlington tracer study. Model evaluation techniques are discussed briefly, and the results of the comparison of model calculations with the field data are presented and reviewed.

  13. Perfluorocarbon Gas Tracer Studies to Support Risk Assessment Modeling of Critical Infrastructure Subjected to Terrorist Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Terry M.; Heiser, John H.; Watson, Tom; Allwine, K Jerry; Flaherty, Julia E.

    2006-05-06

    Development of real-time predictive modeling to identify the dispersion and/or source(s) of airborne weapons of mass destruction including chemical, biological, radiological, and nuclear material in urban environments is needed to improve response to potential releases of these materials via either terrorist or accidental means. These models will also prove useful in defining airborne pollution dispersion in urban environments for pollution management/abatement programs. Predicting gas flow in an urban setting on a scale of less than a few kilometers is a complicated and challenging task due to the irregular flow paths that occur along streets and alleys and around buildings of different sizes and shapes, i.e., “urban canyons”. In addition, air exchange between the outside and buildings and subway areas further complicate the situation. Transport models that are used to predict dispersion of WMD/CBRN materials or to back track the source of the release require high-density data and need defensible parameterizations of urban processes. Errors in the data or any of the parameter inputs or assumptions will lead to misidentification of the airborne spread or source release location(s). The need for these models to provide output in a real-time fashion if they are to be useful for emergency response provides another challenge. To improve the ability of New York City’s (NYC's) emergency management teams and first response personnel to protect the public during releases of hazardous materials, the New York City Urban Dispersion Program (UDP) has been initiated. This is a four year research program being conducted from 2004 through 2007. This paper will discuss ground level and subway Perfluorocarbon tracer (PFT) release studies conducted in New York City. The studies released multiple tracers to study ground level and vertical transport of contaminants. This paper will discuss the results from these tests and how these results can be used for improving

  14. Public information on radioactive waste: a study of an emerging issue

    Energy Technology Data Exchange (ETDEWEB)

    Bronfman, L.M.; Bronfman, B.H.; Regens, J.L.

    1979-10-01

    Through an analysis of information provided in the printed media on the topic of radioactive waste, the study analyzes the emergence of radioactive waste as a public issue in the press. Over eight hundred articles printed in both specialized and non-specialized sources from 1973 to 1978 have been content-analyzed in order to describe how the problem of radioactive waste is defined and what dimensions of the problems are receiving attention. Between 1973 and 1978, there was a substantial increase in the amount of information on the topic of radioactive waste available to the public through a variety of popular and specialized media sources. This increase coincides with documented public concern with the problem of radioactive waste. Discussions of radioactive waste have focused for all sources more frequently on themes not directly related to the technical problems of radioactive waste storage or isolation. A substantial amount of the information available to a variety of segments of the public is composed of discussions of real or perceived risk related to the existence of waste or to methods of disposing of it. In addition to risk, a substantial proportion of the discussions deal with institutional themes. Over time, the total amount of information on most dimensions of the radioactive waste problem has increased substantially. Institutional themes have gained relative to other issues over the three time periods. National and local press sources infrequently specify the form of waste being discussed thus providing evidence that the quality of technical information available to some members of the public is very low.

  15. Radioactive isotopes in solid-state physics

    CERN Document Server

    Deicher, M

    2002-01-01

    Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as M\\"ossbauer spectroscopy, perturbed angular correlation, $\\beta$-NMR, and emission channelling have used nuclear properties (via hyperfine interactions or emitted particles) to gain microscopical information on the structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as a clean ion beam at ISOL facilities such as ISOLDE at CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Extremely sensitive spectroscopic techniques like deep-level transient spectroscopy (DLTS), photoluminescence (PL), and Hall effect have gained a new quality by using radioactive isotopes. Because of their decay the chemical origin of an observed electronic and optical b...

  16. Isotope tracer study of hydrogen spillover on carbon-based adsorbents for hydrogen storage.

    Science.gov (United States)

    Lachawiec, Anthony J; Yang, Ralph T

    2008-06-17

    A composite material comprising platinum nanoparticles supported on molecular sieve templated carbon was synthesized and found to adsorb 1.35 wt % hydrogen at 298 K and 100 atm. The isosteric heat of adsorption for the material at low coverage was approximately 14 kJ/mol, and it approached a value of 10.6 kJ/mol as coverage increased for pressures at and above 1 atm. The increase in capacity is attributed to spillover, which is observed with the use of isotopic tracer TPD. IRMOF-8 bridged to Pt/C, a material known to exhibit hydrogen spillover at room temperature, was also studied with the hydrogen-deuterium scrambling reaction for comparison. The isotherms were reversible. For desorption, sequential doses of H2 and D2 at room temperature and subsequent TPD yield product distributions that are strong indicators of the surface diffusion controlled reverse spillover process.

  17. Studies of pear-shaped nuclei using accelerated radioactive beams

    CERN Document Server

    Gaffney, L P; Scheck, M; Hayes, A B; Wenander, F; Albers, M; Bastin, B; Bauer, C; Blazhev, A; Bonig, S; Bree, N; Cederkall, J; Chupp, T; Cline, D; Cocolios, T E; Davinson, T; DeWitte, H; Diriken, J; Grahn, T; Herzan, A; Huyse, M; Jenkins, D G; Joss, D T; Kesteloot, N; Konki, J; Kowalczyk, M; Kroll, Th; Kwan, E; Lutter, R; Moschner, K; Napiorkowski, P; Pakarinen, J; Pfeiffer, M; Radeck, D; Reiter, P; Reynders, K; Rigby, S V; Robledo, L M; Rudigier, M; Sambi, S; Seidlitz, M; Siebeck, B; Stora, T; Thoele, P; Van Duppen, P; Vermeulen, M J; von Schmid, M; Voulot, D; Warr, N; Wimmer, K; Wrzosek-Lipska, K; Wu, C Y; Zielinska, M

    2013-01-01

    There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are ‘octupole deformed’, that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on and $^{224}$Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental...

  18. The study on safety facility criteria for radioactive waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. H.; Choi, M. H.; Han, S. H. and others [Dongbang Electron Industry Corporation, (Korea, Republic of)

    1992-12-15

    The radioactive waste repository are necessary to install the engineered safety systems to secure the safety for operation of the repository in the event of fire and earthquake. Since the development of safety facility criteria requires a thorough understanding about the characteristics of the engineered safety systems, we should investigate by means of literature survey and visit SKB. In particular, definition, composition of the systems, functional requirement of the systems, engineered safety systems of foreign countries, system design, operation and maintenance requirement should be investigated : fire protection system, ventilation system, drainage system, I and C system, electric system, radiation monitoring system. This proposed criteria consist of purpose, scope of application, ventilation system, fire protection system, drainage system, electric system and this proposed criteria can be applied as a basic reference for the final criteria.

  19. Human biokinetic data and a new compartmental model of zirconium - A tracer study with enriched stable isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Greiter, Matthias B., E-mail: matthias.greiter@helmholtz-muenchen.de; Giussani, Augusto, E-mail: AGiussani@BfS.de; Hoellriegl, Vera, E-mail: vera.hoellriegl@helmholtz-muenchen.de; Li Weibo, E-mail: wli@helmholtz-muenchen.de; Oeh, Uwe, E-mail: uwe.oeh@helmholtz-muenchen.de

    2011-09-01

    Biokinetic models describing the uptake, distribution and excretion of trace elements are an essential tool in nutrition, toxicology, or internal dosimetry of radionuclides. Zirconium, especially its radioisotope {sup 95}Zr, is relevant to radiation protection due to its production in uranium fission and neutron activation of nuclear fuel cladding material. We present a comprehensive set of human data from a tracer study with stable isotopes of zirconium. The data are used to refine a biokinetic model of zirconium. Six female and seven male healthy adult volunteers participated in the study. It includes 16 complete double tracer investigations with oral ingestion and intravenous injection, and seven supplemental investigations. Tracer concentrations were measured in blood plasma and urine collected up to 100 d after tracer administration. The four data sets (two chemical tracer forms in plasma and urine) each encompass 105-240 measured concentration values above detection limits. Total fractional absorption of ingested zirconium was found to be 0.001 for zirconium in citrate-buffered drinking solution and 0.007 for zirconium oxalate solution. Biokinetic models were developed based on the linear first-order kinetic compartmental model approach used by the International Commission on Radiological Protection (ICRP). The main differences of the optimized systemic model of zirconium to the current ICRP model are (1) recycling into the transfer compartment made necessary by the observed tracer clearance from plasma, (2) different parameters related to fractional absorption for each form of the ingested tracer, and (3) a physiologically based excretion pathway to urine. The study considerably expands the knowledge on the biokinetics of zirconium, which was until now dominated by data from animal studies. The proposed systemic model improves the existing ICRP model, yet is based on the same principles and fits well into the ICRP radiation protection approach. - Research

  20. Comparative study of gas diffusion in subsurface using dual-gas tracer SF6 and halon 1211

    Directory of Open Access Journals (Sweden)

    Wang Weixian

    2016-01-01

    Full Text Available Field experiment and soil column test were performed to study the gas diffusion in the soil subsurface using dual-gas tracer SF6 and halon 1211. Gas samples collected from pre-set sampling sites were measured. These two tracer gases showed the similar trend. At the different directions from injecting site, concentrations increased rapidly at the beginning, the peak value concentration of SF6 was higher than that of halon 1211, implied SF6 diffuse further. At the different depth from injecting site, tracer gases preferred to transport horizontal or downwards rather than upwards, meant gravity settling was an important factor affecting the gas diffusion. The effect of temperature and water content on the gas diffusion revealed that gases migrated fast obviously with the temperature increase, the change of water content had influence slightly. Gas desorption test indicated that much more halon 1211 was adsorbed on the soil, which led the diffusion process slow down.

  1. Conducting Graduate Tracer Studies for Quality Assurance in East African Universities: A Focus on Graduate Students Voices on Quality Culture

    Science.gov (United States)

    Badiru, Egesah Omar; Wahome, Mary

    2016-01-01

    The purpose of this paper is to propose a guide for graduate trace studies (GTS) to be adopted by universities and other higher education institutions (HEIs) in East Africa. Their essential role notwithstanding, graduate tracer studies present viable opportunities through which quality assurance (QA) can be institutionalized and mainstreamed in…

  2. {sup 99m}TcO(BAT-NI), a novel nitroimidazole tracer: in vivo uptake studies in ischaemic myocardium

    Energy Technology Data Exchange (ETDEWEB)

    Hoffend, J.; Linke, G.; Mohammed, A.; Haberkorn, U. [Department of Radiology, Division of Nuclear Medicine, University of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg (Germany); Tiefenbacher, C.P. [Department of Internal Medicine, Division of Cardiology, University of Heidelberg, Heidelberg (Germany); Eisenhut, M. [German Cancer Research Centre, Heidelberg (Germany)

    2003-04-01

    Myocardial perfusion single-photon emission tomography (SPET) performed with cationic technetium-99m complexes indicates ischaemic areas as cold lesions. By contrast, nitroimidazole derivatives labelled with fluorine-18 or {sup 99m}Tc have recently shown promising results for hot spot imaging of ischaemic myocardium. This study evaluates {sup 99m}TcO(BAT-NI), a new {sup 99m}Tc complex comprising the nitroimidazole ligand, 2,10-dimercapto-2,10-dimethyl-4,8-diaza-6-[4-(2-nitroimidazolyl)butyl]undecane, in a low-flow in vivo model of myocardial ischaemia in thoracotomised rats. To elucidate the influence of the 2-nitroimidazole group on ischaemia-induced uptake, comparisons with ligand derivatives were performed where (a) the 2-nitro group was deleted [{sup 99m}TcO(BAT-I)], (b) the 2-nitroimidazole functionality was replaced by a Br atom [{sup 99m}TcO(BAT-Br)] and (c) the {sup 99m}TcO(BAT) moiety was replaced by an iodine-125 iodophenoxybutyl ligand ({sup 125}IP-NI). The radiolabelled compounds were i.v. injected 15 min after reducing resting myocardial blood flow by 50-60% and the uptake of radioactivity was assessed 90 min post injection. Autoradiography of left ventricular short-axis slices showed median uptake ratios of ischaemic/non-ischaemic myocardium (I/N) of 3.4, 4.5 and 3.4 for {sup 99m}TcO(BAT-NI), {sup 99m}TcO(BAT-I) and {sup 99m}TcO(BAT-Br), respectively. In contrast, {sup 125}IP-NI was not preferentially taken up by ischaemic myocardium. Accumulation of {sup 99m}TcO(BAT-NI) in ischaemic heart regions was comparable to that in the liver. Biodistribution studies showed a median uptake of 0.65% ID/g of {sup 99m}TcO(BAT-NI) in ischaemic tissue and an I/N of 3.3. On planar images of the thorax and upper abdomen the ischaemic hearts were visualised faintly; the median heart to lung count ratio for {sup 99m}TcO(BAT-NI) was 1.7, and the median heart to liver count ratio was 1.0. We conclude that uptake of {sup 99m}TcO(BAT-NI) in ischaemic myocardium does not

  3. The effect of bioturbation in pelagic sediments: Lessons from radioactive tracers and planktonic foraminifera in the Gulf of Aqaba, Red Sea

    Science.gov (United States)

    Steiner, Zvi; Lazar, Boaz; Levi, Shani; Tsroya, Shimon; Pelled, Omer; Bookman, Revital; Erez, Jonathan

    2016-12-01

    Studies of recent environmental perturbations often rely on data derived from marine sedimentary records. These records are known to imperfectly inscribe the true sequence of events, yet there is large uncertainty regarding the corrections that should be employed to accurately describe the sedimentary history. Here we show in recent records from the Gulf of Aqaba, Red Sea, how events of the abrupt disappearance of the planktonic foraminifer Globigerinoides sacculifer, and episodic deposition of the artificial radionuclide 137Cs, are significantly altered in the sedimentary record compared to their known past timing. Instead of the abrupt disappearance of the foraminifera, we observe a prolonged decline beginning at core depth equivalent to ∼30 y prior to its actual disappearance and continuing for decades past the event. We further observe asymmetric smoothing of the radionuclide peak. Utilization of advection-diffusion-reaction models to reconstruct the original fluxes based on the known absolute timing of the events reveal that it is imperative to use a continuous function to describe bioturbation. Discretization of bioturbation into mixed and unmixed layers significantly shifts the location of the modeled event. When bioturbation is described as a continuously decreasing function of depth, the peak of a very short term event smears asymmetrically but remains in the right depth. When sudden events repeat while the first spike is still mixed with the upper sediment layer, bioturbation unifies adjacent peaks. The united peak appears at an intermediate depth that does not necessarily correlate with the timing of the individual events. In a third case, a long lasting sedimentary event affected by bioturbation, the resulting peak is rather weak compared to the actual event and appears deeper in the sediment column than expected based on the termination of the event. The model clearly shows that abrupt changes can only endure in the record if a thick sediment layer

  4. Studies on Inhibition of the Intestinal Absorption of Radioactive Strontium

    Science.gov (United States)

    Tanaka, Y.; Inoue, S.; Skoryna, S. C.

    1970-01-01

    The inhibitory action of alginate on intestinal absorption of radioactive strontium was investigated in order to correlate the biological activity with the chemical composition. Alginate from Laminaria hyperborea was partially hydrolyzed with oxalic acid and the degradation products were fractionated into polymannuronic and polyguluronic acid. The activity of these products was assessed biologically in rats and morphologically by electron microscopy. Sodium polymannuronate was found to be less effective than sodium polyguluronate in preventing absorption of radiostrontium. The inhibition of absorption of radio-calcium was low and not affected by hydrolysis or fractionation. When dried from dilute aqueous solutions, the polymannuronate retained the original helical structure of alginate, while the polyguluronate showed a strong tendency to coagulate, forming granules. The variation in the biological activity was attributed to the morphological differences between these alginic acid components and it is suggested that the degree of uncoiling of the polyguluronate chain in water is greater than that of the polymannuronate chain, thus making the carboxylate ions more accessible to strontium. ImagesFIG. 2FIG. 3 PMID:5469618

  5. Numerical study of tracers transport by a mesoscale convective system over West Africa

    Directory of Open Access Journals (Sweden)

    J.-P. Pinty

    2011-05-01

    Full Text Available A three-dimensional cloud-resolving model is used to investigate the vertical transport from the lower to the upper troposphere in a mesoscale convective system (MCS that occurred over Niger on 15 August 2004. The redistribution of five passive tracers initially confined in horizontally homogeneous layers is analyzed. The monsoon layer tracer (0–1.5 km is the most efficiently transported in the upper troposphere with concentrations 3 to 4 times higher than the other tracers in the anvil. On the contrary the African Easterly Jet tracer (~3 km has the lowest contribution above 5 km. The vertical profiles of the mid-troposphere tracers (4.5–10 km in the MCS exhibit two peaks: one in their initial layers, and the second one at 13–14 km altitude, underlying the importance of mid-tropospheric air in feeding the upper troposphere. Mid-tropospheric tracers also experience efficient transport by convective downdrafts with a consequent increase of their concentrations at the surface. The concentration of the upper troposphere–lower stratosphere tracer exhibits strong gradients at the edge of the cloud, meaning almost no entrainment of this tracer into the cloud. No downward transport from the upper troposphere is simulated below 5 km. A proxy for lightning produced NOx is transported preferentially in the forward anvil in the upper troposphere. Additionally, lateral inflows significantly contribute to the updraft and downdraft airflows emphasizing the three-dimensional structure of the West African MCSs.

  6. The Experience of Receiving and Then Losing a Scholarship: A Tracer Study of Secondary School Scholarship Recipients in Uganda

    Science.gov (United States)

    Watson, Cathy; Chapman, David W.; Okurut, Charles Opolot

    2014-01-01

    This study reports findings of a tracer that investigated differences in the profile and subsequent experiences of scholarship recipients in Uganda who were able to complete the lower secondary school cycle (O level) without interruption (N = 174) and those that dropped out before completing their O-level cycle (N = 51), thereby losing their…

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1948-05-24

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

  8. Chemical Tracer Methods: Chapter 7

    Science.gov (United States)

    Healy, Richard W.

    2017-01-01

    Tracers have a wide variety of uses in hydrologic studies: providing quantitative or qualitative estimates of recharge, identifying sources of recharge, providing information on velocities and travel times of water movement, assessing the importance of preferential flow paths, providing information on hydrodynamic dispersion, and providing data for calibration of water flow and solute-transport models (Walker, 1998; Cook and Herczeg, 2000; Scanlon et al., 2002b). Tracers generally are ions, isotopes, or gases that move with water and that can be detected in the atmosphere, in surface waters, and in the subsurface. Heat also is transported by water; therefore, temperatures can be used to trace water movement. This chapter focuses on the use of chemical and isotopic tracers in the subsurface to estimate recharge. Tracer use in surface-water studies to determine groundwater discharge to streams is addressed in Chapter 4; the use of temperature as a tracer is described in Chapter 8.Following the nomenclature of Scanlon et al. (2002b), tracers are grouped into three categories: natural environmental tracers, historical tracers, and applied tracers. Natural environmental tracers are those that are transported to or created within the atmosphere under natural processes; these tracers are carried to the Earth’s surface as wet or dry atmospheric deposition. The most commonly used natural environmental tracer is chloride (Cl) (Allison and Hughes, 1978). Ocean water, through the process of evaporation, is the primary source of atmospheric Cl. Other tracers in this category include chlorine-36 (36Cl) and tritium (3H); these two isotopes are produced naturally in the Earth’s atmosphere; however, there are additional anthropogenic sources of them.

  9. PERFLUOROCARBON GAS TRACER STUDIES TO SUPPORT RISK ASSESSMENT MODELING OF CRITICAL INFRASTRUCTURE SUBJECTED TO TERRORIST ATTACKS.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.M.; HEISER, J.; WATSON, T.; ALLWINE, K.J.; FLAHERTY, J.E.

    2006-05-06

    Development of real-time predictive modeling to identify the dispersion and/or source(s) of airborne weapons of mass destruction including chemical, biological, radiological, and nuclear material in urban environments is needed to improve response to potential releases of these materials via either terrorist or accidental means. These models will also prove useful in defining airborne pollution dispersion in urban environments for pollution management/abatement programs. Predicting gas flow in an urban setting on a scale of less than a few kilometers is a complicated and challenging task due to the irregular flow paths that occur along streets and alleys and around buildings of different sizes and shapes, i.e., ''urban canyons''. In addition, air exchange between the outside and buildings and subway areas further complicate the situation. Transport models that are used to predict dispersion of WMD/CBRN materials or to back track the source of the release require high-density data and need defensible parameterizations of urban processes. Errors in the data or any of the parameter inputs or assumptions will lead to misidentification of the airborne spread or source release location(s). The need for these models to provide output in a real-time fashion if they are to be useful for emergency response provides another challenge. To improve the ability of New York City's (NYC's) emergency management teams and first response personnel to protect the public during releases of hazardous materials, the New York City Urban Dispersion Program (UDP) has been initiated. This is a four year research program being conducted from 2004 through 2007. This paper will discuss ground level and subway Perfluorocarbon tracer (PFT) release studies conducted in New York City. The studies released multiple tracers to study ground level and vertical transport of contaminants. This paper will discuss the results from these tests and how these results can be used

  10. Cobalt-57 as a SPET tracer in the visualization of ischaemic brain damage in patients with middle cerebral artery stroke

    NARCIS (Netherlands)

    Stevens, H; Knollema, S; Piers, DA; Van de Wiele, C; Jansen, HML; De Jager, AEJ; De Reuck, J; Dierckx, RA; Korf, J

    1998-01-01

    In PET studies we have shown the usefulness of cobalt radionuclides for the visualization and quantification of ischaemic damage in stroke. In the present study, we explored Co-57(2+) as a SPET tracer. Uptake of radioactivity was estimated by using a cobalt enhancement ratio defined as the ratio of

  11. Development of radioisotope tracer technology

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee; Park, Soon Chul; Lim, Dong Soon; Kim, Jae Ho; Lee, Jae Choon; Lee, Doo Sung; Cho, Yong Suk; Shin, Sung Kuan

    2000-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and to build a strong tracer group to support the local industries. In relation to the tracer technology in 1999, experiments to estimate the efficiencies of a sludge digester of a waste water treatment plant and a submerged biological reactor of a dye industry were conducted. As a result, the tracer technology for optimization of facilities related to wastewater treatment has been developed and is believed to contribute to improve their operation efficiency. The quantification of the experimental result was attempted to improve the confidence of tracer technology by ECRIN program which basically uses the MCNP simulation principle. Using thin layer activation technique, wear of tappet shim was estimated. Thin layer surface of a tappet shim was irradiated by proton beam and the correlation between the measured activity loss and the amount of wear was established. The equipment was developed to adjust the energy of proton which collides with the surface of tappet. The tracer project team has participated into the tracer test for estimating the efficiency of RFCC system in SK cooperation. From the experiment the tracer team has obtained the primary elements to be considered for judging the efficiency of RFCC unit. By developing the tracer techniques to test huge industrial units like RFCC, the tracer team will be able to support the local industries that require technical services to solve any urgent trouble. (author)

  12. Effect of radioactivity on stent-graft incorporation after endovascular treatment of aneurysms: An animal study.

    Science.gov (United States)

    Lerouge, Sophie; Raymond, Jean; Schloesser, Klaus; Gaboury, Louis; Soulez, Gilles

    2006-12-01

    Poor stent-graft (SG) incorporation into the vessel wall, following endovascular repair of abdominal aortic aneurysms (EVAR), can lead to endoleaks and SG migration. Low-dose radiation can prevent aneurysm recurrence after coil embolization, and has been associated with a "paradoxical" increase in neointima formation after stenting in a few studies. It was hypothesized that in situ beta radiation emitted from SG could improve its incorporation by preventing the persistence of circulating channels between the implant and the vessel wall and increasing neointima formation around the SG. Phosphorus 32 ((32)P, 200 or 400 kBq per SG (n = 6 each)) was ion implanted on the external surface of balloon-expandable SGs. Twelve radioactive and six non-radioactive SGs were deployed in iliac arteries of nine Mongrel dogs. Neointima formation inside the graft and the persistence of circulating flow through an artificial groove created during the endovascular procedure were assessed by follow-up imaging and by blinded, computerized histomorphometric analysis after animal sacrifice at 3 months. Occlusion occurred in four radioactive SGs. A lesser number of patent grooves was observed along high-activity SGs than along control SGs (1/3 versus 4/4). No difference in neointima formation was observed in radioactive and non-radioactive SGs. Alteration of external graft surface was observed after ion implantation. Ion implantation of (32)P on SGs does not seem to be a viable strategy to improve incorporation and prevent type-I endoleak after EVAR.

  13. Use of /sup 75/Se tracer and autoradiographic techniques in the study of schistosomiasis

    Energy Technology Data Exchange (ETDEWEB)

    Chandiwana, S.K. (New York State Veterinary Coll., Ithaca, NY (USA))

    1988-12-01

    The paper provides an overview of recent studies on the use of /sup 75/Se to tag larval schistosomes and to monitor their migration and distribution patterns in naive mice and those previously exposed to cercariae. The principles and techniques of radioassay and autoradiography in studying various aspects of /sup 75/Se-labelled larval schistosomes are described. The main shortcoming of radioassay in monitoring location and movement of labelled schistosomula is that some of the label dissociates from the schistosomula and accumulates in host tissues, notably the liver. Dissociated label is indistinguishable from schistosomula-bound label making monitoring of parasite migration extremely difficult. This difficulty is overcome by compressed tissue autoradiography where labelled schistosomula can be seen as reduced silver foci on an autoradiographic film, whereas dissociated label is too diffusely distributed to produce such reduced silver foci. Furthermore, using autoradiography, quantitative information on parasite migration in normal and immunized laboratory animals can be obtained that would be impossible using traditional recovery techniques. In addition to using /sup 75/Se tracer in migration studies, the radio-isotope has potential for elucidating various aspects of schistosome transmission ecology and snail population dynamics in natural waters. (author).

  14. 11C-harmine as a potential PET tracer for ductal pancreas cancer: in vitro studies.

    Science.gov (United States)

    Herlin, G; Persson, B; Bergström, M; Långström, B; Aspelin, P

    2003-04-01

    Our objective was to find a tracer in diagnosing human pancreatic cancer using positron emission tomography (PET). For this purpose in vitro test of pancreatic tissues with autoradiography was used. Autoradiography was performed with (11)C-harmine (a MAO-A-inhibitor) with and without competitive inhibition. Tissue preparations were obtained from normal human pancreas and pancreatic cancer. The uptake was compared with rat brain or pig brain, tissues with high expression of MAO-A. Nine autoradiography studies on 16 samples from five different human pancreatic cancers gave a significant level of specific binding of (11)C-harmine in 13, and 3 samples did not give a significant level of specific binding of (11)C-harmine. All 16 samples were analysed with autoradiography. Compared with rat brain, the uptake in the human cancers varied between 9 and 43% except for one tissue preparation which had a too low value for measurement. This study shows expression of MAO-A in human pancreatic cancer. This is readily characterised in vitro. The potential use of (11)C-harmine in the diagnosis of pancreatic cancer using PET might be limited, but further PET studies are necessary.

  15. Tracer-based studies of soil water movement in semi-arid forests of New Mexico

    Science.gov (United States)

    Newman, Brent D.; Campbell, Andrew R.; Wilcox, Bradford P.

    1997-09-01

    The related issues of water movement and contaminant transport in arid and semi-arid environments have generated considerable interest and concern in the last few decades. Essential to understanding these issues is knowledge of how water moves through the soils that form the uppermost part of the vadose zone. The use of tracers, both natural and artificially introduced, is proving to be an effective method for gaining such knowledge in dry regions, where investigation by other means is difficult. In this study, natural stable-isotope and chloride tracers were used to investigate water movement in the soils of a piñon-juniper woodland and of a ponderosa pine forest on the Pajarito Plateau in northern New Mexico. The objectives were to (1) estimate and compare near-surface flux rates and evaluate the importance of evaporation in the two communities, and (2) determine to what extent differences in flux rates and evaporation are due to differences in plant cover and/or soil hydraulic properties. The results of this study will aid in evaluating the potential for contaminant mobility in semi-arid systems such as the Pajarito Plateau and, in addition, will increase understanding of nutrient distributions and plant water use in semi-arid environments. The stable-isotope data indicate a similarity between the piñon-juniper and ponderosa communities with respect to evaporation: in both, it is restricted mainly to the upper 10 cm of soil. Chloride profiles from the two communities, on the other hand, show a distinct difference with respect to downward fluxes: in the ponderosa pine forest, these fluxes (≈0.02 cm year -1) are an order of magnitude lower than those in the piñon-juniper woodland (≈0.2 cm year -1), even though total precipitation is about 4 cm year -1 higher in the ponderosa pine forest. This difference, however, appears to be related not to plant cover, but to differences in soil hydraulic properties. The soils of the ponderosa pine forest contain clay

  16. Resting Study of Tracer Experiment on Catalytic Wet Oxidation Reactor under Micro-gravity and Earth Gravity Conditions

    Institute of Scientific and Technical Information of China (English)

    YANG Ji; JIA Jin-ping

    2005-01-01

    The International Space Station(ISS) employs catalytic wet oxidation carried out in a Volatile Reactor Assembly (VRA) for water recycling. Previous earth gravity experiments show that the VRA is very effective at removing polar,low molecular weight organics. To compare the reactor performance under micro-gravity and Earth gravity conditions,a tracer study was performed on a space shuttle in 1999 by using 0. 2% potassium carbonate as the chemical tracer.In this paper, the experimental data were analyzed and it is indicated that the reactor can be considered as a plug flow one under both micro-gravity and earth gravity experimental conditions. It has also been proved that dispersion is not important in the VRA reactor under the experimental conditions. Tracer retardation was observed in the experiments and it is most likely caused by catalyst adsorption. It is concluded that the following reasons may also have influence on the retardation of mean residence time: (1) the liquid can be held by appurtenances, which will retard the mean residence time; (2) the pores can hold the tracer, which can also retard the mean residence time.

  17. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain Site characterization study; Progress report, April 1, 1993--June 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Dombrowski, T.; Stetzenbach, K.

    1993-08-01

    This report is in two parts one for the fluorinated benzoic acids and one for the fluorinated aliphatic acids. The assumptions made in the report regarding the amount of tracer that will be used, dilution of the tracer during the test and the length of exposure (if any) to individuals drinking the water were made by the authors. These assumptions must really come from the USGS hydrologists in charge of the c-well tracer testing program. Accurate estimates of dilution of the tracer during the test are also important because of solubility limitations of some of the tracers. Three of the difluorobenzoic acids have relatively low solubilities and may not be usable if the dilution estimates are large. The toxicologist that reviewed the document agreed with our conclusion that the fluorinated benzoic and toluic acids do not represent a health hazard if used under the conditions as outlined in the report. We are currently testing 15 of these compounds, and if even if three difluorobenzoic acids cannot be used because of solubility limitations we will still have 12 tracers. The toxicologist felt that the aliphatic fluorinated acids potentially present more of a health risk than the aromatic. This assessment was based on the fact of a known allergic response to halothane anesthetic. This risk, although minimal, is known and he felt that was enough reason to recommend against their use. The authors feel that the toxicologists interpretation of this risk was overly conservative, however, we will not go against his recommendation at this time for the following reasons. First, without the aliphatic compounds we still have 12 to 15 fluorinated aromatic acids which, should be enough for the c-well tests. Second, to get a permit to use aliphatic compounds would undoubtedly require a hearing which could be quite lengthy.

  18. Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stetzenbach, K.; Farnham, I.

    1996-06-01

    Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability of these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test.

  19. Radioactive Waste.

    Science.gov (United States)

    Blaylock, B. G.

    1978-01-01

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

  20. A pilot study of the behavior of gas- and particle-phase ETS tracers in residences

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael; Gundel, Lara; Dod, Raymond; Chang, Gee-Min; Sextro, Richard

    2002-02-01

    Our previous study of environmental tobacco smoke (ETS) in a three-room environmental chamber showed that smoking history significantly influenced inter-room ETS transport, particularly of gas-phase nicotine. We conducted a three-home pilot study where smoking was limited to one room. Single-smoker residences were monitored during five one-week periods while the smoker participated in a smoking cessation program. Nicotine traced ETS particles were detected reliably in the smoking rooms (SRs) and unreliably in the non-smoking rooms (NSRs). On average, the ventilation- and volume-normalized smoking rate, 0.1 Cigarette-h{sup -1} m{sup -3}, added about 17 and 4 {micro}g m{sup -3} of ETS particles into the SR and NSR, while average nicotine concentration increases were 2 and 0.06 {micro}g m{sup -3}, respectively. Thus, nicotine tracers may underestimate ETS particle exposure in a NSR (e.g., a child's bedroom) by a factor of 2 to 8. In other words, ETS exposure predicted from nicotine concentrations could be almost an order of magnitude lower than actual exposure.

  1. A DEPTH OPTIMIZATION STUDY FOR GEOLOGIC ISOLATION OF RADIOACTIVE WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Thadani, M.

    1980-02-01

    Current Federal plans for the isolation of high-level radioactive wastes and spent fuel include the possible placement of these wastes in deep geologic repositories. It is generally assumed that increasing the emplacement depth increases safety because the wastes are farther removed from the phenomena that might compromise the integrity of their isolation. Also, the path length for the migration of radionuclides to the biosphere increases with depth, thus delaying their arrival. However, increasing the depth of emplacement adds cost and operatiunal penalties. Therefore, a trade-off between the safety and the cost of waste isolation exists. A simple algorithm has been developed to relate the repository construction and operation costs, the costs associated with construction and operational hazards, and the costs resulting from radiological exposures to future generations to the depth of emplacement: The application of the algorithm is illustrated by SdDlP 1 e ca leul at ions u t il i zing se 1 ec ted parameters. The cost-optimum emplacement depths are estimated by summing the cost elements and determining the depth at which the sum would be the least. The relationship between the repository construction costs and the depth of the depository was derived from simplified rock mechanics and stability considerations applied to repository design concepts selected from the current literature and the available data base on mining and excavation costs. In developing the relationship between the repository costs and the depth of the depository, a worldwide cost information data base was used. The relationships developed are suitable for application to bedded sa1t, shale, and basalt geologies. The incremental impacts of hazards as a function of repository depth resulting from drilling, construction of repositories and hoisting systems, and operation of repositories were developed from the reported data on accidents involving shafts and mine construction activities and shaft

  2. Sinks for nitrogen inputs in terrestrial ecosystems: a meta-analysis of 15N tracer field studies

    Science.gov (United States)

    Templer, P.H.; Mack, M.C.; Chapin, F. S.; Christenson, L.M.; Compton, J.E.; Crook, H.D.; Currie, W.S.; Curtis, C.J.; Dail, D.B.; D'Antonio, C. M.; Emmett, B.A.; Epstein, H.E.; Goodale, C.L.; Gundersen, P.; Hobbie, S.E.; Holland, K.; Hooper, D.U.; Hungate, B.A.; Lamontagne, S.; Nadelhoffer, K.J.; Osenberg, C.W.; Perakis, S.S.; Schleppi, P.; Schimel, J.; Schmidt, I.K.; Sommerkorn, M.; Spoelstra, J.; Tietema, A.; Wessel, W.W.; Zak, D.R.

    2012-01-01

    Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e., total ecosystem 15N recovery in plant and soil pools) across natural systems and N partitioning among ecosystem pools. The greatest recoveries of ecosystem 15N tracer occurred in shrublands (mean, 89.5%) and wetlands (84.8%) followed by forests (74.9%) and grasslands (51.8%). In the short term (15N tracer application), total ecosystem 15N recovery was negatively correlated with fine-root and soil 15N natural abundance, and organic soil C and N concentration but was positively correlated with mean annual temperature and mineral soil C:N. In the longer term (3–18 months after 15N tracer application), total ecosystem 15N retention was negatively correlated with foliar natural-abundance 15N but was positively correlated with mineral soil C and N concentration and C: N, showing that plant and soil natural-abundance 15N and soil C:N are good indicators of total ecosystem N retention. Foliar N concentration was not significantly related to ecosystem 15N tracer recovery, suggesting that plant N status is not a good predictor of total ecosystem N retention. Because the largest ecosystem sinks for 15N tracer were below ground in forests, shrublands, and grasslands, we conclude that growth enhancement and potential for increased C storage in aboveground biomass from atmospheric N deposition is likely to be modest in these ecosystems. Total ecosystem 15N recovery decreased with N fertilization, with an apparent threshold fertilization rate of 46 kg N·ha-1·yr-1 above which most ecosystems showed net losses of applied 15N tracer in response to N fertilizer addition.

  3. Tracer-based quantification of individual frac discharge in single-well multiple-frac backflow: sensitivity study

    Science.gov (United States)

    Ghergut, Julia; Behrens, Horst; Sauter, Martin

    2014-05-01

    Within the deep-geothermal research project at GroßSchönebeck in the NE German Basin, targeting volcanic rocks (Lower Rotliegend) and siliciclastics (Upper Rotliegend) in the Lower Permian by means of a well doublet with several screening intervals between 3815 and 4247 m b.s.l., several artificial fractures with different geometric and hydraulic characteristics were created at each well, aiming to increase reservoir performance [1], [2]. It could not be told a priori which of the various fracturing treatments was to prove as most promising in terms of future reservoir productivity. At the intended-production well (GS-4), one large-area waterfrac was created in the low-permeability volcanic rocks, and two gel-proppant fractures in selected sandstone layers. Each fracturing treatment was accompanied by the injection of a water-dissolved tracer slug, followed by a defined volume of tracer-free ('chaser') fluid [3]. Each frac received a different species of a sulfonated aromatic acid salt, as a conservative water tracer. During subsequent backflow tests (either gas-based lifting, or production by means of a downhole submersible pump), each frac can contribute a certain (more or less constant) amount to the measured total discharge (also depending on whether and when each frac 'starts' contributing, and which effective aperture and area it actually 'manifests' during the process). Since these individual-frac discharge amounts cannot be measured directly, it was endeavoured to indirectly determine ('resolve') them from tracer signals as detectable in the overall backflow discharge. Therefore, we need to examine how these tracer signals depend on local discharge values and on local hydrogeologic parameters (matrix porosity, permeability distribution; frac transmissivity, thickness, effective area and aperture), and to what extent hydrogeological uncertainty will impede the inversion of local discharge values. To this end, a parameter sensitivity study was conducted on

  4. Lead isotope ratios as a tracer for lead contamination sources: A lake Andong case study

    Directory of Open Access Journals (Sweden)

    Kim Y. H

    2013-04-01

    Full Text Available The objective of this study was to evaluate stable Pb isotope signatures as a tracer for Pb contamination in Lake Andong. For Pb isotope analysis, we collected water and sediment from Lake Andong, particles in the air, soils, and stream water, mine tailings, sludge and wastewater from zinc smelting around lake Andong watershed. The results showed that Pb isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for zinc concentrate were 18.809 ± 0.322, 15.650 ± 0.062, and 38.728 ± 0.421, respectively. In wastewater, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb were 17.363 ± 0.133, 15.550 ± 0.025, and 37.217 ± 0.092, respectively. Additionally, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for sludge were 17.515 ± 0.155, 15.537 ± 0.018, and 37.357 ± 0.173, respectively. These values were similar to those in zinc and lead concentrate originated from Canada and South America. In contrast, Pb isotope ratios of soil, tailings and sediment from Lake Andong were similar to those of Korean ore. Atmospheric particles showed different patterns of Pb isotope ratios from sediments, soils, and zinc smelting and this needs further investigation in order to identify atmospheric Pb sources.

  5. Sediments as tracers for transport and deposition processes in peri-alpine lakes: A case study

    Science.gov (United States)

    Righetti, Maurizio; Toffolon, Marco; Lucarelli, Corrado; Serafini, Michele

    2011-12-01

    SummaryThe benthic sediment fingerprint is analysed in the small peri-alpine lake Levico (Trentino, Italy) to identify the causes of recurrent phenomena of turbidity peaks, particularly evident in a littoral region of the water body. In order to study the sediment transport processes, we exploit the fact that the sediment supply from the major tributary has a specific chemical composition, which differs from that of the nearby lake basin. Three elements (Fe, Al, K) have been used as tracers to identify the source and the deposition patterns of tributary sediments, and another typical element, Si, has been critically analysed because of its dual (allochthonous and autochthonous) origin. Several samples of the benthic material have been analysed using SEM-EDS, and the results of the sedimentological characterisation have been compared with the patterns of sediment accumulation at the bed of the lake obtained using a three-dimensional numerical model, in response to the tributary supply under different external forcing and stratification conditions. The coupled use of field measurements and numerical results suggests that the turbidity phenomena are strongly related to the deposition of the sediments supplied by the tributary stream, and shows that it is possible to reconstruct the process of local transport when the tributary inflow is chemically specific.

  6. Clinical studies of bone metabolism using a simple model of calcium tracer kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Roncari, G.

    1981-08-01

    Bone metabolism studies were performed in 44 subjects with and without bone disease using a calcium tracer kinetics model, the central feature of which is an expanding exchangeable calcium pool. In normal subjects the accretion rate and the exchangeable calcium pool ranged from 1.49 to 8.45 (mean 3.9 +- 2.05) mg.d/sup -1/kg/sup -1/ and from 60 to 131 (mean 81.25 +- 18.11) mg.kg/sup -1/, respectively. The patients with osteogenesis imperfecta, Pierre Marie's disease and one out of two cases of hypoparathyroidism had values which fell within the normal range. Both the accretion rate and the exchangeable calcium pool were significantly elevated in patients with Paget's disease and with hyperparathyroidism. Uremic patients with generalizated bone lesions had accretion rates or both parameters elevated. As far as patients with successful renal transplant are concerned, the results suggest that this method is a very poor means for detecting bone disorders with only focal lesions. In contrast, the method can be very useful when persistent renal osteodystrophy or secondary hyperparathyroidism are suspected.

  7. A DEPTH OPTIMIZATION STUDY FOR GEOLOGIC ISOLATION OF RADIOACTIVE WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Thadani, M.

    1980-02-01

    Current Federal plans for the isolation of high-level radioactive wastes and spent fuel include the possible placement of these wastes in deep geologic repositories. It is generally assumed that increasing the emplacement depth increases safety because the wastes are farther removed from the phenomena that might compromise the integrity of their isolation. Also, the path length for the migration of radionuclides to the biosphere increases with depth, thus delaying their arrival. However, increasing the depth of emplacement adds cost and operatiunal penalties. Therefore, a trade-off between the safety and the cost of waste isolation exists. A simple algorithm has been developed to relate the repository construction and operation costs, the costs associated with construction and operational hazards, and the costs resulting from radiological exposures to future generations to the depth of emplacement: The application of the algorithm is illustrated by SdDlP 1 e ca leul at ions u t il i zing se 1 ec ted parameters. The cost-optimum emplacement depths are estimated by summing the cost elements and determining the depth at which the sum would be the least. The relationship between the repository construction costs and the depth of the depository was derived from simplified rock mechanics and stability considerations applied to repository design concepts selected from the current literature and the available data base on mining and excavation costs. In developing the relationship between the repository costs and the depth of the depository, a worldwide cost information data base was used. The relationships developed are suitable for application to bedded sa1t, shale, and basalt geologies. The incremental impacts of hazards as a function of repository depth resulting from drilling, construction of repositories and hoisting systems, and operation of repositories were developed from the reported data on accidents involving shafts and mine construction activities and shaft

  8. Fate of thymic lymphocytes. [/sup 125/IudR and /sup 3/HTdR tracer studies in mice

    Energy Technology Data Exchange (ETDEWEB)

    Laissue, J A; Chanana, A D; Cronkite, E P; Joel, D D

    1976-01-01

    Data are summarized from a number of studies on the fate of thymic lymphocytes. Results are reported from studies in mice in which /sup 125/IudR and /sup 3/HTdR were used as tracers to study the production, maturation, migration, and life span of thymic lymphocytes. It is pointed out that thymus-derived cells constitute the majority of recirculating lymphocytes and that peripheral, differentiated thymus-derived lymphocytes exhibit a number of immunological functions. 114 references.

  9. Tracer methods for investigating biosynthetic pathways and the metabolism of bioactive substances in plants. [Herbicides; Plant growth regulators

    Energy Technology Data Exchange (ETDEWEB)

    Schuette, H.R. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1984-03-01

    Proceeding from the general terms of investigating the courses of reactions in plants by means of tracer methods, problems and possibilities of the methods are discussed on the basis of examples referring in particular to double labelling techniques and to the determination of the distribution of radioactivity in the resulting products. Examples of herbicides and plant growth regulators are used for describing metabolism studies.

  10. Radioactive iodine in the treatment of medullary thyroid carcinoma : a controlled multicenter study

    NARCIS (Netherlands)

    Meijer, J. A. A.; Bakker, L. E. H.; Valk, G. D.; de Herder, W. W.; de Wilt, J. H. W.; Netea-Maier, R. T.; Schaper, N.; Fliers, E.; Lips, P.; Plukker, J. T.; Links, T. P.; Smit, J. A.

    2013-01-01

    Objective: Radioactive iodine (RAI) therapy in medullary thyroid carcinoma (MTC) is applied in some centers, based on the assumption that cross-irradiation from thyroid follicular cells may be beneficial. However, no systematic studies on the effect of RAI treatment in MTC have been performed. The a

  11. Radioactive iodine in the treatment of medullary thyroid carcinoma: a controlled multicenter study

    NARCIS (Netherlands)

    Meijer, J.A.M.; Bakker, L.E.; Valk, G.D.; Herder, W.W. de; Wilt, J.H.W. de; Netea-Maier, R.T.; Schaper, N.; Fliers, E.; Lips, P.; Plukker, J.T.; Links, T.P.; Smit, Jan

    2013-01-01

    OBJECTIVE: Radioactive iodine (RAI) therapy in medullary thyroid carcinoma (MTC) is applied in some centers, based on the assumption that cross-irradiation from thyroid follicular cells may be beneficial. However, no systematic studies on the effect of RAI treatment in MTC have been performed. The a

  12. Radioactive iodine in the treatment of medullary thyroid carcinoma: A controlled multicenter study

    NARCIS (Netherlands)

    J.A.A. Meijer (J. A A); L.E.H. Bakker (Leontine); G.D. Valk (Gerlof); W.W. de Herder (Wouter); J.H.W. de Wilt (Johannes); R.T. Netea-Maier (Romana ); N. Schaper; E. Fliers (Eric); P. Lips (Paul); J.T. Plukker (John); T.P. Links (Thera); J.A. Smit (J.)

    2013-01-01

    textabstractObjective: Radioactive iodine (RAI) therapy in medullary thyroid carcinoma (MTC) is applied in some centers, based on the assumption that cross-irradiation from thyroid follicular cells may be beneficial. However, no systematic studies on the effect of RAI treatment in MTC have been perf

  13. Teacher Education Graduate Tracer Study from 2010 to 2014 in One State University in Batangas, Philippines

    Directory of Open Access Journals (Sweden)

    Anania B. Aquino

    2015-12-01

    Full Text Available Teacher Education institutions primarily aim of producing competent and highly qualified graduates employable here and abroad. Tracer studies on graduates can appropriately provide valuable information for evaluating the results of the education and training of a specific institution of higher education. It collects essential information concerning the employment profile of graduates, their undergraduate experience, the first and current jobs of graduates and the relevance of their educational background and skills required in their job. The main objective of this study was to trace the employment profile of the graduates after they obtained their teacher education degree. The descriptive survey method of research was applied to this research with a survey questionnaire as the main data gathering instrument. It analyzed data from 129 respondents characterized by a preponderance of females over male as females and unmarried or single graduates as opposed to those who were married. The study found that there were more respondents who finished Bachelor of Secondary Education (BSED over Bachelor of Elementary Education. They obtained this degree as they believed that teaching is a rewarding and challenging profession, Majority are Licensure Examination for Teachers (LET passers and are employed in public schools at the time of the study. Their present job, mostly professional in nature, was also their first job and relevant to their degree. It took only a moderate period of time for most graduates to land a job. Most stay in their job for economic reason, finding communication skills and human relation skills as part of their teacher education preparation very relevant to their jobs.

  14. Axillary sentinel node identification in breast cancer patients: degree of radioactivity present at biopsy is critical

    DEFF Research Database (Denmark)

    Nielsen, Kristina R; Oturai, Peter S; Friis, Esbern;

    2011-01-01

    The radioactivity present in the patient (Act(rem) ) at sentinel node (SN) biopsy will depend on injected activity amount as well as on the time interval from tracer injection to biopsy, which both show great variations in the literature. The purpose of this study was to analyse the influence...

  15. An investigation of radial tracer flow in naturally fractured reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Jetzabeth, Ramirez-Sabag; Fernando, Samaniego V.; Jesus, Rivera R.; Fernando Rodriguez

    1991-01-01

    This study presents a general solution for the radial flow of tracers in naturally fractured reservoirs. Continuous and finite step injection of chemical and radioactive tracers are considered. The reservoir is treated as being composed of two regions: a mobile region where longitudinal dispersion and convection take place and a stagnant region where only diffusion and adsorption are allowed. Radioactive decay is considered in both regions. The model of this study is thoroughly compared to those previously presented in literature by Moench and Ogata, Tang et al., Chen et al., and Hsieh et al. The solution is numerically inverted by means of the Crump algorithm. A detailed validation of the model with respect to solutions previously presented and/or simplified physical conditions solutions (i.e., homogeneous case) or limit solutions (i.e., for short times) was carried out. The influence of various dimensionless parameters that enter into the solution was investigated. A discussion of results obtained through the Crump and Stehfest algorithm is presented, concluding that the Crump method provides more reliable tracer concentrations.

  16. Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

    Energy Technology Data Exchange (ETDEWEB)

    Luong, Elise [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 ± 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 ± 0.4 ng/g, while the certified value is 11.5 ± 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 ± 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry (GC-combustion-IRMS). Trytophan, myoglobin, and β-cyclodextrin are chosen for the study, initial observation of spectral interference of 13C+ with 12C 1H+ comes from the incomplete dissociation of myoglobin and/or β-cyclodextrin.

  17. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, K.R.

    1992-01-01

    Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

  18. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO{sub 2} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, K.R.

    1992-01-01

    Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

  19. Comparison of [11C]cocaine binding at tracer and pharmacological doses of baboon brain: A PET study

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Fowler, J.S.; Logan, J. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1994-05-01

    In vitro studies have shown that cocaine (C) binds to both high and low affinity sites on the dopamine transporter (DAT). We have previously characterized the binding of tracer doses of [{sup 11}C]cocaine (C*)to a high affinity site on the DAT. To assess if in vivo C also binds to low affinity sites we used PET to compare binding of tracer doses (17.8{plus_minus}12.2 {mu}g C) of C* to pharmacological doses (8 mg of C coadministered with C*). Sixteen paired studies were done to assess test/retest variability, specific versus non specific binding and to characterize binding profile. Dynamic scans were started immediately after injection of C* (5-8 mCi) for 50 min on the CTI-931 (6 x 6 x 6.5 mm FWHM). Time activity curves for tissue concentration and for unchanged tracer in plasma were used to calculate the transport constant between plasma and tissue (K1) and to obtain the distribution volume (DV). The ratio of the DV in striatum (ST) to that in cerebellum (CB) (which corresponds to Bmax/Kd-1) was used as model parameter. Peak brain uptake of C* was significantly higher for tracer than for pharmacological doses (0.041 versus 0.033 % dose/cc), as were the values for K1 (1.07{plus_minus}0.21 versus 0.68{plus_minus}0.26 (t=3.0 p<0.01)). Repeated measures were reproducible for tracer ({plus_minus}2%) and pharmacological doses of C* ({plus_minus}4%). Tracer dose C* showed highest binding and slowest clearance in ST which was reduced by C (0.5-2.0 mg/kg iv, -25 to -30%) and by drugs that inhibit DAT (2mg/kg nomifensine - 21%, 0.5 mg/kg methylphenidate -12%) and was increased by serotonin transporter inhibitors (5HT-Ti) (2 mg/kg citalopram +11%, 0.5 mg/kg fluoxetine +6%) and not changed by NE transporter inhibitors (0.5 mg/kg desipramine or 2 mg/kg tomoxetine). The increase with (5HT-Ti) may reflect neurotransmitter interactions or changes in bioavailability. At pharmacological doses C* showed homogeneous distribution and was not changed by C nor by any of the above drugs.

  20. Transport study in unsaturated porous media by tracer experiment in a dichromatic X-ray experimental device

    Directory of Open Access Journals (Sweden)

    Néel M.C.

    2013-05-01

    Full Text Available Estimating contaminant migration in the context of waste disposal and/or environmental remediation of polluted soils requires a complete understanding of the underlying transport processes. In unsaturated porous media, water content is one of the most determining parameters to describe solute migration because it impacts directly on solute pore velocity. However, numerous studies are satisfied with only a global or a partial spatial distribution of water content within the studied porous media. Therefore, distribution of water content in porous media must be precisely achieved to optimize transport processes modeling. Tracer experiments with downward flow were performed on the BEETI experimental device equipped with a sand column. Water content and concentration profiles of tracer (KI were measured along the column during experiment. The relative dispersion of water content, calculated along the column, gives an idea of influence of this parameter on transport properties. A relationship between pore velocity, Darcy flow velocity and water content is proposed.

  1. Transport study in unsaturated porous media by tracer experiment in a dichromatic X-ray experimental device

    Science.gov (United States)

    Latrille, C.; Néel, M. C.

    2013-05-01

    Estimating contaminant migration in the context of waste disposal and/or environmental remediation of polluted soils requires a complete understanding of the underlying transport processes. In unsaturated porous media, water content is one of the most determining parameters to describe solute migration because it impacts directly on solute pore velocity. However, numerous studies are satisfied with only a global or a partial spatial distribution of water content within the studied porous media. Therefore, distribution of water content in porous media must be precisely achieved to optimize transport processes modeling. Tracer experiments with downward flow were performed on the BEETI experimental device equipped with a sand column. Water content and concentration profiles of tracer (KI) were measured along the column during experiment. The relative dispersion of water content, calculated along the column, gives an idea of influence of this parameter on transport properties. A relationship between pore velocity, Darcy flow velocity and water content is proposed.

  2. Tracer Study of Dentistry Graduates of one Higher Education Institution in the Philippines from 2008 to 2012

    OpenAIRE

    Jennifer D. Maderazo

    2016-01-01

    This tracer study determines the employment status of the graduates of Doctor of Dental Medicine of Lyceum of the Philippines University (LPU) from 2008-2012. It assessed the relevance of the Dentistry curriculum, knowledge, skills and attitude acquired by the graduates deemed to be relevant for their employment; identify the personal and professional characteristics and job placement of Dentistry graduates and the school related factors associated with their employment. This trac...

  3. Sinks for nitrogen inputs in terrestrial ecosystems: a meta-analysis of 15N tracer field studies.

    Science.gov (United States)

    Templer, P H; Mack, M C; Chapin, F S; Christenson, L M; Compton, J E; Crook, H D; Currie, W S; Curtis, C J; Dail, D B; D'Antonio, C M; Emmett, B A; Epstein, H E; Goodale, C L; Gundersen, P; Hobbie, S E; Holland, K; Hooper, D U; Hungate, B A; Lamontagne, S; Nadelhoffer, K J; Osenberg, C W; Perakis, S S; Schleppi, P; Schimel, J; Schmidt, I K; Sommerkorn, M; Spoelstra, J; Tietema, A; Wessel, W W; Zak, D R

    2012-08-01

    Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e., total ecosystem 15N recovery in plant and soil pools) across natural systems and N partitioning among ecosystem pools. The greatest recoveries of ecosystem 15N tracer occurred in shrublands (mean, 89.5%) and wetlands (84.8%) followed by forests (74.9%) and grasslands (51.8%). In the short term (ecosystem 15N recovery was negatively correlated with fine-root and soil 15N natural abundance, and organic soil C and N concentration but was positively correlated with mean annual temperature and mineral soil C:N. In the longer term (3-18 months after 15N tracer application), total ecosystem 15N retention was negatively correlated with foliar natural-abundance 15N but was positively correlated with mineral soil C and N concentration and C:N, showing that plant and soil natural-abundance 15N and soil C:N are good indicators of total ecosystem N retention. Foliar N concentration was not significantly related to ecosystem 15N tracer recovery, suggesting that plant N status is not a good predictor of total ecosystem N retention. Because the largest ecosystem sinks for 15N tracer were below ground in forests, shrublands, and grasslands, we conclude that growth enhancement and potential for increased C storage in aboveground biomass from atmospheric N deposition is likely to be modest in these ecosystems. Total ecosystem 15N recovery decreased with N fertilization, with an apparent threshold fertilization rate of 46 kg N x ha(-1) x yr(-1) above which most ecosystems showed net losses of applied 15N tracer in response to N fertilizer addition.

  4. Natural analogue studies for the safety case development of radioactive waste disposal in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyung-Woo [Korea Institute of Nuclear Safety, 305-338 Daejeon (Korea, Republic of); Baik, Min-Hoon [Korea Atomic Energy Research Institute, 305-353 Daejeon (Korea, Republic of)

    2014-07-01

    The natural analogue study is an analogy approach to investigate natural occurrences of materials, conditions and processes that are similar to those known or predicted to occur in some part of a radioactive waste disposal system. Countries considering the disposal of radioactive waste have been working on their domestic natural analogue studies for developing the safety case and improving the disposal safety. Natural analogue study can effectively be applied to the understanding of a long-term behavior of the post-closure repository, the provision of quantitative data required for the safety assessment models, and the supplementary safety indicator to prove the safety of deep geological disposal. Therefore the natural analogue studies play an important role in the safety case which requires a multiple lines of evidence including the safety assessment for the geological disposal of radioactive wastes. In this study, current status of foreign natural analogue studies was investigated by summarizing their results related with repository materials, radionuclide migration and retardation. Main results, issues, and their applicability of the foreign natural analogue studies were also analyzed. The results of natural analogue studies in Korea were categorized and summarized according to the studies on the uranium ore bodies, rocks, groundwater, and archeological artifacts. Although so many studies on the natural analogue have been carried out during last several decades in Korea, their results have not been actively applied to the safety assessment and safety case development for radioactive waste disposal. Therefore, applicable methods of natural analogues were summarized and a methodology for improving their applicability was examined. Additionally, in order to improve the application of these results from natural analogue studies, build-up of a natural analogue information database was in progress and its status will be presented. (authors)

  5. A historical perspective on radioisotopic tracers in metabolism and biochemistry.

    Science.gov (United States)

    Lappin, Graham

    2015-01-01

    Radioisotopes are used routinely in the modern laboratory to trace and quantify a myriad of biochemical processes. The technique has a captivating history peppered with groundbreaking science and with more than its share of Nobel Prizes. The discovery of radioactivity at the end of the 19th century paved the way to understanding atomic structure and quickly led to the use of radioisotopes to trace the fate of molecules as they flowed through complex organic life. The 1940s saw the first radiotracer studies using homemade instrumentation and analytical techniques such as paper chromatography. This article follows the history of radioisotopic tracers from meager beginnings, through to the most recent applications. The author hopes that those researchers involved in radioisotopic tracer studies today will pause to remember the origins of the technique and those who pioneered this fascinating science.

  6. The Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRA*CER) trial: study design and rationale.

    Science.gov (United States)

    2009-09-01

    The protease-activated receptor 1 (PAR-1), the main platelet receptor for thrombin, represents a novel target for treatment of arterial thrombosis, and SCH 530348 is an orally active, selective, competitive PAR-1 antagonist. We designed TRA*CER to evaluate the efficacy and safety of SCH 530348 compared with placebo in addition to standard of care in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) and high-risk features. TRA*CER is a prospective, randomized, double-blind, multicenter, phase III trial with an original estimated sample size of 10,000 subjects. Our primary objective is to demonstrate that SCH 530348 in addition to standard of care will reduce the incidence of the composite of cardiovascular death, myocardial infarction (MI), stroke, recurrent ischemia with rehospitalization, and urgent coronary revascularization compared with standard of care alone. Our key secondary objective is to determine whether SCH 530348 will reduce the composite of cardiovascular death, MI, or stroke compared with standard of care alone. Secondary objectives related to safety are the composite of moderate and severe GUSTO bleeding and clinically significant TIMI bleeding. The trial will continue until a predetermined minimum number of centrally adjudicated primary and key secondary end point events have occurred and all subjects have participated in the study for at least 1 year. The TRA*CER trial is part of the large phase III SCH 530348 development program that includes a concomitant evaluation in secondary prevention. TRA*CER will define efficacy and safety of the novel platelet PAR-1 inhibitor SCH 530348 in the treatment of high-risk patients with NSTE ACS in the setting of current treatment strategies.

  7. $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

    CERN Multimedia

    We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

  8. Microfluidics: A Groundbreaking Technology for PET Tracer Production?

    Directory of Open Access Journals (Sweden)

    Björn Wängler

    2013-07-01

    Full Text Available Application of microfluidics to Positron Emission Tomography (PET tracer synthesis has attracted increasing interest within the last decade. The technical advantages of microfluidics, in particular the high surface to volume ratio and resulting fast thermal heating and cooling rates of reagents can lead to reduced reaction times, increased synthesis yields and reduced by-products. In addition automated reaction optimization, reduced consumption of expensive reagents and a path towards a reduced system footprint have been successfully demonstrated. The processing of radioactivity levels required for routine production, use of microfluidic-produced PET tracer doses in preclinical and clinical imaging as well as feasibility studies on autoradiolytic decomposition have all given promising results. However, the number of microfluidic synthesizers utilized for commercial routine production of PET tracers is very limited. This study reviews the state of the art in microfluidic PET tracer synthesis, highlighting critical design aspects, strengths, weaknesses and presenting several characteristics of the diverse PET market space which are thought to have a significant impact on research, development and engineering of microfluidic devices in this field. Furthermore, the topics of batch- and single-dose production, cyclotron to quality control integration as well as centralized versus de-centralized market distribution models are addressed.

  9. Study of research needs and priorities in radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    Carson, W.E.; Mitchell, W. III

    1984-02-01

    This report presents the results of an assessment of long-range research needs in nuclear waste management. The purpose is to aid the Director of Energy Research in determining the health of DOE's research programs. The intent of the project reported here was to identify additional, basic research necessary in the 1980s and 1990s to develop an adequate scientific data base for nuclear waste management activities likely to be important around the turn of the century. The recommendations resulted from an overview of the entire area of nuclear waste management, not from focused examinations of narrow topics within that area. The suggested research may be the subject of future studies or more intense work by DOE. The recommendations presented in this report are not accompanied by designations of responsible program offices within DOE. It is anticipated that the contents of the report will be shared with the program offices involved and that those offices will recognize and respond to recommendations within their purviews.

  10. Study on effect of geometrical configuration of radioactive source material to the radiation intensity of betavoltaic nuclear battery

    Energy Technology Data Exchange (ETDEWEB)

    Badrianto, Muldani Dwi; Riupassa, Robi D.; Basar, Khairul, E-mail: khbasar@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung (Indonesia)

    2015-09-30

    Nuclear batteries have strategic applications and very high economic potential. One Important problem in application of nuclear betavoltaic battery is its low efficiency. Current efficiency of betavoltaic nuclear battery reaches only arround 2%. One aspect that can influence the efficiency of betavoltaic nuclear battery is the geometrical configuration of radioactive source. In this study we discuss the effect of geometrical configuration of radioactive source material to the radiation intensity in betavoltaic nuclear battery system. received by the detector. By obtaining the optimum configurations, the optimum usage of radioactive materials can be determined. Various geometrical configurations of radioactive source material are simulated. It is obtained that usage of radioactive source will be optimum for circular configuration.

  11. Preparation of radioactive rare earth targets for neutron capture study

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G. G. (Geoffrey G.); Rogers, P. S. Z. (Pamela S. Z.); Palmer, P. D. (Phillip D.); Dry, D. E. (Donald E.); Rundberg, R. S. (Robert S.); Fowler, Malcolm M.; Wilhelmy, J. B. (Jerry B.)

    2002-01-01

    The understanding of thc details of nucleosynthesis in stars remains a great challenge. Though the basic mechanisms governing the processes have been known since the pioneering work of Burbidge, Burbidge, Fowler and Hoyle (l), we are now evolving into a condition where we can ask more specific questions. Of particular interest are the dynamics of the s ('slow') process. In this process the general condition is one in which sequential neutron captures occur at time scales long compared with the beta decay half lives of the capturing nuclides. The nucleosynthesis period for C or Ne burning stellar shells is believed to be in the year to few year time frame (2). This means that radionuclides with similar half lives to this burning period serve as 'branch point' nuclides. That is, there will be a competition between a capture to the next heavier isotope and a beta decay to the element of nexl higher atomic number. By understanding the abundances of these competing reactions we can learn about the dynamics of the nucleosynthesis process in the stellar medium. Crucial to this understanding is that we have a knowledge of the underlying neutron reaction cross sections on these unstable nuclides in the relevant stellar energy regions (neutrons of 0.1-100 KeV). Tm (1.9 years) and ls'Sm (90 ycws) have decay properties that permit their handling in an open fume hood. These Iwo were therefore selected to be the first radionuclides for neutron capture study in what will be an ongoing effort.

  12. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    CERN Document Server

    Fraser, M A; Jones, R M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering...

  13. Systematic Study of Trace Radioactive Impurities in Candidate Construction Materials for EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, D.S.; Grinberg, P.; Weber, P.; Baussan, E.; Djurcic, Z.; Keefer, G.; Piepke, A.; Pocar, A.; Vuilleumier, J.-L.; Vuilleumier, J.-M.; Akimov, D.; Bellerive, A.; Bowcock, M.; Breidenbach, M.; Burenkov, A.; Conley, R.; Craddock, W.; Danilov, M.; DeVoe, R.; Dixit, M.; Dolgolenko, A.; /Alabama U. /NRC-INMS /Neuchatel U. /Stanford U., Phys. Dept. /SLAC /Colorado State U. /Laurentian U. /Maryland U. /UC, Irvine

    2007-10-24

    The Enriched Xenon Observatory (EXO) will search for double beta decays of 136Xe. We report the results of a systematic study of trace concentrations of radioactive impurities in a wide range of raw materials and finished parts considered for use in the construction of EXO-200, the first stage of the EXO experimental program. Analysis techniques employed, and described here, include direct gamma counting, alpha counting, neutron activation analysis, and high-sensitivity mass spectrometry.

  14. Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, J. Matthew; Cullinan, Valerie I.; Barnett, Debra S.; Trang-Le, Truc LT; Bliss, Mary; Greenwood, Lawrence R.; Ballinger, Marcel Y.

    2009-02-17

    Since the mid-1980s, Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as the correction factor for self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. This value accounts for activity that cannot be detected by direct counting of alpha and beta particles. Emissions can be degraded or blocked by filter fibers for particles buried in the filter material or by inactive dust particles collected with the radioactive particles. These filters are used for monitoring air emissions from PNNL stacks for radioactive particles. This paper describes an effort to re-evaluate self-absorption effects in particulate radioactive air sample filters (Versapor® 3000, 47 mm diameter) used at PNNL. There were two methods used to characterize the samples. Sixty samples were selected from the archive for acid digestion to compare the radioactivity measured by direct gas-flow proportional counting of filters to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection. Thirty different sample filters were selected for visible light microscopy to evaluate filter loading and particulate characteristics. Mass-loading effects were also considered. Filter ratios were calculated by dividing the initial counts by the post-digestion counts with the expectation that post-digestion counts would be higher because digestion would expose radioactivity embedded in the filter in addition to that on top of the filter. Contrary to expectations, the post digestion readings were almost always lower than initial readings and averaged approximately half the initial readings for both alpha and beta activity. Before and after digestion readings appeared to be related to each other, but with a low coefficient of determination (R^2) value. The ratios had a wide range of values indicating that this method did not provide sufficient precision to quantify self

  15. Safety study of a radioactive facility with TLD dosimetry; Estudio de seguridad de una instalacion radiactiva con dosimetria TLD

    Energy Technology Data Exchange (ETDEWEB)

    Diez Villafanez, M.; Benavente Ruiz, M. A.; Ruiz Penalba, F. J.; Enriquez Payan, F.; Sotelo Garcia, O.; Rey Martinez, M.; Pardos Ibanez, R.

    2011-07-01

    The project purpose is to confirm experimentally the radiation safety using the technique of thermoluminescence dosimetry (TLD), using the reference desk study carried out for gamma irradiation room in the Safety Study was authorized by the radioactive facility.

  16. Simulation studies of the response function of a radioactive waste assay system.

    Science.gov (United States)

    Gurau, Daniela; Sima, Octavian

    2012-01-01

    A simulation program based on GEANT 3.21 toolkit was developed to simulate the response function of ISOCART (Ortec) gamma-ray spectrometry system applied to radioactive waste drum assessment. In view of studying the effects of possible non-homogeneous radioactivity distribution in the drum, the volume of the drum was fictitiously divided into several spatial domains. The simulation program was applied repeatedly considering each time the source distributed in another domain. In this way the expected spectra in the energy range from 50 to 2000keV as well as the full energy peak and the total efficiencies were obtained for the case when the source is distributed in each domain and also for the case when the source is uniformly distributed in the entire drum. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. A study on characterization and evaluation methodologies of radioactive waste forms for safe disposal

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. C.; Lee, G. S.; Kim, G. J.; Nam, H.; Seok, J. H. [Yonsei Univ., Seoul (Korea, Republic of)

    2004-02-15

    The contents and scope of the study are summarized as follows : elicitation of significant items for characteristic assessment about stability analysis of radioactive waste forms for safe disposal, compressive strength, free water, leaching rate, and weatherability. Suggestion of assessment methods through the characteristic test of waste forms, comparison of assessment methods and suggestion of suitable testing methods about the above stated 4 items. Assessment modeling development for long-term stability of radioactive waste forms, weatherometric test of waste forms, expectation modeling development through VOM(Valance-Oxygen Model). Suggestion of determination standard together assessment testing methods and description about the standard. Explanation to be suitable guideline and regulation of waste handling and acceptance.

  18. Experimental study of radioactive aerosols in the vicinity of the Chernobyl Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, S.F.; Lomonosova, E.M.; Zhuk, I.V.; Yaroshevich, O.I.; Kudrjashov, V.P.; Mironov, V.P

    1999-12-01

    Study of radioactive aerosols in the relocation zone and in the populated areas have been carried out for a number of years. The experiments on modelling resuspension were performed while conducting agricultural work. Nuclear track radiography and alpha spectrometry with radiochemical extraction of plutonium were used as analytical methods for the determination of the transuranium elements contents. The distributions of radioactive particles were obtained as to activity and sizes. Specific activity of 'hot particles' increases with decreasing diameter. In aerosols selected at a distance of more than 10 km from the Chernobyl NPP pure fuel particles with sizes of more than 5 {mu}m were not found. The activity of the finely dispersed fraction of aerosols, which is more dangerous when inhaled by the organism, is comparable with a total activity of large particles.

  19. The study on the overseas recycling technology of the radioactive metallic wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. R.; Jung, Y. S.; Sin, J. I. [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    It was understood that regulation criteria for material release varied with countries and that international standards were not setup. But, most advanced countries are continuously studying on the recycling of metallic wastes for the purpose of the reuse of resources and disposal cost reduction. Practically, the advanced countries make a lot of cost profits compared with disposal as their metallic wastes are recycled and reused through technology like melting. In our case, the recycle criteria for radioactive waste containing radioactive nuclide with long half-life such as Cs-137(half-life: 30y) and Co-60(half-life: 5.26y) including others, which are generated from the nuclear fission or dismantling of nuclear facilities, are not yet established. Therefore, it is required that the recommendation and legalization of the regulatory criteria be carried out for the recycle and reuse of metallic wastes to be generated from the dismantling of domestic nuclear facilities in the future.

  20. Study on patient-induced radioactivity during proton treatment in hengjian proton medical facility.

    Science.gov (United States)

    Wu, Qingbiao; Wang, Qingbin; Liang, Tianjiao; Zhang, Gang; Ma, Yinglin; Chen, Yu; Ye, Rong; Liu, Qiongyao; Wang, Yufei; Wang, Huaibao

    2016-09-01

    At present, increasingly more proton medical facilities have been established globally for better curative effect and less side effect in tumor treatment. Compared with electron and photon, proton delivers more energy and dose at its end of range (Bragg peak), and has less lateral scattering for its much larger mass. However, proton is much easier to produce neutron and induced radioactivity, which makes radiation protection for proton accelerators more difficult than for electron accelerators. This study focuses on the problem of patient-induced radioactivity during proton treatment, which has been ignored for years. However, we confirmed it is a vital factor for radiation protection to both patient escort and positioning technician, by FLUKA's simulation and activation formula calculation of Hengjian Proton Medical Facility (HJPMF), whose energy ranges from 130 to 230MeV. Furthermore, new formulas for calculating the activity buildup process of periodic irradiation were derived and used to study the relationship between saturation degree and half-life of nuclides. Finally, suggestions are put forward to lessen the radiation hazard from patient-induced radioactivity.

  1. Radioactive ion beams for solid state research

    CERN Document Server

    Correia, J G

    1996-01-01

    Radioactive isotopes are widely used in many research fields. In some applications they are used as tracers after diffusion or after activation in the material itself through nuclear reactions. For research in solid state physics, the ion implantation technique is the most flexible and convenient method to introduce the radioactive isotopes in the materials to be studied, since it allows the control of the ion dose, the implantation depth and the isotopic purity. The on-line coupling of isotope separators to particle accelerators, as is the case of the ISOLDE facility at CERN, allows the obtention of a wide range of high purity short lived isotopes. Currently, the most stringent limitation for some applications is the low acceleration energy of 60 keV of the ISOLDE beam. In this communication a short review of the current applications of the radioactive beams for research in solid state physics at ISOLDE is done. The development of a post-accelerator facility for MeV radioactive ions is introduced and the adv...

  2. Study of radioactivity levels in detergent powders samples by gamma spectroscopy

    Directory of Open Access Journals (Sweden)

    Ali A. Abojassim

    2014-10-01

    Full Text Available This study focuses on the evaluation of the natural radioactivity levels in ten samples of the detergent powders that available in Iraqi markets. We have determined the specific activities of uranium, thorium and potassium using gamma spectroscopy and calculation of radiation hazard indices. The results of the activities of radionuclides (238U, 232Th, 40K for detergent powders samples, are found that the 238U specific activities were varied from (11.489 ± 2.089 Bq/kg to (36.062 ± 2.478 Bq/kg, while the 232th specific activities were varied from (1.411 ± 0.609 Bq/kg to (9.272 ± 1.642 Bq/kg and 40K were varied from (8.189 ± 2.339 Bq/kg to (91.888 ± 4.164 Bq/kg. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The radium equivalent activity Raeq, the external hazard index Hex and the internal hazard index Hin dose due to natural radioactivity estimated below the regulatory standard recommended which are (370 Bq/kg, 1 and 1 according to OECD 1979 and ICRP 2000, allows us to show that Detergent powders samples products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.

  3. A study on the radioactive waste management for DUPIC fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kwan Sik; Park, H. S.; Park, J. J.; Kim, J. H.; Cho, Y. H.; Shin, J. M.; Kim, Y. K.; Kim, J. S.; Kim, J. G.; Park, S. D.; Suh, M. Y.; Sohn, S. C.; Song, B. C.; Lee, C. H.; Jeon, Y. S.; Jo, K. S.; Jee, K. Y.; Jee, C. S.; Han, S. H.

    1997-09-01

    Part 1: The characteristics if the radioactive wastes coming from the DUPIC fuel manufacturing process were analyzed and evaluated. The gross {alpha}-activity and {alpha}-, {gamma}-spectrum of irradiated zircaloy specimens form KORI unit 1 were analyzed. In order to develop the trapping media of radioactive ruthenium oxides, trapping behavior of volatilized ruthenium oxides on various metal oxides or carbonates was analyzed. Fly ash was selected as a trapping materials for gaseous cesium. And reaction characteristics of CsNO{sub 3} and CsI with fly ash have been investigated. Also, trapping material were performed to test fly ash filter for removal of gaseous cesium under the air and hydrogen atmosphere. The applicability of fly ash to the vitrification of the spent filter was analyzed in the aspects of predictability, leachability. Good quality of Borosilicate glass was formed using Cesium spent filter. Offgas treatment system of DUPIC fuel manufacturing facility was designed and constructed in order to trap of gaseous radioactive waste from 100 batch of OREOXA furnace (the capacity : 500 g/batch). Part II: To develop chemical analysis techniques necessary for understanding chemical properties of the highly radioactive materials related to the development of DUPIC fuel cycle technology, the following basic studies were performed : dissolution of SIMFUEL (simulated fuel), determination of uranium by potentiometry and UV/Vis absorption spectrophotometry, separation of PWR spent fuel, group separation of fission products from uranium, individual separation for analysis of actinides, determination of free acid in a artificial dissolved solution of PWR spent fuel, group separation of fission products form uranium, individual separation of Sm from a mixed rare earth elements and measurement of its isotopes by TI-mass spectrometry, and characteristics of detectors in inductively coupled plasma atomic emission spectrometer (ICP-AES) suitable for analysis of trace fission

  4. Identification of airborne radioactive spatial patterns in Europe - Feasibility study using Beryllium-7.

    Science.gov (United States)

    Hernández-Ceballos, M A; Cinelli, G; Tollefsen, T; Marín-Ferrer, M

    2016-05-01

    The present study proposes a methodology to identify spatial patterns in airborne radioactive particles in Europe. The methodology is based on transforming the activity concentrations in the set of stations for each month (monthly index), due to the tightly spaced sampling intervals (daily to monthly), in combination with hierarchical and non-hierarchical clustering approaches, due to the lack of a priori knowledge of the number of clusters to be created. Three different hierarchical cluster methodologies are explored to set the optimal number of clusters necessary to initialize the non-hierarchical one (k-means). To evaluate this methodology, cosmogenic beryllium-7 ((7)Be) data, collected between 2007 and 2010 at 19 sampling stations in European Union (EU) countries and stored in the Radioactivity Environmental Monitoring (REM) database, are used. This methodology yields a solution with three distinguishable clusters (south, central and north), each with a different evolution of the (7)Be monthly index. Clear differences between monthly indices are shown in both intensity and time trends, following a latitudinal distribution of the sampling stations. This cluster result is evaluated performing ANOVA analysis, considering the original (7)Be activity concentrations grouped in each cluster. The statistical results (among clusters and sampling stations within clusters) confirm the spatial distribution of (7)Be in Europe, and, hence, reinforce the use of this methodology. Finally, the impact of tropopause height on this grouping is successfully tested, suggesting its influence on the spatial distribution of (7)Be in Europe. For airborne radioactive particles the analysis gave valuable results that improve knowledge of these atmospheric compounds in Europe. Hence, this work addresses a methodology to a grouping of airborne sampling stations, 1) allowing a better understanding of the distribution of (7)Be activity concentrations in the EU, and 2) serving as a basis for

  5. A pilot study to assess the feasibility of using naturally-occurring radionuclides as mass balance tracers to estimate soil ingestion.

    Science.gov (United States)

    Doyle, J R; White, P A; Blais, J M

    2012-09-01

    The relatively few soil ingestion studies that have been conducted to date to support soil ingestion rate values used for contaminated site human health risk assessments (HHRAs) typically have measured mass balance elemental tracers (e.g., Al, Si, Ba, Ce, Mn, Ti, V, Zr), found in soil to estimate soil ingestion. This pilot study, involving a canine subject fed a known amount of tracer on a daily basis, assessed the use of alternative mass balance tracers, specifically naturally occurring radionuclides of the (238)U and (232)Th decay series, to estimate soil ingestion. A novel method of estimating soil ingestion via difference in isotopic ratios between the two decay series in food and soil was also assessed. The results of the study showed that the mean (214)Pb and (212)Pb activities measured in fecal samples were greater than what was contained in the soil inoculant, suggesting that the tracers were not being significantly absorbed in the GI tract. The mean daily soil ingestion rates, calculated after subtracting the contribution of tracers in the soil inoculant, were 3.9 g d(-1) (standard deviation 3.6 g d(-1)) for the isotope tracers, and 1.9 g(-1) (standard deviation 2.1 g d(-1)) for the 3 most reliable elemental tracers. The differences were not statistically significant and further evaluation of isotopic tracers for soil ingestion studies is warranted. Similarly, soil ingestion estimates calculated using the Isotope Ratio Method were not significantly different than when calculated using (212)Pb; however, the Isotope Ratio Method was observed to positively bias the soil ingestion estimates by approximately 50%. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Simulation studies of the response function of a radioactive waste assay system

    Energy Technology Data Exchange (ETDEWEB)

    Gurau, Daniela, E-mail: daniela.gurau@ymail.com [Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, RO-077125 Magurele (Romania); Sima, Octavian [Physics Department, Bucharest University, P.O.B. MG-11, RO-077125 Magurele (Romania)

    2012-01-15

    A simulation program based on GEANT 3.21 toolkit was developed to simulate the response function of ISOCART (Ortec) gamma-ray spectrometry system applied to radioactive waste drum assessment. In view of studying the effects of possible non-homogeneous radioactivity distribution in the drum, the volume of the drum was fictitiously divided into several spatial domains. The simulation program was applied repeatedly considering each time the source distributed in another domain. In this way the expected spectra in the energy range from 50 to 2000 keV as well as the full energy peak and the total efficiencies were obtained for the case when the source is distributed in each domain and also for the case when the source is uniformly distributed in the entire drum. - Highlights: Black-Right-Pointing-Pointer Calculation technique for calibration of radioactive waste. Black-Right-Pointing-Pointer The Monte Carlo simulation program was based on GEANT 3.21 toolkit. Black-Right-Pointing-Pointer Response function of ISOCART gamma-ray spectrometry evaluated. Black-Right-Pointing-Pointer Volume of the drum fictitiously divided into several spatial domains. Black-Right-Pointing-Pointer Full energy peak and total efficiencies evaluated.

  7. ESR dosimetry study for the residents of Kazakhstan exposed to radioactive fallout on 24, August 1956

    Energy Technology Data Exchange (ETDEWEB)

    Zhumadilov, K., E-mail: kassym@hiroshima-u.ac.jp [Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Ivannikov, A. [Medical Radiological Research Center, Obninsk 249036 (Russian Federation); Zharlyganova, D. [Astana Medical University, 51a, Beibitshilik str., Astana 010000 (Kazakhstan); Zhumadilov, Zh. [Nazarbayev University, Life Sciences Center, D. Kunayev str., Astana 010000 (Kazakhstan); Stepanenko, V. [Medical Radiological Research Center, Obninsk 249036 (Russian Federation); Abralina, Sh.; Sadvokasova, L. [Semey State Medical Academy, Semey 071400, Abay str. 103 (Kazakhstan); Zhumadilova, A. [Astana Medical University, 51a, Beibitshilik str., Astana 010000 (Kazakhstan); Toyoda, S. [Department of Applied Physics, Faculty of Science, Okayama University of Science, Okayama 700-0005 (Japan); Endo, S. [Department of Quantum Energy Applications, Graduated School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Okamoto, T. [Department of Molecular Oral Medicine and Maxillofacial Surgery, Division of Frontier Medical Science, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8553 (Japan); Hoshi, M. [Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)

    2011-09-15

    The method of electron spin resonance (ESR) dosimetry has been applied to human tooth enamel in order to obtain individual absorbed doses from the population of settlements within the vicinity of the central axis of the radioactive fallout trace from the contaminating nuclear surface test of 24, August 1956. Most of the settlements (Glubokoe, Tavriya, and Gagarino) are located near Ust-Kamenogorsk city, in Kazakhstan (about 400 km to the east from the epicenter of the explosion at the Semipalatinsk Nuclear Test Site (SNTS)). It was found that the excess doses obtained after the subtraction of natural background radiation ranged up to about 120 mGy for the residents of Ust-Kamenogorsk city, whose tooth enamel was formed before 1956. For the residents of Gagarino, excess doses do not exceed 47 mGy for all ages. For the residents of Tavriya, the maximum of excess dose was determined as 54 mGy and for the residents of Glubokoe, the maximum excess dose was about 83 mGy. For the population of the Shemonaikha settlements (about 70 km from the centerline of the radioactive fallout trace) the highest excess dose is 110 mGy. Also for this study, Znamenka village (about 130 km from the epicenter) was included. The Kokpekty settlement was chosen as a control and not subjected to any radioactive contamination and is located 400 km to the Southeast from SNTS.

  8. Studies on the Extraction of Gold (Ⅰ) Cyanide by Quaternary Ammonium Salt Using 198Au as Tracer%用198Au示踪法研究季铵盐体系萃取金

    Institute of Scientific and Technical Information of China (English)

    张天喜; 周维金; 高宏成; 陈景; 吴瑾光

    2002-01-01

    The solvent extraction of KAu(CN)2 from alkaline solution by quaternary ammonium salts (trialkylmethylammonium chloride or cetyltrimethylammonium bromide) was investigated by means of 198Au radioactive tracer method. Various parameters, such as the gold (Ⅰ) concentration in aqueous phase, the modifier, emulsification at the interface of two phases, and phase ratio used in the extraction of gold (Ⅰ) were studied. The results demonstrate that almost all gold (Ⅰ) in the aqueous phase was practically extracted into the organic phase. The water content in the organic phase decreased significantly with increase of gold (Ⅰ) concentration using long chain alcohol as modifier, in contrast with the system with tributyl phosphate (TBP) as modifier. Emulsification at the interface of two phases decreases with an increase of modifier concentration in the organic phase or with the addition of a small amount of lysozyme into the aqueous phase. The method with 198Au tracer can be directly used to determine the Au(Ⅰ) concentration both in aqueous and organic phases, which is especially suitable for the low concentration of Au(Ⅰ).

  9. Kajian Profil Lulusan STAIN Samarinda Program Studi Pendidikan Agama Islam (PAI Tahun 2009 – 2013 dengan Pendekatan Tracer Study

    Directory of Open Access Journals (Sweden)

    Wahdatunnisa Wahdatunnisa

    2014-06-01

    Full Text Available Islamic higher education is targeted to create a high qualified human resources. A tracer study could be used to gain a data about the flaws, both of the process of education and the process of learning, of the quality of Islamic higher educations. by knowing the flaws, it can be used to make a better planning in the future. The problem of this study are: 1 How is the appropriateness of the work-field of the alumnae and the study program of Islamic education program of IAIN Samarinda?, 2 How is the contributions of the curriculum of Islamic education program of IAIN Samarinda to the work-field?, 3 How is the improvement of curriculum of Islamic education program of IAIN Samarinda to create a high qualified alumnae? This is and evaluative research design which is objected to describe the profil of alumnae and the curriculum relevance at Islamic education program at IAIN Samarinda. In this study, the researcher used interview and documentation to collect the data. The researcher used interview guide and recording tools as the instruments. The result of the study shows that: firstly, most of alumnae work in the schools as teachers or administration staff. Secondly, curriculum of PAI at STAIN Samarinda proves in supporting the work of alumnae. Thirdly, the improvement of curriculum can be done by adjusting the content of curriculum with the work field, improving lecturers’ qualification, erlarging the practicum, empowering the alumnae with some competencies, and strengthening the subjects of teachers and educational content.

  10. A Study to Determine Clearance Levels of Radioactive Wastes in Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Mukakaa, Zaphania O. [KAIST, Daejeon (Korea, Republic of); Kim, Sung Il [KINS, Daejeon (Korea, Republic of)

    2015-10-15

    Due to lack of a radioactive waste disposal facility in Kenya, radioactive wastes are stored in a bonded warehouse until such a time when their activity is low and they meet the criterion for clearance. The International Atomic Energy Agency (IAEA) has established activity concentrations of radionuclides to act as a universal guideline or standard for clearance in member countries. Radioactive wastes whose activity would yield a trivial risk to the people and environment, i.e. with an annual dose below 10 µSv are usually cleared from regulatory control with no further regulatory control mechanisms being taken. The Radiation Protection Board currently depends on the IAEA's generic clearance level activity concentrations for purposes of clearing the radiation wastes within its inventory. This study aims to determine activity concentrations of radionuclides in the Kenyan inventory that correspond to the clearance level dose of 10 µSv/a as set by the IAEA. The RESidual RADioactivity (RESRAD) computer code, an important tool developed in 1989 to aid in evaluation of sites with radioactive contamination, will aid in modeling these clearance level values using a pathways analysis method and available site-specific data from Kenya. Afterwards, the obtained clearance level values will be compared with the IAEA's generic clearance level values of the corresponding radionuclides. The results modeled using the RESRAD code are conservative. For most of the radionuclides in the Kenyan inventory, the values do correspond with the IAEA standard generic clearance level values, albeit with minor differences. For most of the radionuclides, the difference is within the acceptable uncertainty limit. For these low probability events the effective dose resulting from them should not exceed 1 mSv per year. Thus, consideration was given to doses to the skin and an equivalent dose to the skin of 50 mSv per year was duly used in estimating the clearance level activities. The

  11. Characterization of defects in semiconductors using radioactive isotopes

    CERN Document Server

    Deicher, Manfred

    2007-01-01

    Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as Mossbauer spectroscopy, perturbed angular correlation, and emission channeling have used nuclear properties to gain microscopical information on the structural and dynamical properties of solids. The availability of many different radioactive isotopes as a clean ion beam at facilities like ISOLDE/CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Spectroscopic techniques like photoluminescence (PL), deep-level transient spectroscopy (DLTS), and Hall effect gain a new quality by using radioactive isotopes. Due to their decay the chemical origin of an observed electronic and optical behavior of a specific defect or dopant can be unambiguously identified. This contribution will highlight a few examples to illustrat...

  12. Regularized image reconstruction algorithms for dual-isotope myocardial perfusion SPECT (MPS) imaging using a cross-tracer prior.

    Science.gov (United States)

    He, Xin; Cheng, Lishui; Fessler, Jeffrey A; Frey, Eric C

    2011-06-01

    In simultaneous dual-isotope myocardial perfusion SPECT (MPS) imaging, data are simultaneously acquired to determine the distributions of two radioactive isotopes. The goal of this work was to develop penalized maximum likelihood (PML) algorithms for a novel cross-tracer prior that exploits the fact that the two images reconstructed from simultaneous dual-isotope MPS projection data are perfectly registered in space. We first formulated the simultaneous dual-isotope MPS reconstruction problem as a joint estimation problem. A cross-tracer prior that couples voxel values on both images was then proposed. We developed an iterative algorithm to reconstruct the MPS images that converges to the maximum a posteriori solution for this prior based on separable surrogate functions. To accelerate the convergence, we developed a fast algorithm for the cross-tracer prior based on the complete data OS-EM (COSEM) framework. The proposed algorithm was compared qualitatively and quantitatively to a single-tracer version of the prior that did not include the cross-tracer term. Quantitative evaluations included comparisons of mean and standard deviation images as well as assessment of image fidelity using the mean square error. We also evaluated the cross tracer prior using a three-class observer study with respect to the three-class MPS diagnostic task, i.e., classifying patients as having either no defect, reversible defect, or fixed defects. For this study, a comparison with conventional ordered subsets-expectation maximization (OS-EM) reconstruction with postfiltering was performed. The comparisons to the single-tracer prior demonstrated similar resolution for areas of the image with large intensity changes and reduced noise in uniform regions. The cross-tracer prior was also superior to the single-tracer version in terms of restoring image fidelity. Results of the three-class observer study showed that the proposed cross-tracer prior and the convergent algorithms improved the

  13. Numerical simulation of a natural gradient tracer experiment for the natural attenuation study: flow and physical transport.

    Science.gov (United States)

    Julian, H E; Boggs, J M; Zheng, C; Feehley, C E

    2001-01-01

    Results are presented for numerical simulations of ground water flow and physical transport associated with a natural gradient tracer experiment conducted within a heterogeneous alluvial aquifer of the Natural Attenuation Study (NATS) site near Columbus, Mississippi. A principal goal of NATS is to evaluate biogeochemical models that predict the rate and extent of natural biodegradation under field conditions. This paper describes the initial phase in the model evaluation process, i.e., calibration of flow and physical transport models that simulate conservative bromide tracer plume evolution during NATS. An initial large-scale flow model (LSM) is developed encompassing the experimental site and surrounding region. This model is subsequently scaled down in telescopic fashion to an intermediate-scale ground water flow model (ISM) covering the tracer-monitoring network, followed by a small-scale transport model (SSM) focused on the small region of hydrocarbon plume migration observed during NATS. The LSM uses inferred depositional features of the site in conjunction with hydraulic conductivity (K) data from aquifer tests and borehole flowmeter tests to establish large-scale K and flow field trends in and around the experimental site. The subsequent ISM incorporates specified flux boundary conditions and large-scale K trends obtained from the calibrated LSM, while preserving small-scale K structure based on some 4000 flowmeter data for solute transport modeling. The configuration of the ISM-predicted potentiometric surface approximates that of the observed surface within a root mean squared error of 0.15 m. The SSM is based on the dual-domain mass-transfer approach. Despite the well-recognized difficulties in modeling solute transport in extremely heterogeneous media as found at the NATS site, the dual-domain model adequately reproduced the observed bromide concentration distributions. Differences in observed and predicted bromide concentration distributions are

  14. Using Tracer Technology to Characterize Contaminated Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Maresca, Joseph, W., Jr., Ph.D.; Bratton, Wesley, L., Ph.D., P.E.; Dickerson, Wilhelmina; Hales, Rochelle

    2005-12-30

    The Pipeline Characterization Using Tracers (PCUT) technique uses conservative and partitioning, reactive or other interactive tracers to remotely determine the amount of contaminant within a run of piping or ductwork. The PCUT system was motivated by a method that has been successfully used to characterize subsurface soil contaminants and is similar in operation to that of a gas chromatography column. By injecting a ?slug? of both conservative and partitioning tracers at one end (or section) of the piping and measuring the time history of the concentration of the tracers at the other end (or another section) of the pipe, the presence, location, and amount of contaminant within the pipe or duct can be determined. The tracers are transported along the pipe or duct by a gas flow field, typically air or nitrogen, which has a velocity that is slow enough so that the partitioning tracer has time to interact with the contaminant before the tracer slug completely passes over the contaminate region. PCUT not only identifies the presence of contamination, it also can locate the contamination along the pipeline and quantify the amount of residual. PCUT can be used in support of deactivation and decommissioning (D&D) of piping and ducts that may have been contaminated with hazardous chemicals such as chlorinated solvents, petroleum products, radioactive materials, or heavy metals, such as mercury.

  15. Study of Radioactivity Measurement Using Well Type NaI(Tl) γ Spectrometer

    Institute of Scientific and Technical Information of China (English)

    GUO; Xiao-qing; YANG; Qiao-ling; DIAO; Li-jun; CHEN; Xi-lin; LV; Xiao-xia

    2015-01-01

    Using a well type NaI(Tl)gamma spectrometer,the radioactivity of 125I was measured with absolute measurement method.125I radioactive source was prepared with the same batch of radioactive solution,and its activity range is 102-104 Bq.By different strength activity measurement

  16. Study of particle size distribution and formation mechanism of radioactive aerosols generated in high-energy neutron fields

    CERN Document Server

    Endo, A; Noguchi, H; Tanaka, S; Iida, T; Furuichi, S; Kanda, Y; Oki, Y

    2003-01-01

    The size distributions of sup 3 sup 8 Cl, sup 3 sup 9 Cl, sup 8 sup 2 Br and sup 8 sup 4 Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45 MeV and 65 MeV quasi-monoenergetic neutrons were measured in order to study the formation mechanism of radioactive particles in high energy radiation fields. The effects of the size distribution of the radioactive aerosols on the size of the added DOP aerosols, the energy of the neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols. (author)

  17. Gallium-67 activated charcoal: a new method for preparation of radioactive capsules for colonic transit study

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Kai-Yuan [Department of Radiological Technology, ChungTai Institute of Health Sciences and Technology, Taichung (Taiwan); Tsai, Shih-Chuan [Department of Nuclear Medicine, Show Chwan Memorial Hospital, Changhua (Taiwan); Lin, Wan-Yu. [Department of Nuclear Medicine, Taichung Veterans General Hospital, 160 Taichung Harbor Road, Section 3, 40705, Taichung (Taiwan)

    2003-06-01

    Indium-111 is currently the radionuclide of choice for colonic transit study. However, it is expensive and not available in many hospitals. Technetium-99m has been proposed for colonic transit study but the short half-life has limited its use. Gallium-67 citrate is inexpensive and available in most countries. Most importantly, it has a suitable half-life for colonic transit study. Attempts have been made in some studies to use {sup 67}Ga citrate to label activated charcoal, but the results have not been good because of poor stability. In this study, we successfully labelled activated charcoal with {sup 67}Ga citrate by adding alcohol and 5% glucose solution. To evaluate the in vitro stability, the {sup 67}Ga-activated charcoal was incubated in a milieu mimicking the intestinal content, containing lipase, trypsin and glycochenodeoxycholate at different pH values (6.0, 7.0, 7.4 and 8.0) and for different durations (0 h, 24 h, 48 h, 72 h and 96 h). For the in vivo study, the {sup 67}Ga-activated charcoal was loaded into a commercial empty enteric capsule. Colonic transit scintigraphy was performed in five volunteers, including three healthy people and two constipated patients, after intake of the radioactive capsule. Images were obtained at 2 h, 4 h, 6 h, 8 h, 24h, 48 h, 72 h etc. until no radioactivity was detected in the bowel. Our data show that the in vitro stability of {sup 67}Ga-activated charcoal was good. The labelling efficiency still exceeded 91% at 96 h at pH values of 6.0, 7.0 and 7.4. In the group with a pH value of 8.0, the labelling efficiency gradually fell during the 4-day incubation but was still higher than 88% at the end of the fourth day. In the in vivo study, most capsules disintegrated in the caecum/colon region, and the {sup 67}Ga-activated charcoal mixed very well with bowel content. In addition, the radioactive charcoal could be detected clearly on the 72-h image, which is very important for the evaluation of colonic transit time in patients

  18. A Study on sediment sources in a small watershed by using REE tracer method

    Institute of Scientific and Technical Information of China (English)

    石辉; 田均良; 刘普灵; 周佩华

    1997-01-01

    In simulation experiments, rare earth element (REE) tracer method was first used to sludy the sources of sediment yield in a small watershed. The experimental results have shown that the chief parts of sediment sources are constantly changing with the development of gullies. The cutting erosion plays a major role in the primary stage of watershed development. Slope erosion intensity increased gradually with gully development of the watershed, while gully erosion intensity decreased. Similar process was also observed in an individual rainfall. The simulation experiments have shown that the method can satisfactorily interpret the origins of sediment yield of a small watershed on an effective way. The simulation experiments have also provided basic information for field researches.

  19. Study of organic N transformation in red soils by 15N tracer method

    Institute of Scientific and Technical Information of China (English)

    YeQing-Fu; ZhangQin-Zheng; 等

    1997-01-01

    Uniformly 15N-labelled ryegrass was used to investigate NH4+-production,microbial transformation and humification of organic N in two types of red soils by incubating the soils amended with labelled material.The results showed that there was little significant difference in biomass N transformation in the tested solis between 15N tracer method and conventional method,but the amount of NH4++-N released form the ryegrass in the clayey soil than in the sandy soil at all sampling time .By 120d of incubation,humified N was less than 10% of the amount of the applied N in two types of red soils and the amount of residual N in the clayey red soil was obviously higher than that in the sandy red soil.

  20. PET Radiopharmaceuticals for Imaging Integrin Expression: Tracers in Clinical Studies and Recent Developments

    Directory of Open Access Journals (Sweden)

    Roland Haubner

    2014-01-01

    Full Text Available Noninvasive determination of integrin expression has become an interesting approach in nuclear medicine. Since the discovery of the first 18F-labeled cyclic RGD peptide as radiotracer for imaging integrin αvβ3 expression in vivo, there have been carried out enormous efforts to develop RGD peptides for PET imaging. Moreover, in recent years, additional integrins, including α5β1 and αvβ6, came into the focus of pharmaceutical radiochemistry. This review will discuss the tracers already evaluated in clinical trials and summarize the preliminary outcome. It will also give an overview on recent developments to further optimize the first-generation compounds such as [18F]Galacto-RGD. This includes recently developed 18F-labeling strategies and also new approaches in 68Ga-complex chemistry. Furthermore, the approaches to develop radiopharmaceuticals targeting integrin α5β1 and αvβ6 will be summarized and discussed.

  1. Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale 15N enrichment tracer study

    Science.gov (United States)

    Messer, Tiffany L.; Burchell, Michael R.; Böhlke, John Karl; Tobias, Craig R.

    2017-01-01

    Quantitative information about the fate of applied nitrate (NO3-N) in pulse-flow constructed wetlands is essential for designing wetland treatment systems and assessing their nitrogen removal services for agricultural and stormwater applications. Although many studies have documented NO3-N losses in wetlands, controlled experiments indicating the relative importance of different processes and N sinks are scarce. In the current study, 15NO3-N isotope enrichment tracer experiments were conducted in wetland mesocosms of two different wetland soil types at two realistic agricultural NO3-N source loads. The 15N label was traced from the source NO3-N into plant biomass, soil (including organic matter and ammonium), and N-gas constituents over 7–10 day study periods. All sinks responded positively to higher NO3-N loading. Plant uptake exceeded denitrification 2–3 fold in the low NO3-N loading experiments, while both fates were nearly equivalent in the high loading experiments. One to two years later, soils largely retained the assimilated tracer N, whereas plants had lost much of it. Results demonstrated that plant and microbial assimilation in the soil (temporary N sinks) can exceed denitrification (permanent N loss) in pulse-flow environments and must be considered by wetland designers and managers for optimizing nitrogen removal potential.

  2. A new method for studying water mass origins on basin scales: using multiple passive tracers to study Atlantic Cold Tongue variability

    Science.gov (United States)

    White, Rachel

    2015-04-01

    Multiple passive tracers are used in a dynamical ocean model to demonstrate a new method to study water mass origins on a basin-wide scale. This method has previously only been used in estuary-scale studies. A case study is chosen to highlight when this multiple passive tracer method may provide benefits over the standard method of tracing water mass origins on basin-scales: using a single passive tracer in an adjoint model. 31 passive tracers are used to determine the origin regions of the Atlantic cold tongue (ACT). At the time of the ACT minimum in sea surface temperature, 38 ± 3% of the surface water in the central equatorial Atlantic is found to originate in the western side of the basin, with 11 ± 2% originating in the east. The multiple passive tracer method can show how origin regions change with time, allowing seasonal differences in origin regions to be discerned. The identification of origin regions of cold water that increase their supply to the equatorial Atlantic in phase with the ACT cooling identifies those regions that are important to the ACT variability. Sensitivity tests show that the temporal evolution of the concentrations of such tracers within the ACT region is not sensitive to the month in which the tracers are initialised. The region of the North Brazil undercurrent is found to be the most important origin region for the central Atlantic ACT region, for a 6-8 month lead time. Using the Met Office EN4 observational dataset of ocean temperatures, correlations are found between January temperatures in the North Brazil undercurrent region and both the ACT mean temperature and ACT spatial extent in July-August, significant at the 0.95 level. This suggests that the 6-month lead-time predictability of the ACT may be increased by improved knowledge of the North Brazil undercurrent temperature. Results from previous studies suggest that such increased predictability of the ACT could potentially help improve predictions of the West African monsoon.

  3. North Atlantic ventilation using chlorofluorocarbons and idealised-tracer simulations

    Directory of Open Access Journals (Sweden)

    Yan-Chun He

    2012-10-01

    Full Text Available The simulated chlorofluorocarbon CFC-11 and 29 geographically defined CFC-11 tracers, as well as 29 geographically defined idealised tracers, are used to quantify the regional contribution to the ventilation of the North Atlantic Ocean in a global version of the Miami Isopycnal Coordinate Ocean Model (MICOM driven by the daily NCEP/NCAR forcing. Age tracers attached to 29 idealised tracers are also used to estimate the timescales for the water masses’ transports. Our results show that the simulated overturning circulation matches the available observed data for both intensity and variability, and the simulated distribution of CFC-11 concentration in the subtropical North Atlantic Ocean is in good agreement with the observations, particularly above 800 m in depth. We found that the sandwich-like distribution of CFC-11 concentration in the subtropical North Atlantic in both the observations and simulations is mainly caused by subduction from the western and eastern subpolar North Atlantic, but the contribution of the former (56.0% is almost four times larger than that of the latter (15.7%. We demonstrated that the ocean dynamics, instead of the source function, determine the annual and inter-annual variability in both dynamically active tracer (such as water temperature and salinity and passive tracer (such as CFC-11 and idealised tracer concentrations in the deep North Atlantic. The ‘apparent age’ distribution shows that the surface water in the western subpolar North Atlantic takes about 12 yr to reach the Nordic Seas and takes 20 yr from the Nordic Seas to the subtropical deep North Atlantic. The transit-time derived by ‘optimum time lag’ approach shows a 9.3–13.6 yr lag for the signals propagating from the western subpolar North Atlantic to the subtropical North Atlantic, which is generally consistent with that of about 10 yr derived from the ‘apparent age’. The study suggests that geographically defined tracers can be used as

  4. Study of Nuclear Reactions with 11C and 15O Radioactive Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongwon [Univ. of California, Berkeley, CA (United States)

    2007-05-14

    Nuclear reaction study with radioactive ion beams is one of the most exciting research topics in modern nuclear physics. The development of radioactive ion beams has allowed nuclear scientists and engineers to explore many unknown exotic nuclei far from the valley of nuclear stability, and to further our understanding of the evolution of the universe. The recently developed radioactive ion beam facility at the Lawrence Berkeley National Laboratory's 88-inch cyclotron is denoted as BEARS and provides 11C, 14O and 15O radioactive ion beams of high quality. These moderate to high intensity, proton-rich radioactive ion beams have been used to explore the properties of unstable nuclei such as 12N and 15F. In this work, the proton capture reaction on 11C has been evaluated via the indirect d(11C, 12N)n transfer reaction using the inverse kinematics method coupled with the Asymptotic Normalization Coefficient (ANC) theoretical approach. The total effective 12N → 11C+p ANC is found to be (C eff12N = 1.83 ± 0.27 fm-1. With the high 11C beam intensity available, our experiment showed excellent agreement with theoretical predictions and previous experimental studies. This study also indirectly confirmed that the 11C(p,γ) reaction is a key step in producing CNO nuclei in supermassive low-metallicity stars, bypassing the slow triple alpha process. The newly developed 15O radioactive ion beam at BEARS was used to study the poorly known level widths of 16F via the p(15O,15O)p reaction. Among the nuclei in the A=16, T=1 isobaric triad, many states in 16N and 16O have been well established, but less has been reported on 16F. Four states of 16F below 1 MeV have been identified experimentally: 0-, 1

  5. Laboratory study of the radioactivity from fission products in microscopic fallout particles

    Energy Technology Data Exchange (ETDEWEB)

    Smith, H.A.; Ward, T.E.; Wesick, J.

    1978-03-01

    An experiment is described wherein simple ..gamma..-ray detection and analysis techniques were utilized to study the radioactivity in local precipitation. Gamma spectra from filtered particulate, evaporation residue, and water from a sample of freshly fallen snow were counted, and the relative amount of several radionuclides present were identified. These data show that several isotopes produced in the recent Chinese nuclear detonation (Lop Nor testing ground, Sinkiang Province, 17 November 1976) are observable. Furthermore the data are sufficient to estimate the date of the detonation and to determine some of the characteristics of the explosion.

  6. Letter report: Minor component study for low-level radioactive waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.

    1996-03-01

    During the waste vitrification process, troublesome minor components in low-level radioactive waste streams could adversely affect either waste vitrification rate or melter life-time. Knowing the solubility limits for these minor components is important to determine pretreatment options for waste streams and glass formulation to prevent or to minimize these problems during the waste vitrification. A joint study between Pacific Northwest Laboratory and Rensselaer Polytechnic Institute has been conducted to determine minor component impacts in low-level nuclear waste glass.

  7. [Cytogenetic studies on submerged plants from the Yenisei river area in the zone of radioactive contamination].

    Science.gov (United States)

    Muratova, E N; Goriachkina, O V; Kornilova, M G; Pimenov, A V; Sedel'nikova, T S; Bolsunovskiĭ, A Ia

    2014-01-01

    Cytogenetic studies on three species of submerged plants from different parts of the Yenisei river area subjected to radioactive impact of the Krasnoyarsk Mining-and-Chemical Plant and the Electrochemical Factory have been conducted. A high level of irregularities in anatelophase and metaphase of mitoses has been revealed in test samples compared to the control: agglutination and fragmentation of chromosomes, lagging chromosomes, bridges, fragments, misdivisions, and others. The natuie of the disorders indicates that they are related in part to the direct damage to the chromosome structure and in part to damage to the spindle.

  8. Biodistribution study of [61Cu] pyruvaldehyde-bis (N-4-methylthiosemicarbazone) in normal rats as a PET tracer

    Institute of Scientific and Technical Information of China (English)

    Amir Reza JALILIAN; Saeed SHANESAZZADEH; Pejaman ROWSHANFARZAD; Fatemeh BOLOURINOVIN; Abbas MAJDABADI

    2008-01-01

    [61Cu]-labeled pyruvaldehyde-bis (N-4-methylthiosemicarbazone) (61Cu-PTSM), a promising agent made for imaging blood perfusion, was produced via the natZn(p,x)61Cu nuclear reaction in a 30 MeV cyclotron, and separated by a two-step column chromatography method developed in our laboratory using a cation and an anion exchange resin. After 150μA irradiation for 76 min, about 6.006 Ci of 61Cu2+ was obtained with a radiochemical separation yield of 95% and a radionuclidic purity of 99%. 61Cu-PTSM was prepared using an optimized method with in-house synthesized PTSM ligand for radiolabeling following quality control procedures using RTLC and HPLC. The tracer is mostly incorporated in heart, kidneys and brain compared to free copper cation as a control. These are in agreement with former reports. In conclusion, [61Cu]-PTSM was prepared at the radiopharmaceutical scales with high quality and is a potential PET tracer in the perfusion study of the heart, kidney, brain and tumors.

  9. Experimental and modelling investigations of tracer transport in variably saturated agricultural soil of Thailand: Column study

    Directory of Open Access Journals (Sweden)

    Tulaya Masipan

    2016-03-01

    Full Text Available Tracer (Bromide movement through the unsaturated agricultural soil was investigated in soil columns. Two tracer column experiments, with a diameter of 7 cm and a depth of 25 cm, were vertically homogeneous packed with sandy loam and then carried out to investigate bromide (Br− transport under different water contents (at steady flow condition. One soil column (Column 1 represents the unsaturated agricultural soil in dry season (with water content ranging from 0.23 to 0.26 and the other (Column 2 represents the soil in wet season (water content from 0.24 to 0.35. Bromide samples were periodically collected by vacuum tubes inserted at 6.25 cm equally spaced intervals (e.g., 6.25, 12.5, 18.75 and 25 cm along the length of the column and the effluent collected at the end of the column. The observed breakthrough curves (BTCs of bromide in both columns represented a relative smooth and sigmodal curves at different distances (sampling ports. Dispersivity (α, cm for sandy loam at different locations was numerically estimated by curve fitting the experimental data with HYDRUS-1D. The α can be well described by the convection–dispersion equation and these values derived from Column 1 (ranging from 0.37 to 0.98 cm are more than those from Column 2 (0.25–0.59. Moreover, the α in both columns increases with the travel distance due to the scale-dependent effect. Furthermore, the α values were plotted on a log–log scale against travel distances and they yield empirical power law relationships with an excellent correlation (α = 0.102 (L0.697, R2 = 0.999 and α = 0.086 (L0.579, R2 = 0.963 for Column 1 and 2, respectively.

  10. Cluster Radioactivity

    Science.gov (United States)

    Poenaru, Dorin N.; Greiner, Walter

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

  11. iRadioactivity--Possibilities and Limitations for Using Smartphones and Tablet PCs as Radioactive Counters: Examples for Studying Different Radioactive Principles in Physics Education

    Science.gov (United States)

    Kuhn, Jochen; Molz, Alexander; Gröber, Sebastian; Frübis, Jan

    2014-01-01

    A study conducted in 2013 showed that about 70-80% of teens and young adults in the United States own a smartphone. Furthermore the number of tablet PC users in the United States will increase up to more than 80% by 2015. As a result, these devices have increasingly become everyday tools, particularly for the younger generation. In recent years,…

  12. iRadioactivity--Possibilities and Limitations for Using Smartphones and Tablet PCs as Radioactive Counters: Examples for Studying Different Radioactive Principles in Physics Education

    Science.gov (United States)

    Kuhn, Jochen; Molz, Alexander; Gröber, Sebastian; Frübis, Jan

    2014-01-01

    A study conducted in 2013 showed that about 70-80% of teens and young adults in the United States own a smartphone. Furthermore the number of tablet PC users in the United States will increase up to more than 80% by 2015. As a result, these devices have increasingly become everyday tools, particularly for the younger generation. In recent years,…

  13. Traçadores: o uso de agentes químicos para estudos hidrológicos, ambientais, petroquímicos e biológicos Tracers: the use of chemical agents for hydrological, environmental, petrochemical and biological studies

    Directory of Open Access Journals (Sweden)

    Láuris Lucia da Silva

    2009-01-01

    Full Text Available This paper presents a revision of the history, definitions, and classification of tracers (natural and artificial, internal and external. The fundamental ideas concerning tracers are described, followed by their application illustrated by typical examples. The advantages and disadvantages of five classes among the most frequently used external tracers (fluorescent, microbial, chemical, radioactive and activable isotopes are also described in detail. This review also presents some interesting and modern applications of tracers in the areas of diagnostics in medical practice, environmental pollution, hydrology and petroleum chemistry.

  14. Radioactive Material

    CERN Multimedia

    2004-01-01

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

  15. Radioactive Material

    CERN Multimedia

    2004-01-01

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

  16. Driven tracers in narrow channels

    Science.gov (United States)

    Cividini, J.; Mukamel, D.; Posch, H. A.

    2017-01-01

    Steady-state properties of a driven tracer moving in a narrow two-dimensional (2D) channel of quiescent medium are studied. The tracer drives the system out of equilibrium, perturbs the density and pressure fields, and gives the bath particles a nonzero average velocity, creating a current in the channel. Three models in which the confining effect of the channel is probed are analyzed and compared in this study: the first is the simple symmetric exclusion process (SSEP), for which the stationary density profile and the pressure on the walls in the frame of the tracer are computed. We show that the tracer acts like a dipolar source in an average velocity field. The spatial structure of this 2D strip is then simplified to a one-dimensional (1D) SSEP, in which exchanges of position between the tracer and the bath particles are allowed. Using a combination of mean-field theory and exact solution in the limit where no exchange is allowed gives good predictions of the velocity of the tracer and the density field. Finally, we show that results obtained for the 1D SSEP with exchanges also apply to a gas of overdamped hard disks in a narrow channel. The correspondence between the parameters of the SSEP and of the gas of hard disks is systematic and follows from simple intuitive arguments. Our analytical results are checked numerically.

  17. Testing cosmic ray acceleration with radio relics: a high-resolution study using MHD and tracers

    Science.gov (United States)

    Wittor, D.; Vazza, F.; Brüggen, M.

    2017-02-01

    Weak shocks in the intracluster medium may accelerate cosmic-ray protons and cosmic-ray electrons differently depending on the angle between the upstream magnetic field and the shock normal. In this work, we investigate how shock obliquity affects the production of cosmic rays in high-resolution simulations of galaxy clusters. For this purpose, we performed a magnetohydrodynamical simulation of a galaxy cluster using the mesh refinement code ENZO. We use Lagrangian tracers to follow the properties of the thermal gas, the cosmic rays and the magnetic fields over time. We tested a number of different acceleration scenarios by varying the obliquity-dependent acceleration efficiencies of protons and electrons, and by examining the resulting hadronic γ-ray and radio emission. We find that the radio emission does not change significantly if only quasi-perpendicular shocks are able to accelerate cosmic-ray electrons. Our analysis suggests that radio-emitting electrons found in relics have been typically shocked many times before z = 0. On the other hand, the hadronic γ-ray emission from clusters is found to decrease significantly if only quasi-parallel shocks are allowed to accelerate cosmic ray protons. This might reduce the tension with the low upper limits on γ-ray emission from clusters set by the Fermi satellite.

  18. Chemical parameters as natural tracers in hydrogeology: a case study of Louros karst system, Greece

    Science.gov (United States)

    Katsanou, K.; Lambrakis, N.; D'Alessandro, W.; Siavalas, G.

    2017-03-01

    The Louros Basin hosts one of the most important karst systems of Epirus Prefecture (Greece) and plays a key role in supplying three counties with drinking water. Aiming to investigate the origin of groundwater and its flow patterns, a multi-tracer approach was used to describe and evaluate the hydrogeology of the system. Therefore, 271 surface water and groundwater samples were collected and analyzed for physicochemical parameters, major ions, and trace and rare earth elements, as well as stable isotopes (δ18O and δ2H). These data provided meaningful tracing of the water origin, water-rock interaction processes, and relationships among the aquifers. In particular, the elaboration of the major ions supported by the distribution of rare earth elements indicated that there are three aquifers located at different levels hosted in the Senonian and Pantokrator limestone formations. These aquifers are hydraulically interconnected by a cascade and constitute the Louros karst system which is drained by the homonymous river. Hydrochemical and isotopic data revealed that the Louros karst system is isolated from the adjacent northern Ioannina Basin and it is being recharged by precipitation. Higher groundwater salinity, where present, is mainly associated with increased water-rock interaction due to longer and deeper hydrologic flow, favoring the dissolution of evaporitic, carbonate and phosphate minerals.

  19. Experimental studies of healing process of rat mandibular condylar fracture, using /sup 45/Ca as tracer

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Tatsuaki (Gifu Univ. (Japan). Faculty of Medicine)

    1982-09-01

    The cervical region of the mandibular condylus of young rats was fractured. The healing process was observed pathohistologically, autoradiographically using /sup 45/Ca as a tracer, and by ultra soft roentgenography. Condylectomy of the mandibular condylus was done at the same time and its regeneration observed. The results of the observation are as follows: The fractured portion is bonded with the soft tissue 1 - 2 weeks postoperatively. Histologically, new-blood vessels in the granulation tissue and the connective tissue's change into fibers are seen. On the second week chondrocytes appeared in the neck of the capitulum mandibulae and the stump of the ascending branch. On the 3rd postoperative week, the stump of the fracture of the bone is bonded with proliferated cartilaginous tissue and an osseous bond was seen in part by autoradiograph and ultra soft x-ray picture. New bone due to periosteal ossification is seen around the stump on the ascending branch side, and the bone reconstruction with osteoclasts was seen in the inside the trabeculae. On the 4th postoperative week, osseous concrescence is observed in the fractured portion. Regeneration of the capitulum mandibulae after extirpation of the capitulum mandibulae is seen in all the cases. On the postoperative 12th week, the macroscopic form of the degenerated capitulum mandibulae which seemed to be excessive becomes almost the same morphologically with that of the contralateral side and it was observed histologically that the construction of the capitulum mandibulae is completely restored.

  20. Methods for studying the radioactive contamination of plants (1963); Methodes d'etude de la contamination radioactive des vegetaux (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, R.; Jeanmaire, L.; Michon, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1963-07-01

    The authors first define the doctrine which led to the devising of a method for studying the radioactive pollution of plants, based on the use of simple techniques, having the possibility of being adapted for routine work, and so devised that each stage is proceeded with only if the preceding one justifies it. For each stage a study is effected comparing the results obtained by the use of more exact techniques. The second part describes in detail the techniques used. (authors) [French] Dans une premiere partie lea auteurs definissent la doctrine qui leur a permis d'elaborer une methode d'etude de la pollution radioactive des vegetaux, basee sur l'utilisation de techniques simples, se pretant au travail de serie et concues de telle maniere que chaque etape n'est abordee que si la precedente le justifie. Chaque etape fait l'objet d'une etude qui compare les resultats a ceux obtenue par des techniques plus precises. La deuxieme partie decrit dans le detail les techniques utilisees. (auteurs)

  1. A Case Study of the Weather Research and Forecasting Model Applied to the Joint Urban 2003 Tracer Field Experiment. Part 2: Gas Tracer Dispersion

    Science.gov (United States)

    Nelson, Matthew A.; Brown, Michael J.; Halverson, Scot A.; Bieringer, Paul E.; Annunzio, Andrew; Bieberbach, George; Meech, Scott

    2016-12-01

    The Quick Urban & Industrial Complex (QUIC) atmospheric transport, and dispersion modelling, system was evaluated against the Joint Urban 2003 tracer-gas measurements. This was done using the wind and turbulence fields computed by the Weather Research and Forecasting (WRF) model. We compare the simulated and observed plume transport when using WRF-model-simulated wind fields, and local on-site wind measurements. Degradation of the WRF-model-based plume simulations was cased by errors in the simulated wind direction, and limitations in reproducing the small-scale wind-field variability. We explore two methods for importing turbulence from the WRF model simulations into the QUIC system. The first method uses parametrized turbulence profiles computed from WRF-model-computed boundary-layer similarity parameters; and the second method directly imports turbulent kinetic energy from the WRF model. Using the WRF model's Mellor-Yamada-Janjic boundary-layer scheme, the parametrized turbulence profiles and the direct import of turbulent kinetic energy were found to overpredict and underpredict the observed turbulence quantities, respectively. Near-source building effects were found to propagate several km downwind. These building effects and the temporal/spatial variations in the observed wind field were often found to have a stronger influence over the lateral and vertical plume spread than the intensity of turbulence. Correcting the WRF model wind directions using a single observational location improved the performance of the WRF-model-based simulations, but using the spatially-varying flow fields generated from multiple observation profiles generally provided the best performance.

  2. A Remote Radioactivity Experiment

    Science.gov (United States)

    Jona, Kemi; Vondracek, Mark

    2013-01-01

    Imagine a high school with very few experimental resources and limited budgets that prevent the purchase of even basic laboratory equipment. For example, many high schools do not have the means of experimentally studying radioactivity because they lack Geiger counters and/or good radioactive sources. This was the case at the first high school one…

  3. Review of recent reports of INLA study group V: radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, E.H.

    1995-12-31

    As an introduction to this 1993 report, Working Group V offers this brief review of its three previous reports made in 1987, 1989 and 1991. the principal topics addressed in these reports were: clear definitions of terms such as radioactive waste, storage and final disposal; respective technical and financial responsibilities of waste producers management agencies, public authorities; the various phases of waste management such as production, package, transport, storage, preclosure and post closure of disposal installations; financing of these phases; information and participation of the public in choice and licensing of storage and final disposal installations; The aim of these studies is ti explore the nature of appropriate actions in radioactive waste management necessary to ensure adequate protection of man and environment. Moreover, it is important to assure adequate protection for the full life of the waste, even though that time may reach hundreds or thousands of years or more. Although this raises both technical and juridical problems, the study group focused mainly the juridical ones. (author).

  4. Analysis of tracer and thermal transients during reinjection

    Energy Technology Data Exchange (ETDEWEB)

    Kocabas, I.

    1989-10-01

    This work studied tracer and thermal transients during reinjection in geothermal reserviors and developed a new technique which combines the results from interwell tracer tests and thermal injection-backflow tests to estimate the thermal breakthrough times. Tracer tests are essential to determine the degree of connectivity between the injection wells and the producing wells. To analyze the tracer return profiles quantitatively, we employed three mathematical models namely, the convection-dispersion (CD) model, matrix diffusion (MD) model, and the Avodnin (AD) model, which were developed to study tracer and heat transport in a single vertical fracture. We considered three types of tracer tests namely, interwell tracer tests without recirculation, interwell tracer tests with recirculation, and injection-backflow tracer tests. To estimate the model parameters, we used a nonlinear regression program to match tracer return profiles to the solutions.

  5. Tracer tomography (in) rocks!

    Science.gov (United States)

    Somogyvári, Márk; Jalali, Mohammadreza; Jimenez Parras, Santos; Bayer, Peter

    2016-04-01

    Physical behavior of fractured aquifers is rigorously controlled by the presence of interconnected conductive fractures, as they represent the main pathways for flow and transport. Ideally, they are simulated as a discrete fracture network (DFN) in a model to capture the role of fracture system geometry, i.e. fracture length, height, and width (aperture/transmissivity). Such network may be constrained by prior geological information or direct data resources such as field mapping, borehole logging and geophysics. With the many geometric features, however, calibration of a DFN to measured data is challenging. This is especially the case when spatial properties of a fracture network need to be calibrated to flow and transport data. One way to increase the insight in a fractured rock is by combining the information from multiple field tests. In this study, a tomographic configuration that combines multiple tracer tests is suggested. These tests are conducted from a borehole with different injection levels that act as sources. In a downgradient borehole, the tracer is recorded at different levels or receivers, in order to maximize insight in the spatial heterogeneity of the rock. As tracer here we chose heat, and temperature breakthrough curves are recorded. The recorded tracer data is inverted using a novel stochastic trans-dimensional Markov Chain Monte Carlo procedure. An initial DFN solution is generated and sequentially modified given available geological information, such as expected fracture density, orientation, length distribution, spacing and persistency. During this sequential modification, the DFN evolves in a trans-dimensional inversion space through adding and/or deleting fracture segments. This stochastic inversion algorithm requires a large number of thousands of model runs to converge, and thus using a fast and robust forward model is essential to keep the calculation efficient. To reach this goal, an upwind coupled finite difference method is employed

  6. The study on recycle scheme of the metallic radioactive wastes (II)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, J. I.; Park, J. H.; Jung, K. J. [and others

    2003-01-01

    It was understood that regulation criteria for material release varied with countries and that international standards were not setup. But, most advanced countries are continuously studying on the recycling of metallic wastes for the purpose of the reuse of resources and disposal cost reduction. Practically, the advanced countries make a lot of cost profits compared with disposal as their metallic wastes are recycled and reused through technology like melting. The reasonable international standards are also expected to be set in the near future because of the aggressive cooperation between international agencies such as IAEA and NEA toward recycling these wastes. In our case, the recycle criteria for radioactive waste containing radioactive nuclide with long half-life such as Cs-137(half-life: 30y) and Co-60(half-life: 5.26y) including others, which are generated from the nuclear fission or dismantling of nuclear facilities, are not yet established. Therefore, it is required that the recommendation and legalization of the regulatory criteria be carried out for the recycle and reuse of metallic wastes to be generated from the dismantling of domestic nuclear facilities in the future.

  7. Radon as tracer to identify discharge sections at Juatuba basin

    Energy Technology Data Exchange (ETDEWEB)

    Chagas, Claudio Jose; Ferreira, Vinicius Verna Magalhaes; Fonseca, Raquel Luisa Mageste; Rocha, Zildete; Moreira, Rubens Martins; Lemos, Nayron Cosme; Menezes, Angela de Barros Correia, E-mail: vvmf@cdtn.br, E-mail: rlmf@cdtn.br, E-mail: cjc@cdtn.br, E-mail: rochaz@cdtn.br, E-mail: rubens@cdtn.br, E-mail: menezes@cdtn.br, E-mail: lemosnc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Santos, Talita Oliveira, E-mail: talitaolsantos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2015-07-01

    The use of natural tracers in hydrological studies is a very useful tool, being applied in several studies. One of these tracers is the radon, {sup 222}Rn, noble gas derived from natural sources, been found in all underground waters, as a product of radioactive decay of the {sup 226}Ra. This gas can be found in the air, water, rocks or soil. In this paper, the {sup 222}Rn detection in surface water was used as tracer in order to identify aquifer discharge sections in surface water at the Fundao stream, which belongs to the Juatuba river basin, through the second semester of 2014 and the first semester of 2015, in three sampling campaigns. The {sup 222}Rn measurements at Fundao stream were carried out using the equipment RAD 7. The results showed that {sup 222}Rn is present in some sections of the water course suggesting that there is a connection between groundwater and surface water. It also justifies the variation in the water level in the stream, recorded by a fluviometric station. (author)

  8. Evaluation of short-term tracer fluctuations in groundwater and soil air in a two year study

    Science.gov (United States)

    Jenner, Florian; Mayer, Simon; Aeschbach, Werner; Weissbach, Therese

    2016-04-01

    The application of gas tracers like noble gases (NGs), SF6 or CFCs in groundwater studies such as paleo temperature determination requires a detailed understanding of the dynamics of reactive and inert gases in the soil air with which the infiltrating water equilibrates. Due to microbial gas consumption and production, NG partial pressures in soil air can deviate from atmospheric air, an effect that could bias noble gas temperatures estimates if not taken into account. So far, such an impact on NG contents in groundwater has not been directly demonstrated. We provide the first long-term study of the above mentioned gas tracers and physical parameters in both the saturated and unsaturated soil zone, sampled continuously for more than two years near Mannheim (Germany). NG partial pressures in soil air correlate with soil moisture and the sum value of O2+CO2, with a maximal significant enhancement of 3-6% with respect to atmospheric air during summer time. Observed seasonal fluctuations result in a mass dependent fractionation of NGs in soil air. Concentrations of SF6 and CFCs in soil air are determined by corresponding fluctuations in local atmospheric air, caused by industrial emissions. Arising concentration peaks are damped with increasing soil depth. Shallow groundwater shows short-term NG fluctuations which are smoothed within a few meters below the water table. A correlation between NG contents of soil air and of groundwater is observable during strong recharge events. However, there is no evidence for a permanent influence of seasonal variations of soil air composition on shallow groundwater. Fluctuating NG contents in shallow groundwater are rather determined by variations of soil temperature and water table level. Our data gives evidence for a further temperature driven equilibration of groundwater with entrapped air bubbles within the topmost saturated zone, which permanently occurs even some years after recharge. Local subsurface temperature fluctuations

  9. Modeling of meteorology, tracer transport and chemistry for the Uintah Basin Winter Ozone Studies 2012 and 2013

    Science.gov (United States)

    Ahmadov, R.; McKeen, S. A.; Angevine, W. M.; Frost, G. J.; Roberts, J. M.; De Gouw, J. A.; Warneke, C.; Peischl, J.; Brown, S. S.; Edwards, P. M.; Wild, R. J.; Pichugina, Y. L.; Banta, R. M.; Brewer, A.; Senff, C. J.; Langford, A. O.; Petron, G.; Karion, A.; Sweeney, C.; Schnell, R. C.; Johnson, B.; Zamora, R. J.; Helmig, D.; Park, J.; Evans, J.; Stephens, C. R.; Olson, J. B.; Trainer, M.

    2013-12-01

    The Uintah Basin Winter Ozone Studies (UBWOS) field campaigns took place during winter of 2012 and 2013 in the Uintah Basin, Utah. The studies were aimed at characterizing meteorology, emissions of atmospheric constituents and air chemistry in a region abundant with oil and gas production, with associated emissions of various volatile organic compounds (VOCs) and NOx. High ozone pollution events were observed throughout the Uintah Basin during the winter of 2013, but not during the winter of 2012. A clear understanding of the processes leading to high ozone events is still lacking. We present here high spatiotemporal resolution simulations of meteorology, tracer transport and gas chemistry over the basin during January-February, 2012 and 2013 using the WRF/Chem regional photochemical model. Correctly characterizing the meteorology poses unique challenges due to complex terrain, cold-pool conditions, and shallow inversion layers observed during the winter of 2013. We discuss the approach taken to adequately simulate the meteorology over the basin and present evaluations of the modeled meteorology using surface, lidar and tethersonde measurements. Initial simulations use a passive tracer within the model as a surrogate for CH4 released from oil and gas wells. These tracer transport simulations show that concentrations of inert, emitted species near the surface in 2013 were 4-8 times higher than 2012 due to much shallower boundary layers and reduced winds in 2013. This is supported by in-situ measurements of CH4 made at the Horse Pool surface station during the field campaigns. Full photochemical simulations are forced by VOC and NOx emissions that are determined in a top-down approach, using observed emission ratios of VOC and NOx relative to CH4, along with available information of active wells, compressors, and processing plants. We focus on differences in meteorology, temperature, and radiation between the two winters in determining ozone concentrations in the

  10. Metabolic conversion of dicarboxylic acids to succinate in rat liver homogenates. A stable isotope tracer study.

    Science.gov (United States)

    Tserng, K Y; Jin, S J

    1991-02-15

    The metabolic conversion of dicarboxylic acids into succinate and other gluconeogenic intermediates in rat liver homogenates was investigated using [1,2,4-13C4]dodecanedioic acid as tracer. Isotope enrichments in 3-hydroxybutyrate, succinate, fumarate, and malate, as well as dicarboxylates (dodecanedioic, sebacic, suberic, and adipic acids) were measured with selected ion monitoring capillary column gas chromatograph-mass spectrometry. Significant enrichment in the M + 4 (four labeled carbons) ion of succinate (0.4-2.9%) was detected, unequivocally demonstrating the direct conversion of dicarboxylate into succinate. In addition, significant enrichment of the M + 2 ion of succinate was also observed. This labeled species was generated from labeled acetyl-CoA through the tricarboxylic acid cycle. The partition of acetyl-CoA into the tricarboxylic acid cycle relative to ketone body formation was higher in the beta oxidation of dicarboxylate than monocarboxylate. Therefore, in addition to the production of succinate, the beta oxidation of dodecanedioate resulted in the channeling of the acetyl-CoA produced to the tricarboxylic acid cycle instead of to acetoacetate production. The enrichments in lower chain dicarboxylates are consistent with a partial bidirectional beta oxidation of dodecanedioic acid. In addition to the expected M + 0 and M + 4 labels, significant M + 2 species were detected in suberic and adipic acids. These M + 2-labeled species were produced from the released free dicarboxylate intermediates which were then reactivated and metabolized. In these experiments, the overall succinate production was derived 4% from the direct conversion of dodecanedioic acid and 11% from the indirect route via acetyl-CoA through tricarboxylic acid.

  11. Tracer Study of Dentistry Graduates of one Higher Education Institution in the Philippines from 2008 to 2012

    Directory of Open Access Journals (Sweden)

    Jennifer D. Maderazo

    2016-08-01

    Full Text Available This tracer study determines the employment status of the graduates of Doctor of Dental Medicine of Lyceum of the Philippines University (LPU from 2008-2012. It assessed the relevance of the Dentistry curriculum, knowledge, skills and attitude acquired by the graduates deemed to be relevant for their employment; identify the personal and professional characteristics and job placement of Dentistry graduates and the school related factors associated with their employment. This tracer study used a descriptive research design. The study described the experiences of the graduates before and after employment. The graduates conveyed their personal observations regarding the situations they faced after graduation. The findings showed that majority of the Dentistry graduate-respondents are presently employed except for one whose primary reason is family concern and decided not to find a job. Most of the graduates had their first job as associate dentist with recommendation from the department or alumni of the college and opted to put up their own private practice after 6 months. Rewarding salaries and benefits are the main reason for staying on the job and are all enjoying a professional career in dentistry with initial gross income of 25,000 pesos and above. The following school related factors for job placement such as curriculum and instruction for the general education and professional subjects, student services and faculty instruction were found to be relevant in meeting the demands of the graduates’ dental profession. And the following are the work related values gained by the graduates such a love for God, honesty and truth, professional integrity and leadership. These values were found to be very relevant in the practice of the profession.

  12. Studies on deposition, adhesion and resuspension of radioactive substances on the ground surface and ground cover

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Susumu; Kurihara, Kazuo [Meteorological Research Inst., Tsukuba, Ibaraki (Japan)

    1999-03-01

    After the Chernobyl` nuclear power plant accident, resuspension of radioactive nuclei into the atmosphere is recognized as the one of the important processes that must be considered in the estimation of inhalation doses to humans. In this study, resuspensions of particles from soil and grass have been studied. The resuspension of particles from bare soil was modelized by using Shao`s method. The resuspension of particles from grass was studied by a wind tunnel and a field experiment. Dependencies of the resuspension rate on time and on friction velocity were obtained clearly. And it was also found that the other meteorological parameters, such as temperature, relative humidity, solar radiation and condensation, affected the resuspension rate in the field. (author)

  13. sup 26 Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi

    1990-12-01

    Accelerator mass spectrometry (AMS) was applied for {sup 26}Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using {sup 26}Al as a tracer. When {sup 26}Al was intraperitoneally injected into rats, a considerable amount of {sup 26}Al was incorporated into the cerebrum after 5-35 days of the injection. (author).

  14. O-18 tracer studies of Al2O3 scale formation on NiCrAl alloys

    Science.gov (United States)

    Reddy, K. P. R.; Cooper, A. R.; Smialek, J. L.

    1982-01-01

    Diffusion processes in Al2O3 scales formed on NiCrAl + Zr alloys were studied by the proton activation technique employing the O-18 isotope as a tracer. The O-18 profiles identified a zone of oxide penetration beneath the external scale. Both this subscale formation and the outer Al2O3 scale thickness were shown by this technique to increase with Zr content in the alloy. Estimated kp's from scale thicknesses were in agreement with gravimetric measurements for various Zr levels. Alternate exposures in O-16 and O-18 revealed that oxygen inward transport was the primary growth mechanism. A qualitative analysis of these O-18 profiles indicated that the oxygen transport was primarily via short-circuit paths, such as grain boundaries.

  15. On the use of flow-storage repartitions derived from artificial tracer tests for geothermal reservoir characterization in the Malm-Molasse basin: a theoretical study

    Science.gov (United States)

    Dewi, Dina Silvia; Osaigbovo Enomayo, Augustine; Mohsin, Rizwan; Karmakar, Shyamal; Ghergut, Julia; Sauter, Martin

    2016-04-01

    needed to calculate FSR. Looking at the Sauerlach example, we find that premature interruption of tracer sampling systematically leads to overestimating the reservoir's storage capacity and underestimating its flow capacity, with misestimation generally increasing as the bedded/reef interfacial area per volume is increased. It is interesting to correlate these findings with the tracer-based approach to facies identification for the shallower Malm aquifers of the Southern Franconian Alb, proposed by Seiler et al. (1989, 1995) and with expectations from the direct (i. e., distributed-parameter) modeling of matrix-diffusive effects (Maloszewski and Zuber 1985) on measured tracer signals. References: Maloszewski P, Zuber A (1985) On the theory of tracer experiments in fissured rocks with a porous matrix, Journal of Hydrology, 79, 333-358 Seiler K-P, Behrens H, Wolf M (1995) Use of artificial and environmental tracers to study storage and drainage of groundwater in the Franconian Alb, Germany, and the consequences for groundwater protection, Proc Isotopes in Water Resources Management, 2, 135-146 (IAEA, Vienna) Seiler K-P, Maloszewski P, Behrens H (1989) Hydrodynamic dispersion in karstified limestones and dolomites in the Upper Jurassic of the Franconian Alb, FRG, Journal of Hydrology, 108, 235-247 Shook G M (2003) A Simple, Fast Method of Estimating Fractured Reservoir Geometry from Tracer Tests, Geothermal Resources Council Transactions, 27, 407-411 Financial support from the German Federal Ministry for Economic Affairs and Energy is gratefully acknowledged. - Gefördert durch BMWi aufgrund eines Beschlusses des Deutschen Bundestages (FKZ 0325515 "TRENDS").

  16. Problems concerning food production, supply and use caused by radioactive deposition: A study directed towards needs for early decision making after radioactive fallout; Radiakproblem inom livsmedelssektorn: En studie inriktad paa behoven foer beslutsfattande i tidigt skede efter radioaktivt nedfall

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, R.

    1995-12-01

    The primary aim of this study is to analyze and describe how a radioactive deposition after nuclear weapons employment outside Sweden would affect the domestic food production in a short time perspective and in the sequence of events from primary production over processing and transport to food consumption. The study is an attempt at a comprehensive treatment of knowledge needed as a basis for decisions on operative issues, often of a time-urgent nature. Actions to alleviate the problems pertinent to the food supply in the event of radioactive fallout are also discussed, although without any claim of exhaustive coverage. Other aspects, as the economical consequences of the disturbances due to the fallout situation (or of possible counteractions) are not dealt with, however. With certain restrictions mentioned in the text the results are also applicable in connection with radioactive deposition caused by accidental release from a nuclear power plant. 60 refs, 32 figs.

  17. The Transient Tracers in the Ocean (TTO) program: The North Atlantic Study, 1981; The Tropical Atlantic Study, 1983

    Science.gov (United States)

    Brewer, Peter G.; Sarmiento, Jorge L.; Smethie, William M.

    1985-01-01

    The scientific papers here collected result from the Transient Tracers in the Ocean (TTO) program. The two parts of this major geochemical and physical oceanographie expedition took place in the North Atlantic Ocean in 1981 and in the Tropical Atlantic in 1983 on the research vessel Knorr of the Woods Hole Oceanographie Institution. The expeditions, sponsored by the National Science Foundation and the U.S. Department of Energy (North Atlantic only), were designed to observe the passage of man-made geochemical tracers into the interior of the ocean. The foundations for such an experiment were laid in the 1972-1978 GEOSECS program. Here, for the first time, a systematic survey revealed the penetration into the thermocline and deep ocean of the products of man's military/industrial activities, principally tritium and carbon-14 resulting from atmospheric testing of nuclear weapons, which terminated with the nuclear test ban treaty in 1962.

  18. Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

    Energy Technology Data Exchange (ETDEWEB)

    Clerico, A. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Iervasi, G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Manfredi, C. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Salvadori, S. [Dept. of Pharmaceutical Sciences, Univ. of Ferrara (Italy); Marastoni, M. [Dept. of Pharmaceutical Sciences, Univ. of Ferrara (Italy); Del Chicca, M.G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Giannessi, D. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Del Ry, S. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Andreassi, M.G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Sabatino, L. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Iascone, M.R. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Biagini, A. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Donato, L. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica

    1995-09-01

    The authors evaluate the optimum chemical conditions for labelling atrial natriuretic peptide (ANP) and its metabolites and for preparing highly purified radiotracers which can be used for in vivo kinetic studies of ANP in humans. Synthetic {alpha} h{sub 1-28}ANP and some hormone metabolites were iodinated with Na{sup 125}I or Na{sup 131}I by means of the lactoperoxidase (ANP) or the chloramine-T (ANP metabolites) technique. The biological activity of labelled ANP was tested by means of a binding study using mouse cardiac membranes. A high-performance liquid chromatography (HPLC) procedure was used to purify the labelled hormone and the principal labelled metabolites in venous plasma samples collected up to 50 min after the injection of {sup 125}I-labelled ANP from nine healthy men. The main ANP kinetic parameters were derived from the disappearance curves of the [{sup 125}I]ANP, which were satisfactorily fitted by a bi-exponential function in all subjects. The main advantages of this tracer technique are high accuracy, allowing the identification of the metabolites produced in vivo under steady-state conditions after injection of the precursor (labelled hormone) high sensitivity, allowing the detection of minimal quantities of metabolites high specificity, allowing the detection of possible in vitro artefactual generation of cleavage products of ANP using an internal labelled standard. Utilizing this tracer method, it was possible to estimate the principal parameters of ANP kinetics and also to plot the appearance curves of the labelled metabolites produced in vivo after the injection of the labelled precursor. (orig.). With 5 figs.

  19. Beam Dynamics Design Studies of a Superconducting Radioactive Ion Beam Post-accelerator

    CERN Document Server

    Fraser, MA; Pasini, M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post- accelerated by the normal conducting REX linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of trans- verse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wa...

  20. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    Directory of Open Access Journals (Sweden)

    M. A. Fraser

    2011-02-01

    Full Text Available The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wave resonator and the asymmetry of the rf defocusing forces in the solenoid focusing channel. A racetrack shaped beam port aperture was shown to improve the symmetry of the fields in the high-β quarter-wave resonator and reduce the loss of acceptance under the offset used to compensate the steering force. The methods used to compensate the beam steering are described and an optimization routine written to minimize the steering effect when all cavities of a given family are offset by the same amount, taking into account the different velocity profiles across the range of mass-to-charge states accepted. The assumptions made in the routine were shown to be adequate and the results well correlated with the beam quality simulated in multiparticle beam dynamics simulations. The specification of the design tolerances is outlined based on studies of the sensitivity of the beam to misalignment and errors, with particular

  1. Assessment of radioactive residues arising from radiolabel instability in a multiple dose tissue distribution study in rats

    Energy Technology Data Exchange (ETDEWEB)

    Slatter, J.G. [Pharmacia Corp., Peapack, NJ (United States); Sams, J.P.; Easter, J.A. [Pharmacia Corp., Kalamazoo, MI (United States)] [and others

    2003-05-01

    Our study objectives were to quantitatively determine the effect of radiolabel instability on terminal phase radioactive tissue residues in a multiple dose tissue distribution study, to quantitatively compare tissue residue artifacts (non drug-related radioactivity) from two chemically-distinct radiolabel locations, and to conduct a definitive multiple dose tissue distribution study using the better of the two radiolabeled compounds. We compared the excretion and tissue distribution in rats of [{sup 14}C]linezolid, radiolabeled in two different locations, after 7 consecutive once daily [{sup 14}C] oral doses. The radiolabels were in the acetamide (two carbon) and oxazolidinone (isolated carbon) functional groups. Terminal phase tissue residue and excretion data were compared to data from rats dosed orally with [{sup 14}C]sodium acetate. Drug-related radioactivity was excreted rapidly over 24 h. After a single dose, the acetamide and oxazolidinone radiolabel sites both gave 3% of dose as exhaled {sup 14}CO{sub 2}. After 7 daily [{sup 14}C] oral doses, terminal phase radioactive tissue residues were higher from the acetamide radiolabel, relative to the oxazolidinone radiolabel, and were primarily not drug-related. In the definitive tissue distribution study, low concentrations of drug-related radioactivity in skin and thyroid were observed. We conclude that although small amounts of radiolabel instability do not significantly affect single dose tissue radioactivity C{sub max} and area under the curve (AUC), artifacts arising from radiolabel instability can prolong the apparent terminal phase half life and complicate study data interpretation. When possible, it is always preferable to use a completely stable radiolabel site. (author)

  2. Sedimentological study of a lagoon through natural radioactivity and 137Cs determinations

    Science.gov (United States)

    San Miguel, E. G.; Pérez-Moreno, J. P.; Aguado, J. L.; Bolívar, J. P.; García-Tenorio, R.

    2003-01-01

    Profiles of artificial fallout (such as 137Cs) and natural radioactivity radionuclides in sediment cores are useful tools to study sedimentological properties of different aquatic environments as well as to evaluate average sedimentation rates. In the Portil lagoon, a small natural reservoir located in Huelva province (southwest of Spain), and through the analysis of 210Pb, 226Ra, 137Cs, 238U and 210Po vertical profiles in sediment cores, it is shown how the accumulative or transport character of the collection zones may be inferred. In the accumulation zone of the lagoon the influence of focusing effects has been analysed and an average sedimentation rate has been determined through 210Pb in one sediment core. This 210Pb-sedimentation rate is consistent with sediment dating based on the 137Cs data.

  3. Radioactive iodine therapy and breast cancer. A follow-up study of hyperthyroid women

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, M.B.; Maloof, F.; Monson, R.R.; Aschengrau, A.; Cooper, D.S.; Ridgway, E.C.

    1988-05-01

    A follow-up study of 1762 hyperthyroid women who were treated at the Massachusetts General Hospital Thyroid Unit between 1946 and 1964 was conducted. The average length of follow-up was 17.2 years. A 1978 mailing address or a death certificate was located for 92% of the women, and 88% of 1058 living patients responded to a mail questionnaire. The standardized mortality ratio (SMR) for all causes of death was 1.3 (95% confidence interval (CI) 1.2-1.4). The standardized mortality ratios for all malignant neoplasms and for breast cancer were 0.9 (95% CI 0.7-1.1) and 1.3 (95% CI 0.8-1.9), respectively. More deaths than expected were observed from endocrine and metabolic diseases (SMR = 1.8, 95% CI 1.2-2.7), circulatory system diseases (SMR = 1.4, 95% CI 1.3-1.6), and respiratory system diseases (SMR = 1.9, 95% CI 1.3-2.6). The standardized incidence ratios (SIR) for all malignant neoplasms and for breast cancer were 0.9 (95% CI 0.8-1.1) and 1.2 (95% CI 0.9-1.5), respectively. A nonsignificant excess breast cancer risk was observed 10 years after the onset of thyroid symptoms and was present at the end of 30 years of observation. A statistically significant excess number of pancreatic cancer cases (SIR = 2.0, 95% CI 1.0-3.7) and a nonsignificant excess of brain cancer cases (SIR = 2.3, 95% CI 0.7-5.3) were observed. Eighty per cent of the women were treated with radioactive iodine. When age at treatment and year of treatment were controlled, women who were ever treated with radioactive iodine had a standardized rate ratio for breast cancer of 1.9 (95% CI 0.9-4.1), compared with those who were never treated with radioactive iodine. Women who developed hypothyroidism as a result of their treatment for hyperthyroidism did not have an increased risk of developing breast cancer (SIR = 1.1, 95% CI 0.8-1.6).

  4. Tracer tests in geothermal resource management

    OpenAIRE

    Axelsson G.

    2013-01-01

    Geothermal reinjection involves injecting energy-depleted fluid back into geothermal systems, providing an effective mode of waste-water disposal as well as supplementary fluid recharge. Cooling of production boreholes is one of the main disadvantages associated with reinjection, however. Tracer testing is an important tool for reinjection studies because tracer tests actually have a predictive power since tracer transport is orders of magnitude faster than cold-front advancement around reinj...

  5. A study on Prediction of Radioactive Source-term from the Decommissioning of Domestic NPPs by using CRUDTRAN Code

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jong Soon; Lee, Sang Heon; Cho, Hoon Jo [Department of Nuclear Engineering Chosun University, Gwangju (Korea, Republic of)

    2016-10-15

    For the study, the behavior mechanism of corrosion products in the primary system of the Kori no.1 was analyzed, and the volume of activated corrosion products in the primary system was assessed based on domestic plant data with the CRUDTRAN code used to predict the volume. It is expected that the study would be utilized in predicting radiation exposure of workers performing maintenance and repairs in high radiation areas and in selecting the process of decontaminations and decommissioning in the primary system. It is also expected that in the future it would be used as the baseline data to estimate the volume of radioactive wastes when decommissioning a nuclear plant in the future, which would be an important criterion in setting the level of radioactive wastes used to compute the quantity of radioactive wastes. The results of prediction of the radioactive nuclide inventory in the primary system performed in this study would be used as baseline data for the estimation of the volume of radioactive wastes when decommissioning NPPs in the future. It is also expected that the data would be important criteria used to classify the level of radioactive wastes to calculate the volume. In addition, it is expected that the data would be utilized in reducing radiation exposure of workers in charge of system maintenance and repairing in high radiation zones and also predicting the selection of decontaminations and decommissioning processes in the primary systems. In future researches, it is planned to conduct the source term assessment against other NPP types such as CANDU and OPR-1000, in addition to the Westinghouse type nuclear plants.

  6. Studies of radioactive cisplatin ({sup 191}Pt) for tumour imaging and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Areberg, J

    2000-01-01

    A radioactive variant of the cytostatic agent cis-dichlorodiammineplatinum(II), cisplatin, was synthesised from {sup 191}PtCl{sub 4}. The {sup 191}Pt-cisplatin was found to be a sterile product of high radionuclide, radiochemical and chemical purity. The pharmacokinetics of platinum in tumour tissue and organs at risk of fourteen patients undergoing treatment with cisplatin were studied by exchanging a small fraction of the prescribed amount of cisplatin with {sup 191}Pt-cisplatin. The uptake and retention of platinum were investigated by gamma camera measurements up to ten days after infusion of {sup 191}Pt-cisplatin. Highest concentration of platinum was found in the liver, on average 5.7 {+-} 0.5 {mu}g/g normalised to a given amount of 180 mg cisplatin. Corresponding value for the kidneys was 1.9 {+-} 0.3 {mu}g/g. Uptake of platinum in tumours was visualised in five patients with an average maximum concentration of 4.9 {+-} 1.0 {mu}g/g normalised to a given amount of 180 mg cisplatin. The data from the pharmacokinetic study was used together with data from the literature to estimate the absorbed dose and effective dose to patients receiving radioactive cisplatin. The effective doses were calculated to be 0.10 {+-} 0.02 mSv/MBq, 0.17 {+-} 0.04 mSv/MBq and 0.23 {+-} 0.05 mSv/MBq for {sup 191}Pt-, {sup 193m}Pt-, and {sup 195m}Pt-cisplatin respectively. The combined effect of the radio- and chemotoxicity from {sup 191}Pt-cisplatin was investigated both in vitro and in vivo. A cervical cancer cell line was incubated with cisplatin or {sup 191}Pt-cisplatin with various concentrations and specific activities. It was shown that the surviving fraction was smaller for cells treated with {sup 191}Pt-cisplatin than for cells treated with the same concentration of non-radioactive cisplatin. The surviving fraction decreased with increasing specific activity. Isobologram technique showed that the radio- and chemotoxicity interacted in a supra-additive (synergistic) manner. In

  7. Collection of a radioactive source of $^{83}$Kr to study the gas distribution dynamics in a large GRPC detector

    CERN Multimedia

    An ultra-granular hadronic calorimeter was built using Glass Resistive Plate Chamber (GRPC) detectors as the sensitive medium. The gas of those detectors of $1 \\times 1$ m$^{2}$ each is constrained to be on one side of the detector. To ensure good gas distribution a prototype was built. Such a scheme could be extended to larger GRPC detectors of more than 2 m$^{2}$ if found efficient. To check the performance a radioactive gas could be used in association with the usual gas mixture used to operate the GRPC. The distribution of the radioactive gas can be monitored thanks to the 1 cm$^2$ resolution provided by the embedded electronics used to read out the detector. The radioactive $^{83}$Kr source (obtained from $^{83}$Rb decay) could be produced at the ISOLDE facility and will be used to study larger GRPC detectors at CERN.

  8. Simulated Radioactivity

    Science.gov (United States)

    Boettler, James L.

    1972-01-01

    Describes the errors in the sugar-cube experiment related to radioactivity as described in Project Physics course. The discussion considers some of the steps overlooked in the experiment and generalizes the theory beyond the sugar-cube stage. (PS)

  9. Radioactivity Calculations

    Science.gov (United States)

    Onega, Ronald J.

    1969-01-01

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

  10. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  11. Tracer gas dispersion in ducts-study of a new compact device using arrays of sonic micro jets

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.R. [Instituto Nacional de Engenharia e Tecnologia Industrial (INETI), Lisboa (Portugal); Afonso, C.F. [Faculdade de Engenharia, Universidade do Porto Departmento de Mecanica e Gestao Industrial, Porto (Portugal)

    2004-07-01

    One of the most feasible ways to measure duct airflows is by tracer gas techniques, especially for complex situations when the duct lengths are short as well as their access, which makes extremely difficult or impossible other methods to be implemented. One problem associated with the implementation of tracer gas technique when the ducts lengths are short is due to the impossibility of achieving complete mixing of the tracer with airflow and its sampling. In this work, the development of a new device for the injection of tracer gas in ducts is discussed as well as a new tracer-sampling device. The developed injection device has a compact tubular shape, with magnetic fixation to be easy to apply in duct walls. An array of sonic micro jets in counter current direction, with the possibility of angular movement according to its main axle ensures a complete mixing of the tracer in very short distances. The tracer-sampling device, with a very effective integration function, feeds the sampling system for analysis. Both devices were tested in a wind tunnel of approximately 21 m total length. The tests distances between injection and integration device considered were: X/Dh = 22; X/Dh = 4; X/Dh 2; and X/Dh = 1. For very short distances of X/Dh = 2 and X/Dh = 1, semi-empirical expressions were needed. A good reproducibility of airflow rate values was obtained. These preliminary tests showed that the practical implementation of tracer gas techniques in HVAC systems for measuring airflow rates with a very short mixing distance is possible with the devices developed. (author)

  12. Radium uptake during barite recrystallization at 23 ± 2 °C as a function of solution composition: An experimental 133Ba and 226Ra tracer study

    Science.gov (United States)

    Curti, E.; Fujiwara, K.; Iijima, K.; Tits, J.; Cuesta, C.; Kitamura, A.; Glaus, M. A.; Müller, W.

    2010-06-01

    High-purity synthetic barite powder was added to pure water or aqueous solutions of soluble salts (BaCl 2, Na 2SO 4, NaCl and NaHCO 3) at 23 ± 2 °C and atmospheric pressure. After a short pre-equilibration time (4 h) the suspensions were spiked either with 133Ba or 226Ra and reacted under constant agitation during 120-406 days. The pH values ranged from 4 to 8 and solid to liquid (S/L) ratios varied from 0.01 to 5 g/l. The uptake of the radiotracers by barite was monitored through repeated sampling of the aqueous solutions and radiometric analysis. For both 133Ba and 226Ra, our data consistently showed a continuous, slow decrease of radioactivity in the aqueous phase. Mass balance calculations indicated that the removal of 133Ba activity from aqueous solution cannot be explained by surface adsorption only, as it largely exceeded the 100% monolayer coverage limit. This result was a strong argument in favor of recrystallization (driven by a dissolution-precipitation mechanism) as the main uptake mechanism. Because complete isotopic equilibration between aqueous solution and barite was approached or even reached in some experiments, we concluded that during the reaction all or substantial fractions of the initial solid had been replaced by newly formed barite. The 133Ba data could be successfully fitted assuming constant recrystallization rates and homogeneous distribution of the tracer into the newly formed barite. An alternative model based on partial equilibrium of 133Ba with the mineral surface (without internal isotopic equilibration of the solid) could not reproduce the measured activity data, unless multistage recrystallization kinetics was assumed. Calculated recrystallization rates in the salt solutions ranged from 2.8 × 10 -11 to 1.9 × 10 -10 mol m -2 s -1 (2.4-16 μmol m -2 d -1), with no specific trend related to solution composition. For the suspensions prepared in pure water, significantly higher rates (˜5.7 × 10 -10 mol m -2 s -1 or ˜49 μmol m

  13. Axillary sentinel node identification in breast cancer patients: degree of radioactivity present at biopsy is critical

    DEFF Research Database (Denmark)

    Nielsen, Kristina R; Oturai, Peter S; Friis, Esbern

    2011-01-01

    The radioactivity present in the patient (Act(rem) ) at sentinel node (SN) biopsy will depend on injected activity amount as well as on the time interval from tracer injection to biopsy, which both show great variations in the literature. The purpose of this study was to analyse the influence...... of varying Act(rem) levels on the outcome of axillary SN biopsy in patients with breast cancer (BC)....

  14. A study on the trend of international radioactive material regulation since the terrorist attacks of September 11, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, J. S. [KAERI, Taejon (Korea, Republic of)

    2003-07-01

    AI-Qaeda and other terrorist groups have tried to obtain the radioactive material which could be used to make a dirty bomb, and their documents relating to dirty bombs were found in the January 2003. International communities especially, the United States has made efforts to improve infrastructure of radiation regulation and security of radioactive material for protecting its people from radiological attacks. This study examines the likelihood of radiological terrorism and the radiological dispersal devices which could be used by determined terrorists, and the trend of international communities to respond it through improvement on radiation regulation and security.

  15. Developing new PET tracers to image the growth hormone secretagogue receptor 1a (GHS-R1a).

    Science.gov (United States)

    Kawamura, Kazunori; Fujinaga, Masayuki; Shimoda, Yoko; Yamasaki, Tomoteru; Zhang, Yiding; Hatori, Akiko; Xie, Lin; Wakizaka, Hidekatsu; Kumata, Katsushi; Ohkubo, Takayuki; Kurihara, Yusuke; Ogawa, Masanao; Nengaki, Nobuki; Zhang, Ming-Rong

    2017-09-01

    `The growth hormone secretagogue receptor 1a (GHS-R1a) is the orphan G-protein-coupled receptor, and its endogenous ligand is ghrelin. GHS-R1a contributes to regulation of glucose homeostasis, memory and learning, food addiction, and neuroprotection. Several PET tracers for GHS-R1a have been developed, but none have been reported to be clinically applicable to GHS-R1a imaging. In this study, we developed three new PET tracers for GHS-R1a: (18)F-labeled 6-(4-chlorophenyl)-3-((1-(2-fluoroethyl)piperidin-3-yl)methyl)-2-(o-tolyl)quinazolin-4(3H)-one (1), (11)C-labeled 6-(4-chlorophenyl)-3-((1-(2-methoxyethyl)piperidin-3-yl)methyl)-2-(o-tolyl)quinazolin-4(3H)-one (2), and (11)C-labeled (S)-(4-(1H-indole-6-carbonyl)-3-methylpiperazin-1-yl)(4'-methoxy-[1,1'-biphenyl]-4-yl)methanone (3). [(18)F]1 was synthesized by the (18)F-fluoroethylation; [(11)C]2 or [(11)C]3 was synthesized by the (11)C-methylation. Biodistribution studies and PET studies were conducted in mice. We successfully radiosynthesized [(18)F]1, [(11)C]2, and [(11)C]3 with appropriate radioactivity for the animal study. In the ex vivo biodistribution study, 60min following injection, the radioactivity level of [(18)F]1 was relatively high in the small intestine, that of [(11)C]2 was high in the liver, and that of [(11)C]3 was high in the pancreas. The radioactivity levels of the three PET tracers were relatively low in the brain. Under pretreatment with YIL781 (a selective and high affinity antagonist for GHS-R1a), the pancreas radioactivity level at 30min following [(11)C]3 injection was significantly reduced to 55% of control, but the radioactivity in the brain was not changed. In the PET study under control conditions, high radioactivity levels in the liver and pancreas were observed following [(11)C]3 injection. With YIL781 pretreatment, the accumulated radioactivity in the pancreas 15-60min after [(11)C]3 injection was significantly decreased to 78% of control. [(11)C]3 exhibited relatively high uptake

  16. Rainfall simulation experiments to study sediment redistribution using rare earth element oxides as tracers under conventional and conservation agricultural practices

    Science.gov (United States)

    Tóth, Adrienn; Jakab, Gergely; Sipos, Péter; Karlik, Máté; Madarász, Balázs; Zacháry, Dóra; Szabó, Judit; Szalai, Zoltán

    2017-04-01

    Rare earth elements (REE) have very favourable characteristics for being ideal sediment tracers as they are characterised by strong binding to soil particles, low mobility, low background concentration in soils, environmental benignity, high analytical sensitivity and they can be detected relatively easily and inexpensively in soils. The group of REEs consist of 16 elements with similar chemical properties, but at the same time, they are clearly distinguishable enabling multiple tracking of sediment deriving from different parts of the studied area, as well as mapping redistribution processes by appropriate designing of subareas marked by different REEs. In this study, rainfall simulation experiments were carried out to compare the loss and redistribution of soil sediments in two plots under conventional and conservation agricultural practices. Five different rainfall intensities (up to 80 mm/h) were applied to both plots. Sources and pathways of sediments within the two plots were studied using REE-oxides as tracers. Approximately 1,000 mg/kg of Er2O3, Ho2O3 and Sm2O3 (calculated to the upper 1 cm of the soil) were dispersed to the soil surface with banded distribution; each transversal band covered the third of the surface are of the plots. Concentration of the REE-oxides in the sediment leaving the plots, and that of the surface soil before and after the experiment were analysed by X-Ray fluorescence spectrometry. Significant sediment losses were found for both plots after the experiments, with slightly different characteristics between the conventional and conservation ones. Highest difference in loss of added REEs was found in the upper third of the plots with 81 ± 19% in the conventional and 71 ± 21% in the conservation ones. These values have been equalized downwards with almost complete losses in the lower third of the plots (99 ± 2% and 97 ± 4%, respectively). Only very small part of the removed sediment has been accumulated in the lower parts of the

  17. Packet Tracer network simulator

    CERN Document Server

    Jesin, A

    2014-01-01

    A practical, fast-paced guide that gives you all the information you need to successfully create networks and simulate them using Packet Tracer.Packet Tracer Network Simulator is aimed at students, instructors, and network administrators who wish to use this simulator to learn how to perform networking instead of investing in expensive, specialized hardware. This book assumes that you have a good amount of Cisco networking knowledge, and it will focus more on Packet Tracer rather than networking.

  18. PRODUCTION AND TRANSPORT OF CARBON DIOXIDE IN A CONTAMINATED VADOSE ZONE: A STABLE AND RADIOACTIVE CARBON ISOTOPE STUDY

    Science.gov (United States)

    Analyses of soil gas compositions and stable and radioactive carbon isotopes in the vadose zone above an alluvial aquifer were conducted at an organic solvent disposal site in southeast Phoenix, AZ. The study investigated the source and movement of carbon dioxide above a plume of...

  19. {sup 11}C-harmine as a potential PET tracer for ductal pancreas cancer: in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    Herlin, G.; Persson, B.; Laangstroem, B.; Aspelin, P. [Department of Diagnostic Radiology, Huddinge University Hospital, 141-86 Stockholm (Sweden); Bergstroem, M. [Uppsala University PET Centre, Uppsala (Sweden)

    2003-04-01

    Our objective was to find a tracer in diagnosing human pancreatic cancer using positron emission tomography (PET). For this purpose in vitro test of pancreatic tissues with autoradiography was used. Autoradiography was performed with {sup 11}C-harmine (a MAO-A-inhibitor) with and without competitive inhibition. Tissue preparations were obtained from normal human pancreas and pancreatic cancer. The uptake was compared with rat brain or pig brain, tissues with high expression of MAO-A. Nine autoradiography studies on 16 samples from five different human pancreatic cancers gave a significant level of specific binding of {sup 11}C-harmine in 13, and 3 samples did not give a significant level of specific binding of {sup 11}C-harmine. All 16 samples were analysed with autoradiography. Compared with rat brain, the uptake in the human cancers varied between 9 and 43% except for one tissue preparation which had a too low value for measurement. This study shows expression of MAO-A in human pancreatic cancer. This is readily characterised in vitro. The potential use of {sup 11}C-harmine in the diagnosis of pancreatic cancer using PET might be limited, but further PET studies are necessary. (orig.)

  20. A unique automation platform for measuring low level radioactivity in metabolite identification studies.

    Directory of Open Access Journals (Sweden)

    Joel Krauser

    Full Text Available Generation and interpretation of biotransformation data on drugs, i.e. identification of physiologically relevant metabolites, defining metabolic pathways and elucidation of metabolite structures, have become increasingly important to the drug development process. Profiling using (14C or (3H radiolabel is defined as the chromatographic separation and quantification of drug-related material in a given biological sample derived from an in vitro, preclinical in vivo or clinical study. Metabolite profiling is a very time intensive activity, particularly for preclinical in vivo or clinical studies which have defined limitations on radiation burden and exposure levels. A clear gap exists for certain studies which do not require specialized high volume automation technologies, yet these studies would still clearly benefit from automation. Use of radiolabeled compounds in preclinical and clinical ADME studies, specifically for metabolite profiling and identification are a very good example. The current lack of automation for measuring low level radioactivity in metabolite profiling requires substantial capacity, personal attention and resources from laboratory scientists. To help address these challenges and improve efficiency, we have innovated, developed and implemented a novel and flexible automation platform that integrates a robotic plate handling platform, HPLC or UPLC system, mass spectrometer and an automated fraction collector.

  1. A Unique Automation Platform for Measuring Low Level Radioactivity in Metabolite Identification Studies

    Science.gov (United States)

    Krauser, Joel; Walles, Markus; Wolf, Thierry; Graf, Daniel; Swart, Piet

    2012-01-01

    Generation and interpretation of biotransformation data on drugs, i.e. identification of physiologically relevant metabolites, defining metabolic pathways and elucidation of metabolite structures, have become increasingly important to the drug development process. Profiling using 14C or 3H radiolabel is defined as the chromatographic separation and quantification of drug-related material in a given biological sample derived from an in vitro, preclinical in vivo or clinical study. Metabolite profiling is a very time intensive activity, particularly for preclinical in vivo or clinical studies which have defined limitations on radiation burden and exposure levels. A clear gap exists for certain studies which do not require specialized high volume automation technologies, yet these studies would still clearly benefit from automation. Use of radiolabeled compounds in preclinical and clinical ADME studies, specifically for metabolite profiling and identification are a very good example. The current lack of automation for measuring low level radioactivity in metabolite profiling requires substantial capacity, personal attention and resources from laboratory scientists. To help address these challenges and improve efficiency, we have innovated, developed and implemented a novel and flexible automation platform that integrates a robotic plate handling platform, HPLC or UPLC system, mass spectrometer and an automated fraction collector. PMID:22723932

  2. A unique automation platform for measuring low level radioactivity in metabolite identification studies.

    Science.gov (United States)

    Krauser, Joel; Walles, Markus; Wolf, Thierry; Graf, Daniel; Swart, Piet

    2012-01-01

    Generation and interpretation of biotransformation data on drugs, i.e. identification of physiologically relevant metabolites, defining metabolic pathways and elucidation of metabolite structures, have become increasingly important to the drug development process. Profiling using (14)C or (3)H radiolabel is defined as the chromatographic separation and quantification of drug-related material in a given biological sample derived from an in vitro, preclinical in vivo or clinical study. Metabolite profiling is a very time intensive activity, particularly for preclinical in vivo or clinical studies which have defined limitations on radiation burden and exposure levels. A clear gap exists for certain studies which do not require specialized high volume automation technologies, yet these studies would still clearly benefit from automation. Use of radiolabeled compounds in preclinical and clinical ADME studies, specifically for metabolite profiling and identification are a very good example. The current lack of automation for measuring low level radioactivity in metabolite profiling requires substantial capacity, personal attention and resources from laboratory scientists. To help address these challenges and improve efficiency, we have innovated, developed and implemented a novel and flexible automation platform that integrates a robotic plate handling platform, HPLC or UPLC system, mass spectrometer and an automated fraction collector.

  3. Study on assessment safety of geological disposal of high level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Department of Environmental Safety Research of Japan Atomic Energy Research Institute has conducted the study on safety of geological disposal of high level radioactive waste. The long-term safety of the geological disposal is proposed to be secured by the multi barrier system which consists of engineered and natural barriers. Thus, in order to clarify the performance of the engineered barrier, we have studied on the long-term behaviors of waste forms, canister, overpack, back fill materials. We have developed a new waste form, i.e. ceramic waste form. And in order to clarify the performance of the natural barrier, we have studied on the hydrology, rock properties, geochemistry of actinides, sorption and fixation of radionuclides on and to rocks and/or minerals, alteration of minerals, dispersion behavior of radionuclides. Natural analogue studies and in-situ experiments have also been conducted. According to the methodology for the assessment established, the assessment model has been developed. (J.P.N.).

  4. Studies of High-T$_{c}$ Superconductors Doped with Radioactive Isotopes

    CERN Multimedia

    Alves, E J; Goncalves marques, J; Cardoso, S; Lourenco, A A; Sousa, J B

    2002-01-01

    %title\\\\ \\\\We propose to study High T$_{c} $ Superconductors~(HTSc) doped with radioactive elements at ISOLDE, in order to investigate some of the problems that persist after use of conventional characterization techniques. Three main topics are proposed: \\begin{enumerate} \\item Characterization of the order/disorder of Hg in the Hg-planes of the HTSc family Hg$_{1}$Ba$_{2}$R$_{(n-1)}$Cu$_{n}$O$_{(2n+2+\\delta)}$ (T$_{c}$ > 130 K) due to defects or impurities such as C and Au. \\item Studies of the doping of Infinite Layers Cuprates (RCuO$_{2}$)$_{n}$, R=Ca, Sr or Ba, using unstable nuclei of the alkaline-earth (IIA) group which decay to the alkaline nuclei (IA) group. The purpose is to introduce charge carriers in these materials by changing the valence of the cations during the nuclear transmutation. The possibility of using ion implantation to introduce directly an alkaline dopant will also be studied. \\item Studies of the Hg/Au doping of high quality YBa$_{2}$Cu$_{3}$O$_{6+x}$ thin films. We intend to chara...

  5. Studies on biosorption of Cr(VI) on a green resin: dry cow dung powder and tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Barot, N.S.; Bagla, H.K. [Kishinchand Chellaram College, Mumbai (India). Nuclear and Radiochemistry Dept.

    2012-07-01

    The present investigation entails the application of dry cow dung powder (DCP) as an indigenous, inexpensive and eco-friendly material for the removal of Cr(VI) from aqueous medium. Batch biosorption experiments were conducted employing {sup 51}Cr(VI) as a tracer and the effect of various process parameters such as optimum pH, temperature, amount of resin, time of equilibration, agitation speed, concentration of metal ions and interfering effect of different salts etc. were studied. The kinetic studies were carried out employing various models but the best fitting was given by Lagergren Pseudo-second order model with high correlation coefficient R{sup 2} value of 0.997 and adsorption capacity of 10.20 mg/g. The thermodynamic parameters for biosorption were evaluated as {Delta}G = -2.837 kJ/mol, {Delta}H = -4.757 kJ/mol and {Delta}S = 16.64 J/mol K, which indicated spontaneous and exothermic process with high affinity of DCP for Cr(VI). Many naturally available materials are used for the biosorption of heavy metal pollutants, where most of them are physically or chemically modified. In this research work, DCP has been utilized without any pre or post chemical treatment. Thus it manifests the principle of green chemistry and proves to be an eco-friendly resin. (orig.)

  6. Open and Distance Education Systems: do they enhance Graduates' Soft Skills? The results from 2009 Universitas Terbuka Tracer Study

    Directory of Open Access Journals (Sweden)

    Dewi Juliah Ratnaningsih

    2013-11-01

    Full Text Available The vision and mission of Universitas Terbuka (UT is to become a highly qualified open and distance education institution and to provide higher education access to all communities. Graduates of UT are expected to acquire adequate knowledge, hard skills and soft skills. Soft skills play important roles in the world of work. The aim of this article is to describe: (1 whether the open and distance education systems are capable of providing graduates with soft skills, (2 how soft skills are acquired during the period of study, and (3 how are the range of soft skills acquired by graduates and required by stakeholders at work. This article uses 2009 UT tracer study, which employed survey and in-depth interviews to selected respondents and stakeholders. 2.417 pairs data (graduates and stakeholders were analysed. The rating scales were from 1 (very poor to 4 (excellent. The attributes analysed were personal, interpersonal and situational skills. The results show that learning systems that are based on individual learning and tutorial did provide graduates with soft skills. Graduates and stakeholders perceived interpersonal skills as fair. In general, soft skills required at work were time management, self-confidence, problem solving, creativity and team-work.

  7. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    Energy Technology Data Exchange (ETDEWEB)

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-05-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references.

  8. Extended application of radon as a natural tracer in oil reservoirs

    Directory of Open Access Journals (Sweden)

    Moreira R.M.

    2013-05-01

    Full Text Available In the 80's it was a common practice in the study of contamination by NAPL to incorporate a tracer to the medium to be studied. At that time the first applications focused on the use of 222Rn, a naturally occurring radioactive isotope as a natural tracer, appropriate for thermodynamics studies, geology and transport properties in thermal reservoirs. In 1993 the deficit of radon was used to spot and quantify the contamination by DNAPL under the surface. For the first time these studies showed that radon could be used as a partitioning tracer. A methodology that provides alternatives to quantify the oil volume stored in the porous space of oil reservoirs is under development at CDTN. The methodology here applied, widens up and adapts the knowledge acquired from the use of radon as a tracer to the studies aimed at assessing SOR. It is a postulation of this work that once the radon partition coefficient between oil and water is known, SOR will be determined considering the increased amount of radon in the water phase as compared to the amount initially existent as the reservoir is flooded with water. This paper will present a description of the apparatus used and some preliminary results of the experiments.

  9. Geomechanical Studies on Granite Intrusions in Alxa Area for High-Level Radioactive Waste Disposal

    Directory of Open Access Journals (Sweden)

    Cheng Cheng

    2016-12-01

    Full Text Available Geological storage is an important concept for high-level radioactive waste (HLW disposal, and detailed studies are required to protect the environment from contamination by radionuclides. This paper presents a series of geomechanical studies on the site selection for HLW disposal in the Alxa area of China. Surface investigation in the field and RQD analyses on the drill cores are carried out to evaluate the rock mass quality. Laboratory uniaxial and triaxial compressive tests on the samples prepared from the drill cores are conducted to estimate the strength properties of the host rock. It is found that the NRG sub-area has massive granite intrusions, and NRG01 cored granite samples show the best rock quality and higher peak strength under various confinements (0–30 MPa. NRG01 granite samples are applied for more detailed laboratory studies considering the effects of strain rate and temperature. It is observed that the increasing strain rate from 1.0 × 10−5–0.6 × 10−2·s−1 can lead to a limited increase on peak strength, but a much more violent failure under uniaxial compressive tests on the NRG01 granite samples, and the temperature increasing from 20 °C–200 °C may result in a slight increase of UCS, as well as more ductile post-peak behavior in the triaxial compressive tests.

  10. Immunologic studies in two patients with persistent lymphocytic thyroiditis, thyrotoxicosis, and low radioactive iodine uptake

    Energy Technology Data Exchange (ETDEWEB)

    Elliot, I.; Gupta, M.; Hostetter, A.; Sheeler, L.; Skillern, P.; Tubbs, R.

    1984-08-01

    Two patients with persistent lymphocytic thyroiditis and thyrotoxicosis were studied. Both patients presented with severe hyperthyroidism of nine months' duration and had nontender, small thyroid glands. Uptake of radioactive iodine (131I) was consistently low. Serum thyroxine and triiodothyronine levels remained elevated without remission until thyroidectomy. The serum thyroglobulin level was normal, but testing for microsomal antibody gave weakly positive results in one case. Thyroglobulin and thyroid stimulatory antibodies were not found. The ratio of helper to suppressor T cells was elevated in one case. Neither patient showed response to propranolol, prednisone, or iodine. Light microscopic and immunohistologic studies showed severe lymphocytic thyroiditis with formation of secondary lymphoid follicles. Lymphocytes were predominately T cells (OKT11-positive), primarily helper/inducer T cells (OKT4-positive). Hyperplastic nodules contained high immunoreactive thyroglobulin and thyroxine levels. Aberrant thymus was seen within the thyroid. These studies suggest the possibility of intrathyroidal stimulation and hydrolysis of thyroglobulin within thyroid cells and also support the hypothesis that T and B cell immunoregulatory defects are important in the pathogenesis of this disease.

  11. Challenges in proton radioactivity studies - new emitters in the rare earth region.

    Science.gov (United States)

    Grzywacz, Robert

    2004-10-01

    Proton emitter studies offer a sensitive probe of the wave function composition for nuclei beyond the proton drip-line. In particular, the experiments on proton radioactivities in the rare earth region are allowing us to study the evolution of proton-emitting states as a function of changing deformation, from nearly spherical (e.g.^150Lu [1] or ^145Tm [2]) to strongly deformed (e.g. ^131Eu [3], ^135Tb [4] or ^141Ho [5]) shapes. The link between the measured observables (decay lifetimes and energies) and structure of the nuclei is provided by recently developed theories, which are able to model the proton tunneling process through the three dimensional potential barrier, see refs [6-8]. Very high detection efficiency and high sensitivity enable experiments at extremely low production cross sections, e.g. at the nanobarn level for the observation of ^135Tb in a (p6n) fusion-evaporation reaction channel [4]. Recent discoveries of proton radioactive nuclei will be reported. The experimental challenges will be illustrated with the example of the identification of new odd-odd emitter ^144Tm at the Recoil Mass Spectrometer [9] of Oak Ridge National Laboratory. The ^144Tm events were found in a weak ( 10 nb) p5n channel of the fusion reaction of ^58Ni beam at 340 MeV on a ^92Mo target. The observed decay energy of about 1.8 MeV and the half-life of the order of 1 μs suggest proton emission from the πh_11/2 orbital dominating the π-ν wave function. The detection of this very short proton emitter was made possible by use of a double-sided silicon strip detector connected to a fast data acquisition system [10] based on Digital Signal Processing. [1] P.G. Sellin et al., Phys. Rev. C47, 1933 (1993). [2] M. Karny et al., Phys. Rev. Lett. 90 , 012502 (2003). [3] A.A. Sonzogni et al., Phys. Rev. Lett. 83 , 1116 (1999). [4] P.J. Woods et al., Phys. Rev. C69 , 051302(R) (2004). [5] K. Rykaczewski, K. P. et al., in Proc. of Int. Conf. on Nuclear Structure ``Mapping the Triangle

  12. Source apportionment of atmospheric water over East Asia - a source tracer study in CAM5.1

    Science.gov (United States)

    Pan, Chen; Zhu, Bin; Gao, Jinhui; Kang, Hanqing

    2017-02-01

    The atmospheric water tracer (AWT) method is implemented in the Community Atmosphere Model version 5.1 (CAM5.1) to quantitatively identify the contributions of various source regions to precipitation and water vapour over East Asia. Compared to other source apportionment methods, the AWT method was developed based on detailed physical parameterisations, and can therefore trace the behaviour of atmospheric water substances directly and exactly. According to the simulation, the northern Indian Ocean (NIO) is the dominant oceanic moisture source region for precipitation over the Yangtze River valley (YRV) and southern China (SCN) in summer, while the north-western Pacific (NWP) dominates during other seasons. Evaporation over the South China Sea (SCS) is responsible for only 2.7-3.7 % of summer precipitation over the YRV and SCN. In addition, the Indo-China Peninsula is an important terrestrial moisture source region (annual contribution of ˜ 10 %). The overall relative contribution of each source region to the water vapour amount is similar to the corresponding contribution to precipitation over the YRV and SCN. A case study for the SCS shows that only a small part ( ≤ 5.5 %) of water vapour originates from local evaporation, whereas much more water vapour is supplied by the NWP and NIO. In addition, because evaporation from the SCS represents only a small contribution to the water vapour over the YRV and SCN in summer, the SCS mainly acts as a water vapour transport pathway where moisture from the NIO and NWP meet.

  13. Study of chemical additives in the cementation of radioactive waste of PWR reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Vanessa Mota; Tello, Cledola Cassia Oliveira de, E-mail: tellocc@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Cementation is a very useful process to solidify radioactive wastes. Depending on the waste it can be necessary to use of chemical additives (admixtures) to improve the cementation process and its product. Admixtures are materials, other than cement, aggregate and water, that are added either before or during the mixing to alter some properties, such as workability, curing temperature range, and setting time. However there are a large variety of these materials that are frequently changed or taken out of the market. In this changeable scenario it is essential to know the commercially available materials and their characteristics. In this research the effects of chemical admixtures in the solidification process has been studied. For the tests it was prepared a solution simulating the evaporator concentrate waste, cemented by two different formulations, and three chemical admixtures from two manufacturers. The tested admixtures were accelerators, set retarders and super plasticizers. The experiments were organized by a planning factorial 23 to quantify the effects of formulations, of the admixtures, its quantity and manufacturer in properties of the paste and products. The measured parameters were the density, the viscosity and the setting time of the paste, and the product compressive strength. The parameter evaluated in this study was the compressive strength at age of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products. (author)

  14. Photoluminescence studies of ZnO doped with stable and radioactive impurities

    CERN Document Server

    Cullen, Joseph; Martin O, Henry

    In this work the IIb-VI compound semiconductor ZnO is doped, via ion implantation of stable and radioactive isotopes, in order to investigate the chemical nature of exciton re-combinations bound to previously unidentified defects. Photo-luminescence (PL) is discussed and is used extensively as the primary investigative technique. A new defect emission feature, centred around 3.324 eV, is found to be related to Ge impurities occupying substitutional Zn sites in ZnO. This centre is investigated by temperature dependent PL, piezo-spectroscopy and Zeeman spectroscopy. The centre is donor-like in nature. Uniaxial stress measurements indicate that the defect centre has trigonal symmetry and applied magnetic field measurements reveal the neutral charge state of the centre and the donor-like binding mechanism. Subsequent to this, a study is undertaken of the iso-electronic defect Hg in ZnO studying the zero phonon feature at 3.279 eV and its associated phonon replica band. Temperature dependent measurements reveal tw...

  15. Study of chemical additives in the cementation of radioactive waste of PWR reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Vanessa Mota; Tello, Cledola Cassia Oliveira de, E-mail: vanessamotavieira@gmail.com, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2012-03-15

    In this research it has been studied the effects of chemical admixtures in the cementation process of radioactive wastes. These additives are used to improve the properties of waste cementation process, both of the paste and of the solidified product. However there are a large variety of these materials that are frequently changed or taken out of the market. Then it is essential to know the commercially available materials and their effects. The tests were carried out with a solution simulating the evaporator concentrate waste coming from PWR nuclear reactors. It was cemented using two formulations, A and B, incorporating higher or lower amount of waste, respectively. It was added chemical admixtures from two manufacturers (S and H), which were: accelerators, set retarders and superplasticizers. The experiments were organized by a factorial design 23. The measured parameters were: the viscosity, the setting time, the paste and product density and the compressive strength. The parameter evaluated in this study was the compressive strength at age of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products. (author)

  16. Hydrogeochemical and spectroscopic studies of radioactive materials in Ayrakan and Cheshmeh Shotori areas, northeastern Isfahan province

    Directory of Open Access Journals (Sweden)

    Mostafa Esmaeili Vardanjani

    2011-11-01

    Full Text Available Groundwaters hydrochemistry of Ayrakan and Cheshmeh Shotori areas and geochemistry of rare earth elements, indicate Ayrakan alkali granite as the origin of uranium and other dissolved elements in groundwaters of these areas. Geochemical and hydrogeochemical studies as well as the trend of uranium and thorium transition and mobility in aqueous environments of these areas indicate uranium adsorption by iron hydroxide (goethite as the deterrent agent against uranium transition and mobility from depth to surface. Gamma-ray spectroscopic study of sediments from Cheshmeh Shotori area by HPGe detector indicates the presence of 226Ra in high contents and as the radioactive nuclide that is the reason for high activity of these sediments. Production of 226Ra from 238U decay, shorter half-life of 226Ra compared to 238U, radium transition by groundwaters from depth to surface as well as hydrogeochemical evidences, all suggest the possibility of existence of hidden uranium deposit and uranium mineralization in depth and the distance between Ayrakan and Cheshmeh Shotori areas.

  17. Study of large eddy simulation of the effects of boundary layer convection on tracer uplift and transport

    Science.gov (United States)

    Huang, Qian; Wang, Rong

    2016-04-01

    Using large eddy model (LEM) and observed data from Dunhuang meteorological station during the intensive period of land-atmosphere interaction field experiment over arid region of North-west China, a series of sensitivity experiments have been performed to investigate the effects of the surface heat flux and wind shear on the strength and the organization of boundary layer convection as well as the growth of the convective boundary layer (CBL). The results show that surface heat flux increases with constant wind shear will give rise to a thicker and warmer CBL, stronger convections and larger thermal eddies due to intense surface turbulence transporting more energy to the upper layer. On the other hand wind shear increases with constant surface heat flux lead to a thicker and warmer CBL because of the entrainment of warm air from the inversion layer to the mixed layer, while the boundary layer convection became weaker with broken thermal eddies. To investigate the quantitative linkage of surface heat flux, wind shear with the tracer uplift rate and transport height, a passive tracer with a constant value of 100 was added at all model levels below the 100 m in all simulations. The least square analysis reveals that the tracer uplift rate increases linearly with the surface heat flux when wind shear is less than 10.5×10-3 s-1 owing to the enhancement of the downward transport of higher momentum. However, the tracer uplift rate decreases with increasing wind shear when the surface heat flux is less than 462.5 W/m2 because of the weakened convection. The passive tracer in the model is also shown to be transported to the higher altitude with increasing surface heat flux and under constant wind shear. However, under a constant surface heat flux, the tracer transport height increases with increasing wind shear only when the shear is above a certain threshold and this threshold depend on the magnitude of surface heat fluxes.

  18. Uranium-series radionuclides as tracers of geochemical processes in Long Island Sound. [Natural /sup 210/Pb tracer study of estuarine geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Benninger, L.K.

    1976-05-01

    An estuary can be visualized as a membrane between land and the deep ocean, and the understanding of the estuarine processes which determine the permeability of this membrane to terrigenous materials is necessary for the estimation of fluxes of these materials to the oceans. Natural radionuclides are useful probes into estuarine geochemistry because of the time-dependent relationships among them and because, as analogs of stable elements, they are much less subject to contamination during sampling and analysis. In this study the flux of heavy metals through Long Island Sound is considered in light of the material balance for excess /sup 210/Pb, and analyses of concurrent seston and water samples from central Long Island Sound are used to probe the internal workings of the estuary.

  19. Radiological safety studies on ground disposal of low-level radioactive wastes. Environmental simulation test

    Energy Technology Data Exchange (ETDEWEB)

    Wadachi, Yoshiki; Yamamoto, Tadatoshi; Takebe, Shinichi; Ohnuki, Toshihiko; Washio, Masakazu (Japan Atomic Energy Research Inst., Tokai, Ibaraki. Tokai Research Establishment)

    1982-03-01

    As the method of disposing low level radioactive wastes on land, the underground disposal method disposing the wastes in the structures constructed underground near the ground surface has been investigated as a feasible method. In order to contribute to the environmental safety assessment for this underground disposal method, environmental simulation test is planned at present, in which earth is sampled in the undisturbed state, and the behavior of radioactive nuclides is examined. The testing facilities are to be constructed in Japan Atomic Energy Research Institute from fiscal 1981. First, the research made so far concerning the movement of radioactive nuclides in airing layer and aquifer which compose natural barrier is outlined. As for the environmental simulation test, the necessity and method of the test, earth sampling, the underground simulation facility and the contribution to environmental safety assessment are explained. By examining the movement of radioactive nuclides through natural barrier and making the effective mddel for the underground movement of radioactive nuclides, the environmental safety assessment for the disposal can be performed to obtain the national consensus.

  20. Development of an activatable nanospheres tracer for use in industry and the environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Raquel Luiza M.; Moreira, Rubens M., E-mail: rlmf@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (SEMAM/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Departamento de Servico ao Meio Ambiente; Moura, Igor Felipe S., E-mail: igorfelipedx@yahoo.com.br [Universidade Federal de Minas Gerais (DEN/PCTN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2015-07-01

    Nanoparticles (NP's) can act as tracers for the study of several transport phenomena in industrial practice and environmental processes provided their physical and chemical properties meet specific requirements dictated by the application. Silica-coated gold nanoparticles in the size interval from 20 to 200 nm can be produced by gamma-ray irradiation. Submitted to neutron bombardment in a nuclear reactor, they will convert gold nuclides into {sup 198}Au (E{sub γ} = 412 keV). These NP's can used as a tracer in oil fields, in petrochemical and refinery industrial processes in which conventional organic radioactive labeled compounds would not withstand, as well as in some hydrology and hydrogeology studies. (author)

  1. NOAA EPA Near-Roadway Sound Barrier Atmospheric Tracer Study 2008

    Science.gov (United States)

    A roadway toxics dispersion study was conducted at the Idaho National Laboratory to document the effects on concentrations of roadway emissions behind a roadside sound barrier in various conditions of atmospheric stability. The key finding was that reduced concentrations were me...

  2. Study on the Metal Fiber Filter Modeling for Capturing Radioactive Aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seunguk; Lee, Chanhyun; Park, Minchan; Lee, Jaekeun [EcoEnergy Research Institute, Busan (Korea, Republic of)

    2015-05-15

    The components of air cleaning system are demisters to remove entrained moisture, pre-filters to remove the bulk of the particulate matter, high efficiency particulate air (HEPA) filters, iodine absorbers(generally, activated carbon) and HEPA filters after the absorbers for redundancy and collection of carbon fines. The HEPA filters are most important components to prevent radioactive aerosols from being released to control room and adjacent environment. The Conventional HEPA filter has pleated media for low pressure drop. Consequently, the filters must provide high collection efficiency as well as low pressure drop. Unfortunately, conventional HEPA filters are made of glass fiber and polyester, and pose disposal issues since they cannot be recycled. In fact, 31,055 HEPA filters used in nuclear facilities in the U.S are annually disposed. The Analyses at face velocities 1cm/s and 10cm/s are also carried out, and they also show R2 value of 0.995. However, since official HEPA filter standards are established at face velocity of 5cm/s, this value will be used in further analysis. From the comparative studies carried out at different filter thickness and face velocities, a good correlation is found between the model and the experiment.

  3. Numerical Studies of Radioactive Sediment Deposition on Reservoirs in Fukushima Coastal Area

    Science.gov (United States)

    Yamada, Susumu; Itakura, Mitsuhiro; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro

    2014-05-01

    The transportation of radioactive Cs is mainly brought about by movement of silt- and clay-sized particles in rivers. Therefore, predicting such a fine sediment flow and deposition in rivers has been one of central issues toward environmental recovery after the Fukushima Dai-ichi nuclear power plant (FDNPP) accident. For the purpose of the Cs transport prediction, we concentrate on a few reservoirs in Fukushima costal area, since they are temporal destinations for contaminated silt and clay transported by rivers. We numerically study how the river water together with floating silt and clays penetrate into the reservoirs and where the sediments settle on the bottom surface of the reservoirs by using 2D river simulation framework named iRIC developed by Shimizu et al. In this presentation, we reveal the typical deposition pattern in the target reservoirs and compare the results with direct sampling data for the sediments on the reservoir bottom surfaces. We believe that the obtained information is useful in planning the water supply and treatment for highly-contaminated districts in Fukushima costal area.

  4. Studies of nuclei using radioactive beams. [Space Astronomy Lab. , Univ. of Florida, Gainesville, Florida

    Energy Technology Data Exchange (ETDEWEB)

    Piercey, R.B.

    1989-07-01

    The 12 month period from May 1988 to July 1989 represents the first full year of our 18 month pilot program in nuclear structure research. In this period, research was initiated to develop a capability for radioactive secondary beams at Argonne National Laboratory using the Atlas and the new Fragment Mass Analyzer (FMA), which is currently under construction. Two major new detector facilities are currently in the final stages of design and testing. The Large-Area, Scintillator Telescope (LAST) detector is fully operational and will be shipped to Argonne National Laboratory in August for fit-tests and in-beam calibrations. The first segments of a new sixteen-segment neutron multiplicity detector have been built and tested. The remaining segments are currently being constructed. Research was continued in the areas of (1) Coulomb excitation studies of rare earth and actinide nuclei; (2) In-beam, gamma-ray spectroscopy of nuclei in the mass 100 region, and (3) Advanced detector design. Several journal articles and abstracts were published or submitted for publication in the reporting period, and others are currently in preparation. Three graduate students participated in the program, one from the University of Florida and two from the Royal Institute of Technology, Stockholm, Sweden.

  5. Studies of nuclei using radioactive beams. Progress report, May 1988--July 1989

    Energy Technology Data Exchange (ETDEWEB)

    Piercey, R.B.

    1989-07-01

    The 12 month period from May 1988 to July 1989 represents the first full year of our 18 month pilot program in nuclear structure research. In this period, research was initiated to develop a capability for radioactive secondary beams at Argonne National Laboratory using the Atlas and the new Fragment Mass Analyzer (FMA), which is currently under construction. Two major new detector facilities are currently in the final stages of design and testing. The Large-Area, Scintillator Telescope (LAST) detector is fully operational and will be shipped to Argonne National Laboratory in August for fit-tests and in-beam calibrations. The first segments of a new sixteen-segment neutron multiplicity detector have been built and tested. The remaining segments are currently being constructed. Research was continued in the areas of (1) Coulomb excitation studies of rare earth and actinide nuclei; (2) In-beam, gamma-ray spectroscopy of nuclei in the mass 100 region, and (3) Advanced detector design. Several journal articles and abstracts were published or submitted for publication in the reporting period, and others are currently in preparation. Three graduate students participated in the program, one from the University of Florida and two from the Royal Institute of Technology, Stockholm, Sweden.

  6. Engineering study of 50 miscellaneous inactive underground radioactive waste tanks located at the Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Freeman-Pollard, J.R.

    1994-03-02

    This engineering study addresses 50 inactive underground radioactive waste tanks. The tanks were formerly used for the following functions associated with plutonium and uranium separations and waste management activities in the 200 East and 200 West Areas of the Hanford Site: settling solids prior to disposal of supernatant in cribs and a reverse well; neutralizing acidic process wastes prior to crib disposal; receipt and processing of single-shell tank (SST) waste for uranium recovery operations; catch tanks to collect water that intruded into diversion boxes and transfer pipeline encasements and any leakage that occurred during waste transfer operations; and waste handling and process experimentation. Most of these tanks have not been in use for many years. Several projects have, been planned and implemented since the 1970`s and through 1985 to remove waste and interim isolate or interim stabilize many of the tanks. Some tanks have been filled with grout within the past several years. Responsibility for final closure and/or remediation of these tanks is currently assigned to several programs including Tank Waste Remediation Systems (TWRS), Environmental Restoration and Remedial Action (ERRA), and Decommissioning and Resource Conservation and Recovery Act (RCRA) Closure (D&RCP). Some are under facility landlord responsibility for maintenance and surveillance (i.e. Plutonium Uranium Extraction [PUREX]). However, most of the tanks are not currently included in any active monitoring or surveillance program.

  7. Pilot studies to achieve waste minimization and enhance radioactive liquid waste treatment at the Los Alamos National Laboratory Radioactive Liquid Waste Treatment Facility

    Energy Technology Data Exchange (ETDEWEB)

    Freer, J.; Freer, E.; Bond, A. [and others

    1996-07-01

    The Radioactive and Industrial Wastewater Science Group manages and operates the Radioactive Liquid Waste Treatment Facility (RLWTF) at the Los Alamos National Laboratory (LANL). The RLWTF treats low-level radioactive liquid waste generated by research and analytical facilities at approximately 35 technical areas throughout the 43-square-mile site. The RLWTF treats an average of 5.8 million gallons (21.8-million liters) of liquid waste annually. Clarifloculation and filtration is the primary treatment technology used by the RLWTF. This technology has been used since the RLWTF became operable in 1963. Last year the RLWTF achieved an average of 99.7% removal of gross alpha activity in the waste stream. The treatment process requires the addition of chemicals for the flocculation and subsequent precipitation of radionuclides. The resultant sludge generated during this process is solidified in drums and stored or disposed of at LANL.

  8. Practical uses of a quantitative renal scintillation camera study. [/sup 131/I tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bueschen, A.J.; Lloyd, L.K.

    1976-10-01

    A quantitative renal scintillation camera study has been described for the evaluation of total renal function and the split function of the two kidneys by a noninvasive technic. It requires no patient preparation, is not affected by bowel gas, and no allergic reactions have been reported. Six cases are reported to illustrate its usefulness with renal tumors, neurogenic bladders, pyelonephritis, nephrolithiasis, congenital anomalies, and renal insufficiency.

  9. Using natural isotopes as tracers of Saharan dust dispersion: a case study in the Azores - Portugal

    Directory of Open Access Journals (Sweden)

    Charles Holmes

    2005-06-01

    Full Text Available After mineral aerosol transport from Sahara Desert, through the North Atlantic, analysis on beryllium 7 and lead 210 were carried out on Azorean aerosol samples. Knowing about the isotope activity of beryllium 7 and lead 210 on aerosol, will permit to study stratospheric intrusions and others physical characteristics of the North Atlantic atmospheric transport. Based on beryllium 7/lead 210 ratios it is possible to differentiate insular and marine aerosol from continental aerosol.

  10. Radioassay of granulocyte chemotaxis. Studies of human granulocytes and chemotactic factors. [/sup 51/Cr tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Gallin, J.I.

    1974-01-01

    The above studies demonstrate that the /sup 51/Cr radiolabel chemotactic assay is a relatively simple and objective means for studying leukocyte chemotaxis in both normal and pathological conditions. Application of this method to studies of normal human chemotaxis revealed a relatively narrow range of normal and little day-to-day variability. Analysis of this variability revealed that there is more variability among the response of different granulocytes to a constant chemotactic stimulus than among the chemotactic activity of different sera to a single cell source. Utilizing the /sup 51/Cr radioassay, the abnormal granulocyte chemotactic behavior reported in Chediak-Higashi syndrome and a patient with recurrent pyogenic infections and mucocutaneous candidiasis has been confirmed. The /sup 51/Cr chemotactic assay has also been used to assess the generation of chemotactic activity from human serum and plasma. The in vitro generation of two distinct chemotactic factors were examined; the complement product (C5a) and kallikrein, an enzyme of the kinin-generating pathway. Kinetic analysis of complement-related chemotactic factor formation, utilizing immune complexes or endotoxin to activate normal sera in the presence or absence of EGTA as well as kinetic analysis of activation of C2-deficient human serum, provided an easy means of distinguishing the classical (antibody-mediated) complement pathway from the alternate pathway. Such kinetic analysis is necessary to detect clinically important abnormalities since, after 60 min of generation time, normal chemotactic activity may be present despite complete absence or inhibition of one complement pathway. The chemotactic factor generated by either pathway of complement activation appears to be predominately attributable to C5a.

  11. Dorsal and median Raphe nuclei projection to MD of Thalamus in rat: A retrograde tracer study

    Directory of Open Access Journals (Sweden)

    Pas Bakhsh P

    2000-06-01

    Full Text Available In order to understand the function of mammalians serotonin system, we have to know the anatomical structure, because physiological changes are influenced through the anatomical changes. A number of thalamic nuclei are associated with functions known to be influenced by serotonergic input in brainstem, among them mediodorsal thalamic nucleus has relationship with limbic system and prefrontal cortex. The precise topographical projections of mesencephalic raphe nuclei to the MD nucleus of thalamus were identified in the rat using horseradish peroxidase (HRP retrograde tracing substance. Injection of HRP in MD labeled a large number of neurons in rostral to caudal part of dorsal raphe nucleus. It exhibited a strong number of neurons in ipsilateral part of DR and a few cells in its contralateral part. Numerously labeled cells were also observed ipsilateral in rostral and medial part of MnR (86% and a few cells in it's contralateral part. The present study has provided that the MD innervation by DR is more greater in density than that observed at the MnR. Upon these results and previous study, mesencephalic raphe nuclei are involved in several specific functions of thalamus as limbic system behavioral mechanism. A much more detailed knowledge is needed to show topographic relationships between mesencephalic raphe nuclei and forebrain.

  12. Kinetic and Related Determinants of Plasma Triglyceride Concentration in Abdominal Obesity: Multicenter Tracer Kinetic Study.

    Science.gov (United States)

    Borén, Jan; Watts, Gerald F; Adiels, Martin; Söderlund, Sanni; Chan, Dick C; Hakkarainen, Antti; Lundbom, Nina; Matikainen, Niina; Kahri, Juhani; Vergès, Bruno; Barrett, P Hugh R; Taskinen, Marja-Riitta

    2015-10-01

    Patients with obesity and diabetes mellitus have increased risk of cardiovascular disease. A major cause is an atherogenic dyslipidemia related primarily to elevated plasma concentrations of triglyceride-rich lipoproteins. The aim of this study was to clarify determinants of plasma triglyceride concentration. We focused on factors that predict the kinetics of very-low density lipoprotein 1 (VLDL1) triglycerides. A multicenter study using dual stable isotopes (deuterated leucine and glycerol) and multicompartmental modeling was performed to elucidate the kinetics of triglycerides and apoB in VLDL1 in 46 subjects with abdominal obesity and additional cardiometabolic risk factors. Results showed that plasma triglyceride concentrations were dependent on both the secretion rate (r=0.44, Ptriglycerides and VLDL1-apoB. Liver fat mass was independently and directly associated with secretion rates of VLDL1-triglycerides (r=0.56, Ptriglycerides (r=0.48, Ptriglyceride concentrations in abdominal obesity are determined by the kinetics of VLDL1 subspecies, catabolism being mainly dependent on apoC-III concentration and secretion on liver fat content. Reduction in liver fat and targeting apoC-III may be an effective approach for correcting triglyceride metabolism atherogenic dyslipidemia in obesity. © 2015 American Heart Association, Inc.

  13. Study of chemically synthesized ZnO nano particles under a bio template using radioactive ion beam

    CERN Multimedia

    This is a project proposal to study nano sized semiconductor ZnO system, useful in biology and medicinal purposes, using radioactive ion beam from ISOLDE. Doping of the nano particles with Cu, Cd and Ga ions (in their variable valancy states) are expected to impart changes in the electrical structure and properties in the said system under study. The morphological changes, chemical environment, micro structure, electrical and optical properties of the nano size particles of ZnO system (developed under a bio template of folic acid) after the interaction with radioactive ion beam will be studied. The provision of perturbed angular correlation (PAC) study with respect to the changes in chemical environment, where ever possible will be attempted.

  14. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer

    Energy Technology Data Exchange (ETDEWEB)

    Di Tullo, Pamela, E-mail: pamela.ditullo@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Pannier, Florence, E-mail: florence.pannier@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Thiry, Yves, E-mail: yves.thiry@andra.fr [Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Le Hécho, Isabelle, E-mail: isabelle.lehecho@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Bueno, Maïté, E-mail: maite.bueno@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France)

    2016-08-15

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for {sup 77}Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas {sup 77}Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on K{sub d} distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium.

  15. Management of radioactive waste: A review

    Directory of Open Access Journals (Sweden)

    Luis Paulo Sant'ana

    2016-06-01

    Full Text Available The issue of disposal of radioactive waste around the world is not solved by now and the principal reason is the lack of an efficient technologic system. The fact that radioactive waste decays of radioactivity with time are the main reasons for setting nuclear or radioactive waste apart from the other common hazardous wastes management. Radioactive waste can be classified according to the state of matter and level of radioactivity and this classification can be differently interpreted from country to country. Furthermore, microbiological procedures, plasma vitrification process, chemical precipitation, ion exchange, evaporation and reverse osmosis are strategies used for the treatment of radioactive wastes. The major challenge is to manage these radioactive substances after being used and discharged. This report brings data from the literature published worldwide from 2009 to 2014 on radioactive waste management studies and it covers production, classification and management of radioactive solid, liquid and gas waste.

  16. Bioremediation of radioactive waste: radionuclide-microbe interactions in laboratory and field-scale studies.

    Science.gov (United States)

    Lloyd, Jonathan R; Renshaw, Joanna C

    2005-06-01

    Given the scale of the contamination associated with 60 years of global nuclear activity, and the inherent high financial and environmental costs associated with invasive physical and chemical clean-up strategies, there is an unparalleled interest in new passive in situ bioremediation processes for sites contaminated with nuclear waste. Many of these processes rely on successfully harnessing newly discovered natural biogeochemical cycles for key radionuclides and fission products. Recent advances have been made in understanding the microbial colonization of radioactive environments and the biological basis of microbial transformations of radioactive waste in these settings.

  17. pH dependence and unsuitability of fluorescein dye as a tracer for pesticide mobility studies in acid soil

    Science.gov (United States)

    Chris Peterson

    2009-01-01

    The mobility of fluorescein and bromide used as tracers in packed soil columns was investigated.Five different soils were used in two application methods: soil surface application and soil incorporation, both of which simulate accepted methods of soil application of termiticides to prevent structural infestation. The...

  18. Far-infrared study of tracers of oxygen chemistry in diffuse clouds

    CERN Document Server

    Wiesemeyer, H; Heyminck, S; Hübers, H W; Menten, K M; Neufeld, D A; Richter, H; Simon, R; Stutzki, J; Winkel, B; Wyrowski, F

    2016-01-01

    Context. The chemistry of the diffuse interstellar medium rests upon three pillars: exothermic ion-neutral reactions (" cold chemistry "), endothermic neutral-neutral reactions with significant activation barriers (" warm chemistry "), and reactions on the surfaces of dust grains. While warm chemistry becomes important in the shocks associated with turbulent dissipation regions, the main path for the formation of interstellar OH and H2O is that of cold chemistry. Aims. The aim of this study is to observationally confirm the association of atomic oxygen with both atomic and molecular gas phases, and to understand the measured abundances of OH and OH + as a function of the available reservoir of H2. Methods. We obtained absorption spectra of the ground states of OH, OH+ and OI with high-velocity resolution, with GREAT on-board SOFIA, and with the THz receiver at the APEX. We analyzed them along with ancillary spectra of HF and CH from HIFI. To deconvolve them from the hyperfine structure and to separate the ble...

  19. Radioiodinated ganglioside G/sub M1/: A potential tracer for neurological studies

    Energy Technology Data Exchange (ETDEWEB)

    Zalutsky, M.R.; Gallagher, P.; Magistretti, P.L.; Ghidoni, R.

    1985-05-01

    Ganglioside G/sub M1/ is a glycosphingolipid which appears to be involved in the regeneration of damaged neuronal tissue. In addition, it is being investigated clinically in the treatment of various neuropathies. If labeled with the appropriate isotope, G/sub M1/ might be useful as a probe of these processes, particularly if it accumulates preferentially in cerebral infarcts. The G/sub M1/ -tyr derivative was labeled with I-125 in 75% yield using the Iodogen method and at micellar concentration was isolated using gel chromatography. Binding of I-125 (G/sub M1/ -tyr) to rat neuronal membranes was measured at concentrations of 5,50, and 500 nM. The amount bound (8,26, and 158 pmol/gm membrane) was similar to that reported for H-3(G/sub M1/). The biodistribution of I-125(G/sub M1/ -tyr) in mice at both micellar and monomeric concentrations was also similar to that of H-3(G/sub M1/). However, at monomeric concentrations, thyroid uptake of I-125 was about 10 times higher than at micellar concentrations, suggesting differential dehalogenation of the two forms. Initial studies in the gerbil stroke model suggest that the uptake of I-125(G/sub M1/ -tyr) in damaged brain is twice that in normal tissue.

  20. Feasibility study of production of radioactive carbon black or carbon nanotubes in cyclotron facilities for nanobioscience applications.

    Science.gov (United States)

    Abbas, K; Simonelli, F; Holzwarth, U; Cydzik, I; Bulgheroni, A; Gibson, N; Kozempel, J

    2013-03-01

    A feasibility study regarding the production of radioactive carbon black and nanotubes has been performed by proton beam irradiation. Experimental and theoretical excitation functions of the nuclear reaction (nat)C(p,x)(7)Be in the proton energy range 24-38 MeV are reported, with an acceptable agreement. We have demonstrated that sufficient activities of (7)Be radioisotope can be produced in carbon black and nanotube that would facilitate studies of their possible impact on human and environment.

  1. Nitrate retention and removal in Mediterranean streams with contrasting land uses: a 15N tracer study

    Directory of Open Access Journals (Sweden)

    J. L. Riera

    2008-08-01

    Full Text Available We used 15N-labelled nitrate (NO−3 additions to investigate nitrogen (N cycling at the whole-reach scale in three Mediterranean streams subjected to contrasting land uses (i.e. forested, urban and agricultural. Our aim was to examine: i the magnitude and relative importance of NO−3 retention (i.e. assimilatory uptake, and removal, (i.e. denitrification, ii the relative contribution of the different primary uptake compartments to NO−3 retention, and iii the regeneration, transformation and export pathways of the retained N. The concentration of NO−3 increased and that of dissolved oxygen (DO decreased from the forested to the agricultural stream, with intermediate values in the urban stream. Standing stocks of primary uptake compartments were similar among streams and dominated by detritus compartments (i.e. fine and coarse benthic organic matter. In agreement, metabolism was net heterotrophic in all streams, although the degree of heterotrophy increased from the forested to the agricultural stream. The NO−3 uptake length decreased along this gradient, whereas the NO−3 mass-transfer velocity and the areal NO−3 uptake rate were highest in the urban stream. Denitrification was not detectable in the forested stream, but accounted for 9% and 68% of total NO−3 uptake in the urban and the agricultural stream, respectively. The relative contribution of detritus compartments to NO−3 assimilatory uptake was highest in the forested and lowest in the agricultural stream. In all streams, the retained N was rapidly transferred to higher trophic levels and regenerated back to the water column. Due to a strong coupling between regeneration and nitrification, most retained N was exported from the experimental reaches in the form of NO−3. This study evidences fast N cycling in Mediterranean streams. Moreover, results indicate that permanent NO−3 removal via denitrification may be enhanced over temporary NO−3 retention via assimilatory

  2. Organotin persistence in contaminated marine sediments and porewaters: In situ degradation study using species-specific stable isotopic tracers

    Energy Technology Data Exchange (ETDEWEB)

    Furdek, Martina; Mikac, Nevenka [Division for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenicka 54, Zagreb (Croatia); Bueno, Maite; Tessier, Emmanuel; Cavalheiro, Joana [Laboratoire de Chimie Analytique Bio-inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l’Environnement et les Matériaux, CNRS UMR 5254, Université de Pau et des Pays de l’Adour, Hélioparc Pau Pyrénées, 2, Av. P. Angot, 64053 Pau Cedex 9 (France); Monperrus, Mathilde, E-mail: mathilde.monperrus@univ-pau.fr [Laboratoire de Chimie Analytique Bio-inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l’Environnement et les Matériaux, CNRS UMR 5254, Université de Pau et des Pays de l’Adour, Hélioparc Pau Pyrénées, 2, Av. P. Angot, 64053 Pau Cedex 9 (France)

    2016-04-15

    Highlights: • Limiting step in OTC degradation in sediments is their desorption into porewater. • TBT persistence in contaminated sediments increases in sediments rich in organic matter. • DBT does not accumulate in sediments as degradation product of TBT. • TBT and DBT degradation in porewaters occurs with half-lives from 2.9 to 9.2 days. • PhTs degradation is slower than BuTs degradation in oxic porewaters. - Abstract: This paper provides a comprehensive study of the persistence of butyltins and phenyltins in contaminated marine sediments and presents the first data on their degradation potentials in porewaters. The study’s aim was to explain the different degradation efficiencies of organotin compounds (OTC) in contaminated sediments. The transformation processes of OTC in sediments and porewaters were investigated in a field experiment using species-specific, isotopically enriched organotin tracers. Sediment characteristics (organic carbon content and grain size) were determined to elucidate their influence on the degradation processes. The results of this study strongly suggest that a limiting step in OTC degradation in marine sediments is their desorption into porewaters because their degradation in porewaters occurs notably fast with half-lives of 9.2 days for tributyltin (TBT) in oxic porewaters and 2.9 ± 0.1 and 9.1 ± 0.9 days for dibutyltin (DBT) in oxic and anoxic porewaters, respectively. By controlling the desorption process, organic matter influences the TBT degradation efficiency and consequently defines its persistence in contaminated sediments, which thus increases in sediments rich in organic matter.

  3. Determination of stream reaeration coefficients by use of tracers

    Science.gov (United States)

    Kilpatrick, F.A.; Rathbun, R.E.; Yotsukura, Nobuhiro; Parker, G.W.; DeLong, L.L.

    1989-01-01

    Stream reaeration is the physical absorption of oxygen from the atmosphere by a flowing stream. This is the primary process by which a stream replenishes the oxygen consumed in the biodegradation of organic wastes. Prior to 1965, reaeration rate coefficients could be estimated only by indirect methods. In 1965, a direct method of measuring stream reaeration coefficients was developed whereby a radioactive tracer gas was injected into a stream-the principle being that the tracer gas would be desorbed from the stream inversely to how oxygen would be absorbed. The technique has since been modified by substituting hydrocarbon gases for the radioactive tracer gas. This manual describes the slug-injection and constant-rate-injection methods of measuring gas-tracer desorption. Emphasis is on the use of rhodamine WT dye as a relatively conservative tracer and propane as the nonconservative gas tracer, on planning field tests, on methods of injection, sampling, and analysis, and on techniques for computing desorption and reaeration coefficients.

  4. Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

    Science.gov (United States)

    Fedosseev, Valentin; Chrysalidis, Katerina; Day Goodacre, Thomas; Marsh, Bruce; Rothe, Sebastian; Seiffert, Christoph; Wendt, Klaus

    2017-08-01

    At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments. This article belongs to the Focus on

  5. Tracer attenuation in groundwater

    Science.gov (United States)

    Cvetkovic, Vladimir

    2011-12-01

    The self-purifying capacity of aquifers strongly depends on the attenuation of waterborne contaminants, i.e., irreversible loss of contaminant mass on a given scale as a result of coupled transport and transformation processes. A general formulation of tracer attenuation in groundwater is presented. Basic sensitivities of attenuation to macrodispersion and retention are illustrated for a few typical retention mechanisms. Tracer recovery is suggested as an experimental proxy for attenuation. Unique experimental data of tracer recovery in crystalline rock compare favorably with the theoretical model that is based on diffusion-controlled retention. Non-Fickian hydrodynamic transport has potentially a large impact on field-scale attenuation of dissolved contaminants.

  6. Developments in radiological assessment and biosphere modelling studies to support radioactive waste disposal in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Sanchez, D. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas - CIEMAT (Spain); Thorne, M. [Mike Thorne and Associates Limited (United States)

    2014-07-01

    Long-term safety assessments for the disposal of radioactive waste in Spain involve the demonstration that annual radiation doses to humans due to potential releases of radionuclides from the waste disposal facility into the biosphere will satisfy the regulatory criteria. For several years, CIEMAT has been developing, for ENRESA, a conceptual approach and tool to support modelling of the migration and accumulation of radionuclides within environmental media once those radionuclides have been released to some component of the biosphere (atmosphere, water bodies or soils). The CIEMAT modelling approach calculates the concentrations of radionuclides in different components of the biosphere and then the calculated radionuclide concentrations are used to estimate the radiation doses to humans due to various exposure paths. In this paper, we not only describe the methodology and modelling approach, we also describe recent developments of that approach to better quantify the resultant doses to humans. First, we present recent developments in the mathematical model for the behaviour of {sup 79}Se and {sup 238}U-series radionuclides in soils and their uptake by plants, taking into account seasonal variations in soil hydrology in Spain. Initial studies with the model that are reported here demonstrate that it is a powerful tool for exploring the behaviour of redox-sensitive radionuclides and {sup 238}U decay chain members in soil-plant systems under different hydrological regimes. In particular, it permits studies of the degree to which secular equilibrium assumptions are appropriate when modelling the {sup 238}U decay chain. Further studies are currently being undertaken examining sensitivities of model results to input parameter values and also applying the model to sites contaminated with {sup 238}U-series radionuclides. It is anticipated that results from these studies will also be reported. A particular interest in biosphere safety assessment is how environmental

  7. Preparation of Plant 41Ca Tracer Samples for Accelerator Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    ZHAO Qing-zhang1;JANG Ping-ping3;LIN De-yu4;YANG Xian-lin1;DOU Liang1;PANG Yi-jun1;WANG Xiao-ming1;ZHANG Hui1,5;YANG Xu-ran1;WU Shao-yong1;GAO Dong-sheng2;LI Ling2;WANG Lei2;SUN Ke-peng2;ZHOU Jun2;DONG Ke-jun1;HE Ming1

    2016-11-01

    Full Text Available Calcium plays an important role in the metabolism of plants and animals. In this paper, the preparation method of plant 41Ca for accelerator mass spectrometry (AMS measurement was developed for the first time in China. AMS, with its advantages of high sensitivity, small dose of radioactivity, high accuracy, large measuring range, and long tracer cycle, can be used to measure cosmogenic nuclide 41Ca , which has long half-life. The intensity of the beam in ion source is an important parameter for the sensitivity of AMS measurement. The high beam current can improve the sensitivity of AMS. The preparation methods of plant samples of 41Ca tracer were systematically studied to obtain high beam current using wet, dry and a combining method with wet and dry re-fluoride. A reliable preparation procedure of plant samples for 41Ca tracer and its optimization parameters were determined by testing beam currents of various samples and lay a foundation for the 41Ca-AMS technology at plant tracer applications.

  8. Study of Spatial and Temporal Processes of Soil Erosion on Sloping Land Using Rare Earth Elements As Tracers

    Institute of Scientific and Technical Information of China (English)

    薛亚洲; 刘普灵; 杨明义; 琚彤军

    2004-01-01

    Rare earth elements(REE) were used to study the temporal and spatial processes of soil erosion from different depths and sections of a slope. Two simulated rainfall events were applied to a prepared plot with a slope of 22°. The total runoff and sediment yield were collected every minute during the rainfall events. During the first twenty minutes of the first rainfall event,the average rate of rill erosion and the accumulated sediment yield due to rill erosion was 0.5 and 0.3 times higher than for sheet erosion. During this time,most of the erosion occurred on the lower one third of the plot. After 20 min,rill erosion became the dominant process on the slope. The average acceleration in the rate of rill erosion,the rate of rill erosion and the accumulated sediment yield due to rill erosion were 42,6 and 4 times higher than that of sheet erosion,respectively. During the first 35 minutes of the second rainfall event,the average acceleration in the rate of rill erosion was 6~9 times higher than that of sheet erosion. Afterwards,the slope became nearly stable with little change in either rill or sheet erosion rates. Initially,most of the rill erosion occurred in the lower third of the slope but later the preexisting rillhead in the middle section of the slope became reactivated and erosion in this section of the slope increased rapidly. These results indicate that REE tracer technology is a valuable tool for quantifying spatial and temporal changes in erosion from a soil slope.

  9. Laminar segregation of GABAergic neurons in the avian nucleus isthmi pars magnocellularis: a retrograde tracer and comparative study.

    Science.gov (United States)

    Faunes, Macarena; Fernández, Sara; Gutiérrez-Ibáñez, Cristián; Iwaniuk, Andrew N; Wylie, Douglas R; Mpodozis, Jorge; Karten, Harvey J; Marín, Gonzalo

    2013-06-01

    The isthmic complex is part of a visual midbrain circuit thought to be involved in stimulus selection and spatial attention. In birds, this circuit is composed of the nuclei isthmi pars magnocellularis (Imc), pars parvocellularis (Ipc), and pars semilunaris (SLu), all of them reciprocally connected to the ipsilateral optic tectum (TeO). The Imc conveys heterotopic inhibition to the TeO, Ipc, and SLu via widespread γ-aminobutyric acid (GABA)ergic axons that allow global competitive interactions among simultaneous sensory inputs. Anatomical studies in the chick have described a cytoarchitectonically uniform Imc nucleus containing two intermingled cell types: one projecting to the Ipc and SLu and the other to the TeO. Here we report that in passerine species, the Imc is segregated into an internal division displaying larger, sparsely distributed cells, and an external division displaying smaller, more densely packed cells. In vivo and in vitro injections of neural tracers in the TeO and the Ipc of the zebra finch demonstrated that neurons from the external and internal subdivisions project to the Ipc and the TeO, respectively, indicating that each Imc subdivision contains one of the two cell types hodologically defined in the chick. In an extensive survey across avian orders, we found that, in addition to passerines, only species of Piciformes and Rallidae exhibited a segregated Imc, whereas all other groups exhibited a uniform Imc. These results offer a comparative basis to investigate the functional role played by each Imc neural type in the competitive interactions mediated by this nucleus.

  10. Comparative study on the radioactivity of TE-NORM in different components of oil separator tanks

    Energy Technology Data Exchange (ETDEWEB)

    Attallah, M.F.; Awwad, N.S.; Aly, H.F. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories and Management Center (HLWMC); El Afifi, E.M. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories and Management Center (HLWMC); Sebha Univ. (Libyan Arab Jamahiriya). Faculty of Engineering and Technology

    2013-03-01

    Natural radioactivity in the crude oil, produced water, sludge and scale wastes from the petroleum industry on the Suez gulf (Abu Redeis), Egypt were investigated. A low radioactivity was found in the produced water and crude oil samples. In the sludge waste samples, the levels of radioactivity were found to be 11.96 and 1.75 kBq kg{sup -1} for Ra-226 (of U-series) and Ra-228 (of Th-series), respectively. In the scale waste samples, the levels of radioactivity were 11.7 and 4.2 kBq kg{sup -1} for Ra-226 and Ra-228, respectively. Leaching of different radionuclides in the sludge and scale wastes was investigated using mineral acid alone or after treatment with certain carbonate solutions. The different parameters affecting the treatment were optimized. It is found that high removal of Ra-226 was achieved from sludge and scale wastes when pretreated with 10% sodium carbonate solution, followed by acid dissolution. Removal % of Ra-226 reached 77 and 87% from the sludge and scale wastes, respectively. (orig.)

  11. Study on the Apparatus Accessory to Seal Radioactive Samples for XRD Measurement

    Institute of Scientific and Technical Information of China (English)

    LIU; Xie-chun; LUO; Fang-xiang; LI; Hui-rong; XIAO; Song-tao; YANG; He; LAN; Tian; MENG; Zhao-kai

    2012-01-01

    <正>According to the principle of XRD determination, we tried to seal radioactive powder effectively when it was measured by XRD. After the measure- ments, we must make sure that the surroundings are not contaminated. Now, by a few times of modifica- tions, a suit of apparatus which is able to seal radio-

  12. A study of production of radioactive environmental reference materials used for proficiency testing program in Taiwan.

    Science.gov (United States)

    Peng, En-Chi; Wang, Jeng-Jong

    2013-11-01

    To realise radioactive environmental reference materials in Taiwan, seven environmental materials of soil, water, vegetation, meat, airborne particles (filter paper), milk and mushroom samples that are frequently encountered were used to establish the preparation of the reference materials. These seven environmental materials were collected, checked for freedom from radioactivity and prepared according to their properties. The preparation was carried out by using activity about 10-100 times that of the minimum detectable activity (MDA) in routine measurements in the radioactive standard used to spike the inactive material and this standard is traceable to national ionising radioactivity standards (TAF, 2004). To demonstrate sample traceability to the added standard, each sample was carefully measured and its uncertainty evaluated. Based on the recommendations of ISO Guide 35 for evaluation of reference materials and with the above assessment and verification procedures, the uncertainties (k=1) of the spike activity used in making reference materials were: (60)Co≤4.6%, (134)Cs≤4.7%, (137)Cs≤5.0%, total β≤0.6% and (3)H≤1.3%.

  13. Mining-impacted sources of metal loading to an alpine stream based on a tracer-injection study, Clear Creek County, Colorado

    Science.gov (United States)

    Fey, David L.; Wirt, Laurie

    2007-01-01

    Base flow water in Leavenworth Creek, a tributary to South Clear Creek in Clear Creek County, Colorado, contains copper and zinc at levels toxic to aquatic life. The metals are predominantly derived from the historical Waldorf mine, and sources include an adit, a mine-waste dump, and mill-tailings deposits. Tracer-injection and water-chemistry synoptic studies were conducted during low-flow conditions to quantify metal loads of mining-impacted inflows and their relative contributions to nearby Leavenworth Creek. During the 2-year investigation, the adit was rerouted in an attempt to reduce metal loading to the stream. During the first year, a lithium-bromide tracer was injected continuously into the stream to achieve steady-state conditions prior to synoptic sampling. Synoptic samples were collected from Leavenworth Creek and from discrete surface inflows. One year later, synoptic sampling was repeated at selected sites to evaluate whether rerouting of the adit flow had improved water quality.

  14. A studies on characteristics of groundwater system in discontinuous rockmass for evaluation of safety on disposal site of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yeong Hoon; Han, Jeong Sang; Kim, Kyu Sang; Shin, Hyeon Joon; Lee, Chee Hyeong [Yonsei Univ., Seoul (Korea, Republic of)

    1997-07-15

    This study contains the development of numerical model of groundwater system and its application for the evaluation of safety in disposal site of radioactive waste. Through the identification of hydraulic properties, characteristics of discontinuity and selection of discontinuity model around LPG underground storage facility, the application of continuum model and discrete fracture network model was evaluated for the analysis of groundwater flow and solute transport.

  15. Study on the environmental movements and distributions of natural radioactive nuclides on the granite area (II)

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst

    1999-03-01

    The natural radionuclides as K-40, uranium decay series and thorium decay series etc. are widely distributed on environment, but are not uniformly. These have various forms as the sources of terrecial environmental {gamma} radiation and of radon and make wide fluctuation seasonal and spatially on the environment. We have selected Ikeda mineral spring district, Shimane pref., Misasa spa district, Tottori pref., Muro district, Hachibuse district, Nara pref. and Arima spa district, Hyogo-pref. for HBRA, and Kawanishi-shi, Hyogo pref. and Higashi-osaka-shi, Osaka pref. as CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon and decay nuclides. Radon measurements have been carried using cup typed radon and thoron monitors, pico-rad method by active charcoal sampling and Pilon scintillation-cell by grub sampling. Accumulated radon monitors have been used with cellulose nitrate as solid state track detector. Rn-222 concentrations in air at Misasa spa ranged 2 - 150 Bq/m{sup 3} outdoor and 8 - 194 Bq/m{sup 3} indoor. Rn-222 concentrations on Misasa district, Asahi district and Takeda district geologically formed from granite strata are high, and those on Osika district and Mitoku district formed from volcanic rocks (Andesite and Basalt) are low level. Rn-222 concentration variations in well water used as drinking water were 2 - 138 Bq/l (mean value 31 Bq/l) and those in ground waters varied from non detectable to 4620 Bq/l (mean 875 Bq/l) on sampling time and places. Mean Rn-222 concentration in the spring water at Arima spa area, Hyogo prefecture is 26 Bq/l at Tansan spring source and the other spring sources are comparatively low level. (J.P.N.)

  16. International program to study subseabed disposal of high-level radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Carlin, E.M.; Hinga, K.R.; Knauss, J.A.

    1984-01-01

    This report provides an overview of the international program to study seabed disposal of nuclear wastes. Its purpose is to inform legislators, other policy makers, and the general public as to the history of the program, technological requirements necessary for feasibility assessment, legal questions involved, international coordination of research, national policies, and research and development activities. Each of these major aspects of the program is presented in a separate section. The objective of seabed burial, similar to its continental counterparts, is to contain and to isolate the wastes. The subseabed option should not be confuesed with past practices of ocean dumping which have introduced wastes into ocean waters. Seabed disposal refers to the emplacement of solidified high-level radioactive waste (with or without reprocessing) in certain geologically stable sediments of the deep ocean floor. Specially designed surface ships would transport waste canisters from a port facility to the disposal site. Canisters would be buried from a few tens to a few hundreds of meters below the surface of ocean bottom sediments, and hence would not be in contact with the overlying ocean water. The concept is a multi-barrier approach for disposal. Barriers, including waste form, canister, ad deep ocean sediments, will separate wastes from the ocean environment. High-level wastes (HLW) would be stabilized by conversion into a leach-resistant solid form such as glass. This solid would be placed inside a metallic canister or other type of package which represents a second barrier. The deep ocean sediments, a third barrier, are discussed in the Feasibility Assessment section. The waste form and canister would provide a barrier for several hundred years, and the sediments would be relied upon as a barrier for thousands of years. 62 references, 3 figures, 2 tables.

  17. The Fischa-Dagnitz spring, Southern Vienna Basin: a multi tracer time series study re-assessing earlier conceptual assumptions.

    Science.gov (United States)

    Suckow, Axel; Gerber, Christoph; Kralik, Martin; Sültenfuss, Jürgen; Purtschert, Roland

    2013-04-01

    The gravel aquifer of the Southern Vienna Basin is a very important backup drinking water resource for the city of Vienna. A discharge location, the Fischa-Dagnitz spring in the Southern Vienna Basin, Austria, was re-investigated in 2011, five years after the gas exchange tracer test published in (Stolp et al., 2010), and sampled for stable isotopes 18O/2H, tritium, 3He, SF6 and 85Kr (Gerber et al., 2012). Additionally, new tritium time series data (Davis et al., 1967), previously not considered in Stolp et al. (2010), were included. These show a higher and earlier tritium peak of >300 TU in 1965 in the discharge of the Fischa-Dagnitz spring as compared to 221 TU in 1972 considered in Stolp et al. (2010). The new 3He, SF6 and 85Kr gas tracer data from 2011 confirm the earlier finding for 3He of Stolp et al. (2010) and indicate a more recent equilibration with the atmosphere than the water bound tracers 18O, 2H and tritium. A new modelling attempt using the Lumpy code (Suckow, 2012) confirmed the discrepancy between the tritium data and the gaseous tracers 3He, SF6 and 85Kr. No steady-state combination of local recharge (represented by an exponential model) and Schwarza river infiltration flowing through the gravel aquifer (represented by a parallel dispersion model) can equally well explain both the tritium time series and the gas tracer results. A revised conceptual model proposes that a pinching of the aquifer at unconformities in the gravel body or a fault zone known in the gravel body forces groundwater along the flow path closer to the surface and exposes it to the atmosphere. This would tend to reset the "dating" clock for the gaseous tracers 3He, SF6 and 85Kr, which can equilibrate quickly with the atmosphere, but not for tritium, which marks the transport behaviour of the water itself. These findings are of importance also for other multi-tracer assessments of groundwater movement in phreatic aquifer systems. References: Davis, G.H., Payne, B.R., Dincer, T

  18. Study of the radiation and radioactivity in dairy formulas; Estudio de la radiacion y radiactividad en formulas lacteas

    Energy Technology Data Exchange (ETDEWEB)

    Mireles G, F.; Pinedo V, J.L.; Quirino T, L.L.; Davila R, J.I.; Rios M, C.; Leal A, B.; Lopez del Rio, H. [Unidad Academica de Estudios Nucleares, UAZ, Cipres 10, Frac. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: fmireles@cantera.reduaz.mx

    2006-07-01

    The radiation and natural radioactivity is present in the man's food chain, like it is the case of the milk, and it comes from the natural series of radioactive decay of the {sup 238} U, {sup 235} U and {sup 232} Th, and of the {sup 40} K radioisotope. Since the radioisotopes can be found in floor of where its are transferred to the grasses and in the water that serve as food and of drinking to the cows, then to enter the milk and its derived to the human consumption. In this work it is presented the study of the radiation and gamma radioactivity of 40 samples of dairy formulas of the trademarks and presentations more sold in the market of the private and public sectors. The measurements of the gamma ray spectra were carried out with a spectrometry system based on an Hyper pure Germanium detector (HPGe). The detector has a resolution (FWHM) of 1.9 keV for an energy of the gamma ray of 1.332 keV of the {sup 60} Co. This study presents the results of the concentration in activity of dairy formulations of the radioisotopes of interest. Also, the results are related with possible damages to the health. (Author)

  19. Wear measurement of highly cross-linked UHMWPE using a 7Be tracer implantation technique.

    Science.gov (United States)

    Wimmer, Markus A; Laurent, Michel P; Dwiwedi, Yasha; Gallardo, Luis A; Chipps, Kelly A; Blackmon, Jeffery C; Kozub, Raymond L; Bardayan, Daniel W; Gross, Carl J; Stracener, Daniel W; Smith, Michael S; Nesaraja, Caroline D; Erikson, Luke; Patel, Nidhi; Rehm, Karl E; Ahmad, Irshad; Greene, John P; Greife, Uwe

    2013-04-01

    The very low wear rates achieved with the current highly cross-linked ultrahigh molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are therefore being explored. The purpose of this study was to perform a proof-of-concept experiment on the use of the radioactive tracer beryllium-7 ((7)Be) for the determination of in vitro wear in a highly cross-linked orthopedic UHMWPE. Three cross-linked and four conventional UHMWPE pins made from compression-molded GUR 1050, were activated with 10(9) to 10(10) (7)Be nuclei using a new implantation setup that produced a homogenous distribution of implanted nuclei up to 8.5 μm below the surface. The pins were tested for wear in a six-station pin-on-flat apparatus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross-linked UHMWPE pins was readily detected and estimated to be 17 ± 3 μg per million cycles. The conventional-to-cross-linked ratio of the wear rates was 13.1 ± 0.8, in the expected range for these materials. Oxidative degradation damage from implantation was negligible; however, a weak dependence of wear on implantation dose was observed limiting the number of radioactive tracer atoms that can be introduced. Future applications of this tracer technology may include the analysis of location-specific wear, such as loss of material in the post or backside of a tibial insert.

  20. Nitrogen metabolism as effect parameter for air pollution in plant bioindicators - a {sup 15}N-tracer study

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, C.; Jung, K.; Schueuermann, G. [UFZ - Umweltforschungszentrum, Leipzig (Germany). Sektion Chemische Oekotoxikologie; Kostka-Rick, R. [Biologisch Ueberwachen und Bewerten, Echterdingen (Germany); Hahn, H.U. [DaimlerChrysler AG, Sindelfingen (Germany)

    2002-07-01

    Since many years, bioindicator plants have been used for effect monitoring of air pollution. In this paper it is demonstrated that the determination of the nitrogen metabolism activity of plants using stable isotope tracer techniques has proven a suitable method for detecting sublethal effects of multiple, low-dose and chronic pollution load. This method permits to diagnose air pollution on a metabolic level of an early stage before visible damages on plants occur. (orig.)

  1. Methodology Measuring Rare Earth Elements in High TDS Reservoir Brines Application as Natural Tracers in CCUS Studies

    Science.gov (United States)

    Smith, W.; Mcling, T. L.; Smith, R. W.; Neupane, H.

    2013-12-01

    In recent years rare earth elements (REE) have been demonstrated to be useful natural tracers for geochemical processes in aqueous environments. The application of REE's to carbon dioxide utilization and storage (CCUS) could provide researchers with a sensitive, inexpensive tool for tracking the movement of CO2 and displaced formation brines. By definition, geologic reservoirs that have been deemed suitable for carbon capture and storage contain formation brine with total dissolved solids (TDS) greater than 10,000 ppm and often these formation brines exceed 75,000 ppm TDS. This high TDS water makes it very difficult to measure REE, which typically occur at part per trillion concentrations. Critical to the use of REE for CCUS studies is the development of a procedure, which allows for the pre-concentration of REE's across a wide range of water quality. Additionally, due to the large number of samples that will need analysis, any developed procedure must be inexpensive, reproducible, and quick to implement. As part of the Big Sky Carbon Sequestration Project the INL's Center for Advance Energy Studies is developing REE pre-concentration procedures based on methods reported in the literature. While there are many REE pre-concentration procedures in the literature, our tests have shown these methods have difficulty at TDS greater than seawater (roughly 35,000 ppm TDS). Therefore, the ability to quantitatively measure REE's in formation brines with very high TDS has required the modification of an already developed procedure. After careful consideration and testing we selected methods modified after those described by Kingston et al., 1978 and Strachan et al., 1989 utilizing chelating media for very high TDS waters and ion-exchange media as detailed by Crock et al., 1984; Robinson et al., 1985; and Stetzenbach et al., 1994 for low TDS (<10,000 ppm TDS) waters. These modified procedures have been successfully tested in our laboratory and have proven effective in greatly

  2. Pre-feasibility study for final disposal of radioactive waste. Disposal concepts. Main report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, L.; Skov, C.; Kueter, A.; Schepper, L.; Gottberg Roemer, H.; Refsgaard, A.; Utko, M.; Kristiansen, Torben (COWI A/S, Kgs. Lyngby (Denmark))

    2011-05-15

    This prefeasibility study is part of the overall process related to the decision on placement and design of a repository for the Danish low and medium level radioactive waste primarily from the facilities at Risoe. The prefeasibility study encompasses the preliminary design of a number of repository types based on the overall types set out in the 'Parliamentary decision' together with a preliminary safety assessment of these repository types based on their possible placement in a set of typical Danish geologies. The report consists of three parts. Part I is the descriptive part containing information on the waste to be disposed of, the potential conditioning (packaging) possibilities for the waste before placement in a repository, the suggested preliminary design of the different repository types, and the suggested visual appearance of the repository. Part II is the assessment part. It contains an introduction to the concepts used in the preliminary safety assessment, which encompasses: the assessment of potential long term impact and the assessment of possible accidental incidents. The division of the preliminary safety assessment in to these two categories has several reasons. One is that the criteria to which impact is to be compared are different for the two types of impact, another is that while the possible variation in the long term impact is primarily due to the possible variation in the parameters influencing the impact, the impact from accidental incidents is governed by the probability of the occurrence of these incidents and the potential consequence of the impact, which calls for a different assessment approach. Since the suggestions for packaging of the different waste types is a result of both types of assessments, part II also contains a description of these suggestions based on the preliminary safety assessments. Finally part II contains the costs related to the different types of repositories and the suggested packaging. Part III of the

  3. Studies of the radioactive waste confinement matrix using neutron scattering methods

    Science.gov (United States)

    Dragolici, C. A.; Balasoiu, M.; Ionascu, L.; Nicu, M.

    2016-09-01

    The management of the radioactive waste implies the conditioning in a cement matrix as an embedding, stable, disposal material. Cement matrix is the first and most important engineering barrier against the migration in the environment of the radionuclides contained in the packages. Chemically, after mixing with water, cement produces a reacting matrix with a porous microstructure. Knowing how the microstructure develops is therefore desirable in order to assess the compatibility of radioactive streams with cement and predict waste form performance during storage and disposal. This article highlights the work performed in SANS investigation of a new type of cements to be used for conditioning of aluminium waste coming from reactor decommissioning activities. It is well known that the expansion of corrosion products formed on aluminium can lead to cracking of the waste form.

  4. Study on melting conditions of radioactive miscellaneous solid waste. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Toshiki; Nakashio, Nobuyuki; Isobe, Motoyasu; Otake, Atsushi; Wakui, Takuji; Nakashima, Mikio [Department of Decommissioning and Waste Management, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Hirabayashi, Takakuni [Radiation Application Develpment Association, Tokai, Ibaraki (Japan)

    2001-02-01

    Improvement of fluidity of molten slag is one of the most important factors for plasma melting treatment of low level radioactive miscellaneous wastes generated from nuclear facilities. In general, it is considered that elevating molten slag temperature of addition of flux is of certain use in improvement of fluidity of molten slag. However, these ways are not necessarily suitable from the viewpoints of refractory erosion or reduction of waste volume. In this report, we suggested that fluidity of molten slag could be improved by controlling chemical compositions of molten slag. On the Basic of the investigation using phase diagram and viscosity data, FeO was selected as a key component for improving fluidity: Viscosity and melting point of molten slag decreased with increasing relative concentration of FeO in molten slag. Accordingly, we concluded that it is important to adjust basicity of molten slag for melting treatment of low-level radioactive miscellaneous solid wastes. (author)

  5. Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms

    Energy Technology Data Exchange (ETDEWEB)

    Arikawa, Hiroshi, E-mail: arikawa@cyric.tohoku.ac.jp; Ando, S.; Aoki, T.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kawamura, H.; Kato, K.; Kato, T.; Uchiyama, A.; Sakemi, Y. [Cyclotron and Radioisotope Center, Tohoku University, Miyagi 980-8578 (Japan); Aoki, T. [Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902 (Japan); Furukawa, T. [Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Hatakeyama, A. [Department of Applied Physics, Tokyo University of Agriculture and Technology, Tokyo 184-8588 (Japan); Hatanaka, K.; Yoshida, H. P. [Research Center for Nuclear Physics, Osaka University, Osaka 606-8502 (Japan); Imai, K. [Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki 319-1184 (Japan); and others

    2014-02-15

    The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a {sup 18}O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line.

  6. Methodology study for fixation of radioactive iodine in polymeric substrate for brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruna T.; Rostelato, Maria Elisa C.M.; Souza, Carla D.; Tiezzi, Rodrigo; Souza, Daiane B. de; Benega, Marcos A.G.; Souza, Anderson S. de; Peleias Junior, Fernando S.; Zeituni, Calos A.; Fernandes, Vagner; Melo, Emerson Ronaldo de; Camargo, Anderson Rogerio de, E-mail: bteigarodrigues@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Cancer is now the second leading cause of death by disease in several countries, including Brazil. Prostate cancer is the most common among men. Brachytherapy is a modality of radiotherapy in which radioactive seeds are placed inside or in contact with the organ to be treated. The most widely used radioisotope in prostate brachytherapy is Iodine-125 which is presented fixated on a silver substrate that is subsequently placed inside a titanium capsule. A large dose of radiation is released only in the targeted tumor protecting healthy surrounding tissues. The technique requires the application of 80 - 120 seeds per patient. The implants of seeds have low impact and non-surgical procedures. Most patients can return to normal life within three days with little or no pain. This work proposes an alternative to the seeds that have already been developed, in order to reduce the cost by obtaining a better efficiency on fixing the radioactive iodine onto the epoxy resin. Methods have been developed to perform the fixation of Iodine-125 onto polymeric substrates. The parameters analyzed were the immersion time, type of static or dynamic reaction, concentration of the adsorption solution, the specific activity of the radioactive source, the need for carrier and chemical form of the radioactive Iodine. These experiments defined the most effective method to fixate the Iodine onto the polymeric material (epoxy resin), the Iodine activity in the polymeric substrate, the activity of the distribution of variation in a plot of polymeric cores and the efficiency of the epoxy resin to seal the seed. (author)

  7. Analysis of metabolism of 6FDG: a PET glucose transport tracer

    Energy Technology Data Exchange (ETDEWEB)

    Muzic, Raymond F., E-mail: raymond.muzic@case.edu [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Chandramouli, Visvanathan [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Huang, Hsuan-Ming [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Wu Chunying; Wang Yanming [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Ismail-Beigi, Faramarz [Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2011-07-15

    Introduction: We are developing {sup 18}F-labeled 6-fluoro-6-deoxy-D-glucose ([{sup 18}F]6FDG) as a tracer of glucose transport. As part of this process it is important to characterize and quantify putative metabolites. In contrast to the ubiquitous positron emission tomography (PET) tracer {sup 18}F-labeled 2-fluoro-2-deoxy-D-glucose ([{sup 18}F]2FDG) which is phosphorylated and trapped intracellularly, the substitution of fluorine for a hydroxyl group at carbon-6 in [{sup 18}F]6FDG should prevent its phosphorylation. Consequently, [{sup 18}F]6FDG has the potential to trace the transport step of glucose metabolism without the confounding effects of phosphorylation and subsequent steps of metabolism. Herein the focus is to determine whether, and the degree to which, [{sup 18}F]6FDG remains unchanged following intravenous injection. Methods: Biodistribution studies were performed using 6FDG labeled with {sup 18}F or with the longer-lived radionuclides {sup 3}H and {sup 14}C. Tissues were harvested at 1, 6, and 24 h following intravenous administration and radioactivity was extracted from the tissues and analyzed using a combination of ion exchange columns, high-performance liquid chromatography, and chemical reactivity. Results: At the 1 h time-point, the vast majority of radioactivity in the liver, brain, heart, skeletal muscle, and blood was identified as 6FDG. At the 6-h and 24-h time points, there was evidence of a minor amount of radioactive material that appeared to be 6-fluoro-6-deoxy-D-sorbitol and possibly 6-fluoro-6-deoxy-D-gluconic acid. Conclusion: On the time scale typical of PET imaging studies radioactive metabolites of [{sup 18}F]6FDG are negligible.

  8. 1993 Annual progress report for subsidiary agreement No. 2 (1991--1996) between AECL and US/DOE for a radioactive waste management technical co-operative program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    A coordinated research program on radioactive waste disposal is being carried out by the Atomic Energy of Canada Limited and the US Department of Energy. This annual report describes progress in the following eight studies: Fundamental materials investigations; In-situ stress determination; Development of a spent fuel dissolution model; Large block tracer test--Experimental testing of retardation models; Laboratory and field tests of in-situ hydrochemical tools; Cigar Lake--Analogue study, actinide and fission product geochemistry; Performance assessment technology exchange; and Development of multiple-well hydraulic test and field tracer test methods.

  9. Evaluation of leakage from fume hoods using tracer gas, tracer nanoparticles and nanopowder handling test methodologies.

    Science.gov (United States)

    Dunn, Kevin H; Tsai, Candace Su-Jung; Woskie, Susan R; Bennett, James S; Garcia, Alberto; Ellenbecker, Michael J

    2014-01-01

    The most commonly reported control used to minimize workplace exposures to nanomaterials is the chemical fume hood. Studies have shown, however, that significant releases of nanoparticles can occur when materials are handled inside fume hoods. This study evaluated the performance of a new commercially available nano fume hood using three different test protocols. Tracer gas, tracer nanoparticle, and nanopowder handling protocols were used to evaluate the hood. A static test procedure using tracer gas (sulfur hexafluoride) and nanoparticles as well as an active test using an operator handling nanoalumina were conducted. A commercially available particle generator was used to produce sodium chloride tracer nanoparticles. Containment effectiveness was evaluated by sampling both in the breathing zone (BZ) of a mannequin and operator as well as across the hood opening. These containment tests were conducted across a range of hood face velocities (60, 80, and 100 ft/min) and with the room ventilation system turned off and on. For the tracer gas and tracer nanoparticle tests, leakage was much more prominent on the left side of the hood (closest to the room supply air diffuser) although some leakage was noted on the right side and in the BZ sample locations. During the tracer gas and tracer nanoparticle tests, leakage was primarily noted when the room air conditioner was on for both the low and medium hood exhaust airflows. When the room air conditioner was turned off, the static tracer gas tests showed good containment across most test conditions. The tracer gas and nanoparticle test results were well correlated showing hood leakage under the same conditions and at the same sample locations. The impact of a room air conditioner was demonstrated with containment being adversely impacted during the use of room air ventilation. The tracer nanoparticle approach is a simple method requiring minimal setup and instrumentation. However, the method requires the reduction in

  10. Assessment on regulatory framework for safety of radioactive waste management as preparation for future NPP in Indonesia; a comparison study with South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Setianingsih, Lilis Susanti [KAIST, Daejeon (Korea, Republic of); Jeong, Seung Young [KINS, Daejeon (Korea, Republic of)

    2012-10-15

    information regarding natural radioactive sources downhole in oil and gas exploration and exploitation. Tracer is another type of nuclear energy utilization in industrial facilities. Tracer is operated by utilizing radioactive source attached to the system to follow the behavior pathway of one or more components of the particular system. It is used to detect easily and clearly on low concentration radioactive level of the system, as well as to detect and take samples without destroying the active system. Number of total radioactive and/or nuclear facilities for industrial purposes in Indonesia tends to be increasing as the implementation is getting wider. One of the nuclear authorities in Indonesia is the Nuclear Regulatory Agency (BAPETEN) which on behalf of the government grants the licenses to the respective facilities and monitors the regulation implementation on the facilities to ensure the safety, security and safeguard for the purpose providing protection to the people, property and environment. Considering the wide use of nuclear energy application and implementation in industrial purposes facilities, qualified human resources for controlling the law enforcement to ensure the proper standards of safety and security including the management of the waste generated by various nuclear energy utilization. Wide progressive demands of electricity for the future give challenges to the government to meet the projected needs of energy to be fulfilled. One of the options which can be considered reasonable in answering such problem to provide the high request of energy is by building nuclear power plant. Understanding the much wider use of nuclear energy implementation within the country, nuclear and radioactive waste facilities need to be developed in meeting the capacity required for prospective requirements.

  11. Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2007-08-01

    This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to provide the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.

  12. Trapping radioactive ions

    CERN Document Server

    Kluge, Heinz-Jürgen

    2004-01-01

    Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.

  13. Testing and comparison of four ionic tracers to measure stream flow loss by multiple tracer injection

    Science.gov (United States)

    Zellweger, G.W.

    1994-01-01

    An injectate containing lithium, sodium, chloride and bromide was added continuously at five sites along a 507 m study reach of St Kevin Gulch, Lake County, Colorado to determine which sections of the stream were losing water to the stream bed and to ascertain how well the four tracers performed. The acidity of the stream (pH 3.6) made it possible for lithium and sodium, which are normally absorbed by ion exchange with stream bed sediment, to be used as conservative tracers. Net flow losses as low as 0.81 s-1, or 8% of flow, were calculated between measuring sites. By comparing the results of simultaneous injection it was determined whether subsections of the study reach were influent or effluent. Evaluation of tracer concentrations along 116 m of stream indicated that all four tracers behaved conservatively. Discharges measured by Parshall flumes were 4-18% greater than discharges measured by tracer dilution. -from Author

  14. Use of geochemical and isotope tracers to assess groundwater dependency of a terrestrial ecosystem: case study from southern Poland

    Science.gov (United States)

    Zurek, Anna J.; Witczak, Stanislaw; Kania, Jaroslaw; Rozanski, Kazimierz; Dulinski, Marek; Wachniew, Przemyslaw

    2015-04-01

    The presented study was aimed at better understanding of the functioning of groundwater dependent terrestrial ecosystem (GDTE) located in the south of Poland. The studied GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Bloto fen). It relies not only on shallow, unconfined aquifer but indirectly also on groundwater originating from the deeper confined aquifer, underlying the Quaternary cover and separated from it by an aquitard of variable thickness. The main objective of the study was to evaluate the contribution of groundwater to the water balance of the studied GDTE and thereby assess the potential risk to this system associated with intense exploitation of the deeper aquifer. The Wielkie Błoto fen area and the adjacent parts of Niepolomice Forest are drained by the Dluga Woda stream with 8.2 km2 of gauged catchment area. Hydrometric measurements, carried out on the Dluga Woda stream over two-year period (August 2011 - August 2013) were supplemented by chemical and isotope analyses of stream water, monitored on monthly basis. Physico-chemical parameters of the stream water (SEC, pH, Na content, Na/Cl molar ratio) and isotope tracers (deuterium, oxygen-18 and tritium) were used to quantify the expected contribution of groundwater seepage from the deeper aquifer to the water balance of the Dluga Woda catchment. The mean transit time of water through the catchment, derived from temporal variations of δ18O and tritium content in the Dluga Woda stream, was in the order of three months. This fast component of the total discharge of Dluga Woda stream is associated surface runoff and groundwater flow paths through the Quaternary cover. The slow component devoid of tritium and probably originated from the deeper Neogene aquifer is equal to approximately 30% of the total discharge. The relationships between the physico-chemical parameters of the stream water and the flow rate of Dluga Woda clearly indicate that the monitored

  15. Experimental study of the effect of test-well arrangement for partitioning interwell tracer test on the estimation of NAPL saturation

    Science.gov (United States)

    Kim, B.; Kim, Y.; Yeo, I.; Yongcheol Kim, In Wook Yeo

    2011-12-01

    Partitioning interwell tracer test (PITT) is a method to quantify and qualify a contaminated site with NAPLs through a degree of retardation of partitioning tracers compared to a conservative one. Although PITT is known to be a more effective method to measure the saturation of spatially-distributed NAPL contaminant than the point investigation method, the saturation estimation from PITT is reported to be underestimated due to various factors including heterogeneity of the media, adsorption, source zone NAPL architecture, and long tailing in breakthrough curves of partitioning tracers. Analytical description of PITT assumes that the injection-pumping well pair is on the line of ambient groundwater flow direction, but the test-well pair could easily be off the line in the field site, which could be another erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair to ambient groundwater flow direction based on the result from PITT. The experiments were conducted in a small-scale 3D sandbox with dimensions of 0.5 m × 0.4 m × 0.15 m (LWH) of stainless steel. The surface is covered and sealed with a plexiglass plate to make the physical model a confined aquifer. Eight full-screened wells of Teflon material were installed along the perimeter of a 50 mm circle with 45 degree intervals in the middle of the physical model. Both ends of the sand box are connected to constant head reservoirs. The physical model was wet-packed with sieved and washed sand. Trichloroethylene (TCE) and bromide were used as the contaminant and the conservative tracer, respectively. Hexanol, 2,4-dimethyl-3-pentanol and 6-methyl-2-heptanol were used as partitioning tracers. Before the injection of TCE, a PITT was conducted to measure adsorption coefficient of partitioning tracers to the sand material. TCE of 4.5 mL, dyed with Sudan IV, was injected into the inner part of the circle of the wells. PITTs using the test-well pair

  16. Study on the environmental movements and distributions of natural radioactive nuclides on the granite area (III)

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Atomic Energy Research Institute, Higashi-Osaka, Osaka (Japan)

    2000-03-01

    The natural radionuclides as K-40, uranium decay series and thorium decay series etc. are widely distributed on environment, but are not uniformly. These have influences various forms as the sources of terrecial environmental {gamma} radiation and of radon in to the human life environment and make wide fluctuation seasonal and spatially on the environment. The environmental radiation is higher than that of the other on the west Japan where generally consist rich of granite strata. We deeply appreciate in regard to natural radiation and would carry the studies on the movement and distribution of natural radioactive nuclides on high background radiation area consisted rich granite strata. We have selected and observed on Ikeda mineral spring district Ota-shi Shimane pref., Misasa spa district, Tohaku-gun, Tottori pref. on Chugoku area, Muro district Uda-gun, Hachibuse district, Nafa-shi Nara pref., and Arima spa district, Hyogo-pref., Kawanishi-shi, Hyogo pref. on Kinki area and Masutomi spa, Koma-gun, Yamanashi pref., for HBRA, and Higashi-osaka-shi, Osaka pref., for CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon and decay nuclides, and reported these results on following; (1) Radon measurements have been carried using cup typed radon and thoron monitors which are easy handling in spite of need of long sampling period, pico-rad method by active charcoal sampling and Pilon scintillation-cell with 300 ml volume by grub sampling. Accumulated radon monitors have been used cellulose nitrate (LR-115 type II, Kodak Co.) as solid state track detector. Among these characteristics of radon monitors, though minimum detectable limit of cup method for 3 months sampling is higher than those by the other method, it is able to measure mean Rn-222 concentration for 3 months. Rn-222 concentration by pico-rad method is able to get briefly mean concentration for 24 hours, is small detector and many

  17. Trojan Horse method and radioactive ion beams: study of $^{18}$F(p,$\\alpha$)$^{15}$O reaction at astrophysical energies

    CERN Document Server

    Gulino, M; Rapisarda, G G; Kubono, S; Lamia, L; La Cognata, M; Yamaguchi, H; Hayakawa, S; Wakabayashi, Y; Iwasa, N; Kato, S; Komatsubara, H; Teranishi, T; Coc, A; De Séréville, N; Hammache, F; Spitaleri, C

    2012-01-01

    The Trojan Horse Method was applied for the first time to a Radioactive Ion Beam induced reaction to study the reaction $^{18}$F(p,$\\alpha$)$^{15}$O via the three body reaction $^{18}$F(d,$\\alpha$ $^{15}$O)n at the low energies relevant for astrophysics. The abundance of $^{18}$F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy $^{18}$F in Novae. $^{18}$F(p,$\\alpha$)$^{15}$O is one of the main $^{18}$F destruction channels. Preliminary results are presented in this paper.

  18. Assessment of site conditions for disposal of low- and intermediate-level radioactive wastes: a case study in southern China.

    Science.gov (United States)

    Yi, Shuping; Ma, Haiyi; Zheng, Chunmiao; Zhu, Xiaobin; Wang, Hua'an; Li, Xueshan; Hu, Xueling; Qin, Jianbo

    2012-01-01

    Near surface disposal of low- and intermediate-level radioactive wastes (LILW) requires evaluating the field conditions of the candidate site. However, assessment of the site conditions may be challenging due to the limited prior knowledge of some remote sites, and various multi-disciplinary data requirements at any given site. These situations arise in China as in the rest of the industrialized world, particularly since a regional strategy for LILW disposal has been implemented to protect humans and the environment. This paper presents a demonstration of the site assessment process through a case study focusing mainly on the geologic, hydrogeologic and geochemical characteristics of the candidate site. A joint on-site and laboratory investigation, supplemented by numerical modeling, was implemented in this assessment. Results indicate that no fault is present in the site area, although there are some minor joints and fractures, primarily showing a north-south trend. Most of the joints are filled with quartz deposits and would thus function hydraulically as impervious barriers. Investigation of local hydrologic boundaries has shown that the candidate site represents an essentially isolated hydrogeologic unit, and that little or no groundwater flow occurs across its boundaries on the north or east, or across the hilly areas to the south. Groundwater in the site area is recharged by precipitation and discharges primarily by evapo-transpiration and surface flow through a narrow outlet to the west. Groundwater flows slowly from the hilly area to the foot of the hills and discharges mainly into the inner brooks and marshes. Some groundwater circulates in deeper granite in a slower manner. The vadose zone in the site was investigated specially for their significant capability for restraining the transport of radionuclides. Results indicate that the vadose zone is up to 38m in thickness and is made up of alluvial clay soils and very highly weathered granite. The vadose

  19. Tracer-based prediction of thermal reservoir lifetime: scope, limitations, and the role of thermosensitive tracers

    Science.gov (United States)

    Ghergut, I.; Behrens, H.; Karmakar, S.; Licha, T.; Nottebohm, M.; Sauter, M.

    2012-04-01

    correlation between (early) tracer signals and (later) thermal breakthrough can be re-established. Thus, thermosensitive tracers are indispensable for predicting thermal breakthrough, in such geothermal reservoirs whose 'hydrogeological personality' is given by a finite set of fractures, with flow occurring both across and along the fractures. In terms of the 'gebo benchmark-model' typology investigated by Hördt et al. (2011) [http://eposters.agu.org/abstracts/models-of-geothermal-reservoirs-as-a-basis-for-interdisciplinary-cooperation/] , such systems combine flow and transport patterns of the 'petrothermal' type and of the so-called 'deep-aquifer' type: across the fractures, heat is travelling faster than conservative-solute tracers; along the fractures, conservative-solute tracers experience much less retardation by transversal exchange (matrix diffusion), than heat; fluid (and tracer) flow is not limited to the fractures; matrix flow yields essential contribution to prolonging the fluid (and tracer) residence time. Thermal lifetime results from the opposite effects of fracture aperture as an: advection-related parameter: fluid travel time increases with increasing fracture aperture advection-unrelated parameter: fracture - matrix exchange rate increases with decreasing fracture aperture, which accelerates transport across the fracture, but retards transport along the fracture. In conservative-solute tracer signals, all these fracture aperture effects on tracer transport are masked by the very long residence time associated with the matrix flow component. Thermosensitive tracers are able to 'magnify' the visibility of fracture aperture effects against matrix flow effects. Acknowledgment: This study benefits from thermosensitive-tracer research conducted within the projects Smart Tracers and LOGRO, funded by the German Ministry for Environment, Nature Conservation and Nuclear Safety (BMU, 0327579 and 0325111B) and by Energie Baden-Württemberg (EnBW).

  20. Study on radioactive material management plan and environmental analysis of water (I) study of radioactive substance in water management and analyse to eat of the US environmental protection agency (environmental protection agency)

    Energy Technology Data Exchange (ETDEWEB)

    Her, Jae; Min, Hye Lim; Han, Seong Gyu; Lim, Hyun Jong; Jo, Han Byeol; Noh, Young Hoon; Lee, Ho Sun [Dept. of Bio-convergence Engineering, Graduate School of Korea University, Seoul (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, Korea University, Seoul (Korea, Republic of); Park, Min Suk [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2015-06-15

    The interest of the people in the radioactive contamination of the water has increased significantly and the study about analysis and management of radioactive materials are being actively conducted. And monitoring spots have been expanded to the range of public water as well as drinking water by publishing the rule of drinking water quality standards and examination in the Environmental Enforcement Ordinance No. 553 of Korea. In this study, US EPA was investigated as the foreign advanced cases and the way that is appropriate for the Korea was sought by analyzing investigate radionuclide, interval and management. As a result, in the selection part of investigate radionuclide, geological survey, status of nuclear power plants and the presence of the use of artificial radionuclides of the Korea should be investigated and additionally after the selection of a few radionuclides, the systems should be extended to cover all possible radionuclides by considering radioactive pollution levels in humans may be exposed due to the annual drinking water. In the part of the investigate interval, the concept(MCL, DL) should be set up for preventing concentration detection of above MCL and it needs to the maintenance and management. For example, when the concentration is more than MCL, it should be investigated on a quarterly and when the concentration is lower than MCL, it should be investigated to each different interval and management. And the US EPA divided the management area and make the road map for managing drinking water. The each classified area has been organized to match the state budget and labor force and the individual data have been managed effectively by HPGe, the NaI, TLD and so on.

  1. A cubic matrix-fracture geometry model for radial tracer flow in naturally fractured reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Jetzabeth Ramirez-Sabag; Fernando Samaniego V.

    1992-01-01

    This study presents a general solution for the radial flow of tracers in naturally fractured reservoirs, with cubic blocks matrix-fracture geometry. Continuous and finite step injection of chemical and radioactive tracers are considered. The reservoir is treated as being composed of two regions: a mobile where dispersion and convection take place and a stagnant where only diffusion and adsorption are allowed. Radioactive decay is considered in both regions. The model of this study is thoroughly compared under proper simplified conditions to those previously presented in the literature. The coupled matrix to fracture solution in the Laplace space is numerically inverted by means of the Crump algorithm. A detailed validation of the model with respect to solutions previously presented and/or simplified physical conditions solutions (i.e., homogeneous case) or limit solutions (i.e., naturally fractured nearly homogeneous) was carried out. The influence of the three of the main dimensionless parameters that enter into the solution was carefully investigated. A comparison of results for three different naturally fractured systems, vertical fractures (linear flow), horizontal fractures (radial flow) and the cubic geometry model of this study, is presented.

  2. Introduction to Astronomy with Radioactivity

    CERN Document Server

    Diehl, Roland

    2010-01-01

    In the late nineteenth century, Antoine Henri Becquerel discovered radioactivity and thus the physics of weak interactions, well before atomic and quantum physics was known. The different types of radioactive decay, alpha, beta, and gamma decay, all are different types of interactions causing the same, spontaneous, and time-independent decay of an unstable nucleus into another and more stable nucleus. Nuclear reactions in cosmic sites re-arrange the basic constituents of atomic nuclei (neutrons and protons) among the different configurations which are allowed by Nature, thus producing radioactive isotopes as a by-product. Throughout cosmic history, such reactions occur in different sites, and lead to rearrangements of the relative abundances of cosmic nuclei, a process called cosmic chemical evolution, which can be studied through the observations of radioactivity. The special role of radioactivity in such studies is contributed by the intrinsic decay of such material after it has been produced in cosmic site...

  3. Study of extraterrestrial disposal of radioactive wastes. Part 3: Preliminary feasibility screening study of space disposal of the actinide radioactive wastes with 1 percent and 0.1 percent fission product contamination

    Science.gov (United States)

    Hyland, R. E.; Wohl, M. L.; Finnegan, P. M.

    1973-01-01

    A preliminary study was conducted of the feasibility of space disposal of the actinide class of radioactive waste material. This waste was assumed to contain 1 and 0.1 percent residual fission products, since it may not be feasible to completely separate the actinides. The actinides are a small fraction of the total waste but they remain radioactive much longer than the other wastes and must be isolated from human encounter for tens of thousands of years. Results indicate that space disposal is promising but more study is required, particularly in the area of safety. The minimum cost of space transportation would increase the consumer electric utility bill by the order of 1 percent for earth escape and 3 percent for solar escape. The waste package in this phase of the study was designed for normal operating conditions only; the design of next phase of the study will include provisions for accident safety. The number of shuttle launches per year required to dispose of all U.S. generated actinide waste with 0.1 percent residual fission products varies between 3 and 15 in 1985 and between 25 and 110 by 2000. The lower values assume earth escape (solar orbit) and the higher values are for escape from the solar system.

  4. Development of a novel two color tracer perfusion technique for the hydrodynamic study of aqueous outflow in bovine eyes

    Institute of Scientific and Technical Information of China (English)

    ZHU Jing-yin; YE Wen; GONG Hai-yan

    2010-01-01

    Background Elevation of intraocular pressure is usually associated with primary open angle glaucoma and caused by increased outflow resistance. A two-color fluorescent tracer technique was developed to investigate the hydrodynamics of aqueous humor outflow with changing intraocular pressure within the same eye, to better understand the relationship between outflow facility and effective filtration area. Methods Eighteen enucleated bovine eyes were first perfused at 30 mmHg with Dulbecco's phosphate-buffered saline containing 5.5 mmol/L D-glucose. After a stable baseline facility, red fluorescent microspheres (0.5 μm, 0.002% v/v) were exchanged and perfused. Eyes in the one-color control group (n=6) were immediately perfused with fixative. In the experimental group (n=6), eyes were perfused with green tracer after intraocular pressure reduced to 7 mmHg, while in the two-color control group (n=6), eyes were perfused with green tracer with intraocular pressure remaining at 30 mmHg. All 12 eyes were then perfusion-fixed. Outflow facility was continuously recorded in all eyes. Confocal images were taken along the inner wall of the aqueous plexus and the percent of the effective filtration length (PEFL; length of inner wall exhibiting tracer labeling/total length of inner wall) was measured. The relationships between outflow facility and PEFL were analyzed statistically. Results No significant differences were found in baseline facilities (ulmin~(-1)·mmHg~(-1)) among the three groups (the experimental group: 0.93 0.12; the two-color control group: 0.90 0.19; the one-color control group: 0.98 0.13). In the experimental group, the outflow facility was significantly higher at 7 mmHg (4.29±1.01) than that at 30 mmHg (1.90±0.67, P <0.001), which corresponded to a significant increase in the PEFL at 7 mmHg (54.70±8.42) from that at 30 mmHg ((11.76±4.56)%, P<0.001). The PEFL labeled by red fluorescent microspheres in the experimental group ((11.76±4.56)%) showed no

  5. Lessons learned from case studies of inhalation exposures of workers to radioactive aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, M.D.; Fencl, A.F.; Newton, G.J. [and others

    1995-12-01

    Various Department of Energy requirements, rules, and orders mandate that lessons learned be identified, evaluated, shared, and incorporated into current practices. The recently issued, nonmandatory DOE standard for Development of DOE Lessons Learned Program states that a DOE-wide lessons learned program will {open_quotes}help to prevent recurrences of negative experiences, highlight best practices, and spotlight innovative ways to solve problems or perform work more safely, efficiently, and cost effectively.{close_quotes} Additional information about the lessons learned program is contained in the recently issued DOE handbook on Implementing U.S. Department of Energy Lessons Learned Programs and in October 1995 DOE SAfety Notice on Lessons Learned Programs. This report summarizes work in progress at ITRI to identify lessons learned for worker exposures to radioactive aerosols, and describes how this work will be incorporated into the DOE lessons learned program, including a new technical guide for measuring, modeling, and mitigating airborne radioactive particles. Follow-on work is focusing on preparation of {open_quotes}lessons learned{close_quotes} training materials for facility designers, managers, health protection professionals, line supervisors, and workers.

  6. Study of acid solution bonding in epoxy matrix for sealed radioactive sources production

    Energy Technology Data Exchange (ETDEWEB)

    Benega, Marcos A.G.; Nagatomi, Helio R.; Rostelato, Maria Elisa C.M.; Tiezzi, Rodrigo; Rodrigues, Bruna T.; Peleias Junior, Fernando; Souza, Carla D.; Souza, Daiane C.C. de; Souza, Anderson S. de; Silva, Thais H. da, E-mail: carladdsouza@yahoo.com.br, E-mail: marcosagbenega@gmail.com, E-mail: hrnagato@ipen.br, E-mail: elisaros@ipen.br, E-mail: rktiezzi@gmail.com, E-mail: bteigarodrigues@gmail.com, E-mail: fernandopeleias@gmail.com, E-mail: dcsouza@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    The present work aims to analyze different resin formulations. These formulations are used in the production of radioactive sealed sources that are used in many fields such as nuclear medicine; environmental analyzes, radiation detectors accuracy check, and so on. These sources can be produced with different radioisotopes and different activities, it all depending on the use they will have. Certain types of resins have the same density water. This property is appreciated when we consider that radiotracers used in nuclear medicine are applied in aqueous solutions. So the sources used for checking and calibrating equipment must have their radioisotopes sealed in a material having similar properties, thus the measures are reproducible and repetitive. The most important aspect that is brought to attention in this work is the miscibility those resins have with water. The radioisotopes for the production of the sources are supplied in an aqueous form. In case the resin and the radioisotope solution do not mix, the source will not be sturdy enough to seal the radioisotopes in its structure and the source will not be safe. There were prepared different formulations with different amounts of acid solution, and the cured formulations were analyzed by Wipe Test, DSC (Differential Splanatory Calorimetry) and also, the possible volatile aspect of the radionuclide used. All to evaluate the integrity of the sources. The obtained results were satisfactory and show that when the resin is well cured, the radioisotope remains sealed in the matrix, making it possible to produce radioactive sealed sources. (author)

  7. Study of natural radioactivity in riverbank soils along the Chao Phraya river basin in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Santawamaitre, T., E-mail: tods_education@hotmail.com [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Malain, D.; Al-Sulaiti, H.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Matthews, M. [Centre for Environmental Health Engineering, Department of Civil Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Bradley, D.A.; Regan, P.H. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2011-10-01

    Levels of naturally occurring radioactivity in surface soils along the Chao Phraya river have been investigated. The activity concentrations of radionuclides in the {sup 238}U and {sup 232}Th decay chains and from {sup 40}K were determined through gamma-ray spectrometry measurements made using a hyperpure germanium detector in a low background configuration. Activity concentrations of {sup 238}U, {sup 232}Th and {sup 40}K were found to be 55.3{+-}1.2{r_reversible}65.2{+-}1.4, 60.7{+-}1.2{r_reversible}69.1{+-}1.3 and 393{+-}13{r_reversible}478{+-}16 Bq/kg, respectively. Concerning radiological risk, the absorbed gamma dose rate in air from those soils was estimated to lie in the range 81.6{+-}1.9{r_reversible}90.4{+-}2.1 nGy/h; the outdoor annual effective dose equivalent was calculated to be 100.1{+-}2.3{r_reversible}110.8{+-}2.5 {mu}Sv/yr. These results are compared with radioactivity measurements with world mean values.

  8. Study of natural radioactivity in riverbank soils along the Chao Phraya river basin in Thailand

    Science.gov (United States)

    Santawamaitre, T.; Malain, D.; Al-Sulaiti, H. A.; Matthews, M.; Bradley, D. A.; Regan, P. H.

    2011-10-01

    Levels of naturally occurring radioactivity in surface soils along the Chao Phraya river have been investigated. The activity concentrations of radionuclides in the 238U and 232Th decay chains and from 40K were determined through gamma-ray spectrometry measurements made using a hyperpure germanium detector in a low background configuration. Activity concentrations of 238U, 232Th and 40K were found to be 55.3±1.2↔65.2±1.4, 60.7±1.2↔69.1±1.3 and 393±13↔478±16 Bq/kg, respectively. Concerning radiological risk, the absorbed gamma dose rate in air from those soils was estimated to lie in the range 81.6±1.9↔90.4±2.1 nGy/h; the outdoor annual effective dose equivalent was calculated to be 100.1±2.3↔110.8±2.5 μSv/yr. These results are compared with radioactivity measurements with world mean values.

  9. A method for comparing intra-tumoural radioactivity uptake heterogeneity in preclinical positron emission tomography studies

    Energy Technology Data Exchange (ETDEWEB)

    Grafström, Jonas; Ahlzén, Hanna-Stina [Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm (Sweden); Stone-Elander, Sharon [Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm (Sweden); PET Radiochemistry, Neuroradiology Department, Karolinska University Hospital, SE-17176 Stockholm (Sweden)

    2015-09-08

    Non-uniformity influences the interpretation of nuclear medicine based images and consequently their use in treatment planning and monitoring. However, no standardised method for evaluating and ranking heterogeneity exists. Here, we have developed a general algorithm that provides a ranking and a visualisation of the heterogeneity in small animal positron emission tomography (PET) images. The code of the algorithm was written using the Matrix Laboratory software (MATLAB). Parameters known to influence the heterogeneity (distances between deviating peaks, gradients and size compensations) were incorporated into the algorithm. All data matrices were mathematically constructed in the same format with the aim of maintaining overview and control. Histograms visualising the spread and frequency of contributions to the heterogeneity were also generated. The construction of the algorithm was tested using mathematically generated matrices and by varying post-processing parameters. It was subsequently applied in comparisons of radiotracer uptake in preclinical images in human head and neck carcinoma and endothelial and ovarian carcinoma xenografts. Using the developed algorithm, entire tissue volumes could be assessed and gradients could be handled in an indirect manner. Similar-sized volumes could be compared without modifying the algorithm. Analyses of the distribution of different tracers gave results that were generally in accordance with single plane preclinical images, indicating that it could appropriately handle comparisons of targeting vs. non-targeting tracers and also for different target levels. Altering the reconstruction algorithm, pixel size, tumour ROI volumes and lower cut-off limits affected the calculated heterogeneity factors in expected directions but did not reverse conclusions about which tumour was more or less heterogeneous. The algorithm constructed is an objective and potentially user-friendly tool for one-to-one comparisons of heterogeneity in

  10. Study on the post-closure surveillance methods at low- and intermediate-level radioactive waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Joo Ho; Shin, Jin Seong; Lee, Jae Min; Choi, Won Cheol; Cheon, Tae Hoon [Kyunghee Univ., Seoul (Korea, Republic of)

    1996-02-15

    Presidential decree, of atomic energy act of Korea, number 233.3.9 requires that the repository, after closure, of low- and intermediate-level radioactive waste be controlled and monitored an Ministry of Science and Technology decides. This study emphasizes on establishing a direction of technical guides, considering rock cavern disposal as a domestic project. Other types of repositories will also be referred to for their technical matter. Review of domestic and foreign requirements, review of the objectives of post-closure surveillance, suggestion of surveillance methods and technical guides.

  11. Dating of young groundwater using tritium and gaseous tracers (SF6, SF5CF3, CFC-12, H-1301): case study from southern Poland

    Science.gov (United States)

    Rozanski, Kazimierz; Bartyzel, Jakub; Dulinski, Marek; Kuc, Tadeusz; Sliwka, Ireneusz; Mochalski, Pawel; Kania, Jaroslaw; Witczak, Stanislaw

    2013-04-01

    Groundwater is an important source of potable water in many countries. While it covers ca. 50% of the global drinking water needs, in Europe this share is even higher, reaching approximately 70%. Nowadays, this strategic resource is at risk due to anthropogenic pollutants of various nature entering shallow aquifers. Proper management of groundwater resources requires thorough understanding of groundwater dynamics on time scales characteristic for the history of pollutant input to groundwater. The bomb-tritium has been used for several decades now as a tracer of choice to detect recent recharge and to quantify groundwater residence times on time scales extending from several years to several decades. The lumped-parameter modeling was the most often employed approach in this context. Since nowadays atmospheric concentrations of tritium are approaching natural levels in most parts of the world, the usage of this tracer has become more problematic. Therefore, there is a growing interest in alternative indicators of groundwater age in shallow aquifers. Anthropogenic trace gases present in the atmosphere, such as freons (CFC-11, CFC-12, CFC-113) and sulfur hexafluoride (SF6), have been applied in numerous case studies as substitutes of tritium. Here we present the results of a comprehensive study aimed at quantifying mean residence time of groundwater in the recharge area of porous sandy aquifer system located in the southern Poland. The principal economic role of the aquifer, consisting of two water-bearing strata, is to provide potable water for public and private users. The yield of the aquifer is insufficient to meet all the needs and, as a consequence, licensing conflicts arise between water supply companies and industry on the amount of water available for safe exploitation. To quantify residence time distribution (RTD) functions of water parcels arriving at the production wells located in the recharge area of the aquifer, tritium along with several gaseous tracers

  12. Tracer studies on the incorporation of [2-14C]-DL-mevalonate into chlorophylls a and b, alpha-chaconine, and alpha-solanine of potato sprouts.

    Science.gov (United States)

    Kozukue, N; Tsuchida, H; Friedman, M

    2001-01-01

    Chlorophyll and glycoalkaloids are synthesized in different parts of the potato plant including leaves, tubers, and sprouts. Although light stimulates the biosynthesis of both constituents, the question of whether the two biosynthetic pathways are under the same genetic control has not been resolved. This study investigated the dynamics of incorporation of labeled [2-(14)C]-DL-mavalonate into chlorophyll a, chlorophyll b, and the glycoalkaloids alpha-chaconine and alpha-solanine in potato sprouts after 7 and 14 days of storage in the light and in the dark. No chlorophyll synthesis occurred in the dark. Fractionation of the "glycoalkaloid" extract followed by high-performance liquid chromatography produced four peaks. The fractions were collected and analyzed for radioactivity. About 80% of the radioactivity resided in fraction 1, the composition of which is unknown. Two of the fractions, with 1-14% of the original label, were alpha-chaconine and alpha-solanine. The radioactivity derived from mevalonate largely resides in unidentified compound(s) eluting as a single peak on the HPLC column before the peaks associated with the glycoalkaloids. The specific radioactivity of alpha-chaconine and alpha-solanine increased approximately 2-fold in going from 7 to 14 days of exposure in the light and in the dark. These and additional observations point to the near identity of the dynamics of biosynthesis of the two glycoalkaloids. These data also implicate a non-mevalonate pathway for the synthesis of both chlorophylls and the glycoalkaloids and are consistent with independent genetic control of the concurrent formation of the two classes of compounds during greening of potatoes.

  13. Strontium and bromide as tracers in X-ray microanalysis of biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Wroblewski, J.; Sagstroem, S.M.; Mulders, H.; Roomans, G.M. (Karolinska Institutet, Stockholm (Sweden))

    1989-09-01

    Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection of strontium chloride. Exchange of calcium for strontium was enhanced by prior injection with isoproterenol. In a second experiment, rats were injected with sodium bromide, and the uptake of bromide by the submandibular acinar cells was followed in time, both in pilocarpine-stimulated and unstimulated glands. Under the experimental conditions, bromide was rapidly taken up by the cells, and the cellular Br/Cl ratio was close to that found in serum. Submandibular glands take up Br somewhat faster than other tissues (liver, heart muscle, skeletal muscle). The uptake of Br in pancreatic acinar cells was studied in vitro. These experiments showed a 1:1 ratio (molar) exchange of Cl for Br.

  14. A dual tracer (68)Ga-DOTANOC PET/CT and (18)F-FDG PET/CT pilot study for detection of cardiac sarcoidosis.

    Science.gov (United States)

    Gormsen, Lars C; Haraldsen, Ate; Kramer, Stine; Dias, Andre H; Kim, Won Yong; Borghammer, Per

    2016-12-01

    Cardiac sarcoidosis (CS) is a potentially fatal condition lacking a single test with acceptable diagnostic accuracy. (18)F-FDG PET/CT has emerged as a promising imaging modality, but is challenged by physiological myocardial glucose uptake. An alternative tracer, (68)Ga-DOTANOC, binds to somatostatin receptors on inflammatory cells in sarcoid granulomas. We therefore aimed to conduct a proof-of-concept study using (68)Ga-DOTANOC to diagnose CS. In addition, we compared diagnostic accuracy and inter-observer variability of (68)Ga-DOTANOC vs. (18)F-FDG PET/CT. Nineteen patients (seven female) with suspected CS were prospectively recruited and dual tracer scanned within 7 days. PET images were reviewed by four expert readers for signs of CS and compared to the reference standard (Japanese ministry of Health and Welfare CS criteria). CS was diagnosed in 3/19 patients. By consensus, 11/19 (18)F-FDG scans and 0/19 (68)Ga-DOTANOC scans were rated as inconclusive. The sensitivity of (18)F-FDG PET for diagnosing CS was 33 %, specificity was 88 %, PPV was 33 %, NPV was 88 %, and diagnostic accuracy was 79 %. For (68)Ga-DOTANOC, accuracy was 100 %. Inter-observer agreement was poor for (18)F-FDG PET (Fleiss' combined kappa 0.27, NS) and significantly better for (68)Ga-DOTANOC (Fleiss' combined kappa 0.46, p = 0.001). Despite prolonged pre-scan fasting, a large proportion of (18)F-FDG PET/CT images were rated as inconclusive, resulting in low agreement among reviewers and correspondingly poor diagnostic accuracy. By contrast, (68)Ga-DOTANOC PET/CT had excellent diagnostic accuracy with the caveat that inter-observer variability was still significant. Nevertheless, (68)Ga-DOTANOC PET/CT looks very promising as an alternative CS PET tracer. Current Controlled Trials NCT01729169 .

  15. Preliminary 3-D site-scale studies of radioactive colloid transortin the unsaturated zone at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Hu, Q.; Wu, Y.-S.; Bodvarsson, G.S.

    2001-09-01

    The U.S: Department of Energy is actively investigating the technical feasibility of permanent disposal of high-level nuclear waste in a repository to be situated in the unsaturated zone at Yucca Mountain, Nevada. In this study we investigate, by means of numerical simulation, the transport of radioactive colloids under ambient conditions from the potential repository horizon to the water table. The site hydrology and the effects of the spatial distribution of hydraulic and transport properties in the Yucca Mountain subsurface are considered. The study of migration and retardation of colloids accounts for the complex processes in the unsaturated zone of Yucca Mountain, and includes advection, diffusion, hydrodynamic dispersion, kinetic colloid filtration, colloid straining, and radioactive decay. The results of the study indicate that the most important factors affecting colloid transport are the subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The transport of colloids is strongly influenced by their size (as it affects diffusion into the matrix, straining at hydrogeologic unit interfaces, and transport velocity) and by the parameters of the kinetic-filtration model used for the simulations. Arrival times at the water table decrease with an increasing colloid size because of smaller diffusion, increased straining, and higher transport velocities. The importance of diffusion as a retardation mechanism increases with a decreasing colloid size, but appears to be minimal in large colloids.

  16. A comprehensive study of the spread of radioactive contamination in the geological medium near Lake Karachai, Chelyabinsk oblast

    Science.gov (United States)

    Laverov, N. P.; Velichkin, V. I.; Malkovsky, V. I.; Tarasov, N. N.; Dikov, Yu. P.

    2010-02-01

    The spread of radioactive contamination in the subsurface medium near Lake Karachai is considered. The complexity of this process requires a comprehensive approach to its study. The source of radioactive contamination is overviewed. The map of faults in subsurface medium is considered in order to determine the prevailing direction of contaminated groundwater flow. Photometry in observation wells has been used for structural geological estimation of transport properties of the shallow aquifer, where contaminated groundwater is moving. This study was carried out along with hydrochemical logging, which makes it possible to estimate the dynamics of contamination of subsurface medium and vertical distribution of groundwater contamination. Special attention is paid to transport of radionuclides in the form of radiocolloid particles. Groundwater samples were taken from various depths corresponding to different contamination levels near Lake Karachai. The depth intervals of sampling were determined from the data of hydrochemical logging. Ultrafiltration through membranes with a specific pore size in combination with gamma spectrometry was used to characterize radionuclide transfer with colloidal particles differing in size. The local elemental composition of the radiocolloid surface was studied by Auger spectroscopy. The chemical composition and structure of radiocolloid particles were determined by X-ray photoelectron spectroscopy with consecutive etching of the particle surface by argon ions for a certain depth. The data obtained indicate that radiocolloid particles are heterogeneous and an organic shell consisting of humic and fulvic acids and technogenic organic compounds coat their surface.

  17. Air Masses Origin and Isotopic Tracers: A Study Case of the Oceanic and Mediterranean Rainfall Southwest of France

    Directory of Open Access Journals (Sweden)

    Issam Moussa

    2013-05-01

    Full Text Available Aquifers recharge mainly by local rainfall, which depend on the air mass humidity and orographic lifting, causing rain. The stable isotopes of the water molecule, i.e., oxygen-18 and deuterium, are useful tracers to determine the water source origin. Moreover, the calculation of the deuterium excess enables one to differentiate between the air masses from the Atlantic Ocean or the Mediterranean Sea. A transect from one coast to the other one and going through the city of Toulouse have been made to sample the groundwater and determine their isotopic characteristic. A monthly rainfall sampling has also been done over one year, close to the city Toulouse, to see how the d-excess values range over the season. The discussion replaces these results in available isotopic data.

  18. Applications of isotopes. [Need and cost of stable iotopes for use as tracers in biomedical and environmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Kirby-Smith, J.S.

    1976-01-01

    Current and potential applications of stable isotopes as tracers in a number of biomedical and environmental areas are discussed. It is pointed out that a wide variety of problems exist in these fields whose solutions in principle are amenable to the isotopic approach. The number and diversity of these problems as well as the unique role stable isotopes can play in their solution illustrate the importance of achieving and maintaining a broad inventory of isotopic species. Experience has demonstrated unequivocally an additional overriding requirement for widespread exploration of stable isotopes by the scientific and technical community, i.e., the need for low cost availability of the materials in quantity. Some representative applications of /sup 12/C, /sup 13/C, /sup 14/N, /sup 15/N, /sup 16/O, /sup 17/O, and /sup 18/O are discussed.

  19. Comparison of /sup 13/C nuclear magnetic resonance and /sup 14/C tracer studies of hepatic metabolism. [Rats and mice

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, S.M. (Merck Inst. for Therapeutic Research, Rathway, NJ); Rognstad, R.; Shulman, R.G.; Katz, J.

    1981-04-10

    The gluconeogenic pathway from /sup 13/C-labeled substrates, each of which contained the /sup 14/C-labeled counterpart at a tracer level, has been followed in isolated rat liver cells and in isolated perfused mouse liver. The gluconeogenic flux from glycerol, the synthesis of glycogen, the synthesis of glycogen, the stimulation of glycogenolysis by glucagon, the recycling of triacylglycerol, and an increase in pentose cycle activity under the influence of phenazine methosulfate were all observed directly in the /sup 13/C NMR spectra of perfused liver or isolated hepatocytes. The relative concentrations of /sup 13/C label at specific carbons measured by the NMR spectra under these conditions agreed closely with /sup 14/C isotopic distributions measured in extracts of the same doubly labeled samples for specific activities of greater than or equal to 3%. The label distributions measured by both methods were the same to within the experimental errors, which ranged from +-2% to +-7% in these experiments.

  20. A study of radioactive elements of various rocks in Pattani Province with gamma ray spectrometer

    Directory of Open Access Journals (Sweden)

    Kaewtubtim, P.

    2002-01-01

    Full Text Available The radioactivity of the three elements, potassium, uranium and thorium, in rocks of various types in Pattani Province was investigated by using a gamma ray spectrometer. It was found that potassium contents in igneous rocks, sedimentary rocks and metamorphic rocks were 6.29 %, 2.21% and 1.54 % respectively. Uranium equivalent contents in igneous rock, sedimentary rocks and metamorphic rocks were found to be 22.51 ppm, 11.25 ppm and 14.13 ppm, while thorium contents in these rocks were 21.78 ppm, 18.88 ppm and 18.15 ppm respectively. The results obtained were similar to those reported by Pungtip Ranglek (1995 for igneous rock at Liwong Pluton site in Thepha, Na Thawi, Chana and Saba Yoi Districts, Songkhla Province, and were about six times higher than those reported by Kittichai Wattananikorn (1994 for igneous rock in the northern part of Thailand.

  1. A study on the gas generation from radioactive waste packages under disposal conditions in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo wan; Kim, Chang Lak; Choi, Heui Joo; Yoon, Jeong Hyoun [Korea Electric Power Corporation, Nuclear Environment Institute, Taejon (Korea, Republic of)

    1999-07-01

    In order to confirm the compliance to acceptance criteria , the performance of radioactive waste packages currently used at the nuclear power plants in Korea in aspect of gas generation is investigated. As the principal gas generation mechanisms radiolysis, corrosion of metals, and microbial activity of organic materials are considered. For calculating rates and total volumes of radiolytic hydrogen gas generated in waste packages a computer program that accommodates interactions among adjacent packages is used. Gas production due to metal corrosion and microbial degradation of Dry Active Waste (DAW) packages and the others is estimated over an assessment period of one thousand years under a given set of repository condition, respectively. Flammability hazard caused by radiolytic hydrogen formation inside a sealed waste package, pressure build-up inside the engineered barrier structure under repository condition is also assessed. (author)

  2. Study and survey of assembling parameters to a radioactive source production laboratory used to verify equipment

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Erica; Nagatomy, Helio Rissei; Moura, Eduardo S.; Zeituni, Carlos Alberto; Hilario, Katia A. Fonseca; Rostelato, Maria Elisa C.M., E-mail: egauglitz@ipen.b, E-mail: elisaros@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Karam Junior, Dib, E-mail: dib.karan@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Escola de Artes, Ciencias e Humanidades

    2009-07-01

    This paper presents the survey of parameters for the installation and implementation of a laboratory for radioactive sources production at immobilized resin. These sources are used in nuclear medicine for verification of dose calibrators, as the standard guidelines of the National Commission of Nuclear CNEN-NE-3.05 'Radioprotection and safety requirements for nuclear medicine services.' The radioisotopes used for this purpose are: Co-57, Cs-137 and Ba-133, with activities of 185 MBq, 9.3 MBq and 5.4 MBq, respectively. The parameters for the assembly of the laboratory shall be defined according to guidelines that guide the deployment of radiochemical laboratories and standards of the National Commission of Nuclear Energy. (author)

  3. Experimental and Computer Simulation Study of Radioactivity of Materials Irradiated by Intermediate Energy Protons

    CERN Document Server

    Titarenko, Y E; Batyaev, V F; Karpikhin, E I; Zhivun, V M; Mulambetov, R D; Mashnik, S G; Prael, R E; Wilson, W B; Titarenko, Yu. E.

    1999-01-01

    The results of measurements and computer simulations of radioactivities and dose rates as functions of decay time are presented for Pb-nat and Bi-209 irradiated by 1.5-GeV protons, Co-59, Cu-63, and Cu-65 irradiated by 0.13- and 1.2-GeV protons, and Th-232 and U-nat irradiated by 0.1- and 0.8-GeV protons. The activities and dose rates are measured by direct high-precision gamma spectrometry. The irradiations were made using external beams extracted from the ITEP U-10 proton synchrotron. Simulations made using the LCS and CINDER'90 code systems are compared with measurements.

  4. Hydrochemistry and boron isotopes as natural tracers in the study of groundwaters from North Chianan Plain, Taiwan.

    Science.gov (United States)

    Lu, Hsueh-Yu

    2014-01-01

    In this paper, hydrochemistry and boron isotopes are successfully applied to elucidate hydrogeological processes by the use of natural tracers. The hydrochemical analysis identifies four end-members in the hydrochemical evolution of groundwater from the North Chianan plain groundwater district. A few groundwater contain extraordinary chlorine concentrations of up to 48,000 mg l(-1). However, the hydrochemistry of groundwater only reveals that high saline water is a dominant factor in groundwater hydrochemistry. It is thought that these groundwater experienced precipitation of carbonates during seawater evaporation that did not involve the precipitation of gypsum. Boron isotopes are very efficient tracers in determining the source of salinisation. The boron isotopes reveal the results of mixing of evaporated seawater and water-sediment interaction. In general, the boron isotope ratio of the groundwater is controlled by a two-end-member mixing system, which is composed of evaporated seawater (isotopically heavy) and fresh surface water (isotopically light). Due to a long lagoonal period in the coastal plain, the groundwaters in the downstream area generally have high Cl/B ratios and relatively heavy boron isotope ratios while those in the upstream area are composed of low Cl/B and light boron isotopes. However, there is not a resolvable mixing trend between the Cl/B ratio and the isotopic composition of boron. It is probably obscured by a highly variable boron isotope ratio in fresh surface water and through fractionation associated with water-rock interaction. Both factors would decrease the boron isotope ratio but one effect cannot be distinguished from the other.

  5. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 10. Repository preconceptual design studies: granite

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    This volume, Volume 10 ''Repository Preconceptual Design Studies: Granite,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This document describes a preconceptual design for a nuclear waste storage facility in granite. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area, and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/11, ''Drawings for Repository Preconceptual Design Studies: Granite.''

  6. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 8. Repository preconceptual design studies: salt

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    This volume, Volume 8 ''Repository Preconceptual Design Studies: Salt,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This document describes a preconceptual design for a nuclear waste storage facility in salt. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area, and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/9, ''Drawings for Repository Preconceptual Design Studies: Salt.''

  7. Rapid pharmacokinetic and biodistribution studies using cholorotoxin-conjugated iron oxide nanoparticles: a novel non-radioactive method.

    Directory of Open Access Journals (Sweden)

    Michelle Jeung-Eun Lee

    Full Text Available BACKGROUND: Recent advances in nanotechnology have led to the development of biocompatible nanoparticles for in vivo molecular imaging and targeted therapy. Many nanoparticles have undesirable tissue distribution or unacceptably low serum half-lives. Pharmacokinetic (PK and biodistribution studies can help inform decisions determining particle size, coatings, or other features early in nanoparticle development. Unfortunately, these studies are rarely done in a timely fashion because many nanotechnology labs lack the resources and expertise to synthesize radioactive nanoparticles and evaluate them in mice. METHODOLOGY/PRINCIPAL FINDINGS: To address this problem, we developed an economical, radioactivity-free method for assessing serum half-life and tissue distribution of nanoparticles in mice. Iron oxide nanoparticles coated with chitosan and polyethylene glycol that utilize chlorotoxin as a targeting molecule have a serum half-life of 7-8 hours and the particles remain stable for extended periods of time in physiologic fluids and in vivo. Nanoparticles preferentially distribute to spleen and liver, presumably due to reticuloendothelial uptake. Other organs have very low levels of nanoparticles, which is ideal for imaging most cancers in the future. No acute toxicity was attributed to the nanoparticles. CONCLUSIONS/SIGNIFICANCE: We report here a simple near-infrared fluorescence based methodology to assess PK properties of nanoparticles in order to integrate pharmacokinetic data into early nanoparticle design and synthesis. The nanoparticles tested demonstrate properties that are excellent for future clinical imaging strategies and potentially suitable for targeted therapy.

  8. Synthesis of a novel polyamidoamine dendrimer conjugating with alkali blue as a lymphatic tracer and study on the lymphatic targeting in vivo.

    Science.gov (United States)

    Yang, Rui; Xia, Suxia; Ye, Tiantian; Yao, Jianhua; Zhang, Ruizhi; Wang, Shujun; Wang, Siling

    2016-09-01

    In this study, a novel lymphatic tracer polyamidoamin-alkali blue (PAMAM-AB) was synthesized in order to evaluate the intra-lymphatic targeting ability and lymphatic tropism of PAMAM-AB after subcutaneous administration. UV-Vis, FT-IR, NMR and HPLC characterization were performed to prove the successful synthesis of PAMAM-AB. The calculated AB payload of PAMAM-AB conjugate was seven per dendrimer molecule (27.16% by weight). Hydrolysis stability of PAMAM-AB in vitro was evaluated, which was stable in PBS and human plasma. Lymphatic tracing were studied to determine the blue-stained intensity of PAMAM-AB in right popliteral lymph nodes (PLNs), iliac lymph nodes (ILNs) and para-aortic lymph nodes (PALNs) after subcutaneous administration. The pharmacokinetics and biodistribution of PAMAM-AB in mice were investigated. PLNs, ILNs and PALNs could be obviously blue-stained within 10 min after PAMAM-AB administration, and displayed a more rapid lymphatic absorption, a higher AUC value in lymph nodes and a longer lymph nodes residence time compared with methylene blue solution (MB-S), MB water-in-oil microemulsion (MB-ME), MB multiple microemulsion (MB-MME). Enhanced lymphatic drainage from the injection site and uptake into lymph of PAMAM-AB indicated that PAMAM-AB possesses the double function of lymphatic tracing and lymphatic targeting, and suggested the potential for the development of lymphatic targeting vectors or as a lymphatic tracer in its own right.

  9. Database dictionary for the results of groundwater tracer tests using tritiated water, conducted at the Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, B.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Civil Engineering; Huff, D.D. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

    1997-05-01

    In 1977, the United States Geological Survey (USGS) conducted two tracer tests at the Oak Ridge National Laboratory (ORNL) using tritiated water to study the relative importance of bedding-plane openings on shallow groundwater flow. Through a cooperative agreement between the USGS and the US Department of Energy (DOE), the data were made available to researchers at the Oak Ridge National Laboratory (ORNL), who organized the data into a data management format. The results of these groundwater tracer tests have been compiled into a collection of four SAS data sets. This report documents these SAS data sets, including their structure, methodology, and content. The SAS data sets include information on precipitation, tritium, water levels, and well construction for wells at or near ORNL radioactive waste burial grounds 4, 5, and 6.

  10. Environmental radioactive intercomparison program and radioactive standards program

    Energy Technology Data Exchange (ETDEWEB)

    Dilbeck, G. [Environmental Monitoring Systems Laboratory, Las Vegas, NV (United States)

    1993-12-31

    The Environmental Radioactivity Intercomparison Program described herein provides quality assurance support for laboratories involved in analyzing public drinking water under the Safe Drinking Water Act (SDWA) Regulations, and to the environmental radiation monitoring activities of various agencies. More than 300 federal and state nuclear facilities and private laboratories participate in some phase of the program. This presentation describes the Intercomparison Program studies and matrices involved, summarizes the precision and accuracy requirements of various radioactive analytes, and describes the traceability determinations involved with radioactive calibration standards distributed to the participants. A summary of program participants, sample and report distributions, and additional responsibilities of this program are discussed.

  11. Radionuclides as tracers of coastal processes in Brazil: review, synthesis, and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Isaac R.; Burnett, William C., E-mail: santos@ocean.fsu.edu [Florida State University, Tallahassee, FL (United States). Dept. of Oceanography. Environmental Radioactivity Measurement Facility; Godoy, Jose M. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2008-04-15

    We review the usefulness, limitations, significance, and coastal management implications of radionuclide measurements in Brazilian coastal environments. We focus on the use of radionuclides as tracers of sedimentary processes and submarine groundwater discharge (SGD). We also discuss artificial radionuclide contamination and high natural radioactivity areas. The interpretation of {sup 14}C-, {sup 137}Cs-, and {sup 210}Pb-derived sedimentation rates has provided evidence that inappropriate soil use by urban and agricultural activities has intensified erosion processes on land, which is reflected in depositional environments, such as coastal lagoons, estuaries and mangroves. Of the processes discussed in this paper, SGD is the one that requires the most scientific effort in the short-term. There have been only two case studies using {sup 222}Rn and radium isotopes as groundwater tracers in Brazil. These investigations showed that SGD can be a major source of nutrients and other dissolved species to the coastal ocean. Baseline {sup 137}Cs, {sup 90}Sr, {sup 239+240}Pu, and {sup 238}Pu concentrations in seawater from the whole Brazilian coastal zone are very low. Therefore, in spite of contamination problems in many ecosystems in the northern hemisphere, artificial radionuclide pollution appears to be negligible along the Brazilian coast. Phosphate fertilizer industries and petroleum processing facilities are the main economic activities producing Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM). Even though a few attempts have been made to assess the radiological effects of these activities, their potential threats indicate a need for the radiological control of their wastes. This review showed that the number of studies within the field of environmental radioactivity is still small in Brazil and much more research is needed to understand processes of high interest for environmental managers. In the near future, it is likely that such studies

  12. A preliminary study on the geochemical environment for deep geological disposal of high level radioactive waste in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chun Soo; Bae, Dae Seok; Kim, Kyung Su; Koh, Yong Kwon; Park, Byoung Yun

    2000-03-01

    Geochemical study on the groundwater from crystalline rocks (granite and gneiss) for the deep geological disposal of high-level radioactive waste was carried out in order to elucidate the hydrogeochemical and isotope characteristics and geochemical evolution of the groundwater. Study areas are Jungwon, Chojeong, Youngcheon and Yusung for granite region, Cheongyang for gneiss region, and Yeosu for volcanic region. Groundwaters of each study areas weree sampled and analysed systematically. Groundwaters can be grouped by their chemistry and host rock. Origin of the groundwater was proposed by isotope ({sup 18}O, {sup 2}H, {sup 13}C, {sup 34}S, {sup 87}Sr, {sup 15}N) studies and the age of groundwater was inferred from their tritium contents. Based ont the geochemical and isotope characteristics, the geochemical evolutions of each types of groundwater were simulated using SOLVEQ/CHILLER and PHREEQC programs.

  13. Hybrid dynamic radioactive particle tracking (RPT) calibration technique for multiphase flow systems

    Science.gov (United States)

    Khane, Vaibhav; Al-Dahhan, Muthanna H.

    2017-04-01

    The radioactive particle tracking (RPT) technique has been utilized to measure three-dimensional hydrodynamic parameters for multiphase flow systems. An analytical solution to the inverse problem of the RPT technique, i.e. finding the instantaneous tracer positions based upon instantaneous counts received in the detectors, is not possible. Therefore, a calibration to obtain a counts-distance map is needed. There are major shortcomings in the conventional RPT calibration method due to which it has limited applicability in practical applications. In this work, the design and development of a novel dynamic RPT calibration technique are carried out to overcome the shortcomings of the conventional RPT calibration method. The dynamic RPT calibration technique has been implemented around a test reactor with 1foot in diameter and 1 foot in height using Cobalt-60 as an isotopes tracer particle. Two sets of experiments have been carried out to test the capability of novel dynamic RPT calibration. In the first set of experiments, a manual calibration apparatus has been used to hold a tracer particle at known static locations. In the second set of experiments, the tracer particle was moved vertically downwards along a straight line path in a controlled manner. The obtained reconstruction results about the tracer particle position were compared with the actual known position and the reconstruction errors were estimated. The obtained results revealed that the dynamic RPT calibration technique is capable of identifying tracer particle positions with a reconstruction error between 1 to 5.9 mm for the conditions studied which could be improved depending on various factors outlined here.

  14. A review of methods for modelling environmental tracers in groundwater: Advantages of tracer concentration simulation

    Science.gov (United States)

    Turnadge, Chris; Smerdon, Brian D.

    2014-11-01

    Mathematical models of varying complexity have been developed since the 1960s to interpret environmental tracer concentrations in groundwater flow systems. This review examines published studies of model-based environmental tracer interpretation, the progress of different modelling approaches, and also considers the value of modelling tracer concentrations directly rather than estimations of groundwater age. Based on citation metrics generated using the Web of Science and Google Scholar reference databases, the most highly utilised interpretation approaches are lumped parameter models (421 citations), followed closely by direct age models (220 citations). A third approach is the use of mixing cell models (99 citations). Although lumped parameter models are conceptually simple and require limited data, they are unsuitable for characterising the internal dynamics of a hydrogeological system and/or under conditions where large scale anthropogenic stresses occur within a groundwater basin. Groundwater age modelling, and in particular, the simulation of environmental tracer transport that explicitly accounts for the accumulation and decay of tracer mass, has proven to be highly beneficial in constraining numerical models. Recent improvements in computing power have made numerical simulation of tracer transport feasible. We argue that, unlike directly simulated ages, the results of tracer mass transport simulation can be compared directly to observations, without needing to correct for apparent age bias or other confounding factors.

  15. EVALUATION OF LEAKAGE FROM FUME HOODS USING TRACER GAS, TRACER NANOPARTICLES AND NANOPOWDER HANDLING TEST METHODOLOGIES

    OpenAIRE

    Dunn, Kevin H.; Tsai, Candace Su-Jung; Woskie, Susan R.; Bennett, James S.; Garcia, Alberto; Ellenbecker, Michael J.

    2014-01-01

    The most commonly reported control used to minimize workplace exposures to nanomaterials is the chemical fume hood. Studies have shown, however, that significant releases of nanoparticles can occur when materials are handled inside fume hoods. This study evaluated the performance of a new commercially available nano fume hood using three different test protocols. Tracer gas, tracer nanoparticle, and nanopowder handling protocols were used to evaluate the hood. A static test procedure using tr...

  16. Nuclear Structure Studies of Exotic Nuclei with Radioactive Ion Beams A Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Winger, Jeff Allen [Mississippi State Univ., Mississippi State, MS (United States)

    2016-04-21

    Beta-decay spectroscopy provides important information on nuclear structure and properties needed to understand topics as widely varied as fundamental nuclear astrophysics to applied nuclear reactor design. However, there are significant limitations of our knowledge due to an inability to experimentally measure everything. Therefore, it is often necessary to rely on theoretical calculations which need to be vetted with experimental results. The focus of this report will be results from experimental research performed by the Principal Investigator (PI) and his research group at Mississippi State University in which the group played the lead role in proposing, implementing, performing and analyzing the experiment. This research was carried out at both the National Superconduction Cyclotron Laboratory (NSCL) at Michigan State University and the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. The primary emphasis of the research was the use of \\bdec spectroscopy as a tool to understand the evolution of nuclear structure in neutron-rich nuclei which could then be applied to improve theory and to increase the overall knowledge of nuclear structure.

  17. Study of the Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    KamLAND Collaboration; Abe, S.; Enomoto, S.; Furuno, K.; Gando, Y.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Nakajima, K.; Nakajima, K.; Nakamura, K.; Nakamura, M.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takemoto, Y.; Tamae, K.; Terashima, A.; Watanabe, H.; Yonezawa, E.; Yoshida, S.; Kozlov, A.; Murayama, H.; Busenitz, J.; Classen, T.; Grant, C.; Keefer, G.; Leonard, D. S.; McKee, D.; Piepke, A.; Banks, T. I.; Bloxham, T.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Gray, F.; Guardincerri, E.; Hsu, L.; Ichimura, K.; Kadel, R.; Lendvai, C.; Luk, K.-B.; O' Donnell, T.; Steiner, H. M.; Winslow, L. A.; Dwyer, D. A.; Jillings, C.; Mauger, C.; McKeown, R. D.; Vogel, P.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Pakvasa, S.; Foster, J.; Horton-Smith, G. A.; Tang, A.; Dazeley, S.; Downum, K. E.; Gratta, G.; Tolich, K.; Bugg, W.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Heeger, K. M.; Piquemal, F.; Ricol, J.-S.; Decowski, M. P.

    2009-06-30

    Radioactive isotopes produced through cosmic muon spallation are a background for rare event detection in {nu} detectors, double-beta-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of {sup 11}C. Data from the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillator, and for checking estimates from current simulations based upon MUSIC, FLUKA, and Geant4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be (2.8 {+-} 0.3) x 10{sup -4} n/({mu} {center_dot} (g/cm{sup 2})). For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.

  18. Study on Shielding Requirements for Radioactive Waste Transportation in a Mo-99 Production Plant - 13382

    Energy Technology Data Exchange (ETDEWEB)

    Melo Rego, Maria Eugenia de; Kazumi Sakata, Solange; Vicente, Roberto; Hiromoto, Goro [Nuclear and Energy Research Institute, IPEN-CNEN/SP (Brazil)

    2013-07-01

    Brazil is currently planning to produce {sup 99}Mo from fission of low enriched uranium (LEU) targets. The planned end of irradiation activity of {sup 99}Mo is about 185 TBq (5 kCi) per week to meet the present domestic demand of {sup 99m}Tc generators. The radioactive wastes from the production plant will be transferred to a waste treatment facility at the same site. The total activity of the actinides, fission and activation products present in the wastes can be predicted based on the yields of fission and activation data for the irradiation conditions, such as composition and mass of uranium targets, irradiation time, neutron flux, production schedule, etc., which were in principle already established by the project management. The transportation of the wastes from the production plant to the treatment facility will be done by means of special shielded packages. An assessment of the shielding required for the packages has been done and the results are presented here, aiming at contributing to the design of the waste management facility for the {sup 99}Mo production plant. (authors)

  19. Journal: Efficient Hydrologic Tracer-Test Design for Tracer ...

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for the determination of basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowledge of the basic hydraulic and geometric parameters desired and the appropriate tracer mass to release. A new efficient hydrologic tracer-test design (EHTD) methodology has been developed to facilitate the design of tracer tests by root determination of the one-dimensional advection-dispersion equation (ADE) using a preset average tracer concentration which provides a theoretical basis for an estimate of necessary tracer mass. The method uses basic measured field parameters (e.g., discharge, distance, cross-sectional area) that are combined in functional relatipnships that descrive solute-transport processes related to flow velocity and time of travel. These initial estimates for time of travel and velocity are then applied to a hypothetical continuous stirred tank reactor (CSTR) as an analog for the hydrological-flow system to develop initial estimates for tracer concentration, tracer mass, and axial dispersion. Application of the predicted tracer mass with the hydraulic and geometric parameters in the ADE allows for an approximation of initial sample-collection time and subsequent sample-collection frequency where a maximum of 65 samples were determined to be necessary for descri

  20. Natural tracer profiles across argillaceous formations

    Energy Technology Data Exchange (ETDEWEB)

    Mazurek, Martin, E-mail: mazurek@geo.unibe.ch [Rock-Water Interaction, Institute of Geological Sciences, University of Bern (Switzerland); Alt-Epping, Peter [Rock-Water Interaction, Institute of Geological Sciences, University of Bern (Switzerland); Bath, Adrian [Intellisci, Willoughby on the Wolds, Loughborough LE12 6SZ (United Kingdom); Gimmi, Thomas [Rock-Water Interaction, Institute of Geological Sciences, University of Bern (Switzerland)] [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Niklaus Waber, H. [Rock-Water Interaction, Institute of Geological Sciences, University of Bern (Switzerland); Buschaert, Stephane [Andra, Parc de la Croix Blanche, 92298 Chatenay-Malabry Cedex (France); Canniere, Pierre De; Craen, Mieke De [SCK-CEN, 2400 Mol (Belgium); Gautschi, Andreas [Nagra, 5430 Wettingen (Switzerland); Savoye, Sebastien [IRSN, 92262 Fontenay-aux-Roses Cedex (France); Vinsot, Agnes [Andra, Parc de la Croix Blanche, 92298 Chatenay-Malabry Cedex (France); Wemaere, Isabelle [SCK-CEN, 2400 Mol (Belgium); Wouters, Laurent [Ondraf/Niras, 1210 Brussels (Belgium)

    2011-07-15

    Highlights: > Solute transport processes in clay and shale formations at nine sites are examined. > Conservative pore-water tracers (e.g. Cl{sup -}, {delta}{sup 18}O, {delta}{sup 2}H, He) show regular profiles. > These indicate the dominance of diffusive transport over times of 10{sup 5}-10{sup 6} years. > The contribution of vertical advection to transport is limited or negligible. > Modelled evolution times are in line with independent palaeo-hydrogeological data. - Abstract: Argillaceous formations generally act as aquitards because of their low hydraulic conductivities. This property, together with the large retention capacity of clays for cationic contaminants, has brought argillaceous formations into focus as potential host rocks for the geological disposal of radioactive and other waste. In several countries, programmes are under way to characterise the detailed transport properties of such formations at depth. In this context, the interpretation of profiles of natural tracers in pore waters across the formations can give valuable information about the large-scale and long-term transport behaviour of these formations. Here, tracer-profile data, obtained by various methods of pore-water extraction for nine sites in central Europe, are compiled. Data at each site comprise some or all of the conservative tracers: anions (Cl{sup -}, Br{sup -}), water isotopes ({delta}{sup 18}O, {delta}{sup 2}H) and noble gases (mainly He). Based on a careful evaluation of the palaeo-hydrogeological evolution at each site, model scenarios are derived for initial and boundary pore-water compositions and an attempt is made to numerically reproduce the observed tracer distributions in a consistent way for all tracers and sites, using transport parameters derived from laboratory or in situ tests. The comprehensive results from this project have been reported in . Here the results for three sites are presented in detail, but the conclusions are based on model interpretations of the

  1. Communication: Ab initio study of O{sub 4}H{sup +}: A tracer molecule in the interstellar medium?

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, George D.; Bernal-Uruchurtu, Margarita I.; Hernández-Lamoneda, Ramón, E-mail: ramon@uaem.mx [Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, 62210 Cuernavaca, Morelos (Mexico)

    2014-08-28

    The structure and energetics of the protonated molecular oxygen dimer calculated via ab initio methods is reported. We find structures that share analogies with the eigen and zundel forms for the protonated water dimer although the symmetrical sharing of the proton is more prevalent. Analysis of different fragmentation channels show charge transfer processes which indicate the presence of conical intersections for various states including the ground state. An accurate estimate for the proton affinity of O{sub 4} leads to a significantly larger value (5.6 eV) than for O{sub 2} (4.4 eV), implying that the reaction H{sub 3}{sup +} + O{sub 4} → O{sub 4}H{sup +} + H{sub 2} is exothermic by 28 Kcal/mol as opposed to the case of O{sub 2} which is nearly thermoneutral. This opens up the possibility of using O{sub 4}H{sup +} as a tracer molecule for oxygen in the interstellar medium.

  2. Novel and non-traditional use of stable isotope tracers to study metal bioavailability from natural particles

    Science.gov (United States)

    Croteau, Marie-Noële; Cain, Daniel J.; Fuller, Christopher C.

    2013-01-01

    We devised a novel tracing approach that involves enriching test organisms with a stable metal isotope of low natural abundance prior to characterizing metal bioavailability from natural inorganic particles. In addition to circumventing uncertainties associated with labeling natural particles and distinguishing background metals, the proposed "reverse labeling" technique overcomes many drawbacks inherent to using radioisotope tracers. Specifically, we chronically exposed freshwater snails (Lymnaea stagnalis) to synthetic water spiked with Cu that was 99.4% 65Cu to increase the relative abundance of 65Cu in the snail’s tissues from 32% to >80%. The isotopically enriched snails were then exposed to benthic algae mixed with Cu-bearing Fe–Al particles collected from the Animas River (Colorado), an acid mine drainage impacted river. We used 63Cu to trace Cu uptake from the natural particles and inferred their bioavailability from calculation of Cu assimilation into tissues. Cu assimilation from these particles was 44%, indicating that 44% of the particulate Cu was absorbed by the invertebrate. This demonstrates that inorganic particulate Cu can be bioavailable. The reverse labeling approach shows great potential in various scientific areas such as environmental contamination and nutrition for addressing questions involving uptake of an element that naturally has multiple isotopes.

  3. Testing cosmic-ray acceleration with radio relics: a high-resolution study using MHD and tracers

    CERN Document Server

    Wittor, Denis; Brüggen, Marcus

    2016-01-01

    Weak shocks in the intracluster medium may accelerate cosmic-ray protons and cosmic-ray electrons differently depending on the angle between the upstream magnetic field and the shock normal. In this work, we investigate how shock obliquity affects the production of cosmic rays in high-resolution simulations of galaxy clusters. For this purpose, we performed a magneto-hydrodynamical simulation of a galaxy cluster using the mesh refinement code \\enzo. We use Lagrangian tracers to follow the properties of the thermal gas, the cosmic rays and the magnetic fields over time. We tested a number of different acceleration scenarios by varying the obliquity-dependent acceleration efficiencies of protons and electrons, and by examining the resulting hadronic $\\gamma$-ray and radio emission. We find that the radio emission does not change significantly if only quasi-perpendicular shocks are able to accelerate cosmic-ray electrons. Our analysis suggests that radio emitting electrons found in relics have been typically sho...

  4. Plasma apolipoprotein B-48 transport in obese men: a new tracer kinetic study in the postprandial state.

    Science.gov (United States)

    Wong, Annette T Y; Chan, Dick C; Pang, Jing; Watts, Gerald F; Barrett, P Hugh R

    2014-01-01

    The mechanisms responsible for impaired chylomicron metabolism have not been adequately investigated in obese subjects. We aimed to compare apolipoprotein (apo) B-48 kinetics in obese and lean men by developing a new model to describe the kinetics of apoB-48 particles in the postprandial state. Seven obese and 13 age-matched lean men were given an oral fat load. apoB-48 tracer to tracee ratios were measured after intravenous d3-leucine administration using gas chromatography-mass spectrometry. Kinetic parameters were derived using a multicompartmental model. Plasma total and incremental apoB-48 0-10 hour areas under the curve as well as apoB-48 secretion and fractional catabolic rate. Compared with lean men, fasting plasma triglyceride (+148%) and apoB-48 (+110%) concentrations as well as plasma total and incremental triglycerides (+184% and +185%, respectively) and apoB-48 (+182% and 224%, respectively) areas under the curve were significantly higher in obese men (Pkinetic model, which describes the non-steady-state postprandial metabolism of apoB-48.

  5. Study of sensitivity and application of some tracers of use in hydrologic works; Estudio de sensibilidad y aplicacion de algunos trazadores de empleo en trabajos hidrologicos

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, M.C. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1980-05-15

    Inside the Industrial Applications Management, particularly in the Hydrology department, in the ININ outlined diverse problems are had in the study of underground waters and surface waters that either in a particular way, or in inter institutional collaboration (SARH, CFE, UNAM) it seen the necessity to solve this problem in the interconnection aspects in aquifer, expenses and contamination. One of the medullary parts that are had in this study is the applied evaluation of the tracer one that it presents two general aspects: a) determination method and b) Applicability depending on the land type that one has in the current to be applied. This study seeks according to: the sensibility reached with each one, and the evaluation of some other parameters like used time, cost and mainly realization feasibility at field level, to present some alternative for the use of them. (Author)

  6. Environmental impact assessment of radioactive materials during sea transportation: Case study of plutonium released in the ocean

    Energy Technology Data Exchange (ETDEWEB)

    Niel, J.Ch.

    1996-12-31

    The objectives of the environmental impact assessments of radioactive materials are at first given. The NSPI (Nuclear Safety Protection Institut) is jointly involved in these assessments. Currently, the NSPI is studying the case of plutonium release. The summary of this study is given. Indeed, to perform this assessment, the marine environment has to be modelled on a large scale and the exposure path to be calculated. Hypothesis has been made on the release phenomena as well. The proposed model, the origin of contamination, the hypothesis for the calculation and the exposure pathway are then explained. All the sea products are supposed to be eaten within the European countries. Cumulated collective doses for European countries after 50 years should be 160 man Sv in the western part of the Channel and 4.47 man Sv in the north eastern part of the atlantic ocean. (O.M.). 2 refs.

  7. Study of casks shielded with heavy metal to transport highly radioactive substances; Estudo de embalados com blindagem em metal pesado para transporte de substancias altamente radioativas

    Energy Technology Data Exchange (ETDEWEB)

    Lucchesi, R.F.; Hara, D.H.S.; Martinez, L.G.; Mucsi, C.S.; Rossi, J.L., E-mail: rflguimaraes@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    Nowadays, Brazil relies on casks produced abroad for transportation in its territory of substances that are sources of high radioactivity, especially the Mo-99. The product of the radioactive decay of the Mo-99 is the Tc-99m, which is used in nuclear medicine for administration to humans in the form of injectable radioactive drugs for the image diagnosis of numerous pathologies. This paper aims to study the existing casks in order to propose materials for the construction of the core part as shielding against gamma radiation. To this purpose, the existing literature on the subject was studied, as well as evaluation of existing and available casks. The study was focused on the core of which is made of heavy metals, especially depleted uranium for shielding the emitted radiation. (author)

  8. Wear Measurement of Highly Cross-linked UHMWPE using a 7Be Tracer Implantation Technique

    Energy Technology Data Exchange (ETDEWEB)

    Wimmer, Markus A. [Rush Uniiv. Medical Center; Laurent, Michael P. [Rush Univ. Medical Center; Dwivedi, Yasha [Rush Univ. Medical Center; Gallardo, Luis A. [Rush Univ. Medical Center; Chipps, K. [Colorado School of Mines, Golden; Blackmon, Jeffery C [Louisiana State University; Kozub, R. L. [Tennessee Technological University; Bardayan, Daniel W [ORNL; Gross, Carl J [ORNL; Stracener, Daniel W [ORNL; Smith, Michael Scott [ORNL; Nesaraja, Caroline D [ORNL; Erikson, Luke [Colorado School of Mines, Golden; Patel, Nidhi [Colorado School of Mines, Golden; Rehm, Karl E. [Argonne National Laboratory (ANL); Ahmad, Irshad [Argonne National Laboratory (ANL); Greene, John P. [Argonne National Laboratory (ANL); Greife, Uwe [Colorado School of Mines, Golden

    2013-01-01

    The very low wear rates achieved with the current highly cross-linked ultrahigh molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are there- fore being explored. The purpose of this study was to perform a proof-of-concept experiment on the use of the radioactive tracer beryllium-7 (7Be) for the determination of in vitro wear in a highly cross-linked orthopedic UHMWPE. Three cross-linked and four conventional UHMWPE pins made from compression- molded GUR 1050, were activated with 109 to 1010 7Be nuclei using a new implantation setup that produced a homogenous distribution of implanted nuclei up to 8.5 lm below the surface. The pins were tested for wear in a six-station pin-on-flat appara- tus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross-linked UHMWPE pins was readily detected and esti- mated to be 17 6 3 lg per million cycles. The conventional-to- cross-linked ratio of the wear rates was 13.1 6 0.8, in the expected range for these materials. Oxidative degradation dam- age from implantation was negligible; however, a weak depend- ence of wear on implantation dose was observed limiting the number of radioactive tracer atoms that can be introduced. Future applications of this tracer technology may include the analysis of location-specific wear, such as loss of material in the post or backside of a tibial insert.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

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

  10. Tracer Dispersion in a Multi-compartment Structure

    CERN Document Server

    Skvortsov, A; Gamble, G; Roberts, M; Ilaya, O; Pitaliadda, D

    2012-01-01

    An experimental study of the tracer dispersion in a complex structure is presented. A point source of tracer (dyed salt) was placed inside a multi-compartment structure embedded in water tank. This experimental setting corresponds to a hazardous tracer release inside the engineering structure (building, ship, aircarft etc). A system of conductivity sensors was deployed to monitor the propagation of a tracer plume in the structure, including tracer trapping inside some compartments and its release to the outside environment through the external openings. The experimental data is processed by employing the ideas of scaling and self-similarity of underlying transport processes. The established and validated scaling laws provide a rigorous way to up-scale the results of laboratory modeling to real operational scenarios and can be used as an important step in the development of risk-assessment models for the first responders to hazardous releases. Keywords: hazardous plume, tracer dispersion, diffusion and advecti...

  11. A Probabilistic Performance Assessment Study of Potential Low-Level Radioactive Waste Disposal Sites in Taiwan

    Science.gov (United States)

    Knowlton, R. G.; Arnold, B. W.; Mattie, P. D.; Kuo, M.; Tien, N.

    2006-12-01

    For several years now, Taiwan has been engaged in a process to select a low-level radioactive waste (LLW) disposal site. Taiwan is generating LLW from operational and decommissioning wastes associated with nuclear power reactors, as well as research, industrial, and medical radioactive wastes. The preliminary selection process has narrowed the search to four potential candidate sites. These sites are to be evaluated in a performance assessment analysis to determine the likelihood of meeting the regulatory criteria for disposal. Sandia National Laboratories and Taiwan's Institute of Nuclear Energy Research have been working together to develop the necessary performance assessment methodology and associated computer models to perform these analyses. The methodology utilizes both deterministic (e.g., single run) and probabilistic (e.g., multiple statistical realizations) analyses to achieve the goals. The probabilistic approach provides a means of quantitatively evaluating uncertainty in the model predictions and a more robust basis for performing sensitivity analyses to better understand what is driving the dose predictions from the models. Two types of disposal configurations are under consideration: a shallow land burial concept and a cavern disposal concept. The shallow land burial option includes a protective cover to limit infiltration potential to the waste. Both conceptual designs call for the disposal of 55 gallon waste drums within concrete lined trenches or tunnels, and backfilled with grout. Waste emplaced in the drums may be solidified. Both types of sites are underlain or placed within saturated fractured bedrock material. These factors have influenced the conceptual model development of each site, as well as the selection of the models to employ for the performance assessment analyses. Several existing codes were integrated in order to facilitate a comprehensive performance assessment methodology to evaluate the potential disposal sites. First, a need

  12. Ultrastructural examination of the corticocollicular pathway in the guinea pig: a study using electron microscopy, neural tracers, and GABA immunocytochemistry

    Directory of Open Access Journals (Sweden)

    Kyle T Nakamoto

    2013-05-01

    Full Text Available Projections from auditory cortex (AC can alter the responses of cells in the inferior colliculus (IC to sounds. Most IC cells show excitation and inhibition after stimulation of the AC. AC axons release glutamate and excite their targets, so inhibition is presumed to result from cortical activation of GABAergic IC cells that inhibit other IC cells via local projections. However, it is not known whether cortical axons contact GABAergic IC cells directly. We labeled corticocollicular axons by injecting fluorescent dextrans into the AC in guinea pigs. We visualized the tracer with diaminobenzidine and processed the tissue for electron microscopy. We identified presumptive GABAergic profiles with post-embedding anti-GABA immunogold histochemistry on ultrathin sections. We identified dextran-labeled cortical boutons in the IC and identified their postsynaptic targets according to morphology (e.g., spine, dendrite and GABA-reactivity. Cortical synapses were observed in all IC subdivisions, but were comparatively rare in the central nucleus. Cortical boutons contain round vesicles and few mitochondria. They form asymmetric synapses with spines (most frequently, dendritic shafts and, least often, with cell bodies. Excitatory boutons in the IC can be classified as large, medium or small; most cortical boutons belong to the small excitatory class, while a minority (~14% belong to the medium excitatory class. Approximately 4% of the cortical targets were GABA-positive; these included dendritic shafts, spines, and cell bodies.We conclude that the majority of cortical boutons contact non-GABAergic (i.e., excitatory IC cells and a small proportion (4% contact GABAergic cells. Given that most IC cells show inhibition (as well as excitation after cortical stimulation, it is likely that the majority of cortically-driven inhibition in the IC results from cortical activation of a relatively small number of IC GABAergic cells that have extensive local axons.

  13. Atomic Batteries: Energy from Radioactivity

    OpenAIRE

    Kumar, Suhas

    2015-01-01

    With alternate, sustainable, natural sources of energy being sought after, there is new interest in energy from radioactivity, including natural and waste radioactive materials. A study of various atomic batteries is presented with perspectives of development and comparisons of performance parameters and cost. We discuss radioisotope thermal generators, indirect conversion batteries, direct conversion batteries, and direct charge batteries. We qualitatively describe their principles of operat...

  14. How to chase a tracer - combining conventional salt tracer testing and direct push electrical conductivity profiling for enhanced aquifer characterization

    Science.gov (United States)

    Vienken, Thomas; Huber, Emanuel; Kreck, Manuel; Huggenberger, Peter; Dietrich, Peter

    2017-01-01

    Tracer testing is a well-established technique in hydrogeological site characterization. However, certain a priori knowledge of the hydraulic regime is required beforehand to avoid test failure, e.g. miss of tracer. In this study, we propose a novel tracer test concept for the hydraulic characterization of shallow unconsolidated sedimentary deposits when only scarce a priori information on the hydraulic regime is available. Therefore, we combine conventional salt tracer testing with direct push vertical high resolution electrical conductivity logging. The proposed tracer test concept was successfully tested on coarse, braided river deposits of the Tagliamento River, Italy. With limited a priori information available two tracer tests were performed in three days to reliably determine ground water flow direction and velocity allowing on-site decision-making to adaptively install observation wells for reliable breakthrough curve measurements. Furthermore, direct push vertical electrical profiling provided essential information about the plume characteristics with outstanding measurement resolution and efficiency.

  15. Positional enrichment by proton analysis (PEPA). A one-dimensional {sup 1}H-NMR approach for {sup 13}C stable isotope tracer studies in metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Vinaixa, Maria; Yanes, Oscar [Department of Electronic Engineering-Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Rodriguez, Miguel A.; Capellades, Jordi [Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Aivio, Suvi; Stracker, Travis H. [Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (Spain); Gomez, Josep; Canyellas, Nicolau [Department of Electronic Engineering-, Universitat Rovira i Virgili, Tarragona (Spain)

    2017-03-20

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of {sup 13}C-satellite peaks using 1D-{sup 1}H-NMR spectra. In comparison with {sup 13}C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of {sup 13}C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of {sup 1}H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  16. A pilot study of the feasibility of long-term human bone balance during perimenopause using a {sup 41}Ca tracer

    Energy Technology Data Exchange (ETDEWEB)

    Hui, S.K. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel) and Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota, 420 Delaware Street SE, Mayo Mail Code 494, Minneapolis, MN 55455 (United States)]. E-mail: huixx019@umn.edu; Prior, J. [Deparment of Medicine/Endocrinology, University of British Columbia, Vancouver, B.C., V5Z 1C6 (Canada); Gelbart, Z. [TRIUMF, Vancouver, B.C., V6T2A3 (Canada); Johnson, R.R. [TRIUMF, Vancouver, B.C., V6T2A3 (Canada); Lentle, B.C. [Department of Radiology, University of British Columbia, British Columbia, V8M 1V4 (Canada); Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

    2007-06-15

    The mechanisms governing calcium fluxes during bone remodeling processes in perimenopausal women are poorly known. Despite higher, albeit erratic, estradiol levels in perimenopause, spine bone loss is greater than during the first five years past the final menstrual flow when estradiol becomes low. Understanding changes during this dynamic transition are important to prevent fragility fractures in midlife and older women. The exploration of long-lived {sup 41}Ca (T {sub 1/2} = 1.04 x 10{sup 5} yrs) tracer measurements using accelerator mass spectrometry (AMS) leads to the possibility of monitoring bone remodeling balance. With this new technology, we explored a pilot long-term feasibility study of bone health by measuring the {sup 41}Ca trace element in urine for six years from premenopausal to later perimenopausal phases in one midlife woman. We measured bone mineral density in parallel.

  17. Tracking groundwater discharge to a large river using tracers and geophysics.

    Science.gov (United States)

    Harrington, Glenn A; Gardner, W Payton; Munday, Tim J

    2014-01-01

    Few studies have investigated large reaches of rivers in which multiple sources of groundwater are responsible for maintaining baseflow. This paper builds upon previous work undertaken along the Fitzroy River, one of the largest perennial river systems in north-western Australia. Synoptic regional-scale sampling of both river water and groundwater for a suite of environmental tracers ((4) He, (87) Sr/(86) Sr, (222) Rn and major ions), and subsequent modeling of tracer behavior in the river, has enabled definition and quantification of groundwater input from at least three different sources. We show unambiguous evidence of both shallow "local" groundwater, possibly recharged to alluvial aquifers beneath the adjacent floodplain during recent high-flow events, and old "regional" groundwater introduced via artesian flow from deep confined aquifers. We also invoke hyporheic exchange and either bank return flow or parafluvial flow to account for background (222) Rn activities and anomalous chloride trends along river reaches where there is no evidence of the local or regional groundwater inputs. Vertical conductivity sections acquired through an airborne electromagnetic (AEM) survey provide insights to the architecture of the aquifers associated with these sources and general groundwater quality characteristics. These data indicate fresh groundwater from about 300 m below ground preferentially discharging to the river, at locations consistent with those inferred from tracer data. The results demonstrate how sampling rivers for multiple environmental tracers of different types-including stable and radioactive isotopes, dissolved gases and major ions-can significantly improve conceptualization of groundwater-surface water interaction processes, particularly when coupled with geophysical techniques in complex hydrogeological settings.

  18. The application of radioactive isotopes to the study of motion of silt and pebbles in the rivers and in the sea; Application des isotopes radioactifs a l'etude des mouvements des sediments et des galets dans les cours d'eau et en mer

    Energy Technology Data Exchange (ETDEWEB)

    Hours, R. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

    1959-07-01

    The application of radioactive tracers to the study of sediments drift has received considerable attention since 1954 in various countries. A comparative review is made of a number of techniques of labelling, immersing and detecting silts, sands, and pebbles. The influence of the burying of the active material is emphasized. The different experiments which have been so far carried out are described. (author) [French] L'application des traceurs radioactifs a l'etude des deplacements de sediments a fait depuis 1954 l'objet de travaux nombreux dans divers pays. On passe en revue et on compare differentes techniques de marquage, d'immersion et de detection des vases, sables et galets; on insiste sur l'influence de l'enfouissement du materiau actif. On decrit les differentes experiences effectuees jusqu'a ce jour. (auteur)

  19. Can positron emission tomography/computed tomography with the dual tracers fluorine-18 fluoroestradiol and fluorodeoxyglucose predict neoadjuvant chemotherapy response of breast cancer?--A pilot study.

    Directory of Open Access Journals (Sweden)

    Zhongyi Yang

    Full Text Available OBJECTIVE: To assess the clinical value of dual tracers Positron emission tomography/computed tomography (PET/CT (18F-fluoroestradiol ((18F-FES and (18F-fluorodeoxyglucose ((18F-FDG in predicting neoadjuvant chemotherapy response (NAC of breast cancer. METHODS: Eighteen consecutive patients with newly diagnosed, non-inflammatory, stage II and III breast cancer undergoing NAC were included. Before chemotherapy, they underwent both (18F-FES and (18F-FDG PET/CT scans. Surgery was performed after three to six cycles of chemotherapy. Tumor response was graded and divided into two groups: the responders and non-responders. We used the maximum standardized uptake value (SUVmax to qualify each primary lesion. RESULTS: Pathologic analysis revealed 10 patients were responders while the other 8 patients were non-responders. There was no statistical difference of SUVmax-FDG and tumor size between these two groups (P>0.05. On the contrary, SUVmax-FES was lower in responders (1.75±0.66 versus 4.42±1.14; U=5, P=0.002; and SUVmax-FES/FDG also showed great value in predicting outcome (0.16±0.06 versus 0.54±0.22; U=5, P=0.002. CONCLUSIONS: Our study showed (18F-FES PET/CT might be feasible to predict response of NAC. However, whether the use of dual tracers (18F-FES and (18F-FDG has complementary value should be further studied.

  20. Assessment study for multi-barrier system used in radioactive borate waste isolation based on Monte Carlo simulations.

    Science.gov (United States)

    Bayoumi, T A; Reda, S M; Saleh, H M

    2012-01-01

    Radioactive waste generated from the nuclear applications should be properly isolated by a suitable containment system such as, multi-barrier container. The present study aims to evaluate the isolation capacity of a new multi-barrier container made from cement and clay and including borate waste materials. These wastes were spiked by (137)Cs and (60)Co radionuclides to simulate that waste generated from the primary cooling circuit of pressurized water reactors. Leaching of both radionuclides in ground water was followed and calculated during ten years. Monte Carlo (MCNP5) simulations computed the photon flux distribution of the multi-barrier container, including radioactive borate waste of specific activity 11.22KBq/g and 4.18KBq/g for (137)Cs and (60)Co, respectively, at different periods of 0, 15.1, 30.2 and 302 years. The average total flux for 100cm radius of spherical cell was 0.192photon/cm(2) at initial time and 2.73×10(-4)photon/cm(2) after 302 years. Maximum waste activity keeping the surface radiation dose within the permissible level was calculated and found to be 56KBq/g with attenuation factors of 0.73cm(-1) and 0.6cm(-1) for cement and clay, respectively. The average total flux was 1.37×10(-3)photon/cm(2) after 302 years. Monte Carlo simulations revealed that the proposed multi-barrier container is safe enough during transportation, evacuation or rearrangement in the disposal site for more than 300 years. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. RADIO-ACTIVE TRANSDUCER

    Science.gov (United States)

    Wanetick, S.

    1962-03-01

    ABS>ure the change in velocity of a moving object. The transducer includes a radioactive source having a collimated beam of radioactive particles, a shield which can block the passage of the radioactive beam, and a scintillation detector to measure the number of radioactive particles in the beam which are not blocked by the shield. The shield is operatively placed across the radioactive beam so that any motion normal to the beam will cause the shield to move in the opposite direction thereby allowing more radioactive particles to reach the detector. The number of particles detected indicates the acceleration. (AEC)

  2. Radioactive waste storage issues

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Daniel E. [Colorado Christian Univ., Lakewood, CO (United States)

    1994-08-15

    In the United States we generate greater than 500 million tons of toxic waste per year which pose a threat to human health and the environment. Some of the most toxic of these wastes are those that are radioactively contaminated. This thesis explores the need for permanent disposal facilities to isolate radioactive waste materials that are being stored temporarily, and therefore potentially unsafely, at generating facilities. Because of current controversies involving the interstate transfer of toxic waste, more states are restricting the flow of wastes into - their borders with the resultant outcome of requiring the management (storage and disposal) of wastes generated solely within a state`s boundary to remain there. The purpose of this project is to study nuclear waste storage issues and public perceptions of this important matter. Temporary storage at generating facilities is a cause for safety concerns and underscores, the need for the opening of permanent disposal sites. Political controversies and public concern are forcing states to look within their own borders to find solutions to this difficult problem. Permanent disposal or retrievable storage for radioactive waste may become a necessity in the near future in Colorado. Suitable areas that could support - a nuclear storage/disposal site need to be explored to make certain the health, safety and environment of our citizens now, and that of future generations, will be protected.

  3. [{sup 18}F]FE rate at SUPPY: a suitable PET tracer for the adenosine A3 receptor? An in vivo study in rodents

    Energy Technology Data Exchange (ETDEWEB)

    Haeusler, Daniela; Zeilinger, Markus; Wadsak, Wolfgang; Hacker, Marcus; Mitterhauser, Markus [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); Kuntner, Claudia; Wanek, Thomas; Langer, Oliver [AIT Austrian Institute of Technology GmbH, Biomedical Systems, Health and Environment Department, Seibersdorf (Austria); Nics, Lukas [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); University of Vienna, Department of Nutritional Sciences, Vienna (Austria); Savli, Markus; Lanzenberger, Rupert R. [Medical University of Vienna, Department of Psychiatry and Psychotherapy, Vienna (Austria); Karagiannis, Panagiotis [King' s College London, Cutaneous Medicine and Immunotherapy, St. John' s Institute of Dermatology, Division of Genetics and Molecular Medicine King' s College London School of Medicine, Guy' s Hospital, London (United Kingdom); Shanab, Karem; Spreitzer, Helmut [University of Vienna, Department of Drug and Natural Product Synthesis, Vienna (Austria)

    2015-04-01

    The adenosine A{sub 3} receptor (A3R) is involved in cardiovascular, neurological and tumour-related pathologies and serves as an exceptional pharmaceutical target in the clinical setting. A3R antagonists are considered antiinflammatory, antiallergic and anticancer agents, and to have potential for the treatment of asthma, COPD, glaucoma and stroke. Hence, an appropriate A3R PET tracer would be highly beneficial for the diagnosis and therapy monitoring of these diseases. Therefore, in this preclinical in vivo study we evaluated the potential as a PET tracer of the A3R antagonist [{sup 18}F]FE rate at SUPPY. Rats were injected with [{sup 18}F]FE rate at SUPPY for baseline scans and blocking scans (A3R with MRS1523 or FE rate at SUPPY, P-gp with tariquidar; three animals each). Additionally, metabolism was studied in plasma and brain. In a preliminary experiment in a mouse xenograft model (mice injected with cells expressing the human A3R; three animals), the animals received [{sup 18}F]FE rate at SUPPY and [{sup 18}F]FDG. Dynamic PET imaging was performed (60 min in rats, 90 min in xenografted mice). In vitro stability of [{sup 18}F]FE rate at SUPPY in human and rat plasma was also evaluated. [{sup 18}F]FE rate at SUPPY showed high uptake in fat-rich regions and low uptake in the brain. Pretreatment with MRS1523 led to a decrease in [{sup 18}F]FE rate at SUPPY uptake (p = 0.03), and pretreatment with the P-gp inhibitor tariquidar led to a 1.24-fold increase in [{sup 18}F]FE rate at SUPPY uptake (p = 0.09) in rat brain. There was no significant difference in metabolites in plasma and brain in the treatment groups. However, plasma concentrations of [{sup 18}F]FE rate at SUPPY were reduced to levels similar to those in rat brain after blocking. In contrast to [{sup 18}F]FDG uptake (p = 0.12), the xenograft model showed significantly increased uptake of [{sup 18}F]FE rate at SUPPY in the tissue masses from CHO cells expressing the human A3R (p = 0.03). [{sup 18}F

  4. A rapid method for the measurement of sulfur hexafluoride (SF6), trifluoromethyl sulfur pentafluoride (SF5CF3), and Halon 1211 (CF2ClBr) in hydrologic tracer studies

    Science.gov (United States)

    Busenberg, Eurybiades; Plummer, L. Niel

    2010-01-01

    A rapid headspace method for the simultaneous laboratory determination of intentionally introduced hydrologic tracers, sulfur hexafluoride (SF6), trifluoromethyl sulfur pentafluoride (SF5CF3), Halon 1211 (CF2ClBr), and other halocarbons in water and gases is described. The high sensitivity of the procedure allows for introduction of minimal tracer mass (a few grams) into hydrologic systems with a large dynamic range of analytical detection (dilutions to 1:108). Analysis times by gas chromatography with electron capture detector are less than 1 min for SF6; about 2 min for SF6 and SF5CF3; and 4 min for SF6, SF5CF3, and Halon 1211. Many samples can be rapidly collected, preserved in stoppered septum bottles, and analyzed at a later time in the laboratory. Examples are provided showing the effectiveness of the gas tracer test studies in varied hydrogeological settings.

  5. Suitability of 239+240Pu and 137Cs as tracers for soil erosion assessment in mountain grasslands.

    Science.gov (United States)

    Alewell, Christine; Meusburger, Katrin; Juretzko, Gregor; Mabit, Lionel; Ketterer, Michael E

    2014-05-01

    Anthropogenic radionuclides have been distributed globally due to nuclear weapons testing, nuclear accidents, nuclear weapons fabrication, and nuclear fuel reprocessing. While the negative consequences of this radioactive contamination are self-evident, the ubiquitous fallout radionuclides (FRNs) distribution form the basis for the use as tracers in ecological studies, namely for soil erosion assessment. Soil erosion is a major threat to mountain ecosystems worldwide. We compare the suitability of the anthropogenic FRNs, 137Cs and 239+240Pu as soil erosion tracers in two alpine valleys of Switzerland (Urseren Valley, Canton Uri, Central Swiss Alps and Val Piora, Ticino, Southern Alps). We sampled reference and potentially erosive sites in transects along both valleys. 137Cs measurements of soil samples were performed with a Li-drifted Germanium detector and 239+240Pu with ICP-MS. Our data indicates a heterogeneous deposition of the 137Cs, since most of the fallout origins from the Chernobyl April/May 1986 accident, when large parts of the European Alps were still snow-covered. In contrast, 239+240Pu fallout originated mainly from 1950s to 1960s atmospheric nuclear weapons tests, resulting in a more homogenous distribution and thus seems to be a more suitable tracer in mountainous grasslands. Soil erosion assessment using 239+240Pu as a tracer pointed to a huge dynamic and high heterogeneity of erosive processes (between sedimentation of 1.9 and 7 t ha(-1) yr(-1) and erosion of 0.2-16.4 t ha(-1) yr(-1) in the Urseren Valley and sedimentation of 0.4-20.3 t ha(-1) yr(-1) and erosion of 0.1-16.4 t ha(-1) yr(-1) at Val Piora). Our study represents a novel and successful application of 239+240Pu as a tracer of soil erosion in a mountain environment.

  6. Optimization of detector positioning in the radioactive particle tracking technique.

    Science.gov (United States)

    Dubé, Olivier; Dubé, David; Chaouki, Jamal; Bertrand, François

    2014-07-01

    The radioactive particle tracking (RPT) technique is a non-intrusive experimental velocimetry and tomography technique extensively applied to the study of hydrodynamics in a great variety of systems. In this technique, arrays of scintillation detector are used to track the motion of a single radioactive tracer particle emitting isotropic γ-rays. This work describes and applies an optimization strategy developed to find an optimal set of positions for the scintillation detectors used in the RPT technique. This strategy employs the overall resolution of the detectors as the objective function and a mesh adaptive direct search (MADS) algorithm to solve the optimization problem. More precisely, NOMAD, a C++ implementation of the MADS algorithm is used. First, the optimization strategy is validated using simple cases with known optimal detector configurations. Next, it is applied to a three-dimensional axisymmetric system (i.e. a vertical cylinder, which could represent a fluidized bed, bubble column, riser or else). The results obtained using the optimization strategy are in agreement with what was previously recommended by Roy et al. (2002) for a similar system. Finally, the optimization strategy is used for a system consisting of a partially filled cylindrical tumbler. The application of insights gained by the optimization strategy is shown to lead to a significant reduction in the error made when reconstructing the position of a tracer particle. The results of this work show that the optimization strategy developed is sensitive to both the type of objective function used and the experimental conditions. The limitations and drawbacks of the optimization strategy are also discussed.

  7. A study on the development of regulatory guide to stability conformation and classification criteria of low and intermediate level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Jae; Paek, Min Hoon; Park, Jong Gil; Han, Byeong Seop; Cheong, Jae Hak; Lee, Hae Chan; Yang, Jin Yeong; Hong, Hei Kwan; Park, Jin Baek [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1994-01-15

    The objectives of this study are to examine basic principles and terms and to suggest and recommend definite methods and criteria necessary for the classification and stability conformation of radioactive wastes. In this study, following studies were performed : investigate the domestic regulations related with the stability conformation and classification of radioactive wastes in order to keep mutual relationship and consistency between the regulations, investigate the sources, types and characteristics of domestic radioactive wastes as a basis for this study, investigate the classification criteria and methods of others countries in a general point of view and in the view point of disposal method, select the classification criteria factors for the domestic case and general case in the both general and domestic points of view, investigate the general test items for the stability conformation of radioactive waste forms and analysis on the test items and criteria of others countries for the mined cavity disposal and shallow land disposal in the view point of disposal method, experimental leaching and immersion tests for the borate and spent resin wastes as a study on the stability conformation of waste forms, selection of acceptance criteria for the both of disposal methods in the domestic and general cases.

  8. Radioactivity in consumer products

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-08-01

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

  9. Behaviors of sea water studied with chemical transient tracers. Lecture by the member awarded the Okada prize of the Oceanographic Society of Japan for 1996

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Y.W. [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

    1997-02-01

    Chemical tracers are useful tools for clarifying the behaviors of sea water in the ocean. The present article reviews my works concerning chemical tracers. Based on my chemical tracers data, it was concluded that the turnover time of the Japan Sea deep water and the residence time of water within the Japan Sea were about 100 years and 1000 years, respectively, and that the exchange coefficient of CO{sub 2} in the Japan Sea was smaller than that in the North Pacific. Furthermore, chemical tracers and carbonate species data set in the North Pacific suggested that the production rate of intermediate water in the North Pacific was about 24 Sv and that the North Pacific subpolar region was an important sink of CO{sub 2} released from human activities after the industrial era. (author)

  10. The distribution of radioactivity in brains of rats given (N-methyl- sup 11 C)PK 11195 in vivo after induction of a cortical ischaemic lesion

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, J.E.; Hume, S.P.; Cullen, B.M.; Myers, R.; Manjil, L.G.; Turton, D.R.; Luthra, S.K.; Bateman, D.M.; Pike, V.W. (Hammersmith Hospital, London (United Kingdom). M.R.C. Cyclotron Unit)

    1992-02-01

    PK 11195 is a selective ligand for the peripheral-type benzodiazepine bindings site (PTBBS). There are few sites in normal brain but their number increases in association with tissue necrosis. The time-course of appearance of PTBBS around a focally induced ischaemic lesion in frontal cortex of rat brain was established by autoradiography using (N-methyl-{sup 3} H )PK 11195. Using this information and the same experimental model of ischaemia, the distribution of radioactivity after injection of carbon-11 labelled PK 11195 was studied. The purpose was to synthesize (N-methyl-{sup 11}C)PK 11195 and to test its suitability as a tracer for depicting the presence of PTBB in ischaemic lesions. The time-profiles of distribution of radioactivity in brain regions after intravenous injection of tracer and the ratio of radioactivity in lesioned compared with unlesioned cortex were determined. Data for the temporal (days after lesion induction) and for the regional retention of radioactivity were consistent with independent evidence (autoradiographic and immunohistochemical) for the occurence of increased numbers of PTBBS, predominantly in association with macrophages, in areas undergoing necrosis. (Author).

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

    Science.gov (United States)

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

    2015-02-01

    The Excavation Damaged Zone (EDZ) surrounding a drift, and in particular its evolution, is being studied for the performance assessment of a radioactive waste underground repository. A specific experiment (called CDZ) was designed and implemented in the Meuse/Haute-Marne Underground Research Laboratory (URL) in France to investigate the EDZ. This experiment is dedicated to study the evolution of the EDZ hydrogeological properties (conductivity and specific storage) of the Callovo-Oxfordian claystone under mechanical compression and artificial hydration. Firstly, a loading cycle applied on a drift wall was performed to simulate the compression effect from bentonite swelling in a repository drift (bentonite is a clay material to be used to seal drifts and shafts for repository closure purpose). Gas tests (permeability tests with nitrogen and tracer tests with helium) were conducted during the first phase of the experiment. The results showed that the fracture network within the EDZ was initially interconnected and opened for gas flow (particularly along the drift) and then progressively closed with the increasing mechanical stress applied on the drift wall. Moreover, the evolution of the EDZ after unloading indicated a self-sealing process. Secondly, the remaining fracture network was resaturated to demonstrate the ability to self-seal of the COx claystone without mechanical loading by conducting from 11 to 15 repetitive hydraulic tests with monitoring of the hydraulic parameters. During this hydration process, the EDZ effective transmissivity dropped due to the swelling of the clay materials near the fracture network. The hydraulic conductivity evolution was relatively fast during the first few days. Low conductivities ranging at 10-10 m/s were observed after four months. Conversely, the specific storage showed an erratic evolution during the first phase of hydration (up to 60 days). Some uncertainty remains on this parameter due to volumetric strain during the

  12. Fractal tracer distributions in turbulent field theories

    DEFF Research Database (Denmark)

    Hansen, J. Lundbek; Bohr, Tomas

    1998-01-01

    We study the motion of passive tracers in a two-dimensional turbulent velocity field generated by the Kuramoto-Sivashinsky equation. By varying the direction of the velocity-vector with respect to the field-gradient we can continuously vary the two Lyapunov exponents for the particle motion and t...

  13. Study of extraterrestrial disposal of radioactive wastes. Part 2: Preliminary feasibility screening study of extraterrestrial disposal of radioactive wastes in concentrations, matrix materials, and containers designed for storage on earth

    Science.gov (United States)

    Hyland, R. E.; Wohl, M. L.; Thompson, R. L.; Finnegan, P. M.

    1972-01-01

    The results are reported of a preliminary feasibility screening study for providing long-term solutions to the problems of handling and managing radioactive wastes by extraterrestrial transportation of the wastes. Matrix materials and containers are discussed along with payloads, costs, and destinations for candidate space vehicles. The conclusions reached are: (1) Matrix material such as spray melt can be used without exceeding temperature limits of the matrix. (2) The cost in mills per kw hr electric, of space disposal of fission products is 4, 5, and 28 mills per kw hr for earth escape, solar orbit, and solar escape, respectively. (3) A major factor effecting cost is the earth storage time. Based on a normal operating condition design for solar escape, a storage time of more than sixty years is required to make the space disposal charge less than 10% of the bus-bar electric cost. (4) Based on a 10 year earth storage without further processing, the number of shuttle launches required would exceed one per day.

  14. Analysis of multicomopnent groundwater flow in karst aquifer by CFC, tritium, tracer test and modelling, case study at Skaistkalnes vicinity, Latvia

    Science.gov (United States)

    Bikshe, Janis; Babre, Alise; Delina, Aija; Popovs, Konrads

    2014-05-01

    Groundwater in karst environments tends to have difficulties to distinguish multiple flows if several sources of water are present. Skaistkalne vicinity faces with such situation where old groundwater, fresh groundwater and inflow from river Iecava occurs. Attempts were made to distinguish groundwater residence time of multiple components of water applying CFC and tritium dating techniques supplied by tracer test and numerical model of study area. Study area covers territory between two rivers Iecava and Memele with water level difference of 7 meters and horizontal distance of 2.2 kilometres between both. Study area consists of karst affected Devonian gypsum and carbonaceous rocks covered by Quaternary low to high permeable deposits. Confined groundwater at depth of 10-25 meters where analysed by CFC's and tritium. At this depth groundwater exhibits anoxic reducing environment that has caused degradation of CFC's at similar degree in all samples. Taking it into account, mean residence time based on CFC piston flow model is 22 - 42 years and 28 - 34 years based on binary mixing model. Tritium results show signs of incensement of groundwater residence time towards discharge area. CFC combined with tritium proved increased vertical velocity in middle part between the rivers likely caused by hydrogeological window in Quaternary deposits created by karst processes. Numerical model (Delina et al. 2012) was applied and calculations yielded groundwater flow velocity rate at 0.3 - 1 m/day in area between the rivers. Investigation of CFC data resulted in possible groundwater flow rate of at a minimum of 0.2 m/day although it's not applicable to all sampled wells due to specific hydrogeological conditions. Tracer test was made between the rivers in order to distinguish main water flow paths and flow velocity. Results showed that very high permeable conduits connect rivers and karst lakes with velocity rates of 800 - 1300 m/day. Complex investigation leads to conclude that

  15. Kinetic and metabolic considerations in the use of (I-125) HIPDM as a tracer for quantitative measurement of regional cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Lucignani, G.; Nehlig, A.; Blasberg, R.; Patlak, C.S.; Anderson, L.; Kung, H.F.; Fieschi, C.; Fazio, F.; Sokoloff, L.

    1984-01-01

    The kinetics of cerebral uptake and the metabolism of radioactive iodine labeled HIPDM (N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-(I-125)iodobenzyl) -1,3-propanediamine)(I-125)HIPDM were studied in vivo in male adult Sprague-Dawley rats in order to evaluate the potential usefulness of this compound for quantitative measurement of regional cerebral blood flow (rCBF). The first pass extraction fraction of (I-125)HIPDM in brain was found to be about 80%. The arterial concentration of unmetabolized (I-125)HIPDM following an i.v. pulse drops rapidly and represents only 30% of the blood sample total radioactivity at 60 minutes, whereas 92% of the radioactivity in brain tissue at the same time is in unaltered (I-125)HIPDM. The rate constant for (I-125)HIPDM transport across the blood-brain barrier (BBB) was calculated on the basis of a distribution model in which bi-directional exchange of the tracer between brain tissue and vascular space is assumed. A kinetic model and an operational equation have been derived for determination of rCBF with this molecule. The model and equation take into account the three following factors: (a) incomplete first pass extraction; (b) HIPDM metabolism; (c) bi-directional flux of tracer across the BBB. The observations suggest that this molecule might be of potential usefulness for rCBF measurements with single photon emission tomography, provided that all these factors are evaluated in man.

  16. Basic investigation and analysis for preferred host rocks and natural analogue study area with reference to high level radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Ryul; Park, J. K.; Hwang, D. H.; Lee, J. H.; Yun, H. S.; Kim, D. Y.; Park, H. S.; Koo, S. B.; Cho, J. D.; Kim, K. E. [Korea Inst. of Geology, Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    The purpose of this study is basic investigation and analysis for preferred host rocks and natural analogue study area to develope underground disposal technique of high level radioactive waste in future. The study has been done for the crystalline rocks(especially granitic rocks) with emphasis of abandoned metallic mines and uranium ore deposits, and for the geological structure study by using gravity and aeromagnetic data. 138 refs., 54 tabs., 130 figs. (author)

  17. Radioactive Waste and Clean-up: Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Collard, G

    2000-07-01

    SCK-CEN's Radioactive Waste and Clean-up Division performs studies and develops strategies, techniques and technologies in the area of radioactive waste management, the decontamination and decommissioning of nuclear installations and the remediation of radioactive-contaminated sites. These activities are performed in the context of our responsibility towards the safety of present and future generations and contribute to achieve intrageneration equity.

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 7. Characterization and description of areas. Langeland, Taasinge and Fyn

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities, high sorption capacity for many radionuclides and self-sealing properties. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier focused on deep seated salt deposits and basement rocks. Nevertheless, the Tertiary clays were mapped as well. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas where a waste disposal potentially can be located. The 20 areas have to be reduced to 1-3 most potential locations where detailed field investigations of the geological, hydrogeological - hydrochemical and geotechnical conditions will be performed. The present report describes the areas 7,8,9,10, and 11 on the islands Langeland, Taasinge and Funen. (LN)

  20. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 8. Characterization and description of areas. OEstjylland

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities, high sorption capacity for many radionuclides and self-sealing properties. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier focused on deep seated salt deposits and basement rocks. Nevertheless, the Tertiary clays were mapped as well. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas where a waste disposal potentially can be located. The 20 areas have to be reduced to 1-3 most potential locations where detailed field investigations of the geological, hydrogeological - hydrochemical and geotechnical conditions will be performed. The present report describes the areas 12,13,14 and 15 in Eastern Jutland. (LN)

  1. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 6. Characterization and description of areas. Sjaelland

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities, strong sorption capacity for many radionuclides and self-sealing properties. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier focused on deep seated salt deposits and basement rocks. Nevertheless, the Tertiary clays were mapped as well. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas potentially useful for a waste disposal. The 20 areas have to be reduced to 1-3 most potential locations where detailed field investigations of the geological, hydrogeological - hydrochemical and geotechnical conditions will be performed. The present report describes the areas 5 and 6 on Zealand. (LN)

  2. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 4. Characterization and description of areas. Bornholm

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low - and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities and high sorption potentials of the sediments or rocks. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier been focused on deep seated salt deposits and basement rocks, but the Tertiary clays were also mapped. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas where a waste disposal potentially can be located. The 20 areas have to be reduced to 2-3 more precise locations, where detailed field investigations of the geological, hydrogeological-hydrochemical and technical conditions will be performed. The present report describes areas 1 and 2 on Bornholm, East Denmark. (LN)

  3. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 5. Characterization and description of areas. Falster and Lolland

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities, strong sorption capacity for many radionuclides and self-sealing properties. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier focused on deep seated salt deposits and basement rocks. Nevertheless, the Tertiary clays were mapped as well. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas potentially useful for a waste disposal. The 20 areas have to be reduced to 1-3 most potential locations where detailed field investigations of the geological, hydrogeological, hydrochemical and geotechnical conditions will be performed. The present report describes areas 3 and 4 on Falster and Lolland. (LN)

  4. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 10. Characterization and description of areas. Nordjylland

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities, strong sorption capacity for many radionuclides and self-sealing properties. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier focused on deep seated salt deposits and basement rocks. Nevertheless, the Tertiary clays were mapped as well. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas potentially useful for a waste disposal. The 20 areas have to be reduced to 1-3 most potential locations where detailed field investigations of the geological, hydrogeological, hydrochemical and geotechnical conditions will be performed. The present report describes the area 22 in Northern Jutland. (LN)

  5. Low- and intermediate level radioactive waste from Risoe, Denmark. Location studies for potential disposal areas. Report no. 9. Characterization and description of areas. Limfjorden

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, P.; Nilsson, B.; Schack Pedersen, S.A.; Binderup, M.

    2011-07-01

    The low and intermediate level radioactive waste from Risoe: the nuclear reactor buildings, different types of material from the research periods and waste from hospitals and research institutes have to be stored in a final disposal in Denmark for at least 300 years. The task is to locate and recognize sediments or rocks with low permeability which can isolate the radioactive waste from the surrounding deposits, the groundwater resources, the recipients and from human activities. The sediments or rocks shall also act as a protection if the waste disposal leaks radioactive material to the surroundings. This goal can be reached by low water flow possibilities, strong sorption capacity for many radionuclides and self-sealing properties. The investigation of geological deposits as potential waste disposals for high radioactive waste from nuclear power plants has earlier focused on deep seated salt deposits and basement rocks. Nevertheless, the Tertiary clays were mapped as well. The salt diapirs and the salt deposits are not included in the present study. The task is to find approximately 20 areas potentially useful for a waste disposal. The 20 areas have to be reduced to 1-3 most potential locations where detailed field investigations of the geological, hydrogeological, hydrochemical and geotechnical conditions will be performed. The present report describes the areas 16,17,18,19,20 and 21 around Limfjorden. (LN)

  6. Urban Pollutant Transport and Infiltration into Buildings Using Perfluorocarbon Tracers

    Science.gov (United States)

    Matthews, James C.; Bacak, Asan; Khan, M. Anwar H.; Wright, Matthew D.; Priestley, Michael; Martin, Damien; Percival, Carl J.; Shallcross, Dudley E.

    2017-01-01

    People spend the majority of their time indoors and therefore the quality of indoor air is worthy of investigation; indoor air quality is affected by indoor sources of pollutants and from pollutants entering buildings from outdoors. In this study, unique perfluorocarbon tracers were released in five experiments at a 100 m and ~2 km distance from a large university building in Manchester, UK and tracer was also released inside the building to measure the amount of outdoor material penetrating into buildings and the flow of material within the building itself. Air samples of the tracer were taken in several rooms within the building, and a CO2 tracer was used within the building to estimate air-exchange rates. Air-exchange rates were found to vary between 0.57 and 10.90 per hour. Indoor perfluorocarbon tracer concentrations were paired to outdoor tracer concentrations, and in-out ratios were found to vary between 0.01 and 3.6. The largest room with the lowest air-exchange rate exhibited elevated tracer concentrations for over 60 min after the release had finished, but generally had the lowest concentrations, the room with the highest ventilation rates had the highest concentration over 30 min, but the peak decayed more rapidly. Tracer concentrations indoors compared to outdoors imply that pollutants remain within buildings after they have cleared outside, which must be considered when evaluating human exposure to outdoor pollutants. PMID:28230812

  7. Urban Pollutant Transport and Infiltration into Buildings Using Perfluorocarbon Tracers.

    Science.gov (United States)

    Matthews, James C; Bacak, Asan; Khan, M Anwar H; Wright, Matthew D; Priestley, Michael; Martin, Damien; Percival, Carl J; Shallcross, Dudley E

    2017-02-21

    People spend the majority of their time indoors and therefore the quality of indoor air is worthy of investigation; indoor air quality is affected by indoor sources of pollutants and from pollutants entering buildings from outdoors. In this study, unique perfluorocarbon tracers were released in five experiments at a 100 m and ~2 km distance from a large university building in Manchester, UK and tracer was also released inside the building to measure the amount of outdoor material penetrating into buildings and the flow of material within the building itself. Air samples of the tracer were taken in several rooms within the building, and a CO₂ tracer was used within the building to estimate air-exchange rates. Air-exchange rates were found to vary between 0.57 and 10.90 per hour. Indoor perfluorocarbon tracer concentrations were paired to outdoor tracer concentrations, and in-out ratios were found to vary between 0.01 and 3.6. The largest room with the lowest air-exchange rate exhibited elevated tracer concentrations for over 60 min after the release had finished, but generally had the lowest concentrations, the room with the highest ventilation rates had the highest concentration over 30 min, but the peak decayed more rapidly. Tracer concentrations indoors compared to outdoors imply that pollutants remain within buildings after they have cleared outside, which must be considered when evaluating human exposure to outdoor pollutants.

  8. Nuclear medicine and coronary artery disease: evaluation of tracers of myocardial perfusion and vulnerable atherosclerotic plaque; Medecine nucleaire et maladie coronarienne: evaluation de traceurs de la perfusion myocardique et de la plaque d'atherome vulnerable

    Energy Technology Data Exchange (ETDEWEB)

    Broisat, A

    2005-04-15

    Coronary artery disease is one of the primary cause of mortality worldwide. Nuclear medicine is the major imaging technique for diagnosis and following of this disease. perfusion: nowadays, major radioactive agents used in clinical practice are myocardial perfusion tracers. The reference tracer is thallium-201. However, {sup 201}Tl presents some drawbacks. {sup 99m}Tcn-noet has been proposed for its replacement. This study shows that in contrast with previous studies realized in vitro on cardio myocytes, verapamil, an l-type calcium channel inhibitor, does not inhibit myocardial fixation of {sup 99m}Tcn-noet in vivo in dog. This data is in agreement with the hypothesis of a non specific endothelial fixation of this tracer. Moreover, this study shows that as a pure tracer of myocardial perfusion, {sup 99m}Tcn-noet can also be used to assess myocardial viability on a model of myocardial chronic infarction in rat. atherosclerosis: disruption of vulnerable atherosclerotic plaques is the main event leading to coronary accidents. The second part of this study concerns the evaluation of new potential tracers of the vulnerable atherosclerotic plaque in an experimental model of rabbit with an inheritable hypercholesterolemia. The four tracers evaluated (b2702(r), b2702-I, b2702-Tc and Tc-raft-b2702) are synthetic peptides comprising the residues 75-84 of hla-b2702, a molecule known to link vcam-1, an adhesion molecule expressed in vulnerable atherosclerotic plaque. The autoradiography studies show that all tracers accumulate within atherosclerotic plaque expressing vcam- and that. i-b2702 shows the best plaque/control fixation ratio. (author)