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Sample records for actinium a

  1. A new method for the determination of low-level actinium-227 in geological samples

    We developed a new method for the determination of 227Ac in geological samples. The method uses extraction chromatographic techniques and alpha-spectrometry and is applicable for a range of natural matrices. Here we report on the procedure and results of the analysis of water (fresh and seawater) and rock samples. Water samples were acidified and rock samples underwent total dissolution via acid leaching. A DGA (N,N,N',N'-tetra-n-octyldiglycolamide) extraction chromatographic column was used for the separation of actinium. The actinium fraction was prepared for alpha spectrometric measurement via cerium fluoride micro-precipitation. Recoveries of actinium in water samples were 80 ± 8 % (number of analyses n = 14) and in rock samples 70 ± 12 % (n = 30). The minimum detectable activities (MDA) were 0.017-0.5 Bq kg-1 for both matrices. Rock sample 227Ac activities ranged from 0.17 to 8.3 Bq kg-1 and water sample activities ranged from below MDA values to 14 Bq kg-1of 227Ac. From the analysis of several standard rock and water samples with the method we found very good agreement between our results and certified values. (author)

  2. Production of high-purity radium-223 from legacy actinium-beryllium neutron sources.

    Soderquist, Chuck Z; McNamara, Bruce K; Fisher, Darrell R

    2012-07-01

    Radium-223 is a short-lived alpha-particle-emitting radionuclide with potential applications in cancer treatment. Research to develop new radiopharmaceuticals employing (223)Ra has been hindered by poor availability due to the small quantities of parent actinium-227 available world-wide. The purpose of this study was to develop innovative and cost-effective methods to obtain high-purity (223)Ra from (227)Ac. We obtained (227)Ac from two surplus actinium-beryllium neutron generators. We retrieved the actinium/beryllium buttons from the sources and dissolved them in a sulfuric-nitric acid solution. A crude actinium solid was recovered from the solution by coprecipitation with thorium fluoride, leaving beryllium in solution. The crude actinium was purified to provide about 40 milligrams of actinium nitrate using anion exchange in methanol-water-nitric acid solution. The purified actinium was then used to generate high-purity (223)Ra. We extracted (223)Ra using anion exchange in a methanol-water-nitric acid solution. After the radium was separated, actinium and thorium were then eluted from the column and dried for interim storage. This single-pass separation produces high purity, carrier-free (223)Ra product, and does not disturb the (227)Ac/(227)Th equilibrium. A high purity, carrier-free (227)Th was also obtained from the actinium using a similar anion exchange in nitric acid. These methods enable efficient production of (223)Ra for research and new alpha-emitter radiopharmaceutical development. PMID:22697483

  3. The sorption of polonium, actinium and protactinium onto geological materials

    This paper describes a combined experimental and modeling program of generic sorption studies to increase confidence in the performance assessment for a potential high-level radioactive waste repository in Japan. The sorption of polonium, actinium and protactinium onto geological materials has been investigated. Sorption of these radioelements onto bentonite, tuff and granodiorite from equilibrated de-ionized water was studied under reducing conditions at room temperature. In addition, the sorption of actinium and protactinium was investigated at 60 C. Thermodynamic chemical modeling was carried out to aid interpretation of the results

  4. Separation of Actinium 227 from the uranium minerals

    The purpose of this work was to separate Actinium 227, whose content is 18%, from the mineral carnotite found in Gomez Chihuahua mountain range in Mexico. The mineral before processing is is pre-concentrated and passed, first through anionic exchange resins, later the eluate obtained is passed through cationic resins. The resins were 20-50 MESH QOWEX and 100-200 MESH 50 X 8-20 in some cased 200-400 MESH AG 50W-X8, 1X8 in other cases. The eluates from the ionic exchange were electrodeposited on stainless steel polished disc cathode and platinum electrode as anode; under a current ODF 10mA for 2.5 to 5 hours and of 100mA for .5 of an hour. it was possible to identify the Actinium 227 by means of its descendents, TH-227 and RA-223, through alpha spectroscopy. Due to the radiochemical purity which the electro deposits were obtained the Actinium 227 was low and was not quantitatively determined. A large majority of the members of the natural radioactive series 3 were identified and even alpha energies reported in the literature with very low percentages of non-identified emissions were observed. We conclude that a more precise study is needed concerning ionic exchange and electrodeposit to obtain an Actinium 227 of radiochemical purity. (Author)

  5. Discovery of the actinium, thorium, protactinium, and uranium isotopes

    Fry, C; Thoennessen, M

    2012-01-01

    Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  6. Spectroscopic and computational investigation of actinium coordination chemistry.

    Ferrier, Maryline G; Batista, Enrique R; Berg, John M; Birnbaum, Eva R; Cross, Justin N; Engle, Jonathan W; La Pierre, Henry S; Kozimor, Stosh A; Lezama Pacheco, Juan S; Stein, Benjamin W; Stieber, S Chantal E; Wilson, Justin J

    2016-01-01

    Actinium-225 is a promising isotope for targeted-α therapy. Unfortunately, progress in developing chelators for medicinal applications has been hindered by a limited understanding of actinium chemistry. This knowledge gap is primarily associated with handling actinium, as it is highly radioactive and in short supply. Hence, Ac(III) reactivity is often inferred from the lanthanides and minor actinides (that is, Am, Cm), with limited success. Here we overcome these challenges and characterize actinium in HCl solutions using X-ray absorption spectroscopy and molecular dynamics density functional theory. The Ac-Cl and Ac-OH2O distances are measured to be 2.95(3) and 2.59(3) Å, respectively. The X-ray absorption spectroscopy comparisons between Ac(III) and Am(III) in HCl solutions indicate Ac(III) coordinates more inner-sphere Cl(1-) ligands (3.2±1.1) than Am(III) (0.8±0.3). These results imply diverse reactivity for the +3 actinides and highlight the unexpected and unique Ac(III) chemical behaviour. PMID:27531582

  7. Reflection asymmetry in odd-A and odd-odd actinium nuclei

    Theoretical calculations and measurements indicate that octupole correlations are at a maximum in the ground states of the odd-proton nuclei Ac and Pa. It has been expected that odd-odd nuclei should have even larger amount of octupole-octupole correlations. We have recently made measurements on the structure of 224Ac. Although spin and parity assignments could not be made, two bands starting at 354.1 and 360.0 keV have properties characteristic of reflection asymmetric shape. These two bands have very similar rotational constants and also similar alpha decay rates, which suggest similarity between the wavefunctions of these bands. These signatures provide evidence for octupole correlations in these nuclides

  8. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    Harvey, James T.; Nolen, Jerry; Vandergrift, George; Gomes, Itacil; Kroc, Tom; Horwitz, Phil; McAlister, Dan; Bowers, Del; Sullivan, Vivian; Greene, John

    2011-12-30

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 Ge

  9. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces ∼100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 GeV protons

  10. Purification of radium-226 for the manufacturing of actinium-225 in a cyclotron for alpha-immunotherapy

    The thesis describes the development of methods for the purification of Ra-226. The objective was to obtain the radionuclide in the quality that is needed to be used as starting material in the manufacturing process for Ac-225 via proton-irradiated Ra-226. The radionuclide has been gained efficiently out of huge excesses of impurities. The high purity of the obtained radium affords its use as staring material in a pharmaceutical manufacturing process.

  11. Purification of radium-226 for the manufacturing of actinium-225 in a cyclotron for alpha-immunotherapy; Radium-Aufreinigung zur Herstellung von Actinium-225 am Zyklotron fuer die Alpha-Immuntherapie

    Marx, Sebastian Markus

    2014-09-23

    The thesis describes the development of methods for the purification of Ra-226. The objective was to obtain the radionuclide in the quality that is needed to be used as starting material in the manufacturing process for Ac-225 via proton-irradiated Ra-226. The radionuclide has been gained efficiently out of huge excesses of impurities. The high purity of the obtained radium affords its use as staring material in a pharmaceutical manufacturing process.

  12. Neutron-Induced Fission of Actinium-227, Protactinium-231 and Neptunium-237: Mass Distribution

    Results of radiochemical studies on the mass distribution in the neutron-induced fission of actinium-227, protactinium-231 and neptunium-237 have been presented. This work has been carried out as part of a programme to determine the mass distribution in the fission of heavy elements as a function of Z and A. All irradiations have been carried out in the core of the swimming-pool type reactor APSARA with cadmium shielding wherever necessary. Relative yields of several fission product nuclides have been obtained by a method involving a comparison of the fission product activities from the respective targets with those formed from uranium-235 simultaneously irradiated. Thermal-neutron fission yields of uranium-235 have been assumed. These results indicate a predominantly asymmetric mass distribution in all the three cases, and also a distinct though small symmetric peak in the case of actinium-227. (author)

  13. Extraction of actinium with di-(2-ethylhexyl)phosphoric acid from hydrochloric and nitric acid solutions

    The extraction of actinium with HDEHP from Cl- and NO3- systems has been investigated. It was found that extraction of actinium from HCl solutions is much better than from HNO3 solutions. Stability constants of actinium complexes Ac(X-)+2 with Cl- and NO3- ligands were determined. Our results show that the actinium formed less stable complexes with Cl- than with NO3- ligands. 5 refs., 3 figs., 1 tab. (author)

  14. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    Momeni, M.H.

    1981-09-01

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore.

  15. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore

  16. In-source laser spectroscopy developments at TRILIS—towards spectroscopy on actinium and scandium

    Resonance Ionization Laser Ion Sources (RILIS) have become a versatile tool for production and study of exotic nuclides at Isotope Separator On-Line (ISOL) facilities such as ISAC at TRIUMF. The recent development and addition of a grating tuned spectroscopy laser to the TRIUMF RILIS solid state laser system allows for wide range spectral scans to investigate atomic structures on short lived isotopes, e.g., those from the element actinium, produced in uranium targets at ISAC. In addition, development of new and improved laser ionization schemes for rare isotope production at ISAC is ongoing. Here spectroscopic studies on bound states, Rydberg states and autoionizing (AI) resonances on scandium using the existing off-line capabilities are reported. These results allowed to identify a suitable ionization scheme for scandium via excitation into an autoionizing state at 58,104 cm − 1 which has subsequently been used for ionization of on-line produced exotic scandium isotopes.

  17. Radium, thorium, and actinium extraction from seawater using an improved manganese-oxide-coated fiber

    Laboratory experiments were conducted to determine the efficiency with which improved manganese-oxide-coated acrylic fibers extract radium, thorium, and actinium from seawater. Tests were made using surface seawater spiked with 227Ac, 227Th and 223Ra. For sample volumes of approximately 30 liters and flow rates up to 0.5 liters per minute, radium and actinium are removed quantitatively. Approximately 80-95% of the thorium is removed under these same conditions. (Auth.)

  18. Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

    Raeder, S.; Bastin, B.; Block, M.; Creemers, P.; Delahaye, P.; Ferrer, R.; Fléchard, X.; Franchoo, S.; Ghys, L.; Gaffney, L. P.; Granados, C.; Heinke, R.; Hijazi, L.; Huyse, M.; Kron, T.; Kudryavtsev, Yu.; Laatiaoui, M.; Lecesne, N.; Luton, F.; Moore, I. D.; Martinez, Y.; Mogilevskiy, E.; Naubereit, P.; Piot, J.; Rothe, S.; Savajols, H.; Sels, S.; Sonnenschein, V.; Traykov, E.; Van Beveren, C.; Van den Bergh, P.; Van Duppen, P.; Wendt, K.; Zadvornaya, A.

    2016-06-01

    To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

  19. Removal of actinium from europium for the determination of specific radioactivity of ultra low-level Eu-152 in a sample exposed to atomic-bomb neutrons in Nagasaki

    Measurements of specific radioactivities of residual neutron-induced radionuclides such as 152Eu and 60Co have been carried out to check the validity of a series of computer calculations employed for the atomic-bomb neutron dosimetry in Hiroshima (exposed to uranium bomb) and Nagasaki (exposed to plutonium bomb). The use of these nuclides for atomic-bomb neutron dosimetry, however, has been limited by the following difficulties: (1) today, these radionuclides are found only at extremely low concentrations in materials exposed to the atomic-bomb and (2) the neutrons that induced these radionuclides were thermal and epithermal, while the neutron dose received in Hiroshima and Nagasaki is attributable to fast neutrons. In order to overcome the first difficulty, we established a chemical procedure to extract Eu and Co from materials exposed to the atomic-bomb, and the chemical procedure has been successful for the materials exposed to atomic-bomb within 1400 m in slant distance from the explosion point. As for Nagasaki, materials exposed in the distances farther than 1200 m have never been subjected to the measurement of residual neutron-induced radionuclides. In this work, determination of specific radioactivity of 152Eu (half-life: 13.542 y) in a sample exposed to Nagasaki atomic-bomb at a distant place from the explosion point was undertaken. But, because of radioactive decay during this ∝60 years since 1945 and long distance from the explosion point, the present specific radioactivity of 152Eu in the sample is extremely low (estimated to be ∝3 x 10-4 Bq-152Eu/mg-Eu), and a serious problem is interferences from daughters of 227Ac (half-life: 21.8 y) in the measurement of ultra low-level radioactivity of 152Eu. Hence, our chemical procedure to obtain Eu-enriched counting source should be improved, and much attention is being denoted to removal of Ac from Eu. (orig.)

  20. Groundwater seepage from the Ranger uranium mine tailings dam: radioisotopes of radium, thorium and actinium. Supervising Scientist report 106

    Monitoring of bores near the Ranger uranium mine tailings dam has revealed deterioration in water quality in several bores since 1983. In a group of bores to the north of the dam, increases have been observed of up to 500 times for sulphate concentrations and of up to 5 times for 226Ra concentrations. Results are presented here of measurements of members of the uranium, thorium and actinium decay series in borewater samples collected between 1985 and 1993. In particular, measurements of all four naturally-occurring radium isotopes have been used in an investigation of the mechanism of radium concentration changes. For the most seepage-affected bores the major findings of the study include: 228Ra/226Ra 223Ra /226Ra and 224Ra/228Ra ratios all increased over the course of the study; barium concentrations show high seasonal variability, being lower in November than May, but strontium concentrations show a steady increase with time. Calculations show that the groundwater is probably saturated with respect to barite but not with respect to celestite or anglesite; sulphide concentrations are low in comparison with sulphate, and are higher in November than in May; and 227Ac concentrations have increased with time, but do not account for the high 223Ra/226Ra ratios. It is concluded on the basis of these observations that increases in Ra isotope concentrations observed in a number of seepage-affected bores arise from increases in salinity leading to desorption of radium from adsorption sites in the vicinity of the bore rather by direct transport of radium from the tailings. Increased salinity is also causing the observed increases in 227Ac and strontium concentrations, while formation of a barite solid phase in the groundwater is causing the removal of some radium from solution. This is the cause of the increasing radium isotope ratios noted above

  1. Actinium: A RESTful Runtime Container for Scriptable Internet of Things Applications

    Kovatsch, Matthias; Lanter, Martin; Duquennoy, Simon

    2012-01-01

    Programming Internet of Things (IoT) applications is challenging because developers have to be knowledgeable in various technical domains, from low-power networking, over embedded operating systems, to distributed algorithms. Hence, it will be challenging to find enough experts to provide software for the vast number of expected devices, which must also be scalable and particularly safe due to the connection to the physical world. To remedy this situation, we propose an architecture that pr...

  2. Linear free energy relationship applied to trivalent cations with lanthanum and actinium oxide and hydroxide structure

    Linear free energy relationships for trivalent cations with crystalline M2O3 and, M(OH)3 phases of lanthanides and actinides were developed from known thermodynamic properties of the aqueous trivalent cations, modifying the Sverjensky and Molling equation. The linear free energy relationship for trivalent cations is as ΔGf,MvX0=aMvXΔGn,M3+0+bMvX+βMvXrM3+, where the coefficients aMvX, bMvX, and βMvX characterize a particular structural family of MvX, rM3+ is the ionic radius of M3+ cation, ΔGf,MvX0 is the standard Gibbs free energy of formation of MvX and ΔGn,M3+0 is the standard non-solvation free energy of the cation. The coefficients for the oxide family are: aMvX=0.2705, bMvX=-1984.75 (kJ/mol), and βMvX=197.24 (kJ/molnm). The coefficients for the hydroxide family are: aMvX=0.1587, bMvX=-1474.09 (kJ/mol), and βMvX=791.70 (kJ/molnm).

  3. Purification of selenium from thorium, uranium, radium, actinium and potassium impurities for low background measurements

    A technique of selenium purification from 232Th, 238U, 226,228Ra, 227Ac and 40K was developed. This technique is simple to perform and employs a minimum number of highly pure reagents (bidistilled water, nitric acid). Operations carried out during purification (elution, evaporation) practically exclude losses of the target product (chemical yields of Se > 99%). A test purification of 100 g of selenium was carried out using this technique. The efficiency of this technique was confirmed by low background gamma spectrometry of the purified selenium sample. Distribution coefficients of Th, U, Ra and Ac on DOWEX 50W- x 8 cation-exchange resin at different concentrations of selenium and nitric acid were experimentally determinated. Instrumental neutron activation analysis of bidistilled water, deionized water and nitric acid was performed. (orig.)

  4. Purification of selenium from thorium, uranium, radium, actinium and potassium impurities for low background measurements

    Rakhimov, A.V. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation); Uzbek Academy of Sciences, Tashkent (Uzbekistan). Inst. of Nuclear Physics (INP AS RUz); Warot, G. [CEA-CNRS, Modane (France). Laboratoire Souterrain de Modane (LSM); Karaivanov, D.V. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation); Institute for Nuclear Research and Nuclear Energy (INRNE), Sofia (Bulgaria); Kochetov, O.I.; Lebedev, N.A.; Filosofov, D.V. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation); Mukhamedshina, N.M.; Sadikov, I.I. [Uzbek Academy of Sciences, Tashkent (Uzbekistan). Inst. of Nuclear Physics (INP AS RUz)

    2013-07-01

    A technique of selenium purification from {sup 232}Th, {sup 238}U, {sup 226,228}Ra, {sup 227}Ac and {sup 40}K was developed. This technique is simple to perform and employs a minimum number of highly pure reagents (bidistilled water, nitric acid). Operations carried out during purification (elution, evaporation) practically exclude losses of the target product (chemical yields of Se > 99%). A test purification of 100 g of selenium was carried out using this technique. The efficiency of this technique was confirmed by low background gamma spectrometry of the purified selenium sample. Distribution coefficients of Th, U, Ra and Ac on DOWEX 50W- x 8 cation-exchange resin at different concentrations of selenium and nitric acid were experimentally determinated. Instrumental neutron activation analysis of bidistilled water, deionized water and nitric acid was performed. (orig.)

  5. Radium-228 analysis of natural waters by Cherenkov counting of Actinium-228

    The activities of 228Ra in natural waters were determined by the Cherenkov counting of the daughter nuclide 228Ac. The radium was pre-concentrated on MnO2 and the radium purified via ion exchange and, after a 2-day period of incubation to allow for secular equilibrium between the parent-daughter 228Ra(228Ac), the daughter nuclide 228Ac was isolated by ion exchange according to the method of Nour et al. [2004. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin. Appl. Radiat. Isot. 61, 1173-1178]. The Cherenkov photons produced by 228Ac were counted directly without the addition of any scintillation reagents. The optimum Cherenkov counting window, sample volume, and vial type were determined experimentally to achieve optimum Cherenkov photon detection efficiency and lowest background count rates. An optimum detection efficiency of 10.9±0.1% was measured for 228Ac by Cherenkov counting with a very low Cherenkov photon background of 0.317±0.013 cpm. The addition of sodium salicylate into the sample counting vial at a concentration of 0.1 g/mL yielded a more than 3-fold increase in the Cherenkov detection efficiency of 228Ac to 38%. Tests of the Cherenkov counting technique were conducted with several water standards of known activity and the results obtained compared closely with a conventional liquid scintillation counting technique. The advantages and disadvantages of Cherenkov counting compared to liquid scintillation counting methods are discussed. Advantages include much lower Cherenkov background count rates and consequently lower minimal detectable activities for 228Ra and no need for expensive environmentally unfriendly liquid scintillation cocktails. The disadvantages of the Cherenkov counting method include the need to measure 228Ac Cherenkov photon detection efficiency and optimum Cherenkov counting volume, which are not at all required when liquid scintillation analysis is

  6. Synthesis of chelating agents for actinium 225 complexation and its application in radioimmunotherapy

    Immunotherapy with radiolabeled antibodies should allow fairly specific targeting of certain cancers. However, iodine 131 may not be the best isotope for tumor therapy because of its limited specific activity, low beta-energy, relatively long half life and strong gamma emission. Another approach to improve therapeutic efficacy is the use of replacement isotopes with better physical properties. Chelator that can hold radio-metals with high stability under physiological conditions are essential to avoid excessive damage to non-target cells; Moreover, the development of new bifunctional chelating agents is essential for this purpose. Accordingly, our efforts have been directed, for several years, to the synthesis of original chelating agents likely to form stable complexes in vivo with the numerous potential candidates for such applications. Therefore, we have developed a new simple and efficient synthesis pathway of 2-(4-iso-thio-cyanate-benzyl)-1,4,7,10,13,16- hexa-aza-cyclo-hexadecane- 1,4,7,10,13,16-hexa-acetic acid, though functionalized on the cycle by a termination allowed coupling to an antibody or any other biological substance such as a hapten. (author)

  7. New method for large scale production of medically applicable Actinium-225 and Radium-223

    Alpha-emitters (211At, 212Bi, 213Bi, 223Ra, 225Ac) are promising for targeted radiotherapy of cancer. Only two alpha decays near a cell membrane result in 50% death of cancer cell and only a single decay inside the cell is required for this. 225Ac may be used either directly or as a mother radionuclide in 213Bi isotope generator. Production of 225Ac is provided by three main suppliers - Institute for Transuranium Elements in Germany, Oak Ridge National Laboratory in USA and Institute of Physics and Power Engineering in Obninsk, Russia. The current worldwide production of 225Ac is approximately 1.7 Ci per year that corresponds to only 100-200 patients that could be treated annually. The common approach for 225Ac production is separation from mother 229Th or irradiation of 226Ra with protons in a cyclotron. Both the methods have some practical limitations to be applied routinely. 225Ac can be also produced by irradiation of natural thorium with medium energy protons . Cumulative cross sections of 225Ac, 227Ac, 227Th, 228Th formations have been obtained recently. Thorium targets (1-9 g) were irradiated by 114-91 MeV proton beam (1-50 μA) at INR linear accelerator. After dissolution in 8 M HNO3 + 0.004 M HF thorium was removed by double LLX by HDEHP in toluene (1:1). Ac and REE were pre-concentrated and separated from Ra and most fission products by DGA-Resin (Triskem). After washing out by 0.01 M HNO3 Ac was separated from REE by TRU Resin (Triskem) in 3 M HNO3 media. About 6 mCi 225Ac were separated in hot cell with chemical yield 85%. The method may be upscaled for production of Ci amounts of the radionuclide. The main impurity is 227Ac (0.1% at the EOB) but it does not hinder 225Ac from being used for medical 225Ac/213Bi generators. (author)

  8. Renal uptake of bismuth-213 and its contribution to kidney radiation dose following administration of actinium-225-labeled antibody

    Schwartz, J; O' Donoghue, J A; Humm, J L [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 (United States); Jaggi, J S [Bristol-Myers Squibb, Plainsboro, NJ (United States); Ruan, S; Larson, S M [Nuclear Medicine Service Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065 (United States); McDevitt, M; Scheinberg, D A, E-mail: schwarj1@mskcc.org [Molecular Pharmacology and Chemistry, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065 (United States)

    2011-02-07

    Clinical therapeutic studies using {sup 225}Ac-labeled antibodies have begun. Of major concern is renal toxicity that may result from the three alpha-emitting progeny generated following the decay of {sup 225}Ac. The purpose of this study was to determine the amount of {sup 225}Ac and non-equilibrium progeny in the mouse kidney after the injection of {sup 225}Ac-huM195 antibody and examine the dosimetric consequences. Groups of mice were sacrificed at 24, 96 and 144 h after injection with {sup 225}Ac-huM195 antibody and kidneys excised. One kidney was used for gamma ray spectroscopic measurements by a high-purity germanium (HPGe) detector. The second kidney was used to generate frozen tissue sections which were examined by digital autoradiography (DAR). Two measurements were performed on each kidney specimen: (1) immediately post-resection and (2) after sufficient time for any non-equilibrium excess {sup 213}Bi to decay completely. Comparison of these measurements enabled estimation of the amount of excess {sup 213}Bi reaching the kidney ({gamma}-ray spectroscopy) and its sub-regional distribution (DAR). The average absorbed dose to whole kidney, determined by spectroscopy, was 0.77 (SD 0.21) Gy kBq{sup -1}, of which 0.46 (SD 0.16) Gy kBq{sup -1} (i.e. 60%) was due to non-equilibrium excess {sup 213}Bi. The relative contributions to renal cortex and medulla were determined by DAR. The estimated dose to the cortex from non-equilibrium excess {sup 213}Bi (0.31 (SD 0.11) Gy kBq{sup -1}) represented {approx}46% of the total. For the medulla the dose contribution from excess {sup 213}Bi (0.81 (SD 0.28) Gy kBq{sup -1}) was {approx}80% of the total. Based on these estimates, for human patients we project a kidney-absorbed dose of 0.28 Gy MBq{sup -1} following administration of {sup 225}Ac-huM195 with non-equilibrium excess {sup 213}Bi responsible for approximately 60% of the total. Methods to reduce renal accumulation of radioactive progeny appear to be necessary for the

  9. System for recovery of daughter isotopes from a source material

    Tranter, Troy J [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Lewis, Leroy C [Idaho Falls, ID; Henscheid, Joseph P [Idaho Falls, ID

    2009-08-04

    A method of separating isotopes from a mixture containing at least two isotopes in a solution is disclosed. A first isotope is precipitated and is collected from the solution. A daughter isotope is generated and collected from the first isotope. The invention includes a method of producing an actinium-225/bismuth-213 product from a material containing thorium-229 and thorium-232. A solution is formed containing nitric acid and the material containing thorium-229 and thorium-232, and iodate is added to form a thorium iodate precipitate. A supernatant is separated from the thorium iodate precipitate and a second volume of nitric acid is added to the thorium iodate precipitate. The thorium iodate precipitate is stored and a decay product comprising actinium-225 and bismuth-213 is generated in the second volume of nitric acid, which is then separated from the thorium iodate precipitate, filtered, and treated using at least one chromatographic procedure. A system for producing an actinium-225/bismuth-213 product is also disclosed.

  10. Study of the origin of elements of the uranium-235 family observed in excess in the vicinity of the experimental nuclear EL4 reactor under dismantling. Lessons got at this day and conclusions; Etude de l'origine des elements de la famille de l'uranium-235 observes en exces dans les environs du reacteur nucleaire experimental EL4 en cours de demantelement. Enseignements retires a ce jour et conclusion

    NONE

    2007-07-01

    This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible relationship with the gaseous effluents of the nuclear power plant in the past, historical study of radioactive effluents releases in the fifty last years by the analysis of the sedimentary deposits in the Saint-Herbiot reservoir, search of a possible correlation between the excess of actinium 227 and the nuclear power plant activity; search of a possible correlation with a human activity without any relationship with the nuclear activities, search of a correlation with the underground waters, search of a correlation with the geological context, collect of information on the possible transfers in direction of the food chain, determination of the radiological composition of the underground waters ( not perturbed by human activity), search of the cause of an excess of actinium 227 in the old channel of liquid effluents release of the nuclear power plant. The results are given and discussed. And contrary to all expectations the origin of the excess of actinium 227 is completely natural. (N.C.)

  11. A study of uranium and thorium migration at the Koongarra uranium deposit with application to actinide transport from nuclear waste repositories

    One way to gain confidence in modelling possible radionuclide releases is to study natural systems which are similar to components of the multibarrier waste repository. Several such analogues are currently under study and these provide useful data about radionuclide behaviour in the natural environment. One such system is the Koongarra uranium deposit in the Northern Territory. In this dissertation, the migration of actinides, primarily uranium and thorium, has been studied as an analogue for the behaviour of transuranics in the far-field of a waste repository. The major findings of this study are: 1. the main process retarding uranium migration in the dispersion fan at Koongarra is sorption, which suppresses dissolved uranium concentrations well below solubility limits, with ferrihydrite being a major sorbing phase; 2. thorium is extremely immobile, with very low dissolved concentrations and corresponding high distribution ratios for 230Th. Overall, it is estimated that colloids are relatively unimportant in Koongarra groundwater. Uranium migrates mostly as dissolved species, whereas thorium and actinium are mostly adsorbed to larger, relatively immobile particles and the stationary phase. However, of the small amount of 230Th that passes through a 1μm filter, a significant proportion is associated with colloidal particles. Actinium appears to be slightly more mobile than thorium and is associated with colloids to a greater extent, although generally present in low concentrations. These results support the possibility of colloidal transport of trivalent and tetravalent actinides in the vicinity of a nuclear waste repository. 112 refs., 23 tabs., 32 figs

  12. A francium-223 reservoir source

    By improving and accelerating a method which had been earlier tried for caesium-rubidium separation on a cellulose column, i.e. elution with 2N HCl-equilibrated phenol, the author succeeded in obtaining consecutive and quasi-selective elutions of francium-223, starting with actinium-227 fixed at the top of a small cellulose column to which ZrO2 had been added. The francium-223, rapidly eluted under pressure, is extracted by water while the phenol is extracted by ether; it can easily be cleared of any residual traces of radioactive contaminants (thallium-207, radium-223, thorium-227) by two consecutive BaSO4 precipitations. The preparation of a Fr223 solution (HCl-H2SO4) requires approximately 20 min; the time noted for Fr223 was closer to 22 than to 21 min. (author)

  13. Generator method of 225Ac production without a carrier for nuclear medicine

    The two-steps isotope generator scheme of 225Ac production from 229Th has been developed. The first step is used for separation of thorium, actinium, radium and daughter decay products (DDP), and removals of parent radionuclide. The second step provides additional separation of actinium from traces of radium and DDP, and conversion of actinium in the nitrate form. The chosen solutions provide optimal conditions for carry out of process. The yield of the 225Ac was 99.9% at minimal losses of parent 229Th (less than 0.1%)

  14. Origin of elements of the Uranium-235 family observed in the Ellez river near the EL-4 experimental nuclear reactor in dismantling (Monts d'Arree- Finistere department); Origine des elements de la famille de l'uranium-235 observes dans la riviere Ellez a proximite du reacteur nucleaire experimental EL4 en cours de demantelement (Mont d'Arree - departement du Finistere). Resultats et premiers constats annee 2006

    NONE

    2006-07-01

    In a previous study which concerned the catchment basin of the harbour of Brest, the A.C.R.O. put in evidence a marking by artificial radioelements around the power plant of Brennilis which can be imputed without ambiguities to the nuclear installation. It also put in evidence abnormalities concerning the natural radioactivity which justifies this new study. In the area of the Monts d'Arree, actinium 227 ({sup 227}Ac), non born by its ascendents which are {sup 235}U and {sup 231}Pa is observed. This phenomenon is characterized by mass activities superior to these ones of {sup 235}U and able to reach these ones of {sup 238}U. Its presence corresponds with the drainage of the Ellez river since the former channel of radioactive effluents releases from the nuclear power plant EL-4 up to the reservoir Saint-Herblot situated 6 km downstream. The strongest values of radioactivity are registered near the disused power plant, at this place a relationship exists between the level of actinium 227 and this one of the artificial radioactivity as it exists a relationship with the decay products of radon exhaled from the subsoil ({sup 210}Pb). But its presence is not limited to a part of the Ellez river, it is equally observed in terrestrial medium, in places in priori not influenced by the direct liquid effluents of the power plant. This place is situated at more than 4 km and without any connection with the Ellez waters. At this stage of the study, it is not possible to answer with certainty the question of the origin of this phenomenon. A new reorientation is considered indispensable to clarify definitively the origin of this unknown phenomenon in the scientific publications and the environmental monitoring. (N.C.)

  15. Minor Actinide Burning in Thermal Reactors. A Report by the Working Party on Scientific Issues of Reactor Systems

    The actinides (or actinoids) are those elements in the periodic table from actinium upwards. Uranium (U) and plutonium (Pu) are two of the principal elements in nuclear fuel that could be classed as major actinides. The minor actinides are normally taken to be the triad of neptunium (Np), americium (Am) and curium (Cm). The combined masses of the remaining actinides (i.e. actinium, thorium, protactinium, berkelium, californium, einsteinium and fermium) are small enough to be regarded as very minor trace contaminants in nuclear fuel. Those elements above uranium in the periodic table are known collectively as the transuranics (TRUs). The operation of a nuclear reactor produces large quantities of irradiated fuel (sometimes referred to as spent fuel), which is either stored prior to eventual deep geological disposal or reprocessed to enable actinide recycling. A modern light water reactor (LWR) of 1 GWe capacity will typically discharge about 20-25 tonnes of irradiated fuel per year of operation. About 93-94% of the mass of uranium oxide irradiated fuel is comprised of uranium (mostly 238U), with about 4-5% fission products and ∼1% plutonium. About 0.1-0.2% of the mass is comprised of neptunium, americium and curium. These latter elements accumulate in nuclear fuel because of neutron captures, and they contribute significantly to decay heat loading and neutron output, as well as to the overall radio-toxic hazard of spent fuel. Although the total minor actinide mass is relatively small - approximately 20-25 kg per year from a 1 GWe LWR - it has a disproportionate impact on spent fuel disposal, and thus the longstanding interest in transmuting these actinides either by fission (to fission products) or neutron capture in order to reduce their impact on the back end of the fuel cycle. The combined masses of the trace actinides actinium, thorium, protactinium, berkelium and californium in irradiated LWR fuel are only about 2 parts per billion, which is far too low for

  16. Bestimmung der Ionisationsenergie von Actinium und Ultraspurenanalyse von Plutonium mit resonanter Ionisationsmassenspektrometrie (RIMS)

    Waldek, Achim Marcus

    2001-01-01

    ZusammenfassungDie Resonanzionisationsmassenspektrometrie (RIMS) verbindet hohe Elementselektivität mit guter Nachweiseffizienz. Aufgrund dieser Eigenschaften ist die Methode für Ultraspurenanalyse und Untersuchungen an seltenen oder schwer handhabbaren Elementen gut geeignet. Für RIMS werden neutrale Atome mit monochromatischem Laserlicht ein- oder mehrfach resonant auf energetisch hoch liegende Niveaus angeregt und anschließend durch einen weiteren Laserstrahl oder durch ein elektrisches Fe...

  17. Liquid Scintillation Counting of Environmental Radioisotopes: A Review of the Impact of Background Reduction

    Douglas, Matthew; Bernacki, Bruce E.; Erchinger, Jennifer L.; Finn, Erin C.; Fuller, Erin S.; Hoppe, Eric W.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Wright, Michael E.

    2016-03-09

    Liquid scintillation counting (LSC) is a versatile and commonplace method for radiometric measurement of charged particle emitting radionuclides. The LSC method provides utility in a range of environmental science applications including hydrological studies of water transport, anthropogenic releases of radionuclides into the environment, and vertical mixing rates within oceans. Instrumental measurement background is one limiting factor of radiometric measurement sensitivity. As part of the development of a custom low background LSC system located in a shallow underground laboratory at Pacific Northwest National Laboratory, a number of measurement applications of LSC have been considered and are summarized here. The focus is on determining which aspects of such measurements would gain the greatest benefit from the reduction of LSC backgrounds by a factor of 10-100 relative to values reported in the literature. Examples of benefits include lowering the minimum detectable activity, reducing the sample size required, and shortening the elapsed timeline of the processing and analysis sequence. In particular tritium, strontium, and actinium isotopes are examined as these isotopes cover a range of requirements related to the LSC measurement method (e.g., 3H: low energy; Sr: spectral deconvolution; Ac: alpha/beta discrimination).

  18. Study of Thorium Utilization in a Large Scale Sodium Cooled Fast Reactor

    The breeding performance of 232Th in fast reactor is better than 238U, since the capture cross section of 232Th is slightly higher than 238U under the fast neutron spectrum. There are much less fission neutrons in the blanket, so the proportion of neutron with energy above 6MeV (the threshold energy of (n,2n) reaction of 232Th) is very small. Therefore, the 233U produced in fast reactor blanket would have high purity. In this paper, an large scale fast reactor core was taken as the reference core for 232Th utilization study. In the calculation results, the whole capability of 233U production is about 443kg/(GWe•a) in the blanket; at the end of the first cycle (160EFPD), the 233U production per unit mass of 232Th is about 10.71g/(kgTh), and the weight fraction of 232U in actinium is less than 0.019%. It is an attractive technology option to produce 233U in the blanket. (author)

  19. A Critical Review of Alpha Radionuclide Therapy-How to Deal with Recoiling Daughters?

    de Kruijff, Robin M; Wolterbeek, Hubert T; Denkova, Antonia G

    2015-01-01

    This review presents an overview of the successes and challenges currently faced in alpha radionuclide therapy. Alpha particles have an advantage in killing tumour cells as compared to beta or gamma radiation due to their short penetration depth and high linear energy transfer (LET). Touching briefly on the clinical successes of radionuclides emitting only one alpha particle, the main focus of this article lies on those alpha-emitting radionuclides with multiple alpha-emitting daughters in their decay chain. While having the advantage of longer half-lives, the recoiled daughters of radionuclides like 224Ra (radium), 223Ra, and 225Ac (actinium) can do significant damage to healthy tissue when not retained at the tumour site. Three different approaches to deal with this problem are discussed: encapsulation in a nano-carrier, fast uptake of the alpha emitting radionuclides in tumour cells, and local administration. Each approach has been shown to have its advantages and disadvantages, but when larger activities need to be used clinically, nano-carriers appear to be the most promising solution for reducing toxic effects, provided there is no accumulation in healthy tissue. PMID:26066613

  20. A Critical Review of Alpha Radionuclide Therapy—How to Deal with Recoiling Daughters?

    de Kruijff, Robin M.; Wolterbeek, Hubert T.; Denkova, Antonia G.

    2015-01-01

    This review presents an overview of the successes and challenges currently faced in alpha radionuclide therapy. Alpha particles have an advantage in killing tumour cells as compared to beta or gamma radiation due to their short penetration depth and high linear energy transfer (LET). Touching briefly on the clinical successes of radionuclides emitting only one alpha particle, the main focus of this article lies on those alpha-emitting radionuclides with multiple alpha-emitting daughters in their decay chain. While having the advantage of longer half-lives, the recoiled daughters of radionuclides like 224Ra (radium), 223Ra, and 225Ac (actinium) can do significant damage to healthy tissue when not retained at the tumour site. Three different approaches to deal with this problem are discussed: encapsulation in a nano-carrier, fast uptake of the alpha emitting radionuclides in tumour cells, and local administration. Each approach has been shown to have its advantages and disadvantages, but when larger activities need to be used clinically, nano-carriers appear to be the most promising solution for reducing toxic effects, provided there is no accumulation in healthy tissue. PMID:26066613

  1. A Critical Review of Alpha Radionuclide Therapy—How to Deal with Recoiling Daughters?

    Robin M. de Kruijff

    2015-06-01

    Full Text Available This review presents an overview of the successes and challenges currently faced in alpha radionuclide therapy. Alpha particles have an advantage in killing tumour cells as compared to beta or gamma radiation due to their short penetration depth and high linear energy transfer (LET. Touching briefly on the clinical successes of radionuclides emitting only one alpha particle, the main focus of this article lies on those alpha-emitting radionuclides with multiple alpha-emitting daughters in their decay chain. While having the advantage of longer half-lives, the recoiled daughters of radionuclides like 224Ra (radium, 223Ra, and 225Ac (actinium can do significant damage to healthy tissue when not retained at the tumour site. Three different approaches to deal with this problem are discussed: encapsulation in a nano-carrier, fast uptake of the alpha emitting radionuclides in tumour cells, and local administration. Each approach has been shown to have its advantages and disadvantages, but when larger activities need to be used clinically, nano-carriers appear to be the most promising solution for reducing toxic effects, provided there is no accumulation in healthy tissue.

  2. Quantification of radionuclide transfer in terrestrial and freshwater environments: A summary

    Exposure may occur as a result of incidental releases and discharges from all stages of the nuclear fuel cycle. This includes uranium mines, fuel fabrication facilities, reactors, reprocessing plants and low, intermediate and high level radioactive waste repository sites. Each of these releases involves mainly fission and neutron activation products as well as actinides. Uranium mining and fuel fabrication also involve radionuclides of the uranium, actinium and thorium decay series. In addition, some industries such as mineral sands production and processing, phosphate ore processing, coal burning and oil and gas production can generate naturally occurring radioactive materials (NORMs) as waste. Other sources of human exposure include nuclear weapon testing and radiation accidents or incidents. Any radiological assessments are based on an analysis of radionuclide transport patterns and processes governing radionuclide behaviour in the environment. Therefore, it is an aim of the IAEA to support Member States to enhance their capability for evaluating radionuclide transport, geochemical and biochemical enrichment, and radiation effects on human beings and other biota

  3. Distribution of trace elements in land plants and botanical taxonomy with special reference to rare earth elements and actinium

    Distribution profiles of trace elements in land plants were studied by neutron activation analysis and radioactivity measurements without activation. Number of botanical samples analyzed were more than three thousand in which more than three hundred botanical species were included. New accumulator plants of Co, Cr, Zn, Cd, rare earth elements, Ac, U, etc., were found. Capabilities of accumulating trace elements can be related to the botanical taxonomy. Discussions are given from view points of inorganic chemistry as well as from botanical physiology

  4. Alpha-emitting isotopes and chromium in a coastal California aquifer

    Densmore, Jill N.; Izbicki, John A.; Murtaugh, Joseph M.; Swarzenski, Peter W.; Bullen, Thomas D.

    2014-01-01

    The unadjusted 72-h gross alpha activities in water from two wells completed in marine and alluvial deposits in a coastal southern California aquifer 40 km north of San Diego were 15 and 25 picoCuries per liter (pCi/L). Although activities were below the Maximum Contaminant Level (MCL) of 15 pCi/L, when adjusted for uranium activity; there is concern that new wells in the area may exceed MCLs, or that future regulations may limit water use from the wells. Coupled well-bore flow and depth-dependent water-quality data collected from the wells in 2011 (with analyses for isotopes within the uranium, actinium, and thorium decay-chains) show gross alpha activity in marine deposits is associated with decay of naturally-occurring 238U and its daughter 234U. Radon activities in marine deposits were as high as 2230 pCi/L. In contrast, gross alpha activities in overlying alluvium within the Piedra de Lumbre watershed, eroded from the nearby San Onofre Hills, were associated with decay of 232Th, including its daughter 224Ra. Radon activities in alluvium from Piedra de Lumbre of 450 pCi/L were lower than in marine deposits. Chromium VI concentrations in marine deposits were less than the California MCL of 10 μg/L (effective July 1, 2014) but δ53Cr compositions were near zero and within reported ranges for anthropogenic chromium. Alluvial deposits from the nearby Las Flores watershed, which drains a larger area having diverse geology, has low alpha activities and chromium as a result of geologic and geochemical conditions and may be more promising for future water-supply development.

  5. Investigation for determining the retention properties of rock over the ASSE II mine for dissolved radionuclides

    For a model consideration of groundwater movement and the associated transport of dissolved substance in deep groundwater, the retention properties of the ASSE II mine for radionuclides dissolved in water were determined. A series of properties of rocks were examined and described for this purpose. Apart from the chemical, mineralogical and petrophysical characteristics of the rocks, the retention was determined by 3 different methods and stated in the form of distribution coefficients for specific elements. A comparison of the results of vibration and diffusion experiments gave good agreement, while the results in through column experiments only reached the same order of magnitude after an expensive determination with the aid of a place concentration distribution. The distribution coefficients for the elements carbon, selenium, strontium, technetium, iodine, caesium, lead, radium, actinium, proto-actinium, uranium, neptunium, plutonium, americium and curium are listed and collected for model rock packages. (orig./HP)

  6. LASL experience in decontamination of the environment

    This discussion represents one part of a major effort in soil decontamination at the Los Alamos site. A contaminated industrial waste line in the Los Alamos townsite was removed, and a plutonium incineration facility, and a filter building contaminated with actinium-227 were dismantled. The former plutonium handling facility has been decontaminated, and canyons and an old firing site contaminated with strontium-90 have been surveyed

  7. The discoveries of uranium 237 and symmetric fission — From the archival papers of Nishina and Kimura

    IKEDA, Nagao

    2011-01-01

    Shortly before the Second World War time, Nishina reported on a series of prominent nuclear physical and radiochemical studies in collaboration with Kimura. They artificially produced 231Th, a member of the natural actinium series of nuclides, by bombarding thorium with fast neutrons. This resulted in the discovery of 237U, a new isotope of uranium, by bombarding uranium with fast neutrons, and confirmed that 237U disintegrates into element 93 with a mass number of 237. They also identified t...

  8. Sorption studies of radioelements on geological materials

    Batch sorption experiments have been carried out to study the sorption of uranium, technetium, curium, neptunium, actinium, protactinium, polonium, americium and plutonium onto bentonite, granodiorite and tuff. Mathematical modelling using the HARPHRQ program and the HATCHES database was carried out to predict the speciation of uranium and technetium in the equilibrated seawater, and neptunium, americium and plutonium in the rock equilibrated water. Review of the literature for thermodynamic data for curium, actinium, protactinium and polonium was carried out. Where sufficient data were available, predictions of the speciation and solubility were made. This report is a summary report of the experimental work conducted by AEA Technology during April 1991-March 1998, and the main results have been presented at Material Research Society Symposium Proceedings and published as proceedings of them. (author)

  9. Purification of cerium, neodymium and gadolinium for low background experiments

    Boiko R.S.; Barabash A.S.; Belli P.; Bernabei R.; Cappella F.; Cerulli R.; Danevich F.A.; Incicchitti A.; Laubenstein M.; Mokina V.M.; Nisi S.; Poda D.V.; Polischuk O.G.; Tretyak V.I.

    2014-01-01

    Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search), 136Ce (2β+ candidate with one of the highest Q2β). The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical an...

  10. History of the unraveling of the natural decay series

    Milestones in the subject of radioactivity, which were important to the unraveling of natural decay series, have been identified and described. The interplay between all these issues is very complex, and some aspects of the development of the uranium series is discussed as an example, the thorium and actinium series evolved in a similar way from research by many of the same people. All three series as understood in 1913 are compared with their present-day representation. (orig.)

  11. History of the unraveling of the natural decay series

    Milestones in the subject of radioactivity, which were important to the unraveling of natural decay series, have been identified and described. The interplay between all these issues is very complex, and some aspects of the development of the uranium series is discussed as an example, the thorium and actinium series evolved in a similar way from research by many of the same people. All three series as understood in 1913 are compared with their present-day representation. (author)

  12. Behaviour of uranium series radionuclides in surface water (Crouzille, Limousin). Geochemical implications

    Understanding natural radionuclides behaviour in surface water is a required step to achieve uranium mine rehabilitation and preserve water quality. The first objective of this thesis is to determine which are the radionuclides sources in a drinking water reservoir. The second objective is to improve the knowledge about the behaviour of uranium series radionuclides, especially actinium. The investigated site is a brook (Sagnes, Limousin, France) which floods a peat bog contaminated by a former uranium mine and which empties into the Crouzille lake. It allows studying radionuclides transport in surface water and radionuclides retention through organic substance or water reservoir. Radionuclides distribution in particulate, colloidal and dissolved phases is determined thanks to ultra-filtrations. Gamma spectrometry allows measuring almost all natural radionuclides with only two counting stages. However, low activities of 235U series radionuclides impose the use of very low background well-type Ge detectors, such as those of the Underground Laboratory of Modane (France). Firstly, this study shows that no or few radionuclides are released by the Sagnes peat bog, although its radioactivity is important. Secondly, it provides details on the behaviour of uranium series radionuclides in surface water. More specifically, it provides the first indications of actinium solubility in surface water. Actinium's behaviour is very close to uranium's even if it is a little less soluble. (author)

  13. Alpha-emitting isotopes and chromium in a coastal California aquifer

    Highlights: • Alluvium in Piedra de Lumbre basin higher radionuclides likely from natural Th. • Natural uranium decay-chain isotopes, including Ra, present in marine deposits. • Marine deposits also contain low concentrations of chromium. • Radionuclides and chromium concentrations lower in alluvium in the Las Flores basin. - Abstract: The unadjusted 72-h gross alpha activities in water from two wells completed in marine and alluvial deposits in a coastal southern California aquifer 40 km north of San Diego were 15 and 25 picoCuries per liter (pCi/L). Although activities were below the Maximum Contaminant Level (MCL) of 15 pCi/L, when adjusted for uranium activity; there is concern that new wells in the area may exceed MCLs, or that future regulations may limit water use from the wells. Coupled well-bore flow and depth-dependent water-quality data collected from the wells in 2011 (with analyses for isotopes within the uranium, actinium, and thorium decay-chains) show gross alpha activity in marine deposits is associated with decay of naturally-occurring 238U and its daughter 234U. Radon activities in marine deposits were as high as 2230 pCi/L. In contrast, gross alpha activities in overlying alluvium within the Piedra de Lumbre watershed, eroded from the nearby San Onofre Hills, were associated with decay of 232Th, including its daughter 224Ra. Radon activities in alluvium from Piedra de Lumbre of 450 pCi/L were lower than in marine deposits. Chromium VI concentrations in marine deposits were less than the California MCL of 10 μg/L (effective July 1, 2014) but δ53Cr compositions were near zero and within reported ranges for anthropogenic chromium. Alluvial deposits from the nearby Las Flores watershed, which drains a larger area having diverse geology, has low alpha activities and chromium as a result of geologic and geochemical conditions and may be more promising for future water-supply development

  14. Study on laser atomic spectroscopy

    Laser atomic spectroscopic study on actinium element has been performed in many areas of spectroscopy. The study on characteristic of atomic vapor has been proceeded for copper atom and the spatial density distribution of copper vapor is measured. This experimental data has been compared with the theoretically calculated data. In spectroscopic experiment, the first and second excited states for actinium element are identified and the most efficient ionization scheme for actinium element is identified. In addition, the corrosion problem for filament material due to the heating of the actinium element has been studied. (Author)

  15. Purification of cerium, neodymium and gadolinium for low background experiments

    Boiko R.S.

    2014-01-01

    Full Text Available Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search, 136Ce (2β+ candidate with one of the highest Q2β. The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  16. Purification of cerium, neodymium and gadolinium for low background experiments

    Boiko, R. S.; Barabash, A. S.; Belli, P.; Bernabei, R.; Cappella, F.; Cerulli, R.; Danevich, F. A.; Incicchitti, A.; Laubenstein, M.; Mokina, V. M.; Nisi, S.; Poda, D. V.; Polischuk, O. G.; Tretyak, V. I.

    2014-01-01

    Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search), 136Ce (2β+ candidate with one of the highest Q2β). The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides) was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  17. An aerial radiological survey of the Sandia National Laboratories and surrounding area

    A team from the Remote Sensing Laboratory conducted an aerial radiological survey of the area surrounding the Sandia National Laboratories and Kirtland Air Force Base in Albuquerque, New Mexico, during March and April 1993. The survey team measured the terrestrial gamma radiation at the site to determine the levels of natural and man-made radiation. This survey includes the areas covered by a previous survey in 1981. The results of the aerial survey show a background exposure rate which varies between 5 and 18 μR/h plus an approximate 6 μR/h contribution from cosmic rays. The major radioactive isotopes found in this survey were: potassium-40, thallium-208, bismuth-214, and actinium-228, which are all naturally-occurring isotopes, and cobalt-60, cesium-137, and excess amounts of thallium-208 and actinium-228, which are due to human actions in the survey area. In regions away from man-made activity, the exposure rates inferred from this survey's gamma ray measurements agree almost exactly with the exposure rates inferred from the 1981 survey. In addition to the aerial measurements, another survey team conducted in situ and soil sample radiation measurements at three sites within the survey perimeter. These ground-based measurements agree with the aerial measurements within ± 5%

  18. Proposed training program for construction personnel involved in remedial action work at sites contaminated by naturally occurring radionuclides

    Many sites used during the early days of the US atomic energy program are contaminated with radionuclides of the primordial decay chains (uranium, thorium, and actinium series). This contamination consists of residues resulting from refining and processing uranium and thorium. Preparation of these sites for release to unrestricted private use will involve the assistance of construction workers, many of whom have limited knowledge of the hazards associated with radioactive materials. Therefore, there is a need to educate these workers in the fundamentals of radioactive material handling to minimize exposures and possible spread of contamination. This training should disseminate relevant information at an appropriate educational level and should instill a cautious, common-sense attitude toward the handling of radioactive materials. The training should emphasize basic information concerning environmental radiation within a context of relative risk. A multi-media format, including colorful visual aids, demonstration, and discussion, should be used to maximize motivation and retention. A detailed, proposed training program design is presented

  19. Purification system of gram-amount neptunium using anion exchange chromatography

    To develop a purification system of gram-amount neptunium using anion exchange chromatography, adsorption elution of excess amount of actinium in 6M HNO3 aqueous solution was studied using thorium and uranium tracer. The partition coefficient (Kd) of Th (IV) decreased from Kd=99.1 of tracer to Kd=44.0, 5% load. By decreasing the partition coefficient, we can wash until 30 Vs under the purification conditions of 1% load and 95% recovery. The retention volume of U (IV) was about 300 Vs, a large value. The partition coefficient of Np (IV) may be larger than it and the large amount of washable eluting solution may be obtained. Washing of impurity of 3d transition metal and actinide (VI) can be done until 20Vs. With washing of 150Vs, impurity of alkali earth metal, metals (III) and platinum group metals decreased less than 0.1%. (S.Y.)

  20. origin of elements of the Uranium-235 family observed in the Ellez river near the EL-4 experimental nuclear reactor in dismantling (Monts d'Arree- Finistere department)

    In a previous study which concerned the catchment basin of the harbour of Brest, the A.C.R.O. put in evidence a marking by artificial radioelements around the power plant of Brennilis which can be imputed without ambiguities to the nuclear installation. It also put in evidence abnormalities concerning the natural radioactivity which justifies this new study. In the area of the Monts d'Arree, actinium 227 (227Ac), non born by its ascendents which are 235U and 231Pa is observed. This phenomenon is characterized by mass activities superior to these ones of 235U and able to reach these ones of 238U. Its presence corresponds with the drainage of the Ellez river since the former channel of radioactive effluents releases from the nuclear power plant EL-4 up to the reservoir Saint-Herblot situated 6 km downstream. The strongest values of radioactivity are registered near the disused power plant, at this place a relationship exists between the level of actinium 227 and this one of the artificial radioactivity as it exists a relationship with the decay products of radon exhaled from the subsoil (210Pb). But its presence is not limited to a part of the Ellez river, it is equally observed in terrestrial medium, in places in priori not influenced by the direct liquid effluents of the power plant. This place is situated at more than 4 km and without any connection with the Ellez waters. At this stage of the study, it is not possible to answer with certainty the question of the origin of this phenomenon. A new reorientation is considered indispensable to clarify definitively the origin of this unknown phenomenon in the scientific publications and the environmental monitoring. (N.C.)

  1. Radionuclide interactions with marine sediments

    A critical review of the literature on the subject of the interactions of radionuclides with marine sediments has been carried out. On the basis of the information available, an attempt has been made to give ranges and 'best estimates' for the distribution ratios between seawater and sediments. These estimates have been based on an understanding of the sediment seawater system and the porewater chemistry and mineralogy. Field measurements, laboratory measurements and estimates based on stable-element geochemical data are all taken into account. Laboratory measurements include distribution-ratio and diffusion-coefficient determinations. The elements reviewed are carbon, chlorine, calcium, nickel, selenium, strontium, zirconium, niobium, technetium, tin, iodine, caesium, lead, radium, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium and curium. (author)

  2. Physical Measurements and Clinical Findings of Persons with Radium Burdens

    Results of physical measurements and some clinical findings of persons with radium burdens are reported and discussed. Ten workers of the dial painting industry, two chemists, who have been working for between 10 and 20 yr in the radium- industry, one technician, who has been- working for over 20 yr with high-emanation radium preparations and one person with high radium intake of rather unknown history were measured in a whole-body counter for evaluation of the body burdens of radium-226 and radium-228+ actinium-228. In some cases the radon concentration of expired air was also measured. For four of the measured persons the radium-226 burden is of the order of the maximum permissible amount (MPA : 10-7 c) or more. In one case the burden amounts to more than three times the MPA, (3.4 x 10-7 c), in another case to more than 100 times the MPA (160 x 10-7 c). In one case the radium-228 + actinium-228 burden exceeds the MPA (6 x 10-8 c in bone). The measured radon concentrations in the expired air were used to calculate the excretion rate of radon. The average was 67%. Clinical findings with some of the measured persons are related to the measured body burdens. The patient with the high body burden of 160 x 10-7 c radium-226 shows heavy bone changes leading to spontaneous bone fractures. The blood picture shows a decrease in the number of erythrocytes and a low haemoglobin content but puncture of the sternum indicates normal haematopoiesis. It seems that the low number of erythrocytes is caused by chronic nephropathia, the reason for which might be an additional intake of uranium because.uranium was found in the urine by gamma spectroscopy. The results are discussed with respect to the MPA of radium-226 recommended by the International Commission on Radiological Protection. (author)

  3. TRASH TO TREASURE: CONVERTING COLD WAR LEGACY WASTE INTO WEAPONS AGAINST CANCER

    Nicholas, R.G.; Lacy, N.H.; Butz, T.R.; Brandon, N.E.

    2004-10-06

    As part of its commitment to clean up Cold War legacy sites, the U.S. Department of Energy (DOE) has initiated an exciting and unique project to dispose of its inventory of uranium-233 (233U) stored at Oak Ridge National Laboratory (ORNL), and extract isotopes that show great promise in the treatment of deadly cancers. In addition to increasing the supply of potentially useful medical isotopes, the project will rid DOE of a nuclear concern and cut surveillance and security costs. For more than 30 years, DOE's ORNL has stored over 1,200 containers of fissile 233U, originally produced for several defense-related projects, including a pilot study that looked at using 233U as a commercial reactor fuel. This uranium, designated as special nuclear material, requires expensive security, safety, and environmental controls. It has been stored at an ORNL facility, Building 3019A, that dates back to the Manhattan Project. Down-blending the material to a safer form, rather than continuing to store it, will eliminate a $15 million a year financial liability for the DOE and increase the supply of medical isotopes by 5,700 percent. During the down-blending process, thorium-229 (229Th) will be extracted. The thorium will then be used to extract actinium-225 (225Ac), which will ultimately supply its progeny, bismuth-213 (213Bi), for on-going cancer research. The research includes Phase II clinical trials for the treatment of acute myelogenous leukemia at Sloan-Kettering Memorial Cancer Center in New York, as well as other serious cancers of the lungs, pancreas, and kidneys using a technique known as alpha-particle radioimmunotherapy. Alpha-particle radioimmunotherapy is based on the emission of alpha particles by radionuclides. 213Bi is attached to a monoclonal antibody that targets specific cells. The bismuth then delivers a high-powered but short-range radiation dose, effectively killing the cancerous cells but sparing the surrounding tissue. Production of the actinium and

  4. TRASH TO TREASURE: CONVERTING COLD WAR LEGACY WASTE INTO WEAPONS AGAINST CANCER

    As part of its commitment to clean up Cold War legacy sites, the U.S. Department of Energy (DOE) has initiated an exciting and unique project to dispose of its inventory of uranium-233 (233U) stored at Oak Ridge National Laboratory (ORNL), and extract isotopes that show great promise in the treatment of deadly cancers. In addition to increasing the supply of potentially useful medical isotopes, the project will rid DOE of a nuclear concern and cut surveillance and security costs. For more than 30 years, DOE's ORNL has stored over 1,200 containers of fissile 233U, originally produced for several defense-related projects, including a pilot study that looked at using 233U as a commercial reactor fuel. This uranium, designated as special nuclear material, requires expensive security, safety, and environmental controls. It has been stored at an ORNL facility, Building 3019A, that dates back to the Manhattan Project. Down-blending the material to a safer form, rather than continuing to store it, will eliminate a $15 million a year financial liability for the DOE and increase the supply of medical isotopes by 5,700 percent. During the down-blending process, thorium-229 (229Th) will be extracted. The thorium will then be used to extract actinium-225 (225Ac), which will ultimately supply its progeny, bismuth-213 (213Bi), for on-going cancer research. The research includes Phase II clinical trials for the treatment of acute myelogenous leukemia at Sloan-Kettering Memorial Cancer Center in New York, as well as other serious cancers of the lungs, pancreas, and kidneys using a technique known as alpha-particle radioimmunotherapy. Alpha-particle radioimmunotherapy is based on the emission of alpha particles by radionuclides. 213Bi is attached to a monoclonal antibody that targets specific cells. The bismuth then delivers a high-powered but short-range radiation dose, effectively killing the cancerous cells but sparing the surrounding tissue. Production of the actinium and

  5. Soil and river sediments radionuclides monitoring at Aramar Experimental Center: an historical overview

    In order to evaluate possible effects to the environment resulting from the implementation of the Centro Tecnologico da Marinha - Centro Experimental Aramar (CTMSP-CEA) at Ipero in Sao Paulo state, Brazil, which came into operation in 1989, an Environmental Monitoring Program (PMA) was established in October, 1987. One of the aims of this program is to monitor the soil and river sediments radionuclides levels at CEA and beyond its boundary. The utilization of statistical tools to evaluate the results of radiometric environmental monitoring is a procedure required by National Nuclear Energy Commission (CNEN). The box plot is a simple statistical tool for displaying data. The central tendency and dispersion of the results as well as the observation of unusual results (outliers) in the dataset are easily visualized. Control chart is a graph that maps data and provides a picture of how a process is performing over time. A control chart always has a central line for the mean, an upper line for the upper control limit and a lower line for the lower control limit. Box plots and control charts were used to visualize the annual amount of natural uranium, lead-214, actinium-228 and lead-212 in soil and river sediment detected between 1987 and 2011, considering the measurements of all monitored places each year. This historical observation shows that, in average, the results obtained are below than the 1987-1988 levels (CEA's pre-operational) or below than the backgrounds radionuclides values. (author)

  6. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin

    The objective of this work was to establish a new procedure for 228Ra determination of natural waters via preconcentration of radium on MnO2 and separation of its daughter, 228Ac, using Diphonix ion exchange resin. Following removal of potential interferences via passage through an initial Diphonix Resin column, the first daughter of 228Ra, 228Ac, is isolated by chromatographic separation via a second Diphonix column. A holding time of >30 h for 228Ac ingrowth in between the two column separations ensures secular equilibrium. Barium-133 is used as a yield tracer. Actinium-228 is eluted from the second Diphonix Resin with 5 ml 1 M 1-Hydroxyethane-1,1-diphosphonic acid (HEDPA) and quantified by addition of scintillation cocktail and LSC counting. Radium (and 133Ba) from the load and rinse solutions from the 2nd Diphonix column may be prepared for alpha spectrometry (for determination of 223Ra, 224Ra, and 226Ra) by BaSO4 microprecipitation and filtration. Decontamination tests indicate that U, Th, and Ra series nuclides do not interfere with these measurements, although high contents of 90Sr (90Y) require additional treatment for accurate measurement of 228Ra. Addition of stable Sr as a 'hold back' carrier during the initial MnO2 preconcentration step was shown to remove most 90Sr interference

  7. Study of Soil Decontamination Method Using Supercritical Carbon Dioxide and TBP

    The result of this study means that we have a possible new method for cheap and less wasteful nuclear waste decontamination. When severe accidents such as the incident at the Fukushima nuclear site occur, the soil near the power plant is contaminated with fission products or the activation metal structure of the power plant. The soil pollution form depends on the environment and soil characteristics of the contaminated areas. Thus, a- single-decontamination method is not effective for site cleanup. In addition, some soil decontamination methods are expensive and large amounts of secondary waste are generated. Therefore, we need new soil decontamination methods. In this study, instead of using a conventional solvent method that generates secondary waste, supercritical carbon dioxide was used to remove metal ions from the soil. Supercritical carbon dioxide is known for good permeation characteristics. We expect that we will reduce the cost of soil pollution management. Supercritical carbon dioxide can decontaminate soil easily, as it has the ability to penetrate even narrow gaps with very good moisture permeability. We used TBP, which is a known for extractant of actinium metal. TBP is usually used for uranium and strontium extraction. Using TBP-HNO3 complex and supercritical carbon dioxide, we did extraction experiments for several heavy metals in contaminated soil

  8. Selective Decontamination Effect of Metal Ions in Soil Using Supercritical CO2 and TBP Complex

    Decontamination of soil pollution is difficult because the type of contamination largely depends on the characteristics of the pollutant and the area. Also, existing soil decontamination methods generate large quantities of secondary waste and additional process costs. For this reason, new decontamination methods are always under active investigation. A method involving the use of supercritical carbon dioxide with excellent permeability in place of chemical solvents is currently being studied. Unlike other heavy metals in fission products, uranium is used as fuel, and must be handled carefully. Therefore, in this paper, we studied a supercritical carbon dioxide method for decontaminating heavy metal ions in soil using tri-n-butyl phosphate(TBP), which is well known as a ligand for the extraction of metal ions of actinium. We investigated the decontamination effect of heavy metal ions in the soil using TBP-HNO3 Complex and supercritical carbon dioxide. The study results showed that when heavy metals in soil are extracted using supercritical carbon dioxide, the extraction efficiency is different according to the type of pollutant metal ions in the soil. When TBP-HNO3 Complex is used with an extractant, uranium extraction is very effective, but lithium, strontium, and cesium extraction is not effective. Therefore, in the case of a mixture of uranium and other metals such as lithium, strontium, cesium, and so on in soil contaminated by fission product leaks from nuclear power plants, we can selectively decontaminate uranium with supercritical carbon dioxide and TBP-HNO3 Complex

  9. Radionuclides in coastal swampland soils in South Australia - An unusual distribution?

    A plant processing uranium ore was constructed during the 1950's on coastal swamplands at Port Pirie, South Australia, with tailings and chemical residues stored in clay-lined dams on site. Environmental soil samples collected recently from this area showed an unusual radionuclide distribution which suggested possible contamination from the former uranium plant nearby. On subsequent investigation it appears this distribution is a general property of swampland soils. The concentration of uranium in these soils is significantly greater (2-10 times) than that of its decay products, with an observed range of uranium concentrations from 50 to 300 Bq/kg. In contrast, 'normal' soils in South Australia contain between 5 and 60 Bq/kg, with decay products close to secular equilibrium. In addition, actinium (and its parent, protactinium) occur in sediments in greater concentration than expected - 6 to 36 Bq/kg compared with a 'normal soil' range of 0.2 to 3 Bq/kg. Results obtained suggest: organic residues in the sediments play a major part in the concentration of radionuclides; and the probable source of radionuclides is sea-water. These observations are consistent with results of other workers who examined the incorporation of stable trace metals into coastal swampland sediments in South Australia. Representative data are presented and discussed

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

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

  11. Selective Decontamination Effect of Metal Ions in Soil Using Supercritical CO{sub 2} and TBP Complex

    Park, Jihye; Park, Kwangheon; Jung, Wonyoung [Kyunghee Univ., Yongin (Korea, Republic of)

    2014-10-15

    Decontamination of soil pollution is difficult because the type of contamination largely depends on the characteristics of the pollutant and the area. Also, existing soil decontamination methods generate large quantities of secondary waste and additional process costs. For this reason, new decontamination methods are always under active investigation. A method involving the use of supercritical carbon dioxide with excellent permeability in place of chemical solvents is currently being studied. Unlike other heavy metals in fission products, uranium is used as fuel, and must be handled carefully. Therefore, in this paper, we studied a supercritical carbon dioxide method for decontaminating heavy metal ions in soil using tri-n-butyl phosphate(TBP), which is well known as a ligand for the extraction of metal ions of actinium. We investigated the decontamination effect of heavy metal ions in the soil using TBP-HNO{sub 3} Complex and supercritical carbon dioxide. The study results showed that when heavy metals in soil are extracted using supercritical carbon dioxide, the extraction efficiency is different according to the type of pollutant metal ions in the soil. When TBP-HNO{sub 3} Complex is used with an extractant, uranium extraction is very effective, but lithium, strontium, and cesium extraction is not effective. Therefore, in the case of a mixture of uranium and other metals such as lithium, strontium, cesium, and so on in soil contaminated by fission product leaks from nuclear power plants, we can selectively decontaminate uranium with supercritical carbon dioxide and TBP-HNO{sub 3} Complex.

  12. Exposure to radioactive aerosols in mining and milling operations: the importance of 227Ac and 231Pa

    'Full-Text:' 227Ac (half-life of 21.8 y) is the daughter or 231Pa; a beta emitter and parent of a subseries with five short-lived alpha-emitters. 231Pa (half-life of 3.27x104 y) is an alpha-emitter of the actinium series, the decay chain of 235U. As daughters of this uranium isotope they are thought to be unimportant as a radiological hazard, despite the fact that their ALI values for ingestion and inhalation are the lowest of any other radionuclide. Both nuclides can be considered as being in secular equilibrium with uranium in most geological media and so the mass concentration of 231Pa is the same of the 226Ra and that of 227Ac is the same of the 210Pa, to mention only two radionuclides of radiological concern. It is shown in this paper that if 231Pa and 227Ac are considered in the evaluations of dose commitments incurred by inhalation of aerosols in mining and milling operations, the results can be 70% higher than those calculated by the methodology of ICRP Publication 47. (author)

  13. Neutron measurements with miniature fission chambers

    This report analyses the use and qualification of miniature fission chambers for two types of neutron measurements: 1) relative measurements in nuclear power reactors, or nuclear irradiation reactors. We consider the problem of burnable fissile material in detectors, under important neutron exposures and conclude on recommending the use of regenerating neutron detectors. 2) Measurements of integral physical parameters in experimental reactors. This method has been applied to measurements of fission rates in detectors with strong alpha-rays emitter deposits in order to establish standard tables of physical parameters. It has been used in particular for detectors including very radioactive actinium series. After a discussion of the instrumentation choice and data processing, specific to each measurements, we provide results on: 1) the technological and neutron behaviour of regenerating miniature fission chambers, in the swimming pool reactor 'TRITON', under a neutron exposure of 7.1020 n cm-2 and a gamma-rays exposure of 1,5.1011 rads about. The fissile material is 235U and the fertile material 234U. 2) The integral measurements of effective cross sections for 241Am and 238Pu in the experimental reactor 'MINERVE' use for study of problems of fast neutron reactors

  14. Tumor immunotargeting using innovative radionuclides.

    Kraeber-Bodéré, Françoise; Rousseau, Caroline; Bodet-Milin, Caroline; Mathieu, Cédric; Guérard, François; Frampas, Eric; Carlier, Thomas; Chouin, Nicolas; Haddad, Ferid; Chatal, Jean-François; Faivre-Chauvet, Alain; Chérel, Michel; Barbet, Jacques

    2015-01-01

    This paper reviews some aspects and recent developments in the use of antibodies to target radionuclides for tumor imaging and therapy. While radiolabeled antibodies have been considered for many years in this context, only a few have reached the level of routine clinical use. However, alternative radionuclides, with more appropriate physical properties, such as lutetium-177 or copper-67, as well as alpha-emitting radionuclides, including astatine-211, bismuth-213, actinium-225, and others are currently reviving hopes in cancer treatments, both in hematological diseases and solid tumors. At the same time, PET imaging, with short-lived radionuclides, such as gallium-68, fluorine-18 or copper-64, or long half-life ones, particularly iodine-124 and zirconium-89 now offers new perspectives in immuno-specific phenotype tumor imaging. New antibody analogues and pretargeting strategies have also considerably improved the performances of tumor immunotargeting and completely renewed the interest in these approaches for imaging and therapy by providing theranostics, companion diagnostics and news tools to make personalized medicine a reality. PMID:25679452

  15. Tumor Immunotargeting Using Innovative Radionuclides

    Françoise Kraeber-Bodéré

    2015-02-01

    Full Text Available This paper reviews some aspects and recent developments in the use of antibodies to target radionuclides for tumor imaging and therapy. While radiolabeled antibodies have been considered for many years in this context, only a few have reached the level of routine clinical use. However, alternative radionuclides, with more appropriate physical properties, such as lutetium-177 or copper-67, as well as alpha-emitting radionuclides, including astatine-211, bismuth-213, actinium-225, and others are currently reviving hopes in cancer treatments, both in hematological diseases and solid tumors. At the same time, PET imaging, with short-lived radionuclides, such as gallium-68, fluorine-18 or copper-64, or long half-life ones, particularly iodine-124 and zirconium-89 now offers new perspectives in immuno-specific phenotype tumor imaging. New antibody analogues and pretargeting strategies have also considerably improved the performances of tumor immunotargeting and completely renewed the interest in these approaches for imaging and therapy by providing theranostics, companion diagnostics and news tools to make personalized medicine a reality.

  16. Development of an Ultra-Low Background Liquid Scintillation Counter for Trace Level Analysis

    Erchinger, Jennifer L.; Orrell, John L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Finn, Erin C.; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Panisko, Mark E.; Shaff, Sarah M.; Warren, Glen A.; Wright, Michael E.

    2015-09-01

    Low-level liquid scintillation counting (LSC) has been established as one of the radiation detection techniques useful in elucidating environmental processes and environmental monitoring around nuclear facilities. The Ultra-Low Background Liquid Scintillation Counter (ULB-LSC) under construction in the Shallow Underground Laboratory at Pacific Northwest National Laboratory aims to further reduce the MDAs and/or required sample processing. Through layers of passive shielding in conjunction with an active veto and 30 meters water equivalent overburden, the background reduction is expected to be 10 to 100 times below typical analytic low-background liquid scintillation systems. Simulations have shown an expected background of around 14 counts per day. A novel approach to the light collection will use a coated hollow light guide cut into the inner copper shielding. Demonstration LSC measurements will show low-energy detection, spectral deconvolution, and alpha/beta discrimination capabilities, from trials with standards of tritium, strontium-90, and actinium-227, respectively. An overview of the system design and expected demonstration measurements will emphasize the potential applications of the ULB-LSC in environmental monitoring for treaty verification, reach-back sample analysis, and facility inspections.

  17. Workplace monitoring and related health hazard evaluation in South African mining and mineral processing industries by application of nuclear and related analytical techniques

    The South African Government notice R 849 (23 April 1994) requires application to the South African Council for Nuclear Safety (CNS) for a nuclear licence if materials are dealt with that contain more than 0,2 but less than 1 Becquerel per gram of any radionuclide of the natural uranium, thorium and actinium decay series. If the material is to be used in the construction of buildings the application should have been made before 1 April 1996, otherwise before 31 March 1999. The first phase of the monitoring programme assesses the observed radioactivity levels of waste products and the possible radiological impact on people working on site and living in the direct environment of the operational site. Information has been obtained on the radionuclide content and elemental composition of the various sources of the coal, waste ash, ash related products, crusher materials and effluent water. Except for the effluent and coal samples all other materials showed activity levels for one or more nuclides above the 0,2 Bq/g but not exceeding the 1 Bq/g level. Accordingly a first order assessment of the possible radiological impact on workers and the public has been performed for water consumption and dust inhalation. Actual dust concentrations recorded at various sites within the operational area are used to evaluate the yearly dose to workers. (author)

  18. Formerly utilized MED/AEC sites remedial action program. Radiological survey of the E. I. Du Pont de Nemours and Co. , Deepwater, New Jersey. Final report

    None

    1978-12-01

    The results of a radiological survey of the E. I. Du Pont Company, Deepwater, New Jersey, are presented in this report. During the 1940's this site was used for development of a process for the conversion of uranium oxide to produce uranium tetrafluoride and small quantities of uranium metal. The survey included measurements of the following: residual alpha and beta--gamma contamination levels, both fixed and transferable, in the one remaining uranium tetrafluoride operations building; external gamma radiation levels at 1 m above the surface inside this building and at outdoor locations where radioactive materials were handled; radon and radon daughter concentrations in the air in the operations building; uranium, radium, actinium, and thorium concentrations in soil and water on and near the site; and the airborne concentrations of uranium, thorium, and radium in the operations building. Elevated concentrations of uranium were found in residues from the operations building and in some surface and subsurface soil samples. Alpha and beta--gamma contamination levels in some areas of the operations building were above the limits of current federal guidelines set for the release of property for unrestricted use. 18 figures, 11 tables.

  19. Geological disposal: security and R and D. Security of 'second draft for R and D of geological disposal'

    The second draft for R and D of geological disposal (second draft) was arranged in 1999. The idea of security of geological disposal in the second draft is explained. The evaluation results of the uncertainty analysis and an example of evaluation of the effect of separation nuclear transmutation on the geological disposal are shown. The construction of strong engineered barrier is a basic idea of geological disposal system. Three processes such as isolation, engineering countermeasures and safety evaluation are carried out for the security of geological disposal. The security of geological environment for a long time of 12 sites in Japan was studied by data. Provability of production and enforcement of engineered barrier were confirmed by trial of over pack, tests and the present and future technologies developed. By using the conditions of reference case in the second draft, the evaluation results of dose effects in the two cases: 1) 90 to 99% Cs and Sr removed from HLW (High Level radioactive Waste) and 2) high stripping ratio of actinium series are explained. (S.Y.)

  20. Enhanced radioactivity due to natural oil and gas production and related radiological problems

    Within the scope of a research contract, the following aspects are considered: External radiation exposure at production sites; internal radiation exposures during cleaning operations such as removing of scale by sand blasting; problems of waste disposal; internal radiation exposure due to radon inhalation by consumers; the origin of the high radium content of brines from oil and gas fields. Enhanced dose rates up to 50 μSv/h have been found at the external surface of saltwater tanks, but 72% of the 160 sites investigated did not show any increase above the natural background. Brines from gas contained radium-226 up to 286 Bq/1 and scale up to 1 kBq/g. In brines and scale from oil fields radium-228 was usually the dominating radionuclide. Some samples contained significant amounts of lead-210 and even actinium-227, too, but practically no uranium or thorium. The radon-222 concentrations in natural gas samples varied between 0.004 and 4 Bq/l with an average value of 0.6 Bq/l. Related radiological problems are discussed. (orig./HP)

  1. I. The metabolic properties of plutonium and allied materials

    Hamilton, J.G.

    1948-05-24

    This report on the metabolic properties of plutonium and related radioactive materials presents experimental information in the following areas: radioautographic studies; tracer studies (with tables of accumulation in tissues) of actinium, radio-zirconium, technetium, radio-rubidium, radio-germanium, beryllium, and cadmium; decontamination and bone metabolism studies; and radio-chemical isolation.

  2. Report for General Research July 10 to October 2, 1950 (Supporting Research Volume)

    Haring, M M

    1950-11-06

    The efficient prosecution of the research and process development on polonium, radium, actinium, waste disposal, and alpha-neutron sources requires the use of a wide variety of instrumental techniques such as: alpha, beta, gamma, and neutron counters and survey meters; emission, absorption, and mass spectroscopy: x-ray and electron diffraction; microbalances; and calorimeters. The complex and kaleidoscopic aspects of our research program require; (1) The application of standard instruments and techniques to a variety of problems; (2) The development of new techniques for the use of standard instruments; and (3) The development of new or improved Instruments. The sum of the above three categories constitutes the field of supporting research. The amplifier for counting pulses of wide dynamic range which was developed for counting beta particles in the presence of alphas has operated so satisfactorily that it has been decided to attempt to adopt it for neutron counting. Substantial improvement at medium counting rates has already been obtained but results at high counting rates are not as satisfactory. The development of a survey meter for monitoring fast neutrons has been under way for sometime. The attainment of higher efficiency has been attempted by the use of a dual-chambered counter tube. The tube operates with a filling of methane gas at two atmospheres pressure. The achievement of leak-proof seals and highest purity methane has been under investigation as their necessity has been indicated by tests. The development of a scintillation counter for surveying and measuring low levels of alpha activity has been continued. Recent efforts have been directed towards determining the correct voltages to be applied to the photomultiplier tube in order to operate under optimum conditions. Recent tests of the coincidence counter to detect scintillations in water containing alpha-active waste material have indicated the necessity of obtaining photomultiplier tubes with low

  3. Alpha Emitting Radionuclides and Radiopharmaceuticals for Therapy

    Today, cancer treatments mainly rely on surgery or external beam radiation to remove or destroy bulky tumors. Chemotherapy is given when tumours cannot be removed or when dissemination is suspected. However, these approaches cannot permanently treat all cancers and relapse occurs in up to 50% of the patients’ population. Radioimmunotherapy (RIT) and peptide receptor radionuclide therapy (PRRT) are effective against some disseminated and metastatic diseases, although they are rarely curative. Most preclinical and clinical developments in this field have involved electron-emitting radionuclides, particularly iodine-131, yttrium-90 and lutetium-177. The large range of the electrons emitted by these radionuclides reduces their efficacy against very small tumour cell clusters or isolated tumour cells present in residual disease and in many haematological tumours (leukaemia, myeloma). The range of alpha particles in biological tissues is very short, less than 0.1 mm, which makes alpha emitters theoretically ideal for treatment of such isolated tumour cells or micro-clusters of malignant cells. Thus, over the last decade, a growing interest for the use of alpha-emitting radionuclides has emerged. Research on targeted alpha therapy (TAT) began years ago in Nantes through cooperation between Subatech, a nuclear physics laboratory, CRCNA, a cancer research centre with a nuclear oncology team and ITU (Karlsruhe, Germany). CD138 was demonstrated as a potential target antigen for Multiple Myeloma, which is a target of huge clinical interest particularly suited for TAT because of the disseminated nature of the disease consisting primarily of isolated cells and small clusters of tumour cells mainly localized in the bone marrow. Thus anti-CD138 antibodies were labelled with bismuth-213 from actinium-225/bismuth-213 generators provided by ITU and used to target multiple myeloma cells. In vitro studies showed cell cycle arrest, synergism with chemotherapy and very little induction

  4. The Properties of Trilaurylmethylammonium Nitrate as an Extractant for Trivalent Actinides. RCN Report

    The concept of the group of the actinide elements as a f-type transition series within the periodic system was first launched by G.T. Seaborg in 1944]. In this transition series the filling up of the 5 f electron shell would cause a close similarity with the lanthanide series. This proved to be a very fruitful hypothesis in the prediction of the properties of the new elements americium and curium that soon were discovered. The new hypothesis necessitated a shift of the accepted ideas concerning the place of the elements thorium, protactinium and uranium in the periodic table. In fact, the chemistry of these elements had never been considered to be so closely parallel to that of the lanthanides. On the contrary, the trend in the stability of the oxidation states had been interpreted to indicate that these elements would belong to group IVA, VA and VIA respectively. It is undeniable that there are marked differences in oxidation states between the lanthanide elements and the first six elements of the actinide series. However, physical and chemical investigations both of the newly discovered elements and the elements actinium to uranium disclosed many resemblances with the lanthanides that had not been noticed before in this group. The actinide elements - and more in particular the transuranium elements - have been the subject of a number of monographs covering the discovery, the synthesis, the systematics, the chemistry, and (or) the nuclear properties of these elements. It is for this reason that the scope of the following sections in this chapter will be limited to a summary of the chemistry in sofar as it is relevant to the investigations described in the following chapters, viz., the properties of the elements in aqueous systems and more in particular in those systems containing nitrate ions

  5. Determination of radium in water

    These detailed work instructions (DWIs) are tailored for the analysis of radium-226 and radium-228 in drinking water supplies from ground water and surface water sources and composites derived from them. The instructions have been adapted from several sources, including a draft EPA method. One objective was to minimize the generation of mixed wastes. Quantitative determinations of actinium-228 are made at 911 keV. The minimum detection level (MDL) for the gamma spectrometric measurements at this energy vary with matrix, volume, geometry, detector, background, and counting statistics. The range of MDL's for current detectors is 0.07 to 0.5 Bq/sample. Quantitative determinations of radium-226 are made by counting the high energy alpha particles which radium-226 progeny emit using liquid scintillation counting (LSC). The minimum detectable activity (MDA) is 3.8 E-3 Bq/sample. The maximum concentration which may be counted on available instruments without dilution is about 2 E + 5 Bq/sample. Typically, this determination of radium in a 2 L sample has a yield of 80%. If radium-228 is determined using a 16 h count after 50 h grow-in, the typical MDL is 1 E-9 to 8 E-9 μCi/mL (1 to 8 pCi/L). If radium-226 is determined using a 2.5 h count after 150 h grow-in, the typical MDA is about 1 E-10 μCi/mL (0. 1 pCi/L)

  6. Determination of radium in water

    Hohorst, F.A.; Huntley, M.W.; Hartenstein, S.D.

    1995-10-01

    These detailed work instructions (DWIs) are tailored for the analysis of radium-226 and radium-228 in drinking water supplies from ground water and surface water sources and composites derived from them. The instructions have been adapted from several sources, including a draft EPA method. One objective was to minimize the generation of mixed wastes. Quantitative determinations of actinium-228 are made at 911 keV. The minimum detection level (MDL) for the gamma spectrometric measurements at this energy vary with matrix, volume, geometry, detector, background, and counting statistics. The range of MDL`s for current detectors is 0.07 to 0.5 Bq/sample. Quantitative determinations of radium-226 are made by counting the high energy alpha particles which radium-226 progeny emit using liquid scintillation counting (LSC). The minimum detectable activity (MDA) is 3.8 E-3 Bq/sample. The maximum concentration which may be counted on available instruments without dilution is about 2 E + 5 Bq/sample. Typically, this determination of radium in a 2 L sample has a yield of 80%. If radium-228 is determined using a 16 h count after 50 h grow-in, the typical MDL is 1 E-9 to 8 E-9 {mu}Ci/mL (1 to 8 pCi/L). If radium-226 is determined using a 2.5 h count after 150 h grow-in, the typical MDA is about 1 E-10 {mu}Ci/mL (0. 1 pCi/L).

  7. The effects of actinide separation on the radiological consequences of disposal of high-level radioactive waste on the ocean bed

    One option in the management of high-level radioactive wastes is to separate the actinides prior to vitrification and disposal. This option is examined in the context of disposal of high-level wastes on the deep ocean bed. The initial quantity of waste corresponds to the generation of 1000 GW(e)y of nuclear energy, and the actinide-separation process is assumed to remove 99% of all elements of atomic number greater than that of actinium. The models used to describe the dispersion of activity from a single disposal site on the bed of the Atlantic Ocean represent both local dispersion and long-term mixing. Collective doses and doses to individuals are calculated for six potential pathways: ingestion of fish, crustacea, molluscs, plankton and seaweed, and external irradiation from contaminated beach sediments. The period from 400 to 1,000,000 years after disposal is considered. The potential radiological impact from disposal of high-level waste without separation of actinides on the ocean bed arises from the actinides; isotopes of americium, neptunium and plutonium give the highest doses. Actinide separation would reduce these doses in proportion to the effectiveness of the separation process, until doses become determined by fission products rather than actinides: the achievable dose reduction would be a factor of approximately a hundred, or less for certain pathways. This reduction applies only to doses to the public from waste disposal: no account was taken of doses arising from the separation process itself or from the management of the separated actinides. The results of the assessment are contrasted with those of similar studies based on toxicity indices. Major deficiencies are identified in the use of toxicity indices as a basis for decision-making. (author)

  8. An aerial radiological survey of the Nevada Test Site

    A team from the Remote Sensing Laboratory conducted an aerial radiological survey of the US Department of Energy's Nevada Test Site including three neighboring areas during August and September 1994. The survey team measured the terrestrial gamma radiation at the Nevada Test Site to determine the levels of natural and man-made radiation. This survey included the areas covered by previous surveys conducted from 1962 through 1993. The results of the aerial survey showed a terrestrial background exposure rate that varied from less than 6 microroentgens per hour (mR/h) to 50 mR/h plus a cosmic-ray contribution that varied from 4.5 mR/h at an elevation of 900 meters (3,000 feet) to 8.5 mR/h at 2,400 meters (8,000 feet). In addition to the principal gamma-emitting, naturally occurring isotopes (potassium-40, thallium-208, bismuth-214, and actinium-228), the man-made radioactive isotopes found in this survey were cobalt-60, cesium-137, europium-152, protactinium-234m an indicator of depleted uranium, and americium-241, which are due to human actions in the survey area. Individual, site-wide plots of gross terrestrial exposure rate, man-made exposure rate, and americium-241 activity (approximating the distribution of all transuranic material) are presented. In addition, expanded plots of individual areas exhibiting these man-made contaminations are given. A comparison is made between the data from this survey and previous aerial radiological surveys of the Nevada Test Site. Some previous ground-based measurements are discussed and related to the aerial data. In regions away from man-made activity, the exposure rates inferred from the gamma-ray measurements collected during this survey agreed very well with the exposure rates inferred from previous aerial surveys

  9. Radiological analysis of environmental samples in some points of the coast of the Gulf of Mexico and Coast of Quintana Roo, Mexico

    Full text: We describe in this paper the results obtained by the project 'Radiological analysis of environmental samples in some points of the coast of the Gulf of Mexico and coast of Quintana Roo, Mexico'. The purpose of the study is to identify and quantify the natural and anthropogenic radionuclides present from sediments, sand and seawater from several sites located along the coast of the Gulf of Mexico and the Caribean Sea. The samples are analysed in a Canberra Multichannel analyzer system for gamma spectrometry, equipped with a detector of hyper pure germanium and a Genie 2000 software, in the 'Laboratory of Radiological Analysis of Environmental Samples', belonging to the Physics Department, Faculty of Sciences, National Autonomous University of Mexico (UNAM). The geographic sites were samples were taken include the states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. The results of this studies will be published at the end of the project and we hope they will be useful for the national health and industrial sectors. Until now we have identified and measured the presence of natural radionuclides such as Potassium-40 (K-40), Bismuth 212 (Bi-212), Lead-212 (Pb-212), Bismuth-214 (Bi-214), Lead-214 (Pb-214), Radium-226 (Ra-226), Actinium 228 (Ac-228), Uranium-235 (U-235), as well as some anthropogenic radionuclides found near the Laguna Verde Nuclear Power Plant. The project is scheduled to last for three years, finishing in 2009. At its ending we shall be able to present conclusions and identify some tendencies, in connection with the background and possible radioactive contamination of the studied zones. This project takes place under the auspice of the 'Program of Support to Projects of Research and Technological Innovation' of the National Autonomous University of Mexico. (author)

  10. Leaching of uranyl-silica complexes from the host metapelite rock favoring high radon activity of subsoil air: case of Castanar cave (Spain)

    Castanar cave is a subterranean site with an outstanding natural environmental radioactivity. The maintaining of high radon activity of cave air and the detection of spatially anomalies of this gas in some cave emplacements, suggests that some natural geochemical processes are involved on the mobilization of radioactivity sources to cave environment, other than a simple exhalation of radon from the host-rock. The host rocks are interlaid dolostone-metapelite beds with radioactive nuclides of the three actinium, thorium and uranium decay series. In situ measurements on the spatial distribution of radioactivity, uranyl group's luminescence and radon gas concentrations inside cave were main focus of this work to model lixiviation and deposition mechanisms of radioactive elements from the host rock to the karstic system. In addition, collected micro-samples were also analyzed by a multi-approach suite of analytical techniques: inductively coupled plasma mass spectrometry, environmental scanning electron microscopy with an attached X-ray energy dispersive system and spectral cathodoluminescence detector, thermoluminescence, Raman spectroscopy, X-ray diffraction, differential-thermal and thermogravimetry analysis, Alpha-spectrometry and Gamma-spectrometry techniques. The host metapelitic beds contain Zr(Hf)-Th(U)-Ti-P-REE phases such as zircon, xenotime-(Y), monazite-(Ce, La) and poly-metallic mineralization veins of hydrothermal origin. Carbonated host beds and speleothems show frequently chemical elements leaked from the upper host rock masses. The weathering leakage processes are favored by the existence of pyrite and limonite in the dolostone masses. The cave exhibits under UV lamps abundant hydrous silica-uranyl coatings covering carbonated speleothems with radionuclides of 238U natural decay series. The long-lived radio-nuclides of the radium radioactive decay chain are responsible of the continuous regeneration of radon gas inside cave. The experimental work was

  11. Radiological survey of the Mallinckrodt Chemical Works, St. Louis, Missouri

    Goldsmith, W A; Leggett, R W; Haywood, F F

    1981-12-01

    The results of a radiological survey of part of the Mallinckrodt Chemical Works (former Destrehan and Broadway Street plants), St. Louis, Missouri, are presented. During the period 1942 through 1957, this site was used for various projects involving the production of purified uranium from pitchblende concentrates. The survey included measurements of the following: residual alpha and beta-gamma contamination levels in the existing buildings that were used in the uranium projects; external gamma radiation levels at 1 m above the surface in these buildings and outdoors around these buildings; radon and radon daughter concentrations in the air in these buildings; uranium, radium, actinium, and thorium concentrations in surface and subsurface soil on the site; concentrations of radionuclides in water and sediment found in drains both inside and outside the buildings; and concentrations of radionuclides in ground and surface water on the site and in river water taken near the site. Alpha and beta-gamma contamination levels inside and outside some of the buildings were above limits set by current federal guidelines concerning the release of property for unrestricted use. Elevated external gamma radiation levels were measured at some outdoor locations and in some of the buildings. Licensable concentrations of uranium were found in soil at some places, and the concentration of uranium in a water sample taken from a core hole between Buildings 100 and 101 was in excess of limits set by current federal standards. Radon and radon daughter concentrations in three buildings were in excess of current federal guidelines for nonoccupational radiation exposure.

  12. Track 8: health and radiological applications. Isotopes and radiation: general. 3. Extraction of 229Th from 233U for Medical Research Applications

    the handling of 233U. After separation, the thorium is transferred to the ORNL Radiochemical Development Laboratory (RDL) for decay and periodic extraction of actinium. The safety basis for the RMAL has recently been upgraded to allow the processing of batches containing up to 500 g of 233U. The 233U from Mound Laboratories was delivered in 20 packages, each containing 232U contamination ranges from 2 to 16 ppm. Individual packages of uranium oxide are transferred from the RDF to the RMAL, the package is opened, and the quantity of uranium is verified. The uranium oxide is dissolved in nitric acid, and the solution is adjusted to 8 M. The solution is passed over a Bio-Rad 1x4 anion exchange column at a rate of ∼5 ml/ min. Thorium and plutonium load on the column; uranium, radium, and actinium pass through. The column is washed with 8 M nitric acid to remove residual uranium. Thorium is then eluted from the resin with 0.1 M nitric acid. This solution, typically containing ∼4 mCi of 229Th, is transferred to the RDL for further purification and is then added to the existing thorium inventory. The uranium and acid wash solutions are combined and evaporated to 3O8 by heating in air to 800 deg. C. The oxide is sampled, weighed, packaged, and returned to storage in the RDF. In fiscal year 2000, the process was set up and two small batches of uranium, with 2 ppm 232U, were processed. Because of the low dose associated with this material and to allow refinements to the process, these initial batches were processed in a glove box. The process performed well, with more than 90% recovery of thorium. Just over 5 mCi of 229Th was added to the inventory. Funding already provided for fiscal year 2001 will allow the extraction of another 30 mCi of 229Th; if additional funding can be identified, a total of nearly 70 mCi can be separated by the end of the fiscal year. With this additional thorium, and with other improvements to the actinium extraction facilities at the RDL, the

  13. Astatine-211 Pathway from Radiochemistry to Clinical Investigation

    Particularly in clinical settings where tumour burden is low and cancers are located in close proximity to essential normal tissue structures, α-particle emitting radionuclides can offer significant advantages for targeted radionuclide therapy. One of the first alpha emitters to be evaluated for this purpose is the 7.2-h half-life radiohalogen Astatine-211 (211At). From a commercialization-potential perspective 211At, is less appealing than the longer half-life alpha particle emitters Radium-223, Actinium-225 and Thorium-227, which have become the focus of many laboratories. However, if methods for providing a better supply of 211At could be developed, this alpha emitter would be the radionuclide of choice for many potential therapeutic applications. With regard to the production of 211At, this can be readily be accomplished by bombarding natural bismuth targets with 28−29.5 MeV alpha particles via the 209Bi(α,2n)211At reaction. The goal is to utilize an alpha particle beam energy that provides the required balance for maximizing 211At production while minimizing creation of 210At, which is problematic because of its 138.4-day half life alpha-particle emitting daughter, 210Po. For most intended clinical applications, alpha particle beam energy of about 29 MeV offers the best compromise between maximizing yield and providing 211At with sufficient radionuclidic purity for clinical use. Clinically relevant levels of 211At have been produced at several institutions using both internal and external cyclotron targets

  14. Selective alpha-particle mediated depletion of tumor vasculature with vascular normalization.

    Jaspreet Singh Jaggi

    Full Text Available BACKGROUND: Abnormal regulation of angiogenesis in tumors results in the formation of vessels that are necessary for tumor growth, but compromised in structure and function. Abnormal tumor vasculature impairs oxygen and drug delivery and results in radiotherapy and chemotherapy resistance, respectively. Alpha particles are extraordinarily potent, short-ranged radiations with geometry uniquely suitable for selectively killing neovasculature. METHODOLOGY AND PRINCIPAL FINDINGS: Actinium-225 ((225Ac-E4G10, an alpha-emitting antibody construct reactive with the unengaged form of vascular endothelial cadherin, is capable of potent, selective killing of tumor neovascular endothelium and late endothelial progenitors in bone-marrow and blood. No specific normal-tissue uptake of E4G10 was seen by imaging or post-mortem biodistribution studies in mice. In a mouse-model of prostatic carcinoma, (225Ac-E4G10 treatment resulted in inhibition of tumor growth, lower serum prostate specific antigen level and markedly prolonged survival, which was further enhanced by subsequent administration of paclitaxel. Immunohistochemistry revealed lower vessel density and enhanced tumor cell apoptosis in (225Ac-E4G10 treated tumors. Additionally, the residual tumor vasculature appeared normalized as evident by enhanced pericyte coverage following (225Ac-E4G10 therapy. However, no toxicity was observed in vascularized normal organs following (225Ac-E4G10 therapy. CONCLUSIONS: The data suggest that alpha-particle immunotherapy to neovasculature, alone or in combination with sequential chemotherapy, is an effective approach to cancer therapy.

  15. Sorption studies of radioelements on geological materials

    Berry, J. A; 油井 三和; 北村 暁

    2007-01-01

    Batch sorption experiments have been carried out to study the sorption of uranium, technetium, curium, neptunium, actinium, protactinium, polonium, americium and plutonium onto bentonite, granodiorite and tuff. Mathematical modelling using the HARPHRQ program and the HATCHES database was carried out to predict the speciation of uranium and technetium in the equilibrated seawater, and neptunium, americium and plutonium in the rock equilibrated water. Review of the literature for thermodynamic ...

  16. Imaging and treating tumor vasculature with targeted radiolabeled carbon nanotubes

    Alessandro Ruggiero

    2010-09-01

    imaging. Near-infrared three-dimensional fluorescent-mediated tomography was used to image the LS174T tumor model, collect antibody-alone PK data, and calculate the number of copies of VE-cad epitope per cell. All of these studies were performed as a single administration of construct and were found to be safe and well tolerated by the murine model. These data have implications that support further imaging and radiotherapy studies using a SWCNT-based platform and focusing on the tumor vessels as the target.Keywords: actinium-225 (225Ac, zirconium-89 (89Zr, angiogenesis, vascular endothelial-cadherin, radioimmunotherapy (RIT, radioimmunoPET

  17. Study of the production of residual evaporation nuclei issued from the spallation reaction of uranium-238 by 1 GeV protons

    The spallation reaction by high energy protons is one of the envisaged nuclear reactions for production of exotic nuclei. We have measured the production of more than 300 different evaporation residues issued by the spallation reaction of Uranium-238 by 1 GeV protons. We used the reverse kinematics technique in order to produce the relativistic nuclei and therefore to be able to detect those nuclides within a very short time, shorter in most cases than the radioactive disintegration period. The achieved nuclear charge and mass resolution are excellent. They allow a good accuracy on the values of the measured cross-sections (10 to 15%). We have observed for the first time the nuclide Actinium-235 obtained consequently to the loss of 3 protons by the projectile. The measured isotopic distribution are strongly influenced by the mechanism of fission which leads to a strong reduction of the production of the heavy neutron deficient isotopes. We have compared our results to some other measurements achieved with radio-chemical methods at a similar energy. We observed a systematic disagreement of about 40%. Some comparison with the available systematics show that those are presently not able to reproduce the data with a reasonable precision. We could also measure the recoil momentum distribution for each studied isotopes. We show that Goldhaber's model agrees very well with the experiment in case. of 'cold' channels where the evaporation of particles never occurs. On the other hand, when the produced pre-fragment is excited the data show that Goldhaber's model does not reproduce.the data showing the limitation of such an approach. We finally tried to reproduce the measurement of evaporation residue cross-section thanks to the coupling of intra-nuclear cascade and statistical evaporation codes. The influence of the fission process is rather important is the system p+U; we therefore had to account for the dynamical aspect of the fission. We also showed the determinant role

  18. Natural and manmade radionuclides in the environment

    Human beings are constantly exposed to ionizing radiations in nature. These natural background radiations have both terrestrial and extraterrestrial origin. The extraterrestrial radiation is largely due to cosmic rays. Earth's atmosphere is continuously bombarded with high energy cosmic rays which originate from our own cosmos. The primary interaction of high energy cosmic rays with the atmosphere produces a number of secondary radiations in the form of neutrons and protons of various energies which in turn produce a variety of radionuclides through nuclear reactions with nitrogen, oxygen and other nuclei in atmosphere and through other processes. In addition, sub-atomic particles like mesons, muons and electrons are also produced. The radiation dose rate in India at sea level due to cosmic rays is 32 nGy h-1. The naturally occurring terrestrial radionuclides can be divided into those that occur singly and those that are components of the three chains of radioactive series namely, the Uranium series, the Thorium series and the Actinium series. Among the singly occurring radionuclides Potassium-40 with half life of 1.3x109 years is the most prominent and is widely distributed in rocks and soil. 40K is fairly abundant, forming about 0.012% of' total potassium, and is widely distributed in environmental matrix and it is an essential element for most life forms. Uranium-238 and Thorium 232 and their daughters generate the bulk of natural ionising radiation in our environment. Uranium-238 is the head of a series of 15 principal radionuclides, It is the most abundant (99.28%) isotope of natural uranium and is found in all rocks and soil in varied concentration. The radionuclide 238U decays through 234U and 230Th to 226Ra, which has a relatively long half life of 1628 years. 226Ra and its daughter products constitute an important part of natural radiation exposure. About 98% of the external dose from uranium series is delivered by 226Ra and its daughter products

  19. DNA double strand breaks as predictor of efficacy of the alpha-particle emitter Ac-225 and the electron emitter Lu-177 for somatostatin receptor targeted radiotherapy.

    Franziska Graf

    Full Text Available RATIONALE: Key biologic effects of the alpha-particle emitter Actinium-225 in comparison to the beta-particle emitter Lutetium-177 labeled somatostatin-analogue DOTATOC in vitro and in vivo were studied to evaluate the significance of γH2AX-foci formation. METHODS: To determine the relative biological effectiveness (RBE between the two isotopes (as - biological consequence of different ionisation-densities along a particle-track, somatostatin expressing AR42J cells were incubated with Ac-225-DOTATOC and Lu-177-DOTATOC up to 48 h and viability was analyzed using the MTT assay. DNA double strand breaks (DSB were quantified by immunofluorescence staining of γH2AX-foci. Cell cycle was analyzed by flow cytometry. In vivo uptake of both radiolabeled somatostatin-analogues into subcutaneously growing AR42J tumors and the number of cells displaying γH2AX-foci were measured. Therapeutic efficacy was assayed by monitoring tumor growth after treatment with activities estimated from in vitro cytotoxicity. RESULTS: Ac-225-DOTATOC resulted in ED50 values of 14 kBq/ml after 48 h, whereas Lu-177-DOTATOC displayed ED50 values of 10 MBq/ml. The number of DSB grew with increasing concentration of Ac-225-DOTATOC and similarly with Lu-177-DOTATOC when applying a factor of 700-fold higher activity compared to Ac-225. Already 24 h after incubation with 2.5-10 kBq/ml, Ac-225-DOTATOC cell-cycle studies showed up to a 60% increase in the percentage of tumor cells in G2/M phase. After 72 h an apoptotic subG1 peak was also detectable. Tumor uptake for both radio peptides at 48 h was identical (7.5%ID/g, though the overall number of cells with γH2AX-foci was higher in tumors treated with 48 kBq Ac-225-DOTATOC compared to tumors treated with 30 MBq Lu-177-DOTATOC (35% vs. 21%. Tumors with a volume of 0.34 ml reached delayed exponential tumor growth after 25 days (44 kBq Ac-225-DOTATOC and after 21 days (34 MBq Lu-177-DOTATOC. CONCLUSION: γH2AX-foci formation, triggered

  20. Use of gamma-ray spectrometry for analysis of Uranium isotopic composition in soil of Iran

    The use of depleted uranium (DU) in various weaponry and ammunition during the Iraq war in April, 2003 caused serious concern in Iran over possible uranium contamination of the Iran environment and consequently long health effect. After a shell explosion, uranium is discharged by the fire in the air in the form of oxidized particles and can be dispersed within a radius of several kilometers. Gamma-ray spectrometry was used to determine uranium concentration in soil samples collected from 8 sites in Iranian sectors of Iraq border. All soil samples were dried ,gently grounded and passed through a 2 mm sieve. Three hundred grams of each sample were placed in plastic container and sealed for at least 20 days to allow equilibrium in uranium, thorium and actinium series. Gamma-ray intensities were measured with 40% HPGe (CANBERRA) detector. The detector was shielded by 10 cm lead on all sides with cadmium-copper in inner sides. The system is equipped with software for data acquisition and analyzing. The counting time was 6x104 seconds and background spectra were also collected for the same period of time. The concentrations of 238U assessed from 63.3 keV and 92.4 keV emission of its first daughter nuclide, 234Th. To assess the isotopic ratio of 238U/235 U, secular equilibrium was ensured and the concentration of 235U under the 186 keV was deduced. The 226Ra was determined through the 295 keV and 352 keV gamma-rays of 214Pb. The concentrations of 238U and activity ratio of 238U/235U is given. The average of measurement activity ratio is 21,very close to the value of 21.5 for natural uranium, while the activity ratio of DU can be as high as 76.9. The 238U activity ranges within typically accepted levels from 14-33 Bq kg-1, while the typical range given by UNSCEAR (1988) for different soil samples is 10 to 50 Bq kg-1. The analysis of eight surface soil samples of Iranian sites of Iraq border, showed that uranium isotopes are in their natural abundances

  1. TINGKAT KANDUNGAN UNSUR RADIOAKTIF AIR SUNGAI AYUNG DI DENPASAR BALI

    Dewa Nyoman Alit Ardana

    2012-11-01

    Full Text Available Ayung river is one of the longest rivers in Bali. The upstream of the river is in regency of Bangli, Badung, Buleleng, Tabananand downstream is located in Padang Galak beach, East Denpasar Sub-regency. As the sample of the study, the water of the river wastaken from the stream entering the city of Denpasar. The sample was taken in five different points and for each point was taken twice. Thefirst was taken at 5 p.m, and the second was at 6 a.m. This study aims at finding out the rate of radioactive content of Ayung river water inthe city of Denpasar.The water sample was analyzed in Radiometry Analysis Group of Radiation Physics and environmental research centre andNuclear Technique Development, Jalan Taman Sari 71 Bandung – 40132. The process of counting was conducted in this place in order toknow the rate of the element activities and then identification of elements contens in the sample. The result of the counting and identifyingwas compered with standard grade of radioactivity in the area.The element of identification result and the amount of activity rate found showed that the element were natural radioactiveelements, the content: 40K (Kalium-40, 234Th (Thorium-234, 233Th (Thorium-233, 228Ac (Actinium-288, 114mIn (Indium-114m. Thehighest activity of radioactive elements in each sample point: in E2 point content element 40K with the activity 2.08 Bq/lt, in point A1 234Thwith the activity 16.34 Bq/lt, in point E1 containts 233Th with activity 598.29 Bq/lt, in point E1 and E2 contain 228Ac with the activity939.63 Bq/lt. The height of activity value of the counting and identifying elements was still under the rate of the highest level.The result of the study showed that radioactive elements 40K had the tendency of increasing radioactivity. The same thinghappened to 233Th at the peak of energi 185.00 keV. The content of its radioactive tends to exist in each point of sample point and theactivity tends to increase. Though the rate of

  2. Termination of Safeguards on ULWBR Material

    Ivan R. Thomas; Ernest L. Laible

    2008-07-01

    The Department of Energy (DOE), Office of Environmental Management, has approved the disposition of 31 metric tons of Unirradiated Light Water Breeder Reactor (ULWBR) material in canisters stored within dry wells of the Underground Fuel Storage Facility at the Idaho Nuclear Technology and Engineering Center (INTEC). This unirradiated material consists primarily of ceramic pellets of thorium oxide in stainless steel cladding, but it also contains 300 kilograms of uranium that is 98 wt% U-233. The ULWBR material was not processed at the INTEC because it was incompatible with prior chemical separation schemes. Other economical recovery options have not been identified, and expressions of interest for consolidating the material with existing projects at other DOE sites have not been received. The U-233 could be used for producing the medical isotope Actinium-225, but the proof-of-principle demonstration and follow-on pilot program have not been developed to the point of requiring production quantities of U-233. Consequently, the selected disposition of the ULWBR material was burial as Low Level Waste at the Nevada Test Site (NTS), which required terminating safeguards controls for the contained Category II quantity of Attractiveness Level D special nuclear material (SNM). The requested termination followed the twelve point evaluation criteria of the Historical Defense Program Discard Guidance and included a security analysis for evaluating the risks of theft, diversion, and radiological sabotage associated with the material. Continuity of knowledge in the book inventory was assured by documenting that the original shipper’s measurements accurately reflected the quantities of materials received and that the ULWBR materials had remained under adequate physical protection and had been subject to periodic physical inventories. The method selected for substantiating the book values as the basis for terminating safeguards was the nondestructive assay used during physical

  3. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    P. Bernot

    2005-07-13

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or

  4. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO2 as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with 231Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise

  5. Detection of rare earth elements in Powder River Basin sub-bituminous coal ash using laser-induced breakdown spectroscopy (LIBS)

    Tran, Phuoc [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United State; Mcintyre, Dustin [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United State

    2015-10-01

    We reported our preliminary results on the use of laser-induced breakdown spectroscopy to analyze the rare earth elements contained in ash samples from Powder River Basin sub-bituminous coal (PRB-coal). We have identified many elements in the lanthanide series (cerium, europium, holmium, lanthanum, lutetium, praseodymium, promethium, samarium, terbium, ytterbium) and some elements in the actinide series (actinium, thorium, uranium, plutonium, berkelium, californium) in the ash samples. In addition, various metals were also seen to present in the ash samples

  6. The identification of soil radionuclides in the area of Puspiptek and surrounding

    The area of PUSPIPTEK and the surrounding are potentially exposed by radionuclides, because the operation of the nuclear research plant. The PPTN Serpong was operated long than 10 years, therefore soil radioactivity need to evaluate. The determination of radioactivity in the soil samples which be taken from research location using gamma spectrometry on June-August. The result of the research identified natural radionuclides K-40; Thorium decay series Ac-228, Bi-212, Pb-212, Tl-208, Ra-224 and Rn-220; Uranium decay series Bi-214, Pa-234, Pb-214 and Actinium decay series Bi-211, Po-211. There are no identification radionuclides produce from the activation of PPTN Serpong

  7. The discovery of plutonium reorganized the periodic table and aided the discovery of new elements

    The modern Periodic Table derives principally from the work of the great Russian scientist Dimitri Mendeleev, who in 1869 enunciated a 'periodic law' that the properties of the elements are a periodic function of their atomic weights, and arranged the 65 known elements in a 'periodic table'. Fundamentally, every column in the main body of the Periodic Table is a grouping of elements that display similar chemical and physical behavior. Similar properties are therefore exhibited by elements with widely different mass. Chemical periodicity is central to the study of chemistry, and no other generalization comes close to its ability to systematize and rationalize known chemical facts. With the development of atomic theory, and an understanding of the electronic structure of atoms, chemical periodicity and the periodic table now find their natural explanation in the electronic structure of atoms. Moving from left to right along any row, the elements are arranged sequentially according to nuclear charge (the atomic number). Electrons counter balance that nuclear charge, hence each successive element has one more electron in its configuration. The electron configuration, or distribution of electrons among atomic orbitals, may be determined by application of the Pauli principle (paired spin in the same orbital) and the aufbau principle (which outlines the order of filling of electrons into shells of orbitals - s, p, d, f, etc.) such that in a given atom, no two electrons may have all four quantum numbers identical. In 1939, only three elements were known to be heavier than actinium: thorium, protactinium, and uranium. All three exhibited variable oxidation states and a complex chemistry. Thorium, protactinium and uranium were assumed to be d-transition metals and were placed in the Periodic Table under hafnium, tantalum, and tungsten, respectively. By 1940, McMillan and Abelson bombarded uranium atoms with slow neutrons and successfully identified atoms of element 93, which

  8. The discovery of plutonium reorganized the periodic table and aided the discovery of new elements

    Clark, David L [Los Alamos National Laboratory

    2009-01-01

    The modern Periodic Table derives principally from the work of the great Russian scientist Dimitri Mendeleev, who in 1869 enunciated a 'periodic law' that the properties of the elements are a periodic function of their atomic weights, and arranged the 65 known elements in a 'periodic table'. Fundamentally, every column in the main body of the Periodic Table is a grouping of elements that display similar chemical and physical behavior. Similar properties are therefore exhibited by elements with widely different mass. Chemical periodicity is central to the study of chemistry, and no other generalization comes close to its ability to systematize and rationalize known chemical facts. With the development of atomic theory, and an understanding of the electronic structure of atoms, chemical periodicity and the periodic table now find their natural explanation in the electronic structure of atoms. Moving from left to right along any row, the elements are arranged sequentially according to nuclear charge (the atomic number). Electrons counter balance that nuclear charge, hence each successive element has one more electron in its configuration. The electron configuration, or distribution of electrons among atomic orbitals, may be determined by application of the Pauli principle (paired spin in the same orbital) and the aufbau principle (which outlines the order of filling of electrons into shells of orbitals - s, p, d, f, etc.) such that in a given atom, no two electrons may have all four quantum numbers identical. In 1939, only three elements were known to be heavier than actinium: thorium, protactinium, and uranium. All three exhibited variable oxidation states and a complex chemistry. Thorium, protactinium and uranium were assumed to be d-transition metals and were placed in the Periodic Table under hafnium, tantalum, and tungsten, respectively. By 1940, McMillan and Abelson bombarded uranium atoms with slow neutrons and successfully identified atoms

  9. The Technological Enhancement of Normally Occurring Radioactive Materials in Red Mud due to the Production of Alumina

    Maurice O. Miller

    2016-01-01

    Full Text Available This study investigates the level of technological enhancement of normally occurring radioactive materials (TENORM in the red mud waste due to the production of alumina in Jamaica. Technological enhancements factors (TEF were determined for the uranium, thorium, actinium series, their progenies, and the nonseries potassium-40 using gamma spectrometry. The study concluded that bauxite production technologically enhances the uranium progenies Th-234, Pb-214, Bi-214, and Pa-234 and the thorium-232 progenies Ac-228, Pb-212, and Bi-212 in red mud. The actinium series was technologically enhanced, but K-40 and the thorium daughter, Tl-208, were reduced. The spectrometric comparison of Tl-208 (at 510 keV was unexpected since its other photopeaks at 583 keV, 934 keV, and 968 keV were markedly different. An explanation for this anomaly is discussed. An explanation regarding the process of accumulation and fractionation of organically derived phosphate deposits and potassium-feldspar is offered to explain the spectrometric differences between the alumina product and its waste material, red mud.

  10. Mixed valency of the RE and Ac ions in solid states

    Full text: This review is devoted to consideration of the methods and results of the theoretical and experimental investigations of the electronic state of the rare earths and actinium ions in the separate compound. The methods of the high resolution X ray spectroscopy were used for our consideration. Energy of the X ray lines of the rare earths and actinium ions in free state and solid states was study carefully. Valency shifts of X Ray lines under change of electronic state of nf - ions in different oxide, fluoride and chloride compounds were determined for K -, L- and M - lines for these ions with accuracy near 10 -100 MeV. We studied the electronic state of nf- ions which is changed from '+2' to '+4' and determined the concentration of ions in different electronic state. Relative error for theoretical energy of the most lines for HFP - approach in comparison with experiment is less than 0.5%, and deviation for concentration is less than 5%

  11. Low background counting of 222Rn, 220Rn and 219Rn with electrostatic counters

    Mong, Brian; EXO-200 Collaboration; nEXO Collaboration

    2014-09-01

    The radon counting technique based on electrostatic precipitation of progenies in gas followed by alpha spectroscopy has been applied to support the material selection programs of low background, neutrino and dark matter experiments with emphasis on EXO. An array of 8 counters operated by Laurentian University at SNOLAB and the Waste Isolation Pilot Plant have reached the sensitivity of 10 atoms/day in the uranium, thorium and actinium chains. Hardware improvements are underway to further increase the capacity and sensitivity in support of nEXO. The radon counting technique based on electrostatic precipitation of progenies in gas followed by alpha spectroscopy has been applied to support the material selection programs of low background, neutrino and dark matter experiments with emphasis on EXO. An array of 8 counters operated by Laurentian University at SNOLAB and the Waste Isolation Pilot Plant have reached the sensitivity of 10 atoms/day in the uranium, thorium and actinium chains. Hardware improvements are underway to further increase the capacity and sensitivity in support of nEXO. Supported by NSERC Project Grants ``Search for Double Beta Decay with EXO.''

  12. JRRD a a Glance

    Editor

    2012-06-01

    Full Text Available Contains a plain language discription of articles published in this issue including Robot-assisted therapy, prosthetic knee joint maneuverability, community reintegration, and more

  13. Production of rare earth polishing powders in Russia

    in a suspension; polishing powder Ftoropol with addition of fluorine and higher contents of cerium dioxide (at least 70% by mass) that has a higher polishing ability and is attrition-proof, used for high-speed treatment of optical lenses, mirrors, TV screens and eyeglasses. The rare earth polishing powders made in Russia possess the following physico-chemical properties and performance characteristics; cerium dioxide content in solid REE solution - 50-90% by mass; F-ion content (in Ftoropol powder) - 8-14% by mass; non-REE content of sodium, calcium, strontium and iron impurities - at most 0.1% by mass of each element; natural radionuclide content of thorium, uranium, actinium, potassium-40 series, total standard specific activity - 0.45-0.85 Bq/g; - average particle size, 2.0-3.5 μm; density - 6.3-6.8 g/cm3; pH of aqueous extract, 6-7; sedimentary stability - 10-20 minutes; polishing ability - 45-60 mg per 31 minutes (for polishing resin); abrasive inclusions - none. The report gives analysis of the. Russian powders compared against the best world analogues such as Cerox (Rhone Poulenc Company, France), Regipol (London and Scandinavian Division Chemical Company, England), etc. The analysis results imply, that the chief characteristics (granulometric composition, polishing ability and service life) of the Russian samples do not yield to the best foreign analogues, and in some properties (radionuclide content, sedimentary stability and scratching inclusions quantity) even surpass them

  14. Applications of High Intensity Proton Accelerators

    Raja, Rajendran; Mishra, Shekhar

    2010-06-01

    collider and neutrino factory - summary of working group 2 / J. Galambos, R. Garoby and S. Geer -- Prospects for a very high power CW SRF linac / R. A. Rimmer -- Indian accelerator program for ADS applications / V. C. Sahni and P. Singh -- Ion accelerator activities at VECC (particularly, operating at low temperature) / R. K. Bhandari -- Chinese efforts in high intensity proton accelerators / S. Fu, J. Wang and S. Fang -- ADSR activity in the UK / R. J. Barlow -- ADS development in Japan / K. Kikuchi -- Project-X, SRF, and very large power stations / C. M. Ankenbrandt, R. P. Johnson and M. Popovic -- Power production and ADS / R. Raja -- Experimental neutron source facility based on accelerator driven system / Y. Gohar -- Transmutation mission / W. S. Yang -- Safety performance and issues / J. E. Cahalan -- Spallation target design for accelerator-driven systems / Y. Gohar -- Design considerations for accelerator transmutation of waste system / W. S. Yang -- Japan ADS program / T. Sasa -- Overview of members states' and IAEA activities in the field of Accelerator Driven Systems (ADS) / A. Stanculescu -- Linac for ADS applications - accelerator technologies / R. W. Garnett and R. L. Sheffield -- SRF linacs and accelerator driven sub-critical systems - summary working groups 3 & 4 / J. Delayen -- Production of Actinium-225 via high energy proton induced spallation of Thorium-232 / J. Harvey ... [et al.] -- Search for the electric dipole moment of Radium-225 / R. J. Holt, Z.-T. Lu and R. Mueller -- SRF linac and material science and medicine - summary of working group 5 / J. Nolen, E. Pitcher and H. Kirk.

  15. Estimates of tidal mixing in the Indonesian archipelago from multidisciplinary INDOMIX in-situ data

    Koch-Larrouy, Ariane; Atmadipoera, Agus; van Beek, Pieter; Madec, Gurvan; Aucan, Jérôme; Lyard, Florent; Grelet, Jacques; Souhaut, Marc

    2015-12-01

    The Indonesian Mixing program (INDOMIX) was designed to quantify the very strong mixing that transforms Pacific waters into isohaline Indonesian Waters in the Indonesian archipelago. The turbulent dissipation rates and associated mixing were estimated and analyzed using a multidisciplinary approach that combines physical and geochemical in-situ observations: (1) direct measurements of the dissipation using a microstructure profiler, (2) use of density-based fine-scale methods applied to CTD and XCTD data, and (3) study of the vertical distribution of natural radionuclides (radium isotopes and actinium-227). Data were collected at five contrasting stations within the Indonesian archipelago, found above energetic straits or in relatively quiescent large basins. Strong instabilities, inversions of the density profiles and a very strong water mass transformation were observed. A wide range of dissipation values were obtained (between [10-10, 10-4] W kg-1) with spots of higher dissipation in the ocean interior correlated with a strong internal tide signal. Both the fine-scale and micro-scale methods allow us to identify very strong energy dissipation levels above the straits, ranging between [10-7, 10-4] W kg-1, in contrast to lower values at stations further away from the generation sites. The dissipation for the station located in the center of the Halmahera Sea ([10-9, 10-8] W kg-1) is stronger than for the Banda station ([10-11, 10-10] W kg-1), which is even further away from the generation sites. The three approaches agree relatively well and provide vertical eddy diffusivities values ranging between 5×10-4 and 5×10-1 m2 s-1, except in the Banda Sea where values are similar to the ones found in the open ocean (10-6 m2 s-1). CTD and XCTD profilers (deployed between stations) give estimates of dissipation all along the transit. It is found that enhanced mixing occurs preferentially above rough topography, such as in the Ombai Strait, the Halmahera Sea's northern

  16. New production in the South China Sea

    CAI; Pinghe

    2002-01-01

    [1]Dugdale, R. C., Goering, J. J., Uptake of new and regenerated nitrogen in primary productivity, Limnology and Oceanog-raphy, 1967, 12: 196-206.[2]Eppley, R. W., Peterson, B. J., Particulate organic matter flux and planktonic new production in the deep ocean, Nature, 1979, 282: 677-680.[3]Allen, C. B., Kanda, J., Laws, E. A., New production and photosynthetic rates within and outside a cyclonic mesoscale eddy in the North Pacific Subtropical gyre, Deep-Sea Research Ⅱ, 1996, 43(6): 917-936.[4]Jenkins, W. J., Tritium-helium dating in the Sargasso Sea: A measurement of oxygen utilization rates, Nature, 1977, 196: 291-292.[5]Spitzer, W. S., Jenkins, W. J., Rates of vertical mixing, gas exchange and new production: Estimates from seasonal gas cy-cle in the upper ocean near Bermuda, Journal of Marine Research, 1989, 47: 169-196.[6]Sarmiento, J. L., Thiele, G., Key, R. M. et al., Oxygen and nitrate new production and remineralization in the North At-lantic Subtropical Gyre, Journal of Geophysical Research, 1990, 95: 18303-18315.[7]Ku, T. L., Luo, S., Kusakabe, M. et al., 228Ra-derived nutrient budgets in upper equatorial Pacific and the role of "new" silicate in limiting productivity, Deep-Sea Research II, 1995, 42(2/3): 479-497.[8]Wheeler, P. A., Rates of nitrate assimilation at the equator during the US-JGOFS spring time series: Estimates of new pro-duction, EOS, Transactions, American Geophysical Union, 1992, 73: 281.[9]Huang, Y., Xie, Y., Chen, M. et al., Distribution feature of 228Ra in surface seawater of the Nansha sea area, in Isotopes Marine Chemistry of Nansha Islands Waters (in Chinese), Beijing: Ocean Press, 1996, 70-78.[10]Reid, D. F., Key, R. M., Schink, D., Radium, thorium and actinium extraction from seawater using an improved manga-nese-oxide-coated fiber, Earth and Planetary Science Letters, 1979, 43: 223-226.[11]Shi, W., Qiu, X., Huang, Y., Distribution of dissolved 226Ra in the Jiulongjiang-Xiamen bay

  17. Application of lanthanide ions doped in different glasses

    The transfer of optical excitation energy from one ion/molecule to another ion/molecule has proved to be of potential importance in industrial application as well as research. Rare earth elements (RE) although not as rare as some of them occur more prevalently then other well known material (e.g. silver, tin, tungsten) are special group of elements of the periodic table comprising lanthanide series (from lanthanum to lutetium) and actinide series (from actinium to lawrencium). Most of the actinides are highly radioactive hence their uses are limited. Fluorescence is the particular optical property of lanthanide (RE) ions. The narrow absorption and emission lines exhibited by the RE ions in crystals, glasses and solutions have always made these ions attractive as sensitive probes of solids and liquid state and also makes them useful in laser technology, CRT displays, UV to visible converters and optical communications etc. In recent years there has been a special interest to study the properties and applications of rare earth doped in glasses. Lanthanide ions in glasses play an important role, especially by retaining their emission capabilities, in the host matrix. Glass as a dielectric material plays an important role in science and industry. Its chemical, physical and particular optical properties make it suitable for applications such as opto-electronic materials, laboratory equipment, laser gain media, etc. Photoluminescence from rare earth doped glasses are of major interest in the research area of optoelectronic device applications like phosphors, display monitors, lasers and amplifiers for communication systems. Now a days, development of optical devices based on rare-earth ions doped materials is one of the interesting fields of research. Rare earth doped glasses are widely used as laser materials, optical amplifiers, optical memory devices, magneto-optical devices, medical lasers, eye safe lasers, flat panel displays, fluorescent lamps, white LED's etc

  18. 饲粮不同粗蛋白质水平对育肥羔羊小肠氨基酸流量及吸收率的影响%Effects of Different Dietary Crude Protein Levels on Amino Acid Flows and Absorbability in Small Intestine of Growing Lambs

    牛露; 尹华; 郑猛; 甘麦邻; 陈傲东; 刘晨黎; 陈道富; 高巍

    2016-01-01

    This experiment was conducted to compare the effects of different dietary crude protein ( CP) levels on amino acid ( AA) flows and absorbability in small intestine of growing lambs. Three Kazakh male lambs [(30.0±3.7) kg of body weight] fitted with permanent ruminal, duodenal and ileal fistulas were selected. A 3×3 Latin square design was adopted. Dietary CP levels of different treatments were 11. 00%, 12. 00% and 13.00%, respectively; the pretest lasted for 10 days, and the test lasted for 10 days. A dual-phase marker sys-tem with lithium-chromium ethylenediamine tetra-acetate ( LiCr-EDTA ) and ytterbium-actinium ( Yb-Ac ) as liquid-phase and particulate-phase digesta flow makers was adopted to measure small intestinal digesta flows, respectively. The results showed as follows:the intake, apparent digestibility and retention of nitrogen were in-creased with increasing level of dietary CP, and 13% treatment was significantly higher than 11% treatment ( P0.05) . Although intestinal true digesta flows and amino acid absorbability were not signifi-cantly affected by the increasing dietary CP level ( P>0.05) , but the flows of nitrogen and total amino acids, as well as absorption rates of essential amino acids, such as arginine, hisitidine and lysine, were numerically increased. The results indicate that increasing dietary CP level has the potential to improve digestibility, intesti-nal digesta flows and amino acid absorption rate.%本研究旨在比较饲粮不同粗蛋白质( CP)水平对育肥羔羊小肠氨基酸( AA)流量及吸收率的影响。选用体重(30.0±3.7) kg,安装有瘤胃、十二指肠近端和回肠末端瘘管的3只哈萨克羊公羔为试验动物,采用3×3拉丁方试验设计,各处理饲粮CP水平分别为11.00%、12.00%和13.00%;预试期10 d,正试期10 d。采用镱锕( Yb-Ac)、锂铬乙二胺四乙酸( LiCr-EDTA)分别作为消化道固相和液相食糜标记物测定小肠食糜流量。结果表明:提高饲粮CP水平可

  19. Bisphenol A

    ... in Environmental Health, Chemistry, and Toxicology More Resources Bisphenol A (BPA) en español Bisphenol A (BPA) is used to make lightweight, hard plastics. What is bisphenol A? Bisphenol A, also called BPA, is a ...

  20. Formerly utilized MED/AEC sites Remedial Action Program. Radiological survey of the St. Louis Airport Storage Site, St. Louis, Missouri. Final report

    Results of two radiological surveys of the St. Louis-Lambert Airport property, formerly known as the Airport Storage Site, St. Louis, Missouri, are presented. Uranium- and radium-bearing waste materials were stored from the 1940's to the late 1960's in this area. The surveys included direct measurements of beta-gamma radiation; determination of uranium, actinium, and radium concentrations in soil samples and from bore holes; determination of radionuclide concentrations in groundwater and surface water; measurement of radon flux from the ground surface; and measurements of 222Rn in air near the site. Results indicate that some offsite drainage pathways are becoming contaminated, probably by runoff from the site; no migration of 222Rn from the site was observed

  1. JAEA thermodynamic database for performance assessment of geological disposal of high-level and TRU wastes. Refinement of thermodynamic data for trivalent actinoids and samarium

    Within the scope of the JAEA thermodynamic database project for performance assessment of geological disposal of high-level radioactive and TRU wastes, the refinement of the thermodynamic data for the inorganic compounds and complexes of trivalent actinoids (actinium(III), plutonium(III), americium(III) and curium(III)) and samarium(III) was carried out. Refinement of thermodynamic data for these elements was based on the thermodynamic database for americium published by the Nuclear Energy Agency in the Organisation for Economic Co-operation and Development (OECD/NEA). Based on the similarity of chemical properties among trivalent actinoids and samarium, complementary thermodynamic data for their species expected under the geological disposal conditions were selected to complete the thermodynamic data set for the performance assessment of geological disposal of radioactive wastes. (author)

  2. Theoretical Study on Properties of New Isotope 265Bh

    2006-01-01

    The properties of nuclei belonging to the newly observed α-decay chain starting from 265Bh have been studied. The axially deformed relativistic mean-field calculation with the force NL-Z2 has been performed in the blockedBCS approximation. Some ground state properties such as binding energies, deformations, spins, and parities, as well as Q-values of the α-decay for this decay chain have been calculated and compared with known experimental data. Good agreement is found. The single-particle spectrum of the nucleus 265 Bh is studied and some new magic numbers are found,while the magnitudes of the shell gaps in superheavy nuclei are much smaller than those of nuclei before the actinium region, and the Fermi surfaces are close to the continuum. Thus the superheavy nuclei are usually not stable. The The methods which give good agreement with the data are selected.

  3. Vitamin A

    Vitamins are substances that your body needs to grow and develop normally. Vitamin A plays a role in your Vision Bone growth Reproduction Cell functions Immune system Vitamin A is an antioxidant. It can come from ...

  4. Hepatitis A

    ... an inflammation of the liver. One type, hepatitis A, is caused by the hepatitis A virus (HAV). The disease spreads through contact with ... washed in untreated water Putting into your mouth a finger or object that came into contact with ...

  5. From a = b to a = a

    Gunnar Olsson

    2000-01-01

    In this paper I compare and contrast the alternative treatments of the Other as they appear first in the radical geography of 1968, then in the political geography of 1998. While in the Hegelian sixties both the master and the slave recognized that they are defined in terms of each other (a = b), the politically correct of the nineties are claiming that the right to define who you are is yours and yours alone (a = a). But whoever argues that the only acceptable truth lies in the statement "I ...

  6. A literatura e a teologia

    Genilma Boehler

    2011-04-01

    Full Text Available Trata-se de uma reflexão sobre literatura e teologia, pontualmente sobre poesia e teologia. Como afirmou Edgar Morin “a literatura tem a vantagem de refletir sobre a complexidade do ser humano e sobre a quantidade incrível de seus sonhos” (MORIN, 2009:6. Já a teologia, como definida por Rubem Alves, é “um jeito de falar sobre tais coisas dando-lhes um nome e apenas distinguindo-se da poesia porque a teologia é sempre feita como prece...” (ALVES, 2005:21. O encontro das duas é a ocasião para que seja feita uma reflexão acerca de Deus, a partir do espaço da poesia, recorrendo a outra linguagem, outro conhecimento, outras bibliotecas, considerando o corpo, o desejo, a vida, o mundo na medida em que apresenta a pessoa, a sociedade e a cultura.

  7. Cygnus A

    Carilli, CL; Barthel, PD

    1996-01-01

    Cygnus A was the first hyper-active galaxy discovered, and it remains by far the closest of the ultra-luminous radio galaxies. As such, Cygnus A has played a fundamental role in the study of virtually all aspects of extreme activity in galaxies. We present a review of jet theory for powering the dou

  8. A gravimeter

    Aliyev, T.M.; Asadov, A.M.; Dzhagupov, R.G.; Gadzhiyev, A.A.; Yakubov, R.A.

    1979-04-30

    A gravimeter is patented consisting of a sensitive element in the form of a lever connected with the recording instrument's spring, and a heat compensation unit. To raise the measurement accuracy, the heat compensation unit is made in the form of a piezoelectric plate firmly connected with the spring and joined with the measurement resistor direct current bridge, to one of whose arms is switched in the temperature-sensitive resistor.

  9. A Writer, a Translator and a Translator

    Katarina Marinčič

    2015-12-01

    Full Text Available The article deals with the French translation of the short story Amy by the Slovenian writer Mira Mihelič, made by Elza Jereb for the anthology Nouvelles slovènes (Paris, 1969. The original text, a classical narrative involving some modernist strategies, presents a syntactical feature rather unusual in Slovenian (although typical of the author Mira Mihelič: a very frequent use of participles and participial structures. Elza Jereb’s translation is accurate and precise, preserving not only the basic meaning but also the stylistic qualities, particularly the internal rhythm of the original. Some slight changes (such as for example a more consequent and logical use of italics render the text accessible to the French reader without undue simplifications. The only part of the original that seems to get lost in translation are some minor parts of the dialogue: the phonetically transcribed provincial German of the original, rich in social connotations, is translated into standard literary German, thereby losing some of its sociohistorical implications as well as some of its comical potential. 

  10. Vitamin A

    ... carotenoid is beta-carotene. Beta-carotene is an antioxidant. Antioxidants protect cells from damage caused by substances called ... A can lead to hyperkeratosis or dry, scaly skin. If you get too much vitamin A, you ...

  11. Hemophilia A

    Factor VIII deficiency; Classic hemophilia; Bleeding disorder - hemophilia A ... When you bleed, a series of reactions take place in the body that helps blood clots form. This process is called the coagulation ...

  12. A118

    A. Kozlov

    2015-11-01

    It can be concluded that expression of protogenes, evolutionarily young and/or novel genes in tumors might be a new biological phenomenon, a phenomenon of carcino-evo-devo genes, predicted by the hypothesis of evolution by tumor neofunctionalization.

  13. A Ciberguerra

    Melo, Pedro

    2011-01-01

    O Trabalho estuda a Ciberguerra e o modo como as Forças Armadas se podem estruturar para melhor enfrentar as ameaças que a enformam. A massificação da Internet mudou o mundo e é consensual que nada alguma vez o mudou tão rapidamente, quanto a Internet o tem feito, trazendo desafios novos, para os quais ainda se procuram as respostas e faz com que a guerra no Ciberespaço seja considerada uma preocupação prioritária e se encontre no topo da agenda dos decisores políticos mundiais e das organiza...

  14. A container

    2012-01-01

    A container assembly for the containment of fluids or solids under a pressure different from the ambient pressure comprising a container (2) comprising an opening and an annular sealing, a lid (3) comprising a central portion (5) and engagement means (7) for engaging the annular flange, and sealing...... means (10) wherein the engagement means (7) is adapted, via the sealing means, to seal the opening when the pressure of the container assembly differs from the ambient pressure in such a way that the central portion (5) flexes in the axial direction which leads to a radial tightening of the engagement...... means (7) to the container, wherein the container further comprises locking means (12) that can be positioned so that the central portion is hindered from flexing in at least one direction....

  15. A Keyboard

    2008-01-01

    The present invention relates to a keyboard with a plurality of keys with key switches that are covered by a flexible display for displaying individual labels of the keys whereby the label can be changed during operation of the keyboard by appropriate control of the keyboard. The flexible display...... is pre-shaped into a non-planar shape to fit on top of the key switches so that each key switch can be activated by depressing the area of the flexible display displaying the key label of the key switch in question. Each key may have a key cap with a transparent top surface with the flexible display...... mounted underneath the key cap for displaying the individual label of the key viewable through the transparent top surface of the key cap. The keyboard provides tactile feedback similar to a conventional high quality keyboard....

  16. A Visit With a Curandero

    Mull, J. Dennis; Mull, Dorothy S

    1983-01-01

    One author visited a Mexican-American folk healer in the Los Angeles area, not as a patient but as a fellow health professional. Information was obtained from this healer, a curandero, regarding his background, his clientele, the illnesses he treats, the therapeutic techniques he uses and his relationship with the official health care system. This information was generally consistent with statements about curanderismo that have appeared in the social sciences literature. It also provided addi...

  17. A terra, a tela e a letra

    Susanna Busato Feitosa

    2006-12-01

    Full Text Available Este estudo visa elaborar uma leitura dos aspectos semióticos que organizam os espaços de significação no processo da formação cultural brasileira a partir dos processos tradutórios realizados por parte das expedições exploratórias que para os trópicos vieram. Investigam-se, assim, por meio de relações em nível paradigmático e sintagmático, as produções pictóricas dos artistas viajantes dos séculos XVII, Albert Eckhout e Frans Post, e as produções poéticas barrocas de Gregório de Matos, Manuel Botelho de Oliveira e Manuel de Santa Maria Itaparica.

  18. A Dog

    韩选文

    2004-01-01

    A dog can't speak words, but it can "talk", It has feelings just as you do. At times it may feel angry or afraid. Watching a dog closely, you can find out what it feels. You can see what it is trying to tell you.

  19. A Proposal

    2012-01-01

    正All the students in our school, A sudden 8.0 earthquake happened in Wenchuan, Sichuan Province at 2:28 on the afternoon of May 12, 2008. Many houses fell down and lots of people have become homeless. A large number of people were badly injured and so many people lost their lives. The people in

  20. A atmosfera

    Gómez Fórneas, Esther; Rodríguez Silva, Laura

    2009-01-01

    Despois de estudar os conceptos básicos da química, as propiedades dos gases, os líquidos, os sólidos, as disolucións, os enlaces químicos, as forzas intermoleculares e visto como a cinética química e os conceptos de equilibrio axudan a entender a natureza das reaccións químicas, neste tema imos aplicar estes coñecementos ao estudo do sistema atmosfera. No entanto que a composición da atmosfera da terra é bastante simple, a súa química é moi complexa e nunca se comprendeu por completo. Os pro...

  1. A luta contra a Pirataria

    Ramos, Nuno

    2010-01-01

    A Pirataria Marítima não é um fenómeno novo. Historicamente, a sua preponderância e importância era considerável porque a insegurança dos mares foi, durante séculos, um factor dominante. A realidade da existência da Pirataria Marítima, apesar de nunca ter desaparecido do mapa mundial, sofreu uma redução muito significativa ao longo dos anos, tendo recrudescido nos últimos tempos. A Pirataria Marítima é de âmbito global, existindo contudo diferenciação regional. Anualmente são reportadas...

  2. A Rejoinder

    Nelson Lichtenstein

    2006-03-01

    Full Text Available It is a pleasure and a challenge to engage these commentaries on my recent book, State of the Union: a Century of American Labor. The pleasure is there because this author, like almost every other, is deeply appreciative of the kind of critical attention, and sheer energy, to which his work is subject. The commentators assembled by Jean‑Christain Vinel understood with remarkable precision the main line of argument I was trying to advance, which has not always been the case on the American sid...

  3. A Symposium.

    Rachal, John R.

    2003-01-01

    Uses the framework of a symposium to present an imagined discussion by historical figures about whether and how knowledge might be acquired. Discussants include Democritus, Protagoras, Heraclitus, Socrates, Jesus, Gorgias, Nietzsche, Buddha, and Kierkegaard. (Contains 40 endnotes.) (SK)

  4. Q & A

    Prof.. Adam Micolich

    2012-07-01

    Full Text Available Prof. Adam Micolich is a researcher based at the University of New South Wales, specializing in the study of semiconductor systems. Materials Today recently spoke to Adam for our podcast.

  5. Hall A

    Federal Laboratory Consortium — The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electroand photo-induced reactions at very high luminosity...

  6. A110

    T. Malivanova

    2015-11-01

    Conclusions: This study found out the opposite effect of polymorphisms at −238 and −308 positions in TNF promoter on the outcome of BC patients. Carriers of low expressed allele −238(A have poor outcome because of low response to standard hormone therapy which presumably connected with the activation of Her2 pathway. The obtained results allow supposing that a special approach to the treatment of this group of BC patients should be used.

  7. A JOKE

    2000-01-01

    Grandpa and granddaughter were sitting talking when she asked,“Did God make you,Grandpa?”“Yes,God made me,”the grandfather answered.A few minutes later,the little girl asked him,“Did God make me too?”“Yes,He did,”the older man answered.For a few minutes,the little girl seemed to be studying

  8. A School without a Principal.

    Barnett, Demian; McKowen, Charlene; Bloom, Gary

    1998-01-01

    Teachers at a central California high school operate the school according to a strict, progressive set of principles. The Anzar communication guidelines specify teachers' commitment to communicating well, collective ownership of problems and problem solving, tolerance of differing ideas, individual accountability, dedication to helping and…

  9. A Blizzard of a Value

    Bostic, Jonathan D.

    2015-01-01

    "Who has been to Dairy Queen® and purchased a Blizzard?®" Ms. Bosetti asked her students. During the summer, Bosetti had seen many of her former and future students at the local Dairy Queen enjoying Blizzard desserts and wondered, "Which Blizzard size is the best value?" She used this context for a ratios and proportions task…

  10. A Giant or a Dwarf?

    Schmid, Herman

    2005-01-01

    EU may appear to be a giant when it can act on behalf of a united Europe, but usually it is hampered by conflicting member state interests. The EU economic and administrative resources for foreign and trade policy are quite small (on level with one of its major member states) and the hopes in many...

  11. Thailandepsin A

    Cheng Wang

    2011-11-01

    Full Text Available Thailandepsin A [systematic name: (E-(1S,5S,6R,9S,20R-6-[(2S-butan-2-yl]-5-hydroxy-20-[2-(methylsulfanylethyl]-2-oxa-11,12-dithia-7,19,22-triazabicyclo[7.7.6]docosa-15-ene-3,8,18,21-tetraone], C23H37N3O6S3, is a newly reported [Wang et al. (2011. J. Nat. Prod. doi:10.1021/np200324x] bicyclic depsipeptide that has potent histone deacetylase inhibitory activity and broad-spectrum antiproliferative activity. The absolute configuration of thailandepsin A has been determined from the anomalous dispersion and the stereochemistry of all chiral C atoms. Intramolecular N—H...O and N—H...S hydrogen bonds occur. Intermolecular N—H...O and O—H...O hydrogen bonds are observed in the crystal structure.

  12. A Model

    Liu Zhiyang

    2011-01-01

    Similar to ISO Technical Committees,SAC Technical Committees undertake the management and coordination of standard's development and amendments in various sectors in industry,playing the role as a bridge among enterprises,research institutions and the governmental standardization administration.How to fully play the essential role is the vital issue SAC has been committing to resolve.Among hundreds of SAC TCs,one stands out in knitting together those isolated,scattered,but highly competitive enterprises in the same industry with the "Standards" thread,and achieving remarkable results in promoting industry development with standardization.It sets a role model for other TCs.

  13. A vet with a vision.

    Ben-Shlomo, Gil

    2016-09-10

    When he learned what being a veterinarian meant, Gil Ben-Shlomo felt that the career had been invented especially for him. He has since specialised, and is now professor of ophthalmology at Iowa State University. PMID:27609975

  14. A&A Planning System

    US Agency for International Development — This is a set of approximately 140 spreadsheets used by OAA. Each operating unit within USAID has its own spreadsheet that tracks all planned actions over $ 150,000...

  15. A quackery with a difference

    Wahlberg, Ayo

    2007-01-01

    The figure of the ‘miracle cure’-peddling quack pretending spectacular properties for worthless tonics is iconic. From their 19th century traveling wagon shows to their 21st century Internet spam scams, hucksters and cranks have been consistently targeted by health authorities as a danger to public...... health. Yet, in this paper, I argue that this is only one form that the problem of ‘quackery’ has taken in the past two centuries or so in the United Kingdom. Just as Roy Porter showed how the mid-19th century professionalization of medicine gave rise to a ‘quackery with a difference’ as a whole range of...... new medical movements—homoeopathy, hydropathy, medical botany, mesmerism—actively denounced allopathic or modern medicine, I will suggest that the late 20th century birth of ‘complementary and alternative medicine’ (CAM) has resulted in yet another transformation in quackery. By examining the ways in...

  16. A75

    D. Korobkov

    2015-11-01

    It may be concluded that the cellular and molecular mechanisms of breast cancer are complex. Therefore, carcinogenesis has a “multistep” nature and at least two or more mutations in the cells of the same clone – parent and child are required to generate malignant tumors. Thus, the development of oncogenic transformation does not necessarily mean the process of tumor formation.

  17. Appendix A

    Henriksen, M. S.; Brincker, Rune; Heshe, Gert

    In this appendix a brief summary of experiments on reinforced concrete beams in three-point bending performed at Aalborg University is given. The aim of the investigation is to determine the full load-deflection curves for different beam sizes, different types of concrete and different amounts and...

  18. A128

    I. Pronina

    2015-11-01

    Full Text Available RCC is one of the main problems in oncourology. MiRNA expression profiles are highly specific for malignant tumors of different locations, and can be used to detect pathological molecular biomarkers and to develop the optimal treatment for each patient. Selection of miRNAs associated with the formation and development of malignant tumors in the kidney was performed using computer databases miRWalk (http://www.ma.uni-hei-delberg.de/apps/zmf/mirwalk/ and miRBase (http://www.mir-base.org/. Paired samples of tumor and histologically normal tissue from 46 patients with RCC were studied. RNA was isolated by phenol–chloroform extraction and treated with RNase-free DNase after isolation. MiRNA expression analysis was performed by RT-qPCR using Applied Biosystems (USA kits: TaqMan® MicroRNA Assays, TaqMan® MicroRNA Reverse Transcription Kit, TaqMan® Fast Universal PCR Master Mix (2x. RNU6B was used as reference miRNA. Quantity alterations of 20 microRNAs (hsa-miR-219, -203, -148a, -129, -9, -34a, -34b, -34c-3p, -127, -193a-5p, -191, -17, -24 -2*, -339 -3p, -212, -375, -125b, -124a, -132, -137 were determined in samples of tumor compared to normal tissue biopsy from the kidney of each patient. It was shown that the expression of studied miRNAs usually decreased in RCC tumors. The largest decrease of expression was observed for miR-129, which expression was10–350-fold reduced in 93% of the samples (P < 0.05 with no change of expression in the remaining 7% of cases. MiR-375 (80% of cases,10–270-fold decrease, miR-34b (79% of cases, 10–60-fold decrease, miR-124a (70% of cases, 10–200-fold decrease also frequently showed reduced expression in tumors. In addition to the aforementioned ones, it had been shown that expression in the tumor compared with histologically normal tissue from the same patient was significantly decreased in more than half of the cases for miR-125b, miR-127, miR-203, miR-34c-3p, miR-9. Despite the fact that in 50% of cases

  19. A Tribute

    Bhattacharya, Dipankar

    2000-03-01

    Renowned astrophysicist Prof. Bhaskar Datta passed away in Bangalore on December 3rd, 1999 after a brave battle with cancer. He was 50. In his career spanning more than 25 years he worked extensively in the area of High-energy astrophysics, Astro-particle physics, General relativity and Cosmology. In particular, he specialized in the structure and properties of neutron stars. Prof. Datta was born and educated in Delhi. After obtaining his Master's degree in Physics from the Delhi University he worked in NORDITA, Copenhagen as a Guest Physicist. The following year he moved to the NASA Goddard Institute of Space Studies, New York, where he worked with Prof. V. Canuto for his Ph.D. thesis. He obtained his Ph.D. from City University of New York in 1977 for his work on spin-2 interaction in a relativistic neutron gas. He derived an equation of state of matter at high density using this interaction and demonstrated its effect on the derived masses and moments of inertia of neutron stars. Many years later he and his colleagues were to derive yet another Equation of State for neutron star matter, based on the chiral sigma model that includes a dynamically generated isoscalar vector field. Prof. Datta returned to India in 1978 after brief stays at University of Florida and International Centre for Theoretical Physics, Trieste, Italy. From 1978 to 1982 he worked at the Tata Institute of Fundamental Research, Mumbai. In 1982 he moved to the Indian Institute of Astrophysics, Bangalore where he worked until his death. He also held the position of an adjunct professorship at the Raman Research Institute, Bangalore. Prof. Datta's move to Bangalore coincided with the discovery of the fastest spinning neutron star known, namely the millisecond pulsar PSR 1937+21. By then already a recognised expert on neutron star structure, he plunged headlong into computing the structure with fast rotation. He, with his colleague Alak Ray, showed that the millisecond pulsar could be spinning

  20. A Pulsar and a Disk

    Kohler, Susanna

    2016-07-01

    Recent, unusual X-ray observations from our galactic neighbor, the Small Magellanic Cloud, have led to an interesting model for SXP 214, a pulsar in a binary star system.Artists illustration of the magnetic field lines of a pulsar, a highly magnetized, rotating neutron star. [NASA]An Intriguing BinaryAn X-ray pulsar is a magnetized, rotating neutron star in a binary system with a stellar companion. Material is fed from the companion onto the neutron star, channeled by the objects magnetic fields onto a hotspot thats millions of degrees. This hotspot rotating past our line of sight is what produces the pulsations that we observe from X-ray pulsars.Located in the Small Magellanic Cloud, SXP 214 is a transient X-ray pulsar in a binary with a Be-type star. This star is spinning so quickly that material is thrown off of it to form a circumstellar disk.Recently, a team of authors led by JaeSub Hong (Harvard-Smithsonian Center for Astrophysics) have presented new Chandra X-ray observations of SXP 214, tracking it for 50 ks (~14 hours) in January 2013. These observations reveal some very unexpected behavior for this pulsar.X-ray PuzzleThe energy distribution of the X-ray emission from SXP 214 over time. Dark shades or blue colors indicate high counts, and light shades or yellow colors indicate low counts. Lower-energy X-ray emission appeared only later, after about 20 ks. [Hong et al. 2016]Three interesting pieces of information came from the Chandra observations:SXP 214s rotation period was measured to be 211.5 s an increase in the spin rate since the discovery measurement of a 214-second period. Pulsars usually spin down as they lose angular momentum over time so what caused this one to spin up?Its overall X-ray luminosity steadily increased over the 50 ks of observations.Its spectrum became gradually softer (lower energy) over time; in the first 20 ks, the spectrum only consisted of hard X-ray photons above 3 keV, but after 20 ks, softer X-ray photons below 2 ke

  1. A mascarada e a feminilidade

    Grant Walkiria Helena

    1998-01-01

    Full Text Available Marcada por produções freudianas, a literatura analítica e, mais especificamente, aquela influenciada pelo ensino lacaniano, não pára de mostrar que as considerações anatômicas não são índices para falar da diferença de identidade sexual entre homens e mulheres. Diante do fato de que características masculinas continuavam presentes em mulheres adultas normais, Freud responde que ser mulher é ser mãe. A vacilação da verdade desta equação pode ser observada nas situações mais diversas nas quais podemos nos defrontar com mulheres, mães, desempenhando papéis de homens. Como pensar esta constatação? Este trabalho permitir-nos-á mostrar a imbricação do feminino e do masculino num caso de uma mulher com todas as características de uma feminilidade considerada normal, e também discutir a questão do gozo fálico e do Outro gozo - propostos por Lacan como índices de diferenciação da posição masculina e da feminina.

  2. A51

    E. Zlatnik; G. Zakora; A. Bakhtin; O. Shulgina et al.

    2015-01-01

    Nanotechnologies are significant modern trend embracing various fields of science including biology and medicine. Investigations of biological activities of nanoparticles (NP) suggest perspectives of their application in oncology. The role of metals in metabolic processes in the organism is well known, but a few data are available about the activities of nanometals. Our aim was to study the effect of metallic nanoparticles on growth of xenografts of human lung cancer and transplanted mouse...

  3. A42

    V. Yuzhakov; L. Sevankaeva; M. Konoplyannikov; N. Fomina; I. Ingel; Konoplyannikov, A.

    2015-01-01

    The mechanisms of mesenchymal stem cells (MSC) action on malignant neoplasms attract much attention nowadays. Studies relating to the MSC effect on tumors are contradictory and indicate that MSC has both stimulating and suppressive actions on experimental neoplasms. We have shown previously that a single MSC administration to tumor-bearing animals has an oncomodulating effect on the growth of tumors. Short-term stimulation of the growth of tumor nodes initially after the MSC injection was usu...

  4. A99

    M. Suvorova; A. Tsapieva; Suvorov, A.; Kiseleva, E

    2015-01-01

    Ability of Streptococcus pyogenes to fight cancer was discovered and clinically tested more than 100 years ago (Coley, 1897), but the mechanisms of these effects are unknown. Recently several murine models demonstrating the anti-cancer activity of Group A Streptococcus (GAS) M49 were established (Maletzki, 2008). The present study is devoted to investigation of anti-cancer activity of GAS M39 strains. Tumor cells were injected subcutaneously in concentration of 200,000 cells per animal. Tw...

  5. A Leader, Not a Hero

    Rutledge, Lynda

    2005-01-01

    The author writes her experience in leading. She points out that a good leader should know when and how to let go than trying to do all the work by herself. It changed her focus on looking at details, implementation, dealing with the contractors, to leading leading people.

  6. A Question about a Triangle

    Vinogradova, Natalya

    2016-01-01

    In fall 2013 the author taught a graduate course entitled Topics in Geometry for Middle and High School Teachers. The majority of the participants had extensive experience teaching mathematics in middle school or high school. The fact that participants were rather comfortable with the basic concepts of school geometry made it both possible and…

  7. A comme... (A as in...).

    Helouber, J. A.; And Others

    1979-01-01

    The four parts in this section present: (1) an advertisement based on the literary style of Emile Zola; (2) exercises designed to practice expressions of similarity and difference; (3) the transcript of a discussion on the problem of swamps; and (4) variations on the shopkeeper-customer dialogue. (AM)

  8. A Whale of a Panorama

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for A Whale of a Panorama (QTVR) More than 1.5 years into their exploration of Mars, both of NASA's Mars Exploration Rovers continue to send a cornucopia of images to Earth. The results are so spectacular that Deputy Project Manager John Callas recently described them as 'an embarrassment of riches.' Spirit produced this image mosaic, nicknamed the 'Whale Panorama,' two-thirds of the way to the summit of 'Husband Hill,' where the rover investigated martian rocks. On the right side of the panorama is a tilted layer of rocks dubbed 'Larry's Outcrop,' one of several tilted outcrops that scientists examined in April, 2005. They used spatial information to create geologic maps showing the compass orientation and degree of tilting of rock formations in the vicinity. Such information is key to geologic fieldwork because it helps establish if rock layers have been warped since they formed. In this case, scientists have also been studying the mineral and chemical differences, which show that some rocks have been more highly altered than others. In the foreground, in the middle of the image mosaic, Spirit is shown with the scientific instruments at the end of its robotic arm positioned on a rock target known as 'Ahab.' The rover was busy collecting elemental chemistry and mineralogy data on the rock at the same time that it was taking 50 individual snapshots with its five panoramic camera filters to create this stunning view of the martian scenery. The twin tracks of the rover's all-terrain wheels are clearly visible on the left. This mosaic of images spans about 220 degrees from left to right and is an approximate true-color rendering of the Mars terrain acquired through the panoramic camera's 750-, 530-, and 430-nanometer filters. Spirit collected these images from its 497th martian day, or sol, through its 500th sol (May 27 through May 30, 2005).

  9. Bisphenol A: a scientific evaluation.

    Kamrin, Michael A

    2004-01-01

    Bisphenol A (BPA) is used in the production of high-volume polycarbonate and epoxy resin compounds found in a number of consumer products, including plastic bottles and the linings of canned goods. As a result of such applications, very small amounts of BPA can migrate into food and drink. In light of reports suggesting that low doses of BPA cause estrogenic effects in laboratory animals, concerns were raised about the safety of these consumer products, particularly plastic bottles used for feeding milk to babies. To evaluate the risk, if any, from BPA, investigations were undertaken to more precisely determine human exposure levels and more carefully study the validity of the low-dose effects reported. On the basis of the most realistic studies of BPA levels in food and drink, as well as in human urine, it has been estimated that human exposures, including those of children, are very low and range from about .001 to .1 mcg/kg body weight (bw)/day. The results of the additional toxicology studies indicated that the low-dose effects could not be consistently replicated. In light of this, a number of governments and agencies brought together independent expert panels to carefully evaluate the toxicologic studies and provide regulatory guidance. These panels came to a similar conclusion, namely, that low-dose effects have not been demonstrated. They also supported the acceptable daily intake levels previously calculated on the basis of high-dose effects shown in laboratory animals. Comparing these acceptable intakes with the best exposure estimates reveals that human doses of BPA from migration of the compound into food and drink are orders of magnitude lower than acceptable daily intakes. Thus, it is very unlikely that humans, including infants and young children, are at risk from the presence of BPA in consumer products. PMID:15520629

  10. A92

    M. Mukhacheva

    2015-11-01

    Full Text Available This work is devoted to the actual problem of studying modern ideas about the systemic treatment of brain tumors, in particular on the implementation and effectiveness of modern methods of immunomodulation in neuro-oncology. The aim is to clarify the existence of patients with brain tumors immunosuppression, resulting in testimony to the development and application of methods of immunotherapy. Method of research consistent with the goal and objectives of the study, which included a dynamic examination of 32 operated patients with hemispheric brain gliomas. Cycloferon interferonogens from the group, which has antiviral and antitumor action potential was used as an immunomodulator us. It is of interest to determine the effectiveness of immunomodulatory action of cycloferon in patients with brain tumors in different phases of development of cancer. This work represents a scientific novelty and practical significance for solving urgent problems of neurology and neurosurgery – the study of the cycloferon drug, has proved its effectiveness in the reinforcement of clinical remission and increased the life expectancy of patients with brain tumors after surgery.

  11. A new

    P. Upadhyay

    2016-07-01

    Full Text Available In this paper a population based evolutionary optimization methodology called firefly algorithm (FFA is applied for the optimization of system coefficients of the infinite impulse response (IIR system identification problem. FFA is inspired by the flash pattern and characteristics of fireflies. In FFA technique, behaviour of flashing firefly towards its competent mate is structured. In this algorithm attractiveness depends on brightness of light and a bright firefly feels more attraction for the brighter one. For this optimization problem, brightness varies inversely proportional to the error fitness value, so the position of the brightest firefly gives the optimum result corresponding to the least error fitness in multidimensional search space. Incorporation of different control parameters in basic movement equation results in balancing of exploration and exploitation of search space. The proposed FFA based system identification approach has alleviated from inherent drawbacks of premature convergence and stagnation, unlike genetic algorithm (GA, particle swarm optimization (PSO and differential evolution (DE. The simulation results obtained for some well known benchmark examples justify the efficacy of the proposed system identification approach using FFA over GA, PSO and DE in terms of convergence speed, identifying plant coefficients and mean square error (MSE fitness values produced for both same order and reduced order models of adaptive IIR filters.

  12. A Whale of A Controversy

    2008-01-01

    Despite heavy international criticism,the Japanese refuse to end their national tradition of whale hunting When the Japanese whale-hunting fleet set sail for the Antarctic waters on November 18,the crew members must have known that their voyage would not be smooth sailing. Japan’s annual whaling program rou- tinely sets off a firestorm of protest from anti-whaling countries and organizations. In January 2006,Greenpeace’s icebreaker Arctic Sunrise collided with the Jaoanese

  13. A Response

    W. Warren Wagar

    2015-08-01

    Full Text Available Let me begin by thanking everyone who commented on my ASA paper, "Toward a Praxis of World Integration," both those who were generally sympathetic to its thesis and those who were not. It is inconceivable to me that any two freethinking human beings living in our time could share the same preferred model of the good society. So of course I am not surprised that no one found every aspect of my vision appealing or that some found almost nothing to applaud. I would probably react to each of your utopias in muchthe same ways. Nonetheless, our species needs, perhaps more than anything else, to think together about where we want to go, and how, and why. Without tclos, how can we speak of praxis? And without praxis, what use is analysis? The point is to change the world and change it for the better.

  14. A whale of a problem

    Showstack, Randy

    While the Makah Indian tribe recently killed a gray whale off the coast of the U.S. state of Washington, and Japan and Norway have threatened to bolt from the International Whaling Commission (IWC) over disagreements about commercial catches, on May 26, the U.S. commissioner to the IWC told delegates about another, and far more widespread, threat affecting cetaceans.Global environmental changes could jeopardize whale stocks throughout the world, said Commissioner James Baker, who also serves as administrator for the National Oceanic and Atmospheric Administration.

  15. A Mosque in a Mosque

    Cantone, Cleo

    2006-01-01

    Une mosquée dans une mosquée. Quelques observations sur la mosquée de la rue Blanchot à Dakar et ses relations avec les autres mosquées pendant la période coloniale. — L’impact du colonialisme sur l’architecture sénégalaise a produit un nouveau type de mosquée. Construite à partir de matériaux durables et alliant l’architecture des églises à des éléments nord-africains, ce style semble avoir été utilisé pour perpétuer la notion de supériorité de l’islam « blanc », ou arabe, sur l’islam « noir...

  16. A Volumetric Flask as a Projector

    Limsuwan, P.; Asanithi, P.; Thongpool, V.; Piriyawong, V.; Limsuwan, S.

    2012-01-01

    A lens based on liquid in the confined volume of a volumetric flask was presented as a potential projector to observe microscopic floating organisms or materials. In this experiment, a mosquito larva from a natural pond was selected as a demonstration sample. By shining a light beam from a laser pointer of any visible wavelength through the…

  17. Being a Parent with a Learning Disability: A Qualitative Study

    Shewan, Laura

    2011-01-01

    This research portfolio aims to further explore the issues faced by parents with a learning disability. Firstly, a systematic review of qualitative research into the social support of parents with a learning disability is presented. This not only indicated that a range of social support is provided to parents with a learning disability and received with different perceptions, but also highlighted the need for further qualitative research in the area, to gain a better insight...

  18. Choosing a Breast Prosthesis: A Survivor's Perspective

    ... Survivor’s Perspective Print to PDF Choosing a Breast Prosthesis: A Survivor’s Perspective Andrea Zinn June 16, 2015 · ... did you decide to wear a breast form/prosthesis rather than have a reconstruction? Andrea: After weighing ...

  19. Internship: A Transition From A Medical Student To A Doctor

    2012-01-01

    The internship, a transition from a medical student to a doctor, is a period of one year after passing the final year exam of MBBS, where an intern works in various departments in a hospital. Doing so exposes them to the practical aspects of things they have studied during the four and a half year MBBS course. As a part of the physician’s team taking care of the patients s/he absorbs the skills to approach and management of the patients under direct supervision of their seniors. This also hel...

  20. A Russia e a segurança europeia

    Gaspar, Carlos

    2005-01-01

    As relações entre a Rússia e a Europa, chave da segurança regional, mudaram profundamente com o fim da guerra fria. Desde 1991, o período de transição na reestruturação dos equilíbrios regionais, foi marcado por crises sucessivas - a crise latente entre a Rússia e a Ucrânia, a decomposição da antiga Jugoslávia e as divergências sobre a expansão da Aliança Atlântica - que criaram oportunidades de cooperação entre a Rússia e as potências ocidentais, e contribuiram para moldar ...

  1. Repurposing with a purpose: A story with a happy ending

    Greaves, Lyn; Roller, Sibel; Bradley, Claire

    2010-01-01

    Abstract: The work reported here forms part of a UK Joint Information Systems Committee (JISC) funded project (BL4ACE) (http://bl4ace.tvu.ac.uk/). This project built on previous work that evaluated the effectiveness of a learning design to underpin academic competence in a Business Studies degree. A significant concern of the blended learning design was to scaffold independent learning activities by incorporating and reusing interactive Reusable Learning Objects (RLOs) within a Virtual Learni...

  2. A Pilocytic Astrocytoma Mimicking a Clinoidal Meningioma

    Hong, Christopher S.; Lehman, Norman L.; Eric Sauvageau

    2014-01-01

    Pilocytic astrocytomas and meningiomas are benign, primary brain tumors that may involve the optic tract. Classically, the presence of a dural “tail” sign may differentiate a meningioma from other intracranial lesions. In this report, we describe a mass with the typical appearance of a clinoidal meningioma on magnetic resonance imaging (MRI) but postoperatively diagnosed as a pilocytic astrocytoma. This case illustrates the rare occurrence of a pilocytic astrocytoma mimicking a meningioma on ...

  3. A batuta da morte a orquestrar a vida

    Altair Macedo Lahud Loureiro

    2008-12-01

    Full Text Available Com colocações de outros estudiosos da morte, teço e apresento apontamentos rápidos sobre a morte a organizar a vida. Esposo a idéia da necessidade da morte para que a vida tenha sentido nesta busca humana da completude. Endereço o olhar para uma situação especial de relação com a morte: a reação dos que ficam ao presenciar e sentir a morte de um dos seus idosos; daquele familiar, ou não, que assume o seu cuidado e acompanha o seu fim iminente; que presencia, humanamente impotente, a hora da solitária partida. Solitária morte, pois que exclusiva, própria daquele idoso do qual cuidava, do seu fim natural, por ser humano.

  4. A House For A River Rat

    Matthews, David Stansfield

    2014-01-01

    This is a house situated by a river. It is a retreat, or a cabin, and is not occupied on a full time basis. Its form is an interpretation of a cube, and retains its general appearance. It is lifted off the ground to prevent damage when the river floods, and has a deep foundation to achieve stability on the loose floodplain soil. It has three levels, the first containing the main living areas, the second, a lofted space containing the bed and bath, and the third, a roof terrace. It is for two ...

  5. Helping a Child Manage a Chronic Illness

    ... https://medlineplus.gov/news/fullstory_160011.html Helping a Child Manage a Chronic Illness Feeling they have control over their ... News) -- Children and teens who feel confident handling a chronic illness on their own appear better able ...

  6. A diagrammatic categorification of a Clifford algebra

    Tian, Yin

    2013-01-01

    We give a graphical calculus for a categorification of a Clifford algebra and its Fock space representation via differential graded categories. The categorical action is motivated by the gluing action between the contact categories of infinite strips.

  7. Having a Whale of a Time

    du Feu, Chris

    2009-01-01

    A classroom practical exercise exploring the reliability of a basic capture-mark-recapture method of population estimation is described using great whale conservation as a starting point. Various teaching resources are made available.

  8. Aplyzanzine A, a new dibromotyrosine derivative from a Verongida sponge.

    Evan, T; Rudi, A; Ilan, M; Kashman, Y

    2001-02-01

    Aplyzanzine A (1), a novel bisdibromotyrosine derivative, has been isolated from the Indo-Pacific sponge Aplysina sp. Its structure was elucidated mainly on the basis of 1D and 2D NMR and MS spectroscopic data. PMID:11430007

  9. Vitamin A: a missing link in diabetes?

    Trasino, Steven E.; Gudas, Lorraine J.

    2015-01-01

    Vitamin A has a critical role in embryonic development, immunity and the visual cycle. In recent years, evidence has demonstrated that vitamin A can also regulate metabolic pathways implicated in the pathogenesis of obesity and diabetes. This has increased interest in the possible antiobesity and antidiabetic properties of natural and synthetic vitamin A derivatives. However, whether vitamin A deficiency or aberrations in vitamin A metabolism contribute to the pathogenesis of diabetes is not ...

  10. Bacterial Sortase A as a drug target

    Larsson, Caroline

    2012-01-01

    Sortase A is a housekeeping enzyme of Gram-positive bacteria that catalyses the anchoring of surface proteins to the bacterial peptidoglycan. The enzyme works to establish an interaction between bacteria and host cells and is essential for pathogenesis. This makes Sortase A a potential suitable target for inhibition, in order to treat bacterial infections. In this degree project Sortase A from Staphylococcus aureus was explored and potential inhibitors were investigated by performing enzyme a...

  11. A stump appendicitis in a child: a case report

    Jemaï Radhia; Sahli Sondes; Fitouri Fatma; Gasmi Manef; Hamzaoui Mourad

    2009-01-01

    Abstract Background Stump appendicitis is a delayed complication of appendectomy. It is rare and few cases reported in the paediatric literature. The authors report on another case in a child and focus on the diagnostic peculiarities of this entity. Case A 9-year-old boy with previous history of open appendectomy was admitted for a right lower quadrant pain with bilious vomiting and fever. Physical examination demonstrated tenderness in the right lower quadrant and guarding over the appendect...

  12. A missed orthopaedic injury following a seizure: a case report

    O'Connor-Read Laurence

    2007-05-01

    Full Text Available Abstract Numerous orthopaedic injuries can follow a seizure and are often diagnosed late. This is the first documented case of a missed bilateral anterior shoulder dislocation following a seizure. The possible reasons for the greater incidence of posterior dislocations are examined and why bilateral anterior dislocations following a seizure are so rare. The article discusses the reasons for the delay and highlights potential pitfalls and learning points for junior emergency department doctors.

  13. A recursive algorithm to compute a basis of a similarity

    Garmendia Salvador, Luis; Recasens, Jordi; Salvador Alcaide, Adela

    2012-01-01

    Se definen conceptos y se aplica el teorema de Valverde para escribir un algoritmo que computa bases de similaridades. This paper studies sorne theory and methods to build a representation theorem basis of a similarity from the basis of its subsimilarities, providing an alternative recursive method to compute the basis of a similarity.

  14. A State-Run Enterprise: A Bane or a Boon?

    Sungjune KIM

    2015-09-01

    Full Text Available In the less than 70 years since Korean liberation, Korea has grown to be one of the world's top five ship-owning countries in 2014. This can be attributed to a few factors such as government policy, Korea Shipping Corporation (KSC, hereafter and merchant marine officers. This paper will expound the true motivations of the establishment and the privatization of KSC in 1950 and in 1968, respectively. KSC, as Korea's national shipping company, sailed along a very unusual course of development. It was established in 1950 not to foster and develop Korea's shipping industry but to help alleviate the financial burdens of the fledgling Korean government. The main cause of privatizing KSC in 1968 was a purely political decision, not an economic one as it overlapped with the rapid growth period of the shipping industry in the world, as well as in Korea. In sum, KSC, a state-run enterprise, was a bane in the short run but a boon in the long run for both the Korean government and Korea's shipping industry. If we can believe KSC followed the ordinary sailing route as a state-run enterprise, we might develop a new opinion that the national shipping company might be a financial burden in a short period, but various benefits over a long period.

  15. A CLUSTER PAIR: A3532 AND A3530

    Lakhchaura, Kiran; Singh, K. P. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005 (India); Saikia, D. J. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune University Campus, Pune 411 007 (India); Hunstead, R. W., E-mail: kiran_astro@tifr.res.in [Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)

    2013-04-10

    We present a detailed study of a close pair of clusters of galaxies, A3532 and A3530, and their environments. The Chandra X-ray image of A3532 reveals the presence of substructures on scales of {approx}20'' in its core. XMM-Newton maps of the clusters show excess X-ray emission from an overlapping region between them. Spectrally determined projected temperature and entropy maps do not show any signs of cluster scale mergers either in the overlapping region or in any of the clusters. In A3532, however, some signs of the presence of galaxy scale mergers are visible, e.g., anisotropic temperature variations in the projected thermodynamic maps, a wide-angle-tailed (WAT) radio source in the brighter nucleus of its dumbbell brightest cluster galaxy, and a candidate X-ray cavity coincident with the northwestern extension of the WAT source in the low-frequency radio observations. The northwestern extension in A3532 seems either a part of the WAT or an unrelated diffuse source in A3532 or in the background. There is an indication that the cool core in A3532 has been disrupted by the central activity of the galactic nucleus. A reanalysis of the redshift data reinforces the close proximity of the clusters. The excess emission in the overlapping region appears to be a result of tidal interactions as the two clusters approach each other for the first time. However, we cannot rule out the possibility of the excess being due to the chance superposition of their X-ray halos.

  16. Life of a Tooth: A Visual Timeline

    Full Text Available ... Disorder What is Baby Bottle Tooth Decay? Men: Looking for a Better Job? Start by Visiting the Dentist When Should My Child First See a Dentist? Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | ...

  17. [A woman with a locked knee].

    Boersma, A R; van Raay, J J A M

    2015-01-01

    A 25-year-old female presented with locking of the left knee after an assertiveness training. The MRI scan showed a bucket-handle tear of the medial meniscus. The medial meniscus was dislocated into the intercondylar fossa, in which the image of a second posterior cruciate ligament (PCL) was simulated. This is also called a 'double PCL sign'. PMID:26959734

  18. Geogas - a tracer or a carrier?

    This report is a review of the literature about geogas and the migration of radioactive materials from a repository. The results indicate that nitrogen gas may cause a migration of plutonium colloids and other small particles. (64 refs.) (K.A.E.)

  19. A1-algebraic topology over a field

    Morel, Fabien

    2012-01-01

    This text deals with A1-homotopy theory over a base field, i.e., with the natural homotopy theory associated to the category of smooth varieties over a field in which the affine line is imposed to be contractible. It is a natural sequel to the foundational paper on A1-homotopy theory written together with V. Voevodsky. Inspired by classical results in algebraic topology, we present new techniques, new results and applications related to the properties and computations of A1-homotopy sheaves, A1-homotogy sheaves, and sheaves with generalized transfers, as well as to algebraic vector bundles over affine smooth varieties.

  20. Niemann Pick type A, a case report

    M. Qasemi; F. Mojtahedzadeh

    2006-01-01

    Niemann Pick type A is a very rare hereditary disease with an incidence 1 in 20000-40000 live birth, which is calassified as a shingolipidoses.The disease is marked by the abnormal accumulation of sphingomyelin in most tissues, secondary to sphingomylinase deficiency.The most clinical manifestations are:Splenohepatomegaly–cherry red maculae-neuropathologic findings .This is a case report of an infant with clinical manifestation of Niemann Pick disease type A.

  1. Bisphenol A polycarbonate as a reference material

    Hilado, C. J.; Cumming, H. J.; Williams, J. B.

    1977-01-01

    Test methods require reference materials to standardize and maintain quality control. Various materials have been evaluated as possible reference materials, including a sample of bisphenol A polycarbonate without additives. Screening tests for relative toxicity under various experimental conditions were performed using male mice exposed to pyrolysis effluents over a 200-800 C temperature range. It was found that the bisphenol A polycarbonate served as a suitable reference material as it is available in large quantities, and does not significantly change with time.

  2. [A fetus is a person with a right to exist].

    Bischofberger, E

    1989-12-27

    This article is the contribution of a Jesuit priest, a teacher of medical ethics at Uppsala, to a debate inspired by a Swedish official report "The pregnant woman and fetus--2 individuals. On fetal diagnostics. On late abortions." In a society which depends upon a structured consensus as much as Sweden does, the report has been criticized for not making clearer recommendations. The author points out that the ethical dilemmas involved are so complex that they cannot be treated from a simple either/or point of view. Fetal diagnostics, for example, serve the cause of life when the aim is to avoid abortion of a healthy fetus and make it possible to cure, even at the fetal stage, or to strengthen prospective parents' readiness to accept a handicapped child. The use of fetal diagnostic for sorting out damaged and sick fetuses, however, is selective abortion and implies a violation of the principle that all human life is of equal value. The question is no longer if one will have a child or not, but which child will one have. This collision of values has inspired so many polemic statements that it is worthwhile recalling that there is always a tension between the ethically desirable and the politically possible, The report has succeeded in formulating the ethical principles in spite of the impossibility of seeing them presented as concrete recommendations. Even so, Thomas Aquinas wrote in 13th century that one cannot always apply ethical rules to laws of society. That can lead to more evil than good. PMID:2607863

  3. A Project Team: a Team or Just a Group?

    Kateřina; Daniela,, Ghirardello; Martina (Author)

    2014-01-01

    This paper deals with issues related to work in either teams or groups. The theoretical part discusses a team and a group with regards to its definition, classification and basic distinction, brings in more on the typology of team roles, personality assessment and sociometric methods. The analytical part tests the project (work) team of a medical center represented in terms of personality and motivational types, team roles and interpersonal team relations concerning the willingness of coopera...

  4. A Project Team: A Team or Just a Group?

    Katerina Hrazdilova Bockova; Daniela Maťovcikova

    2013-01-01

    This paper deals with issues related to work in either teams or groups. The theoretical part which discusses a team and a group with regards to its definition, classification and basic distinction brings in more on the typology of team roles, personality assessment and sociometric methods. The analytical part tests the project (work) team of a medical center represented in terms of personality and motivational types, team roles and interpersonal team relations concerning t...

  5. A search for a new gauge boson A'

    Jensen, Eric L. [William and Mary College

    2013-08-01

    In the Standard Model, gauge bosons mediate the strong, weak, and electromagnetic forces. New forces could have escaped detection only if their mediators are either heavier than order(TeV) or weakly coupled to charged matter. New vector bosons with small coupling {alpha}' arise naturally from a small kinetic mixing with the photon and have received considerable attention as an explanation of various dark matter related anomalies. Such particles can be produced in electron-nucleus fixed-target scattering and then decay to e{sup +}e{sup -} pairs. New light vector bosons and their associated forces are a common feature of Standard Model extensions, but existing constraints are remarkably sparse. The APEX experiment will search for a new vector boson A' with coupling {alpha}'/{alpha}{sub fs} > 6 × 10{sup -8} to electrons in the mass range 65MeV < mass A' < 550MeV. The experiment will study e{sup +}e{sup -} production off an electron beam incident on a high-Z target in Hall A at Jefferson Lab. The e{sup -} and e{sup +} will be detected in the High Resolution Spectrometers (HRSs). The invariant mass spectrum of the e{sup +}e{sup -} pairs will be scanned for a narrow resonance corresponding to the mass of the A'. A test run for the APEX experiment was held in the summer of 2010. Using the test run data, an A' search was performed in the mass range 175-250 MeV. The search found no evidence for an A' --> e{sup +}e{sup -} reaction, and set an upper limit of {alpha}'/{alpha}{sub fs} ~ 10{sup -6}.

  6. RelA: a tale of a stitch in time.

    Korc, Murray

    2016-08-01

    Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer in which NF-κB pathways promote biological aggressiveness. In this issue of the JCI, Lesina et al. investigated the role of RelA, the p65 partner of p50 that together form the most common NF-κB complex, in the early stages of pancreatic malignant transformation and in established PDAC. By deleting Rela in the context of an oncogenic Kras-driven autochthonous model of PDAC, the authors demonstrated that RelA is a mediator of oncogene-induced senescence (OIS) and the senescence-associated secretory phenotype (SASP) that attenuates acinar-to-ductal metaplasia, pancreatic intraepithelial neoplasia (PanIN) formation, and PanIN progression to PDAC. Loss of the tumor-suppressor function of RelA in the early stages of Kras-driven pancreatic neoplastic transformation was associated with decreased OIS and SASP and a protumorigenic tumor microenvironment that harbored more M2 macrophages and myeloid-derived suppressor cells. The beneficial effects of RelA were mediated by increased expression of CXCL1 and its activation of CXCR2. By contrast, in advanced stages of Kras-driven murine PDAC, loss of p53 or p16 was associated with senescence bypass, and RelA deficiency in this context attenuated cancer cell proliferation and prolonged mouse survival, indicating that RelA enhances tumor progression in established PDAC. PMID:27454293

  7. A Proposal for a Mindset of a Project Manager

    Eriksson, Joakim; Hansen, Claus Thorp

    2008-01-01

    A company’s product strategy and its management of the product development process have been found to be key factors for a product’s success on the market [1]. Project managers of development projects need support to make process decisions and defining goals that are consistent with the business’s goals while bearing in mind the ability of the development team to deliver a product to the market that satisfies the customer’s expectations and needs [2]. Uncertainty is a part of the product deve...

  8. A metaphysical journey in a comatose state.

    Gimenez, R

    1992-01-01

    This paper is about the intense experience of being in the hospital in a comatose state resulting from an aneurysm with a massive brain hemorrhage and two subsequent surgeries. The event begins with a premonition of what will happen from a street name. The experience of brain surgeries, along with the fine care of the nurses, left me with a truly memorable impression. This paper describes the various feelings and strong emotions that I experienced while in a comatose state. It suggests that a patient in a comatose state can exist in a deep state of emotions close to ecstasy. The paper concludes with gratefulness to all the people who followed me step by step on this journey. PMID:1286457

  9. A toy model for a diatomic molecule

    Hecker Denschlag, Johannes

    2016-08-01

    We introduce a toy model for a diatomic molecule which is based on coupling electronic and nuclear spins to a rigid rotor. Despite its simplicity, the model can be used scientifically to analyze and understand complex molecular hyperfine spectra. In addition, the model has educational value as a number of fundamental symmetries and conservation laws of the molecule can be studied. Because of its simple structure, the model can be readily implemented as a computer program with comparatively short computing times on the order of a few seconds.

  10. When a Family Requests a White Doctor.

    Reynolds, Kimberly L; Cowden, John D; Brosco, Jeffrey P; Lantos, John D

    2015-08-01

    Parents sometimes request that a doctor of a particular race or ethnic group not care for their child. Such requests sometimes seem legitimate and other times seem offensive. The difference reflects a clash of fundamental values. Generally, we try to respect patient or parental preferences. Requests based on racist attitudes, however, do not seem worthy of respect. But where should we draw the line? In this ethics rounds, we present a situation in which parents requested a white doctor and analyze the ways in which doctors might think about and respond to such a request. PMID:26169433

  11. The a-MEU Model: A Comment

    Jurgen Eichberger; Simon Grant; David Kelsey; Koshevoy, Gleb A.

    2009-01-01

    In [7] Ghirardato, Macheroni and Marinacci (GMM) propose a method for distinguishing between perceived ambiguity and the decision-maker's reaction to it. They study a general class of preferences which they refer to as invariant biseparable. This class includes CEU and MEU. They axiomatize a subclass of a-MEU preferences. If attention is restricted to finite state spaces, we show that any a-MEU preference relation, satisfies GMM's axioms if and only if a = 0 or 1, that is, the preferences mus...

  12. Building a Database for a Quantitative Model

    Kahn, C. Joseph; Kleinhammer, Roger

    2014-01-01

    A database can greatly benefit a quantitative analysis. The defining characteristic of a quantitative risk, or reliability, model is the use of failure estimate data. Models can easily contain a thousand Basic Events, relying on hundreds of individual data sources. Obviously, entering so much data by hand will eventually lead to errors. Not so obviously entering data this way does not aid linking the Basic Events to the data sources. The best way to organize large amounts of data on a computer is with a database. But a model does not require a large, enterprise-level database with dedicated developers and administrators. A database built in Excel can be quite sufficient. A simple spreadsheet database can link every Basic Event to the individual data source selected for them. This database can also contain the manipulations appropriate for how the data is used in the model. These manipulations include stressing factors based on use and maintenance cycles, dormancy, unique failure modes, the modeling of multiple items as a single "Super component" Basic Event, and Bayesian Updating based on flight and testing experience. A simple, unique metadata field in both the model and database provides a link from any Basic Event in the model to its data source and all relevant calculations. The credibility for the entire model often rests on the credibility and traceability of the data.

  13. A Project Team: a Team or Just a Group?

    Kateřina

    2014-06-01

    Full Text Available This paper deals with issues related to work in either teams or groups. The theoretical part discusses a team and a group with regards to its definition, classification and basic distinction, brings in more on the typology of team roles, personality assessment and sociometric methods. The analytical part tests the project (work team of a medical center represented in terms of personality and motivational types, team roles and interpersonal team relations concerning the willingness of cooperation and communication. The main objective of this work is to verify the validity of the assumptions that the analyzed team represents a very disparate group as for its composition from the perspective of personality types, types of motivation, team roles and interpersonal relations in terms of the willingness of cooperation and communication. A separate output shall focus on sociometric investigation of those team members where willingness to work together and communicate is based on the authors’ assumption of tight interdependence.

  14. A simple model of a swing

    Mayer, V. V.; Varaksina, E. I.

    2016-07-01

    The paper presents a simple model of a swing meant for undergraduates’ educational experiments. The purpose of these experiments is the experimental study of physical principles of self-oscillations, free, forced and parametric oscillations. The model contains a pendulum. A coil with a movable steel core serves as its load. A neodymium magnet is placed at the lower end of the core. A magnetically operated sealed switch is stationed under the magnet at the equilibrium position of the pendulum. The switch is connected in series with the coil and a battery. If we displace the pendulum from the equilibrium position, the pendulum makes undamped oscillations. The system receives energy every time the core is drawn into the coil at the lower position of the pendulum.

  15. A porous metal cathode (a thermoemission converter)

    Kozlov, V.I.; Avdeyev, V.Ye.

    1983-01-01

    The porous metallic cathode, which contains a body and the basic sponge attached to it with an active substance, made in the form of a base with an emitting projection, is distinguished by the fact that in order to increase the service life of the cathode, the based sponges on the side opposite the projection have a groove in which the replenishing chamber made of a difficulty fusible metal and filled with a mixture of tungsten and an active substance with a porosity of 35 to 80 percent which is open towards the projection is positioned, where the transverse cross section of the replenishing chamber intersects the transverse cross section of the projection, while the porosity of the basic sponge is 24 to 26 percent. The cathode is distinguished by the fact that a screen made of a difficultly fusible metal is installed on the facial surface with an opening for the projection and is connected with the body and with this surface.

  16. A Cultural Sexuality or a Sexual Culture?

    Vandermeersch, Patrick

    1990-01-01

    P. Vandermeersch, A Cultural Sexuality or a Sexual Culture? In: F. VAN DE VIJVER & G. HUTSCHEMAEKERS (ed.), The Investigation of Culture. Current Issues in Cultural Psychology, Tilburg, Tilburg University Press, 1990, 43-58.

  17. Broadcasting a message in a parallel computer

    Berg, Jeremy E.; Faraj, Ahmad A.

    2011-08-02

    Methods, systems, and products are disclosed for broadcasting a message in a parallel computer. The parallel computer includes a plurality of compute nodes connected together using a data communications network. The data communications network optimized for point to point data communications and is characterized by at least two dimensions. The compute nodes are organized into at least one operational group of compute nodes for collective parallel operations of the parallel computer. One compute node of the operational group assigned to be a logical root. Broadcasting a message in a parallel computer includes: establishing a Hamiltonian path along all of the compute nodes in at least one plane of the data communications network and in the operational group; and broadcasting, by the logical root to the remaining compute nodes, the logical root's message along the established Hamiltonian path.

  18. [A simulation exercise in a flu clinic].

    Barthe, Juliette; Aubert, Jean-Pierre; Lecapitaine, Anne-Lise; Lecompte, Françoise; Szwebel-Chikli, Céline

    2011-01-01

    A simulation exercise aimed at assessing the management and provision of ambulatory care in the context of a highly pathogenic influenza pandemic was conducted in a specifically dedicated consultation center (Centre de Consultation Dédié (CCD) à la grippe) based on official French guidelines. The exercise was carried out in a school in Paris equipped to simulate a "flu clinic". 3 practitioners provided treatment lasting 2 hours to nursing students acting as patients. The exercise highlighted a number of major organizational issues. Staff were found to be unable to manage the center and to perform patient transfers; face masks were not routinely and consistently worn by doctors and patients; and communication between professionals within the clinic was limited. The exercise showed that much remains to be done to ensure that "flu clinics" are effective and functional. The results suggest that the exercise will need to be repeated on a larger scale and over a longer period. PMID:22365047

  19. Morphing a Plasmonic Nanodisk into a Nanotriangle

    Schmidt, Franz P.; Ditlbacher, Harald; Hofer, Ferdinand; Krenn, Joachim R; Hohenester, Ulrich

    2014-01-01

    We morph a silver nanodisk into a nanotriangle by producing a series of nanoparticles with electron beam lithography. Using electron energy loss spectroscopy (EELS), we map out the plasmonic eigenmodes and trace the evolution of edge and film modes during morphing. Our results suggest that disk modes, characterized by angular order, can serve as a suitable basis for other nanoparticle geometries and are subject to resonance energy shifts and splittings, as well as to hybridization upon morphi...

  20. Persistence of a pinch in a pipe

    Mahadevan, L.; Vaziri, A.; Das, Moumita

    2006-01-01

    The response of low-dimensional solid objects combines geometry and physics in unusual ways, exemplified in structures of great utility such as a thin-walled tube that is ubiquitous in nature and technology. Here we provide a particularly surprising consequence of this confluence of geometry and physics in tubular structures: the anomalously large persistence of a localized pinch in an elastic pipe whose effect decays very slowly as an oscillatory exponential with a persistence length that di...

  1. A new hospital library: a marketing opportunity.

    Walker, M E

    1995-01-01

    A new or remodeled library presents a unique marketing opportunity for the hospital librarian. Furthermore, a well-designed library markets itself through its convenience, attractiveness, and ease of use. A marketing approach to library planning takes into account needs of users and of library staff and considers the librarian's relations with the architect as well as with hospital employees. This paper describes ways to combine library planning with marketing techniques and specifies aspects...

  2. Ankylosing Spondylitis: a Reflection and a Question

    Annia Deysi Hernández Martín

    2014-07-01

    Full Text Available Ankylosing spondylitis is a chronic inflammatory disease that affects the synovial membrane, joint entheses and para-articular structures of the spine, including the sacroiliac joints and limbs. We present a case of ankylosing spondylitis that had evolved for 12 years despite the relatively early diagnosis and treatment, showing flexion deformity and limitation of spinal movements. On radiological examination an early evolution to ankylosis was observed, which motivated us to make a reflection and a question.

  3. A masonic poem on a masonic opera?

    Sanz Sainz, Inmaculada

    1998-01-01

    Estudio del poema Logic and "The Magic Flute", escrito por Marianne Moore (Kirkwood, Missouri. 1887-New York. 1972) y publicado en su libro de poemas Like a Bulwark (1956). Se analiza el poema tomando como punto de partida el libreto de la ópera de W.A. Mozart Die Zauberflotë, y se ofrece una interpretación del mismo a la luz de la simbología que aparece en este.

  4. A little knowledge is a dangerous thing

    Robbins RA

    2012-01-01

    No abstract available. Article truncated at 150 words. An article entitled “A Comprehensive Care Management Program to Prevent Chronic Obstructive Pulmonary Disease Hospitalizations: A Randomized, Controlled Trial” from the VA cooperative studies program was recently published in the Annals of Internal Medicine (1). This article describes the BREATH trial mentioned in a previous editorial (2). BREATH was a randomized, controlled, multi-center trial performed at 20 VA medical centers comparin...

  5. A microcomputer for a packet switched network

    The Bubble Chamber Research Group of the Rutherford and Appleton Laboratory has a large film analysis facility. This comprises 16 digitising tables used for the measurement of bubble chamber film. Each of these tables has an associated microcomputer. These microcomputers are linked by a star structured packet switched local area network (LAN) to a VAX 11/780. The LAN, and in particular a microcomputer of novel architecture designed to act as the central switch of the network, is described. (author)

  6. Radioactivity: a history of a mysterious science

    In this work is summarized in french the book 'Radioactivity: a history of a mysterious science' written by Marjorie C. Malley. The fascinating history of radioactivity is at first presented in a way that is both accessible and appealing to the general reader. Not merely a historical account, the book examines philosophical issues connected with radioactivity, and relates its topics to broader issues regarding the nature of science. (O.M.)

  7. Raising a Fit Preschooler

    ... skills and coordination to ride a tricycle or chase a butterfly. Preschoolers also are discovering what it ... something to find, like a red door, a cat, a flag, and something square. Sing songs or ...

  8. Life of a Tooth: A Visual Timeline

    Full Text Available ... Decay? Check Menstrual Calendar for Tooth Extraction The History of Dental Advances Men: Looking for a Better Job? Start by Visiting the Dentist Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a ...

  9. A modified total synthesis of cystothiazole A

    2009-01-01

    A modified total synthesis of cystothiazole A is described. In this synthetic strategy, a one-step transformation of acylated oxazolidinone to β-ketoester has been successfully applied, thus making the synthetic route more efficient. This method may also be potentially applied in synthesis of other related β-substituted-β-methoxyl acrylates (bb-MOAs).

  10. Once a Nightmare, Always a Nightmare?

    Picchioni, Dante; DeBrule, Daniel S.

    2005-01-01

    While counterintuitive, there is evidence that some nightmares may serve a beneficial function. The theory behind this idea is presented within the context of a continuity hypothesis of dreaming where the negative emotions presented in a nightmare can lead to psychosocial development, just as some negative experiences do so during wake. The…

  11. A Bayesian Bootstrap for a Finite Population

    Lo, Albert Y.

    1988-01-01

    A Bayesian bootstrap for a finite population is introduced; its small-sample distributional properties are discussed and compared with those of the frequentist bootstrap for a finite population. It is also shown that the two are first-order asymptotically equivalent.

  12. Life of a Tooth: A Visual Timeline

    Full Text Available ... a Composite Resin (White Filling)? Why is Oral Health Important for Men? How Do I Care for My Child's Baby Teeth? What is Orofacial Pain? Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  13. A microfluidic device with a diffusion barrier

    2014-01-01

    The invention provides a microfiuidic device for macromoiecuie amplification by sequential addition of liquid reagents. The device of the invention comprises a chip forming a plurality of reaction chambers each extending between an inlet and an outlet, each inlet being in fluid communication with...

  14. A case of tripody in a pigeon

    In a pigeon of the breed ''Thuringian White Bib'' a stunted third leg was found, which was attached to the left of the ventral cloacal aspect. A disturbance of the embryonic development at the third to fourth day of incubation was thought to be the cause of this anomaly

  15. A review of a pleural service.

    Aujayeb, A; Parker, S; Bourke, S; Miller, J; Cooper, D

    2016-12-01

    This paper reviews the organisation and outcomes of a pleural service, specifically geared towards the management of malignant pleural effusions, in a district general hospital in the north east of England. We summarise the evidence behind local anaesthetic thoracoscopy and indwelling pleural catheters. We then summarise the review of our service, including a discussion around complications. PMID:27092367

  16. Teaching a Course around a Textbook.

    Healey, Mick; Ilbery, Brian

    1993-01-01

    Outlines the advantages and disadvantages of using a single textbook in a college-level economic geography course. Argues that, if a course text is used thoughtfully, the advantages can outweigh the disadvantages. Asserts that students must take greater responsibility for their own learning and develop independent inquiry skills. (CFR)

  17. A minimal model of a tidewater glacier

    Oerlemans, J.; Nick, Faezeh Maghami

    2005-01-01

    We propose a simple, highly parameterized model of a tidewater glacier. The mean ice thickness and the ice thickness at the glacier front are parameterized in terms of glacier length and, when the glacier is calving, water depth. We use a linear relation between calving rate and water depth. The cha

  18. When a regulation becomes a learning process

    Nunez, Heilyn Camacho; Cespedes, Paula

    Adoption and effective use of information and communication technology (ICT) becomes a need for organizations of any size and type, however, ICT adoption is still a challenge for organizations, its implementation must be a strategic decision that involves design, delivery and use of software...... small consulting company from Costa Rica, is using action learning to implement COBIT in the financial sector in Costa Rica....

  19. "Score Choice": A Tempest in a Teapot?

    Hoover, Eric

    2009-01-01

    A new option that allows students to choose which of their test scores to send to colleges has generated renewed criticism of the College Board. College Board officials tout the option, called Score Choice, as a way to ease test taker anxiety. Some prominent admissions officials have publicly described Score Choice as a sales tactic that will…

  20. A Model Technology Educator: Thomas A. Edison

    Pretzer, William S.; Rogers, George E.; Bush, Jeffery

    2007-01-01

    Reflecting back over a century ago to the small village of Menlo Park, New Jersey provides insight into a remarkable visionary and an exceptional role model for today's problem-solving and design-focused technology educator: Thomas A. Edison, inventor, innovator, and model technology educator. Since Edison could not simply apply existing knowledge…

  1. A. F. Ames, Village Schoolmaster. A Memoir.

    Ames, Edward C.

    This booklet sketches the life, educational theories, and accomplishments of Albert F. Ames (1888-1931). Ames was trained as a mathematician, and served six years as a mathematics teacher in Canada before becoming superintendent of schools in Riverside, Illinois. He co-authored five mathematics textbooks with J. A. McLellan. These texts,…

  2. A Method of Operating a Fuel Cell

    2013-01-01

    The present invention relates to a method of determining the net water drag coefficient (rd) in a fuel cell. By measuring the velocity of the fluid stream at the outlet of the anode, rd can be determined. Real time monitoring and adjustments of the water balance of a fuel cell may be therefore...

  3. Sterilization: A Conference and a Report.

    Dillingham, Brint

    1978-01-01

    This article continues a series on Native American sterilization, based on a conference of the National Council of Churches' Interreligious Foundation for Community Organization (IFCO). Also included are an article and a report by the American Civil Liberties Union. (Author/RTS)

  4. Teratogenia da vitamina A Vitamin A teratogenicity

    Maria Helena de Castro Chagas

    2003-09-01

    Full Text Available A vitamina A é essencial à preservação e ao funcionamento normal dos tecidos, assim como, ao crescimento e desenvolvimento. No humano há evidência indireta que a vitamina A em excesso, durante as primeiras semanas de gestação é teratogênica. Do contrário, não há dúvidas sobre os efeitos deletérios, de uma alimentação carente neste micronutriente e sobre a disponibilidade do conhecimento técnico para evitá-los. A preocupação com o fato de que a vitamina A conduziria a teratogenia em humanos, tem retardado a implementação de programas de combate a carência de vitamina A, atingindo principalmente os programas de enriquecimento de alimentos. A literatura é controvertida e dispõe de poucas informações sobre as doses para suplementação de gestantes. Como o retinol circulante materno é controlado homeostaticamente após o consumo de alimentos fonte de vitamina A, espera-se a mesma resposta metabólica após o consumo de alimentos fortificados, indicando que não há risco de teratogenia. Consequentemente, parece altamente improvável que o consumo de alimentos enriquecidos ou de suplementos de vitamina A pré-formada, nas doses unitárias habituais, tenha efeito teratogênico no homem.The vitamin A is essential to the preservation and the normal functioning of tissues, as well as, to the growth and development. In the human being it has indirect evidence that the vitamin A in excess, during the first weeks of gestation is teratogenic. Of the opposite, it does not have doubts on the deleterious effect, of a devoid feeding in this micronutrient and on the availability of the knowledge technician to prevent them. The concern with the fact of that the vitamin A would lead it the teratogenicity in human beings, has delayed the implementation of combat programs the vitamin A lack, mainly reaching the programs of food enrichment. Literature is controverted and makes use of few information on the doses for supplementation of

  5. A reversible conversion between a skyrmion and a domain-wall pair in a junction geometry

    Zhou, Y.; Ezawa, M

    2014-01-01

    A skyrmion is a topological texture in the continuum field theory. Recent experimental observation of skyrmions in chiral magnet evokes a flourish of its extensive study. Skyrmion is expected to be a key component of the next generation spintronics device called skyrmionics. On the other hand, there is a well established memory device encoded by a sequence of domain walls. A skyrmion carries a topological number, whereas a domain wall does not. Nevertheless, we show a conversion is possible b...

  6. A Psychological Factor Affecting a Cardiac Condition in a Psychotherapist

    R Waxman

    2009-03-01

    Full Text Available It has been established that intense emotions can affect the development and course of cardiac arrhythmias. This study sought to convey that a lack of expression of emotion can also have an effect on arrhythmias. A psychotherapist with Idiopathic Ventricular Fibrillation and an Implantable Cardioverter Defibrillator measured his rate of Premature Ventricular Contractions using a Holter monitor during three separate six-week periods and in three domains: A work days vs. off days, B a 27 hour work week vs. 22 hour work week, and C in 5 different modalities including 1 Meeting with department head 2 Individual psychotherapy with patients 3 Group therapy with patients 4 Supervision of residents 5 Personal psychoanalysis. The results showed more than a 3-fold increase of arrhythmogenic activity during the 27-hour work week vs. 22 and a 5-fold increase in arrhythmogenic activity on work days compared to days off. Department Head meetings were found to be most arrhythmogenic and personal psychoanalysis was least. The data suggest that the psychiatrist’s lack of emotional expression in his clinical work has been demonstrated to markedly worsen his arrhythmia. The results also point to the potential ameliorating effects of the therapist’s own psychotherapy.

  7. A PURCHASING DECISION: SELECTING A SUPPLIER FOR A CONSTRUCTION COMPANY

    Ozden BAYAZIT; Birsen KARPAK; Ayhan YAGCI

    2006-01-01

    Supplier selection is one of the most crucial activities performed by organizations because of its strategic importance. Supplier selection is a multi-objective problem involving both quantitative and qualitative criteria. Over the years a number of quantitative approaches have been tried. Although the Analytic Hierarchy Process (AHP) has previously been used in supplier selection problems, one major weakness of the application-oriented AHP literature is that it tends to focus on the mechanics of AHP instead of on the theoretical and practical implications associated with finding a solution. Though it is one of the most extensively used Multiple Criteria Decision Analysis methodologies, our literature search indicated that most studies found the best solution and stopped there, ignoring sensitivity analysis. Performing sensitivity analysis is very important for practical decision making, sometimes even as important as finding the best solution. In this paper for the first time a comprehensive application of AHP for a real-world case is presented along with sensitivity analysis in choosing the best suppliers for a Turkish construction company. As a result of this study the company decided to allocate the order quantities between the two top suppliers.

  8. Pellets - A fuel with a future

    This special brochure presents a series of articles on the topic of wood pellets as a fuel of the future. Dr. Walter Steinmann, director of the Swiss Federal Office of Energy (SFOE) introduces the topic, stressing that the Swiss Confederation and the Cantons are supporting efforts to increase the sustainable use of wood fuels. Further articles take a closer look at pellets and their form. Pellets-fired heating units are introduced as a viable alternative to traditional oil-fired units. Tips are presented on the various ways of storing pellets. Quality-assurance aspects are examined and manufacturers and distributors of wood pellets are listed. A further article takes a closer look at a large Swiss manufacturer of pellets and describes the production process used as well as the logistics necessary for the transportation of raw materials and finished products. The brochure also presents a selection of pellet ovens and heating systems from various manufacturers. A further article illustrates the use of pellets as a means of heating apartment blocks built to the MINERGIE low-energy-consumption standard. In the example quoted, the classic combination of solar energy for the pre-heating of hot water and pellets for the central heating and hot water supply is used. The use of a buried spherical tank to store pellets - and thus the saving of space inside the building - is described in a further article that takes a look at the refurbishment of the heating system in a single-family home. Finally, various contributions presented at the Pellets Forum held in Berne in November 2003 are summarised in a short article

  9. Eurasian Union: A Utopia, a Dream or a Coming Reality?

    Tuğçe Varol SEVIM

    2013-11-01

    Full Text Available Twenty years passed after the dissolution of the USSR and the re-birth of Russian Federation and Central Asian states in the world arena in such a unipolar world. Since the rise of Vladimir Putin to power Russia resists on unipolar system and sees that as a treat to its security. Hence, Kremlin perceives that the economic strength is the sine qua non for the future of Russia in order to sustain a Big Power status not only in its region but also in the world. In 2011, Russia, Belarus and Kazakhstan have achieved to form a Customs Union among them and invited all the states in the region to join the organization. There were thesis which mainly argued that Russia would no longer be a “power” in the Central Asia and could only be a regional power just in case of maintaining of its own unity. However, the circumstances have changed in the region accordingly Russian weight as a result of the new conjuncture. In 2012, Russia had a new presidential election and Putin returned to Kremlin as President himself. It has been understood from his words that Kremlin's new strategy to be focused on creating a Eurasian Union including Kyrgyzstan and Tajikistan at the first stage. It is aimed to analyze in this study that whether this project could be successful and if so, what could be the impacts on world order in terms of competition between Russia, the United States and China also. And finally, what could be the result of such an organization for the Russia.

  10. Josephine Baker: A Chanteuse and a Fighter

    Konomi Ara

    2010-03-01

    Full Text Available This excerpt is from her newly-published biography of Josephine Baker, “A Fighting Diva.” It tells the intriguing story of Baker’s travels to Japan, her close friendship with the Japanese humanitarian Miki Sawada, and her adoption of a pair of Japanese orphans. Even after she achieved celebrity in France, Baker’s experience as a Black American led her to develop an antiracist philosophy at a worldwide level, and she combined political militancy in the public sphere with a personal commitment through the formation of an international multiracial household of children, the “Rainbow Tribe.”