WorldWideScience

Sample records for stars cs 29491-069

  1. New Pulse Timing Measurements of the sdBV Star CS 1246

    Directory of Open Access Journals (Sweden)

    Hutchens Zackary L.

    2017-12-01

    Full Text Available CS 1246 is a hot subdwarf B star discovered in 2009 to exhibit a single, large-amplitude radial pulsation. An O-C diagram constructed from this mode revealed reflex motion due to the presence of a low-mass M dwarf, as well as a long-term trend consistent with a decrease in the pulsational period. The orbital reflex motion was later confirmed with radial velocity measurements. Using eight years of data collected with the Skynet Robotic Telescope Network, we show that the pulsation amplitude of CS 1246 is decaying nonlinearly. We also present an updated O-C diagram, which might now indicate a positive Ṗ and a new 2.09 ± 0.05 yr oscillation consistent with orbital reflex motion of the entire inner sdB+dM binary, possibly due to the gravitational influence of a circumbinary planet with minimum mass . However, unlike the presence of the M dwarf, we hesistate to claim this object as a definitive detection since intrinsic variability of the pulsation phase could theoretically produce a similar effect.

  2. The Hamburg/ESO R-process Enhanced Star survey (HERES). XI. The highly r-process-enhanced star CS 29497-004

    Science.gov (United States)

    Hill, V.; Christlieb, N.; Beers, T. C.; Barklem, P. S.; Kratz, K.-L.; Nordström, B.; Pfeiffer, B.; Farouqi, K.

    2017-11-01

    We report an abundance analysis for the highly r-process-enhanced (r-II) star CS 29497-004, a very metal-poor giant with solar system Teff = 5013 K and [Fe/H] = -2.85, whose nature was initially discovered in the course of the HERES project. Our analysis is based on high signal-to-noise ratio, high-resolution (R 75 000) VLT/UVES spectra and MARCS model atmospheres under the assumption of local thermodynamic equilibrium, and obtains abundance measurements for a total of 46 elements, 31 of which are neutron-capture elements. As is the case for the other 25 r-II stars currently known, the heavy-element abundance pattern of CS 29497-004 well-matches a scaled solar system second peak r-process-element abundance pattern. We confirm our previous detection of Th, and demonstrate that this star does not exhibit an "actinide boost". Uranium is also detected (log ɛ(U) = -2.20 ± 0.30), albeit with a large measurement error that hampers its use as a precision cosmo-chronometer. Combining the various elemental chronometer pairs that are available for this star, we derive a mean age of 12.2 ± 3.7 Gyr using the theoretical production ratios from published waiting-point approximation models. We further explore the high-entropy wind model (Farouqi et al. 2010, ApJ, 712, 1359) production ratios arising from different neutron richness of the ejecta (Ye), and derive an age of 13.7 ± 4.4 Gyr for a best-fitting Ye = 0.447. The U/Th nuclei-chronometer is confirmed to be the most resilient to theoretical production ratios and yields an age of 16.5 ± 6.6 Gyr. Lead (Pb) is also tentatively detected in CS 29497-004, at a level compatible with a scaled solar r-process, or with the theoretical expectations for a pure r-process in this star. Based on observations collected at the European Southern Observatory, Paranal, Chile (Proposal Number 170.D-0010).Table B.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  3. Spectrophotometry of peculiar B and A stars. XVII. 63 Andromedae, HD 34452, epsilon Ursae Majoris, CQ Ursae Majoris, CU Virginis, CS Virginis and Beta Coronae Borealis

    International Nuclear Information System (INIS)

    Pyper, D.M.; Adelman, S.J.

    1985-01-01

    Optical region spectrophotometry results are presented for seven Ap stars. Additional data for two silicon stars, HD 34452 and CU Vir, show that both have energy distributions that can be fit by a single global model atmosphere, except for the lambda 4200 and lambda 5200 broad absorption features. These features are strong in HD 34452 and show no evidence of variation, while they are weak in CU Vir but show clear evidence of variations. The energy distributions of the five cooler Ap stars cannot be fit by a single model atmosphere. CQ UMa, CS Vir and β CrB all show complicated variations with phase at different wavelengths. Their energy distributions show combined effects of flux redistribution and differential line blanketing. Except for epsilon UMa, none of these five stars show evidence of variations of the lambda 4200 or lambda 5200 broad absorption features

  4. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.; Miao, Mao-sheng; Merino, Gabriel; Hoffmann, Roald

    2015-01-01

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  5. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.

    2015-06-03

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  6. Molecular CsF{sub 5} and CsF{sub 2}{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Rogachev, Andrey Yu. [Illinois Institute of Technology, IL (United States). Dept. of Biological and Chemical Sciences; Miao, Mao-sheng [California State Univ., Northridge, CA (United States). Dept. of Chemistry and Biochemistry; Beijing Computational Science Research Center (China); Merino, Gabriel [Centro de Investigacion y de Estudios Avanzados, Unidad Merida (Mexico). Dept. de Fisica Aplicada; Hoffmann, Roald [Cornell Univ., Ithaca, NY (United States). Dept. of Chemistry and Chemical Biology

    2015-07-06

    D{sub 5h} star-like CsF{sub 5}, formally isoelectronic with known XeF{sub 5}{sup -} ion, is computed to be a local minimum on the potential energy surface of CsF{sub 5}, surrounded by reasonably large activation energies for its exothermic decomposition to CsF + 2F{sub 2}, or to CsF{sub 3} (three isomeric forms) + F{sub 2}, or for rearrangement to a significantly more stable isomer, a classical Cs{sup +} complex of F{sub 5}{sup -}. Similarly the CsF{sub 2}{sup +} ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  7. CS Informativeness Governs CS-US Associability

    Science.gov (United States)

    Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

    2012-01-01

    In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

  8. Neutron stars

    International Nuclear Information System (INIS)

    Irvine, J.M.

    1978-01-01

    The subject is covered in chapters entitled: introduction (resume of stellar evolution, gross characteristics of neutron stars); pulsars (pulsar characteristics, pulsars as neutron stars); neutron star temperatures (neutron star cooling, superfluidity and superconductivity in neutron stars); the exterior of neutron stars (the magnetosphere, the neutron star 'atmosphere', pulses); neutron star structure; neutron star equations of state. (U.K.)

  9. CS EMISSION NEAR MIR-BUBBLES

    International Nuclear Information System (INIS)

    Watson, C.; Devine, Kathryn; Quintanar, N.; Candelaria, T.

    2016-01-01

    We survey 44 young stellar objects located near the edges of mid-IR-identified bubbles in CS (1–0) using the Green Bank Telescope. We detect emission in 18 sources, indicating young protostars that are good candidates for being triggered by the expansion of the bubble. We calculate CS column densities and abundances. Three sources show evidence of infall through non-Gaussian line-shapes. Two of these sources are associated with dark clouds and are promising candidates for further exploration of potential triggered star formation. We obtained on-the-fly maps in CS (1–0) of three sources, showing evidence of significant interactions between the sources and the surrounding environment

  10. CS EMISSION NEAR MIR-BUBBLES

    Energy Technology Data Exchange (ETDEWEB)

    Watson, C. [Manchester University, Department of Physics, 604 E. College Ave., North Manchester, IN 46962 (United States); Devine, Kathryn [College of Idaho, Department of Physics, 2112 Cleveland Blvd, Caldwell, ID 83605 (United States); Quintanar, N. [Texas A and M University, Department of Nuclear Engineering, 401 Joe Routt Blvd, College Station, TX 77843 (United States); Candelaria, T., E-mail: cwatson@manchester.edu, E-mail: KDevine@collegeofidaho.edu, E-mail: nrquintanar@tamu.edu, E-mail: tcandela@nmt.edu [New Mexico Institute of Mining and Technology, Department of Physics, 801 Leroy Place, Socorro, NM 87801 (United States)

    2016-02-10

    We survey 44 young stellar objects located near the edges of mid-IR-identified bubbles in CS (1–0) using the Green Bank Telescope. We detect emission in 18 sources, indicating young protostars that are good candidates for being triggered by the expansion of the bubble. We calculate CS column densities and abundances. Three sources show evidence of infall through non-Gaussian line-shapes. Two of these sources are associated with dark clouds and are promising candidates for further exploration of potential triggered star formation. We obtained on-the-fly maps in CS (1–0) of three sources, showing evidence of significant interactions between the sources and the surrounding environment.

  11. Improving CS regulations.

    Energy Technology Data Exchange (ETDEWEB)

    Nesse, R.J.; Scheer, R.M.; Marasco, A.L.; Furey, R.

    1980-10-01

    President Carter issued Executive Order 12044 (3/28/78) that required all Federal agencies to distinguish between significant and insignificant regulations, and to determine whether a regulation will result in major impacts. This study gathered information on the impact of the order and the guidelines on the Office of Conservation and Solar Energy (CS) regulatory practices, investigated problems encountered by the CS staff when implementing the order and guidelines, and recommended solutions to resolve these problems. Major tasks accomplished and discussed are: (1) legislation, Executive Orders, and DOE Memoranda concerning Federal administrative procedures relevant to the development and analysis of regulations within CS reviewed; (2) relevant DOE Orders and Memoranda analyzed and key DOE and CS staff interviewed in order to accurately describe the current CS regulatory process; (3) DOE staff from the Office of the General Counsel, the Office of Policy and Evaluation, the Office of the Environment, and the Office of the Secretary interviewed to explore issues and problems encountered with current CS regulatory practices; (4) the regulatory processes at five other Federal agencies reviewed in order to see how other agencies have approached the regulatory process, dealt with specific regulatory problems, and responded to the Executive Order; and (5) based on the results of the preceding four tasks, recommendations for potential solutions to the CS regulatory problems developed. (MCW)

  12. Symbiotic stars

    International Nuclear Information System (INIS)

    Boyarchuk, A.A.

    1975-01-01

    There are some arguments that the symbiotic stars are binary, where one component is a red giant and the other component is a small hot star which is exciting a nebula. The symbiotic stars belong to the old disc population. Probably, symbiotic stars are just such an evolutionary stage for double stars as planetary nebulae for single stars. (Auth.)

  13. Tunable CsPbBr3/Cs4PbBr6 phase transformation and their optical spectroscopic properties.

    Science.gov (United States)

    Chen, Xiao; Chen, Daqin; Li, Junni; Fang, Gaoliang; Sheng, Hongchao; Zhong, Jiasong

    2018-04-24

    As a novel type of promising materials, metal halide perovskites are a rising star in the field of optoelectronics. On this basis, a new frontier of zero-dimensional perovskite-related Cs4PbBr6 with bright green emission and high stability has attracted an enormous amount of attention, even though its photoluminescence still requires to clarification. Herein, the controllable phase transformation between three-dimensional CsPbBr3 and zero-dimensional Cs4PbBr6 is easily achieved in a facile ligand-assisted supersaturated recrystallization synthesis procedure via tuning the amount of surfactants, and their unique optical properties are investigated and compared in detail. Both Cs4PbBr6 and CsPbBr3 produce remarkably intense green luminescence with quantum yields up to 45% and 80%, respectively; however, significantly different emitting behaviors are observed. The fluorescence lifetime of Cs4PbBr6 is much longer than that of CsPbBr3, and photo-blinking is easily detected in the Cs4PbBr6 product, proving that the zero-dimensional Cs4PbBr6 is indeed a highly luminescent perovskite-related material. Additionally, for the first time, tunable emissions over the visible-light spectral region are demonstrated to be achievable via halogen composition modulations in the Cs4PbX6 (X = Cl, Br, I) samples. Our study brings a simple method for the phase control of CsPbBr3/Cs4PbBr6 and demonstrates the intrinsic luminescence nature of the zero-dimensional perovskite-related Cs4PbX6 products.

  14. CS Bond formation by

    Indian Academy of Sciences (India)

    2017-02-02

    Feb 2, 2017 ... a thiol substituent at position-2 of the quinazoline ring. ... coupling reactions represent great contribution to the recent growth of organic synthesis.2 ... Difficulties in C-S ...... Experimental Advances (Amsterdam: Elsevier) 19; (b).

  15. Stars and Star Myths.

    Science.gov (United States)

    Eason, Oliver

    Myths and tales from around the world about constellations and facts about stars in the constellations are presented. Most of the stories are from Greek and Roman mythology; however, a few Chinese, Japanese, Polynesian, Arabian, Jewish, and American Indian tales are also included. Following an introduction, myths are presented for the following 32…

  16. Evolution of S stars in the Magellanic Clouds

    International Nuclear Information System (INIS)

    Evans, T.L.

    1984-01-01

    Early S stars occur between M and C stars in the colour magnitude diagrams of intermediate age globular clusters in the Magellanic Clouds. Most have -4.2 >= Msub(bol) >= -4.8 and are probably brighter in younger or more metal rich clusters. The galactic globular cluster NGC 6723 contains two marginal S stars at Msub(bol) approx. -3.3. The rare CS stars have Msub(bol) approx. -6, with no faint examples. (Auth.)

  17. 137Cs in man organism

    International Nuclear Information System (INIS)

    Marej, A.N.; Barkhudarov, R.M.

    1980-01-01

    Considered are the levels of 137 Cs content in the organism of adult urban population of the USSR and the main regularities of their alterations during 1962-1974. The non-uniform distribution of levels of 137 Cs buildup in adult population is shown to be connected with soil and geographic conditions. Food stuffs of local production have a noticeable effect on the levels of 137 Cs buildup in the organism of urban population. Calculation methods are used to study 137 Cs administration in a human organism. No significant difference is found between the indexes of 137 Cs content in the organism of rural and urban population. Presented are the levels of 137 Cs content in the organisms of inhabitants of such regions as Far North and Byelorussian-Ukrainian woodlands. Given are the reasons for the increased content of 137 Cs in the organism of rural population of these zones

  18. Theoretical study of the Cs isotope exchange reaction of CsI + Cs' → Cs + ICs' (Contract research)

    International Nuclear Information System (INIS)

    Kobayashi, Takanori; Hashimoto, Masashi; Yokoyama, Keiichi

    2015-12-01

    To discuss the exchange reaction of Cs isotope by CsI + Cs' → Cs + ICs', the structure and chemical properties of Cs 2 I intermediate and potential energy surface of the entrance reaction are calculated using M06/def2-TZVPPD density functional calculation. The calculation shows that the reaction to the intermediate has no barrier and the two Cs-I bonds of Cs 2 I are chemically equivalent. These results suggest that the rate of the Cs exchange reaction of CsI + Cs' → Cs + ICs' is as high as the collision rate. (author)

  19. Frameworks in CS1

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Caspersen, Michael Edelgaard

    2002-01-01

    In this paper we argue that introducing object-oriented frameworks as subject already in the CS1 curriculum is important if we are to train the programmers of tomorrow to become just as much software reusers as software producers. We present a simple, graphical, framework that we have successfull...... point for introducing graphical user interface frameworks such as Java Swing and AWT as the students are not overwhelmed by all the details of such frameworks right away but given a conceptual road-map and practical experience that allow them to cope with the complexity....

  20. CS Seminar Videos

    OpenAIRE

    Ong, Derek; Tona, Glen; Gibb, Kyle; Parbadia, Sivani

    2013-01-01

    Main site for our project can be found at this URL: http://vtechworks.lib.vt.edu/handle/10919/19036. From here you can find videos of all the CS seminars and distinguished lectures given this semester. Each video has its own abstract and description. The files attached in this section are a final report in both raw Word Document and archival PDF formats and a presentation in both raw Powerpoint and archival PDF formats. Computer Science seminars are a very educational and interesting as...

  1. Frameworks in CS1

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Caspersen, Michael Edelgaard

    2002-01-01

    point for introducing graphical user interface frameworks such as Java Swing and AWT as the students are not overwhelmed by all the details of such frameworks right away but given a conceptual road-map and practical experience that allow them to cope with the complexity.......In this paper we argue that introducing object-oriented frameworks as subject already in the CS1 curriculum is important if we are to train the programmers of tomorrow to become just as much software reusers as software producers. We present a simple, graphical, framework that we have successfully...

  2. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star.......Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star....

  3. Determination of Cs-134 and Cs-137 rain water samples

    International Nuclear Information System (INIS)

    Lima, M.F.; Mazzilli, B.

    1988-01-01

    In order to setting an environmental monitoring program at IPEN, was developed a fast and simple methodology for concentration of Cs-134 and Cs-137 in rain water. This procedure consists in the precipitation of cesium and others cathions of its family (NH 4 + , K + and Rb + ) by ammonium molybdophosphate. The measures of the desintegration rates of Cs-134 and Cs-137 was done by gamma spectrometry in a Ge(Li) detector. After setting up the ideal experimental conditions, the procedure was used to analyze four samples of rain water. (author) [pt

  4. Foundation Fireworks CS4

    CERN Document Server

    Smith, N; Heerema, Matt; Mallott, Chuch; King, R; Erskine, Craig

    2009-01-01

    Are you a web designer who is looking for a new and quicker way to prototype and create for the web? Perhaps you are a programmer who finds most design tools to be overkill for what you need to get done. Or, maybe you're an old Fireworks pro, who wants to keep up to date on the latest changes in Creative Suite 4. Either way, this book has something for you. * Coverage of all that's new and powerful for the Web designer and developer in Fireworks CS4* Targets developers who want design tools that don't get in their way and designers who want development tools that don't constrain their creativi

  5. Frameworks in CS1

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Caspersen, Michael Edelgaard

    2002-01-01

    point for introducing graphical user interface frameworks such as Java Swing and AWT as the students are not overwhelmed by all the details of such frameworks right away but given a conceptual road-map and practical experience that allow them to cope with the complexity.......In this paper we argue that introducing object-oriented frameworks as subject already in the CS1 curriculum is important if we are to train the programmers of tomorrow to become just as much software reusers as software producers. We present a simple, graphical, framework that we have successfully...... used to introduce the principles of object-oriented frameworks to students at the introductory programming level. Our framework, while simple, introduces central abstractions such as inversion of control, event-driven programming, and variability points/hot-spots. This has provided a good starting...

  6. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.

    1976-01-01

    Any discussion of the radio emission from stars should begin by emphasizing certain unique problems. First of all, one must clarify a semantic confusion introduced into radio astronomy in the late 1950's when most new radio sources were described as radio stars. All of these early 'radio stars' were eventually identified with other galactic and extra-galactic objects. The study of true radio stars, where the radio emission is produced in the atmosphere of a star, began only in the 1960's. Most of the work on the subject has, in fact, been carried out in only the last few years. Because the real information about radio stars is quite new, it is not surprising that major aspects of the subject are not at all understood. For this reason this paper is organized mainly around three questions: what is the available observational information; what physical processes seem to be involved; and what working hypotheses look potentially fruitful. (Auth.)

  7. Shooting stars

    International Nuclear Information System (INIS)

    Maurette, M.; Hammer, C.

    1985-01-01

    A shooting star passage -even a star shower- can be sometimes easily seen during moonless black night. They represent the partial volatilization in earth atmosphere of meteorites or micrometeorites reduced in cosmic dusts. Everywhere on earth, these star dusts are searched to be gathered. This research made one year ago on the Greenland ice-cap is this article object; orbit gathering projects are also presented [fr

  8. Activity standardization of 134Cs and 137Cs

    International Nuclear Information System (INIS)

    Sochorová, Jana; Auerbach, Pavel

    2014-01-01

    The paper presents the results from a primary standardization of 137 Cs using two independent methods – efficiency tracing using PC-NaI coincidence and the TDCR method. The nuclides 60 Co and 134 Cs were used as the tracers. Primary standardization of the 134 Cs is also discussed. The efficiency extrapolation was carried out by measuring samples of varying mass and using the wet extrapolation method. The results obtained are in good agreement; the differences did not exceed 0.5%. The advantages, pitfalls and also possibilities for improvement of the procedures are discussed

  9. 1+ collective states of 124Cs and 126Cs nuclei

    International Nuclear Information System (INIS)

    Ivanova, S.P.; Kuliev, A.A.; Salamov, D.I.

    1977-01-01

    Within the framework of the random phase approximation β-decay properties of the 1 + states of 124 Cs and 126 Cs have been investigated. Greatly collectivized 1 + states in odd-odd nuclei are produced by the spin-dependent charge-exchange nucleon interaction. For numerical calculations the scheme of single-particle levels in the deformed Saxon-Woods potential has been used

  10. Star Polymers.

    Science.gov (United States)

    Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

    2016-06-22

    Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings.

  11. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star.......Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star....

  12. Star Imager

    DEFF Research Database (Denmark)

    Madsen, Peter Buch; Jørgensen, John Leif; Thuesen, Gøsta

    1997-01-01

    The version of the star imager developed for Astrid II is described. All functions and features are described as well as the operations and the software protocol.......The version of the star imager developed for Astrid II is described. All functions and features are described as well as the operations and the software protocol....

  13. Innocent Bystanders and Smoking Guns: Dwarf Carbon Stars

    Science.gov (United States)

    Green, Paul J.

    2014-01-01

    As far as we know, most carbon throughout the Universe is created and dispersed by AGB stars. So it was at first surprising to find that the carbon stars most prevalent in the Galaxy are in fact dwarfs. We suspect that dC stars are most likely innocent bystanders in post-mass transfer binaries, and may be predominantly metal-poor. Among 1200 C stars found in the SDSS (Green 2013), we confirm 724 dCs, of which a dozen are DA/dC stars in composite spectrum binaries, quadrupling the total sample of these "smoking guns" for AGB binary mass transfer. The dCs likely span absolute magnitudes M_i from about 6.5 to 10.5. G-type dC stars with weak CN and relatively blue colors are probably the most massive dCs still cool enough to show C_2 bands. Eleven very red C stars with strong red CN bands appear to be N-type AGB stars at large Galactocentric distances, one likely a new discovery in the dIrr galaxy Le A. Two such stars within 30arcmin of each other may trace a previously unidentified dwarf galaxy or tidal stream at ~40 kpc. We describe follow-up projects to study the spatial, kinematic, and binary properties of these C-enriched dwarfs.

  14. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.; Gibson, D.M.

    1985-01-01

    Studies of stellar radio emission became an important field of research in the 1970's and have now expanded to become a major area of radio astronomy with the advent of new instruments such as the Very Large Array in New Mexico and transcontinental telescope arrays. This volume contains papers from the workshop on stellar continuum radio astronomy held in Boulder, Colorado, and is the first book on the rapidly expanding field of radio emission from stars and stellar systems. Subjects covered include the observational and theoretical aspects of stellar winds from both hot and cool stars, radio flares from active double star systems and red dwarf stars, bipolar flows from star-forming regions, and the radio emission from X-ray binaries. (orig.)

  15. Learning Flash CS4 Professional

    CERN Document Server

    Shupe, Rich

    2009-01-01

    Learning Flash CS4 Professional offers beginners and intermediate Flash developers a unique introduction to the latest version of Adobe's powerful multimedia application. This easy-to-read book is loaded with full-color examples and hands-on tasks to help you master Flash CS4's new motion editor, integrated 3D system, and character control using the new inverse kinematics bones animation system. No previous Flash experience is necessary.

  16. Symbiotic stars

    International Nuclear Information System (INIS)

    Kafatos, M.; Michalitsianos, A.G.

    1984-01-01

    Among the several hundred million binary systems estimated to lie within 3000 light years of the solar system, a tiny fraction, no more than a few hundred, belong to a curious subclass whose radiation has a wavelength distribution so peculiar that it long defied explanation. Such systems radiate strongly in the visible region of the spectrum, but some of them do so even more strongly at both shorter and longer wavelengths: in the ultraviolet region and in the infrared and radio regions. This odd distribution of radiation is best explained by the pairing of a cool red giant star and an intensely hot small star that is virtually in contact with its larger companion. Such objects have become known as symbiotic stars. On photographic plate only the giant star can be discerned, but evidence for the existence of the hot companion has been supplied by satellite-born instruments capable of detecting ultraviolet radiation. The spectra of symbiotic stars indicate that the cool red giant is surrounded by a very hot ionized gas. Symbiotic stars also flared up in outbursts indicating the ejection of material in the form of a shell or a ring. Symbiotic stars may therefore represent a transitory phase in the evolution of certain types of binary systems in which there is substantial transfer of matter from the larger partner to the smaller

  17. Star formation

    International Nuclear Information System (INIS)

    Woodward, P.R.

    1978-01-01

    Theoretical models of star formation are discussed beginning with the earliest stages and ending in the formation of rotating, self-gravitating disks or rings. First a model of the implosion of very diffuse gas clouds is presented which relies upon a shock at the edge of a galactic spiral arm to drive the implosion. Second, models are presented for the formation of a second generation of massive stars in such a cloud once a first generation has formed. These models rely on the ionizing radiation from massive stars or on the supernova shocks produced when these stars explode. Finally, calculations of the gravitational collapse of rotating clouds are discussed with special focus on the question of whether rotating disks or rings are the result of such a collapse. 65 references

  18. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star....

  19. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Andersen, Thomas Lykke

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star....

  20. STARS no star on Kauai

    International Nuclear Information System (INIS)

    Jones, M.

    1993-01-01

    The island of Kuai, home to the Pacific Missile Range Facility, is preparing for the first of a series of Star Wars rocket launches expected to begin early this year. The Strategic Defense Initiative plans 40 launches of the Stategic Target System (STARS) over a 10-year period. The focus of the tests appears to be weapons and sensors designed to combat multiple-warhead ICBMs, which will be banned under the START II Treaty that was signed in January. The focus of this article is to express the dubious value of testing the STARS at a time when their application will not be an anticipated problem

  1. Flare stars

    International Nuclear Information System (INIS)

    Nicastro, A.J.

    1981-01-01

    The least massive, but possibly most numerous, stars in a galaxy are the dwarf M stars. It has been observed that some of these dwarfs are characterized by a short increase in brightness. These stars are called flare stars. These flare stars release a lot of energy in a short amount of time. The process producing the eruption must be energetic. The increase in light intensity can be explained by a small area rising to a much higher temperature. Solar flares are looked at to help understand the phenomenon of stellar flares. Dwarfs that flare are observed to have strong magnetic fields. Those dwarf without the strong magnetic field do not seem to flare. It is believed that these regions of strong magnetic fields are associated with star spots. Theories on the energy that power the flares are given. Astrophysicists theorize that the driving force of a stellar flare is the detachment and collapse of a loop of magnetic flux. The mass loss due to stellar flares is discussed. It is believed that stellar flares are a significant contributor to the mass of interstellar medium in the Milky Way

  2. INNOCENT BYSTANDERS: CARBON STARS FROM THE SLOAN DIGITAL SKY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Green, Paul [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2013-03-01

    Among stars showing carbon molecular bands (C stars), the main-sequence dwarfs, likely in post-mass transfer binaries, are numerically dominant in the Galaxy. Via spectroscopic selection from the Sloan Digital Sky Survey, we retrieve 1220 high galactic latitude C stars, {approx}5 times more than previously known, including a wider variety than past techniques such as color or grism selection have netted, and additionally yielding 167 DQ white dwarfs. Of the C stars with proper motion measurements, we identify 69% clearly as dwarfs (dCs), while {approx}7% are giants. The dCs likely span absolute magnitudes M{sub i} from {approx}6.5 to 10.5. 'G-type' dC stars with weak CN and relatively blue colors are probably the most massive dCs still cool enough to show C{sub 2} bands. We report Balmer emission in 22 dCs, none of which are G-types. We find 8 new DA/dC stars in composite spectrum binaries, quadrupling the total sample of these 'smoking guns' for AGB binary mass transfer. Eleven very red C stars with strong red CN bands appear to be 'N'-type AGB stars at large Galactocentric distances, one likely a new discovery in the dIrr galaxy Leo A. Two such stars within 30' of each other may trace a previously unidentified dwarf galaxy or tidal stream at {approx}40 kpc. We explore the multiwavelength properties of the sample and report the first X-ray detection of a dC star, which shows strong Balmer emission. Our own spectroscopic survey additionally provides the dC surface density from a complete sample of dwarfs limited by magnitude, color, and proper motion.

  3. INNOCENT BYSTANDERS: CARBON STARS FROM THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Green, Paul

    2013-01-01

    Among stars showing carbon molecular bands (C stars), the main-sequence dwarfs, likely in post-mass transfer binaries, are numerically dominant in the Galaxy. Via spectroscopic selection from the Sloan Digital Sky Survey, we retrieve 1220 high galactic latitude C stars, ∼5 times more than previously known, including a wider variety than past techniques such as color or grism selection have netted, and additionally yielding 167 DQ white dwarfs. Of the C stars with proper motion measurements, we identify 69% clearly as dwarfs (dCs), while ∼7% are giants. The dCs likely span absolute magnitudes M i from ∼6.5 to 10.5. 'G-type' dC stars with weak CN and relatively blue colors are probably the most massive dCs still cool enough to show C 2 bands. We report Balmer emission in 22 dCs, none of which are G-types. We find 8 new DA/dC stars in composite spectrum binaries, quadrupling the total sample of these 'smoking guns' for AGB binary mass transfer. Eleven very red C stars with strong red CN bands appear to be 'N'-type AGB stars at large Galactocentric distances, one likely a new discovery in the dIrr galaxy Leo A. Two such stars within 30' of each other may trace a previously unidentified dwarf galaxy or tidal stream at ∼40 kpc. We explore the multiwavelength properties of the sample and report the first X-ray detection of a dC star, which shows strong Balmer emission. Our own spectroscopic survey additionally provides the dC surface density from a complete sample of dwarfs limited by magnitude, color, and proper motion.

  4. Innocent Bystanders: Carbon Stars from the Sloan Digital Sky Survey

    Science.gov (United States)

    Green, Paul

    2013-03-01

    Among stars showing carbon molecular bands (C stars), the main-sequence dwarfs, likely in post-mass transfer binaries, are numerically dominant in the Galaxy. Via spectroscopic selection from the Sloan Digital Sky Survey, we retrieve 1220 high galactic latitude C stars, ~5 times more than previously known, including a wider variety than past techniques such as color or grism selection have netted, and additionally yielding 167 DQ white dwarfs. Of the C stars with proper motion measurements, we identify 69% clearly as dwarfs (dCs), while ~7% are giants. The dCs likely span absolute magnitudes Mi from ~6.5 to 10.5. "G-type" dC stars with weak CN and relatively blue colors are probably the most massive dCs still cool enough to show C2 bands. We report Balmer emission in 22 dCs, none of which are G-types. We find 8 new DA/dC stars in composite spectrum binaries, quadrupling the total sample of these "smoking guns" for AGB binary mass transfer. Eleven very red C stars with strong red CN bands appear to be "N"-type AGB stars at large Galactocentric distances, one likely a new discovery in the dIrr galaxy Leo A. Two such stars within 30' of each other may trace a previously unidentified dwarf galaxy or tidal stream at ~40 kpc. We explore the multiwavelength properties of the sample and report the first X-ray detection of a dC star, which shows strong Balmer emission. Our own spectroscopic survey additionally provides the dC surface density from a complete sample of dwarfs limited by magnitude, color, and proper motion.

  5. Symbiotic stars

    Science.gov (United States)

    Kafatos, M.; Michalitsianos, A. G.

    1984-01-01

    The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

  6. Dark stars

    DEFF Research Database (Denmark)

    Maselli, Andrea; Pnigouras, Pantelis; Nielsen, Niklas Grønlund

    2017-01-01

    to the formation of compact objects predominantly made of dark matter. Considering both fermionic and bosonic (scalar φ4) equations of state, we construct the equilibrium structure of rotating dark stars, focusing on their bulk properties and comparing them with baryonic neutron stars. We also show that these dark......Theoretical models of self-interacting dark matter represent a promising answer to a series of open problems within the so-called collisionless cold dark matter paradigm. In case of asymmetric dark matter, self-interactions might facilitate gravitational collapse and potentially lead...... objects admit the I-Love-Q universal relations, which link their moments of inertia, tidal deformabilities, and quadrupole moments. Finally, we prove that stars built with a dark matter equation of state are not compact enough to mimic black holes in general relativity, thus making them distinguishable...

  7. Hybrid stars

    Indian Academy of Sciences (India)

    Hybrid stars. AsHOK GOYAL. Department of Physics and Astrophysics, University of Delhi, Delhi 110 007, India. Abstract. Recently there have been important developments in the determination of neutron ... number and the electric charge. ... available to the system to rearrange concentration of charges for a given fraction of.

  8. Pulsating stars

    CERN Document Server

    Catelan, M?rcio

    2014-01-01

    The most recent and comprehensive book on pulsating stars which ties the observations to our present understanding of stellar pulsation and evolution theory.  Written by experienced researchers and authors in the field, this book includes the latest observational results and is valuable reading for astronomers, graduate students, nuclear physicists and high energy physicists.

  9. Variable stars

    International Nuclear Information System (INIS)

    Feast, M.W.; Wenzel, W.; Fernie, J.D.; Percy, J.R.; Smak, J.; Gascoigne, S.C.B.; Grindley, J.E.; Lovell, B.; Sawyer Hogg, H.B.; Baker, N.; Fitch, W.S.; Rosino, L.; Gursky, H.

    1976-01-01

    A critical review of variable stars is presented. A fairly complete summary of major developments and discoveries during the period 1973-1975 is given. The broad developments and new trends are outlined. Essential problems for future research are identified. (B.R.H. )

  10. Star Products and Applications

    OpenAIRE

    Iida, Mari; Yoshioka, Akira

    2010-01-01

    Star products parametrized by complex matrices are defined. Especially commutative associative star products are treated, and star exponentials with respect to these star products are considered. Jacobi's theta functions are given as infinite sums of star exponentials. As application, several concrete identities are obtained by properties of the star exponentials.

  11. 'Wash-out' of Cs-134 and Cs-137 from river sediment; 'Ispiranja' Cs-134 i Cs-137 iz recnog sedimenta

    Energy Technology Data Exchange (ETDEWEB)

    Skrbic, Z; Conkic, Lj; Bikit, I; Veskovic, M; Slivka, J; Marinkov, L [Institut za Fiziku, Novi Sad Univ. (Yugoslavia)

    1988-07-01

    Natural elimination and 'wash out' period of the Cs-134 and Cs-137 from the river sediment has been investigated. Obtained results suggest the possibility to describe these processes by exponential low and determination of the corresponding half lives. (author)

  12. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter; Brorsen, Michael

    Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004.......Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004....

  13. Uptake and distribution of 137Cs, stable Cs and K in rice plants

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Hasegawa, Hidenao

    2003-01-01

    The uptake and distributions of 137 Cs, stable Cs and K were determined for rice plant components, including polished rice, rice bran, hulls, leaves, stems, and roots. The distribution of 137 Cs in polished rice and rice bran was similar to that of stable Cs, while that of K was different. The concentration ratios of Cs/K in leaves increased in older leaf blade positions, which meant that the translocation rate of stable Cs, was slower than that of K. At harvest the dry weight of polished rice accounted for 34% of the entire rice plant, while the distributions of stable Cs in the polished rice and the non-edible parts were 7 and 93%, respectively. These findings suggest that the transfer and distribution of stable Cs in rice plants are different from those of K, and the behavior of stable Cs provides a useful analogue in predicting the fate of 137 Cs in an agricultural environment. (author)

  14. SEEDisCs: How Clusters Form and Galaxies Transform in the Cosmic Web

    Science.gov (United States)

    Jablonka, P.

    2017-08-01

    This presentation introduces a new survey, the Spatial Extended EDisCS Survey (SEEDisCS), which aims at understanding how clusters assemble and the level at which galaxies are preprocessed before falling on the cluster cores. I focus on the changes in galaxy properties in the cluster large scale environments, and how we can get constraints on the timescale of star formation quenching. I also discuss new ALMA CO observations, which trace the fate of the galaxy cold gas content along the infalling paths towards the cluster cores.

  15. Adobe Photoshop CS6 bible

    CERN Document Server

    Dayley, Brad

    2012-01-01

    The comprehensive, soup-to-nuts guide to Photoshop, fully updated Photoshop CS6, used for both print and digital media, is the industry leader in image-editing software. The newest version adds some exciting new features, and this bestselling guide has been revised to cover each of them, along with all the basic information you need to get started. Learn to use all the tools, including the histogram palette, Lens Blur, Match Color, and the color replacement tool, as well as keyboard shortcuts. Then master retouching and color correction, work with Camera Raw images, prepare photos for print

  16. The binary fraction of planetary nebula central stars - III. the promise of VPHAS+

    Science.gov (United States)

    Barker, Helen; Zijlstra, Albert; De Marco, Orsola; Frew, David J.; Drew, Janet E.; Corradi, Romano L. M.; Eislöffel, Jochen; Parker, Quentin A.

    2018-04-01

    The majority of planetary nebulae (PNe) are not spherical, and current single-star models cannot adequately explain all the morphologies we observe. This has led to the Binary Hypothesis, which states that PNe are preferentially formed by binary systems. This hypothesis can be corroborated or disproved by comparing the estimated binary fraction of all PNe central stars (CS) to that of the supposed progenitor population. One way to quantify the rate of CS binarity is to detect near infrared excess indicative of a low-mass main-sequence companion. In this paper, a sample of known PNe within data release 2 of the ongoing VPHAS+ is investigated. We give details of the method used to calibrate VPHAS+ photometry, and present the expected colours of CS and main-sequence stars within the survey. Objects were scrutinized to remove PN mimics from our sample and identify true CS. Within our final sample of seven CS, six had previously either not been identified or confirmed. We detected an i-band excess indicative of a low-mass companion star in three CS, including one known binary, leading us to conclude that VPHAS+ provides the precise photometry required for the IR excess method presented here, and will likely improve as the survey completes and the calibration process finalized. Given the promising results from this trial sample, the entire VPHAS+ catalogue should be used to study PNe and extend the IR excess-tested CS sample.

  17. Reactive barriers for 137Cs retention

    International Nuclear Information System (INIS)

    Krumhansl, James L.; Brady, Patrick V.; Anderson, Howard L.

    2000-01-01

    137 Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137 Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137 Cs is only 30.2 years, remediation might be more effective (and less costly) if 137 Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with 135 Cs (half life 2.3x10 6 years) in addition to 137 Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO 3 and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

  18. Determination of {sup 135}Cs and {sup 137}Cs in environmental samples: A review

    Energy Technology Data Exchange (ETDEWEB)

    Russell, B.C., E-mail: ben.russell@npl.co.uk [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Croudace, Ian W.; Warwick, Phil E. [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom)

    2015-08-26

    Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products ({sup 135}Cs and {sup 137}Cs) and activation products ({sup 134}Cs and {sup 136}Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst {sup 137}Cs, {sup 134}Cs and {sup 136}Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived {sup 135}Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the {sup 135}Cs/{sup 137}Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products {sup 134}Cs and {sup 136}Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of {sup 135}Cs (and {sup 137}Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from {sup 135}Ba and {sup 137}Ba, and elimination of peak tailing of stable {sup 133}Cs on {sup 135}Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures

  19. CHEMICAL DIAGNOSTICS OF THE MASSIVE STAR CLUSTER-FORMING CLOUD G33.92+0.11. I. {sup 13}CS, CH{sub 3}OH, CH{sub 3}N, OCS, H{sub 2}S, SO{sub 2}, and SiO

    Energy Technology Data Exchange (ETDEWEB)

    Minh, Young Chol [Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong, Daejeon 34055 (Korea, Republic of); Liu, Hauyu Baobab [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Galvań-Madrid, Roberto [Centro de Radioastronoma y Astrofísica, UNAM, A.P. 3-72, Xangari, Morelia 58089 (Mexico)

    2016-06-20

    Large chemical diversity was found in the gas clumps associated with the massive star cluster-forming G33.92+0.11 region with sub-arcsecond angular resolution (0.″6–0.″8) observations with ALMA. The most prominent gas clumps are associated with the dust emission peaks A1, A2, and A5. The close correlation between CH{sub 3}OH and OCS in the emission distributions strongly suggests that these species share a common origin of hot core grain mantle evaporation. The latest generation of star clusters are forming in the A5 clump, as indicated by multiple SiO outflows and its rich hot core chemistry. We also found a narrow SiO emission associated with the outflows, which may trace a cooled component of the outflows. Part of the chemical complexity may have resulted from the accreting gas from the ambient clouds, especially in the northern part of A1 and the southern part of A2. The chemical diversity found in this region is believed to mainly result from the different chemical evolutionary timescales of massive star formation. In particular, the abundance ratio between CH{sub 3}OH and CH{sub 3}CN may be a good chemical clock for the early phase of star formation.

  20. CRL 2688: A post-carbon-star object and probable planetary nebula progenitor

    International Nuclear Information System (INIS)

    Zuckerman, B.; Gilra, D.P.; Turner, B.E.; Morris, M.; Palmer, P.

    1976-01-01

    Millimeter-wavelength emission is observed toward CRL 2688 from H 12 CN, H 13 CN, CS, and HC 3 N. The similarity of this emission and that from the molecular envelope of the carbon star IRC+10216 establishes, beyond a reasonable doubt, that CRL 2688 is a post--carbon-star object. It appears probable that both of these objects will evolve into planetary nebulae. An evolutionary sequence leading from carbon stars to planetary nebulae is outlined

  1. The Role of Gender in Asking Questions at Cool Stars 18 and 19

    OpenAIRE

    Schmidt, Sarah J.; Douglas, Stephanie; Gosnell, Natalie M.; Muirhead, Philip S.; Booth, Rachel S.; Davenport, James R. A.; Mace, Gregory N.

    2017-01-01

    We examine the gender balance of the 18th and 19th meetings of the Cambridge Workshop on Cool Stellar Systems and the Sun (CS18 and CS19). The percent of female attendees at both meetings (31% at CS18 and 37% at CS19) was higher than the percent of women in the American Astronomical Society (25%) and the International Astronomical Union (18%). The representation of women in Cool Stars as SOC members, invited speakers, and contributed speakers was similar to or exceeded the percent of women at...

  2. Life of a star

    International Nuclear Information System (INIS)

    Henbest, Nigel.

    1988-01-01

    The paper concerns the theory of stellar evolution. A description is given of:- how a star is born, main sequence stars, red giants, white dwarfs, supernovae, neutron stars and black holes. A brief explanation is given of how the death of a star as a supernova can trigger off the birth of a new generation of stars. Classification of stars and the fate of our sun, are also described. (U.K.)

  3. Cs-137 migration in soil near NPPs

    International Nuclear Information System (INIS)

    Silant'ev, A.N.; Shkuratova, I.G.; Khatskevich, R.N.

    1984-01-01

    A convective-diffusion model has been employed for describing Cs-137 migration in soil. The migration parameters were determined by comparing the calculated vertical distribution profiles with the experimental ones. The migration parameters dependence on the soil state has been studied. Cs-137 penetration rate was found to be function of the soil type, surface state, soil wetness and orography. The obtained values are presented. A method is suggested for revealing the soil surface contamination by Cs-137 produced during NPP operation with distinguishing it from the global contamination background. For this purpose Cs-137 content in the upper 5 mm soil layer is estimated [ru

  4. Exercise for laboratory comparison of calibration coefficient in 137Cs beam, radiation protection - 2013/2014

    International Nuclear Information System (INIS)

    Cabral, T.S.; Potiens, M.P.A.; Soares, C.M.A.; Silveira, R.R.; Khoury, H.; Borges, J.C.

    2015-01-01

    This work deals with the preliminary results of the second exercise of comparing the radiation monitors calibration laboratories in Brazil. The exercise involved eight laboratories and the measured quantity is the air kerma in a beam of 137 Cs for radioprotection. The exercise was conducted by the LNMRI/IRD, in a star shaped arrangement from October 2013 to July 2015. The largest deviation was 2% of the calibration coefficient that is acceptable for applications in radioprotection. (author)

  5. Study of the Quantum Efficiency of CsI Photocathodes Exposed to Oxygen and Water Vapour

    CERN Document Server

    Di Mauro, A; Piuz, François; Schyns, E M; Van Beelen, J B; Williams, T D

    2000-01-01

    The operation of CsI photocathodes in gaseous detectors requires special attention to the purity of the applied gas mixtures.We have studied the influence of oxygen and water vapour contaminations on the performance of CsI photocathodes for theALICE HMPID RICH prototype. Measurements were done through comparison of Cherenkov rings obtained from beamtests. Increased levels of oxygen and water vapour did not show any effect on the performance. The results of this studyfound a direct application in the way of storing CsI photocathodes over long periods nad in particular in the shipment of theHMPID prototype from CERN to the STAR experiment at BNL. (Abstract only available,full text to follow)

  6. Technetium in late-type stars. I. Observations

    International Nuclear Information System (INIS)

    Little-Marenin, I.R.; Little, S.J.

    1979-01-01

    An analysis of about 90 spectra (11 or 13A/mm) of nonvariable and variable (mostly Mira variables) M, MS, S, CS, and C stars for the presence of the radioactive element technetium (T/sub 1/2/approx. =2 x 10 5 y) suggests that Tc is most often present at certain variability periods. Stars with no Tc I lines in their spectra can be found at most periods (P-bar=234/sup d/), whereas stars with Tc I lines have periods in most cases in excess of 300 days (P-bar=330/sup d/ +- 83/sup d/). Interpreting our data in terms of kinematic studies by Feast (1963) suggests that the stars with Tc are Pop I and that variables without Tc are largely Pop II type stars

  7. Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

    KAUST Repository

    Schmid, Marc R.; Mahfouz, Remi; Bouhrara, Mohamed; Saih, Youssef; Mehring, Michael; Basset, Jean-Marie; Goze-Bac, Christophe; Abou-Hamad, Edy

    2012-01-01

    present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs

  8. O stars and Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Conti, P.S.; Underhill, A.B.; Jordan, S.; Thomas, R.

    1988-01-01

    Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented

  9. O stars and Wolf-Rayet stars

    Science.gov (United States)

    Conti, Peter S.; Underhill, Anne B.; Jordan, Stuart (Editor); Thomas, Richard (Editor)

    1988-01-01

    Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented.

  10. Temperature and Pressure Dependence of the Reaction S plus CS (+M) -> CS2 (+M)

    DEFF Research Database (Denmark)

    Glarborg, Peter; Marshall, Paul; Troe, Juergen

    2015-01-01

    Experimental data for the unimolecular decomposition of CS2 from the literature are analyzed by unimolecular rate theory with the goal of obtaining rate constants for the reverse reaction S + CS (+M) -> CS2 (+M) over wide temperature and pressure ranges. The results constitute an important input...

  11. Vertical profile of 137Cs in soil.

    Science.gov (United States)

    Krstić, D; Nikezić, D; Stevanović, N; Jelić, M

    2004-12-01

    In this paper, a vertical distribution of 137Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of 137Cs in soil could be investigated. Activity of 137Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of 137Cs in soil which was measured for each of 10 locations, the diffusion coefficient of 137Cs in soil was determined. In the next half-century, 137Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of 137Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of 137Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them.

  12. 137Cs concentration in some Philippine foods

    International Nuclear Information System (INIS)

    dela Cruz, B.; Marzan, A.M.; Lagmay, N.; Anden, A.

    1977-01-01

    The current investigation being made by the Philippine Atomic Research Center on the 137 Cs content of the different foods commonly used by the Filipinos is described and preliminary results are reported. The 137 Cs content is determined radiochemically only for the edible portion of the food

  13. Egyptian "Star Clocks"

    Science.gov (United States)

    Symons, Sarah

    Diagonal, transit, and Ramesside star clocks are tables of astronomical information occasionally found in ancient Egyptian temples, tombs, and papyri. The tables represent the motions of selected stars (decans and hour stars) throughout the Egyptian civil year. Analysis of star clocks leads to greater understanding of ancient Egyptian constellations, ritual astronomical activities, observational practices, and pharaonic chronology.

  14. MAGNETIC FIELDS OF STARS

    OpenAIRE

    Bychkov, V. D.; Bychkova, L. V.; Madej, J.

    2008-01-01

    Now it is known about 1212 stars of the main sequence and giants (from them 610 stars - it is chemically peculiarity (CP) stars) for which direct measurements of magnetic fields were spent (Bychkov et al.,2008). Let's consider, what representations were generated about magnetic fields (MT) of stars on the basis of available observations data.

  15. {sup 137}Cs in northern Adriatic sediments

    Energy Technology Data Exchange (ETDEWEB)

    Barisic, D; Lulic, S; Vdovic, N; Vertacnik, A [Center for Marine Research - Department Zagreb, ' Ruder Boskovic' Institute, Zagreb (Croatia); Juracic, M [Department of Geology, Faculty of Natural Sciences, University of Zagreb, Zagreb (Croatia)

    1996-01-01

    The activity of {sup 137}Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. {sup 137}Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, {sup 137}Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for {sup 137}Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher {sup 137}Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

  16. 137Cs in northern Adriatic sediments

    International Nuclear Information System (INIS)

    Barisic, D.; Lulic, S.; Vdovic, N.; Vertacnik, A.; Juracic, M.

    1996-01-01

    The activity of 137 Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. 137 Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, 137 Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for 137 Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher 137 Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

  17. Cs2UPd3Se6

    Directory of Open Access Journals (Sweden)

    George N. Oh

    2011-02-01

    Full Text Available Dicaesium uranium(IV tripalladium(II hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2, Cs1 (222, Cs2 (m2m, Pd1 (.m., Pd2 (2mm, Se1 (m.., and Se2 (1. This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010. The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.

  18. Compact stars

    Science.gov (United States)

    Estevez-Delgado, Gabino; Estevez-Delgado, Joaquin

    2018-05-01

    An analysis and construction is presented for a stellar model characterized by two parameters (w, n) associated with the compactness ratio and anisotropy, respectively. The reliability range for the parameter w ≤ 1.97981225149 corresponds with a compactness ratio u ≤ 0.2644959374, the density and pressures are positive, regular and monotonic decrescent functions, the radial and tangential speed of sound are lower than the light speed, moreover, than the plausible stability. The behavior of the speeds of sound are determinate for the anisotropy parameter n, admitting a subinterval where the speeds are monotonic crescent functions and other where we have monotonic decrescent functions for the same speeds, both cases describing a compact object that is also potentially stable. In the bigger value for the observational mass M = 2.05 M⊙ and radii R = 12.957 Km for the star PSR J0348+0432, the model indicates that the maximum central density ρc = 1.283820319 × 1018 Kg/m3 corresponds to the maximum value of the anisotropy parameter and the radial and tangential speed of the sound are monotonic decrescent functions.

  19. Biokinetic model for 137 Cs

    International Nuclear Information System (INIS)

    Melo, Dunstana Rabelo de

    1995-01-01

    The main objective of this work was to provide a realistic biokinetic model for 137 Cs metabolism. This model was based on the retention of cesium in 57 people contaminated in the Goiania accident, ages 1 to 73 y old, complemented by data obtained in an experiment with beagle dogs, and data taken from the open literature. Cesium is distributed among all tissues and organs of the body. Its main retention site is the skeletal muscle tissue. Mathematically, cesium retention in the body may be described by a sum of three terms exponential equation. The first term represents the fraction which is rapidly eliminated in urine. This fraction is weight dependent (negative correlation). The second term represents the retention of cesium in tissues and organs of the body. For children and adolescents, the second term biological half-life is a function of the weight. For adults, it is correlated with sex. Men present a higher retention of cesium than women. The third term correspond to a retention fraction of the order of 0,1% of the initial body burden. It is characterized by a very long half-life and represents a subcellular retention of cesium in the skeletal muscle tissue. During pregnancy the transfer factor from the mother to the fetus is correlated to the amount of cesium in the blood and it is equal to 1, if the intake of cesium occurs pregnancy. (author)

  20. Neutron Stars and NuSTAR

    Science.gov (United States)

    Bhalerao, Varun

    2012-05-01

    My thesis centers around the study of neutron stars, especially those in massive binary systems. To this end, it has two distinct components: the observational study of neutron stars in massive binaries with a goal of measuring neutron star masses and participation in NuSTAR, the first imaging hard X-ray mission, one that is extremely well suited to the study of massive binaries and compact objects in our Galaxy. The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing high energy X-ray telescope to orbit. NuSTAR has an order-of-magnitude better angular resolution and has two orders of magnitude higher sensitivity than any currently orbiting hard X-ray telescope. I worked to develop, calibrate, and test CdZnTe detectors for NuSTAR. I describe the CdZnTe detectors in comprehensive detail here - from readout procedures to data analysis. Detailed calibration of detectors is necessary for analyzing astrophysical source data obtained by the NuSTAR. I discuss the design and implementation of an automated setup for calibrating flight detectors, followed by calibration procedures and results. Neutron stars are an excellent probe of fundamental physics. The maximum mass of a neutron star can put stringent constraints on the equation of state of matter at extreme pressures and densities. From an astrophysical perspective, there are several open questions in our understanding of neutron stars. What are the birth masses of neutron stars? How do they change in binary evolution? Are there multiple mechanisms for the formation of neutron stars? Measuring masses of neutron stars helps answer these questions. Neutron stars in high-mass X-ray binaries have masses close to their birth mass, providing an opportunity to disentangle the role of "nature" and "nurture" in the observed mass distributions. In 2006, masses had been measured for only six such objects, but this small sample showed the greatest diversity in masses

  1. Analysis of 137Cs radionuclides activities in Cs-zeolite using gamma spectrometry

    International Nuclear Information System (INIS)

    Noviarty; Ginting, Aslina Br; Anggraini, Dian; Rosika K

    2013-01-01

    137 Cs Radionuclide activity analysis has been carried out. The objective is to determine the activity of the 137 Cs radionuclide in Cs-zeolite are packaged in the form of point source. Analysis of 137 Cs Radionuclide activities in Cs zeolite samples was determined by measuring intensity of the isotope 137 Cs gamma energy at 661.7 keV use-y spectrometer. Before measurement the sample, was first carried out measurements of 137 Cs radionuclide in certified point standards from Amersham, to determine the efficiency value. Result the standard sample measurement obtained the efficiency value of 43.98%. Efficiency values obtained are used in the calculation of sample activity. On the measurement of the intensity of the sample obtained results dose rate 196.4537 cps with a standard deviation of 0.5274. By using standard measurement efficiency values obtained by the calculation of the average activity of the radionuclide 137 Cs in Cs-zeolite 524.9082 Bq. Deviation measurements were below 5% (0.27% ) so that the analysis of the activity of radionuclide 137 Cs in Cs-zeolite samples using gamma spectrometer can be accepted with a 95% confidence level. (author)

  2. A novel vanadosilicate with hexadeca-coordinated Cs+ ions as a highly effective Cs+ remover

    International Nuclear Information System (INIS)

    Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung

    2014-01-01

    The effective removal of 137 Cs + ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various 137 Cs + removers have been developed, but more effective 137 Cs + removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V 4+ and V 5+ ) ions is now reported, which shows an excellent ability for Cs + capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs + concentrations, it was found to be the most effective material for the removal of radioactive Cs + ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs + ions, which corresponds to the highest coordination number ever described.

  3. Transfer of 137Cs to wild vegetables

    International Nuclear Information System (INIS)

    Ito, Nobuhiko; Natsuhori, Masahiro; Mezawa, Akane; Kawakami, Akira

    1998-01-01

    For the evaluation of internal radiation dose, it is needed to estimate the amount of radionuclide incorporated to human body using a simulation model. 137 Cesium (Cs) is easily transferred associating with food intake as well as potassium and so, Cs is an important nuclide for evaluation of internal radiation. 137 Cs concentrations in wild vegetables are higher than those of cultured vegetables and milk. Therefore, the transfer coefficients of 137 Cs from soil to wild vegetables were estimated in this study. Wild vegetables and soils of their farms were collected in the Hakkoda Mountain range of Aomori Prefecture. The levels of 137 Cs in wild vegetables were 0.42-18.35 (Bq/kg), whereas those in cabbage and spinach were 0.08 and 0.01 (Bq/kg), respectively, indicating that the Cs level is dozens to several hundreds times higher in wild vegetables than cultured ones. And the transfer coefficient was estimated as 0.003-0.94 for the former and 0.001-0.8 for the latter. On the other hand, 1 37 Cs levels of the soils on which wild vegetables grew was 28.0 Bq/kg and it was 3.9 Bq/kg for the farm soil. Furthermore, the effects of water content and pH of the soil on the transfer coefficient were studied. (M.N.)

  4. Potential value of Cs-137 capsules

    Energy Technology Data Exchange (ETDEWEB)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

    1985-04-01

    We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions.

  5. Potential value of Cs-137 capsules

    International Nuclear Information System (INIS)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

    1985-04-01

    We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions

  6. Giant CP stars

    International Nuclear Information System (INIS)

    Loden, L.O.; Sundman, A.

    1989-01-01

    This study is part of an investigation of the possibility of using chemically peculiar (CP) stars to map local galactic structure. Correct luminosities of these stars are therefore crucial. CP stars are generally regarded as main-sequence or near-main-sequence objects. However, some CP stars have been classified as giants. A selection of stars, classified in literature as CP giants, are compared to normal stars in the same effective temperature interval and to ordinary 'non giant' CP stars. There is no clear confirmation of a higher luminosity for 'CP giants', than for CP stars in general. In addition, CP characteristics seem to be individual properties not repeated in a component star or other cluster members. (author). 50 refs., 5 tabs., 3 figs

  7. 137Cs distribution in guava trees

    International Nuclear Information System (INIS)

    Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M.

    2004-01-01

    This paper presents results of 137 Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the 137 Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of 137 Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

  8. {sup 137}Cs distribution in guava trees

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica

    2004-09-15

    This paper presents results of {sup 137}Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the {sup 137}Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of {sup 137}Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

  9. CsI and some new photocathodes

    International Nuclear Information System (INIS)

    Anderson, D.F.; Kwan, S.; Peskov, V.

    1993-06-01

    A discussion of the possible sources of discrepancies in the measurements of the quantum efficiency of CsI photocathodes is presented. We propose that the major causes for disagreements in QE are due to the QE dependence on the current density extracted from the photocathode, on the electric field, and on the temperature of the photocathode. Preliminary results on TMAE enhanced GaAs and Si, plus TMAE protected CsTe and SbCs photocathodes, operated in gas, are also presented

  10. Coordination polyhedra CsCln in crystals

    International Nuclear Information System (INIS)

    Serezhkin, V.N.; Serezhkina, L.B.

    1999-01-01

    Characteristics of the Voronoi-Dirichlet polyhedrons are estimated for 133 crystallographic cesium atoms in chlorides Cs x M y Cl z (M=Cd, Sc, V, Nb, Mo, W, Ru, Re, etc.). It is found that cesium atoms have coordination numbers 6,8,9,10, 11 and 12 as regards the chlorine atoms. The results of cesium atom coordination sphere examination by the crossing spheres method are presented. Metal-metal interactions (including Cs-Cs) in the structure of certain chlorides are revealed

  11. Regeneration of Used Frying Palm Oil with Coffee Silverskin (CS), CS Ash (CSA) and Nanoparticles of CS (NCS).

    Science.gov (United States)

    Ismail, Samir Abd-Elmonem A; El-Anany, Ayman Mohammed; Ali, Rehab Farouk M

    2017-01-01

    The present investigation aimed to evaluate the efficiency of coffee silverskin (CS), CS ash (CSA) and nanoparticles of CS (NCS) in regeneration the quality of used frying palm oil. The adsorbents were mixed individually with used frying palm oil at level 4% (w/v) for 60 min. The properties of CS, CSA and NCS adsorbents were studied using (SEM) scanning electron microscopy technique. Some of physico-chemical characteristics of used frying palm oil (UFPO) and UFPO treated with adsorbents were determined. The results showed that the CS ash particles composed of irregular spherical and semispherical grains with deep cavities. The size of particles of CS ash ranged in diameter from 1.1 to 1.7 µm. The morphology of NCS consisted of cluster-type spherical nanoparticles and flakes. The particle size of NCS varies from 0.9 to 1.7 µm. Purification treatments caused marked (poil compared to untreated oil. The treatment of UFPO with 4% of adsorbents caused significant reductions in the content of free fatty acids ranged from 51.2 to 65.0%. The lowest level of peroxide (2.1 meq/kg) was recorded for UFPO treated with 4% of NCS. The highest reductions (72.8; 70.0%) in p-anisidine value were observed in UFPO treated with 4% of CSA and NCS, respectively. Treatment of UFPO with 4% of CS, CSA and NCS significantly lowered the polar content from 13.9% to 6.3, 4.8 and 3.9%, respectively. The results also indicate that CSA and NCS have nearly the same adsorption efficiency in lowering polymer content of UFPO. Filtration treatment of UFPO with 4% of CS, CSA and NCS markedly lowered the viscosity and colour values of treated UFPO.

  12. [Energy pooling collisions for K(4P) + Cs(5D) in a K-Cs mixture].

    Science.gov (United States)

    Aihemaiti, Pulati; Dai, Kang; Lu, Xin-hong; Shen, Yi-fan

    2005-04-01

    The rate coefficients for energy-pooling collisions K(4P) + Cs(5D) --> Cs(6S) + K(4D, 6S) in the K-Cs vapor mixture were measured relative to a known energy-pooling rate coefficient of a homonuclear reaction [i. e., Cs(6P) + Cs(5D) --> Cs(6S) + Cs (7D(J))]. Populations of the Cs(6P, 5D) and K(4P) states were produced by photodissociation of K2 and Cs2 molecules through the use of a dye laser radiation. The resulting fluorescence included the direct components emitted in the decay of the excited states produced by photodissociation and the induced components arising from the collisionally populated states. By combining relative intensities of the components with the effective lifetimes of Cs(6P) and K(4P) states, the rate coefficients (in units of 10(-9) cm3 x s(-1)) for the heteronuclear energy-pooling were found to be 2.6 and 3.6, respectively. The contribution to the rate coefficients from other processes are discussed.

  13. Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

    KAUST Repository

    Schmid, Marc R.

    2012-11-01

    In the present study, we investigated Cs-intercalated single wall carbon nanotubes (SWCNTs) using 133Cs Nuclear Magnetic resonance. We show that there are two types of Cs cations depending on the insertion level. Indeed, at low concentrations, Static spectra analysis shows that the Cs (α)+ species are fully ionized, i.e. α equal ca.1, while at higher concentrations a second paramagnetically shifted line appears, indicating the formation of Cs (β)+ ions with β < α ∼ +1. At low concentrations and low temperatures the Cs (α)+ ions exhibit a weak hyperfine coupling to the SWCNT conduction electrons, whereas, at higher temperatures, a thermally activated slow-motion diffusion process of the Cs (α)+ ions occurs along the interstitial channels present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs nuclei and conduction electrons in the carbon nanotubes and a partial charge transfer, which suggest a plausible Cs(6s)-C(2p) hybridization. © 2012 Elsevier Ltd. All rights reserved.

  14. Rates of star formation

    International Nuclear Information System (INIS)

    Larson, R.B.

    1977-01-01

    It is illustrated that a theoretical understanding of the formation and evolution of galaxies depends on an understanding of star formation, and especially of the factors influencing the rate of star formation. Some of the theoretical problems of star formation in galaxies, some approaches that have been considered in models of galaxy evolution, and some possible observational tests that may help to clarify which processes or models are most relevant are reviewed. The material is presented under the following headings: power-law models for star formation, star formation processes (conditions required, ways of achieving these conditions), observational indications and tests, and measures of star formation rates in galaxies. 49 references

  15. Energy production in stars

    International Nuclear Information System (INIS)

    Bethe, Hans.

    1977-01-01

    Energy in stars is released partly by gravitation, partly by nuclear reactions. For ordinary stars like our sun, nuclear reactions predominate. However, at the end of the life of a star very large amounts of energy are released by gravitational collapse; this can amount to as much as 10 times the total energy released nuclear reactions. The rotational energy of pulsars is a small remnant of the energy of gravitation. The end stage of small stars is generally a white dwarf, of heavy stars a neutron star of possibly a black hole

  16. Regular Generalized Star Star closed sets in Bitopological Spaces

    OpenAIRE

    K. Kannan; D. Narasimhan; K. Chandrasekhara Rao; R. Ravikumar

    2011-01-01

    The aim of this paper is to introduce the concepts of τ1τ2-regular generalized star star closed sets , τ1τ2-regular generalized star star open sets and study their basic properties in bitopological spaces.

  17. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.

    Science.gov (United States)

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-04-07

    (135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.

  18. Quark core stars, quark stars and strange stars

    International Nuclear Information System (INIS)

    Grassi, F.

    1988-01-01

    A recent one flavor quark matter equation of state is generalized to several flavors. It is shown that quarks undergo a first order phase transition. In addition, this equation of state depends on just one parameter in the two flavor case, two parameters in the three flavor case, and these parameters are constrained by phenomenology. This equation of state is then applied to the hadron-quark transition in neutron stars and the determination of quark star stability, the investigation of strange matter stability and possible strange star existence. 43 refs., 6 figs

  19. New technology of CRDM-CS

    International Nuclear Information System (INIS)

    Yasushi Nozaki; Hiroyuki Ukon; Toshiaki Matsumura; Yoshihiro Sakurai; Sigenori Hatazawa; Hitoshi Yamagishi; Katsuji Kaneizumi; Hisashi Yasuda

    2005-01-01

    Control Rod Drive Mechanism Control System (CRDM-CS) for PWR Nuclear Power Plant was developed as a domestic product in 1975 and it has been applied to the commercial power plants. Since then, the CRDM-CS has been continuously improved through applying a double-hold-system, an intensified monitoring system, etc. As the result of these modifications unexpected rod drops have never occurred more than ten years in Japanese PWR plants. The system is still so high reliable, however, the technologies of employed devices are old-fashioned and we face on the difficulty to keep spare-parts these days. On the other hand, there are new movements to seek after the plant life extension of 60 years. These situations require a modernized CRDM-CS to accomplish the reliability in accordance to the plant life extension. to comply the above-mentioned object we developed a new CRDM-CS applied with following technologies; 1) Digitalized logic cabinet, 2) I.G.B.T in the main circuit of power cabinet, 3) Standardized cabinet by employing the unit structure, 4) Unnecessary DC hold power cabinet. These measures can play an important role in cost cutting and space reduction in replacing CRDM-CS. The concepts in developing the new CRDM-CS, the applied technologies to the power cabinet, the system structure and characteristics of the logic cabinet and the outline of verification test and result are discussed in this paper. (authors)

  20. Fast CsI-phoswich detector

    International Nuclear Information System (INIS)

    Langenbrunner, J.R.

    1996-01-01

    An improved phoswich radiation detector used pure CsI crystal and a fast plastic scintillator and a single photomultiplier tube. The plastic is arranged to receive incident radiation, and that which passed through then strikes the CsI crystal. Scintillation light from both the plastic and CsI crystal are applied to the photomultiplier tube, with the light from the plastic passing through the crystal without absorption therein. Electronics are provided for analyzing the output of the photomultiplier tube to discriminate responses due to the plastic and the CsI crystal, through short gate and long gate integration, to produce results which are indicative of the characteristics of the different types of incident radiation, even in the presence of large amounts of radiation. The phoswich detector has excellent timing resolution. The scintillators of the CsI- phoswich were chosen for their fast risetimes, of about 3 ns for NE102A, and 30 ns for the pure CsI. 5 figs

  1. 137Cs metabolism in pregnant women

    International Nuclear Information System (INIS)

    Melo, D.R.; Lipsztein, J.L.; Oliveira, C.A.N.; Bertelli, L.

    2000-01-01

    Data from two pregnant women contaminated with 137 Cs, body burdens of 0.2 and 300 MBq, respectively at the time of the Goiania accident, were compared. The first one, with lower body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137 Cs intake. For the first woman 137 Cs concentrations were equal for the mother, infant and placenta, indicating an easy and homogeneous transport of 137 Cs from mother to foetus. The whole body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four years after intake, Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of the organs and tissues except brain, liver and skeletal muscle tissue. (author)

  2. ENERGY STAR Certified Displays

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Displays that are effective as of July 1, 2016....

  3. ENERGY STAR Certified Boilers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Boilers that are effective as of October 1,...

  4. ENERGY STAR Certified Televisions

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Televisions that are effective as of October 30,...

  5. ENERGY STAR Certified Dehumidifiers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Dehumidifiers that are effective as of October...

  6. Observations of central stars

    International Nuclear Information System (INIS)

    Lutz, J.H.

    1978-01-01

    Difficulties occurring in the observation of central stars of planetary nebulae are reviewed with emphasis on spectral classifications and population types, and temperature determination. Binary and peculiar central stars are discussed. (U.M.G.)

  7. ENERGY STAR Certified Telephones

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Telephony (cordless telephones and VoIP...

  8. Wolf-Rayet stars

    Energy Technology Data Exchange (ETDEWEB)

    Sahade, J

    1981-12-01

    Aspects of the problems of the Wolf-Rayet stars related to their chemical composition, their evolutionary status, and their apparent dichotomy in two spectral sequences are discussed. Dogmas concerning WR stars are critically discussed, including the belief that WR stars lack hydrogen, that they are helium stars evolved from massive close binaries, and the existence of a second WR stage in which the star is a short-period single-lined binary. The relationship of WR stars with planetary nebulae is addressed, as is the membership of these stars in clusters and associations. The division of WR stars into WN and WC sequences is considered, questioning the reasonability of accounting for WR line formation in terms of abundance differences.

  9. Star formation: Cosmic feast

    Science.gov (United States)

    Scaringi, Simone

    2017-03-01

    Low-mass stars form through a process known as disk accretion, eating up material that orbits in a disk around them. It turns out that the same mechanism also describes the formation of more massive stars.

  10. Concentration of 134Cs and 137Cs in Malaysian palm products

    International Nuclear Information System (INIS)

    Yii Mei Wo; Nor Aza Hassan; Narizan Sanusi

    2008-08-01

    Until today, countries importing food products from Malaysia, in region such as Indian Continental, Middle East, Central Europe and Central America still require the products to be tested for the radioactive contamination particularly for 134 Cs and 137 Cs. Information extracted from 3371 analytical results observed on isotopic concentration for 134 Cs and 137 Cs in the exported Malaysia origins palm products between years 2002 until 2007 had been summarized and reported in this work. Data shown that the concentration level of the concerned radio nuclides are below the minimum detectable activity and also well below maximum permissible limits adopted by Malaysian Government and also the international bodies. (Author)

  11. Autonomous Star Tracker Algorithms

    DEFF Research Database (Denmark)

    Betto, Maurizio; Jørgensen, John Leif; Kilsgaard, Søren

    1998-01-01

    Proposal, in response to an ESA R.f.P., to design algorithms for autonomous star tracker operations.The proposal also included the development of a star tracker breadboard to test the algorithms performances.......Proposal, in response to an ESA R.f.P., to design algorithms for autonomous star tracker operations.The proposal also included the development of a star tracker breadboard to test the algorithms performances....

  12. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  13. America's Star Libraries

    Science.gov (United States)

    Lyons, Ray; Lance, Keith Curry

    2009-01-01

    "Library Journal"'s new national rating of public libraries, the "LJ" Index of Public Library Service, identifies 256 "star" libraries. It rates 7,115 public libraries. The top libraries in each group get five, four, or three Michelin guide-like stars. All included libraries, stars or not, can use their scores to learn from their peers and improve…

  14. Abundance patterns of the light neutron-capture elements in very and extremely metal-poor stars

    Science.gov (United States)

    Spite, F.; Spite, M.; Barbuy, B.; Bonifacio, P.; Caffau, E.; François, P.

    2018-03-01

    Aims: The abundance patterns of the neutron-capture elements in metal-poor stars provide a unique record of the nucleosynthesis products of the earlier massive primitive objects. Methods: We measured new abundances of so-called light neutron-capture of first peak elements using local thermodynamic equilibrium (LTE) 1D analysis; this analysis resulted in a sample of 11 very metal-poor stars, from [Fe/H] = -2.5 to [Fe/H] = -3.4, and one carbon-rich star, CS 22949-037 with [Fe/H] = -4.0. The abundances were compared to those observed in two classical metal-poor stars: the typical r-rich star CS 31082-001 ([Eu/Fe] > +1.0) and the r-poor star HD 122563 ([Eu/Fe] < 0.0), which are known to present a strong enrichment of the first peak neutron-capture elements relative to the second peak. Results: Within the first peak, the abundances are well correlated in analogy to the well-known correlation inside the abundances of the second-peak elements. In contrast, there is no correlation between any first peak element with any second peak element. We show that the scatter of the ratio of the first peak abundance over second peak abundance increases when the mean abundance of the second peak elements decreases from r-rich to r-poor stars. We found two new r-poor stars that are very similar to HD 122563. A third r-poor star, CS 22897-008, is even more extreme; this star shows the most extreme example of first peak elements enrichment to date. On the contrary, another r-poor star (BD-18 5550) has a pattern of first peak elements that is similar to the typical r-rich stars CS 31082-001, however this star has some Mo enrichment. Conclusions: The distribution of the neutron-capture elements in our very metal-poor stars can be understood as the combination of at least two mechanisms: one that enriches the forming stars cloud homogeneously through the main r-process and leads to an element pattern similar to the r-rich stars, such as CS 31082-001; and another that forms mainly lighter

  15. White Dwarf Stars

    OpenAIRE

    Kepler, S. O.; Romero, Alejandra Daniela; Pelisoli, Ingrid; Ourique, Gustavo

    2017-01-01

    White dwarf stars are the final stage of most stars, born single or in multiple systems. We discuss the identification, magnetic fields, and mass distribution for white dwarfs detected from spectra obtained by the Sloan Digital Sky Survey up to Data Release 13 in 2016, which lead to the increase in the number of spectroscopically identified white dwarf stars from 5000 to 39000. This number includes only white dwarf stars with log g >= 6.5 stars, i.e., excluding the Extremely Low Mass white dw...

  16. Rotating Stars in Relativity

    Directory of Open Access Journals (Sweden)

    Stergioulas Nikolaos

    2003-01-01

    Full Text Available Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on the equilibrium properties and on the nonaxisymmetric instabilities in f-modes and r-modes have been updated and several new sections have been added on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity.

  17. Nuclear physics of stars

    CERN Document Server

    Iliadis, Christian

    2015-01-01

    Most elements are synthesized, or ""cooked"", by thermonuclear reactions in stars. The newly formed elements are released into the interstellar medium during a star's lifetime, and are subsequently incorporated into a new generation of stars, into the planets that form around the stars, and into the life forms that originate on the planets. Moreover, the energy we depend on for life originates from nuclear reactions that occur at the center of the Sun. Synthesis of the elements and nuclear energy production in stars are the topics of nuclear astrophysics, which is the subject of this book

  18. VERA-CS Verification & Validation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-02-01

    This report summarizes the current status of VERA-CS Verification and Validation for PWR Core Follow operation and proposes a multi-phase plan for continuing VERA-CS V&V in FY17 and FY18. The proposed plan recognizes the hierarchical nature of a multi-physics code system such as VERA-CS and the importance of first achieving an acceptable level of V&V on each of the single physics codes before focusing on the V&V of the coupled physics solution. The report summarizes the V&V of each of the single physics codes systems currently used for core follow analysis (ie MPACT, CTF, Multigroup Cross Section Generation, and BISON / Fuel Temperature Tables) and proposes specific actions to achieve a uniformly acceptable level of V&V in FY17. The report also recognizes the ongoing development of other codes important for PWR Core Follow (e.g. TIAMAT, MAMBA3D) and proposes Phase II (FY18) VERA-CS V&V activities in which those codes will also reach an acceptable level of V&V. The report then summarizes the current status of VERA-CS multi-physics V&V for PWR Core Follow and the ongoing PWR Core Follow V&V activities for FY17. An automated procedure and output data format is proposed for standardizing the output for core follow calculations and automatically generating tables and figures for the VERA-CS Latex file. A set of acceptance metrics is also proposed for the evaluation and assessment of core follow results that would be used within the script to automatically flag any results which require further analysis or more detailed explanation prior to being added to the VERA-CS validation base. After the Automation Scripts have been completed and tested using BEAVRS, the VERA-CS plan proposes the Watts Bar cycle depletion cases should be performed with the new cross section library and be included in the first draft of the new VERA-CS manual for release at the end of PoR15. Also, within the constraints imposed by the proprietary nature of plant data, as many as possible of the FY17

  19. Evolution of variable stars

    International Nuclear Information System (INIS)

    Becker, S.A.

    1986-08-01

    Throughout the domain of the H R diagram lie groupings of stars whose luminosity varies with time. These variable stars can be classified based on their observed properties into distinct types such as β Cephei stars, δ Cephei stars, and Miras, as well as many other categories. The underlying mechanism for the variability is generally felt to be due to four different causes: geometric effects, rotation, eruptive processes, and pulsation. In this review the focus will be on pulsation variables and how the theory of stellar evolution can be used to explain how the various regions of variability on the H R diagram are populated. To this end a generalized discussion of the evolutionary behavior of a massive star, an intermediate mass star, and a low mass star will be presented. 19 refs., 1 fig., 1 tab

  20. Relative injectivity and CS-modules

    Directory of Open Access Journals (Sweden)

    Mahmoud Ahmed Kamal

    1994-01-01

    Full Text Available In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.

  1. Separation of 134Cs and 137Cs from 125I solution for medical applications

    International Nuclear Information System (INIS)

    Ram, Ramu; Dash, Ashutosh; Banerjee, Dayamoy

    2015-01-01

    While neutron irradiation of natural Xe gas followed by wet chemical dissolution of activation products constitutes a successful paradigm for the small scale production 125 I, the concomitant production of 134 Cs and 137 Cs emerged as the primary impediment which necessitates purification of 125 I solution. This paper describes an ion-exchange chromatographic technique using Resorcinol Formaldehyde (RF) resin to purify 125 I solution from 134 Cs and 137 Cs impurities. A thorough investigation of the adsorption parameters of RF resin was carried out to arrive at the experimental conditions resulting optimum retention of 134 Cs and 137 Cs impurities. Based on the experimental findings, an optimized separation procedure was developed in which the neutron irradiated dissolved products at pH ∝ 13 was passed through a chromatography column containing RF resin where in 134 Cs and 137 Cs impurities gets adsorbed leaving behind 125 I to appear in the effluent. The overall recovery of 125 I was >90% with acceptable purity amenable for clinical applications.

  2. Molecular structures and thermodynamic properties of 12 gaseous cesium-containing species of nuclear safety interest: Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I)

    Science.gov (United States)

    Badawi, Michael; Xerri, Bertrand; Canneaux, Sébastien; Cantrel, Laurent; Louis, Florent

    2012-01-01

    Ab initio electronic structure calculations at the coupled cluster level with a correction for the triples extrapolated to the complete basis set limit have been made for the estimation of the thermochemical properties of Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I). The standard enthalpies of formation and standard molar entropies at 298 K, and the temperature dependence of the heat capacities at constant pressure were evaluated. The calculated thermochemical properties are in good agreement with their literature counterparts. For Cs 2, CsH, CsOH, Cs 2(OH) 2, CsCl, Cs 2Cl 2, CsBr, CsI, and Cs 2I 2, the calculated ΔfH298K∘ values are within chemical accuracy of the most recent experimental values. Based on the excellent agreement observed between our calculated ΔfH298K∘ values and their literature counterparts, the standard enthalpies of formation at 298 K are estimated to be the following: ΔfH298K∘ (CsO) = 17.0 kJ mol -1 and ΔfH298K∘ (Cs 2Br 2) = -575.4 kJ mol -1.

  3. The Godparent Plan: A Pedagogical Strategy for CS1 Accompaniment and CS2 Pedagogical Enhancement

    Directory of Open Access Journals (Sweden)

    Pedro Guillermo Feijóo-García

    2018-02-01

    Full Text Available Courses such as CS1 and CS2 can present an interesting pedagogical challenge when it comes to the theory-practice relationship, along with aspects that involve the course's logistics, the programming language used, and the characteristics of the students involved in the process. This study presents an innovative didactic approach, oriented towards the accompaniment of CS1 students by CS2 students at Universidad El Bosque, Colombia, seeking with this Godparent Plan, to provide a personalized accompaniment to first semester students, whereby CS2 students enhance their domain over concepts and skills while accompanying, explaining and teaching younger peers. The results of this study are favorable, outlining a didactic scheme that can be adapted and replicated in other curricular scenarios.

  4. Derivation of 137Cs deposition density from measurement of 137Cs inventories in undisturbed soils

    International Nuclear Information System (INIS)

    Hien, P.D.; Hiep, H.T.; Quang, N.H.; Huy, N.Q.; Binh, N.T.; Hai, P.S.; Long, N.Q.; Bac, V.T

    2012-01-01

    The 137 Cs inventories in undisturbed soils were measured for 292 locations across the territory of Vietnam. the logarithmic inventory values were regressed against characteristics of sampling sites, such as geographical coordinates, annual rainfall and physico-chemical parameters of soil. The regression model containing latitude and annual rainfall as determinants could explain 76% of the variations in logarithmic inventory values across the territory. The model part was interpreted as the logarithmic 137 Cs deposition density. At the 95% confidence level, 137 Cs deposition density could be predicted be the model ± 7% relative uncertainty. the latitude mean 137 Cs deposition density increases northward from 237 Bq m -2 to 1097 Bq m -2 , while the corresponding values derived from the UNSCEAR (1969) global pattern are 300 Bq m -2 and 600 Bq m -2 . High 137 Cs inputs were found in high-rainfall areas in northern and central parts of the territory. (author)

  5. 135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

    International Nuclear Information System (INIS)

    Snow, Mathew S.; Snyder, Darin C.

    2016-01-01

    135 Cs/ 137 Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135 Cs/ 137 Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135 Cs/ 137 Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135 Cs/ 137 Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135 Cs/ 137 Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in 135 Cs/ 137 Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135 Cs/ 137 Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. - Highlights: • 135 Cs/ 137 Cs useful for tracking anthropogenic environmental radiocesium releases. • European surface soils/vegetation have uniform ratio consistent with Chernobyl. • 135 Cs/ 137 Cs in Irish sea represents thermal fission ratio distinct from Chernobyl. • Can distinguish between major source terms in Europe based on 135 Cs/ 137 Cs.

  6. Radiochemical determination of 137Cs in foods

    International Nuclear Information System (INIS)

    Kastner, Geraldo F.; Ferreira, Andrea Vidal; Monteiro, Roberto P.G.

    2013-01-01

    A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, 137 Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of 137 Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The 137 Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

  7. Retention of 137Cs in three humans

    International Nuclear Information System (INIS)

    Soegaard-Hansen, J.; Lauridsen, B.

    1992-01-01

    In two experiments the retention of 137 Cs after a single intake have been measured with whole-body counting. In the first experiment, two persons ingested a prepared liquid solution of 137 CsCl. In the second experiment these two persons together with a third person ingested 137 Cs naturally incorporated in a piece of meat. The obtained data have been fitted to a retention function with a small compartment having a fast excretion rate and a large compartment having a slow excretion rate, as given by the International Commission on Radiological Protection (ICRP). The effective biological half-lives were in both experiments significantly different from the value given by ICRP. (au)

  8. 137Cs in Norwegian Lapps, spring 1980

    International Nuclear Information System (INIS)

    Westerlund, E.A.; Gjertsen, L.; Lind, B.

    1980-01-01

    Measurements show that the body burden of 137 in Lapps in Norway fell from 1965 to 1975 with an apparent half-life of 4-5 years. Since then the reduction has been considerably slower due to fallout from Chinese nuclear weapon tests. The content of 137 Cs in reindeer meat follows the same pattern. Seasonal variations occur due to the migration of the reindeer between winter grazing on lichen with a high 137 Cs content and summer grazing on grass with a lower 137 Cs content. For annual dose calculations it is found that whole body mearurements at the end of March or the beginning of April give good values. Radiation doses to Lapps working small holdings are about 3/4 of those of nomadic reindeer-herding Lapps. (JIW)

  9. Cs-137 for irradiation of sewage sludge

    International Nuclear Information System (INIS)

    Lessel, T.

    1986-01-01

    Since 1973, the Geiselbullach sewage treatment works have been continuously operating their first system for gamma irradiation of sewage sludge. Within the framework of a German-American agreement, nine Cs-137 sources with a total activity of 56.000 Ci have been made available to the works free of charge in 1983, in order to test in practice and to demonstrate the applicability of these radiation sources in comparison to the Co-60 sources exclusively used up to then. This first study on the applicability of Cs-137 as a radiation source for sewage sludge treatment revealed no findings or effects speaking against Cs-137 as a radiation source for this purpose. (orig./RB) [de

  10. WESF (173)Cs gamma ray sources

    Science.gov (United States)

    Kenna, B. T.

    1984-10-01

    The Waste Encapsulation and Storage Facility (WESP) at Hanford, Washington has been separating cesium from stored liquid defense waste since 1945. This is done to alleviate the heat generated by the decay of radioactive Cs137. The cesium is converted to CsCl, doubly encapsulated in 316l stainless steel, and placed in storage. The potential utility of these Cs137 capsules as gamma radiation sources was demonstrated. Registration of the capsule with the NRC as a sealed gamma source would facilitate the licensing of non-DOE irradiation facilities using this source. To grant this registration, the NRC requires characteristics of the capsule. It must also be demonstrated that the capsule will maintain its integrity under both normal circumstances and specified abnormal conditions. The required information is provided through collation of results of studies and tests done previously by other laboratories.

  11. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira; Hayashi, Mayumi; Ito, Shotaro; Goseki, Raita; Higashihara, Tomoya; Hadjichristidis, Nikolaos

    2015-01-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic

  12. Phonon dispersion curves for CsCN

    International Nuclear Information System (INIS)

    Gaur, N.K.; Singh, Preeti; Rini, E.G.; Galgale, Jyostna; Singh, R.K.

    2004-01-01

    The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique. (author)

  13. Mastering Adobe Premiere Pro CS6

    CERN Document Server

    Ekert, Paul

    2013-01-01

    Designed to be practical and engaging, Mastering Adobe Premiere Pro CS6 is a project-based book to help you truly augment your skills and become a film editing hotshot.If you're just starting out or even migrating from existing video editing software, then this book is for you. With rapid progression through practical examples constructed to be both engaging and useful, Mastering Adobe Premiere Pro CS6 is ideal for learning the sometimes complex workflows of this powerful application.

  14. Study of the 137Cs Stabilizer Source

    Directory of Open Access Journals (Sweden)

    GAO Yan;WANG Yan-ling;XU Zhi-jian;XU Liang;REN Chun-xia;TAN Xiao-ming;CUI Hong-qi

    2014-02-01

    Full Text Available The attenuation laws of the Cesium -137 γ-ray penetrating the ceramic core、stainless steel and tungsten steel were studied. The radioactivity of the 137Cs stabilizer source was determined through the surface dose rate of 137Cs stabilizer sources. In addition, the adsorption properties of the ceramic core were studied to improve the stability of the output rate, and established a production line. The application results showed that the output rate of ray source was accurate and was of a good consistency. At present, the source had been used in logging lithology, and achieved the realization of domestic product.

  15. The Photoshop CS4 Companion for Photographers

    CERN Document Server

    Story, Derrick

    2009-01-01

    "Derrick shows that Photoshop can be friendly as well as powerful. In part, he does that by focusing photographers on the essential steps of an efficient workflow. With this guide in hand, you'll quickly learn how to leverage Photoshop CS4's features to organize and improve your pictures."-- John Nack, Principal Product Manager, Adobe Photoshop & BridgeMany photographers -- even the pros -- feel overwhelmed by all the editing options Photoshop provides. The Photoshop CS4 Companion for Photographers pares it down to only the tools you'll need most often, and shows you how to use those tools as

  16. CS model coil experimental log book

    International Nuclear Information System (INIS)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  17. Near-Ultraviolet Observations of CS 29497-030: New Constraints on Neutron-Capture Nucleosynthesis Processes

    Science.gov (United States)

    Ivans, Inese I.; Sneden, Christopher; Gallino, Roberto; Cowan, John J.; Preston, George W.

    2005-07-01

    Employing spectra obtained with the new Keck I HIRES near-UV-sensitive detector, we have performed a comprehensive chemical composition analysis of the binary blue metal-poor star CS 29497-030. Abundances for 29 elements and upper limits for an additional seven have been derived, concentrating on elements largely produced by means of neutron-capture nucleosynthesis. Included in our analysis are the two elements that define the termination point of the slow neutron-capture process, lead and bismuth. We determine an extremely high value of [Pb/Fe]=+3.65+/-0.07 (σ=0.13) from three features, supporting the single-feature result obtained in previous studies. We detect Bi for the first time in a metal-poor star. Our derived Bi/Pb ratio is in accord with those predicted from the most recent FRANEC calculations of the slow neutron-capture process in low-mass asymptotic giant branch (AGB) stars. We find that the neutron-capture elemental abundances of CS 29497-030 are best explained by an AGB model that also includes very significant amounts of pre-enrichment of rapid neutron-capture process material in the protostellar cloud out of which the CS 29497-030 binary system formed. Mass transfer is consistent with the observed [Nb/Zr]~0. Thus, CS 29497-030 is both an r+s and ``extrinsic AGB'' star. Furthermore, we find that the mass of the AGB model can be further constrained by the abundance of the light odd-element Na. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  18. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira

    2015-09-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm ABC, 9-arm ABC, 12-arm ABC, 13-arm ABCD, 9-arm AB, 17-arm AB, 33-arm AB, 7-arm ABC, 15-arm ABCD, and 31-arm ABCDE miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

  19. Massive stars in galaxies

    International Nuclear Information System (INIS)

    Humphreys, R.M.

    1987-01-01

    The relationship between the morphologic type of a galaxy and the evolution of its massive stars is explored, reviewing observational results for nearby galaxies. The data are presented in diagrams, and it is found that the massive-star populations of most Sc spiral galaxies and irregular galaxies are similar, while those of Sb spirals such as M 31 and M 81 may be affected by morphology (via differences in the initial mass function or star-formation rate). Consideration is also given to the stability-related upper luminosity limit in the H-R diagram of hypergiant stars (attributed to radiation pressure in hot stars and turbulence in cool stars) and the goals of future observation campaigns. 88 references

  20. Properties of CsI and CsI-TMAE photocathodes

    International Nuclear Information System (INIS)

    Anderson, D.F.; Kwan, S.; Peskov, V.; Hoeneisen, B.

    1992-06-01

    The importance of heating the CsI or CsI-TMAE photocathodes during preparation, as well as the importance of the gas environment on the quantum efficiency is presented. The dependence of the aging characteristics of these photocathodes on the operating temperature, on the presence of gas, and on the charge amplification of the chamber is also discussed. For CsI photocathodes charges in excess of 2x10 14 e - /mm 2 can be collected with little degradation of performance. A timing resolution of 0.55 ns is also achieved for single photoelectrons suggesting a possible time-of-flight detector

  1. Evolution of massive stars

    International Nuclear Information System (INIS)

    Loore, C. de

    1984-01-01

    The evolution of stars with masses larger than 15 sun masses is reviewed. These stars have large convective cores and lose a substantial fraction of their matter by stellar wind. The treatment of convection and the parameterisation of the stellar wind mass loss are analysed within the context of existing disagreements between theory and observation. The evolution of massive close binaries and the origin of Wolf-Rayet Stars and X-ray binaries is also sketched. (author)

  2. Effect of 137Cs on immunological reactivity

    International Nuclear Information System (INIS)

    Shubik, V.M.

    1975-01-01

    An important role of 137 Cs as a new ecological factor was shown by analyzing 31 different studies. The radioisotope may at present be detected in the organisms of all inhabitants of this planet. The migration of 137 Cs along the chain lichen-deer-man leads to its accumulation in the organism of humans living in the Extreme North and taking venison in their food. Although the high sensitivity of immunological reactions to various unfavourable environmental factors is well known, data on the effect of incorporated 137 Cs on immunity are scanty. Experiments on animals showed changes in factors of nonspecific immunity (phagocytic reaction of blood neutrophils, bactericidal activity, lysozyme and complement titres of blood serum) and specific immunity (formation of antiviral antibodies). The blood of animals injured by the isotope displays complete and incomplete autoantibodies. The dependence of immunobiological changes on the dose absorbed by the organism is shown. The 137 Cs intake of inhabitants of the Extreme North who eat venison did not, with the absorbed dose equalling up to 50 Mrem per year, lead to changes in their immunological reactivity. (author)

  3. Flash CS4: The Missing Manual

    CERN Document Server

    Grover, Chris

    2008-01-01

    Unlock the power of Flash and bring gorgeous animations to life onscreen. Flash CS4: The Missing Manual includes a complete primer on animation, a guided tour of the program's tools and capabilities, lots of new illustrations, and more details on working with video. Beginners will learn to use the software in no time, and experienced Flash designers will improve their skills.

  4. Fast pulsars, strange stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1990-02-01

    The initial motivation for this work was the reported discovery in January 1989 of a 1/2 millisecond pulsar in the remnant of the spectacular supernova, 1987A. The status of this discovery has come into grave doubt as of data taken by the same group in February, 1990. At this time we must consider that the millisecond signal does not belong to the pulsar. The existence of a neutron star in remnant of the supernova is suspected because of recent observations on the light curve of the remnant, and of course by the neutrino burst that announced the supernova. However its frequency is unknown. I can make a strong case that a pulsar rotation period of about 1 ms divides those that can be understood quite comfortably as neutron stars, and those that cannot. What we will soon learn is whether there is an invisible boundary below which pulsar periods do not fall, in which case, all are presumable neutron stars, or whether there exist sub- millisecond pulsars, which almost certainly cannot be neutron stars. Their most plausible structure is that of a self-bound star, a strange-quark-matter star. The existence of such stars would imply that the ground state of the strong interaction is not, as we usually assume, hadronic matter, but rather strange quark matter. Let us look respectively at stars that are bound only by gravity, and hypothetical stars that are self-bound, for which gravity is so to speak, icing on the cake

  5. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  6. Introduction to neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Lattimer, James M. [Dept. of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

    2015-02-24

    Neutron stars contain the densest form of matter in the present universe. General relativity and causality set important constraints to their compactness. In addition, analytic GR solutions are useful in understanding the relationships that exist among the maximum mass, radii, moments of inertia, and tidal Love numbers of neutron stars, all of which are accessible to observation. Some of these relations are independent of the underlying dense matter equation of state, while others are very sensitive to the equation of state. Recent observations of neutron stars from pulsar timing, quiescent X-ray emission from binaries, and Type I X-ray bursts can set important constraints on the structure of neutron stars and the underlying equation of state. In addition, measurements of thermal radiation from neutron stars has uncovered the possible existence of neutron and proton superfluidity/superconductivity in the core of a neutron star, as well as offering powerful evidence that typical neutron stars have significant crusts. These observations impose constraints on the existence of strange quark matter stars, and limit the possibility that abundant deconfined quark matter or hyperons exist in the cores of neutron stars.

  7. Strangeon and Strangeon Star

    Science.gov (United States)

    Xiaoyu, Lai; Renxin, Xu

    2017-06-01

    The nature of pulsar-like compact stars is essentially a central question of the fundamental strong interaction (explained in quantum chromo-dynamics) at low energy scale, the solution of which still remains a challenge though tremendous efforts have been tried. This kind of compact objects could actually be strange quark stars if strange quark matter in bulk may constitute the true ground state of the strong-interaction matter rather than 56Fe (the so-called Witten’s conjecture). From astrophysical points of view, however, it is proposed that strange cluster matter could be absolutely stable and thus those compact stars could be strange cluster stars in fact. This proposal could be regarded as a general Witten’s conjecture: strange matter in bulk could be absolutely stable, in which quarks are either free (for strange quark matter) or localized (for strange cluster matter). Strange cluster with three-light-flavor symmetry is renamed strangeon, being coined by combining “strange nucleon” for the sake of simplicity. A strangeon star can then be thought as a 3-flavored gigantic nucleus, and strangeons are its constituent as an analogy of nucleons which are the constituent of a normal (micro) nucleus. The observational consequences of strangeon stars show that different manifestations of pulsarlike compact stars could be understood in the regime of strangeon stars, and we are expecting more evidence for strangeon star by advanced facilities (e.g., FAST, SKA, and eXTP).

  8. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  9. Polarization of Be stars

    International Nuclear Information System (INIS)

    Johns, M.W.

    1975-01-01

    Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

  10. ENERGY STAR Unit Reports

    Data.gov (United States)

    Department of Housing and Urban Development — These quarterly Federal Fiscal Year performance reports track the ENERGY STAR qualified HOME units that Participating Jurisdictions record in HUD's Integrated...

  11. SR-XRF imaging of Cs highly accumulated in vegetables

    International Nuclear Information System (INIS)

    Nakai, Izumi; Oda, Nahoko; Terada, Yasuko

    2011-01-01

    Accumulation of Cs in vegetables was studied with regard to the remediation of radioactive Cs from a nuclear plant accident in Fukushima. It was found that Brassica oleracea var. capitata, Brassica campestris var. perviridis, and Lactuca sativa accumulated Cs to a level of more than 10000 ppm (dry weight) when they were cultivated in 1 mM Cs solution. Two-dimensional distributions of Cs were revealed by SR-XRF imaging showing a homogeneous distribution of Cs in the plant bodies. (author)

  12. Radiation damage in undoped CsI and CsI(Tl)

    International Nuclear Information System (INIS)

    Woody, C.L.; Kierstead, J.A.; Levy, P.W.; Stoll, S.

    1992-01-01

    Radiation damage has been studied in undoped CsI and CsI(TI) crystals using 60 Co gamma radiation for doses up to ∼ 4.2 x 10 6 . Samples from various manufacturers were measured ranging in size from 2.54 cm long cylinders to a 30 cm long block. Measurements were made on the change in optical transmission and scintillation light output as a function of dose. Although some samples showed a small change in transmission, a significant change in light output was observed for all samples. Recovery from damage was also studied as a function of time and exposure to UV light. A short lived phosphorescence was observed in undoped CsI, similar to the phosphorescence seen in CsI(TI)

  13. Ab Initio investigation of cesium monoxide of CsO and CsO+

    International Nuclear Information System (INIS)

    Zialenina, M.; Kelloe, V.; Cernusak, I.

    2015-01-01

    Cesium is material with a low work function and, accordingly, atomic Cs has a low value of ionization energy. Therefore cesium is regarded as a good source material for electrons in plasma heating module. One of plasma heating technologies using Cs grid is foreseen as a candidate for the tokamak within the framework of project ITER. Among the possible impurities that can coexist in this module are CsO or CsO + , due to presence of oxygen traces in the heating chamber. We conducted CCSD(T) energy calculations of the cesium oxide (X 2 Σ + ) and its cation (X 3 Σ - ). Here are presented the bond lengths and spectroscopic parameters of both species and ionization energy (IE). Our IE (6.88 eV) is in good agreement with previous theoretical results, experiment indicates substantially lower value (6.22 eV). (authors)

  14. Calculation of inelastic cross sections for H+ + Cs → H(n=2) + Cs+

    International Nuclear Information System (INIS)

    Valance, A.; Spiess, G.

    1975-01-01

    The cross sections for the processes H + +Cs → H(2p and 2s) +Cs + were calculated in the center of mass energy range 250--2400 eV using a simple pseudopotential formalism for the potential curves and coupling matrix elements and a perturbed stationary state (pss) formulation for the calculation of the cross sections. The results are found to be in reasonable agreement with experiment. (auth)

  15. Stars and Flowers, Flowers and Stars

    Science.gov (United States)

    Minti, Hari

    2012-12-01

    The author, a graduated from the Bucharest University (1964), actually living and working in Israel, concerns his book to variable stars and flowers, two domains of his interest. The analogies includes double stars, eclipsing double stars, eclipses, Big Bang. The book contains 34 chapters, each of which concerns various relations between astronomy and other sciences and pseudosciences such as Psychology, Religion, Geology, Computers and Astrology (to which the author is not an adherent). A special part of the book is dedicated to archeoastronomy and ethnoastronomy, as well as to history of astronomy. Between the main points of interest of these parts: ancient sanctuaries in Sarmizegetusa (Dacia), Stone Henge(UK) and other. The last chapter of the book is dedicated to flowers. The book is richly illustrated. It is designed for a wide circle of readers.

  16. The 134Cs uptake by sunflower (Helianthus anuus, Less) cultivated on soil contaminated with 134Cs

    International Nuclear Information System (INIS)

    Poppy Intan Tjahaja; Putu Sukmabuana

    2008-01-01

    One of the methods for remediation of contaminated environment is phytoremediation techniques, i.e. the environmental remediation using plants. In this research the bioavailability of sunflower plant (Helianthus anuus, Less) in radiocaesium uptake from soil was studied for being considered as a phytoremediator later. Sunflower plants were cultivated on soil contaminated with 134 Cs with the concentrations of 29,3 kBq/kg ; 117,2 kBq/kg ; 557 kBq/kg for 45 days. As control the sunflowers were also cultivated on non contaminated soil. Observation was carried out every 5 days by sampling 3 plants and soils. The plant and soil samples were dried using infra red lamp for 24 hours, and then counted using gamma spectrometer. The counting results i.e. 134 Cs concentration on soil and plant parts were then analyzed to obtain transfer factor (TF) values. The highest TF values was reached on 26 th day, i.e. 0,87; 1,89 ; 2,82 for initial soil 134 Cs concentrations of 29,3 Bq/g ; 117,2 Bq/g ; 557 Bq/g, respectively. The TF values obtained expressed the capability of plants to accumulate 134 Cs from soils. The observation to the plants growth showed that the plants grew normally on the 134 Cs contaminated soil until the concentration of 557 Bq/g. The sunflower can be considered to be phytoremediator of andosol soil contaminated with Cs radionuclides. (author)

  17. Science Through ARts (STAR)

    Science.gov (United States)

    Kolecki, Joseph; Petersen, Ruth; Williams, Lawrence

    2002-01-01

    Science Through ARts (STAR) is an educational initiative designed to teach students through a multidisciplinary approach to learning. This presentation describes the STAR pilot project, which will use Mars exploration as the topic to be integrated. Schools from the United Kingdom, Japan, the United States, and possibly eastern Europe are expected to participate in the pilot project.

  18. European Stars and Stripes

    National Research Council Canada - National Science Library

    Hendricks, Nancy

    1994-01-01

    The European Stars and Stripes (ES&S) organization publishes a daily newspaper, The Stars and Stripes, for DoD personnel stationed in Germany, Italy, the United Kingdom, and other DoD activities in the U.S. European Command...

  19. Nebraska STARS: Achieving Results

    Science.gov (United States)

    Roschewski, Pat; Isernhagen, Jody; Dappen, Leon

    2006-01-01

    In 2000, the state of Nebraska passed legislation requiring the assessment of student performance on content standards, but its requirements were very different from those of any other state. Nebraska created what has come to be known as STARS (School-based Teacher-led Assessment and Reporting System). Under STARS, each of Nebraska's nearly 500…

  20. Convective overshooting in stars

    NARCIS (Netherlands)

    Andrássy, R.

    2015-01-01

    Numerous observations provide evidence that the standard picture, in which convective mixing is limited to the unstable layers of a star, is incomplete. The mixing layers in real stars are significantly more extended than what the standard models predict. Some of the observations require changing

  1. By Draconis Stars

    Science.gov (United States)

    Bopp, Bernard W.

    An optical spectroscopic survey of dK-M stars has resulted in the discovery of several new H-alpha emission objects. Available optical data suggest these stars have a level of chromospheric activity midway between active BY Dra stars and quiet dM's. These "marginal" BY Dra stars are single objects that have rotation velocities slightly higher than that of quiet field stars but below that of active flare/BY Dra objects. The marginal BY Dra stars provide us with a class of objects rotating very near a "trigger velocity" (believed to be 5 km/s) which appears to divide active flare/BY Dra stars from quiet dM's. UV data on Mg II emission fluxes and strength of transition region features such as C IV will serve to fix activity levels in the marginal objects and determine chromosphere and transition-region heating rates. Simultaneous optical magnetic field measures will be used to explore the connection between fieldstrength/filling-factor and atmospheric heating. Comparison of these data with published information on active and quiet dM stars will yield information on the character of the stellar dynamo as it makes a transition from "low" to "high" activity.

  2. Observing Double Stars

    Science.gov (United States)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  3. Neutron Stars and Pulsars

    CERN Document Server

    Becker, Werner

    2009-01-01

    Neutron stars are the most compact astronomical objects in the universe which are accessible by direct observation. Studying neutron stars means studying physics in regimes unattainable in any terrestrial laboratory. Understanding their observed complex phenomena requires a wide range of scientific disciplines, including the nuclear and condensed matter physics of very dense matter in neutron star interiors, plasma physics and quantum electrodynamics of magnetospheres, and the relativistic magneto-hydrodynamics of electron-positron pulsar winds interacting with some ambient medium. Not to mention the test bed neutron stars provide for general relativity theories, and their importance as potential sources of gravitational waves. It is this variety of disciplines which, among others, makes neutron star research so fascinating, not only for those who have been working in the field for many years but also for students and young scientists. The aim of this book is to serve as a reference work which not only review...

  4. Spectrophotometry of carbon stars

    Energy Technology Data Exchange (ETDEWEB)

    Oganesyan, R.K.; Karapetyan, M.S.; Nersisyan, S.E.

    1986-01-01

    The results are given of the spectrophotometric investigation of 56 carbon stars in the spectral range from 4000 to 6800 A with resolution 3 A. The observed energy distributions of these stars are determined relative to the flux at the wavelength /sub 0/ = 5556; they are presented in the form of graphs. The energy distributions have been obtained for the first time for 35 stars. Variation in the line Ba II 4554 A has been found in the spectra of St Cam, UU Aur, and RV Mon. Large changes have taken place in the spectra of RT UMa and SS Vir. It is noted that the spectra of carbon stars have a depression, this being situated in different spectral regions for individual groups of stars.

  5. Rotating stars in relativity.

    Science.gov (United States)

    Paschalidis, Vasileios; Stergioulas, Nikolaos

    2017-01-01

    Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on equilibrium properties and on nonaxisymmetric oscillations and instabilities in f -modes and r -modes have been updated. Several new sections have been added on equilibria in modified theories of gravity, approximate universal relationships, the one-arm spiral instability, on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity including both hydrodynamic and magnetohydrodynamic studies of these objects.

  6. On the evolution of stars

    International Nuclear Information System (INIS)

    Kippenhahn, R.

    1989-01-01

    A popular survey is given of the present knowledge on evolution and ageing of stars. Main sequence stars, white dwarf stars, and red giant stars are classified in the Hertzsprung-Russell (HR)-diagram by measurable quantities: surface temperature and luminosity. From the HR-diagram it can be concluded to star mass and age. Star-forming processes in interstellar clouds as well as stellar burning processes are illustrated. The changes occurring in a star due to the depletion of the nuclear energy reserve are described. In this frame the phenomena of planetary nebulae, supernovae, pulsars, neutron stars as well as of black holes are explained

  7. Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

    Energy Technology Data Exchange (ETDEWEB)

    Theodorakis, P E [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Avgeropoulos, A [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Freire, J J [Departamento de Ciencias y Tecnicas FisicoquImicas, Universidad Nacional de Educacion a Distancia, Facultad de Ciencias, Senda del Rey 9, 28040 Madrid (Spain); Kosmas, M [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece); Vlahos, C [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

    2007-11-21

    The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

  8. Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

    Science.gov (United States)

    Theodorakis, P. E.; Avgeropoulos, A.; Freire, J. J.; Kosmas, M.; Vlahos, C.

    2007-11-01

    The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

  9. Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

    International Nuclear Information System (INIS)

    Theodorakis, P E; Avgeropoulos, A; Freire, J J; Kosmas, M; Vlahos, C

    2007-01-01

    The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results

  10. Biological effects of 137Cs, incorporated into organism of rats

    International Nuclear Information System (INIS)

    Monakhov, A.S.; Strekalov, S.A.; Sokolov, A.V.; Aver'yanova, T.K.

    1987-01-01

    Results of investigating mutagenous and hemotoxic effects of 137 Cs on blood lymphocytes of rats are presented. 137 Cs was orally administrated into organism of rats as 270 kBq/g chloride solution. 137 Cs mutagenous effect was studied on metaphase plates of rat blood lymphocytes in course of rats lifetime experiment. It is stated that 137 Cs inducing severe disturbances of genetic material in a great quantity of blood lymphocytes, causes their total killing

  11. Synthesis, thermal decomposition and sensitivity study of CsDNBF

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shaozong; Zhang, Tonglai; Yang, Li; Zhang, Jianguo; Sun, Yuanhua [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2007-02-15

    CsDNBF (cesium 7-hydroxy-4,6-dinitro-5,7-dihydrobenzofuroxanide) was synthesized from the sodium salt of DNBF and cesium nitrate. The thermal decomposition process has been investigated and the results show that the solid residues at 240 C are RCOOCs, CsNCO, RNO{sub 2} and CsNO{sub 3}. The sensitivity results demonstrate that CsDNBF has better properties than KDNBF, which has been widely used. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  12. CS model coil experimental log book

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  13. Magnetic correlations in CsVBr3

    International Nuclear Information System (INIS)

    Itoh, Shinichi; Kakurai, Kazuhisa; Endoh, Yasuo

    2001-01-01

    The static magnetic correlation function, S(q), in and S=3/2, one-dimensional Heisenberg antiferromagnet, CsVBr 3 , was measured at temperatures between 40 K and 200 K above the three-dimensional ordering temperature (T N =20.3 K), on a chopper spectrometer install at a pulsed neutron source. The observed S(q) was well fitted to a Lorentzian function convoluted with the instrumental resolution function. The inverse correlation length, κ(T), determined as a half width of the correlation function, showed a linear temperature dependence in the observed temperature range, and, qualitatively well agreed with classical theory. This is consistent with current theory, also, with κ(T) reported for a similar system, CsVCl 3 . (author)

  14. 137Cs behaviour in fruit trees

    International Nuclear Information System (INIS)

    Monte, L.; Quaggia, S.; Pompei, F.; Fratarcangeli, S.

    1989-01-01

    The results of measurements carried out during the period 1987-1988, to evaluate the levels of 137 Cs and 134 Cs contamination in fruit samples and in various components of fruit-trees have been reported. It has been demonstrated that, in the case of an accidental contamination of the air, the contamination of fruit is mainly due to the foliar translocation of radionuclide. Data of radioactivity content in fruits collected through a period of three years show that the radioactivity content in fruit diminishes exponentially. Rough estimates of ''translocation coefficient'' defined as the ratio (radionuclide concentration in fruit)/(radionuclide deposition on soil), and of the ''biological half time'' have been carried out in the case of hazel-nut, walnut, apple, chestnut and olive

  15. Teaching the Five Cs with Cinema

    Directory of Open Access Journals (Sweden)

    Rimma Garn

    2012-08-01

    Full Text Available This paper discusses teaching the five Cs (as noted in the following introduction, delineated in the “National Standards for Foreign Language Learning in the 21st Century,” through a college content course based on cinema. It provides an overview of a 2009 Berkeley workshop, “Teaching Language and Culture with Film,” that addressed larger issues related to such courses within the curriculum, their design and teaching. The paper goes on to describe three Russian courses based on the same textbook, KinoTalk, yet designed for different student audiences: for traditional third year students and for various kinds of non-traditional students, for heritage speakers, and for former missionaries with two-years experience in the target country but minimal formal training in the language. In conclusion, the paper suggests ideas for further courses taught using the same textbook and for teaching the five Cs through language and cinema in general.

  16. On Gács' quantum algorithmic entropy

    Directory of Open Access Journals (Sweden)

    Toru Takisaka

    2014-12-01

    Full Text Available We define an infinite dimensional modification of lower-semicomputability of density operators by Gács with an attempt to fix some problem in the paper. Our attempt is partly achieved by showing the existence of universal operator under some additional assumption. It is left as a future task to eliminate this assumption. We also see some properties and examples which stimulate further research. In particular, we show that universal operator has certain nontrivial form if it exists.

  17. Flash CS3 The Missing Manual

    CERN Document Server

    Grover, Chris

    2008-01-01

    Flash CS3, the latest version of the premier tool for creating web animations and interactive web sites, can be intimidating to learn. This entertaining reference tutorial provides a reader-friendly animation primer and a guided tour of all the program's tools and capabilities. Beginners will learn to use the software in no time, and experienced users will quickly take their skills to the next level.

  18. 137Cs in Research Polygon 'Sumbar'

    International Nuclear Information System (INIS)

    Skoko, B.; Marovic, G.; Babic, D.; Vickovic, I.

    2011-01-01

    In 2009, Radiation Protection Unit of the Institute for Medical Reseach and Occupational Health started a radioactivity measurement programme in research polygon ''Sumbar''. The purpose of these investigations is to collect as many data as possible about the contamination of the polygon that is mainly covered by a forest of English oak (Quercus robur) and hornbeam (Carpinus betulus). Once contaminated, forests represent long-term sources of radiation exposure to specific population groups which are using them as a source of foodstuffs. After the Chernobyl accident, researchers have shown that there has been more variability in radionuclide activity concentration in forests than in agricultural ecosystems. In order to carry out a radioactivity screening of the polygon, we randomly chosed three sampling sites for collecting soil, grass and moss samples. Different species of mushrooms were collected over the whole polygon area. The average activity concentration of 137Cs in soil for two sampling sites is (123 @ 9) Bq kg -1 , while the result for the third site is lower by an order of magnitude ((16.1@0.5) Bq kg -1 ). The activity concentration of 137Cs in grass samples ranges from (0.43 @ 0.03) Bq kg -1 to (13.2 @ 0.1) Bq kg -1 , and in moss samples from (8.7 @ 0.2) Bq kg -1 to (57.8 @ 0.3) Bq kg - 1. In five collected mushroom species, the activity of 137Cs is in the range between (4.1 @ 0.5) Bq kg -1 and (610 @ 5) Bq kg -1 , the lowest and the highest values referreing to Clitocybe nebularis and Gymnopus dryophilus, respectively. Parasitic mushrooms exhibit activity below the minimum detection level. Our preliminary results show and confirm variability of the activity concentration of 137Cs in different parts of this ecosystem. (author)

  19. Star Cluster Structure from Hierarchical Star Formation

    Science.gov (United States)

    Grudic, Michael; Hopkins, Philip; Murray, Norman; Lamberts, Astrid; Guszejnov, David; Schmitz, Denise; Boylan-Kolchin, Michael

    2018-01-01

    Young massive star clusters (YMCs) spanning 104-108 M⊙ in mass generally have similar radial surface density profiles, with an outer power-law index typically between -2 and -3. This similarity suggests that they are shaped by scale-free physics at formation. Recent multi-physics MHD simulations of YMC formation have also produced populations of YMCs with this type of surface density profile, allowing us to narrow down the physics necessary to form a YMC with properties as observed. We show that the shallow density profiles of YMCs are a natural result of phase-space mixing that occurs as they assemble from the clumpy, hierarchically-clustered configuration imprinted by the star formation process. We develop physical intuition for this process via analytic arguments and collisionless N-body experiments, elucidating the connection between star formation physics and star cluster structure. This has implications for the early-time structure and evolution of proto-globular clusters, and prospects for simulating their formation in the FIRE cosmological zoom-in simulations.

  20. Fractionation of 137Cs and Pu in natural peatland

    International Nuclear Information System (INIS)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-01-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137 Cs and its increase in residual fraction with depth. • High 137 Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

  1. Rejuvenation of the Innocent Bystander: Testing Spin-Up in a Dwarf Carbon Star Sample

    Science.gov (United States)

    Green, Paul

    2014-09-01

    Carbon stars (C>O) were long assumed to all be giants, because only AGB stars dredge up significant carbon into their atmospheres. We now know that dwarf carbon (dC) stars are actually far more common than C giants. These dC stars are hypothesized to have accreted C-rich envelope material from an AGB companion, in systems that have likely undergone a planetary nebula phase, eventually yielding a white dwarf and a dC star that has gained both significant mass and angular momentum. To test whether the X-ray emission strength and spectral properties are consistent with a rejuvenated dynamo, we propose a Chandra pilot study of dCs selected from the SDSS; some have hot white dwarf companions (indicating more recent mass transfer), and all show Balmer emission lines (a sign of activity).

  2. A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

    International Nuclear Information System (INIS)

    Darko, E.O.; Osae, E.K.; Schandorf, C.

    1998-01-01

    A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

  3. Development of certified matrix reference materials for quality assurance of screening 134Cs and 137Cs in food

    International Nuclear Information System (INIS)

    Ishizu, H.; Yamada, T.

    2013-01-01

    A certified reference material using activated alumina powder certified for activity of 134 Cs and 137 Cs was developed. The results of the verification and the certification are described. The certified reference material can be used for quality assurance of screening activity measurements of 134 Cs and 137 Cs in food/foodstuffs. Commercially available equipments were experimentally tested using the CRM and another CRM including 40 K. The results of these tests are also shown. - Highlights: • CRM of 134 Cs and 137 Cs using activated alumina was developed. • CRM including 134 Cs, 137 Cs and 40 K was also developed. • Results of experimental performance test of commercial inspection equipments using CRMs were shown

  4. Cesium platinide hydride 4Cs{sub 2}Pt.CsH: an intermetallic double salt featuring metal anions

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, Volodymyr [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Mudring, Anja-Verena [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa, 50011-3111 (United States)

    2016-11-14

    With Cs{sub 9}Pt{sub 4}H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs{sub 9}Pt{sub 4}H exhibits a complex crystal structure containing Cs{sup +} cations, Pt{sup 2-} and H{sup -} anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs{sub 2}Pt, and the salt cesium hydride CsH according to Cs{sub 9}Pt{sub 4}H≡4 Cs{sub 2}Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Rejuvenation of the Innocent Bystander: Testing Spin-Up in Dwarf Carbon Stars

    Science.gov (United States)

    Green, Paul

    2013-09-01

    Carbon stars (C>O) were long assumed to all be giants, because only AGB stars dredge up significant carbon into their atmospheres. We now know that dwarf carbon (dC) stars are actually far more common than C giants. These dCs are hypothesized to have accreted C-rich envelope material from an AGB companion, in systems that have likely undergone a planetary nebula phase, eventually yielding a white dwarf and a dC that has gained both significant mass and angular momentum. To test whether the X-ray emission strength and spectral properties are consistent with a rejuvenated dynamo, we propose a Chandra pilot study of dCs selected from the SDSS; some have hot white dwarf companions (indicating more recent mass transfer), and all show Balmer emission lines (a sign of activity).

  6. Making star teams out of star players.

    Science.gov (United States)

    Mankins, Michael; Bird, Alan; Root, James

    2013-01-01

    Top talent is an invaluable asset: In highly specialized or creative work, for instance, "A" players are likely to be six times as productive as "B" players. So when your company has a crucial strategic project, why not multiply all that firepower and have a team of your best performers tackle it? Yet many companies hesitate to do this, believing that all-star teams don't work: Big egos will get in the way. The stars won't be able to work with one another. They'll drive the team Leader crazy. Mankins, Bird, and Root of Bain & Company believe it's time to set aside that thinking. They have seen all-star teams do extraordinary work. But there is a right way and a wrong way to organize them. Before you can even begin to assemble such a team, you need to have the right talent management practices, so you hire and develop the best people and know what they're capable of. You have to give the team appropriate incentives and leaders and support staffers who are stars in their own right. And projects that are ill-defined or small scale are not for all-star teams. Use them only for critical missions, and make sure their objectives are clear. Even with the right setup, things can still go wrong. The wise executive will take steps to manage egos, prune non-team-players, and prevent average coworkers from feeling completely undervalued. She will also invest a lot of time in choosing the right team Leader and will ask members for lots of feedback to monitor how that leader is doing.

  7. Stability of boson stars

    International Nuclear Information System (INIS)

    Gleiser, M.

    1988-01-01

    Boson stars are gravitationally bound, spherically symmetric equilibrium configurations of cold, free, or interacting complex scalar fields phi. As these equilibrium configurations naturally present local anisotropy, it is sensible to expect departures from the well-known stability criteria for fluid stars. With this in mind, I investigate the dynamical instability of boson stars against charge-conserving, small radial perturbations. Following the method developed by Chandrasekhar, a variational base for determining the eigenfrequencies of the perturbations is found. This approach allows one to find numerically an upper bound for the central density where dynamical instability occurs. As applications of the formalism, I study the stability of equilibrium configurations obtained both for the free and for the self-interacting [with V(phi) = (λ/4)chemical bondphichemical bond 4 ] massive scalar field phi. Instabilities are found to occur not for the critical central density as in fluid stars but for central densities considerably higher. The departure from the results for fluid stars is sensitive to the coupling λ; the higher the value of λ, the more the stability properties of boson stars approach those of a fluid star. These results are linked to the fractional anisotropy at the radius of the configuration

  8. From clouds to stars

    International Nuclear Information System (INIS)

    Elmegreen, B.G.

    1982-01-01

    At the present time, the theory of star formation must be limited to what we know about the lowest density gas, or about the pre-main sequence stars themselves. We would like to understand two basic processes: 1) how star-forming clouds are created from the ambient interstellar gas in the first place, and 2) how small parts of these clouds condense to form individual stars. We are interested also in knowing what pre-main sequence stars are like, and how they can interact with their environment. These topics are reviewed in what follows. In this series of lectures, what we know about the formation of stars is tentatively described. The lectures begin with a description of the interstellar medium, and then they proceed along the same direction that a young star would follow during its creation, namely from clouds through the collapse phase and onto the proto-stellar phase. The evolution of viscous disks and two models for the formation of the solar system are described in the last lectures. The longest lectures, and the topics that are covered in most detail, are not necessarily the ones for which we have the most information. Physically intuitive explanations for the various processes are emphasized, rather then mathematical explanations. In some cases, the mathematical aspects are developed as well, but only when the equations can be used to give important numerical values for comparison with the observations

  9. Using Multiple Paths in NoCs for Guaranteed Resource Allocation and Improved Best Effort Performance in NoCs.

    NARCIS (Netherlands)

    Ovadia, I.; Ha, Y.; Corporaal, H.

    2005-01-01

    Networks-on-Chips (NoCs) provide communication platforms to Systems-on-Chips (SoCs). In NoCs, channels are generally shared between traffic flows, resulting in contention. However, certain flows require delivery guarantees. Differentiated quality-of-service (QoS) is achieved by providing guaranteed

  10. Nuclear physics of stars

    CERN Document Server

    Iliadis, Christian

    2007-01-01

    Thermonuclear reactions in stars is a major topic in the field of nuclear astrophysics, and deals with the topics of how precisely stars generate their energy through nuclear reactions, and how these nuclear reactions create the elements the stars, planets and - ultimately - we humans consist of. The present book treats these topics in detail. It also presents the nuclear reaction and structure theory, thermonuclear reaction rate formalism and stellar nucleosynthesis. The topics are discussed in a coherent way, enabling the reader to grasp their interconnections intuitively. The book serves bo

  11. Entropy Production of Stars

    Directory of Open Access Journals (Sweden)

    Leonid M. Martyushev

    2015-06-01

    Full Text Available The entropy production (inside the volume bounded by a photosphere of main-sequence stars, subgiants, giants, and supergiants is calculated based on B–V photometry data. A non-linear inverse relationship of thermodynamic fluxes and forces as well as an almost constant specific (per volume entropy production of main-sequence stars (for 95% of stars, this quantity lies within 0.5 to 2.2 of the corresponding solar magnitude is found. The obtained results are discussed from the perspective of known extreme principles related to entropy production.

  12. Carbon Stars T. Lloyd Evans

    Indian Academy of Sciences (India)

    that the features used in estimating luminosities of ordinary giant stars are just those whose abundance ... This difference between the spectral energy distributions (SEDs) of CH stars and the. J stars, which belong to .... that the first group was binaries, as for the CH stars of the solar vicinity, while those of the second group ...

  13. Distribution of 137Cs in the American Coot (Fulica americana)

    International Nuclear Information System (INIS)

    Potter, C.M.; Brisbin, I.L. Jr.; McDowell, S.G.; Whicker, F.W.

    1989-01-01

    Caesium-137 concentrations were determined for major tissue and organ components of Americal Coots (Fulica americana) wintering on two contaminated reactor cooling reservoirs on the US Department of Energy's Savannah River Plant. Concentrations reflected the relative contamination levels of the two reservoirs. A low ratio of 137 Cs in gut contents to that in muscle indicated that the coots used in the study were established winter residents and tissue 137 Cs had probably reached equilibrium with intake. The contributions of each component to the whole body weight and total 137 Cs body burden were calculated. Skeletal muscle exhibited the highest 137 Cs concentrations and comprised 35% of the total 137 Cs body burden. Gut contents represented 17% of the total body burden. Various other organs were intermediate and bone exhibited the lowest 137 Cs concentrations. Linear regressions were determined for 137 Cs concentrations in skeletal muscle, liver, kidney, gastrointestinal (GI) tract tissue and gut contents, as functions of whole-body concentrations. (author)

  14. Water culture of the rice containing Cs-137

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Keum, Dong Kwon; Lim, Kwang Muk; Jun, In; Park, Doo Won

    2008-10-01

    Pot experiments were carried out in a greenhouse in order to produce Cs-137-containing rice seeds as a source material for use in manufacturing reference rice samples of a high Cs-137 activity. Two kinds of soil were used and two pots were prepared for each kind of soil. Rice plants were water-cultured in the pots and Cs-137 was applied to the surface water to induce a Cs-137 contamination of rice seeds via a plant uptake of Cs-137. Mature rice plants were harvested and Cs-137-containing rice seeds were obtained after some treatment of the harvested plants. These produced rice seeds are going to be provided for the KRISS so as to be used in manufacturing reference rice samples for Cs-137

  15. 133Cs NMR investigation of 2D frustrated Heisenberg antiferromagnet, Cs2CuCl4

    Science.gov (United States)

    Vachon, M.-A.; Kundhikanjana, W.; Straub, A.; Mitrovic, V. F.; Reyes, A. P.; Kuhns, P.; Coldea, R.; Tylczynski, Z.

    2006-10-01

    We report 133Cs nuclear magnetic resonance (NMR) measurements on the 2D frustrated Heisenberg antiferromagnet Cs2CuCl4 down to 2 K and up to 15 T. We show that 133Cs NMR is a good probe of the magnetic degrees of freedom in this material. Cu spin degrees of freedom are sensed through a strong anisotropic hyperfine coupling. The spin excitation gap opens above the critical saturation field. The gap value was determined from the activation energy of the nuclear spin-lattice relaxation rate in a magnetic field applied parallel to the Cu chains (\\skew3\\hat{b} axis). The values of the g-factor and the saturation field are consistent with the neutron-scattering and magnetization results. The measurements of the spin spin relaxation time are exploited to show that no structural changes occur down to the lowest temperatures investigated.

  16. AgSTAR

    Science.gov (United States)

    AgSTAR promotes biogas recovery projects, which generate renewable energy and other beneficial products from the anaerobic digestion of livestock manure and organic wastes while decreasing greenhouse gas emissions from the agriculture sector.

  17. Orbiting radiation stars

    International Nuclear Information System (INIS)

    Foster, Dean P; Langford, John; Perez-Giz, Gabe

    2016-01-01

    We study a spherically symmetric solution to the Einstein equations in which the source, which we call an orbiting radiation star (OR-star), is a compact object consisting of freely falling null particles. The solution avoids quantum scale regimes and hence neither relies upon nor ignores the interaction of quantum mechanics and gravitation. The OR-star spacetime exhibits a deep gravitational well yet remains singularity free. In fact, it is geometrically flat in the vicinity of the origin, with the flat region being of any desirable scale. The solution is observationally distinct from a black hole because a photon from infinity aimed at an OR-star escapes to infinity with a time delay. (paper)

  18. Cataclysmic Variable Stars

    Science.gov (United States)

    Hellier, Coel

    2001-01-01

    Cataclysmic variable stars are the most variable stars in the night sky, fluctuating in brightness continually on timescales from seconds to hours to weeks to years. The changes can be recorded using amateur telescopes, yet are also the subject of intensive study by professional astronomers. That study has led to an understanding of cataclysmic variables as binary stars, orbiting so closely that material transfers from one star to the other. The resulting process of accretion is one of the most important in astrophysics. This book presents the first account of cataclysmic variables at an introductory level. Assuming no previous knowledge of the field, it explains the basic principles underlying the variability, while providing an extensive compilation of cataclysmic variable light curves. Aimed at amateur astronomers, undergraduates, and researchers, the main text is accessible to those with no mathematical background, while supplementary boxes present technical details and equations.

  19. SX Phoenicis stars

    International Nuclear Information System (INIS)

    Nemec, J.; Mateo, M.

    1990-01-01

    The purpose of this paper is to review the basic observational information concerning SX Phe stars, including recent findings such as the discovery of about 40 low-luminosity variable stars in the Carina dwarf galaxy and identification of at least one SX Phe star in the metal-rich globular cluster M71. Direct evidence supporting the hypothesis that at least some BSs are binary systems comes from the discovery of two contact binaries and a semidetached binary among the 50 BSs in the globular cluster NGC 5466. Since these systems will coalesce on a time scale 500 Myr, it stands to reason that many (if not most) BSs are coalesced binaries. The merger hypothesis also explains the relatively-large masses (1.0-1.2 solar masses) that have been derived for SX Phe stars and halo BSs, and may also account for the nonvariable BSs in the 'SX Phe instability strip'. 132 refs

  20. Sounds of a Star

    Science.gov (United States)

    2001-06-01

    Acoustic Oscillations in Solar-Twin "Alpha Cen A" Observed from La Silla by Swiss Team Summary Sound waves running through a star can help astronomers reveal its inner properties. This particular branch of modern astrophysics is known as "asteroseismology" . In the case of our Sun, the brightest star in the sky, such waves have been observed since some time, and have greatly improved our knowledge about what is going on inside. However, because they are much fainter, it has turned out to be very difficult to detect similar waves in other stars. Nevertheless, tiny oscillations in a solar-twin star have now been unambiguously detected by Swiss astronomers François Bouchy and Fabien Carrier from the Geneva Observatory, using the CORALIE spectrometer on the Swiss 1.2-m Leonard Euler telescope at the ESO La Silla Observatory. This telescope is mostly used for discovering exoplanets (see ESO PR 07/01 ). The star Alpha Centauri A is the nearest star visible to the naked eye, at a distance of a little more than 4 light-years. The new measurements show that it pulsates with a 7-minute cycle, very similar to what is observed in the Sun . Asteroseismology for Sun-like stars is likely to become an important probe of stellar theory in the near future. The state-of-the-art HARPS spectrograph , to be mounted on the ESO 3.6-m telescope at La Silla, will be able to search for oscillations in stars that are 100 times fainter than those for which such demanding observations are possible with CORALIE. PR Photo 23a/01 : Oscillations in a solar-like star (schematic picture). PR Photo 23b/01 : Acoustic spectrum of Alpha Centauri A , as observed with CORALIE. Asteroseismology: listening to the stars ESO PR Photo 23a/01 ESO PR Photo 23a/01 [Preview - JPEG: 357 x 400 pix - 96k] [Normal - JPEG: 713 x 800 pix - 256k] [HiRes - JPEG: 2673 x 3000 pix - 2.1Mb Caption : PR Photo 23a/01 is a graphical representation of resonating acoustic waves in the interior of a solar-like star. Red and blue

  1. Spectrophotometry of carbon stars

    International Nuclear Information System (INIS)

    Gow, C.E.

    1975-01-01

    Observations of over one hundred carbon stars have been made with the Indiana rapid spectral scanner in the red and, when possible, in the visual and blue regions of the spectrum. Five distinct subtypes of carbon stars (Barium, CH, R, N, and hydrogen deficient) are represented in the list of observed stars, although the emphasis was placed on the N stars when the observations were made. The rapid scanner was operated in the continuous sweep mode with the exit slit set at twenty angstroms, however, seeing fluctuations and guiding errors smear the spectrum to an effective resolution of approximately thirty angstroms. Nightly observations of Hayes standard stars yielded corrections for atmospheric extinction and instrumental response. The reduction scheme rests on two assumptions, that thin clouds are gray absorbers and the wavelength dependence of the sky transparency does not change during the course of the night. Several stars have been observed in the blue region of the spectrum with the Indiana SIT vidicon spectrometer at two angstroms resolution. It is possible to derive a color temperature for the yellow--red spectral region by fitting a black-body curve through two chosen continuum points. Photometric indices were calculated relative to the blackbody curve to measure the C 2 Swan band strength, the shape of the CN red (6,1) band to provide a measure of the 12 C/ 13 C isotope ratio, and in the hot carbon stars (Barium, CH, and R stars) the strength of an unidentified feature centered at 400 angstroms. An extensive abundance grid of model atmospheres was calculated using a modified version of the computer code ATLAS

  2. Young Stars with SALT

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Adric R. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Alam, Munazza K.; Rice, Emily L.; Cruz, Kelle L. [Department of Astrophysics, The American Museum of Natural History, New York, NY 10024 (United States); Henry, Todd J., E-mail: arr@caltech.edu [RECONS Institute, Chambersburg, PA (United States)

    2017-05-10

    We present a spectroscopic and kinematic analysis of 79 nearby M dwarfs in 77 systems. All of these dwarfs are low-proper-motion southern hemisphere objects and were identified in a nearby star survey with a demonstrated sensitivity to young stars. Using low-resolution optical spectroscopy from the Red Side Spectrograph on the South African Large Telescope, we have determined radial velocities, H-alpha, lithium 6708 Å, and potassium 7699 Å equivalent widths linked to age and activity, and spectral types for all of our targets. Combined with astrometric information from literature sources, we identify 44 young stars. Eighteen are previously known members of moving groups within 100 pc of the Sun. Twelve are new members, including one member of the TW Hydra moving group, one member of the 32 Orionis moving group, 9 members of Tucana-Horologium, one member of Argus, and two new members of AB Doradus. We also find 14 young star systems that are not members of any known groups. The remaining 33 star systems do not appear to be young. This appears to be evidence of a new population of nearby young stars not related to the known nearby young moving groups.

  3. STAR facility tritium accountancy

    International Nuclear Information System (INIS)

    Pawelko, R. J.; Sharpe, J. P.; Denny, B. J.

    2008-01-01

    The Safety and Tritium Applied Research (STAR) facility has been established to provide a laboratory infrastructure for the fusion community to study tritium science associated with the development of safe fusion energy and other technologies. STAR is a radiological facility with an administrative total tritium inventory limit of 1.5 g (14,429 Ci) [1]. Research studies with moderate tritium quantities and various radionuclides are performed in STAR. Successful operation of the STAR facility requires the ability to receive, inventory, store, dispense tritium to experiments, and to dispose of tritiated waste while accurately monitoring the tritium inventory in the facility. This paper describes tritium accountancy in the STAR facility. A primary accountancy instrument is the tritium Storage and Assay System (SAS): a system designed to receive, assay, store, and dispense tritium to experiments. Presented are the methods used to calibrate and operate the SAS. Accountancy processes utilizing the Tritium Cleanup System (TCS), and the Stack Tritium Monitoring System (STMS) are also discussed. Also presented are the equations used to quantify the amount of tritium being received into the facility, transferred to experiments, and removed from the facility. Finally, the STAR tritium accountability database is discussed. (authors)

  4. Asteroseismology of white dwarf stars

    OpenAIRE

    Córsico, A. H.

    2014-01-01

    Most of low- and intermediate-mass stars that populate the Universe will end their lives as white dwarf stars. These ancient stellar remnants have encrypted inside a precious record of the evolutionary history of the progenitor stars, providing a wealth of information about the evolution of stars, star formation, and the age of a variety of stellar populations, such as our Galaxy and open and globular clusters. While some information like surface chemical composition, temperature and gravity ...

  5. Foundation Flash CS4 for Designers

    CERN Document Server

    Green, Tom

    2008-01-01

    In this book, you'll learn:* How to create effective animations using the new Motion Editor and animation tools * How to use the new 3D features to animate objects in 3D space * Best-practice tips and techniques from some of the top Flash practitioners on the planet * How to create captioned video and full-screen video, and deploy HD video using Flash * Techniques for using the Flash UI components as well as XML documents to create stunning,interactive presentations If you're a Flash designer looking for a solid overview of Flash CS4, this book is for you. Through the use of solid and practica

  6. Reactor Configuration Development for ARIES-CS

    International Nuclear Information System (INIS)

    Ku LP

    2005-01-01

    New compact, quasi-axially symmetric stellarator configurations have been developed as part of the ARIES-CS reactor studies. These new configurations have good plasma confinement and transport properties, including low losses of α particles and good integrity of flux surfaces at high β. We summarize the recent progress by showcasing two attractive classes of configurations--configurations with judiciously chosen rotational transforms to avoid undesirable effects of low order resonances on the flux surface integrity and configurations with very small aspect ratios (∼2.5) that have excellent quasi-axisymmetry and low field ripples

  7. 137Cs - Brachytherapy sources : a technology scenario

    International Nuclear Information System (INIS)

    Varma, R.N.

    2001-01-01

    Cancer has emerged as one of the major cause of morbidity and mortality all over the world. India houses world's second largest population and registers 4-5 lakhs new cancer cases every year. Cancer of cervix is most common form of malignancy among Indian women. Radiation therapy, especially intracavity brachytherapy in conjunction with other modalities like surgery, chemotherapy has been found to be highly effective for the management and control of cervical carcinoma at all stages. A technology has been developed indigenously for the fabrication of 137 Cs sources for brachytherapy applications

  8. Dreamweaver CS55 The Missing Manual

    CERN Document Server

    McFarland, David

    2011-01-01

    Dreamweaver is the tool most widely used for designing and managing professional-looking websites, but it's a complex program. That's where Dreamweaver CS5.5: The Missing Manual comes in. With its jargon-free explanations, 13 hands-on tutorials, and savvy advice from Dreamweaver expert Dave McFarland, you'll master this versatile program with ease. Get A to Z guidance. Go from building your first web page to creating interactive, database-driven sites.Build skills as you learn. Apply your knowledge through tutorials and downloadable practice files.Create a state-of-the-art website. Use powerf

  9. Adobe Photoshop CS5 for photographers

    CERN Document Server

    Evening, Martin

    2010-01-01

    With the new edition of this proven bestseller, Photoshop users can master the power of Photoshop CS5 with internationally renowned photographer and Photoshop hall-of-famer Martin Evening by their side.  In this acclaimed reference work, Martin covers everything from the core aspects of working in Photoshop to advanced techniques for professional results. Subjects covered include organizing a digital workflow, improving creativity, output, automating Photoshop, and using Camera RAW. The style of the book is extremely clear, with real examples, diagrams, illustrations, and step-by-step ex

  10. Flash CS5 The Missing Manual

    CERN Document Server

    Grover, Chris

    2010-01-01

    Once you know how to use Flash, you can create everything from simple animations to high-end desktop applications, but it's a complex tool that can be difficult to master on your own-unless you have this Missing Manual. This book will help you learn all you need to know about Flash CS5 to create animations that bring your ideas to life. Learn animation basics. Find everything you need to know to get started with FlashMaster the Flash tools. Learn the animation and effects toolset, with clear explanations and hands-on examplesUse 3D effects. Rotate and put objects in motion in three dimensions

  11. 137CS in cod from Barents sea

    International Nuclear Information System (INIS)

    Kellermann, H.-J.; Kanisch, G.; Krueger, A.

    2003-01-01

    After publication of the Yablovkov report about dumping of radioactive waste by the former Soviet Union the Institute for Fishery Ecology has analysed fish from Barents Sea for radioactivity. In all studies 137 Cs concentrations in cod fillet showed a clear dependance from fish length. Results from an analysis of covariance for cod of 70 cm length have minor changes within Barents Sea and indicate a rapid decay to a value as is expected for marine fish which is only influenced by global fallout. (orig.)

  12. Foundation Flash CS5 for Designers

    CERN Document Server

    Green, T

    2010-01-01

    Flash is one of the most engaging, innovative, and versatile technologies available - allowing the creation of anything from animated banners and simple cartoons to Rich Internet Applications, interactive videos, and dynamic user interfaces for web sites, kiosks, devices, or DVDs. The possibilities are endless, and now it just got better. Flash CS5 boasts a host of new features, including better support for mobile devices, a whole new animation engine enabling full manipulation of tweens and paths, custom easing, improved inverse kinematics, a revamped timeline, built-in 3D, and much more. Thi

  13. A robust star identification algorithm with star shortlisting

    Science.gov (United States)

    Mehta, Deval Samirbhai; Chen, Shoushun; Low, Kay Soon

    2018-05-01

    A star tracker provides the most accurate attitude solution in terms of arc seconds compared to the other existing attitude sensors. When no prior attitude information is available, it operates in "Lost-In-Space (LIS)" mode. Star pattern recognition, also known as star identification algorithm, forms the most crucial part of a star tracker in the LIS mode. Recognition reliability and speed are the two most important parameters of a star pattern recognition technique. In this paper, a novel star identification algorithm with star ID shortlisting is proposed. Firstly, the star IDs are shortlisted based on worst-case patch mismatch, and later stars are identified in the image by an initial match confirmed with a running sequential angular match technique. The proposed idea is tested on 16,200 simulated star images having magnitude uncertainty, noise stars, positional deviation, and varying size of the field of view. The proposed idea is also benchmarked with the state-of-the-art star pattern recognition techniques. Finally, the real-time performance of the proposed technique is tested on the 3104 real star images captured by a star tracker SST-20S currently mounted on a satellite. The proposed technique can achieve an identification accuracy of 98% and takes only 8.2 ms for identification on real images. Simulation and real-time results depict that the proposed technique is highly robust and achieves a high speed of identification suitable for actual space applications.

  14. Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3.

    Science.gov (United States)

    Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

    2017-09-07

    Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX 3 , X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr 3 , its synthesis can also yield nanocrystals of Cs 4 PbBr 6 and the properties of the two are easily confused. Here, we investigate in detail the optical characteristics of simultaneously synthesized green-emitting CsPbBr 3 and insulating Cs 4 PbBr 6 nanocrystals. We demonstrate that, in this case, the two materials inevitably hybridize, forming nanoparticles with a spherical shape. The actual amount of these Cs 4 PbBr 6 nanocrystals and nanohybrids increases for synthesis at lower temperatures, i.e., the condition typically used for the development of perovskite CsPbBr 3 nanocrystals with smaller sizes. We use state-of-the-art electron energy loss spectroscopy to characterize nanoparticles at the single object level. This method allows distinguishing between optical characteristics of a pure Cs 4 PbBr 6 and CsPbBr 3 nanocrystal and their nanohybrid. In this way, we resolve some of the recent misconceptions concerning possible visible absorption and emission of Cs 4 PbBr 6 . Our method provides detailed structural characterization, and combined with modeling, we conclusively identify the nanospheres as CsPbBr 3 /Cs 4 PbBr 6 hybrids. We show that the two phases are independent of each other's presence and merge symbiotically. Herein, the optical characteristics of the parent materials are preserved, allowing for an increased absorption in the UV due to Cs 4 PbBr 6 , accompanied by the distinctive efficient green emission resulting from CsPbBr 3 .

  15. Luminescent CsPbI.sub.3./sub. and Cs.sub.4./sub.PbI.sub.6./sub. aggregates in annealed CsI:Pb crystals

    Czech Academy of Sciences Publication Activity Database

    Babin, V.; Fabeni, P.; Nikl, Martin; Nitsch, Karel; Pazzi, G.P.; Zazubovich, S.

    2001-01-01

    Roč. 226, č. 2 (2001), s. 419-428 ISSN 0370-1972 Institutional research plan: CEZ:AV0Z1010914 Keywords : CsPbI 3 * Cs 4 PbI 6 * nanoaggregates * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.873, year: 2001

  16. Photodissociation of CS from Excited Rovibrational Levels

    Science.gov (United States)

    Pattillo, R. J.; Cieszewski, R.; Stancil, P. C.; Forrey, R. C.; Babb, J. F.; McCann, J. F.; McLaughlin, B. M.

    2018-05-01

    Accurate photodissociation cross sections have been computed for transitions from the X 1Σ+ ground electronic state of CS to six low-lying excited electronic states. New ab initio potential curves and transition dipole moment functions have been obtained for these computations using the multi-reference configuration interaction approach with the Davidson correction (MRCI+Q) and aug-cc-pV6Z basis sets. State-resolved cross sections have been computed for transitions from nearly the full range of rovibrational levels of the X 1Σ+ state and for photon wavelengths ranging from 500 Å to threshold. Destruction of CS via predissociation in highly excited electronic states originating from the rovibrational ground state is found to be unimportant. Photodissociation cross sections are presented for temperatures in the range between 1000 and 10,000 K, where a Boltzmann distribution of initial rovibrational levels is assumed. Applications of the current computations to various astrophysical environments are briefly discussed focusing on photodissociation rates due to the standard interstellar and blackbody radiation fields.

  17. The radiation chemistry of the Cs-7SB modifier used in Cs and Sr extraction

    International Nuclear Information System (INIS)

    Swancutt, Katy L.; Cullen, Thomas D.; Mezyk, Stephen P.; Elias, Gracy; Bauer, William F.; Peterman, Dean R.; Riddle, Catherine L.; Ball, R. Duane; Mincher, Bruce J.; Muller, James J.

    2011-01-01

    The compound 1-(2,2,3,3,-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, also called Cs-7SB, is used as a solvent modifier in formulations containing calixarenes and crown ethers for cesium and/or strontium extraction from nuclear waste solutions. The compound solvates complexes of both metals and concentration decreases result in lowered extraction efficiency for both. The use of Cs-7SB in nuclear solvent extraction ensures that it will be exposed to high radiation doses, and thus its radiation chemical robustness is a matter of interest in the design of extraction systems employing it. The behavior of the compound in irradiated solution, both in the presence and absence of a nitric acid aqueous phase was investigated here using steady state and pulsed radiolysis techniques. The rate constants for the aqueous reactions of Cs-7SB with H, OH, NO 3 and NO 2 radicals are reported. UPLC-UV-MS results were used to identify major products of the radiolysis of Cs-7SB in contact with nitric acid, and revealed the production of hydroxylated nitro-derivatives. Reaction mechanisms are proposed and it is concluded that the aryl ether configuration of this molecule makes it especially susceptible to nitration in the presence of radiolytically-produced nitrous acid. Fluoride yields are also given under various conditions.

  18. Postsynthesis Transformation of Insulating Cs4PbBr6 Nanocrystals into Bright Perovskite CsPbBr3 through Physical and Chemical Extraction of CsBr.

    Science.gov (United States)

    Palazon, Francisco; Urso, Carmine; De Trizio, Luca; Akkerman, Quinten; Marras, Sergio; Locardi, Federico; Nelli, Ilaria; Ferretti, Maurizio; Prato, Mirko; Manna, Liberato

    2017-10-13

    Perovskite-related Cs 4 PbBr 6 nanocrystals present a "zero-dimensional" crystalline structure where adjacent [PbBr 6 ] 4- octahedra do not share any corners. We show in this work that these nanocrystals can be converted into "three-dimensional" CsPbBr 3 perovskites by extraction of CsBr. This conversion drastically changes the optoelectronic properties of the nanocrystals that become highly photoluminescent. The extraction of CsBr can be achieved either by thermal annealing (physical approach) or by chemical reaction with Prussian Blue (chemical approach). The former approach can be simply carried out on a dried film without addition of any chemicals but does not yield a full transformation. Instead, reaction with Prussian Blue in solution achieves a full transformation into the perovskite phase. This transformation was also verified on the iodide counterpart (Cs 4 PbI 6 ).

  19. Wolf-Rayet Stars

    Science.gov (United States)

    Hamann, Wolf-Rainer; Sander, Andreas; Todt, Helge

    Nearly 150 years ago, the French astronomers Charles Wolf and Georges Rayet described stars with very conspicuous spectra that are dominated by bright and broad emission lines. Meanwhile termed Wolf-Rayet Stars after their discoverers, those objects turned out to represent important stages in the life of massive stars. As the first conference in a long time that was specifically dedicated to Wolf-Rayet stars, an international workshop was held in Potsdam, Germany, from 1.-5. June 2015. About 100 participants, comprising most of the leading experts in the field as well as as many young scientists, gathered for one week of extensive scientific exchange and discussions. Considerable progress has been reported throughout, e.g. on finding such stars, modeling and analyzing their spectra, understanding their evolutionary context, and studying their circumstellar nebulae. While some major questions regarding Wolf-Rayet stars still remain open 150 years after their discovery, it is clear today that these objects are not just interesting stars as such, but also keystones in the evolution of galaxies. These proceedings summarize the talks and posters presented at the Potsdam Wolf-Rayet workshop. Moreover, they also include the questions, comments, and discussions emerging after each talk, thereby giving a rare overview not only about the research, but also about the current debates and unknowns in the field. The Scientific Organizing Committee (SOC) included Alceste Bonanos (Athens), Paul Crowther (Sheffield), John Eldridge (Auckland), Wolf-Rainer Hamann (Potsdam, Chair), John Hillier (Pittsburgh), Claus Leitherer (Baltimore), Philip Massey (Flagstaff), George Meynet (Geneva), Tony Moffat (Montreal), Nicole St-Louis (Montreal), and Dany Vanbeveren (Brussels).

  20. Models of symbiotic stars

    Science.gov (United States)

    Friedjung, Michael

    1993-01-01

    One of the most important features of symbiotic stars is the coexistence of a cool spectral component that is apparently very similar to the spectrum of a cool giant, with at least one hot continuum, and emission lines from very different stages of ionization. The cool component dominates the infrared spectrum of S-type symbiotics; it tends to be veiled in this wavelength range by what appears to be excess emission in D-type symbiotics, this excess usually being attributed to circumstellar dust. The hot continuum (or continua) dominates the ultraviolet. X-rays have sometimes also been observed. Another important feature of symbiotic stars that needs to be explained is the variability. Different forms occur, some variability being periodic. This type of variability can, in a few cases, strongly suggest the presence of eclipses of a binary system. One of the most characteristic forms of variability is that characterizing the active phases. This basic form of variation is traditionally associated in the optical with the veiling of the cool spectrum and the disappearance of high-ionization emission lines, the latter progressively appearing (in classical cases, reappearing) later. Such spectral changes recall those of novae, but spectroscopic signatures of the high-ejection velocities observed for novae are not usually detected in symbiotic stars. However, the light curves of the 'symbiotic nova' subclass recall those of novae. We may also mention in this connection that radio observations (or, in a few cases, optical observations) of nebulae indicate ejection from symbiotic stars, with deviations from spherical symmetry. We shall give a historical overview of the proposed models for symbiotic stars and make a critical analysis in the light of the observations of symbiotic stars. We describe the empirical approach to models and use the observational data to diagnose the physical conditions in the symbiotics stars. Finally, we compare the results of this empirical

  1. Molecular Cloud Structures and Massive Star Formation in N159

    Science.gov (United States)

    Nayak, O.; Meixner, M.; Fukui, Y.; Tachihara, K.; Onishi, T.; Saigo, K.; Tokuda, K.; Harada, R.

    2018-02-01

    The N159 star-forming region is one of the most massive giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC). We show the 12CO, 13CO, CS molecular gas lines observed with ALMA in N159 west (N159W) and N159 east (N159E). We relate the structure of the gas clumps to the properties of 24 massive young stellar objects (YSOs) that include 10 newly identified YSOs based on our search. We use dendrogram analysis to identify properties of the molecular clumps, such as flux, mass, linewidth, size, and virial parameter. We relate the YSO properties to the molecular gas properties. We find that the CS gas clumps have a steeper size–linewidth relation than the 12CO or 13CO gas clumps. This larger slope could potentially occur if the CS gas is tracing shocks. The virial parameters of the 13CO gas clumps in N159W and N159E are low (<1). The threshold for massive star formation in N159W is 501 M ⊙ pc‑2, and the threshold for massive star formation in N159E is 794 M ⊙ pc‑2. We find that 13CO is more photodissociated in N159E than N159W. The most massive YSO in N159E has cleared out a molecular gas hole in its vicinity. All the massive YSO candidates in N159E have a more evolved spectral energy distribution type in comparison to the YSO candidates in N159W. These differences lead us to conclude that the giant molecular cloud complex in N159E is more evolved than the giant molecular cloud complex in N159W.

  2. Transfer of Chernobyl-derived 134Cs, 137Cs, 131I and 103Ru from flowers to honey and pollen

    International Nuclear Information System (INIS)

    Bunzl, K.; Kracke, W.

    1988-01-01

    The activity concentrations of 137 Cs, 134 Cs, 131 I and 103 Ru were determined separately in honey and pollen samples collected from a single bee colony during several months after the deposition of Chernobyl fallout. The source of each honey and pollen sample was determined by pollen analysis. Although the activity concentrations in honey and pollen varied with time, the concentrations of 137 Cs and 134 Cs were, in general, higher in pollen than in honey. For 103 Ru and 131 I, these differences were comparatively small. The mean 131 I/ 137 Cs and 103 Ru/ 137 Cs ratios were about one order of magnitude higher in honey than in pollen. The mean 131 I/ 103 Ru ratio was about the same for honey and pollen. This observation, in the light of the corresponding nuclide ratios found in the deposition, suggests that 137 Cs, 134 Cs, 131 I and 103 Ru were taken up by the plant leaves and transported to nectar and pollen. The higher activity concentrations of 137 Cs and 134 Cs in pollen, relative to honey, indicate that these radionuclides behave analogously to potassium, which is also found in higher quantities in pollen. (author)

  3. The behavior of radioactive 137Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan

    International Nuclear Information System (INIS)

    Iwamoto, Kazumi; Kimura, Makio; Ando, Kenji; Amano, Hikaru

    2003-01-01

    The behavior of radioactive 137 Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan was studied for the pond water, the sedimentary grains and the soil near the pond. The concentrations of 137 Cs and stable Cs in the pond water ranged from 0.23 to 0.85 Bq/m 3 and from 0.005 to 0.018 mg/m 3 , respectively. The sedimentary grains were sorted by sieving into fractions with diameter from 2 mm to less than 38 μm. The concentrations of 137 Cs and stable Cs in the sorted grains were measured, and those of the adsorbed state were determined by subtracting the concentration of the grain matrix. The adsorbed concentrations increased with decrease in particle diameter and depended less on the kind of samples. The in-situ distribution coefficient Kd depended largely on particle diameter and increased with the decrease in diameter. The values of Kd ranged from about 20 to 1200 m 3 /kg for stable Cs and about 15 to 1000 m 3 /kg for 137 Cs, and the Kd of 137 Cs seemed to be slightly smaller than that of stable Cs. The concentration of stable Cs in the sedimentary mud was found to be close to that of the fine grains. The concentrations of stable Cs in the soil near the pond was about 7.7 mg/kg, and that of 137 Cs was about 0.6 kBq/kg for the surface layer soil and decreased with increase in soil depth. (author)

  4. Circulation of Stars

    Science.gov (United States)

    Boitani, P.

    2016-01-01

    Since the dawn of man, contemplation of the stars has been a primary impulse in human beings, who proliferated their knowledge of the stars all over the world. Aristotle sees this as the product of primeval and perennial “wonder” which gives rise to what we call science, philosophy, and poetry. Astronomy, astrology, and star art (painting, architecture, literature, and music) go hand in hand through millennia in all cultures of the planet (and all use catasterisms to explain certain phenomena). Some of these developments are independent of each other, i.e., they take place in one culture independently of others. Some, on the other hand, are the product of the “circulation of stars.” There are two ways of looking at this. One seeks out forms, the other concentrates on the passing of specific lore from one area to another through time. The former relies on archetypes (for instance, with catasterism), the latter constitutes a historical process. In this paper I present some of the surprising ways in which the circulation of stars has occurred—from East to West, from East to the Far East, and from West to East, at times simultaneously.

  5. Pulsed Cs beam development for the BNL polarized H- source

    International Nuclear Information System (INIS)

    Alessi, J.G.

    1983-01-01

    A pulsed Cs + beam has been developed for use on a polarized H - source. Cesium ion production is by surface ionization using a porous tungsten ionizer. While satisfactory current pulses (5 to 10 mA greater than or equal to 0.5 ms) can be obtained, the pulse shapes are a sensitive function of the ionizer temperature and Cs surface coverage. The beam optical requirements are stringent, and the optics have been studied experimentally for both Cs + and Cs 0 beams. Computer calculations are in good agreement with the observed results. The present source has delivered 2.6 mA of Cs + through the interaction region of the polarized ion source, and as much as 2.0 particle mA of Cs 0 . A new source is being built which is designed to give 15 mA through the interaction region

  6. Four new Delta Scuti stars

    Science.gov (United States)

    Schutt, R. L.

    1991-01-01

    Four new Delta Scuti stars are reported. Power, modified into amplitude, spectra, and light curves are used to determine periodicities. A complete frequency analysis is not performed due to the lack of a sufficient time base in the data. These new variables help verify the many predictions that Delta Scuti stars probably exist in prolific numbers as small amplitude variables. Two of these stars, HR 4344 and HD 107513, are possibly Am stars. If so, they are among the minority of variable stars which are also Am stars.

  7. Dynamic modelling of Cs-137 contamination in Denmark

    International Nuclear Information System (INIS)

    Oehlenschlaeger, M.

    1989-01-01

    The paper describes the structure of a dynamic food-chain transport model for Cs-137 in the Danish terrestrial environment. The model solves a set of linear, coupled differential equations in order to estimate the inventories and concentrations of Cs-137 in the soil, vegetation, animal tissue and animal product as a function of time based on the Cs-137 concentrations in the air after an accidental release. Meteorological conditions and seasonal variations in agricultural practice are included. (orig.)

  8. Uptake of Cs 137 from farmland 1986-1989

    International Nuclear Information System (INIS)

    Holmberg, M.

    1986-12-01

    The basic mechanisms of the accumulation of Cs 137 in grass, corn, oleiferous plants, potatoes etc are described. It is also presented as a function of time after the deposition. Transport of Cs 137 to milk, meat and bacon is described. A prognosis of Cs 137 in food products for the coming two years is made on basis of the estimated data. (G.B.)

  9. Evaluation of caesium atomic fountain NICT-CsF1

    International Nuclear Information System (INIS)

    Kumagai, M.; Ito, H.; Kajita, M.; Hosokawa, M.

    2008-01-01

    In this paper, we describe the first caesium atomic fountain primary frequency standard NICT-CsF1 of National Institute of Information Communications Technology (NICT) in Tokyo, Japan. The structure of the NICT-CsF1 system and evaluation procedure of the systematic frequency shifts and their uncertainties are presented. Typically, NICT-CsF1 has a frequency stability of 4 * 10 -13 /τ 1/2 and a frequency uncertainty of 1.9 * 10 -15 . (authors)

  10. 137Cs in man due to nuclear fallout

    International Nuclear Information System (INIS)

    Poulheim, K.F.

    1981-01-01

    137 Cs has been determined in man with the aid of a whole-body counter. It is shown that the specific 137 Cs content (as related to the potassium content in man) continuously decreased from 1965 through 1974. After a slight increase in 1975, possibly caused by a Chinese atmospheric nuclear test in June 1974, the 137 Cs content again decreased in the following years. (author)

  11. Neutron star/red giant encounters in globular clusters

    International Nuclear Information System (INIS)

    Bailyn, C.D.

    1988-01-01

    The author presents a simple expression for the amount by which xsub(crit) is diminished as a star evolves xsub(crit) Rsub(crit)/R*, where Rsub(crit) is the maximum distance of closest approach between two stars for which the tidal energy is sufficient to bind the system, and R* is the radius of the star on which tides are being raised. Also it is concluded that tidal capture of giants by neutron stars resulting in binary systems is unlikely in globular clusters. However, collisions between neutron stars and red giants, or an alternative process involving tidal capture of a main-sequence star into an initially detached binary system, may result either in rapidly rotating neutron stars or in white dwarf/neutron star binaries. (author)

  12. Heavy Metal Stars

    Science.gov (United States)

    2001-08-01

    La Silla Telescope Detects Lots of Lead in Three Distant Binaries Summary Very high abundances of the heavy element Lead have been discovered in three distant stars in the Milky Way Galaxy . This finding strongly supports the long-held view that roughly half of the stable elements heavier than Iron are produced in common stars during a phase towards the end of their life when they burn their Helium - the other half results from supernova explosions. All the Lead contained in each of the three stars weighs about as much as our Moon. The observations show that these "Lead stars" - all members of binary stellar systems - have been more enriched with Lead than with any other chemical element heavier than Iron. This new result is in excellent agreement with predictions by current stellar models about the build-up of heavy elements in stellar interiors. The new observations are reported by a team of Belgian and French astronomers [1] who used the Coude Echelle Spectrometer on the ESO 3.6-m telescope at the La Silla Observatory (Chile). PR Photo 26a/01 : A photo of HD 196944 , one of the "Lead stars". PR Photo 26b/01 : A CES spectrum of HD 196944 . The build-up of heavy elements Astronomers and physicists denote the build-up of heavier elements from lighter ones as " nucleosynthesis ". Only the very lightest elements (Hydrogen, Helium and Lithium [2]) were created at the time of the Big Bang and therefore present in the early universe. All the other heavier elements we now see around us were produced at a later time by nucleosynthesis inside stars. In those "element factories", nuclei of the lighter elements are smashed together whereby they become the nuclei of heavier ones - this process is known as nuclear fusion . In our Sun and similar stars, Hydrogen is being fused into Helium. At some stage, Helium is fused into Carbon, then Oxygen, etc. The fusion process requires positively charged nuclei to move very close to each other before they can unite. But with increasing

  13. Atomic diffusion in stars

    CERN Document Server

    Michaud, Georges; Richer, Jacques

    2015-01-01

    This book gives an overview of atomic diffusion, a fundamental physical process, as applied to all types of stars, from the main sequence to neutron stars. The superficial abundances of stars as well as their evolution can be significantly affected. The authors show where atomic diffusion plays an essential role and how it can be implemented in modelling.  In Part I, the authors describe the tools that are required to include atomic diffusion in models of stellar interiors and atmospheres. An important role is played by the gradient of partial radiative pressure, or radiative acceleration, which is usually neglected in stellar evolution. In Part II, the authors systematically review the contribution of atomic diffusion to each evolutionary step. The dominant effects of atomic diffusion are accompanied by more subtle effects on a large number of structural properties throughout evolution. One of the goals of this book is to provide the means for the astrophysicist or graduate student to evaluate the importanc...

  14. Dynamical Boson Stars

    Directory of Open Access Journals (Sweden)

    Steven L. Liebling

    2012-05-01

    Full Text Available The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called geons, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name boson stars. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.

  15. GRACE star camera noise

    Science.gov (United States)

    Harvey, Nate

    2016-08-01

    Extending results from previous work by Bandikova et al. (2012) and Inacio et al. (2015), this paper analyzes Gravity Recovery and Climate Experiment (GRACE) star camera attitude measurement noise by processing inter-camera quaternions from 2003 to 2015. We describe a correction to star camera data, which will eliminate a several-arcsec twice-per-rev error with daily modulation, currently visible in the auto-covariance function of the inter-camera quaternion, from future GRACE Level-1B product releases. We also present evidence supporting the argument that thermal conditions/settings affect long-term inter-camera attitude biases by at least tens-of-arcsecs, and that several-to-tens-of-arcsecs per-rev star camera errors depend largely on field-of-view.

  16. Molecules in stars

    International Nuclear Information System (INIS)

    Tsuji, T.

    1986-01-01

    Recently, research related to molecules in stars has rapidly expanded because of progress in related fields. For this reason, it is almost impossible to cover all the topics related to molecules in stars. Thus, here the authors focus their attention on molecules in the atmospheres of cool stars and do not cover in any detail topics related to circumstellar molecules originating from expanding envelopes located far from the stellar surface. However, the authors do discuss molecules in quasi-static circumstellar envelopes (a recently discovered new component of circumstellar envelopes) located near the stellar surface, since molecular lines originating from such envelopes show little velocity shift relative to photospheric lines, and hence they directly affect the interpretation and analysis of stellar spectra

  17. CARBON NEUTRON STAR ATMOSPHERES

    International Nuclear Information System (INIS)

    Suleimanov, V. F.; Klochkov, D.; Werner, K.; Pavlov, G. G.

    2014-01-01

    The accuracy of measuring the basic parameters of neutron stars is limited in particular by uncertainties in the chemical composition of their atmospheres. For example, the atmospheres of thermally emitting neutron stars in supernova remnants might have exotic chemical compositions, and for one of them, the neutron star in Cas A, a pure carbon atmosphere has recently been suggested by Ho and Heinke. To test this composition for other similar sources, a publicly available detailed grid of the carbon model atmosphere spectra is needed. We have computed this grid using the standard local thermodynamic equilibrium approximation and assuming that the magnetic field does not exceed 10 8  G. The opacities and pressure ionization effects are calculated using the Opacity Project approach. We describe the properties of our models and investigate the impact of the adopted assumptions and approximations on the emergent spectra

  18. Instability and star evolution

    International Nuclear Information System (INIS)

    Mirzoyan, L.V.

    1981-01-01

    The observational data are discussed which testify that the phenomena of dynamical instability of stars and stellar systems are definite manifestations of their evolution. The study of these phenomena has shown that the instability is a regular phase of stellar evolution. It has resulted in the recognition of the most important regularities of the process of star formation concerning its nature. This became possible due to the discovery in 1947 of stellar associations in our Galaxy. The results of the study of the dynamical instability of stellar associations contradict the predictions of classical hypothesis of stellar condensation. These data supplied a basis for a new hypothesis on the formation of stars and nebulae by the decay of superdense protostars [ru

  19. The twinkling of stars

    International Nuclear Information System (INIS)

    Jakeman, E.; Parry, G.; Pike, E.R.; Pusey, P.N.

    1978-01-01

    This article collects together some of the main ideas and experimental results on the twinkling of stars. Statistical methods are used to characterise the features of the scintillation and to investigate the ways in which these depend on the zenith angle of the star, the bandwidth of the light and various other parameters. Some new results are included which demonstrate the advantages of using photon counting methods in experiments on stellar scintillation. Since the twinkling of stars is a consequence of the turbulence in the Earth's magnetic atmosphere then measurements can be used to deduce some features of the structure of the turbulence. Some of the experiments designed to do this are discussed and the results reported. (author)

  20. Study of Cs recovery by extraction chromatography (2)

    International Nuclear Information System (INIS)

    Hoshi, Harutaka; Zhang, Anyun; Uchida, Hiromi; Kuraoka, Etsushu

    2005-02-01

    In order to apply CalixR14 extractant to extraction chromatography for Cs separation, basic characteristics of CalixR14 adsorbent were studied. CalixR14 impregnated resin and CalixR14 + TBP impregnated resin were prepared. CalixR14 extractant showed no adsorption for Cs by liquid-liquid extraction and CalixR14 impregnated resin also showed no adsorption for Cs. Therefore, it is concluded that CalixR14 itself has no affinity for Cs. On the other hand, Cs was adsorbed onto CalixR14-TBP impregnated resin from a concentrated nitric acid solution. The distribution coefficients of Cs were more than 10 cm 3 /g from 2 to 6 M nitric acid. While Rb showed week adsorption, Na, K, Sr and La showed no adsorption and separation factor was over 100. A slight amount of CalixR14 and TBP was leaked from impregnated resin into the aqueous phase. Separation from simulated liquid waste was carried out by using a column packed with CalixR14-TBP adsorbent. Na, K, Sr and La were not adsorbed onto the column, however, Cs and Rb were adsorbed onto the column. Cs and Rb were eluted from the column by water. Cs and Rb were quantitatively recovered. (author)

  1. Behaviour of 134Cs in the aquatic ecosystems

    International Nuclear Information System (INIS)

    Xu Yinliang; Chen Chuanqun

    1992-07-01

    The diminution of 134 Cs in the aquatic phases and the absorption of 134 Cs by aquatic lives observe the exponential expression. i.e. Y Ae be . The relationships between the enrichment factor of 134 Cs(K) and the time(t) in the aquatic lives can be represented by a linear equation, K A + Bt. The value of K in the Alternanthera philoxeroides was about 560. That can be used for monitoring and purifying the water phase contaminated by 134 Cs. Fish can absorb 134 Cs from water phase and store it in liver and kidney. The specific activity of 134 Cs in fish flesh was low but the percentage of radioactivity was high that was about 30% of total radioactivity in the fish. River mud can strongly absorb 134 Cs and reduce the absorption by aquatic lives. It is a good adsorbent and purifying agent with low cost for treatment of 134 Cs. The K + can prevent aquatic lives from absorbing Cs + because of antagonistic function

  2. Initial interaction of {sup 137}Cs with soils

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaki, S., E-mail: nagasaki@mcmaster.ca [McMaster Univ., Hamilton, Ontario (Canada); Makino, H.; Saito, T. [Univ. of Toyko, Tokyo (Japan)

    2013-07-01

    It is critical to understand the physicochemical behaviour of Cs in soil in order to progress the decontamination of soils which were contaminated by nuclear power plant accident and to improve the reliability of safety assessment of used nuclear fuel disposal. In this paper, the initial interactions of {sup 137}Cs with soils, which were sampled in Fukushima 38 days after Fukushima Accident, were investigated with sequential extraction method. It was found that there were fast and slow processes of fixation of {sup 137}Cs in clay minerals and that the organic substances might play an important role on kinetics of {sup 137}Cs in soils. (author)

  3. Behaviour of {sup 137} Cs in oxysoils and Goiania soil

    Energy Technology Data Exchange (ETDEWEB)

    Wassermann, Maria Angelica [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

    1997-12-31

    {sup 137} Cs soil-to-plant transfer factor obtained in oxy soils accidentally contaminated in Goiania and artificially contaminated shows that these soils present higher transfer when compared with data obtained under temperate climates. These differences were discussed in the light of pedology and geochemical partitioning. Some tropical soil characteristics as acidity, low available nutritive elements and low content of 2:1 clay type seems determine high availability for {sup 137} Cs. Results of sequential extraction showed {sup 137} Cs weakly bound to soil components and underline the importance of Fe oxides in the control of {sup 137} Cs availability in tropical climates. (author) 25 refs., 2 figs., 2 tabs.

  4. Fractionation of (137)Cs and Pu in natural peatland.

    Science.gov (United States)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-08-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Effect of nutrition peculiarities on 137Cs uptake

    International Nuclear Information System (INIS)

    Knizhnikov, V.A.; Marej, A.N.; Borisov, B.K.; Petukhova, Eh.V.

    1980-01-01

    Reasons for different 137 Cs uptake from diets of the vegetable-animal type are studied. Indexes of accumulation multiplicity for Moscow and the Byelorussian-Ukrainian wooded district are compared. 137 Cs buildup levels in the organism of the USSR and the USA population are presented. The most probable reason for peculiarities in 137 Cs uptake from various types of diet, as well as the reason for the alterations in the uptake of this radionuclide from the diet of the same type, is the non-uniformity of 137 Cs contribution of aerial and nonaerial origin

  6. Modelling 137Cs uptake in plants from undisturbed soil monoliths

    International Nuclear Information System (INIS)

    Waegeneers, Nadia; Smolders, Erik; Merckx, Roel

    2005-01-01

    A model predicting 137 Cs uptake in plants was applied on data from artificially contaminated lysimeters. The lysimeter data involve three different crops (beans, ryegrass and lettuce) grown on five different soils between 3 and 5 years after contamination and where soil solution composition was monitored. The mechanistic model predicts plant uptake of 137 Cs from soil solution composition. Predicted K concentrations in the rhizosphere were up to 50-fold below that in the bulk soil solution whereas corresponding 137 Cs concentration gradients were always less pronounced. Predictions of crop 137 Cs content based on rhizosphere soil solution compositions were generally closer to observations than those based on bulk soil solution composition. The model explained 17% (beans) to 91% (lettuce) of the variation in 137 Cs activity concentrations in the plants. The model failed to predict the 137 Cs activity concentration in ryegrass where uptake of the 5-year-old 137 Cs from 3 soils was about 40-fold larger than predicted. The model generally underpredicted crop 137 Cs concentrations at soil solution K concentration below about 1.0 mM. It is concluded that 137 Cs uptake can be predicted from the soil solution composition at adequate K nutrition but that significant uncertainties remain when soil solution K is below 1 mM

  7. Cs separation from nitric acid solutions of radioactive waste

    International Nuclear Information System (INIS)

    Heckmann, K.; Pieronczyk, W.; Strnad, J.; Feldmaier, F.

    1989-01-01

    It was the objective of this study to selectively separate active caesium (Cs-134 and Cs-137) from acid radioactive waste solutions (especially MAW and HAWC). The following 'strategy' was designed for a separation process: synthesis of reagents which are acid-resistant and selective for caesium; precipitation of Cs + and separation of the precipitates by filtration or centrifugation or precipitation of Cs + and separation of the precipitates by flotation; caesium separation by liquid-liquid extraction. As precipitating agents, sodium tetraphenylborate (kalignost) and several of its fluorine derivatives were examined. (orig./RB) [de

  8. Weighing the Smallest Stars

    Science.gov (United States)

    2005-01-01

    VLT Finds Young, Very Low Mass Objects Are Twice As Heavy As Predicted Summary Thanks to the powerful new high-contrast camera installed at the Very Large Telescope, photos have been obtained of a low-mass companion very close to a star. This has allowed astronomers to measure directly the mass of a young, very low mass object for the first time. The object, more than 100 times fainter than its host star, is still 93 times as massive as Jupiter. And it appears to be almost twice as heavy as theory predicts it to be. This discovery therefore suggests that, due to errors in the models, astronomers may have overestimated the number of young "brown dwarfs" and "free floating" extrasolar planets. PR Photo 03/05: Near-infrared image of AB Doradus A and its companion (NACO SDI/VLT) A winning combination A star can be characterised by many parameters. But one is of uttermost importance: its mass. It is the mass of a star that will decide its fate. It is thus no surprise that astronomers are keen to obtain a precise measure of this parameter. This is however not an easy task, especially for the least massive ones, those at the border between stars and brown dwarf objects. Brown dwarfs, or "failed stars", are objects which are up to 75 times more massive than Jupiter, too small for major nuclear fusion processes to have ignited in its interior. To determine the mass of a star, astronomers generally look at the motion of stars in a binary system. And then apply the same method that allows determining the mass of the Earth, knowing the distance of the Moon and the time it takes for its satellite to complete one full orbit (the so-called "Kepler's Third Law"). In the same way, they have also measured the mass of the Sun by knowing the Earth-Sun distance and the time - one year - it takes our planet to make a tour around the Sun. The problem with low-mass objects is that they are very faint and will often be hidden in the glare of the brighter star they orbit, also when viewed

  9. General Relativity and Compact Stars

    International Nuclear Information System (INIS)

    Glendenning, Norman K.

    2005-01-01

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10 14 times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed

  10. Microhydration of caesium compounds: Cs, CsOH, CsI and Cs₂I₂ complexes with one to three H₂O molecules of nuclear safety interest.

    Science.gov (United States)

    Sudolská, Mária; Cantrel, Laurent; Cernušák, Ivan

    2014-04-01

    Structure and thermodynamic properties (standard enthalpies of formation and Gibbs free energies) of hydrated caesium species of nuclear safety interest, Cs, CsOH, CsI and its dimer Cs₂I₂, with one up to three water molecules, are calculated to assess their possible existence in severe accident occurring to a pressurized water reactor. The calculations were performed using the coupled cluster theory including single, double and non-iterative triple substitutions (CCSD(T)) in conjunction with the basis sets (ANO-RCC) developed for scalar relativistic calculations. The second-order spin-free Douglas-Kroll-Hess Hamiltonian was used to account for the scalar relativistic effects. Thermodynamic properties obtained by these correlated ab initio calculations (entropies and thermal capacities at constant pressure as a function of temperature) are used in nuclear accident simulations using ASTEC/SOPHAEROS software. Interaction energies, standard enthalpies and Gibbs free energies of successive water molecules addition determine the ordering of the complexes. CsOH forms the most hydrated stable complexes followed by CsI, Cs₂I₂, and Cs. CsOH still exists in steam atmosphere even at quite high temperature, up to around 1100 K.

  11. CS-Studio Scan System Parallelization

    Energy Technology Data Exchange (ETDEWEB)

    Kasemir, Kay [ORNL; Pearson, Matthew R [ORNL

    2015-01-01

    For several years, the Control System Studio (CS-Studio) Scan System has successfully automated the operation of beam lines at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) and Spallation Neutron Source (SNS). As it is applied to additional beam lines, we need to support simultaneous adjustments of temperatures or motor positions. While this can be implemented via virtual motors or similar logic inside the Experimental Physics and Industrial Control System (EPICS) Input/Output Controllers (IOCs), doing so requires a priori knowledge of experimenters requirements. By adding support for the parallel control of multiple process variables (PVs) to the Scan System, we can better support ad hoc automation of experiments that benefit from such simultaneous PV adjustments.

  12. Correlations between potassium, rubidium and cesium (133Cs and 137Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

    International Nuclear Information System (INIS)

    Vinichuk, M.; Rosen, K.; Johanson, K.J.; Dahlberg, A.

    2011-01-01

    An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ( 133 Cs and 137 Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and 133 Cs mass concentrations with 137 Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg -1 for K (mean ± SD, dwt), 0.40 ± 0.09 g kg -1 for Rb, 8.7 ± 4.36 mg kg -1 for 133 Cs and 63.7 ± 24.2 kBq kg -1 for 137 Cs. The mass concentrations of 133 Cs correlated with 137 Cs activity concentrations (r = 0.61). There was correlation between both 133 Cs concentrations (r = 0.75) and 137 Cs activity concentrations (r = 0.44) and Rb, but the 137 Cs/ 133 Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The 133 Cs mass concentrations, 137 Cs activity concentrations and 137 Cs/ 133 Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, 133 Cs and 137 Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: → We studied uptake of Cs ( 133 Cs and 137 Cs), K and Rb by Suillus variegates sporocarps. → Genotypic origin of fungus did not affect uptake of studied elements (isotopes). → Genotypic origin did not affect correlation between Cs ( 133 Cs and 137 Cs), K and Rb.

  13. Determination of /sup 131/I, /sup 134/Cs, /sup 137/Cs in grass and cheese after Chernobyl accident in Austria

    Energy Technology Data Exchange (ETDEWEB)

    Teherani, D K

    1987-09-14

    Various samples from Styria (grass) and Salzburg (cheese) were analyzed for /sup 131/I, /sup 134/Cs and /sup 137/Cs concentration during April - July 1986 by ..gamma..-ray spectroscopy. The concentrations are reported in nCi kg/sup -1/ wet weight. The values found for /sup 131/I were 0.2-17.2 (grass), 0.1-0.5 (cheese), for /sup 134/Cs 1.1-6.2 (grass), 0.2-1.3 (cheese), for /sup 137/Cs 1.6-15.7 (grass), 0.3-2.2 (cheese). While radioactivity of /sup 131/I, /sup 134/Cs and /sup 137/Cs in cheese samples increased from May to June, it decreased in grass samples from May to July. (author) 5 refs

  14. Uptake and accumulation of 137Cs by upland grassland soil fungi: a potential pool of Cs immobilization

    International Nuclear Information System (INIS)

    Dighton, J.; Clint, G.M.; Poskitt, J.

    1991-01-01

    Reports of high concentrations of fallout radiocaesium in basidiomycete fruit bodies after the Chernobyl nuclear reactor accident and speculation that fungi could be long-term 137 Cs accumulators led us to ask if fungi could be long-term 137 Cs accumulators. We used six common upland grassland species to try to estimate their importance in the immobilization of 137 Cs. Uptake of Cs by these species ranged from 44 to 235 nmol Cs g − 1d.w. h − 1. Efflux studies indicate that more than 40% of the Cs taken up is bound within the hyphae. We estimate that the fungal component of the soil could immobilize the total radiocaesium fallout received in upland grasslands following the Chernobyl accident

  15. Coefficients of distribution and accumulation of K, Rb, Cs and 137Cs in the intensive poultry breeding cycle

    International Nuclear Information System (INIS)

    Djuric, G.; Ajdacic, N.; Institut za Nuklearne Nauke Boris Kidric, Belgrade

    1984-01-01

    The concentration of K,Rb,Cs and the activity level of Cs-137 in samples from the intensive poultry breeding cycle (feed, meat, eggs), under the condition of chronic alimentary contamination is presented. Concentrations of Cs and Rb were determined by non-destructive neutron activation analysis, concentration of K by atomic absorption flame photometry and activity of Cs-137 by gamma spectrometric analysis. On the basis of these results, coefficients of distribution and accumulation were calculated. The distribution coefficients of the analysed stable isotopes in meat have values close to 1, whereas for various parts of egg these coefficients vary between 0.5 and 1.5. Significant differences in Cs-137 distribution in various parts of egg were established. The values of accumulation coefficients indicate that all analysed elements selectively accumulate in the meat of young birds (broilers), and Cs-137 accumulates in the egg white as well. (orig.)

  16. Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

    Science.gov (United States)

    Sharma, Surendra; Weiden, Norbert; Weiss, Alarich

    1991-04-01

    The phase transitions in CsSnCl3 and CsPbBr3 have been studied by X-ray powder diffraction, by 81Br-NQR and by 'H-, 119Sn-, and 113Cs-NMR. At room temperature in air CsSnCl3 forms a hydrate which can be dehydrated to the monoclinic phase II of CsSnCl3. The high temperature phase I has the Perovskite structure, as the X-ray and NMR experiments show. The three phases of CsPbBr3, known from literature, have been corroborated. The results are discussed in the framework of the group ABX3, A = alkalimetal ion, B = IV main group ion, and X = Halogen ion

  17. Atmospheres of central stars

    International Nuclear Information System (INIS)

    Hummer, D.G.

    1978-01-01

    The author presents a brief summary of atmospheric models that are of possible relevance to the central stars of planetary nebulae, and then discusses the extent to which these models accord with the observations of both nebulae and central stars. Particular attention is given to the significance of the very high Zanstra temperature implied by the nebulae He II lambda 4686 A line, and to the discrepancy between the Zanstra He II temperature and the considerably lower temperatures suggested by the appearance of the visual spectrum for some of these objects. (Auth.)

  18. The Drifting Star

    Science.gov (United States)

    2008-04-01

    By studying in great detail the 'ringing' of a planet-harbouring star, a team of astronomers using ESO's 3.6-m telescope have shown that it must have drifted away from the metal-rich Hyades cluster. This discovery has implications for theories of star and planet formation, and for the dynamics of our Milky Way. ESO PR Photo 09a/08 ESO PR Photo 09a/08 Iota Horologii The yellow-orange star Iota Horologii, located 56 light-years away towards the southern Horologium ("The Clock") constellation, belongs to the so-called "Hyades stream", a large number of stars that move in the same direction. Previously, astronomers using an ESO telescope had shown that the star harbours a planet, more than 2 times as large as Jupiter and orbiting in 320 days (ESO 12/99). But until now, all studies were unable to pinpoint the exact characteristics of the star, and hence to understand its origin. A team of astronomers, led by Sylvie Vauclair from the University of Toulouse, France, therefore decided to use the technique of 'asteroseismology' to unlock the star's secrets. "In the same way as geologists monitor how seismic waves generated by earthquakes propagate through the Earth and learn about the inner structure of our planet, it is possible to study sound waves running through a star, which forms a sort of large, spherical bell," says Vauclair. The 'ringing' from this giant musical instrument provides astronomers with plenty of information about the physical conditions in the star's interior. And to 'listen to the music', the astronomers used one of the best instruments available. The observations were conducted in November 2006 during 8 consecutive nights with the state-of-the-art HARPS spectrograph mounted on the ESO 3.6-m telescope at La Silla. Up to 25 'notes' could be identified in the unique dataset, most of them corresponding to waves having a period of about 6.5 minutes. These observations allowed the astronomers to obtain a very precise portrait of Iota Horologii: its

  19. The star of Bethlehem

    International Nuclear Information System (INIS)

    Hughes, D.W.

    1976-01-01

    It is stated that the cause and form of the star are still uncertain. The astrologically significant triple conjunction of Saturn and Jupiter in the constellation of Pisces appears to be the most likely explanation, although the two comets of March 5 BC and April 4 BC cannot be dismissed, nor can the possibility that the 'star' was simply legendary. The conjunction occurred in 7 BC and there are indications that Jesus Christ was probably born in the Autumn of that year, around October 7 BC. (U.K.)

  20. The formation of stars

    CERN Document Server

    Stahler, Steven W

    2008-01-01

    This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text f

  1. Chaplygin dark star

    International Nuclear Information System (INIS)

    Bertolami, O.; Paramos, J.

    2005-01-01

    We study the general properties of a spherically symmetric body described through the generalized Chaplygin equation of state. We conclude that such an object, dubbed generalized Chaplygin dark star, should exist within the context of the generalized Chaplygin gas (GCG) model of unification of dark energy and dark matter, and derive expressions for its size and expansion velocity. A criteria for the survival of the perturbations in the GCG background that give origin to the dark star are developed, and its main features are analyzed

  2. ENERGY STAR Certified Commercial Dishwashers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Commercial Dishwashers that are effective as of...

  3. ENERGY STAR Certified Commercial Ovens

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.2 ENERGY STAR Program Requirements for Commercial Ovens that are effective as of...

  4. Star Formation in Irregular Galaxies.

    Science.gov (United States)

    Hunter, Deidre; Wolff, Sidney

    1985-01-01

    Examines mechanisms of how stars are formed in irregular galaxies. Formation in giant irregular galaxies, formation in dwarf irregular galaxies, and comparisons with larger star-forming regions found in spiral galaxies are considered separately. (JN)

  5. ENERGY STAR Certified Commercial Boilers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Commercial Boilers that are effective as of...

  6. Photometry of faint blue stars

    International Nuclear Information System (INIS)

    Kilkenny, D.; Hill, P.W.; Brown, A.

    1977-01-01

    Photometry on the uvby system is given for 61 faint blue stars. The stars are classified by means of the Stromgren indices, using criteria described in a previous paper (Kilkenny and Hill (1975)). (author)

  7. ENERGY STAR Certified Commercial Griddles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Commercial Griddles that are effective as of May...

  8. ENERGY STAR Certified Smart Thermostats

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Connected Thermostats that are effective as of...

  9. ENERGY STAR Certified Residential Dishwashers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 6.0 ENERGY STAR Program Requirements for Residential Dishwashers that are effective as of...

  10. ENERGY STAR Certified Roof Products

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Roof Products that are effective as of July 1,...

  11. ENERGY STAR Certified Pool Pumps

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.1 ENERGY STAR Program Requirements for Pool Pumps that are effective as of February 15,...

  12. Understand B-type stars

    Science.gov (United States)

    1982-01-01

    When observations of B stars made from space are added to observations made from the ground and the total body of observational information is confronted with theoretical expectations about B stars, it is clear that nonthermal phenomena occur in the atmospheres of B stars. The nature of these phenomena and what they imply about the physical state of a B star and how a B star evolves are examined using knowledge of the spectrum of a B star as a key to obtaining an understanding of what a B star is like. Three approaches to modeling stellar structure (atmospheres) are considered, the characteristic properties of a mantle, and B stars and evolution are discussed.

  13. ENERGY STAR Certified Imaging Equipment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Imaging Equipment that are effective as of...

  14. ENERGY STAR Certified Vending Machines

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Refrigerated Beverage Vending Machines that are...

  15. ENERGY STAR Certified Water Coolers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Water Coolers that are effective as of February...

  16. ENERGY STAR Certified Audio Video

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Audio Video Equipment that are effective as of...

  17. ENERGY STAR Certified Ceiling Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1,...

  18. ENERGY STAR Certified Ventilating Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of...

  19. ENERGY STAR Certified Commercial Fryers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Commercial Fryers that are effective as of...

  20. Lithium in the barium stars

    International Nuclear Information System (INIS)

    Pinsonneault, M.H.; Sneden, C.

    1984-01-01

    New high-resolution spectra of the lithium resonance doublet have provided lithium abundances or upper limits for 26 classical and mild barium stars. The lithium lines always are present in the classical barium stars. Lithium abundances in these stars obey a trend with stellar masses consistent with that previously derived for ordinary K giants. This supports the notion that classical barium stars are post-core-He-flash or core-He-burning stars. Lithium contents in the mild barium stars, however, often are much smaller than those of the classical barium stars sometimes only upper limits may be determined. The cause for this difference is not easily understood, but may be related to more extensive mass loss by the mild barium stars. 45 references

  1. Which of Kepler's Stars Flare?

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    The habitability of distant exoplanets is dependent upon many factors one of which is the activity of their host stars. To learn about which stars are most likely to flare, a recent study examines tens of thousands of stellar flares observed by Kepler.Need for a Broader SampleArtists rendering of a flaring dwarf star. [NASAs Goddard Space Flight Center/S. Wiessinger]Most of our understanding of what causes a star to flare is based on observations of the only star near enough to examine in detail the Sun. But in learning from a sample size of one, a challenge arises: we must determine which conclusions are unique to the Sun (or Sun-like stars), and which apply to other stellar types as well.Based on observations and modeling, astronomers think that stellar flares result from the reconnection of magnetic field lines in a stars outer atmosphere, the corona. The magnetic activity is thought to be driven by a dynamo caused by motions in the stars convective zone.HR diagram of the Kepler stars, with flaring main-sequence (yellow), giant (red) and A-star (green) stars in the authors sample indicated. [Van Doorsselaere et al. 2017]To test whether these ideas are true generally, we need to understand what types of stars exhibit flares, and what stellar properties correlate with flaring activity. A team of scientists led by Tom Van Doorsselaere (KU Leuven, Belgium) has now used an enormous sample of flares observed by Kepler to explore these statistics.Intriguing TrendsVan Doorsselaere and collaborators used a new automated flare detection and characterization algorithm to search through the raw light curves from Quarter 15 of the Kepler mission, building a sample of 16,850 flares on 6,662 stars. They then used these to study the dependence of the flare occurrence rate, duration, energy, and amplitude on the stellar spectral type and rotation period.This large statistical study led the authors to several interesting conclusions, including:Flare star incidence rate as a a

  2. ENERGY STAR Certified Residential Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Residential Refrigerators and Freezers that are...

  3. ENERGY STAR Certified Residential Refrigerators

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Residential Refrigerators and Freezers that are...

  4. Exploring Polaronic, Excitonic Structures and Luminescence in Cs4PbBr6/CsPbBr3.

    Science.gov (United States)

    Kang, Byungkyun; Biswas, Koushik

    2018-02-15

    Among the important family of halide perovskites, one particular case of all-inorganic, 0-D Cs 4 PbBr 6 and 3-D CsPbBr 3 -based nanostructures and thin films is witnessing intense activity due to ultrafast luminescence with high quantum yield. To understand their emissive behavior, we use hybrid density functional calculations to first compare the ground-state electronic structure of the two prospective compounds. The dispersive band edges of CsPbBr 3 do not support self-trapped carriers, which agrees with reports of weak exciton binding energy and high photocurrent. The larger gap 0-D material Cs 4 PbBr 6 , however, reveals polaronic and excitonic features. We show that those lattice-coupled carriers are likely responsible for observed ultraviolet emission around ∼375 nm, reported in bulk Cs 4 PbBr 6 and Cs 4 PbBr 6 /CsPbBr 3 composites. Ionization potential calculations and estimates of type-I band alignment support the notion of quantum confinement leading to fast, green emission from CsPbBr 3 nanostructures embedded in Cs 4 PbBr 6 .

  5. Distances of Dwarf Carbon Stars

    Science.gov (United States)

    Harris, Hugh C.; Dahn, Conard C.; Subasavage, John P.; Munn, Jeffrey A.; Canzian, Blaise J.; Levine, Stephen E.; Monet, Alice B.; Pier, Jeffrey R.; Stone, Ronald C.; Tilleman, Trudy M.; Hartkopf, William I.

    2018-06-01

    Parallaxes are presented for a sample of 20 nearby dwarf carbon stars. The inferred luminosities cover almost two orders of magnitude. Their absolute magnitudes and tangential velocities confirm prior expectations that some originate in the Galactic disk, although more than half of this sample are halo stars. Three stars are found to be astrometric binaries, and orbital elements are determined; their semimajor axes are 1–3 au, consistent with the size of an AGB mass-transfer donor star.

  6. RADIAL STABILITY IN STRATIFIED STARS

    International Nuclear Information System (INIS)

    Pereira, Jonas P.; Rueda, Jorge A.

    2015-01-01

    We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the boundary conditions connecting any two phases within a star and underline its relevance for realistic models of compact stars with phase transitions, owing to the modification of the star's set of eigenmodes with respect to the continuous case

  7. New stars for old

    International Nuclear Information System (INIS)

    Henbest, N.

    1980-01-01

    Observations of novas made through the ages, the identity of the close double stars which make up these cataclysmic variables and the physics of nova explosions, are discussed. A picture is outlined which explains novas, dwarf novas and recurrent novas and provides a basis for interpreting the latest so called x-ray novas. (U.K.)

  8. Hadrons in compact stars

    Indian Academy of Sciences (India)

    At normal nuclear matter density, neutron star matter mainly consists of neutrons, protons and electrons. The particle population is so arranged as to attain a min- imum energy configuration maintaining electrical charge neutrality and chemical equilibrium. At higher baryon density, hyperon formation becomes energetically.

  9. Millet's Shooting Stars

    Science.gov (United States)

    Beech, M.

    1988-12-01

    In this essay two paintings by the French artist Jean-Francois Millet are described. These paintings, Les Etoiles Filantes and Nuit Etoilée are particularly interesting since they demonstrate the rare artistic employment of the shooting-star image and metaphor.

  10. Asteroseismology of Scuti Stars

    Indian Academy of Sciences (India)

    Abstract. We briefly outline the state-of-the-art seismology of Scuti stars from a theoretical point of view: why is it so difficult a task? The recent theoretical advances in the field that these difficulties have influenced are also discussed.

  11. The STAR trigger

    International Nuclear Information System (INIS)

    Bieser, F.S.; Crawford, H.J.; Engelage, J.; Eppley, G.; Greiner, L.C.; Judd, E.G.; Klein, S.R.; Meissner, F.; Minor, R.; Milosevich, Z.; Mutchler, G.; Nelson, J.M.; Schambach, J.; VanderMolen, A.S.; Ward, H.; Yepes, P.

    2003-01-01

    We describe the trigger system that we designed and implemented for the STAR detector at RHIC. This is a 10 MHz pipelined system based on fast detector output that controls the event selection for the much slower tracking detectors. Results from the first run are presented and new detectors for the 2001 run are discussed

  12. Sleeping under the stars

    Science.gov (United States)

    Zirkel, Jack

    Sherlock Holmes and Dr. Watson went on a camping trip. As they lay down for the night, Holmes said, “Watson, look up at the sky and tell me what you see.”Watson:“! see millions and millions of stars.”

  13. Insight into star death

    International Nuclear Information System (INIS)

    Talcott, R.

    1988-01-01

    Nineteen neutrinos, formed in the center of a supernova, became a theorist's dream. They came straight from the heart of supernova 1987A and landed in two big underground tanks of water. Suddenly a new chapter in observational astronomy opened as these two neutrino telescopes gave astronomers their first look ever into the core of a supernova explosion. But the theorists' dream almost turned into a nightmare. Observations of the presupernova star showed conclusively that the star was a blue supergiant, but theorists have long believed only red supergiant stars could explode as supernovae. Do astronomers understand supernovae better now than when supernova 1987A exploded in the Large Magellanic Cloud (LMC) one year ago? Yes. The observations of neutrinos spectacularly confirmed a vital aspect of supernova theory. But the observed differences between 1987A and other supernovae have illuminated and advanced our perception of how supernovae form. By working together, observers and theorists are continuing to hone their ideas about how massive stars die and how the subsequent supernovae behave

  14. StarLogo TNG

    Science.gov (United States)

    Klopfer, Eric; Scheintaub, Hal; Huang, Wendy; Wendel, Daniel

    Computational approaches to science are radically altering the nature of scientific investigatiogn. Yet these computer programs and simulations are sparsely used in science education, and when they are used, they are typically “canned” simulations which are black boxes to students. StarLogo The Next Generation (TNG) was developed to make programming of simulations more accessible for students and teachers. StarLogo TNG builds on the StarLogo tradition of agent-based modeling for students and teachers, with the added features of a graphical programming environment and a three-dimensional (3D) world. The graphical programming environment reduces the learning curve of programming, especially syntax. The 3D graphics make for a more immersive and engaging experience for students, including making it easy to design and program their own video games. Another change to StarLogo TNG is a fundamental restructuring of the virtual machine to make it more transparent. As a result of these changes, classroom use of TNG is expanding to new areas. This chapter is concluded with a description of field tests conducted in middle and high school science classes.

  15. THE STAR OFFLINE FRAMEWORK

    International Nuclear Information System (INIS)

    FINE, V.; FISYAK, Y.; PEREVOZTCHIKOV, V.; WENAUS, T.

    2000-01-01

    The Solenoidal Tracker At RHIC (STAR) is a-large acceptance collider detector, commissioned at Brookhaven National Laboratory in 1999. STAR has developed a software framework supporting simulation, reconstruction and analysis in offline production, interactive physics analysis and online monitoring environments that is well matched both to STAR's present status of transition between Fortran and C++ based software and to STAR's evolution to a fully OO software base. This paper presents the results of two years effort developing a modular C++ framework based on the ROOT package that encompasses both wrapped Fortran components (legacy simulation and reconstruction code) served by IDL-defined data structures, and fully OO components (all physics analysis code) served by a recently developed object model for event data. The framework supports chained components, which can themselves be composite subchains, with components (''makers'') managing ''data sets'' they have created and are responsible for. An St-DataSet class from which data sets and makers inherit allows the construction of hierarchical organizations of components and data, and centralizes almost all system tasks such as data set navigation, I/O, database access, and inter-component communication. This paper will present an overview of this system, now deployed and well exercised in production environments with real and simulated data, and in an active physics analysis development program

  16. Triggered star formation

    Czech Academy of Sciences Publication Activity Database

    Palouš, Jan; Ehlerová, Soňa

    2002-01-01

    Roč. 12, - (2002), s. 35-36 ISSN 1405-2059 R&D Projects: GA AV ČR IAA3003705; GA AV ČR KSK1048102 Institutional research plan: CEZ:AV0Z1003909 Keywords : interstellar medium * star formation * HI shells Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  17. Highlights from STAR

    International Nuclear Information System (INIS)

    Schweda, Kai

    2004-01-01

    Selected results from the STAR collaboration are presented. We focus on recent results on jet-like correlations, nuclear modification factors of identified hadrons, elliptic flow of multi-strange baryons Ξ and Ω, and resonance yields. First measurements of open charm production at RHIC are presented

  18. Supernovae from massive AGB stars

    NARCIS (Netherlands)

    Poelarends, A.J.T.; Izzard, R.G.; Herwig, F.; Langer, N.; Heger, A.

    2006-01-01

    We present new computations of the final fate of massive AGB-stars. These stars form ONeMg cores after a phase of carbon burning and are called Super AGB stars (SAGB). Detailed stellar evolutionary models until the thermally pulsing AGB were computed using three di erent stellar evolution codes. The

  19. Do All O Stars Form in Star Clusters?

    Science.gov (United States)

    Weidner, C.; Gvaramadze, V. V.; Kroupa, P.; Pflamm-Altenburg, J.

    The question whether or not massive stars can form in isolation or only in star clusters is of great importance for the theory of (massive) star formation as well as for the stellar initial mass function of whole galaxies (IGIMF-theory). While a seemingly easy question it is rather difficult to answer. Several physical processes (e.g. star-loss due to stellar dynamics or gas expulsion) and observational limitations (e.g. dust obscuration of young clusters, resolution) pose severe challenges to answer this question. In this contribution we will present the current arguments in favour and against the idea that all O stars form in clusters.

  20. Halo Star Lithium Depletion

    International Nuclear Information System (INIS)

    Pinsonneault, M. H.; Walker, T. P.; Steigman, G.; Narayanan, Vijay K.

    1999-01-01

    The depletion of lithium during the pre-main-sequence and main-sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (nonrotating) stellar models to as much as an order of magnitude in models that include rotational mixing. Recent progress in the study of the angular momentum evolution of low-mass stars permits the construction of theoretical models capable of reproducing the angular momentum evolution of low-mass open cluster stars. The distribution of initial angular momenta can be inferred from stellar rotation data in young open clusters. In this paper we report on the application of these models to the study of lithium depletion in main-sequence halo stars. A range of initial angular momenta produces a range of lithium depletion factors on the main sequence. Using the distribution of initial conditions inferred from young open clusters leads to a well-defined halo lithium plateau with modest scatter and a small population of outliers. The mass-dependent angular momentum loss law inferred from open cluster studies produces a nearly flat plateau, unlike previous models that exhibited a downward curvature for hotter temperatures in the 7Li-Teff plane. The overall depletion factor for the plateau stars is sensitive primarily to the solar initial angular momentum used in the calibration for the mixing diffusion coefficients. Uncertainties remain in the treatment of the internal angular momentum transport in the models, and the potential impact of these uncertainties on our results is discussed. The 6Li/7Li depletion ratio is also examined. We find that the dispersion in the plateau and the 6Li/7Li depletion ratio scale with the absolute 7Li depletion in the plateau, and we use observational data to set bounds on the 7Li depletion in main-sequence halo

  1. Kinematic and spatial distributions of barium stars - are the barium stars and Am stars related?

    International Nuclear Information System (INIS)

    Hakkila, J.

    1989-01-01

    The possibility of an evolutionary link between Am stars and barium stars is considered, and an examination of previous data suggests that barium star precursors are main-sequence stars of intermediate mass, are most likely A and/or F dwarfs, and are intermediate-mass binaries with close to intermediate orbital separations. The possible role of mass transfer in the later development of Am systems is explored. Mass transfer and loss from systems with a range of masses and orbital separations may explain such statistical peculiarities of barium stars as the large dispersion in absolute magnitude, the large range of elemental abundances from star to star, and the small number of stars with large peculiar velocities. 93 refs

  2. Masses of the Planetary Nebula Central Stars in the Galactic Globular Cluster System from HST Imaging and Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jacoby, George H. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Marco, Orsola De [Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Davies, James [Space Telescope Science Institute, Baltimore MD 21218 (United States); Lotarevich, I. [American Museum of Natural History, New York, NY (United States); Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Harrington, J. Patrick [University of Maryland, College Park, MD (United States); Lanz, Thierry, E-mail: gjacoby@lowell.edu, E-mail: orsola.demarco@mq.edu.au, E-mail: jdavies@stsci.edu, E-mail: heb11@psu.edu, E-mail: jph@astro.umd.edu, E-mail: thierry.lanz@oca.eu [Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, F-06304 Nice (France)

    2017-02-10

    The globular cluster (GC) system of our Galaxy contains four planetary nebulae (PNe): K 648 (or Ps 1) in M15, IRAS 18333-2357 in M22, JaFu 1 in Pal 6, and JaFu 2 in NGC 6441. Because single-star evolution at the low stellar mass of present-epoch GCs was considered incapable of producing visible PNe, their origin presented a puzzle. We imaged the PN JaFu 1 with the Hubble Space Telescope (HST) to obtain photometry of its central star (CS) and high-resolution morphological information. We imaged IRAS 18333-2357 with better depth and resolution, and we analyzed its archival HST spectra to constrain its CS temperature and luminosity. All PNe in Galactic GCs now have quality HST data, allowing us to improve CS mass estimates. We find reasonably consistent masses between 0.53 and 0.58 M {sub ⊙} for all four objects, though estimates vary when adopting different stellar evolutionary calculations. The CS mass of IRAS 18333-2357, though, depends strongly on its temperature, which remains elusive due to reddening uncertainties. For all four objects, we consider their CS and nebula masses, their morphologies, and other incongruities to assess the likelihood that these objects formed from binary stars. Although generally limited by uncertainties (∼0.02 M {sub ⊙}) in post-AGB tracks and core mass versus luminosity relations, the high-mass CS in K 648 indicates a binary origin. The CS of JaFu 1 exhibits compact, bright [O iii] and H α emission, like EGB 6, suggesting a binary companion or disk. Evidence is weaker for a binary origin of JaFu 2.

  3. Distribution and behavior of {sup 137}Cs in undisturbed soil

    Energy Technology Data Exchange (ETDEWEB)

    Satta, Naoya [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1996-04-01

    The depth distribution of {sup 137}Cs in soils which has not been artificially disturbed for 100 years was compared to fallout history. The model of {sup 137}Cs distribution rate was established to estimate fallout history from soil samples. (J.P.N.)

  4. Relative volatility of dilute solutions of Rb-Cs system

    International Nuclear Information System (INIS)

    Gromov, P.B.; Izotov, V.P.; Nisel'son, L.A.

    1984-01-01

    Relative volatility of diluted solutions Rb-Cs in the temperature range 650-820 K and pressures 13-200 gPa has been studied. The system Rb-Cs in the range of diluted solutions obeys the Henry law. It is shown, that liquid-vapour equilibrium in diluted solutions of cesium in rubidium is characterized by negative deviation from perfection

  5. Direct and indirect contamination of tree crops with Cs-134

    International Nuclear Information System (INIS)

    Skarlou, V.; Nobeli, C.; Anoussis, J.; Arapis, G.; Haidouti, C.

    1996-01-01

    A long term glasshouse pot experiment was established in 1994 to study the transfer factors of Cs-134 from soil to olive and orange trees for which no relevant data are available. A calcareous-heavy textured and an acid-light textured soil were used in this experiment. Results from two year's experimentation are considered in this study. The ability of the studied plant species for Cs-134 root uptake seems to be significantly influenced by soil type. The contamination of both tree species grown on calcareous and heavy soil was very low and did not change much with the time. On the contrary, trees grown on acid and light soil showed much higher Cs-134 concentration (up to 34 times for orange and 23 for olive trees) which significantly increased with the time. Both olive and orange trees showed a similar behaviour in the studied soils. Effort was also made to study the long term consequences of the direct contamination in a field experiment where an olive tree was contaminated by dry deposition with Cs-134. Six months after contamination 5 % of the Cs-134 deposited on the leaves was measured in the first olive production. However, very small quantities (= 0.5 %) of the olive Cs-134 was detected in the unprocessed olive oil. The following year 15 % of the Cs-134 remained in the leaves while extremely low quantities of Cs-134 were detected in either olives or olive oil. (author)

  6. Quantitative Cs-137 distributions from airborne gamma ray data

    International Nuclear Information System (INIS)

    Oberlercher, G.; Seiberl, W.

    1997-01-01

    The Chernobyl reactor accident caused in Austria Cs-137 activities up to 180 kBq/m 2 . The following paper explains how airborne NaJ-spectroscopy, originally designed for geological surveys, was used as an accurate method to obtain the ground activity of Cs-137 in certain regions of Austria. To retrieve the net count rate in a Cs-137 window it is necessary to subtract all background contributions from the peak, including the Compton continuum and the contribution of overlapping peaks. Therefore the measurement of Cs-137 with a NaJ detector system must take into account radioactive elements with gamma-ray lines near the peak energy of Cs-137 at 662 keV. In regions with higher concentrations of the natural radioactive elements uranium and thorium a peak near 600 keV is found, containing the 609 keV line of Bi-214 and the 585 keV line of TI-208. Additionally a Cs-134 line is located at 604 keV. Because of the poor energy resolution of NaJ detectors it is not possible to find a clear separation between these peaks and the Cs-137 peak. The following section describes the method that was used to obtain accurate quantified Cs-137 activity values. (author)

  7. Antibodies derived from an enterotoxigenic Escherichia coli (ETEC) adhesin tip MEFA (multiepitope fusion antigen) against adherence of nine ETEC adhesins: CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA.

    Science.gov (United States)

    Nandre, Rahul M; Ruan, Xiaosai; Duan, Qiangde; Sack, David A; Zhang, Weiping

    2016-06-30

    Diarrhea continues to be a leading cause of death in children younger than 5 years in developing countries. Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of children's diarrhea and travelers' diarrhea. ETEC bacteria initiate diarrheal disease by attaching to host receptors at epithelial cells and colonizing in small intestine. Therefore, preventing ETEC attachment has been considered the first line of defense against ETEC diarrhea. However, developing vaccines effectively against ETEC bacterial attachment encounters challenge because ETEC strains produce over 23 immunologically heterogeneous adhesins. In this study, we applied MEFA (multiepitope fusion antigen) approach to integrate epitopes from adhesin tips or adhesive subunits of CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA adhesins and to construct an adhesin tip MEFA peptide. We then examined immunogenicity of this tip MEFA in mouse immunization, and assessed potential application of this tip MEFA for ETEC vaccine development. Data showed that mice intraperitoneally immunized with this adhesin tip MEFA developed IgG antibody responses to all nine ETEC adhesins. Moreover, ETEC and E. coli bacteria expressing these nine adhesins, after incubation with serum of the immunized mice, exhibited significant reduction in attachment to Caco-2 cells. These results indicated that anti-adhesin antibodies induced by this adhesin tip MEFA blocked adherence of the most important ETEC adhesins, suggesting this multivalent tip MEFA may be useful for developing a broadly protective anti-adhesin vaccine against ETEC diarrhea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Is 137Cs Dating Becoming Obsolete in North America?

    Science.gov (United States)

    Drexler, J. Z.; Fuller, C.; Salas, A.

    2016-12-01

    Dating of wetland sediments and peat is routinely carried out using 137Cs and 210Pb analysis. Unlike 210Pb, 137Cs is an anthropogenic radionuclide with a history of fallout from nuclear weapons testing. 137Cs is used as a single time marker; its peak is coincident with the height of atmospheric nuclear testing in 1963/4. During its use in the 1970s-90s, 137Cs peaks were usually highly distinct in wetland sediments (e.g., see 137Cs peaks from Louisiana marshes in Feijtel et al., 1988). This enabled its use as a check for dates assigned to a profile by 210Pb and other methods. However, recently, the efficacy of 137Cs dating in North America has deteriorated. In this presentation, we will provide specific examples of 137Cs as well as 210Pb dating in wetland sediments/peats we collected between 2005 and 2015 in Maine, California, Virginia, North Carolina, South Carolina, and Washington. Two main reasons exist for this decline. First, 137Cs activities in our recent cores are 30-40 % of the original activities in 1963/4 due to decay of the original 137Cs in situ (half-life = 30.17 years) and no major new sources. This manifests in lower signal to noise ratio, with some peaks barely recognizable above the noise. Second, 137Cs peaks are much less distinct due to 137Cs migration through time independent of substrate (or sediment) particles. Migration of peaks has resulted in estimated accretion rates being systematically lower or higher than those derived from 210Pb dating. These issues with 137Cs dating have important implications because 137Cs is used with 210Pb dating or even alone to determine rates of recent wetland carbon accumulation. Such rates are required to enter wetland restoration projects into carbon markets and to document IPCC mandated reductions in carbon pollution. Our analysis shows that, although dating by 137Cs alone has always been highly tenuous, now it is especially contraindicated and should be disallowed for the purposes of carbon accounting.

  9. Determination of {sup 135}Cs by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, C.M.; Charles, C.R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Zhao, X.-L.; Kieser, W.E. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Cornett, R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [IsoTrace Laboratory, University of Toronto, 60 St. George St., Toronto, ON M5S 1A7 (Canada)

    2015-10-15

    The ratio of anthropogenic {sup 135}Cs and {sup 137}Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying {sup 135}Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn{sub 2}, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10{sup −3} and 1.7 × 10{sup −7} respectively. This quantification of {sup 135}Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

  10. Recovery of Cs from high level radioactive waste

    International Nuclear Information System (INIS)

    Kumar, Amar; Kaushik, C.P.; Raj, K.; Varshney, Lalit

    2008-01-01

    Separation of Cs + from HLW restricts the personal radiation exposure during the vitrification and prevents thermal deformation of conditioned waste matrix during storage because of the high calorific power of 134 Cs (13.18 W/g) and 137 Cs (0.417 W/g) which would markedly reduce the storage cost. Separation will also reduce its volatility during vitrification and extent of migration from the vitrified mass in repository. In addition 137 Cs has enormous applications as radiation sources in food preservation, sterilization of medical products, brachy therapy, blood irradiation, hygienization of sewage sludge etc. The use of 137 Cs (T 1/2 = 30 years) in place of 60 Co (T 1/2 = 5.2 years) will also reduce the shielding requirement and frequency of source replenishment which will ease the handling/transportation of radioactive source

  11. Star identification methods, techniques and algorithms

    CERN Document Server

    Zhang, Guangjun

    2017-01-01

    This book summarizes the research advances in star identification that the author’s team has made over the past 10 years, systematically introducing the principles of star identification, general methods, key techniques and practicable algorithms. It also offers examples of hardware implementation and performance evaluation for the star identification algorithms. Star identification is the key step for celestial navigation and greatly improves the performance of star sensors, and as such the book include the fundamentals of star sensors and celestial navigation, the processing of the star catalog and star images, star identification using modified triangle algorithms, star identification using star patterns and using neural networks, rapid star tracking using star matching between adjacent frames, as well as implementation hardware and using performance tests for star identification. It is not only valuable as a reference book for star sensor designers and researchers working in pattern recognition and othe...

  12. Transformation of Sintered CsPbBr3 Nanocrystals to Cubic CsPbI3 and Gradient CsPbBrxI3-x through Halide Exchange.

    Science.gov (United States)

    Hoffman, Jacob B; Schleper, A Lennart; Kamat, Prashant V

    2016-07-13

    All-inorganic cesium lead halide (CsPbX3, X = Br(-), I(-)) perovskites could potentially provide comparable photovoltaic performance with enhanced stability compared to organic-inorganic lead halide species. However, small-bandgap cubic CsPbI3 has been difficult to study due to challenges forming CsPbI3 in the cubic phase. Here, a low-temperature procedure to form cubic CsPbI3 has been developed through a halide exchange reaction using films of sintered CsPbBr3 nanocrystals. The reaction was found to be strongly dependent upon temperature, featuring an Arrhenius relationship. Additionally, film thickness played a significant role in determining internal film structure at intermediate reaction times. Thin films (50 nm) showed only a small distribution of CsPbBrxI3-x species, while thicker films (350 nm) exhibited much broader distributions. Furthermore, internal film structure was ordered, featuring a compositional gradient within film. Transient absorption spectroscopy showed the influence of halide exchange on the excited state of the material. In thicker films, charge carriers were rapidly transferred to iodide-rich regions near the film surface within the first several picoseconds after excitation. This ultrafast vectorial charge-transfer process illustrates the potential of utilizing compositional gradients to direct charge flow in perovskite-based photovoltaics.

  13. MAPPING THE LINEARLY POLARIZED SPECTRAL LINE EMISSION AROUND THE EVOLVED STAR IRC+10216

    Energy Technology Data Exchange (ETDEWEB)

    Girart, J. M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, C5p 2, 08193 Bellaterra, Catalunya (Spain); Patel, N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Vlemmings, W. H. T. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Rao, Ramprasad, E-mail: girart@ice.cat [Submillimeter Array, Academia Sinica Institute of Astronomy and Astrophysics, 645 N. Aohoku Place, Hilo, HI 96720 (United States)

    2012-05-20

    We present spectro-polarimetric observations of several molecular lines obtained with the Submillimeter Array toward the carbon-rich asymptotic giant branch star IRC+10216. We have detected and mapped the linear polarization of the CO 3-2, SiS 19-18, and CS 7-6 lines. The polarization arises at a distance of {approx_equal} 450 AU from the star and is blueshifted with respect to the Stokes I. The SiS 19-18 polarization pattern appears to be consistent with a locally radial magnetic field configuration. However, the CO 3-2 and CS 7-6 line polarization suggests an overall complex magnetic field morphology within the envelope. This work demonstrates the feasibility of using spectro-polarimetric observations to carry out tomographic imaging of the magnetic field in circumstellar envelopes.

  14. Soil 137Cs background values in monsoon region of china

    International Nuclear Information System (INIS)

    Zhang Mingli; Yang Hao; Wang Xiaolei; Wang Yihong; Xu Congan; Yang Jiudong; Rong Jing

    2009-01-01

    Land degradation,, which is resulted from the soil erosion, is one of the major environmental problems. It severely affects the food supplies, environmental safety and the sustainable development in China. Some areas in the monsoon region are suffering from the acute soil erosion. To find out the degree of soil erosion, the proven technique of 137 Cs tracer is definitely one of the best methods, and the key is to ascertain the accuracy of soil 137 Cs background value. The distributions of 137 Cs were explored in soil profiles by detecting the 137 Cs of soil cores from the Yimeng mountain area in Shandong Province, hills in the southern area of Jiangsu Province and Dianchi catchment in Yunnan Province, respectively. We found that the depth of 137 Cs distribution is not the same in the soils of various areas. But the 137 Cs activity shows an exponential distribution in the uncultivated soil and demonstrates a strong correlation with the soil depth, while the 137 Cs activity proves uniform in the soil plowing layer of the cultivated land. The study shows the 137 Cs background values of three areas: 1737.1 Bq/m 2 in Yimeng mountain area, 1847.6 Bq/m 2 in southern area of hills in Jiangsu, 918.0 Bq/m 2 in Dianchi catchment. The certainty of 137 Cs background value can technically support the use of 137 Cs technique to study the spatial pattern of soil erosion, deposition and the land degradation, which provides the support for the sustainable utilization of soil resource, the assessment of economical benefit and loss and the evaluation of water and soil conservation measures. (authors)

  15. Rapid determination of {sup 135}Cs and precise {sup 135}Cs/{sup 137}Cs atomic ratio in environmental samples by single-column chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guosheng [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049 (China); Tazoe, Hirofumi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Yamada, Masatoshi, E-mail: myamada@hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan)

    2016-02-18

    For source identification, measurement of {sup 135}Cs/{sup 137}Cs atomic ratio not only provides information apart from the detection of {sup 134}Cs and {sup 137}Cs, but it can also overcome the application limit that measurement of the {sup 134}Cs/{sup 137}Cs ratio has due to the short half-life of {sup 134}Cs (2.06 y). With the recent advancement of ICP-MS, it is necessary to improve the corresponding separation method for rapid and precise {sup 135}Cs/{sup 137}Cs atomic ratio analysis. A novel separation and purification technique was developed for the new generation of triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The simple chemical separation, incorporating ammonium molybdophosphate selective adsorption of Cs and subsequent single cation-exchange chromatography, removes the majority of isobaric and polyatomic interference elements. Subsequently, the ICP-MS/MS removes residual interference elements and eliminates the peak tailing effect of stable {sup 133}Cs, at m/z 134, 135, and 137. The developed analytical method was successfully applied to measure {sup 135}Cs/{sup 137}Cs atomic ratios and {sup 135}Cs activities in environmental samples (soil and sediment) for radiocesium source identification. - Highlights: • A simple {sup 135}Cs/{sup 137}Cs analytical method was developed. • The separation procedure was based on AMP adsorption and one column chromatography. • {sup 135}Cs/{sup 137}Cs was measured by ICP-MS/MS. • Decontamination factors for Ba, Mo, Sb, and Sn were improved. • {sup 135}Cs/{sup 137}Cs atomic ratios of 0.341–0.351 were found in Japanese soil samples.

  16. Bacterial CS2 Hydrolases from Acidithiobacillus thiooxidans Strains Are Homologous to the Archaeal Catenane CS2 Hydrolase

    NARCIS (Netherlands)

    Smeulders, M.J.; Pol, A. van der; Venselaar, H.; Barends, T.R.; Hermans, J.; Jetten, M.S.M.; Camp, H.J.M. op den

    2013-01-01

    Carbon disulfide (CS2) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS2 is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO2) and hydrogen sulfide

  17. Radioecological studies of 137Cs in limnological ecosystems. Biochemical states of 137Cs accumulated in killifish (Medaka, Oryzias latipes) meat

    International Nuclear Information System (INIS)

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro; Nakamura, Fumio.

    1997-01-01

    Biochemical states of 137 Cs accumulated in killifish's (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of 137 Cs radioactivity in the killifish's raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish's control raw meat mixed with 137 Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to 137 CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD 280nm in the samples were different from those of each radioactive peak. It was so suggested that 137 Cs accumulated in the killifish's meat was shown not to be binding to protein's composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with 137 Cs in samples and ammonium phosphomolybdate, 137 Cs in the NPNC fraction of the killifish's meat was not almost different from those of each control and 137 CsCl solution. (author)

  18. Cs/CsPbX3 (X = Br, Cl) epitaxial heteronanocrystals with magic-angle stable/metastable grain boundary

    Science.gov (United States)

    Zhang, Yumeng; Fan, Baolu; Wu, Wenhui; Fan, Jiyang

    2017-05-01

    Metal-semiconductor heteronanostructures are crucial building blocks of nanoscale electronic and optoelectronic devices. However, the lattice misfit remains a challenge in constructing heteronanostructures. Perovskite nanocrystals are superior candidates for constructing nanodevices owing to excellent optical, ferroelectric, and superconducting properties. We report the epitaxial growth of lattice-matched Cs/CsPbBr3 metal-semiconductor heteronanocrystals in a liquid medium. The well-crystallized ultrathin Cs layers grow epitaxially on the surfaces of colloidal CsPbBr3 nanocrystals, forming heteronanocrystals with interface diameters of several nanometers. Most of them are pseudomorphic with coherent interfaces free from dislocations, and the others exhibit discrete high-angle grain boundaries. The model based on the calculation of the elastic potential energy of the epilayer and analysis of the near-coincidence sites explains well the experimental result. The analysis shows that the excellent lattice match between the metal and the semiconductor ensures the ideal epitaxial-growth of both Cs/CsPbBr3 and Cs/CsPbCl3 heteronanocrystals. Such metal/semiconductor heteronanocrystals pave the way for developing perovskite-based nanodevices.

  19. Ecology of blue straggler stars

    CERN Document Server

    Carraro, Giovanni; Beccari, Giacomo

    2015-01-01

    The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution. Such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. They are found to exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group, OB associations and as field stars. This book summarises the many advances in observational and theoretical work dedicated to blue straggler stars. Carefully edited extended contributions by well-known experts in the field cover all the relevant aspects of blue straggler stars research: Observations of blue straggler stars in their various environments; Binary stars and formation channels; Dynamics of globular clusters; Interpretation of observational data and comparison with models. The book also offers an introductory chapter on stellar evolution written by the editors of the book.

  20. What Determines Star Formation Rates?

    Science.gov (United States)

    Evans, Neal John

    2017-06-01

    The relations between star formation and gas have received renewed attention. We combine studies on scales ranging from local (within 0.5 kpc) to distant galaxies to assess what factors contribute to star formation. These include studies of star forming regions in the Milky Way, the LMC, nearby galaxies with spatially resolved star formation, and integrated galaxy studies. We test whether total molecular gas or dense gas provides the best predictor of star formation rate. The star formation ``efficiency," defined as star formation rate divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all the molecular gas. We suggest ways to further develop the concept of "dense gas" to incorporate other factors, such as turbulence.

  1. Spectrophotometry of Symbiotic Stars (Abstract)

    Science.gov (United States)

    Boyd, D.

    2017-12-01

    (Abstract only) Symbiotic stars are fascinating objects - complex binary systems comprising a cool red giant star and a small hot object, often a white dwarf, both embedded in a nebula formed by a wind from the giant star. UV radiation from the hot star ionizes the nebula, producing a range of emission lines. These objects have composite spectra with contributions from both stars plus the nebula and these spectra can change on many timescales. Being moderately bright, they lend themselves well to amateur spectroscopy. This paper describes the symbiotic star phenomenon, shows how spectrophotometry can be used to extract astrophysically useful information about the nature of these systems, and gives results for three symbiotic stars based on the author's observations.

  2. Mass loss from S stars

    International Nuclear Information System (INIS)

    Jura, M.

    1988-01-01

    The mass-loss process in S stars is studied using 65 S stars from the listing of Wing and Yorka (1977). The role of pulsations in the mass-loss process is examined. It is detected that stars with larger mass-loss rates have a greater amplitude of pulsations. The dust-to-gas ratio for the S stars is estimated as 0.002 and the average mass-loss rate is about 6 x 10 to the -8th solar masses/yr. Some of the properties of the S stars, such as scale height, surface density, and lifetime, are measured. It is determined that scale height is 200 pc; the total duration of the S star phase is greater than or equal to 30,000 yr; and the stars inject 3 x 10 to the -6th solar masses/sq kpc yr into the interstellar medium. 46 references

  3. A second generation Cs BEC experiment

    International Nuclear Information System (INIS)

    Gustavsson, M.; Unterwaditzer, P.; Naegerl, H.-C.

    2004-01-01

    We present a new experiment currently under construction in Innsbruck. A Cs BEC will be produced in a glass cell apparatus, allowing maximum optical access and rapid switching of magnetic fields. A high loading rate and a large-volume optical dipole trap at near infrared wavelengths together with optimized 3D Raman sideband cooling should allow for large condensates with more than 10 6 atoms. We plan to load the BEC into a 3D optical lattice. With precisely two or three atoms per site and s-wave interactions tunable through Feshbach resonances at low magnetic fields, it will be possible to study collisions and molecule formation in a very controlled environment. The formation of a molecular BEC made out of bosonic constituents might be stabilized with help of the lattice. A further possible application is the measurement of clock shifts. Another interesting possibility is to study the regime of zero scattering length. A BEC without perturbing mean-field shifts is ideally suited for atom interferometry and precision measurements. For example, it is possible to determine the fine structure constant alpha via measurement of the photon recoil. (author)

  4. Abell 48 - a rare WN-type central star of a planetary nebula

    Science.gov (United States)

    Todt, H.; Kniazev, A. Y.; Gvaramadze, V. V.; Hamann, W.-R.; Buckley, D.; Crause, L.; Crawford, S. M.; Gulbis, A. A. S.; Hettlage, C.; Hooper, E.; Husser, T.-O.; Kotze, P.; Loaring, N.; Nordsieck, K. H.; O'Donoghue, D.; Pickering, T.; Potter, S.; Romero-Colmenero, E.; Vaisanen, P.; Williams, T.; Wolf, M.

    2013-04-01

    A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. Almost all of these H-deficient central stars (CSs) display spectra with strong carbon and helium lines. Most of them exhibit emission-line spectra resembling those of massive WC stars. Therefore these stars are classed as CSPNe of spectral type [WC]. Recently, quantitative spectral analysis of two emission-line CSs, PB 8 and IC 4663, revealed that these stars do not belong to the [WC] class. Instead PB 8 has been classified as [WN/WC] type and IC 4663 as [WN] type. In this work we report the spectroscopic identification of another rare [WN] star, the CS of Abell 48. We performed a spectral analysis of Abell 48 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. We find that the expanding atmosphere of Abell 48 is mainly composed of helium (85 per cent by mass), hydrogen (10 per cent) and nitrogen (5 per cent). The residual hydrogen and the enhanced nitrogen abundance make this object different from the other [WN] star IC 4663. We discuss the possible origin of this atmospheric composition.

  5. ChromaStarPy: A Stellar Atmosphere and Spectrum Modeling and Visualization Lab in Python

    Science.gov (United States)

    Short, C. Ian; Bayer, Jason H. T.; Burns, Lindsey M.

    2018-02-01

    We announce ChromaStarPy, an integrated general stellar atmospheric modeling and spectrum synthesis code written entirely in python V. 3. ChromaStarPy is a direct port of the ChromaStarServer (CSServ) Java modeling code described in earlier papers in this series, and many of the associated JavaScript (JS) post-processing procedures have been ported and incorporated into CSPy so that students have access to ready-made data products. A python integrated development environment (IDE) allows a student in a more advanced course to experiment with the code and to graphically visualize intermediate and final results, ad hoc, as they are running it. CSPy allows students and researchers to compare modeled to observed spectra in the same IDE in which they are processing observational data, while having complete control over the stellar parameters affecting the synthetic spectra. We also take the opportunity to describe improvements that have been made to the related codes, ChromaStar (CS), CSServ, and ChromaStarDB (CSDB), that, where relevant, have also been incorporated into CSPy. The application may be found at the home page of the OpenStars project: http://www.ap.smu.ca/OpenStars/.

  6. Epiphytic fruticose lichens as biomonitors for retrospective evaluation of the 134Cs/137Cs ratio in Fukushima fallout

    International Nuclear Information System (INIS)

    Ramzaev, V.; Barkovsky, A.; Gromov, A.; Ivanov, S.; Kaduka, M.

    2014-01-01

    In 2011–2013, sampling of epiphytic fruticose lichens of the genera Usnea, Bryoria and Alectoria was carried out on Sakhalin and Kuril Islands (the Sakhalin region, Russia) to investigate contamination of these organisms with the Fukushima-derived 134 Cs and 137 Cs. Activities of the radionuclides were determined in all 56 samples of lichens taken for the analysis. After correction for radioactive decay (on 15 March 2011), the activity concentrations ranged from 2.1 Bq kg −1 (d.w.) to 52 Bq kg −1 for 134 Cs and from 2.3 Bq kg −1 to 52 Bq kg −1 for 137 Cs. Cesium-134 and 137 Cs activities for the whole set of lichens (n = 56) were strongly positively correlated; Spearman's rank correlation coefficient was calculated as 0.991 (P < 0.01). The activity concentrations of 134 Cs and 137 Cs in Usnea lichens from the Sakhalin and Kunashir islands declined with a factor of three in the period from 2011 to 2013. The average biological half-time for both cesium radionuclides in lichens of the genus Usnea is estimated as 1.3 y. The mean of 0.99 ± 0.10 and median of 0.99 were calculated for the decay corrected 134 Cs/ 137 Cs activities ratios in the lichens (n = 56). The radionuclides ratio in the lichens did not depend on location of sampling site, species and the time that had passed after the Fukushima accident. The regression analysis has shown the background pre-Fukushima level of 137 Cs of 0.4 ± 0.3 Bq kg −1 , whereas the ratio between the Fukushima-borne 134 Cs and 137 Cs in the lichens was estimated as 1.04. The 134 Cs/ 137 Cs activities ratio in lichens from the Sakhalin region is consistent with the ratios reported by others for the heavy contaminated areas on Honshu Island in Japan following the Fukushima accident. The activity concentrations of natural 7 Be in lichens from the Sakhalin region varied between 100 Bq kg −1 and 600 Bq kg −1 ; the activity concentrations did not exhibit temporal variations during a 2y-period of observations. The

  7. Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

    Science.gov (United States)

    Cha, Ji-Hyun; Han, Jae Hoon; Yin, Wenping; Park, Cheolwoo; Park, Yongmin; Ahn, Tae Kyu; Cho, Jeong Ho; Jung, Duk-Young

    2017-02-02

    High-quality and millimeter-sized perovskite single crystals of CsPbBr 3 and Cs 4 PbBr 6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr 3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs 4 PbBr 6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr 3 , which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr 6 ] 4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

  8. 137Cs in the western South Pacific Ocean

    International Nuclear Information System (INIS)

    Yamada, Masatoshi; Wang Zhongliang

    2007-01-01

    The 137 Cs activities were determined for seawater samples from the East Caroline, Coral Sea, New Hebrides, South Fiji and Tasman Sea (two stations) Basins of the western South Pacific Ocean by γ spectrometry using a low background Ge detector. The 137 Cs activities ranged from 1.4 to 2.3 Bq m -3 over the depth interval 0-250 m and decreased exponentially from the subsurface to 1000 m depth. The distribution profiles of 137 Cs activity at these six western South Pacific Ocean stations did not differ from each other significantly. There was a remarkable difference for the vertical profiles of 137 Cs activity between the East Caroline Basin station in this study and the GEOSECS (Geochemical Ocean Sections Study) station at the same latitude in the Equatorial Pacific Ocean; the 137 Cs inventory over the depth interval 100-1000 m increased from 400 ± 30 Bq m -2 to 560 ± 30 Bq m -2 during the period from 1973 to 1992. The total 137 Cs inventories in the western South Pacific Ocean ranged from 850 ± 70 Bq m -2 in the Coral Sea Basin to 1270 ± 90 Bq m -2 in the South Fiji Basin. Higher 137 Cs inventories were observed at middle latitude stations in the subtropical gyre than at low latitude stations. The 137 Cs inventories were 1.9-4.5 times (2.9 ± 0.7 on average) and 1.7-4.3 times (3.1 ± 0.7 on average) higher than that of the expected deposition density of atmospheric global fallout at the same latitude and that of the estimated 137 Cs deposition density in 10 o latitude by 10 deg. longitude grid data obtained by Aoyama et al. [Aoyama M, Hirose K, Igarashi Y. Re-construction and updating our understanding on the global weapons tests 137 Cs fallout. J Environ Monit 2006;8:431-438], respectively. The possible processes for higher 137 Cs inventories in the western South Pacific Ocean than that of the expected deposition density of atmospheric global fallout may be attributable to the inter-hemisphere dispersion of the atmospheric nuclear weapons testing 137 Cs from

  9. Neutron Star Science with the NuSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-16

    The Nuclear Spectroscopic Telescope Array (NuSTAR), launched in June 2012, helped scientists obtain for the first time a sensitive high-­energy X-­ray map of the sky with extraordinary resolution. This pioneering telescope has aided in the understanding of how stars explode and neutron stars are born. LLNL is a founding member of the NuSTAR project, with key personnel on its optics and science team. We used NuSTAR to observe and analyze the observations of different neutron star classes identified in the last decade that are still poorly understood. These studies not only help to comprehend newly discovered astrophysical phenomena and emission processes for members of the neutron star family, but also expand the utility of such observations for addressing broader questions in astrophysics and other physics disciplines. For example, neutron stars provide an excellent laboratory to study exotic and extreme phenomena, such as the equation of state of the densest matter known, the behavior of matter in extreme magnetic fields, and the effects of general relativity. At the same time, knowing their accurate populations has profound implications for understanding the life cycle of massive stars, star collapse, and overall galactic evolution.

  10. White Dwarf Stars

    Science.gov (United States)

    1999-01-01

    Peering deep inside a cluster of several hundred thousand stars, NASA's Hubble Space Telescope has uncovered the oldest burned-out stars in our Milky Way Galaxy, giving astronomers a fresh reading on the age of the universe. Located in the globular cluster M4, these small, burned-out stars -- called white dwarfs -- are about 12 to 13 billion years old. By adding the one billion years it took the cluster to form after the Big Bang, astronomers found that the age of the white dwarfs agrees with previous estimates that the universe is 13 to 14 billion years old. The images, including some taken by Hubble's Wide Field and Planetary Camera 2, are available online at http://oposite.stsci.edu/pubinfo/pr/2002/10/ or http://www.jpl.nasa.gov/images/wfpc . The camera was designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif. In the top panel, a ground-based observatory snapped a panoramic view of the entire cluster, which contains several hundred thousand stars within a volume of 10 to 30 light-years across. The Kitt Peak National Observatory's .9-meter telescope took this picture in March 1995. The box at left indicates the region observed by the Hubble telescope. The Hubble telescope studied a small region of the cluster. A section of that region is seen in the picture at bottom left. A sampling of an even smaller region is shown at bottom right. This region is only about one light-year across. In this smaller region, Hubble pinpointed a number of faint white dwarfs. The blue circles indicate the dwarfs. It took nearly eight days of exposure time over a 67-day period to find these extremely faint stars. Globular clusters are among the oldest clusters of stars in the universe. The faintest and coolest white dwarfs within globular clusters can yield a globular cluster's age. Earlier Hubble observations showed that the first stars formed less than 1 billion years after the universe's birth in the big bang. So, finding the oldest stars puts astronomers within

  11. Alchemy of stars

    Energy Technology Data Exchange (ETDEWEB)

    Parashar, D [A.R.S.D. Coll., New Delhi (India); Bhatia, V B [Delhi Univ. (India). Dept. of Physics and Astrophysics

    1976-05-01

    Developments in studies on stellar evolution during this century are reviewed. Recent considerations indicate that almost all elements between helium and zinc (a range which comprises more than 99 percent by mass of elements heavier than helium) can be synthesised in nuclear processes occurring during the late violent stages of an exploding star or supernova and a vigorous study in the new field of explosive nucleosynthesis is in progress. The process of nucleosynthesis has been classified into 8 sets of nuclear reactions, namely, (1) hydrogen burning, (2) helium burning, (3) ..cap alpha..-process, (4) e-process, (5) s-process, (6) r-process, (7) p-process and (8) x-process. The abundance of helium and heavier elements are explained and the formation of various elements during supernova explosions is discussed. The questions regarding the appropriate astrophysical conditions for the formation of massive stars (3 to 8 times solar mass) is still unanswered.

  12. Very low mass stars

    International Nuclear Information System (INIS)

    Liebert, J.; Probst, R.G.

    1987-01-01

    This paper discusses several theoretical and observational topics involved in discovering and analyzing very low mass stellar objects below about 0.3 M circle, as well as their likely extension into the substellar range. The authors hereafter refer to these two classes of objects as VLM stars and brown dwarfs, respectively; collectively, they are called VLM objects. The authors outline recent theoretical work on low-mass stellar interiors and atmospheres, the determination of the hydrogen-burning mass limit, important dynamical evidence bearing on the expected numbers of such objects, and the expectations for such objects from star-formation theory. They focus on the properties of substellar objects near the stellar mass limit. Observational techniques used to discover and analyze VLM objects are summarized

  13. Pulsating stars harbouring planets

    Directory of Open Access Journals (Sweden)

    Moya A.

    2013-04-01

    Full Text Available Why bother with asteroseismology while studying exoplanets? There are several answers to this question. Asteroseismology and exoplanetary sciences have much in common and the synergy between the two opens up new aspects in both fields. These fields and stellar activity, when taken together, allow maximum extraction of information from exoplanet space missions. Asteroseismology of the host star has already proved its value in a number of exoplanet systems by its unprecedented precision in determining stellar parameters. In addition, asteroseismology allows the possibility of discovering new exoplanets through time delay studies. The study of the interaction between exoplanets and their host stars opens new windows on various physical processes. In this review I will summarize past and current research in exoplanet asteroseismology and explore some guidelines for the future.

  14. Shells around stars

    International Nuclear Information System (INIS)

    Olnon, F.M.

    1977-01-01

    This thesis deals with optically visible stars surrounded by gas and dust and hot enough to ionize the hydrogen atoms in their envelopes. The ionized gas emits radio continuum radiation by the thermal Bremsstrahlung mechanism. Cool giant stars that show radio line emission from molecules in their circumstellar envelopes are discussed. Under favourable conditions the so-called maser effect gives rise to very intense emission lines. Up till now seven different maser transitions have been found in the envelopes of cool giants. Four of these lines from OH, H 2 O and SiO are studied here. Each of them originates in a different layer so that these lines can be used to probe the envelope. The profile of a maser line gives information about the velocity structure of the region where it is formed

  15. Structure of neutron stars

    International Nuclear Information System (INIS)

    Cheong, C.K.

    1974-01-01

    Structure of neutron stars consisting of a cold and catalyzed superdense matter were investigated by integrating the equations for hydrostatic equilibrium based on the General Relativity theory. The equations of state were obtained with the help of semiempirical nuclear mass formulae. A large phase transition was found between the nuclear and subnuclear density regions. The density phase transition points were calculated as 6.2 x 10 11 and 3.8 x 10 13 g/cm 3 . Due to such a large phase transition, the equation of state practically consists of two parts: The nuclear and subnuclear phases wich are in contact under the thermodynamical equilibrium at the corresponding pressure. Some macroscopic properties of neutron stars are discussed. (Author) [pt

  16. What stars become supernovae

    International Nuclear Information System (INIS)

    Tinsley, B.M.

    1975-01-01

    A variety of empirical lines of evidence is assembled on the masses and stellar population types of stars that trigger supernova (SN) explosions. The main theoretical motivations are to determine whether type I supernovae (SN I) can have massive precursors, and whether there is an interval of stellar mass, between the masses of precursors of pulsars and white dwarfs, that is disrupted by carbon detonation. Statistical and other uncertainties in the empirical arguments are given particular attention, and are found to be more important than generally realized. Relatively secure conclusions include the following. Statistics of stellar birthrates, SN, pulsars, and SN remnants in the Galaxy show that SN II (or all SN) could arise from stars with masses greater than M/sub s/ where M/sub s/ approximately 49 to 12 M solar mass; the precursor mass range cannot be more closely defined from present data; nor can it be said whether all SN leave pulsars and/or extended radio remnants. Several methods of estimating the masses of stars that become white dwarfs are consistent with a lower limit, M/sub s/ greater than or equal to 5 M solar mass, so carbon detonation may indeed be avoided, although this conclusion is not secure. Studies of the properties of galaxies in which SN occur, and their distributions within galaxies, support the usual views that SN I have low-mass precursors (less than or equal to 5 M solar mass and typically less than or equal to 1 M solar mass) and SN II have massive precursors (greater than or equal to 5 M solar mass); the restriction of known SN II to Sc and Sb galaxies, to date, is shown to be consistent, statistically, with massive stars in other galaxies also dying as SN II. Possible implications of the peculiarities of some SN-producing galaxies are discussed. Suggestions are made for observational and theoretical studies that would help answer important remaining questions on the nature of SN precursors

  17. Detector limitations, STAR

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, D. G.

    1998-07-13

    Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

  18. Oscillations in neutron stars

    International Nuclear Information System (INIS)

    Hoeye, Gudrun Kristine

    1999-01-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l → 4) f-modes we were also able to derive a formula that determines II l+1 from II l and II l-1 to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n c , while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  19. Oscillations in neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Hoeye, Gudrun Kristine

    1999-07-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  20. Sequestration and disposal of dissolved Cs+ using zeolite 13X

    Science.gov (United States)

    Park, M.; Park, J.; Jeong, H. Y.

    2017-12-01

    Low-to-intermediate level liquid radioactive wastes (LILLW) typically contain high levels of radioactive 137Cs. Due to the great radiational and thermal stability as well as the high selectivity, zeolite has been commonly utilized to sequester radioactive isotopes from nuclear wastewater effluents. In this study, an Al-rich synthetic zeolite 13X was evaluated for the sorption capacity of Cs+ as a function of pH (4.0-10.5), ionic strength (0.05 and 0.2 M), and initial Cs+ concentration (1×10-6-5×10-3 M). For safe disposal, Cs+-exchanged 13X was both thermally and hydrothermally treated under different temperature and pressure. Subsequently, the resultant materials were examined for the phase transition by X-ray diffraction (XRD) and the local coordination chemistry by X-ray absorption spectroscopy (XAS). Our experimental results will detail the Cs+ sorption behavior by 13X under varying solution compositions. Also, the structural changes of Cs+-exchanged 13X upon thermal and hydrothermal treatment will be delineated to assess the stability of Cs+ in the treated materials.

  1. Cs-137 in Arctic foxes (Alopex lagopus) on Svalbard

    International Nuclear Information System (INIS)

    Gwynn, Justin P.; Fuglei, Eva; Dowdall, Mark

    2007-01-01

    This study presents 137 Cs muscle activity concentrations in Arctic foxes (Alopex lagopus) from Svalbard over a period of several years and discusses the transfer of 137 Cs to Arctic foxes through likely predator-prey relationships. Mean 137 Cs activity concentrations and 137 Cs T ag values (per trapping season) ranged from 0.51 ± 2.76 to 1.32 ± 2.89 Bq/kg (w.w.) and 5.1 x 10 -4 to 1.3 x 10 -3 m 2 /kg, respectively. Mean concentration ratios of 137 Cs in Arctic foxes compared to probable prey ranged from 1.0 to 7.9. On Svalbard, transfer of 137 Cs to Arctic foxes is likely to occur via both marine and terrestrial food chains. The relative contribution of marine and terrestrial food sources to the diet of Arctic foxes may vary by location and by season and may lead to either an increase or decrease in the trophic transfer of 137 Cs to Arctic foxes compared to transfer resulting from terrestrial only diets

  2. Measurement limits to 134Cs concentration in soil

    International Nuclear Information System (INIS)

    Ahn, J.K.; Kim, J.S.; Lee, H.M.; Kim, H.; Kim, T.H.; Park, J.N.; Kang, Y.S.; Lee, H.S.; Kim, S.J.; Park, J.Y.; Ryu, S.Y.; Kim, H.-Ch.; Kang, W.G.; Kim, S.K.

    2011-01-01

    We investigate the caesium concentrations in soils in mountain areas near Gori nuclear power plant in Korea, focusing on the measurement limits to the 134 Cs. In order to lower the minimum detectable amount (MDA) of activity for the 134 Cs, we have used the ammonium molybdophosphate (AMP) precipitation method to get rid of the 40 K existing in natural radioactivity, which reduces the MDA activity about 10 times smaller than those without the AMP precipitation method. The MDA results for the 134 Cs were found to be in the range between 0.015 and 0.044 Bq/kg-dry weight. In order to diminish the background, we also have measured a part of the soil samples in Yangyang, a small town in the east coast of Korea. However, it turns out that in order to detect the 134 Cs in the samples the MDA should be reduced to the level of mBq/kg-dry weight. - Highlights: → We study the caesium concentrations in soils in mountain areas near Gori NPT in Korea. → We use the AMP precipitation method to lower the minimum detectable amount (MDA) of activity for the 134 Cs. → The results of the MDA for the 134 Cs turn out to be in the range between 0.015 and 0.044. → In order to detect the 134 Cs in the samples, the MDA should be reduced to the level of mBq/kg-dry weight.

  3. Measurement of 137Cs activity in living chicken

    International Nuclear Information System (INIS)

    Balas, J.; Poeschl, M.

    1998-01-01

    The possibility of measuring the 137 Cs activity in broiler chickens in vivo was examined. The experiment was conducted with broiler chickens 7 to 22 days old (White Leghorn hybrid, race ISA VEDETTE). Three oral doses of 137 Cs (total activity 5 kBq/chicken) were administered during a day (at 8:00, 12:00 and 16:00). The radioactivity was determined by gamma spectroscopy with a stabilised Nal/Tl detector. The measurement was carried out on days 1, 2, 3, 4, 7, 8, 14 and 15 after the 137 Cs administration in vivo. The detector was put closely to the body in the area of breast muscles. The radiocesium activity concentrations in fresh daily excreta were also determined. A rapid uptake of the orally administered 137 Cs (within a few hours) as well as a rapid loss of radiocesium were observed. The dynamics and accuracy of the in vivo measurement of 137 Cs activity were comparable with the recently published results of in vitro measurement of radiocesium activity. Only the initial 137 Cs activity (during 2 days after 137 Cs application) was higher with regard to the content of contaminated feed mixture in the gastrointestinal tract

  4. Chondroitin Sulfate (CS) Lyases: Structure, Function and Application in Therapeutics.

    Science.gov (United States)

    Rani, Aruna; Patel, Seema; Goyal, Arun

    2018-01-01

    Glycosaminoglycans (GAGs) such as chondroitin sulfate (CS) are the chief natural polysaccharides which reside in biological tissues mainly in extracellular matrix. These CS along with adhesion molecules and growth factors are involved in central nervous system (CNS) development, cell progression and pathogenesis. The chondroitin lyases are the enzyme that degrade and alter the CS chains and hence modify various signalling pathways involving CS chains. These CS lyases are substrate specific, can precisely manipulate the CS polysaccharides and have various biotechnological, medical and therapeutic applications. These enzymes can be used to produce the unsaturated oligosaccharides, which have immune-modulatory, anti-inflammatory and neuroprotective properties. This review focuses on the major breakthrough of the chondroitin sulfate degrading enzymes, their structures and functioning mechanism. This also provides comprehensive information regarding production, purification, characterization of CS lyases and their major applications, both established as well as emerging ones such as neural development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Waste forms based on Cs-loaded silicotitanates

    International Nuclear Information System (INIS)

    Balmer, M.L.; Bunker, B.C.

    1995-04-01

    Silicotitanate ion exchange materials are being considered for removal of radioactive Cs and Sr from tank wastes at the Hanford site. The phase evolution as a function of heat treatment temperature for several sol gel derived compositions within the Cs 2 O-SiO 2 -TiO 2 system was investigated, in order to determine if an adequate waste form can be achieved by direct thermal conversion. The Cs leach rates and Cs loss during heat treatment of select materials were measured. Some compositions which contain large amounts of Ti melt to form a glass with reasonably low aqueous leach rates. A new Cs-silicotitanate material with a structure isomorphous to pollucite was discovered. This material forms at low temperatures (700--800 C) where Cs volatility is negligible. The silicotitanate-pollucite exhibits extremely low leach rates (1.42 g/m 2 day ) at 90 C, and has been identified as a promising waste form for Cs containment

  6. Star clouds of Magellan

    International Nuclear Information System (INIS)

    Tucker, W.

    1981-01-01

    The Magellanic Clouds are two irregular galaxies belonging to the local group which the Milky Way belongs to. By studying the Clouds, astronomers hope to gain insight into the origin and composition of the Milky Way. The overall structure and dynamics of the Clouds are clearest when studied in radio region of the spectrum. One benefit of directly observing stellar luminosities in the Clouds has been the discovery of the period-luminosity relation. Also, the Clouds are a splendid laboratory for studying stellar evolution. It is believed that both Clouds may be in the very early stage in the development of a regular, symmetric galaxy. This raises a paradox because some of the stars in the star clusters of the Clouds are as old as the oldest stars in our galaxy. An explanation for this is given. The low velocity of the Clouds with respect to the center of the Milky Way shows they must be bound to it by gravity. Theories are given on how the Magellanic Clouds became associated with the galaxy. According to current ideas the Clouds orbits will decay and they will spiral into the Galaxy

  7. Stars of strange matter

    International Nuclear Information System (INIS)

    Bethe, H.A.; Brown, G.E.; Cooperstein, J.

    1987-01-01

    We investigate suggestions that quark matter with strangeness per baryon of order unity may be stable. We model this matter at nuclear matter densities as a gas of close packed Λ-particles. From the known mass of the Λ-particle we obtain an estimate of the energy and chemical potential of strange matter at nuclear densities. These are sufficiently high to preclude any phase transition from neutron matter to strange matter in the region near nucleon matter density. Including effects from gluon exchange phenomenologically, we investigate higher densities, consistently making approximations which underestimate the density of transition. In this way we find a transition density ρ tr > or approx.7ρ 0 , where ρ 0 is nuclear matter density. This is not far from the maximum density in the center of the most massive neutron stars that can be constructed. Since we have underestimated ρ tr and still find it to be ∝7ρ 0 , we do not believe that the transition from neutron to quark matter is likely in neutron stars. Moreover, measured masses of observed neutron stars are ≅1.4 M sun , where M sun is the solar mass. For such masses, the central (maximum) density is ρ c 0 . Transition to quark matter is certainly excluded for these densities. (orig.)

  8. Stable dark energy stars

    International Nuclear Information System (INIS)

    Lobo, Francisco S N

    2006-01-01

    The gravastar picture is an alternative model to the concept of a black hole, where there is an effective phase transition at or near where the event horizon is expected to form, and the interior is replaced by a de Sitter condensate. In this work a generalization of the gravastar picture is explored by considering matching of an interior solution governed by the dark energy equation of state, ω ≡ p/ρ < -1/3, to an exterior Schwarzschild vacuum solution at a junction interface. The motivation for implementing this generalization arises from the fact that recent observations have confirmed an accelerated cosmic expansion, for which dark energy is a possible candidate. Several relativistic dark energy stellar configurations are analysed by imposing specific choices for the mass function. The first case considered is that of a constant energy density, and the second choice that of a monotonic decreasing energy density in the star's interior. The dynamical stability of the transition layer of these dark energy stars to linearized spherically symmetric radial perturbations about static equilibrium solutions is also explored. It is found that large stability regions exist that are sufficiently close to where the event horizon is expected to form, so that it would be difficult to distinguish the exterior geometry of the dark energy stars, analysed in this work, from an astrophysical black hole

  9. Spheroidal Populated Star Systems

    Science.gov (United States)

    Angeletti, Lucio; Giannone, Pietro

    2008-10-01

    Globular clusters and low-ellipticity early-type galaxies can be treated as systems populated by a large number of stars and whose structures can be schematized as spherically symmetric. Their studies profit from the synthesis of stellar populations. The computation of synthetic models makes use of various contributions from star evolution and stellar dynamics. In the first sections of the paper we present a short review of our results on the occurrence of galactic winds in star systems ranging from globular clusters to elliptical galaxies, and the dynamical evolution of a typical massive globular cluster. In the subsequent sections we describe our approach to the problem of the stellar populations in elliptical galaxies. The projected radial behaviours of spectro-photometric indices for a sample of eleven galaxies are compared with preliminary model results. The best agreement between observation and theory shows that our galaxies share a certain degree of heterogeneity. The gas energy dissipation varies from moderate to large, the metal yield ranges from solar to significantly oversolar, the dispersion of velocities is isotropic in most of the cases and anisotropic in the remaining instances.

  10. What are the stars?

    CERN Document Server

    Srinivasan, Ganesan

    2014-01-01

    The outstanding question in astronomy at the turn of the twentieth century was: What are the stars and why are they as they are? In this volume, the story of how the answer to this fundamental question was unravelled is narrated in an informal style, with emphasis on the underlying physics. Although the foundations of astrophysics were laid down by 1870, and the edifice was sufficiently built up by 1920, the definitive proof of many of the prescient conjectures made in the 1920s and 1930s came to be established less than ten years ago. This book discusses these recent developments in the context of discussing the nature of the stars, their stability and the source of the energy they radiate.  Reading this book will get young students excited about the presently unfolding revolution in astronomy and the challenges that await them in the world of physics, engineering and technology. General readers will also find the book appealing for its highly accessible narrative of the physics of stars.  “... The reade...

  11. Polarimetry of symbiotic stars

    International Nuclear Information System (INIS)

    Piirola, V.

    1983-01-01

    Five symbiotic stars have been observed for linear polarization (UBVRI) in September 1981. Three systems, CH Cyg, CI Cyg and AG Peg show intrinsic polarization while in the case of Z And and AX Per the observed polarization seems to be mostly of interstellar origin. The position angle of polarization of CI Cyg and AG Peg rotates strongly vs. wavelength, as observed also for CH Cyg in 1977-80. The polarization of CH Cyg has decreased since May 1980, especially in the I, R and U bands, so that the maximum polarization is now in the blue (Psub(B) approx. 0.3%). Probably one is monitoring the formation, growth and disappearance of dust particles in the atmosphere of this star. Two related systems, PU Vul (Nova Vul 1979) and R Aql (Mira) have polarization behaviour rather similar to that of symbiotic stars which suggests that the M type giant present in these systems is responsible for most of the intrinsic polarization. (Auth.)

  12. Improved autonomous star identification algorithm

    International Nuclear Information System (INIS)

    Luo Li-Yan; Xu Lu-Ping; Zhang Hua; Sun Jing-Rong

    2015-01-01

    The log–polar transform (LPT) is introduced into the star identification because of its rotation invariance. An improved autonomous star identification algorithm is proposed in this paper to avoid the circular shift of the feature vector and to reduce the time consumed in the star identification algorithm using LPT. In the proposed algorithm, the star pattern of the same navigation star remains unchanged when the stellar image is rotated, which makes it able to reduce the star identification time. The logarithmic values of the plane distances between the navigation and its neighbor stars are adopted to structure the feature vector of the navigation star, which enhances the robustness of star identification. In addition, some efforts are made to make it able to find the identification result with fewer comparisons, instead of searching the whole feature database. The simulation results demonstrate that the proposed algorithm can effectively accelerate the star identification. Moreover, the recognition rate and robustness by the proposed algorithm are better than those by the LPT algorithm and the modified grid algorithm. (paper)

  13. 134Cs emission probabilities determination by gamma spectrometry

    Science.gov (United States)

    de Almeida, M. C. M.; Poledna, R.; Delgado, J. U.; Silva, R. L.; Araujo, M. T. F.; da Silva, C. J.

    2018-03-01

    The National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) of Rio de Janeiro performed primary and secondary standardization of different radionuclides reaching satisfactory uncertainties. A solution of 134Cs radionuclide was purchased from commercial supplier to emission probabilities determination of some of its energies. 134Cs is a beta gamma emitter with 754 days of half-life. This radionuclide is used as standard in environmental, water and food control. It is also important to germanium detector calibration. The gamma emission probabilities (Pγ) were determined mainly for some energies of the 134Cs by efficiency curve method and the Pγ absolute uncertainties obtained were below 1% (k=1).

  14. Study of /sup 137/Cs absorption by Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Bergamini, P G; Palmas, G; Piantelli, F; Sani, M [Siena Univ. (Italy). Ist. di Fisica; Banditelli, P; Previtera, M; Sodi, F

    1979-09-01

    Absorption of /sup 137/Cs by the floating aquatic plant Lemna minor in relation to /sup 137/Cs concentration in the water was measured under controlled conditions of temperature, pH and light. The method used to analyse the results is described. When applied to this study the method shows the influence on /sup 137/Cs absorption of (1) potassium-cesium exchange due to chemical affinity, (2) the natural colony growth of the organism and (3) the effect of light. Concentration factors were determined for these three processes.

  15. Study of 137Cs absorption by Lemna minor

    International Nuclear Information System (INIS)

    Bergamini, P.G.; Palmas, G.; Piantelli, F.; Sani, M.; Banditelli, P.; Previtera, M.; Sodi, F.

    1979-01-01

    Absorption of 137 Cs by the floating aquatic plant Lemna Minor in relation to 137 Cs concentration in the water was measured under controlled conditions of temperature, pH and light. The method used to analyse the results is described. When applied to this study the method shows the influence on 137 Cs absorption of (1) potassium-cesium exchange due to chemical affinity, (2) the natural colony growth of the organism and (3) the effect of light. Concentration factors were determined for these three processes. (author)

  16. First stars X. The nature of three unevolved carbon-enhanced metal-poor stars

    DEFF Research Database (Denmark)

    Sivarani, T.; Beers, T.C.; Bonifacio, P.

    2006-01-01

    Stars: abundances, stars: population II, Galaxy: abundances, stars: AGB and post-AGB Udgivelsesdato: Nov.......Stars: abundances, stars: population II, Galaxy: abundances, stars: AGB and post-AGB Udgivelsesdato: Nov....

  17. Changing US Attributes After CS-US Pairings Changes CS-Attribute-Assessments: Evidence for CS-US Associations in Attribute Conditioning.

    Science.gov (United States)

    Förderer, Sabine; Unkelbach, Christian

    2016-03-01

    Attribute Conditioning (AC) refers to people's changed assessments of stimuli's (CSs) attributes due to repeated pairing with stimuli (USs) possessing these attributes; for example, when an athletic person (US) is paired with a neutral person (CS), the neutral person is judged to be more athletic after the pairing. We hypothesize that this AC effect is due to CSs' associations with USs rather than direct associations with attributes. Three experiments test this hypothesis by changing US attributes after CS-US pairings. Experiments 1 and 2 conditioned athleticism by pairing neutral men (CSs) with athletic and non-athletic USs. Post-conditioning, USs' athleticism was reversed, which systematically influenced participants' assessment of CS athleticism. Experiment 3 conditioned athleticism and changed USs' musicality after CS-US pairings. This post-conditioning change affected musicality assessments of CSs but did not influence athleticism-assessments. The results indicate that AC effects are based on an associative CS-US-attribute structure. © 2016 by the Society for Personality and Social Psychology, Inc.

  18. StarDOM: From STAR format to XML

    International Nuclear Information System (INIS)

    Linge, Jens P.; Nilges, Michael; Ehrlich, Lutz

    1999-01-01

    StarDOM is a software package for the representation of STAR files as document object models and the conversion of STAR files into XML. This allows interactive navigation by using the Document Object Model representation of the data as well as easy access by XML query languages. As an example application, the entire BioMagResBank has been transformed into XML format. Using an XML query language, statistical queries on the collected NMR data sets can be constructed with very little effort. The BioMagResBank/XML data and the software can be obtained at http://www.nmr.embl-heidelberg.de/nmr/StarDOM/

  19. A novel vanadosilicate with hexadeca-coordinated Cs{sup +} ions as a highly effective Cs{sup +} remover

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung [Sogang Univ., Seoul (Korea, Republic of). Korea Center for Artificial Photosynthesis

    2014-07-07

    The effective removal of {sup 137}Cs{sup +} ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various {sup 137}Cs{sup +} removers have been developed, but more effective {sup 137}Cs{sup +} removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V{sup 4+} and V{sup 5+}) ions is now reported, which shows an excellent ability for Cs{sup +} capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs{sup +} concentrations, it was found to be the most effective material for the removal of radioactive Cs{sup +} ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs{sup +} ions, which corresponds to the highest coordination number ever described.

  20. Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3

    OpenAIRE

    Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

    2017-01-01

    Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr3, its synthesis can also yield nanocrystals of Cs4PbBr6 and the properties of the two are easily confused. Here, we investigate in de...

  1. Plutonium isotopes/137Cs activity ratios for soil in Montenegro

    International Nuclear Information System (INIS)

    Antovic, N. M.; Vukotic, P.; Svrkota, N.; Andrukhovich, S.K.

    2011-01-01

    Plutonium isotopes/ 137 Cs activity ratios were determined for six soil samples from Montenegro, using the results of alpha-spectrometric measurements of 239+240 Pu and 238 Pu, as well as gamma-spectrometric cesium measurements. An average 239+240 Pu/ 137 Cs activity ratio is found to be 0.02, as the 238 Pu/ 137 Cs and 238 Pu/ 239+240 Pu one - 0.0006 and 0.03, respectively. It follows from the results that the source of plutonium in Montenegro soil is nuclear weapon testing during the fifties and sixties of the twentieth century. On the other hand, there is a contribution of the accident at the Chernobyl nuclear power plant to the soil contamination with 137 Cs isotope. [sr

  2. Speciation of 137Cs in the Baltic sea water

    International Nuclear Information System (INIS)

    Lujaniene, G.; Morkuniene, R.; Styra, D.

    1998-01-01

    A possibility of application of Filtrac 391 and Nuclepore filters, Ky-2-8-C exchanger and the Mtilon-T fiber impregnated with Fe, Co, Ni ferrocyanides for separation of particulate and ionic 137 Cs in the sea water was investigated. Physico-chemical forms of 137 Cs were investigated in the Baltic Sea water during 1995-1997. It was determined that 137 Cs was mainly present in ionic form (62-93 %) both in the near-shore and open waters. Concentration of particulate 137 Cs ranged from 255 to 625 Bq/kg (dry weight).The distribution coefficient (K d ) of radiocaesium reached values of 2100-9700. (author)

  3. Quasi-freestanding graphene on Ni(111) by Cs intercalation

    KAUST Repository

    Alattas, Maha Hassan Mohssen; Schwingenschlö gl, Udo

    2016-01-01

    A possible approach to achieve quasi-freestanding graphene on a substrate for technological purpose is the intercalation of alkali metal atoms. Cs intercalation between graphene and Ni(111) therefore is investigated using density functional theory

  4. Quasi-freestanding graphene on Ni(111) by Cs intercalation

    KAUST Repository

    Alattas, Maha Hassan Mohssen; Schwingenschlö gl, Udo

    2017-01-01

    It is of technological interest to achieve quasi-freestanding graphene on a substrate. A possible approach is the intercalation of alkali metal atoms. Cs intercalation between graphene and Ni(111) is investigated using density functional theory

  5. Retention of Cs on zeolite, bentonite and their mixtures

    International Nuclear Information System (INIS)

    Atun, G.

    2002-01-01

    The sorption behavior of cesium on zeolite and bentonite minerals and their mixtures was studied by means of a batch method and a tracer technique. All experiments were carried out in the presence of CsCl spiked with 137 Cs and NaCl as a supporting electrolyte in varying concentrations. The distribution coefficients (K D ) did not show significant differences at low Cs + loadings while they decreased in the high loading region. Freundlich and D-R isotherms were applied to the adsorption data of zeolite and bentonite. Adsorption capacities and mean energies calculated from D-R isotherm parameters decreased by increasing ionic strength on both minerals. The identification of the specific uptake sites was attempted on the basis of the Freundlich isotherm. Experimentally observed distribution coefficients of Cs on two mineral mixtures were smaller than theoretically calculated values, except at the highest NaCl concentration. (author)

  6. Kinetics of Cs adsorption on soils with different mineralogical composition

    International Nuclear Information System (INIS)

    Nakao, Atsushi; Funakawa, Shinya; Kosaki, Takashi

    2004-01-01

    137 Cs is one of the main radioisotopes released into the environment by nuclear powerstation accidents (e.g. Chernobyl) and nuclear weapons tests. Many studies have shown that Cs tends to remain at surface soils due to the high adsorption selectivity of clay minerals for this element. This behavior of the Cs + ion is, however, assumed to vary significantly depending on the mineralogical composition of the soil. The main objective of this study is to analyze the kinetics of Cs adsorption on soils with different mineralogical composition. Soil samples used in this study were Mollisols (Um) and Alfisols (Ua) from Ukraine, Ultisols (Tu) from Thailand and Spodosols (Js) from Japan. The dominant clay species of these soils are montmorillonite (Um, Ua), kaolinite and mica (Tu) and beidellite (Js). The rates of Cs adsorption and Ca or K desorption were measured using a continuous flow method. Soil samples that were previously saturated with Ca 2+ were leached with a 0.75 mmol/l Cs + solution at a constant rate of 2.0 ml/min. The leachate was collected every 10 minutes and the concentrations of Cs + , Ca 2+ and K + of each aliquot were measured by atomic adsorption spectrophotometry (Cs + , Ca 2+ ) and flame spectrophotometry (K + ). The datasets obtained were simulated using the first order kinetic model: y = a(1 - exp(-kt)), where a is the adsorption (desorption) maximum and k the rate constant. It is here assumed that Ca 2+ is desorbed from cation exchange sites and K + desorbed from the frayed edges of micaceous minerals. The values of a obtained for both Cs adsorption and Ca desorption was in the order Js>Um>Tu>Ua, whereas the values of k were in the order Tu>Ua>Um>Js. This result reflects the values of permanent negative charge of clays which are originated from the substitution of cations in the structure of 2:1 clay minerals. The value of a for K + desorption was, however, highest in Tu, suggesting that the values of Cs + -exchangeable K + correspond to the amount

  7. Ultracompact X-ray binary stars

    NARCIS (Netherlands)

    Haaften, L.M. van

    2013-01-01

    Ultracompact X-ray binary stars usually consist of a neutron star and a white dwarf, two stars bound together by their strong gravity and orbiting each other very rapidly, completing one orbit in less than one hour. Neutron stars are extremely compact remnants of the collapsed cores of massive stars

  8. Numerical study of rotating relativistic stars

    International Nuclear Information System (INIS)

    Wilson, J.R.

    1975-01-01

    The equations of structure for rotating stars in general relativity are presented and put in a form suitable for computer calculations. The results of equilibrium calculations for supermassive stars, neutron stars, and magnetically supported stars are reported, as are calculations of collapsing, rotating, and magnetized stars in the slowly changing gravitational field approximation. (auth)

  9. The Spacelab IPS Star Simulator

    Science.gov (United States)

    Wessling, Francis C., III

    The cost of doing business in space is very high. If errors occur while in orbit the costs grow and desired scientific data may be corrupted or even lost. The Spacelab Instrument Pointing System (IPS) Star Simulator is a unique test bed that allows star trackers to interface with simulated stars in a laboratory before going into orbit. This hardware-in-the loop testing of equipment on earth increases the probability of success while in space. The IPS Star Simulator provides three fields of view 2.55 x 2.55 degrees each for input into star trackers. The fields of view are produced on three separate monitors. Each monitor has 4096 x 4096 addressable points and can display 50 stars (pixels) maximum at a given time. The pixel refresh rate is 1000 Hz. The spectral output is approximately 550 nm. The available relative visual magnitude range is 2 to 8 visual magnitudes. The star size is less than 100 arc seconds. The minimum star movement is less than 5 arc seconds and the relative position accuracy is approximately 40 arc seconds. The purpose of this paper is to describe the LPS Star Simulator design and to provide an operational scenario so others may gain from the approach and possible use of the system.

  10. Origin of faint blue stars

    International Nuclear Information System (INIS)

    Tutukov, A.; Iungelson, L.

    1987-01-01

    The origin of field faint blue stars that are placed in the HR diagram to the left of the main sequence is discussed. These include degenerate dwarfs and O and B subdwarfs. Degenerate dwarfs belong to two main populations with helium and carbon-oxygen cores. The majority of the hot subdwarfs most possibly are helium nondegenerate stars that are produced by mass exchange close binaries of moderate mass cores (3-15 solar masses). The theoretical estimates of the numbers of faint blue stars of different types brighter than certain stellar magnitudes agree with star counts based on the Palomar Green Survey. 28 references

  11. Statistical properties of barium stars

    International Nuclear Information System (INIS)

    Hakkila, J.E.

    1986-01-01

    Barium stars are G- and K-giant stars with atmospheric excesses of s-process elements, and a broadband spectral depression in the blue portion of the spectrum. The strength of the λ4554 Ball line is used as a classification parameter known as the Barium Intensity. They have a mean absolute magnitude of 1.0 and a dispersion of 1.2 magnitudes (assuming a Gaussian distribution in absolute magnitude) as measured from secular and statistical parallaxes. These stars apparently belong to a young-disk population from analyses of both the solar reflex motion and their residual velocity distribution, which implies that they have an upper mass limit of around three solar masses. There is no apparent correlation of barium intensity with either luminosity or kinematic properties. The barium stars appear to be preferentially distributed in the direction of the local spiral arm, but show no preference to associate with or avoid the direction of the galactic center. They do not appear related to either the carbon or S-stars because of these tendencies and because of the stellar population to which each type of star belongs. The distribution in absolute magnitude combined with star count analyses implies that these stars are slightly less numerous than previously believed. Barium stars show infrared excesses that correlate with their barium intensities

  12. The birth of star clusters

    CERN Document Server

    2018-01-01

    All stars are born in groups. The origin of these groups has long been a key question in astronomy, one that interests researchers in star formation, the interstellar medium, and cosmology. This volume summarizes current progress in the field, and includes contributions from both theorists and observers. Star clusters appear with a wide range of properties, and are born in a variety of physical conditions. Yet the key question remains: How do diffuse clouds of gas condense into the collections of luminous objects we call stars? This book will benefit graduate students, newcomers to the field, and also experienced scientists seeking a convenient reference.

  13. Radiological Cs-137 accidents/incidents in Estonia

    International Nuclear Information System (INIS)

    Sinisso, Mark

    1997-01-01

    Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

  14. Radiological Cs-137 accidents/incidents in Estonia

    Energy Technology Data Exchange (ETDEWEB)

    Sinisso, Mark [Ministry of Foreign Affairs, Tallin (Estonia)

    1997-12-31

    Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

  15. Detection of CS in Neptune's atmosphere from ALMA observations

    Science.gov (United States)

    Moreno, R.; Lellouch, E.; Cavalié, T.; Moullet, A.

    2017-12-01

    Context. The large and vertically non-uniform abundance of CO in Neptune's atmosphere has been interpreted as the result of past cometary impact(s), either single or distributed in size and time, which could also be at the origin of Neptune's HCN. Aims: We aim to provide observational support for this scenario by searching for other comet-induced species, in particular carbon sulfide (CS) which has been observed continuously in Jupiter since the 1994 Shoemaker-Levy 9 impacts. Methods: In April 2016 we used the ALMA interferometer to search for CS(7-6) at 342.883 GHz in Neptune. Results: We report on the detection of CS in Neptune's atmosphere, the first unambiguous observation of a sulfur-bearing species in a giant planet beyond Jupiter. Carbon sulfide appears to be present only at submillibar levels, with a column density of (2.0-3.1) × 1012 cm-2, and a typical mixing ratio of (2-20) × 10-11 that depends on its precise vertical location. The favoured origin of CS is deposition by a putative large comet impact several centuries ago, and the strong depletion of CS with respect to CO - compared to the Jupiter case - is likely due to the CS sticking to aerosols or clustering to form polymers in Neptune's lower stratosphere. Conclusions: The CS detection, along with recent analyses of the CO profile, reinforces the presumption of a large comet impact into Neptune 1000 yr ago, that delivered CO, CS, and HCN at the same time.

  16. 137Cs content in edible mushrooms of the Transcarpathian region

    Directory of Open Access Journals (Sweden)

    O. O. Parlag

    2013-03-01

    Full Text Available Edible mushrooms (Boletus edulis Bull.: Fr. and Leccinum scabrum (Bull.: Fr. S.F.Gray of Transcarpathian region were analyzed on content of 137Cs. Specific activity of 137Cs in collected mushrooms did not exceed 354 ± 53 Bq/kg (dry substance. Estimation of the contribution into internal exposure dose of population for the condi-tion of 1 kg of mushrooms consumption is carried out.

  17. 137Cs radioactive dating of Lake Ontario sediment cores

    International Nuclear Information System (INIS)

    Ward, T.E.; Breeden, J.; Komisarcik, K.; Porter, R.; Czuczwa, J.; Kaminski, R.; McVeety, B.D.

    1987-12-01

    The distribution of 137 Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210 Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 137 Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs

  18. Obsah Cs-137 v houbách

    OpenAIRE

    ČADOVÁ, Michaela

    2015-01-01

    The aim of this work is to compare the presence of Cs-137 in different kinds of mushrooms in selected locations using semiconductor gamma-ray spectrometry. Research question was determined: Does Cs-137 content amount vary depending on the fungal species? The first part deals with basic knowledge of ionizing radiation, which is important for the complex understanding of thematic problems. This concerns basic radiobiological terms such as radioactivity, ionizing radiation, its biological effect...

  19. The Double Star mission

    Directory of Open Access Journals (Sweden)

    Liu

    2005-11-01

    Full Text Available The Double Star Programme (DSP was first proposed by China in March, 1997 at the Fragrant Hill Workshop on Space Science, Beijing, organized by the Chinese Academy of Science. It is the first mission in collaboration between China and ESA. The mission is made of two spacecraft to investigate the magnetospheric global processes and their response to the interplanetary disturbances in conjunction with the Cluster mission. The first spacecraft, TC-1 (Tan Ce means "Explorer", was launched on 29 December 2003, and the second one, TC-2, on 25 July 2004 on board two Chinese Long March 2C rockets. TC-1 was injected in an equatorial orbit of 570x79000 km altitude with a 28° inclination and TC-2 in a polar orbit of 560x38000 km altitude. The orbits have been designed to complement the Cluster mission by maximizing the time when both Cluster and Double Star are in the same scientific regions. The two missions allow simultaneous observations of the Earth magnetosphere from six points in space. To facilitate the comparison of data, half of the Double Star payload is made of spare or duplicates of the Cluster instruments; the other half is made of Chinese instruments. The science operations are coordinated by the Chinese DSP Scientific Operations Centre (DSOC in Beijing and the European Payload Operations Service (EPOS at RAL, UK. The spacecraft and ground segment operations are performed by the DSP Operations and Management Centre (DOMC and DSOC in China, using three ground station, in Beijing, Shanghai and Villafranca.

  20. Symbiotic star AG Dra

    International Nuclear Information System (INIS)

    Ipatov, A.P.; Yudin, B.F.; Moskovskij Gosudarstvennyj Univ.

    1986-01-01

    The results obtained from photometric (in the UBVRJHKLM system) and spectrophotometric (in the range 0.33-0.75 μm) observations of symbiotic star AG Dra are presented. The cool component of this star is a red giant with approximately constant brightness (ΔJ ≤ 0 m .3) classified as K4-K5. This red giant fills it's Roche loble and probably is on the assymptotic giant branch of the HR diagramm. The presence of IR excess in 5 μm associated with radiation of the gaseous envelope with the mass of M≅ 10 -6 M sun have been detected. Observations of AG Dra indicate that growing of the bolometric flux of a hot component is accompanied with decreasing effective temperature. The hot component of the system is probably an accerting red dwarf with the mass M≅ 0.4 M sun and disk accretion of matter of cool star with the rate M >or ∼ 10 -4 M sun year in equatorial region. Increase of accretion rate during the outburst of AG Dra leads to the increase of stellar wind from the red dwarf surface and the decrease of it's effective temperature. The hot component of AG Dra may also be considered as a white Dwarf with luminosity L 3 L sun and R eff >or approx. 0.2 R sun . In this case gravitational energy of accreting matter M > or ∼ 10 -6 M sun / year would be the source of the hot component outbursts. The luminosity between outbursts is determined by energy generation from the burning hydrogen layer source

  1. Bioaccumulation of 137Cs and 60Co by Helianthus annuus

    International Nuclear Information System (INIS)

    Hornik, M.; Pipiska, M.; Vrtoch, L.; Augustin, J.; Lesny, J.

    2005-01-01

    The 60 Co and 137 Cs bioaccumulation by Helianthus annuus L. was measured during 9 day cultivation at 20 ± 2 o C in hydroponic Hoagland medium. Previous starvation for K + and for NH 4 + 2.2 and 2.7 times, respectively, enhanced 137 Cs uptake rate. Previous cultivation in surplus of K + ions 50 mmol·l -1 has no effect on 137 Cs bioaccumulation rate. Both 137 Cs and 60 Co bioaccumulation significantly increase with dilution of basic Hoagland medium up to 1:7 for caesium and up to 1:3 for cobalt followed by mild decrease at higher dilutions. Root to shoot specific 137 Cs radioactivity ratio (Bq.g -1 /Bq·g -1 , fresh wt.) increased with dilution from 1.46 to 9.6-9.8. The values root to shoot specific radioactivity ratio for 60 Co were less dependent on the nutrient concentrations and were within the range 5.7 to 8.5. 137 Cs was localized mainly in young leaves (30%) and roots (39%) and 60 Co mainly in roots (67%) and leaves (20%). Obtained data showed less sensitivity of 60 Co uptake by sunflower on nutrient concentration in hydroponic media. (author)

  2. Performance verification tests of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Murakami, Haruyuki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-11-15

    Highlights: • The performance of the JT-60SA CS model coil was verified. • The CS model coil comprised a quad-pancake wound with a Nb{sub 3}Sn CIC conductor. • The CS model coil met the design requirements. - Abstract: As a final check of the coil manufacturing method of the JT-60 Super Advanced (JT-60SA) central solenoid (CS), we verified the performance of a CS model coil. The model coil comprised a quad-pancake wound with a Nb{sub 3}Sn cable-in-conduit conductor. Measurements of the critical current, joint resistance, pressure drop, and magnetic field were conducted in the verification tests. In the critical-current measurement, the critical current of the model coil coincided with the estimation derived from a strain of −0.62% for the Nb{sub 3}Sn strands. As a result, critical-current degradation caused by the coil manufacturing process was not observed. The results of the performance verification tests indicate that the model coil met the design requirements. Consequently, the manufacturing process of the JT-60SA CS was established.

  3. Performance Evaluation of the Sysmex CS-5100 Automated Coagulation Analyzer.

    Science.gov (United States)

    Chen, Liming; Chen, Yu

    2015-01-01

    Coagulation testing is widely applied clinically, and laboratories increasingly demand automated coagulation analyzers with short turn-around times and high-throughput. The purpose of this study was to evaluate the performance of the Sysmex CS-5100 automated coagulation analyzer for routine use in a clinical laboratory. The prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (Fbg), and D-dimer were compared between the Sysmex CS-5100 and Sysmex CA-7000 analyzers, and the imprecision, comparison, throughput, STAT function, and performance for abnormal samples were measured in each. The within-run and between-run coefficients of variation (CV) for the PT, APTT, INR, and D-dimer analyses showed excellent results both in the normal and pathologic ranges. The correlation coefficients between the Sysmex CS-5100 and Sysmex CA-7000 were highly correlated. The throughput of the Sysmex CS-5100 was faster than that of the Sysmex CA-7000. There was no interference at all by total bilirubin concentrations and triglyceride concentrations in the Sysmex CS-5100 analyzer. We demonstrated that the Sysmex CS-5100 performs with satisfactory imprecision and is well suited for coagulation analysis in laboratories processing large sample numbers and icteric and lipemic samples.

  4. Cs-137 and Sr-90 level in diary products

    International Nuclear Information System (INIS)

    Petukhov, V.L.; Dukhanov, Y.A.; Sevryuk, I.Z.; Patrashkov, S.A.; Korotkevich, O.S.; Gorb, T.S.; Petukhov, I.V.

    2003-01-01

    About 70% of radioactive substances fell on the territory of the Byelorussian Republic after the Chernobyl Atom Power Station Disaster. Cs-137 and Sr-90 accumulation dynamics was studied in milk of the cows from the highest polluted Braginsky area. 408 milk samples of Black and White cows were investigated. In 1995 average Cs-137 and Sr-90 levels were 61.00 and 3.73 Bk/dm 3 respectively. Cs-137 and Sr-90 levels exceeded Byelorussian Republic upper limits RDU - 96 in 10 and 50% of milk samples respectively. After 5 years (by 2000) Cs-137 and Sr-90 levels had become almost 3 and 2 times less (21.70 Bk/dm 3 and 1.72 Bk/dm 3 respectively). Cs-137 and Sr-90 levels exceeded RDU - 96 in 1.5 and 5.5% of milk samples respectively. In the same periods Cs-137 and Sr-90 levels were 7 and 2 times higher than the similar indexes in the relatively clean Novosibirsk area. Thus, radioactive element levels in milk of Black and White cows of the Byelorussian Republic decreased significantly for the past years. (authors)

  5. Transfer of 137Cs through the food chain to man

    International Nuclear Information System (INIS)

    Evans, C.; Bennett, B.G.

    1976-10-01

    Deposition, concentrations in diet, and body burdens of 137 Cs have been measured since 1954 at various sites throughout the world. This report is a compilation and updating of various fallout 137 Cs measurements and an interpretation of transfer properties of 137 Cs from deposition to diet and from diet to man. An empirical model is used to correlate deposition and diet data. Direct foliar contamination, stored food supplies, and uptake from soil contribute to the dietary levels of 137 Cs. The accumulation of 137 Cs by man is described by a single exponential model. The inferred biological half-times, 200 to 400 days, are somewhat greater than the half-time of about 100 days obtained from shorter term studies. Differences in body burdens due to sex, age, and weight are discussed. During the period 1954 to 1974, the internal dose from fallout 137 Cs, based on average body burdens, is estimated to be 4 to 5 percent of the 21 year radiation dose from 40 K

  6. Stars of heaven

    CERN Document Server

    Pickover, Clifford A

    2004-01-01

    Do a little armchair space travel, rub elbows with alien life forms, and stretch your mind to the furthest corners of our uncharted universe. With this astonishing guidebook, you don't have to be an astronomer to explore the mysteries of stars and their profound meaning for human existence. Clifford A. Pickover tackles a range of topics from stellar evolution to the fundamental reasons why the universe permits life to flourish. He alternates sections that explain the mysteries of the cosmos with sections that dramatize mind-expanding concepts through a fictional dialog between futuristic human

  7. Elemental diffusion in stars

    International Nuclear Information System (INIS)

    Michaud, Georges; Montmerle, Thierry

    1977-01-01

    This paper is dealing with the origin of the elements in the universe. The scheme of nucleosynthesis is kept to explain the stellar generation of helium, carbon, etc... from the initial hydrogen; but a nonlinear theory is then elaborated to account for the anomalous abundances which were observed. The chemical elements would diffuse throughout the outer layers of a star under the action of the opposite forces of gravitation and radiation. This theory, with completing the nucleosynthesis, would contribute to give a consistent scheme of the elemental origin and abundances [fr

  8. Hadronic Resonances from STAR

    Directory of Open Access Journals (Sweden)

    Wada Masayuki

    2012-11-01

    Full Text Available The results of resonance particle productions (ρ0, ω, K*, ϕ, Σ*, and Λ* measured by the STAR collaboration at RHIC from various colliding systems and energies are presented. Measured mass, width, 〈pT〉, and yield of those resonances are reviewed. No significant mass shifts or width broadening beyond the experiment uncertainties are observed. New measurements of ϕ and ω from leptonic decay channels are presented. The yields from leptonic decay channels are compared with the measurements from hadronic decay channels and the two results are consistent with each other.

  9. O3 stars

    International Nuclear Information System (INIS)

    Walborn, N.R.

    1982-01-01

    A brief review of the 10 known objects in this earliest spectral class is presented. Two new members are included: HD 64568 in NGC 2467 (Puppis OB2), which provides the first example of an O3 V((f*)) spectrum; and Sk -67 0 22 in the Large Magellanic Cloud, which is intermediate between types O3 If* and WN6-A. In addition, the spectrum of HDE 269810 in the LMC is reclassified as the first of type O3 III (f*). The absolute visual magnitudes of these stars are rediscussed

  10. The Two Translationally Controlled Tumor Protein Genes, CsTCTP1 and CsTCTP2, Are Negative Modulators in the Cucumis sativus Defense Response to Sphaerotheca fuliginea

    Directory of Open Access Journals (Sweden)

    Xiangnan Meng

    2018-04-01

    Full Text Available Pathogen stress often significantly decreases cucumber production. However, knowledge regarding the molecular mechanism and signals of cucumber disease resistance is far from complete. Here, we report two translationally controlled tumor protein genes, CsTCTP1 and CsTCTP2, that are both negative modulators in the Cucumis sativus defense response to Sphaerotheca fuliginea. Subcellular localization analysis showed that CsTCTP1 and CsTCTP2 were both localized in the cytoplasm. Expression analysis indicated that the transcript levels of CsTCTP1 and CsTCTP2 were linked to the degree of cucumber resistance to S. fuliginea. Transient overexpression of either CsTCTP1 or CsTCTP2 in cucumber cotyledons impaired resistance to S. fuliginea, whereas silencing of either CsTCTP1 or CsTCTP2 enhanced cucumber resistance to S. fuliginea. The relationship of several defense-related genes and ABA and target of rapamycin (TOR signaling pathway-related genes to the overexpressing and silencing of CsTCTP1/CsTCTP2 in non-infested cucumber plants was investigated. The results indicated that CsTCTP1 participates in the defense response to S. fuliginea by regulating the expression of certain defense-associated genes and/or ABA signaling pathway-associated genes, and CsTCTP2 participates through regulating the expression of TOR signaling pathway-associated genes. Our findings will guide enhancing the resistance of cucumber to powdery mildew.

  11. The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2010-02-15

    We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

  12. The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    International Nuclear Information System (INIS)

    Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

    2010-01-01

    We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

  13. The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

    Science.gov (United States)

    Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

    2010-02-01

    We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Star-forming galaxy models: Blending star formation into TREESPH

    Science.gov (United States)

    Mihos, J. Christopher; Hernquist, Lars

    1994-01-01

    We have incorporated star-formation algorithms into a hybrid N-body/smoothed particle hydrodynamics code (TREESPH) in order to describe the star forming properties of disk galaxies over timescales of a few billion years. The models employ a Schmidt law of index n approximately 1.5 to calculate star-formation rates, and explicitly include the energy and metallicity feedback into the Interstellar Medium (ISM). Modeling the newly formed stellar population is achieved through the use of hybrid SPH/young star particles which gradually convert from gaseous to collisionless particles, avoiding the computational difficulties involved in creating new particles. The models are shown to reproduce well the star-forming properties of disk galaxies, such as the morphology, rate of star formation, and evolution of the global star-formation rate and disk gas content. As an example of the technique, we model an encounter between a disk galaxy and a small companion which gives rise to a ring galaxy reminiscent of the Cartwheel (AM 0035-35). The primary galaxy in this encounter experiences two phases of star forming activity: an initial period during the expansion of the ring, and a delayed phase as shocked material in the ring falls back into the central regions.

  15. I-Love relations for incompressible stars and realistic stars

    Science.gov (United States)

    Chan, T. K.; Chan, AtMa P. O.; Leung, P. T.

    2015-02-01

    In spite of the diversity in the equations of state of nuclear matter, the recently discovered I-Love-Q relations [Yagi and Yunes, Science 341, 365 (2013), 10.1126/science.1236462], which relate the moment of inertia, tidal Love number (deformability), and the spin-induced quadrupole moment of compact stars, hold for various kinds of realistic neutron stars and quark stars. While the physical origin of such universality is still a current issue, the observation that the I-Love-Q relations of incompressible stars can well approximate those of realistic compact stars hints at a new direction to approach the problem. In this paper, by establishing recursive post-Minkowskian expansion for the moment of inertia and the tidal deformability of incompressible stars, we analytically derive the I-Love relation for incompressible stars and show that the so-obtained formula can be used to accurately predict the behavior of realistic compact stars from the Newtonian limit to the maximum mass limit.

  16. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-05-20

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  17. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    International Nuclear Information System (INIS)

    Liu Tie; Wu Yuefang; Zhang Huawei; Qin Shengli

    2012-01-01

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10 3 cm –3 and kinematic temperature ∼20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  18. Uptake and distribution of 137Cs and stable Cs by microorganisms isolated from mushroom substrata in the Japanese forests

    International Nuclear Information System (INIS)

    Kuwahara, Chikako; Fukumoto, Atsushi; Kato, Fumio; Sugiyama, Hideo

    2004-01-01

    The pH values of wild mushroom substrata, the influence of pH in medium on the appearance frequencies of microorganisms from mushroom substrata, and growth and Cs uptake by several microorganisms were investigated. The results showed that the pH values of 42 mushroom substrata were slightly acidic. There was no remarkable difference in the appearance frequencies of filamentous actinomycetes and planktonic bacteria at pH 5, 6 and 7, except in the samples of mushroom substrata from Mt. Fuji. The values of Cs concentration ratio (CR) for microorganisms isolated from mushroom substrata and for mushrooms were almost the same level, suggesting that those microorganisms could take up Cs in substrata and reserve Cs in their cells. (author)

  19. Facile synthesis and characterization of CsPbBr3 and CsPb2Br5 ...

    Indian Academy of Sciences (India)

    2018-03-23

    Mar 23, 2018 ... All-inorganic caesium lead-halide perovskite CsPbBr3 and ... optoelectronic materials owing to their stabilities and highly efficient photoluminescence (PL). ... chemical tenability [2], hybrid organic–inorganic lead halide-.

  20. Energy- and temperature dependences of secondary electron emission of CsI- and CsBr layers doped with Cd

    International Nuclear Information System (INIS)

    Galij, P.V.; Tsal', N.A.

    1983-01-01

    The energy and temperature dependences of the secondary electron emission coefficient (SEEC) of CsI-Cd-, CsBr-Cd-, CsI-CsBr layers have been studied. The effect of bivalent cadmium impurity on the SEEC value is investigated. It is shown that implantation of small amounts of Cd 2+ impurity into the lattice of the initial monocrystals might increase the SEEC values of the layers. Temperature dependences (TD) of SEEC are measured and the possibility of comparing experimental results with the Dekker formula is analyzed. A conclusion is drawn that the Dekker model well describes the TD of SEEC of doped layers at temperatures T < or approximately 100 deg C. At elevated temperatures., along with secondary electron scattering on phonons, one should take into account their scattering on vacancies

  1. Comparison of CsI(Tl) and CsI(Na) partially slotted crystals for high-resolution SPECT imaging

    International Nuclear Information System (INIS)

    Giokaris, N.; Loudos, G.; Maintas, D.; Karabarbounis, A.; Lembesi, M.; Spanoudaki, V.; Stiliaris, E.; Boukis, S.; Sakellios, N.; Karakatsanis, N.; Gektin, A.; Boyarintsev, A.; Pedash, V.; Gayshan, V.

    2006-01-01

    Dedicated systems based on Position Sensitive Photomultiplier Tubes (PSPMTs) coupled to scintillators, have been used over the past years for the construction of compact systems, suitable for applications such as small animal imaging and small organs imaging. Most of the proposed systems are based on fully pixelized scintillators. Previous studies have shown that partially slotted scintillators offer a good compromise between cost, energy resolution and spatial resolution. In this work, the performance of two sets of CsI(Tl) and CsI(Na) partially slotted crystals is compared. Initial results show that CsI(Tl) scintillators are more suitable for gamma-ray detection, since their performance in terms of sensitivity, spatial and energy resolution is superior than that of CsI(Na)

  2. Seperation of CsCl from LiCl-CsCl molten salt by cold finger melt cryst allization

    Energy Technology Data Exchange (ETDEWEB)

    Versey, Joshua R. [Dept. of Chemical and Materials Engineering and Nuclear Engineering Program University of Idaho, Idaho (United States); Phongikaroon, Supathorn [Dept. of Mechanical and Nuclear Engineering Virginia Commonwealth University, Richmond (Korea, Republic of); Simpson, Michael F. [Dept. of Metallurgical Engineering University of Utah, Utah (Korea, Republic of)

    2014-06-15

    This study provides a fundamental understanding of a cold finger melt crystallization technique by exploring the heat and mass transfer processes of cold finger separation. A series of experiments were performed using a simplified LiCl-CsCl system by varying initial CsCl concentrations (1, 3, 5, and 7.5 wt%), cold finger cooling rates (7.4, 9.8, 12.3, and 14.9 L/min), and separation times (5, 10, 15, and 30 min). Results showed a potential recycling rate of 0.36 g/min with a purity of 0.33 wt% CsCl in LiCl. A CsCl concentrated drip formation was found to decrease crystal purity especially for smaller crystal formations. Dimensionless heat and mass transfer correlations showed that separation production is primarily influenced by convective transfer controlled by cooling gas flow rate, where correlations are more accurate for slower cooling gas flow rates.

  3. Statistical investigation of flare stars. III. Flare stars in the general galactic star field

    International Nuclear Information System (INIS)

    Mirzoyan, L.V.; Ambaryan, V.V.; Garibdzhanyan, A.T.; Mirzoyan, A.L.

    1989-01-01

    Some questions relating to the existence of a large number of flare stars in the general star field of the Galaxy are discussed. It is shown that only a small proportion of them can be found by photographic observations, and the fraction of field flare stars among such stars found in the regions of star clusters and associations does not exceed 10%. The ratio of the numbers of flare stars of the foreground and the background for a particular system depends on its distance, reaching zero at a distance of about 500 pc. The spatial density of flare stars in the Pleiades is at least two orders of magnitude greater than in the general galactic field. A lower limit for the number of flare stars in the Galaxy is estimated at 4.2 ·10 9 , and the number of nonflare red dwarfs at 2.1·10 10 . There are grounds for believing that they were all formed in star clusters and associations

  4. Physicochemical properties of the CsNO2-CsOH-H2O ternary system at 25 deg C

    International Nuclear Information System (INIS)

    Protsenko, P.I.; Medvedev, B.S.; Popova, T.B.

    1977-01-01

    Saturated solutions of the CsNO 2 - CsOH- H 2 O system have been studied at 25 deg C by the methods of solubility, viscosity, electric conductivity, refractometry and density. It is stated that no solid phase of a new composition is formed in the system. While adding hydroxide to the saturated solution of cesium nitride, a considerable salting-out of the latter takes place

  5. Thermal gravimetric analysis of the CsCuCl3, Cs2CuCl4 and Cs2CuCl4x2H2O crystals

    International Nuclear Information System (INIS)

    Soboleva, L.V.; Vasil'eva, M.G.

    1977-01-01

    The thermal characteristics of crystals of Cs 2 CuCl 4 , Cs 2 CuCl 4 x2H 2 O, and CsCuCl 3 were investigated thermogravimetrically. The derivatogram of the Cs 2 CuCl 4 crystal is characterized by the presence of a single endothermal effect at 505 deg C. The derivatogram of the Cs 2 CuCl 4 x2H 2 O crystal contains three endothermal effects: at 40, 135, and 480 deg C. The derivatogram of the CsCuCl 3 crystal shows the presence of two endothermal effects at 142 and 455 deg C. The thermogravimetric data on Cs 2 CuCl 4 and CsCuCl 3 crystals reveal crystal decomposition on melting; hence, these crystals cannot be grown from melts

  6. The Stars of Heaven

    Science.gov (United States)

    Pickover, Clifford A.

    2004-05-01

    Do a little armchair space travel, rub elbows with alien life forms, and stretch your mind to the furthest corners of our uncharted universe. With this astonishing guidebook, you don't have to be an astronomer to explore the mysteries of stars and their profound meaning for human existence. Clifford A. Pickover tackles a range of topics from stellar evolution to the fundamental reasons why the universe permits life to flourish. He alternates sections that explain the mysteries of the cosmos with sections that dramatize mind-expanding concepts through a fictional dialog between futuristic humans and their alien peers (who embark on a journey beyond the reader's wildest imagination). This highly accessible and entertaining approach turns an intimidating subject into a scientific game open to all dreamers. Told in Pickover's inimitable blend of fascinating state-of-the-art science and whimsical science fiction, and packed with numerous diagrams and illustrations, The Stars of Heaven unfolds a world of paradox and mystery, one that will intrigue anyone who has ever pondered the night sky with wonder.

  7. Stars and Planets

    Science.gov (United States)

    Neta, Miguel

    2014-05-01

    'Estrelas e Planetas' (Stars and Planets) project was developed during the academic year 2009/2010 and was tested on three 3rd grade classes of one school in Quarteira, Portugal. The aim was to encourage the learning of science and the natural and physical phenomena through the construction and manipulation of materials that promote these themes - in this case astronomy. Throughout the project the students built a small book containing three themes of astronomy: differences between stars and planets, the solar system and the phases of the Moon. To each topic was devoted two sessions of about an hour each: the first to teach the theoretical aspects of the theme and the second session to assembly two pages of the book. All materials used (for theoretical sessions and for the construction of the book) and videos of the finished book are available for free use in www.miguelneta.pt/estrelaseplanetas. So far there is only a Portuguese version but soon will be published in English as well. This project won the Excellency Prize 2011 of Casa das Ciências, a portuguese site for teachers supported by the Calouste Gulbenkian Fundation (www.casadasciencias.org).

  8. Chemistry between the stars

    International Nuclear Information System (INIS)

    Kroto, H.W.

    1986-01-01

    During the past 15 years the techniques used by chemists to determine accurate molecular structures have combined with those of radio astronomers to probe the space between the stars. Together they paint a new picture of interstellar space, a picture which shows that vast clouds of gas and dust are continually collapsing to form stars and planets and that the main constituents of these clouds are molecules, some of which are quite complex organic species. It is now known that many of the organic building blocks, useful in the evolution of biologically significant macromolecules, existed long before the Earth was formed. These findings present a challenge to previous widely-accepted theories that such molecules were first generated in the Earth's primaeval atmosphere. In this paper certain aspects of these discoveries are considered with particular emphasis on the contributions made by techniques of use in general chemistry. After a brief astronomical introduction to the Interstellar Medium (ISM) the interaction between chemistry and radioastronomy is discussed. This is followed by details of some exciting, new and quite unexpected advances in our understanding of carbon chemistry, discovered during experiments aimed at understanding some of the more perplexing radioastronomy results. Finally an overview is given of the present knowledge of the molecular composition of the ISM and the resulting implications in so far as the origins of life are concerned. (author)

  9. Chemistry between the stars

    Energy Technology Data Exchange (ETDEWEB)

    Kroto, H W

    1986-01-01

    During the past 15 years the techniques used by chemists to determine accurate molecular structures have combined with those of radio astronomers to probe the space between the stars. Together they paint a new picture of interstellar space, a picture which shows that vast clouds of gas and dust are continually collapsing to form stars and planets and that the main constituents of these clouds are molecules, some of which are quite complex organic species. It is now known that many of the organic building blocks, useful in the evolution of biologically significant macromolecules, existed long before the Earth was formed. These findings present a challenge to previous widely-accepted theories that such molecules were first generated in the Earth's primaeval atmosphere. In this paper certain aspects of these discoveries are considered with particular emphasis on the contributions made by techniques of use in general chemistry. After a brief astronomical introduction to the Interstellar Medium (ISM) the interaction between chemistry and radioastronomy is discussed. This is followed by details of some exciting, new and quite unexpected advances in our understanding of carbon chemistry, discovered during experiments aimed at understanding some of the more perplexing radioastronomy results. Finally an overview is given of the present knowledge of the molecular composition of the ISM and the resulting implications in so far as the origins of life are concerned.

  10. Evaluation of Cs-134 and Cs-137 in sugar by non-destructive analysis

    Energy Technology Data Exchange (ETDEWEB)

    Correira, Filipe Lopes de Barros; Santos Júnior, José Araújo dos; Amaral, Romilton dos Santos; Santos, Josineide Marques do Nascimento; Medeiros, Nilson Vicente da Silva; Santos Junior, Otávio Pereira dos, E-mail: filipelbck@gmail.com, E-mail: jaraujo@ufpe.br, E-mail: romilton@ufpe.br, E-mail: josineide.santos@ufpe.br, E-mail: nilson.medeiros@ufpe.br, E-mail: otavio.santos@vitoria.ifpe.edu.br [Universidade Federal de Pernambuco (RAE/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Grupo de Radioecologia; Vieira, José Wilson, E-mail: jose.wilson59@uol.com.br [Instituto Federal de Pernambuco (IFPE), Recife (Brazil); Valois, Rhaiana Caminha, E-mail: rhaianavalois@hotmail.com [Colégio Militar do Recife, PE (Brazil)

    2017-07-01

    The spread of anthropogenic radioisotopes in the environment comes from nuclear tests and accidents that occurred in the past, which justifies constant monitoring, to guarantee the safety and control of the activities that involve these applications. Brazil, when exporting some food products, depending on the country of origin, a radiometric report is required, especially for sugar that has high world consumption and the possibility of contamination of the population, when radioisotope is present. Therefore, the investigation of the levels of Cs-134 and Cs-137 in sugar matrices is necessary to predict radioecological emergency situations. The National Nuclear Energy Commission, the agency that oversees nuclear applications in Brazil, With Resolution No. 102 of December 22, 2010 approved regulatory positions, including levels of action for food control, recommended to restrict the marketing of food products in Brazil. General, whose specific activity is higher than the limit of 1.0 kBq / kg for the said isotopes of cesium independently. Aiming for improvements in the analyzes that are already performed in the Laboratory of Radioecology and Environmental Control of the Department of Nuclear Energy of the Federal University of Pernambuco to assurance the quality of sugar marketed in Brazil, a standard procedure for the analysis of these radionuclides in this matrix was determined. High resolution gamma spectrometry with non-destructive analysis was used to perform the tests. Priority was given to parameters that directly influence the qualitative and quantitative analysis of these radioactive elements, such as calibration in energy and efficiency, resolution, influence of self-absorption, counting statistics directly associated with the time of analysis, influence of background radiation and geometry analysis. (author)

  11. Evaluation of Cs-134 and Cs-137 in sugar by non-destructive analysis

    International Nuclear Information System (INIS)

    Correira, Filipe Lopes de Barros; Santos Júnior, José Araújo dos; Amaral, Romilton dos Santos; Santos, Josineide Marques do Nascimento; Medeiros, Nilson Vicente da Silva; Santos Junior, Otávio Pereira dos; Valois, Rhaiana Caminha

    2017-01-01

    The spread of anthropogenic radioisotopes in the environment comes from nuclear tests and accidents that occurred in the past, which justifies constant monitoring, to guarantee the safety and control of the activities that involve these applications. Brazil, when exporting some food products, depending on the country of origin, a radiometric report is required, especially for sugar that has high world consumption and the possibility of contamination of the population, when radioisotope is present. Therefore, the investigation of the levels of Cs-134 and Cs-137 in sugar matrices is necessary to predict radioecological emergency situations. The National Nuclear Energy Commission, the agency that oversees nuclear applications in Brazil, With Resolution No. 102 of December 22, 2010 approved regulatory positions, including levels of action for food control, recommended to restrict the marketing of food products in Brazil. General, whose specific activity is higher than the limit of 1.0 kBq / kg for the said isotopes of cesium independently. Aiming for improvements in the analyzes that are already performed in the Laboratory of Radioecology and Environmental Control of the Department of Nuclear Energy of the Federal University of Pernambuco to assurance the quality of sugar marketed in Brazil, a standard procedure for the analysis of these radionuclides in this matrix was determined. High resolution gamma spectrometry with non-destructive analysis was used to perform the tests. Priority was given to parameters that directly influence the qualitative and quantitative analysis of these radioactive elements, such as calibration in energy and efficiency, resolution, influence of self-absorption, counting statistics directly associated with the time of analysis, influence of background radiation and geometry analysis. (author)

  12. Speciation of Cs-137 in fertilizers amended soils

    International Nuclear Information System (INIS)

    Mocanu, N.; Breban, D.C.

    1999-01-01

    One of the most used agricultural countermeasures to reduce the uptake of radionuclides from soil into plants is the chemical treatment of the soil with fertilizers. The distribution of a radionuclide between different physico chemical forms is essential to characterize its behaviour and the biological impact on the environment. To assess a radionuclide bioavailability to the soil-plant transfer, the chemical forms that are most relevant are the water soluble and exchangeable ones. Laboratory experiments were conducted to determine the potential modifications in time of the Cs-137 distribution in the two soil fractions, induced by the treatment with different K-based fertilizers. The two types of soil were selected taking into account their importance for the agricultural use in Romania. By the sequential extraction method the distribution of 137 Cs has been determined in the water soluble and exchangeable fractions separated from the soils after 1 day, 1 week, 1 month and 4 months, respectively. For the reference untreated soils, experimental data revealed that less than 1 percent of Cs-137 is associated to the water soluble fraction for both types of soil. Around 4 percents of the total amount of Cs-137 in the brown-reddish soil and 13 percents in the alluvial one were associated to the exchangeable fraction. The differences between the Cs-137 distribution are correlated to the higher content of dust and clay in the brown reddish soil, which are strong binders for Cs ions. The application of the two fertilizers releasing fast the K ions (KCl and potassium salt), determined from at the first moment after the contamination a reduction of the Cs-137 concentration in both fraction. The effect was most pronounced for the soluble fraction in the brown -reddish soil: with a factor of 8 in case of KCl treatment and 5 in case of potassium salt. For the others experimental cases the concentration of Cs-137 in both fractions was slightly reduced, with factors between (1

  13. Stars Just Got Bigger - A 300 Solar Mass Star Uncovered

    Science.gov (United States)

    2010-07-01

    Using a combination of instruments on ESO's Very Large Telescope, astronomers have discovered the most massive stars to date, one weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses. The existence of these monsters - millions of times more luminous than the Sun, losing weight through very powerful winds - may provide an answer to the question "how massive can stars be?" A team of astronomers led by Paul Crowther, Professor of Astrophysics at the University of Sheffield, has used ESO's Very Large Telescope (VLT), as well as archival data from the NASA/ESA Hubble Space Telescope, to study two young clusters of stars, NGC 3603 and RMC 136a in detail. NGC 3603 is a cosmic factory where stars form frantically from the nebula's extended clouds of gas and dust, located 22 000 light-years away from the Sun (eso1005). RMC 136a (more often known as R136) is another cluster of young, massive and hot stars, which is located inside the Tarantula Nebula, in one of our neighbouring galaxies, the Large Magellanic Cloud, 165 000 light-years away (eso0613). The team found several stars with surface temperatures over 40 000 degrees, more than seven times hotter than our Sun, and a few tens of times larger and several million times brighter. Comparisons with models imply that several of these stars were born with masses in excess of 150 solar masses. The star R136a1, found in the R136 cluster, is the most massive star ever found, with a current mass of about 265 solar masses and with a birthweight of as much as 320 times that of the Sun. In NGC 3603, the astronomers could also directly measure the masses of two stars that belong to a double star system [1], as a validation of the models used. The stars A1, B and C in this cluster have estimated masses at birth above or close to 150 solar masses. Very massive stars produce very powerful outflows. "Unlike humans, these stars are born heavy and lose weight as

  14. The spectrophotometric investigation of 4 parent stars

    International Nuclear Information System (INIS)

    Tereshchenko, V.M.

    2005-01-01

    The absolute energy distribution in spectra of four parent stars was obtained. The synthetic color indexes for the investigated stars were calculated. They were used for determination of the fundamental parameters of the parent stars: effective temperatures and metallicities. (author)

  15. An optical microscopy study of the swelling of wet-spun films of CsDNA as a function of hydration and CsCl concentration

    Science.gov (United States)

    Schwenker, Megan; Marlowe, Robert; Lee, Scott; Rupprecht, Allan

    2005-03-01

    Highly oriented, wet-spun films of DNA expand in the direction perpendicular to the helical axis as the hydration of the film is increased. CsDNA films with a high CsCl content show an unexpected shrinkage at a relative humidity of 92%. Our most recent experiments have been to measure the perpendicular dimension of CsDNA as a function of both hydration and concentration of CsCl. Our preliminary results show that no shrinkage is observed at low contents of CsCl, showing that the CsCl plays an integral role in the shrinkage phenomenon.

  16. Correlations between potassium, rubidium and cesium ({sup 133}Cs and {sup 137}Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Vinichuk, M., E-mail: Mykhailo.Vinichuk@slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Cherniakhovsky Str., 10005 Zhytomyr (Ukraine); Rosen, K.; Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Dahlberg, A. [Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, 750 07 Uppsala (Sweden)

    2011-04-15

    An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ({sup 133}Cs and {sup 137}Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and {sup 133}Cs mass concentrations with {sup 137}Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 {+-} 6.79 g kg{sup -1} for K (mean {+-} SD, dwt), 0.40 {+-} 0.09 g kg{sup -1} for Rb, 8.7 {+-} 4.36 mg kg{sup -1} for {sup 133}Cs and 63.7 {+-} 24.2 kBq kg{sup -1} for {sup 137}Cs. The mass concentrations of {sup 133}Cs correlated with {sup 137}Cs activity concentrations (r = 0.61). There was correlation between both {sup 133}Cs concentrations (r = 0.75) and {sup 137}Cs activity concentrations (r = 0.44) and Rb, but the {sup 137}Cs/{sup 133}Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The {sup 133}Cs mass concentrations, {sup 137}Cs activity concentrations and {sup 137}Cs/{sup 133}Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, {sup 133}Cs and {sup 137}Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: {yields} We studied uptake of Cs ({sup 133}Cs and {sup 137}Cs), K and Rb by Suillus variegates sporocarps. {yields} Genotypic origin of fungus did not affect uptake of studied elements (isotopes). {yields} Genotypic origin did not affect correlation between Cs ({sup 133}Cs and {sup 137}Cs), K and Rb.

  17. CsMYB5a and CsMYB5e from Camellia sinensis differentially regulate anthocyanin and proanthocyanidin biosynthesis.

    Science.gov (United States)

    Jiang, Xiaolan; Huang, Keyi; Zheng, Guangshun; Hou, Hua; Wang, Peiqiang; Jiang, Han; Zhao, Xuecheng; Li, Mingzhuo; Zhang, Shuxiang; Liu, Yajun; Gao, Liping; Zhao, Lei; Xia, Tao

    2018-05-01

    Tea is one of the most widely consumed nonalcoholic beverages worldwide. Polyphenols are nutritional compounds present in the leaves of tea plants. Although numerous genes are functionally characterized to encode enzymes that catalyze the formation of diverse polyphenolic metabolites, transcriptional regulation of those different pathways such as late steps of the proanthcoyanidin (PA) pathway remains unclear. In this study, using different tea transcriptome databases, we screened at least 140 R2R3-MYB transcription factors (TFs) and grouped them according to the basic function domains of the R2R3 MYB TF superfamily. Among 140 R2R3 TFs, CsMYB5a and CsMYB5e were chosen for analysis because they may be involved in PA biosynthesis regulation. CsMYB5a-overexpressing tobacco plants exhibited downregulated anthocyanin accumulation but a high polymeric PA content in the flowers. Overexpression of CsMYB5e in tobacco plants did not change the anthocyanin content but increased the dimethylaminocinnamaldehyde-stained PA content. RNA-seq and qRT-PCR analyses revealed that genes related to PA and anthocyanin biosynthesis pathways were markedly upregulated in both CsMYB5a- and CsMYB5e-overexpressing flowers. Three UGTs and four GSTs were identified as involved in PA and anthocyanin glycosylation and transportation in transgenic plants. These results provide new insights into the regulation of PA and anthocyanin biosynthesis in Camellia sinensis. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Analysis on the influence of forest soil characteristics on radioactive Cs infiltration and evaluation of residual radioactive Cs on surfaces.

    Science.gov (United States)

    Mori, Yoshitomo; Yoneda, Minoru; Shimada, Yoko; Fukutani, Satoshi; Ikegami, Maiko; Shimomura, Ryohei

    2018-03-29

    We investigated the depth profiles of radioactive Cs, ignition loss, and cation exchange capacity (CEC) in five types of forest soils sampled using scraper plates. We then simulated the monitored depth profiles in a compartment model, taking ignition loss as a parameter based on experimental results showing a positive correlation between ignition loss and the CEC. The calculated values were comparable with the monitored values, though some discrepancy was observed in the middle of the soil layer. Based on decontamination data on the surface dose rate and surface contamination concentration, we newly defined a surface residual index (SRI) to evaluate the residual radioactive Cs on surfaces. The SRI value tended to gradually decrease in forests and unpaved roads and was much smaller in forests and on unpaved roads than on paved roads. The radioactive Cs was assumed to have already infiltrated underground 18 months after the nuclear power plant accident, and the sinking was assumed to be ongoing. The SRI values measured on paved roads suggested that radioactive Cs remained on the surfaces, though a gradual infiltration was observed towards the end of the monitoring term. The SRI value is thought to be effective in grasping the rough condition of residual radioactive Cs quickly at sites of decontamination activity in the field. The SRI value may be serviceable for actual contamination works after further research is done to elucidate points such as the relation between the SRI and the infiltration of radioactive Cs in various types of objects.

  19. Elucidation and functional characterization of CsPSY and CsUGT promoters in Crocus sativus L.

    Science.gov (United States)

    Bhat, Archana; Mishra, Sonal; Kaul, Sanjana; Dhar, Manoj K

    2018-01-01

    The dried stigmas of Crocus sativus constitute the saffron, which is considered to be the costliest spice of the world. Saffron is valuable for its constituents, which are mainly apocarotenoids. In order to enhance the production of apocarotenoids, it is imperative to understand the regulation of apocarotenoid biosynthetic pathway. In C. sativus, although the pathway has been elucidated, the information regarding the regulation of the pathwaygenes is scanty. During the present investigation, the characterization of promoters regulating the expression of two important genes i.e. CsPSY and CsUGT was performed. We successfully cloned the promoters of both the genes, which were functionally characterized in Crocus sativus and Nicotiana tabaccum. In silico analysis of the promoters demonstrated the presence of several important cis regulatory elements responding tolight, hormonesand interaction with transcription factors (TFs). Further analysis suggested the regulation of CsPSY promoter by Abscisic acid (ABA) and that of CsUGT by Gibberellic acid (GA). In addition, we also observed ABA and GA mediated modulation in the expression of significant TFs and CsPSY and CsUGT transcripts. Overall, the study addresses issues related to regulation of key genes of apocarotenoid pathway in C.sativus.

  20. Luminescence properties of undoped CsCaCl3 and CsSrCl3 crystalline scintillators

    International Nuclear Information System (INIS)

    Fujimoto, Yutaka; Saeki, Keiichiro; Koshimizu, Masanori; Asai, Keisuke; Yanagida, Takayuki

    2015-01-01

    Intrinsic luminescence properties of undoped CsCaCl 3 and CsSrCl 3 crystalline scintillators were studied. The crystal samples were grown by a vertical Bridgman method. Photoluminescence spectra of the crystals showed Auger-free luminescence (AFL) at 310 nm and self-trapped emission (STE) at 400 nm for CsCaCl 3 and 465 nm for CsSrCl 3 , when vacuum ultraviolet (VUV) light at 84 nm and 160 nm excited the crystals. X-ray excited radioluminescence spectra of the crystals showed some emission bands in the 280-600 nm wavelength range, which are owing to AFL, STE, and other origins such as lattice defects and impurities. Scintillation light yield was 400-300 ph/MeV, and the principal scintillation decay time about 2.5 ns and 12 ns for CsCaCl 3 and 1.8 ns and 13 ns for CsSrCl 3 . (author)

  1. Rotation of White Dwarf Stars

    OpenAIRE

    Kawaler, Steven D.

    2014-01-01

    I discuss and consider the status of observational determinations of the rotation velocities of white dwarf stars via asteroseismology and spectroscopy. While these observations have important implications on our understanding of the angular momentum evolution of stars in their late stages of evolution, more direct methods are sorely needed to disentangle ambiguities.

  2. The STAR-RICH Detector

    CERN Document Server

    Lasiuk, B; Braem, André; Cozza, D; Davenport, M; De Cataldo, G; Dell'Olio, L; Di Bari, D; Di Mauro, A; Dunlop, J C; Finch, E; Fraissard, Daniel; Franco, A; Gans, J; Ghidini, B; Harris, J W; Horsley, M; Kunde, G J; Lasiuk, B; Lesenechal, Y; Majka, R D; Martinengo, P; Morsch, Andreas; Nappi, E; Paic, G; Piuz, François; Posa, F; Raynaud, J; Salur, S; Sandweiss, J; Santiard, Jean-Claude; Satinover, J; Schyns, E M; Smirnov, N; Van Beelen, J; Williams, T D; Xu, Z

    2002-01-01

    The STAR-RICH detector extends the particle idenfication capabilities of the STAR spectrometer for charged hadrons at mid-rapidity. It allows identification of pions and kaons up to ~3 GeV/c and protons up to ~5 GeV/c. The characteristics and performance of the device in the inaugural RHIC run are described.

  3. Physics of Neutron Star Crusts

    Directory of Open Access Journals (Sweden)

    Chamel Nicolas

    2008-12-01

    Full Text Available The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.

  4. Stars get dizzy after lunch

    International Nuclear Information System (INIS)

    Zhang, Michael; Penev, Kaloyan

    2014-01-01

    Exoplanet searches have discovered a large number of h ot Jupiters — high-mass planets orbiting very close to their parent stars in nearly circular orbits. A number of these planets are sufficiently massive and close-in to be significantly affected by tidal dissipation in the parent star, to a degree parameterized by the tidal quality factor Q * . This process speeds up their star's rotation rate while reducing the planet's semimajor axis. In this paper, we investigate the tidal destruction of hot Jupiters. Because the orbital angular momenta of these planets are a significant fraction of their star's rotational angular momenta, they spin up their stars significantly while spiraling to their deaths. Using the Monte Carlo simulation, we predict that for Q * = 10 6 , 3.9 × 10 –6 of stars with the Kepler Target Catalog's mass distribution should have a rotation period shorter than 1/3 day (8 hr) due to accreting a planet. Exoplanet surveys such as SuperWASP, HATnet, HATsouth, and KELT have already produced light curves of millions of stars. These two facts suggest that it may be possible to search for tidally destroyed planets by looking for stars with extremely short rotational periods, then looking for remnant planet cores around those candidates, anomalies in the metal distribution, or other signatures of the recent accretion of the planet.

  5. ENERGY STAR Certified Vending Machines

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Refrigerated Beverage Vending Machines that are effective as of March 1, 2013. A detailed listing of key efficiency criteria are available at

  6. Star formation in the multiverse

    International Nuclear Information System (INIS)

    Bousso, Raphael; Leichenauer, Stefan

    2009-01-01

    We develop a simple semianalytic model of the star formation rate as a function of time. We estimate the star formation rate for a wide range of values of the cosmological constant, spatial curvature, and primordial density contrast. Our model can predict such parameters in the multiverse, if the underlying theory landscape and the cosmological measure are known.

  7. Measuring the Sizes of Stars

    Indian Academy of Sciences (India)

    The nearest star to our solar system, called Proxima Centauri, is about 260,000 ..... We can choose the origin of x to be the maximum of the fringe pattern of one of the stars .... ating day and night, round the year, to explore the universe with.

  8. When a major star dies

    International Nuclear Information System (INIS)

    Joubert, G.

    1988-01-01

    Astrologers are slowly learning what happens when a star dies. On the night of 23-24 February 1987, the light of an exploding star - a supernova with the name SN 1987A - reached the earth. In this article this astrological event of the century are discussed, and its importance for astrologers

  9. KAON CONDENSATION IN NEUTRON STARS

    International Nuclear Information System (INIS)

    RAMOS, A.; SCHAFFNER-BIELICH, J.; WAMBACH, J.

    2001-01-01

    We discuss the kaon-nucleon interaction and its consequences for the change of the properties of the kaon in the medium. The onset of kaon condensation in neutron stars under various scenarios as well its effects for neutron star properties are reviewed

  10. ENERGY STAR Certified Ceiling Fans

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=ceiling_fans.pr_crit_ceiling_fans

  11. ENERGY STAR Certified Ventilating Fans

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of October 1, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=vent_fans.pr_crit_vent_fans

  12. Possibility of stable quark stars

    International Nuclear Information System (INIS)

    Bowers, R.L.; Gleeson, A.M.; Pedigo, R.D.

    1976-08-01

    A recent zero temperature equation of state which contains quark-partons separated from conventional baryons by a phase transition is used to investigate the stability of quark stars. The sensitivity to the input physics is also considered. The conclusions, which are found to be relatively model independent, indicate that a separately identifiable class of stable objects called quark stars does not exist

  13. Stars the size of planets

    International Nuclear Information System (INIS)

    Whitehouse, D.

    1984-01-01

    Red dwarf stars, the faintest and smallest stars that can be seen, sometimes host flares of immense violence. The article discusses the energy of these flares in terms of mass, x-rays, brightness, variation in light output, the sun and magnetic phenomena. (U.K.)

  14. Opdriftsbaserede modeller for Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten

    Formålet med dette skrift er at få en forhåndsvurdering af mulige effektforøgelser for Wave Star ved anvendelse af aktiv akkumulatordrift. Disse vurderinger baseres på simuleringsmodeller for driften af Wave Star i uregelmæssige bølger. Modellen er udarbejdet i programmeringssproget Delphi og er en...

  15. Formation of stars and star clusters in colliding galaxies

    International Nuclear Information System (INIS)

    Belles, Pierre-Emmanuel

    2012-01-01

    Mergers are known to be essential in the formation of large-scale structures and to have a significant role in the history of galaxy formation and evolution. Besides a morphological transformation, mergers induce important bursts of star formation. These starburst are characterised by high Star Formation Efficiencies (SFEs) and Specific Star Formation Rates, i.e., high Star Formation Rates (SFR) per unit of gas mass and high SFR per unit of stellar mass, respectively, compared to spiral galaxies. At all redshifts, starburst galaxies are outliers of the sequence of star-forming galaxies defined by spiral galaxies. We have investigated the origin of the starburst-mode of star formation, in three local interacting systems: Arp 245, Arp 105 and NGC 7252. We combined high-resolution JVLA observations of the 21-cm line, tracing the HI diffuse gas, with UV GALEX observations, tracing the young star-forming regions. We probe the local physical conditions of the Inter-Stellar Medium (ISM) for independent star-forming regions and explore the atomic-to-dense gas transformation in different environments. The SFR/HI ratio is found to be much higher in central regions, compared to outer regions, showing a higher dense gas fraction (or lower HI gas fraction) in these regions. In the outer regions of the systems, i.e., the tidal tails, where the gas phase is mostly atomic, we find SFR/HI ratios higher than in standard HI-dominated environments, i.e., outer discs of spiral galaxies and dwarf galaxies. Thus, our analysis reveals that the outer regions of mergers are characterised by high SFEs, compared to the standard mode of star formation. The observation of high dense gas fractions in interacting systems is consistent with the predictions of numerical simulations; it results from the increase of the gas turbulence during a merger. The merger is likely to affect the star-forming properties of the system at all spatial scales, from large scales, with a globally enhanced turbulence

  16. Uptake and transfer factors of 137Cs by mushrooms

    International Nuclear Information System (INIS)

    Heinrich, G.

    1991-01-01

    The 137 Cs content of 118 species (668 samples) of higher fungi collected in the period from August 1984 to October 1989 at three different locations in Styria, Austria, was determined by gamma-spectrometry. The Cs-content of most mushrooms has been increasing since September 1986. In order to find out which factors determine the 137 Cs-contamination of mushrooms and the transfer-value soil to mushroom, the concentration of total and plant-available radiocesium in soils as well as the pH-value, the content of humus, clay, silt, sand, exchangeable cations, the composition of the clay minerals, and the particle size distribution of the soils of two different locations were examined. The higher the 137 Cs contamination of the soil, the thicker the layer of humus and the higher the content of humus, the lower the pH-value, and the lower the amount of essential cations, especially of K + , the higher the amount of 137 Cs plant-available will be. Therefore, the contamination of the mushrooms in the coniferous forest of Koralpenblick (1000 m) is higher than in the mixed forest at the Rosenberg around Graz at approx. 500 m height. Of 26 different species of mushrooms measured at both sites, only 61% show the highest TF-values soil to mushrooms also at the Koralpenblick. In the spruce forest at Koralpenblick there are many species of mushrooms with high 137 Cs-contamination which were not found at the Rosenberg. However, the properties of the species to which a mushroom belongs are more important than environmental conditions and soil properties. The transfer values of 40 K stay within narrow bounds, whereas those of 137 Cs differ widely. (orig.)

  17. Accurate absolute measurement of trapped Cs atoms in a MOT

    International Nuclear Information System (INIS)

    Talavera O, M.; Lopez R, M.; Carlos L, E. de; Jimenez S, S.

    2007-01-01

    A Cs-133 Magneto-Optical Trap (MOT) has been developed at the Time and Frequency Division of the Centro Nacional de Metrologia, CENAM, in Mexico. This MOT is part of a primary frequency standard based on ultra-cold Cs atoms, called CsF-1 clock, under development at CENAM. In this Cs MOT, we use the standard configuration (σ + - σ - ) 4-horizontal 2-vertical laser beams 1.9 cm in diameter, with 5 mW each. We use a 852 nm, 5 mW, DBR laser as a master laser which is stabilized by saturation spectroscopy. Emission linewidth of the master laser is l MHz. In order to amplify the light of the master laser, a 50 mW, 852 nm AlGaAs laser is used as slave laser. This slave laser is stabilized by light injection technique. A 12 MHz red shift of the light is performed by two double passes through two Acusto-Optic Modulators (AOMs). The optical part of the CENAMs MOT is very robust against mechanical vibration, acoustic noise and temperature changes in our laboratory, because none of our diode lasers use an extended cavity to reduce the linewidth. In this paper, we report results of our MOT characterization as a function of several operation parameters such as the intensity of laser beams, the laser beam diameter, the red shift of light, and the gradient of the magnetic field. We also report accurate absolute measurement of the number of Cs atoms trapped in our Cs MOT. We found up to 6 x 10 7 Cs atoms trapped in our MOT measured with an uncertainty no greater than 6.4%. (Author)

  18. Dark stars in Starobinsky's model

    Science.gov (United States)

    Panotopoulos, Grigoris; Lopes, Ilídio

    2018-01-01

    In the present work we study non-rotating dark stars in f (R ) modified theory of gravity. In particular, we have considered bosonic self-interacting dark matter modeled inside the star as a Bose-Einstein condensate, while as far as the modified theory of gravity is concerned we have assumed Starobinsky's model R +a R2. We solve the generalized structure equations numerically, and we obtain the mass-to-ratio relation for several different values of the parameter a , and for two different dark matter equation-of-states. Our results show that the dark matter stars become more compact in the R-squared gravity compared to general relativity, while at the same time the highest star mass is slightly increased in the modified gravitational theory. The numerical value of the highest star mass for each case has been reported.

  19. Delta isobars in neutron stars

    Directory of Open Access Journals (Sweden)

    Pagliara Giuseppe

    2015-01-01

    Full Text Available The appearance of delta isobars in beta-stable matter is regulated by the behavior of the symmetry energy at densities larger than saturation density. We show that by taking into account recent constraints on the density derivative of the symmetry energy and the theoretical and experimental results on the excitations of delta isobars in nuclei, delta isobars are necessary ingredients for the equations of state used for studying neutron stars. We analyze the effect of the appearance of deltas on the structure of neutron stars: as in the case of hyperons, matter containing delta is too soft for allowing the existence of 2M⊙ neutron stars. Quark stars on the other hand, could reach very massive configurations and they could form from a process of conversion of hadronic stars in which an initial seed of strangeness appears through hyperons.

  20. Numerical evidence for 'multiscalar stars'

    International Nuclear Information System (INIS)

    Hawley, Scott H.; Choptuik, Matthew W.

    2003-01-01

    We present a class of general relativistic solitonlike solutions composed of multiple minimally coupled, massive, real scalar fields which interact only through the gravitational field. We describe a two-parameter family of solutions we call ''phase-shifted boson stars'' (parametrized by central density ρ 0 and phase δ), which are obtained by solving the ordinary differential equations associated with boson stars and then altering the phase between the real and imaginary parts of the field. These solutions are similar to boson stars as well as the oscillating soliton stars found by Seidel and Suen [E. Seidel and W. M. Suen, Phys. Rev. Lett. 66, 1659 (1991)]; in particular, long-time numerical evolutions suggest that phase-shifted boson stars are stable. Our results indicate that scalar solitonlike solutions are perhaps more generic than has been previously thought

  1. Flares on a Bp Star

    Science.gov (United States)

    Mullan, D. J.

    2009-09-01

    Two large X-ray flares have been reported from the direction of a magnetic B2p star (σ Ori E). Sanz-Forcada et al. have suggested that the flares did not occur on the B2p star but on a companion of late spectral type. A star which is a candidate for a late-type flare star near σ Ori E has recently been identified by Bouy et al. However, based on the properties of the flares, and based on a recent model of rotating magnetospheres, we argue that, rather than attributing the two flares to a late-type dwarf, it is a viable hypothesis that the flares were magnetic phenomena associated with the rotating magnetosphere of the B2p star itself.

  2. FLARES ON A Bp STAR

    International Nuclear Information System (INIS)

    Mullan, D. J.

    2009-01-01

    Two large X-ray flares have been reported from the direction of a magnetic B2p star (σ Ori E). Sanz-Forcada et al. have suggested that the flares did not occur on the B2p star but on a companion of late spectral type. A star which is a candidate for a late-type flare star near σ Ori E has recently been identified by Bouy et al. However, based on the properties of the flares, and based on a recent model of rotating magnetospheres, we argue that, rather than attributing the two flares to a late-type dwarf, it is a viable hypothesis that the flares were magnetic phenomena associated with the rotating magnetosphere of the B2p star itself.

  3. Star trackers for attitude determination

    DEFF Research Database (Denmark)

    Liebe, Carl Christian

    1995-01-01

    One problem comes to all spacecrafts using vector information. That is the problem of determining the attitude. This paper describes how the area of attitude determination instruments has evolved from simple pointing devices into the latest technology, which determines the attitude by utilizing...... a CCD camera and a powerful microcomputer. The instruments are called star trackers and they are capable of determining the attitude with an accuracy better than 1 arcsecond. The concept of the star tracker is explained. The obtainable accuracy is calculated, the numbers of stars to be included...... in the star catalogue are discussed and the acquisition of the initial attitude is explained. Finally the commercial market for star trackers is discussed...

  4. The Diversity of Neutron Stars

    Science.gov (United States)

    Kaplan, David L.

    2004-12-01

    Neutron stars are invaluable tools for exploring stellar death, the physics of ultra-dense matter, and the effects of extremely strong magnetic fields. The observed population of neutron stars is dominated by the >1000 radio pulsars, but there are distinct sub-populations that, while fewer in number, can have significant impact on our understanding of the issues mentioned above. These populations are the nearby, isolated neutron stars discovered by ROSAT, and the central compact objects in supernova remnants. The studies of both of these populations have been greatly accelerated in recent years through observations with the Chandra X-ray Observatory and the XMM-Newton telescope. First, we discuss radio, optical, and X-ray observations of the nearby neutron stars aimed at determining their relation to the Galactic neutron star population and at unraveling their complex physical processes by determining the basic astronomical parameters that define the population---distances, ages, and magnetic fields---the uncertainties in which limit any attempt to derive basic physical parameters for these objects. We conclude that these sources are 1e6 year-old cooling neutron stars with magnetic fields above 1e13 Gauss. Second, we describe the hollow supernova remnant problem: why many of the supernova remnants in the Galaxy have no indication of central neutron stars. We have undertaken an X-ray census of neutron stars in a volume-limited sample of Galactic supernova remnants, and from it conclude that either many supernovae do not produce neutron stars contrary to expectation, or that neutron stars can have a wide range in cooling behavior that makes many sources disappear from the X-ray sky.

  5. StarGuides Plus

    Science.gov (United States)

    Heck, A.

    StarGuides Plus represents the most comprehensive and accurately validated collection of practical data on organizations involved in astronomy, related space sciences and other related fields. This invaluable reference source (and its companion volume, StarBriefs Plus) should be on the reference shelf of every library, organization or individual with any interest in these areas. The coverage includes relevant universities, scientific committees, institutions, associations, societies, agencies, companies, bibliographic services, data centers, museums, dealers, distributors, funding organizations, journals, manufacturers, meteorological services, national norms & standard institutes, parent associations & societies, publishers, software producers & distributors, and so on. Besides astronomy and associated space sciences, related fields such as aeronautics, aeronomy, astronautics, atmospheric sciences, chemistry, communications, computer sciences, data processing, education, electronics, engineering, energetics, environment, geodesy, geophysics, information handling, management, mathematics, meteorology, optics, physics, remote sensing, and so on, are also covered where appropriate. After some thirty years in continuous compilation, verification and updating, StarGuides Plus currently gathers together some 6,000 entries from 100 countries. The information is presented in a clear, uncluttered manner for direct and easy use. For each entry, all practical data are listed: city, postal and electronic-mail addresses, telephone and fax numbers, URLs for WWW access, foundation years, numbers of members and/or numbers of staff, main activities, publications titles (with frequencies, ISS-Numbers and circulations), names and geographical coordinates of observing sites, names of planetariums, awards (prizes and/or distinctions) granted, etc. The entries are listed alphabetically in each country. An exhaustive index gives a breakdown not only by different designations and

  6. Radiogenotoxicological effect of signal nuclide 134Cs on somatic and germ cells

    Institute of Scientific and Technical Information of China (English)

    ZhuShou-Peng; XiaFen; 等

    1997-01-01

    Chromosome at aberation rates in bone marrow cells and micronucleus formation in bone marrow polychromatic erythrocytes both rise with increase in radioactivities of 134Cs,and can be fitted to power functions of radioactivities of 134Cs.In spermatogonia 134Cs mainly induced chromatid breakage,and abnormalities in sperm can also be experessed as power functions of radioactivities of 134 Cs.

  7. Double Degenerate Stars

    International Nuclear Information System (INIS)

    Xin-Lian, Luo; Hua, Bai; Lei, Zhao

    2008-01-01

    Regardless of the formation mechanism, an exotic object, the double degenerate star (DDS), is introduced and investigated, which is composed of baryonic matter and some unknown fermion dark matter. Different from the simple white dwarfs (WDs), there is additional gravitational force provided by the unknown fermion component inside DDSs, which may strongly affect the structure and the stability of such kind of objects. Many possible and strange observational phenomena connecting with them are concisely discussed. Similar to the normal WD, this object can also experience thermonuclear explosion as type Ia supernova explosion when DDS's mass exceeds the maximum mass that can be supported by electron degeneracy pressure. However, since the total mass of baryonic matter can be much lower than that of WD at Chandrasekhar mass limit, the peak luminosity should be much dimmer than what we expect before, which may throw a slight shadow on the standard candle of SN Ia in the research of cosmology. (general)

  8. Star spotting at CERN

    CERN Multimedia

    2008-01-01

    This June, two American celebrities (and physics enthusiasts!) came to CERN. Brian Cox gave Mike Einziger (right), lead guitarist with the rock band Incubus, the star treatment in the ATLAS cavern. Jesse Dylan embraces the spirit of ATLAS! Mike Einziger, lead guitarist with the rock band Incubus, visited CERN on Friday 13 June between concerts in Finland and England. Einziger, a lifelong science enthusiast descended into the ATLAS and CMS caverns and visited the SM18 test magnet facility during his brief tour of CERN. Einziger learned about the LHC through watching online lectures from University of Manchester and ATLAS physicist Brian Cox, and was thrilled to have the chance to see the detectors in person. The musician has created an orchestral piece, inspired in part by the work being done at CERN for the LHC, which will have its debut in Los Angeles on 23 August. Just over a week earlier, Jesse Dylan, Hollywood film director a...

  9. Close binary stars

    International Nuclear Information System (INIS)

    Larsson-Leander, G.

    1979-01-01

    Studies of close binary stars are being persued more vigorously than ever, with about 3000 research papers and notes pertaining to the field being published during the triennium 1976-1978. Many major advances and spectacular discoveries were made, mostly due to increased observational efficiency and precision, especially in the X-ray, radio, and ultraviolet domains. Progress reports are presented in the following areas: observational techniques, methods of analyzing light curves, observational data, physical data, structure and models of close binaries, statistical investigations, and origin and evolution of close binaries. Reports from the Coordinates Programs Committee, the Committee for Extra-Terrestrial Observations and the Working Group on RS CVn binaries are included. (Auth./C.F.)

  10. Proton femtoscopy at STAR

    International Nuclear Information System (INIS)

    Zbroszczyk, H.P.

    2011-01-01

    The analysis of two-particle femtoscopy provides a powerful tool to study the properties of matter created in heavy-ion collisions. Applied to identical and nonidentical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing additional information about source characteristics. In this paper we present the correlation functions obtained for protons and antiprotons for Au + Au collisions at √ s NN = 62.4 and 200 GeV. On the other hand, as STAR experiment participates in the Beam Energy Scan (BES) program, we present theoretical predictions of p - p , p-bar - p-bar and p - p-bar femtoscopic measurements, based on UrQMD simulation for √ s NN = 5-39 GeV

  11. Repression of CC16 by cigarette smoke (CS exposure.

    Directory of Open Access Journals (Sweden)

    Lingxiang Zhu

    Full Text Available Club (Clara Cell Secretory Protein (CCSP, or CC16 is produced mainly by non-ciliated airway epithelial cells including bronchiolar club cells and the change of its expression has been shown to associate with the progress and severity of Chronic Obstructive Pulmonary Disease (COPD. In an animal model, the lack of CC16 renders the animal susceptible to the tumorigenic effect of a major CS carcinogen. A recent population-based Tucson Epidemiological Study of Airway Obstructive Diseases (TESAOD has indicated that the low serum CC16 concentration is closely linked with the smoke-related mortality, particularly that driven by the lung cancer. However, the study of CC16 expression in well-defined smoke exposure models has been lacking, and there is no experimental support for the potential causal link between CC16 and CS-induced pathophysiological changes in the lung. In the present study, we have found that airway CC16 expression was significantly repressed in COPD patients, in monkey CS exposure model, and in CS-induced mouse model of COPD. Additionally, the lack of CC16 exacerbated airway inflammation and alveolar loss in the mouse model. Therefore, CC16 may play an important protective role in CS-related diseases.

  12. 137 Cs as a tracer of the Catalan current

    International Nuclear Information System (INIS)

    Sanchez-Cabeza, J.A.; Molero, J.; Merino, J.; Pujol, L.; Mitchell, P.I.

    1995-01-01

    A number of nuclear power installations located in the north-western Mediterranean (NWM) area are known to enhance 137 Cs levels in various marine compartments. The nuclear fuel reprocessing plant at Marcoule (France) has been reported to originate a significant increase of 137 Cs in Rhone river waters and sediments because of the discharge of low-level liquid radioactive waste. This radionuclide may be used as a tracer of oceanographic processes in the NWM; in fact, 137 Cs of Rhone river origin has been detected in the Gulf of Lions by several authors. The results reported in this work correspond to various transect experiments in waters of the Catalan Sea and show that: (i) surface salinity measurements confirmed the presence of the Catalan current in the Cap de Creus area; (ii) the 1991 Cap de Creus transect showed clearly the presence of 137 Cs above a baseline level of 4.3 ± 0.2 Bq.m -3 ; (iii) the Cap de Salou transect showed elevated levels towards the coast; (iv) the 1992 Cap de Creus transect showed no structure at all. Therefore, it was concluded that traces of 137 Cs from the Marcoule nuclear fuel reprocessing plant were transported by the Catalan current and were detectable in the Catalan Sea with a complex spatio-temporal structure. (authors). 25 refs., 4 figs

  13. Cs-137 concentrations in the muscles of Walleye Pollack

    International Nuclear Information System (INIS)

    Morita, T.; Yoshida, K.

    2003-01-01

    High concentrations of Cs-137 were detected in the muscles of Walleye Pollack (Theragra chalcogramm) collected from Kitamiyamato banks (sampling on 25 Jul. 2000), Kamui area (16 Oct. 2000) and Niigata coasts (31 Jan. 2001). The concentrations were 0.35 ± 0.01, 0.41 ± 0.01, and 0.63 ± 0.02 Bq/kg-wet, respectively. The average concentration in our past investigations was about 0.25 ± 0.01 Bq/kg-wet. Samples from other areas, the coat of Kushiro (8 May 2001), North Tishima (13 Nov. 2000) and the Sea of Okhotsk (6 May 2001), had the average concentrations. There were no such high concentrations of Cs-137 in other fish species collected from Kitamiyamato banks, Kamui area, and Niigata coasts. Fish samples with high concentrations all make the migration in the north of Japan sea. These results would indicated that samples took in Cs-137 elements from sea-water or foods on the migration route. Cs-137 concentrations in muscles of walleye pollack does not increase with the body lengths unlike other marine fishes, which enables the comparison of Cs-137 concentrations between areas without considering the body lengths. Walleye Pollac migrates in the large area in the sea of Japan and draws near other country except Japan. These habits make Walleye Pollac the excellent bio indicators to monitor oceanic radioactive pollution

  14. Theoretical investigation of the Cs*Hen>=3 exciplexes

    International Nuclear Information System (INIS)

    Zbiri, Mohamed; Daul, Claude

    2005-01-01

    The X 2 Σ 1/2 , A 2 Π 1/2 , B 2 Σ 1/2 , and A 2 Π 3/2 states of Cs*He n exciplexes, with n={3,...,9}, are studied using first principle density functional theory (DFT) formalism combined with the zeroth order regular approximation (ZORA). The zero points energies (ZPEs) E 0 for Cs*He n are calculated at a first step, in order to estimate the stability of the studied exciplexes. Relativistic calculations are carried out including spin-orbit effect (SO), and potential energy surfaces of Cs*He 6 are shown. The electronic distribution shapes of the studied molecules are also discussed, and their emission lines are evaluated and compared to a new discovered experimental emission spectra, which has been recently assigned, using a semi-empirical model, to Cs(AΠ 1/2 )He 7 . Our first principle calculation suggests that the discovered emission line is most probably due to a decay of Cs(AΠ 1/2 )He 6

  15. Plant remediation of soil contaminated with 137Cs

    International Nuclear Information System (INIS)

    Yang Juncheng; Zhang Jianfeng; Zhu Yongyi; Chen Jingjie; Mei Yong; Jiang Huimin

    2005-01-01

    A pot experiment was conducted to evaluate the bio-remediation of soils contaminated with 137 Cs. The selected plants are Cucurbita moschata Duchesne, Brassica chinensis L, Chloris virgata, Beta oulgaris L. Hongye, Beta oulgaris L. Dongshengye and Beta oulgaris L. The soils samples were taken from the paddy field, 2 km from the Dayawan nuclear power plant and Qinshan nuclear power plant, respectively, and cinnamon soil from the cultivated land in Beijing. The results show that all the employed species of plant have a higher accumulation to 137 Cs with the increased grade of the radioactivity of 137 Cs. A good correlation exist with the coefficient (r 2 ) of 0.9989. When the contaminated radioactivity of 137 Cs is in the same level the uptake of Cucurbita moschata Duchesne, Brassica chinensis L. and Chloris virgata increased with the decrease of pH value ranged 5.22-7.69. The ability of bioremediation in the orders were Chloris virgata, Brassica chinensis L., Beta oulgaris L. Hongye, Cucurbita moschata Duchesne, Beta oulgaris L. and Beta oulgaris L. Dongshengye, according to the comprehensive evaluation of transfer factor, specific activity of plant in dry weight of biomass and total absorption of 137 Cs by the individual plant in the same area. (authors)

  16. Photoelectron Emission Studies in CsBr at 257 nm

    International Nuclear Information System (INIS)

    Maldonado, Juan R.; Liu, Zhi; Sun, Yun; Pianetta, Piero A.; Pease, Fabian W.

    2006-01-01

    CsBr/Cr photocathodes were found [1,2] to meet the requirements of a multi-electron beam lithography system operating with a light energy of 4.8 eV (257nm). The fact that photoemission was observed with a light energy below the reported 7.3 eV band gap for CsBr was not understood. This paper presents experimental results on the presence of intra-band gap absorption sites (IBAS) in CsBr thin film photo electron emitters, and presents a model based on IBAS to explain the observed photoelectron emission behavior at energies below band gap. A fluorescence band centered at 330 nm with a FWHM of about 0.34 eV was observed in CsBr/Cr samples under 257 nm laser illumination which can be attributed to IBAS and agrees well with previously obtained synchrotron photoelectron spectra[1] from the valence band of CsBr films

  17. Energy transfer mechanism in CsI:Eu crystal

    International Nuclear Information System (INIS)

    Yakovlev, V.; Trefilova, L.; Karnaukhova, A.; Ovcharenko, N.

    2014-01-01

    This paper studies the scintillation process in CsI:Eu crystal exposed to the pulse electron irradiation (E=0.25 MeV, t 1/2 =15 ns and W=0.003 J/cm 2 ). It has been proved that the energy transfer from the lattice to Eu 2+ ions in CsI:Eu occurs through the re-absorption of STE emission. The proposed model rests on the following experimental facts: (1) the activator emission at 2.68 eV rises gradually after the decay of the excitation pulse even at temperature lower than 90 K when V k centers are immobile; (2) the rise time of 2.68 eV emission and the decay time of STE emission have the same temperature dependences at T=78–300 K; (3) the excitation spectrum of 2.68 eV emission overlaps the emission spectrum of STE. -- Highlights: • The scintillation process in CsI:Eu was studied under pulsed electron irradiation. • A model of the energy transfer from the lattice to Eu 2+ ions in CsI:Eu was proposed. • Eu 2+ ions in CsI:Eu reabsorb the π-emission of self-trapped excitons

  18. Rotating relativistic neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Weber, F.; Glendenning, N.K.

    1991-07-21

    Models of rotating neutron stars are constructed in the framework of Einstein's theory of general relativity. For this purpose a refined version of Hartle's method is applied. The properties of these objects, e.g. gravitational mass, equatorial and polar radius, eccentricity, red- and blueshift, quadrupole moment, are investigated for Kepler frequencies of 4000 s{sup {minus}1} {le} {Omega}{sub K} {le} 9000 s{sup {minus}1}. Therefore a self-consistency problem inherent in the determination of {Omega}{sub K} must be solved. The investigation is based on neutron star matter equations of state derived from the relativistic Martin-Schwinger hierarch of coupled Green's functions. By means of introducing the Hartree, Hartree-Fock, and ladder ({Lambda}) approximations, models of the equation of state derived. A special feature of the latter approximation scheme is the inclusion of dynamical two-particle correlations. These have been calculated from the relativistic T-matrix applying both the HEA and Bonn meson-exchange potentials of the nucleon-nucleon force. The nuclear forces of the former two treatments are those of the standard scalar-vector-isovector model of quantum hadron dynamics, with parameters adjusted to the nuclear matter data. An important aspect of this work consists in testing the compatibility of different competing models of the nuclear equation of state with data on pulsar periods. By this the fundamental problem of nuclear physics concerning the behavior of the equation of state at supernuclear densities can be treated.

  19. The Destructive Birth of Massive Stars and Massive Star Clusters

    Science.gov (United States)

    Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

    2017-01-01

    Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

  20. Knudsen cell--mass spectrometer studies of cesium--urania interactions. [Cs/sub 2/CO/sub 3/ or CsOH

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J.L.; Osborne, M.F.; Malinauskas, A.P.; Lorenz, R.A.; Manning, S.R.

    1976-06-01

    Limited Knudsen cell--mass spectrometer studies were made of the partial pressures of cesium-containing species (assumed to be primarily Cs(g)) over Cs/sub 2/CO/sub 3/ and over phase equilibria involving UO/sub 2/ and probable Cs-U-O compounds formed from mixtures that initially contained either Cs/sub 2/CO/sub 3/-UO/sub 2/ or CsOH-UO/sub 2/. Although additional work is required to further define the equilibria involved, the data demonstrate unambiguously a significant reduction in cesium partial pressures due to probable Cs-U-O compound formation and indicate essentially identical behavior with either CsOH or Cs/sub 2/CO/sub 3/ as the starting material with UO/sub 2/.

  1. Coprecipitation of 137Cs and 85Sr microquantities with complex compound [M(18-crown-6)]BPH4 (M=Na+, Cs+) from neutral and alkaline solutions

    International Nuclear Information System (INIS)

    Konovalova, N.A.; Rumer, I.A.; Kulyukhin, S.A.

    2009-01-01

    The paper reports the possibility of joint separation of 137 Cs and 85 Sr from neutral and alkaline aqueous solutions by their coprecipitation with the solid phase of complex compounds [M(18-crown-6)]BPh 4 (M=Na + , Cs + ), as well as to study the coprecipitation of 137 Cs and 85 Sr with the solid phase CsBPh 4 . It is found that complex compounds [M(18-crown-6)]BPh 4 (M=Na + , Cs + ) increased the degree of 85 Sr separation from solutions virtually two- to threefold vs. CsBPh 4 . Chloride and nitrate were found to have hardly any impact on the coprecipitation of 137 Cs and 85 Sr with [M(18-crown-6)]BPh 4 (M = Na + , Cs + ). (orig.)

  2. Imbedded Nanocrystals of CsPbBr3 in Cs4 PbBr6 : Kinetics, Enhanced Oscillator Strength, and Application in Light-Emitting Diodes.

    Science.gov (United States)

    Xu, Junwei; Huang, Wenxiao; Li, Peiyun; Onken, Drew R; Dun, Chaochao; Guo, Yang; Ucer, Kamil B; Lu, Chang; Wang, Hongzhi; Geyer, Scott M; Williams, Richard T; Carroll, David L

    2017-11-01

    Solution-grown films of CsPbBr 3 nanocrystals imbedded in Cs 4 PbBr 6 are incorporated as the recombination layer in light-emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr 3 and the nanoinclusion composite are measured and analyzed, indicating second-order kinetics in extended and mainly first-order kinetics in the confined CsPbBr 3 , respectively. Analysis of absorption strength of this all-perovskite, all-inorganic imbedded nanocrystal composite relative to pure CsPbBr 3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub-nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr 3 in melt-grown CsBr host crystals and CsPbBr 3 evaporated films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Potential of monitoring nuclides with the epiphyte Tillandsia usneoides: Uptake and localization of 133Cs.

    Science.gov (United States)

    Li, Peng; Zheng, Guiling; Chen, Xuan; Pemberton, Robert

    2012-12-01

    Epiphytic Tillandsia plants are efficient air pollution biomonitors and traditionally used to monitor atmospheric heavy metal pollution, but rarely nuclides monitoring. Here we evaluated the potential of Tillandsia usneoides for monitoring (133)Cs and investigated if Cs was trapped by the plant external surface structures. The results showed that T. usneoides was able to survive relatively high Cs stress. With the increase of Cs solution concentration, the total of Cs in plants increased significantly, which suggests that the plants could accumulate Cs quickly and effectively. Therefore, T. usneoides has considerable potential for monitoring Cs polluted environments. In addition, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis showed that Cs was detected in each type of cells in foliar trichomes, and the ratio of Cs in the internal disc cell was higher than that in ring cell and wing cell, which indicates that the mechanism of adsorption Cs in Tillandsia has an active component. Copyright © 2012. Published by Elsevier Inc.

  4. A new method for determining which stars are near a star sensor field-of-view

    Science.gov (United States)

    Yates, Russell E., Jr.; Vedder, John D.

    1991-01-01

    A new method is described for determining which stars in a navigation star catalog are near a star sensor field of view (FOV). This method assumes that an estimate of spacecraft inertial attitude is known. Vector component ranges for the star sensor FOV are computed, so that stars whose vector components lie within these ranges are near the star sensor FOV. This method requires no presorting of the navigation star catalog, and is more efficient than tradition methods.

  5. Experimental and computation method for determination of burnup and isotopic composition of the WWER-440 fuel using the 134Cs and 137Cs concentrations

    International Nuclear Information System (INIS)

    Babichev, B.A.; Kozharin, V.V.

    1990-01-01

    An experimental and computational method for determination of burnup and actinoid concentrations in WWER fuel elements using 134 Cs and 137 Cs concentrations in fuel is considered. It is shown that the error in calculation of fuel burnup and U and Pu isotope concentrations in WWER-440 fuel elements is 1.3-4.9% provided that the error in 134 Cs and 137 Cs concentration measurements does not exceed 1.7 and 1.2%. 9 refs.; 10 figs.; 4 tabs

  6. On the cesium-rich part of the Cs-Te phase diagram

    International Nuclear Information System (INIS)

    Boer, R. de; Cordfunke, E.H.P.

    1995-03-01

    The cesium-tellurium system in the region between 33 and 55 at.% Te has been investigated with X-ray diffraction and DSC. The existence of the compounds Cs 5 Te 3 and CsTe is demonstrated. The latter compound exhibits a structural transition at elevated temperature, as does the compound Cs 2 Te. The earlier reported compounds Cs 3 Te 2 and Cs 5 Te 4 do not exist. (orig.)

  7. Star-forming Filament Models

    International Nuclear Information System (INIS)

    Myers, Philip C.

    2017-01-01

    New models of star-forming filamentary clouds are presented in order to quantify their properties and to predict their evolution. These 2D axisymmetric models describe filaments that have no core, one low-mass core, and one cluster-forming core. They are based on Plummer-like cylinders and spheroids that are bounded by a constant-density surface of finite extent. In contrast to 1D Plummer-like models, they have specific values of length and mass, they approximate observed column density maps, and their distributions of column density ( N -pdfs) are pole-free. Each model can estimate the star-forming potential of a core-filament system by identifying the zone of gas dense enough to form low-mass stars and by counting the number of enclosed thermal Jeans masses. This analysis suggests that the Musca central filament may be near the start of its star-forming life, with enough dense gas to make its first ∼3 protostars, while the Coronet filament is near the midpoint of its star formation, with enough dense gas to add ∼8 protostars to its ∼20 known stars. In contrast, L43 appears to be near the end of its star-forming life, since it lacks enough dense gas to add any new protostars to the two young stellar objectsalready known.

  8. Star-forming Filament Models

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Philip C., E-mail: pmyers@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-03-20

    New models of star-forming filamentary clouds are presented in order to quantify their properties and to predict their evolution. These 2D axisymmetric models describe filaments that have no core, one low-mass core, and one cluster-forming core. They are based on Plummer-like cylinders and spheroids that are bounded by a constant-density surface of finite extent. In contrast to 1D Plummer-like models, they have specific values of length and mass, they approximate observed column density maps, and their distributions of column density ( N -pdfs) are pole-free. Each model can estimate the star-forming potential of a core-filament system by identifying the zone of gas dense enough to form low-mass stars and by counting the number of enclosed thermal Jeans masses. This analysis suggests that the Musca central filament may be near the start of its star-forming life, with enough dense gas to make its first ∼3 protostars, while the Coronet filament is near the midpoint of its star formation, with enough dense gas to add ∼8 protostars to its ∼20 known stars. In contrast, L43 appears to be near the end of its star-forming life, since it lacks enough dense gas to add any new protostars to the two young stellar objectsalready known.

  9. Strange-quark-matter stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-11-01

    We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 13 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to consist of individual hadrons. We conclude that it is implausible that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, is a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation if strange matter is stable at an energy density exceeding about 5.4 times that of nuclear matter. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 34 refs., 10 figs., 1 tab

  10. Presupernova evolution of massive stars

    International Nuclear Information System (INIS)

    Weaver, T.A.; Zimmerman, G.B.; Woosley, S.E.

    1977-01-01

    Population I stars of 15 M/sub mass/ and 25 M/sub mass/ have been evolved from the zero-age main sequence through iron core collapse utilizing a numerical model that incorporates both implicit hydrodynamics and a detailed treatment of nuclear reactions. The stars end their presupernova evolution as red supergiants with photospheric radii of 3.9 x 10 13 cm and 6.7 x 10 13 cm, respectively, and density structures similar to those invoked to explain Type II supernova light curves on a strictly hydrodynamic basis. Both stars are found to form substantially neutronized ''iron'' cores of 1.56 M/sub mass/ and 1.61 M/sub mass/, and central electron abundances of 0.427 and 0.439 moles/g, respectively, during hydrostatic silicon burning. Just prior to collapse, the abundances of the elements in the 25 M/sub mass/ star (excluding the neutronized iron core) have ratios strikingly close to their solar system values over the mass range from oxygen to calcium, while the 15 M/sub mass/ star is characterized by large enhancements of Ne, Mg, and Si. It is pointed out on nucleosynthetic grounds that the mass of the neutronized core must represent a lower limit to the mass of the neutron star or black hole remnant that stars in this mass range can normally produce

  11. Quasi-freestanding graphene on Ni(111) by Cs intercalation

    KAUST Repository

    Alattas, Maha Hassan Mohssen

    2016-05-26

    A possible approach to achieve quasi-freestanding graphene on a substrate for technological purpose is the intercalation of alkali metal atoms. Cs intercalation between graphene and Ni(111) therefore is investigated using density functional theory, incorporating van der Waals corrections. It is known that direct contact between graphene and Ni(111) perturbs the Dirac states. We find that Cs intercalation restores the linear dispersion characteristic of Dirac fermions, which agrees with experiments, but the Dirac cone is shifted to lower energy, i.e., the graphene sheet is n-doped. Cs intercalation therefore decouples the graphene sheet from the substrate except for a charge transfer. On the other hand, the spin polarization of Ni(111) does not extend through the intercalated atoms to the graphene sheet, for which we find virtually spin-degeneracy.

  12. Radiochemical determination of {sup 137}Cs in foods

    Energy Technology Data Exchange (ETDEWEB)

    Kastner, Geraldo F.; Ferreira, Andrea Vidal; Monteiro, Roberto P.G., E-mail: gfk@cdtn.br, E-mail: avf@cdtn.br, E-mail: rpgm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    A determination of radionuclides in food samples is important in commodities in order to attend to regulatory requirements for international trade. As a long-lived radioisotope of cesium, {sup 137}Cs is produced as a result of human nuclear activities and than its contamination level evaluation among others radionuclides in foods is necessary. A methodology for the determination of {sup 137}Cs in foods, pork and fish, is described. The procedures covered homogenization and freeze-drying of the samples. The {sup 137}Cs was measured by gamma spectrometry using Canberra 50% HPGe detector. The counting was carried out with Monte Carlo software for detection conditions optimization including geometry and chemical data information. A certified sample, SRM IAEA-375, was analyzed in order to evaluate the reliability of the method, and the results showed good agreement between the measured and certified values. (author)

  13. {sup 134}Cs emission probabilities determination by gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, M.C.M. de, E-mail: candida@cnen.gov.br [Comissão Nacional de Energia Nuclear (DINOR/CNEN), Riode Janeiro, RJ (Brazil); Poledna, R.; Delgado, J.U.; Silva, R.L.; Araujo, M.T.; Silva, C.J. da [Instituto de Radioproteção e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) of Rio de Janeiro performed primary and secondary standardization of different radionuclides reaching satisfactory uncertainties. A solution of {sup 134}Cs radionuclide was purchased from commercial supplier to emission probabilities determination of some of its energies. {sup 134}Cs is a beta gamma emitter with 754 days of half-life. This radionuclide is used as standard in environmental, water and food control. It is also important to germanium detector calibration.The gamma emission probabilities (Pγ) were determined mainly for some energies of the {sup 134}Cs by efficiency curve method and the Pγ absolute uncertainties obtained were below 1% (k=1). (author)

  14. Bioaccumulation of Cs-137 and Co-57 by marine phytoplankton

    International Nuclear Information System (INIS)

    Heldal, H.E.; Stupakoff, I.; Fisher, N.S.

    1999-01-01

    Under controlled laboratory conditions we have examined the bioaccumulation of Cs-137 and Co-57 in three prymnesiophytes, the coccolithophorid Emiliania huxleyi and the non-calcareous species Isochrysis galbana and Phaeocystis globosa, and two diatoms Skeletonema costatum and Thalassiosira pseudonana. We measured uptake in growing and non-growing cells, and determined concentration factors on both volume and dry weight basis. For Co-57 uptake in non-growing cells, volume concentration factors (VCF) at equilibrium ranged from 0.2 * 10 3 for Emiliana huxleyi to 4 * 10 3 for the diatom Thalassiosira pseudonana. For Cs-137 uptake in non-growing cells the VCFs were close to zero. The results suggest that, in contrast to Co, the cycling and bioaccumulation in animals of Cs in marine systems is unlikely to be affected by primary producers. (au)

  15. Medical management of the victims of Goiana 137 Cs accident

    International Nuclear Information System (INIS)

    Brandao-Mello, C.E.; Farina, R.; Oliveira, A.R.; Valverde, N.J.

    1989-01-01

    In September 1987, a radiation accident happened in Gioania due to the theft of a shielded source of 137 Cs. Fifty persons were involved showing whole-body and local acute irradiation and also external and/or internal contamination mainly due to ingestion or absorption of 137 Cs. Fourteen of fifty developed severe bone marrow depression characterized by neutropenia and thrombocytopenia. None were submitted to bone marrow transplantation. Eight of fourteen received intravenously GM-CSF. Four of the fourteen died due to hemorrhage and infection. For those with significant internal contamination, Prussian blue was administered (1.5 to 10.0 gm/per day). Besides blue, other measures were taken to increase decorporation of 137 Cs including diuretics, water overload and ergometric exercises. Radiation induced skin injuries were observed in 28 patients and were treated conservatively. 6 patients required surgical intervention. (author)

  16. Quasi-freestanding graphene on Ni(111) by Cs intercalation

    KAUST Repository

    Alattas, Maha Hassan Mohssen

    2017-01-08

    It is of technological interest to achieve quasi-freestanding graphene on a substrate. A possible approach is the intercalation of alkali metal atoms. Cs intercalation between graphene and Ni(111) is investigated using density functional theory, incorporating van der Waals corrections. It is known that direct contact between graphene and Ni(111) perturbs the Dirac states. Cs intercalation restores the linear dispersion characteristic of Dirac fermions, which is in agreement with experiments1, but the Dirac cone is shifted to lower energy, i.e., the graphene sheet is n-doped. Cs intercalation therefore effectively decouples the graphene sheet from the substrate except for a charge transfer. On the other hand, the spin polarization of Ni(111) does not extend through the intercalated atoms to the graphene sheet, for which we find virtually spin-degeneracy.

  17. Household methods to reduce {sup 137}Cs contents of mushrooms

    Energy Technology Data Exchange (ETDEWEB)

    Kostiainen, E. [Radiation and Nuclear Safety Authority - STUK, Helsinki (Finland)

    2005-09-15

    High radiocaesium contents in different species of mushrooms have been observed in areas contaminated by radiocaesium deposition after the Chernobyl accident in 1986. There has been no significant reduction in the {sup 137}Cs contents of mushrooms during the past ten years, besides via radioactive decay. The internal radiation dose received via mushrooms can be reduced by processing mushrooms before consumption. Various household methods were studied to find out their efficiency to reduce {sup 137}Cs contents of mushrooms. The methods tested were the same as normally used in cooking. The tests were made for the species of edible mushrooms widely consumed. The retention factors for the treatments tested were in most cases 0.2-0.3. The efficiency of treatments in reducing the {sup 137}Cs contents increased with larger water volumes and prolonged treatment times.

  18. Household methods to reduce 137Cs contents of mushrooms

    International Nuclear Information System (INIS)

    Kostiainen, E.

    2005-01-01

    High radiocaesium contents in different species of mushrooms have been observed in areas contaminated by radiocaesium deposition after the Chernobyl accident in 1986. There has been no significant reduction in the 137 Cs contents of mushrooms during the past ten years, besides via radioactive decay. The internal radiation dose received via mushrooms can be reduced by processing mushrooms before consumption. Various household methods were studied to find out their efficiency to reduce 137 Cs contents of mushrooms. The methods tested were the same as normally used in cooking. The tests were made for the species of edible mushrooms widely consumed. The retention factors for the treatments tested were in most cases 0.2-0.3. The efficiency of treatments in reducing the 137 Cs contents increased with larger water volumes and prolonged treatment times

  19. Zulliger (CS in Assessing the Relational Maturity of Children

    Directory of Open Access Journals (Sweden)

    Anna Elisa Villemor-Amaral

    Full Text Available Abstract Relational maturity is an important aspect to be considered in the evaluation of children. Its development in children is considered related to sex and chronological age. The present study aimed to seek evidence of validity for the Zulliger test (Comprehensive System - CS in the evaluation of maturity for interpersonal relationships in children. A total of 566 children, both sexes, of which 52.8% were girls, were submitted to the Zulliger test (CS. For comparison according to age, a subsample was extracted, composed of two groups of six and 12-year-olds, totaling 115 children. The analysis revealed statistically significant differences in the variables H, (H, A, Ad, (A, M, FC and AG. Results show findings in favor of using the Zulliger test (CS in the evaluation of maturity for interpersonal relationships in children.

  20. Studies on diffusion of 137Cs in cement mortar

    International Nuclear Information System (INIS)

    Takebe, Shinichi; Shimooka, Kenji; Wadachi, Yoshiki; Kuramoto, Yuzuru.

    1989-12-01

    Penetration experiment of 137 Cs into the impermeable cement mortar which has been treated by the impermeable reagent (XYPEX reagent) was carried out in order to advance the performance of engineered barrier for Low Level Radioactive Waste. The result showed that the radioactive concentration at deeper region in the impermeable cement mortar specimen was decreased about 1 order of magnitude below that in the untreated specimen. Diffusion coefficient calculated from the radioactive concentration of 137 Cs in the cement mortar specimen was 9.1 x 10 -5 cm 2 /day for untreated cement mortar specimen and 4.0 x 10 -5 cm 2 /day for the impermeable cement mortar specimen, respectively. Treatment of cement mortar by the impermeable reagent was found to be effective to reduce the value of appearent diffusion coefficient for 137 Cs in the cement mortar. (author)

  1. Airborne fallout mapping of 137Cs Finnish defence forces team

    International Nuclear Information System (INIS)

    Kettunen, M.; Heininen, T.; Pulakka, M.

    1997-01-01

    The main task of the team was to create a fallout map of 137 Cs in a specified area in Padasjoki Auttoinen village. The team used an MI-8 helicopter of the Finnish Air Force. The team had an HPGe system (relative efficiency 70%) to measure nuclide specific ground contamination level. For navigation the team took advantage of the DGPS service provided by Finnish Broadcasting company utilizing the RDS-channel to get position accuracy within 2 meters. The correction signal is reachable nationwide on the FM transmitter network. The system produced a distribution map for 40 K and fallout maps for 134,137 Cs using a Micro Station Program with TerraModeler application. The maximum measured 137 Cs ground contamination exceeded 130-140 kBqm -2 . (au)

  2. Measurement of thermal neutron cross section and resonance integral of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Toshio; Nakamura, Shoji; Harada, Hideo [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan); Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu

    1997-03-01

    The thermal neutron(2,200 m/s neutron) capture cross section({sigma}{sub 0}) and the resonance integral(I{sub 0}) of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs were measured by an activation method. Targets of radioactive cesium, which include {sup 135}Cs, {sup 137}Cs and stable {sup 133}Cs, were irradiated with reactor neutrons within or without a Cd shield case. The ratio of the number of nuclei of {sup 135}Cs to that of {sup 137}Cs was measured with a quadrupole mass spectrometer. This ratio and the ratio of activity of {sup 136}Cs to that of {sup 137}Cs were used for deduction of the {sigma}{sub 0} and the I{sub 0} of {sup 135}Cs. The {sigma}{sub 0} and the I{sub 0} of the reaction {sup 135}Cs(n,{sigma}){sup 136}Cs were 8.3 {+-} 0.3 barn and 38.1 {+-} 2.6 barn, respectively. (author)

  3. Estimation of average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors by using the 134Cs/137Cs ratio method

    International Nuclear Information System (INIS)

    Endo, T.; Sato, S.; Yamamoto, A.

    2012-01-01

    Average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors is estimated, using the 134 Cs/ 137 Cs ratio method for measured radioactivities of 134 Cs and 137 Cs in contaminated soils within the range of 100 km from the Fukushima Dai-ichi nuclear power plants. As a result, the measured 134 Cs/ 137 Cs ratio from the contaminated soil is 0.996±0.07 as of March 11, 2011. Based on the 134 Cs/ 137 Cs ratio method, the estimated burnup of damaged fuels is approximately 17.2±1.5 [GWd/tHM]. It is noted that the numerical results of various calculation codes (SRAC2006/PIJ, SCALE6.0/TRITON, and MVP-BURN) are almost the same evaluation values of 134 Cs/ 137 Cs ratio with same evaluated nuclear data library (ENDF-B/VII.0). The void fraction effect in depletion calculation has a major impact on 134 Cs/ 137 Cs ratio compared with the differences between JENDL-4.0 and ENDF-B/VII.0. (authors)

  4. Accreting neutron stars, black holes, and degenerate dwarf stars.

    Science.gov (United States)

    Pines, D

    1980-02-08

    During the past 8 years, extended temporal and broadband spectroscopic studies carried out by x-ray astronomical satellites have led to the identification of specific compact x-ray sources as accreting neutron stars, black holes, and degenerate dwarf stars in close binary systems. Such sources provide a unique opportunity to study matter under extreme conditions not accessible in the terrestrial laboratory. Quantitative theoretical models have been developed which demonstrate that detailed studies of these sources will lead to a greatly increased understanding of dense and superdense hadron matter, hadron superfluidity, high-temperature plasma in superstrong magnetic fields, and physical processes in strong gravitational fields. Through a combination of theory and observation such studies will make possible the determination of the mass, radius, magnetic field, and structure of neutron stars and degenerate dwarf stars and the identification of further candidate black holes, and will contribute appreciably to our understanding of the physics of accretion by compact astronomical objects.

  5. Temporal variations of Cs-137 in Sots Pine

    International Nuclear Information System (INIS)

    Nylen, T.; Plamboeck, A.H.; Boson, J.

    2008-01-01

    In this study the temporal changes in 137 Cs distribution in a Scots pine (Pinus Sylvestris L.) stand was studied during 1986 to 2006 in Northern Sweden. The Chernobyl fallout provided an excellent possibility to study the uptake and retention in conifer trees of 137 Cs, since the deposition lasted for only a few days. The average deposition of 137 Cs in the region that originates from the Chernobyl accident in 1986 was 20 ± 9 kBq M -2 . Also 137 Cs from the atmospheric nuclear weapons tests was present in the area and was only 3 ±2 kBq m -2 . Studies show that the redistribution of radioactive caesium still contribute to high activity concentrations in some compartments of the ecosystem. It has been known that certain fungi continue to produce fruit bodies with high amounts of 137 Cs. The current study adds another aspect to consider: The high activity concentration in branches and current needles during 2006 indicates an uptake of 137 Cs from the soil which could lead to concentrations in Scots Pine that has to be considered in forestry and other kind of utilization of forest products. There are for instance a few game birds such as the capercaillie (Tetrao urogallus) that feed on pine shoots. Another possible effect is on the use of pine branches in the bio fuel industry. Given an activity concentration of 1200 Bq/kg (d.w.) and a concentration factor of 10 during combustion the concentration in ashes would be 12000 bq/kg. According to the recommendations from SSI (the Swedish Radiation Protection Authority) ashes that have concentrations higher than 10 kBq/kg must be stored in special deposits. It would be of interest to investigate the uptake in stands of different ages since the pine stand that was studied was about 30 years old in 1986 and do not represent neither a mature nor a newly established stand (tk)

  6. Development of the CsI Calorimeter Subsystem for AMEGO

    Science.gov (United States)

    Grove, J. Eric; Woolf, Richard; Johnson, W. Neil; Phlips, Bernard

    2018-01-01

    We report on the development of the thallium-doped cesium iodide (CsI:Tl) calorimeter subsystem for the All-Sky Medium-Energy Gamma-ray Observatory (AMEGO). The CsI calorimeter is one of the three main subsystems that comprise the AMEGO instrument suite; the others include the double-sided silicon strip detector (DSSD) tracker/converter and a cadmium zinc telluride (CZT) calorimeter. Similar to the LAT instrument on Fermi, the hodoscopic calorimeter consists of orthogonally layered CsI bars. Unlike the LAT, which uses PIN photodiodes, the scintillation light readout from each end of the CsI bar is done with recently developed large-area silicon photomultiplier (SiPM) arrays. We currently have an APRA program to develop the calorimeter technology for a larger, future space-based gamma-ray observatory. Under this program, we are building and testing a prototype calorimeter consisting of 24 CsI bars (16.7 mm x 16.7 mm x 100 mm) arranged in 4 layers with 6 bars per layer. The ends of each bar are read out with a 2 x 2 array of 6 mm x 6 mm SensL J series SiPMs. Signal readout and processing is done with the IDEAS SIPHRA (IDE3380) ASIC. Performance testing of this prototype will be done with laboratory sources, a beam test, and a balloon flight in conjunction with the other subsystems led by NASA GSFC. Additionally, we will test 16.7 mm x 16.7 mm x 450 mm CsI bars with SiPM readout to understand the performance of longer bars in advance of the developing the full instrument.Acknowledgement: This work was sponsored by the Chief of Naval Research (CNR) and NASA-APRA (NNH15ZDA001N-APRA).

  7. Distribution of 137Cs in environmental soil and crude drugs

    International Nuclear Information System (INIS)

    Kimura, Shoujiro; Yamaoki, Rumi

    1997-01-01

    Radioactivity of 137 Cs and 40 K was determined on commercially available products of Houttuynia Herb which were imported from China and Taiwan or processed in Japan, and of Houttuynia cordata harvested in 15 places in Japan and the surrounding soil. On Houttuynia Herb, the concentrations of 137 Cs and 40 K were LTD (less than detectable)-7.6 Bq/kg dry and 743-1964 Bq/kg dry, respectively, suggesting than the concentration of 137 Cs was less than 1% of that of 40 K. The domestic products were found to contain higher concentrations of 137 Cs and 40 K than the imported ones. The concentration of 137 Cs of Houttuynia cordata harvested in Japan ranged from 0.8 Bq/kg dry to 172 Bq/kg dry, while the concentration of 40 K was almost the same as that of the commercial products. The concentration ratio of 40 K in Houttuynia cordata to that in the soil was correlated with the moisture content and the ignition loss of the soil. However, the concentration ratio of 137 Cs did not show a very clear correlation. When 15 g of Houttuynia Herb or Houttuynia cordata was daily decocted and given for 1 year the former showed the committed dose equivalent of 0.02-0.5 μSv and the latter 0.06-12 μSv. Both of these values were less than 0.5% of the annual effective dose equivalent from the nature, 2.4 mSv. (author)

  8. Changes in 137Cs transfer to agricultural products

    International Nuclear Information System (INIS)

    Goncharov, N.; Timochtchenko, A.; Milutin, A.

    1999-01-01

    The food production and food harvesting systems common in the areas contaminated by the Chernobyl accident in Republic of Belarus can be grouped into three major categories: collective farm produce, private farming produce and natural foods collected from natural ecosystems. The collective farm system provided the smallest contribution (8-12 %) to the intake of 137 Cs. Natural food was the major contributor to the intake at one study site (73 %), and private produce was the major contributor (60 %) at the other study site. Assessment of the situation just after the accident (one year) shows that collective farming was still a minor contributor to 137 CS intake (10 %) whilst private fanning would have been the major contributor wherever private milk production and consumption continued. The extent to which inhabitants consume natural foods from forests has a considerable effect on their 137 CS intake. The comparative importance of food products from natural ecosystems increases with time due to the long effective ecological half lives of 137 Cs in unimproved pastures and forests. Estimation of the contribution to the fluxes of 137 Cs from the different production and harvesting systems showed that the contribution from private farming and food harvesting from natural ecosystems may also be significant, contributing 14-30 % to the total fluxes of 137 Cs from an area even if the quantity of food produced in these systems is small. However, the major contributor to the flux exported from an area was the collective farming system, accounting for about 70-86 % of the total. Refs. 12 (author)

  9. Parameters Affecting 137Cs Migration within Soil Profile

    International Nuclear Information System (INIS)

    Sefien, S.M.; Ibrahim, A.S.; Abdelmalik, W.E.Y.

    2013-01-01

    Some studies have been carried out on the adsorption, distribution and migration of 137 Cs within soils of the area in the vicinity of the Nuclear Research Centre, Egypt, and Ismailia Canal. The soil physicochemical and mineralogical characteristics were carried out and indicated that the soil samples consisted mainly of sand fraction (quartz) and silt fractions (semctite minerals). The kinetics of caesium adsorption and its adsorption isotherms for the tested soils were also studied. The sorption of 137 Cs on soil minerals markedly affects its migration rate. The natural background of both locations of study indicated that the amounts of 137 Cs present in the reactor site were found to be originated from the fallout and from the external contamination which affected the background level. The 137 Cs activity at the canal site was found to be 20.01 Bq/m 2 .cm, while that around the reactor site were found to be 231.15 Bq/m2.cm which may be originating from the fallout and from external contamination which affect the background level at that location. The activity in the canal soil which amounted to 20.01 Bq/m2/cm (0.87 Bq/kg) is about that of background.Based on the distribution data, the vertical distribution of 137 Cs has been studied for soil in both locations (the vicinity of the Nuclear Research Centre (NRC) and Ismailia canal). The vertical migration rates of 137 Cs were calculated for soil samples selected from different locations. These rates were found to be 0.056 and 0.031 cm/year for the reactor and canal site respectively.

  10. Inventories and fluxes of 137Cs in the Syrian land

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Amin, Y.

    2005-03-01

    Cesium-137 inventories and atmospheric fluxes have been determined using radiocesium distributions in undistributed soil profiles, collected from 38 sites distributed all over the Syrian lands. Results have shown that 137 Cs inventories determination by Soil Layers Sum Method is more accurate than the Integration Method, where the best curve fitting of 137 Cs distribution with depth is difficult to establish. 137 Cs inventories ranged from 441 Bq.m - 2 and 13312 Bq.m - 2 using the Layers Sum Method with a mean value of 3679 Bq.m - 2; the highest values observed were in the coastal, middle and north east regions. This is due to the fact that most of Chernobyl accident atmospheric fall-out of cesium 137 had entered the Syrian land came from the west boarders (Mediterranean sea). While the lowest values were found to be in the samples collected from the east south region. In addition, 137 Cs flux ranged from 3.1 kBq m - 2y - 1 and 527.8 kBq m - 2 y - 1 with a mean value of 65.7 kBq m - 2y - 1. Moreover, there was a semi linear relationship found between 137 Cs flux and the height above sea level. While no linear relationship was found between 137 Cs flux and annual rainfall. On the other hand, the external radiation dose to Syrians that due to gamma-rays emitted from cesium 137 decay has been determined and reached a mean value of 166μ Sv.y - 1. This value is about 20% of the radiation dose received by the Syrian from naturally occurring radionuclides in soil. (Author)

  11. The Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Cherepashchuk, A.M.; Khaliullin, K.F.

    1983-01-01

    One may say that the observational evidence now available for Wolf-Rayet stars, particularly the results gained by analyzing eclipsing binary systems prove that at least some of these objects are helium stars. At the same time, the low electron temperatures in the emission-line zones, the indisputable evidence of a highly extended atmosphere and the steady loss of material by these stars all strongly support the fluorescence model proposed by a previous study, whereby Wolf-Rayet envelopes would owe their luminosity to conversion of the short-wavelength radiation emitted by the hot stellar core

  12. Physics of neutron star interiors

    International Nuclear Information System (INIS)

    Blaschke, D.

    2001-01-01

    Neutron stars are the densest observable bodies in our universe. Born during the gravitational collapse of luminous stars - a birth heralded by spectacular supernova explosions - they open a window on a world where the state of the matter and the strength of the fields are anything but ordinary. This book is a collection of pedagogical lectures on the theory of neutron stars, and especially their interiors, at the forefront of current research. It adresses graduate students and researchers alike, and should be particularly suitable as a text bridging the gap between standard textbook material and the research literature

  13. Neutron star structure from QCD

    CERN Document Server

    Fraga, Eduardo S; Vuorinen, Aleksi

    2016-01-01

    In this review article, we argue that our current understanding of the thermodynamic properties of cold QCD matter, originating from first principles calculations at high and low densities, can be used to efficiently constrain the macroscopic properties of neutron stars. In particular, we demonstrate that combining state-of-the-art results from Chiral Effective Theory and perturbative QCD with the current bounds on neutron star masses, the Equation of State of neutron star matter can be obtained to an accuracy better than 30% at all densities.

  14. Thermal evolution of compact stars

    International Nuclear Information System (INIS)

    Schaab, C.; Glendenning, N.K.

    1996-01-01

    A collection of modern, field-theoretical equations of state is applied to the investigation of cooling properties of compact stars. These comprise neutron stars as well as hypothetical strange-matter stars, made up of absolutely stable 3-flavor strange-quark matter. Various uncertainties in the behavior of matter at supernuclear densities, e.g., hyperonic degrees of freedom, behavior of coupling strengths in matter, pion and meson condensation, superfluidity, transition to quark matter, absolute stability of strange-quark matter, and last but not least the many-body technique itself are tested against the body of observed cooling data. (orig.)

  15. New illustrated stars and planets

    CERN Document Server

    Cooper, Chris; Nicolson, Iain; Stott, Carole

    2002-01-01

    Stars & Plantes, written by experts and popular science writers, is a comprehensive overview of our Universe - what is it, where it came from and how we discovered it. This intriguing, information-rich new reference book contains over 300 stunning images from the Hubble Telescope and leading observatories from around the world as well as diagrams to explain the finer points of theory. With extensive sections on everything from the Solar System to how stars form Stars & Planets will appeal to beginners and the serious stargazer alike.

  16. Neutron star moments of inertia

    Science.gov (United States)

    Ravenhall, D. G.; Pethick, C. J.

    1994-01-01

    An approximation for the moment of inertia of a neutron star in terms of only its mass and radius is presented, and insight into it is obtained by examining the behavior of the relativistic structural equations. The approximation is accurate to approximately 10% for a variety of nuclear equations of state, for all except very low mass stars. It is combined with information about the neutron-star crust to obtain a simple expression (again in terms only of mass and radius) for the fractional moment of inertia of the crust.

  17. Flare stars in Pleiades. 5

    International Nuclear Information System (INIS)

    Mirzoyan, L.V.; Chavushyan, O.S.; Erastova, L.K.; Oganyan, G.B.; Melikyan, N.D.; Natsvlishvili, R.Sh.; Tsvetkov, M.K.

    1977-01-01

    The results of photographic observations of stellar flares in the Pleiades region made in the Byurakan and Abastumany astrophysical observatories in 1973-1974 are presented. The observations and revisions of the pictures taken earlier helped to detect 20 new flare stars and 62 repeated flares of flare stars known before. Two-colour photographic and UV observation of 21 flares were carried out. The observation data point to considerable differences in the mean frequency of flares of various flare stars in the Pleiades

  18. Southern high-velocity stars

    International Nuclear Information System (INIS)

    Augensen, H.J.; Buscombe, W.

    1978-01-01

    Using the model of the Galaxy presented by Eggen, Lynden-Bell and Sandage (1962), plane galactic orbits have been calculated for 800 southern high-velocity stars which possess parallax, proper motion, and radial velocity data. The stars with trigonometric parallaxes were selected from Buscombe and Morris (1958), supplemented by more recent spectroscopic data. Photometric parallaxes from infrared color indices were used for bright red giants studied by Eggen (1970), and for red dwarfs for which Rodgers and Eggen (1974) determined radial velocities. A color-color diagram based on published values of (U-B) and (B-V) for most of these stars is shown. (Auth.)

  19. Neutron Star Physics and EOS

    Directory of Open Access Journals (Sweden)

    Lattimer James M.

    2016-01-01

    Full Text Available Neutron stars are important because measurement of their masses and radii will determine the dense matter equation of state. They will constrain the nuclear matter symmetry energy, which controls the neutron star matter pressure and the interior composition, and will influence the interpretation of nuclear experiments. Astrophysical observations include pulsar timing, X-ray bursts, quiescent low-mass X-ray binaries, pulse profiles from millisecond pulsars, neutrino observations from gravitational collapse supernovae,and gravitational radiation from compact object mergers. These observations will also constrain the neutron star interior, including the properties of superfluidity there, and determine the existence of a possible QCD phase transition.

  20. 210Pb-137Cs dating of glacial lake sediments

    International Nuclear Information System (INIS)

    Graham, I.J.; Ditchburn, R.G.; Barry, B.J.

    2004-01-01

    Sediments deposited in New Zealand lakes in the recent past provide excellent archives of local climate change via their trapped biodiversity, varve structure ad sedimentological composition. To unlock the archival information, accurate and fine-scale dating of the deposits is essential. A combination of 210 Pb and 137 Cs dating provides the most reliable and robust approach. Under favourable conditions, 210 Pb dating can provide a detailed chronology to c.120-140 y, and can be accurately calibrated by 137 Cs for the last 40 y or thereabouts. (author). 6 refs., 4 figs