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Sample records for bismuth isotopes

  1. Laser Spectroscopy of Neutron Rich Bismuth Isotopes

    CERN Multimedia

    2002-01-01

    %IS344 :\\\\ \\\\ The aim of the experiment is to measure the optical isotope shifts and hyperfine structures of bismuth isotopes across the N=126 shell closure in order to extract the change in mean square charge radii ($\\delta\\langle r^{2}\\rangle$) and static moments. These include the first isotones of lead to be measured directly above the shell closure and will provide new information on the systematics of the kink ($\\delta\\langle r^{2}\\rangle)$ seen in the lead isotopic chain. After two very successful runs the programme has been extended to include the neutron deficient isotopes below $^{201}$Bi to study the systematics across the $i_{13/2}$ neutron sub-shell closure at N=118.\\\\ \\\\ During the initial 2 runs (9 shifts) the isotope shifts and hyperfine structures of three new isotopes, $ ^{210,212,213}$Bi and the 9$^{-}$ isomer of $^{210}$Bi have been measured. The accuracy of the previous measurements of $^{205,206,208}$Bi have been greatly improved. The samples of $ ^{208,210,210^{m}}$Bi were prepared by c...

  2. Discovery of the thallium, lead, bismuth, and polonium isotopes

    OpenAIRE

    Fry, C; Thoennessen, M

    2012-01-01

    Currently, forty-two thallium, forty-two lead, forty-one bismuth, and forty-two polonium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  3. An evaluation of activated bismuth isotopes in environmental samples from the former Western Pacific Proving Grounds

    International Nuclear Information System (INIS)

    207Bi (T1/2 =32.2 y) was generated by activation of weapons material during a few 'clean' nuclear tests at the U.S. Westren Pacific Provung Grounds of Enewetak and Bikini Atolls. The radionuclides first appeared in the Enewetak environment during 1958 and in the environment of Bikini during 1956. Crater sediments from Bikini with high levels of 207Bi were analyzed by gamma-spectrometry in an attempt to determine the relative concentrations of 208Bi (T1/2 = 3.68 x 105 y). The bismuth isotopes were probably generated during the 'clean', 9.3 Mt Poplar test held on 7/12/58. The atom ratio of 208Bi to 207Bi (R value) ranges from ∼ 12 to over 200 in sections of core sediments from the largest nuclear crater at Bikini atoll. The presence of bismuth in the device is suggested to account for R values in excess of 10. (author)

  4. An Evaluation of Activated Bismuth Isotopes in Environmental Samples From the Former Western Pacific Proving Grounds

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.; Brunk, J.A.; Jokela, T.A.

    2000-03-21

    {sup 207}Bi (t{sub 1/2}=32.2 y) was generated by activation of weapons material during a few ''clean'' nuclear tests at the U.S. Western Pacific Proving Grounds of Enewetak and Bikini Atolls. The radionuclides first appeared in the Enewetak environment during 1958 and in the environment of Bikini during 1956. Crater sediments from Bikini with high levels of {sup 207}Bi were analyzed by gamma spectrometry in an attempt to determine the relative concentrations of {sup 208}Bi (t{sup 1/2} = 3.68 x 10{sup 5} y). The bismuth isotopes were probably generated during the ''clean'', 9.3 Mt Poplar test held on 7/12/58. The atom ratio of {sup 208}Bi to {sup 207}Bi (R value) ranges from {approx}12 to over 200 in sections of core sediments from the largest nuclear crater at Bikini atoll. The presence of bismuth in the device is suggested to account for R values in excess of 10.

  5. Identification and Decay Studies of New, Neutron-Rich Isotopes of Bismuth, Lead and Thallium by means of a Pulsed Release Element Selective Method

    CERN Document Server

    Mills, A; Kugler, E; Van duppen, P L E; Lettry, J

    2002-01-01

    % IS354 \\\\ \\\\ It is proposed to produce, identify and investigate at ISOLDE new, neutron-rich isotopes of bismuth, lead and thallium at the mass numbers A=215 to A=218. A recently tested operation mode of the PS Booster-ISOLDE complex, taking an advantage of the unique pulsed proton beam structure, will be used together with a ThC target in order to increase the selectivity. The decay properties of new nuclides will be studied by means of $\\beta$-, $\\gamma$- and X- ray spectroscopy methods. The expected information on the $\\beta$-half-lives and excited states will be used for testing and developing the nuclear structure models ``south-east'' of $^{208}$Pb, and will provide input data for the description of the r-process path at very heavy nuclei. The proposed study of the yields and the decay properties of those heavy nuclei produced in the spallation of $^{232}$Th by a 1~GeV proton beam contributes also the data necessary for the simulations of a hybrid accelerator-reactor system.

  6. Bismuth, Metronidazole, and Tetracycline

    Science.gov (United States)

    Helidac® (as a kit containing Bismuth Subsalicylate, Metronidazole, Tetracycline) ... Bismuth, metronidazole, and tetracycline is used along with other ulcer medications to treat duodenal ulcers. It is in a class of medications called ...

  7. Novel Bismuth Nanotubes

    Institute of Scientific and Technical Information of China (English)

    苏长荣; 李家明

    2002-01-01

    Theoretical investigations show that bismuth nanotubes are semiconductors for all diameters. For smalldiameter bismuth nanotubes, the band structures and bandgaps vary strongly with the strong hybridization effect. When the diameters are larger than 18 A, the bandgaps ofBi (n, n) and (n, 0) nanotubes approach 0.63 e V, corresponding to the bandgap of bismuth sheet at the Γ point. Thus, bismuth nanotubes are expected to be a potential semiconductor nanomaterial in future nanoelectronics.

  8. Valley polarization in bismuth

    Science.gov (United States)

    Fauque, Benoit

    2013-03-01

    The electronic structure of certain crystal lattices can contain multiple degenerate valleys for their charge carriers to occupy. The principal challenge in the development of valleytronics is to lift the valley degeneracy of charge carriers in a controlled way. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. According to our recent study of angle-dependent magnetoresistance in bismuth, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. As a consequence of a unique combination of high mobility and extreme mass anisotropy in bismuth, the effect is visible even at room temperature in a magnetic field of 1 T. Thus, a modest magnetic field can be used as a valley valve in bismuth. The results of our recent investigation of angle-dependent magnetoresistance in other semi-metals and doped semiconductors suggest that a rotating magnetic field can behave as a valley valve in a multi-valley system with sizeable mass anisotropy.

  9. Energetics of bismuth vanadate

    Energy Technology Data Exchange (ETDEWEB)

    Nagabhushana, G.P.; Tavakoli, A.H.; Navrotsky, A., E-mail: anavrotsky@ucdavis.edu

    2015-05-15

    Bismuth vanadate has gained considerable interest as a photoanode for water splitting reactions under visible light. It exists in four different polymorphs, out of which three of them have been synthesized. Thermodynamic properties of these three polymorphs are investigated using high temperature oxide melt solution calorimetry. The monoclinic scheelite phase which exhibits photocatalytic activity under visible light is found to be the most stable polymorph, followed by tetragonal scheelite which exhibits activity under UV light. The photocatalytically inactive tetragonal zircon form is found to be the least stable polymorph. The small difference in enthalpy of formation between the two scheelite structures (−8 kJ/mol) is in accord with the reversibility of the transformation between them and the larger difference between the most stable monoclinic phase and the least stable tetragonal zircon phase (−23 kJ/mol) is in accord with the irreversible (monoclinic→tetragonal zircon) phase transformation. - Graphical abstract: Schematic representation of polymorphic transitions in BiVO{sub 4} along with their formation enthalpies. - Highlights: • Bismuth vanadate crystallizes in three different polymorphs. • High temperature calorimetric measurements were made to determine their formation enthalpies. • Enthalpy of formation decreases in the order BV-ms→BV-ts→BV-tz. • Photocatalytically active monoclinic-BiVO{sub 4} was found to be the most stable polymorph.

  10. An Unusual Bismuth Ethanedisulfonate Network

    Directory of Open Access Journals (Sweden)

    Fabienne Gschwind

    2012-09-01

    Full Text Available The three dimensional bismuth ethanedisulfonate framework Bi(O3SC2H4SO31.5(H2O2 was synthesized under hydrothermal conditions using the bidentate ligand 1,2-ethanedisulfonate and then characterized through X-ray diffraction and elemental analyses. The bismuth cation coordinates at three different ethanedisulfonate ligands and has a coordination number of eight, which is accompanied by a distorted square antiprismatic configuration. Here, we report on the crystal structure of this bismuth metal–organic framework and its coordination behavior, which has thus far not been reported in heavier main group elements.

  11. Superconducting transition temperature of metastable, crystalline lead-bismuth alloys

    International Nuclear Information System (INIS)

    The increase of the superconducting temperature by ion implantation with bismuth-ions in a saturated lead-bismuth alloy, by recoil-implantation and by quenching of a lead-bismuth alloy with bismuth precipitates was studied. At room-temperature an increase of 11 at% Bi over the thermodynamic solution limit in a lead-bismuth alloy could be measured. The highest superconducting temperature was 9.02 K for a lead-bismuth alloy with 43 at% bismuth. (orig.)

  12. Bismuth bronze from machu picchu, peru.

    Science.gov (United States)

    Gordon, R B; Rutledge, J W

    1984-02-10

    The decorative bronze handle of a tumi excavated at the Inca city of Machu Picchu, Peru, contains 18 percent bismuth and appears to be the first known example of the use of bismuth with tin to make bronze. The alloy is not embrittled by the bismuth because the bismuth-rich constituent does not penetrate the grain boundaries of the matrix phase. The use of bismuth facilitates the duplex casting process by which the tumi was made and forms an alloy of unusual color. PMID:17749940

  13. Comparative Study of Semiconductors Bismuth Iodate, Bismuth Triiodide and Bismuth Trisulphide Crystals

    Directory of Open Access Journals (Sweden)

    T.K. Patil

    2012-12-01

    Full Text Available In the present investigation, crystals of Bismuth Iodate[Bi(IO33], Bismuth Iodide[BiI3] and Bismuth- Tri Sulphide [Bi2S3] were grown by a simple gel technique using single diffusion method. The optimum growth conditions were established by varying various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of reactant etc. Gel was prepared by mixing sodium meta silicate (Na2SiO35H2O, glacial acetic acid (CH3COOH and supernant bismuth chloride (BiCl3 at pH value 4.4 and transferred in glass tube of diameter 2.5 cm and 25 cm in length. The mouth of test tube was covered by cotton plug and kept it for the setting. After setting the gel, it was left for aging. After 13 days duration the second supernant K(IO3, KI3 and H2S water gas solution was poured over the set gel by using pipette then it was kept undisturbed. After 72 hours of pouring the second supernatant, the small nucleation growth was observed at below the interface of gel. The good quality crystals of [Bi(IO33], [BiI3] and [Bi2S3] were grown. These grown crystals were characterized by XRD, FTIR, Chemical Analysis and Electrical Conductivity.

  14. Bismuth absorption from 205 Bi-labelled pharmaceutical bismuth compounds used in the treatment of peptic ulcer disease

    International Nuclear Information System (INIS)

    The absorption of bismuth from five 205Bi-labelled pharmaceutically used bismuth compounds was studied in man. From single oral doses of all compounds under investigation only <0.1% bismuth was absorbed and excreted with the urine. A significantly higher absorption was observed from the colloidal bismuth subcitrate and the basic bismuth gallate than from the basic bismuth salicylate, nitrate and aluminate. No retention of bismuth in the whole body was found from the single dose experiment. The biologic fast-term half-lives of absorbed bismuth were calculated to be 0.12 and 1.5 days. 14 refs., 2 figs., 1 tab

  15. Bismuth absorption from sup 205 Bi-labelled pharmaceutical bismuth compounds used in the treatment of peptic ulcer disease

    Energy Technology Data Exchange (ETDEWEB)

    Dresow, B.; Fischer, R.; Gabbe, E.E.; Wendel, J.; Heinrich, H.C. (Eppendorf University Hospital, Hamburg (Germany))

    1992-04-01

    The absorption of bismuth from five {sup 205}Bi-labelled pharmaceutically used bismuth compounds was studied in man. From single oral doses of all compounds under investigation only <0.1% bismuth was absorbed and excreted with the urine. A significantly higher absorption was observed from the colloidal bismuth subcitrate and the basic bismuth gallate than from the basic bismuth salicylate, nitrate and aluminate. No retention of bismuth in the whole body was found from the single dose experiment. The biologic fast-term half-lives of absorbed bismuth were calculated to be 0.12 and 1.5 days. 14 refs., 2 figs., 1 tab.

  16. Bismuth ions are metabolized into autometallographic traceable bismuth-sulphur quantum dots

    Directory of Open Access Journals (Sweden)

    M Stoltenberg

    2009-06-01

    Full Text Available Bismuth – sulphur quantum dots can be silver enhanced by autometallography (AMG. In the present study, autometallographic silver enhanced bismuth-sulphur nanocrystals were isolated from unfixed cryo-sections of kidneys and livers of rats exposed to bismuth (Bi207 subnitrate. After being subjected to AMG all the organic material was removed by sonication and enzymatic digestion and the silver enhanced Bi- S quantum dots spun down by an ultracentrifuge and analyzed by scintillation. The analysis showed that the autometallographic technique traces approximately 94% of the total bismuth. This implies that the injected bismuth is ultimately captured in bismuthsulphur quantum dots, i.e., that Bi-S nanocrystals are the end product of bismuth metabolism

  17. Extraction and separation of bismuth(III).

    Science.gov (United States)

    Langade, A D; Shinde, V M

    1981-10-01

    Separation of bismuth from beryllium, lead, iron(III), indium, scandium, lanthanum, antimony(III), zirconium, titanium, thorium, vanadium(V), molybdenum(VI), uranium (VI) and chromium(VI) is achieved by selective extraction of bismuth from 0.1M sodium salicylate solution (adjusted to pH 7) into mesityl oxide (MeO). The extracted species is Bi (HOC(6)H(4)COO)(3).3MeO. The results are accurate within +/- 0.5%, with a standard deviation of 0.8%. The separation and determination of bismuth takes only 15 min. PMID:18963000

  18. Gravimetric Analysis of Bismuth in Bismuth Subsalicylate Tablets: A Versatile Quantitative Experiment for Undergraduate Laboratories

    Science.gov (United States)

    Davis, Eric; Cheung, Ken; Pauls, Steve; Dick, Jonathan; Roth, Elijah; Zalewski, Nicole; Veldhuizen, Christopher; Coeler, Joel

    2015-01-01

    In this laboratory experiment, lower- and upper-division students dissolved bismuth subsalicylate tablets in acid and precipitated the resultant Bi[superscript 3+] in solution with sodium phosphate for a gravimetric determination of bismuth subsalicylate in the tablets. With a labeled concentration of 262 mg/tablet, the combined data from three…

  19. Thermal degradation of ultrabroad bismuth NIR luminescence in bismuth-doped tantalum germanate laser glasses.

    Science.gov (United States)

    Wang, Liping; Zhao, Yanqi; Xu, Shanhui; Peng, Mingying

    2016-04-01

    Because of ultra-broadband luminescence in 1000-1700 nm and consequent applications in fiber amplifier and lasers in the new spectral range where traditional rare earth cannot work, bismuth-doped laser glasses have received rising interest recently. For long-term practical application, thermal degradation must be considered for the glasses. This, however, has seldom been investigated. Here we report the thermal degradation of bismuth-doped germanate glass. Heating and cooling cycle experiments at high temperature reveal strong dependence of the thermal degradation on glass compositions. Bismuth and tantalum lead to the reversible degradation, while lithium can produce permanent irreversible degradation. The degradation becomes worse as lithium content increases in the glass. Absorption spectra show this is due to partial oxidation of bismuth near-infrared emission center. Surprisingly, we notice the emission of bismuth exhibits blueshift, rather than redshift at a higher temperature, and the blueshift can be suppressed by increasing the lithium content. PMID:27192231

  20. Hydrothermal synthesis map of bismuth titanates

    International Nuclear Information System (INIS)

    The hydrothermal synthesis of four bismuth titanate materials from common bismuth and titanium precursors under hydrothermal conditions is described. Reaction of NaBiO3·2H2O and anatase TiO2 in concentrated NaOH solution at 240 °C is shown to produce perovskite and sillenite phases Na0.5Bi0.5TiO3 and Bi12TiO20, depending on the ratio of metal precursors used. When KOH solution is used and a 1:1 ratio of the same precursors, a pyrochlore Bi1.43Ti2O6(OH)0.29(H2O)0.66 is formed. The use of a mixture of HNO3 and NaOH is shown to facilitate the formation of the Aurivillius-type bismuth titanate Bi4Ti3O12. The phases have been isolated separately as phase-pure powders and profile refinement of powder X-ray diffraction data allows comparisons with comparable materials reported in the literature. Analysis of Bi LIII-edge X-ray absorption near edge structure (XANES) spectra of the materials shows the oxidation state of bismuth is +3 in all of the hydrothermally derived products. - Graphical abstract: Use of NaBiO3·2H2O and TiO2 as reagents under hydrothermal conditions allows the phase-pure preparation of four crystalline bismuth titanate materials. Highlights: ► NaBiO3 and TiO2 under hydrothermal conditions allow formation of bismuth titanates. ► Synthesis of four distint phases has been mapped. ► Bi LIII-edge XANES shows Bi is reduced to oxidation state +3 in all materials. ► A new hydrated bismuth titanate pyrochlore has been isolated

  1. Metabolism of Bismuth Subsalicylate and Intracellular Accumulation of Bismuth by Fusarium sp. Strain BI

    OpenAIRE

    Dodge, Anthony G.; Wackett, Lawrence P

    2005-01-01

    Enrichment cultures were conducted using bismuth subsalicylate as the sole source of carbon and activated sludge as the inoculum. A pure culture was obtained and identified as a Fusarium sp. based on spore morphology and partial sequences of 18S rRNA, translation elongation factor 1-α, and β-tubulin genes. The isolate, named Fusarium sp. strain BI, grew to equivalent densities when using salicylate or bismuth subsalicylate as carbon sources. Bismuth nitrate at concentrations of up to 200 μM d...

  2. Electrodeposition and Characterization of Bismuth Telluride Nanowires

    Science.gov (United States)

    Frantz, C.; Stein, N.; Gravier, L.; Granville, S.; Boulanger, C.

    2010-09-01

    In this work, we report thermoelectric measurements on electroplated bismuth telluride nanowires. Porous polycarbonate membranes, obtained by ion-track irradiation lithography, were chosen as electroplating templates. Bismuth telluride nanowires were achieved in acidic media under potentiostatic conditions at -100 mV versus saturated silver chloride electrode. The filling ratio of the pores was increased to 80% by adding dimethyl sulfoxide to the electrolyte. Whatever the experimental conditions, the nanowires were polycrystalline in the rhombohedral phase of Bi2Te3. Finally, the power output of arrays of bismuth telluride nanowires was analyzed as a function of load resistance. The results were strongly dependent on the internal resistance, which can be significantly reduced by the presence of dimethyl sulfoxide during electroplating.

  3. Liquid Bismuth Feed System for Electric Propulsion

    Science.gov (United States)

    Markusic, T. E.; Polzin, K. A.; Stanojev, B. J.

    2006-01-01

    Operation of Hall thrusters with bismuth propellant has been shown to be a promising path toward high-power, high-performance, long-lifetime electric propulsion for spaceflight missions. For example, the VHITAL project aims td accurately, experimentally assess the performance characteristics of 10 kW-class bismuth-fed Hall thrusters - in order to validate earlier results and resuscitate a promising technology that has been relatively dormant for about two decades. A critical element of these tests will be the precise metering of propellant to the thruster, since performance cannot be accurately assessed without an accurate accounting of mass flow rate. Earlier work used a pre/post-test propellant weighing scheme that did not provide any real-time measurement of mass flow rate while the thruster was firing, and makes subsequent performance calculations difficult. The motivation of the present work was to develop a precision liquid bismuth Propellant Management System (PMS) that provides real-time propellant mass flow rate measurement and control, enabling accurate thruster performance measurements. Additionally, our approach emphasizes the development of new liquid metal flow control components and, hence, will establish a basis for the future development of components for application in spaceflight. The design of various critical components in a bismuth PMS are described - reservoir, electromagnetic pump, hotspot flow sensor, and automated control system. Particular emphasis is given to material selection and high-temperature sealing techniques. Open loop calibration test results are reported, which validate the systems capability to deliver bismuth at mass flow rates ranging from 10 to 100 mg/sec with an uncertainty of less than +/- 5%. Results of integrated vaporizer/liquid PMS tests demonstrate all of the necessary elements of a complete bismuth feed system for electric propulsion.

  4. Burnout current density of bismuth nanowires

    Science.gov (United States)

    Cornelius, T. W.; Picht, O.; Müller, S.; Neumann, R.; Völklein, F.; Karim, S.; Duan, J. L.

    2008-05-01

    Single bismuth nanowires with diameters ranging from 100nmto1μm were electrochemically deposited in ion track-etched single-pore polycarbonate membranes. The maximum current density the wires are able to carry was investigated by ramping up the current until failure occurred. It increases by three to four orders of magnitude for nanowires embedded in the template compared to bulk bismuth and rises with diminishing diameter. Simulations show that the wires are heated up electrically to the melting temperature. Since the surface-to-volume ratio rises with diminishing diameter, thinner wires dissipate the heat more efficiently to the surrounding polymer matrix and, thus, can tolerate larger current densities.

  5. Holographic data storage in photorefractive bismuth tellurite

    International Nuclear Information System (INIS)

    Bismuth tellurite is a photorefractive material for holographic data storage offering unique fixing capabilities. Important material and electro-optic properties obtained by four-wave-mixing and data storage experiments are reviewed and recent results concerning the applicability of bismuth tellurite for holographic data storage, including dynamic range, multiplexing capabilities and bit-error evaluations, are presented. Furthermore, it is demonstrated how the latest progress in growing Bi2TeO5 made this crystal a candidate for durable holographic recording media.

  6. Electron microscopy of barium bismuth titanate multilayer ceramics

    International Nuclear Information System (INIS)

    For a number of years bismuth containing compounds have been used with pre-calcined barium titanate to reduce the sintering temperature of the capacitor formulations. As reported earlier the backscattered electron (BSE) SEM micrographs of the bismuth containing barium titanate ceramic reveal that the grains having an average size of 1.2μm consist of a two phase structure consisting of relatively pure barium titanate grain cores surrounded by bismuth rich grain shells. The TEM and STEM studies along with the EDS analyses show that the bismuth concentration increases sharply as one steps towards the grain boundary with a maximum bismuth content at the grain boundary. It is the purpose of this work to investigate the distribution of bismuth in these formulations including the bismuth content, if any, at the ceramic metal interface as affected by the sintering temperature. The subsequent effect on the electrical resistivity of these ceramics in the multilayer configuration is reported

  7. Metabolism of bismuth subsalicylate and intracellular accumulation of bismuth by Fusarium sp. strain BI.

    Science.gov (United States)

    Dodge, Anthony G; Wackett, Lawrence P

    2005-02-01

    Enrichment cultures were conducted using bismuth subsalicylate as the sole source of carbon and activated sludge as the inoculum. A pure culture was obtained and identified as a Fusarium sp. based on spore morphology and partial sequences of 18S rRNA, translation elongation factor 1-alpha, and beta-tubulin genes. The isolate, named Fusarium sp. strain BI, grew to equivalent densities when using salicylate or bismuth subsalicylate as carbon sources. Bismuth nitrate at concentrations of up to 200 muM did not limit growth of this organism on glucose. The concentration of soluble bismuth in suspensions of bismuth subsalicylate decreased during growth of Fusarium sp. strain BI. Transmission electron microscopy and energy-dispersive spectroscopy revealed that the accumulated bismuth was localized in phosphorus-rich granules distributed in the cytoplasm and vacuoles. Long-chain polyphosphates were extracted from fresh biomass grown on bismuth subsalicylate, and inductively coupled plasma optical emission spectrometry showed that these fractions also contained high concentrations of bismuth. Enzyme activity assays of crude extracts of Fusarium sp. strain BI showed that salicylate hydroxylase and catechol 1,2-dioxygenase were induced during growth on salicylate, indicating that this organism degrades salicylate by conversion of salicylate to catechol, followed by ortho cleavage of the aromatic ring. Catechol 2,3-dioxygenase activity was not detected. Fusarium sp. strain BI grew with several other aromatic acids as carbon sources: benzoate, 3-hydroxybenzoate, 4-hydroxybenzoate, gentisate, d-mandelate, l-phenylalanine, l-tyrosine, phenylacetate, 3-hydroxyphenylacetate, 4-hydroxyphenylacetate, and phenylpropionate. PMID:15691943

  8. Probing bismuth ferrite nanoparticles by hard x-ray photoemission: Anomalous occurrence of metallic bismuth

    International Nuclear Information System (INIS)

    We have investigated bismuth ferrite nanoparticles (∼75 nm and ∼155 nm) synthesized by a chemical method, using soft X-ray (1253.6 eV) and hard X-ray (3500, 5500, and 7500 eV) photoelectron spectroscopy. This provided an evidence for the variation of chemical state of bismuth in crystalline, phase pure nanoparticles. X-ray photoelectron spectroscopy analysis using Mg Kα (1253.6 eV) source showed that iron and bismuth were present in both Fe3+ and Bi3+ valence states as expected for bismuth ferrite. However, hard X-ray photoelectron spectroscopy analysis of the bismuth ferrite nanoparticles using variable photon energies unexpectedly showed the presence of Bi0 valence state below the surface region, indicating that bismuth ferrite nanoparticles are chemically inhomogeneous in the radial direction. Consistently, small-angle X-ray scattering reveals a core-shell structure for these radial inhomogeneous nanoparticles.

  9. Photosensitive bismuth ions in lead tungstate

    Czech Academy of Sciences Publication Activity Database

    Vazhenin, V.A.; Potapov, A.P.; Asatryan, G.R.; Nikl, Martin

    2013-01-01

    Roč. 55, č. 4 (2013), s. 803-806. ISSN 1063-7834 Institutional support: RVO:68378271 Keywords : PbWO 4 * single crystal * bismuth * electron paramagnetic resonance Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.782, year: 2013

  10. Hydrothermal synthesis map of bismuth titanates

    Science.gov (United States)

    Sardar, Kripasindhu; Walton, Richard I.

    2012-05-01

    The hydrothermal synthesis of four bismuth titanate materials from common bismuth and titanium precursors under hydrothermal conditions is described. Reaction of NaBiO3·2H2O and anatase TiO2 in concentrated NaOH solution at 240 °C is shown to produce perovskite and sillenite phases Na0.5Bi0.5TiO3 and Bi12TiO20, depending on the ratio of metal precursors used. When KOH solution is used and a 1:1 ratio of the same precursors, a pyrochlore Bi1.43Ti2O6(OH)0.29(H2O)0.66 is formed. The use of a mixture of HNO3 and NaOH is shown to facilitate the formation of the Aurivillius-type bismuth titanate Bi4Ti3O12. The phases have been isolated separately as phase-pure powders and profile refinement of powder X-ray diffraction data allows comparisons with comparable materials reported in the literature. Analysis of Bi LIII-edge X-ray absorption near edge structure (XANES) spectra of the materials shows the oxidation state of bismuth is +3 in all of the hydrothermally derived products.

  11. Bismuth titanate ceramics obtained by hot forging

    International Nuclear Information System (INIS)

    In this work, bismuth titanate samples were obtained from powder calcined at 800 deg C for 24 h through conventional sintering (OF) and hot-forging (HF) methods. The plate-like morphology grains were observed in ceramics obtained in both process. Samples produced by HF showed higher grain orientation, ≅ 90%. (author)

  12. Polyvinyl chloride filled with bismuth oxychloride powder

    Czech Academy of Sciences Publication Activity Database

    Polášková, M.; Sedláček, T.; Kharlamov, Alexander; Pivokonský, Radek; Saha, P.

    Larnaca : Polymer Processing Society, 2009, s. 242. [Polymer Processing Society Europe/Africa Regional Meeting. Larnaca (GR), 18.10.2009-21.10.2009] Institutional research plan: CEZ:AV0Z20600510 Keywords : olyvinyl chloride * bismuth oxychloride * radiopaque agents Subject RIV: BK - Fluid Dynamics

  13. Hydrothermal synthesis map of bismuth titanates

    Energy Technology Data Exchange (ETDEWEB)

    Sardar, Kripasindhu [Department of Chemistry, University of Warwick, Coventry, CV4 7AL (United Kingdom); Walton, Richard I., E-mail: r.i.walton@warwick.ac.uk [Department of Chemistry, University of Warwick, Coventry, CV4 7AL (United Kingdom)

    2012-05-15

    The hydrothermal synthesis of four bismuth titanate materials from common bismuth and titanium precursors under hydrothermal conditions is described. Reaction of NaBiO{sub 3}{center_dot}2H{sub 2}O and anatase TiO{sub 2} in concentrated NaOH solution at 240 Degree-Sign C is shown to produce perovskite and sillenite phases Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} and Bi{sub 12}TiO{sub 20}, depending on the ratio of metal precursors used. When KOH solution is used and a 1:1 ratio of the same precursors, a pyrochlore Bi{sub 1.43}Ti{sub 2}O{sub 6}(OH){sub 0.29}(H{sub 2}O){sub 0.66} is formed. The use of a mixture of HNO{sub 3} and NaOH is shown to facilitate the formation of the Aurivillius-type bismuth titanate Bi{sub 4}Ti{sub 3}O{sub 12}. The phases have been isolated separately as phase-pure powders and profile refinement of powder X-ray diffraction data allows comparisons with comparable materials reported in the literature. Analysis of Bi L{sub III}-edge X-ray absorption near edge structure (XANES) spectra of the materials shows the oxidation state of bismuth is +3 in all of the hydrothermally derived products. - Graphical abstract: Use of NaBiO{sub 3}{center_dot}2H{sub 2}O and TiO{sub 2} as reagents under hydrothermal conditions allows the phase-pure preparation of four crystalline bismuth titanate materials. Highlights: Black-Right-Pointing-Pointer NaBiO{sub 3} and TiO{sub 2} under hydrothermal conditions allow formation of bismuth titanates. Black-Right-Pointing-Pointer Synthesis of four distint phases has been mapped. Black-Right-Pointing-Pointer Bi LIII-edge XANES shows Bi is reduced to oxidation state +3 in all materials. Black-Right-Pointing-Pointer A new hydrated bismuth titanate pyrochlore has been isolated.

  14. Geochemistry, geochronology, mineralogy, and geology suggest sources of and controls on mineral systems in the southern Toquima Range, Nye County, Nevada; with geochemistry maps of gold, silver, mercury, arsenic, antimony, zinc, copper, lead, molybdenum, bismuth, iron, titanium, vanadium, cobalt, beryllium, boron, fluorine, and sulfur; and with a section on lead associations, mineralogy and paragenesis, and isotopes

    Science.gov (United States)

    Shawe, Daniel R.; Hoffman, James D.; Doe, Bruce R.; Foord, Eugene E.; Stein, Holly J.; Ayuso, Robert A.

    2003-01-01

    Geochemistry maps showing the distribution and abundance of 18 elements in about 1,400 rock samples, both mineralized and unmineralized, from the southern Toquima Range, Nev., indicate major structural and lithologic controls on mineralization, and suggest sources of the elements. Radiometric age data, lead mineralogy and paragenesis data, and lead-isotope data supplement the geochemical and geologic data, providing further insight into timing, sources, and controls on mineralization. Major zones of mineralization are centered on structural margins of calderas and principal northwest-striking fault zones, as at Round Mountain, Manhattan, and Jefferson mining districts, and on intersections of low-angle and steep structures, as at Belmont mining district. Paleozoic sedimentary rocks, mostly limestones (at Manhattan, Jefferson, and Belmont districts), and porous Oligocene ash-flow tuffs (at Round Mountain district) host the major deposits, although all rock types have been mineralized as evidenced by numerous prospects throughout the area. Principal mineral systems are gold-silver at Round Mountain where about 7 million ounces of gold and more than 4 million ounces of silver has been produced; gold at Gold Hill in the west part of the Manhattan district where about a half million ounces of gold has been produced; gold-mercury-arsenic-antimony in the east (White Caps) part of the Manhattan district where a few hundred thousand ounces of gold has been produced; and silver-lead-antimony at Belmont where more than 150,000 ounces of silver has been produced. Lesser amounts of gold and silver have been produced from the Jefferson district and from scattered mines elsewhere in the southern Toquima Range. A small amount of tungsten was produced from mines in the granite of the Round Mountain pluton exposed east of Round Mountain, and small amounts of arsenic, antimony, and mercury have been produced elsewhere in the southern Toquima Range. All elements show unique

  15. Bismuth pyrochlore thin films for dielectric energy storage

    International Nuclear Information System (INIS)

    Thin films of cubic pyrochlore bismuth zinc niobate, bismuth zinc tantalate, and bismuth zinc niobate tantalate were fabricated using chemical solution deposition. This family of materials exhibited moderate relative permittivities between 55 ± 2 and 145 ± 5 for bismuth zinc tantalate and bismuth zinc niobate, respectively, and low loss tangents on the order of 0.0008 ± 0.0001. Increases in the concentration of the tantalum end member increased the dielectric breakdown strength. For example, at 10 kHz, the room temperature breakdown strength of bismuth zinc niobate was 5.1 MV/cm, while that of bismuth zinc tantalate was 6.1 MV/cm. This combination of a high breakdown strength and a moderate permittivity led to a high discharged energy storage density for all film compositions. For example, at a measurement frequency of 10 kHz, bismuth zinc niobate exhibited a maximum recoverable energy storage density of 60.8 ± 2.0 J/cm3, while bismuth zinc tantalate exhibited a recoverable energy storage density of 60.7 ± 2.0 J/cm3. Intermediate compositions of bismuth zinc niobate tantalate offered higher energy storage densities; at 10 mol. % tantalum, the maximum recoverable energy storage density was ∼66.9 ± 2.4 J/cm3

  16. Superdeformation in the bismuth nuclei

    International Nuclear Information System (INIS)

    High angular-momentum states in 196,197Bi were populated in the reaction 183W (19F,xn) at a beam energy of 108 MeV, and γ rays were detected with the Gammasphere array. Two weakly populated rotational bands, with energy spacings characteristic of superdeformation have been found. Both cascades can be assigned unambiguously to the Bi nuclei; however, their isotopic assignment to 197Bi is tentative. The properties of the bands and their possible structures are discussed. Our results represent the first identification of superdeformed bands in a nucleus of the A∼190 mass region with Z>82

  17. Performance comparison of metallic, actinide burning fuel in lead-bismuth and sodium cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, K.D.; Herring, J.S.; Macdonald, P.E. [Idaho National Engineering and Environment Lab., Advanced Nuclear Energy, Idaho (United States)

    2001-07-01

    Various methods have been proposed to ''incinerate'' or ''transmute'' the current inventory of transuranic waste (TRU) that exits in spent light-water-reactor (LWR) fuel, and weapons plutonium. These methods include both critical (e.g., fast reactors) and non-critical (e.g., accelerator transmutation) systems. The work discussed here is part of a larger effort at the Idaho National Engineering and Environmental Laboratory (INEEL) and at the Massachusetts Institute of Technology (MIT) to investigate the suitability of lead and lead-alloy cooled fast reactors for producing low-cost electricity as well as for actinide burning. The neutronics of non fertile fuel loaded with 20 or 30-wt% light water reactor (LWR) plutonium plus minor actinides for use in a lead-bismuth cooled fast reactor are discussed in this paper, with an emphasis on the fuel cycle life and isotopic content. Calculations show that the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from -1.02 to -1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. However, when using the same parameters, the sodium-cooled case went subcritical after 0.2 to 0.8 effective full power years, and the lead-bismuth cooled case ranged from 1.5 to 4.5 effective full power years. (author)

  18. Performance Comparison of Metallic, Actinide Burning Fuel in Lead-Bismuth and Sodium Cooled Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Kevan Dean; Herring, James Stephen; Mac Donald, Philip Elsworth

    2001-04-01

    Various methods have been proposed to “incinerate” or “transmutate” the current inventory of trans-uranic waste (TRU) that exits in spent light-water-reactor (LWR) fuel, and weapons plutonium. These methods include both critical (e.g., fast reactors) and non-critical (e.g., accelerator transmutation) systems. The work discussed here is part of a larger effort at the Idaho National Engineering and Environmental Laboratory (INEEL) and at the Massachusetts Institute of Technology (MIT) to investigate the suitability of lead and lead-alloy cooled fast reactors for producing low-cost electricity as well as for actinide burning. The neutronics of non-fertile fuel loaded with 20 or 30-wt% light water reactor (LWR) plutonium plus minor actinides for use in a lead-bismuth cooled fast reactor are discussed in this paper, with an emphasis on the fuel cycle life and isotopic content. Calculations show that the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from -1.02 to -1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. However, when using the same parameters, the sodium-cooled case went subcritical after 0.2 to 0.8 effective full power years, and the lead-bismuth cooled case ranged from 1.5 to 4.5 effective full power years.

  19. Performance comparison of metallic, actinide burning fuel in lead-bismuth and sodium cooled fast reactors

    International Nuclear Information System (INIS)

    Various methods have been proposed to ''incinerate'' or ''transmute'' the current inventory of transuranic waste (TRU) that exits in spent light-water-reactor (LWR) fuel, and weapons plutonium. These methods include both critical (e.g., fast reactors) and non-critical (e.g., accelerator transmutation) systems. The work discussed here is part of a larger effort at the Idaho National Engineering and Environmental Laboratory (INEEL) and at the Massachusetts Institute of Technology (MIT) to investigate the suitability of lead and lead-alloy cooled fast reactors for producing low-cost electricity as well as for actinide burning. The neutronics of non fertile fuel loaded with 20 or 30-wt% light water reactor (LWR) plutonium plus minor actinides for use in a lead-bismuth cooled fast reactor are discussed in this paper, with an emphasis on the fuel cycle life and isotopic content. Calculations show that the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from -1.02 to -1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. However, when using the same parameters, the sodium-cooled case went subcritical after 0.2 to 0.8 effective full power years, and the lead-bismuth cooled case ranged from 1.5 to 4.5 effective full power years. (author)

  20. Bismuth( Ⅲ ) Salts: Green Catalysts for Organic Transformations

    Institute of Scientific and Technical Information of China (English)

    C. Le Roux

    2005-01-01

    @@ 1Introduction Bismuth, the heaviest stable element in the periodic table, stands out from other heavy elements (such as mercury, thallium and lead) due to its relatively non-toxic character which confers on bismuth the enviable status of being an eco-friendly element. Therefore, bismuth and its compounds hold considerable promise as useful catalysts for green chemistry. The research presented in this communication is devoted to the applications of bismuth( Ⅲ ) salts as catalysts for organic transformations.After some general comments about bismuth and a short presentation of the various applications of bismuth( Ⅲ ) salts in organic synthesis, this communication will focus on the works done in our research group during the last several years which deals mainly with electrophilic substitutions. When appropriate, some mechanistic details will be given.

  1. Electroanalysis of organic compounds at bismuth electrodes: a short review

    OpenAIRE

    Lezi, Nikolitsa; Vyskočil, Vlastimil; Economou, Anastasios; Barek, Jiří

    2012-01-01

    Over the last twelve years, it has been demonstrated that bismuth electrodes have comparable electroanalytical performance to mercury electrodes in the negative potential range. Since the toxicicty of bismuth is lower than that of mercury, bismuth can serve as an alternative “green” electrode material to mercury. However, the great majority of published work at bismuth–based electrodes is concerned with the determination of trace metals by voltammetric techniques with only few applications de...

  2. Electron Paramagnetic Resonance Study of Thermally Treated Bismuth Subgallate

    OpenAIRE

    2014-01-01

    Complex of bismuth, an anti-inflammatory drug, was studied by EPR spectroscopy. The aim of this study was to determine concentrations and properties of free radicals formed during thermal sterilization of bismuth subgallate according to pharmacopoeia norms to optimize its sterilization process. Different temperatures (160°C, 170°C, and 180°C) and times (120 minutes, 60 minutes, and 30 minutes) of sterilization were used. Interactions of bismuth subgallate with DPPH, the model free radical ref...

  3. Stress-driven growth of bismuth nanowires

    Science.gov (United States)

    Cheng, Yang-Tse; Weiner, Anita M.; Wong, Curtis A.; Balogh, Michael P.; Lukitsch, Michael J.

    2003-03-01

    We recently reported that compressive stresses in thin films can be exploited to grow nanowires (Ref.1). Nanowires of bismuth (Bi) with diameters ranging from 30 to 200 nm and lengths up to several millimeters were formed spontaneously at the rate of a few micrometers per second at room temperature on surfaces of freshly grown composite thin films consisting of Bi and chrome-nitride (CrN). The high compressive stress in the composite thin films was shown to be the driving force responsible for the nanowire formation. In this presentation, the effects of stress, composition, and temperature on the growth and structure of bismuth nanowires will be discussed. This method of growing nanowires can also be extended to other material systems. Ref. 1. Yang-Tse Cheng, Anita M. Weiner, Curtis A. Wong, Michael P. Balogh, and Michael J. Lukitsch, Applied Physics Letters 81, 3248 (2002).

  4. Magnetoconductance fluctuations in open bismuth quantum dots

    Science.gov (United States)

    Hackens, B.; Minet, J. P.; Farhi, G.; Crahay, A.; Faniel, S.; Gustin, C.; Bayot, V.

    2002-03-01

    We investigate the low temperature (300 mK - 10 K) magnetoconductance of open circular bismuth quantum dots (diameter: 500 nm). The structures are fabricated using a combination of electron beam lithography, lift off and plasma etching techniques on bismuth thin films evaporated on heated SiO2 substrates. We observe reproducible magnetoconductance fluctuations (UCFs) up to 5T, qualitatively similar to conductance fluctuations evidenced in open quantum dots patterned in high mobility semiconductor heterostructures. In our samples, UCFs are superposed on a slowly varying negative magnetoconductance background. We also observe a sharp conductance maximum centered in B=0, which is reminescent of the spin-orbit induced anti-localisation phenomenon. The behavior of UCFs and of the conductance maximum is discussed as a function of the temperature, thickness and degree of cristallinity of the cavity.

  5. Electrocatalytic activity of bismuth doped silver electrodes

    CERN Document Server

    Amjad, M

    2002-01-01

    Investigation of redox reactions on silver, and bismuth doped silver electrodes in aqueous KOH solutions, by using potentiostatic steady-state polarization technique, has been carried out. The redox wave potential and current displacements along with multiplicity of the latter have been examined. These electrodes were employed for the oxidation of organic molecules such as ethylamine in alkaline media. Subsequently, these electrodes were ranked with respect to their activity for the redox reactions. (author)

  6. Bismuth film electrodes for heavy metals determination

    Science.gov (United States)

    Rehacek, Vlastimil; Hotovy, Ivan; Vojs, Marian; Mika, Fedor

    2007-05-01

    Bismuth film electrodes (BiFEs) have a potential to replace toxic mercury used most frequently for determination of heavy metals (Cd, Pb, Zn) by anodic stripping voltammetry. We prepared a graphite disc electrode (0.5 mm in diameter) from a pencil-lead rod and developed a nitrogen doped diamond-like carbon (NDLC) microelectrode array consisting of 50 625 microdiscs with 3 μm in diameter and interelectrode distances of 20 μm on a highly conductive silicon substrate as a support for BiFEs. The disc graphite BiFE was used for simultaneous determination of Pb(II), Cd(II) and Zn(II) by square wave voltammetry (SWV) in an aqueous solution. We found the optimum bismuth-to-metal concentration ratio in the solution to be 20. The dependence of the stripping responses on the concentration of target metals was linear in the range from 1×10 -8 to 1.2×10 -7 mol/L. Detection limits 2.4×10 -9 mol/L for Pb(II), 2.9×10 -9 mol/L for Cd(II) and 1.2×10 -8 mol/L for Zn(II) were estimated. A bismuth-plated NDLC microelectrode array was used for Pb(II) determination by differential pulse voltammetry (DPV) in an aqueous solution. We found that the stripping current for bismuth-plated NDLC array was linear in the concentration range of Pb(II) from 2×10 -8 to 1.2×10 -7 mol/L. The detection limit 2.2×10 -8 mol/L was estimated from a calibration plot.

  7. Influence of bismuth content on viscosity of lead-bismuth alloy

    International Nuclear Information System (INIS)

    In this paper, viscosities of Pb44.5 Bi55.5 (LBE), Pb60 Bi40, Pb70 Bi30, Pb80 Bi20 and Pb are studied in a certain temperature range above liquidus, the results show that the viscosities of five melts decrease with the increase of temperature. Excepting for pure Pb, anomalous changes in the viscosity values are found in LBE, Pb60 Bi40, Pb70 Bi30 and Pb80 Bi20 in the test temperature range, it is presumed that melts structure occurs at the anomalous point of the viscosity. In the temperature range of 623∼923 K, viscosity value of Pb60 Bi40 is obviously higher than that of the other proportion of lead bismuth alloy, and it increases with the decrease of bismuth content at temperature above 1023 K. The experimental results provide data support for the choice of lead-bismuth hypoeutectic applied in advanced nuclear reactor. (authors)

  8. Flame spray synthesis under a non-oxidizing atmosphere: Preparation of metallic bismuth nanoparticles and nanocrystalline bulk bismuth metal

    International Nuclear Information System (INIS)

    Metallic bismuth nanoparticles of over 98% purity were prepared by a modified flame spray synthesis method in an inert atmosphere by oxygen-deficient combustion of a bismuth-carboxylate based precursor. The samples were characterized by X-ray diffraction, thermal analysis and scanning electron microscopy confirming the formation of pure, crystalline metallic bismuth nanoparticles. Compression of the as-prepared powder resulted in highly dense, nanocrystalline pills with strong electrical conductivity and bright metallic gloss

  9. Spin dynamics of complex oxides, bismuth-antimony alloys, and bismuth chalcogenides

    Science.gov (United States)

    Sahin, Cuneyt

    The emerging field of spintronics relies on the manipulation of electron spin in order to use it in spin-based electronics. Such a paradigm change has to tackle several challenges including finding materials with sufficiently long spin lifetimes and materials which are efficient in generating pure spin currents. This thesis predicts that two types of material families could be a solution to the aforementioned challenges: complex oxides and bismuth based materials. We derived a general approach for constructing an effective spin-orbit Hamiltonian which is applicable to all nonmagnetic materials. This formalism is useful for calculating spin-dependent properties near an arbitrary point in momentum space. We also verified this formalism through comparisons with other approaches for III-V semiconductors, and its general applicability is illustrated by deriving the spin-orbit interaction and predicting spin lifetimes for strained strontium titanate (STO) and a two-dimensional electron gas in STO (such as at the LAO/STO interface). Our results suggest robust spin coherence and spin transport properties in STO related materials even at room temperature. In the second part of the study we calculated intrinsic spin Hall conductivities for bismuth-antimony (BISb) semimetals with strong spin-orbit couplings, from the Kubo formula and using Berry curvatures evaluated throughout the Brillouin zone from a tight-binding Hamiltonian. Nearly crossing bands with strong spin-orbit interaction generate giant spin Hall conductivities in these materials, ranging from 474 ((h/e)O--1cm--1) for bismuth to 96((h/e)O--1cm --1) for antimony; the value for bismuth is more than twice that of platinum. The large spin Hall conductivities persist for alloy compositions corresponding to a three-dimensional topological insulator state, such as Bi0.83Sb0.17. The spin Hall conductivity could be changed by a factor of 5 for doped Bi, or for Bi0.83Sb0.17, by changing the chemical potential by 0.5 e

  10. Hall-Effect Thruster Utilizing Bismuth as Propellant

    Science.gov (United States)

    Szabo, James; Gasdaska, Charles; Hruby, Vlad; Robin, Mike

    2008-01-01

    A laboratory-model Hall-effect spacecraft thruster was developed that utilizes bismuth as the propellant. Xenon was used in most prior Hall-effect thrusters. Bismuth is an attractive alternative because it has a larger atomic mass, a larger electron-impact-ionization cross-section, and is cheaper and more plentiful.

  11. Optical spectroscopy of Bismuth-doped pure silica fiber preform

    OpenAIRE

    Razdobreev, Igor,; El Hamzaoui, Hicham; Ivanov, V. Yu; Kustov, E. F.; Capoen, Bruno; Bouazaoui, Mohamed

    2010-01-01

    International audience We report on the optical spectroscopy of monolithic fiber preform prepared from nanoporous bismuth-doped silica glass. The experiments reveal the existence of at least two different types of active centers and clearly demonstrate that the presence in the glass matrix of other dopant is not necessary to obtain the near-IR photoluminescence connected to Bismuth.

  12. Bismuth(III) dialkyldithiophosphates: Facile single source precursors for the preparation of bismuth sulfide nanorods and bismuth phosphate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jasmine B. [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India); Garje, Shivram S., E-mail: ssgarje@chem.mu.ac.in [Department of Chemistry, University of Mumbai, Vidyanagari, Santacruz (East), Mumbai 400098 (India); Nuwad, Jitendra; Pillai, C.G.S. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2013-08-15

    Two different phase pure materials (Bi{sub 2}S{sub 3} and Bi{sub 2}P{sub 4}O{sub 13}) have been prepared under different conditions using the same single source precursors. Solvothermal decomposition of the complexes, Bi(S{sub 2}P(OR){sub 2}){sub 3} [where, R=Methyl (Me) (1), Ethyl (Et) (2), n-Propyl (Pr{sup n}) (3) and iso-Propyl (Pr{sup i}) (4)] in ethylene glycol gave orthorhombic bismuth sulfide nanorods, whereas aerosol assisted chemical vapor deposition (AACVD) of the same precursors deposited monoclinic bismuth tetraphosphate (Bi{sub 2}P{sub 4}O{sub 13}) thin films on glass substrates. Surface study of the thin films using SEM illustrated the formation of variety of nanoscale morphologies (spherical-, wire-, pendent-, doughnut- and flower-like) at different temperatures. AFM studies were carried out to evaluate quality of the films in terms of uniformity and roughness. Thin films of average roughness as low as 1.4 nm were deposited using these precursors. Photoluminescence studies of Bi{sub 2}P{sub 4}O{sub 13} thin films were also carried out. - Graphical abstract: Solvothermal decomposition of bismuth(III) dialkyldithiophosphates in ethylene glycol gave Bi{sub 2}S{sub 3} nanoparticles, whereas aerosol assisted chemical vapor deposition of these single source precursors deposited Bi{sub 2}P{sub 4}O{sub 13} thin films. Display Omitted - Highlights: • Preparation of phase pure orthorhombic Bi{sub 2}S{sub 3} nanorods and monoclinic Bi{sub 2}P{sub 4}O{sub 13} thin films. • Use of single source precursors for deposition of bismuth phosphate thin films. • Use of solvothermal decomposition and AACVD methods. • Morphology controlled synthesis of Bi{sub 2}P{sub 4}O{sub 13} thin films. • Bi{sub 2}S{sub 3} nanorods and Bi{sub 2}P{sub 4}O{sub 13} thin films using same single source precursors.

  13. A case of bismuth intoxication with irreversible renal damage

    Directory of Open Access Journals (Sweden)

    Erden A

    2013-11-01

    Full Text Available Abdulsamet Erden, Samet Karahan, Kadir Bulut, Mustafa Basak, Tuncay Aslan, Ali Cetinkaya, Hatice Karagoz, Deniz Avci Internal Medicine Department, Kayseri Training and Research Hospital, Kayseri, Turkey Abstract: Bismuth is a chemical element symbolized as Bi and is a trivalent poor metal, which chemically resembles arsenic and antimony. Colloidal bismuth subcitrate (CBS and bismuth subsalicylate are the bismuth salts widely used in the treatment of peptic ulcers, functional dyspepsia, and chronic gastritis. Intoxications with CBS are rare. In a few case reports, acute renal failure was described, but the literature review revealed no chronic renal failure related to CBS intoxication. In this case report we present a 21-year old female with chronic renal failure after a one year follow-up of CBS intoxication. Keywords: acute renal failure, bismuth, intoxication, chronic renal failure

  14. An evaluated neutronic data file for bismuth

    International Nuclear Information System (INIS)

    A comprehensive evaluated neutronic data file for bismuth, extending from 10-5 eV to 20.0 MeV, is described. The experimental database, the application of the theoretical models, and the evaluation rationale are outlined. Attention is given to uncertainty specification, and comparisons are made with the prior ENDF/B-V evaluation. The corresponding numerical file, in ENDF/B-VI format, has been transmitted to the National Nuclear Data Center, Brookhaven National Laboratory. 106 refs., 10 figs., 6 tabs

  15. Laboratory-Scale Bismuth Phosphate Extraction Process Simulation To Track Fate of Fission Products

    International Nuclear Information System (INIS)

    Recent field investigation that collected and characterized vadose zone sediments from beneath inactive liquid disposal facilities at the Hanford 200 Areas show lower than expected concentrations of a long-term risk driver, Tc-99. Therefore laboratory studies were performed to re-create one of the three processes that were used to separate the plutonium from spent fuel and that created most of the wastes disposed or currently stored in tanks at Hanford. The laboratory simulations were used to compare with current estimates based mainly on flow sheet estimates and spotty historical data. Three simulations of the bismuth phosphate precipitation process show that less that 1% of the Tc-99, Cs-135/137, Sr-90, I-129 carry down with the Pu product and thus these isotopes should have remained within the metals waste streams that after neutralization were sent to single shell tanks. Conversely, these isotopes should not be expected to be found in the first and subsequent cycle waste streams that went to cribs. Measurable quantities (∼20 to 30%) of the lanthanides, yttrium, and trivalent actinides (Am and Cm) do precipitate with the Pu product, which is higher than the 10% estimate made for current inventory projections. Surprisingly, Se (added as selenate form) also shows about 10% association with the Pu/bismuth phosphate solids. We speculate that the incorporation of some Se into the bismuth phosphate precipitate is caused by selenate substitution into crystal lattice sites for the phosphate. The bulk of the U daughter product Th-234 and Np-237 daughter product Pa-233 also associate with the solids. We suspect that the Pa daughter products of U (Pa-234 and Pa-231) would also co-precipitate with the bismuth phosphate induced solids. No more than 1 % of the Sr-90 and Sb-125 should carry down with the Pu product that ultimately was purified. Thus the current scheme used to estimate where fission products end up being disposed overestimates by one order of magnitude the

  16. Laboratory-Scale Bismuth Phosphate Extraction Process Simulation To Track Fate of Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. JEFFREY; Lindberg, Michael J.; Jones, Thomas E.; Schaef, Herbert T.; Krupka, Kenneth M.

    2007-02-28

    Recent field investigation that collected and characterized vadose zone sediments from beneath inactive liquid disposal facilities at the Hanford 200 Areas show lower than expected concentrations of a long-term risk driver, Tc-99. Therefore laboratory studies were performed to re-create one of the three processes that were used to separate the plutonium from spent fuel and that created most of the wastes disposed or currently stored in tanks at Hanford. The laboratory simulations were used to compare with current estimates based mainly on flow sheet estimates and spotty historical data. Three simulations of the bismuth phosphate precipitation process show that less that 1% of the Tc-99, Cs-135/137, Sr-90, I-129 carry down with the Pu product and thus these isotopes should have remained within the metals waste streams that after neutralization were sent to single shell tanks. Conversely, these isotopes should not be expected to be found in the first and subsequent cycle waste streams that went to cribs. Measurable quantities (~20 to 30%) of the lanthanides, yttrium, and trivalent actinides (Am and Cm) do precipitate with the Pu product, which is higher than the 10% estimate made for current inventory projections. Surprisingly, Se (added as selenate form) also shows about 10% association with the Pu/bismuth phosphate solids. We speculate that the incorporation of some Se into the bismuth phosphate precipitate is caused by selenate substitution into crystal lattice sites for the phosphate. The bulk of the U daughter product Th-234 and Np-237 daughter product Pa-233 also associate with the solids. We suspect that the Pa daughter products of U (Pa-234 and Pa-231) would also co-precipitate with the bismuth phosphate induced solids. No more than 1 % of the Sr-90 and Sb-125 should carry down with the Pu product that ultimately was purified. Thus the current scheme used to estimate where fission products end up being disposed overestimates by one order of magnitude the

  17. Electron Paramagnetic Resonance Study of Thermally Treated Bismuth Subgallate

    Directory of Open Access Journals (Sweden)

    Paweł Ramos

    2014-01-01

    Full Text Available Complex of bismuth, an anti-inflammatory drug, was studied by EPR spectroscopy. The aim of this study was to determine concentrations and properties of free radicals formed during thermal sterilization of bismuth subgallate according to pharmacopoeia norms to optimize its sterilization process. Different temperatures (160°C, 170°C, and 180°C and times (120 minutes, 60 minutes, and 30 minutes of sterilization were used. Interactions of bismuth subgallate with DPPH, the model free radical reference, were checked. g-Factors, amplitudes (A, integral intensities (I, and linewidths (ΔBpp were obtained. Integral intensities were obtained by double integration of the first-derivative EPR lines. The influence of microwave power in the range of 2.2–70 mW on shape and parameters of the EPR spectra was examined. Thermal sterilization produced free radicals in bismuth subgallate in all tested cases. Strong interactions with free radicals were pointed out for all the analysed samples containing bismuth independent of sterilization conditions. Optimal conditions of thermal sterilization for bismuth subgallate with the lowest free radical formation are temperature 170°C and time of heating 60 minutes. Strong dipolar interactions exist in thermally sterilized bismuth subgallate. EPR spectroscopy is a useful method of examination of thermal sterilization conditions.

  18. Electron paramagnetic resonance study of thermally treated bismuth subgallate.

    Science.gov (United States)

    Ramos, Paweł; Pilawa, Barbara

    2014-01-01

    Complex of bismuth, an anti-inflammatory drug, was studied by EPR spectroscopy. The aim of this study was to determine concentrations and properties of free radicals formed during thermal sterilization of bismuth subgallate according to pharmacopoeia norms to optimize its sterilization process. Different temperatures (160°C, 170°C, and 180°C) and times (120 minutes, 60 minutes, and 30 minutes) of sterilization were used. Interactions of bismuth subgallate with DPPH, the model free radical reference, were checked. g-Factors, amplitudes (A), integral intensities (I), and linewidths (ΔB pp) were obtained. Integral intensities were obtained by double integration of the first-derivative EPR lines. The influence of microwave power in the range of 2.2-70 mW on shape and parameters of the EPR spectra was examined. Thermal sterilization produced free radicals in bismuth subgallate in all tested cases. Strong interactions with free radicals were pointed out for all the analysed samples containing bismuth independent of sterilization conditions. Optimal conditions of thermal sterilization for bismuth subgallate with the lowest free radical formation are temperature 170°C and time of heating 60 minutes. Strong dipolar interactions exist in thermally sterilized bismuth subgallate. EPR spectroscopy is a useful method of examination of thermal sterilization conditions. PMID:25525421

  19. Determining the background levels of bismuth in tissues of wild game birds: a first step in addressing the environmental consequences of using bismuth shotshells

    International Nuclear Information System (INIS)

    Bismuth shotshells have been approved as a 'nontoxic' alternative to lead in North America. Approval was based on a limited number of studies; even background levels of bismuth in wildfowl were unknown. We report on the concentration of bismuth (and lead) in muscle and liver tissues of wildfowl (Anas platyrhynchos, Anas acuta, Anas crecca, Branta canadensis, Chen caerulescens) harvested with lead shotshell. Average liver-bismuth levels detected in the present study (e.g., teal, 0.05 μg/g dw; mallard, 0.09 μg/g dw) suggest analytical error in other studies examining the effects of bismuth in birds. Significant positive relationships between bismuth- and lead-tissue levels for muscle when all species were combined (and for B. canadensis and C. caerulescens separately) can be explained by noting that bismuth is a contaminant of lead. Thus, more research is recommended to confirm the appropriateness of bismuth as a 'nontoxic' shot alternative

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

    Science.gov (United States)

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

    2009-08-04

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

  1. Metallothionein bioconjugates as delivery vehicles for bismuth-212 alpha particle therapy

    International Nuclear Information System (INIS)

    Metallothioneins (MTHs) are small cysteine-rich polypeptides that binds cationic metals at physiologic pH ranges through noncovalent -SH ligand interactions. Some leucine-rich renal MTHs have a particular avidity for bismuth. The authors have examined the ability of MTHs to selectively incorporate Bi-212, a short-lived high-energy alpha particle emitter currently under exploration as a potential therapeutic radiolabel for use in molecularly targeted cancer therapy. They find that under physiologic conditions, MTH will selectively incorporate Bi-212 after incubation with an equilibrium mixture of its upstream and downstream parents. The MTH moieties may be linked to tumor-binding macromolecules such as antibodies via thiolation reactions using SPDP, and the resultant Bismuth-avid molecules may be used either as primary delivery vehicles for the Bi-212 or as part of a 2-step release-and-catch isotope localization system in which the MTH-antibody conjugate is pre-localized at the tumor site and the radiometal is then administered and chelated in situ. They present the chemistry, dosimetry and potential clinical applications of this system

  2. Hierarchical bismuth phosphate microspheres with high photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Lizhai; Wei, Tian; Lin, Nan; Yu, Haiyun [Anhui University of Technology, Ma' anshan (China). Key Laboratory of Materials Science and Processing of Anhui Province

    2016-05-15

    Hierarchical bismuth phosphate microspheres have been prepared by a simple hydrothermal process with polyvinyl pyrrolidone. Scanning electron microscopy observations show that the hierarchical bismuth phosphate microspheres consist of nanosheets with a thickness of about 30 nm. The diameter of the microspheres is about 1 - 3 μm. X-ray diffraction analysis shows that the microspheres are comprised of triclinic Bi{sub 23}P{sub 4}O{sub 44.5} phase. The formation of the hierarchical microspheres depends on polyvinyl pyrrolidone concentration, hydrothermal temperature and reaction time. Gentian violet acts as the pollutant model for investigating the photocatalytic activity of the hierarchical bismuth phosphate microspheres under ultraviolet-visible light irradiation. Irradiation time, dosage of the hierarchical microspheres and initial gentian violet concentration on the photocatalytic efficiency are also discussed. The hierarchical bismuth phosphate microspheres show good photocatalytic performance for gentian violet removal in aqueous solution.

  3. Bismuth electrodes, an alternative in stripping voltammetry

    International Nuclear Information System (INIS)

    The heavy metals are known as highly toxic contaminants, the processes carried out in industry contribute that finally they remain dispersed in effluents and sewage, doing part of the food chain. The importance of controlling the levels of these heavy metals has become an international policy, so it has generated interest in developing new analytical methodologies for its determination [1, 2, 3, 4]. The stripping voltammetry has been considered as a family of electro-sensitive analytical techniques useful for the determination of trace levels of many metals in environmental, clinical and industrial samples [3, 4]. This work presents an overview of these bismuth-based electrodes which were introduced around 2000, which have interesting characteristics for detection of heavy metals and which represent an alternative to mercury electrodes

  4. Bismuth electrodes, an alternative in stripping voltammetry

    Science.gov (United States)

    Barón-Jaimez, J.; Joya, M. R.; Barba-Ortega, J.

    2013-11-01

    The heavy metals are known as highly toxic contaminants, the processes carried out in industry contribute that finally they remain dispersed in effluents and sewage, doing part of the food chain. The importance of controlling the levels of these heavy metals has become an international policy, so it has generated interest in developing new analytical methodologies for its determination [1, 2, 3, 4]. The stripping voltammetry has been considered as a family of electro-sensitive analytical techniques useful for the determination of trace levels of many metals in environmental, clinical and industrial samples [3, 4]. This work presents an overview of these bismuth-based electrodes which were introduced around 2000, which have interesting characteristics for detection of heavy metals and which represent an alternative to mercury electrodes.

  5. High magnetoresistance in inhomogeneous bismuth microwires

    International Nuclear Information System (INIS)

    The present paper describes investigation of the dependence of magnetoresistance of microwires made of semimetal or semiconductor materials with high electric mobility doped with impurities introduced in the form of deposits at solidification. Till present it has been assumed that microscopic inhomogeneity in semimetals or semiconductors leads to a decrease of mobilities due to additional dispersion of charge carriers on impurities. Wolfe et al. have shown that impurities in the material with high mobility lead to an increase of mobilities due to geometric effect. In our case it is shown that presence of magnetic impurities in bismuth semimetal characterized by high mobility leads to an increase of magnetoresistance. This increase is very important for the technology of magnetic field converters and especially for application of high velocities of record of a magnetic head with a high capability of magnetic record. (authors)

  6. Platinum-Bismuth Bimetallic Catalysts: Synthesis, Characterization and Applications

    OpenAIRE

    Saucedo, Jose A, Jr; Xiao, Yang; Varma, Arvind

    2015-01-01

    Bimetallic catalysts have been explored and shown to exhibit unique characteristics which are not present in monometallic catalysts. Platinum is well known as an effective catalyst for oxidation and reduction reactions, and it can be made more effective when bismuth is introduced as a promotor. Thus, the effectiveness of the Pt-Bi catalyst was demonstrated in prior work. What is not clear, however, is the mechanism behind the catalyst function; why addition of bismuth to platinum decreases de...

  7. Electron cooling and Debye-Waller effect in photoexcited bismuth

    OpenAIRE

    Arnaud, B.; Giret, Y.

    2012-01-01

    By means of first principles calculations, we computed the effective electron-phonon coupling constant $G_0$ governing the electron cooling in photoexcited bismuth. $G_0$ strongly increases as a function of electron temperature, which can be traced back to the semi-metallic nature of bismuth. We also used a thermodynamical model to compute the time evolution of both electron and lattice temperatures following laser excitation. Thereby, we simulated the time evolution of (1 -1 0), (-2 1 1) and...

  8. Piezoelectric bismuth titanate ceramics for high temperature applications

    OpenAIRE

    Shulman, Holly Sue; Setter, Nava

    2005-01-01

    Bismuth titanate (Bi4Ti3O12) shows promise in piezoelectric applications in a temperature range (300-600 °C) which is not well served by standard piezoelectric ceramics. The proposal to use bismuth titanate ceramics for these applications has a major flaw, namely that the high electrical conductivity precludes the efficient polarization of these materials in an electric field. The degree of polarization is critical since it is directly related to the piezoelectric response. In addition, once ...

  9. Studies on bismuth carboxylates—synthesis and characterization of a new structural form of bismuth(III) dipicolinate

    Indian Academy of Sciences (India)

    O Anjaneyulu; K C Kumara Swamy

    2011-03-01

    Synthesis and X-ray structure of a new bismuth dipicolinate cooordination polymer, {[Bi((2,6-O2C)2C5H3N)((2-HO2C-6-O2C)C5H3N)(H2O)]2.5H2O} (7) are presented. Compound 7 has dimeric units with a Bi2O2 skeleton that are linked by additional weak Bi-O interactions leading to a polymeric structure. The overall coordination number at bismuth is 9 [two Bi-N and seven Bi-O bonds]. New routes to a second crystalline modification (4′) of the previously reported coordination polymer, bismuth tris(picolinate), [Bi(2-O2C-C5H4N)3] (4), are described; bond parameters in the two crystalline forms (4 and 4′) are compared. In both the compounds 4′ and 7, bismuth has a distorted tricapped trigonal prismatic geometry.

  10. Synthesis and Characterization of High-Purity Bismuth Nanowires via Seed-Assisted Growth Approach

    Science.gov (United States)

    Mu, Xin; Zhao, Wen-Yu; He, Dan-Qi; Zhou, Hong-Yu; Zhu, Wan-Ting; Zhang, Qing-Jie

    2015-06-01

    Nanowires are considered as high-performance thermoelectric materials with large Seebeck coefficients due to quantum confinement and low thermal conductivity because of enhanced boundary scattering of phonons. In this work, a seed-assisted growth method has been developed to synthesize high-purity bismuth nanowires. The bismuth seeds were first synthesized by reducing BiCl3 in the ice water with NaBH4. The high-purity bismuth nanowires about 40-50 nm in diameter and several tens of micrometers in length were then grown on bismuth seeds by reducing NaBiO3 with ethylene glycol. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were employed to characterize the crystal structure, microstructure, and growth direction of the bismuth seeds and nanowires. The effects of temperature, reductant, and bismuth seeds template on the microstructures of the bismuth nanowires were also investigated. The synthesis conditions of bismuth seeds and nanowires were optimized. The selected area electron diffraction pattern confirms that the growth direction of bismuth nanowires is parallel to [] direction. It was discovered that high-purity bismuth nanowires with high aspect ratio can be synthesized by precisely controlling the temperature to adjust the nucleation rate of the bismuth nuclei, selecting the appropriate reductant to maintain a low nucleation rate, and using bismuth seeds as the template of the epitaxial growth of the bismuth nuclei.

  11. CFD analysis and optimization of a liquid lead–bismuth loop target for ISOL facilities

    International Nuclear Information System (INIS)

    In the context of the forthcoming next generation of Radioactive Ion Beams (RIBs) facilities based on an Isotope Separation On Line (ISOL) method, the development of production targets capable of dissipating the high power deposited by the primary beam is a major challenge. The concept of a high-power target based on a liquid Pb–Bi loop incorporating a heat-exchanger and a diffusion chamber was proposed within EURISOL DS and is being developed within the LIEBE project. Due to the non-static character of the target, specific hydrodynamics issues are of concern. In this paper, these issues are studied mostly based on three-dimensional (3D) Computational Fluid Dynamics analysis of the flow of the Lead Bismuth Eutectic (LBE) target, resulting in optimized designs. The concept and hydrodynamic challenges of generating RIBs from a liquid-metal-loop target irradiated with a high-power primary beam are presented. The optimization of the target design has been conducted keeping in mind the need for a fast and efficient release of short-lived isotopes. This study shows that approximately 100 ms after the proton pulse the irradiated liquid-metal is entirely and uniformly evacuated from the irradiation volume and spread in a shower of small droplets (100-μm radii), in order to reduce the diffusion length of isotopes. Solutions to deal with the typical cavitation risk due to the presence of low-pressure zones in the liquid have also been found and simulated

  12. CFD analysis and optimization of a liquid lead–bismuth loop target for ISOL facilities

    Energy Technology Data Exchange (ETDEWEB)

    Houngbo, D., E-mail: dhoungbo@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Department of Flow, Heat and Combustion Mechanics, Ghent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium); Popescu, L.; Schuurmans, P. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Delonca, M.; Losito, R.; Maglioni, C.; Stora, T. [CERN, 1211 Geneva 23 (Switzerland); Bricault, P. [TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C., V6T 2A3 (Canada); Vierendeels, J. [Department of Flow, Heat and Combustion Mechanics, Ghent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium)

    2015-03-21

    In the context of the forthcoming next generation of Radioactive Ion Beams (RIBs) facilities based on an Isotope Separation On Line (ISOL) method, the development of production targets capable of dissipating the high power deposited by the primary beam is a major challenge. The concept of a high-power target based on a liquid Pb–Bi loop incorporating a heat-exchanger and a diffusion chamber was proposed within EURISOL DS and is being developed within the LIEBE project. Due to the non-static character of the target, specific hydrodynamics issues are of concern. In this paper, these issues are studied mostly based on three-dimensional (3D) Computational Fluid Dynamics analysis of the flow of the Lead Bismuth Eutectic (LBE) target, resulting in optimized designs. The concept and hydrodynamic challenges of generating RIBs from a liquid-metal-loop target irradiated with a high-power primary beam are presented. The optimization of the target design has been conducted keeping in mind the need for a fast and efficient release of short-lived isotopes. This study shows that approximately 100 ms after the proton pulse the irradiated liquid-metal is entirely and uniformly evacuated from the irradiation volume and spread in a shower of small droplets (100-μm radii), in order to reduce the diffusion length of isotopes. Solutions to deal with the typical cavitation risk due to the presence of low-pressure zones in the liquid have also been found and simulated.

  13. Treatment of ulcerative reflux oesophagitis with colloidal bismuth subcitrate in combination with cimetidine.

    OpenAIRE

    Borkent, M V; Beker, J A

    1988-01-01

    Twenty patients took part in a controlled double blind study comparing the efficacy of colloidal bismuth and cimetidine (800 mg at night) with cimetidine alone in the treatment of ulcerative reflux oesophagitis. Colloidal bismuth 120 mg was administered through an intraoesophageal tube four times a day. Cimetidine with colloidal bismuth gives significantly (p less than 0.001) better results than cimetidine alone. Of 10 patients treated with cimetidine and bismuth, seven had no endoscopic sign...

  14. Post-irradiation analysis of an ISOLDE lead-bismuth target: Stable and long-lived noble gas nuclides

    Science.gov (United States)

    Leya, I.; Grimberg, A.; David, J.-C.; Schumann, D.; Neuhausen, J.; Zanini, L.; Noah, E.

    2016-07-01

    We measured the isotopic concentrations of long-lived and stable He, Ne, Ar, Kr, and Xe isotopes in a sample from a lead-bismuth eutectic target irradiated with 1.0 and 1.4 GeV protons. Our data indicate for most noble gases nearly complete release with retention fractions in the range of percent or less. Higher retention fractions result from the decay of long-lived radioactive progenitors from groups 1, 2, or 7 of the periodic table. From the data we can calculate a retention fraction for 3H of 2-3%. For alkaline metals we find retention fractions of about 10%, 30%, and 50% for Na, Rb, and Cs, respectively. For the alkaline earth metal Ba we found complete retention. Finally, the measured Kr and Xe concentrations indicate that there was some release of the halogens Br and I during and/or after the irradiation.

  15. Ultrasonication of Bismuth Telluride Nanocrystals Fabricated by Solvothermal Method

    Science.gov (United States)

    Chu, Sang-Hyon; Choi, Sang H.; Kim, Jae-Woo; King, Glen C.; Elliott, James R.

    2006-01-01

    The objective of this study is to evaluate the effect of ultrasonication on bismuth telluride nanocrystals prepared by solvothermal method. In this study, a low dimensional nanocrystal of bismuth telluride (Bi2Te3) was synthesized by a solvothermal process in an autoclave at 180 C and 200 psi. During the solvothermal reaction, organic surfactants effectively prevented unwanted aggregation of nanocrystals in a selected solvent while controlling the shape of the nanocrystal. The atomic ratio of bismuth and tellurium was determined by energy dispersive spectroscopy (EDS). The cavitational energy created by the ultrasonic probe was varied by the ultrasonication process time, while power amplitude remained constant. The nanocrystal size and its size distribution were measured by field emission scanning electron microscopy (FESEM) and a dynamic light scattering system. When the ultrasonication time increased, the average size of bismuth telluride nanocrystal gradually increased due to the direct collision of nanocrystals. The polydispersity of the nanocrystals showed a minimum when the ultrasonication was applied for 5 min. Keywords: bismuth telluride, nanocrystal, low-dimensional, ultrasonication, solvothermal

  16. Ultrasound in lead-bismuth eutectic

    International Nuclear Information System (INIS)

    The Belgian Nuclear Research Centre (SCK.CEN) is in the process of designing MYRRHA, a new multi-purpose irradiation facility to replace the ageing BR2. MYRRHA is a fast spectrum reactor cooled with lead-bismuth eutectic (LBE). As liquid metal is opaque to visual light, ultrasonic measurement techniques are selected to fulfill essential tasks that, according to our assessment, will be demanded by licensing authorities, in particular: fuel assembly identification and localization of a lost fuel assembly. To that end, a considerable research effort at SCK.CEN is devoted to study ultrasonic propagation in LBE. As ultrasonic experiments in LBE are elaborate and expensive to set up, we are particularly interested in to what extent experiments in water can be extrapolated to LBE - one of the main focuses of this article. We describe and present results of a first experiment with this goal which shows that the signal to noise ratio is better in LBE and that we even see small diffuse reflections up to 40 deg. off normal. On the other hand, we do not see internal reflections in stainless steel objects in LBE which we do in water. Therefore, we conclude that experiments in water can be used to validate algorithms for LBE on the condition that they do not rely on internal reflections. We also present solutions to tackle the essential tasks: fuel assembly identification and lost object localization. The requirements for the ultrasonic equipment implementing these solutions are also discussed. (authors)

  17. Use of Russian technology of ship reactors with lead-bismuth coolant in nuclear power

    International Nuclear Information System (INIS)

    The experience of using lead-bismuth coolant in Russian nuclear submarine reactors has been presented. The fundamental statements of the concept of using the reactors cooled by lead-bismuth alloy in nuclear power have been substantiated. The results of developments for using lead bismuth coolant in nuclear power have been presented. (author)

  18. 40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

    Science.gov (United States)

    2010-07-01

    ...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to waters of...

  19. Prognostic Value of Bismuth Typing and Modified T-stage in Hilar Cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Shengen Yi

    2015-01-01

    Conclusion: The majority of our patients with HCC were characterized as Subtype IV in Bismuth typing and Stage T3 in modified T-stage. Both Bismuth typing and modified T-stage showed prognostic value in HCC. Compared with Bismuth typing, modified T-stage is a better indicator of the resectability of HCC.

  20. Isotopic Biogeochemistry

    Science.gov (United States)

    Hayes, J. M.

    1985-01-01

    An overview is provided of the biogeochemical research. The funding, productivity, personnel and facilities are reviewed. Some of the technical areas covered are: carbon isotopic records; isotopic studies of banded iron formations; isotope effects in microbial systems; studies of organic compounds in ancient sediments; and development in isotopic geochemistry and analysis.

  1. Phase transitions in the Hubbard model for the bismuth nickelate

    Science.gov (United States)

    Kojima, Shoya; Nasu, Joji; Koga, Akihisa

    2016-07-01

    We study low temperature properties of the Hubbard model for the bismuth nickelate, where degenerate orbitals in the nickel ions and a single orbital in the bismuth ions are taken into account, combining dynamical mean-field theory with the continuous-time quantum Monte Carlo method. We discuss the effect of the attractive interactions to mimic the valence skipping phenomenon in the bismuth ions. We demonstrate how the charge and magnetically ordered states are stable against thermal fluctuations. It is furthermore clarified that the ferromagnetically ordered and orbital ordered states are stabilized due to the presence of the orbital degeneracy at low temperatures. The crossover between metallic and insulating states is also discussed.

  2. Inexpensive laser-induced surface modification in bismuth thin films

    International Nuclear Information System (INIS)

    Highlights: • Laser-induced microbumps were formed on bismuth films using a simple, low-cost, laser setup. • The patterns, similar to those typically obtained with high-power lasers, were characterized. • Control of laser ablation conditions is critical in the fabrication of surface microbumps. - Abstract: In this work, we present results on texturing a 500 nm thick bismuth film, deposited by sputtering onto a glass slide using a low-cost homemade, near-infrared pulsed laser platform. A 785 nm laser diode of a CD–DVD pickup head was precisely focused on the sample mounted on a motorized two-axis translation stage to generate localized surface microbumps on the bismuth films. This simple method successfully transferred desired micropatterns on the films in a computer-numerical control fashion. Irradiated zones were characterized by atomic force microscopy and scanning electron microscopy. It was observed that final results are strongly dependent on irradiation parameters

  3. Inexpensive laser-induced surface modification in bismuth thin films

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, A. Reyes [Facultad de Ciencias, Universidad Autónoma del Estado de México, Carretera Toluca, Ixtlahuaca Kilómetro 15.5, C.P. 50200 Edo. de México (Mexico); Hautefeuille, M., E-mail: mathieu_h@ciencias.unam.mx [Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Circuito Exterior S/N, Coyoacán, Ciudad Universitaria, C.P. 04510 D.F. Mexico (Mexico); García, A. Esparza [Fotofísica y Películas Delgadas, Departamento de Tecnociencias, CCADET-UNAM, Circuito exterior s/n C.P. 04510 Cd. Universitaria, D.F. Mexico (Mexico); Mejia, O. Olea [Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco, Km 14.5, Unidad El Rosedal, 50200 San Cayetano, Estado de México (Mexico); López, M.A. Camacho [Facultad de Química, Universidad Autónoma del Estado de México, Tollocan s/n, esq. Paseo Colón, Toluca, Estado de México 50110 (Mexico)

    2015-05-01

    Highlights: • Laser-induced microbumps were formed on bismuth films using a simple, low-cost, laser setup. • The patterns, similar to those typically obtained with high-power lasers, were characterized. • Control of laser ablation conditions is critical in the fabrication of surface microbumps. - Abstract: In this work, we present results on texturing a 500 nm thick bismuth film, deposited by sputtering onto a glass slide using a low-cost homemade, near-infrared pulsed laser platform. A 785 nm laser diode of a CD–DVD pickup head was precisely focused on the sample mounted on a motorized two-axis translation stage to generate localized surface microbumps on the bismuth films. This simple method successfully transferred desired micropatterns on the films in a computer-numerical control fashion. Irradiated zones were characterized by atomic force microscopy and scanning electron microscopy. It was observed that final results are strongly dependent on irradiation parameters.

  4. Characterization of bismuth nanospheres deposited by plasma focus device

    International Nuclear Information System (INIS)

    A new method for producing thin layer of bismuth nanospheres based on the use of low energy plasma focus device is demonstrated. Various techniques such as scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been used to characterize the morphology and the composition of the nanospheres. Experimental parameters may be adjusted to favour the formation of bismuth nanospheres instead of microspheres. Therefore, the formation of large surface of homogeneous layer of bismuth nanospheres with sizes of below 100 nm can be obtained. The natural snowball phenomenon is observed to be reproduced in nanoscale where spheres roll over the small nanospheres and grow up to bigger sizes that can reach micro dimensions. The comet-like structure, a reverse phenomenon to snowball is also observed

  5. Mixed-phase bismuth ferrite nanoflake electrodes for supercapacitor application

    Science.gov (United States)

    Jadhav, Vijaykumar V.; Zate, Manohar K.; Liu, Shude; Naushad, Mu.; Mane, Rajaram S.; Hui, K. N.; Han, Sung-Hwan

    2016-04-01

    Nanoflake bismuth ferrite thin film was synthesized by means of electrodeposition technique at room temperature. The morphology and phase evaluation of the synthesized electrode were analyzed using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and surface wettability techniques. Specifically, the bismuth ferrite nanoflake electrode exhibited high specific capacitance of 72.2 F g-1 at a current density of 1 A g-1, and high rate capability with 37 % retention of capacitance even up to 20A g-1, and excellent cycling stability with 82.8 % retention of the initial capacitance after 1500 charge/discharge cycles, supporting that the bismuth ferrite thin-film electrode could be a potential candidate for supercapacitor application.

  6. Thermal, structural and electrical studies of bismuth zinc borate glasses

    Science.gov (United States)

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V.

    2013-06-01

    Bismuth Zinc Borate glasses with compositions xBi2O3-30ZnO-(70 - x)B2O3 (where x = 30, 35, 40 and 45 mol %) have been prepared by melt quenching method. These glasses were characterized by X-ray diffraction (XRD), Differential Thermal Analysis (DTA), Fourier Transform Infrared Spectrometer (FTIR) and Broad Band Dielectric Spectrometer (BDS). DTA and FTIR analysis reveals that Non-Bridging Oxygens (NBOs) increase with increase of bismuth content in the glass. Electrical data have been analyzed in the framework of impedance and modulus formalisms. The activation energy for dc conductivity decreases with increase of bismuth concentration. The imaginary part of modulus spectra has been fitted to non-exponential Kohlrausch-Williams-Watts (KWW) function and the value of the stretched exponent (β) is found to be almost independent of temperature but slightly dependent on composition.

  7. Characterization of bismuth nanospheres deposited by plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, M., E-mail: cscientific2@aec.org.sy [IBA Laboratory, Chemistry Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); Al-Hawat, Sh.; Akel, M. [Physics Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic); Mrad, O. [Chemistry Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2015-02-14

    A new method for producing thin layer of bismuth nanospheres based on the use of low energy plasma focus device is demonstrated. Various techniques such as scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been used to characterize the morphology and the composition of the nanospheres. Experimental parameters may be adjusted to favour the formation of bismuth nanospheres instead of microspheres. Therefore, the formation of large surface of homogeneous layer of bismuth nanospheres with sizes of below 100 nm can be obtained. The natural snowball phenomenon is observed to be reproduced in nanoscale where spheres roll over the small nanospheres and grow up to bigger sizes that can reach micro dimensions. The comet-like structure, a reverse phenomenon to snowball is also observed.

  8. Compact and Integrated Liquid Bismuth Propellant Feed System

    Science.gov (United States)

    Polzin, Kurt A.; Stanojev, Boris; Korman, Valentin; Gross, Jeffrey T.

    2007-01-01

    Operation of Hall thrusters with bismuth propellant has been shown to be a promising path toward high-power, high-performance, long-lifetime electric propulsion for spaceflight missions [1]. There has been considerable effort in the past three years aimed at resuscitating this promising technology and validating earlier experimental results indicating the advantages of a bismuth-fed Hall thruster. A critical element of the present effort is the precise metering of propellant to the thruster, since performance cannot be accurately assessed without an accurate accounting of mass flow rate. Earlier work used a pre./post-test propellant weighing scheme that did not provide any real-time measurement of mass flow rate while the thruster was firing, and makes subsequent performance calculations difficult. The motivation of the present work is to develop a precision liquid bismuth Propellant Management System (PMS) that provides hot, molten bismuth to the thruster while simultaneously monitoring in real-time the propellant mass flow rate. The system is a derivative of our previous propellant feed system [2], but the present system represents a more compact design. In addition, all control electronics are integrated into a single unit and designed to reside on a thrust stand and operate in the relevant vacuum environment where the thruster is operating, significantly increasing the present technology readiness level of liquid metal propellant feed systems. The design of various critical components in a bismuth PMS are described. These include the bismuth reservoir and pressurization system, 'hotspot' flow sensor, power system and integrated control system. Particular emphasis is given to selection of the electronics employed in this system and the methods that were used to isolate the power and control systems from the high-temperature portions of the feed system and thruster. Open loop calibration test results from the 'hotspot' flow sensor are reported, and results of

  9. Tin-silver-bismuth solders for electronics assembly

    Science.gov (United States)

    Vianco, Paul T.; Rejent, Jerome A.

    1995-01-01

    A lead-free solder alloy for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0tin effective to depress the melting point of the tin-silver composition to a desired level. Melting point ranges from about 218.degree. C. down to about 205.degree. C. depending an the amount of bismuth added to the eutectic tin-silver alloy as determined by DSC analysis, 10.degree. C./min. A preferred alloy composition is 91.84Sn-3.33Ag-4.83Bi (weight percent based on total alloy weight).

  10. High-Q bismuth silicate nonlinear glass microsphere resonators

    OpenAIRE

    Wang, Pengfei; Murugan, Ganapathy; Lee, Timothy; Ding, Ming; Brambilla, Gilberto; Semenova, Yuliya; Wu, Qiang; Koizumi,Fumihito; Farrell, Gerald

    2012-01-01

    The fabrication and characterization of a bismuth-silicate glass microsphere resonator has been demonstrated. At wavelengths near 1550 nm, high-modes can be efficiently excited in a 179-μm diameter bismuth-silicate glass microsphere via evanescent coupling using a tapered silica fiber with a waist diameter of circa 2 μm. Resonances with Q-factors as high as were observed. The dependence of the spectral response on variations in the input power level was studied in detail to gain an insight in...

  11. Lead–bismuth eutectic technology for Hyperion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J., E-mail: Zhang.3558@osu.edu [Dept. of Mechanical and Aerospace Engineering, The Ohio State University, 201 W, 19th Avenue, Columbus, OH 43210 (United States); Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Kapernick, R.J.; McClure, P.R. [Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Trapp, T.J. [Hyperion Power Generation (United States)

    2013-10-15

    A small lead–bismuth eutectic-cooled reactor concept (referred to as the Hyperion reactor concept) is being studied at Los Alamos National Laboratory and Hyperion Power Generation. In this report, a critical assessment of the lead–bismuth eutectic technology for Hyperion reactor is presented based on currently available knowledge. Included are: material compatibility, oxygen control, thermal hydraulics, polonium control. The key advances in the technology and their applications to Hyperion reactor design are analyzed. Also, the near future studies in main areas of the technology are recommended for meeting the design requirements.

  12. Bismuth onion thin film in situ grown on silicon wafer synthesized through a hydrothermal approach

    International Nuclear Information System (INIS)

    Bismuth onion structured nanospheres with the same structure as carbon onions have been synthesized and observed. The nanospheres were synthesized through a hydrothermal method using bismuth hydroxide and silicon wafer as reactants. By controlling the heating temperature, heating time, and the pressure, nanoscale bismuth spheres can be in situ synthesized on silicon wafer, and forms a bismuth onion film on the substrate. The electronic property of the films was investigated. A formation mechanism of the formation of bismuth onions and the onion film has been proposed on the basis of experimental observations.

  13. Bismuth centred magnetic perovskite: A projected multiferroic

    International Nuclear Information System (INIS)

    In recent time substantial attention has been initiated to understand the physics behind multiferroism and to design new multiferroic materials. BiMnO3 and BiFeO3 are the well-studied Bi-centred multiferroic oxides. BiMnO3 is a ferromagnetic–ferroelectric (metastable) phase and require drastic conditions to synthesize. However, lanthanum substituted BiMnO3 phases stabilized at ambient pressure. It is thus of major importance to increase the number of ferromagnetic perovskites with Bi cations that could be designed under ambient conditions. In this article, we have presented an up to date report of investigations on Bi-centred magnetic perovskites, a prospective material for multiferroic application. Central focus is concentrated on La0.5Bi0.5MnO3 perovskite with various substitutions at different levels. A few of these perovskites are found to be of practical importance e.g. La0.5Bi0.5Mn0.67Co0.33O3 with high dielectric permittivity coupled with ferromagnetism. A comprehensive analysis of different physical functionalities and their interrelation for a wide range of compositions of these Bi-centred perovskites is presented. It has been found that the complex magnetic behaviour originates from mixed valence metal ions. The ferroelectricity is associated with the 6s2 lone pair of Bi3+ cations. The magnetic ground state influences the dielectric properties reflecting the multiferroism in a single material. - Highlights: • Multiferroics have attracted increasing attention due to their possible device applications. • Bismuth centred magnetic perovskite is one kind of such promising multiferroic materials. • Ferromagnetic Bi-perovskites, which are synthesized at ambient conditions, have been discussed

  14. Bismuth Ferrite for Active Control of Surface Plasmon Polariton Modes

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Lavrinenko, Andrei

    We propose and investigate several layouts of m etal-insulator-metal waveguide with active core which can be utilized for dynamic switching in photonic integrated circuits. The active material, bismuth ferrite (BiFeO3), is sandwiched between metal plates and changes i ts refractive index through ...

  15. Ultrafast electron diffraction studies of optically excited thin bismuth films

    International Nuclear Information System (INIS)

    This thesis contains work on the design and the realization of an experimental setup capable of providing sub-picosecond electron pulses for ultrafast electron diffraction experiments, and performing the study of ultrafast dynamics in bismuth after optical excitation using this setup. (orig.)

  16. Polymeric architectures of bismuth citrate based on dimeric building blocks

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Four bismuth complexes, (H2En)[Bi2(cit)2(H2O)4/3]·(H2O)x (1), (H2En)3[Bi2(cit)2Cl4]·(H2O)x (2), (HPy)2[Bi2(cit)2(H2O)8/5]·(H2O)x (3) and (H2En)[Bi2(cit)2](H2O)x (4) [cit = citrate4-; En = ethylenediamine; Py = pyridine] have been synthesized and crystallized. The crystal structures reveal that the basic building blocks in all of these complexes are bismuth citrate dimeric units which combine to form polymeric architectures. The embedded protonated ethylenediamine and pyridine moieties in the polymeric frameworks have been identified by X-ray crystallography and solid-state cross polarization/magic angle spinning (CP/MAS) 13C NMR. Based on the framework of complex 1, a structural model of a clinically used antiulcer drug, ranitidine bismuth citrate (RBC) was generated. The behavior of the protonated amine-bismuth citrate complexes in acidic aqueous solution has been studied by electrospray ionization-mass spectrometry (ESI-MS).

  17. Bismuth Ferrite for Active Control of Surface Plasmon Polariton Modes

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Lavrinenko, Andrei

    2014-01-01

    We propose and investigate several layouts of m etal-insulator-metal waveguide with active core which can be utilized for dynamic switching in photonic integrated circuits. The active material, bismuth ferrite (BiFeO3), is sandwiched between metal plates and changes i ts refractive index through...

  18. Synthesis and structural characterization of Ce-doped bismuth titanate

    International Nuclear Information System (INIS)

    Ce-modified bismuth titanate nanopowders Bi4-xCexTi3O12 (x ≤ 1) have been synthesized using a coprecipitation method. DTA/TG, FTIR, XRD, SEM/EDS and BET methods were used in order to investigate the effect of Ce-substitution on the structure, morphology and sinterability of the obtained powders. The phase structure investigation revealed that after calcinations at 600 deg. C powder without Ce addition exhibited pure bismuth titanate phase; however, powders with Ce (x = 0.25, 0.5 and 0.75) had bismuth titanate pyrochlore phase as the second phase. The strongest effect of Ce addition on the structure was noted for the powder with the highest amount of Ce (x = 1) having a cubic pyrochlore structure. The presence of pure pyrochlore phase was explained by its stabilization due to the incorporation of cerium ions in titanate structure. Ce-modified bismuth titanate ceramic had a density over 95% of theoretical density and the fracture in transgranular manner most probably due to preferable distribution of Ce in boundary region

  19. Measured and evaluated neutron cross sections of elemental bismuth

    International Nuclear Information System (INIS)

    Neutron total cross sections of elemental bismuth are measured with broad resolution from 1.2 to 4.5 MeV to accuracies of approx. = 1%. Neutron-differential-elastic-scattering cross sections of bismuth are measured from 1.5 to 4.0 MeV at incident neutron energy intervals of approx.< 0.2 MeV over the scattered-neutron angular range approx. = 20 to 160 deg. Differential neutron cross sections for the excitation of observed states in bismuth at 895 +- 12, 1606 +- 14, 2590 +- 15, 2762 +- 29, 3022 +- 21, and 3144 +- 15 keV are determined at incident neutron energies up to 4.0 MeV. An optical-statistical model is deduced from the measured values. This model, the present experimental results, and information available elsewhere in the literature are used to construct a comprehensive evaluated nuclear data file for elemental bismuth in the ENDF format. The evaluated file is particularly suited to the neutronic needs of the fusion-fission hybrid designer. 87 references, 10 figures, 6 tables

  20. Ultrafast electronic dynamics in laser-excited crystalline bismuth

    Directory of Open Access Journals (Sweden)

    Chekalin S.

    2013-03-01

    Full Text Available Femtosecond spectroscopy was applied to capture complex dynamics of non equilibrium electrons in bismuth. Data analysis reveals significant wavevector dependence of electron-hole and electron-phonon coupling strength along the Γ-T direction of the Brillouin zone

  1. Ultrafast electron diffraction studies of optically excited thin bismuth films

    Energy Technology Data Exchange (ETDEWEB)

    Rajkovic, Ivan

    2008-10-21

    This thesis contains work on the design and the realization of an experimental setup capable of providing sub-picosecond electron pulses for ultrafast electron diffraction experiments, and performing the study of ultrafast dynamics in bismuth after optical excitation using this setup. (orig.)

  2. Phase transition of bismuth telluride thin films grown by MBE

    DEFF Research Database (Denmark)

    Fülöp, Attila; Song, Yuxin; Charpentier, Sophie;

    2014-01-01

    A previously unreported phase transition between Bi2Te3 and Bi4Te3 in bismuth telluride grown by molecular beam epitaxy is recorded via XRD, AFM, and SIMS observations. This transition is found to be related to the Te/Bi beam equivalent pressure (BEP) ratio. BEP ratios below 17 favor the formatio...

  3. Surface depletion in the vacuum distillation of metals from bismuth

    International Nuclear Information System (INIS)

    Surface depletion was investigated in laboratory- and plant-scale distillation units with mixing by natural convection or by mechanical surface agitation. A model was developed for predicting the degree of surface depletion during the distillation of metals from bismuth as a function of temperature, still pot dimensions, and degree of agitation. This paper discusses those findings

  4. Third order nonlinear optical properties of bismuth zinc borate glasses

    International Nuclear Information System (INIS)

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi2O3-30ZnO-(70-x) B2O3 (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σe) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported

  5. Third order nonlinear optical properties of bismuth zinc borate glasses

    Science.gov (United States)

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V.; Kuladeep, R.; Narayana Rao, D.

    2013-12-01

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi2O3-30ZnO-(70-x) B2O3 (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σe) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.

  6. Third order nonlinear optical properties of bismuth zinc borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugavelu, B.; Ravi Kanth Kumar, V. V., E-mail: ravi.phy@pondiuni.edu.in [Department of Physics, Pondicherry University, Puducherry 605 014 (India); Kuladeep, R.; Narayana Rao, D. [School of Physics, University of Hyderabad, Hyderabad 500046, Andhra Pradesh (India)

    2013-12-28

    Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi{sub 2}O{sub 3}-30ZnO-(70-x) B{sub 2}O{sub 3} (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σ{sub e}) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.

  7. Bismuth-based oxide semiconductors: Mild synthesis and practical applications

    Science.gov (United States)

    Timmaji, Hari Krishna

    In this dissertation study, bismuth based oxide semiconductors were prepared using 'mild' synthesis techniques---electrodeposition and solution combustion synthesis. Potential environmental remediation and solar energy applications of the prepared oxides were evaluated. Bismuth vanadate (BiVO4) was prepared by electrodeposition and solution combustion synthesis. A two step electrosynthesis strategy was developed and demonstrated for the first time. In the first step, a Bi film was first electrodeposited on a Pt substrate from an acidic BiCl3 medium. Then, this film was anodically stripped in a medium containing hydrolyzed vanadium precursor, to generate Bi3+, and subsequent BiVO4 formation by in situ precipitation. The photoelectrochemical data were consistent with the in situ formation of n-type semiconductor films. In the solution combustion synthesis procedure, BiVO4 powders were prepared using bismuth nitrate pentahydrate as the bismuth precursor and either vanadium chloride or vanadium oxysulfate as the vanadium precursor. Urea, glycine, or citric acid was used as the fuel. The effect of the vanadium precursor on the photocatalytic activity of combustion synthesized BiVO 4 was evaluated in this study. Methyl orange was used as a probe to test the photocatalytic attributes of the combustion synthesized (CS) samples, and benchmarked against a commercial bismuth vanadate sample. The CS samples showed superior activity to the commercial benchmark sample, and samples derived from vanadium chloride were superior to vanadium oxysulfate counterparts. The photoelectrochemical properties of the various CS samples were also studied and these samples were shown to be useful both for environmental photocatalytic remediation and water photooxidation applications. Silver bismuth tungstate (AgBiW2O8) nanoparticles were prepared for the first time by solution combustion synthesis by using silver nitrate, bismuth nitrate, sodium tungstate as precursors for Ag, Bi, and W

  8. Isotopic geology

    International Nuclear Information System (INIS)

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  9. Isotopic clusters

    International Nuclear Information System (INIS)

    Spectra of isotopically mixed clusters (dimers of SF6) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  10. Hyperfine Clock Transitions of Bismuth Donors in Silicon Detected by Spin Dependent Recombination

    OpenAIRE

    Mortemousque, Pierre-André; Berger, Simon; Sekiguchi, Takeharu; Culan, Christophe; Elliman, Robert G.; Kohei M. Itoh

    2014-01-01

    Bismuth donors ion-implanted in $^{28}$Si and $^\\text{nat}$Si are studied using magnetic resonance spectroscopy based on spin dependent recombination. The hyperfine clock transition, at which the linewidth is significantly narrowed, is observed for the bismuth donors. The experimental results are modeled quantitatively by molecular orbital theory for a coupled pair consisting of a bismuth donor and a spin dependent recombination readout center, including the effect of hyperfine and Zeeman int...

  11. Bismuth nitrate-induced microwave-assisted expeditious synthesis of vanillin from curcumin

    OpenAIRE

    Bandyopadhyay, Debasish; Banik, Bimal K

    2012-01-01

    Background Curcumin and vanillin are the two useful compounds in food and medicine. Bismuth nitrate pentahydrate is an economical and ecofriendly reagent. Method Bismuth nitrate pentahydrate impregnated montmorillonite KSF clay and curcumin were subjected to microwave irradiation. Results Microwave-induced bismuth nitrate-promoted synthesis of vanillin from curcumin has been accomplished in good yield under solvent-free condition. Twenty-five different reaction conditions have been studied to...

  12. Rapid semi-quantitative determination of bismuth in minerals using ascending paper chromatography (1961)

    International Nuclear Information System (INIS)

    The bismuth is separated by a solvent made up of acetone, water, and hydrofluoric and hydrochloric acids. The bismuth is developed with dimercapto-2.5 thio-diazole-1.3.4 and ammonium sulphide. The use of this method for the detection of bismuth in minerals makes it possible to determine the metal at a concentration of 5 x 10-6. (author)

  13. Standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori eradication

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori ) eradication in a randomized, double-blinded, comparative clinical trial in China. METHODS: A total of 215 H. pylori -positive patients were enrolled in the study and randomly allocated into three groups: group A (n = 72) received a 10-d bismuth pectin quadruple therapy (20 mg rabeprazole bid , 1000 mg amoxicillin bid , 100 mg bismuth pectin qid , and 500 mg levofloxaci...

  14. Influence of bismuth on structural, elastic and spectroscopic properties of Nd{sup 3+} doped Zinc–Boro-Bismuthate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Gaurav; Sontakke, Atul D.; Karmakar, P.; Biswas, K.; Balaji, S.; Saha, R.; Sen, R.; Annapurna, K., E-mail: annapurnak@cgcri.res.in

    2014-05-01

    The present investigation reports, influence of bismuth addition on structural, elastic and spectral properties of [(99.5−x) {4ZnO−3B_2O_3}−0.5Nd{sub 2}O{sub 3}−x Bi{sub 2}O{sub 3} where x=0, 5, 10, 20, 30, 40, 50 and 60] glasses. The measured FTIR reflectance spectra facilitated a thorough insight of methodical modifications that are arising in the glass structure from borate (build by BO{sub 3} and BO{sub 4} units) to bismuthate (BiO{sub 3} and BiO{sub 6} units) network due to the increase of bismuth content ensuing with a steady decrease in host phonon energy (ν{sub ph}). The elastic properties estimated from measured longitudinal and shear ultrasonic velocities (U{sub L} and U{sub s}) demonstrated the reduction in network rigidity of glasses on Bi{sub 2}O{sub 3} inclusion. The three phenomenological Judd–Ofelt intensity parameters (Ω{sub 2,4,6}) were obtained from recorded absorption spectra of Nd{sup 3+} ions in these glasses and have been used to predict radiative properties as a function of variation in bismuth content. The reduced host phonon energy and high optical basicity effect due to Bi{sub 2}O{sub 3} incorporation remarkably improved the Nd{sup 3+} luminescence properties such as emission intensity, quantum yield and emission cross-section. The quantum yield showed a strong increase from mere 16% in Zinc–Borate glass to almost 73% in 60 mol% Bi{sub 2}O{sub 3} containing glass. Similarly, the emission cross-section for Nd{sup 3+4}F{sub 3/2}→{sup 4}I{sub 11/2} laser transition raised from 2.43×10{sup −20} cm{sup 2} to 3.95×10{sup −20} cm{sup 2} in studied concentration suggesting a strong improvement in Nd{sup 3+} laser spectroscopic properties in Zinc–Boro-Bismuthate glass. These materials may be promising for compact solid state infrared lasers. - Highlights: • Continuous structural changes associated with reduction in host phonon energy by Bi{sub 2}O{sub 3} inclusion. • Ultrasonic velocity study revealed reduced Debye

  15. Influence of bismuth on structural, elastic and spectroscopic properties of Nd3+ doped Zinc–Boro-Bismuthate glasses

    International Nuclear Information System (INIS)

    The present investigation reports, influence of bismuth addition on structural, elastic and spectral properties of [(99.5−x) {4ZnO−3B2O3}−0.5Nd2O3−x Bi2O3 where x=0, 5, 10, 20, 30, 40, 50 and 60] glasses. The measured FTIR reflectance spectra facilitated a thorough insight of methodical modifications that are arising in the glass structure from borate (build by BO3 and BO4 units) to bismuthate (BiO3 and BiO6 units) network due to the increase of bismuth content ensuing with a steady decrease in host phonon energy (νph). The elastic properties estimated from measured longitudinal and shear ultrasonic velocities (UL and Us) demonstrated the reduction in network rigidity of glasses on Bi2O3 inclusion. The three phenomenological Judd–Ofelt intensity parameters (Ω2,4,6) were obtained from recorded absorption spectra of Nd3+ ions in these glasses and have been used to predict radiative properties as a function of variation in bismuth content. The reduced host phonon energy and high optical basicity effect due to Bi2O3 incorporation remarkably improved the Nd3+ luminescence properties such as emission intensity, quantum yield and emission cross-section. The quantum yield showed a strong increase from mere 16% in Zinc–Borate glass to almost 73% in 60 mol% Bi2O3 containing glass. Similarly, the emission cross-section for Nd3+4F3/2→4I11/2 laser transition raised from 2.43×10−20 cm2 to 3.95×10−20 cm2 in studied concentration suggesting a strong improvement in Nd3+ laser spectroscopic properties in Zinc–Boro-Bismuthate glass. These materials may be promising for compact solid state infrared lasers. - Highlights: • Continuous structural changes associated with reduction in host phonon energy by Bi2O3 inclusion. • Ultrasonic velocity study revealed reduced Debye temperature and elastic properties with bismuth addition. • Correlation of Judd–Ofelt parameters with structural modifications. • Realization of enhanced fluorescence quantum yield with

  16. Ab initio electronic structure and optical conductivity of bismuth tellurohalides

    CERN Document Server

    Schwalbe, Sebastian; Starke, Ronald; Schober, Giulio A H; Kortus, Jens

    2016-01-01

    We investigate the electronic structure, dielectric and optical properties of bismuth tellurohalides BiTeX (X = I, Cl, Br) by means of all-electron density functional theory. In particular, we present the ab initio conductivities and dielectric tensors calculated over a wide frequency range, and compare our results with the recent measurements by Akrap et al. , Makhnev et al. , and Rusinov et al. . We show how the low-frequency branch of the optical conductivity can be used to identify characteristic intra- and interband transitions between the Rashba spin-split bands in all three bismuth tellurohalides. We further calculate the refractive indices and dielectric constants, which in turn are systematically compared to previous predictions and measurements. We expect that our quantitative analysis will contribute to the general assessment of bulk Rashba materials for their potential use in spintronics devices.

  17. Chrysanthemum-like bismuth sulfide microcrystals: Synthesis, characterization, and properties

    Science.gov (United States)

    Jiang, Jinghui; Gao, Guanhua; Yu, Runnan; Qiu, Guanzhou; Liu, Xiaohe

    2011-02-01

    Uniform chrysanthemum-like bismuth sulfide (Bi 2S 3) microcrystals assembled from nanosheet building blocks were successfully synthesized via a convenient hydrothermal synthetic route under mild conditions in which hydrated bismuth nitrate and L-cysteine were employed to supply Bi and S source and ethylenediaminetetraacetic acid disodium salt (EDTA-Na 2) was employed as chelating agent. The influences of reaction temperatures and time on the morphologies of final products were investigated. The phase structures, morphologies, and properties of as-prepared products were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscope, and photoluminescence spectra. The possible growth mechanism for the formation of chrysanthemum-like Bi 2S 3 microcrystals was discussed on the basis of the experimental results.

  18. Quantum nernst effect in a bismuth single crystal

    International Nuclear Information System (INIS)

    We calculate the phonon-drag contribution to the transverse (Nernst) thermoelectric power Syx in a bismuth single crystal subjected to a quantizing magnetic field. The calculated heights of the Nernst peaks originating from the hole Landau levels and their temperature dependence reproduce the right order of magnitude for those of the pronounced magneto-oscillations recently reported by Behnia et al. A striking experimental finding that Syx is much larger than the longitudinal (Seebeck) thermoelectric power Sxx can be naturally explained as the effect of the phonon drag, combined with the well-known relation between the longitudinal and the Hall resistivity ρxx >> |ρyx| in a semi-metal bismuth. The calculation that includes the contribution of both holes and electrons suggests that some of the hitherto unexplained minor peaks located roughly at the fractional filling of the hole Landau levels are attributable to the electron Landau levels. (author)

  19. Thermophysical properties of liquid lead-bismuth eutectic

    International Nuclear Information System (INIS)

    Background: Liquid lead-bismuth eutectic (LBE) is important spallation target materials and candidate coolant materials in accelerator driven subcritical (ADS) system. Purpose: Its thermodynamic physical properties are keys to understand the basic problems in ADS R&D. Methods: By the calculation of scientific laws as well as fitting other scholars' experimental results, we tried to obtain the above thermodynamics physical properties. Results: By the calculation, we got formula about characteristic temperatures, density, specific heat, viscosity and thermal conductivity of liquid lead-bismuth alloy. And by fitting other scholars' experimental results, we got the fitting formula. Conclusions: Finally, by the contrast analysis, we found that the fitting formula and calculation formula agree well, and fitting formula more approaches the experimental value with a high accuracy whose differential deviation is not over 1%. (authors)

  20. Colloidal bismuth subcitrate in non-ulcer dyspepsia.

    Directory of Open Access Journals (Sweden)

    Khanna M

    1992-07-01

    Full Text Available The effect of colloidal bismuth subcitrate (De-Nol on symptoms, Helicobacter pylori status and histological features was studied in 35 patients with non-ulcer dyspepsia. Pain (34 cases and gas bloat (18 were the predominant symptoms. H pylori was present in 26 (74.3% patients. Gastritis and duodenitis were present in 29 of 32 and 22 of 31 cases respectively in whom biopsies were available. Relief in symptoms after treatment was seen in 29 (82.8% cases. Improvement in gastritis and duodenitis was noted in 60.8% and 58.8% respectively; over 70% of H pylori positive patients cleared the organism. These changes did not correlate with the relief in symptoms. We conclude that colloidal bismuth subcitrate is effective in the short term treatment of non-ulcer dyspepsia. It also clears H pylori infection and results in improvement of histological features.

  1. Effects of microwave sintering power on microstructure, dielectric, ferroelectric and magnetic properties of bismuth ferrite ceramics

    International Nuclear Information System (INIS)

    Highlights: ► Single-phase BFO ceramics have been prepared by microwave sintering. ► The lower sintering power is benefit for the decrease of its dielectric loss and leakage. ► Pr and Ec decrease with the increase of sintering power. ► Mr and Hc increase as sintering power increases. -- Abstract: Multiferroic bismuth ferrite ceramics were fabricated via microwave sintering. The microstructure, dielectric, ferroelectric and magnetic properties of bismuth ferrite ceramics sintered at different microwave powers are characterized by X-ray diffraction, scanning electron microscope, impedance analyzers, ferroelectric test system and vibrating sample magnetometer. Bismuth ferrite ceramics sintered at 3.4 kW is single phase and has dense structure and uniform grains. The lower microwave sintering power for bismuth ferrite ceramics is benefit for the decrease of its dielectric loss. The remnant polarization and coercive electric field of bismuth ferrite ceramics decrease with the increasing of microwave sintering power. The remnant polarization and the coercive electric field of bismuth ferrite ceramics decrease simultaneously as frequency increases. The leakage current of bismuth ferrite ceramics increases with the increase of microwave sintering power. Bismuth ferrite ceramics prepared by microwave sintering exhibit typical antiferromagnetic behaviors and the remnant magnetization and coercive magnetic field increase as the microwave sintering power increases. It is inferred that the optimum microwave sintering power for bismuth ferrite ceramics is 3.4 kW

  2. Optimal biliary drainage for inoperable Klatskin's tumor based on Bismuth type

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate differences in the effects of biliary drainage procedures in patients with inoperable Klatskin's tumor based on Bismuth type, considering endoscopic retrograde biliary drainage (ERBD), external percutaneous transhepatic biliary drainage (EPTBD) and internal biliary stenting via the PTBD tract (IPTBD).METHODS: The initial success rate, cumulative patency rate, and complication rate were compared retrospectively, according to the Bismuth type and ERBD,EPTBD, and IPTBD. Patency was defined as the duration for adequate initial bile drainage or to the point of the patient's death associated with inadequate drainage.RESULTS: One hundred thirty-four patients (93 men,41 women; 21 Bismuth type Ⅱ, 47 Ⅲ, 66 Ⅳ; 34 ERBD,66 EPTBD, 34 IPTBD) were recruited. There were no differences in demographics among the groups.Adequate initial relief of jaundice was achieved in 91% of patients without a significant difference in the results among different procedures or Bismuth types. The cumulative patency rates for ERBD and IPTBD were better than those for EPTBD with Bismuth type Ⅲ.IPTBD provided an excellent response for Bismuth type Ⅳ. However, there was no difference in the patency rate among drainage procedures for Bismuth type Ⅱ.Procedure-related cholangitis occurred less frequently with EPTBD than with ERBD and IPTBD.CONCLUSION: ERBD is recommended as the firstline drainage procedure for the palliation of jaundice in patients with inoperable Klatskin's tumor of Bismuth type Ⅱ or Ⅲ, but IPTBD is the best option for Bismuth type Ⅳ.

  3. Preparation of high-purity bismuth by sulphur deleadization in vacuum distillation

    Institute of Scientific and Technical Information of China (English)

    熊利芝; 何则强; 刘文萍; 麻成金; 戴永年

    2004-01-01

    The feasibility of separation of impurities in refined bismuth and sulphur deleadization with vacuum distillation was studied theoretically. Experimental studies on sulphur deleadization were carried out under vacuum.The influences of amount of sulphur, distillation temperature, vacuum degree and distillation time on deleadization were investigated and an optimal technical condition was achieved. The content of lead in refined bismuth can be decreased from 30 μg/g to 0.21 μg/g, which has reached the level of "5N" high-purity bismuth. Other impurities in refined bismuth can be also removed effectively under certain conditions.

  4. Magnetic Properties of Bismuth Ferrite Nanopowder Obtained by Mechanochemical Synthesis

    OpenAIRE

    Szafraniak-Wiza, I.; Andrzejewski, B.; Hilczer, B.

    2014-01-01

    Multiferroic bismuth ferrite (BiFeO3) nanopowders have been obtained in room temperature by mechanical synthesis. Depending on the post-synthesis processing the nanopowders have exhibited differences in the mean sizes, presence of amorphous layer and/or secondary phases. Extended magnetic study performed for fresh, annealed and hot-pressed nanopowders have revealed substantial improvement of the magnetic properties in the as-prepared powder.

  5. The bismuth burden - a challenge for the accident insurance (Berufsgenossenschaften)

    International Nuclear Information System (INIS)

    The Soviet-German Bismuth AG was a state within a state in the former GDR. Uranium mining not only caused great ecological burdens but also gave rise to many problems for the accident insurance. Occupational diseases are of course, very important in the context of malignous growth caused by ionised radiation. The accident insurances (Berufsgenossenschaften) recognised the size of this unique problem and have initiated measures towards its solution. (orig.)

  6. Structural and electromechanical properties of bismuth-strontium titanate ceramics

    International Nuclear Information System (INIS)

    Bismuth-strontium titanate ceramics were obtained by conventional sinterization method (without orientation of grains - OF) and hot-forging (with oriented grains - HF). The physics, dielectrics and plutocracies properties these ceramics were compared. At piezoelectric characterization, the Kt values were higher in ceramics obtained by hot-forging (HF) when compared to ceramics obtained by OF, which indicates the high anisotropy of these materials. (author)

  7. Tunneling behavior of bismuth telluride nanoplates in electrical transport

    OpenAIRE

    Eginligil, Mustafa; Zhang, Weiqing; Kalitsov, Alan; Lu, Xianmao; Yang, Hyunsoo

    2012-01-01

    We study the electrical transport properties of ensembles of bismuth telluride (Bi2Te3) nanoplates grown by solution based chemical synthesis. Devices consisting of Bi2Te3 nanoplates are fabricated by surface treatment after dropping the solution on the structured gold plates and the temperature dependence of resistance shows a nonmetallic behavior. Symmetric tunneling behavior in I-V was observed in both our experimental results and theoretical calculation of surface conductance based on a s...

  8. Dose reduction using Bismuth protectors in chest computed tomography

    International Nuclear Information System (INIS)

    This monography is about the Dose reduction using Bismuth protectors in chest CT. The radiation protection of specific areas is necessary when the tissues or radiosensitive organs are near the path of light beam. The correct use of protection represents a challenge for the radiologist because of the time and materials required. The method used was a prospective investigatio in CHPR (TC service) and the doses was measured with TLD dosimeters. It is important to use these protectors in children hospitals.

  9. In vivo cellular uptake of bismuth ions from shotgun pellets

    OpenAIRE

    Stoltenberg, M; Locht, L.; Larsen, Agnete; Jensen, D.

    2003-01-01

    Shotgun pellets containing bismuth (Bi) are widely used and may cause a rather intense exposure of some wild animals to Bi. A Bi shotgun pellet was implanted intramuscularly in the triceps surae muscle of 18 adult male Wistar rats. Another group of 9 animals had a Bi shotgun pellet implanted intracranially in the neocortex. Eight weeks to 12 months later the release of Bi ions was analysed by autometallography (AMG) of tissue sections from different organs (bra...

  10. Lead-bismuth coolant cleaning from solid impurities using filtration

    International Nuclear Information System (INIS)

    The factors, influencing the efficiency of the circuit cleaning of the lead-bismuth coolant from the solid phase impurities through filtration, are analyzed. The choice of the filtration material is substantiated proceeding from the properties of the given coolant as a dispersion system. The results of the experiments on determining the efficiency of cleaning capacity by retained impurities, throughput and regeneration made it possible to develop the industrial filters for the NPU needs

  11. Weak antilocalization and UCFs in an open bismuth quantum dot

    Science.gov (United States)

    Hackens, B.; Minet, J. P.; Farhi, G.; Faniel, G.; Gustin, C.; Bayot, V.

    2003-04-01

    We report on the observation of weak antilocalization and universal conductance fluctuations in the magnetoconductance of an open quasi-ballistic bismuth nano-cavity. The electron decoherence length is comparable to sample dimensions at low temperature, while the spin-orbit coupling length is smaller. The temperature dependence of both the conductance and the dephasing length are consistent with two-dimensional electron-electron interactions being the dominant decoherence process.

  12. Proton irradiation on textured bismuth based cuprate superconductors

    International Nuclear Information System (INIS)

    Textured bulk polycrystalline samples of bismuth based cuprate superconductors have been subjected to irradiation with 15 MeV protons. In case of Bi-2212, there has been substantial increase in Tc, which may be due to proton induced knock-out of loosely bound oxygen. In case of (Bi,Pb)-2223, there has been a reduction in Tc. The difference in behaviour in these two systems towards proton irradiation has been explained. (author). 7 refs., 3 figs., 1 tab

  13. Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials

    International Nuclear Information System (INIS)

    Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO)2CO3) is one of commonly used antibacterial agents against Helicobacter pylori (H. pylori). Different (BiO)2CO3 nanostructures such as cube-like nanoparticles, nanobars and nanoplates, were fabricated from bismuth nitrate via a simple solvothermal method. The nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that the solvents and precursors have an influence on the morphologies of (BiO)2CO3 nanostructures. The possible formation mechanism of different (BiO)2CO3 nanostructures fabricated under different conditions was also discussed. - Graphical abstract: Different bismuth subcarbonate ((BiO)2CO3) nanostructures were successfully synthesized by a simple solvothermal method. It was found that the solvents and precursors have an influence on the morphologies of (BiO)2CO3 nanostructures.

  14. Aerosol deposition of (Cu,Ti) substituted bismuth vanadate films

    International Nuclear Information System (INIS)

    Bismuth vanadate, Bi4V2O11, and related compounds with various metal (Me) substitutions, Bi4(MexV1−x)2O11−δ, show some of the highest ionic conductivities among the known solid oxide electrolytes. Films of Cu and Ti substituted bismuth vanadate were prepared by an aerosol deposition method, a spray coating process also described as room temperature impact consolidation. Resultant films, several microns in thickness, were dense with good adhesion to the substrate. Scanning electron microscopy and high temperature X-ray diffraction were used to monitor the effects of temperature on the structure and microstructure of the film. The particle size remained nano-scale while microstrain decreased rapidly up to 500 °C, above which coarsening and texturing increased rapidly. Impedance measurements of films deposited on inter-digital electrodes revealed an annealing effect on the ionic conductivity, with the conductivity exceeding that of a screen printed film, and approaching that of bulk ceramic. - Highlights: • Cu and Ti doped bismuth vanadate films were prepared by aerosol deposition (AD). • Dense 3–5 μm thick films were deposited on alumina, silicon and gold electrodes. • Annealing of the AD-layer increases the conductivity by 1.5 orders of magnitude. • Effect of temperature on structure and microstructure was investigated

  15. Atomic Layer Deposition of Bismuth Vanadates for Solar Energy Materials.

    Science.gov (United States)

    Stefik, Morgan

    2016-07-01

    The fabrication of porous nanocomposites is key to the advancement of energy conversion and storage devices that interface with electrolytes. Bismuth vanadate, BiVO4 , is a promising oxide for solar water splitting where the controlled fabrication of BiVO4 layers within porous, conducting scaffolds has remained a challenge. Here, the atomic layer deposition of bismuth vanadates is reported from BiPh3 , vanadium(V) oxytriisopropoxide, and water. The resulting films have tunable stoichiometry and may be crystallized to form the photoactive scheelite structure of BiVO4 . A selective etching process was used with vanadium-rich depositions to enable the synthesis of phase-pure BiVO4 after spinodal decomposition. BiVO4 thin films were measured for photoelectrochemical performance under AM 1.5 illumination. The average photocurrents were 1.17 mA cm(-2) at 1.23 V versus the reversible hydrogen electrode using a hole-scavenging sulfite electrolyte. The capability to deposit conformal bismuth vanadates will enable a new generation of nanocomposite architectures for solar water splitting. PMID:27246652

  16. Study of barium bismuth titanate prepared by mechanochemical synthesis

    Directory of Open Access Journals (Sweden)

    Lazarević Z.Ž.

    2009-01-01

    Full Text Available Barium-bismuth titanate, BaBi4Ti4O15 (BBT, a member of Aurivillius bismuth-based layer-structure perovskites, was prepared from stoichiometric amounts of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Mechanochemical synthesis was performed in air atmosphere in a planetary ball mill. The reaction mechanism of BaBi4Ti4O15 and the preparation and characteristics of BBT ceramic powders were studied using XRD, Raman spectroscopy, particle analysis and SEM. The Bi-layered perovskite structure of BaBi4Ti4O15 ceramic forms at 1100 °C for 4 h without a pre-calcination step. The microstructure of BaBi4Ti4O15 exhibits plate-like grains typical for the Bi-layered structured material and spherical and polygonal grains. The Ba2+ addition leads to changes in the microstructure development, particularly in the change of the average grain size.

  17. Aerosol deposition of (Cu,Ti) substituted bismuth vanadate films

    Energy Technology Data Exchange (ETDEWEB)

    Exner, Jörg, E-mail: Functional.Materials@Uni-Bayreuth.de [University of Bayreuth, Department of Functional Materials, Universitätsstraße 30, 95440 Bayreuth (Germany); Fuierer, Paul [Materials and Metallurgical Engineering Department, New Mexico Institute of Mining and Technology, Socorro, NM 87801 (United States); Moos, Ralf [University of Bayreuth, Department of Functional Materials, Universitätsstraße 30, 95440 Bayreuth (Germany)

    2014-12-31

    Bismuth vanadate, Bi{sub 4}V{sub 2}O{sub 11}, and related compounds with various metal (Me) substitutions, Bi{sub 4}(Me{sub x}V{sub 1−x}){sub 2}O{sub 11−δ}, show some of the highest ionic conductivities among the known solid oxide electrolytes. Films of Cu and Ti substituted bismuth vanadate were prepared by an aerosol deposition method, a spray coating process also described as room temperature impact consolidation. Resultant films, several microns in thickness, were dense with good adhesion to the substrate. Scanning electron microscopy and high temperature X-ray diffraction were used to monitor the effects of temperature on the structure and microstructure of the film. The particle size remained nano-scale while microstrain decreased rapidly up to 500 °C, above which coarsening and texturing increased rapidly. Impedance measurements of films deposited on inter-digital electrodes revealed an annealing effect on the ionic conductivity, with the conductivity exceeding that of a screen printed film, and approaching that of bulk ceramic. - Highlights: • Cu and Ti doped bismuth vanadate films were prepared by aerosol deposition (AD). • Dense 3–5 μm thick films were deposited on alumina, silicon and gold electrodes. • Annealing of the AD-layer increases the conductivity by 1.5 orders of magnitude. • Effect of temperature on structure and microstructure was investigated.

  18. Properties of lead-bismuth coolant and perspectives of non-electric applications of lead-bismuth reactor

    International Nuclear Information System (INIS)

    Key physical and chemical properties of lead-bismuth eutectic alloy are reviewed. Based on the low chemical activity of the alloy to other work media, a new concept of direct contact heat exchangers is proposed. A series of experiments were performed to validate the concept, using water, model salt solutions of sodium chloride, and oil. Key experimental results are summarized in the report. (author)

  19. Bismuth Propellant Feed System Development at NASA-MSFC

    Science.gov (United States)

    Polzin, Kurt A.

    2007-01-01

    NASA-MSFC has been developing liquid metal propellant feed systems capable of delivering molten bismuth at a prescribed mass flow rate to the vaporizer of an electric thruster. The first such system was delivered to NASA-JPL as part of the Very High Isp Thruster with Anode Layer (VHITAL) program. In this system, the components pictured were placed in a vacuum chamber and heated while the control electronics were located outside the chamber. The system was successfully operated at JPL in conjunction with a propellant vaporizer, and data was obtained demonstrating a new liquid bismuth flow sensing technique developed at MSFC. The present effort is aimed at producing a feed-system for use in conjunction with a bismuth-fed Hall thruster developed by Busek Co. Developing this system is more ambitious, however, in that it is designed to self-contain all the control electronics inside the same vacuum chamber as an operating bismuth-fed thruster. Consequently, the entire system, including an on-board computer, DC-output power supplies, and a gas-pressurization electro-pneumatic regulator, must be designed to survive a vacuum environment and shielded to keep bismuth plasma from intruding on the electronics and causing a shortcircuit. In addition, the hot portions of the feed system must be thermally isolated from the electronics to avoid failure due to high heat loads. This is accomplished using a thermal protection system (TPS) consisting of multiple layers of aluminum foil. The only penetrations into the vacuum chamber are an electrically isolated (floating) 48 VDC line and a fiberoptic line. The 48 VDC provides power for operation of the power supplies and electronics co-located with the system in the vacuum chamber. The fiberoptic Ethernet connection is used to communicate user-input control commands to the on-board computer and transmit real-time data back to the external computer. The partially assembled second-generation system is shown. Before testing at Busek, a

  20. Improved lead and bismuth (n,{gamma}) cross sections and their astrophysical impact

    Energy Technology Data Exchange (ETDEWEB)

    Domingo-Pardo, C.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapico, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kiappeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    A series of (n,{gamma}) neutron capture measurements on the lead isotopes and bismuth have been carried out at the CERN n-TOF installation in the neutron energy range from 1 eV up to 1 MeV. At n-TOF, contaminations due to scattered neutrons were reduced down to a negligible level by using improved {gamma}-ray detectors with very low neutron sensitivity. The background level has been determined precisely from a complementary measurement. Other experimental effects related to the electronic threshold in the detectors and the angular distribution of the prompt {gamma}-rays were investigated via Monte Carlo simulations and could be taken into account in the analysis of the capture data. With this set of measurements the energy differential (n,{gamma}) cross sections of {sup 204,206,207}Pb and {sup 209}Bi have been determined with good accuracy. The information obtained in this work becomes of interest for constraining r-process calculations and in particular for the Th/U cosmo-chronometer. (authors)

  1. Improved lead and bismuth (n,γ) cross sections and their astrophysical impact

    International Nuclear Information System (INIS)

    A series of (n,γ) neutron capture measurements on the lead isotopes and bismuth have been carried out at the CERN n-TOF installation in the neutron energy range from 1 eV up to 1 MeV. At n-TOF, contaminations due to scattered neutrons were reduced down to a negligible level by using improved γ-ray detectors with very low neutron sensitivity. The background level has been determined precisely from a complementary measurement. Other experimental effects related to the electronic threshold in the detectors and the angular distribution of the prompt γ-rays were investigated via Monte Carlo simulations and could be taken into account in the analysis of the capture data. With this set of measurements the energy differential (n,γ) cross sections of 204,206,207Pb and 209Bi have been determined with good accuracy. The information obtained in this work becomes of interest for constraining r-process calculations and in particular for the Th/U cosmo-chronometer. (authors)

  2. Distribution and surface enrichment of radionuclides in lead-bismuth eutectic from spallation targets

    Science.gov (United States)

    Hammer-Rotzler, Bernadette; Neuhausen, Jörg; Boutellier, Viktor; Wohlmuther, Michael; Zanini, L.; David, J.-C.; Türler, Andreas; Schumann, Dorothea

    2016-07-01

    With the development of new high-power neutron spallation sources --both for scientific application and as neutron production tool for accelerator-driven systems-- the demand for experimentally obtained nuclear data on the residue nuclei production in the target is constantly increasing. In the present work, we examined two lead-bismuth-eutectic targets, irradiated with high-energy protons, concerning their radionuclide content and the spatial distribution of selected isotopes. The first one was the so-called ISOLDE target, being irradiated with 1-1.4GeV protons at CERN-ISOLDE, the second one was the MEGAPIE target, irradiated at PSI with 590MeV protons. In particular, we investigated the phenomenon of radionuclide enrichment on free surfaces in both targets. It turned out that considerable accumulation can be found especially in the case of lanthanides. The depletion process is enhanced at increased temperatures. The results are compared with theoretical predictions; some possible consequences of the findings are illustrated.

  3. Unusual anti-thermal degradation of bismuth NIR luminescence in bismuth doped lithium tantalum silicate laser glasses.

    Science.gov (United States)

    Tan, Linling; Wang, Liping; Peng, Mingying; Xu, Shanhui; Zhang, Qinyuan

    2016-08-01

    For application of bismuth laser glasses in either fiber amplifier or laser, their performance stability in long run should be understood especially in extreme conditions. However, so far, there are few reports on it. Here, we found, after the cycle experiments on heating and cooling, that the proper increase of lithium content in lithium tantalum silicate laser glass can lead to unusual anti-thermal degradation of bismuth NIR luminescence, which completely differs from the scenario in germanate glass. FTIR, 29Si MAS NMR spectra, absorption and dynamic photoluminescence spectra are employed to unravel how this happens. The results illustrate that it should be due to the decrease of polymerization of silicate glass network, which in turn allows the regeneration at 250°C, and therefore, the content increase of bismuth NIR emission centers. In the meanwhile, we noticed though Bi luminescence can be thermally quenched its peak does not shift along with temperature, which seldom appears in laser materials. The unique property might guarantee the unshift of Bi fiber laser wavelength once such glass was made into fiber devices even as the environmental temperature changes. The role of lithium is discussed in the evolution of glass structures, the suppression of glass heterogeneity, and the thermal stability of Bi luminescence, and it should be helpful to design homogeneous silicate laser glass with outstanding thermal stability. PMID:27505827

  4. Study on corrosion test techniques in lead bismuth eutectic flow. Joint research report in JFY2002

    International Nuclear Information System (INIS)

    The evaluation of corrosion behaviors of core and structural materials in lead bismuth eutectic is one of the key issues for the utilization of lead bismuth eutectic as a coolant of the primary loops of lead bismuth cooled fast breeder reactors (FBRs) and the intermediate heat transport media of new-type steam generators of the sodium cooled FBRs. The purpose of the present study is to establish corrosion test techniques in lead bismuth eutectic flow. The techniques of steel corrosion test and oxygen control in flowing lead bismuth eutectic, and the technologies of a lead bismuth flow test at high temperature and high velocity were developed through corrosion test using a lead bismuth flow test loop of the Tokyo Institute of Technology in JFY2002. The major results are summarized as follows: (1) Techniques of fabrication, mount and rinse of corrosion specimens, measurement method of weight loss, and SEM/EDX analysis method have been established through lead bismuth corrosion test. (2) Weight losses were measured, corrosion and lead bismuth-adhered layers and eroded parts were observed in two 1000 hr-corrosion tests, and the results were compared with each other for twelve existing steels including ODS, F82H and SUH-3. (3) An oxygen sensor made of zirconia electrolyte structurally resistant to thermal stress and thermal shock was developed and tested in the lead bismuth flow loop. Good performance has been obtained. (4) An oxygen control method by injecting argon and hydrogen mixture gas containing steam into lead bismuth was applied to the lead bismuth flow loop, and technical issues for the development of the oxygen control method were extracted. (5) Technical measures for freezing and leakage of lead bismuth in the flow loop were accumulated. (6) Technical measures for flow rate decrease/blockage due to precipitation of oxide and corrosion products in a low temperature section of the lead bismuth flow loop were accumulated. (7) Electromagnetic flow meters with MI

  5. The accurate determination of bismuth in lead concentrates and other non-ferrous materials by AAS after separation and preconcentration of the bismuth with mercaptoacetic acid.

    Science.gov (United States)

    Howell, D J; Dohnt, B R

    1982-05-01

    A method for determining 0.0001% and upwards of bismuth in lead, zinc or copper concentrates, metals or alloys and other smelter residues is described. Bismuth is separated from lead, iron and gangue materials with mercaptoacetic acid after reduction of the iron with hydrazine. Large quantities of tin can be removed during the dissolution. An additional separation is made for materials high in copper and/or sulphate. The separated and concentrated bismuth is determined by atomic-absorption spectrometry using the Bi line at 223.1 nm. The proposed method also allows the simultaneous separation and determination of silver. PMID:18963145

  6. Arkachan: A new gold-bismuth-siderite-sulfide type of deposits in the West Verkhoyansky tin district, Yakutia

    Science.gov (United States)

    Gamyanin, G. N.; Vikent'eva, O. V.; Prokof'ev, V. Yu.; Bortnikov, N. S.

    2015-11-01

    The formation sequence of orebodies, chemical composition of gangue and ore minerals, fluid inclusions, REE patterns, 40Ar/39Ar isotopic age, and relationships of stable isotopes (C, O, S) in minerals of the Arkachan gold-bismuth-siderite-sulfide deposit have been studied. The deposit has been localized in the Kuranakh Anticlinorium of the Verkhoyansky Fold-Nappe Belt at the intersection of the near-meridional Kygyltas and the NE-trending North Tirekhtyakh faults. The orebodies are extended (>2 km) and steeply dipping zones of veins and veinlets are hosted in Carbonaceous and Permian sandstones and siltstones deformed in anticlines and cut through by dikes pertaining to diorite-granodiorite-granite association. The deposit was formed during hydrothermal-metamorphic, productive main gold, silver-polymetallic, and silver-antimony stages. The orebodies are largely composed of quartz and siderite; arsenopyrite, pyrite, and pyrrhotite are widespread; bismuthinite, chalcopyrite, sphalerite, galena, and bismuth sulfosalts (gustavite, cosalite, matildite) are less abundant. The REE patterns of carbonates and quartz are characterized by a negative Eu anomaly. Three types of fluid inclusions (FI) in quartz and carbonates are distinguished: (I) liquid H2O + CO2 ± CH4 + NaCl, (II) gaseous CO2 ± CH4, and (III) aqueous salt solutions. The homogenization temperature and salinity of FI I vary from 385 to 280°C and 18.8 to 26.2 wt % NaCl equiv, respectively, whereas in FI III these parameters vary from 261 to 324°C and 3.7 to 9.5 wt % NaCl equiv. The pressure is estimated at 1830 to 1060 bar. The δ18O of quartz II associated with siderite I, native gold, and sulfosalts changes from +13.6 to 16.3‰(SMOW); δ18O and δ13C of siderite I related to gold-ore stage vary from +13.6 to +17.7‰ (SMOW) and from-6.0 to-3.0 (PDB). A wide range of δ34S from-5.7 to 16.0‰ (CDT) has been obtained for sulfides. The isotopic 40Ar/39Ar age of muscovite is 101.9 ± 1.4 Ma. The isotopic

  7. Selective oxidation of propylene to acrolein by silica-supported bismuth molybdate catalysts

    DEFF Research Database (Denmark)

    Duc, Duc Truong; Ha, Hanh Nguyen; Fehrmann, Rasmus;

    2011-01-01

    Silica-supported bismuth molybdate catalysts have been prepared by impregnation, structurally characterized and examined as improved catalysts for the selective oxidation of propylene to acrolein. Catalysts with a wide range of loadings (from 10 to 90 wt%) of beta bismuth molybdate (β-Bi2Mo2O9) w...

  8. Attenuation and image quality in the use of protective bismuth in chest CT scans

    International Nuclear Information System (INIS)

    For chest CT scans are protective of bismuth (Bi) with the aim of reducing the dose in the breast. The aim of this study was to evaluate the attenuation with thermoluminescent dosimeters in the glandular dose average when using these protective breast CT scans and to evaluate the image quality with and without protective Bismuth.

  9. Electronic Properties of Tin and Bismuth from Angular Correlation of Annihilation Photons

    DEFF Research Database (Denmark)

    Mogensen, O.E.; Trumpy, Georg

    1969-01-01

    liquid-metal curves are smaller and of another form than the tails of polycrystalline curves; no Gaussian with only one adjustable constant factor can give a fit to both tails. No useful method for interpreting liquid-metal angular-correlation curves seems to exist. Two deformed bismuth samples gave......A linear slit setup has been used to obtain results of angular-correlation measurements in (a) tin single crystals in three orientations: [001], [100], and [110], (b) bismuth single crystals in four orientations: [111], [100], [1¯10], and [2¯1¯1], (c) solid and liquid tin and bismuth, and (d......) deformed bismuth. For both metals, the single-crystal angular-correlation curves lie near to the free-electron parabola. The tin curves show more anisotropy than the bismuth curves. An important result is the clear anisotropy found in the high-momentum part of the curves—the tails—for both metals. Little...

  10. Conduction mechanism in bismuth silicate glasses containing titanium

    International Nuclear Information System (INIS)

    Bismuth silicate glasses mixed with different concentrations of titanium dioxide having compositions xTiO2–(60−x)Bi2O3–40SiO2 with x=0, 5, 10, 15 and 20 were prepared by the normal melt quench technique. The frequency dependence of the ac electrical conductivity of different compositions of titanium bismuth silicate glasses has been studied in the frequency range 10−1 Hz to 10 MHz and in the temperature range 623–703 K. The temperature and frequency dependent conductivity is found to obey Jonscher's universal power law for all the compositions of titanium bismuth silicate glass system. The dc conductivity (σdc), so called crossover frequency (ωH), and frequency exponent (s) have been estimated from the fitting of experimental data of ac conductivity with Jonscher's universal power law. Enthalpy to dissociate the cation from its original site next to a charge compensating center (Hf) and enthalpy of migration (Hm) have also been estimated. The conductivity data have been analyzed in terms of different theoretical models to determine the possible conduction mechanism. Analysis of the conductivity data and the frequency exponent shows that the correlated barrier hopping of electrons between Ti3+ and Ti4+ ions in the glasses is the most favorable mechanism for ac conduction. The temperature dependent dc conductivity has been analyzed in the framework of theoretical variable range hopping model (VRH) proposed by Mott which describe the hopping conduction in disordered semiconducting systems. The various polaron hopping parameters have also been deduced. Mott's VRH model is found to be in good agreement with experimental data and the values of inverse localization length of s-like wave function (α) obtained by this model with modifications suggested by Punia et al. are close to the ones reported for a number of oxide glasses

  11. Effect of FGMs on thermoelectric cooling properties of bismuth telluride

    International Nuclear Information System (INIS)

    Every thermoelectric material shows high performance at a specific narrow temperature range. The temperature range with high performance can be expanded by joining the materials with different peak temperature. This is the concept of an FGM. The FGMs for Peltier cooling materials have never been reported though the FGMs for thermoelectric power generation were reported to enhance conversion efficiency. Bismuth telluride is the best material for cooling devices at around room temperature. Then we investigated the thermoelectric cooling properties for bismuth telluride with two steps graded structure FGM. Two kinds of melt-grown materials of p-type bismuth telluride (hereafter, sample 1 and sample 2) were used. The samples 1 and 2 of 3 mm square x 2.5 mm were joined to form an FGM of 3 mm square x 5 mm in length by soldering with ultrasonic vibration. Thermoelectric cooling properties were evaluated by observing the maximum temperature drop to electric current when the high temperature side was kept constant. When the high temperature side is kept at 370 K, the temperature drop of the monolithic sample 1 was 34.6 K, and 39.7 K for sample 2, because of the difference of the carrier density. In the case of the FGM, the temperature drop was 45.2 K when the sample 1 was placed at the high temperature side. On the other hand, the temperature drop was only 27.6 K when the sample 2 was placed at the high temperature side. From these results, it is clear that high performance can be obtained by forming an FGM when the proper material arrangement is performed along the temperature gradient. (orig.)

  12. Yttrium bismuth titanate pyrochlore mixed oxides for photocatalytic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Merka, Oliver

    2012-10-18

    In this work, the sol-gel synthesis of new non-stoichiometric pyrochlore titanates and their application in photocatalytic hydrogen production is reported. Visible light response is achieved by introducing bismuth on the A site or by doping the B site by transition metal cations featuring partially filled d orbitals. This work clearly focusses on atomic scale structural changes induced by the systematical introduction of non-stoichiometry in pyrochlore mixed oxides and the resulting influence on the activity in photocatalytic hydrogen production. The materials were characterized in detail regarding their optical properties and their atomic structure. The pyrochlore structure tolerates tremendous stoichiometry variations. The non-stoichiometry in A{sub 2}O{sub 3} rich compositions is compensated by distortions in the cationic sub-lattice for the smaller Y{sup 3+} cation and by evolution of a secondary phase for the larger Bi{sup 3+} cation on the A site. For TiO{sub 2} rich compositions, the non-stoichiometry leads to a special vacancy formation in the A and optionally O' sites. It is shown that pyrochlore mixed oxides in the yttrium bismuth titanate system represent very active and promising materials for photocatalytic hydrogen production, if precisely and carefully tuned. Whereas Y{sub 2}Ti{sub 2}O{sub 7} yields stable hydrogen production rates over time, the bismuth richer compounds of YBiTi{sub 2}O{sub 7} and Bi{sub 2}Ti{sub 2}O{sub 7} are found to be not stable under irradiation. This drawback is overcome by applying a special co-catalyst system consisting of a precious metal core and a Cr{sub 2}O{sub 3} shell on the photocatalysts.

  13. Determination of lead-210 in bottom sediments via bismuth-210

    International Nuclear Information System (INIS)

    Determination of lead-210 in bottom sediments is applied for evaluation of sedimentation rates and sediments ages by concentration profiles of disequilibrated lead-210 from atmospheric sources. Advances in low level liquid scintillation spectrometry (LS) fitted for natural radioactivity measurements, permit to combine the possibility of immediate bismuth-210 separation with its radioactivity registration using LS spectrometer Quantulus (LKS-1220, Wallak, Finland). The method was tested on bottom sediment samples from Baltic Sea shelf, collected during the 76th cruise of RV 'Academician S. Vavilov'. (author) 6 refs.; 1 tab

  14. Thermal stimulation of exoelectronic emission in bismuth germanate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kalent' ev, V.A.; Kargin, V.F.; Kargin, Yu.F.; Kortov, V.S.; Skorikov, V.M.; Shul' gin, B.V.

    1987-08-01

    A systematic study of the properties of Bi/sub 4/Ge/sub 3/O/sub 12/ (BGO) indicates that these crystals, along with photoemission (luminescence and scintillation) show exoelectronic emission following thermal excitation from x-ray irradiation. Samples of BGO studied in this paper were grown by the Czochralski method. It is found that the relationship between exoemission in BGO and ordinary GeO/sub 2/ indicates the dominant role played by perturbation of the germanium oxide sublattice in the emission process in bismuth germanate.

  15. Thermal-hydraulics of lead bismuth for accelerator driven systems

    International Nuclear Information System (INIS)

    Full text of publication follows: Lead bismuth has been selected as one of the most suitable coolants to be used in accelerator driven systems (ADS) for transmutation of minor actinides. It serves both, as a target material of the spallation source to balance the neutron economy, and as a coolant with high thermal inertia to provide a safe and reliable heat transfer to the secondary power cycle. With the aim to develop the required technologies to enable the later design of such ADS systems, the Karlsruhe Lead bismuth LAboratory KALLA, consisting of three test loops, has been built and set into operation at the Forschungszentrum Karlsruhe since 2000, keeping more than 45 t of PbBi in operation at temperatures up to 550 deg. C. The test program includes oxygen control systems, heat flux simulation tools, electro-magnetic and mechanical pump technologies, heat transfer and flow measurements, reliability and corrosion tests. In a first test campaign, a technology loop called THESYS was built to develop measurement technologies for the acquisition of scalar quantities, like pressures, temperatures, concentrations, and flow rates, as well as velocity fields, which are required for both operational and scientific purposes. THESYS also allowed to perform generic turbulent heat transfer experiments necessary to provide liquid metal adapted turbulent heat transfer models for ADS design analyses. The second loop, the thermalhydraulic loop THEADES with an installed power of 2.5 MW, has been built to conduct prototypical component experiments for beam windows (e.g. MEGAPIE or MYHRRA) or fuel rod configurations. First test results will be reported. The experimental team is supported by a numerical team who studied the thermal hydraulics of the tested components in order to enable a later transfer of the results to industrial systems. Three different types of codes are being improved: lumped parameter codes (e.g. ATHLET) to perform system analyses for lead bismuth in loops

  16. Colloidal bismuth subcitrate in non-ulcer dyspepsia.

    OpenAIRE

    Khanna M; Abraham P; Nair N; Mistry F; Vora I

    1992-01-01

    The effect of colloidal bismuth subcitrate (De-Nol) on symptoms, Helicobacter pylori status and histological features was studied in 35 patients with non-ulcer dyspepsia. Pain (34 cases) and gas bloat (18) were the predominant symptoms. H pylori was present in 26 (74.3%) patients. Gastritis and duodenitis were present in 29 of 32 and 22 of 31 cases respectively in whom biopsies were available. Relief in symptoms after treatment was seen in 29 (82.8%) cases. Improvement in gastri...

  17. Fano interference for large-amplitude coherent phonons in bismuth

    International Nuclear Information System (INIS)

    We report femtosecond time-resolved measurements of lattice dynamics in bismuth made over a wide range of temperatures and excitation levels. We demonstrate that time-integrated Fourier transforms for both the fully symmetric A1g and doubly degenerate Eg coherent oscillations of large amplitude exhibit asymmetric line shapes described by the Fano formula. Measuring the real and imaginary part of the phonon self-energy, we attempt to identify the nature of the continuum responsible for the configuration mixing. Based on the measured pump and temperature dependences, we suggest that the continuum responsible for the interference includes both the electronic and lattice degrees of freedom

  18. Melting and solidification of bismuth inclusions in aluminium

    DEFF Research Database (Denmark)

    Thoft, N.B.; Bohr, J.; Buras, B.;

    1995-01-01

    experimental methods (and on different samples) agree remarkably well. The inclusions melt at temperatures at or below the bismuth bulk melting point, and the solid/liquid phase transition exhibits a hysteresis of 100-150 K. Average inclusion sizes ranged from a few nm to some tens of nm. The x-ray diffraction...... melting data are discussed in relation to different existing models for the melting temperature of an inclusion as a function of its size. From this an approximate size distribution for the inclusions is derived....

  19. Gamma-ray attenuation coefficients in bismuth borate glasses

    International Nuclear Information System (INIS)

    Mass attenuation coefficients of glasses in the system: xBi2O3(1-x)B2O3 (x=0.30, 0.35, 0.40, 0.45 and 0.55) were determined at 356, 662, 1173 and 1332 keV photon energies using a narrow beam transmission method. Appreciable variations were observed in these coefficients due to changes in the chemical composition of glasses. These coefficients were then used to determine effective atomic numbers of glass samples, which were found to be constant with bismuth concentration and energy

  20. STM observation of twin microlayers on cleaved bismuth surfaces

    Science.gov (United States)

    Edel'man, V. S.

    1996-02-01

    Scanning tunneling microscopy of cleaved bismuth surfaces at low temperatures revealed the presence of thin twin microlayers, whose width ∼70 Å is determined by the fact that the height gained in crossing such a microlayer due to its tilt with respect to the surface of the undisturbed crystal equals the interlunar distance in the [0001] direction. The microlayers were strictly aligned with the surface atomic rows. Their lengths were macroscopically large, being no smaller than a few fractions of a micron. It was found that, near the microlayer boundaries, the electron properties were significantly different from those at other points on the surface.

  1. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  2. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  3. Investigation of corrosion, water reaction, polonium evaporation and bismuth resource in liquid metal lead-bismuth technology

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Hideki; Takizuka, Takakazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kitano, Teruaki [Mitsui Shipbuilding and Engineering Co. Ltd., Tokyo (Japan)

    2000-10-01

    Lead-bismuth is the first candidate material for liquid metal target find coolant of fueled blanket system in accelerator-driven system (ADS) studied at JAERI. Advantages of the lead-bismuth utilization are non-active material, very low capture cross section, low melting point of 125degC and high boiling point of 1670degC, and beside coolant void reactivity become negative. But problems are due to the high corrosivity to most of the structural materials and the corrosive data are scarcity. In this report, corrosivity, reaction with water, thermal-hydraulics, chemical toxicity etc. are studied by investigating some facilities utilized and researched really for lead or lead-bismuth. And, furthermore, polonium evaporation rate and bismuth resource are investigated. Main results obtained are as follows: (1) In a refinery, there are enough employment experience for liquid Pb-Bi in period of about 17 years and not corrosion for the thermal conductive materials (1Cr-0.5Mo steel) used under the condition of natural convection with temperature around 400degC. (2) In Russia, extensive experience in the use as Russian submarines and in R and D during about 50 years are available. And as a result, it will be able to lead approximately zero corrosion for Cr-Si materials by adjusting oxygen film with oxygen concentration control between 10{sup -7} to 10{sup -5}% mass. However, the corrosion data are not enough systematically collected involving them in radiation dose field. (3) In liquid-dropping experiment, it is shown that interaction between water and high temperature liquid Pb-Bi is reduced steeply with rising of atmosphere pressure. But, in order to design the second circuit removal model of ADS, the interaction should be evaluated by water continuous injection experiment. (4) Polonium forms PbPo in Pb-Bi, and the evaporation rate become less three factor than that of Po, and furthermore, the rate decreases in the atmosphere. The effects of Po on employee and environment

  4. Investigation of corrosion, water reaction, polonium evaporation and bismuth resource in liquid metal lead-bismuth technology

    International Nuclear Information System (INIS)

    Lead-bismuth is the first candidate material for liquid metal target find coolant of fueled blanket system in accelerator-driven system (ADS) studied at JAERI. Advantages of the lead-bismuth utilization are non-active material, very low capture cross section, low melting point of 125degC and high boiling point of 1670degC, and beside coolant void reactivity become negative. But problems are due to the high corrosivity to most of the structural materials and the corrosive data are scarcity. In this report, corrosivity, reaction with water, thermal-hydraulics, chemical toxicity etc. are studied by investigating some facilities utilized and researched really for lead or lead-bismuth. And, furthermore, polonium evaporation rate and bismuth resource are investigated. Main results obtained are as follows: (1) In a refinery, there are enough employment experience for liquid Pb-Bi in period of about 17 years and not corrosion for the thermal conductive materials (1Cr-0.5Mo steel) used under the condition of natural convection with temperature around 400degC. (2) In Russia, extensive experience in the use as Russian submarines and in R and D during about 50 years are available. And as a result, it will be able to lead approximately zero corrosion for Cr-Si materials by adjusting oxygen film with oxygen concentration control between 10-7 to 10-5% mass. However, the corrosion data are not enough systematically collected involving them in radiation dose field. (3) In liquid-dropping experiment, it is shown that interaction between water and high temperature liquid Pb-Bi is reduced steeply with rising of atmosphere pressure. But, in order to design the second circuit removal model of ADS, the interaction should be evaluated by water continuous injection experiment. (4) Polonium forms PbPo in Pb-Bi, and the evaporation rate become less three factor than that of Po, and furthermore, the rate decreases in the atmosphere. The effects of Po on employee and environment will not be

  5. Synthesis and characterization of bismuth alkaline titanate powders

    International Nuclear Information System (INIS)

    In this work, samples of bismuth alkaline titanate, (K0.5Na0.5)(2-x/2)Bi(x/6)TiO3, (x = 0.05-0.75) have been prepared by conventional ceramic technique and molten salts. Metal oxides or carbonates powders were used as starting raw materials. The crystalline phase of the synthesized powders was identified by the X-ray diffraction (XRD) and particle morphology was characterized by scanning electron microscopy (SEM). Solid state reaction method was unsuccessful to obtain pellets. From XRD results, a rhombohedral structure was detected and the parameter lattice were estimated to be a = 5.5478 A and α = 59.48o. These parameters were used to refine the structure by Rietveld analysis. SEM results showed several morphologies. Apparently, bismuth is promoting the grain growth whose sizes vary from 30 nm to 180 nm It is expected that these materials can be utilized in practical applications as substitutes for lead zirconatetitanate (PZT)-based ceramics.

  6. Production of bismuth germanate ceramic scintillators by combustion synthesis route

    International Nuclear Information System (INIS)

    The present work presents the results from production of ceramic scintillator Bi4Ge3O12 (bismuth germanate – BGO), which is very sensitive to beta, gamma and X-rays. The production route adopted was combustion synthesis. In this route, the precursors germanium oxide and bismuth nitrate were mixed to urea, used as fuel, and heated up to the ignition temperature, 500 °C. The ignition starts an exothermic reaction that promotes the formation of the desired crystalline phase. It was observed a dependency of the agglomeration of the synthesized powders upon the pH of the initial mixture. The pH was controlled through the addition of ammonium dioxide, and was varied from zero up to 9. Intermediate crystalline phases were observed by DRX measurements of the product of the combustion reaction. After calcination at 600 °C/24 h, the Bi12GeO20 content was enhanced. The optimum conditions of synthesis and sintering of the samples were determined through auxiliary techniques such as DTA and SEM. The synthesized powders presented particle size near 10 nm, whereas the sintered grains reached near 2 μm. The relative density of sintered ceramics, obtained from Archimedes’ method, was 96%. (author)

  7. Field-induced polarization of Dirac valleys in bismuth

    Science.gov (United States)

    Behnia, Kamran; Zhu, Zengwei; Callaudin, Aurelie; Fauque, Benoit; Kang, Woun

    2012-02-01

    The principal challenge in the field of ``valleytronics'' is to lift the valley degeneracy of electrons in a controlled way. In graphene, a number of methods to generate a valley-polarized flow of electrons have been proposed, which are yet to be experimentally realized. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high-symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. We present a study of angle-dependent magnetoresistance in bismuth which shows that a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. The effect is visible even at room temperature. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. At high temperature and low magnetic field, the three valleys are interchangeable and the three-fold symmetry of the underlying lattice is respected. As the temperature is decreased or the magnetic field increased, this symmetry is spontaneously lost. This loss may be an experimental manifestation of the recently proposed valley-nematic Fermi liquid state.

  8. Electrodeposition of bismuth alloys by the controlled potential method

    International Nuclear Information System (INIS)

    We worked with the electrodeposition of three bismuth alloys, the composition of the first electrolyte was: 0.3 g/l. Bi; 20 g/l. Ni; and the conditions were pH = 5.2 - 5.6; T = 25 Centigrade degrees; current density 0.3 A / dm2 - 6.6 A / dm2. Following alloy was between Bi - Pb, composition of the electrolyte was 3.18 g/l. Bi (metallic); 31.81 g/l. Pb (Pb(NO3)2) pH : 1; T = 20 Centigrade degrees; current density 10.20 A/dm2 . The third electrolyte was Bi-Cu, its composition was: 20.89 g/l. Bi; (metallic) 63.54 g/l Cu (Cu(NO3)2) pH : 1.5 - 1.8; T = 25-30 Centigrade degrees; current density 1-2 A/dm2 . The best results were obtained with the third electrolyte. The purpose of this work was to experiment with different parameters like temperature, pH and the electrolyte concentration to obtain a bismuth alloy. (Author)

  9. Magnetic anisotropies in ultrathin bismuth iron garnet films

    International Nuclear Information System (INIS)

    Ultrathin bismuth iron garnet Bi3Fe5O12 films were grown epitaxially on (001)-oriented gadolinium gallium garnet substrates. Film thickness varied from two to three dozens of unit cells. Bi3Fe5O12 films grow pseudomorphically on substrates up to a thickness of 20 nm, and then a lattice relaxation occurs. Magnetic properties of the films were studied as a function of bismuth iron garnet thickness. The magnetization and cubic anisotropy decrease with decreasing film thickness. The uniaxial magnetocrystalline anisotropy is constant for all film thicknesses. For two unit cell thick films, the easy magnetization axis changes from in-plane to perpendicular to the plane direction. Such a reorientation takes place as a result of the competition of constant uniaxial perpendicular anisotropy with weakening film magnetization. - Highlights: ► Ultrathin Bi3Fe5O12 films were grown epitaxially on structure-matching substrates. ► Magnetic properties of Bi3Fe5O12 were studied down to the thickness of 2.5 nm. ► Reorientation of easy magnetization axis as a function of film thickness was observed

  10. Layered bismuth oxyhalide nanomaterials for highly efficient tumor photodynamic therapy

    Science.gov (United States)

    Xu, Yu; Shi, Zhenzhi; Zhang, Ling'e.; Brown, Eric Michael Bratsolias; Wu, Aiguo

    2016-06-01

    Layered bismuth oxyhalide nanomaterials have received much more interest as promising photocatalysts because of their unique layered structures and high photocatalytic performance, which can be used as potential inorganic photosensitizers in tumor photodynamic therapy (PDT). In recent years, photocatalytic materials have been widely used in PDT and photothermal therapy (PTT) as inorganic photosensitizers. This investigation focuses on applying layered bismuth oxyhalide nanomaterials toward cancer PDT, an application that has never been reported so far. The results of our study indicate that the efficiency of UV-triggered PDT was highest when using BiOCl nanoplates followed by BiOCl nanosheets, and then TiO2. Of particular interest is the fact that layered BiOCl nanomaterials showed excellent PDT effects under low nanomaterial dose (20 μg mL-1) and low UV dose (2.2 mW cm-2 for 10 min) conditions, while TiO2 showed almost no therapeutic effect under the same parameters. BiOCl nanoplates and nanosheets have shown excellent performance and an extensive range of applications in PDT.

  11. Mechanically activating formation of layered structured bismuth titanate

    International Nuclear Information System (INIS)

    Bismuth titanate-Bi4Ti3O12 (BIT) with wide application in the electronic industry as capacitors, memory devices and sensors is the simplest compound in the Aurivillius family, which consists of (Bi2O2)2+ sheets alternating with (Bi2Ti3O10)2- perovskite-like layers. The synthesis of more resistive BIT ceramics would be preferable advance in obtaining of well-densified ceramic with small grains randomly oriented to limit the conductivity along the (Bi2O2)2+ layers. Having in mind that the conventional ceramic route for the synthesis can lead to non-stoichiometry in composition, in consequence of the undesirable loss in bismuth content through volatilization of Bi2O3 at elevated temperature, our efforts were addressed to preparation of BIT by mechanical activation the constituent oxides. The nucleation and phase formation of BIT, crystal structure, microstructure, powder particle size and specific surface area were followed by XRD, Rietveld refinement analysis, thermal analysis, scanning electron microscopy (SEM) and the BET specific surface area measurements

  12. Genotoxic effects of bismuth (III oxide nanoparticles by comet assay

    Directory of Open Access Journals (Sweden)

    Reecep Liman

    2015-06-01

    Full Text Available Bismuth oxide is one of the important transition metal oxides and it has been intensively studied due to their peculiar characteristics (semiconductor band gap, high refractive index, high dielectric permittivity, high oxygen conductivity, resistivity, photoconductivity and photoluminescence etc.. Therefore, it is used such as microelectronics, sensor technology, optical coatings, transparent ceramic glass manufacturing, nanoenergetic gas generator, biosensor for DNA hybridization, potential immobilizing platforms for glucose oxidase and polyphenol oxidase, fuel cells, a additive in paints, an astringent in a variety of medical creams and topical ointments, and for the determination of heavy metal ions in drinking water, mineral water and urine. In addition this, Bismuth (III oxide nanoparticles (BONPs are favorable for the biomolecules adsorption than regular sized particles because of their greater advantages and novel characteristics (much higher specific surface, greater surface free energy, and good electrochemical stability etc.. Genotoxic effects of BONPs were investigated on the root cells of Allium cepa by Comet assay. A. cepa roots were treated with the aqueous dispersions of BONPs at 5 different concentrations (12.5, 25, 50, 75, and 100 ppm for 4 h. A significant increase in DNA damage was also observed at all concentrations of BONPs except 12.5 ppm by Comet assay. The results were also analyzed statistically by using SPSS for Windows; Duncan’s multiple range test was performed. These result indicate that BONPs exhibit genotoxic activity in A. cepa root meristematic cells.

  13. Superconductivity in Bismuth. A New Look at an Old Problem.

    Science.gov (United States)

    Mata-Pinzón, Zaahel; Valladares, Ariel A; Valladares, Renela M; Valladares, Alexander

    2016-01-01

    To investigate the relationship between atomic topology, vibrational and electronic properties and superconductivity of bismuth, a 216-atom amorphous structure (a-Bi216) was computer-generated using our undermelt-quench approach. Its pair distribution function compares well with experiment. The calculated electronic and vibrational densities of states (eDOS and vDOS, respectively) show that the amorphous eDOS is about 4 times the crystalline at the Fermi energy, whereas for the vDOS the energy range of the amorphous is roughly the same as the crystalline but the shapes are quite different. A simple BCS estimate of the possible crystalline superconducting transition temperature gives an upper limit of 1.3 mK. The e-ph coupling is more preponderant in a-Bi than in crystalline bismuth (x-Bi) as indicated by the λ obtained via McMillan's formula, λc = 0.24 and experiment λa = 2.46. Therefore with respect to x-Bi, superconductivity in a-Bi is enhanced by the higher values of λ and of eDOS at the Fermi energy. PMID:26815431

  14. Synthesis and characterization of bismuth alkaline titanate powders

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Huerta, A.M., E-mail: atorresh@ipn.mx [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Dominguez-Crespo, M.A. [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Hernandez-Perez, M.A. [ESIQIE, Metalurgia, Instituto Politecnico Nacional, Mexico, D. F (Mexico); Garcia-Zaleta, D.S. [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Brachetti-Sibaja, S.B. [CICATA-Altamira, Instituto Politecnico Nacional, Km. 14.5 Carretera Tampico Puerto Industrial Altamira, Altamira, Tamps. 89600 (Mexico); Instituto Tecnologico de Ciudad Madero, Av. 1o. de Mayo esq. Sor Juana Ines de la Cruz s/n Col. Los Mangos C.P.89440 Cd. Madero Tamaulipas (Mexico)

    2011-06-15

    In this work, samples of bismuth alkaline titanate, (K{sub 0.5}Na{sub 0.5}){sub (2-x/2)}Bi{sub (x/6)}TiO{sub 3}, (x = 0.05-0.75) have been prepared by conventional ceramic technique and molten salts. Metal oxides or carbonates powders were used as starting raw materials. The crystalline phase of the synthesized powders was identified by the X-ray diffraction (XRD) and particle morphology was characterized by scanning electron microscopy (SEM). Solid state reaction method was unsuccessful to obtain pellets. From XRD results, a rhombohedral structure was detected and the parameter lattice were estimated to be a = 5.5478 A and {alpha} = 59.48{sup o}. These parameters were used to refine the structure by Rietveld analysis. SEM results showed several morphologies. Apparently, bismuth is promoting the grain growth whose sizes vary from 30 nm to 180 nm It is expected that these materials can be utilized in practical applications as substitutes for lead zirconatetitanate (PZT)-based ceramics.

  15. Superconductivity in Bismuth. A New Look at an Old Problem.

    Directory of Open Access Journals (Sweden)

    Zaahel Mata-Pinzón

    Full Text Available To investigate the relationship between atomic topology, vibrational and electronic properties and superconductivity of bismuth, a 216-atom amorphous structure (a-Bi216 was computer-generated using our undermelt-quench approach. Its pair distribution function compares well with experiment. The calculated electronic and vibrational densities of states (eDOS and vDOS, respectively show that the amorphous eDOS is about 4 times the crystalline at the Fermi energy, whereas for the vDOS the energy range of the amorphous is roughly the same as the crystalline but the shapes are quite different. A simple BCS estimate of the possible crystalline superconducting transition temperature gives an upper limit of 1.3 mK. The e-ph coupling is more preponderant in a-Bi than in crystalline bismuth (x-Bi as indicated by the λ obtained via McMillan's formula, λc = 0.24 and experiment λa = 2.46. Therefore with respect to x-Bi, superconductivity in a-Bi is enhanced by the higher values of λ and of eDOS at the Fermi energy.

  16. Effect of O-vacancies on magnetic properties of bismuth ferrite nanoparticles by solution evaporation method

    Science.gov (United States)

    Afzal, A. M.; Umair, M.; Dastgeer, G.; Rizwan, M.; Yaqoob, M. Z.; Rashid, R.; Munir, H. S.

    2016-02-01

    Bismuth ferrite is a multiferroic material which shows high magnetization and polarization at room temperature. In present work, the effect of Oxygen (O) vacancies on magnetic properties of bismuth ferrite nanoparticles is studied. Bismuth ferrite nanoparticles (BiFeO3) were synthesized by solution evaporation method (SEM) at room temperature. The sample was annealed under two different atmospheres such as in air and oxygen, to check the effect of O-vacancies on magnetic properties. The average crystallite size of Bismuth ferrite nanoparticles (NPs) as calculated by X-ray diffraction (XRD) falls in the range of 23-32 nm and 26-39 nm for the case of air and oxygen respectively. The crystallite size of bismuth ferrite nanoparticles increases as the temperature was varied from 450 °C to 650 °C. Further the influence of annealing temperature on the magnetic properties of the bismuth ferrite nanoparticles was also observed. It was concluded that the magnetic properties of Bismuth ferrite nanoparticles are directly interconnected to annealing atmosphere and annealing temperature. The magnetic properties were increased in the case of oxygen annealing, which actually leads in our case to an improvement of the crystallinity.

  17. Ultra-flat bismuth films for diamagnetic levitation by template-stripping

    Energy Technology Data Exchange (ETDEWEB)

    Kokorian, J. [University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); TU Delft — 3mE-PME, Mekelweg 2, 2628 CD Delft (Netherlands); Engelen, J.B.C. [University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); IBM Research — Zurich, Säumerstrasse 4, CH-8803 Rüschlikon (Switzerland); Vries, J. de; Nazeer, H.; Woldering, L.A. [University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Abelmann, L., E-mail: l.abelmann@utwente.nl [University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2014-01-01

    In this paper we present a method to deposit thin films of bismuth with sub-nanometer surface roughness for application to diamagnetic levitation. Evaporated films of bismuth have a high surface roughness with peak to peak values in excess of 100 nm and average values on the order of 20 nm. We expose the smooth backside of the films using a template stripping method, resulting in a great reduction of the average surface roughness, to 0.8 nm. Atomic force microscope and X-ray diffraction measurements show that the films have a polycrystalline texture with preferential c-axis orientation. On the back side of the film, fine grains are grouped into larger clusters. Cantilever resonance shift measurements indicate that the Young's modulus of the films is on the order of 20 GPa. - Highlights: • We deposited continuous but rough bismuth films of 200–500 nm in thickness by thermal evaporation. • We analyzed the material properties of bismuth films using a variety of measurement techniques. • We reduced the roughness of bismuth films from 20 nm to 0.8 nm by a template stripping method. • The Young's modulus of bismuth thin films is comparable to bulk bismuth.

  18. Bismuth Modified Carbon-Based Electrodes for the Determination of Selected Neonicotinoid Insecticides

    OpenAIRE

    Marko Rodić; Olga Vajdle; Valéria Guzsvány; Jasmina Zbiljić; Zsigmond Papp

    2011-01-01

    Two types of bismuth modified electrodes, a bismuth-film modified glassy carbon (BiF-GCE) and a bismuth bulk modified carbon paste, were applied for the determination of selected nitroguanidine neonicotinoid insecticides. The method based on an ex situ prepared BiF-GCE operated in the differential pulse voltammetric (DPV) mode was applied to determine clothianidin in the concentration range from 2.5 to 23 μg cm−3 with a relative standard deviation (RSD) not exceeding 1.5%. The tricresyl phosp...

  19. Structural and optical characterization of thermally evaporated bismuth and antimony films for photovoltaic applications

    Science.gov (United States)

    Srimathy, N.; Ruban Kumar, A.

    2016-05-01

    In this present study, the thin film of bismuth and antimony is coated by thermal evaporation system equipped with the inbuilt ultra high vacuum system. XRD analysis confirmed the rhombohedral structure of Bismuth and Antimony on the prepared film. The surface roughness and physical appearance is analyzed by Atomic force microscopy. The results of Raman Spectroscopy show the wave functions and the spectrum of electrons. The preparation technique and conditions strongly influence the crystalline structure and the phase composition of bismuth and antimony thin films. The electrical and optical properties for the prepared film are analyzed. The results show a great interest and promising applications in Photovoltaic devices.

  20. Exploiting Chemistry to Improve Performance of Screen-Printed, Bismuth Film Electrodes (SP-BiFE

    Directory of Open Access Journals (Sweden)

    Carlo Dossi

    2016-07-01

    Full Text Available Mercury substitution is a big issue in electroanalysis, and the search for a suitable, and less toxic, replacement is still under development. Of all the proposed alternatives, bismuth films appear to be the most viable solution, although they are still suffering some drawbacks, particularly the influence of deposition conditions and linearity at low concentrations. In this paper, the most promising strategies for bismuth film deposition on screen-printed electrodes (surface modifications, polymeric film deposition, insoluble salt precursors will be evaluated for trace metal analysis. Particular attention will be devoted to bismuth chemistry, aiming to rationalize their electroanalytic performance.

  1. Bismuth ferrite as low-loss switchable material for plasmonic waveguide modulator

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Lavrinenko, Andrei

    2014-01-01

    We propose new designs of plasmonic modulators, which can beused for dynamic signal switching in photonic integrated circuits. We studyperformance of a plasmonic waveguide modulator with bismuth ferrite as atunable material. The bismuth ferrite core is sandwiched between metalplates (metal-insulator-metal...... modulation in both phase andamplitude control schemes. Due to high field confinement between themetal layers, existence of mode cut-offs for certain values of the corethickness, and near-zero material losses in bismuth ferrite, efficientmodulation performance is achieved. For the phase control scheme...

  2. Increased InAs quantum dot size and density using bismuth as a surfactant

    International Nuclear Information System (INIS)

    We have investigated the growth of self-assembled InAs quantum dots using bismuth as a surfactant to control the dot size and density. We find that the bismuth surfactant increases the quantum dot density, size, and uniformity, enabling the extension of the emission wavelength with increasing InAs deposition without a concomitant reduction in dot density. We show that these effects are due to bismuth acting as a reactive surfactant to kinetically suppress the surface adatom mobility. This mechanism for controlling quantum dot density and size has the potential to extend the operating wavelength and enhance the performance of various optoelectronic devices

  3. Inclusive measurement of (p,πsup(-)xn) double charge exchange reactions on bismuth from threshold to 800 MeV

    International Nuclear Information System (INIS)

    The energy dependence of the total angle-integrated cross section for the production of astatine isotopes from (p,πsup(-)xn) double charge exchange reactions on bismuth (sup(209)Bi) was measured from 120 to 800 MeV using activation and radiochemical techniques. Chemical yields were estimated by direct radioassaying of sup(211)At activity in thin (approximately 1 mg/cmsup(2)), irradiated bismuth targets. Calculations of the contributions of secondary (2-step) reactions to these measured astatine yields were performed, based partially upon the observed sup(211)At activity although even at the highest energies, the contribution to products lighter than sup(207)At was negligible. These data for products with as many as 7 neutrons removed from the doubly coherent product (sup(210)At) display nearby gaussian shapes for the mass distributions of the astatine residues with the maximum occurring for about sup(204)At. The most probable momentum transfer deduced from these distributions for the initial πsup(-) production step was 335 MeV/c. The observed excitation functions display a behaviour similar to that observed for the yield of sup(210)Po from a (p,πsup(O)) reaction on sup(209)Bi, but radically different from that observed for inclusive πsup(-) reactions on a heavy nucleus. These data are discussed in terms of recent theoretical approaches to negative pion production from bismuth. In addition, a simple, schematic model is developed to treat the rapidly decreasing percentage of the total inclusive πsup(-) emission which is observed for this double charge exchange reaction. This model reflects the capacity of a nucleus to a source of internal energetic protons

  4. Conduction mechanism in bismuth silicate glasses containing titanium

    Energy Technology Data Exchange (ETDEWEB)

    Dult, Meenakshi; Kundu, R.S. [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001 (India); Murugavel, S. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Punia, R., E-mail: rajeshpoonia13@gmail.com [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001 (India); Kishore, N. [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001 (India)

    2014-11-01

    Bismuth silicate glasses mixed with different concentrations of titanium dioxide having compositions xTiO{sub 2}–(60−x)Bi{sub 2}O{sub 3}–40SiO{sub 2} with x=0, 5, 10, 15 and 20 were prepared by the normal melt quench technique. The frequency dependence of the ac electrical conductivity of different compositions of titanium bismuth silicate glasses has been studied in the frequency range 10{sup −1} Hz to 10 MHz and in the temperature range 623–703 K. The temperature and frequency dependent conductivity is found to obey Jonscher's universal power law for all the compositions of titanium bismuth silicate glass system. The dc conductivity (σ{sub dc}), so called crossover frequency (ω{sub H}), and frequency exponent (s) have been estimated from the fitting of experimental data of ac conductivity with Jonscher's universal power law. Enthalpy to dissociate the cation from its original site next to a charge compensating center (H{sub f}) and enthalpy of migration (H{sub m}) have also been estimated. The conductivity data have been analyzed in terms of different theoretical models to determine the possible conduction mechanism. Analysis of the conductivity data and the frequency exponent shows that the correlated barrier hopping of electrons between Ti{sup 3+} and Ti{sup 4+} ions in the glasses is the most favorable mechanism for ac conduction. The temperature dependent dc conductivity has been analyzed in the framework of theoretical variable range hopping model (VRH) proposed by Mott which describe the hopping conduction in disordered semiconducting systems. The various polaron hopping parameters have also been deduced. Mott's VRH model is found to be in good agreement with experimental data and the values of inverse localization length of s-like wave function (α) obtained by this model with modifications suggested by Punia et al. are close to the ones reported for a number of oxide glasses.

  5. Fractionation of stable isotopes and impurities during zone recrystallization of metals and preparation of single crystals rich in individual isotopes

    International Nuclear Information System (INIS)

    It is shown that a small number of zone melting (recrystallization) passes results in a periodical distribution of individual isotopes along the material. The effect is observed with the Zn64 and Sn119 isotopes in zinc and tin, respectively. An increase of the number of passes to about ten leads to some preferential final isotope distribution. In the case of Sn119, the tail portion of the material becomes enriched (the portion to which the zone movement is directed), provided that the recrystallization rate is high enough (3 mm/min), or the head portion is enriched if the rate is slow (about 0.5 mm/min). In the presence of bismuth impurities, the isotope Sn119 is in all cases displaced towards the head portion of the material, which suggests a complex nature of the behaviour of individual isotopes during zone melting and an effect of impurities on this process. The Zn64 and Cd119 isotopes may be characterized, in accordance with their respective behaviour in the course of zone melting, by some effective distribution coefficients which are less than unity (K 1) in the latter. (author)

  6. Isotope Spectroscopy

    CERN Document Server

    Caffau, E; Bonifacio, P; Ludwig, H -G; Monaco, L; Curto, G Lo; Kamp, I

    2013-01-01

    The measurement of isotopic ratios provides a privileged insight both into nucleosynthesis and into the mechanisms operating in stellar envelopes, such as gravitational settling. In this article, we give a few examples of how isotopic ratios can be determined from high-resolution, high-quality stellar spectra. We consider examples of the lightest elements, H and He, for which the isotopic shifts are very large and easily measurable, and examples of heavier elements for which the determination of isotopic ratios is more difficult. The presence of 6Li in the stellar atmospheres causes a subtle extra depression in the red wing of the 7Li 670.7 nm doublet which can only be detected in spectra of the highest quality. But even with the best spectra, the derived $^6$Li abundance can only be as good as the synthetic spectra used for their interpretation. It is now known that 3D non-LTE modelling of the lithium spectral line profiles is necessary to account properly for the intrinsic line asymmetry, which is produced ...

  7. Shielding property of bismuth glass based on MCNP 5 and WINXCOM simulated calculation

    International Nuclear Information System (INIS)

    Background: Currently, lead glass is widely used as observation window, while lead is toxic heavy metal. Purpose: Non-toxic materials and their shielding effects are researched in order to find a new material to replace lead containing material. Methods: The mass attenuation coefficients of bismuth silicate glass were investigated with gamma-ray's energy at 0.662 MeV, 1.17 MeV and 1.33 MeV, respectively, by MCNP 5 (Monte Carlo) and WINXCOM program, and compared with those of the lead glass. Results: With attenuation factor K, shielding and mechanical properties taken into consideration bismuth glass containing 50% bismuth oxide might be selected as the right material. Dose rate distributions of water phantom were calculated with 2-cm and 10-cm thick glass, respectively, irradiated by 137Cs and 60Co in turn. Conclusion: Results show that the bismuth glass may replace lead glass for radiation shielding with appropriate energy. (authors)

  8. Three-component synthesis of amidoalkyl naphthols catalyzed by bismuth(Ⅲ) nitrate pentahydrate

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Yan Liang; Ting Ting Zhang; Jing Jing Gao

    2012-01-01

    Bismuth(Ⅲ) nitrate pentahydrate catalyzed the three-component condensation of β-naphthol,aldehydes and amines/urea under solvent-free conditions to afford the corresponding amidoalkyl naphthols in excellent yields.

  9. Surface tension of liquid dilute solutions of lead-cesium and bismuth-cesium systems

    International Nuclear Information System (INIS)

    Method of the maximal pressure in a drop was used to measure the surface tension of 15 liquid dilute solutions of lead-cesium system in 0-0.214 at% concentration range and of 12 diluted solutions of bismuth-cesium system in 0-0.160 at.% cesium range from solidification temperature up to 500 dec C. It was found that cesium was characterized as surfactant in lead and bismuth melts. It was established that the temperature coefficient of surface tension changes sufficiently in maximally diluted solutions of alkali metals in bismuth and lead melts. Effect of sodium, potassium, rubidum and cesium on the value of surface tension of lead and bismuth was systematized. Growth of activity in sodium, potassium, rubidium and cesium series was noted

  10. Corrosion by liquid lead and lead-bismuth: experimental results review and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinsuo [Los Alamos National Laboratory

    2008-01-01

    Liquid metal technologies for liquid lead and lead-bismuth alloy are under wide investigation and development for advanced nuclear energy systems and waste transmutation systems. Material corrosion is one of the main issues studied a lot recently in the development of the liquid metal technology. This study reviews corrosion by liquid lead and lead bismuth, including the corrosion mechanisms, corrosion inhibitor and the formation of the protective oxide layer. The available experimental data are analyzed by using a corrosion model in which the oxidation and scale removal are coupled. Based on the model, long-term behaviors of steels in liquid lead and lead-bismuth are predictable. This report provides information for the selection of structural materials for typical nuclear reactor coolant systems when selecting liquid lead or lead bismuth as heat transfer media.

  11. RECYCLING TECHNOLOGY INTO INDUSTRIAL TURNOVER OF BISMUTH AND MOLYBDENUM FROM DEAD CATALYST

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2015-05-01

    Full Text Available The technology of separate extraction of bismuth and molybdenum from spent catalyst was presented and information on the effectiveness of its use in a composition of comprehensive modifier in the iron-carbon alloy was given.

  12. Standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori eradication

    OpenAIRE

    Gao, Xiao-Zhong; Qiao, Xiu-li; Song, Wen-chong; Wang, Xiao-Feng; Liu, Feng

    2010-01-01

    AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori) eradication in a randomized, double-blinded, comparative clinical trial in China.

  13. Azo dyes photobleaching and operando FTIR study of acetaldehyde photoinduced decomposition on bismuth doped titania

    Czech Academy of Sciences Publication Activity Database

    Henych, Jiří; Štengl, Václav; Mattsson, A.; Österlund, L.

    Thessaloniki : Aristotle University of Thessaloniki, 2014. s. 101. [European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications (SPEA) /8./. 25.6.2014-28.6.2014, Thessaloniki] Institutional support: RVO:61388980 Keywords : bismuth doped titania Subject RIV: CA - Inorganic Chemistry

  14. A novel synthesis of perovskite bismuth ferrite nanoparticles

    Directory of Open Access Journals (Sweden)

    Alexandre Z. Simões

    2011-09-01

    Full Text Available Microwave assisted hydrothermal (MAH method was used to synthesize crystalline bismuth ferrite (BiFeO3 nanoparticles (BFO at temperature of 180°C with times ranging from 5 min to 1 h. For comparison, BFO powders were also crystallized by the soft chemistry route in a conventional furnace at a temperature of 850°C for 4 h. X-ray diffraction (XRD results verified the formation of perovskite BFO crystallites while infrared data showed no traces of carbonate. Field emission scanning microcopy (FE/SEM revealed a homogeneous size distribution of nanometric BFO powders. MAH method produced nanoparticles of 96% pure perovskite, with a size of 130 nm. These results are in agreement with Raman scattering values which show that the MAH synthesis route is rapid and cost effective. This method could be used as an alternative to other chemical methods in order to obtain BFO nanoparticles.

  15. Vibrational spectra and structure of bismuth based quaternary glasses

    International Nuclear Information System (INIS)

    Quaternary bismuthate glasses containing Li2O, ZnO and B2O3 have been prepared by melt quench technique and studied by density, DSC, IR and Raman spectroscopy. Raman and infrared spectroscopy have been employed to investigate the (75 - x)Bi2O3-xLi2O-10ZnO-15B2O3 glasses in order to obtain information about the competitive role of Bi2O3 and B2O3 in the formation of glass network. The increase of Bi2O3 content causes a progressive conversion of three- to four-fold coordinated boron. IR and Raman spectra show that these glasses are made up of [BiO3] pyramidal and [BiO6] octahedral units. The formation of Zn in tetrahedral coordination was observed

  16. Evaporation of mercury impurity from liquid lead–bismuth eutectic

    International Nuclear Information System (INIS)

    The equilibrium evaporation of mercury from dilute solutions in liquid lead–bismuth eutectic (LBE) was studied in argon atmosphere. Mercury present as impurity in LBE was evaporated and detected by atomic fluorescence spectroscopy. A method which could accurately simulate the experimental data was developed. Coefficients of the Henry constant temperature correlation for mercury dissolved in LBE were determined. Experiments with samples from several different batches of LBE revealed that mercury at mole fractions between 10−6 and 10−12 and temperatures between 150 and 350 °C evaporated from liquid LBE close to ideal behavior. Evaporation of mercury from solid LBE on the other hand was unexpectedly high. These results are important for safety evaluations of LBE based spallation targets and accelerator driven systems

  17. High power and compact switchable bismuth based multiwavelength fiber laser

    International Nuclear Information System (INIS)

    A compact switchable multiwavelength fibre laser (SWFL) is proposed and demonstrated using a bismuth based erbium doped fibre amplifier (Bi-EDFA) and a Sagnac loop mirror (SLM) in a ring cavity. The proposed compact SWFL can generate up to 6 switchable wavelengths with an average peak power of 11 dBm and also shows good stability over time with a high side mode signal ratio (SMSR) of 40 dB that negates minor fluctuations in the laser output. The Bi-EDF based gain medium gives the SWFL a large usable bandwidth of up to 80 nm, and it is expected that this will allow the SWFL to be used as a tunable laser source for high power applications to meet increasing demand

  18. Structural investigation of Zn doped sodium bismuth borate glasses

    Science.gov (United States)

    Bhatia, V.; Kumar, D.; Singh, D.; Singh, S. P.

    2016-05-01

    A series of Bismuth Borate Oxide Glass samples with composition x(ZnO):(15-x)Na2O:15Bi2O3:70B2O3 (variation in x is from 6 to 12 mole %) have been prepared by conventional melt quenching technique. All the chemicals used were of Analytical Grade. In order to verify the amorphous nature of the prepared samples the X-Ray Diffraction (XRD) was done. The physical and structural properties have been explored by using the techniques such as density, molar volume and FTIR in order to understand the effect of alkali and transition metal ions on the structure of these glasses. The results obtained by these techniques are in good agreement to one another and with literature as well. With the increase in the content of ZnO, the increase in density and some variations in structural coordination (ratio of BO3 & BO4 structural units) have been observed.

  19. Compatibility of structural materials with liquid bismuth, lead, and mercury

    Energy Technology Data Exchange (ETDEWEB)

    Weeks, J.R. [Brookhaven National Lab., Upton, NY (United States)

    1996-06-01

    During the 1950s and 1960s, a substantial program existed at Brookhaven National Laboratory as part of the Liquid Metal Fuel reactor program on the compatibility of bismuth, lead, and their alloys with structural materials. Subsequently, compatibility investigations of mercury with structural materials were performed in support of development of Rankine cycle mercury turbines for nuclear applications. The present talk will review present understanding of the corrosion/mass-transfer reactions of structural materials with these liquid metal coolants. Topics to be discussed include the basic solubility relationships of iron, chromium, nickel, and refractory metals in these liquid metals, the results of inhibition studies, the role of oxygen on the corrosion processes, and specialized topics such as cavitation-corrosion and liquid metal embrittlement. Emphasis will be placed on utilizing the understanding gained in this earlier work on the development of heavy liquid metal targets in spallation neutron sources.

  20. Formic Acid Oxidation at Platinum-Bismuth Clusters

    DEFF Research Database (Denmark)

    Lovic, J. D.; Stevanovic, S. I.; Tripkovic, D. V.; Tripkovic, Vladimir; Stevanovic, R. M.; Popovic, K. Dj.; Jovanovic, V. M.

    2014-01-01

    Formic acid oxidation was studied on platinum-bismuth deposits on glassy carbon (GC) substrate. The catalysts of equimolar ratio were prepared by potentiostatic deposition using chronocoulometry. Bimetallic structures obtained by two-step process, comprising deposition of Bi followed by deposition...... dissolution, deposits were subjected to electrochemical oxidation, in the relevant potential range and supporting electrolyte, prior to use as catalysts for HCOOH oxidation. Anodic striping charges indicated that along oxidation procedure most of deposited Bi was oxidized. ICP mass spectroscopy analysis of...... latter. Catalysts prepared in this way exhibit about 10 times higher activity for formic acid oxidation in comparison to pure Pt, as revealed both by potentiodynamic and quasy-potentiostatic measurements. This high activity is the result of well-balanced ensemble effect induced by Bi-oxide species...

  1. Ni-rich precipitates in a lead bismuth eutectic loop

    Science.gov (United States)

    Kikuchi, K.; Saito, S.; Hamaguchi, D.; Tezuka, M.

    2010-03-01

    Solidified LBE was sampled from the specimens, electro-magnetic pump, filter, drain valve and oxygen sensor at the JAEA Lead Bismuth Loop-1 (JLBL-1) where the structural material was made of SS316. The concentration of Ni, Fe and Cr in LBE were analyzed by the Inductive Coupled Plasma atomic emission spectrometer. It was concluded that the solution of Ni into LBE was not saturated although the concentration of Fe and Cr almost achieved to the values in the literature. A needle-type structure appeared on the surface of solidified LBE inside the tube specimens. It was found to be Ni-rich precipitates by X-ray analyses (Field Emission Scanning Electron Microscope, FE-SEM). LBE samples collected from a circulating loop after discharging did not show the amount of impurities equivalent to the LBE bulk property.

  2. Evaporation of mercury impurity from liquid lead–bismuth eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Aerts, A., E-mail: aaertsl@sckcen.be [SCK-CEN (Belgian Nuclear Research Centre), Boeretang 200, 2400 Mol (Belgium); Danaci, S. [SCK-CEN (Belgian Nuclear Research Centre), Boeretang 200, 2400 Mol (Belgium); Gonzalez Prieto, B. [SCK-CEN (Belgian Nuclear Research Centre), Boeretang 200, 2400 Mol (Belgium); Centre for Surface Chemistry and Catalysis, KU Leuven, Kasteelpark Arenberg 23, 3001 Heverlee (Belgium); Van den Bosch, J. [SCK-CEN (Belgian Nuclear Research Centre), Boeretang 200, 2400 Mol (Belgium); Neuhausen, J. [Laboratory for Radio- and Environmental Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

    2014-05-01

    The equilibrium evaporation of mercury from dilute solutions in liquid lead–bismuth eutectic (LBE) was studied in argon atmosphere. Mercury present as impurity in LBE was evaporated and detected by atomic fluorescence spectroscopy. A method which could accurately simulate the experimental data was developed. Coefficients of the Henry constant temperature correlation for mercury dissolved in LBE were determined. Experiments with samples from several different batches of LBE revealed that mercury at mole fractions between 10{sup −6} and 10{sup −12} and temperatures between 150 and 350 °C evaporated from liquid LBE close to ideal behavior. Evaporation of mercury from solid LBE on the other hand was unexpectedly high. These results are important for safety evaluations of LBE based spallation targets and accelerator driven systems.

  3. Process dependent thermoelectric properties of EDTA assisted bismuth telluride

    Science.gov (United States)

    Kulsi, Chiranjit; Kargupta, Kajari; Banerjee, Dipali

    2016-04-01

    Comparison between the structure and thermoelectric properties of EDTA (Ethylene-diamine-tetra-acetic acid) assisted bismuth telluride prepared by electrochemical deposition and hydrothermal route is reported in the present work. The prepared samples have been structurally characterized by high resolution X-ray diffraction spectra (HRXRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopic images (HRTEM). Crystallite size and strain have been determined from Williamson-Hall plot of XRD which is in conformity with TEM images. Measurement of transport properties show sample in the pellet form (S1) prepared via hydrothermal route has higher value of thermoelectric power (S) than the electrodeposited film (S2). But due to a substantial increase in the electrical conductivity (σ) of the film (S2) over the pellet (S1), the power factor and the figure of merit is higher for sample S2 than the sample S1 at room temperature.

  4. Enhanced multiferroic properties of Pr doped bismuth ferrite ceramics

    International Nuclear Information System (INIS)

    Pr modified Bi0.9-xLa0.1PrxFeO3 (BLPFO-x, x = 0, 0.1 and 0.2) ceramics were prepared by solid state reaction using oxide reagents and a detailed multiferroic properties is reported. X-ray analysis shows the formation of a bismuth ferrite rhombohedral phase. Pr doping significantly increases the resistivity and leads to a successful observation of electrical polarization hysteresis loops. All the samples have been found to possess a spontaneous magnetic moment at room temperature which increases further at low temperatures. The strong dependence of remnant polarization and dielectric constant on the strength of magnetic field is a direct evidence of magnetoelectric coupling in BLPFO ceramics. (author)

  5. Scanning tunneling microscopy of the cleavage surface of bismuth crystals

    International Nuclear Information System (INIS)

    The results of in situ studies of the surface structure of the cleavages of bismuth crystals by the method of scanning tunneling microscopy are presented. It is established that cleavage 'opens' the (111) surface with atomically smooth terraces of diatomic steps whose heights are equal to 0.4 nm or a multiple of this value. If the cleavage is made at room temperature, the boundaries of the terraces are usually curved and diffuse owing to the thermal motion with the activation energy of ∼700 K. The cleavage at liquid nitrogen or helium temperatures provides the formation of straight boundaries along the atomic rows on the surface. Twin interlayers of the quantized width of ∼7 nm are revealed. This width value indicates that the atomic planes on both sides of such interlayers intergrow with the interlayer planes inclined to them at a small angle

  6. Toxicity of Volatile Methylated Species of Bismuth, Arsenic, Tin, and Mercury in Mammalian Cells In Vitro

    OpenAIRE

    Rettenmeier, A W; Zimmermann, U.; Richard, J.; R. A. Diaz-Bone; Hippler, J; U. von Recklinghausen; Dopp, E.; Hirner, A. V.

    2011-01-01

    The biochemical transformation of mercury, tin, arsenic and bismuth through formation of volatile alkylated species performs a fundamental role in determining the environmental processing of these elements. While the toxicity of inorganic forms of most of these compounds are well documented (e.g., arsenic, mercury) and some of them are of relatively low toxicity (e.g., tin, bismuth), the more lipid-soluble organometals can be highly toxic. In the present study we investigated the cyto- and ge...

  7. Determination of vanadium concentration in bismuth titanate monocrystals and its relation to optical properties and photoconductivity

    International Nuclear Information System (INIS)

    Using Czochralski method optically perfect bismuth titanate crytals doped by vanadium (0.14-0.46 mass.%) are prepared. A technique of vanadium concentration measurement by Raman spectra is developed. Photoconductivity and optical properties of tehse monocrystals are studied. It is shown that in λ > 530 nm wave range photoconductivity of doped monocrystals is by 1-2 order higher than in pure bismuth titanate monocrystal

  8. In vitro synergistic activity between bismuth subcitrate and various antimicrobial agents against Campylobacter pyloridis (C. pylori).

    OpenAIRE

    Van Caekenberghe, D L; Breyssens, J

    1987-01-01

    The in vitro interactions between bismuth subcitrate and a variety of antimicrobial agents against 12 Campylobacter pyloridis (C. pylori) isolates were studied by the agar dilution checkerboard technique. The combination of bismuth subcitrate with the older quinolone, oxolinic acid, produced synergistic activity against all strains. This observation, however, could not be extended to the (aryl) fluoroquinolones, norfloxacin, ofloxacin, and difloxacin, since synergy was rare or absent when bis...

  9. Intermetallic growth at the interface between copper and bismuth-tin solder

    OpenAIRE

    Vollweiler, Fred O. P.

    1993-01-01

    Approved for public release; distribution is unlimited. Tin-bismuth alloys have been proposed as alternatives to lead containing solders for interconnection and packaging applications. Consequently, the interface between copper metallizations and bismuth-tin solders needs to be evaluated with respect to brittle intermetallic formation. In the binary Bi-Sn alloys both the Cu6Sn5 and Cu3Sn intermetallic phases were found at the Cu/ solder interface after exposure at 250 deg C, 300 deg C, and...

  10. Shock compression and adiabatic decompression of a dense bismuth plasma at extreme thermal energy densities

    International Nuclear Information System (INIS)

    Experimental results on the shock-wave compression of solid and porous bismuth samples at pressures over the range 0.4-6 Mbar are reported. The course of the supercritical decompression isentropes between a highly compressed condensed state and a low-density plasma has been determined. The experimental results are used to write a thermodynamic description of the high-energy states of a dense bismuth plasma. 11 references

  11. Direct Electrochemical Synthesis of Bismuth(III) Phenoxides and their Coordination Compounds

    OpenAIRE

    Harpreet Kaur; Baljit Singh

    2012-01-01

    Bismuth(III) phenoxides have been synthesized by electrochemical reactions of 1-naphthol, 2-naphthol, 4-aminophenol, 2-nitrophenol, 4-nitrophenol, 2-hydroxybenzoic acid, p-cresol, phenol, resorcinol, 2-tert-butylphenol and 2-tert-butyl-4-methoxyphenol at sacrificial bismuth anode and inert platinum cathode using tetrabutylammonium chloride as supporting electrolyte. The coordination compounds of these phenols with 1, 10-phenanthroline and 2, 2ʼ-bipyridyl have also been synthesized electrochem...

  12. Study of bismuth minerals belonging to the mineralogical collection from the National Museum

    International Nuclear Information System (INIS)

    With the purpose of searching the presence of Tellurium minerals in the Ouro Preto-Mariana country, Minas Gerais State, and considering the existence of a great number of minerals in which this element come across allied with Bismuth, samples of the mineralogical collection of the Museu Nacional, proceeding that region and classified as Bismuth minerals were studied by X-ray fluorescence analysis and diffractometric analysis. In this report the results of this research are presented. (Author)

  13. Lead-bismuth eutectic corrosion behaviors of ferritic/martensitic steels in low oxygen concentration environment

    OpenAIRE

    Liu, Jian; Shi, Quanqiang; Luan, He; Yan, Wei; Sha, Wei; Wang, Wei; Shan, Yiyin; Yang, Ke

    2015-01-01

    In order to investigate the compatibility of candidate structural materials with liquid metals, two kinds of ferritic/martensitic steels were chosen to contact with lead–bismuth eutectic in sealed quartz–glass tubes. The corrosion exposures were for 500 and 3000 h. Results showed that the oxidation layer and carbide dissolution layer on the two steels grew with contact time under oxygen unsaturated condition. Short-term corrosion behavior of a newly developed steel showed better lead–bismuth ...

  14. Comparison of radiation shielding ratios of nano-sized bismuth trioxide and molybdenum

    Science.gov (United States)

    Cho, J. H.; Kim, M. S.; Rhim, J. D.

    2015-07-01

    In this study, radiation shielding fibers using non-hazardous nano-sized bismuth trioxide and molybdenum instead of lead were developed and evaluated. Among the elements with high densities and atomic numbers, non-hazardous elements such as bismuth trioxide and molybdenum were chosen as a shielding element. Then, bismuth trioxide (Bi2O3) with average particle size 1-500 µm was ball milled for 10 min to produce a powdered form of nanoparticles with average particle size of 10-100 nm. Bismuth trioxide nanoparticles were dispersed to make a colloidal suspension, followed by spreading and hardening onto one or two sides of fabric, to create the radiation shielding fabric. The thicknesses of the shielding sheets using nano-sized bismuth and molybdenum were 0.4 and 0.7 mm. According to the lead equivalent test of X-ray shielding products suggested by KS, the equivalent dose was measured, followed by calculation of the shielding rate. The shielding rate of bismuth with 0.4 mm thickness and at 50 kVp was 90.5%, which is comparable to lead of 0.082 mm thickness. The shielding rate of molybdenum was 51.89%%, which is comparable to lead of 0.034 mm. At a thickness of 0.7 mm, the shielding rate of bismuth was 98.73%, equivalent to 0.101 mm Pb, whereas the shielding rate of molybdenum was 74.68%, equivalent to 0.045 mm Pb. In conclusion, the radiation shielding fibers using nano-sized bismuth developed in this study are capable of reducing radiation exposure by X-ray and its low-dose scatter ray.

  15. Ferroelectric thin film bismuth titanate prepared from acetate precursors

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yanxia; Hoelzer, D.T.; Schulze, W.A. [Alfred Univ., NY (United States); Tuttle, B.A.; Potter, B.G. [Sandia National Labs., Albuquerque, NM (United States)

    1994-10-01

    Bismuth titanate (Bi{sub 4}Ti{sub 3}O{sub 12}) thin films were fabricated by spin coat deposition followed by rapid thermal processing (RTP). Acetate derived solutions for deposition were synthesized by blending bismuth acetate in aqueous acetic acid and then adding titanium acetate. A series of electrically insulating, semiconducting and conducting substrates were evaluated for Bi{sub 4}Ti{sub 3}O{sub 12} film deposition. While X-ray diffraction and TEM analyses indicated that the initial perovskite crystallization temperature was 500{degrees}C or less for these Bi{sub 4}Ti{sub 3}O{sub 12} films, a 700{degrees}C crystallization treatment was used to obtain single phase perovskite films. Bi{sub 4}Ti{sub 3}O{sub 12} film crystallographic orientation was shown to depend on three factors: substrate surface morphology, the number of coating layers and thermal processing. While preferred c-direction orientation was observed for Bi{sub 4}Ti{sub 3}O{sub 12} films deposited on silver foil substrates, preferred a-direction orientation was obtained for films deposited on both Si and Pt coated Si wafers. The films were dense, smooth, crack free, and had grain sizes ranging from 20 nm to 100 nm. Film thickness and refractive index were determined using a combination of ellipsometry, waveguide refractometry and TEM measurements. Both low field dielectric and ferroelectric properties were measured for an 800 nm thick film deposited on a Pt coated MgO substrate. A remanent polarization of 38 {mu}C/cm{sup 2} and a coercive field of 98 kV/cm were measured for this film that was crystallized at 700{degrees}C.

  16. Polonium problem in lead-bismuth flow target

    Energy Technology Data Exchange (ETDEWEB)

    Pankratov, D.V.; Yefimov, E.I.; Bugreev, M.I. [State Scientific Centre of Russian Federation-Institute of Physics and Power Engineering, Obninsk (Russian Federation)

    1996-06-01

    Alpha-active polonium nuclides Po198 - Po210 are formed in a lead-bismuth target as results of reactions Bi{sup 209}(n,{gamma})Bi{sup 210} {yields} Po{sup 210}, Bi{sup 209}(p,xn)Po{sup 210} {yields} Po{sup 210 {minus} x} (x = 1-12), Pb{sup 208}({alpha},xn) {yields} Po{sup 210 {minus} x + 2} (x = 2-14). The most important nuclides are Po-210 (T{sub {1/2}}=138.4 day), Po-209 (T{sub {1/2}}=102 years) and Po-208 (T{sub {1/2}}=2.9 years). Polonium activity of the circuit for SINQ - conditions is about 15,000 Ci after 1-year operation. Polonium radiation hazard is connected with its output from the coolant and formation of aerosol and surface alpha-activity after the circuit break-down for repair works or in accidents. One of the important issues of polonium removal system creation is containing and storing polonium removed. Its storage in solidified alkaline is not expedient because of secondary neutron formation as a result of ({alpha},n) - reaction on oxygen and sodium nucleus. The estimations carried out demonstrated that by polonium concentration {approx} 100 Ci/l neutron current on the container surface can reach {approx} 10{sup 4}n/(cm{sup 2}s). Concentration and storage of polonium in solidified lead-bisumth seems the most convenient. The calculations demonstrated that in a 100 l container 50,000 Ci of polonium can be stored (as much as 3 times more than 1-year polonium product in SINQ-conditions) under temperature in the container less than melting point of lead bismuth (the wall temperature is about 100{degrees}C).

  17. Nano sized bismuth oxy chloride by metal organic chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jagdale, Pravin, E-mail: pravin.jagdale@polito.it [Department of Applied Science and Technology (DISAT), Politecnico di Torino, 10129 (Italy); Castellino, Micaela [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Marrec, Françoise [Laboratory of Condensed Matter Physics, University of Picardie Jules Verne (UPJV), Amiens 80039 (France); Rodil, Sandra E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexicom (UNAM), Mexico D.F. 04510 (Mexico); Tagliaferro, Alberto [Department of Applied Science and Technology (DISAT), Politecnico di Torino, 10129 (Italy)

    2014-06-01

    Metal organic chemical vapour deposition (MOCVD) method was used to prepare thin films of bismuth based nano particles starting from bismuth salts. Nano sized bismuth oxy chloride (BiOCl) crystals were synthesized from solution containing bismuth chloride (BiCl{sub 3}) in acetone (CH{sub 3}-CO-CH{sub 3}). Self-assembly of nano sized BiOCl crystals were observed on the surface of silicon, fused silica, copper, carbon nanotubes and aluminium substrates. Various synthesis parameters and their significant impact onto the formation of self-assembled nano-crystalline BiOCl were investigated. BiOCl nano particles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Micro-Raman spectroscopy. These analyses confirm that bismuth nanometer-sized crystal structures showing a single tetragonal phase were indeed bismuth oxy chloride (BiOCl) square platelets 18–250 nm thick and a few micrometres wide.

  18. Adverse events with bismuth salts for Helicobacter pylori eradication:Systematic review and meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Alexander C Ford; Peter Malfertheiner; Monique Giguére; José Santana; Mostafizur Khan; Paul Moayyedi

    2008-01-01

    AIM:To assess the safety of bismuth used in Helicobacter pylori (H pylori) eradication therapy regimens.METHODS:We conducted a systematic review and meta-analysis.MEDLINE and EMBASE were searched (up to October 2007) to identify randomised controlled trials comparing bismuth with placebo or no treatment,or bismuth salts in combination with antibiotics as part of eradication therapy with the same dose and duration of antibiotics alone or,in combination,with acid suppression.Total numbers of adverse events were recorded.Data were pooled and expressed as relative risks with 95% confidence intervals (CI).RESULTS:We identified 35 randomised controlled trials containing 4763 patients.There were no serious adverse events occurring with bismuth therapy.There was no statistically significant difference detected in total adverse events with bismuth [relative risk (RR)=1.01;95% CI:0.87-1.16],specific individual adverse events,with the exception of dark stools (RR = 5.06;95% CI:1.59-16.12),or adverse events leading to withdrawal of therapy (RR = 0.86;95% CI:0.54-1.37).CONCLUSION:Bismuth for the treatment of H pylori is safe and well-tolerated.The only adverse event occurring significantly more commonly was dark stools.

  19. Non-stoichiometry and magneto-optic properties of magnetic bubble thin films of TmIG substituted with bismuth and gallium

    International Nuclear Information System (INIS)

    Thulium iron garnet thin films substituted with bismuth and gallium were prepared by LPE from a PbO.B2O3 flux. Radioactive isotope tracers were added to the melt as the chemical analysis technique. The deviation from the ratio (Pb + Bi + Tm)/(Fe + Ga) = 0.6 of the layers was large and a proportion of the thulium ions possibly lie on the octahedral crystallographic sites. The concentration of Bi, Pb, and Ga as function of the growth temperature was studied. The magneto-optic properties show that the layers are well suited for use in a magneto-optic device. A figure of merit of 2.5 degree per decibel at lambda = 560 nm was obtained and some magnetic bubble parameters are also presented. (orig.)

  20. Electrical transport measurements of individual bismuth nanowires and carbon nanotubes

    Science.gov (United States)

    Jang, Wan Young

    Nanostructures are defined by reducing dimensions. When the reduced size of materials is comparable to the Fermi wavelength, quantum size effect occurs. Dimensionality plays a critical role in determining the electronic properties of materials, because the density of states of materials is quite different. Nanowires have attracted much attention recently due to their fundamental interest and potential applications. A number of materials have been tried. Among them, bismuth has unique properties. Bismuth has the smallest effective mass as small as 0.001me. This small effective mass of Bi nanowires allows one to observe the quantum confinement effect easily. Also Bi nanowires are good candidates for a low-dimensional transport study due to long mean free path. Because of these remarkable properties of Bi nanowires, many efforts have been made to study Bi nanowires. However, because bismuth is extremely sensitive to the oxide, it is very difficult to make a reliable device. So far, array measurements of Bi nanowires have been reported. The study is focused on the synthesis and electric transport measurements of individual Bi nanowires. Bi nanowires are synthesized by electrodeposition using either anodic aluminum oxide (AAO) templates or commercially available track etched polycarbonate membranes (PCTE). The desired nanowire has a heterostructure of Au - Bi - Au. Au wires on both sides serve as contact electrodes with Bi. To extract nanowires from PCTE or AAO, several attempts have been made. Devices consisting of single Bi nanowires grown by hydrothermal method are fabricated and electrical measurements have been carried out after in-situ deposition of Pt electrodes. The temperature dependence of resistance of majority of nanowires increases with decreasing temperature, showing polycrystalline nature of nanowires. However, some nanowires show resistance peaks at low temperature, suggesting quantum size effect (QSE). Magnetoresistance (MR) has also been measured. We

  1. Corrosion behavior of Si-enriched steels for nuclear applications in liquid lead–bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, Yuji, E-mail: kurata.yuji@jaea.go.jp [Japan Atomic Energy Agency, Tokai-mura, Ibaraki-ken 319-1195 (Japan)

    2013-06-15

    Highlights: ► The corrosion behavior of Si-enriched steels in liquid lead–bismuth was studied. ► The corrosion tests were conducted at the two controlled oxygen levels. ► The Si addition reduces the scale thickness under the high oxygen condition. ► The Si addition has no significant effect under the low oxygen condition. -- Abstract: The corrosion behavior of Si-enriched steels in liquid lead–bismuth was studied in order to develop accelerator driven systems for transmutation of long-lived radioactive wastes and lead–bismuth cooled fast reactors. The corrosion tests of 316SS, Si-enriched 316SS, Mod.9Cr–1Mo steel (T91) and Si-enriched T91 were conducted at 550 °C in liquid lead–bismuth at the two controlled oxygen levels. Both the additions of 2.5 wt.% Si to 316SS and 1.5 wt.% Si to T91 had the effect of reducing the thickness of oxide layer in liquid lead–bismuth at the high oxygen concentration (2.5 × 10{sup −5} wt.%). Although the Si addition to 316SS reduced the depth of ferritization caused by Ni dissolution in liquid lead–bismuth at the low oxygen concentration (4.4 × 10{sup −8} wt.%), it could not suppress the ferritization and the penetration of Pb and Bi completely. The Si addition to T91 did not have the effect of preventing the penetration of Pb and Bi in the liquid lead–bismuth at the low oxygen concentration. The oxide scales formed on both Si-enriched steels did not have sufficient corrosion resistance under the low oxygen condition.

  2. Bismuth oxide aqueous colloidal nanoparticles inhibit Candida albicans growth and biofilm formation

    Directory of Open Access Journals (Sweden)

    Hernandez-Delgadillo R

    2013-04-01

    Full Text Available Rene Hernandez-Delgadillo,1 Donaji Velasco-Arias,3 Juan Jose Martinez-Sanmiguel,2 David Diaz,3 Inti Zumeta-Dube,3 Katiushka Arevalo-Niño,1 Claudio Cabral-Romero2 1Facultad de Ciencias Biológicas, Instituto de Biotecnologia, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, Mexico; 2Facultad de Odontología, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, México; 3Facultad de Quimica, Universidad Nacional Autonoma de Mexico, UNAM, Distrito Federal, México Abstract: Multiresistance among microorganisms to common antimicrobials has become one of the most significant concerns in modern medicine. Nanomaterials are a new alternative to successfully treat the multiresistant microorganisms. Nanostructured materials are used in many fields, including biological sciences and medicine. Recently, it was demonstrated that the bactericidal activity of zero-valent bismuth colloidal nanoparticles inhibited the growth of Streptococcus mutans; however the antimycotic potential of bismuth nanostructured derivatives has not yet been studied. The main objective of this investigation was to analyze the fungicidal activity of bismuth oxide nanoparticles against Candida albicans, and their antibiofilm capabilities. Our results showed that aqueous colloidal bismuth oxide nanoparticles displayed antimicrobial activity against C. albicans growth (reducing colony size by 85% and a complete inhibition of biofilm formation. These results are better than those obtained with chlorhexidine, nystatin, and terbinafine, the most effective oral antiseptic and commercial antifungal agents. In this work, we also compared the antimycotic activities of bulk bismuth oxide and bismuth nitrate, the precursor metallic salt. These results suggest that bismuth oxide colloidal nanoparticles could be a very interesting candidate as a fungicidal agent to be incorporated into an oral antiseptic. Additionally, we determined the minimum inhibitory concentration for the synthesized

  3. New bismuth borophosphate Bi4BPO10: Synthesis, crystal structure, optical and band structure analysis

    International Nuclear Information System (INIS)

    New bismuth borophosphate Bi4BPO10 was obtained by spontaneous crystallization from the melt of correspondent composition at 804 °C. Crystal structure with orthorhombic lattice parameters: a = 22.5731(3) Å, b = 14.0523(2) Å, c = 5.5149(1) Å, V = 1749.34(4), Z = 8, SG Pcab was determined by X-ray powder diffraction technique. The [Bi2O2]2+ -layers, which are typical for bismuth oxide compounds, transform into cationic endless strips of 4 bismuth atoms width directed along the c-axis in Bi4BPO10. The strips combining stacks are separated by flat triangle [BO3]3− -anions within stacks. Neighboring stacks are separated by tetrahedral [PO4]3−-anions and shifted relatively to each other. Bismuth atoms are placed in 5–7 vertex oxygen irregular polyhedra. Bi4BPO10 is stable up to 812 °C, then melts according to the peritectic law. The absorption spectrum in the range 350–700 nm was obtained and the width of the forbidden band was estimated as 3.46 eV. The band electronic structure of Bi4BPO10 was modeled using DFT approach. The calculated band gap (3.56 eV) is in good agreement with the experimentally obtained data. - Graphical abstract: Display Omitted - Highlights: • New bismuth borophosphate with composition Bi4BPO10 was synthesized. • The crystal structure was determined by X-ray powder diffraction technique. • Bismuth-oxygen part [Bi4O3]6+ forms endless strips of 4 bismuth atoms width. • Electronic structure was modeled by DFT method. • The calculated band gap (3.56 eV) is very close to the experimental one (3.46 eV)

  4. Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm

    Directory of Open Access Journals (Sweden)

    Hernandez-Delgadillo R

    2012-04-01

    Full Text Available Rene Hernandez-Delgadillo1, Donaji Velasco-Arias2, David Diaz2, Katiushka Arevalo-Niño1, Marianela Garza-Enriquez1, Myriam A De la Garza-Ramos1, Claudio Cabral-Romero11Instituto de Biotecnologia, Centro de Investigacion y Desarrollo en Ciencias de la Salud, CIDICS, Facultad de Odontologia, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, Nuevo Leon, 2Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Distrito Federal, MexicoBackground and methods: Despite continuous efforts, the increasing prevalence of resistance among pathogenic bacteria to common antibiotics has become one of the most significant concerns in modern medicine. Nanostructured materials are used in many fields, including biological sciences and medicine. While some bismuth derivatives has been used in medicine to treat vomiting, nausea, diarrhea, and stomach pain, the biocidal activity of zerovalent bismuth nanoparticles has not yet been studied. The objective of this investigation was to analyze the antimicrobial activity of bismuth nanoparticles against oral bacteria and their antibiofilm capabilities.Results: Our results showed that stable colloidal bismuth nanoparticles had 69% antimicrobial activity against Streptococcus mutans growth and achieved complete inhibition of biofilm formation. These results are similar to those obtained with chlorhexidine, the most commonly used oral antiseptic agent. The minimal inhibitory concentration of bismuth nanoparticles that interfered with S. mutans growth was 0.5 mM.Conclusion: These results suggest that zerovalent bismuth nanoparticles could be an interesting antimicrobial agent to be incorporated into an oral antiseptic preparation.Keywords: zerovalent bismuth nanoparticles, antimicrobial agent, biofilm, Streptococcus mutans

  5. Synthesis, Characterization and Molecular Structures of some Bismuth(III) Complexes with Thiosemicarbazones and Dithiocarbazonic Acid Methylester Derivatives with Activity against Helicobacter Pylori

    OpenAIRE

    Diemer, Rolf; Dittes, Uwe; Nuber, Bernhard; Seifried, Volker; Opferkuch, Wolfgang; Keppler, Bernhard K.

    1995-01-01

    The reactions of bismuth(III) nitrate pentahydrate and bismuth(III) chloride with heterocyclic thiosemicarbazones and derivatives of dithiocarbazonic acid methylester were used to synthesize the respective bismuth(III) complexes, which could be divided into five groups D-H because of their stoichiometrical properties and their molecular structures. The molecular structure and the near coordination sphere of the bismuth(III) central atom of four representative compounds were determined by sing...

  6. Electrochemical study on determination of diffusivity, activity and solubility of oxygen in liquid bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, Rajesh [Liquid Metals and Structural Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Gnanasekaran, T. [Liquid Metals and Structural Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)]. E-mail: gnani@igcar.ernet.in; Srinivasa, Raman S. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400 076 (India)

    2006-06-15

    Diffusivity of oxygen in liquid bismuth was measured by potentiostatic method and is given bylg(D{sub O}{sup Bi}/cm{sup 2}.s{sup -1})(+/-0.042)=-3.706-1377/(TK{sup -1})(804bismuth was determined by coulometric titrations and using the measured data standard free energy of dissolution of oxygen in liquid bismuth was derived for the reaction:1/2O{sub 2}(g)=[O]{sub Bi}(at.%)and is given by{delta}G{sub O(Bi)}{sup o}/(J.g-atomO{sup -1})(+/-720)=-108784+20.356TK{sup -1}(753bismuth was derived as a function of temperature and is given by the following expressions:lg(S/at%O)(+/-0.05)=-4476/TK{sup -1}+4.05(753bismuth is compared with the literature data.

  7. Bismuth nanoparticles synthesized by laser ablation in lubricant oils for tribological tests

    International Nuclear Information System (INIS)

    Highlights: • Bismuth nanoparticles have been obtained by laser ablation of solids in liquids. • The technique allows controlling the size and concentration of the samples. • Bi np’s in base oils can improve the tribological characteristics of the lubricant. - Abstract: The improvement of the tribological properties of mineral base oils through the addition of bismuth nanoparticles as an additive, together with the idea of obtaining lubricants free of heavy metals, was evaluated. Bismuth nanoparticles were produced directly in the heavy and light viscosity mineral base oils (BS900 and BS6500) using the technique of laser ablation of solids immersed in liquids. Transmission electron microscopy measurements showed the presence of pure bismuth nanoparticles. Small Angle X-ray Scattering (SAXS) measurements showed that the average size of the nanoparticles was between 7 and 65 nm depending on the experimental conditions used. The tribological properties of the base oil with the bismuth nanoparticles additives were evaluated using a four-ball tester. Tests were performed using the base oil with and without Bi nanoparticles. It was observed that the coefficient of friction of the oil decrease with an increasing concentration of the nanoparticles. The results also showed that the wear rate was reduced when the Bi nanoparticle additives were used

  8. Crystallinity and electrical properties of neodymium-substituted bismuth titanate thin films

    International Nuclear Information System (INIS)

    We report on the properties of Nd-substituted bismuth titanate Bi4-xNd xTi3O12 (BNdT) thin films for ferroelectric non-volatile memory applications. The Nd-substituted bismuth titanate thin films fabricated by modified chemical solution deposition technique showed much improved properties compared to pure bismuth titanate. A pyrochlore free crystalline phase was obtained at a low annealing temperature of 640 deg. C and grain size was found to be considerably increased as the annealing temperature increased. The film properties were found to be strongly dependent on the Nd content and annealing temperatures. The measured dielectric constant of BNdT thin films was in the range 172-130 for Bi4-xNd xTi3O12 with x 0.0-0.75. Ferroelectric properties of Nd-substituted bismuth titanate thin films were significantly improved compared to pure bismuth titanate. For example, the observed 2P r and E c for Bi3.25Nd0.75Ti3O12, annealed at 680 deg. C, were 38 μC/cm2 and 98 kV/cm, respectively. The improved microstructural and ferroelectric properties of BNdT thin films suggest their suitability for high density ferroelectric random access memory applications

  9. Bismuth Modified Carbon-Based Electrodes for the Determination of Selected Neonicotinoid Insecticides

    Directory of Open Access Journals (Sweden)

    Marko Rodić

    2011-05-01

    Full Text Available Two types of bismuth modified electrodes, a bismuth-film modified glassy carbon (BiF-GCE and a bismuth bulk modified carbon paste, were applied for the determination of selected nitroguanidine neonicotinoid insecticides. The method based on an ex situ prepared BiF-GCE operated in the differential pulse voltammetric (DPV mode was applied to determine clothianidin in the concentration range from 2.5 to 23 μg cm−3 with a relative standard deviation (RSD not exceeding 1.5%. The tricresyl phosphate-based carbon paste electrodes (TCP-CPEs, bulk modified with 5 and 20 w/w% of bismuth, showed a different analytical performance in the determination of imidacloprid, regarding the peak shape, potential window, and noise level. The TCP-CPE with 5% Bi was advantageous, and the developed DPV method based on it allowed the determination in the concentration range from 1.7 to 60 μg cm−3 with an RSD of 2.4%. To get a deeper insight into the morphology of the bismuth-based sensor surfaces, scanning electron microscopic measurements were performed of both the surface film and the bulk modified electrodes.

  10. Bioaccumulation and biosorption of bismuth Bi (III) by filamentous fungus Aspergillus clavatus

    International Nuclear Information System (INIS)

    In this work we focused on bismuth (III) biosorption and bioaccumulation. Prior the bioaccumulation experiments the 7-day-old conidia were collected from mycelia surface of filamentous fungus Aspergillus clavatus and used as inocula for 50 ml of nutrient media with different bismuth (III) concentrations. After 15-day cultivation under laboratory conditions (dark, 25 grad C) the bismuth concentration in grown fungal biomass was measured using ICP OES. Maximum achieved accumulation capacity of dry biomass was 112 μmol.g-1. Batch biosorption experiments were performed in Erlenmeyer flasks with pelletized wet fungal biomass/solution ratio 1.8% and with various bismuth (III) concentrations. The equilibrium time was studied within the time interval of 0-240 min. The reaction kinetics were well described by both pseudo-first and pseudo-second order rate models, and equilibrium was reached after 50 min. Langmuir and Freundlich isotherm models were used to represent equilibrium data, and the calculated maximum biosorption capacity of fungal biomass for bismuth(III) was 0.40 mmol.g-1. (authors)

  11. Bismuth nanoparticles synthesized by laser ablation in lubricant oils for tribological tests

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Castañeda, M., E-mail: mar.floc@hotmail.com [Universidad Autónoma del Estado de México, Av. Instituto Literario No. 100, Oriente Col. Centro, Toluca, Estado de México C.P. 50000, México (Mexico); Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Edo. de México C.P. 52750, México (Mexico); Camps, E. [Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Edo. de México C.P. 52750, México (Mexico); Camacho-López, M. [Universidad Autónoma del Estado de México, Av. Instituto Literario No. 100, Oriente Col. Centro, Toluca, Estado de México C.P. 50000, México (Mexico); Muhl, S. [Instituto de Investigación en Materiales (UNAM), Circuito Exterior, Ciudad Universitaria, Coyoacán, 04510 México, D.F., México (Mexico); and others

    2015-09-15

    Highlights: • Bismuth nanoparticles have been obtained by laser ablation of solids in liquids. • The technique allows controlling the size and concentration of the samples. • Bi np’s in base oils can improve the tribological characteristics of the lubricant. - Abstract: The improvement of the tribological properties of mineral base oils through the addition of bismuth nanoparticles as an additive, together with the idea of obtaining lubricants free of heavy metals, was evaluated. Bismuth nanoparticles were produced directly in the heavy and light viscosity mineral base oils (BS900 and BS6500) using the technique of laser ablation of solids immersed in liquids. Transmission electron microscopy measurements showed the presence of pure bismuth nanoparticles. Small Angle X-ray Scattering (SAXS) measurements showed that the average size of the nanoparticles was between 7 and 65 nm depending on the experimental conditions used. The tribological properties of the base oil with the bismuth nanoparticles additives were evaluated using a four-ball tester. Tests were performed using the base oil with and without Bi nanoparticles. It was observed that the coefficient of friction of the oil decrease with an increasing concentration of the nanoparticles. The results also showed that the wear rate was reduced when the Bi nanoparticle additives were used.

  12. Role of bismuth in improving Helicobacter pylori eradication with triple therapy.

    Science.gov (United States)

    Dore, Maria Pina; Lu, Hong; Graham, David Y

    2016-05-01

    In most regions of the world, antimicrobial resistance has increased to the point where empirical standard triple therapy forHelicobacter pylorieradication is no longer recommended. The treatment outcome in a population is calculated as the sum of the treatment success in the subpopulation with susceptible infections plus treatment success in the subpopulation with resistant infections. The addition of bismuth (ie, 14-day triple therapy plus bismuth) can improve cure rates despite a high prevalence of antimicrobial resistance. The major bismuth effect is to add an additional 30%-40% to the success with resistant infections. The overall result is therefore dependent on the prevalence of resistance and the treatment success in the subpopulation with resistant infections (eg, with proton-pump inhibitor-amoxicillin dual therapy). Here, we explore the contribution of each component and the mechanisms of how bismuth might enhance the effectiveness of triple therapy. We also discuss the limitations of this approach and provide suggestions how triple therapy plus bismuth might be further improved. PMID:26848181

  13. Magnetoelectric Effect in Ceramics Based on Bismuth Ferrite

    Science.gov (United States)

    Jartych, Elżbieta; Pikula, Tomasz; Kowal, Karol; Dzik, Jolanta; Guzdek, Piotr; Czekaj, Dionizy

    2016-04-01

    Solid-state sintering method was used to prepare ceramic materials based on bismuth ferrite, i.e., (BiFeO3)1 - x -(BaTiO3) x and Bi1 - x Nd x FeO3 solid solutions and the Aurivillius Bi5Ti3FeO15 compound. The structure of the materials was examined using X-ray diffraction, and the Rietveld method was applied to phase analysis and structure refinement. Magnetoelectric coupling was registered in all the materials using dynamic lock-in technique. The highest value of magnetoelectric coupling coefficient α ME was obtained for the Bi5Ti3FeO15 compound ( α ME ~ 10 mVcm-1 Oe-1). In the case of (BiFeO3)1 - x -(BaTiO3) x and Bi1 - x Nd x FeO3 solid solutions, the maximum α ME is of the order of 1 and 2.7 mVcm-1 Oe-1, respectively. The magnitude of magnetoelectric coupling is accompanied with structural transformation in the studied solid solutions. The relatively high magnetoelectric effect in the Aurivillius Bi5Ti3FeO15 compound is surprising, especially since the material is paramagnetic at room temperature. When the materials were subjected to a preliminary electrical poling, the magnitude of the magnetoelectric coupling increased 2-3 times.

  14. Ferroelectric and photocatalytic behavior of bismuth ferrite nano wire

    Science.gov (United States)

    William, R. V.; Marikani, A.; Madhavan, D.

    2016-05-01

    Multiferroic bismuth ferrite nanowires are prepared through polyol method with an average diameter of 35 nm with a narrow size distribution. The band gap was determined to be 2.10 eV, indicating their potential application as visible-light-response photo catalyst. The magnificent photocatalytic behaviors of BiFeO3 nanowires are understood from the methyl violet degradation under visible light irradiation. Moreover, the nano-wire takes only a lesser time for the diffusion of electron-hole pair from the surface of the sample. Further the BiFeO3 nano-wire was characterized using XRD, SEM, and U-V. The ferroelectric studies of BiFeO3 nano-wire show a frequency dependent property and maximum coercivity of 2.7 V/cm were achieved with a remanent polarization at 0.5 µC/cm2 at the frequency 4 kHz. The coercivity of BiFeO3 nano wire changes with variation of frequency from 1 kHz to 4 kHz.

  15. Energy levels scheme simulation of divalent cobalt doped bismuth germanate

    International Nuclear Information System (INIS)

    The aim of this paper is to simulate the energy levels scheme for Bismuth Germanate (BGO) doped with divalent cobalt, in order to give a reliable explanation for spectral experimental data. In the semiempirical crystal field theory we first modeled the Crystal Field Parameters (CFPs) of BGO:Cr2+ system, in the frame of Exchange Charge Model (ECM), with actually site symmetry of the impurity ions after doping. The values of CFPs depend on the geometry of doped host matrix and by parameter G of ECM. First, we optimized the geometry of undoped BGO host matrix and afterwards, that of doped BGO with divalent cobalt. The charges effect of ligands and covalence bonding between cobalt cations and oxygen anions, in the cluster approach, also were taken into account. With the obtained values of the CFPs we simulate the energy levels scheme of cobalt ions, by diagonalizing the matrix of the doped crystal Hamiltonian. Obviously, energy levels and estimated Racah parameters B and C were compared with the experimental spectroscopic data and discussed. Comparison of obtained results with experimental data shows quite satisfactory, which justify the model and simulation schemes used for the title system

  16. Characterization of electrodeposited bismuth-tellurium nanowires and nanotubes

    International Nuclear Information System (INIS)

    Arrays of nanowires and nanotubes of bismuth-tellurium (Bi-Te) were fabricated by electrodeposition techniques. Scanning electron microscopy was employed to characterize the morphology of the fabricated BiTe nanowires and nanotubes. The fabricated BiTe nanowire and nanotube arrays are shown to be polycrystalline with no preferred orientation. Wavelength dispersive spectroscopy analysis shows that either p-type (Bi rich) or n-type (Te rich) nanowires or nanotubes can be obtained by changing the electrodeposition potentials. The lamellar thickness of the nanowires and nanotube crystallites were determined using the Scherrer equation and found to be ∼17-24 nm. The Seebeck coefficient measurements at room temperature obtained for the nanowires and nanotubes deposited at -400 mV were +11.5 and +17 μV K-1, respectively, whereas those obtained at -65 mV were -48 and -63 μV K-1, respectively. The electrical resistance measurements indicated that the resistance of the nanowires and nanotubes decreased with increasing temperature, suggesting that these nanostructures behave like semiconductors.

  17. Transport phenomena in nanowires based on bismuth alloys

    International Nuclear Information System (INIS)

    Full text: In this work, we study the conductivity and thermopower of quantum wires (QW) based on bismuth alloys. Calculations are carried out for nanowires with degenerate and nondegenerate gas of carriers at various crystalline orientations taking into account the real band structure of Bi. We find the energy eigenvalues of holes and taking into account the nonparabolicity of the band, the energy eigenvalues for electrons. The conductivity and thermopower determined with the use of the Kubo formulae in the case when the basic mechanism of carrier scattering is assumed to be elastic acoustic-phonon scattering and on a roughness surface of QW. Dependences of kinetic coefficients on temperature, nanowire diameter and crystalline orientation are investigated. The conductivity and thermopower of a QW contains the contributions of electrons and holes. Taking into account values of carrier effective masses and other band parameters of Bi, it is possible to conclude that the contribution of holes to the conductivity of nondegenerate carriers of QWs is more less than that of electrons, which is attributed to smaller effective mass of electrons. For a semiconducting Bi QW the conductivity depends exponentially on a temperature and wire diameter. The thermopower of a semiconducting and of a semimetallic Bi QW at low temperatures can be positive and change sign in more higher temperatures. The theoretical results are close to experiment for Bi wires with diameter of 50-100 nm. (author)

  18. Bismuth alloying properties in GaAs nanowires

    International Nuclear Information System (INIS)

    First-principles calculations have been performed to investigate the structural, electronic and optical properties of bismuth alloying in GaAs nanowires. A typical model of Ga31As31 nanowires is introduced for its reasonable band gap. The band gap of GaAs1−xBix shrinks clearly with the increasing Bi concentration and the band edge shifts when spin–orbit coupling (SOC) is considered. The insertion of Bi atom leads to hybridization of Ga/As/Bi p states which contributes a lot around Fermi level. Scissor effect is involved. The optical properties are presented, including dielectric function, optical absorption spectra and reflectivity, which are also varied with the increasing of Bi concentrations. - Graphical abstract: Top view of Bi-doped GaAs nanowires. Ga, As, and Bi atoms are denoted with grey, purple and red balls, respectively. Display Omitted - Highlights: • A typical model of Ga31As31 nanowires is introduced for its reasonable band gap. • The band gap of GaAs1−xBix shrinks clearly with the increasing Bi concentration. • The band edge shifts when spin–orbit coupling (SOC) is considered. • The insertion of Bi atom leads to hybridization of Ga/As/Bi p states

  19. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Castañeda, Mariela [Instituto Nacional de Investigaciones Nucleares (Mexico); Vega-Jiménez, Alejandro L., E-mail: argelia.almaguer@mac.com; Almaguer-Flores, Argelia [Universidad Nacional Autónoma de México, Facultad de Odontología, DEPeI, I (Mexico); Camps, Enrique; Pérez, Mario [Instituto Nacional de Investigaciones Nucleares (Mexico); Silva-Bermudez, Phaedra [Instituto Nacional de Rehabilitación, Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa (Mexico); Berea, Edgardo [FarmaQuimia SA de CV. (Mexico); Rodil, Sandra E. [Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales (Mexico)

    2015-11-15

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  20. Investigation of solution-processed bismuth-niobium-oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Satoshi, E-mail: s-inoue@jaist.ac.jp [Green Device Research Center, Japan Advanced Institute of Science and Technology (JAIST), 2-13 Asahidai, Nomi, Ishikawa 923-1211 (Japan); School of Material Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Ariga, Tomoki [Green Device Research Center, Japan Advanced Institute of Science and Technology (JAIST), 2-13 Asahidai, Nomi, Ishikawa 923-1211 (Japan); ERATO Shimoda Nano-Liquid Process Project, Japan Science and Technology Agency (JST), 2-13 Asahidai, Nomi, Ishikawa 923-1211 (Japan); Matsumoto, Shin [School of Material Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Onoue, Masatoshi; Miyasako, Takaaki [ERATO Shimoda Nano-Liquid Process Project, Japan Science and Technology Agency (JST), 2-13 Asahidai, Nomi, Ishikawa 923-1211 (Japan); Tokumitsu, Eisuke; Shimoda, Tatsuya [Green Device Research Center, Japan Advanced Institute of Science and Technology (JAIST), 2-13 Asahidai, Nomi, Ishikawa 923-1211 (Japan); School of Material Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); ERATO Shimoda Nano-Liquid Process Project, Japan Science and Technology Agency (JST), 2-13 Asahidai, Nomi, Ishikawa 923-1211 (Japan); Chinone, Norimichi; Cho, Yasuo [Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2014-10-21

    The characteristics of bismuth-niobium-oxide (BNO) films prepared using a solution process were investigated. The BNO film annealed at 550°C involving three phases: an amorphous phase, Bi₃NbO₇ fluorite microcrystals, and Nb-rich cubic pyrochlore microcrystals. The cubic pyrochlore structure, which was the main phase in this film, has not previously been reported in BNO films. The relative dielectric constant of the BNO film was approximately 140, which is much higher than that of a corresponding film prepared using a conventional vacuum sputtering process. Notably, the cubic pyrochlore microcrystals disappeared with increasing annealing temperature and were replaced with triclinic β-BiNbO₄ crystals at 590°C. The relative dielectric constant also decreased with increasing annealing temperature. Therefore, the high relative dielectric constant of the BNO film annealed at 550°C is thought to result from the BNO cubic pyrochlore structure. In addition, the BNO films annealed at 500°C contained approximately 6.5 atm.% carbon, which was lost at approximately 550°C. This result suggests that the carbon in the BNO film played an important role in the formation of the cubic pyrochlore structure.

  1. Optical bleaching of bismuth implanted silica glass: A threshold effect

    International Nuclear Information System (INIS)

    The near surface regions of high purity silica glass discs, Spectrosil A, were modified by implantation with bismuth ions at 160 keV and room temperature. The glasses implanted with a nominal dose of 6 x 1016 Bi/cm2 at ∼5 μA/cm2 were subsequently bleached with a 5.0 eV KrF pulsed excimer laser. The laser had an average pulse duration of ∼20 ns and repetition rate of 10 Hz, It was found that the bleaching was dependent upon the power density of the laser for a constant total integrated energy. Ion backscattering and optical absorption measurements were made before and after laser irradiation. Large changes in optical density and depth distribution of the implanted ions were observed at power densities of ≥45 mJ/cm2-pulse. On the basis of the experimental results, the onset of the threshold for bleaching of silica glass implanted with 6 x 1016 Bi/cm2 at 160 keV and at room temperature is between 30 and 45 mJ/cm2-pulse

  2. Modular Lead-Bismuth Fast Reactors in Nuclear Power

    Directory of Open Access Journals (Sweden)

    Vladimir Petrochenko

    2012-09-01

    Full Text Available On the basis of the unique experience of operating reactors with heavy liquid metal coolant–eutectic lead-bismuth alloy in nuclear submarines, the concept of modular small fast reactors SVBR-100 for civilian nuclear power has been developed and validated. The features of this innovative technology are as follows: a monoblock (integral design of the reactor with fast neutron spectrum, which can operate using different types of fuel in various fuel cycles including MOX fuel in a self-providing mode. The reactor is distinct in that it has a high level of self-protection and passive safety, it is factory manufactured and the assembled reactor can be transported by railway. Multipurpose application of the reactor is presumed, primarily, it can be used for regional power to produce electricity, heat and for water desalination. The Project is being realized within the framework of state-private partnership with joint venture OJSC “AKME-Engineering” established on a parity basis by the State Atomic Energy Corporation “Rosatom” and the Limited Liability Company “EuroSibEnergo”.

  3. A detailed study of 2223 bismuth superconductor system

    International Nuclear Information System (INIS)

    In an attempt to obtain improved Phase conditions, Critical current density and Tc, in Bismuth based 2223 superconducting, eleven batches of samples of Bi/sub 2-x/, (Pb/sub x-y/ Sb/sub y/) Sr/sub 2/ Ca/sub 2/Cu/sub 3/O delta series, where (x,y) =(0.5,0.4), (0.32, 0), (0.4, 0.2), (o.4, 0.1), (0.3, 0.2), (0.3, 0.1), (0.2, 0.1), (0.1, 0.1) and (0.1, 0) were prepared using solid state reaction method. Electrical resistivity measurements on samples showed normal superconductor behavior with a dominating superconducting phase of 110K as well as a quite improved critical current. However two samples of series showed semiconductor behavior up to LN2 temperature. X-ray diffraction analysis have also been made on samples which showed a multiphase. (author)

  4. Synthesis and characterization of bismuth zinc niobate pyrochlore nanopowders

    Directory of Open Access Journals (Sweden)

    Sonia Maria Zanetti

    2007-09-01

    Full Text Available Bismuth zinc niobate pyrochlores Bi1.5ZnNb1.5O7 (alpha-BZN, and Bi2(Zn1/3Nb2/32O 7 (beta-BZN have been synthesized by chemical method based on the polymeric precursors. The pyrochlore phase was investigated by differential scanning calorimetry, infrared spectroscopy, and X ray diffraction. Powder and sintered pellets morphology was examined by scanning electron microscopy. The study of alpha-BZN phase formation reveals that, at 500 °C, the pyrochlore phase was already present while a single-phased nanopowder was obtained after calcination at 700 °C. The crystallization mechanism of the beta-BZN is quite different, occurring through the crystallization of alpha-BZN and BiNbO4 intermediary phases. Both compositions yielded soft agglomerated powders. alpha-BZN pellets, sintered at 800 °C for 2 hours, presented a relative density of 97.3% while those of beta-BZN, sintered at 900 °C for 2 hours, reached only 91.8%. Dielectric constant and dielectric loss, measured at 1 MHz, were 150 and 4 x/10-4 for a-BZN, and 97 and 8 x 10-4 for beta-BZN.

  5. Energy levels scheme simulation of divalent cobalt doped bismuth germanate

    Energy Technology Data Exchange (ETDEWEB)

    Andreici, Emiliana-Laura, E-mail: andreicilaura@yahoo.com [Department of Physics, West University of Timisoara, Bd. V. Parvan 4,300223 Timisoara (Romania); Petkova, Petya [Shumen University “Konstantin Preslavsky”, 115 Universitetska street, 9712 Shumen (Bulgaria); Avram, Nicolae M. [Department of Physics, West University of Timisoara, Bd. V. Parvan 4,300223 Timisoara (Romania); Academy of Romanian Scientists, Independentei 54, 050094-Bucharest (Romania)

    2015-12-07

    The aim of this paper is to simulate the energy levels scheme for Bismuth Germanate (BGO) doped with divalent cobalt, in order to give a reliable explanation for spectral experimental data. In the semiempirical crystal field theory we first modeled the Crystal Field Parameters (CFPs) of BGO:Cr{sup 2+} system, in the frame of Exchange Charge Model (ECM), with actually site symmetry of the impurity ions after doping. The values of CFPs depend on the geometry of doped host matrix and by parameter G of ECM. First, we optimized the geometry of undoped BGO host matrix and afterwards, that of doped BGO with divalent cobalt. The charges effect of ligands and covalence bonding between cobalt cations and oxygen anions, in the cluster approach, also were taken into account. With the obtained values of the CFPs we simulate the energy levels scheme of cobalt ions, by diagonalizing the matrix of the doped crystal Hamiltonian. Obviously, energy levels and estimated Racah parameters B and C were compared with the experimental spectroscopic data and discussed. Comparison of obtained results with experimental data shows quite satisfactory, which justify the model and simulation schemes used for the title system.

  6. Synthesis and characterization of bismuth doped barium sulphide nanoparticles

    International Nuclear Information System (INIS)

    We have synthesized BaS:Bi nanocrystalline powder of average grain size 35 nm by solid-state diffusion method using sodium thiosulphate as a flux. During this work we have optimized the nature and amount of flux, amount of the dopant and temperature of firing for maximum yield of photoluminescence. The samples were characterized by X-ray powder diffraction (XRD) method, transmission electron microscopy (TEM), photoluminescence (PL) and UV-visible techniques. On excitation by 425 nm, these nanophosphors give one emission peak at 575 nm which corresponds to green color. In the excitation spectra of these particles there are two peaks at 350 nm and 425 nm. The effect of dopant concentration on the photoluminescence of BaS:Bi nanocrystallites has been studied which is in agreement with the principle of concentration quenching. The energy band gap of bismuth doped BaS nanopowder has been calculated to be 4.25 eV and is blue shifted in comparison to their bulk counterparts. The blue shift may be due to the quantum confinement in the particles.

  7. Optical bleaching of bismuth implanted silica glass: A threshold effect

    International Nuclear Information System (INIS)

    The near surface regions of high purity silica glass discs, Spectrosil A, were modified by implantation with bismuth ions at 160 key and room temperature. The glasses implanted with a nominal dose of 6x1016 Bi/cm2 at ∼5 μA/cm2 were subsequently bleached with a 5.0 eV KrF pulsed excimer laser. The laser had an average pulse duration of ∼20 ns and repetition rate of 10 Hz. It was found that the bleaching was dependent upon the power density of the laser for a constant total integrated energy. Ion backscattering and optical absorption measurements were made before and after laser irradiation. Large changes in optical density and depth distribution of the implanted ions were observed at power densities of ≥45 mJ/cm2-pulse. Onset of threshold for bleaching of silica glass implanted with 6x1016 Bi/cm2 at 160 key and at room temperature is between 30 and 45 mJ/cm2-pulse

  8. Bismuth nanoparticles integration into heavy metal electrochemical stripping sensor.

    Science.gov (United States)

    Cadevall, Miquel; Ros, Josep; Merkoçi, Arben

    2015-08-01

    Between their many applications bismuth nanoparticles (BiNPs) are showing interest as pre-concentrators in heavy metals detection while being applied as working electrode modifiers used in electrochemical stripping analysis. From the different reported methods to synthesize BiNPs we are focused on the typical polyol method, largely used in these types of metallic and semi-metallic nanoparticles. This study presents the strategy for an easy control of the shape and size of BiNPs including nanocubes, nanosferes and triangular nanostructures. To improve the BiNP size and shape, different reducing agents (ethylene glycol or sodium hypophosphite) and stabilizers (polyvinyl pyrrolidone, PVP, in different amounts) have been studied. The efficiency of BiNPs for heavy metals analysis in terms of detection sensitivity while being used as modifiers of screen-printed carbon electrodes including the applicability of the developed device in real sea water samples is shown. A parallel study between the obtained nanoparticles and their performance in heavy metal sensing has been described in this communication. PMID:25994368

  9. Investigation of solution-processed bismuth-niobium-oxide films

    International Nuclear Information System (INIS)

    The characteristics of bismuth-niobium-oxide (BNO) films prepared using a solution process were investigated. The BNO film annealed at 550 °C involving three phases: an amorphous phase, Bi3NbO7 fluorite microcrystals, and Nb-rich cubic pyrochlore microcrystals. The cubic pyrochlore structure, which was the main phase in this film, has not previously been reported in BNO films. The relative dielectric constant of the BNO film was approximately 140, which is much higher than that of a corresponding film prepared using a conventional vacuum sputtering process. Notably, the cubic pyrochlore microcrystals disappeared with increasing annealing temperature and were replaced with triclinic β-BiNbO4 crystals at 590 °C. The relative dielectric constant also decreased with increasing annealing temperature. Therefore, the high relative dielectric constant of the BNO film annealed at 550 °C is thought to result from the BNO cubic pyrochlore structure. In addition, the BNO films annealed at 500 °C contained approximately 6.5 atm. % carbon, which was lost at approximately 550 °C. This result suggests that the carbon in the BNO film played an important role in the formation of the cubic pyrochlore structure.

  10. Chapter 10. On average contents of bismuth, indium and thallium in secondary sediments of depression of Tajikistan

    International Nuclear Information System (INIS)

    In this part of book author made conclusion that background contents of bismuth, indium and thallium in secondary sediments of depression of Tajikistan depend from petrographic composition of layers of drainage area, facial-climatic conditions and lithologic layer type; accumulation of investigated elements pass at coastal phases; clayey sediments more enriched by bismuth, indium and thallium than sandstones

  11. Overview of the use of ATHENA for thermal-hydraulic analysis of systems with lead-bismuth coolant

    International Nuclear Information System (INIS)

    The INEEL and MIT are investigating the suitability of lead-bismuth cooled fast reactor for producing low-cost electricity as well as for actinide burning. This paper is concerned with the general area of thermal-hydraulics of lead-bismuth cooled reactors. The ATHENA code is being used in the thermal-hydraulic design and analysis of lead-bismuth cooled reactors. The ATHENA code was reviewed to determine its applicability for simulating lead-bismuth cooled reactors. Two modifications were made to the code as a result of this review. Specifically, a correlation to represent heat transfer from rod bundles to a liquid metal and a void correlation based on data taken in a mixture of lead-bismuth and steam were added the code. The paper also summarizes the analytical work that is being performed with the code and plans for future analytical work

  12. Assessment of the Eye Lens Dose Reduction by Bismuth Shields in Rando Phantom Undergoing CT of the Head

    International Nuclear Information System (INIS)

    The aim of this study is to assess the dose reduction of eye lens and availability of bismuth garments resulting from the use of radioprotective bismuth garments to shield the eyes of patients undergoing head CT. Rando phantom and TLDs were used to determine the amount of dose reduction by bismuth shielding of the eye in the following simulated CT scans : (a) scanning of the head including orbits, (b) scanning of the whole head, and (c) angled scanning of the head excluding orbits. The average dose reduction of eye lens was 43.2%, 36.0% and 1.4% for the three CT scans listed above. Significant reduction in the eye lens dose was achieved by using superficial orbital bismuth shielding during head CT scans. However, bismuth shields should not be used for the patients when their eyes are excluded from the primarily exposed region.

  13. Melting behaviour of lead and bismuth nano-particles in quasicrystalline matrix - The role of interfaces

    Indian Academy of Sciences (India)

    Alok Singh; A P Tsai

    2003-02-01

    Nanomaterials are playing an increasingly important role in modern technologies. Interfaces are crucial in nanotechnology. In this study, we have examined the stability of nanoparticles. Major emphasis is on understanding the effect of interfaces on melting. Melting behaviour of nanocrystalline interfaces, created by embedding lead and bismuth nanoparticles in quasicrystalline matrices, was studied. Sharply faceted and coherent interfaces can be related to sharper melting transitions, while irregularly shaped and incoherent interfaces can be directly correlated with lowering of melting temperatures. It is shown here that solid lead forms a high energy interface with phason strain-free quasicrystal (resulting in a lowering of the melting temperature) while bismuth forms a low energy interface with the quasicrystal (resulting in superheating, unusual for bismuth).

  14. Bismuth subcarbonate as filler particle for an Epoxy-based root canal sealer

    Directory of Open Access Journals (Sweden)

    Eduardo Schwartzer

    2013-01-01

    Full Text Available Introduction: The aim of this study was to evaluate the addition of bismuth subcarbonate with different concentrations regarding the rheological properties of an experimental epoxy-based root canal sealer. Materials and Methods: Endodontic sealers were prepared with epoxy resin-based sealer with bismuth subcarbonate additions of 20%, 40%, 60%, 80%, 100%, and 120%. Flow, film thickness, working time, setting time, dimensional change, sorption, solubility, and cytotoxicity were studied according to the ISO standards. Data were statistically analyzed by one-way ANOVA, and Tukey multiple comparisons were used, with a significance level of 5%. Results: The flow, working time, water sorption, and solubility significantly decreased and the film thickness and dimensional change increased with higher filler particle addition. There were no statistically significant differences for setting time and cytotoxicity between the filler particle proportions. Conclusion: Experimental resin-based sealer with bismuth subcarbonate addition up to 40% can be an alternative for root canal sealer.

  15. Fluorescence Emission Centres and the Corresponding Infrared Fluorescence Saturation in a Bismuth-Doped Silica Fibre

    Institute of Scientific and Technical Information of China (English)

    QIU Yan-Qing; SHEN Yong-Hang

    2008-01-01

    We investigate the fluorescence characteristics of bismuth doped silica fibres with and without Al co-dopant which are fabricated by means of modified chemical vapour deposition (MCVD) technique, and find that the fluorescences in the red region (centred around 750nm) and in the infrared region (centred around 1100nm) may originate from different emission sites in the fibre. Strong upconversion phenomena are observed in both Al-codoped and non Al codoped bismuth fibres when the fibres are excited by an acoustic-optic Q-switched Nd: YVO4 laser. Both the aspects indicate that the upper energy level absorption reported in the work of the bismuth doped silica fibre lasers may result from the fluorescence emission sites that are not responsible for the infrared emission. It is thus expected that optimizing the compositions and the fabrication conditions of the fibre and then transferring more fluorescence emission centres are helpful for the infrared emission.

  16. Sintering characteristics of La/Nd doped Bi4Ti3O12 bismuth titanate ceramics

    Directory of Open Access Journals (Sweden)

    Islam Aminul Md.

    2015-01-01

    Full Text Available A good understanding about the properties of La/Nd doped Bismuth Titanate (BIT ceramics at high temperature is very important as the new materials being developed based on the BIT. Pure BIT, La doped (BLT, Nd doped (BNT and La and Nd co-doped BIT (BLNT powders were synthesized by solid state reaction method. Prepared powders were calcined at different temperatures and structural properties measured by XRD. For pure BIT better crystal quality was obtained at 750 0C and for both BLT and BNT better result obtained at 800 0C. Calcined powders were formed into pellets and sintered at different temperatures and its dielectric properties were characterized. Optimum sintering temperature for both BLT and BNT showed was 850 0C and La and Nd co-doped bismuth titanate (BLNT revealed optimum sintering temperature of 950 0C. Therefore, optimum sintering temperature of bismuth titanate was increased due to La and Nd doping.

  17. Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

    International Nuclear Information System (INIS)

    Transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at ~400 keVee. In another configuration, a bismuth-loaded PVT plastic is coated with ZnS(6Li) paint, permitting simultaneous gamma and neutron detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%

  18. Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

    Energy Technology Data Exchange (ETDEWEB)

    Cherepy, Nerine J., E-mail: cherepy1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA (United States); Sanner, Robert D.; Beck, Patrick R.; Swanberg, Erik L.; Tillotson, Thomas M.; Payne, Stephen A. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Hurlbut, Charles R. [Eljen Technology, Sweetwater, TX (United States)

    2015-04-01

    Transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at ~400 keVee. In another configuration, a bismuth-loaded PVT plastic is coated with ZnS({sup 6}Li) paint, permitting simultaneous gamma and neutron detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%.

  19. Design of an Actinide Burning, Lead-Bismuth Cooled Reactor That Produces Low Cost Electricity

    Energy Technology Data Exchange (ETDEWEB)

    C. Davis; S. Herring; P. MacDonald; K. McCarthy; V. Shah; K. Weaver (INEEL); J. Buongiorno; R. Ballinger; K. Doyoung; M. Driscoll; P. Hejzler; M. Kazimi; N. Todreas (MIT)

    1999-07-01

    The purpose of this project is to investigate the suitability of lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The goal is to identify and analyze the key technical issues in core neutronics, materials, thermal-hydraulics, fuels, and economics associated with the development of this reactor concept. The choice of lead-bismuth for the reactor coolant is an actinide burning fast reactor offers enhanced safety and reliability. The advantages of lead-bismuth over sodium as a coolant are related to the following material characteristics: chemical inertness with air and water; higher atomic number; lower vapor pressure at operating temperatures; and higher boiling temperature. Given the status of the field, it was agreed that the focus of this investigation in the first two years will be on the assessment of approaches to optimize core and plant arrangements in order to provide maximum safety and economic potential in this type of reactor.

  20. Poisoning effect of bismuth on modification behaviour of strontium in LM25 alloy

    Indian Academy of Sciences (India)

    S Farahany; A Ourdjini; M H Idris; L T Thai

    2011-10-01

    Nucleation and growth, temperature measurements andmicrostructure observations of silicon phase are presented for strontium modified Al–7%Si (LM25) cast alloy treated with bismuth. The results show that addition of bismuth in strontium modified alloys may have a poisoning effect resulting in lost modification of the silicon phase. With increasing Bi/Sr ratio, thermal analysis measurements showed that the eutectic growth temperature increased remarkably to 573°C and recalescence decreased to 0.2°C and the morphology of silicon displayed the same flakelike structure as in the unmodified alloys. Microstructural observation showed that a minimum Bi/Sr ratio of 1.2 which is equivalent to a Sr/Bi ratio of 0.43 is required for effective strontium modification and neutralization of the poisoning effect of bismuth.

  1. Preparation of bismuth-based nanosheets by ultrasound-assisted liquid laser ablation

    Science.gov (United States)

    Escobar-Alarcón, L.; Velarde Granados, E.; Solís-Casados, D. A.; Olea-Mejía, O.; Espinosa-Pesqueira, M.; Haro-Poniatowski, E.

    2016-04-01

    The preparation of bismuth nanosheets ablating a high purity Bi target immersed in water subjected to an ultrasound wave is reported. The effect of the laser fluence used for ablation on the size and shape of the nanostructures synthesized was investigated. The obtained results reveal the formation of nanosheets with square-like shape and sizes from approximately 140-543 nm. In comparison, experiments without the ultrasound field lead to the formation of quasi-spherical nanoparticles. The nanosheets were characterized by means of transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), UV-Vis and Raman spectroscopies. The bismuth nanosheets, as deposited, are highly crystalline, and depending on the preparation conditions, the α or β phases of Bi2O3 are obtained. UV-Vis measurements show the typical band absorption characteristic of bismuth with nanometric size. Raman spectra confirm the formation of Bi2O3 nanostructures.

  2. Application of Thermodynamic Calculations to the Pyro-refining Process for Production of High Purity Bismuth

    Science.gov (United States)

    Mezbahul-Islam, Mohammad; Belanger, Frederic; Chartrand, Patrice; Jung, In-Ho; Coursol, Pascal

    2016-04-01

    The present work has been performed with the aim to optimize the existing process for the production of high purity bismuth (99.999 pct). A thermo-chemical database including most of the probable impurities of bismuth (Bi-X, X = Ag, Au, Al, Ca, Cu, Fe, Mg, Mn, Na, Ni, Pb, S, Sb, Sn, Si, Te, Zn) has been constructed to perform different thermodynamic calculations required for the refining process. Thermodynamic description for eight of the selected binaries, Bi-Ca, Cu, Mn, Ni, Pb, S, Sb, and Sn, has been given in the current paper. Using the current database, different thermodynamic calculations have been performed to explain the steps involved in the bismuth refining process.

  3. Characteristics of polonium contamination from neutral irradiated lead-bismuth eutectic

    International Nuclear Information System (INIS)

    After neutron capture, bismuth-209 changes to polonium-210 that emits α-particles. Lead-Bismuth eutectic (LBE) in reactor system contaminates the system by polonium. We analyzed adsorbed materials from melted LBE on quartz glass plate. Lead, bismuth and their oxides were confirmed in adsorbed materials. And, we evaluated the baking method in vacuum for removal of polonium and adsorbed materials on quartz glass plate. It was evaluated that it is possible to remove almost all the polonium from the quartz glass plate by baking at temperature more than 300 C. degrees. Unfolding method was applied to calculate polonium distribution in LBE ingot. From measured α-particle pulse height distribution, the polonium distribution in depth of LBE ingot was calculated using quadratic programming code, where response functions are calculated by Monte Carlo method. (authors)

  4. Radioactive Iodine (I-129) Gas Adsorption by Using Bismuth-Embedded SBA-15

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Hwan; Cho, Yong-Jun; Park, Jang Jin; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yim, Man-Sung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-05-15

    The efficient capture of the long-lived I-129, released as off-gas from nuclear fuel reprocessing, have been of significant concern in the waste management field. In this study, bismuth-embedded SBA-15 mesoporous silica was firstly applied for iodine capture and storage. SBA-15 was functionalized with thiol (-SH) groups, followed by bismuth adsorption with Bi-S bonding, which was thermally treated to form Bi{sub 2}S{sub 3} within SBA-15. The bismuth-embedded SBA-15s demonstrated high iodine loading capacities with 540 mg-I/g-sorbent maximally, which benefitted from the high surface area and porosity of SBA-15 as well as the formation of thermodynamically stable BiI{sub 3} compound. Iodine physisorption could effectively be suppressed due to the large pores present in SBA-15, resulting in chemisorption as a main mechanism for iodine confinement.

  5. Influence of bismuth on the charging ability of negative plates in lead-acid batteries

    Science.gov (United States)

    Lam, L. T.; Ceylan, H.; Haigh, N. P.; Manders, J. E.

    To examine the influence of bismuth on the charging ability of negative plates in lead-acid batteries, plates are made from three types of oxides: (i) leady oxide of high quality which contains virtually no bismuth (termed 'control oxide'); (ii) control oxide in which bismuth oxide is blended at bismuth levels from 0.01 to 0.12 wt.%; (iii) leady oxide produced from Pasminco VRLA Refined™ lead (0.05-0.06 wt.%Bi). An experimental tool—the 'conversion indicator'—is developed to assess the charging ability of the test negative plates when cycling under either zero percent state-of-charge (SoC)/full-charge or partial state-of-charge (PSoC) duty. Although the conversion indicator is not the true charging efficiency, the two parameters have a close relationship, namely, the higher the conversion indicator, the greater the charging efficiency. Little difference is found in the charging ability, irrespective of bismuth content and discharge rate, when the plates are subjected to zero percent SoC/full-charge duty; the conversion indicator lies in the range 81-84%. By contrast, there is a marked difference when the negative plates are subjected to PSoC duty, i.e. consecutive cycling through 90-60, 70-40, 80-40 and 90-40% SoC windows. Up to 0.06 wt.%Bi improves the charging ability, especially with a low and narrow PSoC window (40-70% SoC) of the type that will be experienced in 42 V powernet automobile and hybrid electric duties. To maximize this beneficial effect, bismuth must be distributed uniformly in the plates. This is best achieved by using VRLA Refined™ lead for oxide production.

  6. Syntheses, crystal structures and characterizations of two new bismuth(III) arsenites

    International Nuclear Information System (INIS)

    Two new bismuth arsenites with two different structural types, namely, Bi2O(AsO3)Cl (1), Bi8O6(AsO3)2(AsO4)2 (2), have been synthesized by the solid-state reactions. Compound 1 exhibits novel 2D bismuth arsenite layers with Bi4O4 rings capped by oxide anions, which are further interconnected by Bi–Cl–Bi bridges into a 3D network. Compound 2 contains both arsenite and arsenate anions, its 3D structures are based on 1D bismuth arsenite and 1D bismuth arsenate chains both along b-axis, which are interconnected by oxide anions via Bi–O–Bi bridges, forming 1D tunnels of Bi4As4 8-membered rings (MRs) along b-axis, the lone pairs of the arsenite groups are orientated toward the centers of the above tunnels. Thermogravimetric analysis indicated that both compounds display high thermal stability. Optical property measurements revealed that they are wide band-gap semiconductors. Both compounds display broad green-light emission bands centered at 506 nm under excitation at 380 and 388 nm. - Graphical abstract: Solid state reactions of Bi2O3 (BiCl3) and As2O3 yielded two new compounds with two different structural types, namely, Bi2O(AsO3)Cl (1), Bi8O6(AsO3)2(AsO4)2 (2). They represent the first examples of bismuth arsenates. Highlights: ► Solid state reactions of Bi2O3 (BiCl3) and As2O3 yielded two new phases. ► They represent the first examples of bismuth arsenites. ► The two compounds exhibit two different structural types.

  7. The effect of bismuth subcitrate in patients with diarrhea predominant irritable bowel syndrome

    Directory of Open Access Journals (Sweden)

    Kalani M

    2010-09-01

    Full Text Available "nBackground: The irritable bowel syndrome (IBS is one of the most common chronic medical conditions. Various mechanisms, including altered gut flora and/or small bowel bacterial overgrowth, have been suggested to play a role in the development of gas-related symptoms aim of study. The clinical evidence of small intestinal bacterial overgrowth as an important etiology of irritable bowel syndrome continues to accumulate. Clinical symptoms of bacterial overgrowth and irritable bowel syndrome are similar; however, a definitive cause-and-effect relationship remains unproven. It is unclear whether motility dysfunction causes bacterial overgrowth or gas products of"nenteric bacteria affect intestinal motility in irritable bowel syndrome."n "nMethods: In a randomized double-blind placebo-controlled trial consisting of treatment with bismuth subcitrate. Primary efficacy variable was subjective symptoms; frequency of abdominal pain, Number of bowel movement & Bloating/distension."n "nResults: 119 patients were enrolled (59 bismuth subcitrate and 60 placebo recipients. At the end of phase 2, all symptom scores dropped significantly both in bismuth subcitrate and placebo group (p<0.001. There was not a significant difference in symptom relief with bismuth subcitrate versus placebo administration."n "nConclusions: There was not a significant difference in symptom relief with bismuth subcitrate versus placebo in IBS patients. Whether antibiotics can improve quality of life in patients with irritable bowel syndrome warrants further research."nInterventions: Participants were randomly assigned to receive 120mg bismuth subcitrate four times daily for 14 days (n=59 or placebo (n=60.

  8. Basic principles of lead and lead-bismuth eutectic application in blanket of fusion reactors

    International Nuclear Information System (INIS)

    High magnetohydrodynamic pressure drop is an important issue for liquid metal blanket concepts. To decrease magnetohydrodynamic resistance authors propose to form insulating coatings on internal surface of blanket ducts at any moment of fusion reactor exploitation. It may be achieved easily if lead or lead-bismuth eutectic is used and technology of oxidative potential handling is applied. A number of experiments carried out in NNSTU show the availability of the proposed technology. It bases on formation of the insulating coatings that consist of the oxides of components of the structural materials and of the coolant components. In-situ value of the insulating coatings characteristics ρδ is ∼ 10-5 Ohm·m2 for steels and 5,0x10-6 - 5,0x10-5 Ohm·m2 for vanadium alloys. Thermal cycling is possible during exploitation of a blanket. The experimental research of the insulating coatings properties during thermal cycling have shown that the coatings formed into the lead and lead-bismuth coolants save there insulating properties. Experience of many years is an undoubted advantage of the lead-bismuth coolant and less of the lead coolant in comparison with lithium. Russian Federation possesses of experience of exploitation of the research and industrial facilities, of experience of creation of the pumps, steamgenerators and equipment with heavy liquid metal coolants. The unique experience of designing, assembling and exploitation of the fission reactors with lead-bismuth coolant is also available. The problem of technology of lead and lead-bismuth coolants for power high temperature radioactive facilities has been solved. Accidents, emergency situations such as leakage of steamgenerators or depressurization of gas system in facilities with lead and lead-bismuth coolants have been explored and suppressed. (author)

  9. Deposition of Visible Light Active Photocatalytic Bismuth Molybdate Thin Films by Reactive Magnetron Sputtering

    OpenAIRE

    Marina Ratova; Kelly, Peter J; Glen T. West; Xiaohong Xia; Yun Gao

    2016-01-01

    Bismuth molybdate thin films were deposited by reactive magnetron co-sputtering from two metallic targets in an argon/oxygen atmosphere, reportedly for the first time. Energy dispersive X-ray spectroscopy (EDX) analysis showed that the ratio of bismuth to molybdenum in the coatings can be effectively controlled by varying the power applied to each target. Deposited coatings were annealed in air at 673 K for 30 min. The crystalline structure was assessed by means of Raman spectroscopy and X-ra...

  10. Equilibrium distribution of lanthanum, neodymium, and thorium between lithium chloride melt and liquid bismuth

    Science.gov (United States)

    Zagnit'ko, A. V.; Ignat'ev, V. V.

    2013-04-01

    The distribution of lanthanum, neodymium, and thorium between a lithium chloride melt and liquid bismuth with additions of lithium as a reducing agent are investigated at 650°C. Equilibrium values of their distribution constants are measured. It is shown that in contrast to neodymium and lanthanum, thorium cannot be extracted from bismuth into lithium chloride. This allows us to propose an efficient scheme for separating lanthanides and thorium in a system for the extraction of fuel salts in molten-salt nuclear reactors.

  11. Basic principles of lead and lead-bismuth eutectic application in blanket of fusion reactors

    International Nuclear Information System (INIS)

    Full text: One of the main requirements of advanced nuclear-power engineering is inherent safety of power installations. It initiates R and D of heavy liquid metals (lead, lead- bismuth eutectic) application in fission reactors as substitute of sodium. The same requirement makes advisable R and D of the lead and lead-bismuth eutectic application in blanket of fusion reactors as substitute of lithium. High magnetohydrodynamic pressure drop is an important issue for liquid metal blanket concepts. To decrease MHD-resistance authors propose to form electro-insulating coatings on internal surface of blanket ducts at any moment of fusion reactor exploitation. It may be achieved easily if lead or lead-bismuth eutectic is used and technology of oxidative potential handling is applied. A number of experiments carried out in NNSTU show the availability of the proposed technology. It bases on formation of the insulating coatings that consist of the oxides of components of the structural materials and of the coolant components. In-situ value of the electro-insulating coatings characteristics rd (r - specific resistance of coatings, d - thickness) is ∼ 10-5Ω·m2 for steels and 5, 0x10-6 - 5, 0x10-5Ω·m2 for vanadium alloys. Thermal cycling is possible during exploitation of a blanket. The experimental research of the insulating coatings properties during thermal cycling have shown that the coatings formed into the lead and lead-bismuth coolants save there electro-insulating properties. Experience of many years is an undoubted advantage of the lead-bismuth coolant and less of the lead coolant in comparison with lithium. Russian Federation possesses of experience of exploitation of the research and industrial facilities, of experience of creation of the pumps, steam generators and another equipment with heavy liquid metal coolants. The unique experience of designing, assembling and exploitation of the fission reactors with lead-bismuth coolant is also available. The problem

  12. Optical properties of thermally reduced bismuth-doped sodium aluminosilicate glasses

    DEFF Research Database (Denmark)

    Nielsen, K.H.; Smedskjær, Morten Mattrup; Yue, Yuanzheng;

    Heat-treatment of multivalent ion containing glasses in a hydrogen atmosphere may cause both reduction of the multivalent ions and ionic inward diffusion, resulting in improved glass properties. Bismuth-doped glasses are also interesting objects not only concerning the reduction induced diffusion......, but also concerning the metal particle formation, and the broadband near infrared luminescence. Both the inward diffusion and the infrared luminescence depend on the bismuth oxidation state. The latter can be varied by adjusting the parameters of the heat-treatment, e.g., time, temperature, and...

  13. Electrical properties of niobium doped barium bismuth-titanate ceramics

    International Nuclear Information System (INIS)

    Highlights: ► Pure and doped BaBi4Ti4O15 were prepared via the solid-state reaction method. ► The grain size was suppressed in Nb-doped samples. ► The diffuseness of the dielectric peak increased with dopant concentration. ► Niobium affected on relaxor behavior of barium bismuth titanate ceramics. ► The conductivity change was noticed in doped samples. -- Abstract: BaBi4Ti4–5/4xNbxO15 (BBNTx, x = 0, 0.05, 0.15, 0.30) ceramics have been prepared by solid state method. XRD data indicate the formation of single-phase-layered perovskites for all compositions. SEM micrographs suggest that the grain size decreases with Nb doping. The effect of niobium doping on the dielectric and relaxor behavior of BaBi4Ti4O15 ceramics was investigated in a wide range of temperatures (20–777 °C) and frequencies (1.21 kHz to 1 MHz). Nb doping influences Tc decrease as well as the decrease of dielectric permittivity at Curie temperature. At room temperature, undoped BaBi4Ti4O15 exhibits dielectric constant of ∼204 at 100 kHz, that slightly increases with Nb doping. The conductivity of BBNT5 ceramics is found to be lower than that of other investigated compositions. The value of activation energy of σDC was found to be 0.89 eV, 1.01 eV, 0.93 eV and 0.71 eV for BBT, BBNT5, BBNT15 and BBNT30, respectively.

  14. Electrical properties of niobium doped barium bismuth-titanate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Bobić, J.D., E-mail: jelenabobic@yahoo.com [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia); Vijatović Petrović, M.M. [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia); Banys, J. [Faculty of Physics, Vilnius University, 9 Sauletekio Str., Vilnius (Lithuania); Stojanović, B.D. [Institute for Multidisciplinary Researches, Belgrade University, Kneza Viseslava 1, Belgrade (Serbia)

    2012-08-15

    Highlights: ► Pure and doped BaBi{sub 4}Ti{sub 4}O{sub 15} were prepared via the solid-state reaction method. ► The grain size was suppressed in Nb-doped samples. ► The diffuseness of the dielectric peak increased with dopant concentration. ► Niobium affected on relaxor behavior of barium bismuth titanate ceramics. ► The conductivity change was noticed in doped samples. -- Abstract: BaBi{sub 4}Ti{sub 4–5/4x}Nb{sub x}O{sub 15} (BBNTx, x = 0, 0.05, 0.15, 0.30) ceramics have been prepared by solid state method. XRD data indicate the formation of single-phase-layered perovskites for all compositions. SEM micrographs suggest that the grain size decreases with Nb doping. The effect of niobium doping on the dielectric and relaxor behavior of BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics was investigated in a wide range of temperatures (20–777 °C) and frequencies (1.21 kHz to 1 MHz). Nb doping influences T{sub c} decrease as well as the decrease of dielectric permittivity at Curie temperature. At room temperature, undoped BaBi{sub 4}Ti{sub 4}O{sub 15} exhibits dielectric constant of ∼204 at 100 kHz, that slightly increases with Nb doping. The conductivity of BBNT5 ceramics is found to be lower than that of other investigated compositions. The value of activation energy of σ{sub DC} was found to be 0.89 eV, 1.01 eV, 0.93 eV and 0.71 eV for BBT, BBNT5, BBNT15 and BBNT30, respectively.

  15. Formic acid oxidation at platinum-bismuth catalysts

    Directory of Open Access Journals (Sweden)

    Popović Ksenija Đ.

    2015-01-01

    Full Text Available The field of heterogeneous catalysis, specifically catalysis on bimetallic surfaces, has seen many advances over the past few decades. Bimetallic catalysts, which often show electronic and chemical properties that are distinct from those of their parent metals, offer the opportunity to obtain new catalysts with enhanced selectivity, activity, and stability. The oxidation of formic acid is of permanent interest as a model reaction for the mechanistic understanding of the electrooxidation of small organic molecules and because of its technical relevance for fuel cell applications. Platinum is one of the most commonly used catalysts for this reaction, despite the fact that it shows a few significant disadvantages: high cost and extreme susceptibility to poisoning by CO. To solve this problem, several approaches have been used, but generally, they all consist in the modification of platinum with a second element. Especially, bismuth has received significant attention as Pt modifier. According to the results presented in this survey dealing with the effects influencing the formic acid oxidation it was found that two types of Pt-Bi bimetallic catalysts (bulk and low loading deposits on GC showed superior catalytic activity in terms of the lower onset potential and oxidation current density, as well as exceptional stability compared to Pt. The findings in this report are important for the understanding of mechanism of formic acid electrooxidation on a bulk alloy and decorated surface, for the development of advanced anode catalysts for direct formic acid fuel cells, as well as for the synthesis of novel low-loading bimetallic catalysts. The use of bimetallic compounds as the anode catalysts is an effective solution to overcoming the problems of the formic acid oxidation current stability for long term applications. In the future, the tolerance of both CO poisoning and electrochemical leaching should be considered as the key factors in the development

  16. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  17. Stable isotope studies

    International Nuclear Information System (INIS)

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  18. Method for separating isotopes

    Science.gov (United States)

    Jepson, B.E.

    1975-10-21

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether.

  19. Developing isotopic functions

    International Nuclear Information System (INIS)

    Isotopic functions, or ratios of two isotopic variables, are used to verify Pu and U measurements of spent fuels in reprocessing plants. Systematic methods have been developed for forming and evaluating isotopic functions. This paper describes the method used at Battelle to form and evaluate isotopic functions. The data base at Battelle contains measurements and calculations for the fuel from 35 reactors

  20. The isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  1. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    This invention provides a method for separating uranium isotopes comprising the steps of selectively irradiating a photochemically-reactive uranyl source material at a wavelength selective to a desired isotope of uranium at an effective temperature for isotope spectral line splitting below about 77 K, further irradiating the source material within the fluorescent lifetime of the selectively irradiated source material to selectively photochemically reduce the selectively excited isotopic species, and chemically separating the reduced isotope species from the remaining uranyl salt compound

  2. Potentiation of the action of metronidazole on Helicobacter pylori by omeprazole and bismuth subcitrate

    DEFF Research Database (Denmark)

    Andersen, L P; Colding, H; Kristiansen, J E

    2000-01-01

    regimens that include proton pump inhibitors. In the present study, the synergistic effect of subinhibitory concentrations (0.25-0.5 MIC) of either bismuth subcitrate or omeprazole with metronidazole on the susceptibility of 42 H. pylori strains was investigated by agar dilution method and the Epsilometer...

  3. Robust synthesis of bismuth titanate pyrochlore nanorods and their photocatalytic applications.

    Science.gov (United States)

    Murugesan, Sankaran; Subramanian, Vaidyanathan Ravi

    2009-09-14

    A facile and template-free reverse micelle-based method can be employed to synthesize highly crystalline and pure stoichiometric bismuth titanate (Bi(2)Ti(2)O(7)) pyrochlore nanorods 400-500 nm long and 40-50 nm in diameter which demonstrate promising photoactivity. PMID:20448962

  4. Performance of bismuth germanate active shielding on a balloon flight over Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Rester, A.C.; Coldwell, R.L. (Institute for Astrophysics and Planetary Exploration, Univ. of Florida, Alachua, FL (US)); Trombka, J.I. (National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center); Starr, R. (Catholic Univ. of America, Washington, DC (USA). Dept. of Physics); Eichhorn, G. (Steward Observatory, Tucson, AZ (USA)); Lasche, G.P. (Defense Advanced Research Projects Agency, Arlington, VA (USA))(Defense Advanced Research Projects Agency, Arlington, VA (USA))

    1990-04-01

    The GRAD gamma-ray spectrometer was flown on a high-altitude balloon at an altitude of 36.6 km over Antarctica on January 8-10, 1988 where it was used to make observations of Supernova 1987a. The performance of the bismuth germinate active shielding in the near-space environment over Antarctica is examined.

  5. Performance of bismuth germanate active shielding on a balloon flight over Antarctica

    International Nuclear Information System (INIS)

    The GRAD gamma-ray spectrometer was flown on a high-altitude balloon at an altitude of 36.6 km over Antarctica on January 8-10, 1988 where it was used to make observations of Supernova 1987a. The performance of the bismuth germinate active shielding in the near-space environment over Antarctica is examined

  6. Effect of bismuth citrate, lactose, and organic acid on necrotic enteritis in broilers

    Science.gov (United States)

    Clostridium perfringens – associated necrotic enteritis causes significant losses and increased morbidity in poultry. The objective of this study was to evaluate the effect of bismuth citrate and acidifiers on the development of necrotic enteritis in broilers. The first study was a dose response t...

  7. Examination of dielectric dispersion of complex oxides on the basis of bismuth-containing titanates

    International Nuclear Information System (INIS)

    In the present work the samples of complex oxide compounds on the basis of bismuth titanates with chalcolamprite structure type and layered perovskite doped with Cr, Fe and Co were studied at room temperature by the method of dielectric spectroscopy in the frequency range of 30 to 106 Hz

  8. Azo dyes photobleaching and operando FTIR study of acetaldehyde photoinduced decomposition on bismuth doped titania

    Czech Academy of Sciences Publication Activity Database

    Henych, Jiří; Štengl, Václav; Mattsson, A.; Österlund, L.

    Thessaloniki: Aristotle University of Thessaloniki, 2014, 41 PC-2-4. [European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications (SPEA) /8./. Thessaloniki (GR), 25.6.2014-28.6.2014] Institutional support: RVO:61388980 Keywords : bismuth doped titania * photocatalytic Subject RIV: CA - Inorganic Chemistry

  9. Renal pigmentation due to chronic bismuth administration in a rhesus macaque (Macaca mulatta).

    Science.gov (United States)

    Johnson, A L; Blaine, E T; Lewis, A D

    2015-05-01

    Renal pigmentation due to the administration of exogenous compounds is an uncommon finding in most species. This report describes renal pigmentation and intranuclear inclusions of the proximal convoluted tubules due to chronic bismuth administration in a rhesus macaque. An 11-year-old Indian-origin rhesus macaque with a medical history of chronic intermittent vomiting had been treated with bismuth subsalicylate, famotidine, and omeprazole singly or in combination over the course of 8 years. At necropsy, the renal cortices were diffusely dark green to black. Light and electron microscopy revealed intranuclear inclusions within the majority of renal proximal tubular epithelial cells. These inclusions appeared magenta to brown when stained with hematoxylin and eosin and were negative by the Ziehl-Neelsen acid-fast stain. Elemental analysis performed on frozen kidney measured bismuth levels to be markedly elevated at 110.6 ppm, approximately 500 to 1000 times acceptable limits. To our knowledge, this is the first report of renal bismuth deposition in a rhesus macaque resulting in renal pigmentation and intranuclear inclusions. PMID:24990482

  10. A sensitive fluorescence quenching method for determination of bismuth with tiron

    International Nuclear Information System (INIS)

    We describe a fluorescence quenching method for determination of bismuth with tiron. The method is based on the reaction of tiron by bismuth(III) in acidic media. The influence of variables such as the pH, type of buffer, tiron concentration, reaction time and temperature were investigated. Under optimized conditions, the fluorescence quenching extent is proportional to the concentration of bismuth for Bi–tiron system at the range 0.13–2.09 μg mL−1 and the detection limit is 0.05 μg mL−1. The proposed sensor presented good repeatability, evaluated in terms of relative standard deviation (R.S.D.=±0.498%) for 11 replicates. This sensitive, rapid and accurate method has been successfully applied to the determination of trace bismuth(III) in water and hair samples and certified reference materials. -- Highlights: • No previous paper report on use of fluorescence quenching for determination of Bi. • Fluorescence quenching of trion is a sensitive method for determination of Bi(III). • Under the optimum conditions the detection limit is very low (0.05 μg mL−1). • The procedure is simple and safe and has high tolerance limit to interferences

  11. Dynamics and coherent control of high-amplitude optical phonons in bismuth

    Science.gov (United States)

    Decamp, M. F.; Reis, D. A.; Bucksbaum, P. H.; Merlin, R.

    2001-09-01

    High-amplitude optical phonons in bismuth are generated through impulsive stimulated Raman scattering and detected through the induced change in the optical reflectivity. Reflectivity changes greater than 1% have been recorded. Phonon dynamics and coherent control in the high-amplitude regime are reported.

  12. Microwave-assisted facile and rapid Friedel-Crafts benzoylation of arenes catalysed by bismuth trifluoromethanesulfonate

    DEFF Research Database (Denmark)

    Tran, Phoung Hoang; Hansen, Poul Erik; Pham, Thuy Than;

    2014-01-01

    The catalytic activity of metal triflates was investigated in Friedel–Crafts benzoylation under microwave irradiation. Friedel–Crafts benzoylation with benzoyl chloride of a variety of arenes containing electron-rich and electron-poor rings using bismuth triflate under microwave irradiation is...

  13. Nanodomains and nanometer-scale disorder in multiferroic bismuth ferrite single crystals

    Czech Academy of Sciences Publication Activity Database

    Jia, C.L.; Jin, L.; Wang, D.; Mi, S.B.; Alexe, M.; Hesse, D.; Reichlová, Helena; Martí, Xavier; Bellaiche, L.; Urban, K.W.

    2015-01-01

    Roč. 82, Jan (2015), s. 356-368. ISSN 1359-6454 Institutional support: RVO:68378271 Keywords : bismuth ferrite * crystal growth * high-resolution electron microscopy * atomic structure * first-principles calculations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.465, year: 2014

  14. Group III-nitride thin films grown using MBE and bismuth

    Science.gov (United States)

    Kisielowski, Christian K.; Rubin, Michael

    2000-01-01

    The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

  15. Determination of (111) ordered domains on platinum electrodes by irreversible adsorption of bismuth.

    Science.gov (United States)

    Rodríguez, Paramaconi; Solla-Gullón, José; Vidal-Iglesias, Francisco J; Herrero, Enrique; Aldaz, Antonio; Feliu, Juan M

    2005-08-15

    Irreversible adsorbed bismuth can be used to determine the fraction of (111) domains on a given platinum sample. On Pt(111) electrodes, the surface redox process of adsorbed bismuth takes place at 0.63 V in a well-defined peak. The behavior of this redox process on the Pt(111) vicinal surfaces indicates that the bismuth atoms involved in the redox process are only those deposited on the (111) terrace sites and that the charge under the peak at 0.63 V is directly proportional to the number of sites on (111) ordered domains (terraces). The good linear relationship obtained between the charge for the bismuth redox process and the number of (111) terrace sites on the vicinal surfaces allows construction of a calibration curve. This calibration curve has been used to directly estimate the amount of (111) ordered domain terrace sites on polycrystalline platinum samples with different surface ordered domains. The results agree with what we would expect from our knowledge of these surfaces. PMID:16097774

  16. Microwave and magneto-optic properties of bismuth-substituted yttrium iron garnet thin films

    Science.gov (United States)

    Butler, J. C.; Kramer, J. J.; Esman, R. D.; Craig, A. E.; Lee, J. N.; Ryuo, T.

    1990-05-01

    Microwave and magneto-optic measurements have been made on bismuth-substituted yttrium iron garnet (BiYIG) films. Forward-volume (FV) magnetostatic-wave (MSW) attenuation has been measured from ferrimagnetic resonance and from pulse delay data. We report the indirect observation of FV MSW in BiYIG using two independent techniques: a pulse transmission technique and a passband measurement technique. Faraday rotation in the films was also recorded at a wavelength of 1.3 μm. The bismuth-substituted films are grown on carefully cleaned substrates and have yttrium:bismuth ratios of 1:1. The composition of the bismuth substituted films is Y1.5Bi1.5Fe5O12 deduced from lattice parameters and absolute Faraday rotation. These films show particular promise for use in waveguide-type high-speed MSW-optical devices where low MSW attenuation and high Faraday rotation are among the necessary criteria for successful operation.

  17. The antimicrobial effects and metabolomic footprinting of carboxyl-capped bismuth nanoparticles against Helicobacter pylori.

    Science.gov (United States)

    Nazari, P; Dowlatabadi-Bazaz, R; Mofid, M R; Pourmand, M R; Daryani, N E; Faramarzi, M A; Sepehrizadeh, Z; Shahverdi, A R

    2014-01-01

    Organic salts of bismuth are currently used as antimicrobial agents against Helicobacter pylori. This study evaluated the antibacterial effect of elemental bismuth nanoparticles (Bi NPs) using a serial agar dilution method for the first time against different clinical isolates and a standard strain of H. pylori. The Bi NPs were biologically prepared and purified by a recently described method and subjected to further characterization by infrared spectroscopy and anti-H. pylori evaluation. Infrared spectroscopy results showed the presence of carboxyl functional groups on the surface of biogenic Bi NPs. These biogenic nanoparticles showed good antibacterial activity against all tested H. pylori strains. The resulting MICs varied between 60 and 100 μg/ml for clinical isolates of H. pylori and H. pylori (ATCC 26695). The antibacterial effect of bismuth ions was also tested against all test strains. The antimicrobial effect of Bi ions was lower than antimicrobial effect of bismuth in the form of elemental NPs. The effect of Bi NPs on metabolomic footprinting of H. pylori was further evaluated by (1)H NMR spectroscopy. Exposure of H. pylori to an inhibitory concentration of Bi NPs (100 μg/ml) led to release of some metabolites such as acetate, formic acid, glutamate, valine, glycine, and uracil from bacteria into their supernatant. These findings confirm that these nanoparticles interfere with Krebs cycle, nucleotide, and amino acid metabolism and shows anti-H. pylori activity. PMID:24104691

  18. Bio-assisted synthesis and characterization of nanostructured bismuth (III) sulphide using Clostridium acetobutylicum

    International Nuclear Information System (INIS)

    Nanostructured bismuth (III) sulphide is synthesized at room temperature using a hydrogen sulphide producing microorganism namely Clostridium acetobutylicum. On contrary to chemical routes involving both the high and room temperature methods, the present experimental procedure involves a bio-assisted approach. This method is free from the usage of toxic and hazardous chemicals making it an environment friendly route. The synthesized bismuth sulphide is characterized using transmission electron microscope (TEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). From our experiments we find that bismuth sulphide produced using this bio-assisted approach exhibits a hexagonal shaped plate-like structures and is stabilized by the extracellular proteins present in the culture medium. - Graphical abstract: A green chemistry approach towards the synthesis of bismuth (III) sulphide nanostructures at room temperature using a hydrogen sulphide producing microorganism namely, Clostridium acetobutylicum is demonstrated. - Highlights: • Environmentally benign (greener) route towards synthesis of Bi2S3 nanostructures. • Bio-assisted synthesis of Bi2S3 at room temperature using Clostridium acetobutylicum. • Extracellular proteins in H2S producing microorganism as stabilizer for Bi2S3 NPs. • Hexagonal platelets of Bi2S3 possessing an orthorhombic crystalline structure

  19. Electrodeposition of bismuth telluride nanowires with controlled composition in polycarbonate membranes

    International Nuclear Information System (INIS)

    Bismuth telluride nanowires were potentiostatically deposited from a water/DMSO 50%, v/v electrolyte within polycarbonate etched ion-track membranes covered by a platinum substrate. The presence of DMSO shifts the potentials to more negative values and slows down the cation diffusion. Cyclic voltammetries on recessed Pt nanoelectrodes using polycarbonate membranes highlight a complex electrochemical behavior through several cathodic and anodic peaks which are not observed onto platinum discs macroelectrodes. Analytical investigations enabled the determination of appropriate deposition conditions to finely tune the average composition of the nanowires. Calibrated TEM-EDX analyses evidence high aspect ratio nanowires, whose composition is strongly dependent on the deposition potential. In the same manner as for bismuth telluride film electroplating, bismuth enrichment occurs at more cathodic deposition potential whereas tellurium enrichment is observed at low cathodic potentials. Stoichiometric nanowires of 60 nm diameter were obtained at −100 mV vs Ag/AgCl from an electrolyte which contains [Bi3+] = 1.5[HTeO2+] = 15 mM. The composition is homogeneous along the nanowire except at both edges: the cap is rich in bismuth whereas the base is rich in tellurium. The composition at the nanowire base is adjusted by setting a short initial voltage step (Ui = −300 mV vs Ag/AgCl, ti = 2 s). In the case of stoichiometric compounds, the resulting nanostructures were found to be polycrystalline with a preferential orientation along the direction perpendicular to the planes (0 1 5).

  20. Electrodeposition of bismuth telluride thermoelectric films from a nonaqueous electrolyte using ethylene glycol

    NARCIS (Netherlands)

    Nguyen, H.P.; Wu, M.; Su, J.; Vullers, R.J.M.; Vereecken, P.M.; Fransaer, J.

    2012-01-01

    Ethylene glycol was studied as an electrolyte for the electrodeposition of thermoelectric bismuth telluride films by cyclic voltammetry, rotating ring disk electrode and electrochemical quartz crystal microbalance (EQCM). The reduction of both Bi3+ and Te4+ ions proceeds in one step without the form

  1. Structural Engineering of Vacancy Defected Bismuth Tellurides for Thermo-electric Applications

    Directory of Open Access Journals (Sweden)

    Chumakov Y.

    2012-10-01

    Full Text Available Molecular Dynamics and ab-initio simulations are used to find the most stable stoichiometries of Bismuth Tellurides with vacancy defects. The interest is to decrease the thermal conductivity of these compounds a key point to achieve high figure of merits. A reduction of 70% of the thermal conductivity is observed with Te vacancies of only 5%.

  2. Bio-assisted synthesis and characterization of nanostructured bismuth (III) sulphide using Clostridium acetobutylicum

    Energy Technology Data Exchange (ETDEWEB)

    Kamaraj, Sathish Kumar; Venkatachalam, Ganesh; Arumugam, Palaniappan; Berchmans, Sheela, E-mail: sheelaberchmans@yahoo.com

    2014-02-14

    Nanostructured bismuth (III) sulphide is synthesized at room temperature using a hydrogen sulphide producing microorganism namely Clostridium acetobutylicum. On contrary to chemical routes involving both the high and room temperature methods, the present experimental procedure involves a bio-assisted approach. This method is free from the usage of toxic and hazardous chemicals making it an environment friendly route. The synthesized bismuth sulphide is characterized using transmission electron microscope (TEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). From our experiments we find that bismuth sulphide produced using this bio-assisted approach exhibits a hexagonal shaped plate-like structures and is stabilized by the extracellular proteins present in the culture medium. - Graphical abstract: A green chemistry approach towards the synthesis of bismuth (III) sulphide nanostructures at room temperature using a hydrogen sulphide producing microorganism namely, Clostridium acetobutylicum is demonstrated. - Highlights: • Environmentally benign (greener) route towards synthesis of Bi{sub 2}S{sub 3} nanostructures. • Bio-assisted synthesis of Bi{sub 2}S{sub 3} at room temperature using Clostridium acetobutylicum. • Extracellular proteins in H{sub 2}S producing microorganism as stabilizer for Bi{sub 2}S{sub 3} NPs. • Hexagonal platelets of Bi{sub 2}S{sub 3} possessing an orthorhombic crystalline structure.

  3. Fridel-Crafts acylation using bismuth triflate in [BMI][PF6

    DEFF Research Database (Denmark)

    Tran, Phuong Hoang; Duus, Fritz; Le, Thach Ngoc

    2012-01-01

    Bismuth trifluoromethanesulfonate was found to be a good catalyst for the Friedel–Craftsacylation. Bismuthtriflate immobilized in an ionic liquid was the most efficient catalytic system. Bismuthtriflate in [BMI][PF6] catalyzes this reaction under microwave irradiation allowing the rapid synthesis...

  4. Thermodynamics of neptunium in LiCl-KCl eutectic/liquid bismuth systems

    International Nuclear Information System (INIS)

    Thermodynamic properties of neptunium in LiCl-KCl eutectic/liquid bismuth systems in the temperature range 400--500 C have been studied using a galvanic cell method for the pyrometallurgical reprocessing of nuclear spent fuels. The standard potential of the Np/Np(III) couple vs. the Ag/AgCl (1 wt% AgCl) reference electrode in LiCl-KCl eutectic was measured and given by the equation ENp/Np(III)0 = minus2.0667 + 0.0007892 T (σ = 0.0009), where E is in volts, T is in kelvin, and σ is the standard deviation. The potential of neptunium-bismuth alloy, ENp-Bi, was measured as a function of neptunium concentration, XNpinBi. The curves for EBi-Np vs. log XNpinBi indicated the neptunium solubility in liquid bismuth to be 0.34 ± 0.02, 0.61 ± 0.08, and 1.06 ± 0.09 (±σ) atom % at 400, 450, and 500 C, respectively. The excess partial free energy of neptunium in liquid bismuth was represented by the equation, Δbar GNpxs (kcal/g atom) = minus32.5 (±0.7) + 0.0072 (±0.0010) T. The values of the solubility and excess partial free energy for neptunium were closer to those for plutonium rather than uranium

  5. Optimal biliary drainage for inoperable Klatskin's tumor based on Bismuth type

    OpenAIRE

    Lee, Sang Hyub; Park, Joo Kyung; Yoon, Won Jae; Lee, Jun Kyu; Ryu, Ji Kon; Yoon, Yong Bum; Kim, Yong-Tae

    2007-01-01

    AIM: To investigate differences in the effects of biliary drainage procedures in patients with inoperable Klatskin’s tumor based on Bismuth type, considering endoscopic retrograde biliary drainage (ERBD), external percutaneous transhepatic biliary drainage (EPTBD) and internal biliary stenting via the PTBD tract (IPTBD).

  6. Hall Plateaus at magic angles in ultraquantum Bismuth

    Science.gov (United States)

    Benoît, Fauqué.

    2009-03-01

    The behaviour of a three-dimensional electron gas in the presence of a magnetic field strong enough to put all carriers in the first Landau level (i.e. beyond the quantum limit) is a longstanding question of theoretical condensed matter physics [1]. This issue has been recently explored by two high-field experiments on elemental semi-metal Bismuth. In a first study of transport coefficients (which are dominated by hole-like carriers), the Nernst coefficient presented three unexpected maxima that are concomitant with quasi-plateaux in the Hall coefficient [2]. In a second series of experiments, torque magnetometry (which mainly probes the three Dirac valley electron pockets) detected a field-induced phase transition [3]. The full understanding of the electron and hole behaviours above the quantum limit of pure Bi is therefore still under debate. In this talk, we will present our measurement of the Hall resistivity and torque magnetometry with magnetic field up to 31 T and rotating in the trigonal-bisectrix plane [4]. The Hall response is dominated by the hole pockets according to its sign as well as the period and the angular dependence of its quantum oscillations. In the vicinity of the quantum limit, it presents additional anomalies which are the fingerprints of the electron pockets. We found that for particular orientations of the magnetic field (namely ``magic angles''), the Hall response becomes field-independent within the experimental resolution around 20T. This drastic dependence of the plateaux on the field orientation provides strong constraints for theoretical scenarios. [4pt] [1] Bertrand I. Halperin, Japanese Journal of Applied Physics, 26, Supplement 26-3 (1987).[0pt] [2] Kamran Behnia, Luis Balicas, Yakov Kopelevich, Science, 317, 1729 (2008).[0pt] [3] Lu Li, J. G. Checkelsky, Y. S. Hor, C. Uher, A. F. Hebard, R. J. Cava, and N. P. Ong , Science, 321, 5888 (2008).[0pt] [4] Benoît Fauqu'e, Luis Balicas, Ilya Sheikin, Jean Paul Issi and Kamran Behnia

  7. Improvements to a Flow Sensor for Liquid Bismuth-Fed Hall Thrusters

    Science.gov (United States)

    Bonds, Kevin; Polzin, Kurt A.

    2010-01-01

    Recently, there has been significant interest in using bismuth metal as a propellant in Hall Thrusters [1, 2]. Bismuth offers some considerable cost, weight, and space savings over the traditional propellant--xenon. Quantifying the performance of liquid metal-fed Hall thrusters requires a very precise measure of the low propellant flow rates [1, 2]. The low flow rates (10 mg/sec) and the temperature at which free flowing liquid bismuth exists (above 300 C) preclude the use of off-the-shelf flow sensing equipment [3]. Therefore a new type of sensor is required. The hotspot bismuth flow sensor, described in Refs. [1-5] is designed to perform a flow rate measurement by measuring the velocity at which a thermal feature moves through a flow chamber. The mass flow rate can be determined from the time of flight of the thermal peak, [4, 5]. Previous research and testing has been concerned mainly with the generation of the thermal peak and it's subsequent detection. In this paper, we present design improvements to the sensor concept; and the results of testing conducted to verify the functionality of these improvements. A ceramic material is required for the sensor body (see Fig. 1), which must allow for active heating of the bismuth flow channel to keep the propellant in a liquid state. The material must be compatible with bismuth and must be bonded to conductive elements to allow for conduction of current into the liquid metal and measurement of the temperature in the flow. The new sensor requires fabrication techniques that will allow for a very small diameter flow chamber, which is required to produce useful measurements. Testing of various materials has revealed several that are potentially compatible with liquid bismuth. Of primary concern in the fabrication and testing of a robust, working prototype, is the compatibility of the selected materials with one another. Specifically, the thermal expansion rates of the materials relative to the ceramic body cannot expand so

  8. Laser spectroscopy of the ground-state hyperfine structure in H-like and Li-like bismuth

    International Nuclear Information System (INIS)

    The LIBELLE experiment performed at the experimental storage ring (ESR) at the GSI Helmholtz Center in Darmstadt aims for the determination of the ground state hyperfine (HFS) transitions and lifetimes in hydrogen-like (209Bi82+) and lithium-like (209Bi80+) bismuth. The study of HFS transitions in highly charged ions enables precision tests of QED in extreme electric and magnetic fields otherwise not attainable in laboratory experiments. While the HFS transition in H-like bismuth was already observed in earlier experiments at the ESR, the LIBELLE experiment succeeded for the first time to measure the HFS transition in Li-like bismuth in a laser spectroscopy experiment

  9. Synthesis and performance of bismuth trioxide nanoparticles for high energy gas generator use

    Energy Technology Data Exchange (ETDEWEB)

    Martirosyan, K S; Wang, L; Vicent, A; Luss, D, E-mail: kmartirossian@uh.ed [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204 (United States)

    2009-10-07

    Our experiments showed that the combustion of an Al-Bi{sub 2}O{sub 3} nanoparticle mixture generated the highest pressure pulse among common nanothermite reactions and can potentially be used as a nanoenergetic gas generator. The combustion front propagation velocity and rate of energy release increased by up to three orders of magnitude when the particle size was reduced to a nanosize range for both the aluminum and the oxidizer. We developed a novel one-step (metal nitrate-glycine) combustion synthesis of nanostructured amorphous-like and highly crystalline bismuth trioxide nanoparticles. The combustion synthesis was conducted using a solution of molten bismuth nitrate as an oxidizer and glycine as a fuel. The glycine was completely combusted during the thermal decomposition of the bismuth nitrate pentahydrate and generated a temperature front that propagated through the sample. Increasing the fuel concentration increased the maximum combustion temperature from 280 to 1200 {sup 0}C and the Bi{sub 2}O{sub 3} particle size from 20 to 100 nm. The oxidizer/fuel ratio had a strong impact on the bismuth trioxide particle crystallinity. At low temperature (280 {sup 0}C), amorphous-like bismuth trioxide nanoparticles formed, while at T{>=}370 {sup 0}C the structures were crystalline. A peak pressure of {approx}12 MPa and a thermal front propagating velocity of {approx}2500 m s{sup -1} were achieved during the combustion of an Al-Bi{sub 2}O{sub 3} mixture containing 80 wt% of the synthesized Bi{sub 2}O{sub 3} crystalline nanoparticles (size: 40-50 nm).

  10. Study of Neutron-Deficient $^{202-205}$Fr Isotopes with Collinear Resonance Ionization Spectroscopy

    CERN Document Server

    De Schepper, Stijn; Cocolios, Thomas; Budincevic, Ivan

    The scope of this master’s thesis is the study of neutron-deficient $^{202−205}$Fr isotopes. These isotopes are inside the neutron-deficient lead region, a region that has shown evidence of shape coexistence. For this thesis, this discussion is limited to the phenomenon where a low lying excited state has a different shape than the ground state. Shape coexistence is caused by intruder states. These are single-particle Shell Model states that are perturbed in energy due to the interaction with a deformed core. In the neutron-deficient lead region the main proton intruder orbit is the 3s$_{1/2}$orbit. When going towards more neutron-deficient isotopes, deformation increases. The $\\pi3s_{1/2}$orbit will rise in energy and will eventually become the ground state in odd- A bismuth (Z=83) isotopes. It is also observed in odd-A astatine (Z=85) isotopes, already in less neutron-deficient nuclei. The same phenomenon is expected to be present francium (Z=87) isotopes already at $^{199}$Fr. Although it is currently ...

  11. Isotopic geology; Geologie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Allegre, C. [Paris-7 Univ. Denis Diderot, 75 (France); Institut de physique du globe de Paris, 75 - Paris (France)

    2005-07-01

    Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

  12. Optical isotope shifts for unstable samarium isotopes

    International Nuclear Information System (INIS)

    Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144Sm and 154Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

  13. Statistical clumped isotope signatures.

    Science.gov (United States)

    Röckmann, T; Popa, M E; Krol, M C; Hofmann, M E G

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules. PMID:27535168

  14. ELECTRA: A European Lead-bismuth Cooled Training Reactor

    International Nuclear Information System (INIS)

    The lack of low power liquid metal cooled reactors has meant that few engineers within the nuclear power industry and research community are familiar with operational procedures of this family of coolants, expected to be used for Generation IV fast neutron systems. The reasons for this lack may include safety issues related to use of Mercury, NaK or sodium as applied in early low power reactors. Especially in western Europe, no low power liquid metal cooled reactor was ever in operation. Here, we present the design of a 2 MWth lead-bismuth cooled reactor with (Pu,Zr)N fuel, relying on natural convection for full power operation. The combination of low power density with natural convection for heat removal makes the reactor ideal for training purposes. The large thermal expansion of heavy liquid metals makes is possible to design low power fast neutron reactors relying on natural convection. Since at present, there exists no suitable material for pumps operating at high velocity in lead alloy environments, the only possible short term solution for constructing such a reactor is anyway to design for 100% natural circulation of the coolant. For this purpose, a small core height, a large difference between coolant inlet and outlet temperatures and a low coolant velocity is desired. By application of (Pu,Zr)N fuel, criticality can be achieved with a fissile inventory of 100 kg LWR grade plutonium. Monte Carlo simulations show that 19 hexagonal fuel assemblies, each with 91 fuel pins having an outer diameter of 1.1 cm, and an active height of 15 cm is sufficient to obtain a critical core. Including end pellets, gas plenum and end caps, the total core height is limited to 30 cm. Adopting P/D = 1.25 and a heat exchanger elevation of 4 m, it is found that 2 MW of thermal power may be removed by a natural circulation velocity of 0.4 m/s. This corresponds to a linear rating of 8 kW/m and a temperature increase of the coolant equal to 240 degrees. Limiting the clad temperature

  15. In vitro synergy testing of clarithromycin and 14-hydroxyclarithromycin with amoxicillin or bismuth subsalicylate against Helicobacter pylori.

    OpenAIRE

    Meyer, J.M.; Ryu, S; Pendland, S L; Danziger, L H

    1997-01-01

    The activity of clarithromycin-14-hydroxyclarithromycin (2:1 ratio) and bismuth subsalicylate or amoxicillin against Helicobacter pylori was determined by the checkerboard technique in vitro. Clarithromycin-14-hydroxyclarithromycin and amoxicillin resulted in additive effects in 7 of 22 isolates, compared to 14 of 22 isolates when bismuth subsalicylate was substituted for amoxicillin. Synergy was not demonstrated and is probably not responsible for the clinical success of treatment combinatio...

  16. Electrodes modified with bismuth, antimony and tin precursor compounds for electrochemical stripping analysis of trace metals (a short review)

    OpenAIRE

    Lezi, Nikolitsa; Economou, Anastasios; Barek, Jiří

    2014-01-01

    Over the last decade, intensive research is being carried out towards the development of “green” electrochemical sensors. Bismuth, antimony and tin electrodes have been proposed as potential substitutes of mercury electrodes in electrochemical stripping analysis of trace metals. The main advantage of these metals as electrode materials is their lower toxicity compared to mercury. Among the different configuration of bismuth, antimony and tin electrodes, one of the most attractive inv...

  17. Optical properties of bismuth-doped SiO2- or GeO2-based glass core optical fibers

    OpenAIRE

    Firstova, Elena G.

    2015-01-01

    A detailed study of optical properties of bismuth-doped fibers based on SiO2 and GeO2 glasses containing no other dopants has been carried out. To provide important information about spectroscopic properties of IR bismuth-related active centers (BAC) the excitation-emission fluorescence spectra for a spectral region of 220-2000 nm have been measured. The obtained three-dimensional spectra have been presented for different host glass compositions: silicate, germanate, aluminosilicate and phosp...

  18. Calculation of the two-electron vacuum-polarization corrections to the hyperfine splitting in Li-like bismuth

    International Nuclear Information System (INIS)

    Ab initio calculation of the two-electron vacuum-polarization corrections to the hyperfine splitting in Li-like bismuth is presented. The diagrams with electric and magnetic vacuum-polarization loops are evaluated rigorously to all orders in αZ. The accuracy of the theoretical prediction for the screened quantum electrodynamics contribution to the specific difference of the hyperfine splitting values of H- and Li-like bismuth is improved by a factor of 3. (paper)

  19. Pharmacokinetics and bioequivalence of ranitidine and bismuth derived from two compound preparations

    Institute of Scientific and Technical Information of China (English)

    Quan Zhou; Zou-Rong Ruan; Hong Yuan; Bo Jiang; Dong-Hang Xu

    2006-01-01

    AIM: To evaluate the bioequivalence of ranitidine and bismuth derived from two compound preparations.METHODS: The bioavailability was measured in 20healthy male Chinese volunteers following a single oral dose (equivalent to 200 mg of ranitidine and 220 mg of bismuth) of the test or reference products in the fasting state. Then blood samples were collected for 24 h.Plasma concentrations of ranitidine and bismuth were analyzed by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry (ICPMS), respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax,AUC(0-t) and AUC(0-∞) were tested for bioequivalence using ANOVA and Schuirmann two-one sided t-test. Tmax was analyzed by Wilcoxon's test.RESULTS: Various pharmacokinetic parameters of ranitidine derived from the two compound preparations,including Cmax, AUC(0-t), AUC(0-∞), Tmax and T1/2, were nearly consistent with previous observations. These parameters derived from test and reference drug were as follows: Cmax(0.67 ± 0.21 vs 0.68 ± 0.22mg/L), AUC(0-t)(3.1 ± 0.6 vs 3.0 ± 0.7 mg/L per hour),AUC(0-∞)(3.3 ± 0.6 vs 3.2 ± 0.8 mg/L per hour),Tmax (2.3 ± 0.9 vs 2.1 ± 0.9 h) and T1/2 (2.8 ± 0.3 vs 3.1± 0.4 h). In addition, double-peak absorption profiles of ranitidine were found in some Chinese volunteers.For bismuth, those parameters derived from test and reference drug were as follows: Cmax (11.80 ± 7.36 vs 11.40 ± 6.55 μg/L),AUC(0-t) (46.65 ± 16.97 vs 47.03 ±21.49 μg/L per hour), Tmax (0.50 ± 0.20 vs 0.50 ± 0.20 h)and T1/2 (10.2 ± 2.3 vs 13.0 ± 6.9 h). Ninety percent of confidence intervals for the test/reference ratio of Cmax,AUC(0-t) and AUC(0-∞) derived from both ranitidine and bismuth were found within the bioequivalence acceptable range of 80%-125%. No significant difference was found in Tmax derived from both ranitidine and bismuth.CONCLUSION: The two compound preparations are bioequivalent and may be prescribed

  20. Syntheses, crystal structures and characterizations of two new bismuth(III) arsenites

    Energy Technology Data Exchange (ETDEWEB)

    Liu Junhui [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Kong Fang [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Gai Yanli [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Mao Jianggao, E-mail: mjg@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

    2013-01-15

    Two new bismuth arsenites with two different structural types, namely, Bi{sub 2}O(AsO{sub 3})Cl (1), Bi{sub 8}O{sub 6}(AsO{sub 3}){sub 2}(AsO{sub 4}){sub 2} (2), have been synthesized by the solid-state reactions. Compound 1 exhibits novel 2D bismuth arsenite layers with Bi{sub 4}O{sub 4} rings capped by oxide anions, which are further interconnected by Bi-Cl-Bi bridges into a 3D network. Compound 2 contains both arsenite and arsenate anions, its 3D structures are based on 1D bismuth arsenite and 1D bismuth arsenate chains both along b-axis, which are interconnected by oxide anions via Bi-O-Bi bridges, forming 1D tunnels of Bi{sub 4}As{sub 4} 8-membered rings (MRs) along b-axis, the lone pairs of the arsenite groups are orientated toward the centers of the above tunnels. Thermogravimetric analysis indicated that both compounds display high thermal stability. Optical property measurements revealed that they are wide band-gap semiconductors. Both compounds display broad green-light emission bands centered at 506 nm under excitation at 380 and 388 nm. - Graphical abstract: Solid state reactions of Bi{sub 2}O{sub 3} (BiCl{sub 3}) and As{sub 2}O{sub 3} yielded two new compounds with two different structural types, namely, Bi{sub 2}O(AsO{sub 3})Cl (1), Bi{sub 8}O{sub 6}(AsO{sub 3}){sub 2}(AsO{sub 4}){sub 2} (2). They represent the first examples of bismuth arsenates. Highlights: Black-Right-Pointing-Pointer Solid state reactions of Bi{sub 2}O{sub 3} (BiCl{sub 3}) and As{sub 2}O{sub 3} yielded two new phases. Black-Right-Pointing-Pointer They represent the first examples of bismuth arsenites. Black-Right-Pointing-Pointer The two compounds exhibit two different structural types.

  1. Synthesis and characterization of Bismuth ferrite (BiFeO{sub 3}) nanoparticles by solution evaporation method

    Energy Technology Data Exchange (ETDEWEB)

    Manzoor, A., E-mail: alinamanzoor@hotmail.com; Afzal, A.M., E-mail: amirafzal461@gmail.com; Umair, M., E-mail: umairranwerr@gmail.com; Ali, Adnan, E-mail: adnnan_1982@yahoo.com; Rizwan, M., E-mail: h.rizwan70@gmail.com; Yaqoob, M.Z., E-mail: zeeshaan32@yahoo.com

    2015-11-01

    Single phase Bismuth ferrite (BiFeO{sub 3}) with high magnetization and polarization was synthesized by solution evaporation method (SEM) at room temperature. The influence of temperature and size of nanoparticles on magnetic properties was studied. The prepared Bismuth ferrite (BiFeO{sub 3}) was characterized by X-ray diffraction (XRD) to investigate the structure and size of crystal. The average crystallite size of nanoparticles (NPs) as calculated by X-ray diffraction (XRD) falls in the range of 22–31 nm. The crystallite size of Bismuth ferrite increased as the temperature varied from 450 °C to 650 °C. Magnetic properties were studied by using physical properties measurement system (PPMS). It was also observed that the magnetic properties were directly related to the size and temperature of Bismuth ferrite nanoparticles. It has been investigated that the magnetization was decreased as the temperature and crystallite size increased. - Highlights: • Bismuth ferrite magnetic material was synthesized by solution evaporation method. • Bismuth ferrite shows ferromagnetic properties at room temperature. • Influence of temperature and crystallite size on magnetic properties was observed. • The magnetization was decreased as the temperature and crystallite size increased. • The magnetic moments were found larger in the smaller crystalline size.

  2. Colloidal bismuth subcitrate, a new agent for the scintigraphy of inflammatory bowel diseases

    International Nuclear Information System (INIS)

    A correct diagnosis and adequate assessment of disease activity is crucial in the management and surveillance of inflammatory bowel diseases (IBDs). However, in certain occasions the obtained results by traditional techniques are not correlated specifically with the mucosal wall inflammatory state, mainly in case of the small bowel, due to its no accessibility. On the order hand, some of them such as the endoscopy and the histopatological studies have the inconvenience of being bloody and traumatic for the patient. Radioactive isotopes techniques have been used with advantageous in relationship with conventional ones. They are able to detect inflammations along the whole gastrointestinal tract; radiation level is low and tolerated by extreme care patient and children. One of these techniques relates the inflamed state of the mucous with the 111In-leukocytes uptake level of the injured area. Another radioisotopic technique developed by Vazquez et al., consists on detecting the gastric lesion by means of the use of a local action anti ulcerous agent labelled with Tc-99m. This one is simple, cheap and its results are similar to those of conventional techniques. Taking into account that the inflammatory intestinal illnesses develop inflamed and ulcerated areas in the mucous and that Colloidal Bismuth Subcitrate (CBS) K55(NH4)36(C6H7O7)22 [Bi30(OH)55(C6H5O7)20] possesses the capacity to form with the mucus a complex that adheres on ulcerated mucous through a reaction with the detritus derivate from the tissue necrosis. The present work has been proposed as a method to assess disease activity in patients with inflammatory diseases along the entire alimentary tract. This investigation constituted a multicentric clinical trial phase I-II. Forty-four patients were prospectively evaluated with the objective of determining the validity of the scintigraphy with 99mTc-Sn-CBS for the diagnosis of illnesses with ulcerations of the intestinal tube. Of the evaluated patients, 20

  3. Characterization, Leaching, and Filtration Testing for Bismuth Phosphate Sludge (Group 1) and Bismuth Phosphate Saltcake (Group 2) Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn; Edwards, Matthew K.; Fiskum, Sandra K.; Hallen, Richard T.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Sinkov, Sergey I.; Snow, Lanee A.

    2009-02-19

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.() The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. Two of the eight defined groups—bismuth phosphate sludge (Group 1) and bismuth phosphate saltcake (Group 2)—are the subjects of this report. The Group 1 waste was anticipated to be high in phosphorus and was implicitly assumed to be present as BiPO4 (however, results presented here indicate that the phosphate in Group 1 is actually present as amorphous iron(III) phosphate). The Group 2 waste was also anticipated to be high in phosphorus, but because of the relatively low bismuth content and higher aluminum content, it was anticipated that the Group 2 waste would contain a mixture of gibbsite, sodium phosphate, and aluminum phosphate. Thus, the focus of the Group 1 testing was on determining the behavior of P removal during caustic leaching, and the focus of the Group 2 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467.

  4. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  5. Stable isotope applications

    International Nuclear Information System (INIS)

    The following domains of stable isotope applications are presented: - isotope dilution analyses as in trace analyses or volume and mass determinations; - stable isotopes as tracers as applied in environmental studies, agricultural research, products and objects authentification, transport phenomena, reaction mechanisms, determinations of structure and complex biological function, metabolism studies, diagnostic respiration tests, positron emission tomography; - equilibrium isotopic effects as investigated in measurements of effects, studies of equilibrium conditions, the mechanism of drug action, study of natural processes, water circuit, temperature measurements; - kinetic isotopic effects, as, for instance, reaction rates and mechanisms, solvent isotopic effects; - stable isotopes for advanced nuclear reactors as, for instance, uranium nitride with 15 N as nuclear fuel or 157 Gd for reactivity control. In spite of the difficulties regarding stable isotope use and first of all, of the difficult and costly analytical techniques, a continuous growth of the number of stable isotope applications in different fields is registered. The number of works and scientific meetings on the subject, as organized by the International Society of Isotopes and IAEA-Vienna, Gordon Conferences, regional meetings in Germany, France, etc. increase continuously. Development of the stable isotope application on a larger scale requires improving both their production technologies as well as those of labelled substances and, at the same time, the analytical methods

  6. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    Chromium (Cr) stable isotopes are a useful tracer of changes in redox conditions because changes in its oxidation state are accompanied by an isotopic fractionation. For this reason the Cr isotope system is being developed as a potential tool for paleo-redox reconstruction. Dissolved Cr in seawater...... is incorporated into carbonates. Hence, ancient carbonates can potentially record the Cr isotopic composition (δ53Cr ‰) of seawater in the geological past. Reliable application and interpretation of this proxy requires a detailed knowledge about processes that fractionate Cr on the Earth’s surface......, and the quantification the Cr isotope composition of major Cr fluxes into and out of ocean. This thesis adds to the current knowledge of the Cr isotope system and is divided into two studies. The focus of the first study was to determine what processes control the Cr isotopic compositionof river...

  7. Synthesis of α-Bismuth oxide using solution combustion method and its photocatalytic properties

    Science.gov (United States)

    Astuti, Y.; Fauziyah, A.; Nurhayati, S.; Wulansari, A. D.; Andianingrum, R.; Hakim, A. R.; Bhaduri, G.

    2016-02-01

    The monoclinic bismuth oxide was prepared by the solution combustion method using bismuthyl nitrate as the raw material and citric acid as fuel. The synthesis process consisted of the formation of a clear transparent solution and the formation of white powder after heating the mixture at 250 °C for 2 hours. The yellow pale crystalline materials were obtained after calcination of the white powder at 600 °C for 80 minutes. Furthermore, the photocatalytic activity of the product was also studied using methyl orange as a model pollutant. The result showed that the coral reef-like bismuth oxide was able to degrade 50 mL methyl orange (5 ppm) by 37.8% within 12 hours irradiation using 75-watt tungsten lamp.

  8. A route for polonium 210 production from alpha-particle irradiated bismuth-209 target

    International Nuclear Information System (INIS)

    A method is proposed for production of polonium-210 via the 209Bi(α,3n)210 At nuclear reaction. Bombardment of a bismuth-209 target was performed with a 37 MeV alpha-particle beam that leads to the production of astatine-210 (T1/2 = 8.1 h), which decays to polonium-210. It is purified from the bismuth target matrix by employing liquid-liquid extraction using tributyl phosphate (TBP) in para-xylene from 7 M hydrochloric acid. Back extraction of polonium-210 was performed by 9 M nitric acid. This method allows to purify a tracer amount of Po-210 (2.6 x 10-13 mol) from macroscopic amount of Bi (2.8 x 10-2 mol).

  9. Designing and operating experience on solid electrolyte activity meters for oxygen in lead-bismuth coolant

    International Nuclear Information System (INIS)

    The device for measuring the oxygen activity in the lead and bismuth meets within the range of 1-10-7 with the inertia up to 5 s is developed and tested on the basis of applying the ZrO2-Y2O3 solid-electrolytes in combination with the liquid-metal reference electrodes (Bi, In, Pb). The range of the working temperatures of the activity meter constitutes 280-600 deg C; the stability by thermoshocks up to 50 deg C/s is guaranteed. The device is recommended for application in the circulating systems with the lead and bismuth meets at the coolant pressures up to 60 atm

  10. Compatibility tests on steels in molten lead and lead-bismuth

    International Nuclear Information System (INIS)

    The compatibility of steels with liquid lead and liquid lead-bismuth is a critical issue for the development of accelerator-driven system (ADS). In this work the results of a set of preliminary tests carried out in stagnant molten lead at 737 K and in lead-bismuth at 573, 673 and 749 K are summarised. The tests were conducted for 700, 1200, 1500 and 5000 h. Three steels were tested: two martensitic steels (mod. F82H and MANET II) and one austenitic steel (AISI 316L). The martensitic steels underwent oxidation phenomena at the higher testing temperature, due to oxygen dissolved in the melts. At a lower test temperature (573 K) and higher exposure time (5000 h) the oxidation rate of the martensitic steel seems to be lower and the developed oxide layer protective against liquid metal corrosion. The austenitic steel, in turn, exhibited an acceptable resistance to corrosion-oxidation under the test conditions

  11. Elastic properties of bismuth layer-structure perovskite single crystals studied by brillouin scattering

    International Nuclear Information System (INIS)

    Elastic properties of bismuth layered perovskite compounds, LaxBi4-xTi3O12 (LBT-x) and SrBi2Ta2O9 (SBT), were examined at room temperature by Brillouin scattering. Elastic stiffness coefficients, c33 and c44, defined in the pseudotetragonal symmetry, were obtained. The longitudinal sound velocities propagating along the c axis, were 3985 m/s and 3118 m/s for the pure bismuth titanate (BTO) and SBT, respectively. The sound velocity of SBT is very slow and is believed to be related with the weak interlayer bonding of this layer-structure compound. A simple linear chain model showed that the difference in the sound velocity between BTO and SBT is mainly due to the difference in the c axis lattice constant. The sound velocity of LBT-x increased slightly with the increase of x, while c33 seems to be insensitive to x

  12. Recovery of IR luminescence in photobleached bismuth-doped fibers by thermal annealing

    Science.gov (United States)

    Firstov, S. V.; Firstova, E. G.; Alyshev, S. V.; Khopin, V. F.; Riumkin, K. E.; Melkumov, M. A.; Guryanov, A. N.; Dianov, E. M.

    2016-08-01

    The effect of annealing temperature on the luminescent properties of bismuth-doped fibers bleached by 532 nm laser radiation was investigated. The photoluminescence (PL) measurements were performed in pristine and photobleached samples which were thermally annealed at various temperatures ranging from 100 to 900 °C and slowly cooled. We observed that the intensity of the PL band at 1700 nm in the photobleached fibers recovered its pre-bleached level. Moreover, it was shown that a significant increase of the PL level could be achieved using the special annealing regime. Thereby, we obtained the experimental evidence of a thermally activated recovery process of the PL intensity showing that photoinduced changes of PL in bismuth-doped fibers are completely reversible. The mechanism of the thermal recovery of the PL is discussed.

  13. MYRRHA ADS DATABASE: Part I. Thermophysical properties of molten lead-bismuth eutectic. Version 1

    International Nuclear Information System (INIS)

    This report is an update of the internal SCK-CEN report IR-18 'Database of thermal properties for the melted lead-bismuth eutectic' issued in 2002. This compilation takes into account larger amount of original sources and, partially, the work performed in the framework of the preparation of a 'zero' version of the HLMC Handbook by the OECD/NEA Working Group on LBE Technology. An analysis is performed of the previous recommendations using some general physical laws and referencing to the properties of lead and bismuth. The updated and extended version of the molten LBE thermal properties database is developed and the correlations are proposed for the design calculations of ADS MYRRHA. (author)

  14. Graphite felt modified with bismuth nanoparticles as negative electrode in a vanadium redox flow battery.

    Science.gov (United States)

    Suárez, David J; González, Zoraida; Blanco, Clara; Granda, Marcos; Menéndez, Rosa; Santamaría, Ricardo

    2014-03-01

    A graphite felt decorated with bismuth nanoparticles was studied as negative electrode in a vanadium redox flow battery (VRFB). The results confirm the excellent electrochemical performance of the bismuth modified electrode in terms of the reversibility of the V(3+) /V(2+) redox reactions and its long-term cycling performance. Moreover a mechanism that explains the role that Bi nanoparticles play in the redox reactions in this negative half-cell is proposed. Bi nanoparticles favor the formation of BiHx , an intermediate that reduces V(3+) to V(2+) and, therefore, inhibits the competitive irreversible reaction of hydrogen formation (responsible for the commonly observed loss of Coulombic efficiency of VRFBs). Thus, the total charge consumed during the cathodic sweep in this electrode is used to reduce V(3+) to V(2+) , resulting in a highly reversible and efficient process. PMID:24520000

  15. Intercalation of pyridine and its derivatives into crystalline bismuth molybdenum hydrous oxide

    International Nuclear Information System (INIS)

    Bismuth molybdenum hydrous oxide was prepared by water-thermally direct precipitation in relatively concentrated solutions. The composition of the resulting product was Bi2Mo3O12 x 3.86 H2O determined by thermal analysis and ICP. The X-ray powder diffraction patterns of the crystal synthesized was identical with that of Bi2Mo3O12 x 4.75 H2O. Pyridine, 2,5-dimethylpyridine and 4-benzylpiridine were intercalated into inorganic crystal, significantly expanding interlayer distance along b axis in the monoclinic cell unit of bismuth molybdenum hydrous oxide. The organic molecules were intercalated by solvent exchange mechanism which mainly devoted to the expansion of interlayer spacing. (author)

  16. Synthesis of Bismuth Ferrite Nanoparticles via a Wet Chemical Route at Low Temperature

    Directory of Open Access Journals (Sweden)

    Yongming Hu

    2011-01-01

    Full Text Available Nanoparticles (NPs of multiferroic bismuth ferrite (BiFeO3 with narrow size distributions were synthesized via a wet chemical route using bismuth nitrate and iron nitrate as starting materials and excess tartaric acid and citric acid as chelating agent, respectively, followed by thermal treatment. It was found that BiFeO3 NPs crystallized at ∼350∘C when using citric acid as chelating agent. Such crystallization temperature is much lower than that of conventional chemical process in which other types of chelating agent are used. BiFeO3 NPs with different sizes distributions show obvious ferromagnetic properties, and the magnetization is increased with reducing the particle size.

  17. The photorefractive characteristics of bismuth-oxide doped lithium niobate crystals

    International Nuclear Information System (INIS)

    Bismuth-doped lithium niobate (LN:Bi) crystals were grown by Czochralski method and their optical damage resistance, photorefraction, absorption spectra, and defect energy levels were investigated. The experimental results indicate that the photorefractive properties of LN:Bi were enhanced as compared with congruent one, the photorefractive response time was greatly shortened, the photorefractive sensitivity was increased, and the diffraction efficiency of near-stoichiometric LN:Bi (SLN:Bi) reached 31.72% and 49.08% at 532 nm and 488 nm laser, respectively (light intensity of 400 mW/cm2). An absorption peak at about 350 nm was observed in the absorption spectrum of LN:Bi. And the defect energy levels simulation indicates new defect levels appear in the forbidden gap of LN:Bi crystals. Therefore bismuth can act as photorefractive centers in LN crystals

  18. Spectral investigation of highly ionized bismuth plasmas produced by subnanosecond Nd:YAG laser pulses

    Science.gov (United States)

    Wu, Tao; Higashiguchi, Takeshi; Li, Bowen; Arai, Goki; Hara, Hiroyuki; Kondo, Yoshiki; Miyazaki, Takanori; Dinh, Thanh-Hung; Dunne, Padraig; O'Reilly, Fergal; Sokell, Emma; O'Sullivan, Gerry

    2016-02-01

    The unresolved transition arrays (UTAs) emitted from laser produced bismuth (Bi) plasma sources show potential for single-shot live cell imaging. We have measured extreme ultraviolet spectra from bismuth laser produced plasmas in the 1-7 nm region using a λ = 1064 nm Nd:YAG laser with a pulse duration of 150 ps. Comparison of spectra obtained under different laser power densities with calculations using the Hartree-Fock with configuration interaction Cowan suite of codes and the UTA formalism, as well as consideration of previous predictions of isoelectronic trends, are employed to identify lines and a number of new features in spectra from Bi XXIII to Bi XLVII. The results show that Δn = 0, n = 4-4 emission from highly charged ions merges to form intense UTAs in the 4 nm region and Δn = 1, n = 4-5 resonance transitions UTAs dominate the 1-3 nm region of the Bi spectrum.

  19. 67 cm long bismuth-based erbium doped fiber amplifier with wideband operation

    International Nuclear Information System (INIS)

    In this paper, we demonstrate a wideband Bismuth-based erbium doped fiber amplifier (Bi-EDFA) using two pieces of bismuth-based erbium-doped fiber (Bi-EDF) with a total length of 67 cm as gain media in a double pass parallel configuration. Both Bi-EDFs have an erbium ion concentration of 6300 ppm. Compared to conventional silica-based erbium-doped fiber amplifier (Si-EDFA) with the same amount of erbium ions, the Bi-EDFA provides a higher attainable gain as well as a greater amplification bandwidth, which ranging from 1525 to 1620 nm. The proposed Bi-EDFA achieved a wideband gain of around 18 dB within the wavelength region from 1530 to 1565 nm. The noise figures are maintained below 10 dB within a wide wavelength region from 1535 nm to 1620 nm

  20. Mixed-layered bismuth--oxygen--iodine materials for capture and waste disposal of radioactive iodine

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James L; Nenoff, Tina M

    2015-01-06

    Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

  1. Synthesis and Electrochemical Sensing Toward Heavy Metals of Bunch-like Bismuth Nanostructures

    Science.gov (United States)

    Zhang, Zhi; Yu, Ke; Bai, Dan; Zhu, Ziqiang

    2010-02-01

    Large-scale bunch-like bismuth (Bi) nanostructures were the first time to be synthesized via two-step electrochemical deposition. The growth mechanism of the nanostructures was discussed. Such a designed bunch-like Bi electrode has high sensitivity to detect the heavy metal ions due to its unique three-dimensional structures and strong ability of adsorbing the heavy metal ions. The bunch-like Bi electrode’s detection of heavy metals was statically performed using anodic stripping voltammetry (ASV). The detection in the Pb(II) concentration range of 2.5-50 μg/l was also performed. Based on the experimental results, this bunch-like Bi electrode can be considered as an interesting alternative to common mercury electrodes and bismuth film electrodes for possible use in electrochemical studies and electroanalytical applications.

  2. Quantum transport, anomalous dephasing, and spin-orbit coupling in an open ballistic bismuth nanocavity

    Science.gov (United States)

    Hackens, B.; Minet, J. P.; Faniel, S.; Farhi, G.; Gustin, C.; Issi, J. P.; Heremans, J. P.; Bayot, V.

    2003-03-01

    The phase coherence time τφ and spin-orbit coupling time τso are measured in a bismuth quasiballistic nanocavity and in bismuth thin films using weak antilocalization and universal conductance fluctuations. The cavity is found to be zero dimensional for phase-coherent processes at low temperature. Weak antilocalization seems weakly affected by this drastic reduction of dimensionality. The temperature dependence of τφ is similar in both types of samples, qualitatively consistent with low-energy transfer two-dimensional electron-electron interaction effects as the dominant dephasing mechanism. Strikingly, τφ in the dot is found to be an order-of-magnitude smaller than in the film, and orders-of-magnitude smaller than the theoretical prediction.

  3. Equilibrium evaporation of trace polonium from liquid lead–bismuth eutectic at high temperature

    International Nuclear Information System (INIS)

    Highlights: •We studied evaporation of trace polonium from liquid lead–bismuth eutectic. •Our methods for Po are validated through analysis of LBE evaporation. •At low concentration Po evaporates from LBE according to Henry’s law. •New Henry constant-temperature correlations for Po in LBE are presented. -- Abstract: The evaporation of Po from its dilute solution in liquid lead–bismuth eutectic (LBE) was determined between 700 and 1000 °C in Ar/5%H2 by the transpiration method. Concurrent measurements of the evaporation of LBE could be well reproduced by calculations using literature data, confirming conditions of equilibrium and convective vapor transport in our transpiration method experiments. This allowed to model the Po evaporation data and extract accurate temperature correlations for the Henry constant for Po dissolved in LBE at two different Po concentrations. Extrapolations of the new correlations were in excellent agreement with existing data at lower temperature

  4. Ab initio lattice dynamics and thermochemistry of layered bismuth telluride (Bi2Te3)

    Science.gov (United States)

    Zurhelle, Alexander F.; Deringer, Volker L.; Stoffel, Ralf P.; Dronskowski, Richard

    2016-03-01

    We present density-functional theory calculations of the lattice dynamics of bismuth telluride, yielding force constants, mean-square displacements and partial densities of phonon states which corroborate and complement previous nuclear inelastic scattering experiments. From these data, we derive an element- and energy-resolved view of the vibrational anharmonicity, quantified by the macroscopic Grüneisen parameter γ which results in 1.56. Finally, we calculate thermochemical properties in the quasiharmonic approximation, especially the heat capacity at constant pressure and the enthalpy of formation for bismuth telluride; the latter arrives at ▵H f (Bi2Te3)  =  -102 kJ mol-1 at 298 K.

  5. Evaluation of bismuth shielding effectiveness in reducing breast absorbed dose during thoracic CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, T. C.; Mourao, A. P.; Santana, P. C.; Silva, T. A. [Federal University of Minas Gerais, Program of Nuclear Science and Techniques, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Computed Tomography (CT) is an essential method for tracking neoplasia and efficiently diagnosing a wide variety of thoracic diseases. CT is generally considered the most accurate choice for lung examination. Due to the growing use of CT, breast and other superficial and radiosensitive organs are unnecessarily irradiated during radiological procedures, thus requiring the development of strategies appropriate to optimize and, if possible, to reduce the radiation dose. The use of bismuth shielding to reduce radiation dose absorbed by breast during thoracic CT examinations has been the subject of many studies recently published by Brazilian and foreign authors of various fields. The purpose of this paper is both to accurately determine the glandular dose when breast is exposed to radiation and to assess the reduction in absorbed dose during thoracic CT examinations, using a set of Thermoluminescent Dosimeters, an anthropomorphic phantom and bismuth shielding. (Author)

  6. Gamma-ray shielding and structural properties of barium-bismuth-borosilicate glasses

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Yenchai, Chadet; Laopaiboon, Raewat

    2012-07-01

    The attenuation coefficients of barium-bismuth-borosilicate glasses have been measured for gamma-ray photon energies of 662, 1173 and 1332 keV using a narrow beam transmission geometry. These coefficients were then used to obtain the values of mass attenuation coefficients, effective atomic number, effective electron density and mean free path. Good agreement has been observed between experimental and theoretical values of these parameters. From the obtained results it is reported here that from the barium-bismuth-borosilicate glasses are better shields to gamma-radiations in comparison to the standard radiation shielding concretes from the shielding point of view. The molar volume, FTIR and acoustic investigations have been used to study the structural properties of the prepared glass system. The obtained results reveal that the formation of non-bridging oxygens occurs at higher concentration of Bi2O3.

  7. Evaluation of bismuth shielding effectiveness in reducing breast absorbed dose during thoracic CT scan

    International Nuclear Information System (INIS)

    Computed Tomography (CT) is an essential method for tracking neoplasia and efficiently diagnosing a wide variety of thoracic diseases. CT is generally considered the most accurate choice for lung examination. Due to the growing use of CT, breast and other superficial and radiosensitive organs are unnecessarily irradiated during radiological procedures, thus requiring the development of strategies appropriate to optimize and, if possible, to reduce the radiation dose. The use of bismuth shielding to reduce radiation dose absorbed by breast during thoracic CT examinations has been the subject of many studies recently published by Brazilian and foreign authors of various fields. The purpose of this paper is both to accurately determine the glandular dose when breast is exposed to radiation and to assess the reduction in absorbed dose during thoracic CT examinations, using a set of Thermoluminescent Dosimeters, an anthropomorphic phantom and bismuth shielding. (Author)

  8. Structural, optical and glass transition studies on Nd3+-doped lead bismuth borate glasses

    International Nuclear Information System (INIS)

    Nd3+-doped lead bismuth borate (PbO-Bi2O3-B2O3) glasses were prepared with different concentrations of Nd3+. The structural studies were done through FTIR spectral analysis. The glass transition studies were done through differential scanning calorimetry. The optical analysis was done by using Judd-Ofelt theory. The structural study reveals that the glass has [BiO3], BO4, BO3 and PbO4 units as the local structures

  9. Large-scale synthesis of bismuth sulfide nanorods by microwave irradiation

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Research highlights: → Large-scale Bi2S3 nanorods have been prepared by microwave irradiation methods. → CTAB and β-CD are beneficial to the formation of Bi2S3 nanorods. → DMF, EG and DEG were favorable solvents. → Bismuth and sulfur precursors influenced the size and morphology. → A proposed formation mechanism of Bi2S3 nanorods was summarized. - Abstract: Bismuth sulfide (Bi2S3) has attracted considerable interest due to its potential applications in thermoelectric and electronic devices, optoelectronic devices, and biomedicine. In this study, large-scale highly crystalline Bi2S3 nanorods were successfully prepared from bismuth citrate and thiourea (Tu) by microwave irradiation methods. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM, HRTEM) and selected area electron diffraction (SAED). The influences of reaction time, surfactants, solvents, and precursors on the formation of Bi2S3 nanorods were discussed. The microwave irradiation method reduced reaction time by at least 80% in the synthesis of Bi2S3 nanorods compared with the refluxing method. Cetyltrimethylammonium bromide (CTAB) and β-cyclodextrin (β-CD) were found to be beneficial to the formation of Bi2S3 nanorods. N,N-dimethylformamide, ethylene glycol, and diethylene glycol were the favorable solvents in the fabrication of these nanorods. It was found that different bismuth and sulfur precursors influenced the sizes and morphologies of the Bi2S3 nanorods. The proposed growth mechanism of Bi2S3 nanorods was also discussed.

  10. Eye-lens bismuth shielding in paediatric head CT: artefact evaluation and reduction

    International Nuclear Information System (INIS)

    CT scans of the brain, sinuses and petrous bones performed as the initial imaging test for a variety of indications have the potential to expose the eye-lens, considered among the most radiosensitive human tissues, to a radiation dose. There are several studies in adults discussing the reduction of orbital dose resulting from the use of commercially available bismuth-impregnated latex shields during CT examinations of the head. To evaluate bismuth shielding-induced artefacts and to provide suggestions for optimal eye-lens shielding in paediatric head CT. A bismuth shield was placed over the eyelids of 60 consecutive children undergoing head CT. Images were assessed for the presence and severity of artefacts with regard to eye-shield distance and shield wrinkling. An anthropomorphic paediatric phantom and thermoluminescence dosimeters (TLDs) were used to study the effect of eye lens-to-shield distance on shielding efficiency. Shields were tolerated by 56/60 children. Artefacts were absent in 45% of scans. Artefacts on orbits, not affecting and affecting orbit evaluation were noted in 39% and 14% of scans, respectively. Diagnostically insignificant artefacts on intracranial structures were noted in 1 case (2%) with shield misplacement. Mean eye-lens-to-shield distance was 8.8 mm in scans without artefacts, and 4.3 mm and 2.2 mm in scans with unimportant and diagnostically important artefacts, respectively. Artefacts occurred in 8 out of 9 cases with shield wrinkling. Dose reduction remained unchanged for different shield-to-eye distances. Bismuth shielding-related artefacts occurring in paediatric head CT are frequent, superficial and diagnostically insignificant when brain pathology is assessed. Shields should be placed 1 cm above the eyes when orbital pathology is addressed. Shield wrinkling should be avoided. (orig.)

  11. Study of some health physics parameters of bismuth-ground granulated blast furnace slag shielding concretes

    Science.gov (United States)

    Kumar, Sandeep; Singh, Sukhpal

    2016-05-01

    The Bismuth-ground granulated blastfurnace slang (Bi-GGBFS) concrete samples were prepared. The weight percentage of different elements present inBi-GGBFS Shielding concretewas evaluated by Energy Dispersive X-ray Microanalysis (EDX). The exposure rate and absorbed dose rate characteristics were calculated theoretically for radioactive sources namely 241Am and 137Cs. Our calculations reveal that the Bi-GGBFS concretes are effective in shielding material for gamma radiations.

  12. Femtosecond Laser-Written Waveguides in a Bismuth Germanate Single Crystal

    International Nuclear Information System (INIS)

    We demonstrate the fabrication of symmetric waveguides in a bismuth germanate (BGO) single crystal using a double line approach by an 800 nm femtosecond laser. The optical attenuation of the single mode waveguide is measured to be 4.2 dB/cm at 633 nm. The influence of pulse energy and focal depth on the end facet of the irradiated region is also studied. This technique is promising to fabricate buried BGO waveguide arrays used in positron emission tomography systems. (general)

  13. Report - Melter Testing of New High Bismuth HLW Formulations VSL-13R2770-1

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A.; Pegg, I. L.; Kot, W. K.; Gan, H.; Matlack, K. S.

    2013-11-13

    The primary objective of the work described was to test two glasses formulated for a high bismuth waste stream on the DM100 melter system. Testing was designed to determine processing characteristics and production rates, assess the tendency for foaming, and confirm glass properties. The glass compositions tested were previously developed to maintain high waste loadings and processing rates while suppressing the foaming observed in previous tests

  14. Compositional dependence of optical band gap and refractive index in lead and bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mallur, Saisudha B.; Czarnecki, Tyler; Adhikari, Ashish; Babu, Panakkattu K.

    2015-08-15

    Highlights: • Refractive indices increase with increasing PbO/Bi{sub 2}O{sub 3} content. • Optical band gap arises due to direct forbidden transition. • Optical band gaps decrease with increasing PbO/Bi{sub 2}O{sub 3} content. • New empirical relation between the optical band gap and the refractive index. - Abstract: We prepared a series of lead and bismuth borate glasses by varying PbO/Bi{sub 2}O{sub 3} content and studied refractive index and optical band gap as a function of glass composition. Refractive indices were measured very accurately using a Brewster’s angle set up while the optical band gaps were determined by analyzing the optical absorption edge using the Mott–Davis model. Using the Lorentz–Lorentz method and the effective medium theory, we calculated the refractive indices and then compared them with the measured values. Bismuth borate glasses show better agreement between the calculated values of the refractive index and experimental values. We used a differential method based on Mott–Davis model to obtain the type of transition and optical band gap (E{sub opt}) which in turn was compared with the value of E{sub opt} obtained using the extinction coefficient. Our analysis shows that in both lead and bismuth borate glasses, the optical band gap arises due to direct forbidden transition. With increasing PbO/Bi{sub 2}O{sub 3} content, the absorption edge shifts toward longer wavelengths and the optical band gap decreases. This behavior can be explained in terms of changes to the Pb−O/Bi−O chemical bonds with glass composition. We obtained a new empirical relation between the optical band gap and the refractive index which can be used to accurately determine the electronic oxide polarizability in lead and bismuth oxide glasses.

  15. Compositional dependence of optical band gap and refractive index in lead and bismuth borate glasses

    International Nuclear Information System (INIS)

    Highlights: • Refractive indices increase with increasing PbO/Bi2O3 content. • Optical band gap arises due to direct forbidden transition. • Optical band gaps decrease with increasing PbO/Bi2O3 content. • New empirical relation between the optical band gap and the refractive index. - Abstract: We prepared a series of lead and bismuth borate glasses by varying PbO/Bi2O3 content and studied refractive index and optical band gap as a function of glass composition. Refractive indices were measured very accurately using a Brewster’s angle set up while the optical band gaps were determined by analyzing the optical absorption edge using the Mott–Davis model. Using the Lorentz–Lorentz method and the effective medium theory, we calculated the refractive indices and then compared them with the measured values. Bismuth borate glasses show better agreement between the calculated values of the refractive index and experimental values. We used a differential method based on Mott–Davis model to obtain the type of transition and optical band gap (Eopt) which in turn was compared with the value of Eopt obtained using the extinction coefficient. Our analysis shows that in both lead and bismuth borate glasses, the optical band gap arises due to direct forbidden transition. With increasing PbO/Bi2O3 content, the absorption edge shifts toward longer wavelengths and the optical band gap decreases. This behavior can be explained in terms of changes to the Pb−O/Bi−O chemical bonds with glass composition. We obtained a new empirical relation between the optical band gap and the refractive index which can be used to accurately determine the electronic oxide polarizability in lead and bismuth oxide glasses

  16. Analysis of the color alteration and radiopacity promoted by bismuth oxide in calcium silicate cement

    Directory of Open Access Journals (Sweden)

    Marina Angelica Marciano

    2013-07-01

    Full Text Available The aim of the study was to determine if the increase in radiopacity provided by bismuth oxide is related to the color alteration of calcium silicate-based cement. Calcium silicate cement (CSC was mixed with 0%, 15%, 20%, 30% and 50% of bismuth oxide (BO, determined by weight. Mineral trioxide aggregate (MTA was the control group. The radiopacity test was performed according to ISO 6876/2001. The color was evaluated using the CIE system. The assessments were performed after 24 hours, 7 and 30 days of setting time, using a spectrophotometer to obtain the ΔE, Δa, Δb and ΔL values. The statistical analyses were performed using the Kruskal-Wallis/Dunn and ANOVA/Tukey tests (p 3 mm equivalent of Al. The MTA group was statistically similar to the CSC / 30% BO group (p > 0.05. In regard to color, the increase of bismuth oxide resulted in a decrease in the ΔE value of the calcium silicate cement. The CSC group presented statistically higher ΔE values than the CSC / 50% BO group (p < 0.05. The comparison between 24 hours and 7 days showed higher ΔE for the MTA group, with statistical differences for the CSC / 15% BO and CSC / 50% BO groups (p < 0.05. After 30 days, CSC showed statistically higher ΔE values than CSC / 30% BO and CSC / 50% BO (p < 0.05. In conclusion, the increase in radiopacity provided by bismuth oxide has no relation to the color alteration of calcium silicate-based cements.

  17. Ultrasonic and Thermal Properties of Borate and Phosphate Glasses Containing Bismuth and Lead

    International Nuclear Information System (INIS)

    Systematic series of (B2O3,P2O5)-Bi2O3-PbO glasses have been successfully prepared by using the rapid quenching technique in which each oxide content changes for every series on the basis of its weight percentage. Their amorphous natures were confirmed earlier by the x-ray diffraction technique. The experimental results show that the density of both glasses, determined by using the Archimedes principle, increases with the glass modifier content. This is due to the replacement of Bi2O3 and PbO in the borate and phosphate glassy networks. The molar volume for borate glass increases with the addition of bismuth and lead oxides, but a reverse trend occurs for the phosphate glass. The longitudinal and shear ultrasound velocities, determined by the MBS 8000 system, of both lead bismuth borate and phosphate glasses show a decreasing trend as more PbO and Bi2O3 are added to the glass system. The increase in PbO/Bi2O3 content was probably related to the progressive increase in the concentration of non-bridging oxygen (NBOs). Thermal studies of the glass, using the Labsys DTA-Setaram machine, show that the value of the glass transition temperature (Tg) is closely related to the chemical bond in the system. In lead bismuth borate glasses, the addition of more Pb2+ and Bi3+ results in a more dominant ionic bond character in the system and hence decreases Tg of the sample. However, in lead bismuth phosphate glasses, the addition of Pb2+ and Bi3+ not only failed to weaken the covalent character in P-O-P bonds, but strengthened it further, leading to an increment in the values of Tg

  18. Equilibrium distribution of samarium and europium between fluoride salt melts and liquid bismuth

    Science.gov (United States)

    Zagnit'ko, A. V.; Ignat'ev, V. V.

    2016-01-01

    The extraction of samarium and europium from a melt of a molar composition 73LiF-27BeF2 into liquid bismuth with additions of lithium as a reducing agent at a temperature of 600-610°C was studied. The equilibrium distribution coefficients of samarium and europium were measured. In the metal fluoride salt melt under study, the valence of samarium and europium was shown to be equal to two.

  19. Isotopic contamination in electromagnetic isotope separators

    International Nuclear Information System (INIS)

    The mechanisms producing isotopic contamination in the electromagnetic separation of isotopes are studied with the aid of the Separator of Saclay and an electrostatic analyzer in cascade. After a separate investigation the result of which is that no contamination comes from the spreading of initial energies of ions, two principal mechanisms are emphasized; scattering and instability of the regime of the sources. The characters of each type of contamination arising from both mechanisms are described in some detail. An unique scheme of isotopic contamination is then derived from the partial ones. This scheme is successfully verified in several experimental separations. The applications concern principally the performances of magnetic cascades and more complex apparatus. It is found that the isotopic purities that such machines can deliver are extremely high. (author)

  20. Facile production of thermoelectric bismuth telluride thick films in the presence of polyvinyl alcohol.

    Science.gov (United States)

    Lei, C; Burton, M R; Nandhakumar, I S

    2016-06-01

    Bismuth telluride is currently the best performing thermoelectric material for room temperature operations in commercial thermoelectric devices. We report the reproducible and facile production of 600 micron thick bismuth telluride (Bi2Te3) layers by low cost and room temperature pulsed and potentiostatic electrodeposition from a solution containing bismuth and tellurium dioxide in 2 M nitric acid onto nickel in the presence of polyvinyl alcohol (PVA). This was added to the electrolyte to promote thick layer formation and its effect on the structure, morphology and composition of the electrodeposits was investigated by SEM and EDX. Well adherent, uniform, compact and stoichiometric n-type Bi2Te3 films with a high Seebeck coefficient of up to -200 μV K(-1) and a high electrical conductivity of up to 400 S cm(-1) resulting in a power factor of 1.6 × 10(-3) W m(-1) K(-2) at film growth rates of 100 μm h(-1) for potentiostatic electrodeposition were obtained. The films also exhibited a well defined hexagonal structure as determined by XRD. PMID:27166737

  1. Synthesis and characterization of Ce and La modified bismuth titanate

    Directory of Open Access Journals (Sweden)

    Nikolina Pavlović

    2009-06-01

    Full Text Available Bismuth titanate based nanopowders with the different content of La or Ce were synthesized by the modified sol-gel method. After calcination at 600°C, in addition to Aurivillius layered structure, a small quantity of cubic pyrochlore phase was detected in the La modified powders, while this second phase was much more pronounced in the Ce substituted powders. In fact, as the powder with the highest amount of Ce (Bi3CeTi3O12 has the pure pyrochlore phase it seems that the presence of Ce stabilizes the formation of this phase. This different infl uence of cerium and lanthanum could be explained by the incorporation of their ions on the different sites in the titanate structure. Bismuth titanate based ceramics, sintered at 1050°C/2h, had densities above 93% of theoretical density and characteristic plate-like grain morphology. Small quantity of cubic pyrochlore phase was detected only in the Ce modifi ed bismuth titanate ceramics. On the other hand, lanthanum addition caused formation of smaller grain size with pronounced plate-like morphology.

  2. Anisotropic Optical Behavior of Ferroelectric Bismuth Titanate: A Comparison of Experiment and Theory

    Science.gov (United States)

    Roy, Amritendu; Prasad, Rajendra; Auluck, Sushil; Garg, Ashish

    2010-03-01

    Optical properties of bismuth titanate (Bi4Ti3O12 or BiT) are of technological interest as its band gap lies in the visible region. Here we compare the results of theoretical and experimental studies conducted on pure bismuth titanate single crystals. Highly oriented BiT single crystals were synthesized using flux growth method. Spectroscopic ellipsometry measurements were made between 300 to 800 nm for different sample orientations. To obtain the absorption coefficient near the band edge, optical transmission measurements were also made. The refractive index data was fitted to a two-term Sellmeier formula. We also calculated the optical constants for both ferroelectric and paraelectric phases of bismuth titanate using density functional theory as implemented in the Vienna ab-initio simulation package (VASP) in conjunction with projector augmented wave method (PAW). Our calculations show the anisotropy of the optical properties for the electric field parallel and perpendicular to the c-axis of the crystal. Our calculations are in good agreement with the experimental data.

  3. Dirac fermions at high-index surfaces of bismuth chalcogenide topological insulator nanostructures

    Science.gov (United States)

    Virk, Naunidh; Yazyev, Oleg V.

    2016-02-01

    Binary bismuth chalcogenides Bi2Se3, Bi2Te3, and related materials are currently being extensively investigated as the reference topological insulators (TIs) due to their simple surface-state band dispersion (single Dirac cone) and relatively large bulk band gaps. Nanostructures of TIs are of particular interest as an increased surface-to-volume ratio enhances the contribution of surfaces states, meaning they are promising candidates for potential device applications. So far, the vast majority of research efforts have focused on the low-energy (0001) surfaces, which correspond to natural cleavage planes in these layered materials. However, the surfaces of low-dimensional nanostructures (nanoplatelets, nanowires, nanoribbons) inevitably involve higher-index facets. We perform a systematic ab initio investigation of the surfaces of bismuth chalcogenide TI nanostructures characterized by different crystallographic orientations, atomic structures and stoichiometric compositions. We find several stable terminations of high-index surfaces, which can be realized at different values of the chemical potential of one of the constituent elements. For the uniquely defined stoichiometric termination, the topological Dirac fermion states are shown to be strongly anisotropic with a clear dependence of Fermi velocities and spin polarization on the surface orientation. Self-doping effects and the presence of topologically trivial mid-gap states are found to characterize the non-stoichiometric surfaces. The results of our study pave the way towards experimental control of topologically protected surface states in bismuth chalcogenide nanostructures.

  4. Opto-electronic properties of bismuth oxide films presenting different crystallographic phases

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Celia L. [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, UNAM, Unidad de Posgrado, Edificio C, Piso 1, Zona Cultural de CU, México, D.F. 04510 (Mexico); Depablos-Rivera, Osmary, E-mail: osmarydep@yahoo.com [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, UNAM, Unidad de Posgrado, Edificio C, Piso 1, Zona Cultural de CU, México, D.F. 04510 (Mexico); Silva-Bermudez, Phaedra [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Instituto Nacional de Rehabilitación, Calz. México Xochimilco No. 289 Col. Arenal de Guadalupe, C.P.14389, Ciudad de México, D.F. (Mexico); Muhl, Stephen [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Zeinert, Andreas; Lejeune, Michael; Charvet, Stephane; Barroy, Pierre [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens Cedex 1 (France); Camps, Enrique [Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, kilómetro 36.5. La Marquesa, Municipio de Ocoyoacac, CP 52750, Estado de México (Mexico); Rodil, Sandra E. [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico)

    2015-03-02

    The optical, electrical and structural properties of bismuth oxide thin films deposited by radio frequency reactive magnetron sputtering were studied. The Bi{sub 2}O{sub 3} thin films were grown on Si and glass substrates under different power and substrate temperatures in an oxygen-enriched plasma leading to films with different crystalline phase as evidenced by X-ray diffraction and Raman spectroscopy. The optical properties of the films were measured using ellipsometric spectroscopy and optical transmission spectra. In order to parameterize the optical dispersion functions (n, k) of the films, the Tauc–Lorentz dispersion model was used. The optical bandgap was then assessed by different methods and the results are compared to the thermal variations of the electrical resistivity of the films. It was found that the refractive index, extinction coefficient and optical gap strongly depend on the deposition conditions and the crystalline phase; the fluorite defect cubic δ-Bi{sub 2}O{sub 3} phase showed the lowest optical gap and lower resistivity. - Highlights: • Different bismuth oxide phases were obtained by sputtering. • The power and substrate temperature were the two key parameters. • Room temperature delta-Bi{sub 2}O{sub 3} thin films were obtained. • The optical bandgap was around 1.5 and 2.2 eV, depending on the phase. • The bismuth oxide films presented activation energies around 1 eV.

  5. Growth of GaAsBi alloy under alternated bismuth flows by metalorganic vapor phase epitaxy

    Science.gov (United States)

    Chine, Z.; Fitouri, H.; Zaied, I.; Rebey, A.; El Jani, B.

    2011-09-01

    A successful method to epitaxy GaAsBi layer on (0 0 1) GaAs substrate is proposed. During growth, alternated trimethyl bismuth (TMBi) flows were used. These TMBi flashes were switched on for a short time. The growth was monitored in situ by laser reflectometry using a 632.8 nm beam. The reflectance signal is found to change significantly during both bismuth flashes and GaAs growth stages. High-resolution X-ray diffraction (HRXRD), secondary ion mass spectroscopy (SIMS) and photoreflectance spectroscopy (PR) have been used to characterize the obtained GaAsBi layer. HRXRD curve shows a diffraction peak that can be attributed to a GaAsBi epilayer. SIMS measurements of GaAsBi layer suggest that bismuth diffuses faster near the interface. The PR spectrum indicates the band-to-band transition in GaAsBi layer. The band gap energy was determined by adjusting the PR spectrum with a multilayer model.

  6. Synthesis and characterization of barium-doped bismuth cuprate superconductor by modified sol-gel process

    International Nuclear Information System (INIS)

    The effect of barium (Ba) doing on the formation of superconducting oxides have been studied by considering barium (Ba) substitution for bismuth (Bi) or strontium (Sr) sites. The modified sol - gel vertical Hot Column process was used to prepare the un-doped and barium-doped bismuth - cuprate superconductor homogeneous ceramic powder. Characterization of synthesized materials was done through a variety of techniques such as thermo gravimetric (TG). Differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Combination of wet chemical and classical gravimetric analysis were performed for the determination of elemental composition of the as-synthesized and calcined bismuth-cuprate superconductor oxides. The dependence of the electrical resistance versus temperature was made by four probe technique. It has been observed that modified sol-gel process did effect the physico-chemical properties of the materials. The superconducting phase identified by XRD and TG/DTA analysis mainly shows the higher %age of the low-T/sub c/ phase with transition temperature in the range of 70 to 105 K. (author)

  7. Opto-electronic properties of bismuth oxide films presenting different crystallographic phases

    International Nuclear Information System (INIS)

    The optical, electrical and structural properties of bismuth oxide thin films deposited by radio frequency reactive magnetron sputtering were studied. The Bi2O3 thin films were grown on Si and glass substrates under different power and substrate temperatures in an oxygen-enriched plasma leading to films with different crystalline phase as evidenced by X-ray diffraction and Raman spectroscopy. The optical properties of the films were measured using ellipsometric spectroscopy and optical transmission spectra. In order to parameterize the optical dispersion functions (n, k) of the films, the Tauc–Lorentz dispersion model was used. The optical bandgap was then assessed by different methods and the results are compared to the thermal variations of the electrical resistivity of the films. It was found that the refractive index, extinction coefficient and optical gap strongly depend on the deposition conditions and the crystalline phase; the fluorite defect cubic δ-Bi2O3 phase showed the lowest optical gap and lower resistivity. - Highlights: • Different bismuth oxide phases were obtained by sputtering. • The power and substrate temperature were the two key parameters. • Room temperature delta-Bi2O3 thin films were obtained. • The optical bandgap was around 1.5 and 2.2 eV, depending on the phase. • The bismuth oxide films presented activation energies around 1 eV

  8. Fabrication and modeling of bismuth titanate-PZT ceramic transducers for high temperature applications

    Science.gov (United States)

    Reinhardt, B.; Searfass, C.; Cyphers, R.; Sinding, K.; Pheil, C.; Tittmann, B.

    2013-01-01

    Utilization of a spray-on deposition technique of ferroelectric bismuth titanate (Bi4Ti3O12) composites has a competitive advantage to standard ultrasonic transducers. These can conform to curved surfaces, can operate at high temperature (Curie-Weiss temperature 685 °C) and are mechanically well-coupled to a substrate. However, an issue with many high temperature transducers such as bismuth titanate ceramics is that they have relatively low transduction efficiency, i.e. d33 is about 12-14 pC/F in Bi4Ti3O12 versus 650 pC/F in PZT-5H. It is a common conception that high-temperature capability comes at the cost of electro-mechanical coupling. It will be shown that the high temperature capability of bismuth-titanate-PZT composite transducers using the spray-on deposition technique previously developed, improves the electro-mechanical coupling while maintaining the high temperature performance and mechanical coupling. This material could provide advantages in harsh environments where high signal-to-noise ratios are needed.

  9. Efficient gas sensitivity in mixed bismuth ferrite micro (cubes) and nano (plates) structures

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Highlights: ► Micro (cubes) structure embedded in nano (plates) of bismuth ferrite was prepared by a chemical method. ► These structures were characterized by XRD and SEM. ► LPG, CO2 and NH4 gases were exposed. ► Properties related to gas sensors were measured and reported. -- Abstract: Mixed micro (cubes) and nano (plates) structures of bismuth ferrite (BFO) have been synthesized by a simple and cost-effective wet-chemical method. Structural, morphological and phase confirmation characteristics are measured using X-ray diffraction, field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis techniques. The digital FE-SEM photo-images of BFO sample confirmed an incubation of discrete micro-cubes into thin and regularly placed large number of nano-plates. The bismuth ferrite, with mixed structures, films show considerable performance when used in liquefied petroleum (LPG), carbon dioxide (CO2) and ammonium (NH3) gas sensors application. Different chemical entities in LPG have made it more efficient with higher sensitivity, recovery and response times compared to CO2 and NH3 gases. Furthermore, effect of palladium surface treatment on the gas sensitivity and the charge transfer resistances of BFO mixed structures is investigated and reported.

  10. Effect of ferromagnetic dopants on laser induced optical parameters of bismuth doped CaS phosphors

    Science.gov (United States)

    Kumar, Sunil; Jeon, H. C.; Kang, T. W.; Devraj; Sekhon, Jaskanwal; Verma, N. K.; Bhatti, H. S.; Choubey, Ravi Kant

    2015-12-01

    The effect of ferromagnetic impurities (Fe, Co, and Ni) on the laser induced optical parameters of CaS:Bi phosphors has been studied. The studies were done for the Bismuth concentration of 0.4% in CaS phosphors due to the highest value of oscillator strength as reported earlier. The studies were conducted using nitrogen laser as a excitation source in a pulse excitation mode at room temperature. Appreciable changes in the optical properties have been detected after the addition of ferromagnetic impurities in the CaS phosphor doped with bismuth. The nature of the multiple exponential decays remains the same even after the addition of ferromagnetic impurities in the present case of bismuth-doped phosphors which is in agreement with the earlier work reported on other dopants in sulfide type phosphors. As ferromagnetic impurities enhanced the optical parameters of CaS phosphors appreciably, these studies shows that they can be used to control the transition probability and the corresponding optical parameters.

  11. Synthesis, crystal growth and mechanical properties of Bismuth Silicon Oxide (BSO) single crystal

    International Nuclear Information System (INIS)

    Highlights: • Synthesis of Bismuth Silicon Oxide (BSO). • Single crystal growth of BSO by Czochralski (Cz) method. • Complete mechanical analysis by device fabrication point of view. • Theoretical and experimental calculations of mechanical properties. -- Abstract: Bismuth Silicon Oxide (BSO) is an efficient material for piezo-electric and electro-optic applications. In this article, growth of BSO single crystal by high temperature Czochralski melt growth technique and its detailed mechanical characterization by Vickers microhardness, fracture toughness, crack propagation, brittleness index and yield strength have been reported. The raw material was synthesized by solid state reaction using the stoichiometric ratio of high purity bismuth tri-oxide and silicon di-oxide. The synthesized material was charged in the platinum crucible and then melted. The required rotation and pulling rate was optimized for BSO single crystal growth and good quality single crystal has been harvested after a time span of 5 days. Powder X-ray diffraction analysis confirms the parent crystallization phase of BSO. The experimentally studied mechanical behavior of the crystal is explained using various theoretical models. The anisotropic nature of the crystals is studied using Knoop indentation technique

  12. Three new bismuth(III) pyridine-2,6-dicarboxylate compounds: Synthesis, characterization and crystal structures

    Science.gov (United States)

    Hakimi, Mohammad; Motieiyan, Elham; Bertolotti, Federica; Marabello, Domenica; Nunes Rodrigues, Vitor Hugo

    2015-11-01

    Three new metal-organic compounds containing bismuth and pyridine-2,6-dicarboxylate (pydc) formulated as (2-apyH)2[Bi(pydc)2(pydcH)]·2H2O, 1, (4-apyH)[Bi(pydc) (pydcH)2].4H2O, 2 and (pipzeaH)[Bi2(pydc)3(pydcH) (H2O)2]·5H2O, 3, (2-apy = 2-aminopyridine, 4-apy = 4-aminopyridine, pipzea = 2-piperazin-1-ylethanamine), have been synthesized in deionized water and characterized by elemental analysis (C, H and N), spectral (UV-Vis, IR), 1H NMR spectroscopy, TGA and single crystal X-ray diffraction. These compounds were obtained via proton transfer methodology. Compounds 1 and 2 have similar monomeric bismuth coordination units, whereas compound 3 has a dimeric bismuth coordination unit. The compounds are anionic in 1 and 2 and they are connected non-covalently to 2-apyH and 4-apyH, respectively. In 3, two molecules are present, one neutral and one anionic, and both are connected non-covalently to pipzeaH cations. Five different coordination modes of Bi-pydc exist in 1, 2 and 3. These compounds are stabilized in the solid state by a complex network of hydrogen bonds between crystallization water molecules, anionic, cationic and neutral fragments, forming 3D-supramolecular arrays.

  13. Iron modified structural and optical spectral properties of bismuth silicate glasses

    International Nuclear Information System (INIS)

    Iron bismuth silicate glasses have been successfully synthesized by melt quenching technique. The amorphous nature of the glass samples is ascertained by the XRD patterns. The values of density, molar volume and crystalline volume have been measured and are found to decrease with increase in iron content. The glass transition temperature measured using Differential Scanning Calorimetry (DSC) also varies with increase in Fe2O3 content. The Raman and FTIR spectra of the studied glass system taken at room temperature suggests that Fe2O3 modifies the structure of bismuth silicate glasses and it acts as both network modifier as well as network former. Bismuth also plays the role of both network modifier (BiO6 octahedra) as well as network former (BiO3 pyramids) and SiO2 exists in SiO4 tetrahedral structural units with two non-bridging oxygens. The Hydrogenic excitonic model is found to be applicable to the studied glass compositions. The variation in Urbach energy value observed for the studied glass samples suggests the possibility of increase in the number of glass defects. The metallization criterion for the synthesized glass samples is determined and found to be in the range 0.30–0.38

  14. Iron modified structural and optical spectral properties of bismuth silicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Rajesh [Department of Physics, Maharishi Dayanand University, Rohtak, Haryana 124001 (India); Kundu, R.S. [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001 (India); Punia, R., E-mail: rajeshpoonia13@gmail.com [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001 (India); Aghamkar, P. [Department of Physics, Chaudhary Devi Lal University, Sirsa 125055 (India); Kishore, N. [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001 (India)

    2014-10-01

    Iron bismuth silicate glasses have been successfully synthesized by melt quenching technique. The amorphous nature of the glass samples is ascertained by the XRD patterns. The values of density, molar volume and crystalline volume have been measured and are found to decrease with increase in iron content. The glass transition temperature measured using Differential Scanning Calorimetry (DSC) also varies with increase in Fe{sub 2}O{sub 3} content. The Raman and FTIR spectra of the studied glass system taken at room temperature suggests that Fe{sub 2}O{sub 3} modifies the structure of bismuth silicate glasses and it acts as both network modifier as well as network former. Bismuth also plays the role of both network modifier (BiO{sub 6} octahedra) as well as network former (BiO{sub 3} pyramids) and SiO{sub 2} exists in SiO{sub 4} tetrahedral structural units with two non-bridging oxygens. The Hydrogenic excitonic model is found to be applicable to the studied glass compositions. The variation in Urbach energy value observed for the studied glass samples suggests the possibility of increase in the number of glass defects. The metallization criterion for the synthesized glass samples is determined and found to be in the range 0.30–0.38.

  15. Isotope enrichment systems

    International Nuclear Information System (INIS)

    This invention provides a system in which both phases of the countercurrent contact isotope exchange concentration process are recycled continuously and an isotope depleted liquid phase substance thereof has its prior content of the desired isotope of hydrogen and/or oxygen replenished in an isotope regenerator by direct contact isotope exchange with a flow of steam from a source external to the concentrating process, whereby such replenished liquid serves as the feed liquid for the concentration process. As the supply of steam is gaseous, all problems incident to mineral solids in solution in liquid water are eliminated. As the elevated temperature corresponds to that of the steam, the isotope replenishment of the process feed liquid may be conducted without materially altering the characteristics of the steam for use as an energy source in any system

  16. Effect of cadmium doping on some properties of glass-insulated bismuth-based microwires

    International Nuclear Information System (INIS)

    Full text: According to the literature, semiconductor converters based on films and wire crystals are widely used in present-day microelectronics. However, the production of efficient semiconductor converters requires crystals of high structural perfection with a given composition and desired electrical and mechanical properties. In this work, we describe the study of the perfection of the microstructure and mechanical properties of glass-insulated microwires based on Bi doped with cadmium (Cd) and the technique of preparation of micro resistors suitable for instrumentation applications. Microscopic studies of ground, polished, and chemically etched microwires doped with cadmium showed that they have smooth cylindrical surfaces in the entire range of diameters. Sizes of defects in the form of micropores, microcracks, dislocations, and twins on their surface are much smaller than those of pure bismuth microwire. It is also found that the tendency to twinning and the number and size of surface defects decrease with decreasing diameters; at the same time, their homogeneity increases. The tensile strength of the studied microwires with glass insulation is high for all tested diameters and ranges within 33.274.1 kg/mm with respect to internal diameters of 5.6 21.2 m; in addition, they withstand a breaking force up to 130 g and more, whereas the samples of pure bismuth microwires withstood a force up to 80 g. It is also found that the tensile strength of cadmium doped microwires is significantly higher than that of undoped samples. The bending strength as a measure of elasticity was determined using a special installation according to the critical bending radius of the sample at which the sample integrity is violated. The results of bending tests showed that, with increasing diameter of the doped samples, the critical radius linearly increases; that is, in this case, the elasticity increases with decreasing diameter. Metallographic analysis revealed that cadmium in the

  17. Stainless steel protection by in-situ oxide layer formation in stagnant lead-bismuth eutectic

    International Nuclear Information System (INIS)

    Accelerator Driven Systems (ADS) are designed to transmute long life and high activity nuclear wastes. The physico-chemical and nuclear characteristics of lead bismuth eutectic make this heavy liquid metal suitable to be used as spallation target and as coolant in ADS. However, heavy liquid metals, and particularly lead-bismuth eutectic, present a high aggressiveness to most of the structural materials. Nickel, chromium and iron, as constitutive elements of stainless steels, show a high solubility in lead-bismuth eutectic, that prevents their use as structural materials without any protection at temperatures higher than 400 deg. C for austenitic stainless steels and higher than 450 deg. C for martensitic steels. According to the available experience, proceeding from the former USSR, one of the possible ways to improve the performance of structural materials in Pb-Bi is the formation and maintenance of a protective oxide layer, which would constitute a barrier between the liquid metal and the steel. The corrosion resistance is determined by the oxygen thermodynamic activity in the liquid metal. For oxygen concentrations in the liquid metal below the equilibrium concentration for the formation of protective layers, the structural steels will suffer dissolution attack. On the contrary, if the oxygen concentration is higher than the necessary for the formation of oxide layers, the steels will experience an oxidation process, but very high concentrations provoke lead-bismuth oxides. Therefore, the oxygen content should be between these two limits in order to be able to form a protective oxide on the steel surface. The necessary oxygen content in the liquid metal may be obtained by gas injection, lead oxide interacting with the melt or the H2/H2O system. In this work, materials protection by 'in situ' oxidation has been studied in stagnant lead-bismuth, with different oxygen levels (H2/H2O ratios of 0.3, 0.03 and 0.003), at temperatures from 535 deg. C to 600 deg. C

  18. Stainless steel protection by in-situ oxide layer formation in stagnant lead-bismuth eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Soler, L. [CIEMAT, Edificio 30, Dpto. Fision Nuclear, Avda. Complutense 22, 28040 Madrid, (Spain); Martin, F.J.; Hernandez, F.; Gomez-Briceno, D. [CIEMAT, Nuclear Fission Department, Structural Materials Project, Avda. Complutense 22, Building 30, 28040 Madrid (Spain)

    2004-07-01

    Accelerator Driven Systems (ADS) are designed to transmute long life and high activity nuclear wastes. The physico-chemical and nuclear characteristics of lead bismuth eutectic make this heavy liquid metal suitable to be used as spallation target and as coolant in ADS. However, heavy liquid metals, and particularly lead-bismuth eutectic, present a high aggressiveness to most of the structural materials. Nickel, chromium and iron, as constitutive elements of stainless steels, show a high solubility in lead-bismuth eutectic, that prevents their use as structural materials without any protection at temperatures higher than 400 deg. C for austenitic stainless steels and higher than 450 deg. C for martensitic steels. According to the available experience, proceeding from the former USSR, one of the possible ways to improve the performance of structural materials in Pb-Bi is the formation and maintenance of a protective oxide layer, which would constitute a barrier between the liquid metal and the steel. The corrosion resistance is determined by the oxygen thermodynamic activity in the liquid metal. For oxygen concentrations in the liquid metal below the equilibrium concentration for the formation of protective layers, the structural steels will suffer dissolution attack. On the contrary, if the oxygen concentration is higher than the necessary for the formation of oxide layers, the steels will experience an oxidation process, but very high concentrations provoke lead-bismuth oxides. Therefore, the oxygen content should be between these two limits in order to be able to form a protective oxide on the steel surface. The necessary oxygen content in the liquid metal may be obtained by gas injection, lead oxide interacting with the melt or the H{sub 2}/H{sub 2}O system. In this work, materials protection by 'in situ' oxidation has been studied in stagnant lead-bismuth, with different oxygen levels (H{sub 2}/H{sub 2}O ratios of 0.3, 0.03 and 0.003), at temperatures

  19. Crystal structures of a pentavalent bismuthate, SrBi2O6 and a lead bismuth oxide (Pb1/3Bi2/3O1.4

    Directory of Open Access Journals (Sweden)

    Nobuhiro Kumada

    2014-06-01

    Full Text Available The crystal structures of a pentavalent bismuthate, SrBi2O6 with the PbSb2O6-type structure and a lead bismuth oxide, (Pb1/3Bi2/3O1.4 with the fluorite-type structure were refined by using neutron diffraction data. The final R-factors were Rwp = 4.49, Rp = 3.46, RI = 4.50 and RF = 1.70% for SrBi2O6 and Rwp = 5.04, Rp = 3.93, RI = 5.47 and RF = 4.26% for (Pb1/3Bi2/3O1.4. SrBi2O6 prepared from NaBiO3·1.4H2O is the first example of the bismuthate with the PbSb2O6-type structure. The fluorite-type lead bismuth oxide, (Pb1/3Bi2/3O1.4 was obtained by heating the PbSb2O6-type lead bismuthate, PbBi2O5.9·H2O which was prepared also from NaBiO3·1.4H2O.

  20. Research work for utilizing technology of the lead-bismuth eutectic. 2nd report: Research on corrosion resistance of ODS-Al steels in high temperature lead-bismuth eutectic under oxygen concentration control (Joint research)

    International Nuclear Information System (INIS)

    In 2002, the Japan Atomic Energy Agency (past organization name: Japan Nuclear Cycle Development Institute) was made a contract with the Central Research Institute of Electric Power Industry on the research work for utilizing technology of the lead bismuth eutectic. In the contract, research on corrosion of FBR materials in high temperature lead bismuth eutectic was performed. This work was composed of two stages. In the first stage, corrosion test of high chromium martensitic steel, which was one candidate material for structures of advanced fast reactor, was performed in oxygen controlled lead bismuth eutectic at 650degC. Effect of chromium on corrosion in the lead bismuth eutectic was estimated. In this second research, corrosion test of oxide dispersion strengthened ferritic steels whose chemical compositions of chromium and aluminum were differed has been performed in the lead bismuth eutectic for up to 4,000 hours. As the results, although chromium effect on corrosion has not been observed, good corrosion resistance by aluminum oxide formation on the surface has been obtained. (author)

  1. Uses of stable isotopes

    International Nuclear Information System (INIS)

    The most important fields of stable isotope use with examples are presented. In isotope dilution analysis the stable isotopes are used in trace analysis, measurements of volumes and masses. In the field of stable isotope use as tracers the following applications are encountered: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic. In the domain of isotope equilibrium effects applications in the study of mechanism of drug action, study of natural processes, investigation of equilibrium conditions and water cycle as well as in temperature measurements are encountered. Stable isotopes are also used in advanced nuclear reactors, particularly, the uranium nitride with 15 N as nuclear fuel and 157 Gd for reactor control. In spite of some difficulties of stable isotope use, especially related to analytical techniques, which are slow and expensive, the number of papers reporting this subject is steadily growing as well the number of scientific meetings organized by International Isotope Society and IAEA, Gordon Conferences, and regional meetings in Germany, France, etc. Stable isotope application development on large scale is ensured by improving their production technologies, as well as by development of new labelled compounds and of analytical techniques. (author)

  2. Isotopes in hydrogeology

    International Nuclear Information System (INIS)

    Questions of the application of radioactive isotopes in hydrogeology and seismology are considered, as well as their physico-chemical and geochemical properties and the regularities of their occurrence and migration in natural waters. The possibility of application of these isotopes in calculating the age of waters and in solving paleohydrogeological problems is studied. Elucidated are questions of utilization of helium and uranium isotope content in determining the effect of faults on the hydrogeological conditions of regions and in selecting burial sites for industrial wastes. Utilization of changes in the isotopic and gas composition of underground waters during the activization of tectonic movements for earthquake forecasts is considered

  3. PRINCIPAL ISOTOPE SELECTION REPORT

    International Nuclear Information System (INIS)

    Utilizing nuclear fuel to produce power in commercial reactors results in the production of hundreds of fission product and transuranic isotopes in the spent nuclear fuel (SNF). When the SNF is disposed of in a repository, the criticality analyses could consider all of the isotopes, some principal isotopes affecting criticality, or none of the isotopes, other than the initial loading. The selected set of principal isotopes will be the ones used in criticality analyses of the SNF to evaluate the reactivity of the fuel/waste package composition and configuration. This technical document discusses the process used to select the principal isotopes and the possible affect that these isotopes could have on criticality in the SNF. The objective of this technical document is to discuss the process used to select the principal isotopes for disposal criticality evaluations with commercial SNF. The principal isotopes will be used as supporting information in the ''Disposal Criticality Analysis Methodology Topical Report'' which will be presented to the United States Nuclear Regulatory Commission (NRC) when approved by the United States Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM)

  4. The isotope breathe test

    International Nuclear Information System (INIS)

    The foundations of the breath diagnostic test, based on application of the carbon compounds, labeled with the stable (13C) or radioactive isotope are presented. The methodology for conducting the breath isotope test and the apparatuses, making it possible to determine under clinical conditions the isotope composition of the carbon, contained in the expired air, depending on the introduced tracer type, is briefly described. The safety of the method and prospects of its application are discussed. The examples of the breath isotope test practical application are presented

  5. Photovoltaic enhancement based on improvement of ferroelectric property and band gap in Ti-doped bismuth ferrite thin films

    International Nuclear Information System (INIS)

    Highlights: • The leakage current is effectively reduced by adding a certain amount of titanium. • Addition of titanium increases the remnant polarization and decreases the band gap. • The power conversion efficiency increases as titanium content increases. - Abstract: Ti-doped bismuth ferrite thin films were prepared via sol–gel spin-coating method. The effects of titanium on the microstructure, optical, leakage, ferroelectric and photovoltaic characteristics have been investigated systematically. The result shows that bismuth ferrite thin films doped with 0–8 at.% Ti are rhombohedral distortion perovskite structure. The addition of titanium inhibits the grain growth and enhances the thickness uniformity and can decrease the band gap of bismuth ferrite thin films. The leakage current of bismuth ferrite thin films is effectively reduced by adding a certain amount of titanium and the leakage mechanism has been investigated. Addition of titanium increases the remnant polarization of the films. As titanium content increases, the short circuit photocurrent density decrease first and then increase, while the open circuit photovoltage increase first and then decrease. The power conversion efficiency of Ti-doped bismuth ferrite thin films increases as titanium content increases, which can be explained as a result of the increased remnant polarization and decreased band gap

  6. Collinear resonant ionization laser spectroscopy of rare francium isotopes

    CERN Multimedia

    Neyens, G; Flanagan, K; Rajabali, M M; Le blanc, F M; Ware, T; Procter, T J

    2008-01-01

    We propose a programme of collinear resonant ionization spectroscopy (CRIS) of the francium isotopes up to and including $^{201}$Fr and $^{218,219}$Fr. This work aims at answering questions on the ordering of quantum states, and effect of the ($\\pi s_{1/2}^{-1}$)1/2$^{+}$ intruder state, which is currently believed to be the ground state of $^{199}$Fr. This work will also study the edge of the region of reflection asymmetry through measurement of the moments and radii of $^{218,219}$Fr. This proposal forms the first part of a series of experiments that will study nuclei in this region of the nuclear chart. Based on the success of this initial proposal it is the intention of the collaboration to perform high resolution measurements on the isotopes of radium and radon that surround $^{201}$Fr and $^{218}$Fr and thus providing a comprehensive description of the ground state properties of this region of the nuclear chart. Recent in-source spectroscopy measurements of lead, bismuth and polonium have demonstrated a...

  7. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  8. Mass independent isotope separations

    International Nuclear Information System (INIS)

    Mass independent separations between isotopes of an element were first observed by Clayton on 17 O and 18 O from the Allende meteorite and attributed then to nucleosynthesis. Anomalous ratios of isotope abundance known at that time were due to nuclear processes. Later, atmospheric ozone and stratospheric CO2 were shown to exhibit mass independent isotope composition of oxygen. Several formation mechanisms of these 'anomalous' molecules have been proposed, none being completely satisfactory. In the laboratory, these mass independent chemical separation effects were eventually reproduced. Anomalous separations were also obtained between isotopes of uranium, and even of light elements such as magnesium. These were first connected with irregularities in atomic nucleus volumes. Such effects are not recorded on natural terrestrial samples. Two main reasons prevent such observations from having been made. Firstly, laboratories investigating isotope compositions of elements, publish almost exclusively deltas of one isotope only. But, to look for possible anomalies, one needs to compare each isotope abundance in a sample similar to that in the standard used as origin of deltas. An example of such calculation will be given. Secondly, deltas of isotopes published by different laboratories are usually not comparable to better than a few per mil. The reason is that, to calculate deltas, most laboratories use working standards whose absolute values may not be exactly established as they are not crucial to their work. Several per mil differences will be shown to be implied between the 'absolute' isotope abundance of 13 C of standards, reputedly the same, used by different laboratories. Laboratories making surveys of natural samples should be encouraged, e.g. by IUPAC, to cover every isotope of multiple isotope elements, and to make, at not infrequent intervals, a close comparison of their working standards with internationally distributed ones. (author)

  9. Discovery of the Mercury Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2009-01-01

    Forty mercury isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  10. Discovery of the Einsteinium Isotopes

    OpenAIRE

    Bury, A.; Fritsch, A; Ginepro, J. Q.; Heim, M; Schuh, A.; Shore, A.; Thoennessen, M.

    2009-01-01

    Seventeen einsteinium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  11. Discovery of the Titanium Isotopes

    OpenAIRE

    Meierfrankenfeld, D.; Thoennessen, M.

    2009-01-01

    Twentyfive titanium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  12. Discovery of the Scandium Isotopes

    CERN Document Server

    Meierfrankenfeld, D

    2010-01-01

    Twenty-three scandium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  13. Discovery of the Tungsten Isotopes

    OpenAIRE

    A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  14. Discovery of the Vanadium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-four vanadium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Discovery of the Arsenic Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of the Barium Isotopes

    OpenAIRE

    SHORE, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; Schuh, A.; Thoennessen, M

    2009-01-01

    Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the Silver Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-eight silver isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Discovery of the Cadmium Isotopes

    OpenAIRE

    Amos, S.; Thoennessen, M

    2009-01-01

    Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  19. Discovery of the Krypton Isotopes

    OpenAIRE

    Heim, M.; A. Fritsch; Schuh, A.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-two krypton isotopes have been observed so far; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of the Iron Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Twenty-eight iron isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  1. Discovery of the Gold Isotopes

    OpenAIRE

    Schuh, A.; A. Fritsch; Ginepro, J. Q.; Heim, M.; SHORE, A.; Thoennessen, M

    2009-01-01

    Thirty-six gold isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  2. Discovery of the Cobalt Isotopes

    OpenAIRE

    Szymanski, T; Thoennessen, M

    2009-01-01

    Twenty-six cobalt isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  3. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  4. (Carbon isotope fractionation inplants)

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, M.H.

    1990-01-01

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  5. Maximum abundant isotopes correlation

    International Nuclear Information System (INIS)

    The neutron excess of the most abundant isotopes of the element shows an overall linear dependence upon the neutron number for nuclei between neutron closed shells. This maximum abundant isotopes correlation supports the arguments for a common history of the elements during nucleosynthesis. (Auth.)

  6. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  7. Principles of stable isotope distribution

    CERN Document Server

    Criss, Robert E

    1999-01-01

    1. Abundance and Measurement of Stable Isotopes 1.1. Discovery of Isotopes 1.2. Nuclide Types, Abundances, and Atomic Weights 1.3. Properties and Fractionation of Isotopic Molecules 1.4. Material Balance Relationships 1.5. Mass Spectrometers 1.6. Notation and Standards 1.7. Summary 1.8. Problems References 2. Isotopic Exchange and Equilibrium Fractionation 2.1. Isotopic Exchange Reactions 2.2. Basic Equations 2.3. Molecular Models 2.4. Theory of Isotopic Fractionation 2.5. Temperature Dependence of Isotopic Fractionation Factors 2.6. Rule of the Mean 2.7. Isotopic Thermometers

  8. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  9. NIR photoluminescence of bismuth-doped CsCdBr{sub 3} – The first ternary bromide phase with a univalent bismuth impurity center

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, Alexey N., E-mail: alexey.romanov@list.ru [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation); Veber, Alexander A. [Universität Erlangen-Nürnberg, Lehrstuhl für Glas und Keramik, Martensstraße 5, 91058 Erlangen (Germany); Vtyurina, Daria N. [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation); Kouznetsov, Mikhail S.; Zaramenskikh, Ksenia S.; Lisitsky, Igor S. [State Scientific-Research and Design Institute of Rare-Metal Industry “Giredmet” JSC, 5-1 B.Tolmachevsky Lane, 119017 Moscow (Russian Federation); Fattakhova, Zukhra T.; Haula, Elena V. [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation); Loiko, Pavel A.; Yumashev, Konstantin V. [Center for Optical Materials and Technologies, Belarusian National Technical University, 65/17 Nezavisimosti Avenue, 220013 Minsk (Belarus); Korchak, Vladimir N. [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation)

    2015-11-15

    Single crystals of ternary bromide phase CsCdBr{sub 3} doped with univalent bismuth cations are prepared for the first time by the Bridgman method. Bi{sup +} impurity center emits a broadband long-lived near-infrared photoluminescence with a maximum at ~1053 nm. The characteristics of this photoluminescence and its relations with the energy spectrum of Bi{sup +} impurity center are discussed. A comparison of Bi{sup +} photoluminescence in CsCdBr{sub 3} and ternary chlorides (studied previously) is performed. - Highlights: • Single crystals of Bi{sup +}-doped ternary bromide CsCdBr{sub 3} were prepared. • Broadband NIR photoluminescence was observed from Bi{sup +}-doped CsCdBr{sub 3}. • Single optical center is responsible for NIR emission in Bi{sup +}-doped CsCdBr{sub 3}.

  10. Diffusion-controlled intergranular penetration and embrittlement of copper by liquid bismuth between 300 and 600 Celsius degrees

    International Nuclear Information System (INIS)

    Hybrid reactors are a new concept for energy production and nuclear waste treatment. Among other requirements, structural materials have to withstand liquid metal embrittlement. This thesis aimed therefore to identify the controlling mechanism for the intergranular embrittlement of copper in contact with liquid bismuth. Scanning electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy and Rutherford backscattering spectroscopy have been used to analyze fracture surfaces of both copper polycrystals and a copper bicrystal (symmetric tilt boundary 50 degrees ). These analyses reveal both parabolic intergranular penetration kinetics and a maximal intergranular bismuth concentration that is less than two monolayers equivalent. These two results allow us to identify grain boundary diffusion as the controlling mechanism for the intergranular penetration of copper by liquid bismuth between 300 and 600 Celsius degrees, showing the absence of perfect grain boundary wetting. (author)

  11. Structural studies of bismuth nanocrystals embedded in SiO2 or GeO2 matrices

    International Nuclear Information System (INIS)

    The layer of bismuth nanoclusters embedded in glass matrices and the surface layer of bismuth grains have been obtained by thermal treatment in hydrogen atmosphere of Bi0.33Ge0.67O1.84 and Bi0.57Si0.43O1.72 glass. The thickness and structure of such layers strongly depend on temperature and time of reduction. The structural studies of bismuth nanocrystals embedded in SiO2 or GeO2 matrices were performed with optical microscopy and atomic force microscopy. By the use of a slow-positron beam we monitored the structural changes undergoing in near-to-surface layers after the first steps of isothermal annealing. A simple two-layer model of reduced glasses explains the evolution of the surface layer and electrical properties of the material during the reduction process

  12. Development and assessment of flow rate measurement techniques for lead-bismuth

    International Nuclear Information System (INIS)

    Full text of publication follows: Thermohydraulic investigations in liquid lead or lead-bismuth flows, which are necessary for the design of an Accelerator Driven System (ADS) for nuclear waste transmutation, are raising the need for powerful flow measuring techniques. Due to the hostile physical and chemical properties of lead bismuth (PbBi) even the reliable determination of the flow rate is a difficult task. In this paper we present the results of the experimental investigations on four different flow rate measurement techniques for liquid lead-bismuth. In detail there are two magnetic inductive based methods, a permanent magnet flowmeter (PMF) and an electromagnetic frequency flowmeter (EMFM), a turbine flowmeter and an ultrasound transit time system (USTT). For each technique the development of the dedicated measuring device and its application to the Technology Loop THESYS at the Karlsruhe Lead Laboratory is described. The measurement matrix for the experiments contains four different flow rates, controlled by the power of the electromagnetic pump, at different lead-bismuth temperatures between 200 deg. C and 400 deg. C. At each pump power level the effect of the temperature variations on the measuring instrument is recorded. The presentation of the obtained results is divided into two parts. First, the operating behaviour of the flow meters in the liquid lead-bismuth flow is discussed, concerning the long term stability and the material compatibility of the manufactured devices. Second, the acquired data from the meters are analyzed and assessed with respect to accuracy, linearity and response time. A strong temperature dependency of the PMF signal with irregular instabilities was observed, because it depends on the contact resistance at the interface between the PbBi and the structure material. The change of this resistance due to wetting effects or deposition of impurities induces severe discontinuities in the signal. In contrast, the EMFM principle

  13. Oxygen concentration diffusion analysis of lead-bismuth-cooled, natural-circulation reactor

    International Nuclear Information System (INIS)

    The feasibility study on fast breeder reactors in Japan has been conducted at JNC and related organizations. The Phase-I study has finished in March, 2001. During the Phase-I activity, lead-bismuth eutectic coolant has been selected as one of the possible coolant options and a medium-scale plant, cooled by a lead-bismuth natural circulation flow was studied. On the other side, it is known that lead-bismuth eutectic has a problem of structural material corrosiveness. It was found that oxygen concentration control in the eutectic plays an important role on the corrosion protection. In this report, we have developed a concentration diffusion analysis code (COCOA: COncentration COntrol Analysis code) in order to carry out the oxygen concentration control analysis. This code solves a two-dimensional concentration diffusion equation by the finite differential method. It is possible to simulate reaction of oxygen and hydrogen by the code. We verified the basic performance of the code and carried out oxygen concentration diffusion analysis for the case of an oxygen increase by a refueling process in the natural circulation reactor. In addition, characteristics of the oxygen control system was discussed for a different type of the control system as well. It is concluded that the COCOA code can simulate diffusion of oxygen concentration in the reactor. By the analysis of a natural circulation medium-scale reactor, we make clear that the ON-OFF control and PID control can well control oxygen concentration by choosing an appropriate concentration measurement point. In addition, even when a trouble occurs in the oxygen emission or hydrogen emission system, it observes that control characteristic drops away. It is still possible, however, to control oxygen concentration in such case. (author)

  14. Feasibility of preparing patterned molybdenum coatings on bismuth telluride thermoelectric modules.

    Energy Technology Data Exchange (ETDEWEB)

    Sarobol, Pylin; Hall, Aaron Christopher; Miller, Stephen Samuel; Knight, Marlene E.; LePage, William S.; Sobczak, Catherine Elizabeth.; Wesolowski, Daniel Edward

    2013-09-01

    Molybdenum electrical interconnects for thermoelectric modules were produced by air plasma spraying a 30%CE%BCm size molybdenum powder through a laser-cut Kapton tape mask. Initial feasibility demonstrations showed that the molybdenum coating exhibited excellent feature and spacing retention (~170%CE%BCm), adhered to bismuth-telluride, and exhibited electrical conductivity appropriate for use as a thermoelectric module interconnect. A design of experiments approach was used to optimize air plasma spray process conditions to produce a molybdenum coating with low electrical resistivity. Finally, a molybdenum coating was successfully produced on a fullscale thermoelectric module. After the addition of a final titanium/gold layer deposited on top of the molybdenum coating, the full scale module exhibited an electrical resistivity of 128%CE%A9, approaching the theoretical resistivity value for the 6mm module leg of 112%CE%A9. Importantly, air plasma sprayed molybdenum did not show significant chemical reaction with bismuth-telluride substrate at the coating/substrate interface. The molybdenum coating microstructure consisted of lamellar splats containing columnar grains. Air plasma sprayed molybdenum embedded deeply (several microns) into the bismuth-telluride substrate, leading to good adhesion between the coating and the substrate. Clusters of round pores (and cracks radiating from the pores) were found immediately beneath the molybdenum coating. These pores are believed to result from tellurium vaporization during the spray process where the molten molybdenum droplets (2623%C2%B0C) transferred their heat of solidification to the substrate at the moment of impact. Substrate cooling during the molybdenum deposition process was recommended to mitigate tellurium vaporization in future studies.

  15. Lead-bismuth cooled reactor with a high level of natural circulation (RBEC-M)

    International Nuclear Information System (INIS)

    The RBEC-M is a lead-bismuth cooled fast reactor with a high level of primary coolant natural circulation and a gas lift system in the primary circuit to ensure a supply of inert gas (argon) in the coolant under the core. The name reflects the basic technology of the concept: a fast neutron spectrum, heavy metal lead-bismuth coolant, a high level of natural circulation with a nominal operation of inert gas blowers and safe cooldown of the core after the trip of gas supply blowers. The RBEC-M reactor is a conceptual development based on the preliminary design of the RBEC reactor, hereafter referred to as a 'basic project'. The direct predecessor of the RBEC-M is the design named RBEC, one of the Russian-developed designs of fast reactors with heavy metal coolants. The preliminary design of the RBEC reactor of 900 MW(th) and 340 MW(e) was completed in the 1990s by Russian design and scientific institutions: OKB 'Gidropress', Russian Research Centre (RRC) 'Kurchatov Institute' and IPPE, with the participation of VNIINM and RIAR. The main objective of the development of the RBEC lead-bismuth cooled fast reactor was to provide a reliable solution for nuclear fuel breeding, while using an approach alternative to sodium cooled fast reactors. It was assumed that design development of a nuclear power plant (NPP) with such reactor could be completed in a rather short period, with modest expenditures for additional testing and qualification of separate equipment units

  16. Optical property tuning of bismuth chalcogenides using chemical intercalation (Presentation Recording)

    Science.gov (United States)

    Yao, Jie

    2015-10-01

    Two-dimensional (2D) materials with natural layer structures have been proven to provide extraordinary physical and chemical properties. Bismuth chalcogenides are examples of such two-dimensional materials. They are strongly bonded within layers and weak van der Waals interaction ties those layers together. Such naturally layered structure allows chemical intercalation of foreign atoms into the van der Waals gaps. Here, we show that by adding large number of copper atoms into van der Waals gaps of bismuth chalcogenides, we observed counter-intuitive enhancement of optical transparency together with improved electrical conductivity, which is on the contrary to most bulk materials in which doping reduces the light transmission. This surprising behavior is caused by substantial tuning of material optical property and nanophotonic anti-reflection effect unique to ultra-thin nanoplates. With the intercalation of copper atoms, large number of electrons have been added into the semiconducting material system and effectively lift the Fermi level of the resulting material to its conduction band, as proved by our densityfunctional- theory computations. Occupied lower states in the conduction band do not allow the optical excitation of electrons in the valence band to the bottom of the conduction band, leading to an effective widening of optical band gap. Optical transmission is further enhanced by constructive interference of reflected beams as bismuth chalcogenides have large permittivity than the environment. The synergy of these two effects in two-dimensional nanostructures can be exploited for various optoelectronic applications including transparent electrode. The reversible intercalation process allows potential dynamic tuning capability.

  17. Layer formation on metal surfaces in lead-bismuth at high temperatures in presence of zirconium

    Science.gov (United States)

    Loewen, Eric P.; Yount, Hannah J.; Volk, Kevin; Kumar, Arvind

    2003-09-01

    If the operating temperature lead-bismuth cooled fission reactor could be extended to 800 °C, they could produce hydrogen directly from water. A key issue for the deployment of this technology at these temperatures is the corrosion of the fuel cladding and structural materials by the lead-bismuth. Corrosion studies of several metals were performed to correlate the interaction layer formation rate as a function of time, temperature, and alloy compositions. The interaction layer is defined as the narrow band between the alloy substrate and the solidified lead-bismuth eutectic on the surface. Coupons of HT-9, 410, 316L, and F22 were tested at 550 and 650 °C for 1000 h inside a zirconium corrosion cell. The oxygen potential ranged from approximately 10 -22 to 10 -19 Pa. Analyses were performed on the coupons to determine the depth of the interaction layer and the composition, at each time step (100, 300, and 1000 h). The thickness of the interaction layer on F22 at 550 °C was 25.3 μm, the highest of all the alloys tested, whereas at 650 °C, the layer thickness was only 5.6 μm, the lowest of all the alloys tested. The growth of the interaction layer on F22 at 650 °C was suppressed, owing to the presence of Zr (at 1500 wppm) in the LBE. In the case of 316L, the interaction layers of 4.9 and 10.6 μm were formed at 550 and 650 °C, respectively.

  18. On the evaluation of the pressure losses in a lead-bismuth-eutectics cooled fuel assembly with TRACE and SUSA

    International Nuclear Information System (INIS)

    The prediction of the pressure drop in a pool-type reactor operated with lead-bismuth-eutectics is of crucial importance. A pressure drop of e.g. 1 bar is equivalent to a lead-bismuth-eutectics column of about 1 m, which has a big influence on the financial aspects of the design proposal. The paper presents results on the hydraulic evaluation of a fuel assembly with the emphasis on uncertainties and variations of relevant parameters like the mass flow rate, form, and friction loss coefficients. With the subsequent uncertainty and sensitivity study, in connection with thermal hydraulic investigations, the influence of these uncertain parameters was evaluated. (author)

  19. Replacement of lead bricks with non-hazardous polymer-bismuth for low-energy gamma shielding

    International Nuclear Information System (INIS)

    Lead is a hazardous substance, making it a disposal and industrial hygiene problem. The potential for creating mixed waste or mixed TRU waste exists if the lead becomes contaminated. The disposal of either waste stream is extremely difficult and costly. Bismuth is a nonhazardous material with shielding characteristics similar to lead. An HPGe was characterized using detector shielding composed of lead and polyethylene-based-bismuth to compare the shielding efficacy of both materials. Polymerbismuth bricks may be recommended as gamma spectrometer shielding for sensitive low-energy measurements. (author)

  20. Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields

    OpenAIRE

    Seoung, Youl-Hun

    2015-01-01

    The purpose of the present study was to evaluate radiation dose reduction and image quality during CT scanning by using a new dose reduction fiber sheet (DRFS) with commercially available bismuth shields. These DRFS were composed of nano-barium sulfate (BaSO4), filling the gaps left by the large oxide bismuth (Bi2O3) particle sizes. The radiation dose was measured five times at directionss of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom to calculate an average...

  1. Variation of the electronic densities of states as a function of impurity concentration in amorphous bismuth alloys

    Science.gov (United States)

    Mata-Pinzon, Zaahel; Valladares, Ariel Alberto; Valladares, Alexander; Valladares, Renela Maria

    2014-03-01

    The properties of materials are strongly related to their atomic topology, especially when we compare properties related to the ordered and disordered phases. Using Density Functional Theory methods on 64-atom supercells we obtain the structure and calculate the electronic density of states (eDOS) as a function of the concentration of lead, thallium or antimony in an amorphous bismuth supercell. This is done to investigate how the eDOS affects the superconducting transition temperature (Tc), taking into account the measurements made by Shier and Ginsberg[2] on contaminated amorphous bismuth thin films. Supported by CONACYT and DGAPA (UNAM).

  2. Electrical characteristics of bismuth titanate glass-ceramics containing SiO2 and Nd2O3

    OpenAIRE

    Stanislav S. Slavov; Milena Z. Krapchanska; Elena P. Kashchieva; Yanko B. Dimitriev

    2010-01-01

    Bismuth-titanate ceramics containing SiO2 and Nd2O3 as additives are synthesized at two different ways of cooling of the melts. The introduction of SiO2 and Nd2O3 leads to more complex crystallization with participation of several phases including Bi4Ti3O12. It is proved that the applied methods of synthesis are suitable for generation of different microstructures in the bulk doped bismuth titanate ceramics, which is promising basis for modification of their electrical properties. The increas...

  3. Effects of temperature and strain rate on the tensile behaviors of SIMP steel in static lead bismuth eutectic

    Science.gov (United States)

    Liu, Jian; Yan, Wei; Sha, Wei; Wang, Wei; Shan, Yiyin; Yang, Ke

    2016-05-01

    In order to assess the susceptibility of candidate structural materials to liquid metal embrittlement, this work investigated the tensile behaviors of ferritic-martensitic steel in static lead bismuth eutectic (LBE). The tensile tests were carried out in static lead bismuth eutectic under different temperatures and strain rates. Pronounced liquid metal embrittlement phenomenon is observed between 200 °C and 450 °C. Total elongation is reduced greatly due to the liquid metal embrittlement in LBE environment. The range of ductility trough is larger under slow strain rate tensile (SSRT) test.

  4. Study of iron structure stability in high temperature molten lead-bismuth eutectic with oxygen injection using molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Arkundato, Artoto [Physics Department, Faculty of Mathematical and Natural Sciences, Jember University, Jl. Kalimantan 37 Jember (Indonesia); Su' ud, Zaki [Physics Department, Faculty of Mathematical and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung (Indonesia); Sudarko [Chemistry Department, Faculty of Mathematical and Natural Sciences, Jember University, Jl. Kalimantan 37 Jember (Indonesia); Shafii, Mohammad Ali [Physics Department, Faculty of Mathematical and Natural Sciences, Andalas University, Padang (Indonesia); Celino, Massimo [ENEA, CR Casaccia, Via Anguillarese 301, Rome (Italy)

    2014-09-30

    Corrosion of structural materials in high temperature molten lead-bismuth eutectic is a major problem for design of PbBi cooled reactor. One technique to inhibit corrosion process is to inject oxygen into coolant. In this paper we study and focus on a way of inhibiting the corrosion of iron using molecular dynamics method. For the simulation results we concluded that effective corrosion inhibition of iron may be achieved by injection 0.0532 wt% to 0.1156 wt% oxygen into liquid lead-bismuth. At this oxygen concentration the structure of iron material will be maintained at about 70% in bcc crystal structure during interaction with liquid metal.

  5. Dielectric and Piezoelectric Properties of Sodium Bismuth Titanate Ceramics with KCe Substitution

    Institute of Scientific and Technical Information of China (English)

    XU Jian-Xiu; ZHAO Liang; ZHANG Cheng-Ju

    2008-01-01

    @@ The piezoelectric properties of the (KCe)-substituted sodium bismuth titanate (Na0.5Bi4.5 Ti4O15, NBT) piezo-electric ceramics are investigated. The piezoelectric properties of NBT ceramics are significantly enhanced by (KCe) substitution. The Curie temperature Tc, and piezoelectric coefficient d33 for the (KCe)-substituted NBT are found to be 663°C, and 27pC/N, respectively. Dielectric and annealing spectroscopy present that the (KCe) co-substituted NBT piezoelectric ceramics possess stable piezoelectric properties.

  6. Reaction Mechanism for Ammonia Activation in the Selective Ammoxidation of Propene on Bismuth Molybdates

    OpenAIRE

    Pudar, Sanja; Goddard, William A.

    2015-01-01

    In this paper, we report quantum mechanical studies (using the B3LYP flavor of density functional theory) for various pathways of ammonia activation on bismuth molybdates, a process required for ammoxidation of propene to acrylonitrile. Using a Mo_3O_9 cluster to model the bulk surface, we examined the activation of ammonia by both fully oxidized (MoIV) and reduced (Mo^(IV)) molybdenum sites. Our results show that ammonia activation does not take place on the fully oxidized Mo(VI) sites. Here...

  7. Polonium release from an ATW burner system with liquid lead-bismuth coolant

    International Nuclear Information System (INIS)

    The authors analyzed polonium release hazards in a conceptual pool-type ATW burner with liquid lead-bismuth eutectic (LBE) coolant. Simplified quantitative models are used based on experiments and real NPP experience. They found little Po contamination outside the burner under normal operating conditions with nominal leakage from the gas system. In sudden gas leak and/or coolant spill accidents, the P contamination level can reach above the regulation limit but short exposure would not lead to severe health consequences. They are evaluating and developing mitigation methods

  8. Performance of neutron activation analysis in the evaluation of bismuth iodide purification methodology

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria Jose A.; Ferraz, Caue de Mello; Hamada, Margarida M., E-mail: marmelin@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2015-07-01

    Bismuth tri-iodide (BrI{sub 3}) is an attractive material for using as a semiconductor. In this paper, BiI{sub 3} crystals have been grown by the vertical Bridgman technique using commercially available powder. The impurities were evaluated by instrumental neutron activation analysis (INAA). The results show that INAA is an analytical method appropriate for monitoring the impurities of: Ag, As, Br, Cr, K, Mo, Na and Sb in the various stages of the BiI{sub 3} purification methodology. (author)

  9. Observation of dimension dependent magnetic ordering in bismuth ferrite particulate and fiber nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Sakar, M.; Bharathkumar, S.; Balakumar, S., E-mail: balasuga@yahoo.com [National Centre for Nanoscience and Nanotechnology, University of Madras, Chennai 600 025 (India); Saravanan, P. [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India)

    2015-06-24

    Nanoparticles and nanofibers of bismuth ferrite were fabricated by sol-gel and electrospinning methods respectively. The structural and morphological analysis was carried out by XRD and FESEM techniques respectively. The magnetic measurements were carried out by SQUID magnetometer. The BFO nanofibers showed an enhanced magnetic property compared to nanoparticles. The observed magnetic properties were found to be associated with their magnetic ordering in the system where the antiferromagnetic/ferromagnetic core/shell like nature and ‘canted’ spin structure ordering was found to be the magnetic origin in the particulate and fiber nanostructures respectively.

  10. Dielectric properties of pure and lanthanum modified bismuth titanate thin films

    International Nuclear Information System (INIS)

    We investigated the dielectric properties of pure and lanthanum modified bismuth titanate thin films obtained by the polymeric precursor method. X-ray diffraction of the film annealed at 300 deg. C for 2 h indicates a disordered structure. Lanthanum addition increases gradually the dielectric permittivity of films, keeping unchanged their loss tangent. From C-V curve we can see no hysteresis behavior indicating the absence of domain structure. The decrease in the conductivity for the heavily doped Bi4Ti3O12 (BIT) must be associated to the unidentified crystal defects. For comparison, dielectric properties of crystalline BIT film were also investigated

  11. Synthesis and characterization of ferroelectric bismuth titanate (Bi4Ti3O12)

    International Nuclear Information System (INIS)

    The Lead free, Bi4Ti3O12 has been synthesized by sol-gel method. The synthesized samples have been subjected to the structural, morphological, P-E hysteresis loop measurements. The X-Ray diffraction (XRD) studies have confirmed the pure phase Bismuth Titanate Bi4Ti3O12 with orthorhombic symmetry. The Scanning electron microscope (SEM) studies have shown the good surface morphology. The hysteresis measurement of BIT is also done to confirm the ferroelectric property of the material. The values of remnant polarization (Pr) and coercive field (Ec) is found to be dependent on applied electric field

  12. Synthesis and characterization of ferroelectric bismuth titanate (Bi4Ti3O12)

    Science.gov (United States)

    Gupta, Pallavi; Balram, Singh, Dwijendra P.

    2014-04-01

    The Lead free, Bi4Ti3O12 has been synthesized by sol-gel method. The synthesized samples have been subjected to the structural, morphological, P-E hysteresis loop measurements. The X-Ray diffraction (XRD) studies have confirmed the pure phase Bismuth Titanate Bi4Ti3O12 with orthorhombic symmetry. The Scanning electron microscope (SEM) studies have shown the good surface morphology. The hysteresis measurement of BIT is also done to confirm the ferroelectric property of the material. The values of remnant polarization (Pr) and coercive field (Ec) is found to be dependent on applied electric field.

  13. Bismuth-doped fibre amplifier operating between 1600 and 1800 nm

    Science.gov (United States)

    Firstov, S. V.; Alyshev, S. V.; Riumkin, K. E.; Khopin, V. F.; Mel'kumov, M. A.; Gurjanov, A. N.; Dianov, E. M.

    2015-12-01

    We report the first bismuth-doped fibre amplifier operating between 1600 and 1800 nm, which utilises bidirectional pumping (co-propagating and counter-propagating pump beams) by laser diodes at a wavelength of 1550 nm. The largest gain coefficient of the amplifier is 23 dB, at a wavelength of 1710 nm. It has a noise figure of 7 dB, 3-dB gain bandwidth of 40 nm and gain efficiency of 0.1 dB mW-1.

  14. Flow injection potentiometric determination of bismuth(III) in anti-acid formulations.

    Science.gov (United States)

    Teixeira, M F; Fatibello-Filho, O

    2001-06-19

    A flow injection potentiometric procedure is proposed for determining bismuth(III) in anti-acid formulations. In this work, a tubular electrode coated with an ion-pair formed between [Bi(EDTA)](-) and tricaprylylmethylammonium cation (Aliquat 336) in a poly(vinylchloride) (PVC) was constructed and used in a single channel flow injection system. The effect of membrane composition, pH and flow injection parameter over the Bi(III) tubular electrode response (slope (mV/decade)) was initially evaluated in quintuplicate in 0.5 mol l(-1) EDTA solution as carrier. The best response (-59.6+/-0.9 mV/decade) was attained with the 5% m/m ion-pair; 65% m/m o-nitrophenyl octyl ether (o-NPOE) and 30% m/m PVC in pH 6-9. The electrode showed a linear response to E (mV) versus log [Bi(EDTA)](-) in the bismuth(III) concentration range from 2.0x10(-5) to 1.0x10(-2) mol l(-1) and a useful lifetime of at least 5 months (more than 1000 determinations for each polymeric membrane). The detection limit was 1.2x10(-5) mol l(-1) and the R.S.D. was less than 2.0% for a solution containing 5.0x10(-4) mol l(-1) bismuth(III) (n=10). Several species such as Cd(II), Mn(II), Ni(II), Zn(II), Co(II), Cu(II), Mg(II), Cr(III) and Al(III) at 1.0x10(-3) mol l(-1) concentration in 0.5 mol l(-1) EDTA solution did not cause any interference. The frequency rate was 90 determinations per hour and the results obtained for bismuth(III) in anti-acid formulations using this flow procedure and those obtained using a spectrophotometric procedure are in agreement at the 95% confidence level. PMID:11397573

  15. Dielectric and Piezoelectric Properties of Sodium Bismuth Titanate Ceramics with KCe Substitution

    Science.gov (United States)

    Xu, Jian-Xiu; Zhao, Liang; Zhang, Cheng-Ju

    2008-12-01

    The piezoelectric properties of the (KCe)-substituted sodium bismuth titanate (Na0.5Bi4.5Ti4O15, NBT) piezoelectric ceramics are investigated. The piezoelectric properties of NBT ceramics are significantly enhanced by (KCe) substitution. The Curie temperature Tc, and piezoelectric coefficient dss for the (KCe)-substituted NBT are found to be 663°C, and 27pC/N, respectively. Dielectric and annealing spectroscopy present that the (KCe) co-substituted NBT piezoelectric ceramics possess stable piezoelectric properties.

  16. 1700 nm dispersion managed mode-locked bismuth fiber laser

    Science.gov (United States)

    Noronen, Teppo; Firstov, Sergei; Dianov, Evgeny; Okhotnikov, Oleg G.

    2016-04-01

    We demonstrate the first 1.7 μm bismuth-doped fiber laser generating ultrashort pulses via passive mode-locking. Pulse operation has been achieved for both anomalous and normal dispersion of the laser cavity owing to broadband characteristics of carbon nanotube saturable absorber. The laser delivered 1.65 ps pulses in net anomalous dispersion regime. In normal dispersion regime, the laser delivered 14 ps pulses which could be compressed to 1.2 ps using external fiber compressor.

  17. Study Plan for Material Corrosion Test in Lead and Bismuth Eutectic at High Temperature

    International Nuclear Information System (INIS)

    A concept of steam lift pump type lead-bismuth cooled fast reactor (SLPLFR) is proposed as high temperature and high efficiency Pb-Bi cooled fast reactors. Fe-Al alloy-surface treated steels and ceramics of SiC, Si3N4 and SiC/SiC composites have been chosen as candidates of cladding and structural materials, respectively. A corrosion test plan is proposed, where compatibility of steels applied with Al-Fe alloy-surface treatment and the ceramics will be tested in high temperature Pb-Bi flow. A conceptual design of a test apparatus for the corrosion test is provided. (authors)

  18. RBEC lead-bismuth cooled fast reactor: review of conceptual decisions

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, P.; Fomichenko, P.; Mikityuk, K.; Nevinitsa, V.; Shchepetina, T.; Subbotin, S.; Vasiliev, A. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

    2001-07-01

    A concept of the RBEC lead-bismuth fast reactor-breeder is a synthesis, on one hand, of more than 40-year experience in development and operation of fast sodium power reactors and reactors with Pb-Bi coolant for nuclear submarines, and, on the other hand, of large R and D activities on development of the core concept for modified fast sodium reactor. The report briefly presents main parameters of the RBEC reactor, as a candidate for commercial exploitation in structure of the future nuclear power. (author)

  19. Ultrafast optical control of magnetization dynamics in polycrystalline bismuth doped iron garnet thin films

    Energy Technology Data Exchange (ETDEWEB)

    Deb, Marwan, E-mail: marwan.deb@ipcms.unistra.fr; Vomir, Mircea; Rehspringer, Jean-Luc; Bigot, Jean-Yves [Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS, Université de Strasbourg, BP 43, 23 rue du Loess, 67034 Strasbourg Cedex 02 (France)

    2015-12-21

    Controlling the magnetization dynamics on the femtosecond timescale is of fundamental importance for integrated opto-spintronic devices. For industrial perspectives, it requires to develop simple growth techniques for obtaining large area magneto-optical materials having a high amplitude ultrafast Faraday or Kerr response. Here we report on optical pump probe studies of light induced spin dynamics in high quality bismuth doped iron garnet polycrystalline film prepared by the spin coating method. We demonstrate an ultrafast non-thermal optical control of the spin dynamics using both circularly and linearly polarized pulses.

  20. Observation of dimension dependent magnetic ordering in bismuth ferrite particulate and fiber nanostructures

    International Nuclear Information System (INIS)

    Nanoparticles and nanofibers of bismuth ferrite were fabricated by sol-gel and electrospinning methods respectively. The structural and morphological analysis was carried out by XRD and FESEM techniques respectively. The magnetic measurements were carried out by SQUID magnetometer. The BFO nanofibers showed an enhanced magnetic property compared to nanoparticles. The observed magnetic properties were found to be associated with their magnetic ordering in the system where the antiferromagnetic/ferromagnetic core/shell like nature and ‘canted’ spin structure ordering was found to be the magnetic origin in the particulate and fiber nanostructures respectively

  1. Two Octaves Supercontinuum Generation in Lead-Bismuth Glass Based Photonic Crystal Fiber

    OpenAIRE

    Ryszard Buczynski; Henry Bookey; Mariusz Klimczak; Dariusz Pysz; Ryszard Stepien; Tadeusz Martynkien; McCarthy, John E.; Andrew J. Waddie; Kar, Ajoy K.; Taghizadeh, Mohammad R.

    2014-01-01

    In this paper we report a two octave spanning supercontinuum generation in a bandwidth of 700–3000 nm in a single-mode photonic crystal fiber made of lead-bismuth-gallate glass. To our knowledge this is the broadest supercontinuum reported in heavy metal oxide glass based fibers. The fiber was fabricated using an in-house synthesized glass with optimized nonlinear, rheological and transmission properties in the range of 500–4800 nm. The photonic cladding consists of 8 rings of air holes. Th...

  2. New Bismuth Germanate Oxide Nanoparticle Material for Biolabel Applications in Medicine

    OpenAIRE

    M. J. Oviedo; Contreras, O. E.; Y. Rosenstein; Vazquez-Duhalt, R.; Z. S. Macedo; Carbajal-Arizaga, G. G.; G. A. Hirata

    2016-01-01

    Bismuth germanate (Bi4Ge3O12, BGO) has been the focus of several studies due to its scintillation properties. It has been employed as detector in scientific research and medicine, and herein we studied its possible biomedical applications. The photoluminescence properties of the uncoated and protein-coated nanoparticles were analyzed in different body fluids, at different pH. The nanoparticles yielded blueish-white luminescence with a maximum emission peak at 485 nm corresponding to the 3P1→1...

  3. Numerical simulation of Taylor bubble rising in liquid lead-bismuth eutectic based on MPS method

    International Nuclear Information System (INIS)

    The Taylor bubble rising in a vertical tube filled with liquid lead-bismuth eutectic was simulated based on MPS method. Several performed results including shape development, bubble rising terminal speed fitting line, and the thickness and axial velocity profile of the falling film were presented. The simulation results were compared with some experimental results from literature and reveal the corresponding laws obeyed by the terminal speed, velocity profile and film thickness. The computational results agree well with both theoretical analysis and experimental results, which demonstrates the reasonable selection of model as well as the accuracy and reliability of MPS method. (authors)

  4. Numerical Analysis of Lead-Bismuth-Water Direct Contact Boiling Heat Transfer

    Science.gov (United States)

    Yamada, Yumi; Takahashi, Minoru

    Direct contact boiling heat transfer of sub-cooled water with lead-bismuth eutectic (Pb-Bi) was investigated for the evaluation of the performance of steam generation in direct contact of feed water with primary Pb-Bi coolant in upper plenum above the core in Pb-Bi-cooled direct contact boiling water fast reactor. An analytical two-fluid model was developed to estimate the heat transfer numerically. Numerical results were compared with experimental ones for verification of the model. The overall volumetric heat transfer coefficient was calculated from heat exchange rate in the chimney. It was confirmed that the calculated results agreed well with the experimental result.

  5. Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation)

    International Nuclear Information System (INIS)

    An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead-bismuth

  6. Additive-free controllable fabrication of bismuth vanadates and their photocatalytic activity toward dye degradation

    International Nuclear Information System (INIS)

    Bismuth vanadates (BiVO4) with various crystal structures (tetragonal scheelite, monoclinic scheelite, and tetragonal zircon) and morphologies (sphere-, nanosheet-, dendrite-, and flower-like) were controllably fabricated by using a mild additive-free hydrothermal treatment process under the different preparation conditions. The crystal structures, morphologies, and photophysical properties of the products were well-characterized. Subsequently, their UV- as well as visible-light photocatalytic performance was evaluated via dyes rhodamine B (RB) and methylene blue (MB) degradation. Special attention was paid to evaluate the correlation of the reactivity with crystal structure, morphology, and electronic structure of as-prepared BiVO4 samples.

  7. Compatibility of silicon carbide coated graphite with lead-bismuth eutectic at 900 °C

    International Nuclear Information System (INIS)

    A uniform and adherent coating of β-silicon carbide (SiC) was formed over a graphite pellet through slurry based silicon coating technique followed by in-situ reaction at 1600°C. The compatibility of this pellet was studied with molten lead-bismuth eutectic (LBE) at 900°C in static condition for 200 h continuously. Analysis of the exposed pellet through weight loss measurement, X Ray Diffraction (XRD) and Secondary Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) confirmed that the SiC coating could effectively prevent molten LBE from attacking the inner graphite material under the present experimental conditions. (author)

  8. RBEC lead-bismuth cooled fast reactor: review of conceptual decisions

    International Nuclear Information System (INIS)

    A concept of the RBEC lead-bismuth fast reactor-breeder is a synthesis, on one hand, of more than 40-year experience in development and operation of fast sodium power reactors and reactors with Pb-Bi coolant for nuclear submarines, and, on the other hand, of large R and D activities on development of the core concept for modified fast sodium reactor. The report briefly presents main parameters of the RBEC reactor, as a candidate for commercial exploitation in structure of the future nuclear power. (author)

  9. Interaction study between MOX fuel and Eutectic Lead-Bismuth coolant

    OpenAIRE

    VIGIER JEAN-FRANCOIS; POPA KARIN; TYRPEKL VACLAV; GARDEUR Sebastien; FREIS DANIEL; SOMERS Joseph

    2015-01-01

    In the frame of the MYRRHA reactor project, the interaction between fuel pellets and the reactor coolant is essential for safety evaluations, e.g. in case of a pin breach. Therefore, interaction tests between uranium-plutonium mixed oxide (MOX) pellets and molten lead bismuth eutectic (LBE) have been performed and three parameters were studied, namely the interaction temperature (500 °C and 800 °C), the oxygen content in LBE and the stoichiometry of the MOX (U0.7Pu0.3O2-x and U0.7Pu0.3O2.00)....

  10. Corrosion behavior of cold-worked austenitic stainless steels in liquid lead–bismuth eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, Yuji, E-mail: kurata.yuji@jaea.go.jp

    2014-05-01

    Highlights: • Austenitic stainless steels cold-worked up to 50% were exposed to lead–bismuth. • Lead–bismuth with the low oxygen concentration caused deep ferritization at 550 °C. • Ferritization also occurred at 550 °C during 3000 h under the high oxygen condition. • Cold working accelerated ferritization and Pb–Bi penetration without a protective film. • Attention should be also focused on the cold-working effect on corrosion behavior. - Abstract: The effect of cold working on the corrosion behavior of austenitic stainless steels in liquid lead–bismuth eutectic (LBE) was studied to develop accelerator-driven systems for the transmutation of long-lived radioactive wastes and lead–bismuth cooled fast reactors. Corrosion tests on solution-treated, 20% cold-worked and 50% cold-worked 316SS and JPCA (15Cr–15Ni–Ti) were conducted in oxygen-controlled LBE. Slight ferritization caused by Ni dissolution and Pb–Bi penetration were observed for all specimens in the corrosion test conducted at 500 °C for 1000 h in liquid LBE with an intermediate oxygen concentration (1.4 × 10{sup −7} wt.%). In the corrosion test performed at 550 °C for 1000 h in liquid LBE with a low oxygen concentration (4.2 × 10{sup −9} wt.%), the depth of the ferritization of 316SS and JPCA increased with the extent of cold working. Only oxidation was observed in the corrosion test that was performed at 550 °C for 1000 h in liquid LBE with a high oxygen concentration (approximately 10{sup −5} wt.%). Cold working accelerated the formation of the double layer oxide and increased the thickness of the oxide layer slightly. In contrast, the ferritization accompanied by Pb–Bi penetration was widely observed with oxidation for all specimens corrosion tested at 550 °C for 3000 h under the high-oxygen condition. Cold working increased the depth of the ferritization of 316SS and JPCA. It is considered that cold working accelerated the ferritization and Pb–Bi penetration

  11. Optical properties of Dy3+ doped bismuth zinc borate glass and glass ceramics

    Science.gov (United States)

    Shanmugavelu, B.; Kanth Kumar, V. V. Ravi

    2012-06-01

    Dy3+ doped bismuth zinc borate transparent glasses were prepared by melt quenching technique and these glasses were used precursor to obtain transparent glass ceramics by heat treatment method. XRD pattern of the glass ceramic shows the formation of the β-BiB3O6 and Bi2ZnOB2O6 phases. The visible emission intensity of the glass ceramics is stronger than the glass. This can be due to the formation of nano nonlinear optical crystallites in glass matrix.

  12. STM revealing of twin microlayers with quantized width on cleaved bismuth surface

    Science.gov (United States)

    Edelman, V. S.; Sharvin, D. Yu.; Khlyustikov, I. N.; Troyanovskii, A. M.

    1996-04-01

    Scanning tunnelling microscopy of cleaved bismuth surfaces at low temperatures revealed the existence of identical thin twin interlayers, embedded in the main crystal. The interlayers were strictly ordered along the surface atomic rows. They were of the macroscopic lengths of the order of one micrometre. The width of interlayers was about ~ 70 Å. It corresponds nearly to the distance at which the height gained due to the tilt of twin interlayer atomic lattice with respect to the main crystal surface reaches the interplanar spacing in the [0001] direction, i.e. ~ 2 Å. Hence the width "quantization" is connected with the matching of atomic planes at both sides of twin interlayer.

  13. Performance of neutron activation analysis in the evaluation of bismuth iodide purification methodology

    International Nuclear Information System (INIS)

    Bismuth tri-iodide (BrI3) is an attractive material for using as a semiconductor. In this paper, BiI3 crystals have been grown by the vertical Bridgman technique using commercially available powder. The impurities were evaluated by instrumental neutron activation analysis (INAA). The results show that INAA is an analytical method appropriate for monitoring the impurities of: Ag, As, Br, Cr, K, Mo, Na and Sb in the various stages of the BiI3 purification methodology. (author)

  14. Rotational-isotopic symmetries

    International Nuclear Information System (INIS)

    In this note we submit a nonlocal (integral) generalization of the rotational-isotopic symmetries O-circumflex(3) introduced in preceding works for nonlinear and nonhamiltonian systems in local approximation. By recalling that the Lie-isotopic theory naturally admits nonlocal terms when all embedded in the isounit, while the conventional symplectic geometry is strictly local-differential, we introduce the notion of symplectic-isotopic two-forms, which are exact symplectic two-forms admitting a factorization into the Kronecker product of a canonical two-form time the isotopic element of an underlying Euclidean-isotopic space. Topological consistency is then achieved by embedding all nonlocal terms in the isounit of the iso-cotangent bundle, while keeping the local topology for the canonical part. In this way, we identify the symplectic-isotopic geometry as being the natural geometrical counterpart of the Lie-isotopic theory. The results are used for the introduction of the notion of Birkhoffian angular momentum, that is, the generalization of the conventional canonical angular momentum which is applicable to Birkhoffian systems with generally nonlinear, nonlocal and nonhamiltonian internal forces. The generators J (and the parameters θ) coincide with the conventional quantities. Nevertheless, the quantity J is defined on the underlying Euclidean-isotopic space, by therefore acquiring a generalized magnitude. The isocommutation rules and isoexponentiation of the Birkhoffian angular momentum are explicitly computed and shown to characterize the most general known nonlinear and nonlocal realization of the isorotational symmetry. The local isomorphisms between the infinitely possible isotopes O-circumflex(3) and the conventional symmetry O(3) is proved. Finally the isosymmetries O-circumflex(3) are used to characterize the conserved, total, Birkhoffian angular momentum of closed nonselfadjoint systems. (author). 4 refs

  15. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  16. Oxygen isotopes and lakes

    OpenAIRE

    Leng, Melanie; Dean, Jonathan

    2014-01-01

    Isotopes are variations of a particular chemical element. It is all to do with the number of neutrons. Oxygen has two main isotopes: 18O which has 10 neutrons and 8 protons; and 16O which has 8 neutrons and 8 protons. Although these variants have a different number of neutrons (and therefore a different atomic mass), the number of protons remains the same, and they are still classed as the same element. Isotopes are analysed in terms of ratios such as 18O/16O which is shortened to δ18O (δ...

  17. Carbon isotope techniques

    International Nuclear Information System (INIS)

    This book is a hands-on introduction to using carbon isotope tracers in experimental biology and ecology. It is a bench-top reference with protocols for the study of plants, animals, and soils. The 11C, 12C, 13C, and 14C carbon isotopes are considered and standard techniques are described by established authors. The compilation includes the following features: specific, well-established, user-oriented techniques; carbon cycles in plants, animals, soils, air, and water; isotopes in ecological research; examples and sample calculations

  18. Sonochemical synthesis of bismuth(III) nano coordination compound and direct synthesis of Bi.sub.2./sub.O.sub.3./sub. nanoparticles from a bismuth(III) nano coordination compound precursor

    Czech Academy of Sciences Publication Activity Database

    Roodsari, M.S.; Shaabani, B.; Mirtamizdoust, B.; Dušek, Michal; Fejfarová, Karla

    2015-01-01

    Roč. 25, č. 5 (2015), s. 1226-1232. ISSN 1574-1443 Grant ostatní: AV ČR(CZ) Praemium Academiae Institutional support: RVO:68378271 Keywords : nano coordination compound * sonochemical method * intramolecular proton transfer * nano bismuth oxide * isoniazid Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.160, year: 2014

  19. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  20. Method for isotope separation

    International Nuclear Information System (INIS)

    The inventor proposes a method for separating isotopes from gaseous compounds by selective excitation by means of laser beams for such cases where the reaction partners each consist of several isotopes. For example, separation of 235U and 238U in the form of UCl6 is mentioned with 35Cl and 37Cl existing in the natural composition of 76:24. According to the invention, after isolating the reaction product obtained in a way already known, the remaining fraction of the compound mixture is brought together with the reaction partner present in the natural isotope composition, in a heated flow path. Thereby by isotope exchange of the latter regeneration will take place, and the mixture can pass again through the separation plant in initial composition. (orig./PW)

  1. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  2. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  3. Oxidation of steels in liquid lead bismuth: Oxygen control to achieve efficient corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, Laure, E-mail: laure.martinelli@cea.f [CEA, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Jean-Louis, Courouau; Fanny, Balbaud-Celerier [CEA, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France)

    2011-05-15

    Hybrid systems dedicated to waste transmutation are constituted of an accelerator generating a high energy proton flux, a spallation target on which the accelerated proton beam impinges to produce neutrons and a subcritical core. The Pb-Bi eutectic liquid alloy is considered as spallation target material due to its suitable nuclear and physical properties. However, liquid metals can be corrosive towards containment materials (austenitic and Fe9Cr alloys). In the case of liquid lead bismuth alloy, one of the protection means considered against the dissolution of the steels is the in situ protection by the formation of an oxide layer at the steels' surface. However, in order to ensure the efficient protection of the steels by an oxide layer, the control and the monitoring of the oxygen content in the Pb-Bi alloy is a major issue. The paper recalls, first, the oxygen chemistry in a lead alloy system, in order to propose the oxygen operating window that complies with both the contamination by lead oxide of the coolant and the corrosion control by the promotion of an oxide film on the structure. Results of tests performed in stagnant lead bismuth at high oxygen concentrations are also presented showing the effect of various operating parameters on the oxidation kinetics and on the nature of the oxide layer. An oxidation mechanism and model are also proposed and compared with experimental data.

  4. Microwave-assisted synthesis of bismuth oxybromochloride nanoflakes for visible light photodegradation of pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Bijanzad, Keyvan; Tadjarodi, Azadeh; Moghaddasi Khiavi, Mohammad [Research Laboratory of Inorganic Materials Synthesis, Department of Chemistry, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Akhavan, Omid, E-mail: oakhavan@sharif.ir [Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran (Iran, Islamic Republic of)

    2015-10-15

    BiOBr{sub x}Cl{sub 1−x} (0bismuth nitrate pentahydrate, potassium bromide and sodium chloride by a microwave-assisted synthesis method. The X-ray diffraction (XRD) studies confirmed the formation of pure crystalline phase of BiOBr{sub x}Cl{sub 1−x}. The UV–visible diffuse reflectance and photoluminescence (PL) spectroscopies revealed the indirect band gap of ~2.82 eV for the bismuth oxybromochloride nanoflakes. Visible light-assisted photocatalytic studies showed that the degradation efficiency of the as-prepared BiOBr{sub x}Cl{sub 1−x} for (100 mL of 10 mg L{sup −1}) Rhodamine B (RhB), Natural Red 4 (N-Red) dye solutions was 98.14% and for the colorless organic pentachlorophenol (PCP) solution was 91.09% over 150 min. The possible mechanisms involved in the visible light photodegradation of the pollutants by BiOBr{sub x}Cl{sub 1−x} photocatalyst were also discussed.

  5. Extraction of nitric acid, uranyl nitrate, and bismuth nitrate from aqueous nitric acid solutions with CMPO

    International Nuclear Information System (INIS)

    DOE sponsored development of the transuranium extraction (TRUEX) process for removing actinides from radioactive wastes. The solvent is a mixture of CMPO and TBP. Since the extraction characteristics of CMPO are not as well understood as those of TBP, the extraction of nitric acid, uranyl nitrate, and bismuth nitrate with CMPO (dissolved in n-dodecane) were studied. Results indicate that CMPO extracts nitric acid with a 1:1 stoichiometry; equilibrium constant is 2. 660±0.092 at 25 C, and extraction enthalpy is -5. 46±0.46 kcal/mol. Slope analysis indicates that uranyl nitrate extracts with a mixed equilibria of 1:1 and 2:1 stoichiometries in nearly equal proportion. Equil. constant of the 2: 1 extraction was 1.213 x 106±3.56 x 104 at 25 C; reaction enthalpy was -9.610±0.594 kcal/mol. Nitration complexation constant is 8.412±0.579, with an enthalpy of -10.72±1.87 kcal/mol. Bismuth nitrate also extracts with a mixed equilibria of (perhaps) 1:1 and 2:1 stoichiometries. A 2:1 extraction equilibrium and a nitrate complexation adequately model the data. Kinetics and enthalpies were also measured

  6. Thermoelectric properties and micro-structure characteristics of annealed N-type bismuth telluride thin film

    International Nuclear Information System (INIS)

    N-type bismuth telluride (Bi2Te3) thermoelectric thin films were deposited by co-sputtering simple substance Te and Bi targets. The deposited films were annealed under various temperatures. The composition ratio, micro-structure and thermoelectric properties of the prepared films were systematically investigated by energy dispersive spectrometer, X-ray diffraction, four-probe method and Seebeck coefficient measurement system. When the annealing temperature is 400 °C, the stoichiometric N-type Bi2Te3 film is achieved, which has a maximum thermoelectric power factor of 0.821 × 10−3 W m−1 K−2. Furthermore, the dependence of Seebeck coefficient, electrical conductivity and power factor of the stoichiometric N-type Bi2Te3 film annealed at film 400 °C on the applied temperature ranging from 25 °C to 315 °C was investigated. The results show that a highest power factor of 3.288 × 10−3 W m−1 K−2 is obtained at the applied temperature of 275 °C. The structural and thermoelectric properties of the deposited bismuth telluride thin films are greatly improved by annealing and the Seebeck coefficient, electrical conductivity and power factor increase with the applied temperature rising, which are helpful and could be guidance for preparing the high-performance thin film thermoelectric materials for thermoelectric application.

  7. Study of structural, ferromagnetic and ferroelectric properties of nanostructured barium doped Bismuth Ferrite

    International Nuclear Information System (INIS)

    Nanostructured multiferroic Bi(1−x)BaxFeO3x=0.0, 0.1, 0.2 were prepared by hydrothermal technique. All samples belonged to the rhombohedrally distorted perovskite structure. The morphology of the particles changed with the doping of barium. Effect of barium doping on the dielectric constant was studied over a wide frequency range of 1000 Hz–1 MHz. The activation energy due to relaxation and due to conduction was measured from the Cole Cole plot and the AC conductivity versus frequency plot respectively. The activation energy estimated from both the studies was close to each other. The activation energy also enhanced with the increase in the barium content. The magnetization at the highest available field (∼1.6 T) increased from 0.05 emu/g for the sample with x=0.0–12 emu/g for the sample with x=0.2. The magnetic measurements show a significant increase in magnetization around 400 °C. Remnant polarization for x=0.0 was negligible and it increased to 0.06 µC/cm2 for x=0.2. - Highlights: • Bismuth Ferrite nanostructures were synthesized by the hydrothermal technique. • Barium was doped in Bismuth site. • Morphology changed with doping. • Ferromagnetic, Ferroelectric and Dielectric properties enhanced with doping. • An unreported magnetic transition due to spin canting was observed near 550 °C

  8. Performance of bismuth germanate active shielding on a balloon flight over Antarctica

    Science.gov (United States)

    Rester, A. C.; Coldwell, R. L.; Trombka, J. I.; Starr, R.; Eichhorn, G.

    1990-01-01

    The GRAD (Gamma-Ray Advanced Detector) gamma-ray spectrometer was flown on a balloon at an altitude of 36.6 km over Antarctica on January 8-10, 1988, where it was used to make observations of SN 1987A. The performance of the bismuth germanate (BGO) active shielding in the near-space environment over Antarctica is examined. The promised effectiveness of this shielding in the suppression of unwanted background has been demonstrated. The BGO-shielded GRAD spectrometer detected gamma-ray lines with fluxes of 0.002/sq cm sec from SN 1987A in a radiation background approximately a factor of 4 more intense than that over Alice Springs, Australia. This level of sensitivity indicates that BGO is at least as effective as CsI when used as active shielding. Isomerism is common, both in the bismuth and germanium regions of the nuclear chart, but is found to be less of a problem for background suppression in the latter region than in the former.

  9. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    Energy Technology Data Exchange (ETDEWEB)

    Aleme, C.; Mourao, A. P. [Centro Federal de Educacion Tecnologica de Minas Gerais, Biomedical Engineering Center, Belo Horizonte - MG (Brazil); Lyra, M. A., E-mail: carolinaaleme@gmail.com [Universidad Federal de Minas Gerais, Department of Nuclear Engineering, Av. Pdte. Antonio Carlos 6627, Pampulha, 31270-91 Belo Horizonte - MG (Brazil)

    2014-08-15

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  10. Molecular Design for Tailoring a Single-Source Precursor for Bismuth Ferrite.

    Science.gov (United States)

    Bendt, Georg; Schiwon, Rafael; Salamon, Soma; Landers, Joachim; Hagemann, Ulrich; Limberg, Christian; Wende, Heiko; Schulz, Stephan

    2016-08-01

    Nearly phase-pure bismuth ferrite particles were formed by thermolysis of the single-source precursor [Cp(CO)2FeBi(OAc)2] (1) in octadecene at 245 °C, followed by subsequent calcination at 600 °C for 3 h. In contrast, the slightly modified compound [Cp(CO)2FeBi(O2C(t)Bu)2] (2) yielded only mixtures of different bismuth oxide phases, revealing the distinctive influence of molecular design in material synthesis. The chemical composition, morphology, and crystallinity of the resulting materials were investigated by X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. In addition, the optical properties were investigated by Fourier transform infrared and UV-vis spectroscopies, showing a strong band gap absorption in the visible range at 590 nm (2.2 eV). The magnetic behavior was probed by vibrating-sample and superconducting quantum interference device magnetometry, as well as (57)Fe Mössbauer spectroscopy. PMID:27391769

  11. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    International Nuclear Information System (INIS)

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  12. Development and Testing of an Americium/Lanthanide Separation Flowsheet Using Sodium Bismuthate

    Energy Technology Data Exchange (ETDEWEB)

    Jack Law; Bruce Mincher; Troy Garn; Mitchell Greenhalgh; Nicholas Schmitt; Veronica Rutledge

    2014-04-01

    The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. A separation process amenable to process scale-up remains elusive. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series this separation is challenging ; however, higher oxidation states of americium can be prepared using sodium bismuthate and separated via solvent extraction using diamylamylphosphonate (DAAP) extraction. Among the other trivalent metals only Ce is also oxidized and extracted. Due to the long-term instability of Am(VI) , the loaded organic phase is readily selectively stripped to partition the actinide to a new acidic aqueous phase. Batch extraction distribution ratio measurements were used to design a flowsheet to accomplish this separation. Additionally, crossflow filtration was investigated as a method to filter the bismuthate solids from the feed solution prior to extraction. Results of the filtration studies, flowsheet development work and flowsheet performance testing using a centrifugal contactor are detailed.

  13. Bismuth oxide nanoplates-based efficient DSSCs: Influence of ZnO surface passivation layer

    International Nuclear Information System (INIS)

    Graphical abstract: Bismuth oxide nanoplates prepared by chemical bath deposition show high performance when used as photoanode in DSSC. The power conversion efficiency has been improved when coated with ZnO passivation layer. -- Highlights: • Bi2O3 NPLs photoanodes are prepared by a simple one-step chemical bath deposition. • When used in DSSCs as photoanode, Bi2O3 NPLs shows high power conversion efficiency (1%). • ZnO surface passivation layer further improves the efficiency by 50%. • ZnO coating layer suppresses the charge recombination and improves the transport properties. -- Abstract: For the first time, bismuth oxide (Bi2O3) nanoplates synthesized by single-step chemical method were envisaged as photoanodes in dye-sensitized solar cells. The structural elucidation demonstrated tetragonal structure with a predominant β-Bi2O3. The power conversion efficiency (1%) of Bi2O3 nanoplates-based dye-sensitized solar cells was enhanced up to 50% when decorated with zinc oxide thin layer (ZnO). The best performing electrode showed 24% incident photon-to-current conversion efficiency. This high DSSC performance of Bi2O3–ZnO photoanode is attributed to the increased electron transportation due to the suppression of recombination centers by ZnO passivation layer

  14. Structural analysis of bismuth nanowire by X-ray standing wave method

    CERN Document Server

    Saito, A; Kurata, T; Maruyama, J; Kuwahara, Y; Aono, M; Miki, K

    2003-01-01

    Bismuth forms perfect wires without any defects on a clean Si(001) surface. Despite the importance of this self-organized nanowire from the viewpoints of both surface science and device application, an analysis of the internal structure of the wire is quite difficult under the condition of a buried interface. In order to clarify the atomic structure of the wire capped by amorphous Si layers, the three-dimensional bismuth atomic site was measured with respect to the substrate Si lattice by the X-ray standing wave method. The results indicate that the absolute height of Bi atoms is 0.26 A upper from the bulklike Si(004) plane of the Si-dimer layer. For the structure inside the (004) plane, Bi atoms are in the range of +-0.5 A in the [110] direction from an intact Si-dimmer position. This result disagrees with recent reports that were derived from other analytical methods used solely for a clean surface. A new model was proposed and it suggests an influence of a burying effect for the wire structure. (author)

  15. Evaluation of the efficiency of bismuth breast shield in CT chest paediatric examinations

    International Nuclear Information System (INIS)

    The aim of this study is to evaluate the efficiency of bismuth breast shield in CT chest paediatric examinations when automatic exposure control techniques are used. The influence in the radiation dose and the image quality has been evaluated with and without the breast shield in the scoutview. In addition the radiation dose in shielded and non-shielded areas has been compared. Measurements were made in a 16 cm diameter cylindrical PMMA phantom simulating a newborn, and older children were simulated controlling the maximum intensities allowed by the automatic exposure control system AutomA. The highest dose reduction (59%) was obtained with AutomA system and when the breast shield is not used in the scoutview. This reduction in the radiation dose does not mean a significant increase of noise level. The use of the breast shield in the scoutview yielded an increase in the radiation dose in non-shielded areas. The use of bismuth breast shield is recommended only after the scoutview in order to optimise the radiation dose in CT chest paediatric examination when using automatic exposure control AutomA. (Author)

  16. Deposition of Visible Light Active Photocatalytic Bismuth Molybdate Thin Films by Reactive Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Marina Ratova

    2016-01-01

    Full Text Available Bismuth molybdate thin films were deposited by reactive magnetron co-sputtering from two metallic targets in an argon/oxygen atmosphere, reportedly for the first time. Energy dispersive X-ray spectroscopy (EDX analysis showed that the ratio of bismuth to molybdenum in the coatings can be effectively controlled by varying the power applied to each target. Deposited coatings were annealed in air at 673 K for 30 min. The crystalline structure was assessed by means of Raman spectroscopy and X-ray diffraction (XRD. Oxidation state information was obtained by X-ray photoelectron spectroscopy (XPS. Photodegradation of organic dyes methylene blue and rhodamine B was used for evaluation of the photocatalytic properties of the coatings under a visible light source. The photocatalytic properties of the deposited coatings were then compared to a sample of commercial titanium dioxide-based photocatalytic product. The repeatability of the dye degradation reactions and photocatalytic coating reusability are discussed. It was found that coatings with a Bi:Mo ratio of approximately 2:1 exhibited the highest photocatalytic activity of the coatings studied; its efficacy in dye photodegradation significantly outperformed a sample of commercial photocatalytic coating.

  17. The influence of ranitidine bismuth citrate on rat gastric mucosal microcirculation and adherent mucus gel layer

    Directory of Open Access Journals (Sweden)

    . Kotzampassi K., Paramythiotis D., Voudouris A., Milias K., Eleftheriadis E.

    2007-03-01

    Full Text Available Ranitidine Bismuth Citrate (RBC, recently developed to fight H. pylori, exhibits a triple action: anti-bacterial, antisecretive and mucosal-protective. Since less research has focused upon its mucosal protective action, we decided to study two parameters concerning that topic, i.e. the gastric mucosal blood flow and the adherent mucus gel thickness. Twenty rats were treated by gavage with either 25mg/kg RBC or equal volume (1ml of drinking water; 60 min later, laparotomy was performed, the stomach opened along the greater curvature and gastric mucosal blood flow assessed by laser-Doppler flowmetry. After this measurement, five - 20mm long- fullthickness strips were sectioned from the stomach, mounted transversely on glass plates and viewed under a light microscopy using an eyepiece graticule (4 measurements/strip. Rats treated with RBC were found to exhibit a statistically significant increase in gastric mucosal blood flow (36.2916.64 vs 88.9912.23 relative units of flow, p=0.001 as well as in adherent mucus gel thickness (69.3021.7 vs 222.3947.71m, p=0.0001. It is thus concluded that the ability of RBC to increase gastric mucosal blood flow and adherent mucus gel thickness may contribute to the protective action of this compound. Key words: gastric mucosal blood flow, adherent mucus, ranitidine bismuth citrate, H. pylori

  18. Turbulent time scales and the temperature variance dissipation rate in natural convection in lead-bismuth

    International Nuclear Information System (INIS)

    Turbulent heat transfer is of basic interest for the development and analysis of the lead-bismuth cooled accelerator-driven nuclear reactor concept. Results of a direct numerical simulation (DNS) for Rayleigh-Benard convection for the Rayleigh number Ra = 105 in a fluid with the Prandtl number Pr = 0,025, which corresponds to liquid lead-bismuth, are used to analyze turbulent time scales and the temperature variance dissipation rate. These results indicate that an application of the thermal or mixed time scale may considerably improve the standard heat flux model at this Rayleigh- and Prandtl numbers. Standard temperature variance dissipation rate model is investigated using the DNS results for Rayleigh-Benard convection at Pr equals 0,025, Ra equals 105. The analysis of the standard temperature variance dissipation rate model shows the importance of wall functions and the qualitatively good predictions by the standard model for this type of flow. Quantitatively this model over-predicts the results of direct numerical simulation by about 25%. The two-point correlation method is used to model the temperature variance dissipation rate. Comparison with DNS results shows qualitatively and quantitatively good predictions of the new model. The new temperature variance dissipation rate model leads therefore to an increased accuracy of turbulent heat flux models for this type of flow. An additional advantage is a minimal increase in model complexity which makes no special demands on model implementation into computer codes

  19. Facile and Efficient Synthesis of Bismuth Nanowires for Improved Photocatalytic Activity.

    Science.gov (United States)

    Li, Yawen; Zhao, Yan; Wu, Gongjuan; Zhao, Jingzhe

    2016-05-16

    An aqueous reduction method was reported for the synthesis of bismuth nanowires (Bi NWs) 5-10 nm in diameter and several micrometers in length under the guidance of PVP molecules. The reactions were performed at 80 °C by reducing bismuth chloride with sodium hypophosphite first in acid and then under neutral circumstances. The key to successful preparation of the Bi NWs is regulation of the reduction speed by control of the pH value. The morphology evolution of the samples was also found to have a strong dependence on the reaction parameters, including the introduction amount and molecular weight of PVP molecules. A solid-solution-solid (SSS) mechanism was proposed for the nucleation and growth of Bi NWs in our strategy. The as-prepared Bi NWs exhibit excellent visible-light photocatalytic activities for the degradation of the organic pollutant Rhodamine B (RhB) and colorless bisphenol A (BPA). The good recyclability of the Bi NWs on RhB photodegradation demonstrates the possibility of their practical applications. PMID:27145289

  20. Optical and Physical Properties of Bismuth Borate Glasses Doped With Dy3+

    Directory of Open Access Journals (Sweden)

    P. Limsuwan

    2011-01-01

    Full Text Available This study reports on physical and optical properties of Dy3+ doped bismuth borate glass. The glasses containing Dy3+ in (70-xB2O3:30Bi2O3:xDy2O3 (where x = 0.0-2.5 mol% have been prepared by melt-quenching method. In order to understand the role of Dy2O3 in these glasses, the density, molar volume and optical spectra were investigated. The results show that molar volume of the glasses increase with the increasing of Dy2O3 concentration and consequently generating more non-bridging oxygen (NBOs into glass matrix. The absorption spectra of Dy3+ doped in bismuth borate glass correspond with several bands, which are assigned from the ground state, 6H15/2 to 6F3/2(761 nm, 6F5/2(806 nm, 6F7/2(907 nm, (6H7/2, 6F9/2(1099 nm, (6F11/2, 6H9/2 (1283 nm and 6H11/2(1695 nm. Moreover, the optical basicities were also theoretically determined.

  1. Laser-diode excited intense upconversion luminescence of Er3+ in bismuth-lead-germanate glasses

    Institute of Scientific and Technical Information of China (English)

    Li Tao; Zhang Qin-Yuan; Jiang Zhong-Hong

    2007-01-01

    We have investigated infrared-to-visible upconversion luminescence of Er3 in bismuth-lead-germanate glasses.The UV cutoff wavelength is shortened while its lifetime is increased almost linearly, with PbF2 substituting for PbO in the bismuth-lead-germanate glasses. Three emissions centred at around 529, 545 and 657 nm are clearly observed, which are identified as originating from the 2H11/2 →4 I15/2,4 Ss/2 →4 I15/2 and 4F9/2 →4 I15/2 transitions, respectively. It is noted that all the upconversion emission intensities increase with PbF2 concentration increasing. The ratio between the intensities of red and green emissions increases with the increasing of PbF2 content. Energy transfer processes and nonradiative phonon-assisted decays account for the populations of the 2H11/2,4 S3/2 and 4F9/2 levels. The quadratic dependence of fluorescence on excitation laser power confirms a two-photon process to contribute to the upconversion emissions.

  2. Growth of epitaxial sodium-bismuth-titanate films by metal-organic chemical vapor phase deposition

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzkopf, J., E-mail: schwarzkopf@ikz-berlin.de [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Schmidbauer, M.; Duk, A.; Kwasniewski, A. [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Anooz, S. Bin [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Physics Department, Faculty of Science, Hadhramout University of Science and Technology, Mukalla 50511, Republic of Yemen (Yemen); Wagner, G. [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Devi, A. [Inorganic Materials Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, 44801 Bochum (Germany); Fornari, R. [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany)

    2011-10-31

    The liquid-delivery spin metal-organic chemical vapor phase deposition method was used to grow epitaxial sodium-bismuth-titanate films of the system Bi{sub 4}Ti{sub 3}O{sub 12} + xNa{sub 0.5}Bi{sub 0.5}TiO{sub 3} on SrTiO{sub 3}(001) substrates. Na(thd), Ti(O{sup i}Pr){sub 2}(thd){sub 2} and Bi(thd){sub 3}, solved in toluene, were applied as source materials. Depending on the substrate temperature and the Na/Bi ratio in the gas phase several structural phases of sodium-bismuth-titanate were detected. With increasing temperature and/or Na/Bi ratio, phase transitions from an Aurivillius phase with m = 3 to m = 4 via an interleaved state with m = 3.5, and, finally, to Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} with perovskite structure (m = {infinity}) were established. These phase transitions proceed at remarkably lower temperatures than in ceramics or bulk crystals for which they had been exclusively observed so far.

  3. Sol-gel synthesis and property studies of layered perovskite bismuth titanate thin films

    International Nuclear Information System (INIS)

    Layered perovskite bismuth titanate (BTO) thin films were deposited on platinum coated silicon substrates by spin coating. A homogeneous and stable precursor solution was prepared by sol-gel process using bismuth nitrate and titanium(IV) butoxide as starting materials, glacial acetic acid and ethanolamine were selected as solvent and stabilizing agent, respectively. The crystal structure, surface morphology, composition and electrical properties of the films have been investigated. Crystal structure and morphology of the films are strongly influenced by the heat cycle adopted to form crystalline BTO films. Morphology of the films studied by AFM is found to be smooth, dense, and crack free. The deposited films possess good compositional homogeneity and thickness uniformity. The dielectric constant and the dissipation factor measured at 1 kHz at room temperature are found to be 135 and 0.018, respectively, for the films of 0.4-μm thickness annealed at 600 deg. C for 1 h. The remnant polarization and coercive field values are estimated to be 5 μC cm-2 and 45 kV cm-1. The films possess good fatigue properties and useful for application in the non-volatile memories

  4. Sol-gel synthesis and property studies of layered perovskite bismuth titanate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Madeswaran, S.; Giridharan, N.V.; Jayavel, R

    2003-04-29

    Layered perovskite bismuth titanate (BTO) thin films were deposited on platinum coated silicon substrates by spin coating. A homogeneous and stable precursor solution was prepared by sol-gel process using bismuth nitrate and titanium(IV) butoxide as starting materials, glacial acetic acid and ethanolamine were selected as solvent and stabilizing agent, respectively. The crystal structure, surface morphology, composition and electrical properties of the films have been investigated. Crystal structure and morphology of the films are strongly influenced by the heat cycle adopted to form crystalline BTO films. Morphology of the films studied by AFM is found to be smooth, dense, and crack free. The deposited films possess good compositional homogeneity and thickness uniformity. The dielectric constant and the dissipation factor measured at 1 kHz at room temperature are found to be 135 and 0.018, respectively, for the films of 0.4-{mu}m thickness annealed at 600 deg. C for 1 h. The remnant polarization and coercive field values are estimated to be 5 {mu}C cm{sup -2} and 45 kV cm{sup -1}. The films possess good fatigue properties and useful for application in the non-volatile memories.

  5. Potential containment materials for liquid-lead and lead-bismuth eutectic spallation neutron source

    International Nuclear Information System (INIS)

    Lead (Pb) and lead-bismuth eutectic (44Pb-56Bi) have been the two primary candidate liquid-metal target materials for the production of spallation neutrons. Selection of a container material for the liquid-metal target will greatly affect the lifetime and safety of the target subsystem. For the lead target, niobium-1 (wt%) zirconium (Nb-1Zr) is a candidate containment material for liquid lead, but its poor oxidation resistance has been a major concern. The oxidation rate of Nb-1Zr was studied based on the calculations of thickness loss due to oxidation. According to these calculations, it appeared that uncoated Nb-1Zr may be used for a one-year operation at 900 C at PO2 = 1 x 10-6 torr, but the same material may not be used in argon with 5-ppm oxygen. Coating technologies to reduce the oxidation of Nb-1Zr are reviewed, as are other candidate refractory metals such as molybdenum, tantalum, and tungsten. For the Pb-Bi target, three candidate containment materials are suggested based on a literature survey of the materials compatibility and proton irradiation tests: Croloy 2-1/4, modified 9Cr-1Mo, and 12Cr-1Mo (HT-9) steel. These materials seem to be used only if the lead-bismuth is thoroughly deoxidized and treated with zirconium and magnesium

  6. Vibration Monitoring Using Fiber Optic Sensors in a Lead-Bismuth Eutectic Cooled Nuclear Fuel Assembly

    Directory of Open Access Journals (Sweden)

    Ben De Pauw

    2016-04-01

    Full Text Available Excessive fuel assembly vibrations in nuclear reactor cores should be avoided in order not to compromise the lifetime of the assembly and in order to prevent the occurrence of safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants, such as, for example, a molten lead-bismuth eutectic. The flow of molten heavy metal around and through the fuel assembly may cause the latter to vibrate and hence suffer degradation as a result of, for example, fretting wear or mechanical fatigue. In this paper, we demonstrate the use of optical fiber sensors to measure the fuel assembly vibration in a lead-bismuth eutectic cooled installation which can be used as input to assess vibration-related safety hazards. We show that the vibration characteristics of the fuel pins in the fuel assembly can be experimentally determined with minimal intrusiveness and with high precision owing to the small dimensions and properties of the sensors. In particular, we were able to record local strain level differences of about 0.2 μϵ allowing us to reliably estimate the vibration amplitudes and modal parameters of the fuel assembly based on optical fiber sensor readings during different stages of the operation of the facility, including the onset of the coolant circulation and steady-state operation.

  7. Vibration Monitoring Using Fiber Optic Sensors in a Lead-Bismuth Eutectic Cooled Nuclear Fuel Assembly.

    Science.gov (United States)

    De Pauw, Ben; Lamberti, Alfredo; Ertveldt, Julien; Rezayat, Ali; van Tichelen, Katrien; Vanlanduit, Steve; Berghmans, Francis

    2016-01-01

    Excessive fuel assembly vibrations in nuclear reactor cores should be avoided in order not to compromise the lifetime of the assembly and in order to prevent the occurrence of safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants, such as, for example, a molten lead-bismuth eutectic. The flow of molten heavy metal around and through the fuel assembly may cause the latter to vibrate and hence suffer degradation as a result of, for example, fretting wear or mechanical fatigue. In this paper, we demonstrate the use of optical fiber sensors to measure the fuel assembly vibration in a lead-bismuth eutectic cooled installation which can be used as input to assess vibration-related safety hazards. We show that the vibration characteristics of the fuel pins in the fuel assembly can be experimentally determined with minimal intrusiveness and with high precision owing to the small dimensions and properties of the sensors. In particular, we were able to record local strain level differences of about 0.2 μϵ allowing us to reliably estimate the vibration amplitudes and modal parameters of the fuel assembly based on optical fiber sensor readings during different stages of the operation of the facility, including the onset of the coolant circulation and steady-state operation. PMID:27110782

  8. Interaction study between MOX fuel and eutectic lead-bismuth coolant

    Science.gov (United States)

    Vigier, Jean-François; Popa, Karin; Tyrpekl, Vaclav; Gardeur, Sébastien; Freis, Daniel; Somers, Joseph

    2015-12-01

    In the frame of the MYRRHA reactor project, the interaction between fuel pellets and the reactor coolant is essential for safety evaluations, e.g. in case of a pin breach. Therefore, interaction tests between uranium-plutonium mixed oxide (MOX) pellets and molten lead bismuth eutectic (LBE) have been performed and three parameters were studied, namely the interaction temperature (500 °C and 800 °C), the oxygen content in LBE and the stoichiometry of the MOX (U0.7Pu0.3O2-x and U0.7Pu0.3O2.00). After 50 h of interaction in closed containers, the pellet integrity was preserved in all cases. Whatever the conditions, neither interaction compounds (crystalline or amorphous) nor lead and bismuth diffusion into the surface regions of the MOX pellets has been detected. In most of the conditions, actinide releases into LBE were very limited (in the range of 0.01-0.15 mg), with a homogeneous release of the different actinides present in the MOX. Detected values were significantly higher in the 800 °C and low LBE oxygen content tests for both U0.7Pu0.3O2-x and U0.7Pu0.3O2.00, with 1-2 mg of actinide released in these conditions.

  9. Optical and electrical properties of thin films of bismuth ferric oxide

    International Nuclear Information System (INIS)

    The bismuth ferric oxide (BFO) has caused great attention in recent years because of their multi ferric properties, making it very attractive for different technological applications. In this paper simultaneous ablation of two white (Bi and Fe2O3) was used in a reactive atmosphere (containing oxygen) to deposit thin films of BFO. The composition of the films is changed by controlling the plasma parameters such as the average kinetic energy of the ions (E p) and the plasma density (Np). The effects caused by excess of Bi and Fe in atomic structure and the optical and electrical properties of the films BiFeO3 in terms of plasma parameters were studied. The X-ray diffraction patterns of BFO samples with excess of bismuth above 2% at. They exhibited small changes in structure leading to improved levels of leakage currents compared to levels of the film with a stoichiometry close to BiFeO3 composition. These samples showed a secondary phase (Bi25FeO40 selenite type) that led to the increase in the values of band gap and resistivity as well as the improvement of the piezoelectric properties. On the other hand, the films with iron excess showed as secondary phase compounds of iron oxide (α - γ-Fe2O3) that caused increments in the conductivity and decrease in the values of band gap. The results are discussed in terms of the excesses of Bi and Fe which were correlated with the plasma parameters. (Author)

  10. Fe2O3 Modified Physical, Structural and Optical Properties of Bismuth Silicate Glasses

    Directory of Open Access Journals (Sweden)

    Rajesh Parmar

    2013-01-01

    Full Text Available Iron-containing bismuth silicate glasses with compositions 60SiO2·(100−xBi2O3·xFe2O3 have been prepared by conventional melt-quenching technique. The amorphous nature of the glass samples has been ascertained by the X-ray diffraction. The density (d has been measured using Archimedes principle, molar volume (Vm has also been estimated, and both are observed to decrease with the increase in iron content. The glass transition temperature (Tg of these iron bismuth silicate glasses has been determined using differential scanning calorimetry (DSC technique, and it increases with the increase in Fe2O3 content. The IR spectra of these glasses consist mainly of [BiO6], [BiO3], and [SiO4] structural units. The optical properties are measured using UV-VIS spectroscopy. The optical bandgap energy (Eop is observed to decrease with the increase in Fe2O3 content, whereas reverse trend is observed for refractive index.

  11. Cathodic electrophoretic deposition of bismuth oxide (Bi2O3) coatings and their photocatalytic activities

    International Nuclear Information System (INIS)

    Graphical abstract: Bismuth oxide (Bi2O3) coating has been prepared by cathodic electrophoretic deposition method and exhibits high photocatalytic activities for the degradation of Rhodamine B. - Highlights: • The nano-Bi2O3 coatings have been firstly successfully fabricated by EPD method. • The EPD deposition mechanism of Bi2O3 coatings is firstly given. • Deposition dynamics are investigated by regulating different deposition times and applied field strengths in detail. • Obtained coating show great photocatalytic activities for the degradation of Rhodamine B. - Abstract: In this study, cathodic electrophoretic deposition (EPD), a low cost, one-step and flexible method, has been successfully developed to prepare bismuth oxide (Bi2O3) coatings. Stable suspensions consisted of isopropyl alcohol and trace additive-polyethyleneimine. Deposition was achieved on the cathode at applied field strengths of 5–25 V mm−1 using a total solids loading of 0.5–2 g L−1 at ambient temperature and pressure. The deposition mechanism of Bi2O3 coatings was firstly given, and deposition kinetics were investigated in detail. The deposits were characterized qualitatively by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) observation, atomic force microscope (AFM), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) analysis, respectively. Moreover, the photocatalytic activities of obtained coatings were evaluated through degradation of Rhodamine B under ultraviolet and visible light irradiation

  12. Isotopes in everyday life

    International Nuclear Information System (INIS)

    Isotopes represent a tool which can do certain jobs better, easier, quicker, more simply and cheaper than competitive methods. Some measurements could not be done at all without the use of isotopes as there are no alternative methods available. A short review of these tools of science in their different fields is given: food and agriculture, human health applications, industry, hydrology, geology, geochemistry, geophysics and dating, environment, basic scientific research

  13. Canada's medical isotope strategy

    International Nuclear Information System (INIS)

    This paper details Canada's medical isotope strategy and the role of the Canadian Government in the security of the isotope supply chain. The government's role is to promote health and safety of Canadians, establish appropriate regulatory framework, allow the markets to work, facilitate international collaboration, fund high-risk early stage research and development, encourage private sector investment in innovation and support and respect environmental and non-proliferation goals.

  14. Separating isotopes by laser

    International Nuclear Information System (INIS)

    Isotope separation by laser radiation is proving a very promising method for obtaining large scale isotope production at low cost and is particularly relevant to the enrichment of 235U for the nuclear power industry. Various methods for laser separation, differing mainly in the way the selectively excited atoms or molecules are extracted, are discussed. The efficiency of the various methods, which is the controlling factor in determining their practical viability and some of the problems encountered are examined. (UK)

  15. Isotope toolbox turns 10

    DEFF Research Database (Denmark)

    Wenander, Fredrik; Riisager, Karsten

    2012-01-01

    REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes.......REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes....

  16. Isotopes in environmental research

    International Nuclear Information System (INIS)

    Radioactive and stable isotopes have long been considered a very efficient tool for studying physical and biological aspects of how the global ecosystem functions. Their applications in environmental research are numerous, embracing research at all levels. This article looks at only a few of the approaches to environmental problems that involve the use of isotopes. Special attention is given to studies of the Amazon Basin. Environmental isotopes are very efficient tools in water cycle studies. Tritium, a radioactive tracer, is especially useful in studying dynamics of water movement in different compartments of the hydrosphere, both on the local and global scales. Heavy stable isotopes of hydrogen and oxygen (deuterium and oxygen-18) provide information about steady-state characteristics of the water cycle. Isotope methods, some relatively new, have a major role in site-specific studies. Some indicative examples include: Studying turnover of organic matter. Changes in the carbon-13/carbon-12 isotopic ratio of organic matter were used to determine the respective contributions of organic carbon derived from forest and pasture. Studying biological nitrogen fixation. One of the ways nitrogen levels in soil can be maintained for productivity is by biological nitrogen fixation. Studying nitrogen availability and losses. The experimental use of nitrogen-15 is invaluable for defining losses of soil nitrogen to the atmosphere and to groundwater. Studies can similarly be done with stable and radioactive sulphur isotopes. This article indicates some potential uses of isotopes in environmental research. While the major problem of global climate change has not been specifically addressed here, the clearing of the Amazon forest, one focus of the IAEA's environmental programme, may have serious consequences for the global climate. These include substantial reduction of the amount of latent heat transported to the regions outside the tropics and acceleration of the greenhouse

  17. Adaptive statistical iterative reconstruction and bismuth shielding for evaluation of dose reduction to the eye and image quality during head CT

    International Nuclear Information System (INIS)

    There is a concern regarding the adverse effects of increasing radiation doses due to repeated computed tomography (CT) scans, especially in radiosensitive organs and portions thereof, such as the lenses of the eyes. Bismuth shielding with an adaptive statistical iterative reconstruction (ASIR) algorithm was recently introduced in our clinic as a method to reduce the absorbed radiation dose. This technique was applied to the lens of the eye during CT scans. The purpose of this study was to evaluate the reduction in the absorbed radiation dose and to determine the noise level when using bismuth shielding and the ASIR algorithm with the GE DC 750 HD 64-channel CT scanner for CT of the head of a humanoid phantom. With the use of bismuth shielding, the noise level was higher in the beam-hardening artifact areas than in the revealed artifact areas. However, with the use of ASIR, the noise level was lower than that with the use of bismuth alone; it was also lower in the artifact areas. The reduction in the radiation dose with the use of bismuth was greatest at the surface of the phantom to a limited depth. In conclusion, it is possible to reduce the radiation level and slightly decrease the bismuth-induced noise level by using a combination of ASIR as an algorithm process and bismuth as an in-plane hardware-type shielding method.

  18. Isotope heated thermal batteries

    International Nuclear Information System (INIS)

    A deferred action thermal battery is described that includes a quantity of radioactive isotope normally positioned so that only a small part of the thermal energy generated by the isotope is received by the battery, but adapted, when the battery is rendered active, to be moved automatically to a position where a large part of the thermal energy is received. The battery may comprise a chamber containing its cells and a second chamber part of which is remote from the cells for normal storage of the isotope and part of which is adjacent to the cells; the isotope is moved to the latter part when the battery is activated. The cell chamber is preferably toroidal and surrounds the second portion of the isotope chamber. The isotope may be contained in a carriage held by a retaining means adapted for release when the battery is activated, resilient means then moving the carriage to the active position. The retaining means may be a wire that disintegrates on the passage of electric current, the current also igniting a combustible composition to activate the battery. The object is to provide thermal batteries having an extended life. (U.K.)

  19. The isotopic distribution conundrum.

    Science.gov (United States)

    Valkenborg, Dirk; Mertens, Inge; Lemière, Filip; Witters, Erwin; Burzykowski, Tomasz

    2012-01-01

    Although access to high-resolution mass spectrometry (MS), especially in the field of biomolecular MS, is becoming readily available due to recent advances in MS technology, the accompanied information on isotopic distribution in high-resolution spectra is not used at its full potential, mainly because of lack of knowledge and/or awareness. In this review, we give an insight into the practical problems related to calculating the isotopic distribution for large biomolecules, and present an overview of methods for the calculation of the isotopic distribution. We discuss the key events that triggered the development of various algorithms and explain the rationale of how and why the various isotopic-distribution calculations were performed. The review is focused around the developmental stages as briefly outlined below, starting with the first observation of an isotopic distribution. The observations of Beynon in the field of organic MS that chlorine appeared in a mass spectrum as two variants with odds 3:1 lie at the basis of the first wave of algorithms for the calculation of the isotopic distribution, based on the atomic composition of a molecule. From here on, we explain why more complex biomolecules such as peptides exhibit a highly complex isotope pattern when assayed by MS, and we discuss how combinatorial difficulties complicate the calculation of the isotopic distribution on computers. For this purpose, we highlight three methods, which were introduced in the 1980s. These are the stepwise procedure introduced by Kubinyi, the polynomial expansion from Brownawell and Fillippo, and the multinomial expansion from Yergey. The next development was instigated by Rockwood, who suggested to decompose the isotopic distribution in terms of their nucleon count instead of the exact mass. In this respect, we could claim that the term "aggregated" isotopic distribution is more appropriate. Due to the simplification of the isotopic distribution to its aggregated counterpart

  20. EQCM Study of Influence of Anion Nature on Electrochemical Reduction of Bismuth Sulfide in Nickel Plating Solution

    Directory of Open Access Journals (Sweden)

    Loreta TAMAŠAUSKAITĖ-TAMAŠIŪNAITĖ

    2011-03-01

    Full Text Available The influence of anion nature on the reduction of bismuth sulfide film deposited on gold using the successive ionic layer adsorption and reaction method in solutions containing Ni2+ ions has been investigated by electrochemical quartz crystal microbalance combined with cyclic voltammetry and X-ray photoelectron spectroscopy. It has been determined that the reduction of bismuth sulfide film in the nickel plating solution depends on the anion nature: larger cathodic current and mass changes (Dƒ are observed in the solution containing acetate anion as compared to those in the solution containing sulfate anion. As the reduction of bismuth sulfide film in the background solutions depends on the nature of anion, it influences the cathodic reduction of Ni2+ ions prior to OPD of Ni. A greater current and mass change (Dƒ is conditioned by simultaneously occurring reduction of bismuth sulfide film when the film is reduced in the acetate nickel plating electrolyte in contrast to that in the sulfate one.http://dx.doi.org/10.5755/j01.ms.17.1.244