WorldWideScience

Sample records for short-lived radiotracer beams

  1. Simulation study on the measurements of diffusion coefficients in solid materials by short-lived radiotracer beams

    CERN Document Server

    Jeong, S C; Kawakami, H

    2003-01-01

    We have examined, by a computer simulation, an on-line measurement of diffusion coefficients by using a short-lived alpha particle emitter, sup 8 Li (half life of 0.84s), as a radiotracer. The energy spectra of alpha particles emitted from diffusing sup 8 Li primarily implanted in the sample of LiAl ar simulated as a measure of the diffusion of sup 8 Li in the sample. As a possible time sequence for the measurement, a time cycle of 6s, i.e. the implantation of sup 8 Li for 1.5s and subsequent diffusion for 4.5s, is supposed. The sample is primarily set on a given temperature for the measurement. The time-dependent yields of alpha particles during the time cycle reveal the possibility to measure the diffusion coefficient with an accuracy of 10% if larger than 1 x 10 sup - sup 9 cm sup 2 /s, by the comparison with the experimental spectra measured at the temperature, i.e. at a certain diffusion coefficient. (author)

  2. Short-lived positron emitter labeled radiotracers - present status

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1982-01-01

    The preparation of labelled compounds is important for the application of positron emission transaxial tomography (PETT) in biomedical sciences. This paper describes problems and progress in the synthesis of short-lived positron emitter ( 11 C, 18 F, 13 N) labelled tracers for PETT. Synthesis of labelled sugars, amino acids, and neurotransmitter receptors (pimozide and spiroperidol tagged with 11 C) is discussed in particular

  3. Radiotracer diffusion in semiconductors and metallic compounds using short-lived isotopes

    CERN Multimedia

    Deicher, M; Kronenberg, J; Wagner, F E

    The transport of atoms in solids is of central importance for solid state physics, chemistry, metallurgy, and material sciences. Since the mobility of atoms in solids contributes to many physical phenomena the study of diffusion processes is of fundamental interest for solid state physics. Diffusion processes were frequently investigated using radioactive isotopes (radiotracers). The application of short-lived isotopes delivered at ISOLDE extends substantially the possibilities of investigating diffusion processes in solids. In particular, a new experimental set-up to be installed at ISOLDE in this year will enable the use of radioactive isotopes with half-lives down to minutes. Alternatively, in special cases diffusion processes can be investigated with help of hyperfine techniques on an atomic scale, like by perturbed $\\gamma \\gamma$-angular correlation (PAC). Here, the motion of the atom of interest becomes visible directly via characteristic changes in the measured PAC spectra.

  4. Non-destructive investigation of technical plants and processes and natural processes by short-lived radionuclides (radiotracer)

    International Nuclear Information System (INIS)

    Jentsch, Thorsten; Zeuner, Albert

    2009-01-01

    Short lived open radionuclides are very suitable to investigate transport and mixing processes. They do not pollute the product. After decay of the radionuclide, the product can be used without any restrictions. Examples are showed for technical processes investigation by aid of radiotracer. (orig.)

  5. Development of a system for real-time measurements of metabolite transport in plants using short-lived positron-emitting radiotracers

    Science.gov (United States)

    Kiser, Matthew R.

    Over the past 200 years, the Earth's atmospheric carbon dioxide (CO 2) concentration has increased by more than 35%, and climate experts predict that CO2 levels may double by the end of this century. Understanding the mechanisms of resource management in plants is fundamental for predicting how plants will respond to the increase in atmospheric CO 2. Plant productivity sustains life on Earth and is a principal component of the planet's system that regulates atmospheric CO2 concentration. As such, one of the central goals of plant science is to understand the regulatory mechanisms of plant growth in a changing environment. Short-lived positron-emitting radiotracer techniques provide time-dependent data that are critical for developing models of metabolite transport and resource distribution in plants and their microenvironments. To better understand the effects of environmental changes on resource transport and allocation in plants, we have developed a system for real-time measurements of rnetabolite transport in plants using short-lived positron-emitting radio-tracers. This thesis project includes the design, construction, and demonstration of the capabilities of this system for performing real-time measurements of metabolite transport in plants. The short-lived radiotracer system described in this dissertation takes advantage of the combined capabilities and close proximity of two research facilities at. Duke University: the Triangle Universities Nuclear Laboratory (TUNL) and the Duke University Phytotron, which are separated by approximately 100 meters. The short-lived positron-emitting radioisotopes are generated using the 10-MV tandem Van de Graaff accelerator located in the main TUNL building, which provides the capability of producing short-lived positron-emitting isotopes such as carbon-11 (11C: 20 minute half-life), nitrogen-13 (13N; 10 minute half-life), fluorine-18 (18F; 110 minute half-life), and oxygen-15 (15O; 2 minute half-life). The radioisotopes may

  6. Comparison of short-lived medical isotopes activation by laser thin target induced protons and conventional cyclotron proton beams

    Science.gov (United States)

    Murray, Joseph; Dudnikova, Galina; Liu, Tung-Chang; Papadopoulos, Dennis; Sagdeev, Roald; Su, J. J.; UMD MicroPET Team

    2014-10-01

    Production diagnostic or therapeutic nuclear medicines are either by nuclear reactors or by ion accelerators. In general, diagnostic nuclear radioisotopes have a very short half-life varying from tens of minutes for PET tracers and few hours for SPECT tracers. Thus supplies of PET and SPECT radiotracers are limited by regional production facilities. For example 18F-fluorodeoxyglucose (FDG) is the most desired tracer for positron emission tomography because its 110 minutes half-life is sufficient long for transport from production facilities to nearby users. From nuclear activation to completing image taking must be done within 4 hours. Decentralized production of diagnostic radioisotopes will be idea to make high specific activity radiotracers available to researches and clinicians. 11 C, 13 N, 15 O and 18 F can be produced in the energy range from 10-20 MeV by protons. Protons of energies up to tens of MeV generated by intense laser interacting with hydrogen containing targets have been demonstrated by many groups in the past decade. We use 2D PIC code for proton acceleration, Geant4 Monte Carlo code for nuclei activation to compare the yields and specific activities of short-lived isotopes produced by cyclotron proton beams and laser driven protons.

  7. Preparing isomerically pure beams of short-lived nuclei at JYFLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Eronen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 (Finland)], E-mail: tommi.eronen@jyu.fi; Elomaa, V.-V.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Rahaman, S.; Rissanen, J.; Weber, C.; Aystoe, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 (Finland)

    2008-10-15

    A new procedure to prepare isomerically clean samples of short-lived ions with a mass resolving power of more than 1 x 10{sup 5} has been developed at the JYFLTRAP tandem Penning trap system. The method utilises a dipolar rf-excitation of the ion motion with separated oscillatory fields in the precision trap. During a subsequent retransfer to the purification trap, the contaminants are rejected and as a consequence, the remaining bunch is isomerically cleaned. This newly-developed method is suitable for very high-resolution cleaning and is at least a factor of five faster than the methods used so far in Penning trap mass spectrometry.

  8. Laser generation of proton beams for the production of short-lived positron emitting radioisotopes

    International Nuclear Information System (INIS)

    Spencer, I.; Ledingham, K.W.D.; Singhal, R.P.; McCanny, T.; McKenna, P.; Clark, E.L.; Krushelnick, K.; Zepf, M.; Beg, F.N.; Tatarakis, M.; Dangor, A.E.; Norreys, P.A.; Clarke, R.J.; Allott, R.M.; Ross, I.N.

    2001-01-01

    Protons of energies up to 37 MeV have been generated when ultra-intense lasers (up to 10 20 W cm -2 ) interact with hydrogen containing solid targets. These protons can be used to induce nuclear reactions in secondary targets to produce β + -emitting nuclei of relevance to the nuclear medicine community, namely 11 C and 13 N via (p, n) and (p,α) reactions. Activities of the order of 200 kBq have been measured from a single laser pulse interacting with a thin solid target. The possibility of using ultra-intense lasers to produce commercial amounts of short-lived positron emitting sources for positron emission tomography (PET) is discussed

  9. Yield calculations for a facility for short-lived nuclear beams

    CERN Document Server

    Jiang, C L; Gomes, I; Heinz, A M; Nolen, Jerry A; Rehm, K E; Savard, G; Schiffer, J P

    2002-01-01

    Yields for a broad range of radioactive nuclei produced by spallation reactions, neutron-induced fission, in-flight projectile fragmentation and in-flight fission have been calculated for beams of stable nuclei at energies of 100-1000 MeV/u. Calculations of cross-sections and yields, attenuation effects due to absorption, production from secondary reactions, and transport efficiencies for mass selection are discussed. Rare isotope yields as functions of bombarding energies for both reaccelerated and directly produced fast-fragmentation beams are presented. This information provides a foundation for a cost-effective design of a next generation rare isotope accelerator.

  10. A crossed-beam experiment on intramultiplet mixing collisions with short-lived Ne** {(2p)5(3p)} atoms

    NARCIS (Netherlands)

    Manders, M.P.I.; Ruyten, W.M.J.; van de Beucken, F..J.H.M.; Driessen, J.P.J.; Veugelers, W.J.T.; Kramer, P.H.; Vredenbregt, E.J.D.; van Hoek, W.B.M.; Sandker, G.J.; Beijerinck, H.C.W.; Verhaar, B.J.

    1988-01-01

    We describe the design, operation, and calibration of a crossed-beam experiment for the study of intramultiplet mixing collisions of short-lived electronically excited Ne{(2p)5(3p)}≡{α} atoms with ground-state atoms/molecules. The excellent performance of almost 1 kHz/Å2 (number of counts per unit

  11. Probing the Single-Particle Character of Rotational States in F 19 Using a Short-Lived Isomeric Beam

    Science.gov (United States)

    Santiago-Gonzalez, D.; Auranen, K.; Avila, M. L.; Ayangeakaa, A. D.; Back, B. B.; Bottoni, S.; Carpenter, M. P.; Chen, J.; Deibel, C. M.; Hood, A. A.; Hoffman, C. R.; Janssens, R. V. F.; Jiang, C. L.; Kay, B. P.; Kuvin, S. A.; Lauer, A.; Schiffer, J. P.; Sethi, J.; Talwar, R.; Wiedenhöver, I.; Winkelbauer, J.; Zhu, S.

    2018-03-01

    A beam containing a substantial component of both the Jπ=5+ , T1 /2=162 ns isomeric state of F 18 and its 1+, 109.77-min ground state is utilized to study members of the ground-state rotational band in F 19 through the neutron transfer reaction (d ,p ) in inverse kinematics. The resulting spectroscopic strengths confirm the single-particle nature of the 13 /2+ band-terminating state. The agreement between shell-model calculations using an interaction constructed within the s d shell, and our experimental results reinforces the idea of a single-particle-collective duality in the descriptions of the structure of atomic nuclei.

  12. 3. Radiotracers

    International Nuclear Information System (INIS)

    Musilek, L.

    1992-01-01

    The chapter deals with basic characteristics of radiotracer methods, with demands placed on radiotracers, their assets and drawbacks, the applicability of the method to the study of laminar flows, and examples of radiotracer applications in biochemistry, metallurgy, in the investigation of the permeation and passage of gases and liquids, in the examination of wear of machine components, and in criminological practice. An overview of the major radionuclides and of radiotracer applications is given. (Z.S.). 3 tabs., 5 figs., 25 refs

  13. Measurements of Short-Lived Fission Isomers

    Science.gov (United States)

    Finch, Sean; Bhike, Megha; Howell, Calvin; Krishichayan, Fnu; Tornow, Werner

    2016-09-01

    Fission yields of the short lived isomers 134mTe (T1 / 2 = 162 ns) and 136mXe (T1 / 2 = 2 . 95 μs) were measured for 235U and 238U. The isomers were detected by the γ rays associated with the decay of the isomeric states using high-purity germanium detectors. Fission was induced using both monoenergetic γ rays and neutrons. At TUNL's High-Intensity Gamma-ray Source (HI γS), γ rays of 9 and 11 MeV were produced . Monoenergetic 8 MeV neutrons were produced at TUNL's tandem accelerator laboratory. Both beams were pulsed to allow for precise time-gated spectroscopy of both prompt and delayed γ rays following fission. This technique offers a non-destructive probe of special nuclear materials that is sensitive to the isotopic identity of the fissile material.

  14. Radiotracer techniques in hydrological studies

    International Nuclear Information System (INIS)

    Oladipo, M.O.A.; Funtua, I.I.

    2000-07-01

    The use of radioactive tracers particularly short-lived radioisotopes frequently offers advantages over conventional methods of analyses. Applications of nuclear techniques in the field of hydrology constitute important and sometimes unique tools for obtaining critical information needed for water resources management. Essentially, radiotracer techniques offer a safe, cost effective and powerful tool in the assessment, management and protection of water resources. The Centre for Energy Research and Training, Ahmadu Bello University, Zaria of late has been offering consultancy services to some industries in the area of radiotracer technique. The first nuclear reactor in Nigeria, the MNSR, is expected to be commissioned in the Centre very soon. Many short-lived radioisotopes such as Cu-64, Ga-72, Br-82, Hg-197 etc which are very important in hydrological studies can be produced by the MNSR facility. This article reports on the basic principles of the technique and its roles in hydrology

  15. Practical applications of short-lived radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-01-15

    The advantages of the use of short-lived radioisotopes in agriculture, food industry and medicine as well as some industrial uses are discussed. Methods for isotope production in small research reactors and laboratories are presented

  16. Radiotracer methodology

    International Nuclear Information System (INIS)

    Eng, R.R.

    1988-01-01

    In 1923, George Hevesy demonstrated the distribution of radioactive lead in the horsebean plant. This early demonstration of the potential use of radiotracers in biology was reinforced when J.G. Hamilton and colleagues used iodine-131 for diagnostic purposes in patients. Then in 1950 Cassen et al. designed the first scintillation counter for measuring radioiodine in the body, using calcium tungstate crystals coupled to a photomultiplier tube. This was followed by the development of the Anger camera, which permitted visualization of radiotracer distribution in biological systems. From these significant early discoveries to the present, many advances have been made. They include the discovery and production of many useful radioisotopes; the formulation of these radioisotopes into useful radiotracers; the advent of first- , and second-, and third-generation instrumentation for monitoring in vitro and in vivo distributions of new radiotracers; and the application of this knowledge to allow us to better understand physiological processes and treat disease states. Radiotracer techniques are integral to numerous techniques described in this volume. Autoradiography, nuclear scintigraphy, positron emission tomography, and single-photon emission computed tomography (SPECT) are all dependent on an understanding of radiotracer techniques to properly utilize these probe devices

  17. Feasibility of short-lived radionuclide production at Fermilab

    International Nuclear Information System (INIS)

    Ten Haken, R.K.; Awschalom, M.; Rosenberg, I.

    1985-01-01

    The requirements for establishing a short-lived radionuclide production program at Fermilab are explored. Such a program would utilize beam from the linac portion of the injector much like the present Neutron Therapy Facility. It should be possible to use approximately 10 to 20 μA of 66-MeV protons for iodine-123 production. Several additional magnets would need to be acquired and a shielded target facility would need to be constructed. However, the feasibility of establishing such a program hinges upon its harmonious operation with the high energy physics program

  18. Cyclotron production of molecules labelled with short-lived radioisotopes β+ emitters (15O, 13N, 11C) and their clinical uses

    International Nuclear Information System (INIS)

    Bougharouat, B.

    1981-01-01

    Clinical use of three short-lived radioisotopes: 15 O, 13 N and 11 C is studied on two complementary aspects. A production and purification system is realized; detection instruments in medical use are studied. The production of labelled molecules with the three radiotracers 15 O, 13 N, 11 C from the target bombardment with charged and accelerated particles was studied [fr

  19. Separation of short-lived fission products

    International Nuclear Information System (INIS)

    Tamai, Tadaharu; Ohyoshi, Emiko; Ohyoshi, Akira; Kiso, Yoshiyuki; Shinagawa, Mutsuaki.

    1976-01-01

    A rbief review is presented on the various methods of separation available for both gaseous and liquid states, for the separation of short-lived fission products formed by binary fission of neutron irradiated uranium. The means available for gaseous state are the hot atom reaction, the hydride method and on-line mass separation. For liquid state, use can be made of precipitation, ionic or atomic exchange, solvent extraction and paper electrophoresis. Particular reference is made to electrophoretic separation of ions produced by fission in aqueous solution of uranium. The principle of electrophoretic separation and the procedures for separating the element of interest from the other fission products are outlined, with reference made to the results obtained with the method by the present authors. The elements in question are alkalines, alkaline earths, rare earths, halogens, selenium and

  20. Electron scattering off short-lived radioactive nuclei

    International Nuclear Information System (INIS)

    Wang, S.; Emoto, T.; Furukawa, Y.

    2009-01-01

    We have established a novel method which make electron scattering off short-lived radioactive nuclei come into being. This novel method was named SCRIT (Self-Confining RI ion Target). It was based on the well known "ion trapping" phenomenon in electron storage rings. Stable nucleus, 133 Cs, was used as target nucleus in the R&D experiment. The luminosity of interaction between stored electrons and Cs ions was about 1.02(0.06) × 10 26 cm -2 s -1 at beam current around 80 mA. The angular distribution of elastically scattered electrons from trapped Cs ions was measured. And an online luminosity monitor was used to monitor the change of luminosity during the experiment. (author)

  1. The development of fast tantalum foil targets for short-lived isotopes

    CERN Document Server

    Bennett, J R J; Drumm, P V; Ravn, H L

    2003-01-01

    The development of fast tantalum foil targets for short-lived isotopes was discussed. It was found that the effusion was faster but the diffusion out of the foils was a limiting factor. The performance of the targets at ISOLDE with beams of **1**1Li, **1**2Be and **1**4Be was also analyzed. (Edited abstract) 13 Refs.

  2. Radiopharmaceuticals and other compounds labelled with short-lived radionuclides

    CERN Document Server

    Welch, Michael J

    2013-01-01

    Radiopharmaceuticals and Other Compounds Labelled with Short-Lived Radionuclides covers through both review and contributed articles the potential applications and developments in labeling with short-lived radionuclides whose use is restricted to institutions with accelerators. The book discusses the current and potential use of generator-produced radionuclides as well as other short-lived radionuclides, and the problems of quality control of such labeled compounds. The book is useful to nuclear medicine physicians.

  3. Synthesis of new radiotracers

    International Nuclear Information System (INIS)

    Chahed, Ahlem

    2008-01-01

    The brain's sensibility besides to the rigorous selectivity of changes taking place on brain's barriers leads us to synthesis specifics radiotracers based on diamine ethylene and marked with technetium radioisotope to form a radiotracer able to pass these barriers and diagnose illnesses in an early stage. These radiotracers are tested by a biodistribution on a small animal to be ratified. (Author)

  4. Short Lived Fission Product Yield Measurements in 235U, 238U and 239Pu

    Science.gov (United States)

    Silano, Jack; Tonchev, Anton; Tornow, Werner; Krishichayan, Fnu; Finch, Sean; Gooden, Matthew; Wilhelmy, Jerry

    2017-09-01

    Yields of short lived fission products (FPYs) with half lives of a few minutes to an hour contain a wealth of information about the fission process. Knowledge of short lived FPYs would contribute to existing data on longer lived FPY mass and charge distributions. Of particular interest are the relative yields between the ground states and isomeric states of FPYs since these isomeric ratios can be used to determine the angular momentum of the fragments. Over the past five years, a LLNL-TUNL-LANL collaboration has made precision measurements of FPYs from quasi-monoenergetic neutron induced fission of 235U, 238U and 239Pu. These efforts focused on longer lived FPYs, using a well characterized dual fission chamber and several days of neutron beam exposure. For the first time, this established technique will be applied to measuring short lived FPYs, with half lives of minutes to less than an hour. A feasibility study will be performed using irradiation times of < 1 hour, improving the sensitivity to short lived FPYs by limiting the buildup of long lived isotopes. Results from this exploratory study will be presented, and the implications for isomeric ratio measurements will be discussed. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344.

  5. Radiotracer in industry

    International Nuclear Information System (INIS)

    Jaafar Abdullah

    2005-01-01

    The use of radiotracers for troubleshooting and to investigate process phenomena in industrial plant equipment has specific advantages over conventional tracers. The main advantages of radiotracers owes to its physico-chemical compatibility, high detection sensitivity, ability of number of radiotracers for different phases, stability in harsh industrial environment and limited memory effects. This chapter covers the methodology which includes the selection of radiotracer, radioisotope generators, estimation of amount of radiotracer, injection systems, detection system and safety procedure. Leak detection, this topic discussed the detection by flowrate measurement, detection of RTD measurement, detection by direct tracer, detection in underground pipes using the static method and dynamic method. The topic namely Radiotracers for flowrate measurement discussed the following subjects: flowrate measurement, transit time methods, dilution methods, standards for flow measurement, multi-phase flow measurement. RTD measurement, this topic covers the basic flow concepts, the mathematical modelling, RTD software, bypassing or channelling, recirculation, trickle bed reactors studies, process diagnosis and analysis. Lastly, the topic cover other application of radiotracers in industry discussed the following subtopics: mixing and blending studies, measurement of volume, ventilation studies, oil field investigation, corrosion and wear studies, validation of CFD models

  6. Simulation Studies of Diffusion-Release and Effusive-Flow of Short-Lived Radioactive Isotopes

    CERN Document Server

    Zhang, Yan; Kawai, Yoko

    2005-01-01

    Delay times associated with diffusion release from targets and effusive-flow transport of radioactive isotopes to ion sources are principal intensity limiters at ISOL-based radioactive ion beam facilities, and simulation studies with computer models are cost effective methods for designing targets and vapor transport systems with minimum delay times to avoid excessive decay losses of short lived ion species. A finite difference code, Diffuse II, was recently developed at the Oak Ridge National Laboratory to study diffusion-release of short-lived species from three principal target geometries. Simulation results are in close agreement with analytical solutions to Fick’s second equation. Complementary to the development of Diffuse II, the Monte-Carlo code, Effusion, was developed to address issues related to the design of fast vapor transport systems. Results, derived by using Effusion, are also found to closely agree with experimental measurements. In this presentation, the codes will be used in conc...

  7. How Short-Lived Ikaite Affects Calcite Crystallization

    OpenAIRE

    Besselink, R; Rodriguez-Blanco, JD; Stawski, TM; Benning, LG; Tobler, DJ

    2017-01-01

    The pathways of CaCO3 crystallization are manifold, often involving one or several metastable amorphous or nanocrystalline intermediate phases. The presence of such intermediates is often overlooked, because they are short-lived and/or occur at small molar fractions. However, their occurrence does not just impact the mechanisms and pathways of formation of the final stable CaCO3 phase, but also affects their crystal size, shape, and structure. Here we document the presence of a short-lived in...

  8. Radiotracers for medical applications

    International Nuclear Information System (INIS)

    Rayudu, G.A.S.

    1983-01-01

    This book discusses the medical applications of radiotracers. Diagnostic uses and pharmacokinetics of isotopes and radiopharmaceuticals is emphasized. The volume one covers the following topics: Radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; /sup 11/C, /sup 13/N, /sup 15/O, /sup 67/Ga. /sup 111/In, /sup 75/Se, /sup 123m/Te compounds; radioactive noble gases; and miscellaneous radiotracers for imaging. Vol. II: Pertinent nuclear science data such as radiation dosimetry, radionuclide production modes, radionuclides for therapy, human experimentation regulations and consent forms, and radiotracer laboratory designs are presented. 272 pp., 7 x 10, 1983, ISBN-0-8493-6016-1

  9. Principles of radiotracer methodology

    Energy Technology Data Exchange (ETDEWEB)

    Kisieleski, W.E.

    1975-06-01

    Information is presented on the properties of radioisotopes and radiations, methods and equipment for radiation detection, safety in handling radioactive materials, the biological effects of radiation, and the design of radiotracer studies. (LCL)

  10. Measurement of short-lived particles at PETRA

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1987-04-01

    The contribution of PETRA to the measurement of short-lived particles is reviewed with discussion of the detectors and analysis techniques. New results are presented on lifetimes of identified particles and the systematics of b-life measurement outlined. The first application of vertex-tagging to flavour separation is described. (author)

  11. Fast Resonance Raman Spectroscopy of Short-Lived Radicals

    DEFF Research Database (Denmark)

    Pagsberg, Palle Bjørn; Wilbrandt, Robert Walter; Hansen, Karina Benthin

    1976-01-01

    We report the first application of pulsed resonance Raman spectroscopy to the study of short-lived free radicals produced by pulse radiolysis. A single pulse from a flash-lamp pumped tunable dye laser is used to excite the resonance Raman spectrum of the p-terphenyl anion radical with an initial...

  12. Applications of nuclear data on short-lived fission products

    International Nuclear Information System (INIS)

    Rudstam, G.; Aagaard, P.; Aleklett, K.; Lund, E.

    1981-01-01

    The study of short-lived fission products gives information about the nuclear structure on the neutron-rich side of stability. The data are also of interest for various applications both to basic science and to nuclear technology. Some of these applications, taken up by the OSIRIS group at Studsvik, are described in the present contribution. (orig.)

  13. Soot and short-lived pollutants provide political opportunity

    Science.gov (United States)

    Victor, David G.; Zaelke, Durwood; Ramanathan, Veerabhadran

    2015-09-01

    Cutting levels of soot and other short-lived pollutants delivers tangible benefits and helps governments to build confidence that collective action on climate change is feasible. After the Paris climate meeting this December, actually reducing these pollutants will be essential to the credibility of the diplomatic process.

  14. [Hyperfine structure and isotope shift measurements of short lived elements by laser spectroscopy

    International Nuclear Information System (INIS)

    Schuessler, H.A.

    1986-01-01

    The aim of this research is to determine nuclear moments and charge distributions of short-lived isotopes produced both on-line and off-line to a nuclear facility. These measurements give detailed information on the nuclear force and are used to test current nuclear models. The small amounts of nuclei which can be produced off stability constitute the challenge in these experiments. Presently mainly neutron-rich isotopes are being studied by three ultrasensitive high-resolution laser techniques. These are collinear fast ion-beam laser spectroscopy, stored-ion laser spectroscopy and fluorescence spectroscopy. 5 figs

  15. Passive Mobile Bandwidth Classification Using Short Lived TCP Connections

    OpenAIRE

    Michelinakis, Foivos; Kreitz, Gunnar; Petrocco, Riccardo; Zhang, Boxun; Widmer, Joerg

    2015-01-01

    Consumption of multimedia content is moving from a residential environment to mobile phones. Optimizing Quality of Experience—smooth, quick, and high quality playback—is more difficult in this setting, due to the highly dynamic nature of wireless links. A key requirement for achieving this goal is estimating the available bandwidth of mobile devices. Ideally, this should be done quickly and with low overhead. One challenge is that the majority of connections on mobiles are short-lived TCP con...

  16. Quantitative cerebral blood flow patterns with the short lived isotope 195m Au

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1984-01-01

    A previously reported theory for quantitative cerebral blood flow measurements using intravenously injected nondiffusible radiotracers has been applied on patients after stroke and on volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow patterns (in ml/min/100g) not only in p.a. but also in lateral views of the brain are possible by using of the short-lived (30 sec) isotope Au 195m. The energy spectrum of the eluate of the generator shows two strong photon peaks, one at 68 keV and a second at 262 keV. The 68 keV peak is suitable for perfusion studies in lateral views of the hemispheres, no 'look through' effect is seen. The 262 keV peak is good for studies in p.a. positions. The studies last less than 1 minute and can be repeated after 3 minutes. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be made visible. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. After optical stimulation a clear increase of blood flow was seen in the visual cortex. The results prove that not only with freely diffusible (like Xenon) but also with nondiffusible indicators like 195m Au it is possible to measure quantitatively cerebral blood flow patterns. Au 195m is very advantageous for quantitative clinical investigations of cerebrovascular disease. (Author)

  17. Labeling suspended aerosol particles with short-lived radionuclides for determination of particle deposition

    International Nuclear Information System (INIS)

    Smith, M.F.; Bryant, S.; Welch, S.; Digenis, G.A.

    1984-01-01

    Radiotracer techniques were developed to examine parameters that characterize pressurized aerosols designed to deliver insoluble particles suspended in the aerosol formulation. Microaggregated bovine serum albumin microspheres that were to be suspended were labeled with iodine-131 (t1/2 . 8 d). This iodination procedure (greater than 80% effective) is also applicable to iodine-123, which possesses superior characteristics for external imaging and further in vivo studies. This report shows that for pressurized aerosols containing suspended particles, each metered dose is approximately equal (not including the priming doses and the emptying doses). Increase in the delivery of the albumin particles out of the canister was best achieved by pretreating the valve assembly with a solution of 2% (w/v) bovine serum albumin in phosphate buffer. Use of a cascade impactor delineated the particle size distribution of the micropheres, with the majority of particles ranging in size from 2 to 8 microns. The data disclosed here indicate that the techniques developed with short-lived radionuclides can be used to quantitate each metered dose, characterize the particle size distribution profile of the aerosol contents, and determine the extent of deposition of the particles in the aerosol canister and all of its components

  18. Production of exotic, short lived carbon isotopes in ISOL-type facilities

    CERN Document Server

    Franberg, Hanna; Köster, Ulli; Ammann, Markus

    2008-01-01

    The beam intensities of short-lived carbon isotopes at Isotope Separation On-Line (ISOL) facilities have been limited in the past for technical reasons. The production of radioactive ion beams of carbon isotopes is currently of high interest for fundamental nuclear physics research. To produce radioactive ions a target station consisting of a target in a container connected to an ion source via a transfer line is commonly used. The target is heated to vaporize the product for transport. Carbon in elementary form is a very reactive element and react strongly with hot metal surfaces. Due to the strong chemisorption interaction, in the target and ion source unit, the atoms undergo significant retention on their way from the target to the ion source. Due to this the short lived isotopes decays and are lost leading to low ion yields. A first approach to tackle these limitations consists of incorporating the carbon atoms into less reactive molecules and to use materials for the target housing and the transfer line ...

  19. Short-lived radiopharmaceuticals for the diagnosis of ocular melanoma

    International Nuclear Information System (INIS)

    Packer, S.; Lambrecht, R.; Atkins, H.L.; Wolf, A.P.

    1974-01-01

    An experimental procedure has been established to evaluate radiopharmaceuticals for the specific purpose of melanoma detection by scintiscanning. By using the Greene melanoma in the hamster several labeled compounds were compared. Specifically the tumor uptake along with detailed analyses of uptake by various parts of the eye and body were determined in a hamster model. Of those short-lived radionuclides investigated 203 Pb-tris was the most promising as a non-invasive localizing agent for ocular melanoma and it should prove effective for ocular scintigraphy. (U.S.)

  20. Short-lived radionuclide production capability at the Brookhaven Linac Isotope Producer

    International Nuclear Information System (INIS)

    Mausner, L.F.; Richards, P.

    1985-01-01

    The Brookhaven National Linac Isotope Producer is the first facility to demonstrate the capability of a large linear accelerator for efficient and economical production of difficult-to-make, medically useful radionuclides. The linac provides a beam of 200-MeV protons at an integrated beam current of up to 60 μA. The 200-MeV proton energy is very suitable for isotope production because the spallation process can create radionuclides unavailable at lower energy accelerators or reactors. Several medically important short-lived radionuclides are presently being prepared for on-site and off-site collaborative research programs. These are iodine-123, iron-52, manganese-52m, ruthenium-97, and the rubidium-81-krypton-81m system. The production parameters for these are summarized

  1. Production, study and use of short-lived nuclides in pure and applied nuclear research

    International Nuclear Information System (INIS)

    Bjoernstad, T.

    1986-01-01

    The thesis which is based on 17 published papers, reports on the on-line performance of the fast radiochemical separation system SISAK, technical devlopment in the preparation of sources for beta-particles and neutrons, and on important SISAK system improvements concerning liquid hold-up time. It further reports on the development of new production targets at ISOLDE for 600 MeV proton and 910 MeV 3 He-particle irradiations, on tests with a heavy ion beam of 1 GeV 12 C-particles, and on the present availability of mass-separated beams of the halogen elements through new ion source development. Some results from nuclear spectroscopic studies of nuclides in selected mass regions when using such new or improved techniques are given. Examples of techniques for practical application of short-lived nuclides in radiochemical analysis and for radiochemical production for medical purposes are presented

  2. Radiotracers inside the system

    International Nuclear Information System (INIS)

    Savio, Eduardo

    2000-01-01

    The radioactive use of a tracer that you incorporated in a biological, physical or chemicals system can be an indicator of some of the following situations: of the system in general, of a property that is wanted to evaluate, of a biochemical, physiological or pathophysiological. One the radiotracers use inside the system presents the following advantages: 1. it is possible to detect them and to measure them with high precision and sensibility, 2. the radioactivity is independent of the pressure, the temperature, the physical or chemical state 3. the radiotracers do affect the system and they can be used as non destructive methods 4. In most of the cases they can be measured in independent form of the matrix, without necessity of a calibration curve

  3. Radiotracer injections through microfilters

    International Nuclear Information System (INIS)

    Huber, H.; Maschek, G.; Pichler, R.; Giesen, I.; Hatzl-Griesenhofer, M.; Maschek, W.

    2002-01-01

    Full text: Problems with the injection of radiotracers ( 99m Tc-HAMS, 99m Tc-DPD) to infants when administered through polar-filter-protected venous pathways caused us to get a closer look of what happens to a tracer in such a system. We simulated injections of the tracers mainly used at our institution in an in-vitro array and measured full and empty tracer syringes, filters (0.2 μm micropores) and the post-filter receptacle of the radioactivity. We calculated the percentage of filter-trapped activity and of activity in the receptacle. For several tracers we repeated this process with a neutral filter of the same pore size to get a comparison between the behavior in polarized and electrically inert filters. In general injection of a soluble radiotracer through a polar filter system means a dose loss in the filter of about 10 %, up to the tracer molecule size of IgG-antibodies. Suspended tracers, which consist of comparatively large particles, like RES- or pulmonary perfusion markers, are blocked by the filter, as can be foreseen with a particle size of >> 0.2 μm. DMSA and DPD (a biphosphonate), although both being soluble and rather small molecules, were blocked by the polar filter to a high extent, and by the neutral filter to a much lower, almost neglectable degree. The conclusions are: if possible avoid any use of a filter in your tracer injection pathway. Never use a filter with bone scan or DMSA applications. When doing uptake calculations you have to add the filter counts to the empty syringe value in the formula. If you cannot avoid to inject the radiotracer through a filter you have to replace the filter afterwards and treat the used filter as radioactive waste. The polarity of the filter material might severely affect retention of radiotracer in the filter. (author)

  4. Radiotracers in Swedish Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, I.; Erwall, L. G. [Isotope Techniques Laboratory, Stockholm (Sweden); Nyquist, O. [Surahammars Bruks AB, Surahammar (Sweden)

    1967-06-15

    Recent tracer investigations in Swedish steel plants have mainly dealt with problems concerning uon-metallic inclusions, slag weight determination and - labelling of special steel qualities for identification. Suspected inclusion sources, such as furnace slag, ladle-bottom mortar and some brick materials as stopper, nozzle.and channel bricks have been labelled radioactively in different ways. The labelling technique has been studied for the different systems and a new method was developed for brick materials. This includes vacuum impregnation with an aqueous solution of the inactive tracer, reheating to 1300 Degree-Sign C and neutron-irradiation in a reactor. A sufficiently homogeneous labelling of the material was obtained in this way. The tracer used was terbium, which was added as the nitrate and then decomposed to oxide during the heating process. The oxide is strongly bound to the ceramic material. The number of radioactive inclusions was determined by.autoradiography, and related to the total number pf inclusions, obtained by visual slag-counting, to give the percentage of inclusions originating from the labelled object. Some investigations have been made using simultaneous labelling of two or more sources. It seems to be difficult, however, to measure separately more than two tracers: one short-lived (e.g. 140La) and one long-lived (e.g. {sup 160}Tb). The slag weight determinations were made using the isotope dilution technique with {sup 131}Ba and {sup 140}La as tracers. A difference in slag weight is sometimes obtained. An attempt is made to explain these deviations. The material transport through a blast furnace has been followed by using a piece of graphite, labelled with {sup 140}La{sub 2}O{sub 3}, and measuring the radiation intensity outside the furnace walls and in the tuyere. Studies have been made to determine suitable radiotracers for labelling of steel for subsequent identification. Up to three different isotopes can be used simultaneously

  5. Are crab-type supernova remnants (plerions) short-lived

    International Nuclear Information System (INIS)

    Weiler, K.W.; Panagia, N.

    1978-01-01

    Arguments are given for a possible picture of the origin, maintenance, and lifetimes of the so-called Crab-like supernova remnants. It is suggested that these objects imply the existence of at least two distinct types of supernova events. A possible connection of the remnant types with the optically defined supernovae of Type I and Type II is discussed. Accepting that a pulsar is formed in at least some supernova events, the proposal is made that a rapidly rotating, rapidly slowing pulsar is necessary to create and maintain a Crab-like supernova remnant. Finally, arguments are presented that such a supernova remnant will be relatively short lived with respect to the more common shell-type of supernova remnant, perhaps surviving only 10000-20000 yr before fading into the Galactic background. The name of plerion is proposed for these filled-center supernova remnants and observational possiblities for confirming their nature are suggested. (orig.) [de

  6. Kinetic aspects of the syntheses using short-lived radionuclides

    International Nuclear Information System (INIS)

    Laangstroem, B.; Obenius, U.; Sjoeberg, S.; Bergson, G.

    1981-01-01

    In syntheses using short-lived radionuclides, such as 11 C, the reaction conditions are usually such that the concentrations of the reactants, except for the labelled reactant, can be considered constant during the reaction. Two kinetic models have been investigated - irreversible and reversible bimolecular elementary reactions. The influence of the rate constants, of the equilibrium constants, and of the ratio between the starting reactants on the yield of the labelled product has been studied. The results show that, even in cases with unfavourable equilibrium constants, high yields of the labelled products can be obtained if the rate constant for the forward reaction is large. In addition, the specific activity of the labelled product as a function of time has been studied for the irreversible bimolecular case. (author)

  7. Organic synthesis with short-lived positron-emitting radioisotopes

    International Nuclear Information System (INIS)

    Pike, V.W.

    1988-01-01

    Chemistry with short-lived positron-emitting radioisotopes of the non-metals, principally 11 C, 13 N and 18 F, has burgeoned over the last decade. This has been almost entirely because of the emergence of positron emission tomography (PET) as a powerful non-invasive technique for investigating pathophysiology in living man. PET is essentially an external technique for the rapid serial reconstruction of the spatial distribution of any positron-emitting radioisotope that has been administered in vivo. Such a distribution is primarily governed by the chemical form in which the positron-emitting radioisotope is incorporated, and importantly for clinical research, is often perturbed by physical, biological or clinical factors. Judicious choice of the chemical form enables specific biological information to be obtained. For example, the labelling of glucose with a positron-emitting radioisotope could be expected to provide a radiopharmaceutical for the study of glucose utilisation in both health and disease. (author)

  8. Activation analysis with neutron generators using short-lived radionuclides

    International Nuclear Information System (INIS)

    Salma, I.

    1993-01-01

    The short half-life involves a number of important differences in production, transportation and measurement of radionuclides, and in counting statistics as compared with those in traditional activation analysis. Experiments were performed to investigate the analytical possibilities and prospective utilization of short-lived radionuclides produced by 14-MeV neutron irradiation. A rapid pneumatic transfer system for use with neutron generators was installed and applied for detecting radionuclides with a half-life from 300 ms to 30 s. The transport time for samples with a total mass of 1-4 g is between 130 and 160 ms for pressurized air of 0.1-0.4 MPa. 11 elements were studied by the conventional activation method using both a typical pneumatic transport system (run time 3 s) and the fast pneumatic transport facility. The effect of the cyclic activation technique on the elemental sensitivities was also investigated. (orig.)

  9. Nondispersive x-ray diagnostics of short lived plasmas

    International Nuclear Information System (INIS)

    Day, R.H.

    1983-01-01

    In this NATO Advanced Study Institute, we have discussed in detail the diagnosis of many pulse power machine properties, including their electrical behavior, grounding and shielding, and related data acquisition techniques. The purpose for many of these machines is to create high temperature/high density plasmas and, therefore, the subsequent behavior of these plasmas is of critical concern. The energy density of these plasmas is such that they will naturally radiate in the x-ray regime and thus the diagnosis of their x-ray emission is a crucial measurement of the entire system performance. In this lecture, I describe the general techniques used to perform nondispersive x-ray diagnostics of these short lived plasmas

  10. Diffusion in intermetallic compounds studied using short-lived radioisotopes

    CERN Multimedia

    Diffusion – the long range movement of atoms – plays an important role in materials processing and in determining suitable applications for materials. Conventional radiotracer methods for measuring diffusion can determine readily how distributions of radioactive probe atoms in samples evolve under varying experimental conditions. It is possible to obtain limited information about atomic jump rates and pathways from these measurements; however, it is desirable to make more direct observations of the atomic jumps by using experimental methods that are sensitive to atomic scale processes. One such method is time-differential perturbed $\\gamma$–$\\gamma$-angular correlation spectroscopy (PAC). Two series of PAC experiments using $^{111m}$Cd are proposed to contribute to fundamental understanding of diffusion in intermetallic compounds. The goal of the first is to determine the dominant vacancy species in several Li$_{2}$-structured compounds and see if the previously observed change in diffusion mechanism th...

  11. NMR detection of short-lived β-emitter {sup 12}N implanted in water

    Energy Technology Data Exchange (ETDEWEB)

    Sugihara, T., E-mail: sugihara@vg.phys.sci.osaka-u.ac.jp; Mihara, M.; Shimaya, J.; Matsuta, K.; Fukuda, M.; Ohno, J.; Tanaka, M.; Yamaoka, S.; Watanabe, K.; Iwakiri, S.; Yanagihara, R.; Tanaka, Y.; Du, H.; Onishi, K.; Kambayashi, S.; Minamisono, T. [Osaka University, Department of Physics (Japan); Nishimura, D. [Tokyo University of Science, Department of Physics (Japan); Izumikawa, T. [Niigata University, Radioisotope Center (Japan); Ozawa, A. [University of Tsukuba, Department of Physics (Japan); Ishibashi, Y. [RIKEN Nishina Center for Accelerator-Based Science (Japan); and others

    2017-11-15

    The beta-detected nuclear magnetic resonance (β-NMR) in liquid H{sub 2}O has been observed for the first time using a short-lived β-ray emitter {sup 12}N (I{sup π} = 1{sup +},T{sub 1/2}=11 ms). A nuclear spin polarized {sup 12}N beam with an energy of about 20 MeV/nucleon was implanted into an enclosed water sample. About 50 % of implanted {sup 12}N ions maintained nuclear polarization and exhibited a β-NMR spectrum. The chemical shift of {sup 12}N in H{sub 2}O relative to {sup 12}N in Pt was deduced to be −(3.6±0.5) × 10{sup 2} ppm.

  12. Separation efficiency of the MASHA facility for short-lived mercury isotopes

    Science.gov (United States)

    Rodin, A. M.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Kliman, J.; Kondratiev, N. A.; Krupa, L.; Novoselov, A. S.; Oganessian, Yu. Ts.; Podshibyakin, A. V.; Salamatin, V. S.; Siváček, I.; Stepantsov, S. V.; Vanin, D. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Granja, C.; Pospisil, S.

    2014-06-01

    The mass-separator MASHA built to identify Super Heavy Elements by their mass-to-charge ratios is described. The results of the off- and on-line measurements of its separation efficiency are presented. In the former case four calibrated leaks of noble gases were used. In the latter the efficiency was measured via 284 MeV Ar beam and with using the hot catcher. The ECR ion source was used in both cases. The -radioactive isotopes of mercury produced in the complete fusion reaction Ar+SmHg+xn were detected at the mass-separator focal plane. The half-lives and the separation efficiency for the short-lived mercury isotopes were measured. Potentialities of the MEDIPIX detector system have been demonstrated for future use at the mass-separator MASHA.

  13. Production of medical short-lived radionuclides in Canada

    International Nuclear Information System (INIS)

    Wiebe, L.I.

    1985-01-01

    The production of radionuclides for medical and biomedical research in Canada has been reviewed with respect to the national geographic and demographic characteristics which influence their use. The types of facilities available for the production of short-lived radionuclides have been summarized, and a tabulation of the radionuclides that are produced has been presented. In broad terms production facilities can be classified as belonging to one of two groups, nuclear reactor or charged-particle accelerators. The charged-particle accelerators produce the more neutron-deficient and (because of the resultant decay properties) the more useful radionuclides for medical application. The nuclear reactor facilities for radionuclide production range in size and capacity from the high-flux research reactors of AECL to the six SLOWPOKE reactors, five of which are located on university campuses across the country. The McMaster University reactor is used to produce curie quantities of fluorine-18 weekly. Millicurie amounts of a large number of radionuclides, most of which have half-lives ranging from 2 to 50 hr, are produced in the low-flux reactors, in support of basic medical research

  14. Contribution of short-lived nuclides to decay heat

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi

    1987-01-01

    Comments are made on the calculation of decay heat, centering on evaluation of average decay energy. It is difficult to obtain sufficiently useful decay diagrams of short lived nucleides. High-energy levels are often missing in inferior decay diagrams, leading to an overestimation of the intensity of beta-rays at low-energy levels. Such an overestimation or underestimation due to the inferiority of a decay diagram is referred to as pandemonium effect. The pandemonium effect can be assessed by means of the ratio of the measured energy of the highest level of the daughter nuclide to the Q β -value of the beta-decay. When a satisfactory decay diagram cannot be obtained, the average decay energy has to be estimated by theoretical calculation. The gross theory for beta-decay proposed by Yamada and Takahashi is employed for the calculation. To carry out the calculation according to this theory, it is required to determine the value for the parameter Q 00 , the lowest energy of the daughter nuclide that meets the selection rule for beta-decay. Currently, Q 00 to be used for this purpose is estimated from data on the energy of the lowest level found in a decay diagram, even if it is inferior. Some examples of calculation of decay heat using the average beta- or gamma-ray energy are shown and compared with measurements. (author)

  15. Changing-Look AGNs or Short-Lived Radio Sources?

    Energy Technology Data Exchange (ETDEWEB)

    Wołowska, Aleksandra [Toruń Centre for Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Toruń (Poland); Kunert-Bajraszewska, Magdalena; Mooley, Kunal [Centre for Astrophysical Surveys, University of Oxford, Oxford (United Kingdom); Hallinan, Gregg, E-mail: ola@astro.umk.pl [Cahill Center for Astronomy, California Institute of Technology, Pasadena, CA (United States)

    2017-11-17

    The evolution of extragalactic radio sources has been a fundamental problem in the study of active galactic nuclei for many years. A standard evolutionary model has been created based on observations of a wide range of radio sources. In the general scenario of the evolution, the younger and smaller Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources become large-scale FRI and FRII objects. However, a growing number of observations of low power radio sources suggests that the model cannot explain all their properties and there are still some aspects of the evolutionary path that remain unclear. There are indications, that some sources may be short-lived objects on timescales of 10{sup 4}–10{sup 5} years. Those objects represent a new population of active galaxies. Here, we present the discovery of several radio transient sources on timescales of 5–20 yrs, largely associated with renewed AGN (Active Galactic Nucleus) activity. These changing-look AGNs possibly represent behavior typical for many active galaxies.

  16. Emission channeling lattice location experiments with short-lived isotopes

    CERN Multimedia

    Wahl, U; Ronning, C R

    2007-01-01

    Emission channeling with position-sensitive detectors is a well-established technique at ISOLDE for studying the lattice location of radioactive impurities implanted into single crystals. In the case of electron emitting isotopes, however, due to count rate and noise-related limitations of the detection systems, the technique was restricted to isotopes with half lives above 6 h and electron energies above 40 keV. Recently, major technical developments have been realized and new equipment has been acquired which has allowed these limitations to be overcome and made feasible electron emission channeling experiments with short-lived isotopes and at low electron energies.\\\\ As first application, making use of two new on-line emission channeling setups at ISOLDE, we propose to investigate the lattice location of the transition metals Ni (2.5 h) and Co (1.6 h) in semiconductors, in particular in ZnO and GaN, by means of on-line $\\beta^{-}$-emission channeling experiments. In addition, we would like to study the lat...

  17. Quantifying short-lived events in multistate ionic current measurements.

    Science.gov (United States)

    Balijepalli, Arvind; Ettedgui, Jessica; Cornio, Andrew T; Robertson, Joseph W F; Cheung, Kin P; Kasianowicz, John J; Vaz, Canute

    2014-02-25

    We developed a generalized technique to characterize polymer-nanopore interactions via single channel ionic current measurements. Physical interactions between analytes, such as DNA, proteins, or synthetic polymers, and a nanopore cause multiple discrete states in the current. We modeled the transitions of the current to individual states with an equivalent electrical circuit, which allowed us to describe the system response. This enabled the estimation of short-lived states that are presently not characterized by existing analysis techniques. Our approach considerably improves the range and resolution of single-molecule characterization with nanopores. For example, we characterized the residence times of synthetic polymers that are three times shorter than those estimated with existing algorithms. Because the molecule's residence time follows an exponential distribution, we recover nearly 20-fold more events per unit time that can be used for analysis. Furthermore, the measurement range was extended from 11 monomers to as few as 8. Finally, we applied this technique to recover a known sequence of single-stranded DNA from previously published ion channel recordings, identifying discrete current states with subpicoampere resolution.

  18. Fast neutron activation analysis using short-lived radionuclides

    International Nuclear Information System (INIS)

    Salma, I.; Zemplen-Papp, E.

    1993-01-01

    Fast neutron activation analysis experiments were performed to investigate the analytical possibilities and prospective utilization of short-lived activation products. A rapid pneumatic transfer system for use with neutron generators has been installed and applied for detecting radionuclides with a half-life from ∼300 ms to 20 s. The transport time for samples of total mass of 1-4 g is between 130 and 160 ms for pressurized air of 0.1-0.4 MPa. The reproducibility of transport times is less than 2%. The employed method of correcting time-dependent counting losses is based on the virtual pulse generator principle. The measuring equipment consists of CAMAC modules and a special gating circuit. Typical time distributions of counting losses are presented. The same 14 elements were studied by the conventional activation method (single irradiation and single counting) by both a typical pneumatic transport system (run time 3 s) and the fast pneumatic transport facility. Furthermore, the influence of the cyclic activation technique on the elemental sensitivities was investigated. (author) 15 refs.; 5 figs.; 3 tabs

  19. Short-lived radiopharmaceutical development at E.R. Squibb and Sons, Inc

    International Nuclear Information System (INIS)

    Loberg, M.D.

    1985-01-01

    This paper describes the present status and future plans of E.R. Squibb and Sons, Inc. as they relate to the development of short-lived radiopharmaceuticals. The advantages of short-lived radiopharmaceuticals are summarized as are the problems inherent in their manufacture, quality control, and distribution. The nuclear generator is advocated as the best means of distributing short-lived radiopharmaceuticals. The E.R. Squibb and Sons work with the 82 Sr → 82 Rb generator is summarized

  20. Study on short-lived particles with emulsion techniques

    International Nuclear Information System (INIS)

    Prentis, D.D.

    1984-01-01

    Experiments on measuring the lifetimes are reviewed and the decay mechanisms for c-, b-quark, tau-lepton and charmed hadron are disclosed by means of emulsion chambers and hybride techniques (HT) of the emulsion-spectrometer type. The dominant development of hybride emulsion technique is traced beginning with the early experiments on measuring the lifetime of particles with emulsion (approximately 10 -13 s) and emulsion chambers. The layouts of arrangement of emulsions, counters and chambers are presented. Experiments on neutrino beams in the Fermilab and CERN using a foot bubble chamber and the Big European Bubble Chamber (BEBC) are briefly described. HT experiments with a muon beam and neutrino beams in the Fermilab, with a photon beam in CERN with the use of the modified Omega are considered in detail. The results on measuring the lifetimes of the particles investigated are presented. The lengths of decay tracks, hypothetical decays, fitted masses, leVels of permissible limit of kinematic analysis, pulses of charmed baryons and intrinsic lifetimes of candidates for decay Λsub(c)sup(+), D +- , D 0 , F + - mesons are tabulated. The maximum likelihood method has been applied to determine the lifetimes from complete data on decays. It is noted that new developments in the field of semiconductor detectors and automation of emulsion measurements can extend possibilities of HT for investigation of both charmed

  1. Sizes and shapes of short-lived nuclei via laser spectroscopy. Final report

    International Nuclear Information System (INIS)

    Lewis, D.A.

    1985-10-01

    This project, a collaboration involving Iowa State University, Argonne National Lab., and the University of Minnesota, was aimed at the determination of properties of short-lived nuclei through their atomic hyperfine structure and optical isotope shifts. The basic approach was to use a cryogenic He-jet system to thermalize, neutralize, and transport radioactive nuclei produced online into a region suitable for laser spectroscopy. The photon burst method was then used for high sensitivity with the resulting continuous atomic beam. The experiment was located on beamline of the ANL superconducting heavy-ion accelerator. The He-jet system developed would reliably transport approx.10 2 nuclei into phase space useful for high resolution laser spectroscopy. The laser system developed could accurately and reproducibly sweep small frequency ranges for periods greater than or equal to1 day and sensitivity limits less than or equal to1 atom/s were achieved. However the nuclei were not transported as free atoms precluding nuclear determinations. Attempts to obtain free atoms by eliminating turbulence and contamination were not successful. Some of the high sensitivity spectroscopy techniques developed in this work are now being applied in a search for nuclear relics of the Big Bang and in studies of the photon statistics of light scattered by a single atom. 3 refs., 4 figs

  2. Online selection of short-lived particles on many-core computer architectures in the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Zyzak, Maksym

    2016-07-07

    Modern experiments in heavy ion collisions operate with huge data rates that can not be fully stored on the currently available storage devices. Therefore the data flow should be reduced by selecting those collisions that potentially carry the information of the physics interest. The future CBM experiment will have no simple criteria for selecting such collisions and requires the full online reconstruction of the collision topology including reconstruction of short-lived particles. In this work the KF Particle Finder package for online reconstruction and selection of short-lived particles is proposed and developed. It reconstructs more than 70 decays, covering signals from all the physics cases of the CBM experiment: strange particles, strange resonances, hypernuclei, low mass vector mesons, charmonium, and open-charm particles. The package is based on the Kalman filter method providing a full set of the particle parameters together with their errors including position, momentum, mass, energy, lifetime, etc. It shows a high quality of the reconstructed particles, high efficiencies, and high signal to background ratios. The KF Particle Finder is extremely fast for achieving the reconstruction speed of 1.5 ms per minimum-bias AuAu collision at 25 AGeV beam energy on single CPU core. It is fully vectorized and parallelized and shows a strong linear scalability on the many-core architectures of up to 80 cores. It also scales within the First Level Event Selection package on the many-core clusters up to 3200 cores. The developed KF Particle Finder package is a universal platform for short- lived particle reconstruction, physics analysis and online selection.

  3. Online selection of short-lived particles on many-core computer architectures in the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Zyzak, Maksym

    2016-01-01

    Modern experiments in heavy ion collisions operate with huge data rates that can not be fully stored on the currently available storage devices. Therefore the data flow should be reduced by selecting those collisions that potentially carry the information of the physics interest. The future CBM experiment will have no simple criteria for selecting such collisions and requires the full online reconstruction of the collision topology including reconstruction of short-lived particles. In this work the KF Particle Finder package for online reconstruction and selection of short-lived particles is proposed and developed. It reconstructs more than 70 decays, covering signals from all the physics cases of the CBM experiment: strange particles, strange resonances, hypernuclei, low mass vector mesons, charmonium, and open-charm particles. The package is based on the Kalman filter method providing a full set of the particle parameters together with their errors including position, momentum, mass, energy, lifetime, etc. It shows a high quality of the reconstructed particles, high efficiencies, and high signal to background ratios. The KF Particle Finder is extremely fast for achieving the reconstruction speed of 1.5 ms per minimum-bias AuAu collision at 25 AGeV beam energy on single CPU core. It is fully vectorized and parallelized and shows a strong linear scalability on the many-core architectures of up to 80 cores. It also scales within the First Level Event Selection package on the many-core clusters up to 3200 cores. The developed KF Particle Finder package is a universal platform for short- lived particle reconstruction, physics analysis and online selection.

  4. Radiotracer Generators for Industrial Applications

    International Nuclear Information System (INIS)

    2013-01-01

    Radiotracers have been widely used throughout industry to optimize processes, solve problems, improve product quality, save energy and reduce pollution. Their technical, economic and environmental benefits have been recognized by both the industrial and the environmental sectors. The most important radiotracer techniques have been transferred to many developing Member States through IAEA Technical Cooperation projects. However, in spite of their manifest benefits, radiotracer techniques continue to be underutilized, not only by developing countries but also by more industrialized nations. There are a number of factors that restrict the usage of the radioisotope techniques, but chief among them is the timely availability of suitable radiotracers. Ensuring timely availability of suitable radionuclides is a main hurdle to the use of radiotracer techniques in industry. For developing countries that do not possess radioisotope production facilities, the long time required for import of radionuclides not only completely rules out the use of short half-life nuclides, but also makes it impossible for the radioisotope applications teams to respond to problems of an urgent nature. Many possible radiotracer investigations are not being carried out in developing countries because of this problem. Even in industrialized countries, radionuclide supply is often a problem, as many of the former suppliers of industrial radionuclides have switched their production facilities to serve the more lucrative radiopharmaceuticals market. Obtaining continuity of supply of radionuclides with which to carry out extended studies in difficult-to-access locations, such as offshore oil platforms, is also a significant challenge. Making use of tracers from radionuclide generators can alleviate the difficulties associated with radioisotope supply. Two commercially available medical radionuclide generators, 99 Mo/ 99 mTc and 113 Sn/ 113 mIn, have been used for this purpose, but their use has been

  5. Interest of the Department of Energy in production and development of short-lived radionuclides

    International Nuclear Information System (INIS)

    Thiessen, J.W.

    1985-01-01

    The Department of Energy has developed production of potentially useful radionuclides for applications in medicine. The Department's financial commitment and the short-lived radionuclide production program, with emphasis on iodine-123, is discussed

  6. Historical review of short-lived isotope applications in New Zealand

    International Nuclear Information System (INIS)

    More, R.D.

    1986-01-01

    Production of short-lived isotopes, nitrogen 13, fluorine 18 and carbon 11 with a small Van de Graaff accelerator. Applications of these isotopes in uptake and photosynthetic translocation studies in plants, and fluorine tracing in dental studies

  7. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of /sup 11/C, /sup 18/F and /sup 13/N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume.

  8. Application of centrifuge modelling and radiotracers to migration studies of buried toxic waste

    International Nuclear Information System (INIS)

    Villar, H.P.

    1995-01-01

    A new technique to study the migration of souble waste components in soils, based on the application of centrifugue modelling and of selected short-lived radiotracers, is presented. The technique is based on the acceleration of the migration proceses of a specific tracer in a soil model, with simple and well-established scaling laws being used to interpret the results. The use of radiotracers allows geat flexibility and the adoption of a wide range of concentrations. Demosntrations of the technique have been carried out with two elements of radically distinct behaviour: iodine noted for its mobility in soils, and thallium, which tends to be strongly sorbed. Two different soil types have been used. The results semed to confirm what is known about the behaviour of both elements, so that the feasibility of the technique for such studies has been concluded. (author). 7 refs, 4 figs, 1 tab

  9. Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1981-01-01

    A number of reviews, many of them recent, have appeared on various aspects of 11 C, 18 F and 13 N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeled compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume

  10. Probing the Single-Particle Character of Rotational States in F19 Using a Short-Lived Isomeric Beam

    Energy Technology Data Exchange (ETDEWEB)

    Santiago-Gonzalez, D.; Auranen, K.; Avila, M. L.; Ayangeakaa, A. D.; Back, B. B.; Bottoni, S.; Carpenter, M. P.; Chen, J.; Deibel, C. M.; Hood, A. A.; Hoffman, C. R.; Janssens, R. V. F.; Jiang, C. L.; Kay, B. P.; Kuvin, S. A.; Lauer, A.; Schiffer, J. P.; Sethi, J.; Talwar, R.; Wiedenhöver, I.; Winkelbauer, J.; Zhu, S.

    2018-03-01

    A beam containing a substantial component of both the J(pi) = 5(+), T-1/2 = 162 ns isomeric state of F-18 and its 1(+), 109.77-min ground state is utilized to study members of the ground-state rotational band in F-19 through the neutron transfer reaction (d,p) in inverse kinematics. The resulting spectroscopic strengths confirm the single-particle nature of the 13/2(+) band-terminating state. The agreement between shell-model calculations using an interaction constructed within the sd shell, and our experimental results reinforces the idea of a single-particle-collective duality in the descriptions of the structure of atomic nuclei.

  11. Vehicle emissions of short-lived and long-lived climate forcers: trends and tradeoffs.

    Science.gov (United States)

    Edwards, Morgan R; Klemun, Magdalena M; Kim, Hyung Chul; Wallington, Timothy J; Winkler, Sandra L; Tamor, Michael A; Trancik, Jessika E

    2017-08-24

    Evaluating technology options to mitigate the climate impacts of road transportation can be challenging, particularly when they involve a tradeoff between long-lived emissions (e.g., carbon dioxide) and short-lived emissions (e.g., methane or black carbon). Here we present trends in short- and long-lived emissions for light- and heavy-duty transport globally and in the U.S., EU, and China over the period 2000-2030, and we discuss past and future changes to vehicle technologies to reduce these emissions. We model the tradeoffs between short- and long-lived emission reductions across a range of technology options, life cycle emission intensities, and equivalency metrics. While short-lived vehicle emissions have decreased globally over the past two decades, significant reductions in CO 2 will be required by mid-century to meet climate change mitigation targets. This is true regardless of the time horizon used to compare long- and short-lived emissions. The short-lived emission intensities of some low-CO 2 technologies are higher than others, and thus their suitability for meeting climate targets depends sensitively on the evaluation time horizon. Other technologies offer low intensities of both short-lived emissions and CO 2 .

  12. First Isochronous Time-of-Flight Mass Measurements of Short-Lived Projectile Fragments in the ESR

    International Nuclear Information System (INIS)

    Stadlmann, J.; Geissel, H.; Hausmann, M.; Nolden, F.; Radon, T.; Schatz, H.; Scheidenberger, C.; Attallah, F.; Beckert, K.; Bosch, F.; Falch, M.; Franczak, B.; Franzke, B.; Kerscher, Th.; Klepper, O.; Kluge, H.J.; Kozhuharov, C.; Loebner, K.E.G.; Muenzenberg, G.; Novikov, Yu.N.; Steck, M.; Sun, Z.; Suemmerer, K.; Weick, H.; Wollnik, H.

    2000-01-01

    A new method for precise mass measurements of short-lived hot nuclei is presented. These nuclei were produced via projectile fragmentation, separated with the FRS and injected into the storage ring ESR being operated in the isochronous mode. The revolution time of the ions is measured with a time-of-flight detector sensitive to single particles. This new method allows access to exotic nuclei with half-lives in the microsecond region. First results from this novel method obtained with measurements on neutron-deficient fragments of a chromium primary beam with half-lives down to 50 ms are reported. A precision of deltam/m ≤ 5 · 10 -6 has been achieved

  13. Release studies of a thin foil tantalum target for the production of short-lived radioactive nuclei

    CERN Document Server

    Bennett, J R J; Drumm, P V; Lettry, Jacques; Nilsson, T; Catherall, R; Jonsson, O C; Ravn, H L; Simon, H

    2002-01-01

    Measurements have been made at ISOLDE, of the release curves and yields of radioactive beams of lithium, sodium and beryllium from a target constructed from 2 $\\mu$m thick foils. The release curves have been analysed by fitting to a mathematical model to determine the coefficients of diffusion of the particles in the foils and effusion through the target and ionizer at several temperatures. Through a better understanding of the rate of transport of the particles, it is possible to design targets and ionizers with improved yields. This is most important for the rare, short-lived isotopes in which there is considerable interest for physics experiments. This target has demonstrated large increases in the yields of $^{11}$Li and $^{12}$Be, in agreement with the predictions of the model. (11 refs).

  14. Short-lived radionuclides produced on the ORNL 86-inch cyclotron and High-Flux Isotope Reactor

    International Nuclear Information System (INIS)

    Lamb, E.

    1985-01-01

    The production of short-lived radionuclides at ORNL includes the preparation of target materials, irradiation on the 86-in. cyclotron and in the High Flux Isotope Reactor (HFIR), and chemical processing to recover and purify the product radionuclides. In some cases the target materials are highly enriched stable isotopes separated on the ORNL calutrons. High-purity 123 I has been produced on the 86-in. cyclotron by irradiating an enriched target of 123 Te in a proton beam. Research on calutron separations has led to a 123 Te product with lower concentrations of 124 Te and 126 Te and, consequently to lower concentrations of the unwanted radionuclides, 124 I and 126 I, in the 123 I product. The 86-in. cyclotron accelerates a beam of protons only but is unique in providing the highest available beam current of 1500 μA at 21 MeV. This beam current produces relatively large quantities of radionuclides such as 123 I and 67 Ga

  15. Application of accelerator-produced short-lived radionuclides in industry

    International Nuclear Information System (INIS)

    Kupsch, H.

    1986-01-01

    Several problems such as corrosion, catalysis, wear, process optimization and diagnosis, damage analysis, arising in idustry can be solved using short-lived radioisotopes. Some examples of technological target designs which have been developed are demonstrated for the radionuclide production based on p,n; d,α; α,n; α,2n; α,p; γ,n; γ,p nuclear reactions. Applications of short-lived radionuclides in plants and processes of electrodeposition and gas concrete production are described. (author)

  16. A technique for the measurement of electron attachment to short-lived excited species

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Pinnaduwage, L.A.; Bitouni, A.P.

    1990-01-01

    A technique is described for the measurement of electron attachment to short-lived (approx-lt 10 -9 s) excited species. Preliminary results are presented for photoenhanced electron attachment to short-lived electronically-excited states of triethylamine molecules produced by laser two-photon excitation. The attachment cross sections for these excited states are estimated to be >10 -11 cm 2 and are ∼10 7 larger compared to those for the unexcited (ground-state) molecules. 8 refs., 4 figs

  17. The heritage of radiotracers for PET

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1988-01-01

    The history of PET research clearly demonstrates that it is advances in chemistry coupled with a detailed examination of the biochemistry of new radiotracers which has allowed the PET method to be applied to new areas of biology and medicine. Radiotracers whose regional distribution reflects glucose metabolism, neutrotransmitter activity and enzyme activity have all required the development of rapid synthetic methods for the radiotracers themselves and the characterization of their biochemical behavior. This article traces some of the advances in the production of labeled precursors and in radiotracer synthesis and evaluation which have shaped the rapidly expanding application of PET to problems in the neurosciences, in cardiology and in oncology. 54 refs

  18. A new integrative methodology for desertification studies based on magnetic and short-lived radioisotope measurements

    International Nuclear Information System (INIS)

    Oldfield, F.; Higgitt, S.R.; Maher, B.A.; Appleby, P.G.; Scoullos, M.

    1986-01-01

    The use of mineral magnetic measurements and short-lived radioisotope studies with 210 Pb and 137 Cs is discussed within the ecosystem watershed conceptual framework. Used in conjunction with geomorphological, sedimentological, palaeoecological and geochemical techniques, these methods can form the core of an integrated multidisciplinary study of desertification and erosion processes on all relevant temporal and spatial scales. 30 refs.; 4 figs

  19. Applications of short-lived isotopes in agricultural research in New Zealand

    International Nuclear Information System (INIS)

    McCallum, G.J.; More, R.D.; McNaughton, G.S.; Minchin, P.E.H.; Presland, M.R.; Stout, J.D.

    1981-01-01

    The use of the short-lived isotopes 11 C and 13 N in agricultural research studies in New Zealand is reviewed. The methods employed to produce these radioisotopes using a 3 MV Van de Graaff accelerator are given. Experiments on transport processes and the uptake of nutrient by plants, and the study of soil processes are described. (Auth.)

  20. Synthesis of radiopharmaceuticals containing short-lived radionuclides. Comprehensive report, March 1, 1980-February 26, 1986

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1985-09-01

    New methods for the rapid introduction of short-lived radionuclides into agents for use in diagnostic nuclear medicine are reported. Among the new syntheses reported are those for 123 I-labeled fatty acids and steroids, for 11 C-labeled alcohols, for 13 N-labeled amines, and for 15 O-labeled alcohols. 33 refs

  1. Analysing environmental and fishing effects on a short-lived species ...

    African Journals Online (AJOL)

    Short-lived species are extremely dependent on the seasonal and interannual variability of environmental conditions, and determining their stock status is often difficult. This study investigates the effects of environmental variability and fishing pressure on the stock of octopus Octopus vulgaris in Senegalese waters over a ...

  2. Disentangling the effects of CO2 and short-lived climate forcer mitigation

    NARCIS (Netherlands)

    Rogelj, J.; Schaeffer, M.; Meinshausen, M.; Shindell, D.T.; Hare, W.; Klimont, Z.; Velders, G.J.M.; Amann, M.; Schellnhuber, H.J.

    2014-01-01

    Anthropogenic global warming is driven by emissions of a wide variety of radiative forcers ranging from very short-lived climate forcers (SLCFs), like black carbon, to very long-lived, like CO2. These species are often released from common sources and are therefore intricately linked. However, for

  3. Developing role of short-lived radionuclides in nuclear medical practice. DOE symposium series; 56

    International Nuclear Information System (INIS)

    Paras, P.; Thiessen, J.W.

    1985-01-01

    The purpose was to define the developing role and state-of-the-art development of short-lived radionuclides (SLR's) in current nuclear medical practice. Special emphasis was placed on radionuclides with general-purpose labeling capabilities. The need for high-purity labeling-grade iodine-123 was emphasized in the program. Papers have been separately abstracted for the data base

  4. Synthesis of radiopharmaceuticals containing short-lived radionuclides. Progress report, March 1, 1985-February 26, 1986

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1985-09-01

    Methods for the rapid introduction of short-lived radionuclides into agents for use in diagnostic nuclear medicine are reported. Methods to synthesize radioiodinated fatty acids, lipids, and amphetamine derivatives are described. New routes for the introduction of bromine-77, chlorine-34m, and carbon-11 into agents of interest are elaborated. 46 refs

  5. Development of the k0-based cyclic neutron activation analysis for short-lived radionuclides

    NARCIS (Netherlands)

    Dung, H.M.; Blaauw, M.; Beasley, D.; Freitas, M.D.C.

    2011-01-01

    The k0-based cyclic neutron activation analysis (k0-CNAA) technique has been studied to explore the applicability at the Portuguese research reactor (RPI). In particular, for the determination of elements which form short-lived radionuclides, particularly fluorine (20F, 11.16 s half-life) and

  6. Short-lived brain state after cued motor imagery in naive subjects

    NARCIS (Netherlands)

    Pfurtscheller, G.; Scherer, R.; Müller-Putz, G.R.; Lopes da Silva, F.H.

    2008-01-01

    Multi-channel electroencephalography recordings have shown that a visual cue, indicating right hand, left hand or foot motor imagery, can induce a short-lived brain state in the order of about 500 ms. In the present study, 10 able-bodied subjects without any motor imagery experience (naive subjects)

  7. Role of radiotracer in animal science

    International Nuclear Information System (INIS)

    Sivaprasad, N.

    2015-01-01

    Radiotracers have been used as radiopharmaceuticals for diagnosis and treatment of animal diseases in cattle and pet animals. In fact the veterinary nuclear medicine based on radiotracer as radiopharmaceuticals is established medical technique for functional studies and imaging of vital organs such as heart, lung, brain, spleen, liver, kidney etc for diagnosis as well as treatment of diseases such as cancers in animal. Besides, radiation from radioisotopes has been in use for radiation therapy of cancers in animals. The nuclear imaging using positron emitting radiotracer is gaining importance in the evolution of drug in small animals. In this respect, small animals have also contributed significantly in the development of radiopharmaceuticals particularly for biodistribution and bioscan studies. In fact, the quality control of radiopharmaceuticals in animals to test the safety is a mandatory requirement in the production of radiopharmaceuticals. In brief the animal science has contributed in various areas and facets of radiotracer techniques and its application vice versa the radiotracer techniques have contributed towards the progress of animal science. The animal science in combination with radiotracer has also contributed to the progress of other basic and applied sciences. Thus there exists a bond between radiotracer techniques and animal science. Some aspects of mutual dependence of animal science and radiotracer are elaborated

  8. A philosophy for CNS radiotracer design.

    Science.gov (United States)

    Van de Bittner, Genevieve C; Ricq, Emily L; Hooker, Jacob M

    2014-10-21

    Decades after its discovery, positron emission tomography (PET) remains the premier tool for imaging neurochemistry in living humans. Technological improvements in radiolabeling methods, camera design, and image analysis have kept PET in the forefront. In addition, the use of PET imaging has expanded because researchers have developed new radiotracers that visualize receptors, transporters, enzymes, and other molecular targets within the human brain. However, of the thousands of proteins in the central nervous system (CNS), researchers have successfully imaged fewer than 40 human proteins. To address the critical need for new radiotracers, this Account expounds on the decisions, strategies, and pitfalls of CNS radiotracer development based on our current experience in this area. We discuss the five key components of radiotracer development for human imaging: choosing a biomedical question, selection of a biological target, design of the radiotracer chemical structure, evaluation of candidate radiotracers, and analysis of preclinical imaging. It is particularly important to analyze the market of scientists or companies who might use a new radiotracer and carefully select a relevant biomedical question(s) for that audience. In the selection of a specific biological target, we emphasize how target localization and identity can constrain this process and discuss the optimal target density and affinity ratios needed for binding-based radiotracers. In addition, we discuss various PET test-retest variability requirements for monitoring changes in density, occupancy, or functionality for new radiotracers. In the synthesis of new radiotracer structures, high-throughput, modular syntheses have proved valuable, and these processes provide compounds with sites for late-stage radioisotope installation. As a result, researchers can manage the time constraints associated with the limited half-lives of isotopes. In order to evaluate brain uptake, a number of methods are available

  9. Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method

    Directory of Open Access Journals (Sweden)

    Morel P.

    2011-10-01

    Full Text Available The measurement of neutron-induced cross sections of short-lived nuclei is extremely difficult due to the radioactivity of the samples. The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. This method presents the advantage that the target material can be stable or less radioactive than the material required for a neutron-induced measurement. We have successfully used the surrogate reaction method to extract neutron-induced fission cross sections of various short-lived actinides. In this work, we investigate whether this technique can be used to determine neutron-induced capture cross sections in the rare-earth region.

  10. Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method

    Directory of Open Access Journals (Sweden)

    Tassan-Got L.

    2012-02-01

    Full Text Available The measurement of neutron-induced cross sections of short-lived nuclei is extremely difficult due to the radioactivity of the samples. The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. This method presents the advantage that the target material can be stable or less radioactive than the material required for a neutron-induced measurement. We have successfully used the surrogate reaction method to extract neutron-induced fission cross sections of various short-lived actinides. In this work, we investigate whether this technique can be used to determine neutron-induced capture cross sections in the rare-earth region.

  11. Determination of short-lived trace elements in environmental samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Wardani, S.; Sihombing, E.; Hamzah, A.; Rochidi; Hery, P.S.; Hartaman, S.; Iman, J.

    1998-01-01

    Concentration of a short-lived trace elements in environmental samples were determined by neutron activation analysis, a counting loss often occur due to the high counting rate. A Pile-Up Rejecter (PUR) electric circuit was installed in counting a short-lived trace elements by a γ-ray spectrometer in order to correct a counting loss. The samples were irradiated for 30∼60 seconds at neutron flux of 3.5 x 10 12 n.cm -2 .s -1 , then the samples cooled for 120 second and counted for 180 second using this system. The nuclides concentration in the varieties environmental samples have a difference analysis result, was more accurate and precise, which the measured result would be 30 % more higher by PUR system than the result would be counted using a conventional γ-ray spectrometry method

  12. Use of short-lived radionuclides in the agricultural and environmental sciences

    International Nuclear Information System (INIS)

    Krohn, K.A.

    1985-01-01

    In addition to their well-known uses in physiology, biochemistry, and medicine, short-lived radioisotopes have played an important part in promoting the authors knowledge of the agricultural and environmental sciences. Numerous investigators have found that the scientific rewards justify the additional demands associated with use of short-lived radioisotopes when novel or uniquely precise results can be achieved. This is best exemplified by examining the use of 13 N. Nitrogen-13 is the longest lived radioisotope of this very important element. The 10-min half-life of 13 N has required that the agricultural or environmental test model be brought to the laboratory where the isotope is made, but this has been done successfully in numerous instances. One major incentive for this research has probably been the fact that there is no analog of the very useful 14 C tracer to study nitrogen chemistry and biology

  13. Studies on short-lived fission products at the Mainz TRIGA reactor

    International Nuclear Information System (INIS)

    Trautmann, N.

    1974-01-01

    Neutron-rich nuclei of medium mass number are produced by thermal-neutron-induced fission of heavy elements, e.g., 235 U, 239 Pu, and 249 Cf. Pulse irradiations lead to an enhancement of the ratio of short-lived activities to the accompanying longer-lived components. One approach for investigating the properties of short-lived nuclei consists in a combination of rapid chemical separations with higher-resolution gamma spectroscopy. This is demonstrated by the isolation of neutron-rich isotopes of niobium by sorption on glass and of ruthenium by solvent extraction. Other rapid separation procedures from aqueous solutions are briefly summarized and a few examples for their application in nuclear fission- and delayed neutron studies are given. Some experiments with an on-line mass separator of the ISOLDE-type, using chemical targets, are described. (U.S.)

  14. Aube storage centre for short-lived low- and intermediate-level wastes. Annual report 2009

    International Nuclear Information System (INIS)

    2010-06-01

    The National Radioactive Waste Management Agency (Andra), was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. The Andra operates two storage centers in the Aube region (France): the center for short-lived low- and intermediate-level wastes, and the center for very-low-level radioactive wastes. This document is the 2009 activity report of the center for short-lived low- and intermediate-level wastes. It presents a review of the activities of the center: presentation of the installations, safety and radiation protection, events or incidents, environmental monitoring, wastes management, public information, opinion of the Health and safety Committee (CHSCT)

  15. Aube storage center for short-lived low- and intermediate-level wastes. Annual report 2008

    International Nuclear Information System (INIS)

    2009-06-01

    The National Radioactive Waste Management Agency (Andra), was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. The Andra operates two storage centers in the Aube region (France): the center for short-lived low- and intermediate-level wastes, and the center for very-low-level radioactive wastes. This document is the 2008 activity report of the center for short-lived low- and intermediate-level wastes. It presents a review of the activities of the center: presentation of the installations, safety and radiation protection, events or incidents, environmental monitoring, wastes management, public information

  16. Aube storage center for short-lived low- and intermediate-level wastes. Annual report 2010

    International Nuclear Information System (INIS)

    2011-06-01

    The National Radioactive Waste Management Agency (Andra), was established by the December 1991 Waste Act as a public body in charge of the long-term management of all radioactive waste, under the supervision of the Ministry of Ecology, Energy, Sustainable Development and the Sea (formerly the Ministry of Industry and the Ministry of Environment), and the Ministry of Research. The Andra operates two storage centers in the Aube region (France): the center for short-lived low- and intermediate-level wastes, and the center for very-low-level radioactive wastes. This document is the 2010 activity report of the center for short-lived low- and intermediate-level wastes. It presents a review of the activities of the center: presentation of the installations, safety and radiation protection, events or incidents, environmental monitoring, wastes management, public information, recommendations of the Health and safety Committee (CHSCT)

  17. Dynamical Detection of Topological Phase Transitions in Short-Lived Atomic Systems

    OpenAIRE

    Setiawan, F.; Sengupta, K.; Spielman, I. B.; Sau, Jay D.

    2015-01-01

    We demonstrate that dynamical probes provide direct means of detecting the topological phase transition (TPT) between conventional and topological phases, which would otherwise be difficult to access because of loss or heating processes. We propose to avoid such heating by rapidly quenching in and out of the short-lived topological phase across the transition that supports gapless excitations. Following the quench, the distribution of excitations in the final conventional phase carries signat...

  18. Extrinsic and intrinsic factors that shape the life history of the short living scallop Argopecten ventricosus

    OpenAIRE

    Guerra, Citlali

    2011-01-01

    The scallop Argopecten ventricosus is characterized by its high swimming activity, fast growth, high reproductive effort and the early age to get first sexual maturity. These traits may be the result of the adaptation to a specific environment that favors an active lifestyle and a short lifespan (2 years). This opens the question of how environmental factors modulate the way a short living marine ectotherm budget energy investments among life history traits and how this modulation impacts the...

  19. Place of the final disposal of short lived dismantling waste; Plats foer slutfoervaring av kortlivat rivningsavfall

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    This report deals with the short-lived low and intermediate level radioactive waste, which will mainly arise from the dismantling of the Swedish nuclear power plants, but also the dismantling of other nuclear facilities. For these installations to be dismantled, there must be the capacity to receive and dispose of dismantling waste. SKB plans to expand the existing final repository for short-lived radioactive waste (SFR) in Forsmark for this purpose. The legislation requires alternatives to the chosen location. The alternate location for the disposal of decommissioning waste SKB has chosen to compare with is a location in the Simpevarp area outside Oskarshamn. There are currently Oskarshamn nuclear power plant and SKB between stock 'CLAB'. The choice of Simpevarp as alternative location is based on that it's one of the places in the country where data on the bedrock is available to an extent that allows an assessment of the prospects for long-term security, such an assessment is actually showing good potential, and that the location provide realistic opportunities to put into practice the disposal of decommissioning waste. At a comparison between the disposal of short-lived decommissioning waste in an extension of SFR with the option to build a separate repository for short-lived decommissioning waste in Simpevarp, the conclusion is that both options offer potentially good prospects for long-term security. The differences still indicated speaks to the Forsmark advantage. Similar conclusions were obtained when comparing the factors of environment, health and social aspects.

  20. Continuous administration of short-lived isotopes for evaluating dynamic parameters

    International Nuclear Information System (INIS)

    Selikson, M.

    1985-01-01

    In this paper it is shown that continuous but varying infusions (specifically, exponential infusions) of a short-lived radionuclide can be used to evaluate a wide range of dynamic parameters. The detector response to exponential infusions is derived. An example of an inert diffusible substrate for evaluating regional flow and a glucose model for evaluating regional metabolic rate are both worked out. The advantages of using exponential infusion methods are discussed

  1. Identification of short-lived neutron-rich ruthenium and rhodium isotopes in fission

    International Nuclear Information System (INIS)

    Franz, G.; Herrmann, G.

    1975-01-01

    Short-lived ruthenium and rhodium isotopes ( 107 Ru, 108 Ru, 108 Rh, 109 Ru, 109 Rh, 110 Ru, 110 Rh, 111 Ru, 111 Rh, 112 Ru, 112 Rh, 113 Ru) have been separated from fission products by a rapid chemical procedure and identified by means of γ-ray spectroscopy. Nuclides with half-lives down to 3 sec were accessible. Ruthenium isotopes up to mass number 113 have been identified. (author)

  2. Review of short-lived radionuclide activities in the United States

    International Nuclear Information System (INIS)

    Sodd, V.J.

    1985-01-01

    A review is given of the accelerator-produced short-lived radionuclides which are used in radiopharmaceuticals available commercially in the US and of the accelerator facilities devoted primarily to their production. Reactions for the efficient production of 67 Ga, 81 Rb → /sup 81m/Kr, 111 In, 201 Tl, and 123 I are given. Methods for the production of higher purity 123 I are suggested

  3. Development of Radiotracer Techniques in Industry

    International Nuclear Information System (INIS)

    Wardono

    2000-01-01

    Contribution of radiotracer techniques to solve problems in industrial process plants have been recognized since a long time. Radiotracer application was governed by three main components, namely radioisotopes, radiation detection and data interpretation of an experiment. The three main components mentioned above have been continually developed to overcome problems relating to the operation of industrial process plants. The availability of isotope generator is one of the development aspect in radiotracer technique. Radiation hazard in radiotracer experiment may be reduced by applying isotope generator and on the other hand the delivery of radiotracer to the plant site from the radioisotopes producer was made easier. The development of microprocessor in computer system has facilitated data recording, storing and retrieving. Development in mathematical model supported by radiotracer experiment enhance data interpretation and shed light on various phenomena of flow process. Generally a flow dynamic in a process plant in all kind of industries can be studied using radiotracer technique. However the main challenge coming from petroleum, petrochemical and mineral processing industries

  4. Radiotracer design strategies for neurocardiology

    International Nuclear Information System (INIS)

    Wieland, D.M.; Hutchins, G.D.

    1991-01-01

    Nuclear cardiologists have expended an inordinate amount of effort studying the open-quotes plumbingclose quotes of the heart but very little effort on the open-quotes wiringclose quotes. L. Rossi declared in 1988, open-quotes today's desultory information about basic changes in the heart's innervation, if compared with current knowledge about diseases of cardiac muscle and vessels, is largely attributable to an aura of forbidding technical difficulty.close-quote During the past three years, radiotracers have been developed for use in studies of cardiac nerve function by positron emission tomography (PET). The first clinical PET studies in this area were reported in 1990. This chapter discusses the strategies that led to the tracers presently available and the possible nature of future neuronal markers

  5. Clinical variables in radiotracer biodistributions

    International Nuclear Information System (INIS)

    Lentle, B.C.; Scott, J.R.; Schmidt, R.P.; Noujaim, A.A.

    1981-01-01

    Numerous iatrogenic causes of altered radiotracer biodistributions have been described. Cancer chemotherapy is a particularly potent cause of changed biodistributions while even a trivial matter such as preparing the skin with an iodine containing antiseptic may cause displacement of technetium from its compounds. In the blocking of thyroid uptake of radioiodines, there is good precedent for the manipulation of regional tissue dosimetry. It is possible to go beyond the mere cataloguing of these effects to look creatively at the subject of comparative tissue biodistributions and hence comparative dosimetry. Effects such as the clinical observation of the interference by cis-platinum with the usual biodistribution of radio-gallium suggests that such compounds can be used as probes each to lead to a better understanding of the mechanism of action of the other

  6. Last developments in the Belgian disposal programme for low and intermediate short-lived waste

    International Nuclear Information System (INIS)

    Boyazis, Jean-Paul

    2006-01-01

    After an historical reminder of the several phases of the Belgian program for the disposal of low and medium level short-lived waste since the creation of ONDRAF/NIRAS and the bad results obtained in the 90's by using a pure technical approach, the presentation will explain the main lines of the new methodology developed, as a consequence of the government decision of 16 January 1998 in ONDRAF/NIRAS to improve local acceptance for the disposal project. The way local partnerships were created with four nuclear municipalities under the form of a non-profit organization with a clear mission, the functioning, on a voluntary base, of the different partnerships during four to six years and the concrete results obtained until now using this very innovative method will be addressed. The last developments of the Belgian program for the disposal of low and medium level and short-lived waste will be presented, including the recent and very important decision of the Belgian government of 23 June 2006 to dispose of the low and medium active short-lived waste in a surface disposal installation on the territory of the municipality Dessel. (author)

  7. Applications of short lived nuclides in activation analysis, problems and progress

    Energy Technology Data Exchange (ETDEWEB)

    Grass, F [Atominstitut, Vienna (Austria)

    1976-07-01

    Short lived nuclides or isomeric transitions, respectively would have some advantages over long lived ones. Although we published a paper concerning a germanium-determination in iron meteorites some years ago, only few laboratories use this technique, the main reason being that the high matrix activity disturbs the measurement of energy-spectra. A multichannel analyzer in the time sequence mode enables Li-8 determination by a purely instrumental method which is therefore used more frequently. In the time sequence mode much higher counting rates up to 10 - 50 MHz are processed then by taking energy-spectra. This is the reason why activation analysis with short lived isomeric states is seldom applied when counting rate and pulse height are to be detected simultaneously. Exceptional difficulties are encountered in measurement of samples activated by a reactor pulse. Further difficulties arise from the fact that an optimal expelling time depends on the half life of the nuclide, and is more critical if the half life is short and the full width half maximum of the reactor pulse is small. Commercial Ge-Li-detectors can be used only at low counting rates, so that samples with high matrix activities cannot be measured. Modifying the electronic system enables registration of samples with high matrix activities. For short lived nuclides emitting hard beta-rays, e.g. B-12 or Li-8, a Cerenkov-detector is optimal. These problems are discussed in examples. (author)

  8. Radiotracer injector: An Industrial Application (RIIA)

    International Nuclear Information System (INIS)

    Noraishah Othman; Mohd Arif Hamzah; Fadil Ismail; Nurliyana Abdullah

    2011-01-01

    The radiotracer injector is meant for transferring liquid radiotracer in the system for industrial radiotracer application with minimal radiation exposure to the operator. The motivation of its invention is coming from the experience of the workers who are very concern about the radiation safety while handling with the radioactive source. The idea ensuring the operation while handling the radioactive source is fast and safe without interrupting the efficiency and efficacy of the process. Thus, semi automated device assisting with pneumatic technology is applied for its invention. (author)

  9. Quality control and analysis of radiotracer compounds

    International Nuclear Information System (INIS)

    Sheppard, G.; Thomson, R.

    1977-01-01

    Special emphasis was on the problems and errors possible in quality control and analysis. The principles underlying quality control were outlined, and analytical techniques applicable to radiotracers were described. Chapter concluded with a selection of examples showing the effects of impurities on the use of radiotracers. The subject of quality control and analysis was treated from the viewpoint of the user and those research workers who need to synthesize and analyze their own radiochemicals. The quality characteristics for radiotracers are of two kinds, valuable or attributive. These were discussed in the chapter. For counting low radioactive concentration, scintillation techniques are in general use, whereas ionization techniques are now used mainly for the measurement of high radioactive concentrations or large quantities of radioactivity, for scanning chromatograms, and a number of very specific purposes. Determination of radionuclidic purity was discussed. Use of radiotracers in pharmaceuticals were presented. 4 figures, 6 tables

  10. Application of radiotracers in environmental studies

    International Nuclear Information System (INIS)

    Rathore, V.S.

    1994-01-01

    An attempt has been made to present recently emerging trends in the applicability of radiotracers in environmental studies. Since the topic is of general interest and still in the infancy, basic aspects of sampling, instrumentation and methodology are also covered

  11. Synthesis of new technetium brain radiotracers

    International Nuclear Information System (INIS)

    Ben Dhieb, Fatma

    2012-01-01

    The scintigraphic diagnosis is a major mean for detecting neuro degenerative diseases at early stage; this requires specific radiotracers to a particular class of brain receptors. Our goal was the synthesis of radiotracers, cytectrenes derivatives, which are specific to the 5-HT1A receptor, whose dysfunction is an indicator of neuro degeneration. The study of their biodistribution revealed for only one of them, a good brain retention and a retrieval adequate for diagnosis.

  12. Clinical variables in radiotracer biodistributions

    International Nuclear Information System (INIS)

    Lentle, B.C.; Scott, J.R.; Schmidt, R.P.; Noujaim, A.A.

    1981-01-01

    Radionuclide dosimetry must, by its nature, define tissue irradiation in terms of mean exposure in a population of a statistically acceptable size. In the daily practice of clinical nuclear medicine there are, however, quite large variations in the biodistribution of tracers and thus in resulting radiation doses. Age is a variable, particularly in respect of bone-seeking tracers. Sex imposes variations in radiation dose on account of the differing anatomical configurations of the gonads. Breast uptake and excretion of certain tracers in women are additional variables. Activity and occupation are occasional variables. Numerous iatrogenic causes of altered radiotracer biodistributions have been described. Cancer chemotherapy is a particularly potent cause of changed biodistributions while even a trivial matter such as preparing the skin with an iodine containing antiseptic may cause displacement of technetium from its compounds. In the blocking of thyroid uptake of radioiodines, there is good precedent for the manipulation of regional tissue dosimetry. It is possible to go beyond the mere cataloguing of these effects to look creatively at the subject of comparative tissue biodistributions and hence comparative dosimetry. Effects such as the clinical observation of the interference by cis-platinum with the usual biodistribution of radio-gallium suggest that such compounds can be used as probes each to lead to a better understanding of the mechanism of action of the other

  13. Imaging in hearing using radiotracers

    Directory of Open Access Journals (Sweden)

    Berding Georg

    2017-09-01

    Full Text Available Radiotracers offer unique options for brain imaging of functional and molecular processes related to hearing. Such imaging can be applied in a broad spectrum of situations from preclinical research to clinical patient care. Functional imaging to assess activation in brain regions and networks involved in auditory processing uses markers of blood flow or energy-metabolism in well-defined conditions with and without auditory stimulation. Molecular markers can be used in hearing research for example to study changes in inhibitory neurotransmission systems related to hearing loss. For imaging either positron emission tomography (PET or single-photon emission computed tomography (SPECT are employed. Data analysis can encompasses voxel-wise statistical analysis of activation and calculation of quantitative parameters like receptor binding-potentials based on bio-kinetic modeling. Functional imaging has been frequently used in the context of auditory implantation. Before implantation it aims to assess intactness of the central auditory pathway and prognosis. After implantation it is used to improve understanding of the outcome with respect to auditory function and finally speech understanding, e.g. by measuring correlates of central auditory processing and neuroplasticity.

  14. Systematic measurement of beta-decay half-lives of short-lived isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, T.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.; Kasugai, Y.; Ikeda, Y.

    1997-03-01

    We have measured the half-lives of short-lived isotopes for past decade and deduced the half-lives of 6 isotopes further. These results demonstrated that most of the literature values shorter than 10 min systematically deviated from our measurement ones. The cause seems to be that a large number of the previous half-life studies were performed with scintillation counters before 1970 and they had a difficulty in distinguishing the interest {gamma}-ray from the contamination and correcting for pile-up and dead-time losses. Moreover, the deviated data found to be quoted for evaluation. (author)

  15. Quantum non-locality in a two-slit interferometer for short-lived particles

    International Nuclear Information System (INIS)

    Klein, Spencer R.; Nystrand, Joakim

    2001-01-01

    We describe a new test of quantum nonlocality, using an interferometer for short-lived particles. The separation is large compared with the particle lifetimes. This interferometer is realized by vector meson production in distant heavy ion collisions. The mesons decay before waves from the two sources (ions) can overlap, so interference is only possible among the decay products. The post-decay wave function must retain amplitudes for all possible decays. The decay products are spatially separated, necessitating a non-local wave function. The interference is measurable by summing the product momenta. Alternately, the products positions could be observed, allowing new tests of the EPR paradox

  16. Short-lived cyclotron-produced radioisotopes: Medi-Physics, Inc.'s commitment

    International Nuclear Information System (INIS)

    Kramer, H.H.

    1985-01-01

    Medi-Physics, Inc., is a major US supplier of short-lived cyclotron-produced radioisotopes for radiopharmaceuticals, as well as routinely producing and distributing the greatest number of 123 I radiopharmaceuticals. The present commercial production capacity for 123 I is more than ten times the theoretical need for existing procedures and is more than adequate for the research and development of new radiopharmaceuticals. However, production capacity is only one component of many that are required to supply a radioisotope for human use. These components are summarized in this paper

  17. Rapid transfer of short-lived radioisotopes via a 2. 4 km rabbit system

    Energy Technology Data Exchange (ETDEWEB)

    Burgerjon, J J; Gelbart, Z; Lau, V; Lehnart, D; Lenz, J; Pate, B D; Ruth, T J; Sprenger, H P; van Oers, N S.C.

    1984-09-01

    A 2.4 km long pipeline between a cyclotron and a hospital is used for the rapid transfer of short-lived radiopharmaceuticals. The vials containing the pharmaceuticals are placed inside capsules (rabbits) that are blown through a tube by means of compressed air. Travel times as short as 2 min are achieved, which makes the system suitable for the transfer of /sup 15/O, which has a 2 min half-life. The construction and test results of the system are described along with a computer model, developed to explain some properties of the system. 7 references, 15 figures, 2 tables.

  18. Tantalum-178 - a short-lived nuclide for nuclear medicine: development of a potential generator system

    International Nuclear Information System (INIS)

    Neirinckx, R.D.; Jones, A.G.; Davis, M.A.; Harris, G.I.; Holman, B.L.

    1978-01-01

    We describe a chemical separation that may form the basis of a generator system for the short-lived radionuclide Ta-178 (T/sub 1/2/ = 9 min). The parent nuclide W-178 (T/sub 1/2/ = 21.7 days) is loaded on an anion-exchange column and the daughter eluted with a mixture of dilute hydrochloric acid and hydrogen peroxide. The yields of tantalum and the breakthrough of the tungsten parent as a function of the eluting conditions are discussed, and preliminary animal distribution data are presented for various treatments of the eluant solution

  19. Short-lived radioactive nuclides in meteorites and early solar system processes

    International Nuclear Information System (INIS)

    Chaussidon, M.; Gounelle, M.

    2007-01-01

    Now extinct, short-lived radioactive nuclides, such as 7 Be (T 1/2 = 53 days), 10 Be (T 1/2 = 1.5 Ma), 26 Al (T 1/2 = 0.74 Ma), 36 Cl (T 1/2 = 0.3 Ma), 41 Ca (T 1/2 = 0.1 Ma), 53 Mn (T 1/2 = 3.7 Ma) and 60 Fe (T 1/2 = 1.5 Ma), were present in the proto-solar nebula when the various components of meteorites formed. The presence of these radioactive isotopes requires a 'last-minute' origin, either nucleosynthesis in a massive star dying close in space and time to the nascent solar system or production by local irradiation of part of the proto-solar disk by high-energy solar cosmic rays. In this review, we list: (i) the different observations indicating the existence of multiple origins for short-lived radioactive nuclides, namely 7 Be, 10 Be and 36 Cl for irradiation scenario and 60 Fe for injection scenario; (ii) the constraints that exist on their distribution (homogeneous or heterogeneous) in the accretion disk; (iii) the constraints they brought on the timescales of nebular processes (from Ca-Al-rich inclusions to chondrules) and of the accretion and differentiation of planetesimals. (authors)

  20. Behaviour of short-lived fission products within operating UO2 fuel elements

    International Nuclear Information System (INIS)

    Hastings, I.J.; Hunt, C.E.L.; Lipsett, J.J.

    1983-01-01

    We have carried out experiments using a ''sweep gas'' technique to determine the behaviour of short-lived fission products within operating, intact UO 2 fuel elements. The Zircaloy-4-clad elements were 500 mm long and contained fuel of density 10.65-10.71 Mg/m 3 . A He-2% H 2 carrier gas swept gaseous or volatile fission products out of the operating fuel element past a gamma spectrometer for measurement. In tests at linear powers of 45 and 60 kW/m to maximum burnups of 70 MW.h/kg U, the species measured directly at the spectrometer were generally the short-lived xenons and kryptons. We did not observe iodine or bromine during normal operation. However, we have deduced the behaviour of I-133 and I-135 from the decay of Xe-133 and Xe-135 during reactor shutdowns. Plots of R/B (released/born) against lambda (decay constant) or effective lambda for all isotopes observed at 45 and 60 kW/m show that a line of slope -0.5, corresponding with diffusion kinetics, is a good fit to the measured xenon and krypton data. Our inferred release of iodine fits the same line. From this we can extrapolate to an R/B for I-131 of about 5x10 -3 . The ANS 5.4 release correlation gives calculated results in good agreement with our measurements. (author)

  1. Search for short-lived particles produced on nuclei with a heavy liquid mini bubble chamber

    CERN Multimedia

    2002-01-01

    The aim of this experiment is to search for short-lived particles produced in hadronic interactions on nuclei with our high resolution heavy liquid mini bubble chamber BIBC, aiming to establish the cross-section for associated production in hadron-nucleus collisions, its $A$-dependence and an approximate value of the lifetime. The chamber will be operated at a bubble density of 290 bubbles/cm and with an apparent bubble size of 30 $\\mu$m in real space. In test runs at CERN we measured detection efficiencies which, together with simulations of $D\\bar{D}$ production and decay, lead to a sensitivity of 0.25 events/($\\mu$b/N) per day if the lifetime is of the order of $5\\times10^{-13}$s. A null result after 10 days running time would set an upper limit on the production cross section to $3 \\mu$b. \\\\ \\\\ In order to measure the momenta of charged decay products of short-lived particles, the bubble chamber will be placed 1.80 m upstream of the streamer chamber of the NA5 experiment (MPI). The geometrical acceptance ...

  2. Continuous administration of short-lived radioisotope tracers and the analogous Laplace transform

    International Nuclear Information System (INIS)

    Orr, J.S.

    1979-01-01

    Short-lived radioactive tracers are used because of the low radiation dose to patients. Another advantage finding increasing use, however, is that the equilibrium activities achieved by continuous administration to a steady state contain kinetic information. This is not the case with long-lived isotopes. The derivation of quantitative kinetic information in the form of rate constants or flows requires the formulation of a model of the system being studied. Several approaches to this have been published based on a model of single compartments with simultaneous arrival of tracer. To deal with more realistic models a method is proposed which uses the analogy between the procedure of continuous administration of short-lived tracer and the Laplace transform. This analogy permits all the theorems of Laplace transform theory to be applied to the analysis of measured activities. The basis of the analogy is explained and examples are given of its application to a number of models which represent actual physiology more realistically than single compartment models. In these applications the transformed equations representing the model, with measured values of activity inserted for each transform, are solved to derive the rate constants. This is different from the use of Laplace transforms where the constant coefficients are known and the initial value problem is solved to find the behaviour of the variables. (author)

  3. Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies

    Directory of Open Access Journals (Sweden)

    S. Menon

    2008-03-01

    Full Text Available Several short-lived pollutants known to impact Arctic climate may be contributing to the accelerated rates of warming observed in this region relative to the global annually averaged temperature increase. Here, we present a summary of the short-lived pollutants that impact Arctic climate including methane, tropospheric ozone, and tropospheric aerosols. For each pollutant, we provide a description of the major sources and the mechanism of forcing. We also provide the first seasonally averaged forcing and corresponding temperature response estimates focused specifically on the Arctic. The calculations indicate that the forcings due to black carbon, methane, and tropospheric ozone lead to a positive surface temperature response indicating the need to reduce emissions of these species within and outside the Arctic. Additional aerosol species may also lead to surface warming if the aerosol is coincident with thin, low lying clouds. We suggest strategies for reducing the warming based on current knowledge and discuss directions for future research to address the large remaining uncertainties.

  4. Short-lived pollutants in the Arctic: their climate impact and possible mitigation strategies

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Surabi; Quinn, P.K.; Bates, T.S.; Baum, E.; Doubleday, N.; Fiore, A.M.; Flanner, M.; Fridlind, A.; Garrett, T.J.; Koch, D.; Menon, S.; Shindell, D.; Stohl, A.; Warren, S.G.

    2007-09-24

    Several short-lived pollutants known to impact Arctic climate may be contributing to the accelerated rates of warming observed in this region relative to the global annually averaged temperature increase. Here, we present a summary of the short-lived pollutants that impact Arctic climate including methane, tropospheric ozone, and tropospheric aerosols. For each pollutant, we provide a description of the major sources and the mechanism of forcing. We also provide the first seasonally averaged forcing and corresponding temperature response estimates focused specifically on the Arctic. The calculations indicate that the forcings due to black carbon, methane, and tropospheric ozone lead to a positive surface temperature response indicating the need to reduce emissions of these species within and outside the Arctic. Additional aerosol species may also lead to surface warming if the aerosol is coincident with thin, low lying clouds. We suggest strategies for reducing the warming based on current knowledge and discuss directions for future research to address the large remaining uncertainties.

  5. Radiotracer techniques in mineral processing

    International Nuclear Information System (INIS)

    Przewlocki, K.

    1991-01-01

    The value of the smelter metal content in currently exploited polymetallic ores mostly does not exceed 2%. Before metallurgical treatment, ore must pass through the concentration process. The benefication process usually starts from the comminution of excavated material and terminates at the flotation and drying of the concentrate. These operations consume vast quantities of energy. To be economically justified, the process requires optimization and, if possible, automatic control. Radioactive tracers were found to be useful in the identification of particular technological subsystems and their subsequent optimization. A great deal of experience has been gathered in this field so far. The industrial radiotracer test (RTT) is carried out using very sensitive multidetector recording systems which have digital data acquisition capabilities. The optimization strategy consists of periodically adjusting technological process and set points of controlled variables according to certain improvement procedures. If computer facilities are available, data interpretation and calibration of the mathematical models describing the technical process itself can be performed on the spot. This significantly accelerates the whole procedure as RTT may be repeated for particular system configurations. The procedure of plant optimization by means of RTT is illustrated in the paper using the example of the copper ore enrichment process, assuming that it is representative of the whole mineral industry. Identification by RTT of the three main operations involved in the ore enrichment process, such as comminution, flotation and granular classification, is discussed in detail as particular case studies. In reference to this, it is also shown how the technological process can be adjusted to be most efficient. (author). 14 refs, 7 figs

  6. Short-lived Isotopes from a Close-by AGB Star Triggering the Protosolar Nebula

    Science.gov (United States)

    Gallino, R.; Busso, M.; Wasserburg, G. J.; Straniero, O.

    The presence of short-lived isotopes in the early solar system, in particular 26Al, 41Ca, 60Fe, and 107Pd, point to a close-by and fresh nucleosynthesis source, possibly triggering the collapse of the protosolar nebula. We present the results of nucleosynthesis calculations based on an AGB polluting hypothesis. A general concordance of the predicted yields of the above radioactivities relative to 26Al can be obtained in the case of an intermediate mass AGB star with hot bottom burning in the envelope (thus producing 26Al), and mixing through a series of third dredge-up episodes a fraction of the C-rich and s-processed material from the He intershell with the extended envelope. Polution of the protosolar nebula with freshly synthesized material may derive from the efficient winds of the AGB star. In AGB stars, the s-process nucleosynthesis occurs both during the maximum phase of every thermal runaway, driven by the partial activation of the 22Ne(alpha,n)25Mg reaction, and in the interpulse phase, where the 13C nuclei are fully consumed in radiative conditions by the activation of the 13C(alpha,n)16O reaction. We have used different prescriptions for the amount of the 13C nuclei present in the intershell. A minimum amount of 13C is naturally expected in the ashes of H-shell burning. Possible formation of an extra "13C-pocket" derives from the injection of a small amount of protons from the envelope into the 12C-rich intershell during any third dredge-up episode, when the H-shell is inactivated. Prediction for other short-lived, 36Cl, 135Cs, and 205Pb, are given. General consequences for the pollution of the protosolar nebula with newly synthesized stable isotopes from the AGB winds are outlined. The origin of other detected short-lived nuclei, in particular 53Mn, 129I, and 182Hf, which cannot come from an AGB source, is analysed. The alternative trigger hypothesis by a close-by Supernova is discussed.

  7. Measurements of beta-decay half-lives of short-lived nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, T.; Tsurita, Y.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.; Kasugai, Y.; Ikeda, Y.

    1997-03-01

    The {beta}-decay half-lives of short-lived nuclei produced by 14 MeV neutron bombardments were measured with Ge detectors, a High-rate spectroscopy amplifier (EG and G ORTEC model 973) and a Spectrum multi-scaler (Laboratory equipment corporation SMS-48) in the multi-scaling mode. The adequate corrections for pile-up and dead-time losses were made by applying source and pulser methods. The half-lives of {sup 53}V, {sup 53g}Fe, {sup 89m}Y and {sup 162}Tb were determined with uncertainties of 0.13-0.65%. It has been shown that previous values shorter than 10 min were systematically longer than the present ones. (author)

  8. Radioactivity of radon and its short-lived decay products in room air, 2

    International Nuclear Information System (INIS)

    Shimo, Michikuni; Katoh, Takao

    1983-01-01

    In the reactor room of the Kyoto University Research Reactor Institute, the measurements of radon (Rn) and its short-lived decay products (Rn-Dts) were carried out under ventilated and non-ventilated conditions. The indoor activities were equal to outdoor ones under ventilated condition and those activities increased till about 10 times of outdoors under non-ventilated condition. We attempted to explain these results on a basis of a simple model. The calculations were performed taking into account: (1) supply of Rn and Rn-Dts from outdoor, (2) the emanation rate of Rn from the wall materials of building, (3) the removal rate of Rn-Dts by ventilation and wall deposition, and (4) the attachment rate of unattached atom to aerosols. In addition, natural ventilation were considered during periods without artificial ventilation. (author)

  9. New three-count technique for short-lived radon decay products in air

    International Nuclear Information System (INIS)

    Tian Deyuan; Lu Zhizhao

    1998-01-01

    Up to the present, radon and its short-lived decay products in air are usually monitored by means of a detection. But radon progeny, including RaB ( 214 Pb) and RaC ( 214 Bi) which are β and γ emitters, contribute about 90% to the equilibrium equivalent radon concentration (EECRn). Therefore, this paper introduces a new three-count technique by a β detector in the light of radioactive decay law and its boundary conditions during sampling and counting times to solve the Bateman equation. β (even low level β) instruments have been fairly popularized domestically and internationally. It can be used not only as an instrument for radon and its daughters in air, but also as a monitor for β airborne activity in the environment. This new method taps further the latent power of the present instrument and realizes various uses for a unit. (author)

  10. Dynamical Detection of Topological Phase Transitions in Short-Lived Atomic Systems

    Science.gov (United States)

    Setiawan, F.; Sengupta, K.; Spielman, I. B.; Sau, Jay D.

    2015-11-01

    We demonstrate that dynamical probes provide direct means of detecting the topological phase transition (TPT) between conventional and topological phases, which would otherwise be difficult to access because of loss or heating processes. We propose to avoid such heating by rapidly quenching in and out of the short-lived topological phase across the transition that supports gapless excitations. Following the quench, the distribution of excitations in the final conventional phase carries signatures of the TPT. We apply this strategy to study the TPT into a Majorana-carrying topological phase predicted in one-dimensional spin-orbit-coupled Fermi gases with attractive interactions. The resulting spin-resolved momentum distribution, computed by self-consistently solving the time-dependent Bogoliubov-de Gennes equations, exhibits Kibble-Zurek scaling and Stückelberg oscillations characteristic of the TPT. We discuss parameter regimes where the TPT is experimentally accessible.

  11. The short-lived African turquoise killifish: an emerging experimental model for ageing.

    Science.gov (United States)

    Kim, Yumi; Nam, Hong Gil; Valenzano, Dario Riccardo

    2016-02-01

    Human ageing is a fundamental biological process that leads to functional decay, increased risk for various diseases and, ultimately, death. Some of the basic biological mechanisms underlying human ageing are shared with other organisms; thus, animal models have been invaluable in providing key mechanistic and molecular insights into the common bases of biological ageing. In this Review, we briefly summarise the major applications of the most commonly used model organisms adopted in ageing research and highlight their relevance in understanding human ageing. We compare the strengths and limitations of different model organisms and discuss in detail an emerging ageing model, the short-lived African turquoise killifish. We review the recent progress made in using the turquoise killifish to study the biology of ageing and discuss potential future applications of this promising animal model. © 2016. Published by The Company of Biologists Ltd.

  12. Short-lived climate pollutant mitigation and the Sustainable Development Goals

    Science.gov (United States)

    Haines, Andy; Amann, Markus; Borgford-Parnell, Nathan; Leonard, Sunday; Kuylenstierna, Johan; Shindell, Drew

    2017-12-01

    The post-2015 development agenda is dominated by a set of Sustainable Development Goals (SDGs) that arose from the 2012 Rio+20 United Nations Conference on Sustainable Development. The 17 goals and 169 targets address diverse and intersecting aspects of human and environmental needs and challenges. Achieving the SDGs by 2030 requires implementing coordinated and concerted strategies and actions that minimize potential trade-offs and conflicts and maximize synergies to contribute to multiple SDGs. Measures to mitigate emissions of short-lived climate pollutants are an example of actions that contribute to multiple outcomes relevant to development. This Perspective highlights the interlinkages between these pollutants and the SDGs, and shows that implementing emissions reduction measures can contribute to achieving many of the SDGs.

  13. Limited BRC rulemaking: Regulatory approach and experience in Texas for short-lived radioactive waste

    International Nuclear Information System (INIS)

    McBurney, Ruth E.; Pollard, Christine G.

    1992-01-01

    In 1987, the Texas Department of Health (TDH) implemented a rule to allow, under certain conditions, wastes containing limited concentrations of short- lived radionuclides (less than 300-day half-life) to be disposed of in Type I sanitary landfills. The rule was based on a technical analysis that demonstrated the degree of safety for approximately 340 m of radioactive waste generated annually in Texas and identified major restrictions and conditions for disposal. TDH's Bureau of Radiation Control staff have been able to maintain an account of licensees utilizing the rule during the past years. Several research and industrial facilities in the state have saved significantly on waste disposal expenses. Public concerns and economic impacts for licensees as well as other regulatory aspects and experiences with the rule are discussed. (author)

  14. Behaviour of short-lived iodines in operating UO2 fuel elements

    International Nuclear Information System (INIS)

    Lipsett, J.J.; Hastings, I.J.; Hunt, C.E.L.

    1984-11-01

    Sweep gas experiments have been done to determine the behaviour of short-lived fission products within operating UO 2 fuel elements at linear powers of 45, 54, and 60 KW/m, and to burnups of 70, 80, and 50 MWh/kgU respectively. Although radioiodine transport was not observed directly during normal operation, equilibrium gap inventories for I-131 were deduced from the shutdown decay behaviour of the fission gases. These inventories were a strong function of fuel power and ranged from 10 GBq (0.27 Ci) to 100 GBq (2.7 Ci) over the range tested. We conclude that the iodine inventory was adsorbed onto the fuel and/or sheath surfaces with a volatile fraction of less than 10 -2 and a charcoal-filter-penetrating fraction of less than 2x10 -4

  15. Synthesis of radiopharmaceuticals containing short-lived radionuclides: Progress report, March 1, 1987-February 28, 1988

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1987-09-01

    The objective is the creation of new methods for introducing short-lived isotopes into agents for use in diagnostic nuclear medicine. Focus is on the design of new molecular architecture as opposed to the application of known reactions to the synthesis of specific radiopharmaceuticals. The new technology is utilized in nuclear medicine research at the University of Tennessee Medical Imaging Center and in collaboration with colleagues at other DOE facilities. The program provides training for students in the scientific aspects of nuclear medicine. The academic nature of the program facilitates collaborative interactions with other DOE nuclear medicine programs and helps to insure the continued availability of skilled scientists dedicated to the advancement of nuclear medicine. 70 refs., 9 figs

  16. Optimization of irradiation decay and counting times in nuclear activation analysis using short-lived nuclides

    International Nuclear Information System (INIS)

    Bjoernstad, T.

    This work describes a method and outlines a procedure for optim- ization of an activation analysis with respect to the experimental times, irradiation time, t(subi), decay time and counting time. The method is based on the 'minimum relative standard deviation criterion', and specially designed for the use on short-lived nuclides. A computer program, COMB1, is written in the BASIC language in order to make the calculations easier and faster. It is intended to be understandable, and easily applicable on a computer of modest size. Time and cost are important factors, especially for routine analysis on a service basis. In such cases one can often allow a controlled reduction in the analysis quality (through a higher relative standard deviation). The procedure outlined can therefore help find acceptable conditions by calculation of the 'best practical' (or reasonable) experimental time values, and the minimum number of accumulation cycles necessary to fulfil the requirements given. (Auth.)

  17. Simulation of radon short lived decay daughters' inhalation using the lung compartmental model

    International Nuclear Information System (INIS)

    Tomulescu, Vlad C.

    2002-01-01

    Radon and its short-lived decay daughters are the main source of radiation on natural ways for population. The radon gas, released from soil, water or construction materials is producing by radioactive decay the following solid daughters: Po-218, Bi-214, Pb-214, and Po-214, which can attach to aerosols, and consequently penetrate the organism by inhalation. The human respiratory tract can be approximated by aid of a compartment model that takes into account the different anatomical structures exposed to contamination and irradiation, as well as the respective physiological processes. This model is associated to a mathematical equation system that describes the behavior of the radioactive material inside the body. The results represent the dose equivalent on different organs and tissues, as a function of subject and the activity performed in contaminating environment. (author)

  18. Investigation of short-living fission products from the spontaneous fission of Cf-252

    International Nuclear Information System (INIS)

    Klonk, H.

    1976-01-01

    In this paper, a method of separating and measuring fission products of Cf-252 is presented. The measurement was achieved by means of γ-spectrometry and thus provides a quantitative analysis with a good separation of the fission products with respect to both atomic number Z and mass number A. The separation of the fission products from the fission source was achieved by means of solid traps. An automatic changing apparatus made it possible to keep irradiation and measuring times short, so even very short-lived fission products could be registered. The quantitative evaluation of primary fission products was made possible by correction according to Bateman equations. With that, the yields of single nuclides and the dispersion of charge can be determined. (orig./WL) [de

  19. Transport of short lived radioactive contaminants with prologed half-lives of daughters through river water

    International Nuclear Information System (INIS)

    Metwally, S.M.; Prohl, G.

    2005-01-01

    One of the main pathways for transporting contaminants to other parts in the environment, are rivers. This work is devoted for deriving and assessment the concentration of soluble radio contaminants along a river at any time after discharge, including the short-lived radionuclides in comparison with the discharge time interval, and prolonged half-life of the produced daughter nuclei. The assumed boundary conditions and deduced formulas can be applied either in case of accidental release or discharge under authority control. The formulas determining the produced daughter nuclei concentration require inequality of the parent and daughter nuclei half-lives. Because of the regional variation of river morphology, the assumed constancy of the flow velocity and dispersion coefficient requires dividing the river path into zones of similar hydrologic characteristics

  20. External tandem target system for efficient production of short-lived positron emitting radionuclides

    International Nuclear Information System (INIS)

    Koh, K.; Dwyer, J.; Finn, R.; Sheh, Y.; Sinnreich, J.; Wooten, T.

    1983-01-01

    Recent developments in radiopharmaceutical chemistry allow the incorporation of short-lived, positron-emitting radionuclides into a variety of compounds which when used with a positron emission tomograph provide a means of monitoring physiological disorders by a standard technique. To effectively meet the increased ''in-house'' clinical demands while maintaining a production schedule, a tandem target was designed and has been installed for the simultaneous ''on-line'' preparation of oxygen-15 labelled compounds such as CO 2 15 , H 2 O 15 ; and nitrogen-13 labelled compounds such as 13 NH 3 , 13 N 2 O, and 13 N 2 . The processing time required for the synthesis of the nitrogen-13 products as compared to the essentially instantaneous formation of oxygen-15 labelled compounds has provided the necessary time delay for clinical utilization. The characterisitcs of this external tandem target system as well as the automation for the dual processing are presented

  1. Compton suppression spectrometry for analysis of short-lived neutron activation products in foods

    International Nuclear Information System (INIS)

    Anderson, D.L.; Cunningham, W.C.

    2008-01-01

    Compton suppression spectrometry was used to analyze foods for elements with short-lived neutron activation products (half-lives of about 2 minutes to 1.5 days). Analysis conditions were optimized to provide quality assurance analyses for iodine in FDA's Total Diet Study. Iodine mass fractions (0.075 to 2.03 mg/kg) were measured in 19 of 42 foods analyzed, with limits of detection (LODs) ranging from 0.03 to 1.4 mg/kg, mostly depending on NaCl content. LODs were lowered by up to a factor of 2 for 16 elements. Suppression factors ranged from about 2 to 8 over the energy range 400 to 3200 keV. (author)

  2. Magnetic moment of short lived {beta}-emitter {sup 24m}Al

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, D., E-mail: daiki@vg.phys.sci.osaka-u.ac.jp; Komurasaki, J.; Matsuta, K.; Mihara, M.; Matsumiya, R. [Osaka University, Department of Physics (Japan); Momota, S. [Kochi University of Technology (Japan); Ohtsubo, T. [Niigata University, Department of Physics (Japan); Izumikawa, T. [Niigata University, RI Center (Japan); Hirano, H. [Niigata University, Department of Physics (Japan); Kitagawa, A.; Kanazawa, M.; Torikoshi, M.; Sato, S. [National Institute of Radiological Sciences (Japan); Fukuda, M.; Ishikawa, D. [Osaka University, Department of Physics (Japan); Minamisono, T. [Fukui University of Technology (Japan); Watanabe, R.; Kubo, T. [Niigata University, Department of Physics (Japan); Nojiri, Y. [Kochi University of Technology (Japan); Alonso, J. R. [Lawrence Berkeley Laboratory (United States)

    2007-11-15

    The magnetic moment of short lived {beta}-emitter {sup 24m}Al (426 keV, I{sup {pi}} = 1{sup +}, T{sub 1/2} = 131 ms) has been measured by means of {beta}-NMR technique, for the first time. From the {beta}-NMR spectrum, the magnetic moment was determined as |{mu}({sup 24m}Al)|=(2.99{+-}0.09){mu}{sub N}. Combined with the known magnetic moment of the mirror partner {sup 24m}Na, the expectation value of < S{sub z} > is obtained to be (0.08 {+-} 0.12). These values are reproduced well by the shell model calculation.

  3. Industrial applications of radiotracers in Indonesia

    International Nuclear Information System (INIS)

    Wandowo

    1994-01-01

    Applications of isotopes and radiation have been developed since 1970 at the Centre for Application of Isotopes and Radiation, National Atomic Energy Agency or BATAN. The scope of applications cover various fields, namely, agriculture, medicine, hydrology, sedimentology and industry. The use of radiotracers prove to be very beneficial for problem solving in industrial process plants and this technique will continuously be promoted by BATAN to industries in Indonesia. Several examples of radiotracer applications in industries which have been carried out by the Group of Industry of the Centre for Application of Isotopes and Radiation are presented. (author). 7 refs., 4 figs., 1 tab

  4. Synthesis of new radiotracers for tuberculosis diagnosis

    International Nuclear Information System (INIS)

    Keskes, Badis

    2009-01-01

    Tuberculosis remains a worldwide health problem and its diagnosis presents a major challenge. The examinations currently employed are little appreciable and so far there is no reliable diagnosis test. These last years, the development of the new radiopharmaceuticals, referred to diagnosis, has revived interest in the search for new molecules with a tropism to a particular disease. Thanks to this field, which lies at the interface of organic and organometallic chemistry, nuclear medicine and biology, we have been led to synthesize a technetium radiotracer linked to isoniazid. For the identification of this radiotracer, we used its similar rhenium model. (Author)

  5. Radiotracer Applications in Wastewater Treatment Plants

    International Nuclear Information System (INIS)

    2011-01-01

    Wastewater containing pollutants resulting from municipal and industrial activities are normally collected in wastewater treatment plants (WWTPs) for processing before discharge to the environment. The WWTPs are the last barrier against contamination of downstream surface waters such as rivers, lakes and sea. Treated wastewater is reused for irrigation, particularly in arid and semi-arid countries. Therefore, it is very important to maintain optimal operating conditions of WWTPs to eliminate or reduce environmental pollution. Wastewater treatment plants are complicated systems, where the processes of mixing, separation, aeration, biological and chemical reactions occur. A WWTP is basically a multiphase system, and the efficiency of an installation strongly depends on liquid, solid and gas phase flow structures and their residence time distributions (RTDs). However, the fluid dynamic properties of such systems are not yet completely understood, rendering difficult the theoretical prediction of important process parameters such as flow rates, phase distributions, mixing and sediment characteristics. Tracer techniques are very useful tools to investigate the efficiency of purification in WWTPs, aiding both their design and performance optimization. There are many kinds of tracers. Radioactive tracers are the most sensitive and are largely used for on-line diagnosis of various operations in WWTPs. The success of radiotracer applications rests upon their extremely high detection sensitivity, and the strong resistance against severe process conditions. During the last few decades, many radiotracer studies have been conducted worldwide for investigation of various installations for wastewater treatment, such as mixer, aeration tank, clarifiers, digester, filter, wetland and oxidation units. Various radiotracer methods and techniques have been developed by individual tracer groups. However, the information necessary for the preservation of knowledge and transfer of

  6. Synthesis of new radiotracers based on aniline

    International Nuclear Information System (INIS)

    Ayari, Issra

    2008-01-01

    There are several possible applications of radioactivity, we cite: the study of the functional and neurochirnical aspects related to the brain. This study requires the synthesis of specific radiotracers able to cross their target tissue. The synthesis methods need to be constantly updated to respond to the big demand of this domain. The development of the chemistry of metal complexes helped us to find a stable radiotracer based on aniline and marked with technetium. This stability aI 10wed us to realize a possible biodistribution and to envisage to count the radioactivity and to valid the radiopharmaceutical. (Author)

  7. CARIBIC observations of short-lived halocarbons and carbonyl sulphide over Asia

    Science.gov (United States)

    Leedham, E.; Wisher, A.; Oram, D.; Baker, A. K.; Brenninkmeijer, C. A.

    2013-12-01

    The CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container, www.caribic-atmospheric.com) aims to investigate the spatial and temporal distribution of a wide-range of compounds, including those of marine origin/influence, via ~monthly flights to collect in situ data and whole air samples aboard a commercial Lufthansa aircraft. CARIBIC measures up to an altitude of 12 km, allowing the influence of marine compounds on the upper troposphere/lower stratosphere (UTLS) to be explored. In particular, CARIBIC is a useful tool for exploring the impact of very short lived halocarbons (e.g. CH2Br2, CHBr3), whose impact on stratospheric ozone is dependent on convective uplift to the UTLS, a process which is not yet fully quantified. As part of the suite of CARIBIC measurements, whole air samples are analysed at the University of East Anglia (UEA) via gas chromatography mass spectrometry for carbonyl sulphide (OCS) and up to 40 halocarbons (accounting for virtually 100% of organic chlorine, bromine and iodine in the UTLS). Here we present an overview of short-lived halocarbons and OCS measured by CARIBIC. We focus on two regions of particular interest. (1) measurements made in 2012 over the tropical west Pacific to link with UEA measurements made during the SHIVA campaign. (2) measurements made during a collection of flights over India in 2008. Flights over India investigated the impact of monsoon circulation on the distribution of these compounds; for example, elevated concentrations of OCS were seen in CARIBIC samples taken over India during the summer monsoon (July - September). These flights, along with a wider range of flights over Asia (from Frankfurt to Guangzhou, Manila, Bangkok and Kuala Lumpur) can provide unique information on the influence of tropical convection and monsoon circulation on halocarbon and OCS transport within this region.

  8. Evaluation of regional pulmonary function using short-lived radioactive gases

    Energy Technology Data Exchange (ETDEWEB)

    Ashitaka, Tsuyoshi [Toho Univ., Tokyo (Japan). School of Medicine

    1993-05-01

    We investigated the application of short-lived radioactive gases for the assessment of regional pulmonary function, particularly diffusing capacity, in patients with chronic obstructive lung disease and interstitial lung disease. Short-lived radioactive gases including C[sup 15]O-O, [sup 11]CO[sub 2], and [sup 11]CO were produced using a baby cyclotron for medical care. Using a [gamma] camera, breath-holding images were taken serially after inhalation of the radioactive gases. The first exponential component of time-activity curve was analyzed to obtain clearance rate, which was expressed as exponential coefficient ([lambda]). Moreover, we created a functional map which was calculated by the clearance rate of [sup 11]CO[sub 2] as a percentage. Regional clearance rates of each gas in normal volunteers revealed higher values in the lower lung field than in the upper lung field. Whole lung clearance rates ([lambda]) of each gas in patients correlated well with D[sub LCO]/V[sub A], which indicates diffusing capacity. The functional map showed decreased regional diffusion closely matched to the perfusion defects seen by [sup 99m]Tc-MAA perfusion images. However, in certain interstitial lung diseases decreased clearance of [sup 11]CO[sub 2] was observed in regions having no evidence of perfusion defects. We concluded the functional map display of [sup 11]CO[sub 2] is useful indicator of the regional diffusing capacity of both the normal and diseased lung, and that it is beneficial to analyze the pathogenic physiology of diseased lungs by making a comparison between the functional map of [sup 11]CO[sub 2] and [sup 99m]Tc-MAA perfusion images. (author).

  9. Antigen modulation of the immune response. III. Evaluation of the hypothetical short-lived memory cell

    International Nuclear Information System (INIS)

    Feldbush, T.L.; Lande, I.; Bryan, B.; O'Neill, E.

    1974-01-01

    The putative short-lived memory cells, whose existence has been suggested by the results of secondary adoptive transfer experiments, were investigated. On the basis of the following evidences we have concluded that the short-lived memory cell is probably an artifact of the adoptive transfer technique: when immune thoracic duct lymphocytes, known to consist predominantly of long-lived memory cells, were transferred to irradiated recipients and challenged at various times after transfer, approximately 80 to 90 percent of the initial response was absent by Day 14 challenge; preirradiating adoptive recipients with increasing dose of x-irradiation tended to lengthen the observed half life of memory cells; single or multiple treatments of immune donors with 0.3 mg Vinblastin before transfer resulted in neither a depression of the initial secondary response nor an alteration in the rate of decline of the memory potential; reconstitution of irradiated hosts with normal spleen cells one day before transfer of memory cells and challenge resulted in inhibition of the adoptive secondary response; and the transfer of memory cells to antigen free intermediate hosts, in which they were allowed to reside for one day or fourteen days before transfer to irradiated recipients, resulted in only a slight decline in their capacity to respond. We propose that the rapid decline of memory potential in adoptive recipients challenged at various times after transfer is due to modulating effects by the hosts as it recovers from irradiation. These effects may be the result of cell crowding or the loss of irradiation-produced stimulatory factors. The relevance of these findings to adoptive transfer systems in general and the secondary response of intact animals is discussed

  10. Muscle senescence in short-lived wild mammals, the soricine shrews Blarina brevicauda and Sorex palustris.

    Science.gov (United States)

    Hindle, Allyson G; Lawler, John M; Campbell, Kevin L; Horning, Markus

    2009-06-01

    Red-toothed (soricine) shrews are consummate predators exhibiting the highest energy turnovers and shortest life spans (ca. 18 months) of any mammal, yet virtually nothing is known regarding their physiological aging. We assessed the emerging pattern of skeletal muscle senescence (contractile/connective tissue components) in sympatric species, the semi-aquatic water shrew (WS), Sorex palustris, and the terrestrial short-tailed shrew (STS), Blarina brevicauda, to determine if muscle aging occurs in wild, short-lived mammals (H(0): shrews do not survive to an age where senescence occurs), and if so, whether these alterations are species-specific. Gracilis muscles were collected from first-year (n=17) and second-year (n=17) field-caught shrews. Consistent with typical mammalian aging, collagen content (% area) increased with age in both species (S. palustris: approximately 50%; B. brevicauda: approximately 60%). Muscle was dominated by stiffer Type I collagen, and the ratio of collagen Type I:Type III more than doubled with age. The area ratio of muscle:collagen decreased with age in both species, but was considerably lower in adult STS, suggesting species-specificity of senescence. Extracellular space was age-elevated in B. brevicauda, but was preserved in S. palustris ( approximately 50 vs. 10% elevation). Though juvenile interspecific comparisons revealed no significance, adult WS myocytes had 68% larger cross-sectional area and occurred at 28% lower fibers/area than those of adult STS. We demonstrate that age-related muscle senescence does occur in wild-caught, short-lived mammals, and we therefore reject this classic aging theory tenet. Our findings moreover illustrate that differential age adjustments in contractile/connective tissue components of muscle occur in the two species of wild-caught shrews. (c) 2009 Wiley-Liss, Inc.

  11. Muscle Senescence in Short-Lived Wild Mammals, the Soricine Shrews Blarina brevicauda and Sorex palustris

    Science.gov (United States)

    HINDLE, ALLYSON G.; LAWLER, JOHN M.; CAMPBELL, KEVIN L.; HORNING, MARKUS

    2015-01-01

    Red-toothed (soricine) shrews are consummate predators exhibiting the highest energy turnovers and shortest life spans (ca. 18 months) of any mammal, yet virtually nothing is known regarding their physiological aging. We assessed the emerging pattern of skeletal muscle senescence (contractile/connective tissue components) in sympatric species, the semi-aquatic water shrew (WS), Sorex palustris, and the terrestrial short-tailed shrew (STS), Blarina brevicauda, to determine if muscle aging occurs in wild, short-lived mammals (H0: shrews do not survive to an age where senescence occurs), and if so, whether these alterations are species-specific. Gracilis muscles were collected from first-year (n = 17) and second-year (n = 17) field-caught shrews. Consistent with typical mammalian aging, collagen content (% area) increased with age in both species (S. palustris: ~50%; B. brevicauda: ~60%). Muscle was dominated by stiffer Type I collagen, and the ratio of collagen Type I:Type III more than doubled with age. The area ratio of muscle:collagen decreased with age in both species, but was considerably lower in adult STS, suggesting species-specificity of senescence. Extracellular space was age-elevated in B. brevicauda, but was preserved in S. palustris (~50 vs. 10% elevation). Though juvenile interspecific comparisons revealed no significance, adult WS myocytes had 68% larger cross-sectional area and occurred at 28% lower fibers/area than those of adult STS. We demonstrate that age-related muscle senescence does occur in wild-caught, short-lived mammals, and we therefore reject this classic aging theory tenet. Our findings moreover illustrate that differential age adjustments in contractile/connective tissue components of muscle occur in the two species of wild-caught shrews. PMID:19296507

  12. DEMOGRAPHY OF ALPINE SHORT-LIVED PLANTS, LONGEVITY AND ONTOGENY STAGE DURATIONS

    Directory of Open Access Journals (Sweden)

    E. S. Kazantseva

    2016-01-01

    Full Text Available The aim - to evaluate lifespan (full cycle and ontogeny stage durations of nine alpine short-lived North- West Caucasus plants.Methods. For calculation we used a new method which was developed and suggested earlier by us. This method is based on a discrete ontogeny description and on the probability theory and random processes. The data on the monitoring of the marked individuals were collected during six years.Results. We found out that the lifespan of Anthyllis vulneraria is 2.6±0.3 years (hereinafter “±” is Standard error, Draba hispida – 4.5±0.3, Murbeckiella huetii – 4.6±1.1, Carum meifolium – 7.8±1.4, Eritrichium caucasicum – 9.1±1.4, Trifolium badium – 10.3±2.6, Sedum tenellum – 11±2.05, Androsace albana – 12.1±2.5, Minuartia recurva – 22.9±4.5. Also we demonstrated the matrix population models for studied plants, which show the probability of transition of individuals from one ontogeny stage to another in time interval (in our experiment – 1 year.Conclusion. Mortality of seedlings and juvenile plants, except Murbeckiella huetii, is around and more than 50%. Two years is the minimal amount of time that is necessary for full cycle of short-lived alpine plants, as it was shown for Anthyllis vulneraria, Murbeckiella huetii и Trifolium badium. A 3-12 years lifespan was calculated for other studied species. Persistence of Eritrichium caucasicum and Androsace albana populations provided by resistance of adult vegetative plants.

  13. Radiotracer properties determined by high performance liquid chromatography: a potential tool for brain radiotracer discovery

    International Nuclear Information System (INIS)

    Tavares, Adriana Alexandre S.; Lewsey, James; Dewar, Deborah; Pimlott, Sally L.

    2012-01-01

    Introduction: Previously, development of novel brain radiotracers has largely relied on simple screening tools. Improved selection methods at the early stages of radiotracer discovery and an increased understanding of the relationships between in vitro physicochemical and in vivo radiotracer properties are needed. We investigated if high performance liquid chromatography (HPLC) methodologies could provide criteria for lead candidate selection by comparing HPLC measurements with radiotracer properties in humans. Methods: Ten molecules, previously used as radiotracers in humans, were analysed to obtain the following measures: partition coefficient (Log P); permeability (P m ); percentage of plasma protein binding (%PPB); and membrane partition coefficient (K m ). Relationships between brain entry measurements (Log P, P m and %PPB) and in vivo brain percentage injected dose (%ID); and K m and specific binding in vivo (BP ND ) were investigated. Log P values obtained using in silico packages and flask methods were compared with Log P values obtained using HPLC. Results: The modelled associations with %ID were stronger for %PPB (r 2 =0.65) and P m (r 2 =0.77) than for Log P (r 2 =0.47) while 86% of BP ND variance was explained by K m . Log P values were variable dependant on the methodology used. Conclusions: Log P should not be relied upon as a predictor of blood-brain barrier penetration during brain radiotracer discovery. HPLC measurements of permeability, %PPB and membrane interactions may be potentially useful in predicting in vivo performance and hence allow evaluation and ranking of compound libraries for the selection of lead radiotracer candidates at early stages of radiotracer discovery.

  14. Variation in the local population dynamics of the short-lived Opuntia macrorhiza (Cactaceae).

    Science.gov (United States)

    Haridas, C V; Keeler, Kathleen H; Tenhumberg, Brigitte

    2015-03-01

    Spatiotemporal variation in demographic rates can have profound effects for population persistence, especially for dispersal-limited species living in fragmented landscapes. Long-term studies of plants in such habitats help with understanding the impacts of fragmentation on population persistence but such studies are rare. In this work, we reanalyzed demographic data from seven years of the short-lived cactus Opuntia macrorhiza var. macrorhiza at five plots in Boulder, Colorado. Previous work combining data from all years and all plots predicted a stable population (deterministic log lamda approximately 0). This approach assumed that all five plots were part of a single population. Since the plots were located in a suburban-agricultural interface separated by highways, grazing lands, and other barriers, and O. macrorhiza is likely dispersal limited, we analyzed the dynamics of each plot separately using stochastic matrix models assuming each plot represented a separate population. We found that the stochastic population growth rate log lamdaS varied widely between populations (log lamdaS = 0.1497, 0.0774, -0.0230, -0.2576, -0.4989). The three populations with the highest growth rates were located close together in space, while the two most isolated populations had the lowest growth rates suggesting that dispersal between populations is critical for the population viability of O. macrorhiza. With one exception, both our prospective (stochastic elasticity) and retrospective (stochastic life table response experiments) analysis suggested that means of stasis and growth, especially of smaller plants, were most important for population growth rate. This is surprising because recruitment is typically the most important vital rate in a short-lived species such as O. macrorhiza. We found that elasticity to the variance was mostly negligible, suggesting that O. macrorhiza populations are buffered against large temporal variation. Finally, single-year elasticities to means

  15. Harvard--MIT research program in short-lived radiopharmaceuticals. Progress report, September 1, 1977--April 30, 1978

    International Nuclear Information System (INIS)

    Adelstein, S.J.; Brownell, G.L.

    1978-05-01

    Progress is reported on the following studies: chemistry studies designed to achieve a more complete understanding of the fundamental chemistry of technetium in order to facilitate the design of future radiopharmaceuticals incorporating the radionuclide /sup 99m/Tc; the development of new radiopharmaceuticals intended to improve image quality and lower radiation doses by the use of short-lived radionuclides and disease-specific agents; the development of short-lived positron-emitting radionuclides which offer advantages in transverse section imaging of regional physiological processes; and studies of the toxic effects of particulate radiation

  16. Determination of copper in biological materials by neutron activation analysis using short-lived 66Cu

    International Nuclear Information System (INIS)

    Dybczynski, R.; Danko, B.; Kaczorowski, J.

    1989-01-01

    A method for determination of copper traces in biological materials based on neutron activation employing 65 Cu(n, γ) 66 Cu reaction and preconcentration by extraction chromatography has been devised. The 200-500 mg samples after wet digestion and evaporation were dissolved in glycine solution and after pH adjusting to ca. 4.4 were passed through the column with Lix 64N on Bio Beads SM-1 for isolation of copper traces from the matrix elements. Other cations were selectively eluted with 0.1 mol x 1 -1 (glycine-HNO 3 ) buffer, 1 mol x 1 -1 in NH 4 NO 3 (pH = 3.6). The resin bed with quantitatively retained copper was sealed in the PE bag and irradiated together with Cu standards in EWA reactor using pneumatic tube facility. The activity of the short-lived 66 Cu was measured in samples and standard by gamma-ray spectrometry with Ge(Li) detector. Good accuracy of the method was confirmed by analysis of the following certified reference materials: NBS 1571 Orchad leaves, IAEA H-4 Animal muscle, IAEA V-8 Rye flour, IAEA A-11 milk powder. The detection limit amounted to 0.34 mg/kg, for the sample weight of 500 mg. (author)

  17. ''Sleeping reactor'' irradiations: Shutdown reactor determination of short-lived activation products

    International Nuclear Information System (INIS)

    Jerde, E.A.; Glasgow, D.C.

    1998-01-01

    At the High-Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory, the principal irradiation system has a thermal neutron flux (φ) of ∼ 4 x 10 14 n/cm 2 · s, permitting the detection of elements via irradiation of 60 s or less. Irradiations of 6 or 7 s are acceptable for detection of elements with half-lives of as little as 30 min. However, important elements such as Al, Mg, Ti, and V have half-lives of only a few minutes. At HFIR, these can be determined with irradiation times of ∼ 6 s, but the requirement of immediate counting leads to increased exposure to the high activity produced by irradiation in the high flux. In addition, pneumatic system timing uncertainties (about ± 0.5 s) make irradiations of 9 Be(γ,n) 8 Be, the gamma rays principally originating in the spent fuel. Upon reactor SCRAM, the flux drops to ∼ 1 x 10 10 n/cm 2 · s within 1 h. By the time the fuel elements are removed, the flux has dropped to ∼ 6 x 10 8 . Such fluxes are ideal for the determination of short-lived elements such as Al, Ti, Mg, and V. An important feature of the sleeping reactor is a flux that is not constant

  18. Short-Lived Buildings in China: Impacts on Water, Energy, and Carbon Emissions.

    Science.gov (United States)

    Cai, Wenjia; Wan, Liyang; Jiang, Yongkai; Wang, Can; Lin, Lishen

    2015-12-15

    This paper has changed the vague understanding that "the short-lived buildings have huge environmental footprints (EF)" into a concrete one. By estimating the annual floor space of buildings demolished and calibrating the average building lifetime in China, this paper compared the EF under various assumptive extended buildings' lifetime scenarios based on time-series environmental-extended input-output model. Results show that if the average buildings' lifetime in China can be extended from the current 23.2 years to their designed life expectancy, 50 years, in 2011, China can reduce 5.8 Gt of water withdrawal, 127.1 Mtce of energy consumption, and 426.0 Mt of carbon emissions, each of which is equivalent to the corresponding annual EF of Belgium, Mexico, and Italy. These findings will urge China to extend the lifetime of existing and new buildings, in order to reduce the EF from further urbanization. This paper also verifies that the lifetime of a product or the replacement rate of a sector is a very important factor that influences the cumulative EF. When making policies to reduce the EF, adjusting people's behaviors to extend the lifetime of products or reduce the replacement rate of sectors may be a very simple and cost-effective option.

  19. New use of global warming potentials to compare cumulative and short-lived climate pollutants

    Science.gov (United States)

    Allen, Myles R.; Fuglestvedt, Jan S.; Shine, Keith P.; Reisinger, Andy; Pierrehumbert, Raymond T.; Forster, Piers M.

    2016-08-01

    Parties to the United Nations Framework Convention on Climate Change (UNFCCC) have requested guidance on common greenhouse gas metrics in accounting for Nationally determined contributions (NDCs) to emission reductions. Metric choice can affect the relative emphasis placed on reductions of `cumulative climate pollutants' such as carbon dioxide versus `short-lived climate pollutants' (SLCPs), including methane and black carbon. Here we show that the widely used 100-year global warming potential (GWP100) effectively measures the relative impact of both cumulative pollutants and SLCPs on realized warming 20-40 years after the time of emission. If the overall goal of climate policy is to limit peak warming, GWP100 therefore overstates the importance of current SLCP emissions unless stringent and immediate reductions of all climate pollutants result in temperatures nearing their peak soon after mid-century, which may be necessary to limit warming to ``well below 2 °C'' (ref. ). The GWP100 can be used to approximately equate a one-off pulse emission of a cumulative pollutant and an indefinitely sustained change in the rate of emission of an SLCP. The climate implications of traditional CO2-equivalent targets are ambiguous unless contributions from cumulative pollutants and SLCPs are specified separately.

  20. Emission channeling with short-lived isotopes lattice location of impurities in semiconductors and oxides

    CERN Multimedia

    We propose to perform emission channeling lattice location experiments in a number of semiconductor and oxide systems of technological relevance: \\\\- The lattice location of the transition metal probes $^{56}$Mn ($\\textit{t}_{1/2}$=2.6 h), $^{59}$Fe (45 d), $^{61}$Co (1.6 h) and $^{65}$Ni (2.5 h) is to be investigated in materials of interest as dilute magnetic semiconductors, such as GaMnAs, GaMnN, GaFeN, AlGaN, SiC, and in a number of oxides that are candidates for “single ion ferromagnetism”, in particular SrTiO$_3$ and LiNbO$_3$.\\\\- The topic of $\\textit{p}$-type doping of nitride semiconductors shall be addressed by studying the lattice sites of the acceptor dopants Mg and Be in GaN and AlN using the short-lived probes $^{27}$Mg (9.5 min) and $^{11}$Be (13.8 s). The aim is to reach a lattice location precision around 0.05 Å in order to provide critical tests for recent theoretical models which e.g. have predicted displacements of the Mg atom from the ideal substitutional Ga and Al sites of the order...

  1. Applications of short-lived activation products in neutron activation analysis of bio-environmental specimens

    International Nuclear Information System (INIS)

    1987-03-01

    This report discusses the advantages and disadvantages, special techniques, and actual and potential applications of neutron activation analysis (NAA) utilizing short-lived neutron-induced products, with special reference to the analysis of samples of biological and environmental origin. Attention is devoted mainly to products having half-lives in roughly the range of 10 milliseconds to 60 seconds, but with some discussion of the usefulness of even shorter-lived species, and ones with half-lives as long as a few minutes. Important aspects of the analytical methodology include sample preparation, irradiation/transfer systems, activity measurements, data processing and analytical quality assurance. It is concluded that several trace elements can be determined in bio-environmental samples (as well as in samples of industrial, geochemical and other origin). In particular, this method provides analytical possibilities for several elements (e.g. B, F, Li and V) that are difficult to determine in some matrices at trace levels by any other technique. These conclusions are illustrated in an annex by results of calculations in which the applicability of the techniques to the analysis of several biological and environmental reference materials is evaluated by means of an advance computer prediction program. The report concludes with an annotated bibliography of relevant publications (including abstracts, where available) taken from the INIS database. (author)

  2. Harvard-MIT research program in short-lived radiopharmaceuticals. Final report

    International Nuclear Information System (INIS)

    Adelstein, S.J.

    1995-02-01

    The Harvard-MIT Research Program in Short-lived Radiopharmaceuticals was established in 1977 to foster interaction among groups working in radiopharmaceutical chemistry at Harvard Medical School, the Massachusetts Institute of Technology, and the Massachusetts General Hospital. To this was added a group at The Childrens Hospital. From these collaborations and building upon the special strengths of the participating individuals, laboratories and institutions, it was hoped that original approaches would be found for the design of new, clinically useful, radiolabeled compounds. The original thrust of this proposal included: (a) examination of the coordination chemistry of technetium as a basis for rational radiopharmaceutical design, (b) development of an ultrashort-lived radionuclide generator for the diagnosis of congenital heart disease in newborns, (c) synthesis of receptor-site-directed halopharmaceuticals, (d) improved facile labeling of complex molecules with positron-emitting radionuclides. The authors' 1986 proposal was oriented toward organs and disease, emphasizing radiolabeled agents that delineate specific functions and the distribution of receptors in brain, heart, and tumors. In 1989, they further refined their purposes and focused on two major aims: (a) synthesis and utilization of neutral technetium and rhenium complexes of high specific activity, and (b) development of new approaches to the radiolabeling of proteins, peptides, immunoglobulins, and their fragments. In 1992, the authors amended this proposal to concentrate their efforts on biologically active peptides and proteins for targeted radiodiagnosis and therapy

  3. High rate gamma spectroscopy system for activation analysis of short-lived isomeric transitions

    Energy Technology Data Exchange (ETDEWEB)

    Westphall, G P [Atominstitut der Oesterreichischen Hochschulen, Vienna

    1976-07-15

    A high rate spectroscopy system specially suited for measurement of short-lived isomeric transitions is described, which, as part of a fast activation analysis facility at the TRIGA Mark II reactor, provides for automatic recording and immediate evaluation of gamma spectra taken from nuclides activated at stationary or pulsed reactor power. The system consists of a commercial de-coupled Ge(Li)-detector of 70 cm/sup 3/ modified for recycling operation for input rates in excess of 500000 c/s /sup 60/Co, a time variant trapezoidal shaping section and a fast constant dead-time ADC coupled to a programmed multichannel analyzer. Novel circuits for efficient pile-up rejection and time variant base line restoration extend the concept of gated integration up to count rates of more than 200000 c/s /sup 60/Co. Time-sequenced recording of spectra is performed by a minicomputer operated as a front-end processor of a larger laboratory computer, where final data processing takes place. New concepts for very simple and cost-effective implementation of multichannel analyzers by means of general purpose small computers are described.

  4. Dissolved organic matter composition drives the marine production of brominated very short-lived substances.

    Science.gov (United States)

    Liu, Yina; Thornton, Daniel C O; Bianchi, Thomas S; Arnold, William A; Shields, Michael R; Chen, Jie; Yvon-Lewis, Shari A

    2015-03-17

    Brominated very short-lived substances (BrVSLS), such as bromoform, are important trace gases for stratospheric ozone chemistry. These naturally derived trace gases are formed via bromoperoxidase-mediated halogenation of dissolved organic matter (DOM) in seawater. Information on DOM type in relation to the observed BrVSLS concentrations in seawater, however, is scarce. We examined the sensitivity of BrVSLS production in relation to the presence of specific DOM moieties. A total of 28 model DOM compounds in artificial seawater were treated with vanadium bromoperoxidase (V-BrPO). Our results show a clear dependence of BrVSLS production on DOM type. In general, molecules that comprise a large fraction of the bulk DOM pool did not noticeably affect BrVSLS production. Only specific cell metabolites and humic acid appeared to significantly enhance BrVSLS production. Amino acids and lignin phenols suppressed enzyme-mediated BrVSLS production and may instead have formed halogenated nonvolatile molecules. Dibromomethane production was not observed in any experiments, suggesting it is not produced by the same pathway as the other BrVSLS. Our results suggest that regional differences in DOM composition may explain the observed BrVSLS concentration variability in the global ocean. Ultimately, BrVSLS production and concentrations are likely affected by DOM composition, reactivity, and cycling in the ocean.

  5. Short-Lived Electronically-Excited Diatomic Molecules Cooled via Supersonic Expansion from a Plasma Microjet

    Science.gov (United States)

    Houlahan, Thomas J., Jr.; Su, Rui; Eden, Gary

    2014-06-01

    Using a pulsed plasma microjet to generate short-lived, electronically-excited diatomic molecules, and subsequently ejecting them into vacuum to cool via supersonic expansion, we are able to monitor the cooling of molecules having radiative lifetimes as low as 16 ns. Specifically, we report on the rotational cooling of He_2 molecules in the d^3Σ_u^+, e^3Π_g, and f^3Σ_u^+ states, which have lifetimes of 25 ns, 67 ns, and 16 ns, respectively. The plasma microjet is driven with a 2.6 kV, 140 ns high-voltage pulse (risetime of 20 ns) which, when combined with a high-speed optical imaging system, allows the nonequilibrium rotational distribution for these molecular states to be monitored as they cool from 1200 K to below 250 K with spatial and temporal resolutions of below 10 μm and 10 ns, respectively. The spatial and temporal resolution afforded by this system also allows the observation of excitation transfer between the f^3Σ_u^+ state and the lower lying d^3Σ_u^+ and e^3Π_g states. The extension of this method to other electronically excited diatomics with excitation energies >5 eV will also be discussed.

  6. Harvard-MIT research program in short-lived radiopharmaceuticals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Adelstein, S.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Office of Sponsored Programs

    1995-02-01

    The Harvard-MIT Research Program in Short-lived Radiopharmaceuticals was established in 1977 to foster interaction among groups working in radiopharmaceutical chemistry at Harvard Medical School, the Massachusetts Institute of Technology, and the Massachusetts General Hospital. To this was added a group at The Childrens Hospital. From these collaborations and building upon the special strengths of the participating individuals, laboratories and institutions, it was hoped that original approaches would be found for the design of new, clinically useful, radiolabeled compounds. The original thrust of this proposal included: (a) examination of the coordination chemistry of technetium as a basis for rational radiopharmaceutical design, (b) development of an ultrashort-lived radionuclide generator for the diagnosis of congenital heart disease in newborns, (c) synthesis of receptor-site-directed halopharmaceuticals, (d) improved facile labeling of complex molecules with positron-emitting radionuclides. The authors` 1986 proposal was oriented toward organs and disease, emphasizing radiolabeled agents that delineate specific functions and the distribution of receptors in brain, heart, and tumors. In 1989, they further refined their purposes and focused on two major aims: (a) synthesis and utilization of neutral technetium and rhenium complexes of high specific activity, and (b) development of new approaches to the radiolabeling of proteins, peptides, immunoglobulins, and their fragments. In 1992, the authors amended this proposal to concentrate their efforts on biologically active peptides and proteins for targeted radiodiagnosis and therapy.

  7. Impact on short-lived climate forcers increases projected warming due to deforestation.

    Science.gov (United States)

    Scott, C E; Monks, S A; Spracklen, D V; Arnold, S R; Forster, P M; Rap, A; Äijälä, M; Artaxo, P; Carslaw, K S; Chipperfield, M P; Ehn, M; Gilardoni, S; Heikkinen, L; Kulmala, M; Petäjä, T; Reddington, C L S; Rizzo, L V; Swietlicki, E; Vignati, E; Wilson, C

    2018-01-11

    The climate impact of deforestation depends on the relative strength of several biogeochemical and biogeophysical effects. In addition to affecting the exchange of carbon dioxide (CO 2 ) and moisture with the atmosphere and surface albedo, vegetation emits biogenic volatile organic compounds (BVOCs) that alter the formation of short-lived climate forcers (SLCFs), which include aerosol, ozone and methane. Here we show that a scenario of complete global deforestation results in a net positive radiative forcing (RF; 0.12 W m -2 ) from SLCFs, with the negative RF from decreases in ozone and methane concentrations partially offsetting the positive aerosol RF. Combining RFs due to CO 2 , surface albedo and SLCFs suggests that global deforestation could cause 0.8 K warming after 100 years, with SLCFs contributing 8% of the effect. However, deforestation as projected by the RCP8.5 scenario leads to zero net RF from SLCF, primarily due to nonlinearities in the aerosol indirect effect.

  8. Context of the long-term management of low-level short-lived waste

    International Nuclear Information System (INIS)

    Hooft, E.

    2004-01-01

    Until the international moratorium of 1983, Belgium relied on sea disposal for its low-level waste. Since then, ONDRAF/NIRAS, the Belgian radioactive waste management agency, has launched studies to look for land-based solutions. These studies, which are still going on, have gone through various phases. The sometimes harsh reactions in public opinion and the recommendations of independent experts, however, progressively led ONDRAF/NIRAS to question its work methodology. On 16 January 1998 was a milestone in Belgian's nuclear waste management. On that day, the Belgian federal government opted for a final, or potentially final, solution for the long-term management of short-lived, low-level radioactive waste, a solution that also had to be progressive, flexible, and reversible. At the same time, the government entrusted new missions to ONDRAF/NIRAS in particular that of developing methods to enable the integration of final repository project proposals at a local level and restricted the number of potential sites for final disposal to the four existing nuclear sites in Belgium and to possibly interested local districts. The government's decision of 16 January 1998 forced ONDRAF/NIRAS to change its strategy. The agency set up a new work programme and worked out an innovative methodology. This new methodology aims to generate, at the level of the interested towns and villages, draft projects for a final repository supported by a wide public consensus. (author)

  9. Monitoring of processes with gamma-rays of neutron capture and short-living radionuclides

    International Nuclear Information System (INIS)

    Aripov, G.A.; Kurbanov, B.I.; Allamuratova, G.

    2004-01-01

    Element content is a fundamental parameter of a substance, on which all its properties, and also character of physical, chemical, biological, technological and ecological processes depend. Therefore monitoring of element content (in the course of technological process - on line; in natural conditions - in site; or in living organisms - in vivo) becomes necessary for investigation of aforementioned processes. This problem can be successfully solved by using the methods of prompt gamma activation analysis (PGAA) and instrumental neutron activation analysis (INAA) on short-living radionuclides. These methods don't depend on type of substance (biological, geological, technological etc.), since the content is determined by gamma radiation of nuclei, and allows to meet such a serious requirement like the necessity of achieving minimal irradiation of the object and its minimal residual activity. In this work minimal determinable concentrations of various elements are estimated (based on experimental data) by the method of PGAA using radionuclide 252 Cf - source of neutrons with the yield of the oil of 10 8 neutron/sec on the experimental device with preliminary focusing of neutrons /1/, and also data of determination of elements by their isotopes with maximum time efficiency /2,3/ by the method of INAA. (author)

  10. A high rate gamma spectroscopy system for activation analysis of short lived isomeric transitions

    Energy Technology Data Exchange (ETDEWEB)

    Westphal, G P [Atominstitut, Vienna (Austria)

    1976-07-01

    A high rate spectroscopy system specially suited for measurement of short-lived isomeric transitions is described, which, as part of a fast activation analysis facility at the TRIGA Mark II reactor, provides for automatic recording and immediate evaluation of gamma spectra taken from nuclides activated at stationary or pulsed reactor power. The system consists of a commercial DC-coupled Ge(Li)-detector of 70 cm{sup 3} modified for recycling operation for input rates in excess of 500,000 c/s Co-60, a time variant trapezoidal shaping section and a fast constant dead-time ADC coupled to a programmed multi-channel analyzer. Novel circuits for efficient pile-up rejection and time variant base line restoration extend the concept of gated integration up to count rates of more than 300,000 c/s Co-60. Time-sequenced recording of spectra is performed by a mini computer operated as a front-end processor of a larger laboratory computer, where final data processing takes place. New concepts for very simple and cost-effective implementation of multi-channel analyzers by means of general purpose small computers are described. (author)

  11. Determination of gamma-ray exposure rate from short-lived fission products under criticality accident conditions

    International Nuclear Information System (INIS)

    Yanagisawa, Hiroshi; Ohno, Akio; Aizawa, Eijyu

    2002-01-01

    For the assessment of γ-ray doses from short-lived fission products (FPs) under criticality accident conditions, γ-ray exposure rates varying with time were experimentally determined in the Transient Experiment Critical Facility (TRACY). The data were obtained by reactivity insertion in the range of 1.50 to 2.93$. It was clarified from the experiments that the contribution of γ-ray from short-lived FPs to total exposure during the experiments was evaluated to be 15 to 17%. Hence, the contribution cannot be neglected for the assessment of γ-ray doses under criticality accident conditions. Computational analyses also indicated that γ-ray exposure rates from short-lived FPs calculated with the Monte Carlo code, MCNP4B, and photon sources based on the latest FP decay data, the JENDL FP Decay Data File 2000, well agreed with the experimental results. The exposure rates were, however, extremely underestimated when the photon sources were obtained by the ORIGEN2 code. The underestimation is due to lack of energy-dependent photon emission data for major short-lived FP nuclides in the photon database attached to the ORIGEN2 code. It was also confirmed that the underestimation arose in 1,000 or less of time lapse after an initial power burst. (author)

  12. Sizes and shapes of short-lived nuclei via laser spectroscopy. Progress report, May 1, 1980-January 31, 1981

    International Nuclear Information System (INIS)

    Lewis, D.A.

    1981-02-01

    The first stage of the program to study the sizes and shapes of short-lived nuclei through their atomic hyperfine structure is to develop a movable laser spectroscopy system. This system is now almost complete and is described in this report along with plans for measurements at Argonne National Laboratory and Brookhaven National Laboratory

  13. Radiotracer studies for coastal zone management

    International Nuclear Information System (INIS)

    Hughes, C.; Kluss, T.; Airey, P.

    2001-01-01

    Coastal engineers and coastal zone managers increasingly rely on numerical models of fluid, sediment and contaminant dynamics. These are used to underpin coastal structure design and to predict environmental response to specific events such as storms or pollutant spills, and gradual changes such as sea-level rise or changes in bathymetry. Radiotracer techniques can be used to provide dynamic data on the movement of a specific patch of water, sediment or pollutant over time, which can be compared with model predictions. Two case studies are presented where radiotracer studies were used to improve confidence in numerical models of: (1) 2D hydrodynamics and sediment transport at the Port of Songkhla, Thailand; and (2) 3D hydrodynamics and algal bloom transport in Manila Bay, Philippines

  14. Adsorption on smooth electrodes: A radiotracer study

    International Nuclear Information System (INIS)

    Rice-Jackson, L.M.

    1990-01-01

    Adsorption on solids is a complicated process and in most cases, occurs as the early stage of other more complicated processes, i.e. chemical reactions, electrooxidation, electroreduction. The research reported here combines the electroanalytical method, cyclic voltammetry, and the use of radio-labeled isotopes, soft beta emitters, to study adsorption processes at smooth electrodes. The in-situ radiotracer method is highly anion (molecule) specific and provides information on the structure and composition of the electric double layer. The emphasis of this research was on studying adsorption processes at smooth electrodes of copper, gold, and platinum. The application of the radiotracer method to these smooth surfaces have led to direct in-situ measurements from which surface coverage was determined; anions and molecules were identified; and weak interactions of adsorbates with the surface of the electrodes were readily monitored. 179 refs

  15. Green chemistry using radiotracers at SINP

    International Nuclear Information System (INIS)

    Lahiri, Susanta

    2006-01-01

    Green chemistry is utilization of set of principles, which restricts the use, or generation of hazardous substances. In this aim, it is necessary to develop alternative methods, or to find greener reagents for minimum utilization of environmentally hostile substances. Radiotracers can be effectively utilized for development of such methods. This article describes the current status of Green Chemistry research using accelerator/reactor produced radionuclides at Saha Institute of Nuclear Physics, Kolkata, India. (author)

  16. Increased bone radiotracer uptake in renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    de Graaf, P.; Schicht, I.M.; de Graeff, J.; te Velde, J.; Kleiverda, K.; Pauwels, E.K.J.

    1982-04-01

    Bone radiotracer uptake in renal osteodystrophy was investigated in 35 dialysis patients by correlating the results of quantitative bone scintigraphy with those of biochemical and bone morphometric studies. There were highly significant correlations (P < 0.001) between the total skeletal activity and the biochemical (iPTH and alkaline phosphatase), and histologic parameters of hyperparathyroidism. These clinical results strongly suggest that increased bone turnover i.e. hyperparathyroidism, rather than osteomalacia is the major cause of increased skeletal uptake in renal osteodystrophy.

  17. A proposal for assessing study quality: Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument

    Science.gov (United States)

    LaKind, Judy S.; Sobus, Jon R.; Goodman, Michael; Barr, Dana Boyd; Fürst, Peter; Albertini, Richard J.; Arbuckle, Tye E.; Schoeters, Greet; Tan, Yu-Mei; Teeguarden, Justin; Tornero-Velez, Rogelio; Weisel, Clifford P.

    2015-01-01

    The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous chemicals with short physiologic half-lives began relatively recently. These chemicals present several challenges, including their presence in analytical laboratories and sampling equipment, difficulty in establishing temporal order in cross-sectional studies, short- and long-term variability in exposures and biomarker concentrations, and a paucity of information on the number of measurements required for proper exposure classification. To date, the scientific community has not developed a set of systematic guidelines for designing, implementing and interpreting studies of short-lived chemicals that use biomonitoring as the exposure metric or for evaluating the quality of this type of research for WOE assessments or for peer review of grants or publications. We describe key issues that affect epidemiology studies using biomonitoring data on short-lived chemicals and propose a systematic instrument – the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument – for evaluating the quality of research proposals and studies that incorporate biomonitoring data on short-lived chemicals. Quality criteria for three areas considered fundamental to the evaluation of epidemiology studies that include biological measurements of short-lived chemicals are described: 1) biomarker selection and measurement, 2) study design and execution, and 3) general epidemiological study design considerations. We recognize that the development of an evaluative tool such as BEES-C is neither simple nor non-controversial. We hope and anticipate that the instrument will initiate further discussion/debate on this topic. PMID:25137624

  18. Regulatory requirements for fluorine 18-labelled radiotracers

    International Nuclear Information System (INIS)

    Prigent, A.

    2005-01-01

    Although European and French regulations define radiopharmaceuticals and their different conditions for use, there is no legal status of the radiotracer. Radiotracer is commonly known as a molecular entity administered in tracer doses, that means at very low masses (e.g., nano-mol amounts) and, consequently, without any pharmacological effect. A radiotracer can meet the specifications of either a radiochemical (usually restricted to research in animal models) or a radiopharmaceutical (human use for diagnostic imaging or research projects). Besides the 'proprietary medicinal product', different status have been defined to allow other uses in humans, referring to 'magistral formula' preparation, 'officinal formula' preparation, investigational medicinal product for clinical trials, or to a radiopharmaceutical with a 'patient named authorization'. However, because of the short half-life of fluorine 18 and expanding development of molecular imaging techniques using positron emission tomography (PET), the current regulation is sometimes considered as inappropriate with regard to the small-size production required for such on-site manufactured radiopharmaceuticals. It is often claimed that it could be very difficult to comply with the current Good Manufactured Practice (cGMP). As previously done for radiopharmaceuticals based on monoclonal antibodies, specific adjustments for PET radiopharmaceuticals are under discussion and the 'note for guidance on radiopharmaceuticals' will be soon revised by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMEA). In many cases, a status of 'magistral' product might be attributed to a PET radiopharmaceutical manufactured according with European Pharmacopoeia monographs. (author)

  19. Panel discussion: Chemistry aspects of pet radiotracers

    International Nuclear Information System (INIS)

    Kilbourn, M.R.

    1991-01-01

    A panel discussion on the radiotracer development process opened with a question regarding the role of toxicological studies in the process of obtaining a physician-sponsored Investigational New Drug (IND) for a new radiopharmaceutical. Panel members were uniformly supportive of new radiotracer development, expressing their opinions that the regulatory hurdles were there but could be overcome. Several institutions are actively working with regulatory agencies to determine just what toxicology data are relevant to new radiopharmaceutical development in the PET field. The FDA is beginning to understand that the pharmacology of PET tracer doses may be completely different from what is usually important in drug trials. The second part of the panel discussion centered on the role, if any, of the pharmaceutical companies in new radiotracer development. It was pointed out that what the radiochemist is looking for in a radiopharmaceutical is different from what these companies are searching for in a therapeutic drug. Panel and audience members responded to the question: What would a pharmaceutical company gain from collaboration with radiopharmaceutical research laboratories? Several examples were given such as providing crucial data from humans rather than animals; determining individualized drug doses to maximize the therapeutic index of a new drug regimen; and replacing the large amounts of time and money currently invested by drug companies in the radiolabeling and evaluation of metabolites of new drugs

  20. Application of radiotracer methods in streamflow measurements

    International Nuclear Information System (INIS)

    Dincer, T.

    1967-01-01

    An attempt is made to evaluate methods using radiotracers in streamflow measurements. The basic principles of the tracer method are explained and background information given. Radiotracers used in stream discharge measurements are discussed and measurements made by different research workers are described. Problems such as adsorption of the tracer and the mixing length are discussed and the potential use of the radioisotopes as tracer in the routine stream-gauging work is evaluated. It is concluded that, at the present stage of development, radiotracer methods do not seem to be ready for routine use in stream-gauging work, and can only be used in some special cases. For gamma-emitting radioisotopes there are problems related to safety, transport and injection which should be solved. Tritium, though a very attractive tracer in some respects, has the disadvantages of having a relatively long half-life and of disturbing the natural tritium levels in the region. Finally, an attempt is made to define the objectives of the research in the field of application of radioisotopes in hydrometry. (author)

  1. Convective Transport of Very-short-lived Bromocarbons to the Stratosphere

    Science.gov (United States)

    Liang, Qing; Atlas, Elliot Leonard; Blake, Donald Ray; Dorf, Marcel; Pfeilsticker, Klaus August; Schauffler, Sue Myhre

    2014-01-01

    We use the NASA GEOS Chemistry Climate Model (GEOSCCM) to quantify the contribution of two most important brominated very short-lived substances (VSLS), bromoform (CHBr3) and dibromomethane (CH2Br2), to stratospheric bromine and its sensitivity to convection strength. Model simulations suggest that the most active transport of VSLS from the marine boundary layer through the tropopause occurs over the tropical Indian Ocean, the Western Pacific warm pool, and off the Pacific coast of Mexico. Together, convective lofting of CHBr3 and CH2Br2 and their degradation products supplies 8 ppt total bromine to the base of the Tropical Tropopause Layer (TTL, 150 hPa), similar to the amount of VSLS organic bromine available in the marine boundary layer (7.8-8.4 ppt) in the above active convective lofting regions. Of the total 8 ppt VSLS-originated bromine that enters the base of TTL at 150 hPa, half is in the form of source gas injection (SGI) and half as product gas injection (PGI). Only a small portion (Br2, together, contribute 7.7 pptv to the present-day inorganic bromine in the stratosphere. However, varying model deep convection strength between maximum and minimum convection conditions can introduce a 2.6 pptv uncertainty in the contribution of VSLS to inorganic bromine in the stratosphere (BryVSLS). Contrary to the conventional wisdom, minimum convection condition leads to a larger BryVSLS as the reduced scavenging in soluble product gases, thus a significant increase in PGI (2-3 ppt), greatly exceeds the relative minor decrease in SGI (a few 10ths ppt.

  2. Microspheres labelled with short-lived isotopes: Development and application for tumors treatment (Experimental study)

    International Nuclear Information System (INIS)

    Drozdovsky, B.Y.; Rosiev, R.A.; Goncharova, A.Y.; Skvortsov, V.G.; Petriev, V.M.; Grigoriev, A.N.; Schischkanov, N.G.

    1997-01-01

    Analysis of the conducted studies strongly suggests the possibility of usage of the domestic protein microspheres as a vehicle for radionuclide. The neutron-activating method of RPP production enables to utilize a broad spectrum of short-living isotopes that can be delivered into the target organ and anchored there for a long time. Good treatment results were obtained in case of the experimentally induced rheumatoid arthritis in rats after intraarticular loading of 165 Dy-hMSA. Mathematical calculations show that homogeneous distribution of RPP in human articulation cavity with the square of 100 cm 2 can be achieved when the quantity of administered particles exceeds 3000. On the example of 165 Dy-hMSA energy characteristic distribution we demonstrated that the absorbed dose for damaged cells at 2mm distance from the radioactive source is 7 times less than the one for a sphere of 2mm diameter. Analysis of dosimetric data in case of intratumoral loading of 165 Dy-hMSA also point out the necessity of the absorbed dose calculation methods taking into account the distance from the source and possible heterogeneity of RPP distribution inside the tumor to be employed. The prolonged RPP detention in the target causing no essential morphological and functional changes was achieved by embolization on the level of septal and interlobular arteries and of efferent arterioles in the animal's renal. The uniformity of microsphere distribution in the organ and their accumulation in tumors depends on the number of particles being administered. Investigations carried out suggest the efficacy of radionuclide therapy application for treatment of oncological and heavy somatic diseases. They also indicate the necessity of further investigations aimed to optimize the usage of microspheres as a radionuclide carrier usage and to work out the criteria of dosimetric planning

  3. Microspheres labelled with short-lived isotopes: Development and application for tumors treatment (Experimental study)

    Energy Technology Data Exchange (ETDEWEB)

    Drozdovsky, B.Y.; Rosiev, R.A.; Goncharova, A.Y.; Skvortsov, V.G.; Petriev, V.M.; Grigoriev, A.N.; Schischkanov, N.G. [Medical Radiological Research Centre RAMS, Kaluga Region, (Russian Federation)

    1997-10-01

    Analysis of the conducted studies strongly suggests the possibility of usage of the domestic protein microspheres as a vehicle for radionuclide. The neutron-activating method of RPP production enables to utilize a broad spectrum of short-living isotopes that can be delivered into the target organ and anchored there for a long time. Good treatment results were obtained in case of the experimentally induced rheumatoid arthritis in rats after intraarticular loading of {sup 165}Dy-hMSA. Mathematical calculations show that homogeneous distribution of RPP in human articulation cavity with the square of 100 cm{sup 2} can be achieved when the quantity of administered particles exceeds 3000. On the example of {sup 165}Dy-hMSA energy characteristic distribution we demonstrated that the absorbed dose for damaged cells at 2mm distance from the radioactive source is 7 times less than the one for a sphere of 2mm diameter. Analysis of dosimetric data in case of intratumoral loading of {sup 165}Dy-hMSA also point out the necessity of the absorbed dose calculation methods taking into account the distance from the source and possible heterogeneity of RPP distribution inside the tumor to be employed. The prolonged RPP detention in the target causing no essential morphological and functional changes was achieved by embolization on the level of septal and interlobular arteries and of efferent arterioles in the animal`s renal. The uniformity of microsphere distribution in the organ and their accumulation in tumors depends on the number of particles being administered. Investigations carried out suggest the efficacy of radionuclide therapy application for treatment of oncological and heavy somatic diseases. They also indicate the necessity of further investigations aimed to optimize the usage of microspheres as a radionuclide carrier usage and to work out the criteria of dosimetric planning 25 refs.

  4. A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons

    Directory of Open Access Journals (Sweden)

    D. E. Oram

    2017-10-01

    Full Text Available Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the declining atmospheric abundances of many ODSs. An important remaining uncertainty concerns the role of very short-lived substances (VSLSs which, owing to their relatively short atmospheric lifetimes (less than 6 months, are not regulated under the Montreal Protocol. Recent studies have found an unexplained increase in the global tropospheric abundance of one VSLS, dichloromethane (CH2Cl2, which has increased by around 60 % over the past decade. Here we report dramatic enhancements of several chlorine-containing VSLSs (Cl-VSLSs, including CH2Cl2 and CH2ClCH2Cl (1,2-dichloroethane, observed in surface and upper-tropospheric air in East and South East Asia. Surface observations were, on occasion, an order of magnitude higher than previously reported in the marine boundary layer, whilst upper-tropospheric data were up to 3 times higher than expected. In addition, we provide further evidence of an atmospheric transport mechanism whereby substantial amounts of industrial pollution from East Asia, including these chlorinated VSLSs, can rapidly, and regularly, be transported to tropical regions of the western Pacific and subsequently uplifted to the tropical upper troposphere. This latter region is a major provider of air entering the stratosphere, and so this mechanism, in conjunction with increasing emissions of Cl-VSLSs from East Asia, could potentially slow the expected recovery of stratospheric ozone.

  5. Regional scale temperature and circulation impacts of short-lived climate pollutants reductions

    Science.gov (United States)

    Oudar, T.; Kushner, P. J.; Fyfe, J. C.; von Salzen, K.; Shrestha, R.

    2017-12-01

    The role of anthropogenic aerosols on climate is still not clearly understood. Aerosol forcing is spatially heterogeneous and their emissions are controlled by regional economic and regulatory factors. For example, it is known that black carbon is responsible for a global net warming but its regional impacts are less understood. We evaluate the regional climate impacts of anthropogenic aerosol emission changes over the recent past and near future. Specifically, we report on numerical experiments using aerosol emissions from the Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants (ECLIPSE, Stohl et al., 2015) project. These scenarios are alternative mitigation pathways for black carbon and organic aerosol over the period from 1990 to 2050. With these scenarios, we carried out three sets of simulation using the second generation Canadian Earth System Model (CanESM2): 1) A current legislation emission (CLE) scenario for black carbon and organic aerosols; 2) A mitigation (MIT) scenario for black carbon and organic aerosols, and; 3) A black carbon only mitigation scenario (MIT-BC). Five simulations were carried out for each scenario and the response analyzed in the context of a large fifty-member initial condition ensemble of simulations using historical anthropogenic aerosol forcings to 2005 as well as those forcing from the RCP8.5 scenario to 2020. Our main finding is a significant springtime cooling over the Northern midlatitudes that attributable to black carbon. Other cooling signals attributable to black carbon reductions are found in the boreal summer over Southern Europe as well as over the Northern Hemisphere midlatitudes and tropical troposphere in boreal summer and fall. All of these cooling signals are to some degree offset by simultaneous reductions in organic aerosols. As a check on the robustness, we will also report on results of five-member draws from the large ensemble over periods of comparably strong radiative forcing changes, to

  6. Production and Use of Short-Lived Radioisotopes from Reactors. Vol. II. Proceedings of a Seminar on the Practical Applications of Short-Lived Radioisotopes Produced in Small Research Reactors

    International Nuclear Information System (INIS)

    1963-01-01

    There are many radioisotope applications in which it is important that the radiation should rapidly fall to an insignificant level once the initial intense activity has served its purpose. Such applications include diagnostic tests in medicine, where it is essential to reduce the radiation dose to the patient to a minimum, non-destructive testing methods which must be applied without contaminating the material or product concerned, and repeated routine tests which are possible only if the residual activity from the previous test is negligible. All these applications call for radionuclides whose half- lives are measured in hours or even minutes. Similarly, in the new but increasingly important technique of activation analysis, whereby the quantities of elements present in a material can be determined by irradiating the material in a reactor and assaying the radionuclides produced, the latter are mainly short-lived and must be measured immediately. While the production of long-lived radionuclides can most economically be left to the large reactors at the main radioisotope centres, short-lived isotopes must be produced, or materials activation performed, in a reactor at or near the place of intended use or analysis; this, then, represents one of the most important uses for the large number of small reactors which have been installed in recent years, or will come into operation in the near future, in many parts of the world. Since in many countries the new problems of producing, separating and applying short-lived radioisotopes are being faced for the first time, the International Atomic Energy Agency believed it would be valuable to survey the state of the art by convening an international Seminar on Practical Applications of Short-lived Radioisotopes produced in Small Research Reactors at its Vienna headquarters in November, 1962. This Seminar provided an opportunity for the producers and users of short-lived radioisotopes from many countries to meet and discuss the

  7. Production and Use of Short-Lived Radioisotopes from Reactors. Vol. II. Proceedings of a Seminar on the Practical Applications of Short-Lived Radioisotopes Produced in Small Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-03-15

    There are many radioisotope applications in which it is important that the radiation should rapidly fall to an insignificant level once the initial intense activity has served its purpose. Such applications include diagnostic tests in medicine, where it is essential to reduce the radiation dose to the patient to a minimum, non-destructive testing methods which must be applied without contaminating the material or product concerned, and repeated routine tests which are possible only if the residual activity from the previous test is negligible. All these applications call for radionuclides whose half- lives are measured in hours or even minutes. Similarly, in the new but increasingly important technique of activation analysis, whereby the quantities of elements present in a material can be determined by irradiating the material in a reactor and assaying the radionuclides produced, the latter are mainly short-lived and must be measured immediately. While the production of long-lived radionuclides can most economically be left to the large reactors at the main radioisotope centres, short-lived isotopes must be produced, or materials activation performed, in a reactor at or near the place of intended use or analysis; this, then, represents one of the most important uses for the large number of small reactors which have been installed in recent years, or will come into operation in the near future, in many parts of the world. Since in many countries the new problems of producing, separating and applying short-lived radioisotopes are being faced for the first time, the International Atomic Energy Agency believed it would be valuable to survey the state of the art by convening an international Seminar on Practical Applications of Short-lived Radioisotopes produced in Small Research Reactors at its Vienna headquarters in November, 1962. This Seminar provided an opportunity for the producers and users of short-lived radioisotopes from many countries to meet and discuss the

  8. Utility of radiotracer methodology in scientific research of industrial relevancy

    International Nuclear Information System (INIS)

    Kolar, Z.I.

    1990-01-01

    Utilization of radiotracer methodology in industrial research provides substantial scientific rather than directly demonstrable economic benefits. These benefits include better understanding of industrial processes and subsequently the development of new ones. Examples are given of the use of radiotracers in technological studies and the significance of the obtained results is put down. Creative application of radiotracer methodology may contribute to the economic development and technological advancement of all countries including the developing ones. (orig.) [de

  9. Dormancy and germination in short-lived lepidium perfoliatu l. (brassicaceae) seeds

    International Nuclear Information System (INIS)

    Tang, An-Jun; Tian, M.; Long, Chun-Lin

    2010-01-01

    To understand germination timing in an ecological context, the response to environmental events that effect seed dormancy is central and has to be combined with knowledge of germination responses to different ecological factors. In this study, seed dormancy, germination and seedling survival of annual short-lived clasping pepper weed Lepidium perfoliatum L. (Brassicaceae) were investigated. Three types of pre-treatments viz., various temperature dry storage, light and water stress were tested as possible dormancy and survival-affecting environmental events. Fresh mature seeds were greatly dormant. Warm (30 deg. C) dry storage more facilitated breaking dormancy, they germinated well under apt conditions (e.g. 20 deg. C and 10/20 deg. C plus periodic light, 14 h/d). For those seeds which underwent after-ripening, they could germinate at a range of constant temperatures (4, 10, 15, 20, 25, and 30 deg. C) and one alternating temperature (10/20 deg. C). Under alternating temperature regimes, the final percent germination of L. perfoliatum seeds increased from 37 deg. C to 93% when temperature altered from 4/10 deg. C to 10/20 deg. C in light, then decreased with increasing temperature. The germination pattern under constant temperature conditions was similar to that under alternating temperature and significant differences in final percent germinations and rates of germination were observed among different temperatures. Under different light treatments, final germination of showed significant differences, only with 35% of germination percentage in dark, much lower than those in red and white light (i.e. 93% and 91%, respectively). GA3 could promote the germination of non-dormant seeds in dark. When water potentials were reduced, final percent germination decreased dramatically, and few seeds germinated at -0.98 MPa (generated by PEG-8000). The changes of proline content in resultant seedlings were reverse to that of final percent germination with changing water

  10. Seasonal variation in the behaviour of a short-lived rodent.

    Science.gov (United States)

    Eccard, Jana A; Herde, Antje

    2013-11-15

    Short lived, iteroparous animals in seasonal environments experience variable social and environmental conditions over their lifetime. Animals can be divided into those with a "young-of-the-year" life history (YY, reproducing and dying in the summer of birth) and an "overwinter" life history (OW, overwintering in a subadult state before reproducing next spring).We investigated how behavioural patterns across the population were affected by season and sex, and whether variation in behaviour reflects the variation in life history patterns of each season. Applications of pace-of-life (POL) theory would suggest that long-lived OW animals are shyer in order to increase survival, and YY are bolder in order to increase reproduction. Therefore, we expected that in winter and spring samples, when only OW can be sampled, the animals should be shyer than in summer and autumn, when both OW and YY animals can be sampled.We studied common vole (Microtus arvalis) populations, which express typical, intra-annual density fluctuation. We captured a total of 492 voles at different months over 3 years and examined boldness and activity level with two standardised behavioural experiments. Behavioural variables of the two tests were correlated with each other. Boldness, measured as short latencies in both tests, was extremely high in spring compared to other seasons. Activity level was highest in spring and summer, and higher in males than in females. Being bold in laboratory tests may translate into higher risk-taking in nature by being more mobile while seeking out partners or valuable territories. Possible explanations include asset-protection, with OW animals being rather old with low residual reproductive value in spring. Therefore, OW may take higher risks during this season. Offspring born in spring encounter a lower population density and may have higher reproductive value than offspring of later cohorts. A constant connection between life history and animal personality, as

  11. Regional emission metrics for short-lived climate forcers from multiple models

    Directory of Open Access Journals (Sweden)

    B. Aamaas

    2016-06-01

    Full Text Available For short-lived climate forcers (SLCFs, the impact of emissions depends on where and when the emissions take place. Comprehensive new calculations of various emission metrics for SLCFs are presented based on radiative forcing (RF values calculated in four different (chemical-transport or coupled chemistry–climate models. We distinguish between emissions during summer (May–October and winter (November–April for emissions in Europe and East Asia, as well as from the global shipping sector and global emissions. The species included in this study are aerosols and aerosol precursors (BC, OC, SO2, NH3, as well as ozone precursors (NOx, CO, VOCs, which also influence aerosols to a lesser degree. Emission metrics for global climate responses of these emissions, as well as for CH4, have been calculated using global warming potential (GWP and global temperature change potential (GTP, based on dedicated RF simulations by four global models. The emission metrics include indirect cloud effects of aerosols and the semi-direct forcing for BC. In addition to the standard emission metrics for pulse and sustained emissions, we have also calculated a new emission metric designed for an emission profile consisting of a ramping period of 15 years followed by sustained emissions, which is more appropriate for a gradual implementation of mitigation policies.For the aerosols, the emission metric values are larger in magnitude for emissions in Europe than East Asia and for summer than winter. A variation is also observed for the ozone precursors, with largest values for emissions in East Asia and winter for CO and in Europe and summer for VOCs. In general, the variations between the emission metrics derived from different models are larger than the variations between regions and seasons, but the regional and seasonal variations for the best estimate also hold for most of the models individually. Further, the estimated climate impact of an illustrative mitigation

  12. Radon and its short-lived daughter products in the lower atmosphere

    International Nuclear Information System (INIS)

    Servant, J.

    1964-01-01

    The variations of vertical and temporal distributions of natural radioactivity with geographical location in the lower atmospheric layers are shown. The content of radon and its short lived daughters products are measured. Radon content is measured continually with a new apparatus, the sensibility of which is 0,2.10 -11 Ci m -3 i.e. the fiftieth of the mean concentration near the soil, this apparatus allowed us to show that radioactive equilibrium between radon and its daughter products is realised when the atmosphere is stable. Air observations between 0 and 100 meters above the ground point out that radon and its decay products are valuable tracers to mark the stability of the atmosphere. Under very stable nighttime conditions the radon accumulates in the former 30 meters of the air layer, at sunrise it ascends and at 9 o'clock attains 100 meters high. The removal rate of the air in the lower atmosphere is computed from the movement of this radon mass, it is equal to 90 per cent for a summer day. We have show that this radon comes from the soil in which it diffuses by brownian motion the intensity of which varies with the water content of the soil, its value for June 1958 is 6,10 -17 Ci cm -2 s -1 and for January 1959 0.2,10 -17 Ci cm -2 s - 1. During the year 1958-1959 general mean of flux for the sedimentary soil studied is equal to 3. 8 ± 1.3, 10 -17 Ci cm -2 s -1 it is identical to the world wide mean computed by H. Israel. In a hilly site in the Morvan, air movements are well marked by this radioactivity. We observed from one hand downslope and up-slope breezes having, respectively, speeds of 0.2 m s -1 and 0.7 m s -1 and from the other hand by night, in the valley and with a light wind favours the stagnation of the air near the ground, a strong increase of the radioactivity which is proportional to the one of the granitic rocks of the region. The radon flux of this soil is 74,10 -17 Ci cm -2 s -1 and the radioactivity of the air can attain 1.5,10 -8 Ci m

  13. Physics with energetic radioactive ion beams

    International Nuclear Information System (INIS)

    Henning, W.F.

    1996-01-01

    Beams of short-lived, unstable nuclei have opened new dimensions in studies of nuclear structure and reactions. Such beams also provide key information on reactions that take place in our sun and other stars. Status and prospects of the physics with energetic radioactive beams are summarized

  14. Evaluating the climate and air quality impacts of short-lived pollutants

    Science.gov (United States)

    Stohl, A.; Aamaas, B.; Amann, M.; Baker, L. H.; Bellouin, N.; Berntsen, T. K.; Boucher, O.; Cherian, R.; Collins, W.; Daskalakis, N.; Dusinska, M.; Eckhardt, S.; Fuglestvedt, J. S.; Harju, M.; Heyes, C.; Hodnebrog, Ø.; Hao, J.; Im, U.; Kanakidou, M.; Klimont, Z.; Kupiainen, K.; Law, K. S.; Lund, M. T.; Maas, R.; MacIntosh, C. R.; Myhre, G.; Myriokefalitakis, S.; Olivié, D.; Quaas, J.; Quennehen, B.; Raut, J.-C.; Rumbold, S. T.; Samset, B. H.; Schulz, M.; Seland, Ø.; Shine, K. P.; Skeie, R. B.; Wang, S.; Yttri, K. E.; Zhu, T.

    2015-09-01

    This paper presents a summary of the work done within the European Union's Seventh Framework Programme project ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants). ECLIPSE had a unique systematic concept for designing a realistic and effective mitigation scenario for short-lived climate pollutants (SLCPs; methane, aerosols and ozone, and their precursor species) and quantifying its climate and air quality impacts, and this paper presents the results in the context of this overarching strategy. The first step in ECLIPSE was to create a new emission inventory based on current legislation (CLE) for the recent past and until 2050. Substantial progress compared to previous work was made by including previously unaccounted types of sources such as flaring of gas associated with oil production, and wick lamps. These emission data were used for present-day reference simulations with four advanced Earth system models (ESMs) and six chemistry transport models (CTMs). The model simulations were compared with a variety of ground-based and satellite observational data sets from Asia, Europe and the Arctic. It was found that the models still underestimate the measured seasonality of aerosols in the Arctic but to a lesser extent than in previous studies. Problems likely related to the emissions were identified for northern Russia and India, in particular. To estimate the climate impacts of SLCPs, ECLIPSE followed two paths of research: the first path calculated radiative forcing (RF) values for a large matrix of SLCP species emissions, for different seasons and regions independently. Based on these RF calculations, the Global Temperature change Potential metric for a time horizon of 20 years (GTP20) was calculated for each SLCP emission type. This climate metric was then used in an integrated assessment model to identify all emission mitigation measures with a beneficial air quality and short-term (20-year) climate impact. These measures together

  15. Measurements of airborne short-lived radioactivity concentration in a PET facility at a national University hospital

    International Nuclear Information System (INIS)

    Saito, Tadashi

    2006-01-01

    National universities in Japan became under regulation of Industrial Safety and Health Law since 2004FY. One of the legal obligations is working environment measurements such as airborne radioactivity concentration in the rooms where employees handle unsealed radiation sources. Both in 2004FY and in 2005FY, measurements of airborne radioactivity concentration were carried out by two different agencies. The most prominent difference among them is the measurement for short-lived PET nuclides. In 2004FY, one agency measured the radioactivity with a Ge spectrometer at its own laboratory, whereas, in 2005FY, the other agency brought a NaI scintillation counter for gross gamma counting to the Hospital. It can be shown that detection limits for short-lived PET nuclides are in principle almost the same in both methods. It is also found that, in the actual case, gamma spectrometry with a Ge spectrometer is superior in judgement of detection of the radioactivity. (author)

  16. Accurate mass measurements of short-lived isotopes with the MISTRAL rf spectrometer

    CERN Document Server

    Toader, C F; Borcea, C; Doubre, H; Duma, M; Jacotin, M; Henry, S; Képinski, J F; Lebée, G; Le Scornet, G; Lunney, M D; Monsanglant, C; De Saint-Simon, M; Thibault, C

    1999-01-01

    The MISTRAL experiment has measured its first masses at ISOLDE. Installed in May 1997, this radiofrequency transmission spectrometer is to concentrate on nuclides with particularly short half-lives. MISTRAL received its first stable beam in October and first radioactive beam in November 1997. These first tests, with a plasma ion source, resulted in excellent isobaric separation and reasonable transmission. Further testing and development enabled first data taking in July 1998 on neutron-rich Na isotopes having half-lives as short as 31 ms.

  17. Possibilities of chemical isolation of element 106 from aqueous solutions according to the model experiments with short lived tungsten isotopes

    International Nuclear Information System (INIS)

    Szeglowski, Z.; Bruchertseifer, H.; Brudanin, V.B.

    1993-01-01

    A rapid method for continuous separation of short-lived tungsten isotopes from the lanthanides has been developed. It consists in transforming nuclear reaction products from the target by an aerosol jet to an absorber where the KCl particulates are dissolved in 0.2 M HF and percolating the product solution through three successively linked columns filled with ion exchange resins Dowex 50X8 (cationite), Dowex 1X8 (anionite) and again Dowex 50X8. 3 refs

  18. PANTHER Data from SOLVE-II Through CR-AVE: A Contrast Between Long and Short Lived Compounds.

    Science.gov (United States)

    Moore, F. L.; Dutton, G. S.; Elkins, J. W.; Hall, B. D.; Hurst, D. F.; Nance, J. D.; Thompson, T. M.

    2006-12-01

    PANTHER (PAN and other Trace Hydrohalocarbons ExpeRiment) is an airborne 6-channel gas chromatograph that measures approximately 20 important atmospheric trace gases whose changing burdens impact air quality, climate change and both stratospheric and tropospheric ozone. In this presentation we will contrast measurements of the long-lived compounds against the short-lived compounds. The long-lived compounds tend to have well-defined troposphere boundary conditions and develop spatial gradients due to stratospheric processing. These measurements have played a major role in quantifying stratospheric transport, stratosphere- troposphere exchange, and ozone loss. In contrast the short-lived species develop spatial and temporal gradients in the tropical tropopause layer (TTL), due to variations in the surface boundary layer concentrations and the coupling of this surface boundary layer to the TTL via convective processes. Deep convection acts like a "conveyor belt" between the source region in the boundary layer and the relatively stable TTL region, often bypassing the free troposphere where scavenging of these short lived species takes place. Loss rates due to reaction with OH and thermal decomposition are reduced in the cold, dry air of the TTL, resulting in longer survival times. Isolation of the TTL region from the free troposphere can last from days to over a month. Significant amounts of these short-lived compound and their byproducts can therefore be transported into the lower stratosphere (LS). Of particular interest are compounds that contain bromine, iodine, and sulfur, not only because of their intrinsic harmful effects in the atmosphere, but also because they have unique source and sink regions that can help to de- convolve transport.

  19. The ratio of long-lived to short-lived radon-222 progeny concentrations in ground-level air

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Winkler, R. [Institut fuer Strahlenschutz, GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg Oberschleissheim (Germany)

    1996-02-09

    The ratio of {sup 210}Pb air concentration to the short-lived radon ({sup 222}Rn) decay products concentration at ground level was investigated at a semi-rural location 10 km north of Munich, south Germany, for a period of 11 years (1982-1992). The average ratio from 132 monthly mean values has been found to be (7.5{+-}2.2) x 10{sup -5} (arithmetic mean{+-}S.D.). While the time series of the short-lived radon daughter concentration exhibit a distinct seasonal pattern with maxima mostly in October of each year, the course of {sup 210}Pb air concentration is characterized by high values from October through February. Consequently, high ratios of {sup 210}Pb to short-lived decay product concentration are often observed in the winter months of December-February. To study the influence of meteorological conditions on this behaviour, {sup 210}Pb and {sup 214}Pb concentrations were measured on a short-term basis with sampling intervals of 2-3 days from October 1991 to November 1992. The air concentrations obtained within those intervals were then correlated with actual meteorological parameters. On the base of this investigation the seasonal behaviour can essentially be explained by the more frequent inversion weather conditions in winter than in the summer months. At the same location, the average ratio of {sup 210}Po to {sup 210}Pb concentration in ground level air has been found to be 0.079 from 459 weakly mean values between 1976 and 1985. Hence, the corresponding average ratios of the short-lived radon daughters (EEC) to {sup 210}Pb and {sup 210}Po, were 1:7.5x10{sup -5} and 1:0.6 x 10{sup -5}, respectively.

  20. The ratio of long-lived to short-lived radon-222 progeny concentrations in ground-level air

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1996-01-01

    The ratio of 210 Pb air concentration to the short-lived radon ( 222 Rn) decay products concentration at ground level was investigated at a semi-rural location 10 km north of Munich, south Germany, for a period of 11 years (1982-1992). The average ratio from 132 monthly mean values has been found to be (7.5±2.2) x 10 -5 (arithmetic mean±S.D.). While the time series of the short-lived radon daughter concentration exhibit a distinct seasonal pattern with maxima mostly in October of each year, the course of 210 Pb air concentration is characterized by high values from October through February. Consequently, high ratios of 210 Pb to short-lived decay product concentration are often observed in the winter months of December-February. To study the influence of meteorological conditions on this behaviour, 210 Pb and 214 Pb concentrations were measured on a short-term basis with sampling intervals of 2-3 days from October 1991 to November 1992. The air concentrations obtained within those intervals were then correlated with actual meteorological parameters. On the base of this investigation the seasonal behaviour can essentially be explained by the more frequent inversion weather conditions in winter than in the summer months. At the same location, the average ratio of 210 Po to 210 Pb concentration in ground level air has been found to be 0.079 from 459 weakly mean values between 1976 and 1985. Hence, the corresponding average ratios of the short-lived radon daughters (EEC) to 210 Pb and 210 Po, were 1:7.5x10 -5 and 1:0.6 x 10 -5 , respectively

  1. Radiotracers for PETT: new developments and perspectives

    International Nuclear Information System (INIS)

    Fowler, J.S.; Wolf, A.P.

    1983-01-01

    Radiotracer development with positron emitters has its major focus on problems in the neurosciences. Progress is reviewed for high-level isotope production and labelled precurser synthesis with the medical cyclotron. The study of regional brain glucose metabolism represented the first extension of one of the methods of neurochemical autoradiography to humans and the study of brain protein synthesis and neurotransmitter receptors followed. In a more general sense, one PETT instrumentation will provide resolution in the 5 mm range is already emerging. Research status is reviewed. 103 references

  2. Radiotracers for PETT: new developments and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Wolf, A.P.

    1983-01-01

    Radiotracer development with positron emitters has its major focus on problems in the neurosciences. Progress is reviewed for high-level isotope production and labelled precurser synthesis with the medical cyclotron. The study of regional brain glucose metabolism represented the first extension of one of the methods of neurochemical autoradiography to humans and the study of brain protein synthesis and neurotransmitter receptors followed. In a more general sense, one PETT instrumentation will provide resolution in the 5 mm range is already emerging. Research status is reviewed. 103 references. (PSB)

  3. The early use of radiotracers in chemistry

    International Nuclear Information System (INIS)

    Grabowski, K.F.M.

    1986-01-01

    This article describes the historical background to the use of radiotracers, pioneered by de Hevesy and Paneth before World War I. It traces their early use in ion and metal interchange in electrolysis, self-diffusion rates, early biochemical experiments on lead uptake in plants, phosphorus metabolism in rats, through to their wider use with the production of artificial radioisotopes after World War II. Photosynthesis experiments using carbon-11 and carbon-14 are described and their present-day widespread use in kinetics, metabolic pathway studies and therapeutics is discussed. (UK)

  4. Synthesis of a new technetium brain radiotracer

    International Nuclear Information System (INIS)

    El Aissi, Radhia

    2009-01-01

    The radiological diagnosis of brain diseases, including neurodegenerative ones, is still difficult because of the absence of specific biological markers. These diseases are then increasingly the subject of researches and new experiments. The biodistribution of a new cytectrenes-aniline derivative, having a lipophilic character and low molecular weight, showed a prolonged brain retention and a specific tissue distribution of the hippocampus. This radiotracer could contribute to establish early diagnosis of neurodegenerative diseases thanks to its affinity with a serotonin receptors-rich region. (Author)

  5. Synthesis and tissue distribution studies of two novel esters of haloperidol and the application of radiolabelling techniques using short-lived radionuclides in the study of the deposition characteristics of suspended aerosol particles

    International Nuclear Information System (INIS)

    Smith, M.F.

    1982-01-01

    In the present work, the Schotten-Baumann reaction conditions were modified to esterify the tertiary hydroxyl group of haloperidol. The rapid synthesis (less than 20 min) makes this procedure applicable to the preparation of esters of haloperidol containing fluorine-18 (t/sup (1/2)/ 110 min), a γ-emitting radioisotope useful in external scintigraphy. In vivo distribution studies of the synthesized tritiated esters and haloperidol in the rat demonstrated that neither ester prodrug achieved overall higher brain concentration levels than haloperidol. In this study, radiotracer techniques were developed to examine parameters that characterize pressurized aerosols designed to utilize insoluble particles suspended in the aerosol formulation. The suspended micro-aggregated bovine albumin microspheres were labelled with iodine-131 (t/sup (1/2)/ 8 days). The techniques developed illustrate the use of short-lived radionuclides for: 1) quantitation of each metered dose; 2) characterization of particle size distribution by the aerosol; and 3) determination of the extent of deposition of the particles in the aerosol and all of its components

  6. Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008

    Science.gov (United States)

    Quennehen, B.; Raut, J.-C.; Law, K. S.; Daskalakis, N.; Ancellet, G.; Clerbaux, C.; Kim, S.-W.; Lund, M. T.; Myhre, G.; Olivié, D. J. L.; Safieddine, S.; Skeie, R. B.; Thomas, J. L.; Tsyro, S.; Bazureau, A.; Bellouin, N.; Hu, M.; Kanakidou, M.; Klimont, Z.; Kupiainen, K.; Myriokefalitakis, S.; Quaas, J.; Rumbold, S. T.; Schulz, M.; Cherian, R.; Shimizu, A.; Wang, J.; Yoon, S.-C.; Zhu, T.

    2016-08-01

    is too weak to explain the differences between the models. Our results rather point to an overestimation of SO2 emissions, in particular, close to the surface in Chinese urban areas. However, we also identify a clear underestimation of aerosol concentrations over northern India, suggesting that the rapid recent growth of emissions in India, as well as their spatial extension, is underestimated in emission inventories. Model deficiencies in the representation of pollution accumulation due to the Indian monsoon may also be playing a role. Comparison with vertical aerosol lidar measurements highlights a general underestimation of scattering aerosols in the boundary layer associated with overestimation in the free troposphere pointing to modelled aerosol lifetimes that are too long. This is likely linked to too strong vertical transport and/or insufficient deposition efficiency during transport or export from the boundary layer, rather than chemical processing (in the case of sulphate aerosols). Underestimation of sulphate in the boundary layer implies potentially large errors in simulated aerosol-cloud interactions, via impacts on boundary-layer clouds.This evaluation has important implications for accurate assessment of air pollutants on regional air quality and global climate based on global model calculations. Ideally, models should be run at higher resolution over source regions to better simulate urban-rural pollutant gradients and/or chemical regimes, and also to better resolve pollutant processing and loss by wet deposition as well as vertical transport. Discrepancies in vertical distributions require further quantification and improvement since these are a key factor in the determination of radiative forcing from short-lived pollutants.

  7. Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008

    Directory of Open Access Journals (Sweden)

    B. Quennehen

    2016-08-01

    mitigation in Beijing is too weak to explain the differences between the models. Our results rather point to an overestimation of SO2 emissions, in particular, close to the surface in Chinese urban areas. However, we also identify a clear underestimation of aerosol concentrations over northern India, suggesting that the rapid recent growth of emissions in India, as well as their spatial extension, is underestimated in emission inventories. Model deficiencies in the representation of pollution accumulation due to the Indian monsoon may also be playing a role. Comparison with vertical aerosol lidar measurements highlights a general underestimation of scattering aerosols in the boundary layer associated with overestimation in the free troposphere pointing to modelled aerosol lifetimes that are too long. This is likely linked to too strong vertical transport and/or insufficient deposition efficiency during transport or export from the boundary layer, rather than chemical processing (in the case of sulphate aerosols. Underestimation of sulphate in the boundary layer implies potentially large errors in simulated aerosol–cloud interactions, via impacts on boundary-layer clouds.This evaluation has important implications for accurate assessment of air pollutants on regional air quality and global climate based on global model calculations. Ideally, models should be run at higher resolution over source regions to better simulate urban–rural pollutant gradients and/or chemical regimes, and also to better resolve pollutant processing and loss by wet deposition as well as vertical transport. Discrepancies in vertical distributions require further quantification and improvement since these are a key factor in the determination of radiative forcing from short-lived pollutants.

  8. High Accuracy mass Measurement of the very Short-Lived Halo Nuclide $^{11}$Li

    CERN Multimedia

    Le scornet, G

    2002-01-01

    The archetypal halo nuclide $^{11}$Li has now attracted a wealth of experimental and theoretical attention. The most outstanding property of this nuclide, its extended radius that makes it as big as $^{48}$Ca, is highly dependent on the binding energy of the two neutrons forming the halo. New generation experiments using radioactive beams with elastic proton scattering, knock-out and transfer reactions, together with $\\textit{ab initio}$ calculations require the tightening of the constraint on the binding energy. Good metrology also requires confirmation of the sole existing precision result to guard against a possible systematic deviation (or mistake). We propose a high accuracy mass determintation of $^{11}$Li, a particularly challenging task due to its very short half-life of 8.6 ms, but one perfectly suiting the MISTRAL spectrometer, now commissioned at ISOLDE. We request 15 shifts of beam time.

  9. Half-life and mass measurement of the short-lived {sup 215}Po isotope (1.78 ms) at the FRS ion catcher

    Energy Technology Data Exchange (ETDEWEB)

    Rink, Ann-Kathrin; Bergmann, Julian; Ebert, Jens; Hornung, Christine; Miskun, Ivan; Reiter, Moritz P. [Justus-Liebig Universitaet Giessen (Germany); Ayet San Andres, Samuel; Dickel, Timo; Plass, Wolfgang R.; Scheidenberger, Christoph [Justus-Liebig Universitaet Giessen (Germany); GSI, Darmstadt (Germany); Geissel, Hans; Purushothaman, Sivaji [GSI, Darmstadt (Germany)

    2016-07-01

    At the Low-Energy Branch (LEB) of the Super-FRS at FAIR, precision experiments with exotic nuclei will be performed using ion traps and lasers. The nuclei will be produced at relativistic energies, slowed down, thermalised in a cryogenic stopping cell (CSC) and made available to various experiments. The thermalisation is a challenging task because of the large energy straggling of the nuclei after production, which requires a stopping cell with large areal densities. Also, the process needs to be performed on a millisecond time scale in order to give access to short-lived nuclides. This method has already been successfully applied at the FRS Ion Catcher at GSI using a prototype CSC. Recently the potential of the method has been demonstrated by the mass and half-life measurement of the {sup 215}Po nuclide with a half-life of 1.78 ms only. The multiple-reflection time-of-flight mass spectrometer at the FRS Ion Catcher has been used to determine the mass to a sub-ppm accuracy and to provide a mass-selected beam for alpha spectroscopy. Furthermore, experiments have been performed with the prototype CSC in order to test novel concepts to be used with the final version of the CSC for the LEB.

  10. Centuries of thermal sea-level rise due to anthropogenic emissions of short-lived greenhouse gases.

    Science.gov (United States)

    Zickfeld, Kirsten; Solomon, Susan; Gilford, Daniel M

    2017-01-24

    Mitigation of anthropogenic greenhouse gases with short lifetimes (order of a year to decades) can contribute to limiting warming, but less attention has been paid to their impacts on longer-term sea-level rise. We show that short-lived greenhouse gases contribute to sea-level rise through thermal expansion (TSLR) over much longer time scales than their atmospheric lifetimes. For example, at least half of the TSLR due to increases in methane is expected to remain present for more than 200 y, even if anthropogenic emissions cease altogether, despite the 10-y atmospheric lifetime of this gas. Chlorofluorocarbons and hydrochlorofluorocarbons have already been phased out under the Montreal Protocol due to concerns about ozone depletion and provide an illustration of how emission reductions avoid multiple centuries of future TSLR. We examine the "world avoided" by the Montreal Protocol by showing that if these gases had instead been eliminated in 2050, additional TSLR of up to about 14 cm would be expected in the 21st century, with continuing contributions lasting more than 500 y. Emissions of the hydrofluorocarbon substitutes in the next half-century would also contribute to centuries of future TSLR. Consideration of the time scales of reversibility of TSLR due to short-lived substances provides insights into physical processes: sea-level rise is often assumed to follow air temperature, but this assumption holds only for TSLR when temperatures are increasing. We present a more complete formulation that is accurate even when atmospheric temperatures are stable or decreasing due to reductions in short-lived gases or net radiative forcing.

  11. Development of a Method to Assess the Radiation Dose due to Internal Exposure to Short-lived Radioactive Materials

    International Nuclear Information System (INIS)

    Benmaman, D.; Koch, J.; Ribak, J.

    2014-01-01

    Work with radioactive materials requires monitoring of the employees' exposure to ionizing radiation. Employees may be exposed to radiation from internal and/or external exposure. Control of external exposure is mostly conducted through personal radiation dosimeters provided to employees. Control of internal exposure can be performed by measuring the concentration of radioactive substances excreted in urine or through whole-body counting in which the entire body or target organs are scanned with a sensitive detector system (1). According to the regulations in Israel an employee that may be internally exposed must undergo an exposure control at least once every three months. The idea lying behind the control of internal exposure by urine testing is that if radioactive material has penetrated into the employee body, it can be detected even if the test is performed once every three months. A model was fitted for each element describing its dispersion in the body and its excretion therefrom (2). By means of this model, one can estimate the activity that entered the body and calculate the resulting radiation dose to which the worker was exposed. There is a problem to implement this method when it comes to short-lived radioactive materials, for which it is very likely that the material that penetrated into the body has decayed and cannot be detected by testing once every three months. As a result, workers with short-lived radioactive materials are presently not monitored for internal exposure, in contradiction to the requirements of the Safety at Work Regulations. The purpose of the study is to develop an alternative method to assess the amount of radioactive material absorbed in the body and the resulting radiation dose due to internal exposure of workers to short-lived radioactive materials

  12. Harvard-MIT research program in short-lived radiopharmaceuticals. Progress report, March 1, 1985-February 28, 1986

    International Nuclear Information System (INIS)

    1986-03-01

    The Harvard-MIT Research Program in Short-Lived Radiopharmaceuticals was established in 1977 to foster interaction among groups working at Harvard Medical School, the Massachusetts Institute of Technology and the Massachusetts General Hospital in fields related to radiopharmaceutical chemistry. From these collaborations and building upon the special, but different, strengths of the participating individuals, laboratories and institutions, it was hoped that original approaches would be found for the design of new, clinically useful, labeled compounds. We believe that examination of the record demonstrates that this has been a fruitful alliance

  13. Harvard-MIT research program in short-lived radiopharmaceuticals. Progress report, March 1, 1983-February 29, 1984

    International Nuclear Information System (INIS)

    Adelstein, S.J.; Brownell, G.L.

    1984-02-01

    This report describes research efforts towards the achievement of a clearer understanding of the solution chemistry of technetium in order to facilitate the design of future clinical agents labeled with Tc-99m, the development of new receptor binding radiopharmaceuticals for the in vivo assessment of insulin receptors and for imaging the adrenal medulla and the brain, the examination of the utility of monoclonal antibodies and liposomes in the design of radiopharmaceuticals for diagnosis and therapy, and the synthesis of short-lived positron-emitting radiopharmaceuticals for transverse imaging of regional physiological processes

  14. Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

    Science.gov (United States)

    Narama, Chiyuki; Daiyrov, Mirlan; Duishonakunov, Murataly; Tadono, Takeo; Sato, Hayato; Kääb, Andreas; Ukita, Jinro; Abdrakhmatov, Kanatbek

    2018-04-01

    Four large drainages from glacial lakes occurred during 2006-2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000 m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary), and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth-drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i) a debris landform containing ice (ice-cored moraine complex), (ii) a depression with water supply on a debris landform as a potential lake basin, and (iii) no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2) in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s-1 at peak discharge.

  15. Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

    Directory of Open Access Journals (Sweden)

    C. Narama

    2018-04-01

    Full Text Available Four large drainages from glacial lakes occurred during 2006–2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000  m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary, and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth–drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i a debris landform containing ice (ice-cored moraine complex, (ii a depression with water supply on a debris landform as a potential lake basin, and (iii no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2 in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s−1 at peak discharge.

  16. The low to intermediate activity and short living waste storage facility. For a controlled management of radioactive wastes

    International Nuclear Information System (INIS)

    2006-01-01

    Sited at about 50 km of Troyes (France), the Aube facility started in 1992 and has taken over the Manche facility for the surface storage of low to intermediate and short living radioactive wastes. The Aube facility (named CSFMA) is the answer to the safe management of these wastes at the industrial scale and for 50 years onward. This brochure presents the facility specifications, the wastes stored at the center, the surface storage concept, the processing and conditioning of waste packages, and the environmental monitoring performed in the vicinity of the site. (J.S.)

  17. Impact of preindustrial to present-day changes in short-lived pollutant emissions on atmospheric composition and climate forcing

    Science.gov (United States)

    Naik, Vaishali; Horowitz, Larry W.; Fiore, Arlene M.; Ginoux, Paul; Mao, Jingqiu; Aghedo, Adetutu M.; Levy, Hiram

    2013-07-01

    We describe and evaluate atmospheric chemistry in the newly developed Geophysical Fluid Dynamics Laboratory chemistry-climate model (GFDL AM3) and apply it to investigate the net impact of preindustrial (PI) to present (PD) changes in short-lived pollutant emissions (ozone precursors, sulfur dioxide, and carbonaceous aerosols) and methane concentration on atmospheric composition and climate forcing. The inclusion of online troposphere-stratosphere interactions, gas-aerosol chemistry, and aerosol-cloud interactions (including direct and indirect aerosol radiative effects) in AM3 enables a more complete representation of interactions among short-lived species, and thus their net climate impact, than was considered in previous climate assessments. The base AM3 simulation, driven with observed sea surface temperature (SST) and sea ice cover (SIC) over the period 1981-2007, generally reproduces the observed mean magnitude, spatial distribution, and seasonal cycle of tropospheric ozone and carbon monoxide. The global mean aerosol optical depth in our base simulation is within 5% of satellite measurements over the 1982-2006 time period. We conduct a pair of simulations in which only the short-lived pollutant emissions and methane concentrations are changed from PI (1860) to PD (2000) levels (i.e., SST, SIC, greenhouse gases, and ozone-depleting substances are held at PD levels). From the PI to PD, we find that changes in short-lived pollutant emissions and methane have caused the tropospheric ozone burden to increase by 39% and the global burdens of sulfate, black carbon, and organic carbon to increase by factors of 3, 2.4, and 1.4, respectively. Tropospheric hydroxyl concentration decreases by 7%, showing that increases in OH sinks (methane, carbon monoxide, nonmethane volatile organic compounds, and sulfur dioxide) dominate over sources (ozone and nitrogen oxides) in the model. Combined changes in tropospheric ozone and aerosols cause a net negative top

  18. Application of dynamic and transition magnetic fields for determination of magnetic moments of short-lived nuclear states

    International Nuclear Information System (INIS)

    Burgov, N.A.

    1986-01-01

    Problem of measuring magnetic momenta of short-living nuclear states is discussed. Different methods for measuring magnetic momenta using interionic and transient magnetic fields were considered. Possibility for determining a value g by means of measuring correlation attenuation is investigated as well as measuring magnetic momenta by means of inclined foils. At present 2 + level magnetic momenta for many odd-odd nuclei have been determined by means of the above methods. The methods are only ones for determining magnetic momenta of nuclear levels with small lifetimes up to tenth and hundredth of shares of picoseconds

  19. Studies of short-lived products of spallation fission reactions at TRIUMF

    CERN Document Server

    Bischoff, G; D'Auria, J M; Dautet, H; Lee, J K P; Pate, B D; Wiesehahn, W

    1976-01-01

    The gas-jet recoil transport technique has been used to transport products from spallation and fission reactions from a target chamber to a shielded location for nuclear spectroscopic studies. These involve X- beta - gamma coincidence measurements and (shortly) time- of-flight mass spectroscopy. It has been deduced that the proton beam at present intensities has no appreciable effect on the ability of ethylene and other cluster-producing gases to transport radioactivity. Preliminary results will be presented for shortlived fission products from uranium, and for spallation products of iodine and argon. The latter were obtained from the bombardment of gas and aerosol targets mixed with the transporting gas in the target chamber, which appears to be a generally useful technique.

  20. The use of radiotracers in natural rubber research in Malaysia

    International Nuclear Information System (INIS)

    Lai, P.F.; Singh, M.M.

    1981-01-01

    Five main areas where radiotracers have been used in research on natural rubber are on studies on the uptake of plant nutrients by Hevea brasiliensis using 32 P, 86 Rb and 45 Ca as tracers; biosynthesis of Hevea rubber using 14 C or 3 H labelled intermediates; translocation and metabolism of 14 C. Ethephon in Hevea brasiliensis; use of radiotracers as analytical tools and adsorption of labelled fatty acid soaps on natural rubber lattices. These studies are discussed to show the powerful tool that radiotracers provide in agricultural, biochemical and chemical research on natural rubber. (author)

  1. Corrections for the combined effects of decay and dead time in live-timed counting of short-lived radionuclides

    International Nuclear Information System (INIS)

    Fitzgerald, R.

    2016-01-01

    Studies and calibrations of short-lived radionuclides, for example "1"5O, are of particular interest in nuclear medicine. Yet counting experiments on such species are vulnerable to an error due to the combined effect of decay and dead time. Separate decay corrections and dead-time corrections do not account for this issue. Usually counting data are decay-corrected to the start time of the count period, or else instead of correcting the count rate, the mid-time of the measurement is used as the reference time. Correction factors are derived for both those methods, considering both extending and non-extending dead time. Series approximations are derived here and the accuracy of those approximations are discussed. - Highlights: • Derived combined effects of decay and dead time. • Derived for counting systems with extending or non-extending dead times. • Derived series expansions for both midpoint and decay-to-start-time methods. • Useful for counting experiments with short-lived radionuclides. • Examples given for "1"5O, used in PET scanning.

  2. Determination of k0-factors of short-lived nuclides and application of k0-NAA to selected trace elements

    International Nuclear Information System (INIS)

    Acharya, R.; Holzbecher, J.; Chatt, A.

    2012-01-01

    As part of the standardization program of k 0 -based NAA (k 0 -NAA) methods at the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility, the k 0 -factors of 15 analytically important short-lived nuclides (half-life 197 Au). The elemental standards used were prepared mostly from their primary standard solutions. The samples were irradiated in both inner and outer pneumatic sites of the DUSR facility and counted using an HPGe-detector coupled to an ORTEC’s digital gamma-ray spectrometer. The k 0 -factors determined using both inner and outer irradiation sites were found to be within ±5% with respect to either recommended or literature values in most cases. The Z-score values at 95% confidence level were found to be in the range of ±0.03–1.6. The k 0 -NAA method was applied to three different NIST standard reference materials (SRMs) and concentrations of six elements, namely Ag, F, Hf, Rb, Sc, and Se were determined using their short-lived nuclides. The concentrations of these elements were also determined by relative NAA method for comparison purposes.

  3. Production cross sections of short-lived silver radionuclides from natPd(p,xn) nuclear processes

    International Nuclear Information System (INIS)

    Khandaker, Mayeen Uddin; Kim, Kwangsoo; Kim, Guinyun

    2012-01-01

    Production cross-sections of short-lived 103 Ag, 104m Ag and 104g Ag radionuclides from proton-induced reactions on natural palladium (Pd) were measured up to 41 MeV by using a stacked-foil activation technique combined with high resolution γ-ray spectrometry. The present results are compared with the available literature values as well as theoretical data calculated by the TALYS and the ALICE-IPPE computer codes. Note that production cross-sections of the 104m Ag radionuclide from nat Pd(p,xn) processes has been measured here for the first time. Physical thick target yields for the investigated radionuclides were deduced from the respective threshold energy to 41 MeV taking into account that the total energy is absorbed in the targets. Measured data of the short-lived 103 Ag radionuclide are noteworthy due to its possible applications as a precursor for the indirect production of widely used therapeutic 103 Pd radionuclide via nat Pd(p,xn) 103 Ag → 103 Pd processes. On the other hand, the investigated 104 Ag radionuclide finds importance due to its potential use as a diagnostic and positron emission tomography (PET) imaging analogue. Above all, measured data will enrich the literature database leading to various applications in science and technology.

  4. Detection and reconstruction of short-lived particles produced by neutrino interactions in emulsion

    CERN Document Server

    Uiterwijk, J W E

    2007-01-01

    In this dissertation, several different topics related to the chorus experiment are pre- sented. The chorus experiment has been used to study neutrino oscillations using the neutrino beam at cern. The neutrino oscillation hypothesis provided an explanation for the lower than expected fluxes of solar and atmospheric neutrinos. There are three neutrino species in nature corresponding to different weak eigenstates, namely, the elec- tron neutrino (νe ), the muon neutrino (νμ ), and the tau neutrino (ντ ). The lower fluxes could be interpreted as spontaneous oscillations between electron and muon neutrinos and between muon and tau neutrinos. The chorus experiment was designed to detect oscillation of muon neutrinos into tau neutrinos with small mixing probability down to 2 · 10−4 and a mass difference square between νμ and ντ larger than 0.5 eV2 . In the last decade, several disappearance experiments have confirmed the neutrino oscillation hypothesis and showed that oscillations occur between mass eig...

  5. Moments and mean square charge radii of short-lived argon isotopes

    CERN Document Server

    Klein, A; Georg, U; Keim, M; Lievens, P; Neugart, R; Neuroth, M; Silverans, R E; Vermeeren, L

    1996-01-01

    We report on the measurement of optical isotope shifts for $^{32-40}$Ar and for $^{46}$Ar from which the changes in mean square nuclear charge radii across the N = 20 neutron shell closure are deducted. The investigations were carried out by collinear laser spectroscopy in fast beams of neutral argon atoms. The ultra-sensitive detection combines optical pumping, state-selective collisional ionization and counting of $\\beta$-radioactivity. By reaching far into the sd-shell, the results add new information to the systematics of radii in the calcium region (Z $\\approx$ 20). Contrary to all major neutron shell closures with N $\\geq$ 28, the N = 20 shell closure causes no significant slope change in the development of the radii. Information from the hyperfine structure of the odd-A isotopes includes includes the magnetic moments of $^{33}$Ar (I=1/2) and $^{39}$Ar (I=7/2), and the quadrupole moments of $^{35}$Ar, $^{37}$Ar (I=3/2) and $^{39}$Ar. The electromagnetic moments are compared to shell-model predictions fo...

  6. Radiotracers in medical applications, vols 1-2

    International Nuclear Information System (INIS)

    Rayudu, G.V.S.

    1983-01-01

    These volumes will serve as a basis for instruction and reference for professionals such as radiopharmaceutical chemists, radiopharmacologists, radiopharmacists, radiobiochemists, and others involved in the medical applications of radiotracers. Vol. I: Topics include radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; 11 C, 13 N, 15 O, 67 Ga. 111 In, 75 Se, /SUP 123m/ Te compounds; radioactive noble gases; and miscellaneous radiotracers for imaging. Vol. II: Pertinent nuclear science data such as radiation dosimetry, radionuclide production modes, radionuclides for therapy, human experimentation regulations and consent forms, and radiotracer laboratory designs are presented

  7. Radiotracer investigations for sediment transport in ports of India

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Goswami, Sunil; Singh, Gursharan

    2013-01-01

    The knowledge of mixing and transport of sediments in coastal region is of vital importance for evaluating suitability of dumping site for dredged sediments produced during maintenance of shipping channels, expansion of existing projects and construction of new projects. Gamma-emitting radiotracers are commonly used for investigation of movement of sediments on seabed using Scandium-46 (scandium glass powder) as radiotracer. The radiotracer is injected on seabed at a desired location and its movement followed over a period of time using waterproof NaI(Tl) scintillation detectors. The recorded data is analyzed to obtain transport parameters and utilized for assessing the suitability of the dumping sites and optimization of the dredging operations. About 70 large-scale investigations have been carried out in different ports in India leading to significant economical benefits to the Ports. Present paper discusses various aspects of the radiotracer technique for sediment transport, methodology of data analysis and a specific case study. (author)

  8. Synthesis of new radiotracers based of Ethyl Ester

    International Nuclear Information System (INIS)

    Trabelsi, Donia

    2008-01-01

    The in vivo study of a biochemical or physiological process requires the synthesis of specific radiotracers but also the targeting of these compounds so that they can reach their target tissue. Methodologies original synthesis associated with radioisotopes used, the quantities and chemical forms often have to be available developed. The chemistry of metal complexes booming, we were able to use the ethyl ester combined with technetium, forming a stable radiotracer. Finally, a counting of radioactivity in different rat's organs completed our study. (Author)

  9. Radiotracer investigations in oil production and water injection wells

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.; Kirti

    1977-01-01

    Injection of gamma emitting radiotracers into oil wells followed by logging provides information on several aspects such as the identification of zones of seepage of water in the water injection wells and also the location of source of water entering oil producting wells. The experience gained in the application of bromine-82 and rubidium-86 as radiotracers in such studies at the Ankleshwar and Kalol oil fields in Gujarat and Nazira in Assam has been briefly reported. (author)

  10. Radiological protection in the use of radiotracers in industrial process

    International Nuclear Information System (INIS)

    Costa, M.L L.; Gomes, R.S.; Gomes, J.D.R.L.; Costa, E.L.C.; Thomé, Z.D.

    2017-01-01

    The use of radiotracers plays an important role to provide methods to optimize industrial process and improve product quality. An increase in the use of radiotracers investigations has been observed in Brazil, however, as there is no specific standard for the licensing of these facilities, generic radiation protection regulations have been used, but these are not comprehensive or technically suitable for this purpose. Regulatory inspections in radiotracer facilities have reported failures in disagreement with best practices for radiological safety, mainly in radioactive waste management and in the control of workplaces during radiotracer injections. In this work, an assessment of radiological protection aspects of radioactive tracers is performed, based on the licensing process of radiotracers facilities, as well as the experience of regulatory inspections and a review of international standards, pointing out relevant radiation safety aspects for working practices, procedures and protective measures before, during and after injections of radioactive tracers, in order to contribute to the future development of specific safety regulations on radiotracers in Brazil. (author)

  11. Radiological protection in the use of radiotracers in industrial process

    Energy Technology Data Exchange (ETDEWEB)

    Costa, M.L L.; Gomes, R.S.; Gomes, J.D.R.L.; Costa, E.L.C., E-mail: mara@cnen.gov.br, E-mail: rogeriog@cnen.gov.br, E-mail: jlopes@cnen.gov.br, E-mail: evaldo@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Diretoria de Radioproteção e Segurança Nuclear; Thomé, Z.D., E-mail: zielithome@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Seção de Engenharia Nuclear

    2017-07-01

    The use of radiotracers plays an important role to provide methods to optimize industrial process and improve product quality. An increase in the use of radiotracers investigations has been observed in Brazil, however, as there is no specific standard for the licensing of these facilities, generic radiation protection regulations have been used, but these are not comprehensive or technically suitable for this purpose. Regulatory inspections in radiotracer facilities have reported failures in disagreement with best practices for radiological safety, mainly in radioactive waste management and in the control of workplaces during radiotracer injections. In this work, an assessment of radiological protection aspects of radioactive tracers is performed, based on the licensing process of radiotracers facilities, as well as the experience of regulatory inspections and a review of international standards, pointing out relevant radiation safety aspects for working practices, procedures and protective measures before, during and after injections of radioactive tracers, in order to contribute to the future development of specific safety regulations on radiotracers in Brazil. (author)

  12. Flow Rate Measurement in Multiphase Flow Rig: Radiotracer and Conventional

    International Nuclear Information System (INIS)

    Nazrul Hizam Yusoff; Noraishah Othman; Nurliyana Abdullah; Amirul Syafiq Mohd Yunos; Rasif Mohd Zain; Roslan Yahya

    2015-01-01

    Applications of radiotracer technology are prevalent throughout oil refineries worldwide, and this industry is one of the main users and beneficiaries of the technology. Radioactive tracers have been used to a great extent in many applications i.e. flow rate measurement, RTD, plant integrity evaluation and enhancing oil production in oil fields. Chemical and petrochemical plants are generally continuously operating and technically complex where the radiotracer techniques are very competitive and largely applied for troubleshooting inspection and process analysis. Flow rate measurement is a typical application of radiotracers. For flow measurements, tracer data are important, rather than the RTD models. Research is going on in refining the existing methods for single phase flow measurement, and in developing new methods for multiphase flow without sampling. The tracer techniques for single phase flow measurements are recognized as ISO standards. This paper presents technical aspect of laboratory experiments, which have been carried out using Molybdenum-99 - Mo99 (radiotracer) to study and determine the flow rate of liquid in multiphase flow rig. The multiphase flow rig consists of 58.7 m long and 20 cm diameter pipeline that can accommodate about 0.296 m 3 of liquid. Tap water was used as liquid flow in pipeline and conventional flow meters were also installed at the flow rig. The flow rate results; radiotracer and conventional flow meter were compared. The total count method was applied for radiotracer technique and showed the comparable results with conventional flow meter. (author)

  13. New methodology for Ozone Depletion Potentials of short-lived compounds: n-Propyl bromide as an example

    Science.gov (United States)

    Wuebbles, Donald J.; Patten, Kenneth O.; Johnson, Matthew T.; Kotamarthi, Rao

    2001-07-01

    A number of the compounds proposed as replacements for substances controlled under the Montreal Protocol have extremely short atmospheric lifetimes, on the order of days to a few months. An important example is n-propyl bromide (also referred to as 1-bromopropane, CH2BrCH2CH3 or simplified as 1-C3H7Br or nPB). This compound, useful as a solvent, has an atmospheric lifetime of less than 20 days due to its reaction with hydroxyl. Because nPB contains bromine, any amount reaching the stratosphere has the potential to affect concentrations of stratospheric ozone. The definition of Ozone Depletion Potentials (ODP) needs to be modified for such short-lived compounds to account for the location and timing of emissions. It is not adequate to treat these chemicals as if they were uniformly emitted at all latitudes and longitudes as normally done for longer-lived gases. Thus, for short-lived compounds, policymakers will need a table of ODP values instead of the single value generally provided in past studies. This study uses the MOZART2 three-dimensional chemical-transport model in combination with studies with our less computationally expensive two-dimensional model to examine potential effects of nPB on stratospheric ozone. Multiple facets of this study examine key questions regarding the amount of bromine reaching the stratosphere following emission of nPB. Our most significant findings from this study for the purposes of short-lived replacement compound ozone effects are summarized as follows. The degradation of nPB produces a significant quantity of bromoacetone which increases the amount of bromine transported to the stratosphere due to nPB. However, much of that effect is not due to bromoacetone itself, but instead to inorganic bromine which is produced from tropospheric oxidation of nPB, bromoacetone, and other degradation products and is transported above the dry and wet deposition processes of the model. The MOZART2 nPB results indicate a minimal correction of the

  14. Radiotracer applications in industry - A guidebook

    International Nuclear Information System (INIS)

    2004-01-01

    The objective of this guidebook is to provide the radiotracer practitioner with practical, experience based information about all the facets of an investigation: design, planning, implementation, data treatment and interpretation of results. It is aimed at clearly identifying the questions that need to be asked at each stage of the investigation and, as comprehensively as possible, to either provide the answers to those questions or identify appropriate works of reference. The primary focus is on the methodology of radio tracing. Discussed aspects of the methodology are: tracer selection and optimization, methods of tracer injection, detection and measurement of radiation, data treatment and filtering including identification of available software, data analysis, interpretation and modelling. An early consideration in designing an investigation is selection of the tracer. The criteria of critical importance are that (1) the tracer must be compatible with the stream to be traced and (2) its behaviour must be representative of that stream. The first decision to make is whether to use a radioactive tracer or some alternative type. Generally, if the objectives of the investigation can be achieved using a non-radioactive tracer and without incurring disproportionate costs, then that tracer should be used. However, as will become apparent from the case studies presented, there are many problems that can be investigated only by using a radiotracer. In these cases it is necessary to choose a tracer based on the following selection criteria: type of radiation emitted: alpha particle, beta particle or gamma ray, half-life of the radionuclide, energy of the emitted radiation and optimization of the activity injected. The methodology reviewed considers the most commonly used radioisotopes for tracing solid materials, aqueous solutions, organic liquids and gaseous phases. The main emphasis is on the practical aspects of the technology. Various types of injection system are

  15. Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

    International Nuclear Information System (INIS)

    English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Ka-Ngo Leung; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

    2008-01-01

    Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a 'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity. (author)

  16. Microcomputer-based systems for automatic control of sample irradiation and chemical analysis of short-lived isotopes

    International Nuclear Information System (INIS)

    Bourret, S.C.

    1974-01-01

    Two systems resulted from the need for the study of the nuclear decay of short-lived radionuclides. Automation was required for better repeatability, speed of chemical separation after irradiation and for protection from the high radiation fields of the samples. A MCS-8 computer was used as the nucleus of the automatic sample irradiation system because the control system required an extensive multiple-sequential circuit. This approach reduced the sequential problem to a computer program. The automatic chemistry control system is a mixture of a fixed and a computer-based programmable control system. The fixed control receives the irradiated liquid sample from the reactor, extracts the liquid and disposes of the used sample container. The programmable control executes the chemistry program that the user has entered through the teletype. (U.S.)

  17. Synthesis of radiopharmaceuticals containing short-lived radionuclides: Comprehensive progress report, March 1, 1986-February 28, 1989

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1988-06-01

    The primary objective of the DOE Nuclear Medicine Program at The University of Tennessee is the creation of new methods for intoducing short-lived isotopes into agents for use in PET and SPECT. A portion of our effort is directed toward the design and in vivo quantitation of boron-containing neutron therapy agents. The uniqueness of the program is its focus on the design of new chemistry (molecular architecture) and technology as opposed to the application of known reactions to the synthesis of specific radiopharmaceuticals. The following topics are outlined in this paper: new isotope incorporation reactions utilizing nitrogen 13, oxygen 15, and carbon 11; technetium-boron complexes; boron-neutron-capture

  18. Precision mass measurements of very short-lived, neutron-rich Na isotopes using a radiofrequency spectrometer

    CERN Document Server

    Lunney, M D; Doubre, H; Henry, S; Monsanglant, C; De Saint-Simon, M; Thibault, C; Toader, C F; Borcea, C; Bollen, G

    2001-01-01

    Mass measurements of high precision have been performed on sodium isotopes out to $^{30}$Na using a new technique of radiofrequency excitation of ion trajectories in a homogeneous magnetic field. This method, especially suited to very short-lived nuclides, has allowed us to significantly reduce the uncertainty in mass of the most exotic Na isotopes: a relative error of 5x10$^{-7}$ was achieved for $^{28}$Na having a half-life of only 30.5 ms and 9x10$^{-7}$ for the weakly produced $^{30}$Na. Verifying and minimizing binding energy uncertainties in this region of the nuclear chart is important for clarification of a long standing problem concerning the strength of the $N$=20 magic shell closure. These results are the fruit of the commissioning of the new experimental program Mistral.

  19. Time-separated oscillatory fields for high-precision mass measurements on short-lived Al and Ca nuclides

    CERN Document Server

    George, Simon; Blank, B.; Blaum, K.; Breitenfeldt, M.; Hager, U.; Herfurth, F.; Herlert, A.; Kellerbauer, A.; Kluge, H.J.; Kretzschmar, M.; Lunney, D.; Savreux, R.; Schwarz, Andreas S.; Schweikhard, L.; Yazidjian, C.

    2008-01-01

    High-precision Penning trap mass measurements on the stable nuclide $^{27}$Al as well as on the short-lived radionuclides $^{26}$Al and $^{38,39}$Ca have been performed by use of radio-frequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, as recently introduced for the excitation of the ion motion in a Penning trap, was applied. A comparison with the conventional method of a single continuous excitation demonstrates its advantage of up to ten times shorter measurements. The new mass values of $^{26,27}$Al clarify conflicting data in this specific mass region. In addition, the resulting mass values of the superallowed $\\beta$-emitter $^{38}$Ca as well as of the groundstate of the $\\beta$-emitter $^{26}$Al$^{m}$ confirm previous measurements and corresponding theoretical corrections of the ft-values.

  20. The utilisation of short-lived radionuclides in the assessment of formulation and in vivo disposition of drugs

    International Nuclear Information System (INIS)

    Digenis, G.A.

    1982-01-01

    The utilisation of short-lived radionuclides in the assessment of drug formulations, and the in vivo distribution of drugs is discussed. Disintegration of tablets and capsules as a function of the formulation, and gastric emptying are important. The applicability of perturbed angular correlation to the study of the dissolution of water soluble substances from solid dosages in man is shown. Examples are given to illustrate how external scintigraphy can be applied to study the tissue distribution of 18 F-haloperidol, 82 Br-bromperidol, in rat and monkey. 11 C, L-andD-phenylalanine in rats, 11 C, D-leucine in mice with human colon tumours; 13 N-nitrosoureas and 13 N-nitroso-carbamates. (U.K.)

  1. Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

    International Nuclear Information System (INIS)

    Firestone, Richard B; English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Leung, Ka-Ngo; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

    2008-01-01

    Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a 'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents.1-3. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity

  2. A phase-imaging ion-cyclotron-resonance technique for mass measurements of short-lived nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, Sergey; Blaum, Klaus; Doerr, Andreas; Eronen, Tommi; Goncharov, Mikhail; Hoecker, Martin; Ketter, Jochen; Ramirez, Enrique Minaya; Simon, Vanessa [Max-Planck Institute for Nuclear Physics (Germany); Block, Michael [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Chenmarev, Stanislav; Filjanin, Pavel; Nesterenko, Dmitriy; Novikov, Yuri [Petersburg Nuclear Physics Institute (Russian Federation); Droese, Christian; Schweikhard, Lutz [Institute for Physics, Ernst-Moritz-Arndt-University (Germany)

    2014-07-01

    A novel approach to mass measurements on the sub-ppb level even for short-lived nuclides with half-lives well below one second is presented. It is based on the projection of the radial ion motion in a Penning trap onto a position sensitive detector. Compared to the presently employed time-of-flight ion-cyclotron-resonance technique, the novel approach is 25-times faster and provides a 40-fold gain in resolving power. With the new technique low-lying isomeric states with excitation energy on the 10-keV level can be separated from the ground state. Moreover, the new technique possesses a substantially higher sensitivity since just two ions are sufficient to determine the ion cyclotron frequency. A measurement of the mass difference of singly charged ions of {sup 132}Xe and {sup 131}Xe with an uncertainty of 25 eV has demonstrated the great potential of the new approach.

  3. Research reactors serving the radiotracer technique: An overlooked opportunity?

    International Nuclear Information System (INIS)

    Bode, P.

    2010-01-01

    The unique features of using radiotracers are not always fully explored at nuclear research reactor centers. The radiotracer method is a versatile and powerful tool in the study of a wide variety of applications in e.g. chemistry, biology, agriculture, medicine and (industrial) technology. The big advantage of radiotracers above e.g. stable isotope tracers, commonly applied in e.g. nutritional studies, is that radiotracers allow for non-invasive studies of both steady-state and dynamic systems, in equilibrium situations and for transport and exchange phenomena and thus provide information on the chemical and/or physical status of elements. The radiotracer method does not imply huge equipment investments but rather requires that the four interrelated aspects: experimental designs, data treatment including tracer kinetic analysis and data interpretation are careful considered. Radiotracer production with reactors often implies additional fundamental research to use smart nuclear reactions and chemical separations so as to obtain an almost no-carrier added tracer. Nuclear analytical groups, already equipped with gamma-ray spectrometers, can thus extend their research program. Using Ge-spectrometers, multi-labeling experiments are possible which allow for unique applications if different radionuclides exist for the same element, such as 65 Zn and 69m Zn or 64 Cu and 67 Cu. The developments in novel scintillation detectors, room-temperature semiconductor detectors (like CdZnTe) and position-sensitive detectors open the door for an entire new scope of radiotracer applications, such as SPECT. Once applied to in-vitro studies with cell cultures, the nuclear analytical group may position itself into the worlds of medical research, biochemistry and biotechnology. Radiotracers can be used to study the properties of drug-delivering compounds as used in e.g, cancer therapy. Radiotracers can be added as a label to solid particles, to liquids but may also be applied in the

  4. Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure

    International Nuclear Information System (INIS)

    Lessard, E.T.; Brill, A.B.; Adams, W.H.

    1985-01-01

    In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. We determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentially exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individual more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. We computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. 14 refs., 8 tabs

  5. Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure

    International Nuclear Information System (INIS)

    Lessard, E.T.; Brill, A.B.; Adams, W.H.

    1986-01-01

    In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. The authors determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentally exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individuals more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the above literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. The authors computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. The small number of cancers in the exposed population and the influence of increased levels of TSH, nonuniform irradiation of the thyroid, and thyroid cell killing at high dose make it difficult to draw firm conclusions from these studies. 14 references, 8 tables

  6. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    International Nuclear Information System (INIS)

    Breitenfeldt, Martin

    2009-01-01

    ISOLDE side, e.g., by improving the selectivity of the transfer line or on the ISOLTRAP setup by implementing an electrostatic ion beam trap for a fast and efficient isobaric selection. Nevertheless the obtained results contribute to the knowledge of nuclear structure. The trends in the two-neutron separation-energy S2n and the interaction between the last neutrons and last protons δV pn were corrected to more smooth evolutions, as already seen in other regions of the nuclear chart. The strongest corrections have been observed for even-N nuclides, were more new experimental data are available. Thus, new measurements on odd-N nuclides are suggested. This also is underlined by the trends observed in the Garvey-Kelson relations for the neutron-rich Cd nuclides. Furthermore, it has been shown, that the prominent structure of the δV pn for an entire chain of nuclides including inflexion points can be reproduced by using simple relations between quantum numbers of the occupied orbits. This approach connects ten values for each nuclide with only one adjusted parameter. This has been investigated for 63 δV pn values of even-even nuclides in the vicinity of Z = 50 and 50 ≤ N ≤ 82. The simple model works remarkably well for the elements Cd, Sn, and Te. Small deviation have been observed for the Xe and Pd nuclides which were explained with the limitations of the model to the vicinity of the close shells, where the nuclides have only few valence protons and neutrons. Thus, it would be interesting to study the overlap model in the vicinity of the doubly magic nuclide 208 Pb and also for more neutron-rich nuclides in the region of 132 Sn. (orig.)

  7. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Breitenfeldt, Martin

    2009-07-03

    , the r process has not yet been reached. Further technical development on suppression of contaminants are required. This includes improvements on the ISOLDE side, e.g., by improving the selectivity of the transfer line or on the ISOLTRAP setup by implementing an electrostatic ion beam trap for a fast and efficient isobaric selection. Nevertheless the obtained results contribute to the knowledge of nuclear structure. The trends in the two-neutron separation-energy S2n and the interaction between the last neutrons and last protons {delta}V{sub pn} were corrected to more smooth evolutions, as already seen in other regions of the nuclear chart. The strongest corrections have been observed for even-N nuclides, were more new experimental data are available. Thus, new measurements on odd-N nuclides are suggested. This also is underlined by the trends observed in the Garvey-Kelson relations for the neutron-rich Cd nuclides. Furthermore, it has been shown, that the prominent structure of the {delta}V{sub pn} for an entire chain of nuclides including inflexion points can be reproduced by using simple relations between quantum numbers of the occupied orbits. This approach connects ten values for each nuclide with only one adjusted parameter. This has been investigated for 63 {delta}V{sub pn} values of even-even nuclides in the vicinity of Z = 50 and 50 {<=} N {<=} 82. The simple model works remarkably well for the elements Cd, Sn, and Te. Small deviation have been observed for the Xe and Pd nuclides which were explained with the limitations of the model to the vicinity of the close shells, where the nuclides have only few valence protons and neutrons. Thus, it would be interesting to study the overlap model in the vicinity of the doubly magic nuclide {sup 208}Pb and also for more neutron-rich nuclides in the region of {sup 132}Sn. (orig.)

  8. Radiotracer investigation in gold leaching tanks

    Energy Technology Data Exchange (ETDEWEB)

    Dagadu, C.P.K., E-mail: dagadukofi@yahoo.co.uk [Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Akaho, E.H.K.; Danso, K.A. [Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Stegowski, Z.; Furman, L. [Faculty of Physics and Applied Computer Science, AGH-UST, 30-059 Krakow (Poland)

    2012-01-15

    Measurement and analysis of residence time distribution (RTD) is a classical method to investigate performance of chemical reactors. In the present investigation, the radioactive tracer technique was used to measure the RTD of aqueous phase in a series of gold leaching tanks at the Damang gold processing plant in Ghana. The objective of the investigation was to measure the effective volume of each tank and validate the design data after recent process intensification or revamping of the plant. I-131 was used as a radioactive tracer and was instantaneously injected into the feed stream of the first tank and monitored at the outlet of different tanks. Both sampling and online measurement methods were used to monitor the tracer concentration. The results of measurements indicated that both the methods provided identical RTD curves. The mean residence time (MRT) and effective volume of each tank was estimated. The tanks-in-series model with exchange between active and stagnant volume was used and found suitable to describe the flow structure of aqueous phase in the tanks. The estimated effective volume of the tanks and high degree of mixing in tanks could validate the design data and confirmed the expectation of the plant engineer after intensification of the process. - Highlights: Black-Right-Pointing-Pointer I-131 radioactive tracer is suitable for tracing the aqueous phase in gold ore slurry. Black-Right-Pointing-Pointer Online data collection is more convenient method for tracer monitoring in industrial process systems. Black-Right-Pointing-Pointer The tanks-in-series model with exchange between active and stagnant zones is suitable to describe the flow behavior of leaching tanks. Black-Right-Pointing-Pointer The radiotracer RTD technique could be used to validate design data after process intensification in gold leaching tanks.

  9. Radiotracer investigation in gold leaching tanks

    International Nuclear Information System (INIS)

    Dagadu, C.P.K.; Akaho, E.H.K.; Danso, K.A.; Stegowski, Z.; Furman, L.

    2012-01-01

    Measurement and analysis of residence time distribution (RTD) is a classical method to investigate performance of chemical reactors. In the present investigation, the radioactive tracer technique was used to measure the RTD of aqueous phase in a series of gold leaching tanks at the Damang gold processing plant in Ghana. The objective of the investigation was to measure the effective volume of each tank and validate the design data after recent process intensification or revamping of the plant. I-131 was used as a radioactive tracer and was instantaneously injected into the feed stream of the first tank and monitored at the outlet of different tanks. Both sampling and online measurement methods were used to monitor the tracer concentration. The results of measurements indicated that both the methods provided identical RTD curves. The mean residence time (MRT) and effective volume of each tank was estimated. The tanks-in-series model with exchange between active and stagnant volume was used and found suitable to describe the flow structure of aqueous phase in the tanks. The estimated effective volume of the tanks and high degree of mixing in tanks could validate the design data and confirmed the expectation of the plant engineer after intensification of the process. - Highlights: ► I-131 radioactive tracer is suitable for tracing the aqueous phase in gold ore slurry. ► Online data collection is more convenient method for tracer monitoring in industrial process systems. ► The tanks-in-series model with exchange between active and stagnant zones is suitable to describe the flow behavior of leaching tanks. ► The radiotracer RTD technique could be used to validate design data after process intensification in gold leaching tanks.

  10. Leak Detection in Heat Exchangers and Underground Pipelines Using Radiotracers. Material for Education and On-The-Job Training for Practitioners of Radiotracer Technology

    International Nuclear Information System (INIS)

    2009-01-01

    The International Atomic Energy Agency plays a major role in facilitating the transfer of radiotracer technology to developing Member States. The use of radiotracer techniques is well established in many Member States; some hundred radiotracer and end user specialists have been trained in radiotracer techniques and their applications; nearly 50 radiotracer laboratories have been working in this field. The training of radiotracer practitioners is vital for the provision of quality services to industry. Leak detection using radiotracer techniques is probably one of the most widespread applications of radiotracers in industrial troubleshooting. Radiotracer techniques are the most competitive for online leak inspection of heat exchangers and buried pipelines. Radiotracers help in early detection of leaks in heat exchangers and underground transporting pipelines, thus saving money, reducing shutdown time, ensuring safe operation and protecting the environment from pollution. The training course series on leak detection in heat exchangers and underground pipelines using radiotracers addresses the needs of the radiotracer groups and their end users. Besides training purposes, this material will assist radiotracer groups in establishing their quality control and accreditation systems. This training course material is based on lecture notes and practical work delivered by many experts in IAEA-supported activities. In particular, the Technical Cooperation Projects implemented under the Regional Cooperative Agreement (RCA) of the IAEA Member States in the Asia and the Pacific Region have been successful in transferring and implementing radiotracer techniques for leak detection to many end users from oil and gas production, oil refineries and the petrochemical industry. The experience obtained in the RCA Region is presented in the training material illustrated with many case studies carried out in several RCA Member States. Lectures and case studies were reviewed by a number

  11. 182Hf-182W age dating of a 26Al-poor inclusion and implications for the origin of short-lived radioisotopes in the early Solar System

    DEFF Research Database (Denmark)

    Holst, Jesper Christian; Olsen, Mia Bjørg Stolberg; Paton, Chad

    2013-01-01

    provide a unique window into the earliest Solar System, including the origin of short-lived radioisotopes. However, their chronology is unknown. Using the 182Hf–182W chronometer, we show that a FUN CAI recording a condensation origin from a solar gas formed coevally with canonical CAIs, but with 26Al/27Al......Refractory inclusions [calcium–aluminum-rich inclusions, (CAIs)] represent the oldest Solar System solids and provide information regarding the formation of the Sun and its protoplanetary disk. CAIs contain evidence of now extinct short-lived radioisotopes (e.g., 26Al, 41Ca, and 182Hf) synthesized...... in one or multiple stars and added to the protosolar molecular cloud before or during its collapse. Understanding how and when short-lived radioisotopes were added to the Solar System is necessary to assess their validity as chronometers and constrain the birthplace of the Sun. Whereas most CAIs formed...

  12. Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique.

    Science.gov (United States)

    Ghiyas Ud Din; Imran Rafiq Chughtai; Hameed Inayat, Mansoor; Hussain Khan, Iqbal

    2009-01-01

    Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and (99m)Tc in the form of sodium pertechnetate eluted from a (99)Mo/(99m)Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer (99m)Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

  13. Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique

    International Nuclear Information System (INIS)

    Ghiyas Ud Din; Imran Rafiq Chughtai; Mansoor Hameed Inayat; Iqbal Hussain Khan

    2009-01-01

    Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and 99m Tc in the form of sodium pertechnetate eluted from a 99 Mo/ 99m Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer 99m Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

  14. A survey of selected neutron-activation reactions with short-lived products of importance to fusion reactor technology

    International Nuclear Information System (INIS)

    Ward, R.C.; Gomes, I.C.; Smith, D.L.

    1994-11-01

    The status of the cross sections for production of short-lived radioactivities in the intense high-energy neutron fields associated with D-T fusion reactors is investigated. The main concerns relative to these very radioactive isotopes are with radiation damage to sensitive components such as superconducting magnets, the decay-heat problem and the safety of personnel during operation of the facility. The present report surveys the status of nuclear data required to assess these problems. The study is limited to a few high-priority nuclear reactions which appear to be of critical concern in this context. Other reactions of lesser concern are listed but are not treated in the present work. Among the factors that were considered in defining the relevant reactions and setting priorities are: quantities of the elemental materials in a fusion reactor, isotopic abundances within elemental categories, the decay properties of the induced radioactive byproducts, the reaction cross sections, and the nature of the decay radiations. Attention has been focused on radioactive species with half lives in the range from about 1 second to 15 minutes. Available cross-section and reaction-product decay information from the literature has been compiled and included in the report. Uncertainties have been estimated by examining several sets of experimental as well as evaluated data. Comments on the general status of data for various high-priority reactions are offered. On the basis of this investigation, it has been found that the nuclear data are in reasonably good shape for some of the most important reactions but are unacceptable for others. Based on this investigation, the reactions which should be given the greatest attention are: 16 O(n,p) 16 N, 55 Mn(n,p) 55 Cr, 57 Fe(n,p) 57 Mn, 186 W(n,2n) 185m W, and 207 Pb(n,n') 207m Pb. However, the development of fusion power would benefit from an across-the-board refinement in these nuclear data so that a more accurate quantitative

  15. Use of Radiotracers to Study Surface Water Processes

    International Nuclear Information System (INIS)

    2015-03-01

    This publication represents a sound knowledge base for the conduct of radiotracer studies in the environment, with papers on radiotracer methodology, radiation protection and regulation, data analysis and modelling. Environmental case histories from five Member States - Australia, Brazil, France, the Republic of Korea and Sweden - provide information on conducting studies involving he use of radioactive tracers. These case histories are not meant as guidelines for preparing a field study but can rather serve as examples of the type, caution and extent of work involved in environmental studies using radiotracers. This publication can provide guidance for conducting potential future training events in the use of radioactive traces in the environment and can serve as a key reference to all concerned directly with surface water processes

  16. Harvard--MIT research program in short-lived radiopharmaceuticals. Progress report, September 1, 1977--April 30, 1978. [/sup 99m/Tc, positron-emitting radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Adelstein, S.J.; Brownell, G.L.

    1978-05-01

    Progress is reported on the following studies: chemistry studies designed to achieve a more complete understanding of the fundamental chemistry of technetium in order to facilitate the design of future radiopharmaceuticals incorporating the radionuclide /sup 99m/Tc; the development of new radiopharmaceuticals intended to improve image quality and lower radiation doses by the use of short-lived radionuclides and disease-specific agents; the development of short-lived positron-emitting radionuclides which offer advantages in transverse section imaging of regional physiological processes; and studies of the toxic effects of particulate radiation.

  17. Radiotracer techniques for measuring fluid flow and calibrating flow meters

    International Nuclear Information System (INIS)

    Cooper, E.L.

    1987-08-01

    Radiotracer techniques can be used to measure accurately both gas and liquid flow rates under operating conditions in a wide range of flow systems. They are ideally suited for calibrating flow meters as well as for measuring unmetered flows in industrial plants. Applications of these techniques range from measuring the flows of fuels and process fluids for energy and mass balance studies to measuring the flows of liquid and airborne effluents for pollution control. This report describes the various radiotracer techniques which can be used to measure fluid flows. The range of application and inherent accuracy of each technique is discussed

  18. CFD simulation of homogenisation time measured by radiotracers

    International Nuclear Information System (INIS)

    Thyn, J.; Novy, M.; Zitny, R.; Mostik, M.; Jahoda, M.

    2004-01-01

    A methodology for CFD (Computational Fluid Dynamics) simulation of radiotracer experiments was suggested. The most important parts of the methodology for validation of CFD results by radiotracers are: a) successful simulation of tracer experiment by CFD code (numerical solution of tracer dispersion in a stirred tank), which results in tracer concentration field at several time intervals; b) post-process data treatment, which uses detection chain description and which enables to simulate the detector measurement of homogenisation time from the tracer concentration field evaluated by CFD code. (author)

  19. Radiotracer technique for leakage detection under simulated conditions

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Sharma, V.K.; Tapase, A.S.

    2001-01-01

    Radiotracer techniques are often used to locate leaks in underground pipelines. An attempt was made to standardize radiotracer pulse migration in terms of minimum detectable limit. For this purpose a 6 inch diameter 1200 long steel pipe was used. Two leak rates viz. 10 litres per minute and 1 litre per minute with an accuracy of ± 10% were simulated. The experiments on this pipeline showed that this method could be used to locate a leak of the order of 1 litre per minute in a 6 inch diameter isolated underground pipeline. (author)

  20. PET imaging of HSV1-tk mutants with acquired specificity toward pyrimidine- and acycloguanosine-based radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Likar, Yury; Dobrenkov, Konstantin; Olszewska, Malgorzata; Shenker, Larissa; Hricak, Hedvig; Ponomarev, Vladimir [Memorial Sloan-Kettering Cancer Center, Molecular Imaging Laboratory, Department of Radiology, New York, NY (United States); Cai, Shangde [Memorial Sloan-Kettering Cancer Center, Radiochemistry/Cyclotron Core Facility, New York, NY (United States)

    2009-08-15

    The aim of this study was to create an alternative mutant of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene with reduced phosphorylation capacity for acycloguanosine derivatives, but not pyrimidine-based compounds that will allow for successful PET imaging. A new mutant of HSV1-tk reporter gene, suitable for PET imaging using pyrimidine-based radiotracers, was developed. The HSV1-tk mutant contains an arginine-to-glutamine substitution at position 176 (HSV1-R176Qtk) of the nucleoside binding region of the enzyme. The mutant-gene product showed favorable enzymatic characteristics toward pyrimidine-based nucleosides, while exhibiting reduced activity with acycloguanosine derivatives. In order to enhance HSV1-R176Qtk reporter activity with pyrimidine-based radiotracers, we introduced the R176Q substitution into the more active HSV1-sr39tk mutant. U87 human glioma cells transduced with the HSV1-R176Qsr39tk double mutant reporter gene showed high {sup 3}H-FEAU pyrimidine nucleoside and low {sup 3}H-penciclovir acycloguanosine analog uptake in vitro. PET imaging also demonstrated high {sup 18}F-FEAU and low {sup 18}F-FHBG accumulation in HSV1-R176Qsr39tk+ xenografts. The feasibility of imaging two independent nucleoside-specific HSV1-tk mutants in the same animal with PET was demonstrated. Two opposite xenografts expressing the HSV1-R176Qsr39tk reporter gene and the previously described acycloguanosine-specific mutant of HSV1-tk, HSV1-A167Ysr39tk reporter gene, were imaged using a short-lived pyrimidine-based {sup 18}F-FEAU and an acycloguanosine-based {sup 18}F-FHBG radiotracer, respectively, administered on 2 consecutive days. We conclude that in combination with acycloguanosine-specific HSV1-A167Ysr39tk reporter gene, a HSV1-tk mutant containing the R176Q substitution could be used for PET imaging of two different cell populations or concurrent molecular biological processes in the same living subject. (orig.)

  1. The investigation of properties of short-lived SF isotopes (Z > 100 at the focal plane of VASSILISSA separator

    Directory of Open Access Journals (Sweden)

    Svirikhin Alexandr

    2013-12-01

    Full Text Available For experiments aimed at the study of spontaneous fission of transfermium nuclei improvements in the focal plane detector system of recoil separator VASSILISSA have been made. A neutron detector consisting of 54 3He-filled counters has been mounted around the focal-plane detector chamber. The reaction 48Ca + 206Pb = 2n + 252No is used for tuning the separator settings and calibrating the detector system with the spontaneous fission of the 252No. The average neutron number per 252No spontaneous fission event is as large as ν̅ = 4.06 ± 0.12. The short-lived heavy isotopes 244,246Fm, produced in the complete fusion reactions 40Ar + 206,208Pb, are investigated. The average number of neutrons per spontaneous fission of 244,246Fm from the experimental data were (ν̅ = 3.3 ± 0.3 and (ν̅ = 3.55 ± 0.50, respectively. Both values are determined for the first time.

  2. Neutron-captures in Low Mass Stars and the Early Solar System Record of Short-lived Radioactivities

    Science.gov (United States)

    Busso, Maurizio; Vescovi, Diego; Trippella, Oscar; Palmerini, Sara; Cristallo, Sergio; Piersanti, Luciano

    2018-01-01

    Noticeable improvements were recently introduced in the modelling of n-capture nucleosynthesis in the advanced evolutionary stages of giant stars (Asymptotic Giant Branch, or AGB, stars). Two such improvements are closely linked together and concern the introduction of non-parameterized, physical models for extended mixing processes and the adoption of accurate reaction rates for H- and He-burning reactions, including the one for the main neutron source 13C(α,n)16O. These improvements profited of a longstanding collaboration between stellar physicists and C. Spitaleri's team and of his seminal work both as a leader in the Nuclear Astrophysics scenario and as a talent-scout in the recruitment of young researchers in the field. We present an example of the innovative results that can be obtained thanks to the novelties introduced, by estimating the contributions from a nearby AGB star to the synthesis of short-lived (t1/2 ≤ 10 Myr) radioactive nuclei which were alive in early Solar System condensates. We find that the scenario indicating an AGB star as the source of such radioactivities, discussed for many years by researchers in this field, appears now to be no longer viable, when the mentioned improvements of AGB models and nuclear parameters are considered.

  3. Transport and deposition of nano-particles. Application to the free action of short-lived radon daughters

    International Nuclear Information System (INIS)

    Malet, J.

    1997-01-01

    Short-lived radon daughters ( 218 Po, 214 Pb, 214 Bi, and 214 Po) are important contributors to the natural average annual individual dose. The models describing the evolution of these aerosol in a house depend critically on a parameter, the 218 Po deposition velocity, which, although aerosol deposition has been extensively studied, is poorly known. A numerical and experimental study is thus carried out for a simple case: deposition in a cylindrical tube under laminar flow condition. The numerical results help understanding the difference between the transport and deposition of these radionuclides and those of non radioactive aerosols. Comparison of these well environment does not give satisfactory correlation, requiring the study of phenomena that may affect deposition. The first of these is the possible variation in the e 218 Po diffusion coefficient. Furthermore, experiments coupled with numerical calculations show that this variation could be due to 218 Po neutralization. The second phenomenon concerns the effect of the surface type, which is also shown experimentally. By modelling the neutralization and using results with a piratically smooth surface, good numerical/experimental correlations are obtained. Understanding this simple case than makes possible studying a more complex case: deposition in controlled turbulent flow. Two theories are thus experimentally validated. In addition, a 218 Po deposition velocity representative of our experimental conditions is determined. Finally, we report a feasibility study of radon daughters transport and deposition in a ventilated chamber taking into account all the involved phenomena. (author)

  4. Impact of short-lived non-CO2 mitigation on carbon budgets for stabilizing global warming

    International Nuclear Information System (INIS)

    Rogelj, Joeri; Riahi, Keywan; Meinshausen, Malte; Schaeffer, Michiel; Knutti, Reto

    2015-01-01

    Limiting global warming to any level requires limiting the total amount of CO 2 emissions, or staying within a CO 2 budget. Here we assess how emissions from short-lived non-CO 2 species like methane, hydrofluorocarbons (HFCs), black-carbon, and sulphates influence these CO 2 budgets. Our default case, which assumes mitigation in all sectors and of all gases, results in a CO 2 budget between 2011–2100 of 340 PgC for a >66% chance of staying below 2°C, consistent with the assessment of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Extreme variations of air-pollutant emissions from black-carbon and sulphates influence this budget by about ±5%. In the hypothetical case of no methane or HFCs mitigation—which is unlikely when CO 2 is stringently reduced—the budgets would be much smaller (40% or up to 60%, respectively). However, assuming very stringent CH 4 mitigation as a sensitivity case, CO 2 budgets could be 25% higher. A limit on cumulative CO 2 emissions remains critical for temperature targets. Even a 25% higher CO 2 budget still means peaking global emissions in the next two decades, and achieving net zero CO 2 emissions during the third quarter of the 21st century. The leverage we have to affect the CO 2 budget by targeting non-CO 2 diminishes strongly along with CO 2 mitigation, because these are partly linked through economic and technological factors. (letter)

  5. Proceedings of the specialists' meeting on 'nuclear spectroscopy and condensed matter physics using short-lived nuclei'

    International Nuclear Information System (INIS)

    Kobayashi, Yoshio; Shibata, Michihiro; Ohkubo, Yoshitaka

    2016-02-01

    The research reactor at Research Reactor Institute, Kyoto University is a very useful neutron generator, providing us neutron-rich unstable nuclei by bombarding nuclei with those neutrons. The produced unstable nuclei exhibit aspects distinct from those of stable ones. Nuclear structure studies on a variety of excited states reflecting dynamic nuclear properties are one of fascinating research subjects of physics. On the other hand, some radioactive nuclei can be used as useful probes for understanding interesting properties of condensed matters through studies of hyperfine interactions of static nuclear electromagnetic moments with extranuclear fields. Concerning these two research fields and related areas, the 2nd symposium under the title of 'Nuclear Spectroscopy and Condensed Matter Physics Using Short-lived Nuclei' was held at the Institute for two days on November 4 and 5 in 2015. We are pleased that many hot discussions were made. The talks were given on the followings: 1) Nuclear spectroscopic experiments, 2) TDPAC (time-differential perturbed angular correlation), 3) β-NMR (nuclear magnetic resonance), 4) Moessbauer spectroscopy, 5) muon, etc. This issue is the collection of 17 papers presented at the entitled meeting. The 6 of the presented papers are indexed individually. (J.P.N.)

  6. Measurement method of activation cross-sections of reactions producing short-lived nuclei with 14 MeV neutrons

    CERN Document Server

    Kawade, K; Kasugai, Y; Shibata, M; Iida, T; Takahashi, A; Fukahori, T

    2003-01-01

    We describe a method for obtaining reliable activation cross-sections in the neutron energy range between 13.4 and 14.9 MeV for the reactions producing short-lived nuclei with half-lives between 0.5 and 30 min. We noted neutron irradiation fields and measured induced activities, including (1) the contribution of scattered low-energy neutrons, (2) the fluctuation of the neutron fluence rate during the irradiation, (3) the true coincidence sum effect, (4) the random coincidence sum effect, (5) the deviation in the measuring position due to finite sample thickness, (6) the self-absorption of the gamma-ray in the sample material and (7) the interference reactions producing the same radionuclides or the ones emitting the gamma-ray with the same energy of interest. The cross-sections can be obtained within a total error of 3.6%, when good counting statistics are achieved, including an error of 3.0% for the standard cross-section of sup 2 sup 7 Al (n, alpha) sup 2 sup 4 Na. We propose here simple methods for measuri...

  7. Short-lived non-coding transcripts (SLiTs): Clues to regulatory long non-coding RNA.

    Science.gov (United States)

    Tani, Hidenori

    2017-03-22

    Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs). Although the importance of lncRNAs has been documented in previous reports, the biological and physiological functions of lncRNAs remain largely unknown. The role of lncRNAs seems an elusive problem. Here, I propose a clue to the identification of regulatory lncRNAs. The key point is RNA half-life. RNAs with a long half-life (t 1/2 > 4 h) contain a significant proportion of ncRNAs, as well as mRNAs involved in housekeeping functions, whereas RNAs with a short half-life (t 1/2 regulatory ncRNAs and regulatory mRNAs. This novel class of ncRNAs with a short half-life can be categorized as Short-Lived non-coding Transcripts (SLiTs). I consider that SLiTs are likely to be rich in functionally uncharacterized regulatory RNAs. This review describes recent progress in research into SLiTs.

  8. Investigation of short-lived neutron-rich palladium and silver isotopes after fast chemical separation from fission fragments

    International Nuclear Information System (INIS)

    Bruechle, W.

    1976-01-01

    In this paper, chemical separation processes are described permitting fast and neat isolation of short-lived palladium and silver nuclides from fusion product mixtures. The process for palladium is based on the stability of palladium diethyldithiophosphate. From fission products of the reactions 238 U(n,f) and 249 Cf(nth,f), the following palladium niclides could be studied for the first time by gamma spectroscopy: 1.66 min 113 Pd, 2.45 min 114 Pd, 29 sec sup(115a)Pd, 54 sec sup(115b)Pd, 12.5 sec 116 Pd. 113 Pd could also be indentified according to the reaction 116 Cd(n,α) 113 Pd. The separation of silver is based on the fast isotopic exchange on AgCl. With this process, the following nuclides have been separated from fission product mixtures and studied by gamma spectroscopy: 70 sec sup(113m)Ag, 5.0 sec 114 Ag, 19.2 sec sup(115m)Ag, 2.65 min sup(116g)Ag, 10.5 sec sup(116m)Ag, 1.3 min sup(117g)Ag, 6.0 sec sup(117m)Ag, 4.0 sec 118 Ag. (orig./WL) [de

  9. Hyperfine structure and isotope shift measurements of short-lived elements by laser spectroscopy, January 1-December 31, 1984

    International Nuclear Information System (INIS)

    Schuessler, H.A.

    1983-09-01

    Research progress is reported in the areas of stored ion spectroscopy, numerical studies of the trapping of pulse injected ions, beam tests at the TRISTAN mass separator, fluorescence line narrowing technique for Doppler-free observation, observation of the isotope shift on long-lived gold isotopes, and observation of Doppler-free signals in a fast Ar + beam

  10. Research and development in radiotracer methodology and technology

    Energy Technology Data Exchange (ETDEWEB)

    Thereska, J. [International Atomic Energy Agency (IAEA), Vienna (Austria)

    2001-07-01

    An IAEA Coordinated Research Project (CRP) has promoted further the radiotracer technology, in particular has validated the residence time distribution (RTD) function in investigating many chemical engineering reactors, such as grinding mill and flotation cell, incinerator, crystallizer trickle bed reactor and waste water treatment units. (authors)

  11. Research and development in radiotracer methodology and technology

    International Nuclear Information System (INIS)

    Thereska, J.

    2001-01-01

    An IAEA Coordinated Research Project (CRP) has promoted further the radiotracer technology, in particular has validated the residence time distribution (RTD) function in investigating many chemical engineering reactors, such as grinding mill and flotation cell, incinerator, crystallizer trickle bed reactor and waste water treatment units. (authors)

  12. Development and applications of radiotracers technologies and gamma scanning

    International Nuclear Information System (INIS)

    Conejo, Mario; Chaverri, Oscar; Chine, Bruno; Vargas, Celso

    2008-01-01

    The radiotracers and gamma scanning technologies are very consolidated tools for studying, analyzing and evaluating of industrial processes. The development and the results of radiotracers and gamma scanning technologies applied in laboratory and more complex systems, are reported. The radiotracers technology was used to study boron diffusion during the curing process of the wood, to evaluate a lagoon of sewage treatment with aquatic iris plants and to carry out experimental work with controlled variables in a laboratory hydraulic circuit (flow rig). The gamma scanning technique was used to analyze a pilot tower in the laboratories. The main results achieved with the experiments were the following: 1) the boron absorption as a wood curing agent depends on the section of wood exposed to the curing solution; 2) during the tests effectuated with Iodine 131, the aquatic iris plants situated in the water treatment lagoon absorb part of the radiotracer, making difficult the residence time determination; 3) the sensibility of the system Cesium 137 source and detector is sufficiently high and can detect low radioactive absorption materials, situated inside columns with steel walls. (author) [es

  13. History and present status of field application of radiotracers, (2)

    International Nuclear Information System (INIS)

    Koyama, Takeo; Shimizu, Makoto.

    1988-01-01

    In the field of agriculture, radiotracers were first used in 1957 in studies for improvement in fertilizing techniques. Techniques were established for accurate measurement of extremely low radioactivity in crops and for the separate determination of the phosphorus in crops of the fertilizer origin and soil origin. Then, RI or stable isotope tracing test methods were developed using 32 P or 15 N to determine the flow and absorption of fertilizers. Other techniques using radiotracers developed in this period served for the construction of maps of the root activity of crops, investigation of the effects of different fertilizers in farms where double-cropping was practised, identification of suitable fertilizers for orange cultivation, development of new fertilizing techniques for Japanese persimmon cultivation, etc. Practically, no field use of radiotracers has been found since 1970. At present, it is prohibited and replaced by other techniques using stable isotopes, etc. In the field fishery, radiotracers have been used for studies of various dynamic phenomena including the flow of water and deposits in the sea, behaviors of fish, food, chain, circulation of chemical substances in the ecological system, etc. (Nogami, K.)

  14. Use of radiotracers for studies of metal sorption behaviour

    International Nuclear Information System (INIS)

    McCubbin, D.; Leonard, K.S.

    1995-01-01

    Radiotracers provide a convenient tool to study the behaviour of metal ions and other contaminants in natural waters. Furthermore, the use of radiotracers in controlled laboratory experiments provides an ideal approach for investigating, in a systematic manner, the role of individual parameters on processes, at mass concentrations found in the environment. A simplistic procedure has been developed to produce a thorium radiotracer ( 234 Th), in a similar chemical form (non-acidic) to that of the aquatic medium under investigation, to determine the kinetics of sorption to marine particulate material. The benefit of this procedure is that the system is likely to be perturbed to a lesser extent by changes in pH and dissolved Th species following tracer addition. Results from filtering different tracer batches through membranes, to determine the sorption characteristics prior to use, indicate that the physico-chemical behaviour of individual batches was extremely variable. Not surprisingly, the amount of uptake immediately following tracer additions to solutions containing marine particulate material was also variable. It is suggested that the role of tracer may be underestimated if added in acid form. Nevertheless, having accounted for the initial sorption, the subsequent uptake between different batches was reasonably reproducible. The usefulness of radiotracers is discussed in the context of these observations

  15. The effects of short-lived radionuclides and porosity on the early thermo-mechanical evolution of planetesimals

    Science.gov (United States)

    Lichtenberg, Tim; Golabek, Gregor J.; Gerya, Taras V.; Meyer, Michael R.

    2016-08-01

    The thermal history and internal structure of chondritic planetesimals, assembled before the giant impact phase of chaotic growth, potentially yield important implications for the final composition and evolution of terrestrial planets. These parameters critically depend on the internal balance of heating versus cooling, which is mostly determined by the presence of short-lived radionuclides (SLRs), such as 26Al and 60Fe, as well as the heat conductivity of the material. The heating by SLRs depends on their initial abundances, the formation time of the planetesimal and its size. It has been argued that the cooling history is determined by the porosity of the granular material, which undergoes dramatic changes via compaction processes and tends to decrease with time. In this study we assess the influence of these parameters on the thermo-mechanical evolution of young planetesimals with both 2D and 3D simulations. Using the code family I2ELVIS/I3ELVIS we have run numerous 2D and 3D numerical finite-difference fluid dynamic models with varying planetesimal radius, formation time and initial porosity. Our results indicate that powdery materials lowered the threshold for melting and convection in planetesimals, depending on the amount of SLRs present. A subset of planetesimals retained a powdery surface layer which lowered the thermal conductivity and hindered cooling. The effect of initial porosity was small, however, compared to those of planetesimal size and formation time, which dominated the thermo-mechanical evolution and were the primary factors for the onset of melting and differentiation. We comment on the implications of this work concerning the structure and evolution of these planetesimals, as well as their behavior as possible building blocks of terrestrial planets.

  16. Inactivation of Candida glabrata by a humid DC argon discharge afterglow: dominant contributions of short-lived aqueous active species

    International Nuclear Information System (INIS)

    Xiong, Qing; Liu, Hongbin; Xu, Le; Wang, Xia; Zhu, Qunlin; Lu, Weiping; Chen, Qiang; Zeng, Xue; Yi, Ping

    2017-01-01

    Plasma medicine applications are currently attracting significant interest all over the world. Bactericidal treatments of Candida glabrata cultured in saline suspension are performed in this study by a room-temperature reactive afterglow of a DC-driven argon discharge. Water vapor was added to the discharge to study the inactivation contributions of reactive hydrolytic species including OH and H 2 O 2 transporting along the gas flow to the treated solutions. The inactivation results indicate that the dominant roles in the bactericidal treatments are played by the short-lived aqueous active species, but not the stable species like H 2 O 2aq (aq indicates an aqueous species). Further analysis shows that the ·OH aq radicals play an important role in the inactivation process. The ·OH aq radicals in the suspension are mostly produced from the direct dissolution of the OH species in the reactive afterglow. With the increase of added water vapor content, the ·OH aq production increases and enhances the inactivation efficiency of C. glabrata . Furthermore, it is found that the ambient air diffusion shows essential effects on the bactericidal activity of the remote humid argon discharge. Higher bactericidal effects can be obtained in open-space treatments compared to in a controlled Ar + H 2 O gas atmosphere. Key active air-byproduct species are believed to be generated in the suspension during the treatments and contributing to the inactivation process. Based on chemical analysis, the peroxynitrous acid ONOOH aq is considered as the key antimicrobial air-byproduct species. These results indicate the important dependence of plasma biomedical effects on the processing environment, which finally relates to the critical contributions of the key reactive species formed therein. (paper)

  17. Study on the risk of late damage in humans after incorporation of the short-lived alpha emitter Ra-224

    International Nuclear Information System (INIS)

    Wick, R.R.; Nekolla, E.A.; Kellerer, A.M.; Goessner, W.

    2003-01-01

    An epidemiological study has been carried out at the GSF - National Research Center for Environment and Health - between 1948 and 1975, on 1460 ankylosing spondylitis (AS) patients. The aim of the study was to ascertain the late health effects suffered by these patients who had received repeated intravenous injections of the short lived α-emitter 224 Ra. These patients have been followed together with a control group of 1323 ankylosing spondylitis patients not treated with radioactive drugs and/or X-rays. Causes of death have been ascertained for 842 exposed patients and 861 controls by the end of 2002. In the exposed group there has been a total of 219 malignant diseases and 206 cases among the controls. In particular, we observed 15 cases of leukaemia in the exposure group and 8 cases of leukaemia in the control group. Further subclassification of the leukaemias demonstrated a high increase of myeloid leukaemia in the exposure group (9 cases obs. vs. 2.5 cases exp.), and out of these especially the acute myeloid leukaemias (6 cases observed vs. 1.6 expected), whereas in the control group the observed cases are within the expected range (3 myeloid leukaemias vs. 2.6 cases). Out of these 6 cases of myeloid leukaemia, 3 cases have been observed at doses comparable to those of the currently applied 224 Ra treatment with the preparation SpondylAT registered , in one case the 224 Ra-dose was the 0.6fold, in another case 1.6fold, whereas in one case the total dose could not be verified exactly. The enhanced leukaemia incidence in our exposed group is in line with results from animal experiments in mice having been injected with bone seeking α-emitters given at low dose rates. (orig.) [de

  18. Inactivation of Candida glabrata by a humid DC argon discharge afterglow: dominant contributions of short-lived aqueous active species

    Science.gov (United States)

    Xiong, Qing; Liu, Hongbin; Lu, Weiping; Chen, Qiang; Xu, Le; Wang, Xia; Zhu, Qunlin; Zeng, Xue; Yi, Ping

    2017-05-01

    Plasma medicine applications are currently attracting significant interest all over the world. Bactericidal treatments of Candida glabrata cultured in saline suspension are performed in this study by a room-temperature reactive afterglow of a DC-driven argon discharge. Water vapor was added to the discharge to study the inactivation contributions of reactive hydrolytic species including OH and H2O2 transporting along the gas flow to the treated solutions. The inactivation results indicate that the dominant roles in the bactericidal treatments are played by the short-lived aqueous active species, but not the stable species like H2O2aq (aq indicates an aqueous species). Further analysis shows that the ·OHaq radicals play an important role in the inactivation process. The ·OHaq radicals in the suspension are mostly produced from the direct dissolution of the OH species in the reactive afterglow. With the increase of added water vapor content, the ·OHaq production increases and enhances the inactivation efficiency of C. glabrata. Furthermore, it is found that the ambient air diffusion shows essential effects on the bactericidal activity of the remote humid argon discharge. Higher bactericidal effects can be obtained in open-space treatments compared to in a controlled Ar + H2O gas atmosphere. Key active air-byproduct species are believed to be generated in the suspension during the treatments and contributing to the inactivation process. Based on chemical analysis, the peroxynitrous acid ONOOHaq is considered as the key antimicrobial air-byproduct species. These results indicate the important dependence of plasma biomedical effects on the processing environment, which finally relates to the critical contributions of the key reactive species formed therein.

  19. The partnership experience on the disposal of low- and intermediate-level short-lived waste in Belgium

    International Nuclear Information System (INIS)

    Preter, P. de; Cool, W.; Hooft, E.; Waffelaert, A.; Blommaert, J.; Draulans, J.

    2008-01-01

    With the governmental decision of January 16, 1998, the long-term storage option for the low- and intermediate-level short-lived waste (category A waste) was abandoned and ONDRAF/NIRAS was given the mission to further examine the options of deep and surface disposal, in order to prepare a federal decision on the technical option to be developed. ONDRAF/NIRAS was also asked to develop the methods and structures of interaction with the local stakeholders, and to limit its siting activities to nuclear and candidate municipalities. This brought ONDRAF/NIRAS to the concept of local partnerships with interested municipalities, and during the pre-project phase 1998-2006 partnerships were created with the municipalities of Dessel (STOLA-Dessel, 1999), Mol (MONA, 2000) and Fleurus-Farciennes (PaLoFF, 2003). On 23 June, 2006 the Belgian Government decided that category A waste will be disposed of in a near-surface repository on the territory of the Dessel municipality. This decision implies that ONDRAF/NIRAS, in further interaction with the local stakeholders, can start the preparation of a licence application. This decision was the endpoint of the pre-project phase (1998-2006) and was based on the final reports of the partnerships of Dessel (STOLA-Dessel, now STORA) and Mol (MONA), approved by their municipality councils, and on ONDRAF/NIRAS final report, confirming the feasibility of the proposed disposal systems. As the municipality council of Fleurus did not approve the final report of the partnership PaLoFF, ONDRAF/NIRAS did not submit this report to the responsible minister. The preceding positive local decision in both Dessel (May 2005) and Mol (July 2005), and both on the partnership and municipality council level, to accept, under certain conditions, a disposal facility on their territory was the result of a 6 years long process of discussions within the partnership of all aspects of the disposal system and its integration in the municipality. During these

  20. Nuclear physics with use of KUR. Reviews of 30 years studies on short-lived nuclei and perspectives for the future

    International Nuclear Information System (INIS)

    Kawase, Yoichi

    1995-01-01

    The research works which were carried out over the past 30 years on nuclear structure study have been reviewed with emphasis on the technical developments of experimental apparatus for the studies of very short-lived isotopes produced by the Kyoto University reactor(KUR). In the first chapter, nuclear structure studies of neutron-rich nuclei with use of the on-line irradiation apparatus and the on-line isotope separator(ISOL) for fission products have been described. In the second chapter, applications of nuclear methods to solid state physics by the perturbed angular correlation(PAC) technique have been examined to investigate the local electromagnetic fields in metals and compounds through the hyperfine interactions. Perspectives for the future of related research fields are given aiming at the advanced uses of short-lived radioisotopes. (author)

  1. Contribution of the short lived radionuclides in food to the total radiation burden of man after the nuclear accident in Chernobyl

    International Nuclear Information System (INIS)

    Popovic, D.; Djuric, G.; Smelcerovic, M.; Maksimovic, B.

    1989-01-01

    The paper presents the results of the short lived radionuclides (I-131, Te(I)-132, Cs-136, Ce-141,144, Ru-103,106, Ba(La)-140, Zr-95, Mo-99, Nb-95, Sb-125) mass activities estimation in some foodstuff (milk and milk products), immediately after the nuclear accident in Chernobyl, in May 1986. The activities of the radionuclides were determined on Ge(Li) detector by standard gamma spectrometry, with the total error less than 20%. The results enabled the evaluation of the short lived radionuclides contribution in the total dose due to ingestion of milk and milk products, in the first month after the accident, compared to the contribution of I-131 and to the contribution of the main long lived radionuclides: Ce-134 and Cs-137 (author)

  2. Radiotracer experiments and CFD simulation for industrial hydrocyclone performance

    International Nuclear Information System (INIS)

    Stegowski, Z.; Nowak, E.

    2007-01-01

    Hydrocyclone is a device for solid concentration or selection of solid particles from a liquid-solid mixture. It is widely used in the mineral industry for selection of solid particles from a few to a few hundred micrometers. This paper presents a radiotracer experiment and computational simulation of selection of solid particles in a hydrocyclone of Φ-500 μm, which is used in the industrial copper ore concentration process. The simulation, based on computational fluid dynamics (CFD) techniques, allowed obtaining the velocity and concentration distribution for a real mixture flowing in the hydrocyclone. The mixture was composed of water and nine solid phases of different grain sizes. Finally, the selection curve of solid grains was obtained and compared with the experimental radiotracer results. (author)

  3. Hydrodynamic characteristics of high speed settling clarifiers by radiotracer method

    International Nuclear Information System (INIS)

    Griffith Martinez, J.; Flores Juan, P.; Cuesta Borges, J.; Damera Martinez, A.; Ramos Espinosa, K. A

    2005-01-01

    Results achieved in the evaluation of two high-speed settling cane juice Clarifiers, one denominated ICINAZ The Express and the other one with Low Residence Time (BTR), both located at the sugar factory Orlando Gonzalez employing the well established radiotracer method (Tc-99m) are presented. Several trials performed at the two Clarifiers demonstrated that the one identified as BTR was capable to assimilate the whole flow capacity of the factory with adequate characteristic of the pattern flux and residence time in the environment of 1 hour. In the other side, ICINAZ The Express Clarifier could only work at relative low flow capacity of the factory with residence time closely to the two hours and achieving occasionally a pattern flux seriously affected by fluctuations in the milling process. The radiotracer method was able to detect certain differences between the two clear juice outlet of the BTR Clarifier, probably due some problems in the construction of this equipment

  4. Diagnosing plant pipeline system performance using radiotracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kasban, H.; Ali, Elsayed H.; Arafa, H. [Engineering Department, Nuclear Research Center, Atomic Energy Authority, Inshas (Egypt)

    2017-02-15

    This study presents an experimental work in a petrochemical company for scanning a buried pipeline using Tc{sup 99m} radiotracer based on the measured velocity changes, in order to determine the flow reduction along a pipeline. In this work, Tc{sup 99m} radiotracer was injected into the pipeline and monitored by sodium iodide scintillation detectors located at several positions along the pipeline. The flow velocity has been calculated between every two consecutive detectors along the pipeline. Practically, six experiments have been carried out using two different data acquisition systems, each of them being connected to four detectors. During the fifth experiment, a bypass was discovered between the scanned pipeline and another buried parallel pipeline connected after the injection point. The results indicate that the bypass had a bad effect on the volumetric flow rate in the scanned pipeline.

  5. Applications of radiotracer techniques for the toxicology studies of nanomaterials

    International Nuclear Information System (INIS)

    Ma Yuhui; Zhang Zhiyong; Zhang Yuan; He Xiao; Zhang Haifeng; Chai Zhifang

    2008-01-01

    With the rapid development of nanosciences and nanotechnology, a wide variety of manufactured nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. While nanomaterials possess more novel and unique physicochemical properties than bulk materials, they also have an unpredictable impact on human health. In the toxicology studies of nanomaterials, it is essential to know the basic behaviors in vivo, that is absorption, distribution, metabolism, and excretion (ADME) of these newly designed materials. Radiotracer techniques are especially well suited to such studies and has got the chance to demonstrate its enchantment. In this presentation, studies on radiotracer techniques used in nanotoxicology will be reviewed and new progresses at Institute of High Energy Physics, including the label methods and behaviors of labeled nanomaterials, such as fullerene, carbon nanotubes, and nanometer metal oxide in animals and in aquatic environments will be reported. (authors)

  6. Overview of past activities for the use of short-lived radionuclides and the role of the Bureau of Radiological Health

    International Nuclear Information System (INIS)

    Paras, P.

    1985-01-01

    The Bureau of Radiological Health has developed a national program to control unnecessary medical radiation exposures to man and to assure the safe and effective use of radiation. The continuing interest and the role of the Bureau in the use of short-lived radionuclides (SLR's) are emphasized. An overview of the Bureau's SLR program, past accomplishments, and the status of production and use of iodine-123 are presented

  7. Application of analogue computers to radiotracer data processing

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    1979-01-01

    Some applications of analogue computers for processing the flow-system radiotracer-investigation data are presented. Analysis of the impulse response shaped to obtain the frequency response of the system under consideration can be performed on the basis of an estimated transfer function. Furthermore, simulation of the system behaviour for other excitation functions is discussed. Simple approach is made for estimating the model parameters in situations where the input signal is not approximated by the unit impulse function. (author)

  8. Radiotracer technique to predict irritation potential of soap

    International Nuclear Information System (INIS)

    Castaneda, S.S.; Garcia, T.Y.; Santos, F.L.

    1990-01-01

    The application of a radiotracer technique using tritiated water to predict the irritation potentials of some soap products is demonstrated. Collagen films are treated with 0.5% and 1.0% soap solutions and tritiated water then incubated at 50 degrees centigrade for 24 hours. After incubation, the uptake of tritiated water by the collagen films was measured by liquid scintillation counting. (Auth.). 6 refs., 2 tabs

  9. Application of radiotracer technology to the study of coastal processes

    International Nuclear Information System (INIS)

    Airey, P.; Szymczak, R.; Zaw, M.; Tu, J.; Kluss, T.; Barry, J.

    1999-01-01

    Recent progress at ANSTO in the applications of radiotracer techniques to the study of coastal processes is reviewed. Tracers are used in detailed studies of specific components of complex environmental systems and are applied to the evaluation and extension of numerical models. Examples include studies of the aggregation of sewage particles following release from ocean outfalls. The use of tracers to study the impact of storm events on bedload transport at depth has also been demonstrated

  10. Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells

    Science.gov (United States)

    Sugiharto, Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul; Santoso, Sigit Budi; Abidin, Zainal; Santoso, Gatot Budi

    2010-06-01

    Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing 203 Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of ±2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.

  11. Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells

    International Nuclear Information System (INIS)

    Sugiharto; Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul; Santoso, Sigit Budi; Abidin, Zainal; Santoso, Gatot Budi

    2010-01-01

    Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing 203 Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of ±2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.

  12. Radiotracers for SPECT imaging. Current scenario and future prospects

    International Nuclear Information System (INIS)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S.

    2012-01-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [ 123 I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [ 123 I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also makes them more

  13. Radiotracers for SPECT imaging. Current scenario and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S. [GE Healthcare Medical Diagnostics, John F. Welch Technology Center, Bangalore (India).; Bhalla, R.; Pickett, R.; Luthra, S.K. [GE Healthcare Medical Diagnostics, The Grove Centre, Amersham (United Kingdom)

    2012-07-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [{sup 123}I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [{sup 123}I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also

  14. Radionuclides, radiotracers and radiopharmaceuticals for in vivo diagnosis

    International Nuclear Information System (INIS)

    Wiebe, L.I.

    1984-01-01

    Radioactive tracers for in vivo clinical diagnosis fall within a narrow, strictly-defined set of specifications in respect of their physical properties, chemical and biochemical characteristics, and medical applications. The type of radioactive decay and physical half-life of the radionuclide are immutable properties which, along with the demands of production and supply, limit the choice of radionuclides used in medicine to only a small fraction of those known to exist. In use, the biochemical and physiological properties of a radiotracer are dictated by the chemical form of the radionuclide. This chemical form may range from elemental, molecular or ionic, to complex compounds formed by coordinate or covalent bonding of the radionuclide to either simple organic or inorganic molecules, or complex macromolecules. Few of the radiotracers which are tested in model systems ever become radiopharmaceuticals in the strictest sense. Radionuclides, radiotracers and radiopharmaceuticals in use are reviewed. Drug legislation and regulations concerning drug manufacture, as well as hospital ethical constraints and legislation concerning unsealed sources of radiation must all be satisfied in order to translate a radiopharmaceutical from the laboratory to clinical use. (author)

  15. Hydrodynamic characteristics of high speed settling clarifiers by radiotracer method

    International Nuclear Information System (INIS)

    Griffith Martinez, Jose; Damera Martinez, A.; Ramos Espinosa, K.

    2003-01-01

    Results achieved in the evaluation of two high-speed settling cane juice Clarifiers, one denominated ICINAZ The Express and the other one a modified SRI, both located at the sugar factory Orlando Gonzalez employing the well established radiotracer method (Tc-99m) are presented Several trials performed simultaneously at the two Clarifiers demonstrated that the modified SRI was capable to assimilate the whole flow capacity of the factory with adequate characteristic of the pattern flux and residence time in the environment of 1 hour. In the other side, ICINAZ The Express Clarifier could only work at relative low flow capacity of the factory with residence time closely to the two hours and achieving occasionally a pattern flux seriously affected by fluctuations in the milling process. The non-availability of a flow meter did not allow to extract more information related to some pattern flux anomalies, nevertheless, the radiotracer method was able to detect certain differences between the two clear juice outlet of the modified SRI Clarifier, probably due some problems in the construction of this equipment. This fact so as other goals achieved in this work, show once more the potentiality of the radiotracer method for this type of study related to the hydrodynamic characteristics of industrial facilities. (Author)

  16. Radionuclides, radiotracers and radiopharmaceuticals for in vivo diagnosis

    Science.gov (United States)

    Wiebe, Leonard I.

    Radioactive tracers for in vivo clinical diagnosis fall within a narrow, strictly-defined set of specifications in respect of their physical properties, chemical and biochemical characteristics, and (approved) medical applications. The type of radioactive decay and physical half-life of the radionuclide are immutable properties which, along with the demands of production and supply, limit the choice of radionuclides used in medicine to only a small fraction of those known to exist. In use, the biochemical and physiological properties of a radiotracer are dictated by the chemical form of the radionuclide. This chemical form may range from elemental, molecular or ionic, to complex compounds formed by coordinate or covalent bonding of the radionuclide to either simple organic or inorganic molecules, or complex macromolecules. Few of the radiotracers which are tested in model systems ever become radiopharmaceuticals in the strictest sense. Radionuclides, radiotracers and radiopharmaceuticals in use are reviewed. Drug legislation and regulations concerning drug manufacture, as well as hospital ethical constraints and legislation concerning unsealed sources of radiation must all be satisfied in order to translate a radiopharmaceutical from the laboratory to clinical use.

  17. Drag on a Satellite Moving across a Spherical Galaxy: Tidal and Frictional Forces in Short-lived Encounters

    Science.gov (United States)

    Colpi, Monica; Pallavicini, Andrea

    1998-07-01

    The drag force on a satellite of mass M moving with speed V in the gravitational field of a spherically symmetric background of stars is computed. During the encounter, the stars are subject to a time-dependent force that alters their equilibrium. The resulting distortion in the stellar density field acts back to produce a force FΔ that decelerates the satellite. This force is computed using a perturbative technique known as linear response theory. In this paper, we extend the formalism of linear response to derive the correct expression for the back-reaction force FΔ that applies when the stellar system is described by an equilibrium one-particle distribution function. FΔ is expressed in terms of a suitable correlation function that couples the satellite dynamics to the unperturbed dynamics of the stars. At time t, the force depends upon the whole history of the composite system. In the formalism, we account for the shift of the stellar center of mass resulting from linear momentum conservation. The self-gravity of the response is neglected since it contributes to a higher order in the perturbation. Linear response theory applies also to the case of a satellite orbiting outside the spherical galaxy. The case of a satellite moving on a straight line, at high speed relative to the stellar dispersion velocity, is explored. We find that the satellite during its passage raises (1) global tides in the stellar distribution and (2) a wake, i.e., an overdense region behind its trail. If the satellite motion is external to the galaxy, it suffers a dissipative force that is not exclusively acting along V but acquires a component along R, the position vector relative to the center of the spherical galaxy. We derive the analytical expression of the force in the impulse approximation. In penetrating short-lived encounters, the satellite moves across the stellar distribution and the transient wake excited in the density field is responsible for most of the deceleration. We

  18. $^{31}$Si Self-Diffusion in Si-Ge Alloys and Si-(B-)C-N Ceramics and Diffusion Studies for Al and Si Beam Developments

    CERN Multimedia

    Nylandsted larsen, A; Voss, T L; Strohm, A

    2002-01-01

    An invaluable method for studying diffusion in solids is the radiotracer technique. However, its applicability had been restricted to radiotracer atoms with half-lives $t_{1/2}$ of about 1~d or longer. Within the framework of IS372 a facility was developed in which short-lived radiotracer atoms ( 5min $\\scriptstyle{\\lesssim}$ $t_{1/2}\\scriptstyle{\\lesssim}$1 d ) can be used. For the implantation of the short-lived tracers the facility is flanged to the ISOLDE beamline, and all post-implantation steps required in the radiotracer technique are done in situ.\\\\ After successful application of this novel technique in diffusion studies of $^{11}$C ($t_{1/2}$ = 20.3 min), this experiment aims at performing self-diffusion studies of $^{31}$Si ($t_{1/2}$ = 2.6~h) in Si--Ge alloys and in amorphous Si--(B--)C--N ceramics.\\\\ Our motivation for measuring diffusion in Si--Ge alloys is their recent technological renaissance as well as the purpose to test the prediction that in these alloys the self-diffusion mechanism chang...

  19. Laser spectroscopy of short-lived radionuclides in an ion trap: MIRACLS’ proof-of-principle experiment

    CERN Document Server

    Maier, Franziska Maria

    2017-01-01

    Since 1978 Collinear Laser Spectroscopy is done at COLLAPS [1], which is located at ISOLDE,CERN’sfacilityforsynthesizingradioactiveions,toexplorethenuclearshell structure of the most exotic atomic nuclides far away from stability. At COLLAPS a laser beam is overlapped with a radioactive ion beam. If the wavelength of the laser corresponds to the energy difference of the electronic transitions, the laser excites the ions. The excited ions decay back to the ionic ground state and emit fluorescence photons that can be detected with photomultiplier tubes (PMTs). By measuring the hyperfine structure of the involved ionic states one obtains information about the nuclear spin, the nuclear magnetic dipole moment and the nuclear electric quadrupole moment. This hyperfine splitting is caused by the interaction of the bound electrons withtheatomicnucleus. Theelectronsinduceanelectromagneticfieldattheplaceof the nucleus that interacts with the electromagnetic nuclear moments and the nuclear spin. By calculating th...

  20. Fostering the local production and application of industrial radiotracers in developing countries - IAEA's role

    International Nuclear Information System (INIS)

    Mohammad Haji-Saeid, S.; Jin, Joon-Ha; Ramamoorthy, Natesan; )

    2006-01-01

    Radiotracer techniques provide fast and accurate information for solving various process problems in industrial plants. The IAEA is playing an important role in supporting the development and transfer of radiotracer techniques to developing countries. The IAEA has implemented 5 coordinated research projects (CRP), including two on-going projects, in the field of radiotracer and sealed source applications in industry. The CRPs facilitated the acquisition and dissemination of know-how and technology for wear/corrosion measurement, residence time: distribution (RTD) study, validation of computed fluid dynamics data, industrial process tomography and inter-well connectivity study. A number of technical cooperation projects have been executed to strengthen the capability of radiotracer groups in developing Member States and to create awareness in the industries about the technical and economical benefits of radiotracer technology. The IAEA's regional projects have strongly impacted the transfer and adoption of the techniques. The status of radiotracer use in developing countries reveals that the lack of timely availability of radiotracers as one of the major problems. Development of some radionuclide generators is a possible solution. Cooperation among the international radiotracer communities is necessary to enhance the availability and use of radiotracers in developing countries. (author)

  1. Physics with radioactive nuclear beams

    International Nuclear Information System (INIS)

    Boyd, R.N.; Tanihata, I.

    1992-01-01

    Recently developed facilities allow a wide range of new investigations of the reactions and properties of short-lived nuclei. These studies may help to solve puzzles of nuclear structure and the Big Bang. The purpose of nuclear physics is to measure properties of specific nuclides and infer from them global properties common to all nuclides. One goal, for example, is to understand nuclear sizes and matter distributions in terms of basic nuclear forces. Another is to understand the variation throughout the periodic table of the dominant quantum states, which are known as the open-quotes nuclear shell modelclose quotes states and are characterized, much as are atomic states, by a principal quantum number and by orbital and total angular momentum quantum numbers. In turn other nuclear phenomena, such as the collective excitations known as giant resonances, can be understood in terms of the shell-model configurations and basic nuclear parameters. Radioactive nuclear beam studies of reactions of short-lived nuclides have already yielded results with important ramifications in both nuclear physics and astrophysics. Nuclear physicists expect unstable nuclides to exhibit unusual structures or features that may test their understanding of known nuclear phenomena at extreme conditions, and perhaps even to reveal previously unknown nuclear phenomena, Astrophysicists, for their part, have known for several decades that processes in both Big Bang nucleosynthesis and stellar nucleosynthesis involve short-lived nuclides. Indeed, the original motivation for developing radioactive nuclear beams was astrophysical. 25 refs., 7 figs

  2. Physics with radioactive nuclear beams

    International Nuclear Information System (INIS)

    Boyd, R.N.

    1995-01-01

    Recently developed facilities allow a wide range of new investigations of the reactions and properties of short-lived nuclei. These studies may help to solve puzzles of nuclear structure and the Big Bang. The purpose of nuclear physics is to measure properties of specific nuclides and infer from them global properties common to all nuclides, for example, is to understand nuclear sizes and matter distributions in terms of basic nuclear forces. Another is to understand the variation throughout the periodic table of the dominant quantum states, which are known as the open-quotes nuclear shell model close quotes states and are characterized, much as are atomic states, by a principal quantum number and by orbital and total angular momentum quantum numbers. In turn other nuclear phenomena, such as the collective excitations known as giant resonances, can be understood in terms of the shell-model configurations and basic nuclear parameters. Radioactive nuclear beam studies of reactions of short-lived nuclides have already yielded results with important ramifications in both nuclear physics and astrophysics. Nuclear physicists expect unstable nuclides to exhibit unusual structures or features that may test their understanding of known nuclear phenomena at extreme conditions, and perhaps even to reveal previously unknown nuclear phenomena, Astrophysicists, for their part, have known for several decades that processes in both Big Bang nucleosynthesis and stellar nucleosynthesis involve short-lived nuclides. Indeed, the original motivation for developing radioactive nuclear beams was astrophysical. (author). 25 refs., 7 figs

  3. Climate response to projected changes in short-lived species under an A1B scenario from 2000-2050 in the GISS climate model

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Surabi; Shindell, Drew T.; Faluvegi, Greg; Bauer, Susanne E.; Koch, Dorothy M.; Unger, Nadine; Menon, Surabi; Miller, Ron L.; Schmidt, Gavin A.; Streets, David G.

    2007-03-26

    We investigate the climate forcing from and response to projected changes in short-lived species and methane under the A1B scenario from 2000-2050 in the GISS climate model. We present a meta-analysis of new simulations of the full evolution of gas and aerosol species and other existing experiments with variations of the same model. The comparison highlights the importance of several physical processes in determining radiative forcing, especially the effect of climate change on stratosphere-troposphere exchange, heterogeneous sulfate-nitrate-dust chemistry, and changes in methane oxidation and natural emissions. However, the impact of these fairly uncertain physical effects is substantially less than the difference between alternative emission scenarios for all short-lived species. The net global mean annual average direct radiative forcing from the short-lived species is .02 W/m{sup 2} or less in our projections, as substantial positive ozone forcing is largely offset by negative aerosol direct forcing. Since aerosol reductions also lead to a reduced indirect effect, the global mean surface temperature warms by {approx}0.07 C by 2030 and {approx}0.13 C by 2050, adding 19% and 17%, respectively, to the warming induced by long-lived greenhouse gases. Regional direct forcings are large, up to 3.8 W/m{sup 2}. The ensemble-mean climate response shows little regional correlation with the spatial pattern of the forcing, however, suggesting that oceanic and atmospheric mixing generally overwhelms the effect of even large localized forcings. Exceptions are the polar regions, where ozone and aerosols may induce substantial seasonal climate changes.

  4. 182Hf-182W age dating of a 26Al-poor inclusion and implications for the origin of short-lived radioisotopes in the early Solar System.

    Science.gov (United States)

    Holst, Jesper C; Olsen, Mia B; Paton, Chad; Nagashima, Kazuhide; Schiller, Martin; Wielandt, Daniel; Larsen, Kirsten K; Connelly, James N; Jørgensen, Jes K; Krot, Alexander N; Nordlund, Ake; Bizzarro, Martin

    2013-05-28

    Refractory inclusions [calcium-aluminum-rich inclusions, (CAIs)] represent the oldest Solar System solids and provide information regarding the formation of the Sun and its protoplanetary disk. CAIs contain evidence of now extinct short-lived radioisotopes (e.g., (26)Al, (41)Ca, and (182)Hf) synthesized in one or multiple stars and added to the protosolar molecular cloud before or during its collapse. Understanding how and when short-lived radioisotopes were added to the Solar System is necessary to assess their validity as chronometers and constrain the birthplace of the Sun. Whereas most CAIs formed with the canonical abundance of (26)Al corresponding to (26)Al/(27)Al of ∼5 × 10(-5), rare CAIs with fractionation and unidentified nuclear isotope effects (FUN CAIs) record nucleosynthetic isotopic heterogeneity and (26)Al/(27)Al of Solar System, including the origin of short-lived radioisotopes. However, their chronology is unknown. Using the (182)Hf-(182)W chronometer, we show that a FUN CAI recording a condensation origin from a solar gas formed coevally with canonical CAIs, but with (26)Al/(27)Al of ∼3 × 10(-6). The decoupling between (182)Hf and (26)Al requires distinct stellar origins: steady-state galactic stellar nucleosynthesis for (182)Hf and late-stage contamination of the protosolar molecular cloud by a massive star(s) for (26)Al. Admixing of stellar-derived (26)Al to the protoplanetary disk occurred during the epoch of CAI formation and, therefore, the (26)Al-(26)Mg systematics of CAIs cannot be used to define their formation interval. In contrast, our results support (182)Hf homogeneity and chronological significance of the (182)Hf-(182)W clock.

  5. Changes in oxidative stress parameters in relation to age, growth and reproduction in the short-lived catarina scallop Argopecten ventricosus reared in its natural environment.

    Science.gov (United States)

    Guerra, C; Zenteno-Savín, T; Maeda-Martínez, A N; Philipp, E E R; Abele, D

    2012-08-01

    Increase in oxidative damage and decrease in cellular maintenance is often associated with aging, but, in marine ectotherms, both processes are also strongly influenced by somatic growth, maturation and reproduction. In this study, we used a single cohort of the short-lived catarina scallop Argopecten ventricosus, to investigate the effects of somatic growth, reproduction and aging on oxidative damage parameters (protein carbonyls, TBARS and lipofuscin) and cellular maintenance mechanisms (antioxidant activity and apoptosis) in scallops, caged in their natural environment. The concentrations of protein carbonyls and TBARS increased steeply during the early period of fast growth and during reproduction in one-year-old scallops. However, oxidative damage was transient, and apoptotic cell death played a pivotal role in eliminating damage in gill, mantle and muscle tissues of young scallops. Animals were able to reproduce again in the second year, but the reduced intensity of apoptosis impaired subsequent removal of damaged cells. In late survivors low antioxidant capacity and apoptotic activity together with a fast accumulation of the age pigment lipofuscin was observed. Rates of oxygen consumption and oxidative stress markers were strongly dependent on somatic growth and reproductive state but not on temperature. Compared to longer-lived bivalves, A. ventricosus seems more susceptible to oxidative stress with higher tissue-specific protein carbonyl levels and fast accumulation of lipofuscin in animals surviving the second spawning. Superoxide dismutase activity and apoptotic cell death intensity were however higher in this short-lived scallop than in longer-lived bivalves. The life strategy of this short-lived and intensely predated scallop supports rapid somatic growth and fitness as well as early maturation at young age at the cost of fast cellular degradation in second year scallops. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Freshly induced short-lived gamma-ray activity as a measure of fission rates in lightly re-irradiated spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kroehnert, H., E-mail: hanna.kroehnert@psi.c [Paul Scherrer Institut (PSI), OPRA-E07, CH-5232 Villigen (Switzerland); Perret, G., E-mail: gregory.perret@psi.c [Paul Scherrer Institut (PSI), OPRA-E07, CH-5232 Villigen (Switzerland); Murphy, M.F., E-mail: mike.murphy@psi.c [Paul Scherrer Institut (PSI), OPRA-E07, CH-5232 Villigen (Switzerland); Chawla, R., E-mail: rakesh.chawla@epfl.c [Paul Scherrer Institut (PSI), OPRA-E07, CH-5232 Villigen (Switzerland); Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2010-12-01

    A new measurement technique has been developed to determine fission rates in burnt fuel, following re-irradiation in a zero-power research reactor. The development has been made in the frame of the LIFE-PROTEUS program at the Paul Scherrer Institute, which aims at characterizing the interfaces between fresh and highly burnt fuel assemblies in modern LWRs. To discriminate against the high intrinsic gamma-ray activity of the burnt fuel, the proposed measurement technique uses high-energy gamma-rays, above 2000 keV, emitted by short-lived fission products freshly produced in the fuel. To demonstrate the feasibility of this technique, a fresh UO{sub 2} sample and a 36 GWd/t burnt UO{sub 2} sample were irradiated in the PROTEUS reactor and their gamma-ray activities were recorded directly after irradiation. For both fresh and the burnt fuel samples, relative fission rates were derived for different core positions, based on the short-lived {sup 142}La (2542 keV), {sup 89}Rb (2570 keV), {sup 138}Cs (2640 keV) and {sup 95}Y (3576 keV) gamma-ray lines. Uncertainties on the inter-position fission rate ratios were mainly due to the uncertainties on the net-area of the gamma-ray peaks and were about 1-3% for the fresh sample, and 3-6% for the burnt one. Thus, for the first time, it has been shown that the short-lived gamma-ray activity, induced in burnt fuel by irradiation in a zero-power reactor, can be used as a quantitative measure of the fission rate. For both fresh and burnt fuel, the measured results agreed, within the uncertainties, with Monte Carlo (MCNPX) predictions.

  7. The application of radiotracer technique for preconcentration neutron activation analysis

    International Nuclear Information System (INIS)

    Wang Xiaolin; Chen Yinliang; Sun Ying; Fu Yibei

    1995-01-01

    The application of radiotracer technique for preconcentration neutron activation analysis (Pre-NAA) are studied and the method for determination of chemical yield of Pre-NAA is developed. This method has been applied to determination of gold, iridium and rhenium in steel and rock samples and the contents of noble metal are in the range of 1-20 ng·g -1 (sample). In addition, the accuracy difference caused by determination of chemical yield between RNAA and Pre-NAA are also discussed

  8. Recoil generated radiotracers in studies of molecular dynamics

    International Nuclear Information System (INIS)

    Spicer, L.D.

    1981-01-01

    This chapter summarizes many of the contributions that the recoil technique of generating excited radiotracer atoms in the presence of a thermal environment is making to the field of chemical dynamics. Specific topics discussed critically include characterization of the generation and behavior of excited molecules including fragmentation kinetics and energy transfer, measurement of thermal and hot kinetic parameters, and studies of reaction mechanisms and stereochemistry as a function of reaction energy. Distinctive features that provide unique approaches to dynamical problems are evaluated in detail and the complementarity with more conventional techniques is addressed. Prospects for future applications are also presented

  9. Radiotracer laboratory for agricultural research at the Malaysian Nuclear Agency

    International Nuclear Information System (INIS)

    Nashriyah Mat; Misman Sumin; Maizatul Akmam Mhd Nasir

    2007-01-01

    Radiotracer Laboratory for agricultural research at the Malaysian Nuclear Agency was established since 1990. It accommodates three laboratories, three chemical temporary storage compartments plus one compartment for storage of pressurized gas. This facility is situated in ground floor of Block 44, Agrotechnology and Biosciences Division, Dengkil Complex. Currently it houses a liquid scintillation counter, sample oxidizer, gas liquid chromatography, high performance liquid chromatography and auxiliary equipments. A road map for this laboratory will be discussed in relation with present scenario i.e. R and D service, training and consultancy provided by this laboratory; and future requirements and direction. (Author)

  10. FUEL CONTAMINATION IN A MARINE DIESEL ENGINE. A RADIOTRACER STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, B. E.

    1964-04-15

    A radiotracer method was applied to the problem of elucidating the mechanism of contamination of crankcase oil by fuel combustion products in a marine diesel engine. The method consisted of adding an oil soluble radioisotope to the fuel and tracing its route to the various lubricants used in the engine. It was found that of the total amount of combustion products and by-products which enter the crankcase oil, 65% enters by simple contamination via reintroduction of used cylinder lubricant and 35% by a condensation mechanism. (auth)

  11. A general dead-time correction method based on live-time stamping. Application to the measurement of short-lived radionuclides.

    Science.gov (United States)

    Chauvenet, B; Bobin, C; Bouchard, J

    2017-12-01

    Dead-time correction formulae are established in the general case of superimposed non-homogeneous Poisson processes. Based on the same principles as conventional live-timed counting, this method exploits the additional information made available using digital signal processing systems, and especially the possibility to store the time stamps of live-time intervals. No approximation needs to be made to obtain those formulae. Estimates of the variances of corrected rates are also presented. This method is applied to the activity measurement of short-lived radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Measurement of formation cross sections producing short-lived nuclei by 14 MeV neutrons. Pr, Ba, Ce, Sm, W, Sn, Hf

    International Nuclear Information System (INIS)

    Murahira, S.; Satoh, Y.; Honda, N.; Shibata, M.; Yamamoto, H.; Kawade, K.; Takahashi, A.; Iida, T.

    1996-01-01

    Thirteen neutron activation cross sections for (n,2n), (n,p), (n,np) and (n,α) reactions producing short-lived nuclei with half-lives between 56 s and 24 min were measured in the energy range from 13.4 MeV to 14.9 MeV for Pr, Ba, Ce, Sm, W, Sn and Hf. The cross sections of 179 Hf(n,np) 178m Lu and 180 Hf(n,p) 180 Lu were measured for the first time. (author)

  13. Radiotracer studies of fungicide residues in food plants

    International Nuclear Information System (INIS)

    1990-04-01

    Agricultural fungicides are chemicals used on seeds, crops and in soils throughout the growing season. Fungicide treatments may lead to various levels of chemical residues in food commodities. Primary emphasis has been placed on ethylenebisdithiocarbamates (EBDCs), an important group of agrofungicides used in preparations for spraying or dusting major crops such as apples, pears, broccoli, cabbages, egg plants, cauliflower, grapes, lettuce, peppers, celery, cucumbers and tomatoes. Treatments with EBDCs result in terminal residues containing ethylenthiourea (ETU). This is a toxicologically significant decomposition product which has attracted considerable attention in recent years due to indications of its potential goitrogenic and carcinogenic properties. In recognition of the need for a coordinated examination of ETU levels in food, particularly under tropical conditions, the program of radiotracer techniques as a tool for studying fungicide residue problems on food was initiated in 1984. In current studies, three EBDCs, maneb, zineb and mancozeb from different manufacturers in different countries were analysed. This report describes the model protocols (Annexes I, II and III) as they were set up for determination of residues in commodities and soil, using radiotracer and conventional chromatographic techniques . In the 16 papers presented in this report C 14 -labelled EBDCs are determined in plants, vegetables, and soils, before and after cooking, as a function of time and of other agricultural parameters. Refs, figs and tabs

  14. Radiotracer residence time distribution method for industrial and environmental applications. Material for education and on-the-job training for practitioners of radiotracer technology

    International Nuclear Information System (INIS)

    2008-01-01

    The International Atomic Energy Agency (IAEA) plays a major role in facilitating the transfer of the radiotracer technology to developing Member States. The major radiotracer techniques have been implemented through IAEA technical cooperation projects and adopted by many Member States. The expertise and knowledge gained should be preserved. The sustainability of technology and knowledge preservation calls for creation of young specialists and for continuing good practices. As a part of its involvement in human resource development, the IAEA is aware of the important need to prepare standard syllabi and training course materials for the education of specialists in different fields of nuclear technologies. This training course material is intended for the cultivation of radiotracer specialists and for continuing technical education of radiotracer practitioners worldwide. The wide interest in radiotracer technology has created the need for high level professional education and training in this field, which are not necessarily covered by traditional university courses. Radiotracers are playing more and more important roles in industry. These roles will continue to expand, especially if students and engineers are exposed in their academic training to the many possibilities for using this tool in research, development and applications. Besides educational purposes, this publication will assist developing Member States in establishing their quality control and accreditation systems. This publication is based on lecture notes and practical works delivered by many experts in IAEA-supported activities. Lectures, papers, case studies and software were reviewed by a number of specialists in several meetings

  15. Optimization of the recoil-shadow projection method for the investigation of short-lived fission isomers

    Energy Technology Data Exchange (ETDEWEB)

    Helmecke, M.; Thirolf, P.G.; Habs, D.; Gartzke, E.; Kolhinen, V.; Lang, C.; Szerypo, J.; Trepl, L. [Fakultaet f. Physik, LMU Muenchen (Germany); Maier-Leibnitz Laboratory, Garching (Germany)

    2009-07-01

    Spectroscopic studies of super- and hyperdeformed actinide nuclei offer the possibility to gain insight into the multiple-humped fission barrier landscape. With the identification of deep third minima in {sup 234}U and {sup 236}U the systematics of fission isomers in light actinides was revisited, especially searching for isomers in light uranium isotopes with half-lives in the pico-second range. Using the recoil-shadow projection method and solid state nuclear track detectors, an experimental search for their observation has been started. This well-established detection technique nowadays benefits from an efficient analysis technology based on a PC-controlled auto-focus microscope and a CCD camera together with pattern recognition software. The flatness and the definition of the shadow edge of the target is the critical point of this method: Due to the energy loss of the beam the target carrier foil (1{mu}m Ni) may develop thermal distortions in the {mu}m range, leading to misinterpretations of isomeric fission fragments. Therefore the flatness of the target foil is continuously monitored via a capacitance measurement. First results applying this method to the search of a fission isomer in {sup 234}U via the {sup 232}Th({alpha},2n) reaction are presented.

  16. Detection of 210Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room

    International Nuclear Information System (INIS)

    Abu-Jarad, F.; Fazal-ur-Rehman

    2003-01-01

    Radon gas was allowed to accumulate in its radium source and then injected into a 36 m 3 test room, resulting in an initial radon concentration of 15 kBq m -3 . Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10 2 -10 5 particles cm -3 in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, 210 Po (T 1/2 =138 days). This isotope is separated from the short-lived progeny by 210 Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter 210 Po on the same filter papers measured in the year 2000 were studied. The results of the 210 Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and 210 Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker

  17. Detection of {sup 210}Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F. E-mail: falah.abujarad@aramco.com; Fazal-ur-Rehman

    2003-07-01

    Radon gas was allowed to accumulate in its radium source and then injected into a 36 m{sup 3} test room, resulting in an initial radon concentration of 15 kBq m{sup -3}. Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10{sup 2}-10{sup 5} particles cm{sup -3} in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, {sup 210}Po (T{sub 1/2}=138 days). This isotope is separated from the short-lived progeny by {sup 210}Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter {sup 210}Po on the same filter papers measured in the year 2000 were studied. The results of the {sup 210}Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and {sup 210}Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker.

  18. Radiotracer aided optimization of batch mixing of solids

    International Nuclear Information System (INIS)

    Kolar, Z.I.; Bergh, W.J.B. van den; Scarlett, B.

    1989-01-01

    A method for the determination of mixing times has been developed and tested in a model Nauta mixer filled with sand. 128 I-labelled sand particles were used as radiotracer and the progress of mixing was monitored with two radiation detectors located externally. The variance of the radiation intensity decreases with time until a constant value is reached indicating an equilibrium mixture of tracer and sand. The time necessary to achieve this condition (mixing time) appears to be dependent on the rotational speed of the hopper as well as the screw of the mixer. Optimal mixing performance (shortest mixing time) corresponds to the maximal rotational speeds of both rotating parts of the mixer. (author)

  19. Biodistribution of gyroxin using 125I as radiotracer

    International Nuclear Information System (INIS)

    Alves da Silva, J.A.; Ribela, M.T.C.P.; Rogero, J.R.; Camillo, M.A.P.; Muramoto, E.

    2006-01-01

    The use of radiotracers in the research of animal venom has been scarce, although it allows an excellent approach to follow the process of bioavailability, biodistribution and kinetics of toxins. The purpose of this study was to assess gyroxin action mechanism, transport, compartments and action sites. This toxin is a thrombin-like and causes the barrel rotation syndrome. The gyroxin was labeled with 125 I and used as a tracer for the in vivo assay in mice. Blood samples and organs were collected at different time intervals, weighed and analyzed in a gamma-counter. The data was related with tissues distribution of protease activated receptor (PAR). Biodistribution assay allowed dividing the organs into three groups. The first one with the organs that followed the blood kinetics, the second with the organs related to metabolisms and elimination, and the third with the organs in which the gyroxin concentration increased during the observation period. (author)

  20. Radiotracers for per studies of neurotransmitter binding sites: Design considerations

    International Nuclear Information System (INIS)

    Kilbourn, M.R.

    1991-01-01

    Neurotransmitter binding sites, such as receptors, neuronal uptake systems, and vesicular uptake systems, are important targets for new radiopharmaceutical design. Selection of potential radioligands can be guided by in vitro laboratory data including such characteristics as selectivity and affinity for specific binding sites. However, development of PET radiotracers for use in vivo must include considerations of in vivo pharmacokinetics and metabolism. Introduction of potential radioligands is further narrowed by the demands of the radiochemical synthesis, which must produce radioligands of high chemical and radiochemical purity and of high specific activity. This paper will review examples of previous and current attempts by radiopharmaceutical chemists to meet these demands for new positron emitter-labeled radioligands for PET studies of a wide array of neurotransmitter binding sites

  1. The influence of molecular weight in radiotracers of inflamators processes

    International Nuclear Information System (INIS)

    Mesa Duennas, N.; Zayas Crespo, F.; Piedra Mazorra, J.; Diaz Barreto, M; Rodriguez Alfonso, M.E.; Perez Fuentes, A.

    2004-01-01

    Four 99mTc-radiopharmaceuticals (RPs) were compared as a radiotracers of inflammatory process. The RPs were divided in two groups according to their molecular weights and nature. One group included the human IgG and the ior t3 MoAb (anti-CD3), another included the Ciprofloxacine and the DMSA. The RPs were studied by different quality controls, and a biodistribution study in an aseptic inflammatory model made by steril Carragenin. The results obtained in the reduction of the immunoglobulins with 2-mercaptoethanol and sodium metabisulphite demonstrated that both reducing agents were equivalent, because the radiochemical purity obtained were similar and independent of the immunoglobulins. The biodistribution demonstrated a higher incorporation for the radiopharmaceuticals of high molecular weight, and the highest values were obtained with the 2-mercaptoethanol

  2. Vulnerability of positron emission tomography radiotracers to endogenous competition

    International Nuclear Information System (INIS)

    Laruelle, M.; Huang, Y.

    2001-01-01

    PET and SPECT neuro receptor imaging techniques combined with pharmacological challenges have been introduce to measure acute fluctuations of synaptic dopamine (DA) concentrations in the living human brain. Changes in the in vivo binding of radioligands following manipulation of transmitter levels are generally believed to be driven by binding competition between the radioligand and neurotransmitter. This imaging modality has been very successful in the study of DA transmission at D2 receptors. Yet, the extension of this technique to the study of other neurotransmitter systems has proven difficult. This paper reviews recent evidence suggesting that simple binding competition might not be the only phenomenon regulating transmitter-radioligand interactions in vivo, and examines emerging data indicating that receptor trafficking might also be involved. A better understanding of the mechanisms underlying these interactions should facilitate the development of PET and SPECT radiotracers suitable for the reporting of synaptic transmitter levels

  3. Design of laboratory radiotracer studies in marine radioecology

    International Nuclear Information System (INIS)

    Schulte, E.H.

    1997-01-01

    A condensed description of methods used in laboratory radiotracer studies in marine radioecology is presented showing also the difficulties which may be encountered in order to obtain realistic and comparable information on the general behaviour of radionuclides in marine organisms. Practical guidance on the choice of the biological material and how to setup laboratory experiments and to control properly important experimental conditions are given. Key parameters like concentration factors and biological half-lives are defined and the theoretical estimation and practical determination of input, uptake, accumulation and loss of radionuclides in marine biota are formulated by the aid of mathematical equations. Examples of uptake and loss curves obtained in the laboratory are shown. The importance of some environmental factors (temperature, food, growth) on uptake and loss of radionuclides are demonstrated. Comparison of experimental and field data of concentration factors is reported to show the difficulty in extrapolating from laboratory experiments to nature. (author)

  4. Vulnerability of positron emission tomography radiotracers to endogenous competition

    Energy Technology Data Exchange (ETDEWEB)

    Laruelle, M.; Huang, Y. [Columbia University College of Physicians and Surgeons and State Psychiatric Institute, Dept. of Psychiatry and Radiology, New York, NY (United States)

    2001-06-01

    PET and SPECT neuro receptor imaging techniques combined with pharmacological challenges have been introduce to measure acute fluctuations of synaptic dopamine (DA) concentrations in the living human brain. Changes in the in vivo binding of radioligands following manipulation of transmitter levels are generally believed to be driven by binding competition between the radioligand and neurotransmitter. This imaging modality has been very successful in the study of DA transmission at D2 receptors. Yet, the extension of this technique to the study of other neurotransmitter systems has proven difficult. This paper reviews recent evidence suggesting that simple binding competition might not be the only phenomenon regulating transmitter-radioligand interactions in vivo, and examines emerging data indicating that receptor trafficking might also be involved. A better understanding of the mechanisms underlying these interactions should facilitate the development of PET and SPECT radiotracers suitable for the reporting of synaptic transmitter levels.

  5. Radiotracer study in a bubble column reactor (visbreaker)

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Gursharan Singh; Rohit Kulkarni; Pandit, A.B.; Kumar, M.M.; Berne, Ph.

    2004-01-01

    Radiotracer technique was used to measure residence time distribution (RTD) of fuel oil in a pilot-plant visbreaker with an objective to investigate hydrodynamic behaviour at different operating conditions. Bromine-82 as dibromobiphenyle was used as a tracer to measure RTD of the fuel oil. Mean residence times were determined from the measured RTD data. Tanks-in-series with backmixing model was used to simulate the measured RTD data. The results of simulation indicated that the visbreaker did not behave as a plug flow reactor as desired for visbreaking process. The presence of internals i.e. baffles inside the visbreaker decreases the mean residence time and backmixing. Thus, the designed internals have shown promising effect in terms of reduced backmixing in the visbreaker. (author)

  6. Comparison of two peptide radiotracers for prostate carcinoma targeting

    Directory of Open Access Journals (Sweden)

    Bluma Linkowski Faintuch

    2012-01-01

    Full Text Available OBJECTIVES: Scintigraphy is generally not the first choice treatment for prostate cancer, although successful studies using bombesin analog radiopeptides have been performed. Recently, a novel peptide obtained using a phage display library demonstrated an affinity for prostate tumor cells. The aim of this study was to compare the use of a bombesin analog to that of a phage display library peptide (DUP-1 radiolabeled with technetium-99m for the treatment of prostate carcinoma. The peptides were first conjugated to S-acetyl-MAG3 with a 6-carbon spacer, namely aminohexanoic acid. METHODS: The technetium-99m labeling required a sodium tartrate buffer. Radiochemical evaluation was performed using ITLC and was confirmed by high-performance liquid chromatography. The coefficient partition was determined, and in vitro studies were performed using human prostate tumor cells. Biodistribution was evaluated in healthy animals at various time points and also in mice bearing tumors. RESULTS: The radiochemical purity of both radiotracers was greater than 95%. The DUP-1 tracer was more hydrophilic (log P = -2.41 than the bombesin tracer (log P = -0.39. The biodistribution evaluation confirmed this hydrophilicity by revealing the greater kidney uptake of DUP-1. The bombesin concentration in the pancreas was greater than that of DUP-1 due to specific gastrin-releasing peptide receptors. Bombesin internalization occurred for 78.32% of the total binding in tumor cells. The DUP-1 tracer showed very low binding to tumor cells during the in vitro evaluation, although tumor uptake for both tracers was similar. The tumors were primarily blocked by DUP1 and the bombesin radiotracer primarily targeted the pancreas. CONCLUSION: Further studies with the radiolabeled DUP-1 peptide are recommended. With further structural changes, this molecule could become an efficient alternative tracer for prostate tumor diagnosis.

  7. Study of regional pulmonary gas exchange using radiotracers

    International Nuclear Information System (INIS)

    Hichwa, R.D.

    1981-01-01

    Respiration involves the exchange of gases between the environment and the blood across the alveolar membrane. Four processes characterize the dynamics of gas exchange: ventilation, diffusion, perfusion and chemical binding with hemoglobin. A study was undertaken to investigate each of these processes, utilizing accelerator production and high yield synthesis of four gaseous radiotracers (/sup 81m/Kr, Ch 3 18 F, 11 CO, 15 O 2 ). Conventional gamma camera images and ancillary physiological data were acquired. Mathematical models were developed to predict the tracer clearance from the lungs during a breath hold and during washout post breath hold. Images of the insoluble /sup 81m/Kr synchronized with the tidal breathing maneuver depict regional ventilation. Tracer bolus inhalation, relative compliance and regional phase information are obtained from krypton dCynamic studies. More soluble CH 3 18 F is used to determine regional pulmonary perfusion during a breath hold. Respiratory clearance of seven, inert, positron-emitting radiotracers define the tracer volume of distribution. The tight-binding of 11 CO to hemoglobin permits the regional measurement of carbon monoxide pulmonary diffusion capacity. A relative CO blood:gas partition coefficient is calculated from the washout of no-carrier-added levels of 11 CO and verified by in vitro radiometric measurements. Regional oxygen pulmonary diffusion capacity determined from 15 O 2 clearance during a breath hold reveals results similar to those obtained with CO. All experimental data are in good agreement with the predictions of a two-compartment open model. A more advanced oxygen model is presented that incorporates radioactive oxygen exchange with stable oxygen on the hemoglobin molecule and metabolic removal of the tracer at the tissues

  8. Mechanism of action in VIVO of some pet radiotracers

    International Nuclear Information System (INIS)

    Sachinidis, J.J.; Egan, G.F.; Berlangieri, S.U.; Scott, A.M.

    1998-01-01

    Full text: Position Emission Tomography (PET) is a technique that utilises position-emitting radiopharmaceuticals to map the physiology, biochemistry and pharmacology of the human body. PET studies range from standard image displays that provide indices of physiological function to complex kinetic analysis methods for absolute quantification. This paper will review some of the important PET radiopharmaceuticals currently produced at the Austin and Repatriation Medical Centre, Melbourne and discuss their mechanism of action in vivo. Depending on their mechanism of action, PET radiopharmaceuticals may be divided into two categories. The first category is non-specific radiotracers which follow a biochemical pathway. The second category is specific radioligands which are involved in an interaction with a receptor transporter or a receptor site. Radiopharmaceuticals from the first category may be assessed using a single or two compartmental plasma-tissue model and allow a measurement of tissue extraction or metabolism.[ 15 O] water is a freely diffusable inert which is used for cerebral blood flow measurement; [ 18 F] FDG which follows the initial phases of glucose metabolism but does not enter the Krebs cycle after phosphorylation and therefore is effectively trapped in the cells, can be used for tissue glucose metabolism measurement in oncology, cardiology and neurology; and [ 18 F]fluoromisonidazole which is a bio-reductive drug that in vivo follows an intracellular reduction pathway, can be used for hypoxic tissue measurement in stroke and tumour evaluation. Radiopharmaceuticals from the second category may be assessed using a three-compartment model: - unmetabolised free ligand in plasma, - free ligand in tissue, - and specially bound ligand in tissue. These radiotracers such as [ 11 C] flumazenil, which is an antagonist with high affinity and selectivity for a central benzodiazepine receptors, are used to study the changes in density or affinity of these receptors

  9. Study of short-lived fission products with the aid of an isotope separator connected to reactor R2-0

    International Nuclear Information System (INIS)

    Rudstam, G.

    1976-01-01

    This report constitutes a final report on project 74-3289 together with a preliminary report for project 75-3332. These projects have been included in the budget years 1974/75 and 1975/76 as a contribution to the operating costs of reactor R2-0 at Studsvik. The reactor was used for experimental studies on short-lived fission products with OSIRIS isotope-separator equipment. The scientific programme is very broad. It comprises, in the first place, characterisation of fission products (a study of their excitation levels, measurement of decay properties such as half-life and emission of delayed neutrons, determination of neutron energy spectrum, determination of total decay energy, etc.). An important application of this field of research is the determination of decay heat in nuclear fuel. The programme thus comprises research of a fundamental character and applied research. (H.E.G.)

  10. Design a 10 kJ IS Mather Type Plasma Focus for Solid Target Activation to Produce Short-Lived Radioisotopes 12C(d,n)13N

    Science.gov (United States)

    Sadat Kiai, S. M.; Adlparvar, S.; Sheibani, S.; Elahi, M.; Safarien, A.; Farhangi, S.; Zirak, A. R.; Alhooie, S.; Mortazavi, B. N.; Khalaj, M. M.; Khanchi, A. R.; Dabirzadeh, A. A.; Kashani, A.; Zahedi, F.

    2010-10-01

    A 10 kJ (15 kV, 88 μF) IS (Iranian Sun) Mather type plasma focus device has been studied to determine the activity of a compound exogenous carbon solid target through 12C(d,n)13N nuclear reaction. The produced 13N is a short-lived radioisotope with a half-life of 9.97 min and threshold energy of 0.28 MeV. The results indicate that energetic deuterons impinging on the solid target can produce yield of = 6.7 × 10-5 with an activity of A = 6.8 × 104 Bq for one plasma focus shut and A ν = 4 × 105 Bq for 6 shut per mint when the projectile maximum deuterons energy is E max = 3 MeV.

  11. Detailed description of a new management system for solid, short-lived low and intermediate level radioactive waste at Ignalina NPP

    International Nuclear Information System (INIS)

    2002-01-01

    The objective is to modify and extend the existing system at the Ignalina Nuclear Power Plant (INPP) for handling of Very Low Level Waste (VLLW), short lived Low and Intermediate Level Waste (LLW-SL and ILW-SL). The ultimate aim is to reduce the risks and the influence on the personnel and the environment. According to the request from INPP, the modified system is based on the existence of an incineration plant. This system description describes treatment of non-combustible VLLW, LLW-SL and ILW-SL at a new waste handling facility (WHF) located in the future buildings 159/2 and 159/3 at the INPP. The new WHF is also handling Exempt Waste (EW), Reusable Material (RM) and Free Release Goods (FRG). The buildings 159/2 and 159/3 are future extensions of the existing building 159. (author)

  12. Studies of short-lived radicals in the. gamma. -irradiated aqueous solution of uridine-5'-monophosphate by the spin-trapping method and the liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Kominami, S [Hiroshima Univ. (Japan); Rokushika, S; Hatano, H

    1976-12-01

    An aerated aqueous solution of uridine-5'-monophosphate was ..gamma..-irradiated with 2-methyl-2-nitrosopropane as a spin-trapping reagent. Liquid chromatography was applied to separate the stable nitroxide radicals in the irradiated solution. The radicals were detected by U.V. and e.s.r. spectrometry. The e.s.r. detection showed four peaks in the chromatogram. The orcinol method for detection of the residual sugar moieties was applied before and after reduction of the base to determine the existence of the 5,6-double bond for the molecules in each fraction. From the combined results of the e.s.r. and orcinol methods, the short-lived radicals which were trapped by 2-methyl-2-nitrosopropane were identified as radicals of N-1 and C-6 positions of the base moiety and t-butyl radicals which was the radiolytic product of the trapping reagent.

  13. Surface disposal of low-level and medium-level short-lived waste. How safe is the disposal facility in Dessel in the long term?

    International Nuclear Information System (INIS)

    2014-01-01

    A disposal facility for the disposal of low-level and medium-level short-lived waste is planned to be built on a site located in the community of Dessel (Belgium). The facility will consist of 34 modules, corresponding to a storage volume capacity of approximately 70,000 m3. The disposal concept includes waste containers that are encapsulated in a concrete box which is filled with mortar. Approximately 900 of these blocks, or monoliths, fit inside each module. The article discusses the Research and Development programme that has been conducted at the Belgian Nuclear Research Center SCK-CEN in conjunction with the development of this facility. Main emphasis is on the models that have been developed for predicting the long-term containment of the disposal facility.

  14. Formation of short-lived positron emitters in reactions of protons of energies up to 200 MeV with the target elements carbon, nitrogen and oxygen

    CERN Document Server

    Kettern, K; Qaim, S M; Shubin, Yu N; Steyn, G F; Van der Walt, T N; 10.1016/j.apradiso.2004.02.007

    2004-01-01

    Excitation functions were measured by the stacked-foil technique for proton induced reactions on carbon, nitrogen and oxygen leading to the formation of the short-lived positron emitters /sup 11/C (T/sub 1 /2/=20.38 min) and /sup 13/N (T/sub 1/2/=9.96 min). The energy region covered extended up to 200 MeV. The product activity was measured non-destructively via gamma -ray spectrometry. A careful decay curve analysis of the positron annihilation radiation was invariably performed. The experimental results were compared with theoretical data obtained using the modified hybrid nuclear model code ALICE-IPPE for intermediate energies. The agreement was found to be generally satisfactory. The data are of importance in proton therapy.

  15. Fractional release of short-lived noble gases and iodine from HTGR fuel compact containing a fraction of coated fuel particles with through-coating defects

    International Nuclear Information System (INIS)

    Ogawa, Toru; Fukuda, Kosaku; Kobayashi, Fumiaki; Kikuchi, Teruo; Tobita, Tsutomu; Kashimura, Satoru; Kikuchi, Hironobu; Yamamoto, Katsumune.

    1986-10-01

    Fractional release (R/B) data of short-lived noble gases and iodine from sweep-gas irradiated HTGR fuel compacts were analyzed. Empirical formulas to predict R/B of 88 Kr as a function of temperature and fraction through-coating defects, and to calculate ratios of R/B's of other shortlived gases to that of 88 Kr were proposed. A method to predict R/B of iodine was also proposed. As for 131 I, a fission product of major safety concern, (R/B) I 131 ≅ (R/B) Xe 133 was predicted. Applying those methods, R/B from OGL-1 fuel element (5th and 6th) was predicted to show a good agreement with observation. (author)

  16. Unattached fraction of short-lived Rn decay products in indoor and outdoor environments: An improved single-screen method and results

    International Nuclear Information System (INIS)

    Reineking, A.; Porstendoerfer, J.

    1990-01-01

    The unattached fraction fp of potential alpha energy of short-lived Rn decay products was measured under realistic, natural conditions in different dwellings and in the open atmosphere by a single-screen technique. An improved data evaluation method was developed where the measured activities of 218 Po (RaA) and 214 Pb (RaB) were corrected by the screen-attached activities of 214 Bi ( 214 Po) [RaC (RaC')]. This method is based on the experimental observation that the 214 Bi ( 214 Po) unattached activities are negligible under realistic living conditions and that the size distributions of the aerosol-attached activities of all short-lived Rn daughters are identical. In closed rooms without additional aerosol sources, a mean unattached fraction fp of the potential alpha energy of 0.096 was obtained at a mean aerosol particle concentration of 6100 cm-3 and at a mean equilibrium factor F of 0.30. This mean fp value is about three times higher than the value used in the literature for the radiation exposure calculation of the human public. In closed rooms with additional aerosol sources (cigarette smoke, heating systems, aerosols from a burning candle), the aerosol particle concentrations ranged up to 10(6) cm-3 and the attachment rates, X, increased up to 1000 h-1. The fp values sometimes decreased below the detection limit of 0.005, and the F values increased to as high as 0.77. In the ambient atmosphere in the vicinity of Goettingen, a mean unattached fraction fp of 0.02 and a mean aerosol particle concentration of 3.4 x 10(4) cm-3 were measured at 1 m above the ground. The mean equilibrium factor F was determined to be 0.7.A

  17. Investigation concerning the relative formation rate and half-life time of short-lived nuclides with a fast conveyor tube system

    International Nuclear Information System (INIS)

    Kreiner, H.J.

    1976-01-01

    Since the installation of the 'Ultrafast Rabbit System' at the FRN in end of 1974, some research was started concerning the possibility of neutron activation analysis of short-lived nuclides (0.02 1/2 < 1 s) and measurements of short-lived fission products of U-235 and Pu-239. One of the results of the investigations is a more exact gamma-energy determination of the 0.8 s Cl-38m with 671.33 keV. In NAA it was possible to reach a sensitivity for lead and boron near 2 μg per sample respectively 10 ppm. In measurements of light fission products 0.1 - 8s after a pulse irradiation some differences of the relative formation rate and half-life in the region of A approximately 100 were found in comparison to literature. For example a strong build-up could be seen measuring the gamma-energy of 276.1 keV that belongs to Nb-101. Therefore we suppose the existence of an isomeric state of Nb-101. In comparison to our own results of yield ratio of the Pu- and U-fission products a good agreement with known data was found. Furthermore the measuring method gives the possibility of coordination of unknown gamma-lines to nuclides using the rate of formation, the half-life, the yield ratio between U and Pu and the build-up factor. That could be verified in some cases, e.g. Nb-103 and Sr-96. (author)

  18. Low interannual precipitation has a greater negative effect than seedling herbivory on the population dynamics of a short-lived shrub, Schiedea obovata.

    Science.gov (United States)

    Bialic-Murphy, Lalasia; Gaoue, Orou G

    2018-01-01

    Climate projections forecast more extreme interannual climate variability over time, with an increase in the severity and duration of extreme drought and rainfall events. Based on bioclimatic envelope models, it is projected that changing precipitation patterns will drastically alter the spatial distributions and density of plants and be a primary driver of biodiversity loss. However, many other underlying mechanisms can impact plant vital rates (i.e., survival, growth, and reproduction) and population dynamics. In this study, we developed a size-dependent integral projection model (IPM) to evaluate how interannual precipitation and mollusk herbivory influence the dynamics of a Hawaii endemic short-lived shrub, Schiedea obovata (Caryophyllaceae). Assessing how wet season precipitation effects population dynamics it critical, as it is the timeframe when most of the foliar growth occurs, plants flower and fruit, and seedlings establish. Temporal variation in wet season precipitation had a greater effect than mollusk herbivory on S . obovata population growth rate λ, and the impact of interannual precipitation on vital rates shifted across plant ontogeny. Furthermore, wet season precipitation influenced multiple vital rates in contrasting ways and the effect of precipitation on the survival of larger vegetative and reproductively mature individuals contributed the most to variation in the population growth rate. Among all combination of wet season precipitation and herbivory intensities, the only scenario that led to a growing population was when high wet precipitation was associated with low herbivory. Our study highlights the importance of evaluating how abiotic factors and plant-consumer interactions influence an organism across its life cycle to fully understand the underpinning mechanisms that structure its spatial and temporal distribution and abundance. Our results also illustrate that for short-lived species, like S. obovata , seedling herbivory can have

  19. Tests to determine the release of short-lived fission products from UO2 fuel operating at linear powers of 45 and 60 kW/m

    International Nuclear Information System (INIS)

    Hastings, I.J.; Hunt, C.E.L.; Lipsett, J.J.; MacDonald, R.D.

    1985-09-01

    Experiments have been carried out using a 'sweep gas' technique to determine the behaviour of short-lived fission products within operating, intact UO 2 fuel elements. The Zircaloy-4-clad elements were 600 mm long and contained fuel of density 10.65 - 10.71 Mg/m 3 . A He-2% H 2 carrier gas swept gaseous or volatile fission products out of the operating fuel element past a gamma spectrometer for measurement. We outline our loop model and give full details of calculational procedures. In tests at linear powers of 45 (FIO-122) and 60 kW/m (FIO-124) to a maximum burnup of 80 MW.h/kg U, the species measured directly at the spectrometer during normal operation were generally the short-lived xenons and kryptons. Iodines were not observed during normal operation. The behaviour of I-133 and I-135 was deduced from the decay of Xe-133 and Xe-135 during reactor shutdowns. Plots of R/B (released/born) against λ (decay constant) or effective λ for all isotopes observed at 45 and 60 kW/m show that a line of slope -0.5, corresponding with diffusion kinetics, is a good fit to the measured xenon and krypton data. The inferred release of iodine fits the same line. From this we can extrapolate to an R/B for I-131 of about 5 x 10 -4 at 45 kW/m, and 3 x 10 -3 at 60 kW/m. Both tests were terminated by defects. Under defect conditions, R/B dependence on λ was about 0.6. I-131 release under defect conditions was 5 Ci and 60 mCi for FIO-122 and FI0-124, respectively. 22 refs

  20. Status and perspective on radiotracer technology and development of its equipment in Korea

    International Nuclear Information System (INIS)

    Kim, Jong Bum; Jung, Sung Hee; Jin, Joon Ha

    2003-01-01

    The Korean tracer team was organized under the regular research project in the middle of 1990s. The objective of the project is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems. The Korean tracer team started with basic tracer technologies and basic tools for radiotracer experiment. Under the research project, various equipments and skills for radiotracer have been developed. With these skill and equipment, there have been several demonstration experiments in petrochemical industry and waste water treatment facilities. The direction of research using radiotracer technology is highly reflected by each country's industrial situation. There is overview on how the tracer technology has applied to the industries in Korea in this paper. And the case on the application of radiotracer technology and the development of its equipment in Korea are also introduced in this paper

  1. Impurity analysis in EC-99mTC radiotracer using chromatographic techniques

    International Nuclear Information System (INIS)

    Almeida, E.V.; Fukumori, N.T.O.; Mengatti, J.; Silva, C.P.G.; Matsuda, M.M.N.

    2008-01-01

    The objective of this study was to develop two chromatographic methods of impurity analysis in radiotracer 99m Tc-EC: the Thin Layer Chromatography (TLC) and the High Performance Liquid Chromatography Reversed Phase (HPLC-RP)

  2. Current status and trends of cooperation on radiotracer and NCS technologies

    Energy Technology Data Exchange (ETDEWEB)

    Thereska, J. [International Atomic Energy Agency, Vienna (Austria). Industrial Applications and Chemistry Section

    1997-10-01

    Relevant target areas for radiotracer and neutronic control system (NCS) applications are defined. The petroleum and petrochemical industries, mineral processing and waste-water treatment sectors are identified as the most appropriate beneficiaries. The new CRP on `Radiotracer technology for engineering unit operations studies and unit process optimisation` aims to improve the radiotracer methodology, including new radiotracers, development of expert systems, new software for data processing with finite element techniques for flow structure visualisation, as well as to formulate guidelines for problem solving of complex processes. The organisation of a CRP on `Multibeam radiogauging for multi-phase systems studies` to further develop and refine nucleonic gauge methodology and technology, including development of expert systems for optimal design and calibration, quality control according to ISO standards, emerging new applications, and formulation of guidelines and software for on line measurement of multi-phase system parameters of complex processes will be discussed in the near future

  3. Leak detection in a high-pressure heat exchanger system in a refinery using radiotracer technique

    International Nuclear Information System (INIS)

    Samantray, J.S.; Sunil Goswami; Sharma, V.K.; Jayashree Biswal; Pant, H.J.

    2014-01-01

    A radiotracer investigation was carried out in a diesel hydrotreater (DHDT) unit in a refinery for leak detection in a breech-lock heat exchanger system. The main objectives of the study were to identify the leaking heat exchanger in a system with six heat exchangers and estimate the leak rate. Bromine-82 as dibromobiphenyl was selected and used as radiotracer for the investigation. The radiotracer was instantaneously injected into the suction end of the feed pump line to the heat exchanger of the DHDT unit. The movement of the tracer was measured at strategically selected locations using NaI(Tl) scintillation detectors. Based upon the results of the radiotracer investigation, it was found that out of six heat exchangers, exchanger E-1F was leaking. (author)

  4. Application of 99mTc-DTPA Radiotracer in Persian Cat's Renal ...

    African Journals Online (AJOL)

    Keywords: Kidney, Persian cat, Radiotracer, Scintigraphy, Technetium-99m diethylene triamine pentacaetic acid ... tracer can be detected in the body by medical equipment .... studies, such as kidney failure, allergic reactions and fatal side ...

  5. Current status and trends of cooperation on radiotracer and NCS technologies

    International Nuclear Information System (INIS)

    Thereska, J.

    1997-01-01

    Relevant target areas for radiotracer and neutronic control system (NCS) applications are defined. The petroleum and petrochemical industries, mineral processing and waste-water treatment sectors are identified as the most appropriate beneficiaries. The new CRP on 'Radiotracer technology for engineering unit operations studies and unit process optimisation' aims to improve the radiotracer methodology, including new radiotracers, development of expert systems, new software for data processing with finite element techniques for flow structure visualisation, as well as to formulate guidelines for problem solving of complex processes. The organisation of a CRP on 'Multibeam radiogauging for multi-phase systems studies' to further develop and refine nucleonic gauge methodology and technology, including development of expert systems for optimal design and calibration, quality control according to ISO standards, emerging new applications, and formulation of guidelines and software for on line measurement of multi-phase system parameters of complex processes will be discussed in the near future

  6. Radioimmunoassay kit formulation and its validation for serum progesterone using progesterone radiotracer purified by gel filtration

    International Nuclear Information System (INIS)

    Karir, T.; Pal, N.; Sivaprasad, N.

    2003-01-01

    Purification of the radioiodinated progesterone tyrosine methyl ester conjugate by gel filtration and the development, optimization and clinical validation of a direct radioimmunoassay (RIA) of progesterone using this radiotracer are described. High purity radiotracer is essential for the error free performance of any RIA. Progesterone 11α hemisuccinate was conjugated to tyrosine methyl ester (TME) by the mixed anhydride method and this conjugate was then radioiodinated by the chloramine-T method. Purification of the radioiodinated product was carried out by gel filtration. About 12 batches of the radiotracer were prepared and purified. The purification by gel filtration gave reproducible elution pattern and purity. The radiotracer thus purified was found to have consistent quality as compared to that of any other purification methods. Non-specific binding of the radiotracer was found to be 95% as checked by paper electrophoresis. The stability (retention of the immunoreactivity) of the radiotracer was two to three months. No appreciable changes in the assay characteristics were observed during this period. The assay involved 3 hours incubation of progesterone antibody with individual standards or sample and radiotracer at room temperature. The optimized assay was then validated for internal and external quality control parameters. A RIA kit was then formulated with this radiotracer for estimation of progesterone in serum. The assay kit consisted of lyophilized individual standards ranging from 0.25 to 50 ng/ml. The clinical performance of the developed kit was compared with that of a commercial ELISA kit and a correlation of 0.94 was observed. (author)

  7. Investigation of hydrodynamic behaviour of membranes using radiotracer techniques

    Directory of Open Access Journals (Sweden)

    Zakrzewska-Trznadel G.

    2013-05-01

    Full Text Available The aim of the work was to study membrane devices using short-lived radioisotopes like Ba-137m and Ga-68 as tracers. These radioisotopes were obtained from radionuclide generators: Cs-137/Ba-137m and Ge-68/Ga-68. The first radionuclide, namely Ba-137m with a half-life of 2.55 minutes was applied as a liquid phase tracer for studying hydrodynamic conditions inside the membrane apparatus. The membrane module with ceramic membranes was tested by using Ba-137m. The experiments showed that this radionuclide with a short half-life is a perfect tracer for liquid phase, whereas Ga-68 with longer half-life equal to 68 minutes was considered as a solid phase (bentonite tracer. Ga-68 was used to gain more knowledge about the phenomena occurring in the membrane boundary layer. After kinetic studies of isotope adsorption into the carrier material, the growth rate of the deposit layer as well as deposit's thickness on the flat-sheet membrane were studied. The influence of such process parameters like pressure, linear velocity of liquid and feed concentration on formation of the bentonite layer on the membrane surface was studied.

  8. Preliminary study of the use of radiotracers for leak detection in industrial applications

    International Nuclear Information System (INIS)

    Wetchagarun, S; Petchrak, A; Tippayakul, C

    2015-01-01

    One of the most widespread uses of radiotracers in the industrial applications is the leak detection of the systems. This technique can be applied, for example, to detect leak in heat exchangers or along buried industrial pipelines. The ability to perform online investigation is one of the most important advantages of the radiotracer technique over other non-radioactive leak detection methods. In this paper, a preliminary study of the leak detection using radiotracer in the laboratory scale was presented. Br-82 was selected for this work due to its chemical property, its suitable half-life and its on-site availability. The NH 4 Br in the form of aqueous solution was injected into the experimental system as the radiotracer. Three NaI detectors were placed along the pipelines to measure system flow rate and to detect the leakage from the piping system. The results obtained from the radiotracer technique were compared to those measured by other methods. It is found that the flow rate obtained from the radiotracer technique agreed well with the one obtained from the flow meter. The leak rate result, however, showed discrepancy between results obtained from two different measuring methods indicating further study on leak detection was required before applying this technique in the industrial system. (paper)

  9. Preliminary study of the use of radiotracers for leak detection in industrial applications

    Science.gov (United States)

    Wetchagarun, S.; Petchrak, A.; Tippayakul, C.

    2015-05-01

    One of the most widespread uses of radiotracers in the industrial applications is the leak detection of the systems. This technique can be applied, for example, to detect leak in heat exchangers or along buried industrial pipelines. The ability to perform online investigation is one of the most important advantages of the radiotracer technique over other non-radioactive leak detection methods. In this paper, a preliminary study of the leak detection using radiotracer in the laboratory scale was presented. Br-82 was selected for this work due to its chemical property, its suitable half-life and its on-site availability. The NH4Br in the form of aqueous solution was injected into the experimental system as the radiotracer. Three NaI detectors were placed along the pipelines to measure system flow rate and to detect the leakage from the piping system. The results obtained from the radiotracer technique were compared to those measured by other methods. It is found that the flow rate obtained from the radiotracer technique agreed well with the one obtained from the flow meter. The leak rate result, however, showed discrepancy between results obtained from two different measuring methods indicating further study on leak detection was required before applying this technique in the industrial system.

  10. Short Lived Climate Pollutants cause a Long Lived Effect on Sea-level Rise: Analyzing climate metrics for sea-level rise

    Science.gov (United States)

    Sterner, E.; Johansson, D. J.

    2013-12-01

    Climate change depends on the increase of several different atmospheric pollutants. While long term global warming will be determined mainly by carbon dioxide, warming in the next few decades will depend to a large extent on short lived climate pollutants (SLCP). Reducing emissions of SLCPs could contribute to lower the global mean surface temperature by 0.5 °C already by 2050 (Shindell et al. 2012). Furthermore, the warming effect of one of the most potent SLCPs, black carbon (BC), may have been underestimated in the past. Bond et al. (2013) presents a new best estimate of the total BC radiative forcing (RF) of 1.1 W/m2 (90 % uncertainty bounds of 0.17 to 2.1 W/m2) since the beginning of the industrial era. BC is however never emitted alone and cooling aerosols from the same sources offset a majority of this RF. In the wake of calls for mitigation of SLCPs it is important to study other aspects of the climate effect of SLCPs. One key impact of climate change is sea-level rise (SLR). In a recent study, the effect of SLCP mitigation scenarios on SLR is examined. Hu et al (2013) find a substantial effect on SLR from mitigating SLCPs sharply, reducing SLR by 22-42% by 2100. We choose a different approach focusing on emission pulses and analyse a metric based on sea level rise so as to further enlighten the SLR consequences of SLCPs. We want in particular to understand the time dynamics of SLR impacts caused by SLCPs compared to other greenhouse gases. The most commonly used physical based metrics are GWP and GTP. We propose and evaluate an additional metric: The global sea-level rise potential (GSP). The GSP is defined as the sea level rise after a time horizon caused by an emissions pulse of a forcer to the sea level rise after a time horizon caused by an emissions pulse of a CO2. GSP is evaluated and compared to GWP and GTP using a set of climate forcers chosen to cover the whole scale of atmospheric perturbation life times (BC, CH4, N2O, CO2 and SF6). The study

  11. Beam-Beam Effects

    International Nuclear Information System (INIS)

    Herr, W; Pieloni, T

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities

  12. IN-SITU RADIONUCLIDE TRANSPORT NEAR THE NOPAL I URANIUM DEPOSIT AT PENA BLANCA, MEXICO: CONSTRAINTS FROM SHORT-LIVED DECAY-SERIES RADIONUCLIDES

    International Nuclear Information System (INIS)

    Luo, S.; Ku, T.L.; Todd, V.; Murrell, M.; Pineda, J. Alfredo Rodriguez; Dinsmoor, J.; Mitchell, A.

    2005-01-01

    For nuclear waste management, an important mechanism by which radioactive waste components are isolated from returning to the human environment, the biosphere, is by the geological barrier in which the effectiveness of the barrier is characterized by in-situ retardation factor, i.e., the transport rate of a radionuclide relative to that of groundwater. As part of natural analog studies of the Yucca Mountain Project of the U. S. Department of Energy, we propose such characterization by using naturally-occurring decay-series radioisotopes as an analog. We collected large-volume (>1000 liters) groundwater samples from three wells (PB, Pozos, and PB4, respectively) near the Nopal I Uranium Ore site at Pena Blanca, Mexico, by using an in-situ Mn-cartridge filtration technique for analysis of short-lived decay-series radionuclides. Results show that the activities of short-lived radioisotopes ( 228 Ra, 224 Ra and 223 Ra) and activity ratios of 224 Ra/ 228 Ra and 224 Ra/ 223 Ra are higher at PB and Pozos than at PB4. In contrast, the 210 Po activity is much lower at PB and Pozos than at PB4. The high Ra activities and activities ratios at PB and Pozos are attributable to the high alpha-recoil input from the aquifer rocks, while the high 210 Po activity at PB4 is due to the enhanced colloidal transport. Based on a uranium-series transport model, we estimate that the in-situ retardation factor of Ra is (0.43 ± 0.02) x 10 3 at PB, (1.68 ± 0.08) x 10 3 at Pozos, and (1.19 ± 0.08) x 10 3 at PB4 and that the mean fracture width in the aquifer rocks is about 0.23 (micro)m at PB, 0.37 (micro)m at Posos, and 4.0 (micro)m at PB4, respectively. The large fracture width at PB4 as derived from the model provides an additional evidence to the inference from the Po measurements that particle-reactive radionuclides are transported mainly as colloidal forms through the large fractures in rocks. Our model also suggests that in addition to alpha recoil, decay of 226 Ra from the adsorbed

  13. IN-SITU RADIONUCLIDE TRANSPORT NEAR THE NOPAL I URANIUM DEPOSIT AT PENA BLANCA, MEXICO: CONSTRAINTS FROM SHORT-LIVED DECAY-SERIES RADIONUCLIDES

    Energy Technology Data Exchange (ETDEWEB)

    S. Luo; T.L. Ku; V. Todd; M. Murrell; J. Alfredo Rodriguez Pineda; J. Dinsmoor; A. Mitchell

    2005-07-11

    For nuclear waste management, an important mechanism by which radioactive waste components are isolated from returning to the human environment, the biosphere, is by the geological barrier in which the effectiveness of the barrier is characterized by in-situ retardation factor, i.e., the transport rate of a radionuclide relative to that of groundwater. As part of natural analog studies of the Yucca Mountain Project of the U. S. Department of Energy, we propose such characterization by using naturally-occurring decay-series radioisotopes as an analog. We collected large-volume (>1000 liters) groundwater samples from three wells (PB, Pozos, and PB4, respectively) near the Nopal I Uranium Ore site at Pena Blanca, Mexico, by using an in-situ Mn-cartridge filtration technique for analysis of short-lived decay-series radionuclides. Results show that the activities of short-lived radioisotopes ({sup 228}Ra, {sup 224}Ra and {sup 223}Ra) and activity ratios of {sup 224}Ra/{sup 228}Ra and {sup 224}Ra/{sup 223}Ra are higher at PB and Pozos than at PB4. In contrast, the {sup 210}Po activity is much lower at PB and Pozos than at PB4. The high Ra activities and activities ratios at PB and Pozos are attributable to the high alpha-recoil input from the aquifer rocks, while the high {sup 210}Po activity at PB4 is due to the enhanced colloidal transport. Based on a uranium-series transport model, we estimate that the in-situ retardation factor of Ra is (0.43 {+-} 0.02) x 10{sup 3} at PB, (1.68 {+-} 0.08) x 10{sup 3} at Pozos, and (1.19 {+-} 0.08) x 10{sup 3} at PB4 and that the mean fracture width in the aquifer rocks is about 0.23 {micro}m at PB, 0.37 {micro}m at Posos, and 4.0 {micro}m at PB4, respectively. The large fracture width at PB4 as derived from the model provides an additional evidence to the inference from the Po measurements that particle-reactive radionuclides are transported mainly as colloidal forms through the large fractures in rocks. Our model also suggests that

  14. Increased Concentrations of Short-Lived Decay-Series Radionuclides in Groundwaters Underneath the Nopal I Uranium Deposit at Pena Blanca, Mexico

    Science.gov (United States)

    Luo, S.; Ku, T.; Todd, V.; Murrell, M. T.; Dinsmoor, J. C.

    2007-05-01

    The Nopal I uranium ore deposit at Pena Blanca, Mexico, located at > 200 meters above the groundwater table, provides an ideal natural analog for quantifying the effectiveness of geological barrier for isolation of radioactive waste nuclides from reaching the human environments through ground water transport. To fulfill such natural analog studies, three wells (PB1, PB2, and PB3 respectively) were drilled at the site from the land surface down to the saturated groundwater zone and ground waters were collected from each of these wells through large- volume sampling/in-situ Mn-filter filtration for analyses of short-lived uranium/thorium-series radionuclides. Our measurements from PB1 show that the groundwater standing in the hole has much lower 222Rn activity than the freshly pumped groundwater. From this change in 222Rn activity, we estimate the residence time of groundwater in PB1 to be about 20 days. Our measurements also show that the activities of short-lived radioisotopes of Th (234Th), Ra (228Ra, 224Ra, 223Ra), Rn (222Rn), Pb (210Pb), and Po (210Po) in PB1, PB2, and PB3 are all significantly higher than those from the other wells near the Nopal I site. These high activities provide evidence for the enrichment of long-lived U and Ra isotopes in the groundwater as well as in the associated adsorbed phases on the fractured aquifer rocks underneath the ore deposit. Such enrichment suggests a rapid dissolution of U and Ra isotopes from the uranium ore deposit in the vadose zone and the subsequent migration to the groundwater underneath. A reactive transport model can be established to characterize the in-situ transport of radionuclides at the site. The observed change of 222Rn activity at PB1 also suggests that the measured high radioactivityies in ground waters from the site isare not an artifact of drilling operations. However, further studies are needed to assess if or to what extent the radionuclide migration is affected by the previous mining activities at

  15. Daily and seasonal variation of short-lived radon decay product concentrations in ground-level air at Munich-Neuherberg - a long-term study

    International Nuclear Information System (INIS)

    Winkler, R.

    2001-09-01

    Daily and seasonal variation of the equilibrium equivalent radon concentration (EEC Rn-222 ) and of the concentration of the short-lived radon decay product 214 Pb in ground-level air was investigated at Munich-Neuherberg from 1982 to 2000, and from 1989 to 2000, respectively. For this, the EEC was measured continuously with an alpha/beta aerosol monitor at 2.5 m above ground, and 214 Pb was determined by online gamma spectrometry at about 12 m above ground. The resulting time series were analysed statistically. For the respective periods, the measurements yielded a long-term average concentration of 7.8 Bq m -3 (geometric mean: 6.1 Bq m -3 ) for the EEC, and 6.0 Bq m -3 (geom. mean: 5.0 Bq m -3 ) for 214 Pb. In these periods, daily averages ranged from 0.6 to 49 Bq m -3 (EEC), and from 0.6 to 43 Bq m -3 ( 214 Pb). Monthly mean concentrations varied between 3.0 Bq m -3 in March 1988 and 20 Bq m -3 in October 1985 (EEC), and from 3.4 Bq m -3 in April 1992 to 11 Bq m -3 in October 1995 ( 214 Pb), respectively. The annual average concentrations were from 5.9 Bq m -3 in 1999 to 10.6 Bq m -3 in 1985 (EEC), and from 5.3 Bq m -3 in 1999 to 6.8 Bq m -3 in 1991 ( 214 Pb). From the long-term average equilibrium equivalent radon concentration (EEC), an average annual effective dose of 0.13 mSv due to the short-lived radon progeny outdoors was estimated. The time series showed distinct daily and seasonal variations. The variations from day to day are mainly caused by the actual weather conditions (wind, rain, etc.), i.e. the short-term turbulent conditions. The seasonal pattern is characterised by an autumn to winter maximum and an early summer minimum, and reflects the prevailing turbulent conditions at the respective seasons. As known, at Munich-Neuherberg during autumn and winter months (October/November to February) inversion weather conditions frequently occur, while the other months are characterised by more turbulent conditions. (orig.)

  16. Radiotracer studies on radionuclide and trace element cycling in corals

    International Nuclear Information System (INIS)

    Fowler, S.W.; Teyssie, J.L.; Acosta, A.; Gattuso, J.P.; Jaubert, J.

    1999-01-01

    Microcosm experiments were designed in which microcolonies of three coral species were exposed to gamma-emitting radiotracers of trace metals and radionuclides ( 110 Am, 109 Cd. 57 Cocyanocobalamin, 110 Ag, 134 Cs, 65 Zn, 60 Co, 75 Se, 85 Sr, 133 Ba, 54 Mn) to determine uptake and loss as well as distribution in tissue, skeleton and zooxanthellae. Following a seven day exposure in seawater, the degree of uptake (CF = concentration factor) for a given element was highly dependent on species. The highest CF s , in whole colonies were found for 100m Ag(82-172), 57 Co (68-124) and 65 Zn (41-52); the lowest CF s , were noted for the soluble radionuclides Cs (1-2) and Sr (2-9). Low CF s , were recorded in skeleton and increased by roughly an order of magnitude between skeleton, tissue and zooxanthellae. 241 Am is readily taken up by dead skeleton (CF=31-49), whereas in living corals it is preferentially accumulated by the tissue (CF=51-120) which acts as a partial barrier against contamination of the internal skeleton (CF=6-10). The chemical species of the element can also affect uptake by corals, as evidenced by the order of magnitude greater bioaccumulation of organic cobalt compared to the inorganic form in tissues. Once accumulated, some of the elements tested (e.g. Cd, Co) are strongly retained with biological half-lives as long as several months

  17. Radiotracer investigation of phosphoric acid and phosphatic fertilizers production process

    International Nuclear Information System (INIS)

    Ben Abdelouahed, H.; Reguigui, N.

    2011-01-01

    In the phosphoric acid production process, the time a particle spends inside the chemical reactor (residence time) is of paramount importance to process engineers. Residence time distribution (RTD) gives information on the efficiency of the chemical reactor, on the efficiency of the process, and also the availabilities of the reactive volume for the reaction (active volume vs. dead volume). Traditionally, chemical engineers used chemical tracer to determine the RTD. However, first disadvantage is that the chemical tracer could not allow an online diagnosis: the samples containing chemical tracer have to go to a lab for analysis, second disadvantage is that the chemical tracer is less sensitive than radioactive ones because of its adsorption onto strata or its retention in rocks. Consequently, chemical tracer results are not always precise and cannot convincingly explain the multiple flow-path model. Radioactive tracers are the only tracers capable of measuring the active RTD with high degree of precision and give information on the internal recirculation rate. In this work, we will describe the application of radiotracer method for RTD measurement in the phosphoric acid production process and give results and discussion of each case encountered. (author)

  18. The uses of radiotracers in the life sciences

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Thomas J [TRIUMF, Vancouver (Canada)

    2009-01-15

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination.

  19. The uses of radiotracers in the life sciences

    Science.gov (United States)

    Ruth, Thomas J.

    2009-01-01

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination.

  20. The uses of radiotracers in the life sciences

    International Nuclear Information System (INIS)

    Ruth, Thomas J

    2009-01-01

    Radionuclides have been used to follow physical, chemical and biological processes almost from the time of their discovery. Probably the application with the biggest impact has been in the medical field where radionuclides have been incorporated into biologically active molecules and used to diagnose a wide variety of diseases and to treat many disorders. Other uses in the life sciences, in general, are related to using a radioactive isotope as marker for an existing species such as nitrogen-13 in plant studies or copper-67 to track copper catalysts in phytoplankton. This review describes in general terms these uses as well as providing the reader with the background related to the physical properties of radioactive decay, the concepts associated with the production of radionuclides using reactors or accelerators and the fundamentals of imaging radioactivity. The advances in imaging technology in recent years has had a profound impact on the use of radionuclides in positron emission tomography and the coupling of other imaging modalities to provide very precise insights into human disease. The variety of uses for radiotracers in science is almost boundless dependent only upon ones imagination

  1. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, J [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry and Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs.

  2. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    International Nuclear Information System (INIS)

    Rydberg, J.

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs

  3. Study of wastewater treatment plants efficiency using radiotracers

    International Nuclear Information System (INIS)

    Dawi, W. D. A.

    2010-11-01

    This study was performed to investigate and diagnose hydrodynamic behavior of the Military Hospital wastewater treatment plant. The plant comprises two units of treatment, each of them has a separate system. The investigation was carried out using ''1''3''1I as a radiotracer. The concept of residence time distribution (RTD) was used to investigate the efficiency of the aeration tanks, secondary clarifiers and chlorine tanks. Preliminary treatment and modeling of the trace data was performed using two software package applied by the International Atomic Energy Agency (IAEA) namely 4621 counter version 1.0.0 and RTD software. Plug flow pattern (parallel flow) was detected in the aeration tank and secondary clarifier of system 1 in one unit, while no homogeneous mixing was observed in the chlorine tank. Short - circuiting (by - passing) was evident in the aeration tank of system 2 in the other unit, which significantly reduced the operating efficiency. The percentage of dead volumes clearly suggests that the aeration tank and secondary clarifier were well utilized in the whole plant. (Author)

  4. Assessing of bulk materials mixing and sorting by radiotracer methods

    International Nuclear Information System (INIS)

    Thyn, J.

    1983-01-01

    Various applications are indicated of tracer techniques for the evaluation of mixing and sorting of mixtures of solid particles. The evaluation of the process of mixing, i.e., the determination of the homogenization time is done by labelling of the entire volume of the monitored component of the mixture and continuous detection of radiation through the walls of the mixer using one or several detectors. The evaluation of the character of the flow and the evacuation of solid particles from the bin is done by labelling with a radiotracer the material which is spread out on the top along the whole cross-section of the bin, and the concentration is monitored of the tracer in the material outflow. The evaluation of material sorting in bins which takes place during the filling and emptying is done on the basis of significance tests or using self-correlation functions and frequency characteristics. Also monitored was the dependence of the equalizing ability of the continuous gravity mixer at the vertex angle of the tip. (M.D.)

  5. Characterizing root activity of guava trees by radiotracer technique

    International Nuclear Information System (INIS)

    Purohit, A.G.; Mukherjee, S.K.

    1974-01-01

    The distribution pattern of root activity of 12-year-old trees of guava (Psidium guajava L.) was determined by radiotracer technique. 32 P soloution was injected into the soil at lateral distances of 120, 240 and 360 cm from the tree trunk at depths of 15,30,60 and 90 cm. The 32 P uptake by the tree was determined by leaf analysis. In the rainy season the root activity or 32 P uptake was greater near the soil surface and midway between the trunk and the drip-line. The root activity decreased with an increase in the depth and distance from trunk. These results compared well with the actual distribution of feeder roots as determined by the soil-auger method. In summer the roots near the surface become less active in 32 P absorption with a drcrease in surface soil moisture. A decrease in the root activity in the surface soil was accompanied by an increase in 32 P uptake from lower depths. (author)

  6. Radiotracer application in bedload transport: case studies at Calcutta port

    International Nuclear Information System (INIS)

    Pendharkar, A.S.; Yelgoankar, V.N.; Pant, H.J.; Saravana Kumar, U.; Mendhekar, G.N.; Navada, S.V.

    1994-01-01

    Radioactive isotopes as tracers are widely used to study the dynamic behaviour of sediments in navigation channels in harbours, estuaries and in rivers. Four radioactive tracer experiments were carried out in Calcutta Port during 1985-1992, to investigate the suitability of the dumping sites for the dredged sediments. Two experiments were carried out off Sagar island and the other two were carried out off Haldia river buoy. For all the experiments radiotracers used was 46 Sc labelled 1% scandium glass powder having the same specific gravity and particle size distribution as the natural sediment in the areas of investigation. About 370 GBq (10 Ci) each off Sagar island and 185 GBq (5 Ci) each off Haldia river buoy was used. An extensive background survey of the area was carried out using waterproof scintillation detectors to measure the natural radiation level prior to the experiments. The tracer was released on to the sea bed and its movement was followed by waterproof scintillation detector. The studies indicate the general direction of movement of sediment in the area of interest and it is found to be away from the shipping channels. The velocity of transport is calculated from transport diagrams of two successive trackings. The transport thickness E, estimated for the experiments off Haldia river buoy, is about 2 to 3 cm. (author). 3 refs., 7 figs., 2 tabs

  7. AGE-DEPENDENT INHALATION DOSE DUE TO EXPOSURE OF SHORT LIVED PROGENY OF RADON AND THORON FOR DIFFERENT AGE GROUPS IN JAMMU & KASHMIR, HIMALAYAS.

    Science.gov (United States)

    Sharma, Sumit; Kumar, Ajay; Mehra, Rohit

    2018-05-16

    Dosimetric approach is used in this study for the assessment of doses due to inhalation of short lived radon/thoron progeny to the inhabitants of Udhampur district of Jammu & Kashmir. This paper also presents the activity concentrations and unattached fraction of radon and thoron progeny. The observed annual concentration of attached and unattached 222Rn and 220Rn progeny has been found to vary from 8 to 32 and 0.09 to 14 Bq/m3, 0.75 to 3.16 and 0.01 to 1.13 Bq/m3, respectively. The inhalation doses from radon progeny to different body organs of different age groups have been calculated by using the age dependent biokinetic model. The attachment rate of 222Rn and indoor aerosol concentration of 222Rn and 220Rn have been estimated and their relation between them has also been studied. The dose conversion factor for mouth and nasal breathing to different exposure conditions has been obtained from Porstendorfer model.

  8. Studies on the separation of rare earth elements and the nuclear decay properties of short lived rare-earth nuclides in U-235 fission products

    International Nuclear Information System (INIS)

    Ohyoshi, Akira; Ohyoshi, Emiko.

    1980-01-01

    The effect of a complex-forming agent, with which rare earths consecutively form the complexes, on the separation of a pair of adjacent rare earths by electromigration has been investigated. The relation between the separation factor for two complexes and the ligand-ion concentration was examined in the separation of La-Ce and Ce-Pr pairs with nitrilotriacetic acid. Rare earths were able to be isolated rapidly at the optimum ligand-ion concentration in lower one, and this method was applied to study the nuclear decay properties of the short lived isotopes of La, Ce, Pr, Nd and Yt formed in the fission of U-235. This method permits the direct measurement of the decay of La-144 without the interference from the radiation of other fission products. The gamma-ray spectrum of La-144 was measured with a high resolution Ge(Li) detector, and the gamma-transition was observed. From the decay plots of two strong photopeaks, the half-life of La-144 was determined. In the case of Ce fraction, the photopeaks assigned to respective isotopes were observed. In the studies on the decay properties of Pr-148 and Pr-149, the decay plot of the strong photopeak showed good linearity, and the accurate half-life of Pr-148 was determined. Similarly, the half-life of Pr-149 was longer than the previously reported value. (Kako, I.)

  9. 4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution

    International Nuclear Information System (INIS)

    Nien Schuchmann, Man; Naumov, Sergej; Schuchmann, Heinz-Peter; Sonntag, Justus von; Sonntag, Clemens von

    2005-01-01

    In the pulse radiolysis of 2'-deoxycytidine (dCyd) in N 2 O-saturated solutions containing 0.5M tertiary butanol to completely scavenge the water radicals, a short-lived intermediate (λmax=287nm) is observed by UV spectroscopy which is attributed to dCydH + , generated in the reaction of dCyd with H + formed during the pulse. By reacting with OH - , which is formed in the pulse in amounts matching that of H + , this intermediate disappears in the μs time range without a change of the spectrum. Similarly, cytosine (Cyt) gives rise to CytH + which, in contrast, in part transforms into another species (λmax=286nm) which can be assigned to isocytosine 1, 4-amino-3H-pyrimidin-2-one, a tautomer of Cyt which is formed by two routes (i) deprotonation of CytH + at N(1) by OH - and (ii) deprotonation of Cyt and reprotonation of the Cyt anion by water at N(3). Compared to Cyt, 1 is richer in Gibbs' free enthalpy by 14kJmol -1 . Its presence in low equilibrium concentrations has also been observed by conventional UV spectroscopy, making use of the increase of its equilibrium concentration with increasing temperature. From these data, an absorption coefficient of 3.3x10 4 dm 3 mol -1 cm -1 at 286nm has been calculated. Supporting quantum chemical calculations are also reported

  10. FORMATION OF THE SHORT-LIVED RADIONUCLIDE 36Cl IN THE PROTOPLANETARY DISK DURING LATE-STAGE IRRADIATION OF A VOLATILE-RICH RESERVOIR

    International Nuclear Information System (INIS)

    Jacobsen, Benjamin; Yin Qingzhu; Matzel, Jennifer; Hutcheon, Ian D.; Ramon, Erick C.; Weber, Peter K.; Krot, Alexander N.; Nagashima, Kazuhide; Ishii, Hope A.; Ciesla, Fred J.

    2011-01-01

    Short-lived radionuclides (SLRs) in the early solar system provide fundamental insight into protoplanetary disk evolution. We measured the 36 Cl- 36 S-isotope abundance in wadalite ( 36 Cl (τ 1/2 ∼ 3 x 10 5 yr) in the early solar system. Its presence, initial abundance, and the noticeable decoupling from 26 Al raise serious questions about the origin of SLRs. The inferred initial 36 Cl abundance for wadalite, corresponding to a 36 Cl/ 35 Cl ratio of (1.81 ± 0.13) x 10 -5 , is the highest 36 Cl abundance ever reported in any early solar system material. The high level of 36 Cl in wadalite and the absence of 26 Al ( 26 Al/ 27 Al ≤ 3.9 x 10 -6 ) in co-existing grossular (1) unequivocally support the production of 36 Cl by late-stage solar energetic particle irradiation in the protoplanetary disk and (2) indicates that the production of 36 Cl, recorded by wadalite, is unrelated to the origin of 26 Al and other SLRs ( 10 Be, 53 Mn) recorded by primary minerals of CAIs and chondrules. We infer that 36 Cl was largely produced by irradiation of a volatile-rich reservoir in an optically thin protoplanetary disk adjacent to the region in which the CV chondrite parent asteroid accreted while the Sun was a weak T Tauri star. Subsequently, 36 Cl accreted into the Allende CV chondrite together with condensed water ices.

  11. Transport of short-lived climate forcers/pollutants (SLCF/P) to the Himalayas during the South Asian summer monsoon onset

    International Nuclear Information System (INIS)

    Cristofanelli, P; Putero, D; Landi, T C; Marinoni, A; Duchi, R; Calzolari, F; Bonasoni, P; Adhikary, B; Stocchi, P; Verza, G; Vuillermoz, E; Laj, P; Kang, S; Ming, J

    2014-01-01

    Over the course of six years (2006–2011), equivalent black carbon (eqBC), coarse aerosol mass (PM 1–10 ), and surface ozone (O 3 ), observed during the monsoon onset period at the Nepal Climate Observatory–Pyramid WMO/GAW Global Station (NCO-P, 5079 m a.s.l.), were analyzed to investigate events characterized by a significant increase in these short-lived climate forcers/pollutants (SLCF/P). These events occurred during periods characterized by low (or nearly absent) rain precipitation in the central Himalayas, and they appeared to be related to weakening stages (or ‘breaking’) of the South Asian summer monsoon system. As revealed by the combined analysis of atmospheric circulation, air-mass three-dimensional back trajectories, and satellite measurements of atmospheric aerosol loading, surface open fire, and tropospheric NO x , the large amount of SLCF/P reaching the NCO-P appeared to be related to natural (mineral dust) and anthropogenic emissions occurring within the PBL of central Pakistan (i.e., Thar Desert), the Northwestern Indo-Gangetic plain, and the Himalayan foothills. The systematic occurrence of these events appeared to represent the most important source of SLCF/P inputs into the central Himalayas during the summer monsoon onset period, with possible important implications for the regional climate and for hydrological cycles. (letter)

  12. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    Energy Technology Data Exchange (ETDEWEB)

    Bigu, J [Department of Energy, Mines and Resources, Elliot Lake, Ontario (Canada). Elliot Lake Lab.; Raz, R; Golden, K; Dominguez, P [Alpha-NUCLEAR, Toronto, Ontario (Canada)

    1984-08-15

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operation with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross ..cap alpha..-count methods and ..cap alpha..-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of ..cap alpha..-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software.

  13. Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

    Science.gov (United States)

    Monks, P. S.; Archibald, A. T.; Colette, A.; Cooper, O.; Coyle, M.; Derwent, R.; Fowler, D.; Granier, C.; Law, K. S.; Mills, G. E.; Stevenson, D. S.; Tarasova, O.; Thouret, V.; von Schneidemesser, E.; Sommariva, R.; Wild, O.; Williams, M. L.

    2015-08-01

    Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a byproduct of the very oxidation chemistry it largely initiates. Much effort is focused on the reduction of surface levels of ozone owing to its health and vegetation impacts, but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve owing to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner. The review shows that there remain a number of clear challenges for ozone such as explaining surface trends, incorporating new chemical understanding, ozone-climate coupling, and a better assessment of impacts. There is a clear and present need to treat ozone across the range of scales, a transboundary issue, but with an emphasis on the hemispheric scales. New observational opportunities are offered both by satellites and small sensors that bridge the scales.

  14. Triggering Collapse of the Presolar Dense Cloud Core and Injecting Short-lived Radioisotopes with a Shock Wave. V. Nonisothermal Collapse Regime

    Energy Technology Data Exchange (ETDEWEB)

    Boss, Alan P., E-mail: aboss@carnegiescience.edu [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

    2017-08-01

    Recent meteoritical analyses support an initial abundance of the short-lived radioisotope (SLRI) {sup 60}Fe that may be high enough to require nucleosynthesis in a core-collapse supernova, followed by rapid incorporation into primitive meteoritical components, rather than a scenario where such isotopes were inherited from a well-mixed region of a giant molecular cloud polluted by a variety of supernovae remnants and massive star winds. This paper continues to explore the former scenario, by calculating three-dimensional, adaptive mesh refinement, hydrodynamical code (FLASH 2.5) models of the self-gravitational, dynamical collapse of a molecular cloud core that has been struck by a thin shock front with a speed of 40 km s{sup −1}, leading to the injection of shock front matter into the collapsing cloud through the formation of Rayleigh–Taylor fingers at the shock–cloud intersection. These models extend the previous work into the nonisothermal collapse regime using a polytropic approximation to represent compressional heating in the optically thick protostar. The models show that the injection efficiencies of shock front materials are enhanced compared to previous models, which were not carried into the nonisothermal regime, and so did not reach such high densities. The new models, combined with the recent estimates of initial {sup 60}Fe abundances, imply that the supernova triggering and injection scenario remains a plausible explanation for the origin of the SLRIs involved in the formation of our solar system.

  15. 'Sleeping reactor' irradiations. The use of a shut-down reactor for the determination of elements with short-lived activation products

    International Nuclear Information System (INIS)

    Jerde, E.A.; Oak Ridge National Laboratory, TN; Glasgow, D.C.

    1999-01-01

    Neutron activation analysis utilizing the High Flux Isotope Reactor (HFIR) immediately following SCRAM is a workable solution to obtaining data for ultra-short lived species, principally Al, Ti, Mg, and V. Neutrons are produced in the HFIR core within the beryllium reflector due to gamma-ray bombardment from the spent fuel elements. This neutron flux is not constant, varying by over two orders of magnitude during the first 24 hours. The problems associated with irradiation in a changing neutron flux are removed through the use of a specially tailored activation equation. This activation equation is applicable to any irradiation at HFIR in the firs 24 hours after SCRAM since the fuel elements are identical from cycle to cycle, and the gamma-emitting nuclides responsible for the neutrons reach saturation during the fuel cycle. Reference material tests demonstrate that this method is successful, and detection limit estimates reveal that it should be applicable to materials of widely ranging mass and composition. (author)

  16. The origin and disappearance of the late Pleistocene-early Holocene short-lived coastal wetlands along the Carmel coast, Israel

    Science.gov (United States)

    Sivan, Dorit; Greenbaum, Noam; Cohen-Seffer, Ronit; Sisma-Ventura, Guy; Almogi-Labin, Ahuva

    The formation of short-lived backswamps along the Carmel coast of Israel coincides with the rapid global sea-level rise during the late Pleistocene-early Holocene transition. The current study shows that the wetland phenomena originated around 10,000 yr ago and dried up shortly before the local Pre-Pottery Neolithic humans settled on the wetland dark clay sediments 9430 cal yr BP. Palaeontological and stable-isotope data were used in this study to elucidate previously published sedimentological reconstruction obtained from a core drilled into the western trough of the Carmel coastal plain. The water body contained typical brackish calcareous fauna, with variable numerical abundance and low species richness of ostracods and foraminifera. The δ 18O and δ 13C of the ostracod Cyprideis torosa show close similarity to the present Pleistocene coastal aquifer isotopic values. This study therefore concludes that the wetlands were shallow-water bodies fed by groundwater, with no evidence of sea-water mixing. It seems that they developed as the result of high groundwater levels, transportation of sediments landward, and deposition of sand bars at the paleo-river mouths. It is still not fully understood why these wetlands deteriorated abruptly and disappeared within less than 1000 yr.

  17. Design and Performance Assessment of a Conceptual Cover Cap of Near Surface Repository for Short Lived Low and Intermediate Level Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Asaba, Ruth; Kim, Changlak [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-05-15

    The safety of the overall waste disposal system is determined by the performance of its individual components: waste form, waste container, engineered barrier and the host environment. The design of the cover cap helps in preventing percolation of water, and in retarding radionuclide migration from the disposal facility to the biosphere. The cover of a disposal facility is usually a combination of materials such as sand, gravel, concrete, clay and soil conditioned for vegetation growth. The cover system will be designed using models such as EPA's Hydrological Evaluation of Land fill Performance (HELP) code. This paper describes a conceptual design for a cover cap for a land fill as a preferred disposal facility for low and short lived intermediate radioactive waste in Uganda. Majority of the waste is generated from disused sealed and unsealed radioactive sources arising from medical, industrial applications, and research. Radioactive waste management has raised a lot of concern in both developed and developing countries. Each country has a responsibility to come up with a solution to prevent contamination of the environment and humans from radioactive waste. It is important to have thicker soil layers in cap designs so as to support vegetation growth since some activities such as erosion and settlements are expected. Help simulations in this study will assist to demonstrate that it is possible to design a cover cap which can contain radioactive waste packages for hundreds of years provided the proper institutional and performance monitoring schemes are implemented.

  18. Leadership emergence over time in short-lived groups: Integrating expectations states theory with temporal person-perception and self-serving bias.

    Science.gov (United States)

    Kalish, Yuval; Luria, Gil

    2016-10-01

    Research into leadership emergence typically focuses on the attributes of the emergent leader. By considering also the attributes of perceivers and the passage of time, we develop a more complete theory of leadership emergence in short-lived groups. Using expectation states theory as an overarching theoretical framework, and integrating it with the surface- and deep-level diversity literature and with theories of self-serving biases, we examine the predictors of leadership emergence in short timeframes. We conduct a field study in a military assessment boot camp (a pilot study, n = 60; and a main study, n = 89). We use cross-sectional and longitudinal exponential random graph models to analyze data on participants' abilities and on their perceptions of who, in their respective groups, were "leaders." We find that the criteria by which people perceive leadership in others change over time, from easily noticeable attributes to covert leadership-relevant attributes, and that people also rely on leadership-relevant attributes that they possess at high levels to inform their perceptions of leadership in others. The integration of expectation states theory, attribute salience over time and theories of self-serving bias is needed for a full understanding of leadership emergence in groups, because perceivers' own abilities are instrumental in shaping their perceptions of emergent leadership over time. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  19. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    International Nuclear Information System (INIS)

    Bigu, J.

    1984-01-01

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operatin with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross α-count methods and α-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of α-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software. (orig.)

  20. Climate impacts of short-lived climate forcers versus CO2 from biodiesel: a case of the EU on-road sector.

    Science.gov (United States)

    Lund, Marianne T; Berntsen, Terje K; Fuglestvedt, Jan S

    2014-12-16

    Biofuels are proposed to play an important role in several mitigation strategies to meet future CO2 emission targets for the transport sector but remain controversial due to significant uncertainties in net impacts on environment, society, and climate. A switch to biofuels can also affect short-lived climate forcers (SLCFs), which provide significant contributions to the net climate impact of transportation. We quantify the radiative forcing (RF) and global-mean temperature response over time to EU on-road fossil diesel SLCFs and the impact of 20% (B20) and 100% (B100) replacement of fossil diesel by biodiesel. SLCFs are compared to impacts of on-road CO2 using different approaches from existing literature to account for biodiesel CO2. Given the best estimates for changes in emissions when replacing fossil diesel with biodiesel, the net positive RF from EU on-road fossil diesel SLCFs of 3.4 mW/m(2) is reduced by 15% and 80% in B20 and B100, respectively. Over time the warming of SLCFs is likely small compared to biodiesel CO2 impacts. However, SLCFs may be relatively more important for the total warming than in the fossil fuel case if biodiesel from feedstock with very short rotation periods and low land-use-change impacts replaces a high fraction of fossil diesel.

  1. A built-in radiotracer (24Na) for measuring circulation catalyst rates

    International Nuclear Information System (INIS)

    Domondon, D.B; Berbano, M.C.

    1975-01-01

    A local petroleum refinery intended to calibrate its catalyst flow measuring instrument (propeller blade) using the radioactive tracer technique (RTT). For this purpose, a method of incorporating a suitable radiotracer in commercial catalyst beads had to be found. Two methods of labelling are described. One method involved the incorporation of the radiotracer in a gel of the same composition as the commercial catalyst and subsequent conversion of the gel into a from like that of the commercial catalyst beads. Another method utilized the strong adsorptive properties of the commercial catalyst beads for the chosen isotopes, e.g., 144 Cs, 46 Sc. To effect quantitative adsorption, commercial catalyst beads were simply stirred in a slightly acidic (pH4) chloride solution of the radiotracers for some time. The radiotracers were found to distribute almost uniformly over the entire catalyst surface and no evidence of volatilization of the isotopes from the catalyst surface under condition of use in commercial units was observed. Another probable method was suggested by the Research and Development Division, Philippine Atomic Energy Commission. Aluminium is a major component of the ceramic catalyst beads and sodium is present as impurity. Hence, a radiotracer ( 24 Na) can be formed in the beads by the reaction 23 Na (n,gamma) 24 Na, 27 Al (n,alpha) 24 Na. This possible method of simply irradiating the commercial catalyst beads in the reactor thereby inducing the radiotracer. 24 Na in situ fulfils all the criteria for the selection of an appropriate radiotracer. The method is very simple but reliable

  2. Radiotracers For Lipid Signaling Pathways In Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gatley, S. J. [Northeastern Univ., Boston, MA (United States)

    2016-09-26

    The primary focus of this project continues to be the development of radiotracers and radiotracer methodology for studying physiology and biochemistry. The compounds that have been labeled areacylethanolamines and acylglycerols that are, as classes, represented in both in plants and in animals. In the latter, some of these act as ligands for cannabinoid receptors and they are therefore known as endocannabinoids. Cannabinoid receptors are not found in plant genomes so that plants must contain other receptors and signaling systems that use acylethanolamines. Relatively little work has been done on that issue, though acylethanolamines do modulate plant growth and stress resistance, thus possessing obvious relevance to agriculture and energy production. Progress has been described in five peer-reviewed papers and seven meeting abstracts. Preparation of 2-acylglycerol lipid messengers in high purity. A novel enzymatic synthesis was developedthat gave pure 2-acylglycerols free of any rearrrangement to the thermodynamically more stable 1(3)-acylglycerol byproducts. The method utilized 1,3-dibutyryl-2-acylglycerol substrate ethanolysis by a resinimobilized lipase. Thus, pure radiolabeled 2-acylglycerols can now be conveniently prepared just prior to their utilization. These synthetic studies were published in the Journal of Medicinal Chemistry, 2011. Diacylglycerol lipase assay methodology. Diacylglycerol lipases (DAGLs) generate 2- acylglycerols, and are thus potential targets for disease- or growth-modifying agents, by means of reducing formation of 2-acylglycerols. A radioTLC assay of the hydrolysis of radiolabeled diglyceride substrate [1''-carbon-14]2-arachidonoyl-1-stearoyl-sn-glycerol has been implemented, and used to validate a novel, potentially highthroughput fluorescence resonance energy transfer (FRET) based assay. A number of new DAGL inhibitors that have selectivity for DAGLs were synthesized and screened. This work was very recently published in

  3. Production of 41Ar and 79Kr gaseous radiotracers for industrial applications

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Jagadeesan, K.C.; Shivarudrappa, V.; Sharma, V.K.; Chitra, S.

    2007-01-01

    Radiotracers are extensively used in many industries for trouble shooting and optimization of process parameters leading to considerable savings in time and huge economic benefits. In chemical and petrochemical industries different gases and vapours flowing in the conversion reactors play a major role in the final production. Gaseous radiotracers are ideal to study hydrodynamics of gas phases in process vessels. 41 Ar and 79 Kr are the preferred gaseous radiotracers for such studies. Owing to the increase in demand from Indian industries for gas phase radiotracers, efforts have been made to produce 41 Ar and 79 Kr indigenously by irradiation of 40 Ar and enriched 78 Kr gaseous targets in research reactors. Prequalification of the containers used, safety aspects concerning accidental rupture and mandatory tests necessary for irradiation of gaseous targets in the reactors have been studied. The paper describes some of the important safety aspects involved and the results of trial irradiations on the production of 41 Ar and 79 Kr radiotracers. Standardization of suitable assay protocols for their regular production and supply for applications in industries is also described. (author)

  4. Development of equipment and radiotracer experiment using RI labelled sand in the coastal zone

    International Nuclear Information System (INIS)

    Choi, B. J.; Jung, S. H.; Kim, J. B.; Jin, J. H.

    2004-01-01

    On the basis of the radiotracer technology and the related equipments which have been developed for its industrial application through the nuclear long-term research project, a radiotracer study on sediment transport was carried out as a part of the development of the radiotracer technology for a coastal marine environment. The crystalline material doped with iridium having a similar composition and density as those of the bedload sand collected from the research area was produced by the oxide-route method. A radioisotope container was specially designed to inject the radiotracer from 1m above the sea bedload without radioactive contamination during the transport from the nuclear reactor at KAERI. The position data from the DGPS and the radiation measurement data are collected concurrently and stored by means of the application software programmed with the LabVIEW of the National Instrument. The position data is reprocessed to make it represent the real position of the radiation probe under water and not that of the DGPS antenna on board. In order to evaluate the influence of a breakwater on the deviation of the neighboring coastline, the time dependency of the spatial distribution of the sediment was studied in the area through three tracking measurements after the iridium glass was injected. This trial application showed the potential of the radiotracer technology as an important role for maintaining and developing the coastal marine environment in the future

  5. Radiotracer study of phosphate exchange between whey and casein micelles in cow's milk

    International Nuclear Information System (INIS)

    Kolar, Z.I.; Verburg, T.G.; Dijk, H.J.M. van

    1998-01-01

    Radiotracer method has been applied to study exchange of calcium ions between the whey calcium salts and micellar calcium phosphate (MCP). The present paper deals with a similar study pertaining to phosphate ions. 32 P-labelled Na 2 HPO 4 was used as the radiotracer for inorganic phosphates of milk. After addition of the radiotracer to skimmed-milk, samples were taken regularly for 700 hours. In the samples casein micelles were separated from whey by ultracentrifugation and finally the radiotracer quantity i.e. 32 P-concentration in the whey samples was measured using a Liquid Scintillation Counter. Compartmental analysis and modelling were used to evaluate the thus obtained time curves for radiotracer quantity in whey. This analysis revealed the presence of three phosphate compartments i.e. exchangeable phosphate entities; one being the whey phosphate. The other two are associated with the exchangeable phosphates of MCP. The mean residence times of phosphate in the latter two compartment differ considerably pointing at two distinctly different embeddings of phosphate groups in the structure of the micellar calcium phosphate of the cow's milk casein. The obtained results are in fair agreement with the mentioned model of MCP

  6. A study of residence time distribution using radiotracer technique in the large scale plant facility

    Science.gov (United States)

    Wetchagarun, S.; Tippayakul, C.; Petchrak, A.; Sukrod, K.; Khoonkamjorn, P.

    2017-06-01

    As the demand for troubleshooting of large industrial plants increases, radiotracer techniques, which have capability to provide fast, online and effective detections to plant problems, have been continually developed. One of the good potential applications of the radiotracer for troubleshooting in a process plant is the analysis of Residence Time Distribution (RTD). In this paper, the study of RTD in a large scale plant facility using radiotracer technique was presented. The objective of this work is to gain experience on the RTD analysis using radiotracer technique in a “larger than laboratory” scale plant setup which can be comparable to the real industrial application. The experiment was carried out at the sedimentation tank in the water treatment facility of Thailand Institute of Nuclear Technology (Public Organization). Br-82 was selected to use in this work due to its chemical property, its suitable half-life and its on-site availability. NH4Br in the form of aqueous solution was injected into the system as the radiotracer. Six NaI detectors were placed along the pipelines and at the tank in order to determine the RTD of the system. The RTD and the Mean Residence Time (MRT) of the tank was analysed and calculated from the measured data. The experience and knowledge attained from this study is important for extending this technique to be applied to industrial facilities in the future.

  7. Public participation in decision-making processes: ONDRAF/NIRAS' approach to the disposal of low-level and short-lived radioactive waste

    International Nuclear Information System (INIS)

    Hooft, E.

    2000-01-01

    January 16, 1998, is a milestone in the nuclear waste management in Belgium. On that day, the Belgian government effectively opted for a definitive or potentially definitive solution for the Iona term management of low-level, short-lived radioactive waste. The government also wanted this solution to be implemented in a progressive, flexible, and reversible manner. it was thereby definitively abandoning the prolonged interim storage option, in favour of either surface disposal or deep geological disposal. At the same time, the government entrusted new missions to ONDRAFINIRAS, aimed at enabling it to make, around 2001-2002, the necessary technical and economic choice between surface disposal and deep geological disposal. ONDRAFNIRAS had to develop, in particular, methods, including the management and dialogue strictures, necessary to integrate a repository project at the local level. Furthermore, it had to restrict from then on its investigations to the four already existing nuclear zones in Belgium namely those of Doel, Fleurus, Mol-Dessel, and Tihange, and to the local towns or villages having shown an interest in a preliminary field study. Early in 1998, ONDRAFNIRAS set up a new work programme and developed an entirely new work methodology. As we understood that the best way to take involved into account the interests of all parties, is to involve them in the decision making on the project, we developed the idea of the local partnerships. Any party that could be directly affected by a collective decision, must have a say in it. Another innovative aspect of this new methodology is that of integration: an integration at the local level which is meant to enable the development of draft repository projects creating new perspectives for the regions concerned. Extending over four to five years, ONDRAFINIRAS's new work programme assumes the active participation of all the interested local representatives. Because it has understood that any party that could be directly

  8. Short-lived long non-coding RNAs as surrogate indicators for chemical exposure and LINC00152 and MALAT1 modulate their neighboring genes.

    Directory of Open Access Journals (Sweden)

    Hidenori Tani

    Full Text Available Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs. Although accumulating evidence demonstrates that lncRNAs play important roles in regulating gene expression, the detailed mechanisms of action of most lncRNAs remain unclear. We previously reported that a novel class of lncRNAs with a short half-life (t1/2 < 4 h in HeLa cells, termed short-lived non-coding transcripts (SLiTs, are closely associated with physiological and pathological functions. In this study, we focused on 26 SLiTs and nuclear-enriched abundant lncRNA, MALAT1(t1/2 of 7.6 h in HeLa cells in neural stem cells (NSCs derived from human induced pluripotent stem cells, and identified four SLiTs (TUG1, GAS5, FAM222-AS1, and SNHG15 that were affected by the following typical chemical stresses (oxidative stress, heavy metal stress and protein synthesis stress. We also found the expression levels of LINC00152 (t1/2 of 2.1 h in NSCs, MALAT1 (t1/2 of 1.8 h in NSCs, and their neighboring genes were elevated proportionally to the chemical doses. Moreover, we confirmed that the overexpression of LINC00152 or MALAT1 upregulated the expressions of their neighboring genes even in the absence of chemical stress. These results reveal that LINC00152 and MALAT1 modulate their neighboring genes, and thus provide a deeper understanding of the functions of lncRNAs.

  9. TRIGGERING COLLAPSE OF THE PRESOLAR DENSE CLOUD CORE AND INJECTING SHORT-LIVED RADIOISOTOPES WITH A SHOCK WAVE. II. VARIED SHOCK WAVE AND CLOUD CORE PARAMETERS

    Energy Technology Data Exchange (ETDEWEB)

    Boss, Alan P.; Keiser, Sandra A., E-mail: boss@dtm.ciw.edu, E-mail: keiser@dtm.ciw.edu [Department of Terrestrial Magnetism, Carnegie Institution, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

    2013-06-10

    A variety of stellar sources have been proposed for the origin of the short-lived radioisotopes that existed at the time of the formation of the earliest solar system solids, including Type II supernovae (SNe), asymptotic giant branch (AGB) and super-AGB stars, and Wolf-Rayet star winds. Our previous adaptive mesh hydrodynamics models with the FLASH2.5 code have shown which combinations of shock wave parameters are able to simultaneously trigger the gravitational collapse of a target dense cloud core and inject significant amounts of shock wave gas and dust, showing that thin SN shocks may be uniquely suited for the task. However, recent meteoritical studies have weakened the case for a direct SN injection to the presolar cloud, motivating us to re-examine a wider range of shock wave and cloud core parameters, including rotation, in order to better estimate the injection efficiencies for a variety of stellar sources. We find that SN shocks remain as the most promising stellar source, though planetary nebulae resulting from AGB star evolution cannot be conclusively ruled out. Wolf-Rayet (WR) star winds, however, are likely to lead to cloud core shredding, rather than to collapse. Injection efficiencies can be increased when the cloud is rotating about an axis aligned with the direction of the shock wave, by as much as a factor of {approx}10. The amount of gas and dust accreted from the post-shock wind can exceed that injected from the shock wave, with implications for the isotopic abundances expected for a SN source.

  10. Impact on short-lived climate forcers (SLCFs) from a realistic land-use change scenario via changes in biogenic emissions.

    Science.gov (United States)

    Scott, C E; Monks, S A; Spracklen, D V; Arnold, S R; Forster, P M; Rap, A; Carslaw, K S; Chipperfield, M P; Reddington, C L S; Wilson, C

    2017-08-24

    More than one quarter of natural forests have been cleared by humans to make way for other land-uses, with changes to forest cover projected to continue. The climate impact of land-use change (LUC) is dependent upon the relative strength of several biogeophysical and biogeochemical effects. In addition to affecting the surface albedo and exchanging carbon dioxide (CO 2 ) and moisture with the atmosphere, vegetation emits biogenic volatile organic compounds (BVOCs), altering the formation of short-lived climate forcers (SLCFs) including aerosol, ozone (O 3 ) and methane (CH 4 ). Once emitted, BVOCs are rapidly oxidised by O 3 , and the hydroxyl (OH) and nitrate (NO 3 ) radicals. These oxidation reactions yield secondary organic products which are implicated in the formation and growth of aerosol particles and are estimated to have a negative radiative effect on the climate (i.e. a cooling). These reactions also deplete OH, increasing the atmospheric lifetime of CH 4 , and directly affect concentrations of O 3 ; the latter two being greenhouse gases which impose a positive radiative effect (i.e. a warming) on the climate. Our previous work assessing idealised deforestation scenarios found a positive radiative effect due to changes in SLCFs; however, since the radiative effects associated with changes to SLCFs result from a combination of non-linear processes it may not be appropriate to scale radiative effects from complete deforestation scenarios according to the deforestation extent. Here we combine a land-surface model, a chemical transport model, a global aerosol model, and a radiative transfer model to assess the net radiative effect of changes in SLCFs due to historical LUC between the years 1850 and 2000.

  11. Mitigation of Short-Lived Climate Pollutants from Residential Coal Heating and Combined Heating/Cooking Stoves: Impacts on the Cryosphere, Policy Options, and Co-benefits

    Science.gov (United States)

    Chafe, Z.; Anenberg, S.; Klimont, Z.; Kupiainen, K.; Lewis, J.; Metcalfe, J.; Pearson, P.

    2017-12-01

    Residential solid fuel combustion for cooking, heating, and other energy services contributes to indoor and outdoor air pollution, and creates impacts on the cryosphere. Solid fuel use often occurs in colder climates and at higher elevations, where a wide range of combustion emissions can reduce reflectivity of the snow- and ice-covered surfaces, causing climatic warming. Reducing short-lived climate pollutants (SLCPs), such as black carbon (BC), could have substantial climate and health co-benefits, especially in areas where emissions influence the cryosphere. A review of existing literature and emissions estimates, conducted as part of the Warsaw Summit on BC and Other Emissions from Residential Coal Heating Stoves and Combined Cooking/Heating Stoves, found little nationally-representative data on the fuels and technologies used for heating and combined cooking/heating. The GAINS model estimates that 24 million tonnes of coal equivalent were combusted by households for space heating globally in 2010, releasing 190 kilotons (kt) BC. Emissions from combined cooking/heating are virtually unknown. Policy instruments could mitigate cryosphere-relevant emissions of SLCPs from residential heating or cooking. These include indoor air quality guidelines, stove emission limits, bans on the use of specific fuels, regulatory codes that stipulate when burning can occur, stove changeout programs, and voluntary public education campaigns. These measures are being implemented in countries such as Chile (fuelwood moisture reduction campaign, energy efficiency, heating system improvements), Mongolia (stove renovation, fuel switching), Peru (improved stove programs), Poland (district heating, local fuel bans), United States (stove emission regulation) and throughout the European Community (Ecodesign Directive). Few, if any, of these regulations are likely to reduce emissions from combined cooking/heating. This research team found no global platform to create and share model

  12. Contributions of short-lived radioiodines to thyroid doses received by evacuees from the Chernobyl area estimated using early in vivo activity measurements

    International Nuclear Information System (INIS)

    Balonov, M.; Kaidanovsky, G.; Zvonova, I.; Kovtun, A.; Bouville, A.; Luckyanov, L.; Voilleque, P.

    2003-01-01

    A series of in-vivo gamma spectrometric measurements of 65 people, evacuated from Pripyat 1.5 days after the Chernobyl Nuclear Power Plant Unit 4 explosion was performed in St. Petersburg, Russia, as early as 30 April 1986. The historical spectra and interviews were recently processed and the results used for thyroid dose estimation. Activities of 131 I in thyroid and 132 Te in lungs were determined easily; for estimation of 132 I and 133 I activities in thyroid, sophisticated methods of spectra processing were developed. According to thyroid measurement data, the mean ratio of 133 I/ 131 I activities (at the time of the accident) inhaled by residents of Pripyat was 2.0. The mean ratio of thyroid dose from 133 I inhalation to that caused by 131 I amounts to 0.3, which confirms accuracy of dose estimates based on the evolution of the Chernobyl accident. The mean ratio of 132 I activity in thyroid to that of 132 Te in lungs was assessed from the human measurement data to be 0.2, which is in reasonable agreement with the metabolic properties of these radionuclides. The mean ratio of thyroid dose from 132 I originating from 132 Te deposited in lungs to the dose caused by 131 I was 0.13 ± 0.02 for Pripyat residents who did not take KI pills and 0.9 ± 0.1 for persons who took KI pills. Thus, the contribution of short-lived radioiodines to total thyroid dose of Pripyat residents, which was on average 30% for persons who did not apply stable iodine prophylaxis, and about 50% for persons who took KI pills on 26-27 April, should be accounted for in the assessment of thyroid health effects. (author)

  13. RNA-seq of the aging brain in the short-lived fish N. furzeri - conserved pathways and novel genes associated with neurogenesis.

    Science.gov (United States)

    Baumgart, Mario; Groth, Marco; Priebe, Steffen; Savino, Aurora; Testa, Giovanna; Dix, Andreas; Ripa, Roberto; Spallotta, Francesco; Gaetano, Carlo; Ori, Michela; Terzibasi Tozzini, Eva; Guthke, Reinhard; Platzer, Matthias; Cellerino, Alessandro

    2014-12-01

    The brains of teleost fish show extensive adult neurogenesis and neuronal regeneration. The patterns of gene regulation during fish brain aging are unknown. The short-lived teleost fish Nothobranchius furzeri shows markers of brain aging including reduced learning performances, gliosis, and reduced adult neurogenesis. We used RNA-seq to quantify genome-wide transcript regulation and sampled five different time points to characterize whole-genome transcript regulation during brain aging of N. furzeri. Comparison with human datasets revealed conserved up-regulation of ribosome, lysosome, and complement activation and conserved down-regulation of synapse, mitochondrion, proteasome, and spliceosome. Down-regulated genes differ in their temporal profiles: neurogenesis and extracellular matrix genes showed rapid decay, synaptic and axonal genes a progressive decay. A substantial proportion of differentially expressed genes (~40%) showed inversion of their temporal profiles in the last time point: spliceosome and proteasome showed initial down-regulation and stress-response genes initial up-regulation. Extensive regulation was detected for chromatin remodelers of the DNMT and CBX families as well as members of the polycomb complex and was mirrored by an up-regulation of the H3K27me3 epigenetic mark. Network analysis showed extensive coregulation of cell cycle/DNA synthesis genes with the uncharacterized zinc-finger protein ZNF367 as central hub. In situ hybridization showed that ZNF367 is expressed in neuronal stem cell niches of both embryonic zebrafish and adult N. furzeri. Other genes down-regulated with age, not previously associated with adult neurogenesis and with similar patterns of expression are AGR2, DNMT3A, KRCP, MEX3A, SCML4, and CBX1. CBX7, on the other hand, was up-regulated with age. © 2014 The Authors. Aging cell published by the Anatomical Society and John Wiley & Sons Ltd.

  14. Preliminary Results of IS Plasma Focus as a Breeder of Short-Lived Radioisotopes 12C(d,n)13N

    Science.gov (United States)

    Sadat Kiai, S. M.; Elahi, M.; Adlparvar, S.; Shahhoseini, E.; Sheibani, S.; Ranjber akivaj, H.; Alhooie, S.; Safarien, A.; Farhangi, S.; Aghaei, N.; Amini, S.; Khalaj, M. M.; Zirak, A. R.; Dabirzadeh, A. A.; Soleimani, J.; Torkzadeh, F.; Mousazadeh, M. M.; Moradi, K.; Abdollahzadeh, M.; Talaei, A.; Zaeem, A. A.; Moslehi, A.; Kashani, A.; Babazadeh, A. R.; Bagiyan, F.; Ardestani, M.; Roozbahani, A.; Pourbeigi, H.; Tajik Ahmadi, H.; Ahmadifaghih, M. A.; Mahlooji, M. S.; Mortazavi, B. N.; Zahedi, F.

    2011-04-01

    Modified IS (Iranian Sun) plasma focus (10 kJ,15 kV, 94 μF, 0.1 Hz) has been used to produce the short-lived radioisotope 13N (half-life of 9.97 min) through 12C(d,n)13N nuclear reaction. The filling gas was 1.5-3 torr of hydrogen (60%) deuterium (40%) mixture. The target was solid nuclear grade graphite with 5 mm thick, 9 cm width and 13 in length. The activations of the exogenous target on average of 20 shots (only one-third acceptable) through 10-13 kV produced the 511 keV gamma rays. Another peak found at the 570 keV gamma of which both was measured by a NaI portable gamma spectrometer calibrated by a 137Cs 0.25 μCi sealed reference source with its single line at 661.65 keV and 22Na 0.1 μCi at 511 keV. To measure the gamma rays, the graphite target converts to three different phases; solid graphite, powder graphite, and powder graphite in water solution. The later phase approximately has a doubled activity with respect to the solid graphite target up to 0.5 μCi of 511 keV and 1.1 μCi of 570 keV gamma lines were produced. This increment in activity was perhaps due to structural transformation of graphite powder to nano-particles characteristic in liquid water.

  15. Time-series variations of the short-lived Ra in coastal waters: implying input of SGD to the coastal zone of Da-Chia River, Taichung, Taiwan

    Science.gov (United States)

    Hsu, Feng-Hsin; Su, Chih-Chieh; Lin, In-Tain; Huh, Chih-An

    2015-04-01

    Submarine groundwater discharge (SGD) has been recognized as an important pathway for materials exchanging between land and sea. Input of SGD carries the associated nutrients, trace metals, and inorganic carbon that may makes great impacts on ecosystem in the coastal zone. Due to the variability of SGD magnitude, it is difficult to estimate the flux of those associated materials around the world. Even in the same area, SGD magnitude also varies in response to tide fluctuation and seasonal change on hydraulic gradient. Thus, long-term investigation is in need. In Taiwan, the SGD study is rare and the intrusion of seawater in the coastal aquifer is emphasized in previous studies. According to the information from Hydrogeological Data Bank (Central Geological Survey, MOEA), some areas still show potentiality of SGD. Here, we report the preliminary investigation result of SGD at Gaomei Wildlife Conservation Area which located at the south of the Da-Chia River mouth. This study area is characterized by a great tidal rang and a shallow aquifer with high groundwater recharge rate. Time-series measurement of the short-lived Ra in surface water was done in both dry and wet seasons at a tidal flat site and shows different trends of excess Ra-224 between dry and wet seasons. High excess Ra-224 activities (>20 dpm/100L) occurred at high tide in dry season but at low tide in wet season. The plot of salinity versus excess Ra-224, showing non-conservative curve, suggests that high excess Ra-224 activities derive from desorption in dry season but from SGD input in wet season.

  16. Stepwise catalytic mechanism via short-lived intermediate inferred from combined QM/MM MERP and PES calculations on retaining glycosyltransferase ppGalNAcT2.

    Science.gov (United States)

    Trnka, Tomáš; Kozmon, Stanislav; Tvaroška, Igor; Koča, Jaroslav

    2015-04-01

    The glycosylation of cell surface proteins plays a crucial role in a multitude of biological processes, such as cell adhesion and recognition. To understand the process of protein glycosylation, the reaction mechanisms of the participating enzymes need to be known. However, the reaction mechanism of retaining glycosyltransferases has not yet been sufficiently explained. Here we investigated the catalytic mechanism of human isoform 2 of the retaining glycosyltransferase polypeptide UDP-GalNAc transferase by coupling two different QM/MM-based approaches, namely a potential energy surface scan in two distance difference dimensions and a minimum energy reaction path optimisation using the Nudged Elastic Band method. Potential energy scan studies often suffer from inadequate sampling of reactive processes due to a predefined scan coordinate system. At the same time, path optimisation methods enable the sampling of a virtually unlimited number of dimensions, but their results cannot be unambiguously interpreted without knowledge of the potential energy surface. By combining these methods, we have been able to eliminate the most significant sources of potential errors inherent to each of these approaches. The structural model is based on the crystal structure of human isoform 2. In the QM/MM method, the QM region consists of 275 atoms, the remaining 5776 atoms were in the MM region. We found that ppGalNAcT2 catalyzes a same-face nucleophilic substitution with internal return (SNi). The optimized transition state for the reaction is 13.8 kcal/mol higher in energy than the reactant while the energy of the product complex is 6.7 kcal/mol lower. During the process of nucleophilic attack, a proton is synchronously transferred to the leaving phosphate. The presence of a short-lived metastable oxocarbenium intermediate is likely, as indicated by the reaction energy profiles obtained using high-level density functionals.

  17. Stepwise catalytic mechanism via short-lived intermediate inferred from combined QM/MM MERP and PES calculations on retaining glycosyltransferase ppGalNAcT2.

    Directory of Open Access Journals (Sweden)

    Tomáš Trnka

    2015-04-01

    Full Text Available The glycosylation of cell surface proteins plays a crucial role in a multitude of biological processes, such as cell adhesion and recognition. To understand the process of protein glycosylation, the reaction mechanisms of the participating enzymes need to be known. However, the reaction mechanism of retaining glycosyltransferases has not yet been sufficiently explained. Here we investigated the catalytic mechanism of human isoform 2 of the retaining glycosyltransferase polypeptide UDP-GalNAc transferase by coupling two different QM/MM-based approaches, namely a potential energy surface scan in two distance difference dimensions and a minimum energy reaction path optimisation using the Nudged Elastic Band method. Potential energy scan studies often suffer from inadequate sampling of reactive processes due to a predefined scan coordinate system. At the same time, path optimisation methods enable the sampling of a virtually unlimited number of dimensions, but their results cannot be unambiguously interpreted without knowledge of the potential energy surface. By combining these methods, we have been able to eliminate the most significant sources of potential errors inherent to each of these approaches. The structural model is based on the crystal structure of human isoform 2. In the QM/MM method, the QM region consists of 275 atoms, the remaining 5776 atoms were in the MM region. We found that ppGalNAcT2 catalyzes a same-face nucleophilic substitution with internal return (SNi. The optimized transition state for the reaction is 13.8 kcal/mol higher in energy than the reactant while the energy of the product complex is 6.7 kcal/mol lower. During the process of nucleophilic attack, a proton is synchronously transferred to the leaving phosphate. The presence of a short-lived metastable oxocarbenium intermediate is likely, as indicated by the reaction energy profiles obtained using high-level density functionals.

  18. The prolactin response to an acute stressor in relation to parental care and corticosterone in a short-lived bird, the Eurasian hoopoe.

    Science.gov (United States)

    Schmid, Baptiste; Chastel, Olivier; Jenni, Lukas

    2011-10-01

    Prolactin plays an important role in mediating parental care in birds, but little is known about changes in prolactin levels when animals disrupt their reproductive behaviour during emergency life-history stages. We investigated the variation of prolactin levels with breeding stage, sex, body condition and as a response to a standardized acute stressor in a small short-lived bird, the Eurasian hoopoe Upupa epops under natural field conditions. We found higher baseline levels of prolactin in females during the brooding phase than in their mates which feed them and their chicks at this stage. Moreover, this is the first report of a differential prolactin stress-response between sexes with contrasting parental care within a breeding phase. Capture, handling and restraint induced a clear decrease of prolactin levels which was less pronounced in females at the very early stage of brooding compared to females in later stages. In contrast, the prolactin stress response in males remained nearly constant over the breeding stages and was stronger than in females. Baseline levels of prolactin, but not handling-induced levels, were positively correlated with body condition. We found a weak relationship between the decrease in prolactin due to acute handling stress and handling-induced levels of corticosterone. Taken together, both baseline and stress response levels of prolactin were related to the amount of parental care, although we found no relationship with reproductive success. It appears that the response to an acute stressor in prolactin levels is finely tuned to parental duties and investment. Hence, prolactin appears to be involved in mediating the trade-off between current reproduction versus self-maintenance and future reproduction. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Continuous monitoring α-activity on aerosol filters by the pseudo-coincidence-technique. Explicitly taking into account the short lived Po-218 activity; Kontinuierliche Ueberwachung der α-Aktivitaet eines Aerosolfilters mit der Pseudokoinzidenzmesstechnik. Explizite Beruecksichtigung der kurzlebigen Po-218 Aktivitaetsbeitraaege

    Energy Technology Data Exchange (ETDEWEB)

    Kraut, W.; Schwarz, W. [Duale Hochschule Baden-Wuerttemberg (DHBW), Karlsruhe (Germany). Studiengang Sicherheitswesen; Kraut, B. [Berthold Technologies GmbH und Co.KG, Bad Wildbad (Germany)

    2015-07-01

    Pseudo-coincidence-technique is applied to continuous monitoring of α-activity on aerosolfilters by proportional counters. Filter activity can markedly increase or decrease by changing air conditions especially by the amount of short lived Po-218 activity. Conditions of constant proportions of activity concentrations for the short lived species for operating this technique are seldom fulfilled. The dynamic behavior of artificial (long lived) and natural (short lived) activity is mathematically modelled and the measured moving count rates are analyzed under this model by a multivariate regression analysis for activity concentrations of artificial resp. short lived activity. Results are compared to standard recommendations of DIN ISO 11929.

  20. Production of Rare Earth Isotope Beams for Radiotracer-DLTS on SiC

    CERN Multimedia

    2002-01-01

    Electrical properties of semiconductors are extremely sensitive to minor traces of impurities and defects. This fact allows to intentionally modify material properties and is thus the very basis of semiconductor electronics and optoelectronics. In the present project, electronic properties and doping effects of rare-earth elements in the technologically important semiconductor SiC are to be investigated using optical and electrical characterization techniques like Photoluminescence, Deep Level Transient Spectroscopy and Thermal Admittance Spectroscopy. By using the elemental transmutation of radioactive isotopes as a tracer, it will be guaranteed that the impurity-related band gap states can definitively be distinguished from intrinsic or process-induced defects. For SiC up to now only detailed investigation of Er- related deep levels have been reported, preliminary data exist for Sm- and Gd- impurities. In this project we propose the implantation of Pr and Eu isotopes for detailed level studies.

  1. Application of Radiotracer Technology on Solving the Unsolved Leak in Lift Pit

    International Nuclear Information System (INIS)

    Mohd Fitri Abdul Rahman; Jaafar Abdullah; Hearie Hassan

    2016-01-01

    Radiotracers have been used in many fields to optimize processes, solve problems, improve product quality, save energy and reduce pollution. The radiotracer technology is a proven reliable technique and recognized by many sectors such as medical, industrial and environmental. In this work, an unsolved leak problem was present in lift pit within a building in Malaysia. Many techniques have applied such as dye techniques, chemical analyses and engineering plaster to overcome the problem. Unfortunately, none of the techniques solve the problem. Radiotracer was used to find the unidentified source of leak. Basically, Technetium (Tc-99m) has been injected to the several injection points and flow of the tracer was monitored with radiation detectors that have been placed at various locations. The results were successful and pinpoint the problems. (author)

  2. ISOL science at the Holifield Radioactive Ion Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Beene, James R [ORNL; Bardayan, Daniel W [ORNL; Galindo-Uribarri, Alfredo {nmn} [ORNL; Gross, Carl J [ORNL; Jones, K. L. [University of Tennessee, Knoxville (UTK); Liang, J Felix [ORNL; Nazarewicz, Witold [ORNL; Stracener, Daniel W [ORNL; Tatum, B Alan [ORNL; Varner Jr, Robert L [ORNL

    2011-01-01

    The Holi eld Radioactive Ion Beam Facility, located in Oak Ridge, Tennessee, is operated as a National User Facility for the U.S. Department of Energy, producing high quality ISOL beams of short-lived, radioactive nuclei for studies of exotic nuclei, astrophysics research, and various societal applications. The primary driver, the Oak Ridge Isochronous Cyclotron, produces rare isotopes by bombarding highly refractory targets with light ions. The radioactive isotopes are ionized, formed into a beam, mass selected, injected into the 25-MV Tandem, accelerated, and used in experiments. This article reviews HRIBF and its science.

  3. Hyperfine structure and isotope-shift measurements of short-lived elements by laser spectroscopy. Progress report, January 1, 1980-August 31, 1981

    International Nuclear Information System (INIS)

    Schuessler, H.A.

    1981-09-01

    Work is reported on numerical studies of the trapping of continuous ion beams injected into various ion traps, numerical studies of the trapping of the pulsed ion beams injected into a radio frequency ion trap, construction of a plasma ion source and a radio frequency ion trap, development of a laser system for the spectroscopy of stored ions, and experiments with quartz cells at high temperatures

  4. Hyperon Beam Experiment

    CERN Multimedia

    2002-01-01

    The experiment WA89 uses the upgraded Omega facility together with a hyperon beam installed at the end of the H1 beamline. The beam can deliver 2~10$ ^{5} \\% Sigma ^- $ per machine burst at 330 GeV/c with a background of 5 10$ ^{5} \\% \\pi ^- $. \\\\ \\\\ The goals of the experiment are: observation of charmed particles, mainly the charmed-strange baryons and measurements of their production in the kinematical range x$ _{F} $~$>$~0.2, and their decay properties, a search for exotic states such as U(3100) observed in the previous CERN hyperon beam experiment WA62, measurements of hyperon polarization and production properties. \\\\ \\\\ A vertex detector consisting of 24 silicon microstrip planes with 25~$\\mu$m pitch and 6~planes with 50~$\\mu$m pitch provides track measurements of sufficient accuracy to identify the decays of short living charmed particles and measure their lifetimes. A RICH detector provides good $\\pi$/K separation for momenta up to 100~GeV/c and $\\pi$/p separation up to 150~GeV/c. Photons are detecte...

  5. Distributed Microprocessor Automation Network for Synthesizing Radiotracers Used in Positron Emission Tomography [PET

    Science.gov (United States)

    Russell, J. A. G.; Alexoff, D. L.; Wolf, A. P.

    1984-09-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. (DT)

  6. Study of technological parameters influence on homogeneity of rubber mixings by means of radiotracer methods

    International Nuclear Information System (INIS)

    Koczorowska, E.

    1995-01-01

    The radiotracer methods have been worked out for analysis of physico-chemical phenomena. The analysis were carried out for rubber mixings in technological conditions and played a deciding role for quality of manufacturing assortment. The 35 S and 65 Zn have been used as radiotracers. Analysis of different technological parameters influence on behaviour of soluble and polymerized sulfur, zinc compounds as well as other components of the rubber mixing enables to formulate the conclusions important for rubber industry and technology from view point of quality of manufacturing products

  7. Research of pharmacokinetics of L-threonate calcium with 45Ca radiotrace

    International Nuclear Information System (INIS)

    Tong Jian; Niu Huisheng; Li Huaifen

    2001-01-01

    The pharmacokinetics of calcium in L-threonate calcium is studied by radiotrace method. The results show the relationship between drug-time curve, pharmacokinetics parameters and dosage are positive correlation, and calcium distributes in important tissues such as stomach, intestines, blood and bone. In 24 hours, about 40% calcium is drained in urine, 30% calcium is evacuated in feces, 10%-20% calcium deposit in blood or bone. The radiotrace method is a kind of special, sensitive, accurate method of testing calcium metabolism

  8. Distributed microprocessor automation network for synthesizing radiotracers used in positron emission tomography

    International Nuclear Information System (INIS)

    Russell, J.A.G.; Alexoff, D.L.; Wolf, A.P.

    1984-01-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. 20 refs. (DT)

  9. Synthesis and marking with technetium and rhenium of a new radiotracer from para-toluidine

    International Nuclear Information System (INIS)

    Laouini, Emna

    2011-01-01

    The development of nuclear medicine is based on the research of new radiotracers especially those which target the neuro degenerative diseases. In fact, the precocious diagnostic of these diseases using the radiopharmaceuticals is the only mean to defeat it. The biodistribution of a new cytectrene derivative from para-toluidine, having a lipophilic character and a low molecular weight, showed a new radiotracer which is able to clear the blood brain barrier and characterised with prolonged brain retention. The features of this complex contribute to make it a radiopharmaceutical to diagnostic aim in clinical use.

  10. Industrial applications of radiotracer and sealed source technology promoted by IAEA

    International Nuclear Information System (INIS)

    Joon-Ha Jin; Thereska, J.

    2004-01-01

    Great technical and economical benefits can be obtained by applying radioisotope technologies to various industries. The International Atomic Energy Agency (IAEA) has contributed to the development of radiotracer and sealed source technology as applied to industry and environment through coordinated research projects (CRPs). The mature and competitive techniques have been transferred and implemented to developing countries through the Agency's technical co-operation (TC) projects. The paper presents the main achievements in radiotracer and sealed source technology promoted by IAEA as well as the perspective of the technology transfer to developing countries. (author)

  11. A multi-model intercomparison of halogenated very short-lived substances (TransCom-VSLS): linking oceanic emissions and tropospheric transport for a reconciled estimate of the stratospheric source gas injection of bromine

    OpenAIRE

    Hossaini, R.; Patra, P. K.; Leeson, A. A.; Krysztofiak, G.; Abraham, N. L.; Andrews, S. J.; Archibald, A. T.; Aschmann, J.; Atlas, E. L.; Belikov, D. A.; Bonisch, H.; Carpenter, L. J.; Dhomse, S.; Dorf, M.; Engel, A.

    2016-01-01

    The first concerted multi-model intercomparison of halogenated very short-lived substances (VSLS) has been performed, within the framework of the ongoing Atmospheric Tracer Transport Model Intercomparison Project (TransCom). Eleven global models or model variants participated (nine chemical transport models and two chemistry–climate models) by simulating the major natural bromine VSLS, bromoform (CHBr3) and dibromomethane (CH2Br2), over a 20-year period (1993–2012). Except f...

  12. Fluid flow profile in a packed bead column using residence time curves and radiotracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ana Paula F. de; Gonçalves, Eduardo Ramos; Brandão, Luis Eduardo B.; Salgado, Cesar M., E-mail: anacamiqui@gmail.com, E-mail: egoncalves@con.ufrj.br, E-mail: brandao@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Filling columns are extremely important in the chemical industry and are used for purification, separation and treatment processes of gas or liquid mixtures. The objective of this work is to study the hydrodynamics of the fluid for a characterization of aqueous phase flow patterns in the filling column, associating with the methodology of the Curves of Residence Time Distribution (RTD) to analyze and associate theoretical models that put as conditions column operating. RTD can be obtained by using the pulse-stimulus response technique which is characterized by the instantaneous injection of a radiotracer into the system input. In this work, 68Ga was used as radiotracer. Five shielded and collimated NaI (Tl) 1 x 1″ scintillator detectors were suitably positioned to record the movement of the radiotracer's path in the conveying line and filling column. Making possible the analysis of the RTD curve in the regions of interest. With the data generated by the NaI (Tl) detectors with the passage of the radiotracer in the transport line and inside the column, it was possible to evaluate the flow profile of the aqueous phase and to identify operational failures, such as internal conduit and the existence of a retention zone in the inside the column. Theoretical models were used for different flow flows: the piston flow and perfect mixing. (author)

  13. Application of 140La and 24Na as intrinsic radiotracers for investigating catalyst dynamics in FCCUs.

    Science.gov (United States)

    Pant, H J; Sharma, V K; Nair, A G C; Tomar, B S; Nathaniel, T N; Reddy, A V R; Singh, Gursharan

    2009-09-01

    Instrumental neutron activation analysis (INAA) of fluid catalytic cracking (FCC) catalyst samples was carried out with an objective to identify activable elements and evaluate its suitability for use as an intrinsic radiotracer for tracing catalyst itself in Fluid Catalytic Cracking Units (FCCUs) used in petroleum refining. Two catalyst samples obtained from two different refineries were analyzed. Twelve different elements were identified in each catalyst sample and their respective concentrations were determined. From the recorded gamma-ray spectra, it was found that lanthanum-140 ((140)La) and sodium-24 ((24)Na) were the predominantly present and suitable radionuclides that could be used as radiotracers for tracing catalyst in FCCUs. Lanthanum being present in much higher concentration forms the major component of the radiotracer after irradiation. Based on the results of INAA, appropriate quantities of the catalyst samples were irradiated with neutrons to produce the desired amount of activity of lanthanum-140 and sodium-24 to be used as radiotracers for tracing the catalyst itself in a pilot as well as an industrial-scale FCCU. The residence time distribution (RTD) of catalyst was measured and analyzed to determine mean residence time (MRT). The axial dispersion model (ADM) was used to simulate the measured RTD data and investigate the degree of axial mixing. The results of the experiments were used to improve the design of pilot-scale FCCU and optimize the performance of the industrial-scale FCCU.

  14. Fluid flow profile in a packed bead column using residence time curves and radiotracer techniques

    International Nuclear Information System (INIS)

    Almeida, Ana Paula F. de; Gonçalves, Eduardo Ramos; Brandão, Luis Eduardo B.; Salgado, Cesar M.

    2017-01-01

    Filling columns are extremely important in the chemical industry and are used for purification, separation and treatment processes of gas or liquid mixtures. The objective of this work is to study the hydrodynamics of the fluid for a characterization of aqueous phase flow patterns in the filling column, associating with the methodology of the Curves of Residence Time Distribution (RTD) to analyze and associate theoretical models that put as conditions column operating. RTD can be obtained by using the pulse-stimulus response technique which is characterized by the instantaneous injection of a radiotracer into the system input. In this work, 68Ga was used as radiotracer. Five shielded and collimated NaI (Tl) 1 x 1″ scintillator detectors were suitably positioned to record the movement of the radiotracer's path in the conveying line and filling column. Making possible the analysis of the RTD curve in the regions of interest. With the data generated by the NaI (Tl) detectors with the passage of the radiotracer in the transport line and inside the column, it was possible to evaluate the flow profile of the aqueous phase and to identify operational failures, such as internal conduit and the existence of a retention zone in the inside the column. Theoretical models were used for different flow flows: the piston flow and perfect mixing. (author)

  15. Determination of retention period of sewage in a filtration plant using radiotracer technique

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.; Kirti

    1979-01-01

    A radiotracer investigation was carried out at Dadar sewage purification plant, Bombay, for measuring the retention period of a trickling filter unit. The method is based on the addition of 82 Br tracer in the form of NH 4 Br solution at the inlet and continuous recording of the tracer at the flow stream. Results obtained in the actual investigation are also given. (auth.)

  16. Estimation of tritium radiotracer activity for interconnection study in geothermal field

    International Nuclear Information System (INIS)

    Rasi Prasetio; Satrio

    2016-01-01

    Tritium radiotracer (3H) has been applied widely in many geothermal fields around the world. This application was done by injecting radiotracer with certain amount of activity into reinjection well in order to investigate interconnection between reinjection well with surrounding production wells. The activity of injected radiotracer must meets the field condition and the volume of reservoir, detection limit of instrument, as well as safety aspect for the workers and environment from radioactive hazard. The planning of injection process must consider the maximum permissible concentration (MPC) and minimum detection limit (MDL). Based on calculation, tritium radiotracer injection in Kamojang geothermal field can be done with minimal activity of 0.15 Ci and maximum 22100 Ci, while in Lahendong field minimum activity of 0.65 Ci and maximum 7230 Ci. In these two injection studies, tritium was detected in monitoring wells between MDL and MPC limit. By using this estimation calculation, the activity of tritium that released into the environment within safety limit, thus monitoring wells with undetectable tritium infer no connectivity between those wells with reinjection well. (author)

  17. The radiochemical purity of radiotracers as the criterion of their usefulness in investigations of hydrocarbons distillation

    International Nuclear Information System (INIS)

    Kolaczkowski, M.

    1976-01-01

    Among numerous analytic techniques of separation and analysis of radioactive products gas radiochromatography has proved to be particularly suitable. Organic bromides labelled with 82 Br-radionuclide are investigated. The analytic gas chromatographs equipped with appropriately constructed radiochromatographic attachments are used. The results of radiochemical purity determination of radiotracers are compared for various techniques. (author)

  18. Radiotracer investigation of the cold-vapour atomic absorption method of analysis for trace mercury

    International Nuclear Information System (INIS)

    Stuart, D.C.

    1978-01-01

    Because of certain problems found in application of the atomic absorption method for trace analysis of mercury, a careful check of the procedures used was undertaken, with radiotracer mercury to facilitate the investigation. The results obtained, in conjunction with those of sample ashing procedures, indicate that the method is less straightforward than its simplicity suggests. (Auth.)

  19. Leakage investigation in an underground cooling water pipeline at a thermal power station using radiotracer technique

    International Nuclear Information System (INIS)

    Khan, I.H.; Din, U.G.; Gul, S.; Farooq, M.; Qureshi, R.M.

    2004-05-01

    The objective of this study was to locate the leakage point(s) in an underground cooling water pipeline of a Thermal Power Station for pre-shutdown planning purposes. The internal diameter of the pipeline was 2240 mm with 12 mm with 12 (mild steel) wall thickness and it was buried under 1.0 meter reinforced concrete and 0.5-1.0 meter soil/sand cover. The volume flow rate of the pipeline was 29043 m/sup 3/hour at 2kg/cm/sup 2/ pressure. The linear speed of water flowing inside the pipeline was around 2 m/sec. This gave rise to a very high volume fast moving system. Radiotracer technique was used to investigate the problem under investigation. About 50 mCi of /sup 131/I radiotracer, in the form of NaI solution, was injected into the system and radiotracer evolution near suspected leakage point(s) was monitored using radiation detectors (NaI, 2 x 2 inch crystal size). Seven detectors were installed around three teeing off pipes (leakage area) inside the plant building and one at the injection point near the pump outlet. On line data acquisition system was used to acquire the radiotracer data. The leakage water was exiting from the floor just along the pipes carrying main flow of water. The time lag between the arrival, at detectors, of radiotracer flowing inside the pipeline and that present in the leakage water (outside the pipeline) was exploited to identify the position of leakage. The tracer test revealed that there was leakage at two points. The leakage at one point was small as compared at the other points. (author)

  20. Oxygen isotopic and geochemical evidence for a short-lived, high-temperature hydrothermal event in the Chegem caldera, Caucasus Mountains, Russia

    Science.gov (United States)

    Gazis, C.; Taylor, H.P.; Hon, K.; Tsvetkov, A.

    1996-01-01

    Within the 2.8 Ma Chegem ash-flow caldera (11 ?? 15 km), a single cooling unit of rhyolitic to dacitic welded tuff more than 2 km thick is exposed in deep valleys incised during recent rapid uplift of the Caucasus Mountains. The intracaldera tuff is mineralogically fresh and unaltered, and is overlain by andesite lavas and cut by a resurgent granodiorite intrusion. Major- and trace-element compositions for a 1405-m stratigraphic section of intracaldera tuff display trends of upwardly increasing Na2O, CaO, Al2O3, total Fe, MgO, TiO2, Sr and Zr and decreasing SiO2, K2O and Rb. This mafic-upward zoning (from 76.1 to 69.9% SiO2) reflects an inverted view of the upper part of the source magma chamber. Oxygen isotope studies of 35 samples from this 1405-m section define a striking profile with "normal" igneous ??18O values (+7.0 to +8.5) in the lower 600 m of tuff, much lower ??18O values (-4.0 to +4.3) in a 700-m zone above that and a shift to high ??18O values (+4.4 to -10.9) in the upper 100 m of caldera-fill exposure. Data from two other partial stratigraphic sections indicate that these oxygen isotope systematics are probably a caldera-wide phenomenon. Quartz and feldspar phenocrysts everywhere have "normal" igneous ??18O values of about +8.5 and +7.5, respectively, whereas groundmass and glass ??18O values range from -7.7 to +12.3. Consequently, the ??18O values of coexisting feldspar, groundmass and glass form a steep array in a plot of ??feldspar vs. ??groundmass/glass. Such pronounced disequilibrium between coexisting feldspar and groundmass or glass has never before been observed on this scale. It requires a hydrothermal event involving large amounts of low-18O H2O at sufficiently high temperatures and short enough time (tens of years or less) that glass exchanges thoroughly but feldspar does not. The most likely process responsible for the O depletions at Chegem is a very high temperature (500-600??C), short-lived, vigorous meteoric-hydrothermal event that was

  1. Delivery of halogenated very short-lived substances from the west Indian Ocean to the stratosphere during the Asian summer monsoon

    Directory of Open Access Journals (Sweden)

    A. Fiehn

    2017-06-01

    Full Text Available Halogenated very short-lived substances (VSLSs are naturally produced in the ocean and emitted to the atmosphere. When transported to the stratosphere, these compounds can have a significant influence on the ozone layer and climate. During a research cruise on RV Sonne in the subtropical and tropical west Indian Ocean in July and August 2014, we measured the VSLSs, methyl iodide (CH3I and for the first time bromoform (CHBr3 and dibromomethane (CH2Br2, in surface seawater and the marine atmosphere to derive their emission strengths. Using the Lagrangian particle dispersion model FLEXPART with ERA-Interim meteorological fields, we calculated the direct contribution of observed VSLS emissions to the stratospheric halogen burden during the Asian summer monsoon. Furthermore, we compare the in situ calculations with the interannual variability of transport from a larger area of the west Indian Ocean surface to the stratosphere for July 2000–2015. We found that the west Indian Ocean is a strong source for CHBr3 (910 pmol m−2 h−1, very strong source for CH2Br2 (930 pmol m−2 h−1, and an average source for CH3I (460 pmol m−2 h−1. The atmospheric transport from the tropical west Indian Ocean surface to the stratosphere experiences two main pathways. On very short timescales, especially relevant for the shortest-lived compound CH3I (3.5 days lifetime, convection above the Indian Ocean lifts oceanic air masses and VSLSs towards the tropopause. On a longer timescale, the Asian summer monsoon circulation transports oceanic VSLSs towards India and the Bay of Bengal, where they are lifted with the monsoon convection and reach stratospheric levels in the southeastern part of the Asian monsoon anticyclone. This transport pathway is more important for the longer-lived brominated compounds (17 and 150 days lifetime for CHBr3 and CH2Br2. The entrainment of CHBr3 and CH3I from the west Indian Ocean to the stratosphere during the

  2. Radon and its short-lived daughter products in the lower atmosphere; Le radon et ses derives a vie courte dans la basse atmosphere

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    The variations of vertical and temporal distributions of natural radioactivity with geographical location in the lower atmospheric layers are shown. The content of radon and its short lived daughters products are measured. Radon content is measured continually with a new apparatus, the sensibility of which is 0,2.10{sup -11} Ci m{sup -3} i.e. the fiftieth of the mean concentration near the soil, this apparatus allowed us to show that radioactive equilibrium between radon and its daughter products is realised when the atmosphere is stable. Air observations between 0 and 100 meters above the ground point out that radon and its decay products are valuable tracers to mark the stability of the atmosphere. Under very stable nighttime conditions the radon accumulates in the former 30 meters of the air layer, at sunrise it ascends and at 9 o'clock attains 100 meters high. The removal rate of the air in the lower atmosphere is computed from the movement of this radon mass, it is equal to 90 per cent for a summer day. We have show that this radon comes from the soil in which it diffuses by brownian motion the intensity of which varies with the water content of the soil, its value for June 1958 is 6,10{sup -17} Ci cm{sup -2}s{sup -1} and for January 1959 0.2,10{sup -17} Ci cm{sup -2} s{sup -}1. During the year 1958-1959 general mean of flux for the sedimentary soil studied is equal to 3. 8 {+-} 1.3, 10{sup -17} Ci cm{sup -2} s{sup -1} it is identical to the world wide mean computed by H. Israel. In a hilly site in the Morvan, air movements are well marked by this radioactivity. We observed from one hand downslope and up-slope breezes having, respectively, speeds of 0.2 m s{sup -1} and 0.7 m s{sup -1} and from the other hand by night, in the valley and with a light wind favours the stagnation of the air near the ground, a strong increase of the radioactivity which is proportional to the one of the granitic rocks of the region. The radon flux of this soil is 74,10{sup -17} Ci

  3. High spin isomer beam line at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Kishida, T.; Ideguchi, E.; Wu, H.Y. [Institute of Physical and Chemical Research, Saitama (Japan)] [and others

    1996-12-31

    Nuclear high spin states have been the subject of extensive experimental and theoretical studies. For the production of high spin states, fusion reactions are usually used. The orbital angular momentum brought in the reaction is changed into the nuclear spin of the compound nucleus. However, the maximum induced angular momentum is limited in this mechanism by the maximum impact parameter of the fusion reaction and by the competition with fission reactions. It is, therefore, difficult to populate very high spin states, and as a result, large {gamma}-detector arrays have been developed in order to detect subtle signals from such very high spin states. The use of high spin isomers in the fusion reactions can break this limitation because the high spin isomers have their intrinsic angular momentum, which can bring the additional angular momentum without increasing the excitation energy. There are two methods to use the high spin isomers for secondary reactions: the use of the high spin isomers as a target and that as a beam. A high spin isomer target has already been developed and used for several experiments. But this method has an inevitable shortcoming that only {open_quotes}long-lived{close_quotes} isomers can be used for a target: {sup 178}Hf{sup m2} (16{sup +}) with a half-life of 31 years in the present case. By developing a high spin isomer beam, the authors can utilize various short-lived isomers with a short half-life around 1 {mu}s. The high spin isomer beam line of RIKEN Accelerator Facility is a unique apparatus in the world which provides a high spin isomer as a secondary beam. The combination of fusion-evaporation reaction and inverse kinematics are used to produce high spin isomer beams; in particular, the adoption of `inverse kinematics` is essential to use short-lived isomers as a beam.

  4. Production of radioactive molecular beams for CERN-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Seiffert, Christoph

    2015-06-15

    ISOLDE, the Isotope Separation On-Line facility, at CERN is a leading facility for the production of beams of exotic radioactive isotopes. Currently over 1000 different isotopes with half lives down to milliseconds can be extracted with beam intensities of up to 10{sup 11} ions per second. However, due to the reactive target environment not all isotopes are extractable in sufficient amounts. In this work the extraction of short lived carbon and boron isotopes is investigated. Therefore a variety of experimental and computational techniques have been used.

  5. Production of radioactive molecular beams for CERN-ISOLDE

    CERN Document Server

    AUTHOR|(SzGeCERN)703149; Kröll, Thorsten

    SOLDE, the Isotope Separation On-Line facility, at CERN is a leading facility for the production of beams of exotic radioactive isotopes. Currently over 1000 different isotopes with half lives down to milliseconds can be extracted with beam intensities of up to 10^11 ions per second. However, due to the reactive target environment not all isotopes are extractable in sufficient amounts. In this work the extraction of short lived carbon and boron isotopes is investigated. Therefore a variety of experimental and computanional techniques have been used.

  6. Spectrum analysis of radiotracer residence time distribution for industrial and environmental applications

    International Nuclear Information System (INIS)

    Kasban, H.; Ashraf Hamid

    2014-01-01

    Radiotracer signal analysis and recognition still represents challenges in industrial and environmental applications specially in residence time distribution (RTD) measurement. This paper presents a development for the RTD signal recognition method that is based on power density spectrum (PDS). In this development, the features are extracted from the signals and/or from their higher-orders statistics (HOS) (Bispectrum and Trispectrum) instead of PDS. The HOS are estimated using direct, indirect and parametric estimations. The recognition results are analyzed and compared for different HOS estimation in order to select the best HOS estimation method for the purpose of RTD signal recognition. The artificial neural networks are used for training and testing of the proposed method. The proposed method is tested using RTD signals obtained from the measurements carried out using radiotracer technique. The simulation results show that the parametric estimation of the Trispectrum gives the higher recognition rate and is the most reliable for the RTD signal recognition. (author)

  7. The use of rare earth radiotracers in the study of solvent extraction kinetics

    International Nuclear Information System (INIS)

    Lim, T.M.; Tran, T.

    1993-01-01

    The suitability of rare earth radionuclides as tracers in research and industry are assessed. In general, the most desirable characteristics of radiotracers for process studies are a half-life in the range 5-200 days, a high yield, high energy γ-emission and low cost of production. The majority of rare earths have at least one radionuclide with acceptable characteristics. The application of radiotracers to the study of kinetics of rare earth solvent extraction have been studied using a modified Lewis cell. Terbium-160 was selected as the most suitable rare earth radionuclide for our experiments. Samples of both aqueous and organic phases were continuous withdrawn, monitored using an automated γ-counting system based on two sodium iodide detectors and then pumped back to the Lewis cell. Excellent results were obtained and the rate of extraction was shown to be first order with respect to the terbium concentration. 6 refs., 1 tab., 7 figs

  8. Sulfur and Iron Cycling in a Coastal Sediment - Radiotracer Studies and Seasonal Dynamics

    DEFF Research Database (Denmark)

    MOESLUND, L.; THAMDRUP, B.; JØRGENSEN, BB

    1994-01-01

    The seasonal variation in sulfate reduction and the dynamics of sulfur and iron geochemistry were studied throughout a year in sediment of Aarhus Bay, Denmark. A radiotracer method for measuring sulfate reduction rates was applied with incubation times down to 15 min and a depth resolution down...... to 2 mm in the oxidized surface layer of the sediment. The radiotracer data were analyzed by a mathematical model which showed that, due to partial, rapid reoxidation of radioactive sulfide during incubation, the actual reduction rates in this layer were probably underestimated 5-fold. In the deeper......, sulfidic zone, measured rates appeared to be correct. Sulfate reduction followed the seasonal variation in temperature with maximum activity at 1-2 cm depth in late summer. In spite of its rapid production, free H2S was detectable in the porewater only below the depth of free Fe2+ at 6-7 cm throughout...

  9. Estimation of shell thickness in a continuously cast steel billet using radiotracers

    International Nuclear Information System (INIS)

    Prasad, A.S.; Pandey, J.C.; Kaur, G.

    1994-01-01

    In the continuous casting of steel, one of the factors which limits the rate of faster withdrawal of the casting from the mould is the thickness of the solid shell below the mould. If the shell can not contain the liquid pool, breakouts occur and process of casting disrupts. Estimates of shell thickness have been made on the basis of heat- transfer considerations. The shell thickness could also be delineated, to some extent, by adding radiotracers during casting and subsequently determining the dispersion of radioactivity by autoradiography. The paper presents the results of the estimation of shell thickness based on the heat-transfer model and validation of the model by plant trials using radiotracers. (author). 11 refs., 5 figs., 1 tab

  10. The applicability of radiotracers for the investigation of the distillation of hydrocarbons

    International Nuclear Information System (INIS)

    Graczyk, J.; Iller, E.

    1976-01-01

    The use of radioactive tracers provide valuable methods for the investigation of distillation processes and have been applied to determine the characteristics of material streams, the dynamics of flowing phases and the composition in various parts of the distillation equipment. A method is proposed for testing individual radiotracers emplozemployed for the investigation of the distillation of hydrocarbons. The method consists in laboratory-scale distillation of a tracer together with a multicomponent hydrocarbon mixture, namely a gasoline fraction. The purification efficiency, distillation characteristics, and effective radiochemical purity of several tracers (reactor activated bromobenzene and synthesized C 3 H 7 82 Br, C 4 H 9 82 Br, C 5 H 11 82 Br) have been investigated. The distillation characteristics of bromohydrocarbons labelled with 82 Br and selected hydrocarbons tagged with 14 C (benzene and cumene) have been compared. The radiotracers investigated were employed for the determination of the hydrodynamic parameters of hydrocarbon distillation in laboratory packed columns and a commercial distillation tower. (author)

  11. Radiotracer study on the efficiency of a cylindrical 2-stage anaerobic sludge digester

    International Nuclear Information System (INIS)

    Sung-Hee Jung; Joon-Ha Jin; Jong-Bum Kim

    2004-01-01

    Radiotracer experiments were carried out on a cylindrical 2-stage anaerobic sludge digester in order to investigate the improvement of their efficiency by means of RTD (residence time distribution) measurements before and after cleaning up the inside of the digester. The tracer was scandium in an EDTA solution which forms such a stable complex compound to keep the isotope form being adsorbed onto the surface of the pipelines or the wall. It was injected into the digester by pressurized nitrogen gas and its movement was monitored by NaI(Tl) scintillation detectors installed around the digester and recorded for a month by a 24-channel data acquisition system specially developed for radiotracer experiments by the Korea Tracer Group of KAERI. The experimental data was analysed for the MRT (mean residence time) and other parameters characterizing the flow behaviour. (author)

  12. A radiotracer method for the dynamic measurement of the in-process inventory of dissolved materials

    International Nuclear Information System (INIS)

    Iqbal, M.N.; Gardner, R.P.; Verghese, K.

    1990-01-01

    A radioactive tracer method and the associated mathematical models have been developed to determine the in-process inventory of zirconium in a pulse column from the counting rate data taken at the exits of the aqueous and organic phases after an impulse injection of the radiotracer at the aqueous-phase inlet. Model parameters were obtained by applying a nonlinear least-squares fitting of the models to the experimental data. The total inventory of zirconium present in the pulse column under different operating conditions was determined by calculating the average residence time of zirconium in the system using these model parameters. The results indicate that the radiotracer technique provides a viable means of on-line determination of solute mass holdup. (author)

  13. Application of radiotracers in an exotic field of botany. How to feed carnivorous plants

    International Nuclear Information System (INIS)

    Steinhauser, G.; Musilek, A.; Sterba, J.H.; Bichler, M.; Adlassnig, W.; Peroutka, M.; Lichtscheidl, I.K.

    2007-01-01

    In this paper, methods for the application of radiotracers in the Cobra Lily (Darlingtonia californica), a carnivorous pitcher plant, are described. The uptake of radiotracers such as 42 K and 54 Mn into the pitcher trap in aqueous solution could be proven, whereas uptake of 59 Fe ions could not be observed. No-carrier-added 54 Mn was taken up by the plants, regardless of extremely low concentrations. In contrast to earlier experiments using 14 C and 15 N-based tracers, the methodology presented allows quick, simple and reliable quantification of the nutrient uptake. The results of our experiments lead to a deeper biological understanding concerning the trace element household of this carnivorous plant and the absorption of micro- and macronutrients from trapped prey. (author)

  14. Quality control for measurement of soil samples containing 237Np and 241Am as radiotracer

    International Nuclear Information System (INIS)

    Sha Lianmao; Zhang Caihong; Song Hailong; Ren Xiaona; Han Yuhu; Zhang Aiming; Chu Taiwei

    2003-01-01

    This paper reports quality control (QC) for the measurement of soil samples containing 237 Np and 241 Am as radiotracers in migration test of transuranic nuclides. All of the QC were done independently by the QA members of analytical work. It mainly included checking 5%-10% of the total analyzed samples; preparing blank samples, blind replicate sample and spiked samples used as quality control samples to check the quality of analytical work

  15. Overview of radiotracer experiments for better understanding of wastewater and water treatment plants in Lima (Peru))

    International Nuclear Information System (INIS)

    Calvo, C.S.; Maghella, G.; Mamani, E.; Berne, P.; Brisset, P.; Leclerc, J.-P.

    2004-01-01

    The objectives of this paper are to present an overview of possible applications of the radiotracers for better understanding of water and waste water treatment plants. Numerous experiments have been carried out in different plants located in Lima. Four processes have been investigated: desanders, floculators, clarifiers and digesters. Depending on the studied process, the experimental results have been interpreted at different levels of complexity: from simple troubleshooting to the modelling of the flow behaviour inside the process. (author)

  16. Abnormal gastrointestinal accumulation of radiotracer by gastric bleeding during 99mTc-MDP bone scintigraphy

    International Nuclear Information System (INIS)

    Chun, Kyung A.; Lee, Sang Woo; Lee, Jae Tae; Lee, Kyu Bo

    1998-01-01

    We present a case in which a patient with acute hemorrhagic gastritis demonstrated abnormal gastrointestinal accumulation of radiotracer during 99m Tc-methylene diphosphonate (MDP) skeletal scintigraphy. A hemorrhagic gastritis was subsequently demonstrated by endoscopy. The mechanism for the intestinal localization of 99m Tc-MDP in this patients is not clear, but we guess that the extravasated blood containing the radiopharmaceutical cannot recirculate and stays at the bleeding site, so we can see the intestinal activity

  17. Instrumental neutron activation analysis of human hair and related radiotracer experiments on washing and leaching

    International Nuclear Information System (INIS)

    Das, H.A.; Hoede, D.; Sloot, H.A. van der; Herber, R.F.M.

    1981-11-01

    The work done under the IAEA-contract 2440/RB is summarized. The aim was to develop a fast and reliable system for the determination of tracer elements in human head hair by instrumental neutron activation analysis (INAA) and radiotracer washing experiments. The standardized procedure for INAA was applied to hair samples collected by the Coronel Laboratory of the University of Amsterdam. The correlation between trace element contents is considered

  18. A radiotracer technique for testing a high pressure gas compressor for oil leakage

    International Nuclear Information System (INIS)

    Eapen, A.C.; Kirti; Jain, S.K.; Gupta, P.P.

    1979-01-01

    The radiotracer investigations carried out at NOCIL, Bombay, to measure the amount of lubrication oil present in the gas being compressed in a 1000 H.P. centrifugal compressor are described. By injecting a few mCi 131 I labelled glyceryl trioleate tracer and monitoring the radioactivity of the outlet gas for about 20 hours, the extent of the oil present in the gas could be determined. (auth.)

  19. Uses and limits of radiotracers in the study of drugs and xenobiotics metabolism

    International Nuclear Information System (INIS)

    Cohen, Y.

    1980-01-01

    This review deals with scientific papers issued in 1977-1978, on labelling of drugs and xenobiotics and their metabolism. It is divided in five parts: site of label; in vivo metabolism in animals and human beings; in vitro metabolism on tissue slices, cells culture, microsomes, membrane receptors; metabolism of xenobiotics: nutrients, food additives, detergents, plastics and fabrics; discussion. Metabolic studies, nowadays, associate radiotracers, stable isotopes with high performing procedures for analytical separation [fr

  20. Residence time distribution measurements in a pilot-scale poison tank using radiotracer technique.

    Science.gov (United States)

    Pant, H J; Goswami, Sunil; Samantray, J S; Sharma, V K; Maheshwari, N K

    2015-09-01

    Various types of systems are used to control the reactivity and shutting down of a nuclear reactor during emergency and routine shutdown operations. Injection of boron solution (borated water) into the core of a reactor is one of the commonly used methods during emergency operation. A pilot-scale poison tank was designed and fabricated to simulate injection of boron poison into the core of a reactor along with coolant water. In order to design a full-scale poison tank, it was desired to characterize flow of liquid from the tank. Residence time distribution (RTD) measurement and analysis was adopted to characterize the flow dynamics. Radiotracer technique was applied to measure RTD of aqueous phase in the tank using Bromine-82 as a radiotracer. RTD measurements were carried out with two different modes of operation of the tank and at different flow rates. In Mode-1, the radiotracer was instantaneously injected at the inlet and monitored at the outlet, whereas in Mode-2, the tank was filled with radiotracer and its concentration was measured at the outlet. From the measured RTD curves, mean residence times (MRTs), dead volume and fraction of liquid pumped in with time were determined. The treated RTD curves were modeled using suitable mathematical models. An axial dispersion model with high degree of backmixing was found suitable to describe flow when operated in Mode-1, whereas a tanks-in-series model with backmixing was found suitable to describe flow of the poison in the tank when operated in Mode-2. The results were utilized to scale-up and design a full-scale poison tank for a nuclear reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. The low to intermediate activity and short living waste storage facility. For a controlled management of radioactive wastes; Le centre de stockage des dechets de faible et moyenne activite a vie courte. Pour une gestion controlee des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Sited at about 50 km of Troyes (France), the Aube facility started in 1992 and has taken over the Manche facility for the surface storage of low to intermediate and short living radioactive wastes. The Aube facility (named CSFMA) is the answer to the safe management of these wastes at the industrial scale and for 50 years onward. This brochure presents the facility specifications, the wastes stored at the center, the surface storage concept, the processing and conditioning of waste packages, and the environmental monitoring performed in the vicinity of the site. (J.S.)

  2. Preparation of the Nanostructured Radioisotope Metallic Oxide by Neutron Irradiation for Use as Radiotracers

    Directory of Open Access Journals (Sweden)

    Sang-Ei Seo

    2017-10-01

    Full Text Available Metallic oxides manganese dioxide (MnO2, samarium oxide (Sm2O3, and dysprosium oxide (Dy2O3 with nanorod-like structures were synthesized by the hydrothermal synthesis method, respectively. Subsequently, the nanostructured radioisotopes MnO2 with Mn-56, Sm2O3 with Sm-153, and Dy2O3 with Dy-165 were prepared by neutron irradiation from the HANARO research reactor, respectively. The three different elements, Mn, Sm, and Dy, were selected as radiotracers because these elements can be easily gamma-activated from neutrons (activation limits: 1 picogram (Dy, 1–10 picogram (Mn, 10–100 picogram (Sm. Furthermore, the synthesized radioisotopes can be used as radiotracers in Prompt Gamma Neutron Activation Analysis as the rare earth metals Dy and Sm were not present in the Korean environment. The successful synthesis of the radioisotope metallic oxides was confirmed by Transmission Electron Microscopy (TEM, Energy Dispersive X-ray Spectrometry (EDS, X-ray Diffraction (XRD analysis, and gamma spectroscopy analysis. The synthesized nanostructured radioisotope metallic oxides may be used as radiotracers in scientific, environmental, engineering, and industrial fields.

  3. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    International Nuclear Information System (INIS)

    Sugiharto, S.; Kurniadi, R.; Abidin, Z.; Stegowski, Z.; Furman, L.

    2013-01-01

    Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT) having an inner diameter of 24 in (60,96 m). The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD) curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD) simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct. (author)

  4. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    S. Sugiharto1

    2013-04-01

    Full Text Available Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT having an inner diameter of 24 in (60,96 m. The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct

  5. Investigation of liquid phase axial dispersion in Taylor bubble flow by radiotracer residence time distribution analysis

    Directory of Open Access Journals (Sweden)

    Jin J.H.

    2013-05-01

    Full Text Available A gas-liquid Taylor bubble flow occurs in small diameter channels in which gas bubbles are separated by slugs of pure liquid. This type of flow regime is well suited for solid catalyzed gas-liquid reactors in which the reaction efficiency is a strong function of axial dispersion in the regions of pure liquid. This paper presents an experimental study of liquid phase axial dispersion in a Taylor bubble flow developed in a horizontal tube using high speed photography and radiotracer residence time distribution (RTD analysis. A parametric dependence of axial dispersion on average volume fraction of gas phase was also investigated by varying the relative volumetric flow rates of the two phases. 137mBa produced from a 137Cs/137mBa radionuclide generator was used as radiotracer and measurements were made using the NaI(Tl scintillation detectors. Validation of 137mBa in the form of barium chloride as aqueous phase radiotracer was also carried out. Axial Dispersion Model (ADM was used to simulate the hydrodynamics of the system and the results of the experiment are presented. It was observed that the system is characterized by very high values of Peclet Number (Pe∼102 which reveals an approaching plug type flow. The experimental and model estimated values of mean residence times were observed in agreement with each other.

  6. New-generation radiotracers for nAChR and NET

    Energy Technology Data Exchange (ETDEWEB)

    Ding Yushin [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)]. E-mail: ding@bnl.gov; Fowler, Joanna [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2005-10-01

    Advances in radiotracer chemistry and instrumentation have merged to make positron emission tomography (PET) a powerful tool in the biomedical sciences. Positron emission tomography has found increased application in the study of drugs affecting the brain and whole body, including the measurement of drug pharmacokinetics (using a positron-emitter-labeled drug) and drug pharmacodynamics (using a labeled tracer). Thus, radiotracers are major scientific tools enabling investigations of molecular phenomena, which are at the heart of understanding human disease and developing effective treatments; however, there is evidently a bottleneck in translating basic research to clinical practice. In the meantime, the poor ability to predict the in vivo behavior of chemical compounds based on their log P's and affinities emphasizes the need for more knowledge in this area. In this article, we focus on the development and translation of radiotracers for PET studies of the nicotinic acetylcholine receptor (nAChR) and the norepinephrine transporter (NET), two molecular systems that urgently need such an important tool to better understand their functional significance in the living human brain.

  7. Investigation of sediment transport and optimization of dredging operations in Indian ports using radiotracer technique

    International Nuclear Information System (INIS)

    Pant, H.J.

    2012-01-01

    India has a long coastline of about 7,515 km and there are twelve major ports situated on the coastline. Out of them, six are situated on the West Coast whereas other six are situated on the East Coast. In addition to this, there are more than 140 minor ports and other marine establishments situated along the coastline. Each port and marine project has a navigation channel and depth of this navigation channel needs to be maintained to a level of at least 12-15 meters for smooth sailing of ships. Sediments continuously move along the coast due to alongshore currents generated by the waves and tides; and get deposited in navigation channels. For maintaining the required depth of the channels, the dredging operation is carried out. throughout the year or as and when required. Development of a new port or harbour also involves huge capital dredging. The dredged sediments generated during maintenance or capital dredging needs to be dumped at a suitable location, so that it does not find its way back to the channel and obstruct sailing of ships. Moreover the selected site should be such that the turn around time of the dredger is kept minimum to economize the dredging operation. In order to meet the above requirements, the knowledge of transport parameters such as the general direction of movement, extent of lateral and longitudinal movement, transport velocity, transport thickness and bed load movement rate is required. Radiotracer techniques are commonly used to investigate sediment transport on seabed and evaluate the suitability of the proposed dumping sites. Scandium-46 (half-life: 84 days, Gamma energies: 0.89 MeV (100%), 1.12 MeV (100%)) in the form of scandium glass powder is the most suitable radiotracer for tracing sediments on seabed. The activity used in an investigation ranges from 75-300 GBq (2-8 Ci). The suitably prepared particulate radiotracer is injected on seabed at the proposed site using a specially designed injection system and its movement is

  8. Research on activation analysis using short-lived isotopes and a multi-purpose isotopic neutron irradiator. Part of a coordinated programme on on-line X-ray and neutron techniques for industrial process control

    International Nuclear Information System (INIS)

    Ozek, F.

    1981-02-01

    A method of cyclic activation analysis (CA) has been studied and applied. A theoretical comparison between cyclic and conventional neutron activation analysis of gold has been made. The optimum number of cycles in cyclic activation have been investigated and an equation for the rapid calculation of the number of cycles is proposed. The isotopic neutron irradiation system including the 5Ci Pu-Be neutron source was designed and constructed. The system is flexible and transportable and is capable of carrying out prompt and conventional delay gamma-ray analysis and cyclic activation of bulk materials. The advantages as well as the disadvantages of neutron activation analysis with the use of short-lived nuclides were considered, and can be summarized as follows: Advantages: saturation factor approaches unity, speed of analysis, low cost of analysis, increased selectivity, reduced matrix activities. Disadvantages: proximity of neutron source, chemical separation hardly possible or impossible, total number of counts low. Low counting rates can be substantially increased by applying the technique of ''cyclic activation'', which is another reason by the use of short-lived isotopes in neutron activation analysis is steadily becoming more attractive

  9. Beam-beam phenomenology

    International Nuclear Information System (INIS)

    Teng, L.C.

    1980-01-01

    In colliding beam storage rings the beam collision regions are generally so short that the beam-beam interaction can be considered as a series of evenly spaced non-linear kicks superimposed on otherwise stable linear oscillations. Most of the numerical studies on computers were carried out in just this manner. But for some reason this model has not been extensively employed in analytical studies. This is perhaps because all analytical work has so far been done by mathematicians pursuing general transcendental features of non-linear mechanics for whom this specific model of the specific system of colliding beams is too parochial and too repugnantly physical. Be that as it may, this model is of direct interest to accelerator physicists and is amenable to (1) further simplification, (2) physical approximation, and (3) solution by analogy to known phenomena

  10. Investigation of beam purity after in-trap decay and Coulomb excitation of $^{62}$Mn-$^{62}$Fe

    CERN Multimedia

    Clement, E; Gernhaeuser, R A; Diriken, J V J; Huyse, M L

    2008-01-01

    The in-trap decay of short lived radioactive ions is not well understood. This poses a problem for Coulomb excitation experiments at MINIBALL, where the normalization of the experiment depends strongly on observed secondary target excitation, which in turn strongly depends on the knowledge of the beam composition. For pure ISOLDE beams of short lived isotopes, the in-trap decay becomes important since a large fraction of the beam is transformed in unwanted daughter isotopes. In this proposal we intend to quantify the production of these daughter products in the REXTRAP accurately by making use of the short lived isotopes $^{61,62}$Mn and the newly installed Bragg ionization chamber at the end of the REX linear accelerator. Apart from the technical interest, the A=62 beam provides as well a good physics case, concerning the development of collectivity in neutron-rich Fe isotopes. Coulomb excitation, utilizing the standard MINIBALL setup, is proposed on both A=62 Mn and Fe. The Fe beam would be the first post-a...

  11. Short-Lived Human Umbilical Cord-Blood-Derived Neural Stem Cells Influence the Endogenous Secretome and Increase the Number of Endogenous Neural Progenitors in a Rat Model of Lacunar Stroke.

    Science.gov (United States)

    Jablonska, Anna; Drela, Katarzyna; Wojcik-Stanaszek, Luiza; Janowski, Miroslaw; Zalewska, Teresa; Lukomska, Barbara

    2016-11-01

    Stroke is the leading cause of severe disability, and lacunar stroke is related to cognitive decline and hemiparesis. There is no effective treatment for the majority of patients with stroke. Thus, stem cell-based regenerative medicine has drawn a growing body of attention due to the capabilities for trophic factor expression and neurogenesis enhancement. Moreover, it was shown in an experimental autoimmune encephalomyelitis (EAE) model that even short-lived stem cells can be therapeutic, and we have previously observed that phenomenon indirectly. Here, in a rat model of lacunar stroke, we investigated the molecular mechanisms underlying the positive therapeutic effects of short-lived human umbilical cord-blood-derived neural stem cells (HUCB-NSCs) through the distinct measurement of exogenous human and endogenous rat trophic factors. We have also evaluated neurogenesis and metalloproteinase activity as cellular components of therapeutic activity. As expected, we observed an increased proliferation and migration of progenitors, as well as metalloproteinase activity up to 14 days post transplantation. These changes were most prominent at the 7-day time point when we observed 30 % increases in the number of bromodeoxyuridine (BrdU)-positive cells in HUCB-NSC transplanted animals. The expression of human trophic factors was present until 7 days post transplantation, which correlated well with the survival of the human graft. For these 7 days, the level of messenger RNA (mRNA) in the analyzed trophic factors was from 300-fold for CNTF to 10,000-fold for IGF, much higher compared to constitutive expression in HUCB-NSCs in vitro. What is interesting is that there was no increase in the expression of rat trophic factors during the human graft survival, compared to that in non-transplanted animals. However, there was a prolongation of a period of increased trophic expression until 14 days post transplantation, while, in non-transplanted animals, there was a

  12. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    Science.gov (United States)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  13. Radiotracer and sealed source techniques for sediment management. Report of the consultants meeting

    International Nuclear Information System (INIS)

    2008-01-01

    Radioisotopes as tracers and sealed sources have been a useful and often irreplaceable tool for sediment transport studies. Gamma scattering and transmission gauges are used for sediment monitoring. Computational fluid dynamics (CFD) modelling is now an essential tool for the management of the natural systems and are increasingly used to study the fate and behaviour of particulates and contaminants. Radiotracer techniques are often employed to validate CFD models to enhance confidence in the predictive value of the models. Experimental tracing and numerical modelling are complementary methods of studying complex systems. During the last few decades, many radiotracer studies for the investigation of sediment transport in natural systems have been conducted worldwide, and various techniques for tracing and monitoring sediment have been developed by individual tracer groups. However, the developed techniques and methods for sediment tracing have not been compiled yet as a technical document, which is essential for the preservation of the knowledge and transfer of the technology to developing countries. Standard procedures or guidelines for the tracer experiments, which are vital for the reliability of the experiments and the acceptance of end-users, have not been established by the international tracer community either. The use of radiotracers in sediment transport studies demands the additional attention of the community to further develop these techniques and to ensure their transfer to developing countries. The Consultants' Meeting on 'Radiotracer and sealed source techniques for sediment management' was convened at the headquarters of the International Atomic Energy Agency (IAEA) in Vienna, Austria, from 21 to 25 April 2008. Experts from Argentina, Brazil, France, India, Republic of Korea and United Kingdom have been invited to discuss the current status of the tracer and nucleonic gauge technologies as applied for sediment transport investigations and to evaluate

  14. Radiotracer and sealed source techniques for sediment management. Report of the consultants meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Radioisotopes as tracers and sealed sources have been a useful and often irreplaceable tool for sediment transport studies. Gamma scattering and transmission gauges are used for sediment monitoring. Computational fluid dynamics (CFD) modelling is now an essential tool for the management of the natural systems and are increasingly used to study the fate and behaviour of particulates and contaminants. Radiotracer techniques are often employed to validate CFD models to enhance confidence in the predictive value of the models. Experimental tracing and numerical modelling are complementary methods of studying complex systems. During the last few decades, many radiotracer studies for the investigation of sediment transport in natural systems have been conducted worldwide, and various techniques for tracing and monitoring sediment have been developed by individual tracer groups. However, the developed techniques and methods for sediment tracing have not been compiled yet as a technical document, which is essential for the preservation of the knowledge and transfer of the technology to developing countries. Standard procedures or guidelines for the tracer experiments, which are vital for the reliability of the experiments and the acceptance of end-users, have not been established by the international tracer community either. The use of radiotracers in sediment transport studies demands the additional attention of the community to further develop these techniques and to ensure their transfer to developing countries. The Consultants' Meeting on 'Radiotracer and sealed source techniques for sediment management' was convened at the headquarters of the International Atomic Energy Agency (IAEA) in Vienna, Austria, from 21 to 25 April 2008. Experts from Argentina, Brazil, France, India, Republic of Korea and United Kingdom have been invited to discuss the current status of the tracer and nucleonic gauge technologies as applied for sediment transport investigations and to evaluate

  15. Molecular-beam scattering

    International Nuclear Information System (INIS)

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N 2 from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl → NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2 2 P/sub 3/2/) and Na(3 2 P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included

  16. Studies on the electrochemical behaviour of iron by the use of radio-tracer technique, 1. Studies on the electrodeposition and dissolution of iron by the use of radio-tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Moritani, Kimikazu; Ito, Yasuhiko; Kamata, Masahiro; Oishi, Jun

    1984-12-01

    To investigate whether radio-tracer techniques can augment conventional electrochemical techniques, offering useful information about the electrochemical behaviour of iron, the current efficiency of the electrodeposition of iron and the corrosion rate of metallic iron were measured by the radio-tracer method and the results were compared with the results measured by gravimetry and absorption photometry. Major conclusions obtained by the experiments are summarized as: 1) Between ordinary Fe and /sup 59/Fe, no isotope effect was observed. 2) Radiation from /sup 59/Fe had no effect on the electrode reaction. 3) While the use of a Ge semiconductor detector is undoubtedly preferable, Geiger-Mueller counter or NaI(Tl) scintillation counter gave fully satisfactory results. 4) Electrodeposited iron corrodes several times more rapidly than the iron base metal. These results suggests many other interesting applications of the radio-tracer technique when it is desired to obtain more detailed information on the electrochemical behaviour of iron. (author).

  17. Sulfur and Iron Cycling in a Coastal Sediment - Radiotracer Studies and Seasonal Dynamics

    DEFF Research Database (Denmark)

    MOESLUND, L.; THAMDRUP, B.; JØRGENSEN, BB

    1994-01-01

    to 2 mm in the oxidized surface layer of the sediment. The radiotracer data were analyzed by a mathematical model which showed that, due to partial, rapid reoxidation of radioactive sulfide during incubation, the actual reduction rates in this layer were probably underestimated 5-fold. In the deeper......, sulfidic zone, measured rates appeared to be correct. Sulfate reduction followed the seasonal variation in temperature with maximum activity at 1-2 cm depth in late summer. In spite of its rapid production, free H2S was detectable in the porewater only below the depth of free Fe2+ at 6-7 cm throughout...

  18. Radiotracer investigation to study residence time distribution in an evaporator system

    Energy Technology Data Exchange (ETDEWEB)

    Pant, H J; Yelgaonkar, V N; Navada, S V [Isotope Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Determination of mean residence time, residence time distribution and evaluation of flow behavior in industrial process systems is of prime importance in order to control the process and to evaluate the performance of the process systems. This paper describes a case study carried out in an evaporator system in a sugar factory near Pune for determination of the mean residence time and residence time distribution using radiotracer technique. The mean residence time (MRT) was determined to be 4 seconds. The mathematical modelling of residence time distribution (RTD) data indicated the flow behaviour of the system to be a well mixed type. (author). 5 refs., 2 figs., 1 tab.

  19. Radiotracer study to investigate the dilution and dispersion of sewage off Worli coast

    International Nuclear Information System (INIS)

    Yelgaonkar, V.N.; Pendharkar, A.S.; Agashe, S.M.; Kumar, U.S.; Kulkarni, U.P.; Mendhekar, G.N.; Navada, S.V.

    1998-01-01

    Radiotracer experiments were carried out off Worli Coast, Mumbai to study the dilution and dispersion of sewage from the proposed out fall at 3000 m and existing out fall at 500 m from the shore. Dilutions observed were 2.3 x 10 7 at 3.3 km from the injection point for the disposal at 3,000 m and 6.9 x 10 5 at 5 km for the disposal at 500 m. Dispersion coefficients obtained from two dimensional advection dispersion model for the experiment off 500 m are Dx 15-18 m 2 /s and Dy = 0.5-2 m 2 /s. (author)

  20. Mixing studies at low grade vacuum pan using the radiotracer method

    International Nuclear Information System (INIS)

    Griffith, J.M

    1999-01-01

    In this paper, some preliminary results achieved in the evaluation of the homogenization time at a vacuum pan for massecuite b and seed preparation , using two approaches of the radiotracer method, are presented. Practically no difference between the o n line , using small size detector and the sampling methods, in mixing studies performed at the high-grade massecuite was detected. Results achieved during the trials performed at the vacuum station show that the mechanical agitation in comparison with normal agitation improves the performance of mixing in high-grade massecuite b and in seed preparation at the vacuum pan

  1. Mixing studies at low grade vacuum pan using the radiotracer method

    International Nuclear Information System (INIS)

    Griffith, J.M

    1999-01-01

    In this paper, some preliminary results achieved in the evaluation of the homogenization time at a Vacuum Pan for massecuite B and seed preparation , using two approaches of the radiotracer method, are presented. Practically no difference between the Ion Line , using small size detector and the sampling methods, in mixing studies performed at the high-grade massecuite was detected. Results achieved during the trials performed at the vacuum station show that the mechanical agitation in comparison with normal agitation improves the performance of mixing in high-grade massecuite b and in seed preparation at the vacuum pan

  2. Radiotracer studies of agrochemical residues in meat, milk and related products of livestock and poultry

    International Nuclear Information System (INIS)

    1987-01-01

    The joint FAO/IAEA programme was initiated in 1981 and terminates with this report. The specific objectives of the programme have been to evaluate the magnitude, fate and significance of agricultural chemical residues in edible tissues and by-products of livestock and poultry, aided by radiotracer techniques. It was anticipated that the data arising from studies conducted under this programme would be useful in assessing the toxicological significance of studied chemicals to exposed animals and to humans who may consume potentially polluted meat, milk or eggs. A separate abstract was prepared for each of the 13 papers in this report

  3. A simple and efficient in vitro method for metabolism studies of radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Yoon; Choe, Yearn Seong E-mail: yschoe@samsung.co.krjeewoo@snu.ac.kr; Kim, Dong Hyun; Park, Bok-Nam; Kim, Sang Eun; Choi, Yong; Lee, Kyung-Han; Lee, Jeewoo E-mail: yschoe@samsung.co.krjeewoo@snu.ac.kr; Kim, Byung-Tae

    2001-05-01

    In vitro metabolism of acetylcholinesterase inhibitors containing 3-[{sup 18}F]fluoromethylbenzyl- ([{sup 18}F]1) and 4-[{sup 18}F]fluorobenzyl-piperidine moieties ([{sup 18}F]2) was studied and compared with the in vivo metabolism. Defluorination of the [{sup 18}F]1 mainly occurred to generate [{sup 18}F]fluoride ion both in vitro and in vivo. In contrast, the [{sup 18}F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[{sup 18}F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers.

  4. A simple and efficient in vitro method for metabolism studies of radiotracers

    International Nuclear Information System (INIS)

    Lee, Sang-Yoon; Choe, Yearn Seong; Kim, Dong Hyun; Park, Bok-Nam; Kim, Sang Eun; Choi, Yong; Lee, Kyung-Han; Lee, Jeewoo; Kim, Byung-Tae

    2001-01-01

    In vitro metabolism of acetylcholinesterase inhibitors containing 3-[ 18 F]fluoromethylbenzyl- ([ 18 F]1) and 4-[ 18 F]fluorobenzyl-piperidine moieties ([ 18 F]2) was studied and compared with the in vivo metabolism. Defluorination of the [ 18 F]1 mainly occurred to generate [ 18 F]fluoride ion both in vitro and in vivo. In contrast, the [ 18 F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[ 18 F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers

  5. Study of water flowrate using time transient and cross-correlation techniques with 82Br radiotracer

    International Nuclear Information System (INIS)

    Salgado, William L.; Brandao, Luiz E.B.

    2013-01-01

    This paper aims to determinate the water flowrate using Time Transient and Cross-Correlation techniques. The detection system uses two NaI (T1) detectors adequately positioned on the outside of pipe and a gamma-ray source ( 82 Br radiotracer). The water flowrate measurements using Time Transient and Cross-Correlation techniques were compared to invasive conventional measurements of the flowrate previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowmeter previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowrate values were found to be less than 3% in relation to conventional ones. (author)

  6. Evaluation of [11C]metergoline as a PET radiotracer for 5HTR in nonhuman primates

    Energy Technology Data Exchange (ETDEWEB)

    Hooker, J.M.; Hooker, J.M.; Kim, S.W.; Reibel, A.T.; Alexoff, D.; Xu, Y.; Shea, C.

    2010-04-20

    Metergoline, a serotonin receptor antagonist, was labeled with carbon-11 in order to evaluate its pharmacokinetics and distribution in non-human primates using positron emission tomography. [{sup 11}C]Metergoline had moderate brain uptake and exhibited heterogeneous specific binding, which was blocked by pretreatment with metergoline and altanserin throughout the cortex. Non-specific binding and insensitivity to changes in synaptic serotonin limit its potential as a PET radiotracer. However, the characterization of [{sup 11}C]metergoline pharmacokinetics and binding in the brain and peripheral organs using PET improves our understanding of metergoline drug pharmacology.

  7. Determination of the hydrodynamic and morphological parameters of the Luyano River using radiotracer techniques

    International Nuclear Information System (INIS)

    Valcarcel, Lino; Alberro, Nancy; Rodriguez, Maydel; Herrero, Zahily; Borroto, Jorge; Hernandez, Anel; Dominguez, Judith; Derivet, Milagros; Flores, Pedro; Cuesta, Jaime; Griffith, Jose

    2011-01-01

    The hydrodynamic and morphological parameters (the times of travel, velocities and flowrates of the waters, and the average widths, cross sections and depths) in the middle segment of the river Luyano were determined combining the employment of sodium pertechnectate (Na 99m TcO 4 ) as radiotracer with other conventional techniques. The results were used for the calibration of the expanded Streeter and Phelps model of the river. In the work, the methodology and the main results obtained during the journey realized between the second fortnight of March and the first of April 2009 are presented. (Author)

  8. TO THE QUESTION ON THE CHOICE OF RADIOTRACER FOR THE DINAMIC NEPHROSCINTIGRAPHY WITH FUNCTIONAL TESTS

    Directory of Open Access Journals (Sweden)

    D.K. Fomin

    2008-01-01

    Full Text Available The comparison of quality of the images at various stages complex dynamic nephroscintigraphy of the urinary tract received with use of various types of radiotracers. To all patients has been executed dynamic nephroscintigraphy with orthostatic sign and indirect radionuclide cystography, also the analysis of quality of images is lead by a method of expert estimations. It was established, that the best opportunities of a visual estimation of a condition of collective system of kidneys and ureters are provided with application tubular radiotraceres, and for an estimation parenchymatous phases of research — glomerular traceres.Key words: vesicoureteral reflux, secretory function of kidneys, excretory function of kidneys, dinamic scintigraphy, radionuclide cystography.

  9. Intra-operative nuclear imaging based on positron-emitting radiotracers

    International Nuclear Information System (INIS)

    Shakir, Dzhoshkun Ismail

    2014-01-01

    Positron-emitting radiotracers are an important part of nuclear medical imaging processes. Besides the very famous glucose analog [ 18 F]FDG, many not so well known ones exist, among them the particularly interesting amino acid-based tracers like [ 18 F]FET. Although peri-operative imaging with positron-emitting radiotracers has become state-of- the-art in cases of many types of cancer, their capability is not fully exploited in the operating room yet. In this thesis we explore two intra-operative nuclear imaging modalities exploiting different aspects of positron radiation towards quality assurance in challenging surgical treatment scenarios. The first modality freehand PET provides a tomographic image of a volume of interest and aims at minimizing invasiveness by assisting the surgeon in pinpointing target structures marked with a radiotracer. The second imaging modality epiphanography generates an image of the radiotracer distribution on a surface of interest and aims at providing a means for improving the control of tumor resection margins. The word epiphanography is a compound of the Greek words επιφανεια (epiphaneia) for surface and ζωγραφια (ographia) for image, and hence means the image of the surface similar to the compound τομοζ (tomos) for slice/volume and ζωγραφια (ographia) for image, meaning the image of the volume, i.e. tomography. To our knowledge this is the first use of the word epiphanography in the context of nuclear medical imaging. In this thesis we present our approach to modeling, developing and calibrating these two novel imaging modalities. In addition, we present our work towards their clinical integration. In the case of freehand PET, we have already acquired the first intra-operative datasets of a patient. We present this first experience in the operating room together with our phantom studies. In the case of epiphanography, we present our phantom studies with neurosurgeons towards the integration of this

  10. Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

    CERN Document Server

    Baryshevsky, V.G.

    2015-01-01

    We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magnetic moment of negatively-charged particles (e.g., beauty baryons), for which the channeling effect is hampered due to far more rapid dechanneling as compared to that for positively-charged particles. Channeling of particles in either straight or bent crystals with polarized nuclei could be used for polarization and the analysis thereof of high-energy particles.

  11. Determination of the particle size distribution in a powder using radiotracers

    International Nuclear Information System (INIS)

    Revilla D, R.

    1974-01-01

    To determine experimentally the particle size distribution in a powder the meshed method is generally used. This method has the disadvantage that in the obtained distribution is not observed at detail the fine structure of such distribution. In this work, a method for obtaining the distribution of particle size using radiotracers is presented. In the obtained distribution by this method it is observed with more detail the fine structure of the distribution, comparing with the obtained results by the classical method of meshed. The radiotracer method has major resolution for the experimental determination mentioned. In the chapter 1, it is done a brief analysis about theoretical aspects related with the method. In the first part it is analysed the particle behavior (sedimenting) in a fluid. The second part treats the relating with the radioactivity of an activated material as well as its detection. In the chapter 2, a description of the method is done also the experimental problems to applying to the alumina crystals sample are discussed. In the chapter 3 the obtained results and the mistake calculations in such results are showed. Finally, in the chapter 4 the conclusions and recommendations are given which is possible to obtain better results and improve to those in this work were obtained. (Author)

  12. Dynamic PET scanning and compartmental model analysis to determine cellular level radiotracer distribution in vivo

    International Nuclear Information System (INIS)

    Smith, G.T.; Hubner, K.F.; Goodman, M.M.; Stubbs, J.B.

    1992-01-01

    Positron emission tomography (PET) has been used to measure tissue radiotracer concentration in vivo. Radiochemical distribution can be determined with compartmental model analysis. A two compartment model describes the kinetics of N-13 ammonia ( 13 NH 3 ) in the myocardium. The model consists of a vascular space, Q 1 and a space for 13 NH 3 bound within the tissue, Q 2 . Differential equations for the model can be written: X(t) = AX(t) + BU( t), Y(t)= CX(t)+ DU(t) (1) where X(t) is a column vector [Q 1 (t); Q 2 (t)], U(t) is the arterial input activity measured from the left ventricular blood pool, and Y(t) is the measured tissue activity using PET. Matrices A, B, C, and D are dependent on physiological parameters describing the kinetics of 13 NH 3 in the myocardium. Estimated parameter matrices in Equation 1 have been validated in dog experiments by measuring myocardial perfusion with dynamic PET scanning and intravenous injection of 13 NH 3 . Tracer concentrations for each compartment can be calculated by direct integration of Equation 1. If the cellular level distribution of each compartment is known, the concentration of tracer within the intracellular and extracellular space can be determined. Applications of this type of modeling include parameter estimation for measurement of physiological processes, organ level dosimetry, and determination of cellular radiotracer distribution

  13. Radiotracer experiments on the uptake of radionuclides by mushrooms and vegetables

    International Nuclear Information System (INIS)

    Ban-Nai, Tadaaki; Muramatsu, Yasuyuki; Yoshida, Satoshi; Yanagisawa, Kei

    1996-01-01

    Radiotracer experiments were performed to study radionuclide uptake by mushrooms and plants. Four mushroom species, Hebeloma vinosophyllum, Flammulina velutipes, Agrocybe cylindracea and Coprinus phlyctidosporus were cultivated in a flask containing medium with the radiotracers 137 Cs, 85 Sr, 54 Mn, 60 Co and 65 Zn. Mushrooms tended to accumulate Cs, Mn and Zn. The concentration ratio of Cs between mushroom and medium ranged from 2.6 to 21. The highest was observed in H. vinospohyllum. The concentration ratio of Mn was about 10, while the ratio of Zn ranged from 15 to 30. No noticeable accumulations were found for Sr or Co. Transfer factors (TFs) of radionuclides from soil to leaf vegetables (cabbage, Chinese cabbage, komatsuna, spinach and lettuce) were also studied using Andosol (a representative Japanese soil). The TFs of 137 Cs, 85 Sr, 54 Mn, 60 Co and 65 Zn for edible parts of these vegetables were (mean value) 0.11, 0.24, 0.61, 0.05 and 0.52, respectively. The TFs of Mn, Co and Zn for spinach were higher than those for the other vegetables. The distributions of Cs in different organs of the leaf vegetables were rather uniform. The TFs of Sr and Mn were higher for older (outer) leaves than younger (inner) ones. In contrast to Sr and Mn, TFs of Zn for younger leaves were higher than those for older ones

  14. Employment of the technique of radiotracers for analysis of industrial filters

    International Nuclear Information System (INIS)

    Ramos, Vitor Santos; Crispim, Verginia Reis

    2007-01-01

    The main aim of this work is to develop a methodology to evaluate the characteristics of porous media in filter using the radio-tracing technique. To do this, an experimental prototype filter made up of an acrylic cylinder, vertically mounted and supported on the lower side by a controlled leaking valve was developed. Two filters (spheres of acrylic and silica crystals) were used to check the movement of the water through the porous media using 123 I in its MIBG (iodine-123-meta-iodo benzyl-guanidine) form. Further up the filter an instantaneous injection of the substance makes it possible to see the passage of radioactive clouds through the two scintillatory detectors NaI (2x2) ' ' positioned before and immediately after the cylinder with the filtering element (porous media). The are caused by the detectors on the passage of the radioactive cloud are analyzed through statistical functions using the weighted moment method which makes it possible to calculate the Residence-Time (the amount of time the tracer takes to thoroughly pass through the filter) per the equation of dispersion in tubular flow and the one-directional flow of the radiotracer in the porous media. (author)

  15. Radiotracer study on dispersion of sewerage off Mumbai Coast in Western India

    International Nuclear Information System (INIS)

    Kumar, U.S.; Yelgaonkar, V.N.; Navada, S.V.

    1997-01-01

    Municipal Corporation of Greater Mumbai discharges the treated sewage at various locations off Mumbai coast. One such discharge point is located near Colaba near South Mumbai. Screened, degritted and aerated sewage is discharged through a 1 m diameter steel pipe by gravity to the diffuser installed on the sea bed at 1.1 km away from the shore. A radiotracer study was carried out to evaluate the dilution and dispersion pattern of the sewage at different points from the disposal point. The experiment was carried out during high tide. About 110 GBq of 82 Br was used as the tracer. A dilution factor of about 5.5 x 10 3 was obtained at a distance of 4.3 km from the outfall. The dilution downshore was small even for a long distance due to strong unidirectional currents. Comparable dilution factors were also obtained by Brooks' model. Vertical tracer profiles showed that the waste plume was well mixed over a depth of 2 to 3 m from the surface. A 2-D advection simulation model was employed to simulate the spatial and temporal distribution of the radiotracer data. From the model simulation best fit was obtained for dispersion coefficients Dx = 15 m 2 .s -1 and Dy = 2m 2 .s -1 . The dispersion coefficients can be used for predicting the effluent dispersion under different outfall and disposal conditions. The tracer pattern at Colaba and Malad indicated no possibility of contamination of the beaches

  16. Evaluation of radiotracers for the detection of atherosclerotic vulnerable plaque and myocardial angiogenesis

    International Nuclear Information System (INIS)

    Dimastromatteo, Julien

    2010-01-01

    Cardiovascular diseases are the leading cause of mortality worldwide. Coronary events are mainly caused by coronary plaque rupture or erosion. However, at present, there is no noninvasive tool available for the detection of vulnerable plaques. The first part of thesis is about evaluation of new radiotracers for the detection of atherosclerotic vulnerable plaques. 99m Tc-B2702p, 20 derivatives, 99m Tc-VP and 99m Tc-VINP28 were evaluated in an experimental model of atherosclerosis (ApoE-/- mice with left carotid artery ligation). 99m Tc- B2702p1 is a potentially useful radiotracer for the in vivo molecular imaging of VCAM-1 expression in atherosclerotic plaques. Myocardial angiogenesis is an important post infarction phenomenon. Angiogenic therapy improves experimentally cardiac parameters. However, clinical trials using the same therapy are more controversial. At present, clinical imaging tools don't allow us to assess angiogenesis therapy. The second part of thesis is about validation of 99m Tc-RAFT-RGD in the detection of myocardial angiogenesis. 99m Tc-RAFT-RGD allow us to perform noninvasive molecular imaging of myocardial angiogenesis in an experimental model. (author)

  17. Study of dilution of effluent discharged through a sea outfall near Mangalore using radiotracer technique

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.

    1987-01-01

    The fate of effluent discharged into water bodies is a matter of concern from the point of view of environmental pollution. Radiotracer techniques have been successfully used to study the change in concentration of effluents while being mixed with large water bodies. The technique used is to add a known concentration of radioactive tracer into the effluent stream and to measure the dilutions at different locations near the effluent discharge point with radiation detectors. M/s Mangalore Chemicals and Fertilizers Ltd (MCF) at Mangalore on the west coast of India disposes off the treated and initially diluted effluent at the rate of about 360 m 3 /h into the sea near by through an outfall extending about 100 meters into the sea. The effluent mainly contains ammonia in the range of 40-50 ppm as the pollutant. It was desired to measure the extent of dilution occurring to the effluent at a few locations of known distances along the sea shore from the discharge point of the effluent. Radiotracers 82 Br as ammonium bromide solution and tritium as tritiated water were employed for the study. The concentration measurement was done at site for 82 Br and by estimation of samples in the laboratory in the case of tritium. Dilution of the order of 1000 was obtained at about 100 meters distance for a continuous injection of about 4 hours. (author). 3 tables, 3 figures

  18. Combination of sealed source and radiotracer technique to understand malfunctioning in a chemical plant

    Energy Technology Data Exchange (ETDEWEB)

    Yelgaonkar, V.N. [Quality Assurance and Isotope Applications Services, BRIT, Vashi Complex, Navi Mumbai 400705 (India)], E-mail: vivekyel@rediffmail.com; Jayakumar, T.K.; Singh, Sudhir; Sharma, M.K. [Quality Assurance and Isotope Applications Services, BRIT, Vashi Complex, Navi Mumbai 400705 (India)

    2009-07-15

    Pure terphthalic acid (PTA) is produced by the oxidation of paraxylene in an oxidation reactor of a PTA plant. Since the reaction is exothermic, the temperature rises above 210 deg. C. Vapours formed in the reactor are passed through a series of heat exchangers and the cooled liquid is fed back to the reactor, which flows to the reactor by gravity. In one of the heat exchangers, improper flow distribution in the inlet and outlet pipelines was suspected. Maldistribution of flow in the heat exchanger was also suspected. Gamma scanning of the pipelines and a radiotracer experiment were carried out in the heat exchanger to study the malfunctioning. A specially fabricated pipe scanner was used to scan both 24 in diameter and 16 in diameter pipelines. From gamma scanning of the pipelines mostly on the bends, absence of the full bore flow of the liquid was observed. Presence of vapours along with the liquid could be obstructing the liquid flow, thereby causing the malfunctioning. A radiotracer experiment was also carried out to study the flow pattern in the heat exchanger. From the experiment, mean residence time of the heat exchanger was estimated as 470 s, which theoretically should be about 102 s. It indicated that the flow is decelerated in the heat exchanger because of the presence of vapour lock in the tube side.

  19. Investigation of leaching of an antifouling agent from marine paint formulations using radiotracer technique

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Gursharan Singh; Kalgutkar, D.B.; Patil, S.P.; Jayachandran, N.; Unni, V.K.P.

    2012-01-01

    A radiotracer technique was used to investigate the leaching of an antifouling agent from different marine paint formulations with an objective to select the best paint formulation for bulk production. The antifouling agent (Diuron) itself was labeled with carbon-14 (half-life: 5,730 years, β-energy: 156 keV) and used as a radiotracer. The different paint formulations added with radiolabeled Diuron were applied onto suitably selected substrates and measured for initial intensity of β-radiation using a Geiger-Muller detector connected to a ratemeter. The painted substrates were subjected to shower tests for a pre-decided time and subsequently measured for β-radiations. The comparison of intensity of β-radiations in substrates prior and post shower tests provides information about leaching of antifouling agent Diuron from the paint formulation. The high leaching percentage of antifouling agent Diuron post shower tests indicates non-suitability of paint formulation for marine and civil structures. However, low leaching rate of Diuron will make a paint formulation more efficient and suitable. Based on the results of investigation, a paint formulation with minimum leaching rate was identified and selected for bulk production by a paint company. (author)

  20. Novel in situ radiotracer methods for the direct and indirect study of chromate adsorption on alumina

    International Nuclear Information System (INIS)

    Gancs, L.; Nemeth, Z.; Horanyi, G.

    2002-01-01

    Radiotracer methods, particularly the radiotracer thin foil method, provide unique possibility of in situ monitoring of chromate adsorption on powdered adsorbents. Two different versions of the thin foil method can be distinguished. In the direct method, the species to be studied is labelled and the radiation measured gives direct information on the adsorption of this species. In the indirect method, a different labelled indicator species is added to the system and the adsorption of this species is followed and the adsorption of the species to be studied is determined based on analysis of the competitive adsorption processes. Both methods were used in the present study. In the in situ methods, the radiation measured consists of two main parts, one coming from the solution background, the other originating from the adsorption layer. In the case of the thin foil method using isotopes emitting soft β - radiation or low energy X-ray the solution background is governed and minimised by self-absorption of the radiation. In the direct study we applied an experimental methodology based on the energy selective measurement of the characteristic K α,β X-radiation emitted by the 51 Cr-labelled chromate species, whereas 35 S-labelled sulphate ions were used as the indicator species in the indirect study. (P.A.)

  1. Characterization of a radiotracer-based 3-hydroxy-1-methyl peridine by its analogue Rhene

    International Nuclear Information System (INIS)

    Zitouni, Zeineb

    2010-01-01

    Since the discovery of artificial radioactivity in 1934, nuclear doctors have a variety of radioactive isotopes as indicators and markers. With these radioactive isotopes, it is possible to trace an atom or a chemical species without disrupting the physical behavior, chemical or biological. The branch of medicine and medical specialty now devoted to the use of radioactive elements for examination or treatment of patients, particularly the brain. Having a close relationship with radiobiology, radiation protection and Radiopharmacy, Nuclear Medicine Specialist is empowered to handle potentially dangerous isotope, observing precautions and regulations designed to reduce their risks. These radionuclides are used for exploration of cell kinetics, pharmacokinetics or for scans. Activities under this project led to the synthesis of N-methylferrocene, its characterization and its labeling with technetium 99 m. For the characterization of the radiotracer synthesized, we used to study the properties of complex similar models, labeled with rhenium. To verify and confirm this work, we propose the following perspectives: - Confirm the structure of N-methyl rhenium by nuclear magnetic resonance and single crystal X ray crystallography. - Develop and characterize new radiotracers brain.

  2. Development of gold nanoparticle radiotracers for investigating multiphase system in process industries

    International Nuclear Information System (INIS)

    Mohd Amirul Syafiq Mohd Yunos; Jaafar Abdullah; Engku Fahmi Engku Chik; Noraishah Othman

    2010-01-01

    This paper describes the development of colloidal 197 Au-SiO 2 with core-shell structure nanoparticle radiotracers. Using conventional citrate-reduction method, gold nanoparticles were prepared from its corresponding metal salts in aqueous solution then coated with uniform shells of amorphous silica via a sol-gel reaction. This target material of radiotracer application used to investigate multiphase system in process industries without disturbing the system operation. The citrate-reduction-based method provides gold nanoparticles with higher concentration and narrow size distribution. By using transmission electron microscopy (TEM), the resultant of particle size and silica coatings could be varied from tens to several hundred of nanometers by controlling the catalyzer and precipitation time. 197 Au-SiO 2 core-shell nano structure is good to prevent the particles from getting conglomerate resulting in a big mass. In addition, silica surface offer very good chances that make the hydrophobicity behavior on the gold nanoparticles. EDXRF spectrum has proven that 197 Au-SiO 2 core-shell nanoparticles sample consists purely of a gold and silica particles. (author)

  3. Chemical states of localized Fe atoms in ethylene matrices using in-beam Mössbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Y., E-mail: kyoshio@pc.uec.ac.jp [University of Electro-Communications, Graduate School of Engineering Science (Japan); Yamada, Y. [Tokyo University of Science, Department of Chemistry (Japan); Tanigawa, S. [University of Electro-Communications, Graduate School of Engineering Science (Japan); Mihara, M. [Osaka University, Graduate School of Science (Japan); Kubo, M. K. [International Christian University, Division of Arts and Sciences (Japan); Sato, W. [Kanazawa University, Institute of Science and Engineering (Japan); Miyazaki, J. [Tokyo University of Agriculture and Technology, Department of Chemical Engineering (Japan); Nagatomo, T. [RIKEN, Nishina Center for Accelerator-Based Science (Japan); Sato, Y.; Natori, D.; Suzuki, M. [University of Electro-Communications, Graduate School of Engineering Science (Japan); Kobayashi, J. [International Christian University, Division of Arts and Sciences (Japan); Sato, S.; Kitagawa, A. [National Institute of Radiological Science (Japan)

    2016-12-15

    The reaction products of isolated single iron atoms in a low concentration matrix of ethylene were studied using in-beam Mössbauer spectroscopy with a short-lived {sup 57}Mn (T{sub 1/2}=1.45 m) beam. The in-beam Mössbauer spectrum of {sup 57}Fe arising from {sup 57}Mn in a matrix of ethylene and argon measured at 16 K was analyzed with four components. Density functional theory calculations were carried out to confirm the assignments. It was suggested that the reaction produced monoiron species of Fe(C {sub 2}H{sub 4}) with a spin state of S = 2.

  4. Biomedical applications of medium energy particle beams at LAMPF

    International Nuclear Information System (INIS)

    Bradbury, J.N.

    1978-01-01

    At LAMPF an 800-MeV proton accelerator is used to produce intense beams of secondary protons, pi mesons, and muons which are being employed in several areas of biomedical research. The primary proton beam is used to produce short-lived radioisotopes of clinical interest. Carefully tailored secondary proton beams are used to obtain density reconstructions of samples with a dose much less than that required by x-ray CT scanners. The elemental composition of tissue samples is being determined non-destructively with muonic x-ray analysis. Finally, an extensive program, with physical, biological, and clinical components, is underway to evaluate negative pi mesons for use in cancer radiotherapy. The techniques used in these experiments and recent results are described

  5. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  6. Investigation of flow behaviour of coal particles in a pilot-scale fluidized bed gasifier (FBG) using radiotracer technique.

    Science.gov (United States)

    Pant, H J; Sharma, V K; Kamudu, M Vidya; Prakash, S G; Krishanamoorthy, S; Anandam, G; Rao, P Seshubabu; Ramani, N V S; Singh, Gursharan; Sonde, R R

    2009-09-01

    Knowledge of residence time distribution (RTD), mean residence time (MRT) and degree of axial mixing of solid phase is required for efficient operation of coal gasification process. Radiotracer technique was used to measure the RTD of coal particles in a pilot-scale fluidized bed gasifier (FBG). Two different radiotracers i.e. lanthanum-140 and gold-198 labeled coal particles (100 gm) were independently used as radiotracers. The radiotracer was instantaneously injected into the coal feed line and monitored at the ash extraction line at the bottom and gas outlet at the top of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tanks-in-series model. The simulation of RTD data indicated good degree of mixing with small fraction of the feed material bypassing/short-circuiting from the bottom of the gasifier. The results of the investigation were found useful for optimizing the design and operation of the FBG, and scale-up of the gasification process.

  7. UV-photochemical vapor generation of selenium for atomic absorption spectrometry: Optimization and 75Se radiotracer efficiency study

    Czech Academy of Sciences Publication Activity Database

    Rybínová, M.; Musil, Stanislav; Červený, J.; Vobecký, Miloslav; Rychlovský, P.

    2016-01-01

    Roč. 123, SEP (2016), s. 134-142 ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : UV-photochemical vapor generation * Selenium * 75Se radiotracer Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.241, year: 2016

  8. Challenges in the development of dopamine D2- and D3-selective radiotracers for PET imaging studies.

    Science.gov (United States)

    Mach, Robert H; Luedtke, Robert R

    2018-03-01

    The dopamine D2-like receptors (ie, D2/3 receptors) have been the most extensively studied CNS receptor with Positron Emission Tomography (PET). The 3 different radiotracers that have been used in these studies are [ 11 C]raclopride, [ 18 F]fallypride, and [ 11 C]PHNO. Because these radiotracers have a high affinity for both dopamine D2 and D3 receptors, the density of dopamine receptors in the CNS is reported as the D2/3 binding potential, which reflects a measure of the density of both receptor subtypes. Although the development of D2- and D3-selective PET radiotracers has been an active area of research for many years, this by and large presents an unmet need in the area of translational PET imaging studies. This article discusses some of the challenges that have inhibited progress in this area of research and the current status of the development of subtype selective radiotracers for imaging D3 and D2 dopamine receptors with PET. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Absorption and retention studies of trace elements and minerals in rats using radiotracers and whole-body counting

    NARCIS (Netherlands)

    Berg, van den G.J.; Wolterbeek, H.Th.; de Goeij, J.J.M.; Beynen, A.C.

    1995-01-01

    A description is given of a whole-body counting technique using radiotracers, permitting the determination of true absorption and endogenous excretion of trace elements and minerals in the rat in vivo. This non-invasive counting method involves oral and intraperitoneal administration of tracer doses

  10. Blood circulation of the inner ear under the influence of medications. Radiotracer experiments using guinea pig cochlea

    International Nuclear Information System (INIS)

    Neumeier, A.

    1987-01-01

    The dependence of the blood circulation in the inner ear on various medications is discussed. By means of a radiotracer clearance technique the cochlear clearance curves for the guinea pig cochlea after the administration of various circulation stimulants were determined. (MBC) [de

  11. Radiotracer technology as applied to industry. Final report of a co-ordinated research project 1997-2000

    International Nuclear Information System (INIS)

    2001-12-01

    The Co-ordinated Research Project (CRP) on Radiotracer Technology for Engineering Unit Operation Studies and Unit Process Optimization was carried out by the International Atomic Energy Agency (IAEA) from December 1997 until December 2000. The project developed and validated procedures and protocols for investigation of major industrial processes, including fluidized beds, sugar crystallizers, trickle bed reactors, cement rotary kilns, flotation cells, grinding mills, incinerators, wastewater treatment units and interwell communications in oil fields. This publication is the output of the above mentioned CRP. It provides the principles and state of the art of radiotracer methodology and technology as applied to industry and environment. It is expected to provide wider interest for further development of skills and confidence prior to carrying out field work. It facilitates transfer of technology from developed to developing countries and from nuclear research institutions to industrial end users. The publication could be a suitable guide for radiotracer applications in almost all types of process investigations. The case studies described in this publication deal with typical problems in industry and environment common to all countries. It is intended for radiotracer groups as well as for end engineers and managers from chemical and petrochemical industries, mineral ore and raw material processing, wastewater treatment plants, and other industrial sectors

  12. Uptake of heavy metals by the marine algae Padina gymnospora from Sepetiba Bay (RJ, Brazil) through radiotracers

    International Nuclear Information System (INIS)

    Magalhaes, V.F. de.

    1991-01-01

    The accumulation and the loss of 210 Pb, 51 Cr and 65 Zn by the alga Padina gymnospora is studied through radiotracer experiments. The evaluation of the alga as a bio indicator of these heavy metals pollution is presented. The use of this seaweed species to study the transfer of Pb, Cr, and Zn through the food chain is discussed. (M.A.C.)

  13. Characterization of electrochemical cell for production of radiotracer in organic medium

    International Nuclear Information System (INIS)

    Kenup-Hernandes, Hericka O.; Brandão, Luís Eduardo B.; Silva, Ademir X. da; Coordenacao de Pos-Graduacao e Pesquisa de Engenharia

    2017-01-01

    In a petrochemical plant, precise knowledge of the flow of the compounds that flow inside the pipelines that carry oil and these derivatives is crucial. To perform these controls a series of flow meters are installed inside ducts in direct contact with the fluid to be monitored. This invasive method presents a great limitation because the oil aggressive proprieties that require these measurement devices are subjected to frequent calibrations which, in turn, cause the stoppage of the plant and low productivity. In this sense, radiotracers has been used in conjunction with the time transient method, by configuring a precise and non-invasive measurement technique. This work presents the study of the characterization of an electrolytic cell model for the production of petroleum derivatives labeled with Iodine-123 for use as radiotracer in the measurement of flow in ducts and the time transient method. Labelling of organic compounds usually a sequence of solvent separation and extraction steps which, when used for labeling oil and oil derivatives it causes high gamma exposition for the operator at considerable dose rates due to the need for direct interaction with the marking system. The objective of this work is to develop a cell model that is part of a compact, automatically operated labelling system with physics and chemistry parameters defined to optimize the organic phase labelling processes of petroleum derivatives. The labelling cell is composed of a cylindrical reaction vessel where the aqueous medium containing the iodine-123 in the form of sodium iodide (NaI-I123) is inserted with about 2 mCi of activity and the organic medium. In the system are introduced, two Platinum electrodes where a voltage of 0. 8 V is applied. This system allows the production of radiotracer for a rapid pulse injection. The results show that there was no significant variation of the stability of the system in the temperature range of 25 °C to 40 °C and showed a labelling efficiency

  14. Characterization of electrochemical cell for production of radiotracer in organic medium

    Energy Technology Data Exchange (ETDEWEB)

    Kenup-Hernandes, Hericka O.; Brandão, Luís Eduardo B.; Silva, Ademir X. da, E-mail: hkenup@ien.gov.br, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-11-01

    In a petrochemical plant, precise knowledge of the flow of the compounds that flow inside the pipelines that carry oil and these derivatives is crucial. To perform these controls a series of flow meters are installed inside ducts in direct contact with the fluid to be monitored. This invasive method presents a great limitation because the oil aggressive proprieties that require these measurement devices are subjected to frequent calibrations which, in turn, cause the stoppage of the plant and low productivity. In this sense, radiotracers has been used in conjunction with the time transient method, by configuring a precise and non-invasive measurement technique. This work presents the study of the characterization of an electrolytic cell model for the production of petroleum derivatives labeled with Iodine-123 for use as radiotracer in the measurement of flow in ducts and the time transient method. Labelling of organic compounds usually a sequence of solvent separation and extraction steps which, when used for labeling oil and oil derivatives it causes high gamma exposition for the operator at considerable dose rates due to the need for direct interaction with the marking system. The objective of this work is to develop a cell model that is part of a compact, automatically operated labelling system with physics and chemistry parameters defined to optimize the organic phase labelling processes of petroleum derivatives. The labelling cell is composed of a cylindrical reaction vessel where the aqueous medium containing the iodine-123 in the form of sodium iodide (NaI-I123) is inserted with about 2 mCi of activity and the organic medium. In the system are introduced, two Platinum electrodes where a voltage of 0. 8 V is applied. This system allows the production of radiotracer for a rapid pulse injection. The results show that there was no significant variation of the stability of the system in the temperature range of 25 °C to 40 °C and showed a labelling efficiency

  15. Treatment of short-lived radioactive wastes

    International Nuclear Information System (INIS)

    Yamaguchi, Chiri

    1976-01-01

    Recently short life nuclides have come to be utilized increasingly as diagnostic radioisotopes, and Tc-99m (half-life; 6.05 hours) and Ga-67 (half-life 7.79 hours) are replacing the most nuclides fomerly used in vivo test. Such development of radioactive products inevitably causes the rapid increase of their wastes. At present, the radioactive wastes produced by hospitals and university laboratories in Japan are collected by the Japan Radioisotope Association, and treated by the Japan Atomic Energy Research Institute. These wastes are divided into combustibles and incombustibles to store in the store house in the Japan Atomic Energy Research Institute. The present law in Japan contains the contradiction which treats the matter with one several millionth of radioactivity after decay same as the original radioactive matter. Thus solid must be stored permanently, while gas and liquid can be discharged after dilution. (Kobatake, H.)

  16. Short-lived medical isotopes at Harwell

    International Nuclear Information System (INIS)

    Cuninghame, J.G.

    1985-01-01

    This paper describes the small program of medical isotope commercial production and research and development on the Harwell Variable Energy Cyclotron. Because of its complexity, this nuclear research machine is extremely expensive to run, and so the program must be restricted to those isotopes which cannot be more cheaply produced elsewhere in the United Kingdom. At present these are 123 I (in full commercial production), the /sup 195m/Hg → /sup 195m/Au generator (about to go into commercial production), and 211 At (under development). Iodine-123 is produced once or twice a week at a level of 300 to 400 mCi per batch and is sold to an average of 30 customers all over the United Kingdom and Europe. The gold generator is being developed for first-pass heart angiography and is undergoing clinical trials at three U.K. hospitals. A research program in conjunction with the U.K. Medical Research Council is directed to the labeling of monoclonal antibodies with 211 At as a possible agent for cancer therapy

  17. Short-lived isomers in 94Rb

    International Nuclear Information System (INIS)

    Tsekhanovich, I.; Dare, J. A.; Smith, A. G.; Varley, B. J.; Simpson, G. S.; Urban, W.; Soldner, T.; Jolie, J.; Linnemann, A.; Orlandi, R.; Smith, J. F.; Scherillo, A.; Rzaca-Urban, T.; Zlomaniec, A.; Dorvaux, O.; Gall, B. J. P.; Roux, B.

    2008-01-01

    The medium-spin structure of the neutron-rich, odd-odd nucleus 94 Rb was studied by means of γ-ray spectroscopy. Excited levels were populated in the neutron-induced fission of 235 U and in the spontaneous fission of 252 Cf and 248 Cm. Two isomeric states were found at 1485.2 and 2074.8 keV with half-lives of 18 and 107 ns, respectively. The probable structures of the two isomers involve the fully aligned, proton-neutron configurations [π(g 9/2 ) x ν(g 7/2 )] 8 + and [π(g 9/2 ) x ν(h 11/2 )] 10 - , respectively. These new data give information on the single-particle energies in the region

  18. Quail and other short-lived birds.

    Science.gov (United States)

    Ottinger, M A

    2001-04-01

    Japanese quail are small galliforms that are migratory and generally live 2 to 3years in the wild. Although there is evidence for other environmental cues, they primarily respond to long daylength for regulation of reproduction. In contrast to the Common Tern, a long-lived sea bird that shows little evidence of reproductive aging, Japanese quail follow a well-defined process of aging with evidence of declining function in reproductive, metabolic, and sensory systems. Our studies focus on neuroendocrine changes associated with reproductive aging in the Japanese quail, with emphasis on the male in order to study both endocrine and behavioral components of reproduction and the process of reproductive aging.

  19. Clinical studies short-lived isotopes

    International Nuclear Information System (INIS)

    Webber, M.D.; Victery, W.S.; Cragin, M.D.

    1976-01-01

    Progress is reported in the following areas of research: demonstration of intravascular thrombosis using tantalum particles and /sup 99m/Tc; correlation of MAA thrombosis scans with fibrinogen uptake test; RISA and 125 I-fibrinogen accumulation in sites of forming and formed thrombi; and clinicopathologic correlations of the 125 I thyroid scan

  20. Efficient Management of Short-Lived Data

    DEFF Research Database (Denmark)

    Schmidt, Albrecht; Jensen, Christian Søndergaard

    2005-01-01

    Motivated by the increasing prominence of loosely-coupled systems, such as mobile and sensor networks, which are characterised by intermittent connectivity and volatile data, we study the tagging of data with so-called expiration times. More specifically, when data are inserted into a database......, they may be tagged with time values indicating when they expire, i.e., when they are regarded as stale or invalid and thus are no longer considered part of the database. In a number of applications, expiration times are known and can be assigned at insertion time. We present data structures and algorithms...... for online management of data tagged with expiration times. The algorithms are based on fully functional, persistent treaps, which are a combination of binary search trees with respect to a primary attribute and heaps with respect to a secondary attribute. The primary attribute implements primary keys...