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Sample records for short-lived daughter products

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

    International Nuclear Information System (INIS)

    Servant, J.

    1964-01-01

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

  2. Mean size among the particles of short-lived radon daughter products in the atmosphere

    International Nuclear Information System (INIS)

    Nakatani, S.

    1980-01-01

    The diffusion-battery method is used to classify the radioactive particles according to their sizes. The diffusion coefficient is determined from the fractional penetration of the particles through the battery. Particle radii are derived from the diffusion coefficients with the Stokes-Cunningham-Millikan formula. At the exit and entrance of the battery, individual concentrations of radon daughter products 218 Po, 214 Pb, 214 Bi are determined. Thus the mean sizes of individual radon daughters can be obtained from the fractional penetration of individual nuclides through the diffusion battery. Despite large statistical fluctuations the mean size of 214 Bi is always shifted toward the larger size region as compared with those of other radionuclides

  3. Radon and its short-lived daughter products in the lower atmosphere; Le radon et ses derives a vie courte dans la basse atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Servant, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

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

  4. Separation of short-lived fission products

    International Nuclear Information System (INIS)

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

    1976-01-01

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

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

    International Nuclear Information System (INIS)

    Metwally, S.M.; Prohl, G.

    2005-01-01

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

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

    International Nuclear Information System (INIS)

    Tomulescu, Vlad C.

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  8. Biological effects of daily inhalation of radon and its short-lived daughters in experimental animals

    International Nuclear Information System (INIS)

    Palmer, R.F.; Stuart, B.O.; Filipy, R.E.

    1973-01-01

    Syrian golden hamsters, C57BL mice, and specific-pathogen-free rats were exposed simultaneously in groups of 16 animals each for 90 hours per week to aerosols consisting of radon plus 3000--6000 Working Levels of radon-daughters with and without 18 mg/m 3 carnotite uranium ore dust. Condensation nuclei concentrations ranged from 2000--4000 per ml and from 90,000--120,000 per ml in the chamber without and with uranium ore dust, respectively. At 4 months of exposure only one of the rodents remained alive. Histopathology of radon-daughter exposed mice includes acute interstitial pneumonitis, severe pulmonary congestion, and supperative rhinitis; mice inhaling radon-daughters with ore showed these lesions plus macrophage proliferation, alveolar septal cell hyperplasia, and bronchial epithelial hyperplasia. Hamsters inhaling radon-daughters showed proliferating lesions characterized by alveolar septal thickening, bronchiolar epithelial hyperplasia, septal fibrosis, and occasionally adenomatoid metaplasia and squamous metaplasia. Hamsters inhaling radon-daughters with ore dust showed similar effects plus granulomatous response and intense septal fibrosis. Rats inhaling radon-daughters showed lesions similar to those of hamsters but more focalized with classic radiation pneumonitis; rats exposed to radon-daughters with ore showed similar lesions, with greater consolidation and pneumoconiosis. These findings will be discussed in relation to pulmonary pathology in uranium miners

  9. Feasibility of short-lived radionuclide production at Fermilab

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  10. Calibration of apparatus for short living radon daughters monitoring in air

    International Nuclear Information System (INIS)

    Chalupnik, S.; Lebecka, J.; Skubacz, K.

    1988-01-01

    A liquid scintillation method was developed for absolute measurement of radon daughters concentration in air. Calibration of site IRDM equipment appears as a significant problem. Usually it employs simultaneous measurements with the calibrated device and the reference one, of known detection efficiency. This yields systematic errors resulting from errors in evaluation of the detection efficiency. The presenting method is an absolute one. The efficiency for α and β particles is of about 100%. Thanks to this the developed method is excellent as a comparative one for calibration purposes. (author)

  11. Production of medical short-lived radionuclides in Canada

    International Nuclear Information System (INIS)

    Wiebe, L.I.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Malet, J.

    1997-01-01

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

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

    International Nuclear Information System (INIS)

    Tian Deyuan; Lu Zhizhao

    1998-01-01

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

  14. Estimation of ventilation rate in uranium or thorium handling laboratories using short-lived thoron daughter activity

    International Nuclear Information System (INIS)

    Shivade, R.K.; Deshpande, S.B.

    2016-01-01

    Natural uranium in oxide form is used as fuel in the Indian PHWR. Natural 238 U fuel contains 232 Th as an impurity to the extent of 50 - 60 ppm. This thorium impurity is converted to 232 U in reactor during irradiation. 232 U is converted to 224 Ra by alpha decays, 224 Ra further decays to 220 Rn by alpha decays. 220 Rn decays to stable 208 Pb by emitting alpha, beta particles and gamma rays. 220 Rn is inert gas but its daughter products are in particulate form. Effective half-life of Tn decay series is 10.6 hrs and four days are required to reduce the air borne activity concentration to negligible level on a filter paper sample. Uranium or thorium is handled remotely in the glove boxes with proper shielding. Glove boxes are under optimum negative pressure. Exhausts from glove boxes are connected to stack with proper filtration. Amber ares of the Lab is also supplied with conditioned air supply for human comfort and to keep the atmospheric thoron daughter concentration under control. Even after using proper engineering safety features, thoron that is in the gaseous form can came out from glove boxes due to holes on the neoprene gloves of micro or nano dimensions. Probability of thoron gas leakage is more during bagging out or bagging in operations. This gives rise to thoron daughter activity in the working atmosphere of Lab constantly and workers should be protected adequately

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

    International Nuclear Information System (INIS)

    Thiessen, J.W.

    1985-01-01

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

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

    Science.gov (United States)

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

    2017-09-01

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

  17. Some aspects of radon and its daughter-products in man and his environment

    International Nuclear Information System (INIS)

    Rundo, J.; Markun, F.; Plondke, N.J.; Sha, J.Y.

    1981-01-01

    A major but short-lived postprandial increase in the exhalation rate of radon by persons containing no radium was observed. The concentrations of radon and its short-lived daughter-products in houses was unusually high (> 5 to 10 pCi l - 1 , > 185 to 370 Bq m - 3 ) in some houses with unpaved crawl spaces, and with concrete basements. External counting of radon daughter-products in the residents of one of the radon-contaminated houses indicated that there may be interference with the assay of plutonium in the lungs of persons who live in those houses

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

    International Nuclear Information System (INIS)

    Klonk, H.

    1976-01-01

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

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

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

    CERN Document Server

    Franberg, Hanna; Köster, Ulli; Ammann, Markus

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    Mausner, L.F.; Richards, P.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Bjoernstad, T.

    1986-01-01

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

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Shimo, Michikuni; Katoh, Takao

    1983-01-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  6. Present practices of the Department of National Health and Welfare for the area monitoring of radon and daughter products

    International Nuclear Information System (INIS)

    Taniguchi, H.

    1977-01-01

    The present practices of the Radiation Protection Bureau for the measurement of radon and daughter products have been briefly described. For radon gas, the Lucas chamber method is in use. Short-lived radon daughter products are determined by the modified Kusnetz method. These field methods are supported by radioanalytical procedures carried out at the environmental radioactivity laboratory. Some recent studies using these methods have been briefly summarized. Concentrations of daughter products up to 29 WL were found in a columbium mine and 63 WL in a tin mine under development. The level of radon daughters in some homes in a uranium mining community ranged up to 2 WL

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

    Science.gov (United States)

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

    2015-03-17

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

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

    International Nuclear Information System (INIS)

    1987-03-01

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

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

    International Nuclear Information System (INIS)

    Yanagisawa, Hiroshi; Ohno, Akio; Aizawa, Eijyu

    2002-01-01

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

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

    International Nuclear Information System (INIS)

    Trautmann, N.

    1974-01-01

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

  11. Homogeneous aqueous solution nuclear reactors for the production of Mo-99 and other short lived radioisotopes

    International Nuclear Information System (INIS)

    2008-09-01

    Technetium-99m ( 99m Tc), the daughter of Molybdenum-99 ( 99 Mo), is the most commonly used medical radioisotope in the world. It accounts for over twenty-five million medical procedures each year worldwide, comprising about 80% of all radiopharmaceutical procedures. 99 Mo is mostly prepared by the fission of uranium-235 targets in a nuclear reactor with a fission yield of about 6.1%. Currently over 95% of the fission product 99 Mo is obtained using highly enriched uranium (HEU) targets. Smaller scale producers use low enriched uranium (LEU) targets. Small quantities of 99 Mo are also produced by neutron activation through the use of the (n, γ) reaction. The concept of a compact homogeneous aqueous reactor fuelled by a uranium salt solution with off-line separation of radioisotopes of interest ( 99 Mo, 131 I) from aliquots of irradiated fuel solution has been cited in a few presentations in the series of International Conference on Isotopes (ICI) held in Vancouver (2000), Cape Town (2003) and Brussels (2005) and recently some corporate interest has also been noticeable. Calculations and some experimental research have shown that the use of aqueous homogeneous reactors (AHRs) could be an efficient technology for fission radioisotope production, having some prospective advantages compared with traditional technology based on the use of solid uranium targets irradiated in research reactors. This review of AHR status and prospects by a team of experts engaged in the field of homogeneous reactors and radioisotope producers yields an objective evaluation of the technological challenges and other relevant implications. The meeting to develop this report facilitated the exchange of information on the 'state of the art' of the technology related to homogeneous aqueous solution nuclear reactors, especially in connection with the production of radioisotopes. This publication presents a summary of discussions of a consultants meeting which is followed by the technical

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

    Reineking, A.; Porstendoerfer, J.

    1990-01-01

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

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

    International Nuclear Information System (INIS)

    1963-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-03-15

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

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  18. Transport and deposition of nano-particles. Application to the free action of short-lived radon daughters; Transport et depot des aerosols nanometriques. Application a la fraction libre des descendants a vie courte du radon

    Energy Technology Data Exchange (ETDEWEB)

    Malet, J

    1997-10-10

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

  19. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    Energy Technology Data Exchange (ETDEWEB)

    Bigu, J [Department of Energy, Mines and Resources, Elliot Lake, Ontario (Canada). Elliot Lake Lab.; Raz, R; Golden, K; Dominguez, P [Alpha-NUCLEAR, Toronto, Ontario (Canada)

    1984-08-15

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operation with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross ..cap alpha..-count methods and ..cap alpha..-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of ..cap alpha..-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software.

  20. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    International Nuclear Information System (INIS)

    Bigu, J.

    1984-01-01

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operatin with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross α-count methods and α-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of α-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software. (orig.)

  1. A personal dosemeter of radon daughter products

    International Nuclear Information System (INIS)

    Burian, I.; Richter, M.; Ochec, J.; Dohnal, J.

    1990-01-01

    The OD 88 personal dosemeter for radon daughter products uses an alpha particle track detector and is of active type, with forced air aspiration through the detecting system. The pumping device consists of a miniature membrane pump and an electronic speed controller. The air flow rate is little affected by normal changes in supply voltage and/or pneumatic resistance of the pump circuit. The dosemeter is embedded in a miner's lamp and is fed from its accumulator battery. The pumping device is activated as the lamp is taken out of the charger and deactivated as it is slid into the charger again. The dosemeter head accommodates an AFPC filter on which the radon daughter products deposit. The energy of the alpha particles is reduced by an air layer and a Makrofol decelerating foil. The particles hitting the detector give rise to defects with an intensity proportional to the total linear stopping power at the moment of incidence; ideal tracks 10 μm in size require incident energy of 1.1 to 1.3 MeV. The detector is replaced in a month and worked up in an etching vessel, making use of the higher solubility of the detecting layer of the foil in NaOH at the spot of the alpha particle incidence. (P.A.). 4 figs., 17 refs

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

    CERN Document Server

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

    1976-01-01

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

  3. Preparation of imaging kits locally using indium-113 as a suitable short-lived generator product

    International Nuclear Information System (INIS)

    Hamid, Hamid Seidna

    1999-05-01

    In this study forty patients are selected to do brain , lung , bone , liver and spleen imaging. Patients were selected carefully in the bases of the imaging history disorders. Kits prepared and kept frozen in (- 20 degree C) eluent the generator and indium 113 products were added to each kit and imaging sorted out using gamma camera and analysed statistically

  4. Methods to Collect, Compile, and Analyze Observed Short-lived Fission Product Gamma Data

    Energy Technology Data Exchange (ETDEWEB)

    Finn, Erin C.; Metz, Lori A.; Payne, Rosara F.; Friese, Judah I.; Greenwood, Lawrence R.; Kephart, Jeremy D.; Pierson, Bruce D.; Ellis, Tere A.

    2011-09-29

    A unique set of fission product gamma spectra was collected at short times (4 minutes to 1 week) on various fissionable materials. Gamma spectra were collected from the neutron-induced fission of uranium, neptunium, and plutonium isotopes at thermal, epithermal, fission spectrum, and 14-MeV neutron energies. This report describes the experimental methods used to produce and collect the gamma data, defines the experimental parameters for each method, and demonstrates the consistency of the measurements.

  5. Study of the short-lived fission products. Separation of iodine and xenon fission radionuclides

    International Nuclear Information System (INIS)

    Barrachina, M.; Villar, M. A.

    1965-01-01

    The separation by distillation in a sulfuric acid or phosphoric acid-hydrogen peroxide medium of the iodine isotopes (8 day iodine-131, 2,3 hour iodine-132 21 hour iodine-133, 53 minute iodine-134 and 6,7 hour iodine-135) present in a uranium sample after different irradiation and cooling times is here described. It is also reported the use of active charcoal columns for the retention of xenon isotopes (5,27 days xenon-133 and 9,2 hours xenon-135) either released during the dissolution of the uranium irradiated samples or generated along the fission isobaric chains in the solutions of distillated iodine. In both cases the radiochemical purity of the separated products is established by gamma spectrometry. (Author) 15 refs

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

    International Nuclear Information System (INIS)

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

    1994-11-01

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

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

    International Nuclear Information System (INIS)

    Bougharouat, B.

    1981-01-01

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

  8. Behaviour of 222Rn and its daughter products in open atmosphere

    International Nuclear Information System (INIS)

    Ondo-Estok, D.; Holy, K.; Stanys, T.; Polaskova, A.; Hola, O.

    2003-01-01

    In this contribution the influence of the meteorological conditions on activity concentrations of the outdoor 222 Rn and its daughter products is discussed in detail. In addition, the correlation between concentrations of measured radionuclides is studied and empirical relations for concentrations of radon daughter products are presented. he courses of the activity concentrations of 222 Rn and its short-lived decay products in the outdoor atmosphere are very similar even in some details. The average equilibrium factor F determined on the basis of our measurements in the outdoor atmosphere is approximately about 20 % lower than the value F recommended by UNSCEAR 1996 for the open air (F = 0,7). The obtained nonlinear relations between radon and its decay products reduce the applications of decay products in the atmospheric studies on one hand but on the other hand they can be useful at the calculation of the equilibrium equivalent radon concentration with the aim to determine the effective radon dose on the basis of the measurements of its activity concentrations only. (authors)

  9. Practical applications of short-lived radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-01-15

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

  10. A field method for monitoring thoron-daughter working level

    International Nuclear Information System (INIS)

    Khan, A.H.; Dhandayatham, R.; Raghavayya, M.; Nambiar, P.P.V.J.

    1975-01-01

    The concept of working level, generally used for radon daughters, has been extended to the daughter products of thoron. Accordingly, thorondaughter working level (TWL) has been defined as the alpha energy released from the ultimate decay of 100 pCi/1 each of the short-lived decay products of thoron. In order to facilitate the evaluation of inhalation hazard in thorium handling areas, a simple field method has been suggested to measure the thoron-daughter working level. A comparison of the potential alpha energies from radon-daughters and that from thoron-daughter is included. (K.B.)

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

    CERN Document Server

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

    2002-01-01

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

  12. The importance of radon and its daughter products in environmental hygiene

    International Nuclear Information System (INIS)

    Schuettmann, W.

    1985-01-01

    Radon and its daughter products have recently been paid great attention as components of natural ionizing radiation. Their presence in houses and flats are focus of interest. The radon isotopes and their short-lived daughter products are represented briefly, followed by a condensed survey of the historical development of this topic. There are various reasons why this became topical only 80 years after radon had been proved in the atmospheric air. After the listing of the different sources of radon, a rough risk estimation is given regarding the role of radon in lung cancer incidence in the GDR. For environmental hygiene the houses with particularly high radon content of the air, the causes of which are given, are of special importance. Among these causes the ventilation of rooms is the factor having the greatest influence on the radon concentration. From the evidence of occasional, extremely high radon values efforts are derived to elaborate limits of radon concentrations in flats. Finally, the priority of the radon problem for environmental hygiene is pointed out by indicating the current interest of this problem in literature and at congresses. (author)

  13. A comparison of environmental and personal control of short-lived radon decay products in hard-coal mines

    International Nuclear Information System (INIS)

    Skowronek, J.; Skubacz, K.; Chalupnik, S.; Kajdasz, R.; Nalepa, S.

    1993-01-01

    Monitoring of workplaces in the first step of the monitoring of radiation hazard in coal mines. Decision concerning application of individual dosimetry is taken on the basis of the results of workplace monitoring. The system applies to all sources of natural radiation in coal mines. The workplace monitoring is performed at certain preselected points, usually in one air stream while miners change their position during their work. Therefore, a question arises how far one can relay on workplace monitoring when making decision on application of personal dosimetry and when evaluating individual radiation doses. The results of investigations concerning this question are presented in this paper. Results of measurements of radon daughters concentrations at workplaces obtained by ALFA-31 sampling probes and dust samplers are compared with the results of individual exposures measured by active French individual dosimeters and by passive track detectors used as individual dosimeters and for workplace monitoring by the Institute of Occupation Medicine (IOM) in Lodz. The readouts of detectors were performed by its owners: IOM Lodz, Centre de Radioprotection dans les Mines (CRPM) - France and Centre Mining Institute (CMI). The presented results have been obtained in two independent coal mines in Upper Silesia -Ziemowit and Jankowice - during 1991-1992. The results obtained by passive dosimeters (IOM track detectors) were by 1-2 orders of magnitude higher than the results of measurements carried out by active dosimeters (CRPM and CMI). (author). 7 refs, 8 figs, 6 tabs

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

    International Nuclear Information System (INIS)

    Rudstam, G.

    1976-01-01

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

  15. Radon and its daughters in vivo

    International Nuclear Information System (INIS)

    Rundo, J.

    1983-01-01

    Some aspects of the behavior of radon and its short-lived daughters in vivo are described and a relationship between the radon exhalation rate and time after a meal is demonstrated. A major but short-lived postprandial increase in the exhalation rate of radon produced from skeletally-deposited radium was observed and a similar effect in exhalation rate of environmental radon by persons containing no radium was noted. Persons living in houses with elevated concentrations of radon may contain sufficient activity for its detection by external gamma-ray counting. Some of the activity observed is due to inhaled daughter-products in the chest, and some to daughter-products associated with and produced by the decay of radon throughout the body. 3 references, 8 figures. (MF)

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

    International Nuclear Information System (INIS)

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

    1985-09-01

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

  17. Methodology and experimental setup for measuring short-lives fission product yields in actinides induced fission by charged particles

    International Nuclear Information System (INIS)

    Bellido, A.V.

    1995-07-01

    The theoretical principles and the laboratory set-up for the fission products yields measurements are described. The procedures for the experimental determinations are explain in detail. (author). 43 refs., 5 figs

  18. Radiation exposure in homes through radon and thoron daughter products

    International Nuclear Information System (INIS)

    Schmier, H.

    1984-01-01

    In a random selection of about 6000 homes in the Federal Republic of Germany, the radon concentration in room air has been measured using a simple dosemeter developed by Karlsruhe Nuclear Research Centre. The mean radon concentration has been determined to be approximately 40-50 Bqu/m 3 . If this experiment is taken as a representative survey for the FRG, the mean dose contributed by the natural radiation exposure through radon and its short-lived decay products to the effective annual dose to the lungs can be computed to be about 1 mSv (100 mrem), using the internationally accepted conversion factors. Apart from this survey, special radon measuring programmes have been carried out, including simultaneous recording of meteorological data, in order to obtain information on the parameters to be taken into account when describing the daily variations of radon concentrations. (orig./DG) [de

  19. Excitation functions for the formation of some short-lived products in proton-induced reactions on silver

    International Nuclear Information System (INIS)

    Uddin, M.S.; Latif, S.K.A.; Baba, M.; Hagiwara, M.; Qaim, S.M.

    2008-01-01

    Excitation functions of the nat Ag(p, xn) 104, 105 Cd and nat Ag(p, pxn) 103, 104m,g, 104g Ag reactions were measured for the first time over the proton energy range of 32 to about 60 MeV. The data were compared with the results of precompound-hybrid model calculations, whereby only partial agreement was obtained. The contribution of the 103 Ag precursor decay to the total formation of the therapeutic radionuclide 103 Pd in proton activation of silver was estimated: it amounted to about 70%. The various possible routes for the production of 103 Pd were also considered: the nat Ag(p, x) 103 Pd and 103 Rh(p, n) 103 Pd processes were found to be most interesting. Despite its somewhat lower yield, the latter process is preferred because it can be applied at a low-energy cyclotron. (orig.)

  20. Factors influencing indoor concentrations of radon and daughter products

    International Nuclear Information System (INIS)

    Wang Hengde

    1985-01-01

    The correlation between indoor concentrations of 222 Rn and its daughters and some influencing factors is discussed and expressions of concentrations are derived with relation to radon exhalation rate from indoor surfaces, air exchange rate and daughter deposition velocities on indoor surfaces. Experimental methods for determining radon exhalation rate, air exchange rate and daughter deposition velocities are also mentioned

  1. Metrology and monitoring of radon, thoron and their daughter products

    International Nuclear Information System (INIS)

    1985-01-01

    The principles of measurement and monitoring are described as applied to radon- and thoron gases and their daughter products in occupational and non-occupational environments. Various methods of measurement, such as grab-sampling, continuous monitoring, integrated measurements and personal dosimetry are discussed. Uncertainties in different measurement methods are compared. An account of unattached fraction and plateout of radon daughters is included. General principles and guidelines for monitoring are presented for the purposes of practical radiation protection as well as research applications. Calibration aspects of measurement instruments are described and procedures for interlaboratory calibration are suggested. Sampling strategies for occupational and non-occupational environments are discussed and radiation protection training requirements are identified. Where sufficient information and consensus exist, guidelines on apparatus, methods and procedures for monitoring are provided. A summary of regulations in force or being developed and recommendations for monitoring radiation exposure to radon and its decay products in countries of the OECD is provided, together with cost estimates for national indoor radon surveys

  2. Daily and seasonal variation of short-lived radon decay product concentrations in ground-level air at Munich-Neuherberg - a long-term study

    International Nuclear Information System (INIS)

    Winkler, R.

    2001-09-01

    Daily and seasonal variation of the equilibrium equivalent radon concentration (EEC Rn-222 ) and of the concentration of the short-lived radon decay product 214 Pb in ground-level air was investigated at Munich-Neuherberg from 1982 to 2000, and from 1989 to 2000, respectively. For this, the EEC was measured continuously with an alpha/beta aerosol monitor at 2.5 m above ground, and 214 Pb was determined by online gamma spectrometry at about 12 m above ground. The resulting time series were analysed statistically. For the respective periods, the measurements yielded a long-term average concentration of 7.8 Bq m -3 (geometric mean: 6.1 Bq m -3 ) for the EEC, and 6.0 Bq m -3 (geom. mean: 5.0 Bq m -3 ) for 214 Pb. In these periods, daily averages ranged from 0.6 to 49 Bq m -3 (EEC), and from 0.6 to 43 Bq m -3 ( 214 Pb). Monthly mean concentrations varied between 3.0 Bq m -3 in March 1988 and 20 Bq m -3 in October 1985 (EEC), and from 3.4 Bq m -3 in April 1992 to 11 Bq m -3 in October 1995 ( 214 Pb), respectively. The annual average concentrations were from 5.9 Bq m -3 in 1999 to 10.6 Bq m -3 in 1985 (EEC), and from 5.3 Bq m -3 in 1999 to 6.8 Bq m -3 in 1991 ( 214 Pb). From the long-term average equilibrium equivalent radon concentration (EEC), an average annual effective dose of 0.13 mSv due to the short-lived radon progeny outdoors was estimated. The time series showed distinct daily and seasonal variations. The variations from day to day are mainly caused by the actual weather conditions (wind, rain, etc.), i.e. the short-term turbulent conditions. The seasonal pattern is characterised by an autumn to winter maximum and an early summer minimum, and reflects the prevailing turbulent conditions at the respective seasons. As known, at Munich-Neuherberg during autumn and winter months (October/November to February) inversion weather conditions frequently occur, while the other months are characterised by more turbulent conditions. (orig.)

  3. Studies on the separation of rare earth elements and the nuclear decay properties of short lived rare-earth nuclides in U-235 fission products

    International Nuclear Information System (INIS)

    Ohyoshi, Akira; Ohyoshi, Emiko.

    1980-01-01

    The effect of a complex-forming agent, with which rare earths consecutively form the complexes, on the separation of a pair of adjacent rare earths by electromigration has been investigated. The relation between the separation factor for two complexes and the ligand-ion concentration was examined in the separation of La-Ce and Ce-Pr pairs with nitrilotriacetic acid. Rare earths were able to be isolated rapidly at the optimum ligand-ion concentration in lower one, and this method was applied to study the nuclear decay properties of the short lived isotopes of La, Ce, Pr, Nd and Yt formed in the fission of U-235. This method permits the direct measurement of the decay of La-144 without the interference from the radiation of other fission products. The gamma-ray spectrum of La-144 was measured with a high resolution Ge(Li) detector, and the gamma-transition was observed. From the decay plots of two strong photopeaks, the half-life of La-144 was determined. In the case of Ce fraction, the photopeaks assigned to respective isotopes were observed. In the studies on the decay properties of Pr-148 and Pr-149, the decay plot of the strong photopeak showed good linearity, and the accurate half-life of Pr-148 was determined. Similarly, the half-life of Pr-149 was longer than the previously reported value. (Kako, I.)

  4. A radionuclide generator for the production of 211Pb and its daughters

    International Nuclear Information System (INIS)

    Atcher, R.W.; Friedman, A.M.; Huizenga, J.R.

    1989-01-01

    211 Pb and its daughters are produced in a generator system which utilizes the distillation of the intermediate daughter 219 Rn from 223 Ra. The radium is precipitated as the stearate to isolate the parent while allowing the gaseous daughter to emanate. While the yield of the system is low, approximately 10%, the radionuclidic purity is extremely high. No measurable 223 Ra is found in the product. 223 Ra is separated from its parent, 227 Ac, by cation exchange. (author) 7 refs

  5. Measurement of airborne concentrations of radon-220 daughter products by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Kerr, G.D.; Ryan, M.T.; Perdue, P.T.

    1978-01-01

    The decay of naturally occurring uranium-238 and thorium-232 produces radon-222 and radon-220 isotopes which can escape into the atmosphere. If these radon gases become concentrated in air, their daughter products may present an inhalation hazard to man. The airborne concentrations of radon-222 can usually be measured very accurately in the presence of normal airborne concentrations of radon-220 and its daughters. In contrast, the measurements of the airborne concentrations of radon-220 daughters are usually complicated by the presence of radon-222 and its daughters even at normally occurring airborne concentrations. The complications involved in these measurements can be overcome in most situations by using an alpha particle spectrometer to distinguish the activity of radon-222 daughters from that due to radon-220 daughters collected on a filter. A practical spectrometer for field measurements of alpha particle activity on a filter is discussed

  6. Compact detector for radon and radon daughter products

    International Nuclear Information System (INIS)

    Alter, H.W.; Oswald, R.A.

    1986-01-01

    This invention provides an improved compact track registration detector for radon gas. The detector comprises a housing having an open mouth, a bottom, and side walls; track registration means, supported inside the housing, which forms damage tracks along paths traversed by alpha particles; a microporous filter positioned across the mouth of the housing to prevent entry of radon daughters and particulate matter; and a cap that may be placed on the mouth of the housing to retain the filter. The housing has internal wall surfaces dimensioned to optimize the registration of alpha particles from radon and radon daughters present in the housing

  7. Emanation of 232U and its radioactive daughter products from respirable size particles

    International Nuclear Information System (INIS)

    Cuddihy, R.G.; Griffith, W.C.; Hoover, M.D.; Kanapilly, G.M.; Stalnaker, N.D.

    1978-01-01

    This study is to develop a model for the emanation of 232 U and its radioactive daughter products from particles of Th-U fuel material. The radiation doses to internal organs following inhalation of these particles can only be calculated by knowing the rate of emanation of the daughters from particles in the lung and the subsequent excretion or translocation of the daughters to other organs. The emanation mechanisms are recoil of the daughter nuclei from the particle during alpha decay of the parent, diffusion of inert gas daughters from the particle and dissolution of the particle itself in biological fluids. Experiments to evaluate these mechanisms will involve ThO 2 and UO 2 particles in the size range 0.1 to 1.0 μm MMAD uniformly labeled with 232 U. The influence of the material temperature history on emanation will be investigated by heat treating particles at 600 and 1400 0 C

  8. Measure of exposure of short-lived radon products using an alpha spectrometer for measuring indoor aerosol activity concentration and dose evaluation

    International Nuclear Information System (INIS)

    Berico, M.; Castellani, C. M.; Formignani, M.; Mariotti, F.

    2001-01-01

    A new italian law introduces the regulation of occupational exposure to radon. To evaluate the inhalation of radon daughters by the workers a sampling device has been assembled with the aim of evaluation of unattached and aerosol attached radon daughters' fractions. The instrument, based on selection of the aerosuspended particles by means of a wire screen type battery and subsequent collection on a total filter, allows to describe the behaviour of both fractions using defined temporal pattern of collecting particles and counting them by alpha spectroscopy. A measurement campaign to test the radon daughter dichotomous spectrometer in comparison with a commercial Radon Working Level meter, has been performed in a research laboratory of central Italy affected by high radon concentrations. The radon concentration during the measurement campaign has been also measured. The equilibrium factor F e q ad the attachment factor fp have been evaluated during 3 days campaign. Using the measured mean parameters (radon concentration, F e q, f p ) the dose evaluation for workers using dosimetric approach has been performed. A comparison between the epidemiologic approach, based on the radon concentration, and dosimetric approach is also presented [it

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-02-09

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

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

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1996-01-01

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

  11. Development of gas-jet transport systems for fission products and coupling these with methods for continuous separation of short-lived product nuclides

    International Nuclear Information System (INIS)

    Stender, E.

    1979-01-01

    The development of gas-jet transport systems for fission products as well as the coupling of these with continuous separation methods from aqueous solutions (SISAK) and with a mass separator for on-line separation of neutron-rich nuclides are described in this work. Nuclides from the fission of 235 U or other fission materials can be transported using gas-jet systems with thermal neutrons over larger distances (100 m and over). Aerosols (clusters) of either organic (e.g. ethylene) or inorganic nature (e.g. potassium chloride) serve as carrier for the nuclides. The clusters are passed through 1 mm capillaries with a transport gas (nitrogen, helium etc.) under laminar flow conditions. The diameter of the cluster fluctuates between 10 -7 and 10 -6 m. The time required from the production of a nuclide to its detection at the end of a 8 m long capillary tube is 0.8 s for the ethylene/nitrogen and potassium chloride/helium gas-jet systems. By coupling various gas-jet systems with the continuous extraction technique SISAK working with H centrifuges, the elements lanthanum, cerium, praseodymium, zirconium, niobium and technetium can be separated out of the complex fission product mixtures. The on-line technetium chemistry was used with neutron-rich 106 Tc (36 s), 107 Tc (21 s) and 108 Tc (5 s) for γγ(t) measurements. The coupling of a potassium chloride/helium gas jet with a mass separator equiped with a plasma ion source is described. The dependence of the transmission rate of various test parameters is investigated to optimize the system. (orig.) [de

  12. 'Sleeping reactor' irradiations. The use of a shut-down reactor for the determination of elements with short-lived activation products

    International Nuclear Information System (INIS)

    Jerde, E.A.; Oak Ridge National Laboratory, TN; Glasgow, D.C.

    1999-01-01

    Neutron activation analysis utilizing the High Flux Isotope Reactor (HFIR) immediately following SCRAM is a workable solution to obtaining data for ultra-short lived species, principally Al, Ti, Mg, and V. Neutrons are produced in the HFIR core within the beryllium reflector due to gamma-ray bombardment from the spent fuel elements. This neutron flux is not constant, varying by over two orders of magnitude during the first 24 hours. The problems associated with irradiation in a changing neutron flux are removed through the use of a specially tailored activation equation. This activation equation is applicable to any irradiation at HFIR in the firs 24 hours after SCRAM since the fuel elements are identical from cycle to cycle, and the gamma-emitting nuclides responsible for the neutrons reach saturation during the fuel cycle. Reference material tests demonstrate that this method is successful, and detection limit estimates reveal that it should be applicable to materials of widely ranging mass and composition. (author)

  13. Rapid increase in cosmogenic 14C in AD 775 measured in New Zealand kauri trees indicates short-lived increase in 14C production spanning both hemispheres

    Science.gov (United States)

    Güttler, D.; Adolphi, F.; Beer, J.; Bleicher, N.; Boswijk, G.; Christl, M.; Hogg, A.; Palmer, J.; Vockenhuber, C.; Wacker, L.; Wunder, J.

    2015-02-01

    In 2012, Miyake et al. reported a sudden and strong increase of the atmospheric radiocarbon (14C) content in Japanese cedar trees of 1.2% between AD 774 and 775. While their findings were quickly confirmed by a German oak chronology for the Northern Hemisphere (NH), the question remained if the effect was seen in both hemispheres. Here we present the first annually resolved Southern Hemisphere (SH) 14C record spanning the interval AD 760-787, using New Zealand kauri (Agathis australis) chronology wood. An almost identical distinct increase compared to Northern Hemisphere data was observed, suggesting a cosmic event with globally uniform impact as a potential cause for the increase. Deploying a carbon cycle box model a worldwide averaged net 14C production of 2.2 ×108 14C atoms cm-2 was estimated, which is 3.7 times higher than the average annual 14C production. The immediate appearance of the event in tree rings on both hemispheres suggests a short duration event of significantly less than 1 yr.

  14. Concordance of mother-daughter diurnal cortisol production: Understanding the intergenerational transmission of risk for depression.

    Science.gov (United States)

    LeMoult, Joelle; Chen, Michael C; Foland-Ross, Lara C; Burley, Hannah W; Gotlib, Ian H

    2015-05-01

    A growing body of research is demonstrating concordance between mother and child diurnal cortisol production. In the context of maternal history of depression, intergenerational concordance of cortisol production could contribute to hypercortisolemia in children of depressed mothers, which has been shown to increase risk for MDD. The current study is the first to examine concordance in diurnal cortisol production between mothers with a history of depression and their never-depressed, but high-risk, children. We collected salivary cortisol across 2 days from mothers with (remitted; RMD) and without (CTL) a history of recurrent episodes of depression and their never-depressed daughters. As expected, RMD mothers and their daughters both exhibited higher cortisol production than did their CTL counterparts. Moreover, both across and within groups, mothers' and daughters' cortisol production were directly coupled. These findings suggest that there is an intergenerational concordance in cortisol dysregulation that may contribute to hypercortisolemia in girls at familial risk for depression. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Risks from principal components and their daughter products in alpha-contaminated waste

    International Nuclear Information System (INIS)

    Rogers, V.

    1982-01-01

    This paper presents an overview on risk assessment, particularly as it applies to limits for alpha-contaminated waste. The general conclusions are: (1) no special characteristics of transuranic (TRU) waste justify its being a special category; (2) model calculations are largely subjective and can be influenced by the bias of the modeler; (3) ingrowth and concentration of TRU daughter products could be an important consideration in risk assessment. 13 figures

  16. Separation of actinium-227 from its daughter products by cationic resins technique

    International Nuclear Information System (INIS)

    Nastasi, M.J.C.

    1976-01-01

    A method for separating actinium-227 from its daughter products based on ion exchange principle is shown. Radionuclides mixture in perchloric acid 8,5 N and chloridric acid 0,5 N medium pass by a cationic resin column. Thorium-227 and actinium-227, which are retained by the resin, are eluted with nitric acid 6 N which releases actinium-227 while oxalic acid 7% is used for thorium-227 elution [pt

  17. Contribution of short-lived nuclides to decay heat

    International Nuclear Information System (INIS)

    Katakura, Jun-ichi

    1987-01-01

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

  18. Experimental study of the combined effects of inhalation of radon daughter products and tobacco smoke

    International Nuclear Information System (INIS)

    Chameaud, J.; Perraud, R.; Chretien, J.; Masse, R.; Lafuma, J.

    1979-01-01

    For 10 years, over 500 lung cancers have been induced in rats by inhalations of radon daughter products at various concentrations and cumulated doses. Considering several points and the dose-effect relationship especially, such cancers can be compared with human cancers. This type of experiments, fully mastered, has made it possible to undertake under good conditions the study of the co-carcinogenic effect of various inhaled pollutants such as tobacco smoke. In a first experiment, 100 rats were exposed to a 4000WLM cumulated dose of radon daughter products, knowing that this level induces some 30% of lung cancers. 50 animals were then administered tobacco smoke by inhalation in a fume box during 5 months (350 h.) In the group inhaling radon only, 17 cancers appeared; in the radon -tobacco group 32 cancers bigger and more invasive were observed. Under the same conditions, tobacco smoke was inhaled by rats previously exposed to lower doses of radon daughter products (2 groups of 30 rats, 500 and 100 WLM respectively). Again, the number of cancers observed was higher that the number of cancers expected if the rats had inhaled radon only. This co-carcinogenic and potentiating action of tobacco was clearly demonstrated. Further experiments are considered in order to determine the processes involved

  19. Combined effects of inhalation of Radon daughter products and tobacco smoke

    International Nuclear Information System (INIS)

    Chameaud, J.; Perraud, R.; Chretien, J.; Masse, R.; Lafuma, J.

    1980-01-01

    Over the last 10 years, more than 500 lung cancers have been induced in rats by inhalations of radon daughter products at various concentrations and cumulated doses. These cancers were compared with human cancers. Another study examines the cocarcinogenic effect of tobacco smoke. In the first experiment, 100 rats were exposed to a 4000-WLM (working level month) cumulated dose of radon daughter products. Fifty animals were then administered tobacco smoke by inhalation in a fume box during 5 months (i.e., for a total of 352 hr). In the group inhaling radon only, 17 cancers appeared; in the radon-tobacco group, 32 cancers were observed, many of them larger and more invasive than those seen in animals exposed to radon only. Under the same conditions tobacco smoke was inhaled by rats previously exposed to lower doses of radon daughter products (two groups of 30 rats each, at 500 and 100 WLM, respectively). Again, the number of cancers observed was greater than the number of cancers expected if the rats had inhaled radon only. The carcinogenic and potentiating action of tobacco smoke was clearly demonstrated

  20. Recent trends in monitoring radon and daughter products in Indian uranium mines

    International Nuclear Information System (INIS)

    Khan, A.H.; Raghavayya, M.

    1977-01-01

    Uranium mining is of comparatively recent origin in India. In keeping with the ICRP (1959) and IAEA (1967) recommendations on the subject, the radiation practice in this country has been to monitor the mine air for radon. But the fact that radon daughter products are responsible for a major contribution to the radiation dose to the lungs and the comparative ease of correlating incidence of lung cancer with cumulative exposure to radon daughters (WLM), as demonstrated by epidemiologists, cannot be lost sight of. The results of a series of simultaneous measurements of radon, its decay products and their unattached fractions are presented. These measurements of radon have been carried out under different operational and passive conditions in mines. It has been observed that in the mine air, not only RaA but significant fractions of RaB and RaC too, exist in 'free state'. Wide variations have been observed in the unattached fractions with median values around 6% for RaA, 3% for RaB and 1% for RaC. The unattached daughter activities in the return air are maximum under passive conditions and show declining trend as the mining operations assume momentum causing increase in the aerosol concentrations. Relative merits of monitoring the mine air for radon and/or its decay products are also discussed

  1. Assessment of radon-daughter deposition in the respiratory tract

    International Nuclear Information System (INIS)

    Oberstedt, S.; Vanmarcke, H.

    1996-01-01

    Since some decades it is known, that most of the radiation dose to the lung is due to the inhalation of the short-lived decay products of 222 Rn. Their deposition in the respiratory tract strongly depends on the attachment rate to aerosol-particles present in the indoor air and their plate-out rate to the surfaces, instead of measuring the activity size distribution of the airborne decay products, knowledge on the respiratory tract retention has been incorporated in the design of a measurement system, called bronchial dosemeter, to assess the lung dose directly. The simulation of the deposition characteristics of the short-lived radon daughters in the nasal cavity and the bronchial tree is based on the comparison of the model of the respiratory tract with results from screen penetration theory. A bronchial dosemeter consisting of three sampling heads has been built and calibrated. Additionally, an outline of future activities will be given. (author)

  2. Investigation of the concentrations of radon-222 and its daughter products in Loutraki spas (Peloponnese, Greece)

    International Nuclear Information System (INIS)

    Kritidis, Panaiotis; Angelou, Panaiotis.

    1984-07-01

    An express variant of the three-interval total alpha-counting filter method being suitable for the determination of elevated concentrations of 222 Rn decay products in air of increased humidity is described. The method has been used for the determination of radon daughters in air in the major radon spas of Loutraki. Concentrations of 222 Rn and 226 Ra in spa water have been determined as well. Annual effective dose equivalents for the personnel and the patients have been estimated. The need of certain radiation protection measures is pointed out. (author)

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

    International Nuclear Information System (INIS)

    More, R.D.

    1986-01-01

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

  4. An investigation into control of radon and its daughter products in some Cornish mine atmospheres

    International Nuclear Information System (INIS)

    Dungey, C.J.; Hore, J.; Waller, M.D.

    1979-01-01

    Elements of the uranium series are widespread as trace elements in the granitic rocks in which much of Cornwall's mining takes place. The radon gas, together with its decay or daughter products, can be inhaled by the underground worker. It is now realised that even a small concentration of the gas can be harmful; this is reflected by the tightening of control standards in the U.S.A. by a factor of 30 in the past 10 years. The current standards are such that many non-uranium mines must now provide some means of control. As yet, no statutory limits have been set in the United Kingdom mining regulations, but the industry locally is hopeful of achieving reduced levels that will pre-empt any forthcoming legislation. The first requirement of any control technique is the ability to monitor the effects of any action. An instrument developed recently in the U.S.A. now enables the radon daughter concentration to be determined quickly on the spot, so the effectiveness of any control measures can be evaluated more rapidly. The evaluation of the best potential methods of control requires some understanding of the behaviour of the decay products in typical mine environments. Several control techniques are being tested, both in controlled experimental conditions at the Camborne School of Mines and in field conditions at South Crofty and Wheal Pendarves mines. The experience and results of these tests so far are examined. (author)

  5. Measurements of Short-Lived Fission Isomers

    Science.gov (United States)

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

    2016-09-01

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

  6. Hydrogeochemistry of uranium, daughter products and associated elements (lanthanides), application to ore prospection

    International Nuclear Information System (INIS)

    Toulhoat, P.

    1987-09-01

    The behavior in ground water of uranium, daughter products with long half life (U 234 , Th 230 , Ra 226 ) and stable (radiogenic lead) and lanthanides is studied by two complementary methods: 1) In situ multielement tracing in fracturated granitic rocks and porous sedimentary rocks of low permeability allowing to understand interactions between hydrodynamics and geochemistry. 2) Study of the properties of U 234 and Pb 236 which are mineralization tracers and are relatively independent of redox conditions, on the contrary U 238 has a low solubility in reducing medium. Three areas are studied: Bazois and Lodeve basin (France) and Cigar Lake (Canada). Radioactive disequilibriums are thoroughly studied when required by ore/rock interaction. Adsorption-desorption phenomena are of great importance in proposed prospection models. If prospection models based on alpha activity ratio U 234 /U 238 and lead isotope ratio in ground water can be applied, an integrated prospection model requires more in situ and laboratory experiments [fr

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

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

    CERN Document Server

    Welch, Michael J

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    Salma, I.

    1993-01-01

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

  11. Randon daughter exposure of the U.K. population

    International Nuclear Information System (INIS)

    Cliff, K.D.

    1980-01-01

    The highest dose to the body tissues from natural radioactivity is that to the bronchial epithelium arising predominantly from the short-lived daughters of 222 Rn with a lesser contribution from the daughters of 220 Rn. This paper discusses the estimation of current United Kingdom population exposure to these nuclides. At present the exposure for an average member of the population of the UK is 0.15 WLM y -1 when the winter ventilation rate is 0.8 h -1 . This will increase to 0.58 WLM y -1 if the winter ventilation rate is reduced to 0.2 h -1 . The use of electrostatic precipitators would decrease the measured WL but would not affect the unattached fraction of 222 Rn daughter products, which determines the dose to the epithelium. Other methods of reducing 222 Rn daughter concentrations under investigation include prevention of the ingress of 222 Rn from the subsoil and the coating of construction materials with a radon barrier

  12. Field monitoring versus individual miner dosimetry of radon daughter products in mines.

    Science.gov (United States)

    Domański, T; Kluszczyński, D; Olszewski, J; Chruscielewski, W

    1989-01-01

    The paper presents the results realised simultaneously by two different and independent systems of measurement of an assessment of miners' exposure to radon daughter products which naturally occur in the air of mines. The first one, called the Air Sampling System (ASS), was based on the field monitoring of radon progeny in air, the second one, called the Individual Dosimetry System (IDS), was based on the individual dosimeters worn by miners. Experimental comparison of these two systems has been conducted for six years in eleven Polish underground metal-ore mines. This study reveals that no correlation exists between the concentration and annual miners' exposures evaluated by the ASS and IDS. The ratio ASS/IDS for mine population varies from 11.0 to 0.14 in respect of annual concentration means, and in respect to annual exposures, this ratio varies from 4.5 to 0.14. The conclusion to be drawn from six years' observation and comparison of both systems is that correct and true evaluation of miners' exposure to radon progeny can be made only by the use of the Individual Dosimetry System, since the Air Sampling System is too sensitive and too dependent on the Strategy of sampling and its radiation.

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

    International Nuclear Information System (INIS)

    Kupsch, H.

    1986-01-01

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

  14. New ICRP recommendations on occupational limits for radon daughters

    International Nuclear Information System (INIS)

    Jacobi, W.

    1981-01-01

    The ICRP has recommended in 1959 for the first time a maximum permissible concentration (MPC) for the occupational exposure to radon and its short-lived daughters. Since this time more realistic dosimetric models for radon daughters have been developed. Taking into account epidemiological and new dosimetric findings the ICRP has adopted in March this year new recommendations on occupational limits for inhalation of 222 Rn, 220 Rn and their short-lived daughters. This report will be published this year as ICRP Publication 32 (ICRP 1981). The recommended limits for radon daughters were derived from the basic dose and risk limits as they were proposed by ICRP in its new basic recommendations (ICRP Publ. 26, 1977). In the following this basic system of dose limitation is shortly outlined before the special recommendations for radon daughters are described

  15. Short-lived medical isotopes at Harwell

    International Nuclear Information System (INIS)

    Cuninghame, J.G.

    1985-01-01

    This paper describes the small program of medical isotope commercial production and research and development on the Harwell Variable Energy Cyclotron. Because of its complexity, this nuclear research machine is extremely expensive to run, and so the program must be restricted to those isotopes which cannot be more cheaply produced elsewhere in the United Kingdom. At present these are 123 I (in full commercial production), the /sup 195m/Hg → /sup 195m/Au generator (about to go into commercial production), and 211 At (under development). Iodine-123 is produced once or twice a week at a level of 300 to 400 mCi per batch and is sold to an average of 30 customers all over the United Kingdom and Europe. The gold generator is being developed for first-pass heart angiography and is undergoing clinical trials at three U.K. hospitals. A research program in conjunction with the U.K. Medical Research Council is directed to the labeling of monoclonal antibodies with 211 At as a possible agent for cancer therapy

  16. Treatment of short-lived radioactive wastes

    International Nuclear Information System (INIS)

    Yamaguchi, Chiri

    1976-01-01

    Recently short life nuclides have come to be utilized increasingly as diagnostic radioisotopes, and Tc-99m (half-life; 6.05 hours) and Ga-67 (half-life 7.79 hours) are replacing the most nuclides fomerly used in vivo test. Such development of radioactive products inevitably causes the rapid increase of their wastes. At present, the radioactive wastes produced by hospitals and university laboratories in Japan are collected by the Japan Radioisotope Association, and treated by the Japan Atomic Energy Research Institute. These wastes are divided into combustibles and incombustibles to store in the store house in the Japan Atomic Energy Research Institute. The present law in Japan contains the contradiction which treats the matter with one several millionth of radioactivity after decay same as the original radioactive matter. Thus solid must be stored permanently, while gas and liquid can be discharged after dilution. (Kobatake, H.)

  17. Fast neutron activation analysis using short-lived radionuclides

    International Nuclear Information System (INIS)

    Salma, I.; Zemplen-Papp, E.

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Sodd, V.J.

    1985-01-01

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

  19. Proceedings of the specialist meeting on personal dosimetry and area monitoring suitable for radon and daughter products

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The programme of work of the OECD Nuclear Energy Agency includes topics relating to radiation and environmental protection matters in mining and milling operations. A first Specialist Meeting on Personal Dosimetry and Area Monitoring suitable for Radon and Daughter Products was organised in October 1976 at Elliot Lake, Canada. The proceedings were published by NEA some months later. Following an enquiry among interested persons, NEA decided to organise a new meeting on the same subject in Paris from 20th to 22nd November 1978. The meeting dealt with questions relating to personal dosimetry techniques, the monitoring of the atmosphere in mines and their neighbourhood, as well as in buildings

  20. Doses and affects of radon and its daughters

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1982-01-01

    Radon and its short-lived daughters are one of the main contributors to the natural exposures of ionizing radiation to man. Their sources, levels and characteristics are described. By inhalation of radon and its daughters tissues in the lung are irritated by α-particles leading to an increased risk of lung cancer. Methods of calculation of doses and risks using the dosimetric approach and the epidemiological approach are described and discussed. (Author)

  1. How Short-Lived Ikaite Affects Calcite Crystallization

    OpenAIRE

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

    2017-01-01

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

  2. Cement As a Waste Form for Nuclear Fission Products: The Case of (90)Sr and Its Daughters.

    Science.gov (United States)

    Dezerald, Lucile; Kohanoff, Jorge J; Correa, Alfredo A; Caro, Alfredo; Pellenq, Roland J-M; Ulm, Franz J; Saúl, Andrés

    2015-11-17

    One of the main challenges faced by the nuclear industry is the long-term confinement of nuclear waste. Because it is inexpensive and easy to manufacture, cement is the material of choice to store large volumes of radioactive materials, in particular the low-level medium-lived fission products. It is therefore of utmost importance to assess the chemical and structural stability of cement containing radioactive species. Here, we use ab initio calculations based on density functional theory (DFT) to study the effects of (90)Sr insertion and decay in C-S-H (calcium-silicate-hydrate) in order to test the ability of cement to trap and hold this radioactive fission product and to investigate the consequences of its β-decay on the cement paste structure. We show that (90)Sr is stable when it substitutes the Ca(2+) ions in C-S-H, and so is its daughter nucleus (90)Y after β-decay. Interestingly, (90)Zr, daughter of (90)Y and final product in the decay sequence, is found to be unstable compared to the bulk phase of the element at zero K but stable when compared to the solvated ion in water. Therefore, cement appears as a suitable waste form for (90)Sr storage.

  3. Evaluation and control of radon daughter hazards in uranium mines

    International Nuclear Information System (INIS)

    Holaday, D.A.

    1974-11-01

    This monograph discusses primarily those health hazards to uranium miners which are produced by exposure to ionizing radiation. Emphasis is placed on the areas of evaluation of exposures to the radioactive gas radon-222 and its short-lived transformation products, and methods of controlling such exposures. A limited discussion of the biological effects of radon and radon daughters is undertaken, and some procedures are given for evaluating hazards created by other common contaminants of mine atmospheres. A large amount of information exists on these topics, some of which is unpublished or is not readily available. While efforts were made to obtain data from all sources, undoubtedly some valuable work was overlooked. The monograph is an endeavor to assemble pertinent information and make it available to those who are concerned with producing uranium at minimal risks. Where they were available, a variety of procedures for evaluating hazards are given, and examples of systems for controlling hazards are included. 154 references

  4. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France)

    International Nuclear Information System (INIS)

    Hubert, A.

    2005-09-01

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ( 234 U et 238 U), thorium ( 230 Th et 232 Th), 226 Ra and 222 Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during α-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and α-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  6. Measurement of short-lived particles at PETRA

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1987-04-01

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

  7. Fast Resonance Raman Spectroscopy of Short-Lived Radicals

    DEFF Research Database (Denmark)

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

    1976-01-01

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

  8. Soot and short-lived pollutants provide political opportunity

    Science.gov (United States)

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

    2015-09-01

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

  9. Methods and measurements of indoor levels of radon and its daughter products

    International Nuclear Information System (INIS)

    Subba Ramu, M.C.; Muraleedharan, T.S.; Ramachandran, T.V.; Shaikh, G.N.

    1988-01-01

    General population is exposed, some times, to enhanced levels of radon (Rn) and its progeny concontrations in the indoor environment of dwellings, depending on various parameters like type of construction, location and ventilation features of the dwelling as well as on the occupancy factor. The risk involved in the indoor Rn exposure is briefly discussed in this report. Several methods are available for the measurement of Rn and its daughters in dwellings. This report describes in detail some of the suitable and convenient methods for the measurements. Methods for evluating ventilation rate in dwellings is also given. Grab sampling and time integrated measurements are described. The report also gives the results of some preliminary measurements carried out in some rooms and lecture halls of the Bhabha Atomic Research Centre, Bombay. The results are discussed and conclusions drawn with particular reference to a country-wide survey of Rn exposure. (author)

  10. An analytic solution to the time-dependent first-daughter fission-product plateout problem for multi-region isothermal slug flow

    International Nuclear Information System (INIS)

    Durkee, J.W. Jr.; Lee, C.E.

    1985-01-01

    The time-dependent, axisymmetric, isothermal slug flow convective-diffusion equation with radioactive decay is solved analytically to predict the behavior of a first-daughter fission-product undergoing gaseous transport through multiple materials in a cylindrical pipe. The integration coefficients are determined using the Davidon variable metric minimization method. The behavior of fission-product material deposited on the conduit wall is described by a standard mass-transfer model. The time-dependent plateout rate behavior, determined previously for parent fission-product deposition, is again evident for daughter product plateout. Dominance of the daughter plateout by parent deposition characteristics is apparent. The determination of the daughter wall mass-transfer and diffusion coefficient using a least-squares analysis of measured data depends upon a reasonably low ratio of parent/daughter half-lives. This is illustrated with 137 Cs/ 137 Ba(=2x10 5 ) and 140 Ba/ 140 La(=7.6), where for 137 Cs/ 137 Ba the solution sensitivity to the 137 Ba deposition parameters is small and for 140 Ba/ 140 La a reasonable solution is readily obtained. (author)

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

    International Nuclear Information System (INIS)

    Franz, G.; Herrmann, G.

    1975-01-01

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

  12. Radon and its daughter products behaviour in the air of an underground tourist route in the former arsenic and gold mine in Zloty Stok (Sudety Mountains, SW Poland)

    International Nuclear Information System (INIS)

    Przylibski, Tadeusz Andrzej

    2001-01-01

    This paper describes the occurrence of radon and its daughter products in the accessible workings, partially open to the public, in the former arsenic and gold mine in Zloty Stok. The geology of the area and the characteristics of the workings provide the background for explanation of the genesis of radon and its daughter products and of the spatial and temporal variations in their concentrations. The results demonstrate that well-ventilated areas along the tourist route have the lowest values of all the measured parameters and that temporal variations of these parameters are irregular. The highest concentration values for radon (up to 18.50 kBq/m 3 ) and its daughter products (up to 14.49 kBq/m 3 ) have been recorded in the workings with obstructed natural ventilation. These are the areas where seasonal oscillations in the concentrations of these isotopes have been registered, with the maxima in summer and the minima in winter. These sections of the workings are inaccessible to the casual visitor. Radon is supplied to the workings from the side walls and its concentration is influenced, most of all, by ventilation and the degree of rock fissuring. The reason is the uniform and not very high content of 226 Ra in the rocks where the galleries were excavated. Only locally, in the workings of the Gertruda adit lying outside the tourist route, do open fault zones have significant influence on enhanced concentrations of radon and its daughter products. These fault zones constitute effective routes of radon migration to the workings. In spite of this, it must be stated that neither guides nor tourists are exposed to excessive concentrations of radon or its daughter products in the tourist route area. However, the extension of the route to other workings will require the introduction of forced ventilation in order to lower the concentration of radon and its daughter products

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

    International Nuclear Information System (INIS)

    Klein, Spencer R.; Nystrand, Joakim

    2001-01-01

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

  14. Study of the short-lived fission products. Separation of iodine and xenon fission radionuclides; Estudio de los productos de fision de periodo corto. Separacion de los radionuclidos de fision del yodo y del xenon

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, M; Villar, M A

    1965-07-01

    The separation by distillation in a sulfuric acid or phosphoric acid-hydrogen peroxide medium of the iodine isotopes (8 day iodine-131, 2,3 hour iodine-132 21 hour iodine-133, 53 minute iodine-134 and 6,7 hour iodine-135) present in a uranium sample after different irradiation and cooling times is here described. It is also reported the use of active charcoal columns for the retention of xenon isotopes (5,27 days xenon-133 and 9,2 hours xenon-135) either released during the dissolution of the uranium irradiated samples or generated along the fission isobaric chains in the solutions of distillated iodine. In both cases the radiochemical purity of the separated products is established by gamma spectrometry. (Author) 15 refs.

  15. Passive Mobile Bandwidth Classification Using Short Lived TCP Connections

    OpenAIRE

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

    2015-01-01

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

  16. Cyclotron targetry for production of short-lived positron emitters

    International Nuclear Information System (INIS)

    Schlyer, D.J.

    1989-01-01

    The basic concepts of cyclotron target design are presented along with the relevant practical experience gained by workers in this field over the years. Results are presented from several recent studies on the temperature and density distribution inside gas and liquid targets. 5 refs., 3 figs

  17. Radiochemical separation of mostly short-lived neutron activation products

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Kameník, Jan; Povinec, P. P.

    2017-01-01

    Roč. 311, č. 2 (2017), s. 1299-1307 ISSN 0236-5731. [1st International Conference on Radioanalytical and Nuclear chemistry (RANC). Budapest, 10.04.2016-15.04.2016] R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : determination * Vanadium * Iodine * Manganese * Silicon * Mercury * Selenium * Th-232 anad U-238 * SuperNEMO experiment Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 1.282, year: 2016

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

    International Nuclear Information System (INIS)

    Jentsch, Thorsten; Zeuner, Albert

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1974-01-01

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

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

    International Nuclear Information System (INIS)

    Kramer, H.H.

    1985-01-01

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

  1. QA Programme for Radon and its Short-Lived Progeny Measuring Instruments in NRPI Prague

    Czech Academy of Sciences Publication Activity Database

    Jílek, K.; Thomas, J.; Brabec, Marek

    2008-01-01

    Roč. 130, č. 1 (2008), s. 43-47 ISSN 0144-8420 Grant - others:GA SÚJB(CZ) JC_11/2006 Institutional research plan: CEZ:AV0Z10300504 Keywords : calibration * quality assurance * radon daughter products * uncertainty estimation Subject RIV: DI - Air Pollution ; Quality Impact factor: 0.951, year: 2008

  2. Some measurements of the equilibrium factor for radon daughters in houses

    International Nuclear Information System (INIS)

    Toohey, R.E.; Essling, M.A.; Wang, H.; Rundo, J.

    1982-01-01

    Because the radiation dose to the lung from environmental radon is due almost entirely to the inhalation of the short-lived daughter products, measurements of radon levels alone are not sufficient to determine the dose. Typically the activities of the daughter products in air are not in daughters themselves. The working level (WL) was introduced as a convenient unit to overcome this problem in uranium mines, and it is also applicable to other environments where radiation dosimetry is the principal concern. Since it is easier to determine the radon concentration than the working level, the task of determining lung doses would be simplified if those factors which determine equilibrium could be identified and their effects quantified. In order to do this, simultaneous measurements of radon concentrations and working levels must be made in houses under a variety of conditions. In addition, parameters that may affect the equilibrium factor, such as aerosol concentration and ventilation rate, must also be identified and monitored. Although the effects of such parameters may be best determined under controlled conditions in a laboratory, the results must be validated by measurements in houses. This paper describes these measurements

  3. Radon and its daughters in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Rundo, J

    1984-05-01

    Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. If the subject moved to an environment with a lower radon concentration from an environment with a higher level of radon, the result would be an exhalation of radon, and the initial exhalation rate of radon should depend of the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. The author reports a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. 8 figures.

  4. Radon and its daughters in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Rundo, J

    1984-05-01

    Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. Movement of the subject to an environment with a lower radon concentration from an environment with a higher level of radon would result in an exhalation of radon, and the initial exhalation rate of radon should depend on the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. We report a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. (author).

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

    International Nuclear Information System (INIS)

    Weiler, K.W.; Panagia, N.

    1978-01-01

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

  6. Electron scattering off short-lived radioactive nuclei

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

    Pike, V.W.

    1988-01-01

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

  8. Nondispersive x-ray diagnostics of short lived plasmas

    International Nuclear Information System (INIS)

    Day, R.H.

    1983-01-01

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

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

    CERN Multimedia

    2002-01-01

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

  10. Alpha-gamma decay studies of 253No and its daughter products 253Md, 249Fm

    International Nuclear Information System (INIS)

    Hessberger, F.P.; Antalic, S.; Kalaninova, Z.; Saro, S.; Venhart, M.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Kuusiniemi, P.; Lommel, B.; Mann, R.; Sulignano, B.; Hofmann, S.; Streicher, B.; Leino, M.; Nishio, K.

    2012-01-01

    Nuclear structure and decay of the isotope 253 No and its decay products 249 Fm and 253 Md were investigated by means of α - γ spectroscopy. Besides the established strong γ transitions from the 9/2 - [734] Nilsson level in 249 Fm, populated predominantly by the α decay of 253 No, into the ground-state (gs) rotational band, a couple of weaker γ lines (58.3, 129.2, 209.3 and 669.5keV) were observed and placed into the 249 Fm level scheme. The transition from the 7/2 - level in 249 Es, populated by the α decay of 253 Md, into the 9/2 + member of the gs rotational band, so far established for other odd-mass Es isotopes, was observed clearly. GEANT4 simulations were performed to investigate the influence of energy summing between α particles and conversion electrons (CE) on the shape of the α spectra at different implantation energies, leading to evidence for a weak α decay branch of 253 No into the gs of 249 Fm or the ground-state rotational band, respectively. (orig.)

  11. Simultaneous production of buds on mother and daughter cells of Saccharomyces cerevisiae in the presence of hydroxyurea

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, K; Michio, I

    1979-12-01

    Individual budding yeast cells, Saccharomyces cerevisiae, enclosed in small culture chambers were observed through two budding cycles to examine their behavior during growth and division. In the nutrient medium (YHG medium), the duration of the budding cycles was 77 minutes for mother cells and 90 minutes for daughter cells. Continuous exposure of cells to 16 or 32 mm hydroxyurea extended the duration of the cycles and increased the volume of cells, resulting in the formation of abnormally large and equal-sized mother-daughter pairs. Each cell of these pairs subsequently produced buds simultaneously. Stained cell nuclei showed simultaneous nuclear division. This synchronous budding on mother-daughter pairs was repeated in the next budding cycle. The coordination of growth with division is discussed in relation to these results.

  12. Measurement of the absolute activity of alpha or beta emitters by measuring product nuclei (daughter) activity increase or by studing its radioactive decay

    International Nuclear Information System (INIS)

    Campos, L.C. de.

    1981-01-01

    A new method for determining absolute activity of alpha or beta emitters by measuring daughter product radioactive decay is presented. The separation method of UX from hexahydrated uranyl nitrate UO 2 (NO 3 ) 2 6H 2 O based on its dissolution in ethyl ether is described and the accuracy of this method is shown. The factors which accuate on total efficiency of a Geiger Mueller detector for beta particles are determined. The possibility to determine the mass of precursor element by daughter nuclei activity is shown. The results are compared with the one obtained by direct measurement of the mass (or number of atoms) of precursor radioactive substance and with theoretical values calculated for isotopes in secular equilibrium. (Author) [pt

  13. CANALPH-3: a portable three-channel alpha spectrometer for measuring the daughter products of radon and thoron

    International Nuclear Information System (INIS)

    Carson, D.W.

    1979-07-01

    A portable three-channel alpha spectrometer for the measurment of radon and thoron daughters in uranium mines or homes is described. The computer programs for analysing the data to give the working levels of radon and thoron by both the alpha spectrometric and modified Kusnetz methods are included along with some typical results

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-17

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

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

    CERN Multimedia

    Wahl, U; Ronning, C R

    2007-01-01

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

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

    Science.gov (United States)

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

    2014-02-25

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

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Chaussidon, M.; Gounelle, M.

    2007-01-01

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

  19. New data on some short-lived isotopes of ruthenium and rhodium

    International Nuclear Information System (INIS)

    Baumgartner, F.; Plata Bedmar, A.

    1961-01-01

    Ru and Rd isotopes with mass numbers 107 and 108 and 1 09Rh, has been obtained from fission products. 1 07 Ru has also been prepared by the nuclear process 1 10Pd (n,α) 1 07 Ru. Beta and gamma energies of these nuclides have been studied spectropolarimetry and the gamma lines found for 1 07 Ru and 1 08Ru ( and daughter) have been very useful for the precise determination of their half-lives. 1 09Rh has been identified through its daughter 1 09Pd in the mixture of rhodium isotopes from fission products. Irradiation of natural palladium with fast neutrons has lead to an activity that may only be attributed to 1 10rh. Neither its half life nor its decay energy have been possible to determine accurately. (Author) 1 refs

  20. Dosimetry, measurement and properties of radon daughters and thoron daughters

    International Nuclear Information System (INIS)

    Phillips, C.R.

    1982-03-01

    Various properties of radon and thoron daughter products are examined. Dosimeter methods and instrumentation (TLD and personal alpha dosimeters) are investigated as to performance under varying conditions such as humidity and pure or mixed atmospheric conditions. Optimized counting schemes are determined for the daughters of radon and thoron. An optimized counting scheme was experimentally examined under mine conditions. The optimization procedure takes into account the uncertainties associated with concentration, flow rate and radioactive decay. Measurements were made in two uranium mines at Elliot Lake, Ontario of the charged and unattached fractions of radon daughters in the mines. The physicochemical state of 218 Po in air was determined by measurement of rate of neutralization, diffusion coefficient and fraction born charge. Careful control of experimental conditions made it possible to obtain more precise and detailed quantitative data than previously possible

  1. Assessment of Effective Dose Equivalent of Indoor 222Rn Daughters in Inchass

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmad, A.A.

    2000-01-01

    The dominant component of natural radiation dose for the general population comes from the radon gas 222 Rn and its short-lived decay products, Ra A ( 214 Po), Ra B ( 214 Pb), Ra C ( 214 Bi), Ra C( 214 Po) in the breathing air. The objective of the present work is to assess the affective dose equivalent of the inhalation exposure of indoor 222 Rn for occupational workers. Average indon concentrations (Bqm -3 ) were monitored in several departments in Nuclear Research Center by radon monitor. We have calculated the lung dose equivalent and the effective dose equivalent for the Egyptian workers due to inhalation exposure of an equilibrium equivalent concentrations of radon daughters which varies from 0.27 to 2.5 mSvy -1 and 0.016 to 0.152mSvy -1 respectively. The annual effective doses obtained are within the accepted range of ICRP recommendations

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

    International Nuclear Information System (INIS)

    Loberg, M.D.

    1985-01-01

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

  3. Orphan radon daughters at Denver Radium site

    International Nuclear Information System (INIS)

    Holub, R.F.; Droullard, R.F.; Davis, T.H.

    1992-01-01

    During 18 mo of sampling airborne radioactively at a National Priority List (open-quotes Superfundclose quotes) site in metroPOlitan Denver, Bureau of mines personnel discovered radon daughters that are not supported by the parent radon gas. We refer to them as open-quotes orphanclose quotes daughters because the parent, radon, is not present in sufficient concentration to support the measured daughter products. Measurements of the open-quotes orphanclose quotes daughters were made continuously, using the Bureau-developed radon and working-level (radon-daughter) monitors. The data showed high equilibrium ratios, ranging from 0.7 to 3.5, for long periods of time. Repeated, high-volume, 15-min grab samples were made, using the modified Tsivoglou method, to measure radon daughters, to which thoron daughters contributed 26 ± 12%. On average 28 ± 6% of the particulate activity was contributed by thoron daughters. Most samples were mixtures in which the 218 Po concentration was lower than that of 214 Pb and 214 Bi, in agreement with the high-equilibrium factors obtained from the continuous sampling data. In view of the short half-life of radon progeny, we conclude that the source of the orphan daughters is not far from the Superfund sites. The mechanism of this phenomenon is not understood at this time, but we will discuss its possible significance in evaluating population doses

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

    International Nuclear Information System (INIS)

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

    1984-11-01

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

  5. Emanation of /sup 232/U daughter products from submicrometer particles of uranium oxide and thorium dioxide by nuclear recoil and inert gas diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, M.A.; Cuddihy, R.G. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (USA). Inhalation Toxicology Research Inst.)

    1983-01-01

    Emanation of /sup 232/U daughter products by nuclear recoil and inert gas diffusion from spherical, submicrometer particles of uranium oxide and thorium dioxide was studied. Monodisperse samples of particles containing 1% /sup 232/U and having physical diameters between 0.1 and 1 ..mu..m were used for the emanation measurements. Thorium-228 ions recoiling from the particles after alpha-decay of /sup 232/U were collected electrostatically on a recoil cathode. Radon-220 diffusing from the particles was swept by an airstream into a 4 l. chamber where the /sup 220/Rn daughters were collected on a second cathode. Mathematical models of radionuclide emanation from spherical particles were used to calculate the recoil range of /sup 228/Th and the diffusion coefficient of /sup 220/Rn in the particle matrix. A /sup 228/Th recoil range of 0.02 ..mu..m and a /sup 220/Rn diffusion coefficient of 3 x 10/sup -14/ cm/sup 2//sec were obtained in both uranium oxide and thorium dioxide particles.

  6. Radon and its daughter products behaviour in the air of an underground tourist route in the former arsenic and gold mine in Złoty Stok (Sudety Mountains, SW Poland).

    Science.gov (United States)

    Przylibski, T A

    2001-01-01

    This paper describes the occurrence of radon and its daughter products in the accessible workings, partially open to the public, in the former arsenic and gold mine in Zloty Stok. The geology of the area and the characteristics of the workings provide the background for explanation of the genesis of radon and its daughter products and of the spatial and temporal variations in their concentrations. The results demonstrate that well-ventilated areas along the tourist route have the lowest values of all the measured parameters and that temporal variations of these parameters are irregular. The highest concentration values for radon (up to 18.50kBq/m3) and its daughter products (up to 14.49kBq/m3) have been recorded in the workings with obstructed natural ventilation. These are the areas where seasonal oscillations in the concentrations of these isotopes have been registered, with the maxima in summer and the minima in winter. These sections of the workings are inaccessible to the casual visitor. Radon is supplied to the workings from the side walls and its concentration is influenced, most of all, by ventilation and the degree of rock fissuring. The reason is the uniform and not very high content of 226Ra in the rocks where the galleries were excavated. Only locally, in the workings of the Gertruda adit lying outside the tourist route, do open fault zones have significant influence on enhanced concentrations of radon and its daughter products. These fault zones constitute effective routes of radon migration to the workings. In spite of this, it must be stated that neither guides nor tourists are exposed to excessive concentrations of radon or its daughter products in the tourist route area. However, the extension of the route to other workings will require the introduction of forced ventilation in order to lower theconcentration of radon and its daughter products. reserved.

  7. Personal radon daughter dosimetry

    International Nuclear Information System (INIS)

    Stocker, H.

    1979-12-01

    The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

  8. Measurements of 222Rn and its daughters and estimation of internal doses to workers in underground buildings

    International Nuclear Information System (INIS)

    Cao Jianping; Lu Zhizhao; Li Yuanshan

    1993-03-01

    The results of concentration measuring of 222 Ru and its daughters and estimation of internal doses to workers in the underground buildings at Nanjing city are presented. The double filtering membrane method and Thomas method were used in the monitoring of 222 Rn and its daughters, and the dose conversion factor was taken from the latest UNSCEAR report. Concentration distributions of 222 Rn and its daughters were approximately log-normal. The geometric means for 222 Rn was 40.5 Bq · m -3 and for its daughters was 1.4 x 10 -7 J · m -3 . The equilibrium factor was 0.63. The radioactive equilibrium ratio between short-lived 222 Rn daughters was 1:0.57:0.49. The estimation value of annual effective dose equivalent from 222 Rn daughters to workers working at underground sites was 1.3 mSv, which was 86% higher than that of those working on ground sites

  9. History and review of short-lived radionuclide development

    International Nuclear Information System (INIS)

    Myers, W.G.

    1985-01-01

    The use of twinkling atoms in biomedicine is discussed from the historical point of view. Their discovery, production, and applications are described. The development of modern nuclear medicine from its inception, e.g., the first simple applications, to the latest complex studies are described with special emphasis on the applications of the ideal radionuclide - iodine-123

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

    Science.gov (United States)

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

    2015-12-15

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

  11. On Al-26 and other short-lived interstellar radioactivity

    Science.gov (United States)

    Clayton, Donald D.; Hartmann, Dieter H.; Leising, Mark D.

    1993-01-01

    Several authors have shown that massive stars exploding at a rate of about three per century can account for a large portion, if not all, of the observed interstellar Al-26. In a separate argument using models of Galactic chemical evolution, Clayton (1984) showed that the Al-26/Al-27 production ratio was not large enough to maintain enough Al-26 in the Galactic disk gas of about 10 exp 10 solar masses having solar composition. We present a resolution of those conflicting arguments. A past history of Galactic infall growing the Galactic disk so dilutes the stable Al-27 concentration that the two approaches can be brought into near agreement. If massive stars dominate the production of Al-26, we suggest that the apparent shortfall of their Al-26/Al-27 yield ratio is to be interpreted as evidence for significant growth of the Galactic disk. We also discuss the implications of these arguments for other extinct radioactivities in meteorites, using I-129 and Sm-146 as examples.

  12. Tropospheric Ozone as a Short-lived Chemical Climate Forcer

    Science.gov (United States)

    Pickering, Kenneth E.

    2012-01-01

    Tropospheric ozone is the third most important greenhouse gas according to the most recent IPCC assessment. However, tropospheric ozone is highly variable in both space and time. Ozone that is located in the vicinity of the tropopause has the greatest effect on climate forcing. Nitrogen oxides (NOx) are the most important precursors for ozone In most of the troposphere. Therefore, pollution that is lofted upward in thunderstorm updrafts or NOx produced by lightning leads to efficient ozone production in the upper troposphere, where ozone is most important climatically. Global and regional model estimates of the impact of North American pollution and lightning on ozone radiative forcing will be presented. It will be shown that in the Northern Hemisphere summer, the lightning effect on ozone radiative forcing can dominate over that of pollution, and that the radiative forcing signal from North America extends well into Europe and North Africa. An algorithm for predicting lightning flash rates and estimating lightning NOx emissions is being incorporated into the NASA GEOS-5 Chemistry and Climate Model. Changes in flash rates and emissions over an ENSO cycle and in future climates will be assessed, along with the resulting changes in upper tropospheric ozone. Other research on the production of NOx per lightning flash and its distribution in the vertical based on cloud-resolving modeling and satellite observations will be presented. Distributions of NO2 and O3 over the Middle East from the OMI instrument on NASA's Aura satellite will also be shown.

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

    Science.gov (United States)

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

    2017-08-24

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

  14. Measure of exposure of short-lived radon products using an alpha spectrometer for measuring indoor aerosol activity concentration and dose evaluation; Misure di esposizione ai prodotti di decadimento del radon a breve vita tramite uno spettrometro alfa per la misura dell'attivita' del particolato atmosferico indoor e valutazioni dosimetriche

    Energy Technology Data Exchange (ETDEWEB)

    Berico, M.; Castellani, C.M.; Formignani, M. [ENEA, Divisione Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche Ezio Clementel, Bologna (Italy); Mariotti, F. [Bologna Univ., Bologna (Italy). Dipt. di Fisica

    2001-07-01

    A new italian law introduces the regulation of occupational exposure to radon. To evaluate the inhalation of radon daughters by the workers a sampling device has been assembled with the aim of evaluation of unattached and aerosol attached radon daughters' fractions. The instrument, based on selection of the aerosuspended particles by means of a wire screen type battery and subsequent collection on a total filter, allows to describe the behaviour of both fractions using defined temporal pattern of collecting particles and counting them by alpha spectroscopy. A measurement campaign to test the radon daughter dichotomous spectrometer in comparison with a commercial Radon Working Level meter, has been performed in a research laboratory of central Italy affected by high radon concentrations. The radon concentration during the measurement campaign has been also measured. The equilibrium factor F{sub e}q ad the attachment factor fp have been evaluated during 3 days campaign. Using the measured mean parameters (radon concentration, F{sub e}q, f{sub p}) the dose evaluation for workers using dosimetric approach has been performed. A comparison between the epidemiologic approach, based on the radon concentration, and dosimetric approach is also presented. [Italian] L'esposizione a radon in ambiente lavorativo e la conseguente inalazione dei suoi prodotti di decadimento in forma particolata e' oggetto di una recente normativa italiana in materia di protezione dalle radiazioni ionizzanti. Per rispondere a questa necessita', presso l'Istituto per la Radioprotezione dell'ENEA di Bologna e' stato progettato e realizzato uno spettrometro alfa per la misura della progenie del radon con la finalita' di valutare, su brevi periodi di tempo, la concentrazione individuale dei suoi prodotti di decadimento e, con l'impiego di batterie a diffusione a reti, consentire inoltre la discriminazione della concentrazione della frazione attaccata e non

  15. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    This patent describes a portable radon daughter dosimeter unit used to measure radon gas alpha daughters in ambient air. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as in uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout displays the result in terms of working level-hours

  16. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    A portable radon daughter dosimeter unit used to measure Radon gas alpha daughters in ambient air is described. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout diplays the result in terms of working level-hours

  17. Passive radon daughter dosimeters

    International Nuclear Information System (INIS)

    McElroy, R.G.C.; Johnson, J.R.

    1986-03-01

    On the basis of an extensive review of the recent literature concerning passive radon daughter dosimeters, we have reached the following conclusions: 1) Passive dosimeters for measuring radon are available and reliable. 2) There does not presently exist an acceptable passive dosimeter for radon daughters. There is little if any hope for the development of such a device in the foreseeable future. 3) We are pessimistic about the potential of 'semi-passive dosimeters' but are less firm about stating categorically that these devices cannot be developed into a useful radon daughter dosimeter. This report documents and justifies these conclusions. It does not address the question of the worker's acceptance of these devices because at the present time, no device is sufficiently advanced for this question to be meaningful. 118 refs

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

    Science.gov (United States)

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

    2014-01-01

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

  19. Radon and radon daughter monitoring (including thoron daughter monitoring)

    International Nuclear Information System (INIS)

    Leach, V.A.; Grealy, G.; Gan, W.

    1982-01-01

    Radon/radon daughter and thoron daughter measurement techniques are outlined. The necessary precautions and critical assessments of each method are also presented with a view to providing a better understanding of the various measurement methods

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  1. Daughters on Hunger Strike

    Directory of Open Access Journals (Sweden)

    Ann Wan-lih Chang

    2008-03-01

    Full Text Available This essay explores the embattled interactions between mothers and daughters in the stories by Edna O’Brien, Mary Lavin, Éilís Ní Dhuibhne and Mary Leland. This conflict involves an underlying distorted intimacy between women within a patriarchal Irish context. The daughter in the stories seeks to rebel against the ‘choking love’ of the tyrannical ‘patriarchal mother’ through a symbolic anorexia, in which the daughter rejects the mother’s food or the food associated with the mother. The mother is also shown to feel ambivalent and resistant towards the daughter’s attempt to break from her dependence upon the mother. The conflict and resistance between mothers and daughters in these stories can be evaluated against the framework of the patriarchal context in which women as mothers are silenced and made powerless in front of the ‘Father,’ and therefore, this resistance can be interpreted as a reaction to this patriarchal ideology and its framework in Irish society. The lost bond between older and younger women needs to be rediscovered and restored by a realisation of patriarchal ideology and furthermore, identification with female subjectivity. This identification between women seems to act as a source of redemption for women of different generations, which results in both liberating themselves from the patriarchal dogma.

  2. Parent-daughter equilibria in ocean arising out of disposal of solid radioactive wastes on the sea bed

    International Nuclear Information System (INIS)

    Sarma, T.P.; Krishnamoorthy, T.M.

    1986-01-01

    One dimension diffusion model, incorporating geochemical elimination and reflection at ocean boundaries, is employed to show the differences in spatial and temporal distribution of parent and daughter radionuclides, produced in situ, due to the discharge of solid radioactive wastes on to the sea bed. Concentration of daughter is generally lower than that of parent in deep waters. Short-lived daughters (relative to parent) reach spatial equilibrium with parent for finite periods whereas long-lived daughters attain only a fraction of the parent activity. However, when the dumping operation is assumed to be for infinite period, the relative ratio of concentration of daughter to parent would reach value > 1 in surface waters irrespective of the half-lives of the daughter and the magnitude of this ratio increases with increase in half-life of the daughter relative to the parent. This is the result of steep vertical gradient for the parent due to the small physical half-life and more or less uniform concentration of long-lived daughter. Geochemical elimination rate, when becomes significant in the overall removal processes, controls this differential spatial gradient of daughter and parent. However, the integrated activity of daughter over the entire depth is equal to or less than the parent activity. (author)

  3. Periconceptional Heat Stress of Holstein Dams Is Associated with Differences in Daughter Milk Production and Composition during Multiple Lactations.

    Directory of Open Access Journals (Sweden)

    Britni M Brown

    Full Text Available Heat stress at the time of conception affects the subsequent milk production of primiparous Holstein cows; however, it is unknown whether these effects are maintained across multiple lactations. Therefore, the objective of the current study was to examine the relationship between periconceptional heat stress and measurements of milk production and composition in cows retained within a herd for multiple lactations. National Dairy Herd Improvement Association data was obtained from Dairy Records Management Systems. Records included milk production data and milk composition data from over 75,000 and 44,000 Holstein cows, respectively, born between 2000 and 2010 in Florida, Georgia, and Texas. Conception dates were calculated by subtracting 276 d from the recorded birth date. Records for cows conceived within the months of June, July, and August were retained as heat stress conceived (HSC cows; cows conceived within the months of December, January, and February were retained as thermoneutral conceived (TNC contemporaries. Adjusted 305-d mature equivalent milk, protein percent and fat percent were evaluated with a mixed model ANOVA using SAS. Milk production was significantly affected by periconceptional heat stress. When a significant difference or tendency for a difference was detected between the HSC and TNC cows, the TNC produced more milk in all but one comparison. The advantage in milk production for the TNC cows over the HSC cows ranged from 82 ± 42 to 399 ± 61 kg per lactation. Alterations in fat and protein percentage were variable and most often detected in first lactations (first > second or third. Overall, the most striking result of this study is the consistency of the relationship between HSC and milk production. The nature of this relationship suggests that heat stress at or around the time of conception impairs cow milk yield throughout her lifetime.

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

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

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1985-09-01

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

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

    African Journals Online (AJOL)

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

    Paras, P.; Thiessen, J.W.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1985-09-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    CERN Document Server

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  16. TRIENNIAL LACTATION SYMPOSIUM/BOLFA: Late gestation heat stress of dairy cattle programs dam and daughter milk production.

    Science.gov (United States)

    Dahl, G E; Tao, S; Laporta, J

    2017-12-01

    Anticipated increases in the world population to 9 billion people will lead to increased demand for food. Dairy products represent one of the most sustainable animal sources of food protein because ruminants can utilize byproduct and forage feeds unsuitable for human consumption. Continued improvements in productivity will depend on deeper understanding of the biology of lactation, including developmental programming of tissues critical to that process. Although prenatal programming of postnatal phenotype is well documented for growth, behavior, and disease, there may also be instances of "programming" that last for a specific physiological stage (e.g., lactation). We distinguish between these 2 terms by the use of developmental programming to describe a permanent effect, whereas the more general term is used to describe nonpermanent impacts on the mammary gland. Despite this complexity, here we review the evidence that exposure to elevated temperature and humidity during late gestation can program reduced yields in the subsequent lactation, largely through effects at the mammary gland. Furthermore, we provide emerging evidence that adult capacity for milk synthesis can be programmed in the calf that dam is carrying by events during fetal life occurring 2 yr before. Specifically, calves born to dams that are heat stressed for the final 6 wk of gestation produce 19% less milk in lactation relative to calves from dams provided with evaporative cooling. Importantly, the increased milk yield in animals derived from dams under evaporative cooling occurred without a greater decline in BW that accompanies negative energy balance during early lactation. Therefore, the increase in milk production suggests an increase in the efficiency of conversion of feed to milk. These data indicate that a brief period of heat stress late in development reduces the physiological efficiency of the cow in a coordinated manner to result in a substantial decline in productivity. It is likely

  17. Removal of radon daughters from indoor air

    International Nuclear Information System (INIS)

    Jonassen, N.

    1985-01-01

    The internal radiological exposure of the general population is largely due to the airborne daughter products of radon and thoron, which are found in two states, attached to aerosols or unattached, of which the latter species according to several dose models have the highest radiological dose efficiency of the two. The radon daughters may be removed from indoor air by a series of processes like ventilation, filtration, plateout, and electrostatic deposition. Ventilation (with radon-free air) is, on the one hand, a very effective measure, but usually involves introduction of colder air, in variance with energy-saving efforts. Internal filtration will not affect the radon concentration but may reduce the level of daughter activities, roughly inversely proportional to the filtration rate. At the same time, however, filtration may also change the aerosol distribution and concentration of the air and, consequently, the partitioning of the radon daughters between the attached and unattached state. This, in turn, influences the rate of deposition of radon daughters both by diffusional plateout and as an effect of an electric field. Experiments are reported demonstrating reductions in the airborne potential alpha energy by factors of 4 to 5 by use of filtration rates of 3-4 times per hour. In case of low aerosol concentrations, however, the corresponding reduction in radiological dose to critical parts of the respiratory tract may be much smaller, due to the shift toward higher fractions of the radon daughters being in the unattached state caused by the filtration. The possibility of using electrostatic deposition of radon daughters is also discussed

  18. Periconceptional Heat Stress of Holstein Dams Is Associated with Differences in Daughter Milk Production during Their First Lactation.

    Science.gov (United States)

    Brown, Britni M; Stallings, Jon W; Clay, John S; Rhoads, Michelle L

    2016-01-01

    The fertility of lactating Holstein cows is severely reduced during periods of heat stress. Despite this reduction in fertility, however, some inseminations conducted during heat stress result in successful pregnancies from which heifer calves are born. Many of these heifer calves are retained and raised to enter the milking herd as replacement animals. Heat stress experienced by these females around the time they were conceived may confer long-lasting effects that alter subsequent milk production capacity. The objective of this study was to examine the relationship between periconceptional heat stress and subsequent milk production of primiparous cows. National Dairy Herd Improvement Association data was obtained from Dairy Records Management Systems. Records included Holstein cows that had completed at least one lactation in one of three states with large populations of dairy cattle and which are known for having hot, humid summers: Georgia, Florida or Texas. Dates of conception were calculated by subtracting 276 d from the recorded birth date of each individual cow. Records for cows conceived within the months of June, July, and August were retained as heat stress-conceived (HSC) cows (n = 94,440); cows conceived within the months of December, January, and February were retained as thermoneutral-conceived (TNC) contemporaries (n = 141,365). In order to account for the effects of environmental conditions on total milk production for a given lactation, cows were blocked by season of calving (winter, spring, summer or fall). Adjusted 305-day mature-equivalent milk production was evaluated with a mixed model ANOVA using SAS, in which random effects were used to account for variability between herds. Of the cows that calved in the summer, fall and winter, TNC cows had higher milk yield than the HSC cows in all states. Interestingly, the cows that calved in the spring presented a unique relationship, with HSC cows producing more milk. Overall however, heat stress at

  19. Periconceptional Heat Stress of Holstein Dams Is Associated with Differences in Daughter Milk Production during Their First Lactation.

    Directory of Open Access Journals (Sweden)

    Britni M Brown

    Full Text Available The fertility of lactating Holstein cows is severely reduced during periods of heat stress. Despite this reduction in fertility, however, some inseminations conducted during heat stress result in successful pregnancies from which heifer calves are born. Many of these heifer calves are retained and raised to enter the milking herd as replacement animals. Heat stress experienced by these females around the time they were conceived may confer long-lasting effects that alter subsequent milk production capacity. The objective of this study was to examine the relationship between periconceptional heat stress and subsequent milk production of primiparous cows. National Dairy Herd Improvement Association data was obtained from Dairy Records Management Systems. Records included Holstein cows that had completed at least one lactation in one of three states with large populations of dairy cattle and which are known for having hot, humid summers: Georgia, Florida or Texas. Dates of conception were calculated by subtracting 276 d from the recorded birth date of each individual cow. Records for cows conceived within the months of June, July, and August were retained as heat stress-conceived (HSC cows (n = 94,440; cows conceived within the months of December, January, and February were retained as thermoneutral-conceived (TNC contemporaries (n = 141,365. In order to account for the effects of environmental conditions on total milk production for a given lactation, cows were blocked by season of calving (winter, spring, summer or fall. Adjusted 305-day mature-equivalent milk production was evaluated with a mixed model ANOVA using SAS, in which random effects were used to account for variability between herds. Of the cows that calved in the summer, fall and winter, TNC cows had higher milk yield than the HSC cows in all states. Interestingly, the cows that calved in the spring presented a unique relationship, with HSC cows producing more milk. Overall however

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    International Nuclear Information System (INIS)

    Paras, P.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Morel P.

    2011-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Tassan-Got L.

    2012-02-01

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

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

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

    International Nuclear Information System (INIS)

    Krohn, K.A.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    2010-06-01

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

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

    International Nuclear Information System (INIS)

    2009-06-01

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

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

    International Nuclear Information System (INIS)

    2011-06-01

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

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

    CERN Document Server

    Zhang, Yan; Kawai, Yoko

    2005-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

    Guerra, Citlali

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

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

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

    International Nuclear Information System (INIS)

    Selikson, M.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Kawase, Yoichi

    1995-01-01

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

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

    Science.gov (United States)

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

    2001-07-01

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

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

    International Nuclear Information System (INIS)

    Boyazis, Jean-Paul

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Grass, F [Atominstitut, Vienna (Austria)

    1976-07-01

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

  20. Preliminary findings radon daughter levels in structures constructed on reclaimed Florida phosphate land

    International Nuclear Information System (INIS)

    1975-09-01

    Preliminary results are reported from a survey of the radon daughter levels in structures in Polk County, Florida, built on reclaimed phosphate tailings containing various amounts of 226 Ra. The structures surveyed consisted primarily of private dwellings although a few office buildings were also surveyed. Track-etch films and TLD air samplers were used to measure the levels of radon daughters within the structures and in structures built on non-phosphate land. Radiation levels were converted to WL units (the working level (WL) unit is defined as the potential α energy from the short-lived daughters of Rn which will produce 1.3 x 10 5 MeV in one liter of air). The highest observed level in any structure was 0.2 WL. Possible health hazards to long-time occupants are discussed

  1. Time sequence determination of parent–daughter radionuclides using gamma-spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, J. L.; Britton, R. E.; Abrecht, D. G.; Davies, A. V.

    2017-05-06

    The acquisition of time-stamped list (TLIST) data provides additional information useful to gamma-spectrometry analysis. A novel technique is described that uses non-linear least-squares fitting and the Levenberg-Marquardt algorithm to simultaneously determine parent-daughter atoms from time sequence measurements of only the daughter radionuclide. This has been demonstrated for the radioactive decay of short-lived radon progeny (214Pb/214Bi, 212Pb/212Bi) described using the Bateman first-order differential equation. The calculated atoms are in excellent agreement with measured atoms, with a difference of 1.3 – 4.8% for parent atoms and 2.4% - 10.4% for daughter atoms. Measurements are also reported with reduced uncertainty. The technique has potential to redefine gamma-spectrometry analysis.

  2. Methodology and experimental setup for measuring short-lives fission product yields in actinides induced fission by charged particles; Metodologia e montagem experimental para a medicao de rendimentos de produtos de fissao de meia vida curta na fissao de actinideos por particulas carregadas

    Energy Technology Data Exchange (ETDEWEB)

    Bellido, A.V.

    1995-07-01

    The theoretical principles and the laboratory set-up for the fission products yields measurements are described. The procedures for the experimental determinations are explain in detail. (author). 43 refs., 5 figs.

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

    Science.gov (United States)

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

    2015-09-01

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

  4. Alpha-particle dosimetry using solid state nuclear track detectors. Application to 222Rn and its daughters

    International Nuclear Information System (INIS)

    Barillon, R.; Chambaudet, A.

    2000-01-01

    A methodology for the determination of the detection efficiency of a solid state nuclear track detector for radon and its short-lived daughters was presented. First, particular attention is paid to the α-particles having energies and angles of incidence that lead to observable tracks after an adapted chemical etching. The results are then incorporated in a mathematical model to determine the theoretical radon detection efficiency of a polymeric detector placed in a cylindrical cell. When applied to LR115 and CR39 detectors, the model reveals the influence of the position of the radon daughters inside the cell. Radon daughters tend to link up with natural atmospheric aerosols and then settle on the cell's inside wall. This model allows to determine, among other things, the cell size for which the detector response is independent of the fraction daughters plated out. (author)

  5. In situ Ge(Li)-spectrometric measurements of gamma radiation from radon daughters under different weather conditions

    International Nuclear Information System (INIS)

    Finck, R.R.; Persson, B.R.R.

    1980-01-01

    The photon fluence from radionuclides in the ground and air was measured continuously with a Ge(Li) spectrometer during several weeks. The most prominent change in photon fluence rate near the ground was obtained during periods of heavy rainfall. Deposition of the short-lived radon daughters 214 Pb and 214 Bi on the ground surface can cause a temporary increase in the external absorbed dose rate of approximately 2μrads/h. The photon fluence from airborne radon daughters can be correlated to the degree of atmospheric stability. During stable conditions the photon fluence increases and the activity ratio 214 Bi/ 214 Pb decreases

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-09-01

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

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

    International Nuclear Information System (INIS)

    Schuessler, H.A.

    1986-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

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

    International Nuclear Information System (INIS)

    Lamb, E.

    1985-01-01

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

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

    Science.gov (United States)

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

    2014-10-01

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

  12. Computations of concentration of radon and its decay products against time. Computer program; Obliczanie koncentracji radonu i jego produktow rozpadu w funkcji czasu. Program komputerowy

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1996-12-31

    This research is aimed to develop a device for continuous monitoring of radon in the air, by measuring alpha activity of radon and its short lived decay products. The influence of alpha activity variation of radon and its daughters on the measured results is of importance and requires a knowledge of this variation with time. Employing the measurement of alpha radiation of radon and of its short lived decay products, require knowledge of radon concentration variation and its decay products against the time. A computer program in Turbo Pascal language was therefore developed performing the computations employing the known relations involved, the program being adapted for IBM PC computers. The presented program enables computation of activity of {sup 222}Rn and its daughter products: {sup 218}Po, {sup 214}Pb, {sup 214}Bi and {sup 214}Po every 1 min within the period of 0-255 min for any state of radiation equilibrium between the radon and its daughter products. The program permits also to compute alpha activity of {sup 222}Rn + {sup 218}Po + {sup 214}Po against time and the total alpha activity at selected interval of time. The results of computations are stored on the computer hard disk in ASCII format and are used a graphic program e.g. by DrawPerfect program to make diagrams. Equations employed for computation of the alpha activity of radon and its decay products as well as the description of program functions are given. (author). 2 refs, 4 figs.

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

    International Nuclear Information System (INIS)

    Bruechle, W.

    1976-01-01

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

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

    International Nuclear Information System (INIS)

    Orr, J.S.

    1979-01-01

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

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

    Directory of Open Access Journals (Sweden)

    S. Menon

    2008-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-24

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

  17. Direct determination of 222Rn gas using the electret to remove daughters at formation. Annual progress report, June 1, 1981-May 31, 1982

    International Nuclear Information System (INIS)

    Harley, N.H.

    1982-01-01

    This report covers progress made from 1 June 1981 to 31 May 1982 in developing a continuous monitor which measures only 222 Rn without interference from the daughters. Five 222 Rn counters have been built which determine 222 Rn alone by alpha scintillation counting in the presence of an electret to remove the short-lived daughter products from the counting chamber. The chamber design is based on the work of Chittaporn et al., (1981) at New York University's Department of Environmental Medicine. The detection chamber is a 1.8 liter (12.7 cm diameter by 14 cm high) cylinder lined with zinc sulfide alpha phosphor. The detector sits directly on a 12.7 cm diameter phototube. The 5 units have calibration factors which range from 155 to 186 counts/hour per pCi 222 Rn/liter and an average background count of 6 counts/hour. The lower limit of detection for a one hour count is thus 0.03 pCi 222 Rn/l, well below environmental levels

  18. Review of epidemiological studies on hazards of radon daughters

    International Nuclear Information System (INIS)

    Myers, D.K.; Stewart, C.G.; Johnson, J.R.

    1981-01-01

    A review, with nearly 100 references, of the biological effects of radon and radon daughters is presented. Calculations of the relative dose from daughter products, as well as of the variation in dose with such things as unattached fraction, particle size, age and breathing rate are discussed. Estimates of annual risk of lung cancer in miners after inhalation of thoron daughters are given, and compared with hazards of employment in various US industries. The implications of these epidemiological studies for future regulations are discussed

  19. Lung dose and lung cancer risk by inhalation of radon daughters

    International Nuclear Information System (INIS)

    Jacobi, W.

    1983-01-01

    The inhalation of short-lived radon daughters constitutes the most important occupational radiation exposure in mines, particularly in uranium mines. Among some groups of miners exposed in the past to relatively high radon levels, an excess lung cancer incidence has been observed. In addition to this occupational hazard, the observed radon levels in domestic houses indicate that the inhalation of short-lived radon daughters seems to be the most important component of the radiation exposure of the population from natural sources. For the quantification and judgment of the radiological impact by inhalation of radon daughters in mines as well as in houses, it is necessary to estimate the relationships between the inhaled activity or potential alpha (α) energy of these radionuclides, the dose to target tissues in the lung, and the possible associated lung cancer (LC) risk. It is the purpose of this paper to give a condensed review of our present knowledge in this field and to indicate the main gaps and uncertainties where future research seems necessary

  20. Proceedings of the 9. international conference on health effects of incorporated radionuclides emphasis on radium, thorium, uranium and their daughter products - HEIR 2004

    Energy Technology Data Exchange (ETDEWEB)

    Oeh, U.; Roth, P.; Paretzke, H.G. (eds.) [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany)

    2005-07-01

    The ninth international conference on 'Health Effects of Incorporated Radionuclides - Emphasis on Radium, Thorium, Uranium and their Daughter Products' HEIR 2004 was held at GSF-National Research Center for Environment and Health, Neuherberg, Germany, from November 29 until December 1, 2004. The growing popularity of this topic among the scientific community, especially the radiation protection community, was demonstrated by the largest number of participants in comparison to the earlier conferences. In all, there were 157 participants from 20 different countries of the world. In the conference 62 scientific and 12 poster presentations were included in 13 sessions. The scope of the conference covered studies related to the long-term follow-up of thorotrast subjects in Japan, Germany and Portugal, and also of the subjects exposed to Ra-224 for the treatment of bone tuberculosis and ankylosing spondylitis. The studies and discussions on these topics are important in view of the large number of liver cancers observed in the thorotrast patients and the number of bone cancers in the cases treated with Ra-224. A growth stunting was also observed for the subjects who received the Ra-224 injections early in their lives. Besides atom bomb survivors, the data from thorotrast patients could well help towards a better understanding of the health effects of irradiations. In addition to the scientific presentations on the above topics, there were a number of presentations on the incidence of lung cancer from radon exposure of miners and plutonium exposures causing lung cancer among the Mayak workers in the Russian Federation. Other stimulating presentations were on the tissue damaging mechanisms of alpha particles, having very high L.E.T., and also the related radiation weighting factor in comparison to beta and gamma radiations. There were also interesting presentations on the topics of uncertainties involved in the internal dose assessment from radiation exposure and

  1. Proceedings of the 9. international conference on health effects of incorporated radionuclides emphasis on radium, thorium, uranium and their daughter products - HEIR 2004

    International Nuclear Information System (INIS)

    Oeh, U.; Roth, P.; Paretzke, H.G.

    2005-01-01

    The ninth international conference on 'Health Effects of Incorporated Radionuclides - Emphasis on Radium, Thorium, Uranium and their Daughter Products' HEIR 2004 was held at GSF-National Research Center for Environment and Health, Neuherberg, Germany, from November 29 until December 1, 2004. The growing popularity of this topic among the scientific community, especially the radiation protection community, was demonstrated by the largest number of participants in comparison to the earlier conferences. In all, there were 157 participants from 20 different countries of the world. In the conference 62 scientific and 12 poster presentations were included in 13 sessions. The scope of the conference covered studies related to the long-term follow-up of thorotrast subjects in Japan, Germany and Portugal, and also of the subjects exposed to Ra-224 for the treatment of bone tuberculosis and ankylosing spondylitis. The studies and discussions on these topics are important in view of the large number of liver cancers observed in the thorotrast patients and the number of bone cancers in the cases treated with Ra-224. A growth stunting was also observed for the subjects who received the Ra-224 injections early in their lives. Besides atom bomb survivors, the data from thorotrast patients could well help towards a better understanding of the health effects of irradiations. In addition to the scientific presentations on the above topics, there were a number of presentations on the incidence of lung cancer from radon exposure of miners and plutonium exposures causing lung cancer among the Mayak workers in the Russian Federation. Other stimulating presentations were on the tissue damaging mechanisms of alpha particles, having very high L.E.T., and also the related radiation weighting factor in comparison to beta and gamma radiations. There were also interesting presentations on the topics of uncertainties involved in the internal dose assessment from radiation exposure and the

  2. Proceedings of the 9. international conference on health effects of incorporated radionuclides emphasis on radium, thorium, uranium and their daughter products - HEIR 2004

    Energy Technology Data Exchange (ETDEWEB)

    Oeh, U; Roth, P; Paretzke, H G [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany)

    2005-07-01

    The ninth international conference on 'Health Effects of Incorporated Radionuclides - Emphasis on Radium, Thorium, Uranium and their Daughter Products' HEIR 2004 was held at GSF-National Research Center for Environment and Health, Neuherberg, Germany, from November 29 until December 1, 2004. The growing popularity of this topic among the scientific community, especially the radiation protection community, was demonstrated by the largest number of participants in comparison to the earlier conferences. In all, there were 157 participants from 20 different countries of the world. In the conference 62 scientific and 12 poster presentations were included in 13 sessions. The scope of the conference covered studies related to the long-term follow-up of thorotrast subjects in Japan, Germany and Portugal, and also of the subjects exposed to Ra-224 for the treatment of bone tuberculosis and ankylosing spondylitis. The studies and discussions on these topics are important in view of the large number of liver cancers observed in the thorotrast patients and the number of bone cancers in the cases treated with Ra-224. A growth stunting was also observed for the subjects who received the Ra-224 injections early in their lives. Besides atom bomb survivors, the data from thorotrast patients could well help towards a better understanding of the health effects of irradiations. In addition to the scientific presentations on the above topics, there were a number of presentations on the incidence of lung cancer from radon exposure of miners and plutonium exposures causing lung cancer among the Mayak workers in the Russian Federation. Other stimulating presentations were on the tissue damaging mechanisms of alpha particles, having very high L.E.T., and also the related radiation weighting factor in comparison to beta and gamma radiations. There were also interesting presentations on the topics of uncertainties involved in the internal dose assessment from radiation exposure and the

  3. Updating radon daughter bronchial dosimetry

    International Nuclear Information System (INIS)

    Harley, N.H.; Cohen, B.S.

    1990-01-01

    It is of value to update radon daughter bronchial dosimetry as new information becomes available. Measurements have now been performed using hollow casts of the human bronchial tree with a larynx to determine convective or turbulent deposition in the upper airways. These measurements allow a more realistic calculation of bronchial deposition by diffusion. Particle diameters of 0.15 and 0.2 μm were used which correspond to the activity median diameters for radon daughters in both environmental and mining atmospheres. The total model incorporates Yeh/Schum bronchial morphometry, deposition of unattached and attached radon daughters, build up and decay of the daughters and mucociliary clearance. The alpha dose to target cells in the bronchial epithelium is calculated for the updated model and compared with previous calculations of bronchial dose

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

    Science.gov (United States)

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

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

  5. 222Rn and short live progeny in atmospheric environment. Origin and measurement techniques

    International Nuclear Information System (INIS)

    Charuau, J.; Labed, V.; Robe, M.C.; Thevenin, J.C.; Fazileabasse, J.; Klein, D.; Heleschewitz, H.; Tymen, G.; Aubert, C.; Gibaud, C.

    1996-01-01

    Radon is the main source of man's exposure to natural ionizing radiation. This document summarizes the general knowledge of the origin of radon 222 and its development in various air environments. It presents several methods for measuring radon activity concentration and the potential alpha energy from its short life daughters. It has been prepared by the commission M60-3, of the Office for the standardization of nuclear equipments (BNEN in French) under the French association for standardization (AFNOR in French). (author)

  6. Decay properties of short-lived mass-separated fission products

    International Nuclear Information System (INIS)

    Lund, E.

    1977-01-01

    The present work describes determinations of total β-decay energies and studies of delayed neutron emission including the identification and half-life determinations of delayed neutron precursors and the measurement of neutron spectra. It also includes a short review of the OSIRIS on-line isotope separator facility. (Auth.)

  7. Separation and purification of short lived fission products from irradiated uranium

    International Nuclear Information System (INIS)

    Balasubramanian, K.R.; Rao, K.L.N.; Mathai, C.; Varma, R.N.; Dhiwar, V.I.; Saxena, S.K.

    1991-01-01

    Fission produced radioisotopes like 95 Zr, 140 Ba, 103 Ru, 89 Sr and 91 Y whose half lives are less than 1 year find a wide variety of applications in the fields of industry, medicine and research. Isotope Division, BARC has been supplying these isotopes in hudreds of mCi amounts during the past several years. A new method for the sequential separation of these isotopes from irradiated uranium has been developed based on synthetic inorganic exchangers like stannic phosphate, polyphospho antimonic acid, hydrous manganese dioxide, etc. This report describes the new flow sheet worked out and adopted for the regular processing of these isotopes at hundreds of milli curie amounts. (author). 19 refs., 4 tabs. , 1 fig

  8. Development and application of the generator for the short-living nuclides production

    International Nuclear Information System (INIS)

    Tsejner, A.

    1979-01-01

    The results are stated of investigations by means of radioisotopes on the substance transfer in technological equipment. For these purposes, in most cases, nuclides with high gamma-activity are used and, if possible, having short half-life because the short half-life gives certain advantages in the cases when it is impossible to store radioactive substances in the technological equipment for a long time. It is noted that in connection with short half-life of the nucludes used for labelling and for the economic and radiation safety reasons, activity of these nuclides can not be high. It has been established that the most suitable nuclide for the labelling purpose is lanthanum-140 produced either in a nuclear reactor, or by means of separation from barium=-140 transforming into lanthanum-140 in an isotopic generator. Some methods of lanthanum separation from barium are described, in particular, in the isotopic generator described, barium is adsorbed on the cation-exchanger KPS-200 having high enough stability with respect to the ionozing radiations. As an eluent the 10 -2 M solution of the complexone (Na 2 - EDTA) was used. The complexone solution can be easely obtained and, because of the hydrolysis, it serves as a buffer solution. The data are given for radiation purity and yield of lanthanum-=140 [ru

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-15

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

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

    2014-06-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

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

    International Nuclear Information System (INIS)

    McBurney, Ruth E.; Pollard, Christine G.

    1992-01-01

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

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

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1987-09-01

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

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

    International Nuclear Information System (INIS)

    Bjoernstad, T.

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

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

    CERN Multimedia

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

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

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-05-01

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

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

    International Nuclear Information System (INIS)

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

    1974-01-01

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

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

    Science.gov (United States)

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

    2009-06-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    E. S. Kazantseva

    2016-01-01

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

  6. Evaluation of thoron-daughter instruments

    International Nuclear Information System (INIS)

    George, J.L.

    1992-09-01

    Several DOE decontamination and decommissioning sites need to accurately measure thoron-daughter concentrations during decontamination efforts. Because the workers at these sites receive their dose from thoron-daughters rather than thoron gas, the thoron-daughter concentration is the measurement of interest. Some instruments currently used for making radon-daughter concentration measurements also claim the ability to measure thoron-daughter concentrations. This study evaluated the validity of those claims

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-01

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

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

    Science.gov (United States)

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

    2015-03-01

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

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

    International Nuclear Information System (INIS)

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

    1978-05-01

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

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1984-01-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

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

    CERN Multimedia

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

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

    International Nuclear Information System (INIS)

    Adelstein, S.J.

    1995-02-01

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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Westphall, G P [Atominstitut der Oesterreichischen Hochschulen, Vienna

    1976-07-15

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

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

    Science.gov (United States)

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

    2014-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-02-01

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

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

    International Nuclear Information System (INIS)

    Lewis, D.A.

    1985-10-01

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

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

    Science.gov (United States)

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

    2018-01-11

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

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

    International Nuclear Information System (INIS)

    Hooft, E.

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Westphal, G P [Atominstitut, Vienna (Austria)

    1976-07-01

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

  4. New data on some short-lived isotopes of ruthenium and rhodium; Nuevos datos sobre algunos isotopos de rutenio y rodio de vida corta

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, F.; Plata Bedmar, A.

    1961-07-01

    Ru and Rd isotopes with mass numbers 107 and 108 and {sup 1}09Rh, has been obtained from fission products. {sup 1}07 Ru has also been prepared by the nuclear process {sup 1}10Pd (n,{alpha}) {sup 1}07 Ru. Beta and gamma energies of these nuclides have been studied spectropolarimetry and the gamma lines found for {sup 1}07 Ru and {sup 1}08Ru ( and daughter) have been very useful for the precise determination of their half-lives. {sup 1}09Rh has been identified through its daughter {sup 1}09Pd in the mixture of rhodium isotopes from fission products. Irradiation of natural palladium with fast neutrons has lead to an activity that may only be attributed to {sup 1}10rh. Neither its half life nor its decay energy have been possible to determine accurately. (Author) 1 refs.

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

    International Nuclear Information System (INIS)

    Lewis, D.A.

    1981-02-01

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-05-01

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

  8. Lilavatis Daughters | Women in Science | Initiatives | Indian ...

    Indian Academy of Sciences (India)

    Home; Initiatives; Women in Science; Lilavatis Daughters ... The book 'Lilavati's Daughters: The Women Scientists of India' was successfully ... Charusita Chakravarty, one of the stars of our community of women scientists, at a young age of 52, ...

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    D. E. Oram

    2017-10-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  12. Radon daughter control in the Uravan Mineral Belt

    International Nuclear Information System (INIS)

    Swindle, R.W.

    1977-01-01

    The control of radon daughter products in mines of the Uravan Mineral Belt is strongly affected by the erratic nature of the ore deposits. Another problem is the frequent necessity of reactivating mine workings that have been inactive for many years. Ventilation holes and other airways are usually too small to provide adequate ventilation to satisfy current requirements, and they are often caved. The greatest change in ventilation systems in recent years has been the trend toward larger-diameter, drilled ventilation raises that provide more ventilation at considerably lower cost. The increase in raise size has aggrevated ground-support and ice-formation, difficulties, but these problems are being solved by lining the raises with shotcrete and grouting the water bearing horizons. Electronic air cleaners have been effectively used to remove radon daughter products from mine air for several years but their utility is limited by the rate of regrowth of the radon daughters after the air is cleaned. 5 figures

  13. Mass balances by uranium-series disequilibria in natural phosphate deposits and mine products

    International Nuclear Information System (INIS)

    Osmond, J.K.; Cowart, J.B.

    1985-01-01

    In a closed system U-238 is in radioactive equilibrium with its longer lived daughters, U-234, Th-230, and Ra-226. In a system that is open on a time scale of 10 4 to 10 5 years, as in rock weathering, the various daughters and isotopes become separated. Nevertheless, equilibrium still pertains to the total system, so that material balances between weathering components and residual products can be calculated, based on parent-daughter radioactivity ratios. The authors have applied this balancing concept to the weathering of phosphatic ores in central Florida and to phosphate mining products. In the natural system studied in Florida, the leached zones are ten times more extensive than enriched zones, and have higher concentrations of Th-230 and Ra-226 relative to U-238 and U-234. Although there are significant movements of long-lived radio-elements locally, and occasional notable disequilibria of short-lived daughters, leaching by ground water is not a major factor in the regional budget. In the mining process, uranium follows the enriched phosphate and also the clay residues. Thorium and radium follow the clay residues and the gypsum by-product. Mine effluent waters, although somewhat higher in radioactivity than natural waters, do not remove appreciable amounts of the radio-elements

  14. Efficient measurement of radon daughters

    International Nuclear Information System (INIS)

    Rolle, R.

    1992-01-01

    In environmental control there is an increasing need for efficient measurement of radon and thoron daughters in air. Measuring instruments should be rugged and portable for field use, while also permitting unattended operation for several days. Simple operating procedures should permit evaluation of rapidly changing concentrations over extended periods. These requirements demand careful balance in the design of hardware and measuring procedures. The design principles for a continuous flow-through spectrometer, that has been developed for precision sequential measurement of radon and thoron daughters, are described. Because of the high precision of measurement, this type of instrument should find application in environments from technologically enhanced natural radiation to the very lowest natural background situations. (author)

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

    International Nuclear Information System (INIS)

    Kreiner, H.J.

    1976-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Science.gov (United States)

    Eccard, Jana A; Herde, Antje

    2013-11-15

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

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

    Directory of Open Access Journals (Sweden)

    B. Aamaas

    2016-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-12-01

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

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

    CERN Document Server

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

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

    1986-10-01

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

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

    Science.gov (United States)

    Kiser, Matthew R.

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

  3. Environmental radon and radon daughter dosimetry in the respiratory tract

    International Nuclear Information System (INIS)

    McPherson, R.B.

    1979-04-01

    This report describes work performed by Pacific Northwest Laboratory (PNL) for the Nuclear Regulatory Commission's program to determine safety and costs related to decommissioning nuclear fuel cycle facilities. Individual dose factors for the inhalation of radon and its daughter products are calculated for use in environmental dose assessments. The calculated committed dose equivalent factors for 222 Rn and its daughters are tabulated for lungs, bronchi tract and other organs. An activity median aerodynamic diameter of 0.1 μm was used. The dose to an individual is calculated by multiplying the estimated intake from inhalation for a particular radionuclide by the corresponding dose factor. A working level month-to-dose conversion factor is calculated to be 1 rad/WLM to the epithelial tissue of the T-B region, assuming 100% daughter equilibrium and 10% free 218 Po ions. This value is in reasonable agreement with recently reported values

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

    International Nuclear Information System (INIS)

    Saito, Tadashi

    2006-01-01

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

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

    Science.gov (United States)

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

    2006-12-01

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

  6. Short-Lived Radioisotope Production, Processing, Distribution and Applications in Korea; Production, Traitement, Distribution et Applications des Radioisotopes a Courte Periode En Coree; ПРОИЗВОДСТВО КОРОТКОЖИВУЩИХ ИЗОТОПОВ В КОРЕЕ, ИХ ОБРАБОТКА, РАССЫЛКА И ПРИМЕНЕНИЕ; Produccion, Elaboracion, Distribuciony Aplicacion de Radioisotopos de Periodo Corto en Corea

    Energy Technology Data Exchange (ETDEWEB)

    Kuk Kim, Chong [Department of Chemistry, Atomic Energy Research Institute, Seoul (Korea, Republic of)

    1963-03-15

    The production, processing and distribution of short-lived radioisotopes by the Atomic Energy Research Institute of Korea are discussed. The radioisotopes concerned are Na{sup 24}, Cu{sup 64}, K{sup 42}, Mo{sup 99}, W{sup 187}, colloidal Au{sup 198}, Br{sup 82m} and I{sup 128}. The paper also deals with applications of these isotopes in various fields in Korea. The most important application is the use of Na{sup 24} for the detection of leaks in irrigation water storage containers. Since there are nearly 1500 such containers in South Korea, the detection of leaks is a nation-wide problem. Na{sup 24} is also applied to metabolic studies in hypertension and to the study of the mixing mechanism in miscible liquid-liquid phase systems. (author) [French] L'auteur decrit comment l'Institut coreen de recherches sur l'energie atomique produit, traite et distribue des radioisotopes a courte periode, notamment, {sup 24}Na, {sup 64}Cu, {sup 42}K, {sup 99}Mo, {sup 187}W, {sup 198}Au colloiedal, {sup 82m}Br et {sup 128}I. Il donne egalement un apercu de l'emploi de ces radioisotopes dans differents domaines en Coree. Le plus important consiste a utiliser le sodium-24 pour detecter les fuites des reservoirs d'eau d'irrigation. La Coree du Sud possede pres de 1500 reservoirs de ce genre et c'est pourquoi le probleme de la detection dea fuites se pose a l'echelon national. Le sodium-24 est egalement utilise pour des etudes metaboliques l'hypertension et pour des recherches sur le mecanisme de melange dans les systemes miscibles en phase liquide- liquide. Toutes ces etudes, faites a peu de frais, ont ete couronnees de succes. (author) [Spanish] La memoria discute la produccion, elaboracion y distribucion de radioisotopos de periodo corto en el Atomic Energy Research Institute de Corea. Los radioisotopos en cuestion son el {sup 24}Na, {sup 64}Cu, {sup 42}K, {sup 99}Mo, {sup 187}W, {sup 198}Au coloidal, {sup 82m}Br y {sup 128}l. La memoria trata tambien de las aplicaciones de estos

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Directory of Open Access Journals (Sweden)

    B. Quennehen

    2016-08-01

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

  9. Working level measurement of radon daughters and thoron daughters by personal dosimetry and continuous monitoring

    International Nuclear Information System (INIS)

    Phillips, C.R.; Leung, H.

    1981-01-01

    The performance of personal alpha dosimeters in mixed radon daughter and thoron daughter atmospheres in Ontario uranium mines is described together with monitoring developments which enable the radon daughter working level to be determined separately. The theoretical bases for continuous and integrated working level measurements based on individual and gross counts are presented in terms of the weighting factor for combining the thoron daughter working level with the radon daughter working level, and in terms of the in-growth time of the air. Implications for the determination of working level in the presence of thoron daughters are discussed

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

    Science.gov (United States)

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

    2017-01-24

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zyzak, Maksym

    2016-07-07

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

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

    International Nuclear Information System (INIS)

    Zyzak, Maksym

    2016-01-01

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

  14. The preparation of organic radiopharmaceuticals and labelled compounds using short-lived cyclotron-produced radionuclides

    International Nuclear Information System (INIS)

    Uhlenhut, G.J.; Koch, H.

    1982-01-01

    Accelerator-produced nuclides and radiopharmaceutical production are discussed with examples of pertinent methods of isotope production, methods of incorporation into organic molecules, and the general problems attandant on the production and use of these materials in this new and interdisciplinary effort. The literature is surveyed with stress being given to the use of 11 C, 13 N and 15 O. 205 references are included. (author)

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

    International Nuclear Information System (INIS)

    1986-03-01

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

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

    International Nuclear Information System (INIS)

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

    1984-02-01

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

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

    Science.gov (United States)

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

    2018-04-01

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

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

    Directory of Open Access Journals (Sweden)

    C. Narama

    2018-04-01

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

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

    International Nuclear Information System (INIS)

    2006-01-01

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

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

    Science.gov (United States)

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

    2013-07-01

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

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

    International Nuclear Information System (INIS)

    Burgov, N.A.

    1986-01-01

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

  2. Teenage Daughters as a Cause of Divorce

    NARCIS (Netherlands)

    Kabátek, Jan; Ribar, David C.

    2017-01-01

    Evidence from the U.S. that couples with daughters are more likely to divorce than couples with sons has not been found for other Western countries. Using 1995-2015 Dutch marriage registry data, we show that daughters are associated with higher divorce risks, but only when they are 13 to 18 years

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

    International Nuclear Information System (INIS)

    Fitzgerald, R.

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  5. Committed effective dose from thoron daughters inhalation

    International Nuclear Information System (INIS)

    Campos, M.P.; Pecequilo, B.R.S.

    2000-01-01

    Mankind's interest in natural radiation exposure levels has increased over the past fifty years and it is now recognized that the most significant contributors to human irradiation by natural sources are the short-lived decay products of radon ( 222 Rn) and thoron ( 220 Rn). Despite the thoron short half-life of 55 s, effective dose from inhalation of thoron an its progeny ( 212 Pb and 212 Bi) must be considered, owing to the high thorium background in countries like Brazil, China and India, for example. The indoor committed effective dose was assessed by air sampling at the thorium purification plant and the nuclear materials storage site of the Instituto de Pesquisas Energeticas e Nucleares; Sao Paulo, Brazil. A total of 21 glass fiber filter samples was analyzed by high resolution gamma ray spectrometry in order to obtain the 212 Pb and 212 Bi activities. The equilibrium equivalent concentration (EEC) varied from 0.3 Bq/m 3 to 6.8 Bq/m 3 for the storage site air samples and from 9.9 Bq/m 3 to 249.8 Bq/m 3 for the thorium purification plant air samples. As retention studies indicate a biological half-life of a few hours inhaled thoron progeny in the human lungs, the main fraction of the potential alpha energy (PAEC) deposited is absorbed in the lungs, meaning negligible to the effective dose the contribution of the dose in other times. The committed effective dose due thoron progeny was performed by compartimental analysis following the ICRP 66 lung compartimental model and ICRP 67 lead compartimental model. The values obtained varied from 0.03 mSv/a to 0.67 mSv/a for the storage site air samples and from 0.12 mSv/a to 6.00 mSv/a for the thorium purification plant air samples. (author)

  6. Contribution of radon and radon daughters to respiratory cancer

    International Nuclear Information System (INIS)

    Harley, N.; Samet, J.M.; Cross, F.T.; Hess, T.; Muller, J.; Thomas, D.

    1986-01-01

    This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime

  7. The measurement of airborne rodon daughter concentrations in the atmosphere

    International Nuclear Information System (INIS)

    Ha, C.W.; Lee, J.K.; Moon, P.S.

    1979-01-01

    A simple method for determining the airborne concentration of radon daughter products has been developed, which is based on gross alpha counting of the air filter collections at several time intervals after completion of air sampling. The concentration of each nuclide is then obtained from an equation involving the alpha disintegrations, the sampling time, and the known numerical coefficients. The state of radioactive disequilibrium is also inventigated. The atmosphere sampled in the TRIGA Mark-III reactor room was largely in disequilibrium. The extent of radioactive disequilibrium between radon daughter products seems likely depend on sampling times associated with turbulence conditions. The data obtained here will certainly provide useful information on the evaluation of internal exposure and calibration of effluent monitoring instruments. (author)

  8. FORMATION OF THE SHORT-LIVED RADIONUCLIDE 36Cl IN THE PROTOPLANETARY DISK DURING LATE-STAGE IRRADIATION OF A VOLATILE-RICH RESERVOIR

    International Nuclear Information System (INIS)

    Jacobsen, Benjamin; Yin Qingzhu; Matzel, Jennifer; Hutcheon, Ian D.; Ramon, Erick C.; Weber, Peter K.; Krot, Alexander N.; Nagashima, Kazuhide; Ishii, Hope A.; Ciesla, Fred J.

    2011-01-01

    Short-lived radionuclides (SLRs) in the early solar system provide fundamental insight into protoplanetary disk evolution. We measured the 36 Cl- 36 S-isotope abundance in wadalite ( 36 Cl (τ 1/2 ∼ 3 x 10 5 yr) in the early solar system. Its presence, initial abundance, and the noticeable decoupling from 26 Al raise serious questions about the origin of SLRs. The inferred initial 36 Cl abundance for wadalite, corresponding to a 36 Cl/ 35 Cl ratio of (1.81 ± 0.13) x 10 -5 , is the highest 36 Cl abundance ever reported in any early solar system material. The high level of 36 Cl in wadalite and the absence of 26 Al ( 26 Al/ 27 Al ≤ 3.9 x 10 -6 ) in co-existing grossular (1) unequivocally support the production of 36 Cl by late-stage solar energetic particle irradiation in the protoplanetary disk and (2) indicates that the production of 36 Cl, recorded by wadalite, is unrelated to the origin of 26 Al and other SLRs ( 10 Be, 53 Mn) recorded by primary minerals of CAIs and chondrules. We infer that 36 Cl was largely produced by irradiation of a volatile-rich reservoir in an optically thin protoplanetary disk adjacent to the region in which the CV chondrite parent asteroid accreted while the Sun was a weak T Tauri star. Subsequently, 36 Cl accreted into the Allende CV chondrite together with condensed water ices.

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

    CERN Document Server

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

    2002-01-01

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

  10. Technical evaluation of a radon daughter continuous monitor in an underground uranium mine

    International Nuclear Information System (INIS)

    Bigu, J.; Grenier, M.

    1982-07-01

    An evaluation of a radon daughter monitor was carried out in an underground uranium mine. The monitor operates on continuous sampling and time integrating principles. Experimental and theoretical data were compared. Experimental results show that the monitor underestimates the Working Level, a fact which is partly attributed to plate-out of decay products in the monitor sampling head. However, a correction factor experimentally determined by standard calibration procedures can be programmed into the monitor to take into account losses by plate-out and other losses. Although the monitor was originally designed for radon daughters, it can equally be used in thoron daughter atmospheres and radon daughter/thoron daughter mixtures such as those encountered in some Canadian uranium mines. An analytical procedure is outlined to allow the calculation of Working Levels in radon daughter/thoron daughter atmospheres from the monitor α-count rate. The memory capability of the monitor should make it quite useful and flexible in underground and surface environments in the uranium mining industry

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

    International Nuclear Information System (INIS)

    Bourret, S.C.

    1974-01-01

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

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

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1988-06-01

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

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

    CERN Document Server

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

    2001-01-01

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

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

    CERN Document Server

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    Digenis, G.A.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  20. Control of radon daughters in underground mining

    International Nuclear Information System (INIS)

    Swent, L.W.

    1983-01-01

    This paper discusses technical developments that may enable uranium mine operators to improve engineering controls of radon daughter concentrations in mines, and developments in regulatory controls. The origin of radon daughters in underground mines is explained. The procedure for sampling and determining the concentration of alpha radiation in sampled air is reviewed. The principal technical development in the last few years has been the perfection and use of a class of meters which determine radon daughter concentrations in an air sample in a matter of two or three minutes without any aging period. A number of underground uranium mine operators are now using ''instant'' type meters and the Mine Safety and Health Administration (MSHA) has approved their use in a number of mines. The difficulty experienced by uranium mine operators in complying with a MSHA regulation which requires that no person be exposed to radon daughter concentrations exceeding 1 Working Level (WL) in any active working place is discussed

  1. Measurement of Short Living Baryon Magnetic Moment using Bent Crystals at SPS and LHC

    CERN Document Server

    Burmistrov, L; Ivanov, Yu; Massacrier, L; Robbe, P; Scandale, W; Stocchi, A

    2016-01-01

    The magnetic moments of baryons containing u,d and s quarks have been extensively studied and measured. The experimental results are all obtained by a well-assessed method that consists in measuring the polarisation vector of the incoming particles and the precession angle when the particle is travelling through an intense magnetic field. The polarization is evaluated by analysing the angular distribution of the decay products. No measurement of magnetic moments of charm or beauty baryons (and τ leptons) has been performed so far. The main reason is the lifetimes of charm/beauty baryons, too short to measure the magnetic moment by standard techniques. Historically, the prediction of baryon magnetic moments was one of the striking successes of the quark model. The importance of the measurement of heavy quark magnetic moment is to test the possibility that the charmed and/or beauty quarks has an anomalous magnetic moment, arising if those quarks are composite objects. Measurements on magnetic moments of heav...

  2. Determination of nuclear spins of short-lived isotopes by laser induced fluorescence

    International Nuclear Information System (INIS)

    Buchinger, F.; Dabkiewicz, P.; Kremmling, H.; Kuehl, T.; Mueller, A.C.; Schuessler, H.A.

    1980-01-01

    The spins of several nuclear ground and isomeric states have been measured for a number of mercury isotopes. The fluorescent light from the 6s6p 3 P 1 state is observed at 2537 Angstroem after excitation with the frequency doubled output of a pulsed dye laser. Four different laser induced fluorescence techniques were tested for their applicability: double resonance, Hanle effect, time delayed integral Hanle beats, and time resolved quantum beats. The sensitivity and selectivity of these models are compared with emphasis on the determination of spins of nuclei far from beta-stability, where short half lives and low production yields restrict the number of available atoms. The experiments were carried out on-line with the ISOLDE isotope separator at CERN at densities as low as 10 6 atoms/cm 3 . Results for the very neutron deficient high spin mercury isomers with half lives of several seconds, but also for the ground states of the abundant low spin stable mercury isotopes, are given as examples. The test measurements determined the nuclear spins of the odd sup(185m-191m)Hg isomers to be I = 13/2. (orig.)

  3. Second workshop on radon and radon daughters in urban communities associated with uranium mining and processing

    International Nuclear Information System (INIS)

    1979-01-01

    A second meeting of Atomic Energy Control Board staff, federal and provincial government representatives, and consultants was held to discuss progress in reducing the concentrations of radon and its daughter products in houses in communities like Bancroft, Elliot Lake, Port Hope, and Uranium City. Participants discussed successful and unsuccessful remedial techniques, possible sources of radon, and methods of measuring radon and radon daughters in buildings

  4. A Review of the Production of ''Special'' Radioisotopes

    International Nuclear Information System (INIS)

    Stang, L.G. Jr.

    1963-01-01

    Six useful characteristics of radioisotopes and advantages which may be taken of them are cited briefly, with examples. The Information Sheet announcing this Seminar listed four advantages of short-lived over long-lived isotopes. Two other reasons why owners of small research reactors should concern themselves with short half- life isotopes are economy and particular suitability for production, the latter being due to the pronounced effect of half-life on the net rate of production. Besides short half-life, type and energy of emitted radiation should be of concern to producers of isotopes. Nine advantages of a nuclear reactor over a particle accelerator for radioisotope production are outlined. Following this general orientation, a survey of unusual or less frequently used production techniques is presented. These include: (n, p) reactions and secondary reactions such as (t, n) and (t, p) induced by thermal neutrons, various techniques for obtaining useful fluxes of fast neutrons with which to effect other reactions, recoil techniques including classic Szilard-Chalmers reactions, use of charged wires to collect short-lived daughters of gaseous parents, parent-daughter milking system, parasitic irradiations, possible use of ''knocked- on'' protons or deuterons (from the moderator) as a means of effecting reactions such as (p,n), (d,n), etc. and the possible use of circulating ''loops'' in reactors with which to utilize the radiation from ultra-short-lived radioisotopes such as Ag 110 , In 114 , 116 , Dy 155m , etc. Although not a production technique, the possibility of using certain stable isotopes (e. g. of silver) as tracers which can be readily detected via subsequent activation is mentioned. Production figures for Brookhaven's ''special'' radioisotopes are cited to show differences in long- and short-term fluctuations among these isotopes, which are also compared as a class to those in heavier demand supplied by Oak Ridge. Present production methods of all

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  6. Perspective on cancer and radon daughters

    International Nuclear Information System (INIS)

    Archer, V.E.

    1981-01-01

    This paper discusses the hazards from radon and its daughters in the environment and the role they may play in contributing to the general cancer burden. Only in exceptional circumstances can one pick out one mutagen or one carcinogen and scientifically determine what its contribution is o our burden of birth defects and cancer. The risks associated with radon and its daughters are examined in light of this philosophy

  7. Studies of short-lived nuclei in the proximity of closed shells

    International Nuclear Information System (INIS)

    Omtvedt, J.P.

    1995-01-01

    In this work the structure of 84,85 Se at the closed N=50 neutron shell, and the 132 Sb, 132 Sn, and 134 Te nuclei, at the doubly closed N=82,Z=50 shells, was studied. The experiments were performed at the OSIRIS fission product mass separator at Studsvik, Sweden. The excited levels of the studied nuclei were populated in β decay. The sources were produced in fission of 235 U in the OSIRIS combined target and ion source. The nuclei were studied by standard nuclear spectroscopy measuring techniques: Singles γ spectra and γγ-coincidence data were obtained. In addition γγ(θ) angular correlation and βγγ(t) triple coincidence ''fast-timing'' ,measurements were performed on the nuclei in the 132 Sn (N=82,Z=50) region. Detailed level schemes for the 84,85 Se, 132 Sb, 132 Sn, 132 Te nuclei were built, greatly improvi our knowledge of the structure of these nuclei. The experimentally deduced transition rates and multipole mixing ratios of the studied 132 Sn region nuclei were compared to theoretical calculations within the random phase approximation framework and related models. Particular attention was paid to the collective properties of nuclei in the 132 Sn region, parametrized by the electrical octupole effective charge. A range of general software spectroscopic tools were developed for the purpose of analysing the experimental data. This included a program, Yggdrasil, which for the first time allowed a complete two-dimensional γγ-coincidence matrix to be analysed on ordinary ''small'' personal computers (PCs). 49 refs., 10 figs., 2 tabs

  8. Optical and radar characterization of a short-lived auroral event at high latitude

    International Nuclear Information System (INIS)

    Vallance Jones, A.; Gattinger, R.L.; Shih, P.; Meriwether, J.W.; Wickwar, V.B.; Kelly, J.

    1987-01-01

    Observations of optical emission intensities and incoherent scatter radar returns in the magnetic zenith were compared in a study carried out at Sondre Stromfjord (Λ = 76.1 degree) in Greenland. The results were used to test the consistency of a theoretical model of ion chemistry and optical emissions in aurora and to explore the accuracy of relations between optical measurements and the average energy of the incident electrons. The incident primary electron spectrum and its temporal variation were inferred from zenith electron density profiles from the radar. The inferred primary energy spectrum at the peak intensity of the event approximated a Maxwellian distribution of characteristic energy 1.3 keV accelerated by an energy increment between 2 and 5 keV. Average energies inferred from the radar electron density profiles, from the N 2 + rotational temperature and the I(6300)/I(4278) ratio were in good agreement. The variation of the I(8446)/I(4278) ratio was studies and was found to be promising as an index of average incident electron energy. An empirical relation between this ratio and average energy was derived from the data. The observed values of I(4278) exceeded the theoretical values derived from the ionization rate profiles deduced from the radar data by a factor near 2.0. Observed electron density profiles and theoretical profiles calculated from optical data were in good agreement provided that the optically inferred ion production rates were reduced by the same factor of 2. This discrepancy is probably the cumulative result of small errors in instrument calibrations, viewing geometry, recombination coefficients and the excitation and ionization cross sections used in the model

  9. Studies of short-lived nuclei in the proximity of closed shells

    Energy Technology Data Exchange (ETDEWEB)

    Omtvedt, J.P.

    1995-12-31

    In this work the structure of {sup 84,85}Se at the closed N=50 neutron shell, and the {sup 132}Sb, {sup 132}Sn, and {sup 134}Te nuclei, at the doubly closed N=82,Z=50 shells, was studied. The experiments were performed at the OSIRIS fission product mass separator at Studsvik, Sweden. The excited levels of the studied nuclei were populated in {beta} decay. The sources were produced in fission of {sup 235}U in the OSIRIS combined target and ion source. The nuclei were studied by standard nuclear spectroscopy measuring techniques: Singles {gamma} spectra and {gamma}{gamma}-coincidence data were obtained. In addition {gamma}{gamma}({theta}) angular correlation and {beta}{gamma}{gamma}(t) triple coincidence ``fast-timing`` ,measurements were performed on the nuclei in the {sup 132}Sn (N=82,Z=50) region. Detailed level schemes for the {sup 84,85}Se, {sup 132}Sb,{sup 132}Sn, {sup 132}Te nuclei were built, greatly improvi our knowledge of the structure of these nuclei. The experimentally deduced transition rates and multipole mixing ratios of the studied {sup 132}Sn region nuclei were compared to theoretical calculations within the random phase approximation framework and related models. Particular attention was paid to the collective properties of nuclei in the {sup 132}Sn region, parametrized by the electrical octupole effective charge. A range of general software spectroscopic tools were developed for the purpose of analysing the experimental data. This included a program, Yggdrasil, which for the first time allowed a complete two-dimensional {gamma}{gamma}-coincidence matrix to be analysed on ordinary ``small`` personal computers (PCs). 49 refs., 10 figs., 2 tabs.

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

    International Nuclear Information System (INIS)

    Breitenfeldt, Martin

    2009-01-01

    In the present work, mass determinations of the eleven neutron-deficient nuclides 99-109 Cd, of ten neutron-rich silver nuclides 112,114-121,123 Ag, and seven neutron-rich cadmium nuclides 114,120,122-124,126,128 Cd are reported. Due to the clean production of the neutron-deficient nuclides it was possible to reduce the experimental uncertainties down to 2 keV, whereas the measurements of neutron-rich nuclides were hampered by the presence of contaminations from more stable In and Cs nuclides. In the case of 99 Cd and 123 Ag the masses were determined for the first time and for the other nuclides the mass uncertainties could be reduced by up to a factor of 50 as in the case of 100 Cd. In the case of a potential isomeric mixture as for 115,117,119 Ag and 123 Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of a potential isomeric mixture as for 115,117,119 Ag and 123 Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of the neutron-deficient Cd nuclides a conflict between the mass values obtained in the present work and those published by the JYFLTRAP group [EEH + ] could be solved by performing an atomic-mass evaluation. Thus, it was revealed that reason for the conflict was a different value of the JYFLTRAP reference mass 96 Mo. Furthermore, a reduction of the mass uncertainty and a slight increase of the mass of 100 In were obtained. These mass measurements are an important step towards an understanding of the physics of the rp process that will enable a more reliable determination of

  11. Radionuclide daughter inventory generator code: DIG

    International Nuclear Information System (INIS)

    Fields, D.E.; Sharp, R.D.

    1985-09-01

    The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs

  12. Methodology and monitoring of radon, thoron and their daughters

    International Nuclear Information System (INIS)

    Townsend, M.G.

    1984-02-01

    Methods are described for monitoring radon and thoron gases and their daughter products in occupational and non-occupational environments. Grab-sampling, continuous monitoring, integrated measurements and personal dosimetry are discussed. Errors in different measurement methods are compared. Calibration aspects of measurement techniques are described and procedures for interlaboratory calibration are suggested. An account of unattached fraction and plateout of radon daughters is included. Sampling strategies for occupational and non-occupational environments are discussed and a table of regulations and recommendations for monitoring radiation in countries of the OECD is provided. Radiation protection training requirements are identified. Where sufficient information and consensus of opinion exist, guidelines on apparatus, methods and procedures for monitoring are developed

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

    Energy Technology Data Exchange (ETDEWEB)

    Breitenfeldt, Martin

    2009-07-03

    In the present work, mass determinations of the eleven neutron-deficient nuclides {sup 99-109}Cd, of ten neutron-rich silver nuclides {sup 112,114-121,123}Ag, and seven neutron-rich cadmium nuclides {sup 114,120,122-124,126,128}Cd are reported. Due to the clean production of the neutron-deficient nuclides it was possible to reduce the experimental uncertainties down to 2 keV, whereas the measurements of neutron-rich nuclides were hampered by the presence of contaminations from more stable In and Cs nuclides. In the case of {sup 99}Cd and {sup 123}Ag the masses were determined for the first time and for the other nuclides the mass uncertainties could be reduced by up to a factor of 50 as in the case of {sup 100}Cd. In the case of a potential isomeric mixture as for {sup 115,117,119}Ag and {sup 123}Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of a potential isomeric mixture as for {sup 115,117,119}Ag and {sup 123}Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of the neutron-deficient Cd nuclides a conflict between the mass values obtained in the present work and those published by the JYFLTRAP group [EEH{sup +}] could be solved by performing an atomic-mass evaluation. Thus, it was revealed that reason for the conflict was a different value of the JYFLTRAP reference mass {sup 96}Mo. Furthermore, a reduction of the mass uncertainty and a slight increase of the mass of {sup 100}In were obtained. These mass measurements are an important step towards an understanding of the physics of

  14. Reproductive prognosis in daughters of women with and without endometriosis

    DEFF Research Database (Denmark)

    Dalsgaard, T; Hansen, Maj Vadskjær Hjordt; Hartwell, D

    2013-01-01

    Do daughters of women with endometriosis exhibit an increased risk of endometriosis and impaired long-term reproductive prognosis when compared with daughters of women without endometriosis?......Do daughters of women with endometriosis exhibit an increased risk of endometriosis and impaired long-term reproductive prognosis when compared with daughters of women without endometriosis?...

  15. Dynamics of Rn-222 daughter size distribution evolution: modelling and experimental aspects

    International Nuclear Information System (INIS)

    Tymen, G.; El Moussaoui, B.; Renoux, A.

    1989-01-01

    Size distribution of short lived radon daughters is considered as a fundamental parameter in radiation protection in so far as about 40% of human exposure is due to inhalation of such radioactive particles, in mines as well as in indoor environments. Many experiments have been carried out in various conditions: controlled atmospheres, uranium mine atmospheres, atmospheric air, and more recently in houses because of the increasing interest in exposure to natural radiation. From an experimental point of view, previous measurements dealt with the cumulative size distribution of radon progeny alpha activity. Then, in spite of the difficulty in comparing data of different investigators, it was often found that a significant part of the activity was associated with particles above 0.1 μm in diameter. Otherwise, a bimodality was often observed in the case of airborne radioactive particles. The attachment of small radioactive ions or atoms produced by the radon decay on ambient particles has been studied. Differences arise in the calculation of the attachment coefficient and in the choice of the natural particle size distribution. This paper presents our investigation in this field by studying the theoretical and experimental aspects of the radon daughter behaviour in a cylindrical vessel simultaneously. (author)

  16. Measurements of radon daughter concentrations in structures built on or near uranium mine tailings

    International Nuclear Information System (INIS)

    Haywood, F.F.; Kerr, G.D.; Goldsmith, W.A.; Perdue, P.T.; Thorngate, J.H.

    1976-01-01

    A technique is discussed that has been used to measure air concentrations of short-lived daughters of 222 Rn in residential and commercial structures built on or near uranium mill tailings in the western part of the United States. In this technique, the concentrations of RaA, RaB, and RaC are calculated from one integral count of the RaA and two integral counts of the RaC' alpha-particle activity collected on a filter with an air sampling device. A computer program is available to calculate the concentrations of RaA, RaB, and RaC in air and to estimate the accuracy in these calculated concentrations. This program is written in the BASIC language. Also discussed in this paper are the alpha-particle spectrometer used to count activity on the air filters and the results of our radon daughter measurements in Colorado, Utah, and New Mexico. These results and results of other measurements discussed in a companion paper are now being used in a comprehensive study of potential radiation exposures to the public from uranium mill tailing piles

  17. Excitation functions for the formation of some short-lived products in proton-induced reactions on silver

    OpenAIRE

    Uddin, M. S.; Baba, M.; Hagiwara, M.; Latif, S. K. A.; Qaim, S. M.

    2008-01-01

    Excitation functions of the Ag-nat(p, xn)Cd-104,Cd-105 and Ag-nat(p, pxn) Ag-103,Ag-104m.g,Ag- 1049 reactions were measured for the first time over the proton energy range of 32 to about 60 MeV. The data were compared with the results of precompound-hybrid model calculations, whereby only partial agreement was obtained. The contribution of the Ag-103 precursor decay to the total formation of the therapeutic radionuclide Pd-103 in proton activation of silver was estimated: it amounted to about...

  18. Radiation burden in dwelling-houses by Radon and its daughter elements

    International Nuclear Information System (INIS)

    Hofmann, W.

    1982-01-01

    The content of 222 Rn and its short-lived decay products in room air shows large local as well as temporal fluctuations. The local differences are caused mainly by the concentration of 226 Ra in building materials and the exhalation of radon from the walls. Temporal variations result from varying ventilation conditions and changing meteorological parameters. The influence of all these factors on the natural radiation burden of man is discussed. (Author) [de

  19. 182Hf-182W age dating of a 26Al-poor inclusion and implications for the origin of short-lived radioisotopes in the early Solar System

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  20. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study

    International Nuclear Information System (INIS)

    Laurer, G.R.; Cohen, N.; Stark, A.; Ju, C.

    1991-05-01

    The objective of this study is to demonstrate the feasibility of estimating cumulative exposure of individuals to low concentrations of radon by measuring the amount of Pb-A-10 in their skeletons. This report presents progress to date establishing the validity of an vivo technique to measure skeletal burdens of Pb-210, accumulated from exposure to radon and radon progeny. With the skeletal content of Pb--210 and a model for Pb metabolism, cumulative exposure to radon and its short-lived daughters (radon/daughters) may be calculated for use in deriving a dose-response relationship between lung cancer and exposure to radon/daughters. Data are presented for 29 subjects exposed to ''above-average'' radon concentrations in their homes, showing the correlation between measured Pb--210 burdens, and measured pCi/l and WLM exposure estimates. Their results are compared to measurements of a population of 24 subject's presumed exposed to average concentrations. Measurements of a Pennsylvania family exposed for a year in a home with an extremely high radon content are also presented. Update of results of an ongoing study of the biological half-time of Pb--210 in man involving measurements, of a retired radiation worker with a 40 year old skeletal burden of Pb-210

  1. A computer method for simulating the decay of radon daughters

    International Nuclear Information System (INIS)

    Hartley, B.M.

    1988-01-01

    The analytical equations representing the decay of a series of radioactive atoms through a number of daughter products are well known. These equations are for an idealized case in which the expectation value of the number of atoms which decay in a certain time can be represented by a smooth curve. The real curve of the total number of disintegrations from a radioactive species consists of a series of Heaviside step functions, with the steps occurring at the time of the disintegration. The disintegration of radioactive atoms is said to be random but this random behaviour is such that a single species forms an ensemble of which the times of disintegration give a geometric distribution. Numbers which have a geometric distribution can be generated by computer and can be used to simulate the decay of one or more radioactive species. A computer method is described for simulating such decay of radioactive atoms and this method is applied specifically to the decay of the short half life daughters of radon 222 and the emission of alpha particles from polonium 218 and polonium 214. Repeating the simulation of the decay a number of times provides a method for investigating the statistical uncertainty inherent in methods for measurement of exposure to radon daughters. This statistical uncertainty is difficult to investigate analytically since the time of decay of an atom of polonium 218 is not independent of the time of decay of subsequent polonium 214. The method is currently being used to investigate the statistical uncertainties of a number of commonly used methods for the counting of alpha particles from radon daughters and the calculations of exposure

  2. Radon and radon daughters in South African underground mines

    International Nuclear Information System (INIS)

    Rolle, R.

    1980-01-01

    Radon and the radon daughters are the radionuclides which primarily determine the level of the radiation hazard in underground uranium mines and to a smaller extent in non-uranium mines. Radon is a gas, and its daughters adsorb on aerosol particles which are of respirable size. The hazard thus arises from the alpha decay of radon and its daughters in contact with lung tissue. Radon is itself part of the uranium decay chain. The major radionuclide, 238 U, decays successively through thirteen shorter-lived radionuclides to 206 Pb. Radon is the only gaseous decay product at room temperature; the other twelve are solids. The main hazard presented by the uranium decay chain is normally determined by the radon concentration because gaseous transport can bring alpha emitters close to sensitive tissue. There is no such transport route for the other alpha emitters, and the level of beta and gamma radiation caused by the uranium decay chain generally presents a far lower external radiation hazard. Radon itself is the heaviest of the noble gases, which are He, Ne, Ar, Kr, Xe and Rn. Its chemical reactions are of no concern in regard to its potential hazard in mines as it may be considered inert. It does, however, have a solubility ten times higher than oxygen in water, and this can play a significant part in assisting the movement of the gas from the rock into airways. Radon continuously emanates into mine workings from uranium ores and from the uranium present at low concentrations in practically any rock. It has been found that the control of the exposure level is most effectively achieved by sound ventilation practices. In South African mines the standard of ventilation is generally high and exposure to radon and radon daughters is at acceptably low levels

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-05-01

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

  4. Adult Daughters' Descriptions of Their Mother-Daughter Relationship in the Context of Chronic Conflict.

    Science.gov (United States)

    Pickering, Carolyn E Z; Mentes, Janet C; Moon, Ailee; Pieters, Huibrie C; Phillips, Linda R

    2015-01-01

    The purpose of this article is to describe, from the perspective of the adult daughter, the mother-daughter relationship in the context of chronic conflict. Grounded theory methodology was used. An online recruitment strategy was used to identify a sample of adult daughters (N = 13) who self-identified as having an abusive relationship with their aging mother. Data collection was completed through semi-structured telephone interviews. Daughters framed their relationship around their perceptions of past childhood injustices. These injustices invoked strong negative emotions. Daughters had equally strong motivations for sustaining the relationship, driven by desire to reconcile their negative experience through seeking validation and futile-hoping as well as a sense of obligation to do due diligence. Together these factors created an environment of inevitable confrontation and a relationship defined by chronic conflict. Findings from the study provide theoretical insights to the conceptualization of aggression, power relationships, and the development of elder abuse and neglect.

  5. Unattached radon daughter atoms and radon daughter equilibrium ratios in uranium mines. Final report

    International Nuclear Information System (INIS)

    Holaday, D.A.

    1972-01-01

    Uranium mines in Colorado and New Mexico were surveyed for airborne concentrations of radon (10043922) and radon daughters. A procedure for measuring individual daughters and the fraction of each existing as free atoms was developed and used for field monitoring. Samples were taken in working areas and particle counts were made. The data was analyzed to determine the ratio of radon to radon daughters as well as the ratios among the radon daughters. The author concludes that since the radon to working level ratios have not changed much in 20 years, using the ratio as the basis for estimating relative biological hazard is just as uncertain now as then. The large number of daughters present as free atoms indicate that the lung radiation doses calculated using any of the lung models need reexamination

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

    Directory of Open Access Journals (Sweden)

    Svirikhin Alexandr

    2013-12-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    CERN Document Server

    Jeong, S C; Kawakami, H

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Kobayashi, Yoshio; Shibata, Michihiro; Ohkubo, Yoshitaka

    2016-02-01

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

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

    CERN Document Server

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

    2003-01-01

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

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

    Science.gov (United States)

    Tani, Hidenori

    2017-03-22

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

  13. Radon daughters and work at display devices

    International Nuclear Information System (INIS)

    Falk, R.; Nyblom, L.

    1986-01-01

    It has been shown that ions and electrically charged particles in the air can be transported in the electrostatic field between a face and a display device to either the face or the screen. Radon daughters can occur as ions, or sitting on charged particles. This prestudy shows that radon daughters were manifold concentrated on the face of a doll placed in front of a display device, or in a electrostatic field of the kind typical for displaying devices. The radiation dose, in the skin from the radon daughters in an ordinary office environment plus the addition caused by work at a display device, is not strong enough to cause skin damages alone. (BoK)

  14. Teenage Daughters as a Cause of Divorce

    OpenAIRE

    Kabátek, Jan; Ribar, David C.

    2017-01-01

    Evidence from the U.S. that couples with daughters are more likely to divorce than couples with sons has not been found for other Western countries. Using 1995-2015 Dutch marriage registry data, we show that daughters are associated with higher divorce risks, but only when they are 13 to 18 years old. There are no detectable gender differences before or after those ages. These age-specific findings are at odds with son-preference and selection explanations for differences in divorce risks. In...

  15. Laboratory measurements of the influence of air treatment devices on radon daughters

    International Nuclear Information System (INIS)

    Rajala, M.; Janka, K.; Graeffe, G.; Kulmala, V.; Lehtimaeki, M.

    1984-01-01

    This paper presents laboratory measurements in which the effect of air cleaners on radon decay products has been studied. Experiments show that both a high-efficiency particulate air filter and an electrostatic precipitator substantially decrease the total airborne radon daughter concentration leading to a situation where most of the decay products are unattached. However, in some situations the concentration of fine particles generated by the corona discharge in the electronic air cleaner becomes high enough to increase the total radon daughter concentration and decrease the free decay product concentration. Impurities in the air may have a notable role in the formation of these condensation nuclei. (Author)

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

    NARCIS (Netherlands)

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

    1988-01-01

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

  17. Impact on short-lived climate forcers (SLCFs) from a realistic land-use change scenario via changes in biogenic emissions.

    Science.gov (United States)

    Scott, C E; Monks, S A; Spracklen, D V; Arnold, S R; Forster, P M; Rap, A; Carslaw, K S; Chipperfield, M P; Reddington, C L S; Wilson, C

    2017-08-24

    More than one quarter of natural forests have been cleared by humans to make way for other land-uses, with changes to forest cover projected to continue. The climate impact of land-use change (LUC) is dependent upon the relative strength of several biogeophysical and biogeochemical effects. In addition to affecting the surface albedo and exchanging carbon dioxide (CO 2 ) and moisture with the atmosphere, vegetation emits biogenic volatile organic compounds (BVOCs), altering the formation of short-lived climate forcers (SLCFs) including aerosol, ozone (O 3 ) and methane (CH 4 ). Once emitted, BVOCs are rapidly oxidised by O 3 , and the hydroxyl (OH) and nitrate (NO 3 ) radicals. These oxidation reactions yield secondary organic products which are implicated in the formation and growth of aerosol particles and are estimated to have a negative radiative effect on the climate (i.e. a cooling). These reactions also deplete OH, increasing the atmospheric lifetime of CH 4 , and directly affect concentrations of O 3 ; the latter two being greenhouse gases which impose a positive radiative effect (i.e. a warming) on the climate. Our previous work assessing idealised deforestation scenarios found a positive radiative effect due to changes in SLCFs; however, since the radiative effects associated with changes to SLCFs result from a combination of non-linear processes it may not be appropriate to scale radiative effects from complete deforestation scenarios according to the deforestation extent. Here we combine a land-surface model, a chemical transport model, a global aerosol model, and a radiative transfer model to assess the net radiative effect of changes in SLCFs due to historical LUC between the years 1850 and 2000.

  18. Stepwise catalytic mechanism via short-lived intermediate inferred from combined QM/MM MERP and PES calculations on retaining glycosyltransferase ppGalNAcT2.

    Science.gov (United States)

    Trnka, Tomáš; Kozmon, Stanislav; Tvaroška, Igor; Koča, Jaroslav

    2015-04-01

    The glycosylation of cell surface proteins plays a crucial role in a multitude of biological processes, such as cell adhesion and recognition. To understand the process of protein glycosylation, the reaction mechanisms of the participating enzymes need to be known. However, the reaction mechanism of retaining glycosyltransferases has not yet been sufficiently explained. Here we investigated the catalytic mechanism of human isoform 2 of the retaining glycosyltransferase polypeptide UDP-GalNAc transferase by coupling two different QM/MM-based approaches, namely a potential energy surface scan in two distance difference dimensions and a minimum energy reaction path optimisation using the Nudged Elastic Band method. Potential energy scan studies often suffer from inadequate sampling of reactive processes due to a predefined scan coordinate system. At the same time, path optimisation methods enable the sampling of a virtually unlimited number of dimensions, but their results cannot be unambiguously interpreted without knowledge of the potential energy surface. By combining these methods, we have been able to eliminate the most significant sources of potential errors inherent to each of these approaches. The structural model is based on the crystal structure of human isoform 2. In the QM/MM method, the QM region consists of 275 atoms, the remaining 5776 atoms were in the MM region. We found that ppGalNAcT2 catalyzes a same-face nucleophilic substitution with internal return (SNi). The optimized transition state for the reaction is 13.8 kcal/mol higher in energy than the reactant while the energy of the product complex is 6.7 kcal/mol lower. During the process of nucleophilic attack, a proton is synchronously transferred to the leaving phosphate. The presence of a short-lived metastable oxocarbenium intermediate is likely, as indicated by the reaction energy profiles obtained using high-level density functionals.

  19. Stepwise catalytic mechanism via short-lived intermediate inferred from combined QM/MM MERP and PES calculations on retaining glycosyltransferase ppGalNAcT2.

    Directory of Open Access Journals (Sweden)

    Tomáš Trnka

    2015-04-01

    Full Text Available The glycosylation of cell surface proteins plays a crucial role in a multitude of biological processes, such as cell adhesion and recognition. To understand the process of protein glycosylation, the reaction mechanisms of the participating enzymes need to be known. However, the reaction mechanism of retaining glycosyltransferases has not yet been sufficiently explained. Here we investigated the catalytic mechanism of human isoform 2 of the retaining glycosyltransferase polypeptide UDP-GalNAc transferase by coupling two different QM/MM-based approaches, namely a potential energy surface scan in two distance difference dimensions and a minimum energy reaction path optimisation using the Nudged Elastic Band method. Potential energy scan studies often suffer from inadequate sampling of reactive processes due to a predefined scan coordinate system. At the same time, path optimisation methods enable the sampling of a virtually unlimited number of dimensions, but their results cannot be unambiguously interpreted without knowledge of the potential energy surface. By combining these methods, we have been able to eliminate the most significant sources of potential errors inherent to each of these approaches. The structural model is based on the crystal structure of human isoform 2. In the QM/MM method, the QM region consists of 275 atoms, the remaining 5776 atoms were in the MM region. We found that ppGalNAcT2 catalyzes a same-face nucleophilic substitution with internal return (SNi. The optimized transition state for the reaction is 13.8 kcal/mol higher in energy than the reactant while the energy of the product complex is 6.7 kcal/mol lower. During the process of nucleophilic attack, a proton is synchronously transferred to the leaving phosphate. The presence of a short-lived metastable oxocarbenium intermediate is likely, as indicated by the reaction energy profiles obtained using high-level density functionals.

  20. Accurate mass measurements of very short-lived nuclei. Prerequisites for high-accuracy investigations of superallowed β-decays

    International Nuclear Information System (INIS)

    Herfurth, F.; Kellerbauer, A.; Sauvan, E.; Ames, F.; Engels, O.; Audi, G.; Lunney, D.; Beck, D.; Blaum, K.; Kluge, H.J.; Scheidenberger, C.; Sikler, G.; Weber, C.; Bollen, G.; Schwarz, S.; Moore, R.B.; Oinonen, M.

    2002-01-01

    Mass measurements of 34 Ar, 73-78 Kr, and 74,76 Rb were performed with the Penning-trap mass spectrometer ISOLTRAP. Very accurate Q EC -values are needed for the investigations of the Ft-value of 0 + → 0 + nuclear β-decays used to test the standard model predictions for weak interactions. The necessary accuracy on the Q EC -value requires the mass of mother and daughter nuclei to be measured with δm/m ≤ 3 . 10 -8 . For most of the measured nuclides presented here this has been reached. The 34 Ar mass has been measured with a relative accuracy of 1.1 .10 -8 . The Q EC -value of the 34 Ar 0 + → 0 + decay can now be determined with an uncertainty of about 0.01%. Furthermore, 74 Rb is the shortest-lived nuclide ever investigated in a Penning trap. (orig.)

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

    Science.gov (United States)

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

    2016-08-01

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  3. Do Parents Discriminate against Their Heavyweight Daughters?

    Science.gov (United States)

    Crandall, Christian S.

    1995-01-01

    Attempts to support the parental prejudice hypothesis by having students report on their parents' attitudes. Results from two studies indicate that heavyweight women were more likely to pay their own way through college, irrespective of their parents' income. The selection bias against fat women was strongest for daughters of political…

  4. Vocational Preferences of Daughters of Alcoholics

    Science.gov (United States)

    Gade, Eldon M.; Goodman, Ronald E.

    1975-01-01

    This study was designed to examine the vocational interests of daughters of alcoholics. Mixed support was provided for the assumption that their vocational choices are nonperson oriented. Data did support the prediction of high scores on the realistic and intellectual scales of Holland's Vocational Preference Inventory. (SJL)

  5. White piedra in a mother and daughter.

    Science.gov (United States)

    Roshan, Anupama S; Janaki, C; Parveen, B

    2009-07-01

    White Piedra is a superficial fungal infection of the hair caused by Trichosporon asahii. It is also known as trichomycosis nodosa or trichomycosis nodularis. We report two cases of White Piedra in a mother and her daughter for the rarity of such occurrence.

  6. Occupational exposure to radon daughters in buildings

    International Nuclear Information System (INIS)

    Dixon, D.W.

    1985-01-01

    Results are presented for radon daughter concentrations in 70 premises of either factory-type or office-type in Cornwall. It is concluded that attention may need to be directed to offices in parts of the UK, the principal reason being their generally low ventilation rates. (U.K.)

  7. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France); Desequilibres des series de l'uranium dans les aquiferes: quantification des mecanismes de transport de l'uranium et de ses descendants: cas de l'aquifere de la craie (Champagne, France)

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, A

    2005-09-15

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ({sup 234}U et {sup 238}U), thorium ({sup 230}Th et {sup 232}Th), {sup 226}Ra and {sup 222}Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during {alpha}-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and {alpha}-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  8. Paternal smoking habits affect the reproductive life span of daughters

    DEFF Research Database (Denmark)

    Fukuda, Misao; Fukuda, Kiyomi; Shimizu, Takashi

    2011-01-01

    The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span). The study revealed that the smoking habits of the farther shortened the daughters' reproductive life...... span compared with daughters whose fathers did not smoke....

  9. An experimental chamber simulating the equilibrium between radon and its daughters in mine air

    International Nuclear Information System (INIS)

    Domanski, T.; Chruscielewski, W.; Orzechowski, W.

    1981-01-01

    An experimental chamber simulating the equilibrium between radon and its daughters in uranium mine air is described. The apparatus is useful for testing track detectors, air samplers, masks and filters and for determining occupational exposures. Increasing the humidity of the chamber air and increasing the amounts of aerosol injected both increase the values of the equilibrium factor, F. The equilibrium in the chamber air decreases after the aerosol injection but by using controlled pulse injections it was shown that the stability of F could be maintained inside the chamber for 4 hours. Results are also given for the structure of the equilibrium between radon and its daughters Qsub(i)/Q 0 in the chamber air as a function of the chamber air factor F and also for the potential α-energy of unattached products in relation to the total α-potential energy of radon daughter products in the chamber air as a function of factor F. (U.K.)

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  11. Radon daughter plate-out onto Teflon

    Science.gov (United States)

    Morrison, E. S.; Frels, T.; Miller, E. H.; Schnee, R. W.; Street, J.

    2018-01-01

    Radiopure materials for detector components in rare event searches may be contaminated after manufacturing with long-lived 210Pb produced by the decay of atmospheric radon. Charged radon daughters deposited on the surface or implanted in the bulk of detector materials have the potential to cause noticeable backgrounds within dark matter regions of interest. Understanding the mechanics governing these background signals is therefore a paramount concern in dark matter experiments in order to distinguish a real signal from internal detector backgrounds. Teflon (i.e. PTFE) is a specific material of interest because it makes up the walls of the inner detector of many liquid noble detectors such as the LUX-ZEPLIN experiment. The rate of radon daughter plate-out onto Teflon can be orders of magnitude larger than the plate-out rate onto other materials. Mitigation of plate-out onto Teflon and steel by proximity to other materials is demonstrated.

  12. Aging mothers' and their adult daughters' perceptions of conflict behaviors.

    Science.gov (United States)

    Fingerman, K L

    1995-12-01

    Aging parents tend to perceive greater compatibility between themselves and offspring than do off-spring, but there is little research examining differences in perceptions of conflicts. Ninety-six older mothers (M age = 76) and their daughters (M age = 44) together selected a conflictual incident, then individually rated the degree to which they and the other person had engaged in destructive, constructive, or avoidant conflict behaviors. Mothers and daughters reported using constructive approaches more than other approaches. Mothers claimed to engage in constructive behaviors more than daughters recognized. Daughters reported engaging in destructive and avoidant behaviors more than mothers realized. Mothers also thought daughters felt better about the incident than daughters reported feeling about it. Findings suggest older mothers' underestimate daughters' negative behaviors and feelings in conflict situations.

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

    Science.gov (United States)

    Colpi, Monica; Pallavicini, Andrea

    1998-07-01

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

  14. Quantification of the lung cancer risk from radon daughter exposure in dwellings - an epidemiological approach

    International Nuclear Information System (INIS)

    Edling, C.; Wingren, G.; Axelson, O.

    1986-01-01

    Some epidemiological studies have suggested a relationship between the concentration of decay products from radon, i.e., radon daughter exposure, in dwellings and lung cancer. Further experiences made from radon measurements have indicated that both building material and particularly the radioactivity in the ground is of importance for the leakage of radon into the houses. In Sweden, a survey is now ongoing in 15 municipalities with alum shale deposits, and in one area a case-referent evaluation has been made, considering building materials, ground conditions and smoking habits. The size of the study is small, but the results suggest that a risk is at hand and that there is a multiplicative effect from smoking and radon daughter exposure. About 30% of the lung cancers in the studied population might be attributable to elevated and potentially avoidable exposure to radon and radon daughters. (author)

  15. Shared Vision between Fathers and Daughters in Family Businesses: The Determining Factor That Transforms Daughters into Successors

    Directory of Open Access Journals (Sweden)

    Kathy Kessler Overbeke

    2015-05-01

    Full Text Available Family businesses are critical to the United States economy, employing 63% of the workforce and generating 57% of GDP (University of Vermont, 2014. Family business continuity, however, remains elusive as approximately 70% of family businesses do not survive the second generation (Poza, 2013. In order to augment our understanding of how next generation leaders are chosen in family businesses, we examine daughter succession. Using a sample of pairs of family business fathers and daughters and drawing on an earlier study of the dearth of successor daughters in family businesses (Overbeke, Bilimoria, & Perelli, 2013, we reveal that shared vision between fathers and daughters is central to daughter succession. Self-efficacy and gender norms influence shared vision and when fathers and daughters share a vision for the future of the company, daughters are likely to be transformed into successors.

  16. Shared vision between fathers and daughters in family businesses: the determining factor that transforms daughters into successors.

    Science.gov (United States)

    Overbeke, Kathy K; Bilimoria, Diana; Somers, Toni

    2015-01-01

    Family businesses are critical to the United States economy, employing 63% of the workforce and generating 57% of GDP (University of Vermont, 2014). Family business continuity, however, remains elusive as approximately 70% of family businesses do not survive the second generation (Poza, 2013). In order to augment our understanding of how next generation leaders are chosen in family businesses, we examine daughter succession. Using a sample of pairs of family business fathers and daughters and drawing on an earlier study of the dearth of successor daughters in family businesses (Overbeke et al., 2013), we reveal that shared vision between fathers and daughters is central to daughter succession. Self-efficacy and gender norms influence shared vision and when fathers and daughters share a vision for the future of the company, daughters are likely to be transformed into successors.

  17. African American mother-daughter communication about sex and daughters' sexual behavior: does college racial composition make a difference?

    Science.gov (United States)

    Bynum, Mia Smith

    2007-04-01

    This study examined the influence of African American mothers' communication about sexual topics on the sexual attitudes and behavior of their college-enrolled daughters. Daughters were enrolled at a historically Black college/university (HBCU) or a predominantly White institution (PWI) to assess whether and how college racial context might affect daughters' sexual attitudes and behavior. Findings indicated that daughters at the HBCU had less permissive attitudes about premarital sex than their counterparts at the PWI. This result was especially true for daughters of mothers with more conservative attitudes about premarital sex and who discussed such topics infrequently. Last, the combination of positive mother-daughter communication and fewer discussions about sexual topics resulted in lower levels of sexual experience among the daughters. (c) 2007 APA, all rights reserved.

  18. Shared vision between fathers and daughters in family businesses: the determining factor that transforms daughters into successors

    Science.gov (United States)

    Overbeke, Kathy K.; Bilimoria, Diana; Somers, Toni

    2015-01-01

    Family businesses are critical to the United States economy, employing 63% of the workforce and generating 57% of GDP (University of Vermont, 2014). Family business continuity, however, remains elusive as approximately 70% of family businesses do not survive the second generation (Poza, 2013). In order to augment our understanding of how next generation leaders are chosen in family businesses, we examine daughter succession. Using a sample of pairs of family business fathers and daughters and drawing on an earlier study of the dearth of successor daughters in family businesses (Overbeke et al., 2013), we reveal that shared vision between fathers and daughters is central to daughter succession. Self-efficacy and gender norms influence shared vision and when fathers and daughters share a vision for the future of the company, daughters are likely to be transformed into successors. PMID:26074830

  19. Occupational studies of radon daughters and lung cancer

    International Nuclear Information System (INIS)

    Hornung, R.W.; Ballew, M.A.

    1988-01-01

    The relationship between exposure to radon daughters and lung cancer mortality has been established. The purpose of this paper is to review some of the major studies of the health effects due to exposure to the decay products of radon gas and to discuss their potential implications with regard to risk associated with indoor radon. There has been much recent interest in the health hazards associated with radon largely motivated by the discovery of high levels of this radioactive gas in the Reading Prong (a geological area in Pennsylvania and New Jersey) and subsequently throughout the United States. Although at least three studies in the U.S. have been initiated to better estimate the lung cancer risks from low level indoor radon exposure, the results will not be known for several years. Consequently, present knowledge concerning such risks is almost entirely derived from studies of underground exposure to miners. Those studies effectively exclude women and children; therefore, assumptions must be made with regard to risk to a large segment of the population. Before discussing current health studies of radon daughter exposure, some background information is presented

  20. Parents' personality clusters and eating disordered daughters' personality and psychopathology.

    Science.gov (United States)

    Amianto, Federico; Ercole, Roberta; Marzola, Enrica; Abbate Daga, Giovanni; Fassino, Secondo

    2015-11-30

    The present study explores how parents' personality clusters relate to their eating disordered daughters' personality and psychopathology. Mothers and fathers were tested with the Temperament Character Inventory. Their daughters were assessed with the following: Temperament and Character Inventory, Eating Disorder Inventory-2, Symptom Checklist-90, Parental Bonding Instrument, Attachment Style Questionnaire, and Family Assessment Device. Daughters' personality traits and psychopathology scores were compared between clusters. Daughters' features were related to those of their parents. Explosive/adventurous mothers were found to relate to their daughters' borderline personality profile and more severe interoceptive awareness. Mothers' immaturity was correlated to their daughters' higher character immaturity, inadequacy, and depressive feelings. Fathers who were explosive/methodic correlated with their daughters' character immaturity, severe eating, and general psychopathology. Fathers' character immaturity only marginally related to their daughters' specific features. Both parents' temperament clusters and mothers' character clusters related to patients' personality and eating psychopathology. The cluster approach to personality-related dynamics of families with an individual affected by an eating disorder expands the knowledge on the relationship between parents' characteristics and daughters' illness, suggesting complex and unique relationships correlating parents' personality traits to their daughters' disorder. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Tracing Magmatic Degassing Timescales at Soufrière Hills Volcano using Short-Lived Uranium Series Isotopes

    Science.gov (United States)

    Turner, S.; McGee, L. E.; Handley, H. K.; Reagan, M. K.; Turner, M. B.; Berlo, K.; Barclay, J.; Sparks, R. S. J.

    2016-12-01

    Soufrière Hills Volcano, on the Caribbean island of Montserrat, is one of the most intensively studied and constantly monitored volcanic systems in the world. Since 1995, the island has seen five phases of eruption, interspersed with periods of quiescence of varying length. The last eruptive phase ended in 2010, and the current period of quiescence is the longest since 1995. Mafic recharge is thought to contribute volatiles which may lead to system overpressure and trigger a volcanic eruption. At Soufrière Hills Volcano, enclaves of mafic material are a notable feature within the andesitic dome collapse material from all five eruptive phases and have been the focus of several recent petrogenetic studies, meaning that they are extremely well-characterised. We present a 210Pb-226Ra isotope data of enclave-andesite pairs from all five recent eruption phases of Soufrière Hills to investigate the timescale on which volatile transfer occurs prior to eruptions. 210Pb-226Ra disequilibria is a powerful tool in tracing gas movement within recently erupted (<100 years) volcanic material, as one of the intermediary daughters involved in the chain (222Rn) is released in the gas phase of magmas. Subsequent deficits or excesses of 210Pb over 226Ra provide information on whether gas transfer occurred over a short time-frame or if gas fluxing from a mafic magma was maintained for some time previous to each eruption. This vital information may elucidate whether the system is recharging and preparing for a new eruptive phase or draining its current magma supply thus diminishing the possibility of further, explosive eruptions. Preliminary results suggest that gas fluxing from mafic magma was particularly effective in the first two eruptive phases, supporting the mafic-trigger hypothesis. However, we observe a possible change in this behaviour from phase 3 onwards. We complement these time-sensitive geochemical data with comparison to high resolution monitoring data with the hope

  2. Lung pathology and exposure to radon daughters

    International Nuclear Information System (INIS)

    Saccomanno, G.

    1980-01-01

    The data presented suggest that the primary carcinogen of lung cancer in uranium miners is cigarette smoking because the incidence of lung cancer in noncigarette smokers is insignificant. In cigarette-smoking uranium miners, however, the incidence of cancer in those exposed to significant amounts of radon daughters is higher than in the smoking, nonmining population. This suggests that radon is an additive carcinogen if the lung has been injured by the cigarette-smoking carcinogen. Preliminary studies measuring DNA, T cells, and rosette inhibition immunological studies indicate closer monitoring of uranium miners' health during this occupation may be justified

  3. The mother-daughter love affair across the generations.

    Science.gov (United States)

    Klockars, L; Sirola, R

    2001-01-01

    The relationship between mother and daughter is the basis for all love relationships throughout life. Through the eyes and hands of the mother, the intimate and caring nature of love is transmitted from generation to generation. Mother-daughter love is also the beginning of heterosexual love and of sensual pleasure. However, sexuality separates and alienates mother and daughter. As a consequence, the daughter's identification with the mother becomes the most important transmitter of love. We review psychoanalytic studies of the development and fate of the mother-daughter love relationship, with particular attention to the change of the daughter's early love for the mother to identification with the mother and falling in love with a man, and to the significance of sexuality in this developmental process.

  4. Daughter Species Abundances in Comet C/2014 Q2 (Lovejoy)

    Science.gov (United States)

    McKay, Adam; Cochran, Anita; Dello Russo, Neil; Kelley, Michael

    2015-11-01

    We present analysis of high spectral resolution optical spectra of C/2014 Q2 (Lovejoy) acquired with the Tull Coude spectrometer on the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory and the ARCES spectrometer mounted on the 3.5-meter Astrophysical Research Consortium Telescope at Apache Point Observatory. Both Tull Coude and ARCES provide high spectral resolution (R=30,000-60,000) and a large spectral range of approximately 3500-10000 Angstroms. We obtained two observation epochs, one in February 2015 at a heliocentric distance of 1.3 AU, and another in May 2015 at a heliocentric distance of 1.9 AU. Another epoch in late August 2015 at a heliocentric distance of 3.0 AU is scheduled. We will present production rates of the daughter species CN, C3, CH, C2, and NH2. We will also present H2O production rates derived from the [OI]6300 emission, as well as measurements of the flux ratio of the [OI]5577 Angstrom line to the sum of the [OI]6300 and [OI]6364 Angstrom lines (sometimes referred to as the oxygen line ratio). This ratio is indicative of the CO2 abundance of the comet. As we have observations at several heliocentric distances, we will examine how production rates and mixing ratios of the various species change with heliocentric distance. We will compare our oxygen line measurements to observations of CO2 made with Spitzer, as well as our other daughter species observations to those of candidate parent molecules made at IR wavelengths.

  5. Paternal smoking habits affect the reproductive life span of daughters.

    Science.gov (United States)

    Fukuda, Misao; Fukuda, Kiyomi; Shimizu, Takashi; Nobunaga, Miho; Andersen, Elisabeth Wreford; Byskov, Anne Grete; Andersen, Claus Yding

    2011-06-30

    The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span). The study revealed that the smoking habits of the farther shortened the daughters' reproductive life span compared with daughters whose fathers did not smoke. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Overview of current radon and radon daughter research at LBL

    International Nuclear Information System (INIS)

    1983-01-01

    This report provides a brief summary of radon and radon daughter research at Lawrence Berkeley Laboratory. The radon and radon daughter research program has two broad goals: (1) the study of sources of radon and its subsequent transport into houses, and (2) research on the behavior of radon daughters in indoor environments. Additional research effort is directed to several auxiliary areas, including development of instrumentation and monitoring techniques, studies of indoor air movement, and measurement and control of indoor particulate concentrations

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-03-26

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

  8. 182Hf-182W age dating of a 26Al-poor inclusion and implications for the origin of short-lived radioisotopes in the early Solar System.

    Science.gov (United States)

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

    2013-05-28

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

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

    Science.gov (United States)

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

    2012-08-01

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

  10. Mother-daughter in vitro fertilization triplet surrogate pregnancy.

    Science.gov (United States)

    Michelow, M C; Bernstein, J; Jacobson, M J; McLoughlin, J L; Rubenstein, D; Hacking, A I; Preddy, S; Van der Wat, I J

    1988-02-01

    A successful triplet pregnancy has been established in a surrogate gestational mother following the transfer of five embryos fertilized in vitro. The oocytes were donated by her biological daughter, and the sperm obtained from the daughter's husband. The daughter's infertility followed a total abdominal hysterectomy performed for a postpartum hemorrhage as a result of a placenta accreta. Synchronization of both their menstrual cycles was obtained using oral contraceptive suppression for 2 months, followed by stimulation of both the surrogate gestational mother and her daughter such that embryo transfer would occur at least 48 hr after the surrogate gestational mother's own ovulation. This case raises a number of medical, social, psychological, and ethical issues.

  11. [The mother's role in breasfeeding her primiparous daughter: "the togetherness"].

    Science.gov (United States)

    Machado, Ana Rita Marinho; Nakano, Ana Márcia Spanó; de Almeida, Ana Maria; Mamede, Marli Villela

    2004-01-01

    The authors' disquietudes are related to the structure for supporting women to breastfeed within their family environment. It is a qualitative study aiming at understanding the significance of breastfeeding among mothers and primiparous daughters, as well as identifying how the mother perceive herself as a means of support for her primiparous daughter and vice versa. The historic social construction of women for maternity has been used as a theoretical referential. The sample was made up of 10 women--five primiparous daughters and their mothers. The participation of the mother in her daughter's maternity was "to be along with her", sharing knowledge and life experiences.

  12. Einstein's daughter the search for Lieserl

    CERN Document Server

    Zackheim, Michele

    1999-01-01

    A thoroughly gripping and groundbreaking investigation into the mysterious fate of Albert Einstein's illegitimate daughter. Albert Einstein fell in love with Mileva Maric, the woman who would become his first wife, when they were students at the Zurich Polytechnic Institute. When Maric conceived a child out of wedlock, she went home to her family in Serbia to have the child. Lieserl Maric Einstein was born in 1902. Though Einstein and Maric married the following year, Lieserl was left in the care of her grandparents and never became a part of the Einstein family. In fact, her very existence was unknown until the recent discovery of a cache of letters between Einstein and Maric. The final reference to Lieserl comes in a September 1903 letter, when, at the age of approximately eighteen months, she simply disappears. What happened to Einstein's daughter is the most potent mystery to emerge from the mythology that surrounds one of the century's legendary figures, owing in large part to the careful and apparent...

  13. Reducing radon daughter background in alpha continuous air monitors

    International Nuclear Information System (INIS)

    Rodgers, J.C.; McFarland, A.R.

    1991-01-01

    Alpha continuous air monitors are instruments designed to sample aerosols which may contain alpha-emitting radionuclides and, in near-real time, to monitor the sample for alpha emissions. This process is subject to interference from radon decay products. The usual method for overcoming this interference is by signal processing or data processing in such a manner as to accurately subtract a portion of the background from the transuranic count. An innovative alternative approach has been jointly developed in a collaboration between Los Alamos National Laboratory and Texas A ampersand M University. The concept is to attempt to physically remove a portion of the interfering radon daughters from the incoming sample by a diffusion screen before the sample is collected. The results of laboratory tests indicate that a very high removal efficiency for unattached radon progeny can be obtained without excessive loss of efficiency for collection of the contaminant aerosols of concern. 15 refs., 4 figs., 1 tab

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

    Science.gov (United States)

    Chauvenet, B; Bobin, C; Bouchard, J

    2017-12-01

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  16. Production of Short-Lived Radionuclides at the Hahn-Meitner Institute in West Berlin; Production de Radionuclides a Courte Periode a l'Institut Hahn-Meitner de Berlin-Ouest; ПРОИЗВОДСТВО КОРОТКОЖИВУЩИХ РАДИОИЗОТОПОВ В ИНСТИТУТЕ ХАНА-МАЙТНЕРА В ЗАПАДНОМ БЕРЛИНЕ; Produccion de Radionuclidos de Periodo Corto en el Instituto Hahn-Meitner de Berlin Occidental

    Energy Technology Data Exchange (ETDEWEB)

    Felix, F. W.; Pirrwitz, D.; Szabo de Bucs, E. [Hahn - Meitner-Institut fuer Kern Forschung, Berlin, Federal Republic of Germany (Germany)

    1963-03-15

    The Hahn-Meitner Institute for Nuclear Research has produced short-lived radionuclides for medical and scientific purposes in the West Berlin area since 1960. Production now covers, the nuclides commonly used in medical applications, such as Na{sup 25}, K{sup 42} and Au{sup 198}, and other outstanding nuclides such as Cu{sup 64}, Zn{sup 69m} and F{sup 18}; Na{sup 24} and K{sup 42}are produced by neutron irradiation of the chlorides and, after calibration, distributed as solid material; Au{sup 198} is irradiated in metallic form, which is suitable for implantation in cancer therapy; F{sup 18} is produced by the reaction 0{sup 16} (t, n) and irradiation of LiNO{sub 3}. The separation of F{sup 18} by ion exchange showed better results than those usually given in the literature. For the production of Cu{sup 64} and Zn{sup 69m} special electrolytic methods have been developed to extract the radionuclides produced by a Szilard- Chalmers reaction on the phthalocyanines. Both nuclides have found application in medical diagnostics. In the paper details are given of irradiation facilities and techniques, production methods and apparatus, essay and calibration of the radionuclides produced and production capacity. (author) [French] Depuis 1960, l'Institut de recherches nucleaires Hahn-Meitner produit des radionucleides a courte periode a usage medical et scientifique pour la region de Berlin-Ouest. L'Institut prepare maintenant des nucleides utilises couramment en medecine tels que {sup 25}Na, {sup 42}K et {sup 198}Au, ainsi que quelques autres nucleides moins usuels comme {sup 64}Cu, {sup 69m}Zn et {sup 18}F. Le sodium-24 et le potassium-42 sont produits par irradiation neu- tronique des chlorures et distribues sous forme solide apres etalonnage. L'or-198 est irradie sous forme metallique, utilisable pour les implantations dans le traitement du cancer. Le fluor-18 est produit par la reaction {sup 16}0 (t, n) et par irradiation de LiNO{sub 3}. La separation de {sup 18}F par

  17. Radon-daughter chamber instrumentation system reference manual

    International Nuclear Information System (INIS)

    Showalter, R.; Johnson, L.

    1985-01-01

    The radon-daughter chamber instrumentation system collects environmental data from the radon-daughter chamber. These data are then recorded on a Tandberg system tape cartridge and transmitted to the HP-1000 computer for processing. Generators which inject radon and condensation nuclei into the chamber are also included with the instrumentation system

  18. Heritability of menopausal age in mothers and daughters

    NARCIS (Netherlands)

    van Asselt, Kristel M.; Kok, Helen S.; Pearson, Peter L.; Dubas, Judith S.; Peeters, Petra H. M.; te Velde, Egbert R.; van Noord, Paulus A. H.

    2004-01-01

    Objective: To determine the heritability of age at natural menopause from mother-daughter pairs. Design: Two-generation families were selected to study heritability of menopausal age. Setting: Subjects were drawn from a population-based study. Patient(s): One hundred sixty-four mother-daughter pairs

  19. Mother/Daughter Relationship: Psychological Implication of Love in ...

    African Journals Online (AJOL)

    This paper re-examines Toni Morrison's Beloved to identify an example of the types of mother/daughter relationship that existed between black mothers and their daughters and the implications of such relationship on the Black American society. The paper is a psychoanalytic reading, utilizing Melanie Klein's Object ...

  20. The Maternal Gift: Mothers' Investment in Their Daughters' Higher Education

    Science.gov (United States)

    Cooper, Linda

    2017-01-01

    This article explores the degree to which mothers participate in decisions surrounding their daughters' university choices in the English higher education sector, based on a gendered PhD study involving mother and adult daughter pairings in southern England. Examples are given of how extended middle-class mothering practices are enabling their…

  1. Reduction of radon daughter concentrations in structures

    International Nuclear Information System (INIS)

    1982-12-01

    A structure was identified in Salt Lake City wherein uranium mill tailings had been used in the construction and where unusually high levels of radon daughter concentrations (RDC's) existed. The physical and radiological characteristics of the structure were assessed. Ventilation techniques were investigated to assess their effectiveness in reducing RDC's. A preferred set of equipment was identified, installed in the structure and operated to reduce RDC's. Parametric studies were conducted to determine if supplying fresh air or recirculating air through electrostatic precipitators is more effective in reducing RDC's. Fresh air was found to be more effective in reducing RDC's. RDC's have been reduced to levels at or near the target of 0.03 working level under optimal ventilation conditions. Natural gas consumption with the new equipment is about 39% higher than with the original equipment. Electrical energy usage and electrical demand are respectively 50 and 44% higher with the new equipment than with the original equipment. 16 refs., 14 figs., 8 tabs

  2. Mortality and indoor radon daughter concentrations in 13 Canadian cities

    International Nuclear Information System (INIS)

    Letourneau, E.G.; Wigle, D.T.

    1980-01-01

    A study was carried out to determine if lung cancer and general mortality rates in 13 Canadian cities were significantly correlated with average indoor radon daughter concentrations. The radon daughter measurements were obtained from a study of 10,000 homes chosen in a statistically valid grab sample basis. Cancer deaths by year of death, sex, age, and cause were retrieved for each of the cities for the period 1957-1976. Age specific and age standardized mortality rates were calculated. The results showed no evidence of any substantial association between general or lung cancer mortality rates and indoor radon daughter concentrations. The limitations of this study and the feasibility of a common international program of epidemiology of radon daughter exposure are discussed. A proposal is made for the use of case control studies of lung cancer to assess the relative importance of smoking, occupational and domestic exposure to radon daughters

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  5. Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

    International Nuclear Information System (INIS)

    Liu, Xinyue; St Ange, Kalib; Wang, Xiaohua; Lin, Lei; Zhang, Fuming

    2017-01-01

    Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition. Liquid chromatography-mass spectrometry is rapid, robust, and amenable to automated processing and interpretation of both top-down and bottom-up analyses. Nuclear magnetic resonance spectroscopy provides complementary top-down information on the chirality of the uronic acid residues and glucosamine substitution. Principal component analysis (PCA) was applied to the normalized abundance of oligosaccharides, calculated in the bottom-up analysis, to show parent and daughter correlation in oligosaccharide composition. Using these approaches, six pairs of parent heparins and their daughter generic enoxaparins from two different manufacturers were comprehensively analyzed. Enoxaparin is the most widely used LMW heparin and is prepared through controlled chemical β-eliminative cleavage of porcine intestinal heparin. Lovenox"®, the innovator version of enoxaparin marketed in the US, was analyzed as a reference for the daughter LMW heparins. The results, show similarities between LMW heparins from two different manufacturers with Lovenox"®, excellent lot-to-lot consistency of products from each manufacturer, and detects a correlation between each parent heparin and daughter LMW heparin. - Highlights: • Low molecular weight heparins prepared from different heparin parents were analyzed. • An integrated analytical approach relied

  6. Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinyue, E-mail: liux22@rpi.edu [National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong, 250100 (China); Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); St Ange, Kalib, E-mail: stangk2@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); Wang, Xiaohua, E-mail: wangx35@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); School of Computer and Information, Hefei University of Technology, Hefei (China); Lin, Lei, E-mail: Linl5@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); Zhang, Fuming, E-mail: zhangf2@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); and others

    2017-04-08

    Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition. Liquid chromatography-mass spectrometry is rapid, robust, and amenable to automated processing and interpretation of both top-down and bottom-up analyses. Nuclear magnetic resonance spectroscopy provides complementary top-down information on the chirality of the uronic acid residues and glucosamine substitution. Principal component analysis (PCA) was applied to the normalized abundance of oligosaccharides, calculated in the bottom-up analysis, to show parent and daughter correlation in oligosaccharide composition. Using these approaches, six pairs of parent heparins and their daughter generic enoxaparins from two different manufacturers were comprehensively analyzed. Enoxaparin is the most widely used LMW heparin and is prepared through controlled chemical β-eliminative cleavage of porcine intestinal heparin. Lovenox{sup ®}, the innovator version of enoxaparin marketed in the US, was analyzed as a reference for the daughter LMW heparins. The results, show similarities between LMW heparins from two different manufacturers with Lovenox{sup ®}, excellent lot-to-lot consistency of products from each manufacturer, and detects a correlation between each parent heparin and daughter LMW heparin. - Highlights: • Low molecular weight heparins prepared from different heparin parents were analyzed. • An integrated analytical

  7. Observation and modeling of 222Rn daughters in liquid nitrogen

    International Nuclear Information System (INIS)

    Frodyma, N.; Pelczar, K.; Wójcik, M.

    2014-01-01

    The results of alpha spectrometric measurements of the activity of 222 Rn daughters dissolved in liquefied nitrogen are presented. A direct detection method of ionized alpha-emitters from the 222 Rn decay chain ( 214 Po and 218 Po) in a cryogenic liquid in the presence of an external electric field is shown. Properties of the radioactive ions are derived from a proposed model of ion production and transport in the cryogenic liquid. Ionic life-time of the ions was found to be on the order of 10 s in liquid nitrogen (4.0 purity class). The presence of positive and negative ions was observed. - Highlights: • A direct detection method of the alpha-emitters in a cryogenic liquid is shown. • We examine electrostatic drifting of the radioactive ions in liquid nitrogen. • The ions belong to the Radon-222 decay chain; Radon-222 is dissolved in the liquid. • The model of the ions production and behaviour in the liquid is proposed. • The ion production significantly depends on the nuclear decay type (alpha or beta)

  8. Daughter preference in Japan: A reflection on gender role attitudes?

    Directory of Open Access Journals (Sweden)

    Kana Fuse

    2013-05-01

    Full Text Available BACKGROUND Unlike other East Asian nations where preference for sons over daughters still prevails, gender preference for children in Japan has progressively shifted from son preference to a noticeable daughter preference over the past few decades. This emergence of daughter preference is surprising given that gender relations are more traditional in Japan than in other advanced countries. OBJECTIVE I focus on the extent to which individuals' gender preferences are shaped by their gender role attitudes and evaluate whether daughter preference is a reflection of convergence or a persistent divergence in gender roles in Japan. METHODS I use data from the Single Persons subset of the 11th Japanese National Fertility Survey conducted by the National Institute of Population and Social Security Research in 1997. Using multinomial logistic regression, I estimate the relationship between Japanese singles' gender role attitudes and their type of gender preference for children. RESULTS Findings suggest that the effect of gender role attitudes on one's child gender preference differs for men and women. Overall, while daughter preference is associated with nontraditional gender role attitudes for men, daughter preference is associated with traditional attitudes for women. CONCLUSIONS Traditionalism is still driving gender preference, though in a different way for men and women. Emerging daughter preference may not simply be a reflection of improvements in women's status, but in fact it is likely that persistent divergence in gender roles remain in Japan.

  9. Health hazards due to radon and its daughters

    International Nuclear Information System (INIS)

    Khan, H.A.; Qureshi, I.E.; Tufail, M.

    1993-01-01

    The health hazards liked to radon and its daughters have become a matter of great public concern. When inhaled, a fraction of radon is dissolved into the lung fluid, from where it is transported to other parts of the body. The radiation damage is caused to the lungs due to alpha decay of radon during its transit time within the respiratory tract. Radon daughters are found to be even more dangerous than radon itself. These daughters attach themselves to dust particles present in the air. Some of the aerosols so produced enter the lungs and enter the blood stream. It has now been confirmed that radon and its daughters contribute about 70% of the internal dose received by an individual from natural radiation sources. The danger of indoor radon and its daughters is even higher for energy-saving houses and those having poor ventilation systems. This paper briefly describes the health hazards due to radon and its daughters. Different methods employed for the measurement of concentrations of radon and their daughters are described. The experience gained from the nation-wide surveys carried out in different countries is also given. (author). 18 refs, 3 figs, 1 tab

  10. Control of radon and daughters in uranium mines and calculations on biologic effects

    International Nuclear Information System (INIS)

    Holaday, Duncan A.; Rushing, David E.; Coleman, Richard D.; Woolrich, Paul F.; Kusnetz, Howard L.; Bale, William F.

    2006-01-01

    A long range study under way by the Public Health Service since 1950 seeks to define the effects of uranium mining operations on the health of the miners and to derive data leading to the establishment of a healthful working environment. Although no evidence of health damage has been found among American miners, the European experience points to possible serious health effects. As a preventive measure, steps were therefore taken early in the industry's growth to safeguard the health of the miners. The current bulletin describes the results of the environmental study to date, together with the work of other investigators, with reference to methods of measuring atmospheric concentrations of radon and daughter products, the establishment of a safe working level for radon daughter products, and the development of effective control measures. It is believed that the material presented will be found useful by the industry and others, particularly in evaluating health hazards and in deriving economically feasible control methods

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

    Science.gov (United States)

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

    2010-10-01

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

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

    International Nuclear Information System (INIS)

    2002-01-01

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

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

    International Nuclear Information System (INIS)

    2014-01-01

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

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

    Science.gov (United States)

    Bialic-Murphy, Lalasia; Gaoue, Orou G

    2018-01-01

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

  15. Radon/radon-daughter measurement methods and instrumentation

    International Nuclear Information System (INIS)

    Rock, R.L.

    1977-01-01

    Radon-daughter measurement equipment and techniques have been continuously improved over the last 25 years. Improvements have been in the areas of accuracy, time and convenience. We now have miniaturized scalers and detectors available for measuring the alpha particle count rates from aerosol samples collected on filter papers. We also have small lightweight efficient pumps for conveniently collecting samples and we have various counting methods which allow us to choose between making very precise measurements or nominal measurements. Radon-daughter measurement methods used in uranium mines and mills are discussed including a personal radon-daughter-exposure integrating device which can be worn by miners

  16. Estimating long-run equilibrium real exchange rates: short-lived shocks with long-lived impacts on Pakistan.

    Science.gov (United States)

    Zardad, Asma; Mohsin, Asma; Zaman, Khalid

    2013-12-01

    The purpose of this study is to investigate the factors that affect real exchange rate volatility for Pakistan through the co-integration and error correction model over a 30-year time period, i.e. between 1980 and 2010. The study employed the autoregressive conditional heteroskedasticity (ARCH), generalized autoregressive conditional heteroskedasticity (GARCH) and Vector Error Correction model (VECM) to estimate the changes in the volatility of real exchange rate series, while an error correction model was used to determine the short-run dynamics of the system. The study is limited to a few variables i.e., productivity differential (i.e., real GDP per capita relative to main trading partner); terms of trade; trade openness and government expenditures in order to manage robust data. The result indicates that real effective exchange rate (REER) has been volatile around its equilibrium level; while, the speed of adjustment is relatively slow. VECM results confirm long run convergence of real exchange rate towards its equilibrium level. Results from ARCH and GARCH estimation shows that real shocks volatility persists, so that shocks die out rather slowly, and lasting misalignment seems to have occurred.

  17. Lawson Wilkins: recollections by his daughter.

    Science.gov (United States)

    McMaster, Elizabeth Wilkins

    2014-01-01

    Lawson Wilkins is well known as the "father" of the field of pediatric endocrinology, and his scientific accomplishments and legacy are thoroughly documented in this edition and elsewhere. Less well known, though, is what the man himself was like. Here, his daughter, Elizabeth McMaster, recalls the personal side of Dr. Wilkins including his upbringing as the son of a prominent Baltimore doctor, his medical education, establishment of a successful pediatric practice, and eventually the founding of the endocrine clinic at Johns Hopkins. Interwoven with anecdotes and reminiscences, this account provides a vivid sense of Wilkins' personality and life, from his boisterous nature and devotion to his family and career, to the tragic personal losses he endured. He was a man who threw himself fully into everything he did, whether it was making his own liqueur during Prohibition, collecting specimens from abnormally large circus performers as part of his earliest endocrine research, arranging raucous, impromptu singing parties, sailing the Chesapeake with friends, writing a definitive textbook of Pediatric Endocrinology, training a legion of fellows, or the pioneering work for which he is still known today.

  18. The Short-Lived Epidemic of Botulism From Commercially Canned Foods in the United States, 1919 to 1925.

    Science.gov (United States)

    Kazanjian, Powel

    2018-04-17

    In 1919, three deadly outbreaks of botulism caused by consumption of canned olives packed in California captured national headlines. In all of the outbreaks, which occurred in separate locales, unsuspecting people died after consuming tainted food during a banquet or family meal. The press's sensational portrayal of canned food as hazardous aroused alarm among consumers at a time when commercial canning was becoming more common. Intent on restoring the image of their product as safe and wholesome, canning industry leaders funded a "botulism commission" of scientific experts in 1919 to investigate how to systematically eliminate the threat of botulism that had imperiled their business. The commissioners identified the scientific reasons for the outbreaks, and on the basis of their findings, the California Department of Public Health issued explicit recommendations for sterilization procedures intended to ensure safety. However, the department did not mandate inspections for all canneries. When commercially packed fruits and vegetables continued to cause botulism, industry leaders voluntarily backed a cannery inspection act to legally require all California canners to possess appropriate equipment and follow scientifically validated sterilization procedures. After the California legislature approved the act in 1925, canneries were inspected, regulations were enforced, and no further outbreaks occurred. This botulism epidemic is an example of a disease outbreak that was controlled when business interests became aligned with public health goals. The press's portrayal of afflicted persons as innocent victims and worthy citizens galvanized businessmen to implement safeguards to protect consumers from botulism intoxication. To preserve their customer base and salvage their corporations, leaders of the canning industry acknowledged the public health threat of their unregulated procedures and acted on the recommendations of scientists.

  19. Determination of essential and trace elements in milk and measurement of short-lived nuclides using FIMS

    International Nuclear Information System (INIS)

    Demiralp, R.; Kalayoglu, S.; Unseren, E.; Grass, F.; Boeck, H.

    1988-01-01

    In the experiments, Gueluem, Sek and Pinar brand of bottled milks and Pinar milk powder which are commercially available were used. As standards IAEA Milk powder A-11, NBS-Orchard Leaves 1571 and for Cu single standard was used. Samples and standards were irradiated together in the central thimble of I.T.U. TRIGA Mark-II reactor for 1-8 hrs and for 60 sec in the fast pneumatic tube of TRIGA Reactor. Depending on the nuclear characteristics of the isotopes to be analyzed, they are counted at different counting times. The activities were measured with a high-purity Ge detector coupled to Canberra 90 model multichannel analyzer in the ITU. In order to determine short half-life nuclides a very fast irradiation and measuring system (FIMS) has been used. When the average values of the 16 elements are considered, it is observed that the amount of Na, As, Al, Mn, Zn, Rb , Co in the milk powder is greater than that of milk, where as in Pinar milk, which is a durable kind of milk, the amount of Na, K, Br, Al , As, Zn, Co is larger than that in daily milk. When daily products of different brands are compared, it was found that the quantity of Fe, Cr, Mg is higher while Cl, Sb, Zn, Rb, Co is less than that in Gueluem milk. The quantity of Cl is about 10 times as much and Mg 7 times less than in Sek milk. It was not possible to investigate how the seasons and the regions from where the milk was collected affect the quantity of the elements. It will be useful to continue the study in this field

  20. Alternate form and placement of short lived reactor waste and associated fuel hardware for decommissioning of EBR-II

    Energy Technology Data Exchange (ETDEWEB)

    Planchon, H.P.; Singleterry, R.C. Jr.

    1995-12-01

    Upon the termination of EBR-II operation in 1994, the mission has progressed to decommissioning and waste cleanup of the facility. The simplest method to achieve this goal is to bury the raw fuel and activated steel in an approved burial ground or deep geologic repository. While this might be simple, it could be very expensive, consume much needed burial space for other materials, and leave large amounts of fissile easily available to future generations. Also, as with any operation, an associated risk to personnel and the public from the buried waste exists. To try and reduce these costs and risks, alternatives to burial are sought. One alternative explored here for EBR-II is to condition the fuel and store the fission products and steel either permanently or temporarily in the sealed primary boundary of the decommissioned reactor. The first problem is to identify which subassemblies are going to be conditioned and their current composition and decay time. The next problem is to identify the conditioning process and determine the composition and form of the waste streams. The volume, mass, heat, and curie load of the waste streams needs to be determined so a waste-assembly can be designed. The reactor vessel and internals need to be analyzed to determine if they can handle these loads. If permanent storage is the goal, then mechanisms for placing the waste-assembly in the reactor vessel and sealing the vessel are needed. If temporary storage is the goal, then mechanisms for waste-assembly placement and retrieval are needed. This paper answers the technical questions of volume, mass, heat, and curie loads while just addressing the other questions found in a safety analysis. The final conclusion will compare estimated risks from the burial option and this option.

  1. Impact of Behavioral Symptoms in Dementia Patients on Depression in Daughter and Daughter-in-Law Caregivers.

    Science.gov (United States)

    Lee, Juwon; Sohn, Bo Kyung; Lee, Hyunjoo; Seong, Sujeong; Park, Soowon; Lee, Jun-Young

    2017-01-01

    One caregiver relationship that has been neglected in caregiver depression research is the daughter-in-law. Compared with Western countries, in which those who are closer in familial relationships such as the spouse or child usually take care of the patient, in many Asian countries, the daughter-in-law often assumes the caretaker role. However, not much research has been done on how this relationship may result in different caregiver outcomes. We sought to identify whether the association between patient characteristics and caregiver depressive symptoms differs according to the familial relationship between caregiver and patient. Ninety-five daughter (n = 47) and daughter-in-law (n = 48) caregivers of dementia patients were asked to report their own depressive symptoms and patient behavioral symptoms. Patients' cognitive abilities, daily activities, and global dementia ratings were obtained. Hierarchical linear regression was employed to determine predictors of depressive symptoms. Daughters-in-law had marginally higher depressive scores. After adjusting for caregiver and patient characteristics, in both groups, greater dependency in activities of daily living and more severe and frequent behavioral symptoms predicted higher caregiver depressive scores. However, greater severity and frequency of behavioral symptoms predicted depression to a greater degree in daughters compared with daughters-in-law. Although behavioral symptoms predicted depression in both caregiver groups, the association was much stronger for daughters. This suggests that the emotional relationship between the daughter and patient exacerbates the negative effect of behavioral symptoms on caregiver depression. The familial relationship between the caregiver and dementia patient should be considered in managing caregiver stress.

  2. Do mothers affect daughter's behaviors? Diet, physical activity, and sedentary behaviors in Kuwaiti mother-daughter dyads.

    Science.gov (United States)

    Shaban, Lemia H; Vaccaro, Joan A; Sukhram, Shiryn D; Huffman, Fatma G

    2018-01-01

    The objective of the study was to evaluate 169 Kuwaiti mother-daughter dyads and their associations with health behaviors for eating healthy, engaging in physical activity, daughters perceived body weight, time spent with computer/video, and time viewing television. Female students aged 10-14 years were selected from private and public schools in the State of Kuwait. Results demonstrated that daughters exhibited similar behaviors to their mothers in their perceived eating behavior, physical activity, computer/video game use, and TV screen time. Future research is essential to determine the role of mothers in effective health behavior intervention strategies for female Kuwaiti adolescents.

  3. The contribution of AECL CommercialProducts to nuclear medicine and radiation processing

    International Nuclear Information System (INIS)

    Beddoes, J.M.

    1980-02-01

    A review is given of the technology of the uses of radiation equipment and radioisotopes, in which field Canada has long been a world leader. AECL CommercialProducts has pioneered many of the most important applications. The development and sale of Co-60 radiation teletherapy units for cancer treatment is a familiar example of such an application, and CommercialProducts dominates the world market. Another such example is the marketing of Mo-99, which is produced in the reactors at Chalk River, and from which the short-lived daughter Tc-99 is eluted as required for use in in-vivo diagnosis. New products coming into use for this purpose include Tl-201, I-123, Ga-67 and In-111, all produced in the TRIUMF cyclotron in Vancouver, while I-125 continues to be in demand for in-vitro radioimmunoassays. Radioisotopes continue to play an important part in manufacturing, where their well-known uses include controlling thickness, contents, etc., in production, and industrial radiography. The application of large industrial irradiators for the sterilization of medical products is now a major world industry for which Commercial Products is the main manufacturer. Isotopes are also used in products such as smoke detectors. Isotopes continue to find extensive use as tracers, both in industrial applications and in animal and plant biology studies. Some more recent uses include pest control by the 'sterile male' technique and neutron activation and delayed neutron counting in uranium assay. (auth)

  4. Determination of radon daughter activities of different aerosol fractions by gross-α and gross-β measurements

    International Nuclear Information System (INIS)

    Katona, T.; Kanyar, B.; Jobbagy, V.; Kavasi, N.; Molnar, A.; Imre, K.

    2004-01-01

    The aim was to determine the radioactivities of the radon progenies ( 218 Po, 214 Pb, 214 Bi and 214 Po) attached to the carrier aerosol particles with respect to the size distribution in order to improve the assessment of the inhalation dose. We derived the radionuclide-specific activity concentrations from gross alpha and gross beta measurements provided during 2 hours after sampling and model calculations including parameter estimation. For the aerosol sampling we used an electrical low pressure impactor, which is able to collect aerosol particles in 12 different diameter ranges. In our test investigations the aerosol particles were collected from a closed chamber in a common laboratory building. The chamber contained a relatively high radon concentration (60-90 kBq/m 3 ) in equilibrium with the short lived daughters generated previously without any additional aerosol sources. For the nuclear measurements of the aerosol samples ZnS/plastic sandwich detectors have been used. The time series data of gross alpha and gross beta activities were fitted simultaneously and the initial activities of the daughters were estimated. According to the results from two different fractions (0.06 and 0.7 μm) just followed the end of sampling they contain a higher 218 Po activity than the 214 Pb and 214 Bi ones. The preliminary assessments for the special air conditions show that the 214 Pb-to- 218 Po activity ratios are higher for the small aerosol particles than for the larger ones. The estimated errors of the initial activities were near to 50% in a large part of cases. (author)

  5. Measurement of concentrations of radon and its daughters in indoor atmosphere using CR-39 nuclear track detector

    International Nuclear Information System (INIS)

    Farid, S.M.

    1993-01-01

    This paper presents the results of the measurements of indoor 222 Rn and daughter levels in houses of different types located in different parts of Bangladesh. The passive time-integrated method of using a solid state nuclear track detector (CR-39) was employed for measuring both the 222 Rn gas concentration as well as the potential alpha energy exposure (PAEE) level from the short lived daughters of 222 Rn. The 222 Rn concentration from cup exposure and the PAEE from the bare exposure were obtained directly from the track density using calibration curves. A total of 275 exposures were made in the bare mode in 15 locations and 71 exposures in the cup mode in 6 locations. The geometric mean PAEE level obtained is 9.5 mWL with a geometric standard deviation of 1.9. The corresponding value for 222 Rn concentration are 61.3 Bq.M -3 and 2.4. The total data was collected over a period of one and a half year. The monthly variation of the geometric mean of PAEE is also shown. The annual effective dose equivalent has been estimated for each location by using the conversion factor of 9 mWv per WLM as obtained from ICRP-50. The average PAEE level obtained from the total data is below the intervention level as suggested by US EPA. However, the individual averages for each location show that in 8 out of 15 locations intervention may be considered and in others not intervention is called for. The 222 Rn concentrations at the seven locations are equal or less than the equilibrium equivalent 222 Rn concentration value as suggested by EPA. Attempts have also been made to see the variation in the PAEE levels according to different type of construction material used for the houses. (Author)

  6. Radon and its daughters in various British mines

    International Nuclear Information System (INIS)

    Strong, J.C.; Laidlaw, A.J.; O'Riordan, M.C.

    1975-11-01

    The results of surveys of radon and radon daughter concentrations in a large number of mines, other than coal mines, in Great Britain are presented. Measurement methods are described, and estimates of the average radon daughter concentrations are given. A comparison is made between the results of radon and radon daughter determination. The radon daughter exposure of about 40% of the non-coal miners covered by a survey in 1973 was estimated to be above the recommended limit of 4 WLM in a year. Recommendations were made for reducing this exposure and for radiological surveillance. A follow-up survey shows some improvement partly due to the implementation of these recommendations, and by October 1975, the number of miners estimated to have an annual exposure above the recommended limit had fallen to about 30% of those included in the survey. (author)

  7. Instrumentation for collecting and measuring radon and its daughters

    International Nuclear Information System (INIS)

    Essling, M.A.; Hengde, W.; Markun, F.; Toohey, R.E.; Rundo, J.; Miranda, J.E. Jr.

    1982-01-01

    A new sampling can is described for collecting an air sample for determination of its radon content. Instruments which are employed for the continuous monitoring of radon or its daughters in houses are described and their performances discussed

  8. Comparison of two methods for investigating indoor radon daughters

    International Nuclear Information System (INIS)

    Vanmarcke, H.; Raes, F.

    1988-01-01

    The dynamics of radon daughters in realistic indoor environments has been investigated experimentally at the Universities of Gottingen and Gent. Both studies yielded the important result that the fraction of unattached radon daughters is higher than is assumed in earlier studies. Reineking-Porstendorfer and Vanmarcke-Raes adopted quite different methodologies to determine the unattached fraction. In this paper the methodologies are compared by means of joint measurements performed in a house with elevated radon concentrations. The results for the attachment rate, the deposition rate of the unattached daughters and the unattached fraction differ significantly, while the results for the deposition rate of the attached daughters and the equilibrium factor broadly agree. (author)

  9. Factors Associated with Parental Intent not to Circumcise Daughters ...

    African Journals Online (AJOL)

    USER

    Daughters in Enugu State of Nigeria: An Application of the Theory ... dichotomized into two categories and logistic regression analysis was performed to examine the association between the ..... The impact of perceived cost and rewards.

  10. A mother with variant Turner syndrome and two daughters with ...

    Indian Academy of Sciences (India)

    ... and two daughters with trisomy X: a case report ... has been reported, spontaneous pregnancy is rare with risk ... phenotype and includes learning disabilities, speech delays, .... X arise in maternal meiosis make this explanation less likely.

  11. Residential radon daughter monitor based on alpha spectroscopy

    International Nuclear Information System (INIS)

    Nazaroff, W.W.

    1980-05-01

    The radioactive daughters of radon-222 pose a serious indoor air quality problem in some circumstances. A technique for measuring the concentrations of these radioisotopes in air is presented. The method involves drawing air through a filter; then, for two time intervals after sampling, counting the alpha decays from polonium-218 and polonium-214 on the filter. The time intervals are optimized to yield the maximum resolution between the individual daughter concentrations. For a total measurement time of 50 minutes, individual daughter concentrations of 1.0 nanocuries per cubic meter are measured with an uncertainty of 20%. A prototype of a field monitor based on this technique is described, as is a field test in which the prototype was used to measure radon daughter concentrations as a function of ventilation conditions in an energy-efficient house

  12. Predicting radon/radon daughter concentrations in underground mines

    International Nuclear Information System (INIS)

    Leach, V.A.

    1984-01-01

    A detailed description of a computer programme is outlined for the calculation of radon/radon daughter concentrations in air. This computer model is used to predict the radon/radon daughter concentrations in Working Level (WL) at the workplace and at the various junctions at either end of the branches in a typical ventilation network proposed for the Jabiluka mine in the Northern Territory

  13. Background concentrations of radon and radon daughters in Canadian homes

    International Nuclear Information System (INIS)

    McGregor, R.G.; Vasudev, P.; Letourneau, E.G.; McCullough, R.S.; Prantl, F.A.; Taniguchi, H.

    1980-01-01

    Measurements of radon and radon daughters were carried out in 14 Canadian cities on a total of 9999 homes selected in a statistically random manner. The geometric means of the different cities varied from 0.14 to 0.88 pCi/l. for radon and 0.0009 to 0.0036 Working Levels for radon daughters. The radon originates from natural radioactivity in the soil surrounding the homes. (author)

  14. Estimating the mean and variance of measurements from serial radioactive decay schemes with emphasis on 222Rn and its short-lived progeny

    International Nuclear Information System (INIS)

    Inkret, W.C.; Borak, T.B.; Boes, D.C.

    1990-01-01

    Classically, the mean and variance of radioactivity measurements are estimated from poisson distributions. However, the random distribution of observed events is not poisson when the half-life is short compared with the interval of observation or when more than one event can be associated with a single initial atom. Procedures were developed to estimate the mean and variance of single measurements of serial radioactive processes. Results revealed that observations from the three consecutive alpha emissions beginning with 222 Rn are positively correlated. Since the poisson estimator ignores covariance terms, it underestimates the true variance of the measurement. The reverse is true for mixtures of radon daughters only. (author)

  15. Management of radioactive waste from 99Mo production

    International Nuclear Information System (INIS)

    1998-11-01

    99m Tc used for labelling different pharmaceuticals is the most important radionuclide in nuclear medicine practice, and probably will continue to play this important role for the foreseeable future. 99m Tc is the short lived daughter product of the parent 99 Mo, which is mainly produced by the nuclear fission of 235 U. Recognizing the importance of the waste management issue associated with 99 Mo production the IAEA initiated preparation of this report to provide Member States and existing and potential producers of 99 Mo with practical approaches and the available information on the subject. Waste management in the context of this report encompasses all waste-related aspects, for example, handling, treatment, conditioning, storage, transport, and disposal. The document is organized in several chapters giving the following information: short description of the basic nuclear and physical properties of 99 Mo and 99m Tc; an overview of past, present and possible future production methods; characteristics of the various waste streams produced in the aforementioned processes; description of the necessary waste management practices needed to handle the relevant waste streams in a responsible and internationally-accepted manner; conclusion and recommendations

  16. Interference from radon-thoron daughters in plutonium channel of a continuous plutonium-in-air monitor

    International Nuclear Information System (INIS)

    Pendharkar, K.A.; Krishnamony, S.

    1983-01-01

    This paper summarises the results of a study conducted to define the extent of interference from the daughter products of radon/thoron to the plutonium channel of a continuous plutonium-in-air monitor. The effect on the detection limits of the instrument due to chemical form (transportable or non-transportable) and isotopic composition of plutonium aerosol are briefly discussed. (author)

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

    Science.gov (United States)

    Sterner, E.; Johansson, D. J.

    2013-12-01

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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-11

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

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

    Science.gov (United States)

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

    2007-05-01

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

  1. AGE-DEPENDENT INHALATION DOSE DUE TO EXPOSURE OF SHORT LIVED PROGENY OF RADON AND THORON FOR DIFFERENT AGE GROUPS IN JAMMU & KASHMIR, HIMALAYAS.

    Science.gov (United States)

    Sharma, Sumit; Kumar, Ajay; Mehra, Rohit

    2018-05-16

    Dosimetric approach is used in this study for the assessment of doses due to inhalation of short lived radon/thoron progeny to the inhabitants of Udhampur district of Jammu & Kashmir. This paper also presents the activity concentrations and unattached fraction of radon and thoron progeny. The observed annual concentration of attached and unattached 222Rn and 220Rn progeny has been found to vary from 8 to 32 and 0.09 to 14 Bq/m3, 0.75 to 3.16 and 0.01 to 1.13 Bq/m3, respectively. The inhalation doses from radon progeny to different body organs of different age groups have been calculated by using the age dependent biokinetic model. The attachment rate of 222Rn and indoor aerosol concentration of 222Rn and 220Rn have been estimated and their relation between them has also been studied. The dose conversion factor for mouth and nasal breathing to different exposure conditions has been obtained from Porstendorfer model.

  2. 4-Amino-3H-pyrimidin-2-one ('isocytosine') is a short-lived non-radical intermediate formed in the pulse radiolysis of cytosine in aqueous solution

    International Nuclear Information System (INIS)

    Nien Schuchmann, Man; Naumov, Sergej; Schuchmann, Heinz-Peter; Sonntag, Justus von; Sonntag, Clemens von

    2005-01-01

    In the pulse radiolysis of 2'-deoxycytidine (dCyd) in N 2 O-saturated solutions containing 0.5M tertiary butanol to completely scavenge the water radicals, a short-lived intermediate (λmax=287nm) is observed by UV spectroscopy which is attributed to dCydH + , generated in the reaction of dCyd with H + formed during the pulse. By reacting with OH - , which is formed in the pulse in amounts matching that of H + , this intermediate disappears in the μs time range without a change of the spectrum. Similarly, cytosine (Cyt) gives rise to CytH + which, in contrast, in part transforms into another species (λmax=286nm) which can be assigned to isocytosine 1, 4-amino-3H-pyrimidin-2-one, a tautomer of Cyt which is formed by two routes (i) deprotonation of CytH + at N(1) by OH - and (ii) deprotonation of Cyt and reprotonation of the Cyt anion by water at N(3). Compared to Cyt, 1 is richer in Gibbs' free enthalpy by 14kJmol -1 . Its presence in low equilibrium concentrations has also been observed by conventional UV spectroscopy, making use of the increase of its equilibrium concentration with increasing temperature. From these data, an absorption coefficient of 3.3x10 4 dm 3 mol -1 cm -1 at 286nm has been calculated. Supporting quantum chemical calculations are also reported

  3. Transport of short-lived climate forcers/pollutants (SLCF/P) to the Himalayas during the South Asian summer monsoon onset

    International Nuclear Information System (INIS)

    Cristofanelli, P; Putero, D; Landi, T C; Marinoni, A; Duchi, R; Calzolari, F; Bonasoni, P; Adhikary, B; Stocchi, P; Verza, G; Vuillermoz, E; Laj, P; Kang, S; Ming, J

    2014-01-01

    Over the course of six years (2006–2011), equivalent black carbon (eqBC), coarse aerosol mass (PM 1–10 ), and surface ozone (O 3 ), observed during the monsoon onset period at the Nepal Climate Observatory–Pyramid WMO/GAW Global Station (NCO-P, 5079 m a.s.l.), were analyzed to investigate events characterized by a significant increase in these short-lived climate forcers/pollutants (SLCF/P). These events occurred during periods characterized by low (or nearly absent) rain precipitation in the central Himalayas, and they appeared to be related to weakening stages (or ‘breaking’) of the South Asian summer monsoon system. As revealed by the combined analysis of atmospheric circulation, air-mass three-dimensional back trajectories, and satellite measurements of atmospheric aerosol loading, surface open fire, and tropospheric NO x , the large amount of SLCF/P reaching the NCO-P appeared to be related to natural (mineral dust) and anthropogenic emissions occurring within the PBL of central Pakistan (i.e., Thar Desert), the Northwestern Indo-Gangetic plain, and the Himalayan foothills. The systematic occurrence of these events appeared to represent the most important source of SLCF/P inputs into the central Himalayas during the summer monsoon onset period, with possible important implications for the regional climate and for hydrological cycles. (letter)

  4. Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

    Science.gov (United States)

    Monks, P. S.; Archibald, A. T.; Colette, A.; Cooper, O.; Coyle, M.; Derwent, R.; Fowler, D.; Granier, C.; Law, K. S.; Mills, G. E.; Stevenson, D. S.; Tarasova, O.; Thouret, V.; von Schneidemesser, E.; Sommariva, R.; Wild, O.; Williams, M. L.

    2015-08-01

    Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a byproduct of the very oxidation chemistry it largely initiates. Much effort is focused on the reduction of surface levels of ozone owing to its health and vegetation impacts, but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve owing to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner. The review shows that there remain a number of clear challenges for ozone such as explaining surface trends, incorporating new chemical understanding, ozone-climate coupling, and a better assessment of impacts. There is a clear and present need to treat ozone across the range of scales, a transboundary issue, but with an emphasis on the hemispheric scales. New observational opportunities are offered both by satellites and small sensors that bridge the scales.

  5. Triggering Collapse of the Presolar Dense Cloud Core and Injecting Short-lived Radioisotopes with a Shock Wave. V. Nonisothermal Collapse Regime

    Energy Technology Data Exchange (ETDEWEB)

    Boss, Alan P., E-mail: aboss@carnegiescience.edu [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

    2017-08-01

    Recent meteoritical analyses support an initial abundance of the short-lived radioisotope (SLRI) {sup 60}Fe that may be high enough to require nucleosynthesis in a core-collapse supernova, followed by rapid incorporation into primitive meteoritical components, rather than a scenario where such isotopes were inherited from a well-mixed region of a giant molecular cloud polluted by a variety of supernovae remnants and massive star winds. This paper continues to explore the former scenario, by calculating three-dimensional, adaptive mesh refinement, hydrodynamical code (FLASH 2.5) models of the self-gravitational, dynamical collapse of a molecular cloud core that has been struck by a thin shock front with a speed of 40 km s{sup −1}, leading to the injection of shock front matter into the collapsing cloud through the formation of Rayleigh–Taylor fingers at the shock–cloud intersection. These models extend the previous work into the nonisothermal collapse regime using a polytropic approximation to represent compressional heating in the optically thick protostar. The models show that the injection efficiencies of shock front materials are enhanced compared to previous models, which were not carried into the nonisothermal regime, and so did not reach such high densities. The new models, combined with the recent estimates of initial {sup 60}Fe abundances, imply that the supernova triggering and injection scenario remains a plausible explanation for the origin of the SLRIs involved in the formation of our solar system.

  6. The origin and disappearance of the late Pleistocene-early Holocene short-lived coastal wetlands along the Carmel coast, Israel

    Science.gov (United States)

    Sivan, Dorit; Greenbaum, Noam; Cohen-Seffer, Ronit; Sisma-Ventura, Guy; Almogi-Labin, Ahuva

    The formation of short-lived backswamps along the Carmel coast of Israel coincides with the rapid global sea-level rise during the late Pleistocene-early Holocene transition. The current study shows that the wetland phenomena originated around 10,000 yr ago and dried up shortly before the local Pre-Pottery Neolithic humans settled on the wetland dark clay sediments 9430 cal yr BP. Palaeontological and stable-isotope data were used in this study to elucidate previously published sedimentological reconstruction obtained from a core drilled into the western trough of the Carmel coastal plain. The water body contained typical brackish calcareous fauna, with variable numerical abundance and low species richness of ostracods and foraminifera. The δ 18O and δ 13C of the ostracod Cyprideis torosa show close similarity to the present Pleistocene coastal aquifer isotopic values. This study therefore concludes that the wetlands were shallow-water bodies fed by groundwater, with no evidence of sea-water mixing. It seems that they developed as the result of high groundwater levels, transportation of sediments landward, and deposition of sand bars at the paleo-river mouths. It is still not fully understood why these wetlands deteriorated abruptly and disappeared within less than 1000 yr.

  7. Design and Performance Assessment of a Conceptual Cover Cap of Near Surface Repository for Short Lived Low and Intermediate Level Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Asaba, Ruth; Kim, Changlak [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-05-15

    The safety of the overall waste disposal system is determined by the performance of its individual components: waste form, waste container, engineered barrier and the host environment. The design of the cover cap helps in preventing percolation of water, and in retarding radionuclide migration from the disposal facility to the biosphere. The cover of a disposal facility is usually a combination of materials such as sand, gravel, concrete, clay and soil conditioned for vegetation growth. The cover system will be designed using models such as EPA's Hydrological Evaluation of Land fill Performance (HELP) code. This paper describes a conceptual design for a cover cap for a land fill as a preferred disposal facility for low and short lived intermediate radioactive waste in Uganda. Majority of the waste is generated from disused sealed and unsealed radioactive sources arising from medical, industrial applications, and research. Radioactive waste management has raised a lot of concern in both developed and developing countries. Each country has a responsibility to come up with a solution to prevent contamination of the environment and humans from radioactive waste. It is important to have thicker soil layers in cap designs so as to support vegetation growth since some activities such as erosion and settlements are expected. Help simulations in this study will assist to demonstrate that it is possible to design a cover cap which can contain radioactive waste packages for hundreds of years provided the proper institutional and performance monitoring schemes are implemented.

  8. Leadership emergence over time in short-lived groups: Integrating expectations states theory with temporal person-perception and self-serving bias.

    Science.gov (United States)

    Kalish, Yuval; Luria, Gil

    2016-10-01

    Research into leadership emergence typically focuses on the attributes of the emergent leader. By considering also the attributes of perceivers and the passage of time, we develop a more complete theory of leadership emergence in short-lived groups. Using expectation states theory as an overarching theoretical framework, and integrating it with the surface- and deep-level diversity literature and with theories of self-serving biases, we examine the predictors of leadership emergence in short timeframes. We conduct a field study in a military assessment boot camp (a pilot study, n = 60; and a main study, n = 89). We use cross-sectional and longitudinal exponential random graph models to analyze data on participants' abilities and on their perceptions of who, in their respective groups, were "leaders." We find that the criteria by which people perceive leadership in others change over time, from easily noticeable attributes to covert leadership-relevant attributes, and that people also rely on leadership-relevant attributes that they possess at high levels to inform their perceptions of leadership in others. The integration of expectation states theory, attribute salience over time and theories of self-serving bias is needed for a full understanding of leadership emergence in groups, because perceivers' own abilities are instrumental in shaping their perceptions of emergent leadership over time. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Climate impacts of short-lived climate forcers versus CO2 from biodiesel: a case of the EU on-road sector.

    Science.gov (United States)

    Lund, Marianne T; Berntsen, Terje K; Fuglestvedt, Jan S

    2014-12-16

    Biofuels are proposed to play an important role in several mitigation strategies to meet future CO2 emission targets for the transport sector but remain controversial due to significant uncertainties in net impacts on environment, society, and climate. A switch to biofuels can also affect short-lived climate forcers (SLCFs), which provide significant contributions to the net climate impact of transportation. We quantify the radiative forcing (RF) and global-mean temperature response over time to EU on-road fossil diesel SLCFs and the impact of 20% (B20) and 100% (B100) replacement of fossil diesel by biodiesel. SLCFs are compared to impacts of on-road CO2 using different approaches from existing literature to account for biodiesel CO2. Given the best estimates for changes in emissions when replacing fossil diesel with biodiesel, the net positive RF from EU on-road fossil diesel SLCFs of 3.4 mW/m(2) is reduced by 15% and 80% in B20 and B100, respectively. Over time the warming of SLCFs is likely small compared to biodiesel CO2 impacts. However, SLCFs may be relatively more important for the total warming than in the fossil fuel case if biodiesel from feedstock with very short rotation periods and low land-use-change impacts replaces a high fraction of fossil diesel.

  10. Indoor concentrations of radon 222 and its daughters: sources, range, and environmental influences

    International Nuclear Information System (INIS)

    Nero, A.V. Jr.

    1985-04-01

    The author here reviews what is presently known about factors affecting indoor concentrations of radon 222 and its daughters. In US single-family homes, radon concentrations are found to average about 1.5 pCi/1, but substantially higher concentrations occur frequently: perhaps a million US homes have concentrations exceeding 8 pCi/1 (from which occupants receive radiation doses comparable to those now experienced by uranium miners). The major contributor to indoor radon is ordinary soil underlying homes, with this radon being transported indoors primarily by the slight depressurization that occurs toward the bottom of a house interior (due to indoor-outdoor temperature differences and winds). Water from underground sources contributes significantly in a minority of cases, primarily residences with private wells, with public water supplies contributing only a few percent of indoor radon, even when drawn from wells. The strong variability in indoor concentrations is associated primarily with variability in the amount of radon entering homes from these various sources, and secondarily with differences in ventilation rates. However, for a given entry rate, the ventilation rate is the key determinant of indoor concentrations. Human doses are also influenced strongly by the chemical behavior of the daughters (i.e., decay products of radon), and considerable progress has been made recently in investigating a major aspect of this behavior, i.e., the manner in which daughters attach to airborne particles, to walls, and - indeed - to the lining of the lung itself, where the key radiation dose occurs

  11. Workshop on dosimetry for radon and radon daughters

    International Nuclear Information System (INIS)

    Turner, J.E.; Holoway, C.F.; Loebl, A.S.

    1978-05-01

    Emphasis is placed on the dosimetry for radon and daughters, rather than on monitoring and instrumentation. The objectives of the meeting were to exchange scientific information, to identify problem areas in radon-daughter dosimetry, and to make any observations or recommendations by the participants through issuance of this report. The discussion topics included the history of dosimetry for radon and daughters, human data, aerosols, deposition and movement in the respiratory tract, dose calculations, dose-to-working-level-month (WLM) conversion factors, animal experiments, and the development of regulations and remedial criteria for reducing population exposures to radon daughters. This report contains a summary of Workshop discussions plus individual statements contributed by several of the participants. The outstanding problem areas from the standpoint of dosimetry appear to involve the appropriate lung organ mass to be used (average lung-tissue dose vs. high-level local dose); recognition of the discrete, rather than continuous, structure of the mucus; lack of knowledge about lung clearance; the variability of dose with the degree of disequilibrium and the unattached fraction of radon daughters for a given WLM; and questions about the character of uranium mine atmospheres actually breathed in the older mines from which much of the epidemiological information originates. The development of criteria for taking remedial action to reduce exposures involves additional concerns of basing long-term risk assessment on short-term sampling and applying WLM data for miners to general populations

  12. Scavenging of radon daughters by precipitation from the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Fujinami, Naoto [Kyoto Prefectural Inst. of Hygienic and Environmental Sciences (Japan)

    1997-02-01

    By the continuous measurement of the radon daughters concentration in the rain and snow water and atmosphere and the data analysis, the following results were obtained. The radon daughters concentration was almost constant in the rain and snow water in spite of the length during weather without precipitation. It has not tendency to show the high concentration of radon daughters in precipitation and snow during beginning of them. When the precipitation intensity is constant, it`s concentration does not change during precipitation and snowfall. The concentration does not depend on the amount of precipitation, but on the precipitation intensity. We did not observe a correlation between the radon daughters concentration in the rain and snow water and that in the surface air. The atmospheric concentration was decreased by precipitation and snowfall, but that of rain and snow water did not decrease. The above results seems to show that the contribution of washout under the cloud to radon daughters in rain and snow water is small and that of rainout in the cloud is large. This result is agreement with the Jacob`s experimental results. (S.Y.)

  13. Microdosimetry of haemopoietic stem cells irradiated by α particles from the short-lived products of 222Rn decays in fat cells and haemopoietic tissue

    International Nuclear Information System (INIS)

    Charlton, D.E.; Utteridge, T.D.; University of South Australia, Pooraka, SA; Beddoe, A.H.

    1996-01-01

    The Monte Carlo method is used to model fat cells and the nuclei of stem cells in haemopoietic tissue where 222 Rn is dissolved in different amounts in the fat and tissue. Calculations are performed for fat cells of diameters 50 and 100 μm and for stem cell nuclei of 8 and 16 μm diameters for various fractions of fat filling the volume. Average doses (and their distributions) to stem cell nuclei from single passages of α particles are presented. In addition to dose, the relationship between LET and dose is obtained, illustrating the importance of 'stoppers' in the calculations. The annual average dose equivalent for a concentration of 1 Bq/m 3 in air agrees well with other authors at 12 μSv/year. The method also allows the calculation of the fraction of stem cell nuclei hit annually. Here for 1 Bq/m 3 , stem cell nuclei of diameter 8 μm and 100% fat filing 15 x 10 -7 of the stem cell nuclei are hit. (Author)

  14. An advanced method of contributing emissions to short-lived chemical species (OH and HO2: the TAGGING 1.1 submodel based on the Modular Earth Submodel System (MESSy 2.53

    Directory of Open Access Journals (Sweden)

    V. S. Rieger

    2018-06-01

    Full Text Available To mitigate the human impact on climate change, it is essential to determine the contribution of emissions to the concentration of trace gases. In particular, the source attribution of short-lived species such as OH and HO2 is important as they play a crucial role for atmospheric chemistry. This study presents an advanced version of a tagging method for OH and HO2 (HOx which attributes HOx concentrations to emissions. While the former version (V1.0 only considered 12 reactions in the troposphere, the new version (V1.1, presented here, takes 19 reactions in the troposphere into account. For the first time, the main chemical reactions for the HOx chemistry in the stratosphere are also regarded (in total 27 reactions. To fully take into account the main HO2 source by the reaction of H and O2, the tagging of the H radical is introduced. In order to ensure the steady-state assumption, we introduce rest terms which balance the deviation of HOx production and loss. This closes the budget between the sum of all contributions and the total concentration. The contributions to OH and HO2 obtained by the advanced tagging method V1.1 deviate from V1.0 in certain source categories. For OH, major changes are found in the categories biomass burning, biogenic emissions and methane decomposition. For HO2, the contributions differ strongly in the categories biogenic emissions and methane decomposition. As HOx reacts with ozone (O3, carbon monoxide (CO, reactive nitrogen compounds (NOy, non-methane hydrocarbons (NMHCs and peroxyacyl nitrates (PAN, the contributions to these species are also modified by the advanced HOx tagging method V1.1. The contributions to NOy, NMHC and PAN show only little change, whereas O3 from biogenic emissions and methane decomposition increases in the tropical troposphere. Variations for CO from biogenic emissions and biomass burning are only found in the Southern Hemisphere.

  15. On the radiation dose to lung tissues from radon daughters

    International Nuclear Information System (INIS)

    Wise, K.N.

    1980-04-01

    The work of Harley and Pasternak on calculating dose conversion factors for radon daughters is re-examined. It is found that their estimates of the deposit of radon daughters on the lung airways are too low and the factor for converting from equilibrium activity of radon daughters on the airways to dose to basal cells is too high; these are re-calculated. However, it is shown that inter-subject variability of the depth of the basal cells leads to considerable uncertainty in the individual dose. Finally average dose conversion factors are re-calculated for atmospheres which may be charactersitic of underground mines; the dose conversion factors range from 8 mGy/WLM to 40 mGy/WLM as calculated from the Weibel lung model and from 3 mGy/WLM to 17 mGy/WLM as calculated from the Landahl lung model

  16. Atmospheric radon daughters concentration inside and outside of cloud

    International Nuclear Information System (INIS)

    Nishikawa, Tsuguo; Okabe, Shigeru; Aoki, Masayoshi; Imamura, Takakazu; Iwata, Yoshitomo; Tamura, Yukihide; Tsuboguchi, Masayasu

    1987-01-01

    The measurements of the atmospheric radon daughters concentration in and out of the cloud were carried out on the top of the mountain, and in the upper air of the sea by using the airplane. The difference of the concentrations between inside and outside of the stratus measured on the top of the mountain was not clear. The atmospheric radon daughters concentration at the top of the mountain decreased when the amount of precipitation at that point was large. Concerning the cumulus investigated by using the airplane, the concentration in the cloud was a little higher than the concentration out of the cloud. Results of the measurements show that the cloud seems to be constructed of the various air masses whose radon daughters concentrations are different from each other even though it appears to be uniform. (author)

  17. Dowry calculations: daughter's rights in her parental family.

    Science.gov (United States)

    Kishwar, M

    1993-01-01

    The practice of dowry in India has become identified as the primary cause of women's oppression. It sets families apart in the fight over dowry payments and results in violence against daughters including infanticide. Daughter's get their share of inheritance at the time of marriage under traditional Hindu law. The Dowry Prohibition Act outlaws this practice. On the other hand, customary law allowed entitlements to women which Victorian norms bypassed, thereby paving the way for the disinheritance of women. The ownership of land was vested exclusively in men, and, as land became scarce and women's labor became devalued, women came to be treated as mere dependents and considered as a liability. With the entrance of men into government service as policemen and bank and postal clerks, their status increased, while women continued working in the peasant economy. Government job holders received the biggest dowries because of their access to economic opportunities. Under the Hindu Succession Act, fathers were allowed to will away property in whosoever's favor, which led to the disinheritance of daughters in favor of sons. Inheritance laws increasingly moved in favor of men and against women. Changing marriage patterns also emerged, as paying exorbitant dowries was perceived as a way of upward social mobility. The wife inherited everything at the expense of daughters, and widows automatically got a pension after the husband. Therefore, the wife's right had a stronger social sanction than the rights of daughters in parental property, especially the right to live in the parental home and take care of old parents, should be the solution to this injustice. Thus, parents would look at daughters in the same light as sons, and the culture of women's devaluation would come to an end.

  18. Public participation in decision-making processes: ONDRAF/NIRAS' approach to the disposal of low-level and short-lived radioactive waste

    International Nuclear Information System (INIS)

    Hooft, E.

    2000-01-01

    January 16, 1998, is a milestone in the nuclear waste management in Belgium. On that day, the Belgian government effectively opted for a definitive or potentially definitive solution for the Iona term management of low-level, short-lived radioactive waste. The government also wanted this solution to be implemented in a progressive, flexible, and reversible manner. it was thereby definitively abandoning the prolonged interim storage option, in favour of either surface disposal or deep geological disposal. At the same time, the government entrusted new missions to ONDRAFINIRAS, aimed at enabling it to make, around 2001-2002, the necessary technical and economic choice between surface disposal and deep geological disposal. ONDRAFNIRAS had to develop, in particular, methods, including the management and dialogue strictures, necessary to integrate a repository project at the local level. Furthermore, it had to restrict from then on its investigations to the four already existing nuclear zones in Belgium namely those of Doel, Fleurus, Mol-Dessel, and Tihange, and to the local towns or villages having shown an interest in a preliminary field study. Early in 1998, ONDRAFNIRAS set up a new work programme and developed an entirely new work methodology. As we understood that the best way to take involved into account the interests of all parties, is to involve them in the decision making on the project, we developed the idea of the local partnerships. Any party that could be directly affected by a collective decision, must have a say in it. Another innovative aspect of this new methodology is that of integration: an integration at the local level which is meant to enable the development of draft repository projects creating new perspectives for the regions concerned. Extending over four to five years, ONDRAFINIRAS's new work programme assumes the active participation of all the interested local representatives. Because it has understood that any party that could be directly

  19. Short-lived long non-coding RNAs as surrogate indicators for chemical exposure and LINC00152 and MALAT1 modulate their neighboring genes.

    Directory of Open Access Journals (Sweden)

    Hidenori Tani

    Full Text Available Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs. Although accumulating evidence demonstrates that lncRNAs play important roles in regulating gene expression, the detailed mechanisms of action of most lncRNAs remain unclear. We previously reported that a novel class of lncRNAs with a short half-life (t1/2 < 4 h in HeLa cells, termed short-lived non-coding transcripts (SLiTs, are closely associated with physiological and pathological functions. In this study, we focused on 26 SLiTs and nuclear-enriched abundant lncRNA, MALAT1(t1/2 of 7.6 h in HeLa cells in neural stem cells (NSCs derived from human induced pluripotent stem cells, and identified four SLiTs (TUG1, GAS5, FAM222-AS1, and SNHG15 that were affected by the following typical chemical stresses (oxidative stress, heavy metal stress and protein synthesis stress. We also found the expression levels of LINC00152 (t1/2 of 2.1 h in NSCs, MALAT1 (t1/2 of 1.8 h in NSCs, and their neighboring genes were elevated proportionally to the chemical doses. Moreover, we confirmed that the overexpression of LINC00152 or MALAT1 upregulated the expressions of their neighboring genes even in the absence of chemical stress. These results reveal that LINC00152 and MALAT1 modulate their neighboring genes, and thus provide a deeper understanding of the functions of lncRNAs.

  20. TRIGGERING COLLAPSE OF THE PRESOLAR DENSE CLOUD CORE AND INJECTING SHORT-LIVED RADIOISOTOPES WITH A SHOCK WAVE. II. VARIED SHOCK WAVE AND CLOUD CORE PARAMETERS

    Energy Technology Data Exchange (ETDEWEB)

    Boss, Alan P.; Keiser, Sandra A., E-mail: boss@dtm.ciw.edu, E-mail: keiser@dtm.ciw.edu [Department of Terrestrial Magnetism, Carnegie Institution, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

    2013-06-10

    A variety of stellar sources have been proposed for the origin of the short-lived radioisotopes that existed at the time of the formation of the earliest solar system solids, including Type II supernovae (SNe), asymptotic giant branch (AGB) and super-AGB stars, and Wolf-Rayet star winds. Our previous adaptive mesh hydrodynamics models with the FLASH2.5 code have shown which combinations of shock wave parameters are able to simultaneously trigger the gravitational collapse of a target dense cloud core and inject significant amounts of shock wave gas and dust, showing that thin SN shocks may be uniquely suited for the task. However, recent meteoritical studies have weakened the case for a direct SN injection to the presolar cloud, motivating us to re-examine a wider range of shock wave and cloud core parameters, including rotation, in order to better estimate the injection efficiencies for a variety of stellar sources. We find that SN shocks remain as the most promising stellar source, though planetary nebulae resulting from AGB star evolution cannot be conclusively ruled out. Wolf-Rayet (WR) star winds, however, are likely to lead to cloud core shredding, rather than to collapse. Injection efficiencies can be increased when the cloud is rotating about an axis aligned with the direction of the shock wave, by as much as a factor of {approx}10. The amount of gas and dust accreted from the post-shock wind can exceed that injected from the shock wave, with implications for the isotopic abundances expected for a SN source.

  1. Mitigation of Short-Lived Climate Pollutants from Residential Coal Heating and Combined Heating/Cooking Stoves: Impacts on the Cryosphere, Policy Options, and Co-benefits

    Science.gov (United States)

    Chafe, Z.; Anenberg, S.; Klimont, Z.; Kupiainen, K.; Lewis, J.; Metcalfe, J.; Pearson, P.

    2017-12-01

    Residential solid fuel combustion for cooking, heating, and other energy services contributes to indoor and outdoor air pollution, and creates impacts on the cryosphere. Solid fuel use often occurs in colder climates and at higher elevations, where a wide range of combustion emissions can reduce reflectivity of the snow- and ice-covered surfaces, causing climatic warming. Reducing short-lived climate pollutants (SLCPs), such as black carbon (BC), could have substantial climate and health co-benefits, especially in areas where emissions influence the cryosphere. A review of existing literature and emissions estimates, conducted as part of the Warsaw Summit on BC and Other Emissions from Residential Coal Heating Stoves and Combined Cooking/Heating Stoves, found little nationally-representative data on the fuels and technologies used for heating and combined cooking/heating. The GAINS model estimates that 24 million tonnes of coal equivalent were combusted by households for space heating globally in 2010, releasing 190 kilotons (kt) BC. Emissions from combined cooking/heating are virtually unknown. Policy instruments could mitigate cryosphere-relevant emissions of SLCPs from residential heating or cooking. These include indoor air quality guidelines, stove emission limits, bans on the use of specific fuels, regulatory codes that stipulate when burning can occur, stove changeout programs, and voluntary public education campaigns. These measures are being implemented in countries such as Chile (fuelwood moisture reduction campaign, energy efficiency, heating system improvements), Mongolia (stove renovation, fuel switching), Peru (improved stove programs), Poland (district heating, local fuel bans), United States (stove emission regulation) and throughout the European Community (Ecodesign Directive). Few, if any, of these regulations are likely to reduce emissions from combined cooking/heating. This research team found no global platform to create and share model

  2. Contributions of short-lived radioiodines to thyroid doses received by evacuees from the Chernobyl area estimated using early in vivo activity measurements

    International Nuclear Information System (INIS)

    Balonov, M.; Kaidanovsky, G.; Zvonova, I.; Kovtun, A.; Bouville, A.; Luckyanov, L.; Voilleque, P.

    2003-01-01

    A series of in-vivo gamma spectrometric measurements of 65 people, evacuated from Pripyat 1.5 days after the Chernobyl Nuclear Power Plant Unit 4 explosion was performed in St. Petersburg, Russia, as early as 30 April 1986. The historical spectra and interviews were recently processed and the results used for thyroid dose estimation. Activities of 131 I in thyroid and 132 Te in lungs were determined easily; for estimation of 132 I and 133 I activities in thyroid, sophisticated methods of spectra processing were developed. According to thyroid measurement data, the mean ratio of 133 I/ 131 I activities (at the time of the accident) inhaled by residents of Pripyat was 2.0. The mean ratio of thyroid dose from 133 I inhalation to that caused by 131 I amounts to 0.3, which confirms accuracy of dose estimates based on the evolution of the Chernobyl accident. The mean ratio of 132 I activity in thyroid to that of 132 Te in lungs was assessed from the human measurement data to be 0.2, which is in reasonable agreement with the metabolic properties of these radionuclides. The mean ratio of thyroid dose from 132 I originating from 132 Te deposited in lungs to the dose caused by 131 I was 0.13 ± 0.02 for Pripyat residents who did not take KI pills and 0.9 ± 0.1 for persons who took KI pills. Thus, the contribution of short-lived radioiodines to total thyroid dose of Pripyat residents, which was on average 30% for persons who did not apply stable iodine prophylaxis, and about 50% for persons who took KI pills on 26-27 April, should be accounted for in the assessment of thyroid health effects. (author)

  3. RNA-seq of the aging brain in the short-lived fish N. furzeri - conserved pathways and novel genes associated with neurogenesis.

    Science.gov (United States)

    Baumgart, Mario; Groth, Marco; Priebe, Steffen; Savino, Aurora; Testa, Giovanna; Dix, Andreas; Ripa, Roberto; Spallotta, Francesco; Gaetano, Carlo; Ori, Michela; Terzibasi Tozzini, Eva; Guthke, Reinhard; Platzer, Matthias; Cellerino, Alessandro

    2014-12-01

    The brains of teleost fish show extensive adult neurogenesis and neuronal regeneration. The patterns of gene regulation during fish brain aging are unknown. The short-lived teleost fish Nothobranchius furzeri shows markers of brain aging including reduced learning performances, gliosis, and reduced adult neurogenesis. We used RNA-seq to quantify genome-wide transcript regulation and sampled five different time points to characterize whole-genome transcript regulation during brain aging of N. furzeri. Comparison with human datasets revealed conserved up-regulation of ribosome, lysosome, and complement activation and conserved down-regulation of synapse, mitochondrion, proteasome, and spliceosome. Down-regulated genes differ in their temporal profiles: neurogenesis and extracellular matrix genes showed rapid decay, synaptic and axonal genes a progressive decay. A substantial proportion of differentially expressed genes (~40%) showed inversion of their temporal profiles in the last time point: spliceosome and proteasome showed initial down-regulation and stress-response genes initial up-regulation. Extensive regulation was detected for chromatin remodelers of the DNMT and CBX families as well as members of the polycomb complex and was mirrored by an up-regulation of the H3K27me3 epigenetic mark. Network analysis showed extensive coregulation of cell cycle/DNA synthesis genes with the uncharacterized zinc-finger protein ZNF367 as central hub. In situ hybridization showed that ZNF367 is expressed in neuronal stem cell niches of both embryonic zebrafish and adult N. furzeri. Other genes down-regulated with age, not previously associated with adult neurogenesis and with similar patterns of expression are AGR2, DNMT3A, KRCP, MEX3A, SCML4, and CBX1. CBX7, on the other hand, was up-regulated with age. © 2014 The Authors. Aging cell published by the Anatomical Society and John Wiley & Sons Ltd.

  4. Preliminary Results of IS Plasma Focus as a Breeder of Short-Lived Radioisotopes 12C(d,n)13N

    Science.gov (United States)

    Sadat Kiai, S. M.; Elahi, M.; Adlparvar, S.; Shahhoseini, E.; Sheibani, S.; Ranjber akivaj, H.; Alhooie, S.; Safarien, A.; Farhangi, S.; Aghaei, N.; Amini, S.; Khalaj, M. M.; Zirak, A. R.; Dabirzadeh, A. A.; Soleimani, J.; Torkzadeh, F.; Mousazadeh, M. M.; Moradi, K.; Abdollahzadeh, M.; Talaei, A.; Zaeem, A. A.; Moslehi, A.; Kashani, A.; Babazadeh, A. R.; Bagiyan, F.; Ardestani, M.; Roozbahani, A.; Pourbeigi, H.; Tajik Ahmadi, H.; Ahmadifaghih, M. A.; Mahlooji, M. S.; Mortazavi, B. N.; Zahedi, F.

    2011-04-01

    Modified IS (Iranian Sun) plasma focus (10 kJ,15 kV, 94 μF, 0.1 Hz) has been used to produce the short-lived radioisotope 13N (half-life of 9.97 min) through 12C(d,n)13N nuclear reaction. The filling gas was 1.5-3 torr of hydrogen (60%) deuterium (40%) mixture. The target was solid nuclear grade graphite with 5 mm thick, 9 cm width and 13 in length. The activations of the exogenous target on average of 20 shots (only one-third acceptable) through 10-13 kV produced the 511 keV gamma rays. Another peak found at the 570 keV gamma of which both was measured by a NaI portable gamma spectrometer calibrated by a 137Cs 0.25 μCi sealed reference source with its single line at 661.65 keV and 22Na 0.1 μCi at 511 keV. To measure the gamma rays, the graphite target converts to three different phases; solid graphite, powder graphite, and powder graphite in water solution. The later phase approximately has a doubled activity with respect to the solid graphite target up to 0.5 μCi of 511 keV and 1.1 μCi of 570 keV gamma lines were produced. This increment in activity was perhaps due to structural transformation of graphite powder to nano-particles characteristic in liquid water.

  5. Time-series variations of the short-lived Ra in coastal waters: implying input of SGD to the coastal zone of Da-Chia River, Taichung, Taiwan

    Science.gov (United States)

    Hsu, Feng-Hsin; Su, Chih-Chieh; Lin, In-Tain; Huh, Chih-An

    2015-04-01

    Submarine groundwater discharge (SGD) has been recognized as an important pathway for materials exchanging between land and sea. Input of SGD carries the associated nutrients, trace metals, and inorganic carbon that may makes great impacts on ecosystem in the coastal zone. Due to the variability of SGD magnitude, it is difficult to estimate the flux of those associated materials around the world. Even in the same area, SGD magnitude also varies in response to tide fluctuation and seasonal change on hydraulic gradient. Thus, long-term investigation is in need. In Taiwan, the SGD study is rare and the intrusion of seawater in the coastal aquifer is emphasized in previous studies. According to the information from Hydrogeological Data Bank (Central Geological Survey, MOEA), some areas still show potentiality of SGD. Here, we report the preliminary investigation result of SGD at Gaomei Wildlife Conservation Area which located at the south of the Da-Chia River mouth. This study area is characterized by a great tidal rang and a shallow aquifer with high groundwater recharge rate. Time-series measurement of the short-lived Ra in surface water was done in both dry and wet seasons at a tidal flat site and shows different trends of excess Ra-224 between dry and wet seasons. High excess Ra-224 activities (>20 dpm/100L) occurred at high tide in dry season but at low tide in wet season. The plot of salinity versus excess Ra-224, showing non-conservative curve, suggests that high excess Ra-224 activities derive from desorption in dry season but from SGD input in wet season.

  6. The prolactin response to an acute stressor in relation to parental care and corticosterone in a short-lived bird, the Eurasian hoopoe.

    Science.gov (United States)

    Schmid, Baptiste; Chastel, Olivier; Jenni, Lukas

    2011-10-01

    Prolactin plays an important role in mediating parental care in birds, but little is known about changes in prolactin levels when animals disrupt their reproductive behaviour during emergency life-history stages. We investigated the variation of prolactin levels with breeding stage, sex, body condition and as a response to a standardized acute stressor in a small short-lived bird, the Eurasian hoopoe Upupa epops under natural field conditions. We found higher baseline levels of prolactin in females during the brooding phase than in their mates which feed them and their chicks at this stage. Moreover, this is the first report of a differential prolactin stress-response between sexes with contrasting parental care within a breeding phase. Capture, handling and restraint induced a clear decrease of prolactin levels which was less pronounced in females at the very early stage of brooding compared to females in later stages. In contrast, the prolactin stress response in males remained nearly constant over the breeding stages and was stronger than in females. Baseline levels of prolactin, but not handling-induced levels, were positively correlated with body condition. We found a weak relationship between the decrease in prolactin due to acute handling stress and handling-induced levels of corticosterone. Taken together, both baseline and stress response levels of prolactin were related to the amount of parental care, although we found no relationship with reproductive success. It appears that the response to an acute stressor in prolactin levels is finely tuned to parental duties and investment. Hence, prolactin appears to be involved in mediating the trade-off between current reproduction versus self-maintenance and future reproduction. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Health hazards from radon daughters in dwellings in Sweden

    International Nuclear Information System (INIS)

    Axelson, O.; Edling, C.

    1980-01-01

    To clarify the possible etiological role for lung cancer from exposure to the low levels of radon and its daughters in dwellings, a case-control study was made, comparing cases of lung cancer with controls with respect to residency in different types of houses. This pilot study was restricted to include only people who lived in typically rural areas. The results support the hypothesis that radon and radon daughter exposure in dwellings is pertinent to the question of the etiology of lung cancer

  8. The radon daughter radiation hazard in controlled recirculation systems

    International Nuclear Information System (INIS)

    Rolle, R.; Burton, R.C.

    1987-01-01

    In deep South African gold mines, controlled recirculation systems with air cooling are being used to an increasing extent to improve the thermal environment. Recirculation causes some air to reside in the working area for a longer time than would have occurred without recirculation. Since radon daughters grow spontaneously from radon there is some concern that, with the extended residence time, the potential radiation hazard could increase to an unacceptable level. This paper describes the results obtained from a theoretical model of a controlled recirculation system. Guidelines for the design of recirculation systems to control the radon daughter radiation, and to keep it within acceptable limits are provided. 3 refs., 5 figs

  9. EXPLORING FATHER-DAUGHTER RELATIONSHIP IN THE ABHIJNANSAKUNTALAM AND HAMLET

    Directory of Open Access Journals (Sweden)

    Dr. Naveen K. MEHTA

    2011-05-01

    Full Text Available In Shakespearian dramas, the kingly authority merges with the authority of a father. Shakespeare uses the father-daughter relationship fundamentally to discredit the practice of possession and the attitude of cupidity which was under attack in the Renaissance. During the world’s famous Indian dramatist Kalidasa period, the father was considered to be the head of the family. Kalidasa's immortal works also suggest that counsels of parents and teachers must be obeyed without any hesitation. The present paper is an attempt to explore the intricacies of the father-daughter relationship in the „Abhijnansakuntalam” and „Hamlet”, „Prince of Denmark”

  10. Continuous monitoring α-activity on aerosol filters by the pseudo-coincidence-technique. Explicitly taking into account the short lived Po-218 activity; Kontinuierliche Ueberwachung der α-Aktivitaet eines Aerosolfilters mit der Pseudokoinzidenzmesstechnik. Explizite Beruecksichtigung der kurzlebigen Po-218 Aktivitaetsbeitraaege

    Energy Technology Data Exchange (ETDEWEB)

    Kraut, W.; Schwarz, W. [Duale Hochschule Baden-Wuerttemberg (DHBW), Karlsruhe (Germany). Studiengang Sicherheitswesen; Kraut, B. [Berthold Technologies GmbH und Co.KG, Bad Wildbad (Germany)

    2015-07-01

    Pseudo-coincidence-technique is applied to continuous monitoring of α-activity on aerosolfilters by proportional counters. Filter activity can markedly increase or decrease by changing air conditions especially by the amount of short lived Po-218 activity. Conditions of constant proportions of activity concentrations for the short lived species for operating this technique are seldom fulfilled. The dynamic behavior of artificial (long lived) and natural (short lived) activity is mathematically modelled and the measured moving count rates are analyzed under this model by a multivariate regression analysis for activity concentrations of artificial resp. short lived activity. Results are compared to standard recommendations of DIN ISO 11929.

  11. Model dosimetric for Radon and Daughters

    International Nuclear Information System (INIS)

    Puerta, J.A.; Cardenas, H.F.

    1998-01-01

    You elaborates a model dosimetric for radon and their products of decline of short half life starting from the new model of the breathing tract of the publication 66 of the ICRP and the use of the systemic models proposed in the publication 67, 68 and 69 of the same commission. The correlated used methodology the incorporation of these radionuclides with the activity in organs and you excrete, considering the difference of metabolic behavior of the products of decline and of their predecessor

  12. Multagenicity of radon and radon daughters. Final technical report, January 1, 1993--December 31, 1996

    International Nuclear Information System (INIS)

    Evans, H.H.

    1997-01-01

    The objective of this research was to investigate the dose-response relationship with regard to the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence was studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions was investigated by comparing the response of L5178Y strains that differ in their ability to rejoin X radiation-induced DNA double strand breaks. The nature of radon/radon daughter-induced mutational lesions in human lymphoblasts was also investigated

  13. Mother centrioles do a cartwheel to produce just one daughter.

    Science.gov (United States)

    Chen, Jieyan V; Megraw, Timothy L

    2014-07-28

    In this issue of Developmental Cell, Fong et al. (2014) present evidence for a model of centriole duplication whereby the cartwheel-the starting building block in centriole biogenesis-assembles within the lumen of the mother centriole before templating the daughter centriole to ensure a single duplication event per cell cycle. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Peoples' perception of mother-daughter sexual communication ...

    African Journals Online (AJOL)

    Peoples' perception of mother-daughter sexual communication patterns and adolescent girls reproductive health in Enugu North ... become vulnerable to reproductive health problems such as teenage pregnancy, STDs, and HIV/AIDS. ... improved sexual communication skills on sexuality education were recommended.

  15. Limitation schemes to decrease the radon daughters in indoor air

    International Nuclear Information System (INIS)

    Swedjemark, G.A.

    1986-01-01

    The limitation schemes to decrease the radon daughter concentrations in Swedish homes are described. The application of the Swedish provisional limitation system in use since 1980 is also reported. As a background the radon source and the international and national recommedations in other countries are reviewed. (author)

  16. Factors affecting daughters distribution among progeny testing Holstein bulls

    Directory of Open Access Journals (Sweden)

    Martino Cassandro

    2012-01-01

    Full Text Available The aim of this study was to investigate factors influencing the number of daughters of Holstein bulls during the progeny testing using data provided by the Italian Holstein Friesian Cattle Breeders Association. The hypothesis is that there are no differences among artificial insemination studs (AIS on the daughters distribution among progeny testing bulls. For each bull and beginning from 21 months of age, the distribution of daughters over the progeny testing period was calculated. Data were available on 1973 bulls born between 1986 and 2004, progeny tested in Italy and with at least 4 paternal half-sibs. On average, bulls exited the genetic centre at 11.3±1.1 months and reached their first official genetic proof at 58.0±3.1 months of age. An analysis of variance was performed on the cumulative frequency of daughters at 24, 36, 48, and 60 months. The generalized linear model included the fixed effects of year of birth of the bull (18 levels, artificial insemination stud (4 levels and sire of bull (137 levels. All effects significantly affected the variability of studied traits. Artificial insemination stud was the most important source of variation, followed by year of birth and sire of bull. Significant differences among AI studs exist, probably reflecting different strategies adopted during progeny testing.

  17. Size distribution of radon daughter particles in uranium mine atmospheres

    International Nuclear Information System (INIS)

    George, A.C.; Hinchliffe, L.; Sladowski, R.

    1975-01-01

    The size distribution of radon daughters was measured in several uranium mines using four compact diffusion batteries and a round jet cascade impactor. Simultaneously, measurements were made of uncombined fractions of radon daughters, radon concentration, working level, and particle concentration. The size distributions found for radon daughters were log normal. The activity median diameters ranged from 0.09 μm to 0.3 μm with a mean value of 0.17 μm. Geometric standard deviations were in the range from 1.3 to 4 with a mean value of 2.7. Uncombined fractions expressed in accordance with the ICRP definition ranged from 0.004 to 0.16 with a mean value of 0.04. The radon daughter sizes in these mines are greater than the sizes assumed by various authors in calculating respiratory tract dose. The disparity may reflect the widening use of diesel-powered equipment in large uranium mines. (U.S.)

  18. An Exploration of Mothers' Attitudes towards Their Daughters' Menarche

    Science.gov (United States)

    Bennett, Clare; Harden, Jane

    2014-01-01

    Menarche is a significant milestone for young women, representing an important juncture between girlhood and maturation. The limited literature that exists suggests that a mother's reaction to her daughter's first periods can shape her experiences and perceptions of menstruation which, in turn, may impact on her self-image and, consequently,…

  19. Dissident Daughters? The Psychic Life of Class Inheritance

    Science.gov (United States)

    Hey, Valerie; George, Rosalyn

    2013-01-01

    This paper arose through a chance meeting between the two authors who are feminist mothers of teenage and 20 years plus daughters. We were attending an Economic and Social Research Council-funded seminar focusing on "new femininities" in the light of post-feminism and their worth and currency within the new politics of consumption and lifestyle.…

  20. Factors associated with parental intent not to circumcise daughters ...

    African Journals Online (AJOL)

    This study explored intention of parents not to circumcise daughters in Enugu State, Nigeria using theory of planned behavior (TPB) as a framework. A survey of 1345 parents was carried out using structured questionnaire with FGM question items based on TPB constructs of attitude, subjective norm (SN), perceived ...

  1. Humor in Father-Daughter Immigration Narratives of Resistance

    Science.gov (United States)

    Gallo, Sarah

    2016-01-01

    This article draws from an ethnography on Mexican immigrant fathers and their children to examine humor in immigration narratives as acts of resistance. The analysis focuses on the devices employed by a father and daughter during their everyday talk and co-narration of an incident with police officers. Findings illustrate how the form and content…

  2. Development and implementation of radon daughter measurement in Egypt

    International Nuclear Information System (INIS)

    Hussein, A.Z.; Mohamed, I.H.

    2005-01-01

    During the last decade, a programme was developed to study radon daughter risks and to carry out field and experimental measurements. The Egyptian Atomic Energy Authority lead the implementation of this programme in cooperation with the International Atomic Energy Agency through the coordination project EGY/9/020 and EGY/9/030. Several national authorities participated also in this study such as Nuclear Materials Corporation. This work involved the preparation and calibration of equipment, establishment of measuring techniques, survey in some cities and mines countrywide, and preparation of regulations for radiation safety of the workers who may be exposed to high levels of radon daughters. The study shows that there is no major environmental problem for the public due to exposure to radon daughter. Occupational problem may be probable in some underground mines with bad ventilation. Reported values for radon daughter levels in units of working level ranged from 0-0.26 in some buildings and ruins in the Egyptian cities and from 0-3 working level in underground phosphate and uranium mine in the Egyptian Eastern Desert

  3. Biological basis of inhalation exposure of radon and its daughters

    International Nuclear Information System (INIS)

    Matsuoka, Osamu

    1989-01-01

    Since inhalation exposure by radon and its daughters is very specific type of internal exposure, it is necessary to understand its characteristic nature. The specificity originates from the nuclear feature of radon daughters and the biological micro-environment in the respiratory tract. Inhaled radon and its daughters exist in the respiratory tract as ions attached to air dusts and deposit on the mucus surface of the respiratory tract by various mechanisms such as impaction, sedimentation and diffusion. Deposition of radon daughters is predominant around the site of the fourth generation according to Weibel's model. Deposited particles with radon daughters are cleared by muco-ciliary transportation. Its speed is estimated to be about 1.0 cm/min, at the upper region. Alpha decay will happen during transportation in the respiratory tract. Radon has no tissue affinity metabolically. Therefore, the irradiation is limited to the epithelial cells of respiratory tract. The cell components within 30-70 micron in depth are irradiated with alpha particle. Biological effectiveness of alpha radiation is very high compared with beta or gamma radiation. The target cell for carcinogenesis by radon exposure is considered to be the basal cell of epithelium. Lung cancer induced by radon inhalation is recognized to be squamous cell carcinoma, small cell carcinoma, or oat-cell carcinoma and adenocarcinoma. The modification factors which influence the effect of radon exposure are co-inhalation of ore dust and smoking habit. According to epidemiological studies on lung cancer which occurred in uranium miners, it is suggested that the smoking habit strongly promotes lung cancer induction. (author)

  4. Giving Our Daughters What We Never Received: African American Mothers Discussing Sexual Health With Their Preadolescent Daughters.

    Science.gov (United States)

    Grigsby, Sheila R

    2018-04-01

    African American girls experience disparate rates of pregnancy and acquisition of sexually transmitted infections, including human immunodeficiency virus, when compared to their non-Hispanic White counterparts. Among African American girls, current pregnancy rates are equal to the national crisis levels of teen pregnancy reported in 1990. This qualitative elicitation study was conducted to gain insight into the ways in which African American mothers and their daughters, between the ages of 9 and 14, communicate about sexual health. Early sexual health communication between mothers and daughters is known to enhance the sexual health outcomes of girls. A series of four focus groups and three in-depth interviews were conducted between July and September 2014. The theory of planned behavior was the organizing framework. Theoretical constructs that guided this study were attitudes, perceived behavioral control, and subjective norms. Results showed that what African American women share with their daughters about sexual health stems from their personal faith, values, and experiences. Findings from this study can inform interventions to provide support for this understudied population. Moreover, there are implications for health-care providers, particularly school nurses, who are in an ideal position to help increase mothers' self-efficacy to engage in sexual health conversations with their young daughters.

  5. Latina Daughters' Childbearing Attitudes: The Role of Maternal Expectations and Education Communication

    Science.gov (United States)

    Mireles-Rios, Rebeca; Romo, Laura F.

    2014-01-01

    Adolescent girls' and their mothers' expectations for their daughters' college attainment, mother-daughter communication about education, and daughters' early childbearing attitudes were examined in 146 U.S.-raised Latina girls (mean age = 14.4 years) and their mostly immigrant mothers. Through structural equation modeling, we…

  6. Potential laboratory health hazard of /sup 210/Pb and a simple procedure for separation of /sup 210/Pb from the daughters /sup 210/Bi and /sup 210/Po

    Energy Technology Data Exchange (ETDEWEB)

    Pounds, J G [Arkansas Univ., Little Rock (USA). Medical Center; Blakemore, W M [The National Center for Toxicological Research, Department of Health and Human Services, Food and Drug Administration, Jefferson, AR, USA

    1981-12-01

    Lead 210 (Radium D) is a naturally occurring radionuclide which is frequently used in toxicological studies due to its long half-life. The use of /sup 210/Pb in tracer studies poses two problems. First /sup 210/Pb, along with its daughters /sup 210/Bi and /sup 210/Po, presents a significant health hazard to laboratory personnel. Second, the presence of the daughter products may interfere with the detection of /sup 210/Pb, particularly by techniques which discriminate poorly between different radioactive emissions, e.g. autoradiography. The potential laboratory health hazards of /sup 210/Pb and its daughters are briefly reviewed and a simple dithiozone extraction procedure which allows quantitative separation of /sup 210/Pb from the daughters /sup 210/Po and /sup 210/Bi is described. The purified /sup 210/Pb may then be utilized to reduce the health hazard from the daughter products and to construct calibration curves for the quantitation of /sup 210/Pb in the presence of /sup 210/Bi and /sup 210/Po by liquid scintillation counting.

  7. A multi-model intercomparison of halogenated very short-lived substances (TransCom-VSLS): linking oceanic emissions and tropospheric transport for a reconciled estimate of the stratospheric source gas injection of bromine

    OpenAIRE

    Hossaini, R.; Patra, P. K.; Leeson, A. A.; Krysztofiak, G.; Abraham, N. L.; Andrews, S. J.; Archibald, A. T.; Aschmann, J.; Atlas, E. L.; Belikov, D. A.; Bonisch, H.; Carpenter, L. J.; Dhomse, S.; Dorf, M.; Engel, A.

    2016-01-01

    The first concerted multi-model intercomparison of halogenated very short-lived substances (VSLS) has been performed, within the framework of the ongoing Atmospheric Tracer Transport Model Intercomparison Project (TransCom). Eleven global models or model variants participated (nine chemical transport models and two chemistry–climate models) by simulating the major natural bromine VSLS, bromoform (CHBr3) and dibromomethane (CH2Br2), over a 20-year period (1993–2012). Except f...

  8. [Mutagenicity of radon and radon daughters

    International Nuclear Information System (INIS)

    1990-01-01

    The current objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence will be studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions will be investigated by comparing the response of L5178Y strains which differ in their ability to rejoin X radiation-induced DNA double-strand breaks. This report discusses progress incurred from 4/1/1988--10/1/1990. 5 refs., 9 figs., 6 tabs

  9. Latina Mother–Daughter Dyads: Relations Between Attachment and Sexual Behavior Under the Influence of Alcohol or Drugs

    Science.gov (United States)

    Dillon, Frank R.; Rojas, Patria; Schwartz, Seth J.; Duan, Rui

    2009-01-01

    Associations among mother-daughter attachment, mother and daughter substance abuse, and daughter’s sexual behavior under the influence of drugs and alcohol were investigated among 158 adult U.S. Latina daughters. Latina daughters were sampled from four mother–daughter dyad types: substance abusing mother and daughter, substance abusing mother only, substance abusing daughter only, and nonsubstance-abusing mother and daughter. Substance abusing daughters with substance abusing mothers, and daughters who were less strongly attached to their mothers, reported more sex under the influence of drugs. Age, marital status, substance abuse, and mother’s substance abuse all influenced the daughter’s sex under the influence of alcohol. An unexpected positive association between attachment and sex under the influence of alcohol was found for daughters who were more closely attached to a substance abusing mother. Implications for future research, and HIV/AIDS and drug prevention and treatment programs for Latinas are discussed. PMID:19399605

  10. Oxygen isotopic and geochemical evidence for a short-lived, high-temperature hydrothermal event in the Chegem caldera, Caucasus Mountains, Russia

    Science.gov (United States)

    Gazis, C.; Taylor, H.P.; Hon, K.; Tsvetkov, A.

    1996-01-01

    Within the 2.8 Ma Chegem ash-flow caldera (11 ?? 15 km), a single cooling unit of rhyolitic to dacitic welded tuff more than 2 km thick is exposed in deep valleys incised during recent rapid uplift of the Caucasus Mountains. The intracaldera tuff is mineralogically fresh and unaltered, and is overlain by andesite lavas and cut by a resurgent granodiorite intrusion. Major- and trace-element compositions for a 1405-m stratigraphic section of intracaldera tuff display trends of upwardly increasing Na2O, CaO, Al2O3, total Fe, MgO, TiO2, Sr and Zr and decreasing SiO2, K2O and Rb. This mafic-upward zoning (from 76.1 to 69.9% SiO2) reflects an inverted view of the upper part of the source magma chamber. Oxygen isotope studies of 35 samples from this 1405-m section define a striking profile with "normal" igneous ??18O values (+7.0 to +8.5) in the lower 600 m of tuff, much lower ??18O values (-4.0 to +4.3) in a 700-m zone above that and a shift to high ??18O values (+4.4 to -10.9) in the upper 100 m of caldera-fill exposure. Data from two other partial stratigraphic sections indicate that these oxygen isotope systematics are probably a caldera-wide phenomenon. Quartz and feldspar phenocrysts everywhere have "normal" igneous ??18O values of about +8.5 and +7.5, respectively, whereas groundmass and glass ??18O values range from -7.7 to +12.3. Consequently, the ??18O values of coexisting feldspar, groundmass and glass form a steep array in a plot of ??feldspar vs. ??groundmass/glass. Such pronounced disequilibrium between coexisting feldspar and groundmass or glass has never before been observed on this scale. It requires a hydrothermal event involving large amounts of low-18O H2O at sufficiently high temperatures and short enough time (tens of years or less) that glass exchanges thoroughly but feldspar does not. The most likely process responsible for the O depletions at Chegem is a very high temperature (500-600??C), short-lived, vigorous meteoric-hydrothermal event that was

  11. Delivery of halogenated very short-lived substances from the west Indian Ocean to the stratosphere during the Asian summer monsoon

    Directory of Open Access Journals (Sweden)

    A. Fiehn

    2017-06-01

    Full Text Available Halogenated very short-lived substances (VSLSs are naturally produced in the ocean and emitted to the atmosphere. When transported to the stratosphere, these compounds can have a significant influence on the ozone layer and climate. During a research cruise on RV Sonne in the subtropical and tropical west Indian Ocean in July and August 2014, we measured the VSLSs, methyl iodide (CH3I and for the first time bromoform (CHBr3 and dibromomethane (CH2Br2, in surface seawater and the marine atmosphere to derive their emission strengths. Using the Lagrangian particle dispersion model FLEXPART with ERA-Interim meteorological fields, we calculated the direct contribution of observed VSLS emissions to the stratospheric halogen burden during the Asian summer monsoon. Furthermore, we compare the in situ calculations with the interannual variability of transport from a larger area of the west Indian Ocean surface to the stratosphere for July 2000–2015. We found that the west Indian Ocean is a strong source for CHBr3 (910 pmol m−2 h−1, very strong source for CH2Br2 (930 pmol m−2 h−1, and an average source for CH3I (460 pmol m−2 h−1. The atmospheric transport from the tropical west Indian Ocean surface to the stratosphere experiences two main pathways. On very short timescales, especially relevant for the shortest-lived compound CH3I (3.5 days lifetime, convection above the Indian Ocean lifts oceanic air masses and VSLSs towards the tropopause. On a longer timescale, the Asian summer monsoon circulation transports oceanic VSLSs towards India and the Bay of Bengal, where they are lifted with the monsoon convection and reach stratospheric levels in the southeastern part of the Asian monsoon anticyclone. This transport pathway is more important for the longer-lived brominated compounds (17 and 150 days lifetime for CHBr3 and CH2Br2. The entrainment of CHBr3 and CH3I from the west Indian Ocean to the stratosphere during the

  12. Influence of radon daughter exposure rate, unattachment fraction, and disequilibrium on occurrence of lung tumours

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Dagle, G.E.; Busch, R.H.; Buschbom, R.L.

    1984-01-01

    Groups of male, specific-pathogen-free (SPF), Wistar rats were exposed to several concentrations of radon daughters and uranium ore dust to clarify the roles of exposure rate, unattached RaA daughters, and the degree of radon daughter disequilibrium, in the development of respiratory system disease. Modelled, human dosimetric data indicate that the dose to sensitive tissues of the respiratory tract increases with increasing radon daughter unattachment fraction and degree of disequilibrium. Data bearing on these developments as well as updated results of experiments designed to test the role of radon daughter exposure rate on lung tumour incidence are reported. (author)

  13. Influence of various room parameters upon radon daughter equilibrium indoors

    International Nuclear Information System (INIS)

    Islam, G.S.; Mazumdar, S.C.; Ashraf, M.A.

    1995-06-01

    The parameters such as ventilation rate, attachment rate to aerosols and deposition processes, which influence the radon daughter equilibrium indoors, are discussed and the validity of the theoretical model checked by experiments. In agreement with the model calculations, the experimental data show, that the equilibrium factor F in rooms is mainly influenced by the rate of attachment to aerosols and the plateout of radon daughters. The equilibrium factor varies between 0.3 and 0.4 at an attachment rate of 300 h -1 . The influence of ventilation upon the free fraction of RaA( 218 Pp)-atoms is also investigated. This is in good agreement with the results of the measurements carried out in different types of rooms at the University Campus of Rajshahi. (author). 20 refs, 3 figs, 3 tabs

  14. Electronic instrument for radon daughter dosimetry. Report of investigations

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    Due to the daily exposures of uranium mining personnel to 222Rn daughters, a device is needed which will continually monitor the individual's exposure. Such a device has been built and tested and is known as the Radon Daughter Dosimeter. This is an electronic instrument using a solid-state detector and circuitry. The system permits the evaluation of cumulative exposures to airborne radon progeny, expressed in units of Working Level Hours (WL-HRS). The instrument is a personal device worn by the individual throughout the working shift. Since the instrument is in close proximity to the miner and measures continual exposure, it provides an accurate account of total cumulative exposure, thus avoiding the errors caused by the present technique of spot checking of the environment

  15. Develop generic equations to determine radon daughters concentrations in air

    International Nuclear Information System (INIS)

    Shweikani, R.; Jerby, B.

    2011-06-01

    Measurements of radon daughter concentrations in air are very important to determine the human dose from background radiation. Therefore, many studies tried to find measurements methods depending on many specific parameters such as measurement time, air pumping period and sample volume. In this study a general equations to determine radon daughter's concentrations in air was found using direct samples. The Equations results were closed to the results obtained from other well known methods. Many measurements with different places and various conditions were performed; the results showed that the new equations are able to be used with an error less than 10%, The relative error can be reduced by increasing the pumping rate or measuring high concentration cases.(author)

  16. Decommissioning/closeout of Malargue site: measurement of radon daughter

    International Nuclear Information System (INIS)

    Avila Cadena, Guadalberto

    2000-01-01

    In Malargue complex there are about 700,000 mt of uranium tailings disposed off during 32 years of operation of the Malargue facility. The objective of the Malargue Site is to undertake the necessary actions to execute remediation programs. A summary of measurements of concentrations of radon daughter taken in different buildings of the city and in the field shows the influence of radon source. The results obtain for concentrations of radon daughter indicate that they do not differ significantly between each others. The environmental remediation of uranium mill tailings at Malargue Site is a requirement of Nuclear Regulatory Authority (NRA) and of the Mendoza province and a commitment to reduce the doses as low as reasonably achievable, social and economic factors being taken into account (ALARA concept). (author)

  17. Radiation exposure due to radon and radon daughters

    International Nuclear Information System (INIS)

    Ullmann, W.

    1976-01-01

    Underground miners working over long periods of time in mines with a high content of radon and radon daughters belong to that group of occupationally exposed persons who are subject to the greatest somatic risk, with values especially high if the permissible dose limits are exceeded. Follwing an overview of the permissible limits currently in use for radon and radon daughters as well as the results of examinations performed in nationally-owned underground mining of the G.D.R., considerations are presented on the measuring quantities requisite for statistical, control and safety measurements in this field. Finally, conclusions are drawn concerning the measuring procedures and instruments to be employed for practical work. (author)

  18. Development of diffusion-based radon daughter dosimeters

    International Nuclear Information System (INIS)

    Phillips, C.R.; Khan, A.; Leung, H.

    1983-07-01

    The objective of this work is to investigate the possible application of the mechanisms of thermophoresis and electrostatic collection via electrets to the collection of radon daughters with reference to personal alpha dosimeters for use in uranium mines. The potential advantage accruing from adoption of either one of these collection mechanisms is that collection is passive and does not depend upon the use of a pump (active), and is, therefore, intrinsically much more reliable

  19. Daughters Taking Over the Family Business : A Gender Analysis

    OpenAIRE

    Constantinidis, Christina; Cornet, Annie

    2008-01-01

    This paper investigates the succession process as perceived and lived by daughters taking over the family business, with a gender perspective. Despite the rich literature on the succession process in family firms, few studies use a gender approach, though an increasing number of ventures are launched, taken over and managed by women, largely contributing to the economic development. In line with Dumas (1998), Barbot et al. (2005) and Vera & Dean (2005), our research aims at analyzing the succ...

  20. Barber-Say syndrome in a father and daughter.

    Science.gov (United States)

    Roche, Nathalie; Houtmeyers, Philippe; Janssens, Sandra; Blondeel, Philllip

    2010-10-01

    We report on a father to daughter transmission of Barber-Say syndrome (BSS), a rare, congenital disorder characterized by severe generalized hypertrichosis, macrostomia, ocular telecanthus, bulbous nose and atrophic skin. These two cases further support the autosomal dominant inheritance. Both presented with the typical BSS symptoms but the phenotypic expression in the father was milder. Treatment is challenging for both patients and doctors, requiring a multidisciplinary approach. Copyright © 2010 Wiley-Liss, Inc.