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Sample records for bismuth oxides

  1. 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

  2. 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

  3. 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...

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. 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.

  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. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 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

  1. Role of Bismuth Oxide in Bi-MCo2O4(M=Co,Ni,Cu,Zn) Catalysts for Wet Air Oxidation of Acetic Acid

    Institute of Scientific and Technical Information of China (English)

    JIANG Peng-bo; CHENG Tie-xin; ZHUANG Hong; CUI Xiang-hao; BI Ying-li; ZHEN Kai-ji

    2004-01-01

    Two series of cobalt(Ⅲ)-containing spinel catalysts were prepared by the decomposition of the corresponding nitrates. The catalysts doped with bismuth oxide exhibit a higher activity in the wet air oxidation of acetic acid than those without dopant bismuth oxide. The catalysts were investigated by XRD, TEM, ESR, UV-DRS and XPS, and the interaction between Co and Bi was studied as well. It has been found that nano-sized bismuth oxide is paved on the surface of cobalt spinel crystal and the structures of cobalt(Ⅲ)-containing spinel are still maintained. The shift of the binding energy of Bi4f7/2 is related to the catalytic activity of these catalysts doped with bismuth oxide.

  2. 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.

  3. High performance zirconia-bismuth oxide nanocomposite electrolytes for lower temperature solid oxide fuel cells

    Science.gov (United States)

    Joh, Dong Woo; Park, Jeong Hwa; Kim, Do Yeub; Yun, Byung-Hyun; Lee, Kang Taek

    2016-07-01

    We develop a novel nanocomposite electrolyte, consisting of yttria-stabilized zirconia (YSZ) and erbia-stabilized bismuth oxide (ESB). The 20 mol% ESB-incorporated YSZ composite (20ESB-YSZ) achieves the high density (>97%) at the low sintering temperature of 800 °C. The microstructural analysis of 20ESB-YSZ reveals the characteristic nanocomposite structure of the highly percolated ESB phase at the YSZ grain boundaries (a few ∼ nm thick). The ionic conductivity of 20ESB-YSZ is increased by 5 times compared to that of the conventional YSZ due to the fast oxygen ion transport along the ESB phase. Moreover, this high conductivity is maintained up to 580 h, indicating high stability of the ESB-YSZ nanocomposite. In addition, the oxygen reduction reaction at the composite electrolyte/cathode interface is effectively enhanced (∼70%) at the temperature below 650 °C, mainly due to the fast dissociative oxygen adsorption on the ESB surface as well as the rapid oxygen ion incorporation into the ESB lattice. Thus, we believe this ESB-YSZ nanocomposite is a promising electrolyte for high performance solid oxide fuel cells at reduced temperatures.

  4. 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

  5. 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)

  6. 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

  7. Phase evolution of magnetite nanocrystals on oxide supports via template-free bismuth ferrite precursor approach

    Science.gov (United States)

    Cheung, Jeffrey; Bogle, Kashinath; Cheng, Xuan; Sullaphen, Jivika; Kuo, Chang-Yang; Chen, Ying-Jiun; Lin, Hong-Ji; Chen, Chien-Te; Yang, Jan-Chi; Chu, Ying-Hao; Valanoor, Nagarajan

    2012-11-01

    This report investigates the phase evolution pathway of magnetite nanocrystal synthesis on oxide-supported substrates. A template-free phase separation approach, which exploits the thermodynamic instability of ternary perovskite BiFeO3 and inherent volatility of bismuth oxide in low oxygen pressure and high temperature is presented. The formation of an intermediate hematite nanocrystal phase is found as a key step that controls the eventual size and morphology of the magnetite nanocrystals. X-ray absorption spectra measurements and X-ray magnetic circular dichroism confirm that the spectral fingerprints of the magnetite nanocrystals match with that of bulk crystals. Magnetic measurements show that magnetic anisotropy is directly attributed to the nanocrystal morphology.

  8. Selective oxidation of propene on bismuth molybdate and mixed oxides of tin and antimony and of uranium and antimony

    International Nuclear Information System (INIS)

    Propene + 1802 reactions have been studied in a static reaction system on bismuth molybdate and mixed oxides of tin and antimony and of uranium and antimony. The [160] acrolein content of the total acrolein formed and the proportion of 160 in the oxygen of the carbon dioxide by-product have been determined. The results indicate that for each catalyst the lattice is the only direct source of the oxygen in the aldehyde, and that lattice and/or gas phase oxygen is used in carbon dioxide formation. Oxygen anion mobility appears to be greater in the molybdate catalyst than in the other two. (author)

  9. Influence of bismuth oxide concentration on the pH level and biocompatibility of white Portland cement

    Directory of Open Access Journals (Sweden)

    Marina Angélica MARCIANO

    2014-07-01

    Full Text Available Objectives: To investigate if there is a relation between the increase of bismuth oxide and the decrease of pH levels and an intensification of toxicity in the Portland cement. Material and Methods: White Portland cement (WPC was mixed with 0, 15, 20, 30 and 50% bismuth oxide, in weight. For the pH level test, polyethylene tubes were filled with the cements and immersed in Milli-Q water for 15, 30 and 60 days. After each period, the increase of the pH level was assessed. For the biocompatibility, two polyethylene tubes filled with the cements were implanted in ninety albino rats (n=6. The analysis of the intensity of the inflammatory infiltrate was performed after 15, 30 and 60 days. The statistical analysis was performed using the Kruskal-Wallis, Dunn and Friedman tests for the pH level and the Kruskal-Wallis and Dunn tests for the biological analysis (p0.05. For the inflammatory infiltrates, no significant statistical differences were found among the groups in each period (p>0.05. The 15% WPC showed a significant decrease of the inflammatory infiltrate from 15 to 30 and 60 days (p<0.05. Conclusions: The addition of bismuth oxide into Portland cement did not affect the pH level and the biological response. The concentration of 15% of bismuth oxide resulted in significant reduction in inflammatory response in comparison with the other concentrations evaluated.

  10. 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...

  11. Study of ternary-component bismuth molybdate catalysts by 18O2 tracer in the oxidation of propylene to acrolein

    International Nuclear Information System (INIS)

    Participation of lattice oxide ions of ternary-component bismuth molybdate catalysts M-Bi-Mo-O (M = Ni, Co, Mg, Mn, Ca, Sr, Ba, and Pb) was investigated using the 18O2 tracer in the selective oxidation of propylene to acrolein. The participation of the lattice oxide ions in the oxidation is prominent on every catalyst but the extent of the participation varies significantly depending on the structure of the catalyst. Only lattice oxide ions in the bismuth molybdate phase are incorporated into the oxidized products on the catalysts (M = Ni, Co, Mg, and Mn) where M have smaller ionic radius than Bi3+; catalyst particles are composed of a shell of bismuth molybdates and a core of MMoO4. On the other hand, whole oxide ions in the active particles are involved in the oxidation on catalysts having a scheelite-type structure (M = Ca, Sr, Ba, and Pb) where M has a comparable ionic radius to Bi3+

  12. Characterization of oxide layers grown on D9 austenitic stainless steel in lead bismuth eutectic

    International Nuclear Information System (INIS)

    Lead bismuth eutectic (LBE) is a possible coolant for fast reactors and targets in spallation neutron sources. Its low melting point, high evaporation point, good thermal conductivity, low reactivity, and good neutron yield make it a safe and high performance coolant in radiation environments. The disadvantage is that it is a corrosive medium for most steels and container materials. This study was performed to evaluate the corrosion behavior of the austenitic stainless steel D9 in oxygen controlled LBE. In order to predict the corrosion behavior of steel in this environment detailed analyses have to be performed on the oxide layers formed on these materials and various other relevant materials upon exposure to LBE. In this study the corrosion/oxidation of D9 stainless steel in LBE was investigated in great detail. The oxide layers formed were characterized using atomic force microscopy, magnetic force microscopy, nanoindentation, and scanning electron microscopy with wavelength-dispersive spectroscopy (WDS) to understand the corrosion and oxidation mechanisms of D9 stainless steel in contact with the LBE. What was previously believed to be a simple double oxide layer was identified here to consist of at least 4 different oxide layers. It was found that the inner most oxide layer takes over the grain structure of what used to be the bulk steel material while the outer oxide layer consists of freshly grown oxides with a columnar structure. These results lead to a descriptive model of how these oxide layers grow on this steel under the harsh environments encountered in these applications

  13. Characterization of oxide layers grown on D9 austenitic stainless steel in lead bismuth eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Hosemann, P. [CD Laboratory of Localized Corrosion, Montanuniversitaet Leoben, Franz-Josef Strasse 18, 8700 Leoben (Austria); Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States)], E-mail: peterh@lanl.gov; Hawley, M. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States); Koury, D. [University of Nevada, 4505 S. Maryland Parkway, Las Vegas, NV 89154 (United States); Swadener, J.G. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States); Welch, J.; Johnson, A.L. [University of Nevada, 4505 S. Maryland Parkway, Las Vegas, NV 89154 (United States); Mori, G. [CD Laboratory of Localized Corrosion, Montanuniversitaet Leoben, Franz-Josef Strasse 18, 8700 Leoben (Austria); Li, N. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States)

    2008-04-30

    Lead bismuth eutectic (LBE) is a possible coolant for fast reactors and targets in spallation neutron sources. Its low melting point, high evaporation point, good thermal conductivity, low reactivity, and good neutron yield make it a safe and high performance coolant in radiation environments. The disadvantage is that it is a corrosive medium for most steels and container materials. This study was performed to evaluate the corrosion behavior of the austenitic stainless steel D9 in oxygen controlled LBE. In order to predict the corrosion behavior of steel in this environment detailed analyses have to be performed on the oxide layers formed on these materials and various other relevant materials upon exposure to LBE. In this study the corrosion/oxidation of D9 stainless steel in LBE was investigated in great detail. The oxide layers formed were characterized using atomic force microscopy, magnetic force microscopy, nanoindentation, and scanning electron microscopy with wavelength-dispersive spectroscopy (WDS) to understand the corrosion and oxidation mechanisms of D9 stainless steel in contact with the LBE. What was previously believed to be a simple double oxide layer was identified here to consist of at least 4 different oxide layers. It was found that the inner most oxide layer takes over the grain structure of what used to be the bulk steel material while the outer oxide layer consists of freshly grown oxides with a columnar structure. These results lead to a descriptive model of how these oxide layers grow on this steel under the harsh environments encountered in these applications.

  14. Characterization of oxide layers grown on D9 austenitic stainless steel in lead bismuth eutectic

    Science.gov (United States)

    Hosemann, P.; Hawley, M.; Koury, D.; Swadener, J. G.; Welch, J.; Johnson, A. L.; Mori, G.; Li, N.

    2008-04-01

    Lead bismuth eutectic (LBE) is a possible coolant for fast reactors and targets in spallation neutron sources. Its low melting point, high evaporation point, good thermal conductivity, low reactivity, and good neutron yield make it a safe and high performance coolant in radiation environments. The disadvantage is that it is a corrosive medium for most steels and container materials. This study was performed to evaluate the corrosion behavior of the austenitic stainless steel D9 in oxygen controlled LBE. In order to predict the corrosion behavior of steel in this environment detailed analyses have to be performed on the oxide layers formed on these materials and various other relevant materials upon exposure to LBE. In this study the corrosion/oxidation of D9 stainless steel in LBE was investigated in great detail. The oxide layers formed were characterized using atomic force microscopy, magnetic force microscopy, nanoindentation, and scanning electron microscopy with wavelength-dispersive spectroscopy (WDS) to understand the corrosion and oxidation mechanisms of D9 stainless steel in contact with the LBE. What was previously believed to be a simple double oxide layer was identified here to consist of at least 4 different oxide layers. It was found that the inner most oxide layer takes over the grain structure of what used to be the bulk steel material while the outer oxide layer consists of freshly grown oxides with a columnar structure. These results lead to a descriptive model of how these oxide layers grow on this steel under the harsh environments encountered in these applications.

  15. Visible light photooxidative performance of a high-nuclearity molecular bismuth vanadium oxide cluster

    Directory of Open Access Journals (Sweden)

    Johannes Tucher

    2014-05-01

    Full Text Available The visible light photooxidative performance of a new high-nuclearity molecular bismuth vanadium oxide cluster, H3[{Bi(dmso3}4V13O40], is reported. Photocatalytic activity studies show faster reaction kinetics under anaerobic conditions, suggesting an oxygen-dependent quenching of the photoexcited cluster species. Further mechanistic analysis shows that the reaction proceeds via the intermediate formation of hydroxyl radicals which act as oxidant. Trapping experiments using ethanol as a hydroxyl radical scavenger show significantly decreased photocatalytic substrate oxidation in the presence of EtOH. Photocatalytic performance analyses using monochromatic visible light irradiation show that the quantum efficiency Φ for indigo photooxidation is strongly dependent on the irradiation wavelength, with higher quantum efficiencies being observed at shorter wavelengths (Φ395nm ca. 15%. Recycling tests show that the compound can be employed as homogeneous photooxidation catalyst multiple times without loss of catalytic activity. High turnover numbers (TON ca. 1200 and turnover frequencies up to TOF ca. 3.44 min−1 are observed, illustrating the practical applicability of the cluster species.

  16. Development of tellurium oxide and lead-bismuth oxide glasses for mid-wave infra-red transmission optics

    Science.gov (United States)

    Zhou, Beiming; Rapp, Charles F.; Driver, John K.; Myers, Michael J.; Myers, John D.; Goldstein, Jonathan; Utano, Rich; Gupta, Shantanu

    2013-03-01

    Heavy metal oxide glasses exhibiting high transmission in the Mid-Wave Infra-Red (MWIR) spectrum are often difficult to manufacture in large sizes with optimized physical and optical properties. In this work, we researched and developed improved tellurium-zinc-barium and lead-bismuth-gallium heavy metal oxide glasses for use in the manufacture of fiber optics, optical components and laser gain materials. Two glass families were investigated, one based upon tellurium and another based on lead-bismuth. Glass compositions were optimized for stability and high transmission in the MWIR. Targeted glass specifications included low hydroxyl concentration, extended MWIR transmission window, and high resistance against devitrification upon heating. Work included the processing of high purity raw materials, melting under controlled dry Redox balanced atmosphere, finning, casting and annealing. Batch melts as large as 4 kilograms were sprue cast into aluminum and stainless steel molds or temperature controlled bronze tube with mechanical bait. Small (100g) test melts were typically processed in-situ in a 5%Au°/95%Pt° crucible. Our group manufactured and evaluated over 100 different experimental heavy metal glass compositions during a two year period. A wide range of glass melting, fining, casting techniques and experimental protocols were employed. MWIR glass applications include remote sensing, directional infrared counter measures, detection of explosives and chemical warfare agents, laser detection tracking and ranging, range gated imaging and spectroscopy. Enhanced long range mid-infrared sensor performance is optimized when operating in the atmospheric windows from ~ 2.0 to 2.4μm, ~ 3.5 to 4.3μm and ~ 4.5 to 5.0μm.

  17. Sol-Gel Synthesis and Characterization of Cubic Bismuth Zinc Niobium Oxide Nanopowders

    Directory of Open Access Journals (Sweden)

    Ganchimeg Perenlei

    2014-01-01

    Full Text Available Bismuth zinc niobium oxide (BZN was successfully synthesized by a diol-based sol-gel reaction utilizing metal acetate and alkoxide precursors. Thermal analysis of a liquid suspension of precursors suggests that the majority of organic precursors decompose at temperatures up to 150°C, and organic free powders form above 350°C. The experimental results indicate that a homogeneous gel is obtained at about 200°C and then converts to a mixture of intermediate oxides at 350–400°C. Finally, single-phased BZN powders are obtained between 500 and 900°C. The degree of chemical homogeneity as determined by X-ray diffraction and EDS mapping is consistent throughout the samples. Elemental analysis indicates that the atomic ratio of metals closely matches a Bi1.5ZnNb1.5O7 composition. Crystallite sizes of the BZN powders calculated from the Scherrer equation are about 33–98 nm for the samples prepared at 500–700°C, respectively. The particle and crystallite sizes increase with increased sintering temperature. The estimated band gap of the BZN nanopowders from optical analysis is about 2.60–2.75 eV at 500-600°C. The observed phase formations and measured results in this study were compared with those of previous reports.

  18. Flatly broadened supercontinuum generation in nonlinear fibers using a mode locked bismuth oxide based erbium doped fiber laser

    International Nuclear Information System (INIS)

    Supercontinuum generation with considerable flatness and low fluctuation is investigated in nonlinear fibers by amplification of pulsed seed signal of a stable mode locked bismuth oxide based erbium doped fiber laser. Spectral expansion from 980 to 1750 nm is obtained by 340 fs pulses at 1560 nm amplified up to 177 kW in a dispersion flattened highly non-linear fiber. A comparison is made for different types of nonlinear fibers and evaluation of spectral bandwidth at high powers is probed

  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. Evaluation of radiation dose reduction during CT scans by using bismuth oxide and nano-barium sulfate shields

    Science.gov (United States)

    Seoung, Youl-Hun

    2015-07-01

    The purpose of the present study was to evaluate the radiation dose reduction and the 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 bismuth oxide (Bi2O3) particles. The radiation dose was measured five times at a direction of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom by using a CT ionization chamber to calculate an average value. The image quality of measured CT transverse images of the PMMA head phantom depended on the X-ray tube voltage and the type of shielding. Two regions of interest in the CT transverse images were chosen, one from the right area and the other from the left area under the surface of the PMMA head phantom and at a distance of ion chamber holes located in a direction of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce the dosages by 15.61%, 23.05%, and 22.71% at 90 kVp, 120 kVp, and 140 kVp, respectively, than with these of a conventional bismuth shield of the same thickness while maintaining image quality. In addition, the DRFSs produced were about 25% thinness than conventional bismuth. We conclude, therefore, that a DRFS can replace conventional bismuth as a new shield.

  1. Boron-Doped Strontium-Stabilized Bismuth Cobalt Oxide Thermoelectric Nanocrystalline Ceramic Powders Synthesized via Electrospinning

    Science.gov (United States)

    Koçyiğit, Serhat; Aytimur, Arda; Çınar, Emre; Uslu, İbrahim; Akdemir, Ahmet

    2014-01-01

    Boron-doped strontium-stabilized bismuth cobalt oxide thermoelectric nanocrystalline ceramic powders were produced by using a polymeric precursor technique. The powders were characterized by using x-ray diffraction (XRD), scanning electron microscopy (SEM), and physical properties measurement system (PPMS) techniques. The XRD results showed that these patterns have a two-phase mixture. The phases are face-centered cubic (fcc) and body-centered cubic (bcc). Values of the crystallite size, dislocation density, and microstrain were calculated by using the Scherrer equation. The lattice parameters were calculated for fcc and bcc phases. The SEM results showed that needle-like grains are formed in boron-undoped composite materials, but the needle-like grains changed to the plate-like grains with the addition of boron. The distribution of the nanofiber diameters was calculated and the average diameter of the boron-doped sample is smaller than the boron-undoped one. PPMS values showed that the electrical resistivity values decreased, but the thermal conductivity values, the Seebeck coefficients, and figure of merit ( ZT) increased with increasing temperature for the two samples.

  2. Evaluation of Atomic, Physical, and Thermal Properties of Bismuth Oxide Powder: An Impact of Biofield Energy Treatment

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Bismuth oxide (Bi2O3) is known for its application in several industries such as solid oxide fuel cells, optoelectronics, gas sensors and optical coatings. The present study was designed to evaluate the effect of biofield energy treatment on the atomic, physical, and thermal properties of Bi2O3. The Bi2O3 powder was equally divided into two parts: control and treated. The treated part was subjected to biofield energy treatment. After that, both control and treated samples were investigated us...

  3. Multi-wavelength Brillouin fiber laser using a holey fiber and a bismuth-oxide based erbium-doped fiber

    International Nuclear Information System (INIS)

    Multi-wavelength Brillouin fiber laser (BFL) is demonstrated using a holey fiber and a Bismuth-oxide based erbium-doped fiber (Bi-EDF) in a simple ring resonator. The proposed BFL is able to generate up to 13 lines including anti-Stokes with a channel spacing of 0.08 nm at the 1574 nm region. The multi-wavelength BFL is stable at room temperature and also compact due to the use of only a 20 m long of holey fiber and a 215 cm long of Bi-EDF

  4. Crystalline structure and propylene oxidation in complex bismuth-molybdenum oxide catalysts

    International Nuclear Information System (INIS)

    Complex Bi-Mo oxide catalysts supported on amorphous SiO2 were prepared by coprecipitation and tested in the reaction of selective oxidation of propylene to acrolein. They consist of a mixture of molybdate phases and excess MoO3. The Fe2(MoO4)3 phase was found to have a high concentration of lattice defects, induced by a Mo excess. These defects could be related to the catalytic conversion and to the selectivity to total oxidation by varying the calcination temperature. Calcination above 500 0C induced also the transition of the metastable modification β-NiMoO4 to the stable form α, accompanied by a loss of conversion. A complex Bi molybdate with scheelitic structure was found to have a high selectivity to acrolein. (author)

  5. Laser-induced oxidation kinetics of bismuth surface microdroplets on GaAsBi studied in situ by Raman microprobe analysis.

    Science.gov (United States)

    Steele, J A; Lewis, R A

    2014-12-29

    We report the cw-laser-induced oxidation of molecular-beam-epitaxy grown GaAsBi bismuth surface microdroplets investigated in situ by micro-Raman spectroscopy under ambient conditions as a function of irradiation power and time. Our results reveal the surface droplets are high-purity crystalline bismuth and the resultant Bi2O3 transformation to be β-phase and stable at room temperature. A detailed Raman study of Bi microdroplet oxidation kinetics yields insights into the laser-induced oxidation process and offers useful real-time diagnostics. The temporal evolution of new β-Bi2O3 Raman modes is shown to be well described by Johnson-Mehl-Avrami-Kolmogorov kinetic transformation theory and while this study limits itself to the laser-induced oxidation of GaAsBi bismuth surface droplets, the results will find application within the wider context of bismuth laser-induced oxidation and direct Raman laser processing. PMID:25607191

  6. 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

  7. Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields

    CERN Document Server

    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 value using a CT ionization chamber. The image quality measured CT transverse images of the PMMA head phantom depending on X-ray tube voltages and the type of shielding. Two regions of interest in CT transverse images were chosen from the right and left areas under the surface of the PMMA head phantom and from ion chamber holes located at directions of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce dosages to 15.61%, 23.05%, and 22.71% more in ...

  8. One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein.

    Science.gov (United States)

    Schuh, K; Kleist, W; Høj, M; Trouillet, V; Jensen, A D; Grunwaldt, J-D

    2014-12-18

    Flame spray pyrolysis (FSP) of Bi(III)- and Mo(VI)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides α-Bi2Mo3O12 and γ-Bi2MoO6, FSP gave direct access to the metastable β-Bi2Mo2O9 phase with high surface area (19 m(2) g(-1)). This phase is normally only obtained at high calcination temperatures (>560 °C) resulting in lower surface areas. The β-phase was stable up to 400 °C and showed superior catalytic performance compared to α- and γ-phases in selective oxidation of propylene to acrolein at temperatures relevant for industrial applications (360 °C). PMID:25350295

  9. 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...

  10. Nanostructured bismuth vanadate-based materials for solar-energy-driven water oxidation: a review on recent progress

    Science.gov (United States)

    Huang, Zhen-Feng; Pan, Lun; Zou, Ji-Jun; Zhang, Xiangwen; Wang, Li

    2014-11-01

    Water oxidation is the key step for both photocatalytic water splitting and CO2 reduction, but its efficiency is very low compared with the photocatalytic reduction of water. Bismuth vanadate (BiVO4) is the most promising photocatalyst for water oxidation and has become a hot topic for current research. However, the efficiency achieved with this material to date is far away from the theoretical solar-to-hydrogen conversion efficiency, mainly due to the poor photo-induced electron transportation and the slow kinetics of oxygen evolution. Fortunately, great breakthroughs have been made in the past five years in both improving the efficiency and understanding the related mechanism. This review is aimed at summarizing the recent experimental and computational breakthroughs in single crystals modified by element doping, facet engineering, and morphology control, as well as macro/mesoporous structure construction, and composites fabricated by homo/hetero-junction construction and co-catalyst loading. We aim to provide guidelines for the rational design and fabrication of highly efficient BiVO4-based materials for water oxidation.

  11. Synthesis conductivity, and X-ray photoelectron spectrum of Bi2Sr2Cu7+X. A new ternary bismuth-oxide system exhibiting metallic conductivity

    International Nuclear Information System (INIS)

    The preparation and some of the properties relating to the superconductive state of the newly discovered ternary bismuth oxides, Bi2Sr2Cu2O7+x, are described. Conductivity behavior ranging from semiconductive to metallic is observed when four-probe. AC resistivity measurements are carried out on pressed pellet specimens that have been annealed under different conditions. From a determination of the total oxygen present by an iodometric titration, it was found that metallic conductivity was associated with a higher oxygen content. An X-ray photoelectron experiment was carried out in order to determine whether bismuth or copper was present as the mixed-valent species. The XPS spectrum of the Bi 4f orbital electrons in the oxides was nearly identical to that observed in Bi2O3, with no evidence of any Bi5+. 8 refs., 3 figs

  12. Temperature-induced phase changes in bismuth oxides and efficient photodegradation of phenol and p-chlorophenol.

    Science.gov (United States)

    Hu, Yin; Li, Danzhen; Sun, Fuqian; Weng, Yaqing; You, Shengyong; Shao, Yu

    2016-01-15

    A novel, simple and efficient approach for photodegrading phenol and p-chlorophenol, based on BixOy, was reported for the first time. Monoclinic Bi2O4 was prepared by the hydrothermal treatment of NaBiO3·2H2O. A series of interesting phase transitions happened and various bismuth oxides (Bi4O7, β-Bi2O3 and α-Bi2O3) were obtained by sintering Bi2O4 at different temperatures. The results demonstrated that the Bi2O4 and Bi4O7 phase had strong abilities towards the oxidative decomposition of phenol and p-chlorophenol and very high rates of TOC removal were observed. The characterization by XRD and XPS revealed that Bi(4+) in Bi2O4 and Bi(3.5+) in Bi4O7 were reduced to Bi(3+) during the reaction process. Singlet oxygen ((1)O2) was identified as the major reactive species generated by Bi2O4 and Bi4O7 for the photodegradation of p-chlorophenol and phenol. This novel approach could be used as a highly efficient and green technology for treating wastewaters contaminated by high concentrations of phenol and chlorophenols. PMID:26384997

  13. Visible-light-induced water oxidation by a hybrid photocatalyst consisting of bismuth vanadate and copper(II) meso-tetra(4-carboxyphenyl)porphyrin.

    Science.gov (United States)

    Nakashima, Shu; Negishi, Ryo; Tada, Hiroaki

    2016-03-01

    Copper(II) meso-tetra(4-carboxyphenyl)porphyrin surface-modified monoclinic scheelite bismuth vanadate (CuTCPP/BiVO4) has been synthesized via a two-step route involving chemisorption of TCPP on BiVO4 and successive Cu(II) ion incorporation into the TCPP, and the surface modification drastically enhances the water oxidation to oxygen (O2) under visible-light irradiation (λ > 430 nm). PMID:26853997

  14. High-relative-dielectric-constant bismuth-niobium-oxide films prepared using Nb-rich precursor solution

    Science.gov (United States)

    Ariga, Tomoki; Inoue, Satoshi; Matsumoto, Shin; Onoue, Masatoshi; Miyasako, Takaaki; Tokumitsu, Eisuke; Shimoda, Tatsuya

    2015-09-01

    Various ceramic materials have been developed for electronic devices. Bismuth-niobium-oxide (BNO) films prepared by a chemical solution deposition (CSD) method have the cubic pyrochlore phase, high relative dielectric constant, and low tangent loss (tan δ). We found that a BNO cubic pyrochlore crystal was Nb-rich, even though its pyrochlore formula is A2B2O7. The crystallization temperature of BNO increased with increasing Nb ratio. The relative dielectric constants of BNO films were related to the Nb ratio in the precursor solution. The dielectric constant of the BNO films was 250 when the Bi and Nb ratios in BNO precursor solutions were 4 and 6, respectively, and the sintering temperature was 600 °C. In addition, the tan δ was less than 0.01 at 1 kHz, which is higher than the reported values of BNO systems despite using the CSD method. These results show that the properties of BNO films prepared by the CSD method were associated with the Nb ratio in the precursor solution. Furthermore, the dielectric characteristics indicated that the Nb-rich BNO films have potential applications in electronic devices.

  15. Polyaniline–bismuth oxide nanocomposite sensor for quantification of anti-parkinson drug pramipexole in solubilized system

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • PANI–Bi2O3 nanocomposite has been synthesized first time and effectively used for the electrochemical studies. • PANI–Bi2O3/GCE modified sensors have a large surface area greatly enhancing the sensitivity of electroactive species. • Modified sensor was successfully used for the detection of pramipexole utilizing enhancement effect of surfactant. • The reported method showed very good stability as well as reproducibility for the voltammetric analysis of pramipexole. - Abstract: In this study, a new sensor polyaniline–bismuth oxide (PANI–Bi2O3) nanocomposite has been fabricated and characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). SEM was used to provide information about the morphology of the PANI–Bi2O3 nanocomposite. Cyclic voltammetric studies of electroactive species i.e. K3Fe(CN)6 demonstrate almost reversible electrochemical behaviour, with diffusion controlled mass transfer process in the double layer region of the electrode. EIS studies revealed that PANI–Bi2O3/GCE having lower charge transfer resistance which leads to higher electrocatalytic activity. This modified electrode was successfully used for the detection of pramipexole in pharmaceutical formulation in sodium lauryl sulphate (SLS) in Britton Robinson (BR) buffer at pH 4.5. The ease of fabrication, excellent electrochemical performance and high electroactive surface area are the promising features of the fabricated sensor

  16. Microstructure and electrical properties of bismuth and bismuth oxide deposited by magnetron sputtering UBM; Microestructura y propiedades electricas de bismuto y oxido de bismuto depositados por magnetron sputtering UBM

    Energy Technology Data Exchange (ETDEWEB)

    Otalora B, D. M.; Dussan, A. [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Materiales Nanoestructurados y sus Aplicaciones, Carrera 30 No. 45-03, 111321 Bogota (Colombia); Olaya F, J. J., E-mail: jjolayaf@unal.edu.co [Universidad Nacional de Colombia, Facultad de Ingenieria, Departamento de Ingenieria Mecanica y Mecatronica, Carrera 30 No. 45-03, 111321 Bogota (Colombia)

    2015-07-01

    In this work, bismuth (Bi) and bismuth oxide (Bi{sub 2}O{sub 3}) thin films were prepared, at room temperature, by Sputtering Unbalanced Magnetron (UBM - Unbalance Magnetron) technique under glass substrates. Microstructural and electrical properties of the samples were studied by X-ray diffraction (XRD) and System for Measuring Physical Properties - PPMS (Physical Property Measurement System). Dark resistivity of the material was measured for a temperature range between 100 and 400 K. From the XRD measurements it was observed a polycrystalline character of the Bi associated to the presence of phases above the main peak, 2θ = 26.42 grades and a growth governed by a rhombohedral structure. Crystal parameters were obtained for both compounds, Bi and Bi{sub 2}O{sub 3}. From the analysis of the spectra of the conductivity as a function of temperature, it was established that the transport mechanism that governs the region of high temperature (T>300 K) is thermally activated carriers. From conductivity measurements the activation energies were obtained of 0.0094 eV and 0.015 eV for Bi{sub 2}O{sub 3} and Bi, respectively. (Author)

  17. Electrocatalytic oxidations at electrodeposited bismuth (III)-doped beta-lead dioxide film electrodes

    International Nuclear Information System (INIS)

    Heterogeneous rate constants for the anodic oxidation of many inorganic and organic compounds at electrolytically deposited beta-PbO2 film electrodes in 1.0M HClO4 are increased by doping the oxide with Bi(III). The rate constants at the mixed-oxide electrode rise sharply for a change from 0 to 10 mole percent (m/o) Bi(III) in the electrodeposition solution, and reach a mass transport-limited value for some compounds at 40 m/o Bi(III). Results of kinetic, voltammetric, and spectroscopic studies of these electrodes are described. In addition, the lifetime of Bi(III)-doped PbO2 film electrodes is discussed as a function of concentration, rotation speed, analyte, and applied voltage

  18. Investigation of phase stability and oxide ion performance in new perovskite-type bismuth vanadate

    Energy Technology Data Exchange (ETDEWEB)

    Al-Alas, Ahlam [Department of Chemistry, Faculty of Applied Sciences, Taiz University, Taiz, Republic of Yemen (Yemen); Beg, Saba [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India); Al-Areqi, Niyazi A.S., E-mail: niyazi.alareqi@gmail.com [Department of Chemistry, Faculty of Applied Sciences, Taiz University, Taiz, Republic of Yemen (Yemen)

    2012-09-14

    Samples of the BICDVOX system, formulated as Bi{sub 4}Cd{sub x}V{sub 2-x}O{sub 11-(3x/2)-{delta}} in the Cd substitution range 0 {<=} x {<=} 0.25 were synthesized using the standard solid state reaction.The correlation between phase stability and oxide ion performance were investigated by variable temperature XRPD, DSC and AC impedance spectroscopy. The substitution of V{sup 5+} by Cd{sup 2+} exhibited different phase transitions upon varying composition. For compositions with x {<=} 0.05, two successive transitions; {alpha}{r_reversible}{beta}{r_reversible}{gamma} are evident, while the {beta}{r_reversible}{gamma} transition exists in the composition range 0.05 < x < 0.175. However, some temperature dependent phenomena confirmed the exixtence of the {gamma} Prime {r_reversible}{gamma} transition, coupled with the tetragonal symmetry stabilization for x {>=} 0.175. The maximum oxide ion conductivity at lower temperatures was observed for x = 0.20. It has also been found that the slow V{sup 4+} {yields} V{sup 5+} re-oxidation results in increased defect trapping effects in the system at higher temperatures. -- Highlights: Black-Right-Pointing-Pointer {gamma}-Stabilized BICDVOX at lower dopant concentrations. Black-Right-Pointing-Pointer Good oxide-ion conductivity at lower temperatures. Black-Right-Pointing-Pointer High temperature-vanadium reduction with lower dopant concentrations.

  19. Preparation of a Microspherical Silver-Reduced Graphene Oxide-Bismuth Vanadate Composite and Evaluation of Its Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Mao Du

    2016-03-01

    Full Text Available A novel Ag-reduced graphene oxide (rGO-bismuth vanadate (BiVO4 (AgGB ternary composite was successfully synthesized via a one-step method. The prepared composite was characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, scanning electron microscopy (SEM, energy dispersive X-ray (EDX, Brunauer-Emmett-Teller (BET surface area measurement, Raman scattering spectroscopy, and ultraviolet-visible diffuse-reflection spectroscopy (UV-vis DRS. The results showed that bulk monoclinic needle-like BiVO4 and Ag nanoparticles with a diameter of approximately 40 nm formed microspheres (diameter, 5–8 μm with a uniform size distribution that could be loaded on rGO sheets to facilitate the transport of electrons photogenerated in BiVO4, thereby reducing the rate of recombination of photogenerated charge carriers in the coupled AgGB composite system. Ag nanoparticles were dispersed on the surface of the rGO sheets, which exhibited a localized surface plasmon resonance phenomenon and enhanced visible light absorption. The removal efficiency of rhodamine B dye by AgGB (80.2% was much higher than that of pure BiVO4 (51.6% and rGO-BiVO4 (58.3% under visible light irradiation. Recycle experiments showed that the AgGB composite still presented significant photocatalytic activity after five successive cycles. Finally, we propose a possible pathway and mechanism for the photocatalytic degradation of rhodamine B dye using the composite photocatalyst under visible light irradiation.

  20. Polyaniline–bismuth oxide nanocomposite sensor for quantification of anti-parkinson drug pramipexole in solubilized system

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Rajeev, E-mail: rajeevjain54@yahoo.co.in [School of Studies in Chemistry, Jiwaji University, Gwalior, 474011 (India); Tiwari, Dinesh Chandra [School of Studies in Physics, Jiwaji University, Gwalior, 474011 (India); Shrivastava, Swati [School of Studies in Chemistry, Jiwaji University, Gwalior, 474011 (India)

    2014-07-01

    Graphical abstract: - Highlights: • PANI–Bi{sub 2}O{sub 3} nanocomposite has been synthesized first time and effectively used for the electrochemical studies. • PANI–Bi{sub 2}O{sub 3}/GCE modified sensors have a large surface area greatly enhancing the sensitivity of electroactive species. • Modified sensor was successfully used for the detection of pramipexole utilizing enhancement effect of surfactant. • The reported method showed very good stability as well as reproducibility for the voltammetric analysis of pramipexole. - Abstract: In this study, a new sensor polyaniline–bismuth oxide (PANI–Bi{sub 2}O{sub 3}) nanocomposite has been fabricated and characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). SEM was used to provide information about the morphology of the PANI–Bi{sub 2}O{sub 3} nanocomposite. Cyclic voltammetric studies of electroactive species i.e. K{sub 3}Fe(CN){sub 6} demonstrate almost reversible electrochemical behaviour, with diffusion controlled mass transfer process in the double layer region of the electrode. EIS studies revealed that PANI–Bi{sub 2}O{sub 3}/GCE having lower charge transfer resistance which leads to higher electrocatalytic activity. This modified electrode was successfully used for the detection of pramipexole in pharmaceutical formulation in sodium lauryl sulphate (SLS) in Britton Robinson (BR) buffer at pH 4.5. The ease of fabrication, excellent electrochemical performance and high electroactive surface area are the promising features of the fabricated sensor.

  1. Nonlinear optical properties of zinc oxide doped bismuth thin films using Z-scan technique

    Science.gov (United States)

    Abed, S.; Bouchouit, K.; Aida, M. S.; Taboukhat, S.; Sofiani, Z.; Kulyk, B.; Figa, V.

    2016-06-01

    ZnO doped Bi thin films were grown on glass substrates by spray ultrasonic technique. This paper presents the effect of Bi doping concentration on structural and nonlinear optical properties of zinc oxide thin films. These thin films were characterized by X-ray diffractometer technique. XRD analysis revealed that the ZnO:Bi thin films indicated good preferential orientation along c-axis perpendicular to the substrate. The nonlinear optical properties such as nonlinear absorption coefficient (β) and third order nonlinear susceptibility (Imχ(3)) are investigated. The calculations have been performed with a Z scan technique using Nd:YAG laser emitting 532 nm. The reverse saturable absorption (RSA) mechanism was responsible for the optical limiting effect. The results suggest that this material considered as a promising candidate for future optical device applications.

  2. Temperature dependence of dissolution rate of a lead oxide mass exchanger in lead–bismuth eutectic

    International Nuclear Information System (INIS)

    A Computational Fluid Dynamic (CFD) model of a lead oxide mass exchanger (PbO MX) was developed. The mass exchanger consisted of a packed bed of PbO spheres. The geometry was created using Discrete Elements Method (DEM) software while the meshing, the solving and the post-processing were done by the commercial CFD package CFX. The dissolution process was modeled by implementing in the code oxygen mass transfer through the boundary layer. The dissolution rate was then predicted for different temperatures. Experiments were also performed at the LBE material test loop known as the DELTA loop. Oxygen concentration at the outlet of the PbO MX was measured for different conditions using a potentiometric oxygen sensor and the dissolution rate was determined for five different temperatures. The experimental data were compared with the numerical model. The temperature dependence of the dissolution rate was then determined in terms of Sherwood number by fitting the simulation results while keeping constant Reynolds number. The results showed that the Sherwood number for PbO MX in flowing LBE varies with Sc0.323

  3. Enhancement of Er optical efficiency through bismuth sensitization in yttrium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Scarangella, Adriana [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Reitano, Riccardo [Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Franzò, Giorgia; Miritello, Maria, E-mail: maria.miritello@ct.infn.it [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Priolo, Francesco [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Scuola Superiore di Catania, Università di Catania, Via Valdisavoia 9, 95123 Catania (Italy)

    2015-07-27

    The process of energy transfer (ET) between optically active ions has been widely studied to improve the optical efficiency of a system for different applications, from lighting and photovoltaics to silicon microphotonics. In this work, we report the influence of Bi on the Er optical emission in erbium-yttrium oxide thin films synthesized by magnetron co-sputtering. We demonstrate that this host permits to well dissolve Er and Bi ions, avoiding their clustering, and thus to stabilize the optically active Er{sup 3+} and Bi{sup 3+} valence states. In addition, we establish the ET occurrence from Bi{sup 3+} to Er{sup 3+} by the observed Bi{sup 3+} PL emission decrease and the simultaneous Er{sup 3+} photoluminescence (PL) emission increase. This was further confirmed by the coincidence of the Er{sup 3+} and Bi{sup 3+} excitation bands, analyzed by PL excitation spectroscopy. By increasing the Bi content of two orders of magnitude inside the host, though the occurrence of Bi-Bi interactions becomes deleterious for Bi{sup 3+} optical efficiency, the ET process between Bi{sup 3+} and Er{sup 3+} is still prevalent. We estimate ET efficiency of 70% for the optimized Bi:Er ratio equal to 1:3. Moreover, we have demonstrated to enhance the Er{sup 3+} effective excitation cross section by more than three orders of magnitude with respect to the direct one, estimating a value of 5.3 × 10{sup −18} cm{sup 2}, similar to the expected Bi{sup 3+} excitation cross section. This value is one of the highest obtained for Er in Si compatible hosts. These results make this material very promising as an efficient emitter for Si-compatible photonics devices.

  4. Enhancement of Er optical efficiency through bismuth sensitization in yttrium oxide

    International Nuclear Information System (INIS)

    The process of energy transfer (ET) between optically active ions has been widely studied to improve the optical efficiency of a system for different applications, from lighting and photovoltaics to silicon microphotonics. In this work, we report the influence of Bi on the Er optical emission in erbium-yttrium oxide thin films synthesized by magnetron co-sputtering. We demonstrate that this host permits to well dissolve Er and Bi ions, avoiding their clustering, and thus to stabilize the optically active Er3+ and Bi3+ valence states. In addition, we establish the ET occurrence from Bi3+ to Er3+ by the observed Bi3+ PL emission decrease and the simultaneous Er3+ photoluminescence (PL) emission increase. This was further confirmed by the coincidence of the Er3+ and Bi3+ excitation bands, analyzed by PL excitation spectroscopy. By increasing the Bi content of two orders of magnitude inside the host, though the occurrence of Bi-Bi interactions becomes deleterious for Bi3+ optical efficiency, the ET process between Bi3+ and Er3+ is still prevalent. We estimate ET efficiency of 70% for the optimized Bi:Er ratio equal to 1:3. Moreover, we have demonstrated to enhance the Er3+ effective excitation cross section by more than three orders of magnitude with respect to the direct one, estimating a value of 5.3 × 10−18 cm2, similar to the expected Bi3+ excitation cross section. This value is one of the highest obtained for Er in Si compatible hosts. These results make this material very promising as an efficient emitter for Si-compatible photonics devices

  5. Analysis of bi-layer oxide on austenitic stainless steel, 316L, exposed to Lead–Bismuth Eutectic (LBE) by X-ray Photoelectron Spectroscopy (XPS)

    Energy Technology Data Exchange (ETDEWEB)

    Koury, D., E-mail: dan@physics.unlv.edu [Dept. of Physics and Astronomy, MS 4002, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154 (United States); Johnson, A.L. [Harry Reid Center, MS 4009, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154 (United States); Ho, T. [Dept. of Chemistry, MS 4002, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154 (United States); Farley, J.W. [Dept. of Physics and Astronomy, MS 4002, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154 (United States)

    2013-09-15

    Corrosion of the austenitic stainless steel alloy 316L by Lead–Bismuth Eutectic (LBE) was studied using X-ray Photoelectron Spectroscopy (XPS) with Sputter-Depth Profiling (SDP), and compared to data taken by Scanning Electron Microscopy (SEM) and Energy Dispersive X-rays (EDXs). Exposed and unexposed samples were compared. Annealed 316L samples, exposed to LBE for durations of 1000, 2000 and 3000 h, developed bi-layer oxides up to 30 μm thick. Analysis of the charge-states of the 2p{sub 3/2} peaks of iron, chromium, and nickel in the oxide layers reveal an inner layer consisting of iron and chromium oxides (likely spinel-structured) and an outer layer consisting of iron oxides (Fe{sub 3}O{sub 4}). Cold-rolled 316L samples, exposed for the same durations, form a chromium-rich, thin (⩽1 μm) oxide with some oxidized iron in the outermost ∼200 nm of the oxide layer. This is the first experiment to investigate what components of the 316L are oxidized by LBE exposure. It is shown here that nickel is metallic in the inner layer.

  6. One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein

    DEFF Research Database (Denmark)

    Schuh, K.; Kleist, W.; Høj, Martin;

    2014-01-01

    Flame spray pyrolysis (FSP) of Bi(III)-and Mo(VI)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides alpha-Bi2Mo3O12 and gamma-Bi2MoO6, FSP gave direct access to the metastable beta-Bi2Mo2O9 phase with high surface...

  7. Bismuth molybdate catalysts prepared by mild hydrothermal synthesis: Influence of pH on the selective oxidation of propylene

    DEFF Research Database (Denmark)

    Schuh, Kirsten; Kleist, Wolfgang; Høj, Martin; Trouillet, Vanessa; Beato, Pablo; Jensen, Anker Degn; Grunwaldt, Jan-Dierk

    2015-01-01

    performance than samples synthesized with Bi/Mo = 2/3 at pH = 4 and 9 and γ-Bi2MoO6 synthesized by co-precipitation at pH = 7. At temperatures above 440 °C, the catalytic activity of the hydrothermally synthesized bismuth molybdates started to decrease due to sintering and loss of surface area. These results...

  8. 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

  9. 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 ...

  10. Ion exchange properties of crystalline bismuth molybdenum hydrous oxide and its intercalates. Equilibrium and kinetics of UO22+ ions on the crystals

    International Nuclear Information System (INIS)

    The sorption of uranyl ions on crystalline bismuth molybdenum hydrous oxide and its intercalates were investigated from point of view of both equilibrium and kinetics. Ion exchange isotherms of uranyl ions on the crystals were obtained, and ionic sieve effect was employed to describe the characteristics of ion exchange isotherms. The best fitting for sorption of uranyl ions on BMHO was achieved by means of the Langmuir isotherm, while the Freundlich isotherm appeared to best fit for its intercalates. The slightly negative free-energy change indicates that, thermodynamically, the crystals behave less favourable for uranyl ions. The equation derived from SN2 chemical reactions was proved to fit the rate curves, and the rate constants were determined. The comparison between the calculated and observed pH values as a function of time further verified the chemical reaction mechanism. (author)

  11. 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.

  12. Characterization of the mechanism of bi-layer oxide growth on austenitic stainless steels 316L and D9 in oxygen-controlled Lead-Bismuth Eutectic (LBE)

    Science.gov (United States)

    Koury, Daniel

    Lead Bismuth Eutectic (LBE) has been proposed for use in programs for accelerator-based and reactor-based transmutation of nuclear waste. LBE is a leading candidate material as a spallation target (in accelerator-based transmutation) and an option for the sub-critical blanket coolant. The corrosion by LBE of annealed and cold-rolled 316L stainless steels, and the modified austenitic stainless steel alloy D9, has been studied using Scanning Electron Microscopy (SEM), Electron Probe Micro Analysis (EPMA), and X-ray Photoelectron Spectroscopy (XPS). Exposed and unexposed samples have been compared and the differences studied. Small amounts of surface contamination are present on the samples and have been removed by ion-beam sputtering. The unexposed samples reveal typical stainless steel characteristics: a chromium oxide passivation surface layer and metallic iron and nickel. The exposed samples show protective iron oxide and chromium oxide growths on the surface. Oxygen takes many forms on the exposed samples, including oxides of iron and chromium, carbonates, and organic acids from subsequent handling after exposure to LBE. Different types of surface preparation have lead to considerably different modes of corrosion. The cold-rold samples were resistant to thick oxide growth, having only a thin (primary diffusant, as there are fewer fast-diffusion pathways and therefore an amount of chromium insufficient to maintain a chromium based oxide. Even the thick oxide, however, can prolong the life of a steel in LBE, provided proper oxygen control. The mechanisms responsible for the differences in the oxidation behaviors are discussed.

  13. 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

  14. 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.

  15. Oxidation behaviour of P122 and a 9Cr-2W ODS steel at 550 deg. C in oxygen-containing flowing lead-bismuth eutectic

    International Nuclear Information System (INIS)

    The long-term performance of 12Cr-2W ferritic/martensitic steel P122 and a 9Cr-2W ODS steel was tested in oxygen-containing flowing lead-bismuth eutectic (LBE) at 550 deg. C and a flow velocity of 2 m/s by means of exposure experiments in the CORRIDA loop. The target for the enrichment of dissolved oxygen was a concentration, cO, of 10-6 mass%, corresponding to a lead oxide (PbO) activity of approximately 10-3. Owing to initial problems controlling cO, some of the exposed specimens experienced varying conditions, which allowed for investigating the influence of temporarily low cO (down to ∼10-9 mass%), in addition to constantly high cO (averaging 1.6 x 10-6 mass%). Maximum exposure times at constantly high cO were 10,000 and 20,000 h for P122 and the ODS steel, respectively. Under the testing conditions, both steels were affected by moderate oxidation resulting in the formation of a compact layer of a spinel-type oxide on the surface and a more or less pronounced internal oxidation zone. The thickness of the oxide scale was quantified and used for determining the material loss (metal recession). For cO ∼ 10-6 mass%, logarithmic and power rate laws were fitted to the obtained data as a basis for predicting the metal recession at times exceeding the experimental exposure times. Temporarily lower cO proved to be beneficial for the performance of both steels, while, in the case of the ODS steel, excursions to higher cO should be prevented in order to achieve optimum oxidation resistance.

  16. Dissolution and oxidation behaviour of various austenitic steels and Ni rich alloys in lead-bismuth eutectic at 520 °C

    Science.gov (United States)

    Roy, Marion; Martinelli, Laure; Ginestar, Kevin; Favergeon, Jérôme; Moulin, Gérard

    2016-01-01

    Ten austenitic steels and Ni rich alloys were tested in static lead-bismuth eutectic (LBE) at 520 °C in order to obtain a selection of austenitic steels having promising corrosion behaviour in LBE. A test of 1850 h was carried out with a dissolved oxygen concentration between 10-9 and 5 10-4 g kg-1. The combination of thermodynamic of the studied system and literature results leads to the determination of an expression of the dissolved oxygen content in LBE as a function of temperature: RT(K)ln[O](wt%) = -57584/T(K) -55.876T(K) + 254546 (R is the gas constant in J mol-1 K-1). This relation can be considered as a threshold of oxygen content above which only oxidation is observed on the AISI 316L and AISI 304L austenitic alloys in static LBE between 400 °C and 600 °C. The oxygen content during the test leads to both dissolution and oxidation of the samples during the first 190 h and leads to pure oxidation for the rest of the test. Results of mixed oxidation and dissolution test showed that only four types of corrosion behaviour were observed: usual austenitic steels and Ni rich alloys behaviour including the reference alloy 17Cr-12Ni-2.5Mo (AISI 316LN), the 20Cr-31Ni alloy one, the Si containing alloy one and the Al containing alloy one. According to the proposed criteria of oxidation and dissolution kinetics, silicon rich alloys and aluminum rich alloy presented a promising corrosion behaviour.

  17. Synthesis conductivity, and X-ray photoelectron spectrum of Bi sub 2 Sr sub 2 Cu sub 7+X. A new ternary bismuth-oxide system exhibiting metallic conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Porter, L.C.; Appleman, E.; Beno, M.A.; Cariss, C.S.; Carlson, K.D.; Cohen, H.; Geiser, U.; Thorn, R.J.; Williams, J.M.

    1989-01-01

    The preparation and some of the properties relating to the superconductive state of the newly discovered ternary bismuth oxides, Bi{sub 2}Sr{sub 2}Cu{sub 2}O{sub 7+x}, are described. Conductivity behavior ranging from semiconductive to metallic is observed when four-probe. AC resistivity measurements are carried out on pressed pellet specimens that have been annealed under different conditions. From a determination of the total oxygen present by an iodometric titration, it was found that metallic conductivity was associated with a higher oxygen content. An X-ray photoelectron experiment was carried out in order to determine whether bismuth or copper was present as the mixed-valent species. The XPS spectrum of the Bi 4f orbital electrons in the oxides was nearly identical to that observed in Bi{sub 2}O{sub 3}, with no evidence of any Bi{sup 5+}. 8 refs., 3 figs.

  18. Effect of cold rolling on the oxidation resistance of T91 steel in oxygen-saturated stagnant liquid lead-bismuth eutectic at 450 °C and 550 °C

    Science.gov (United States)

    Dong, Hong; Ye, Zhongfei; Wang, Pei; Li, Dianzhong; Zhang, Yutuo; Li, Yiyi

    2016-08-01

    The compatibility of T91 steels having different preparation processes with oxygen-saturated stagnant lead-bismuth eutectic have been investigated at 450 °C and 550 °C. It is found that cold rolling decreases the thickness of the oxide scale of T91 steel by forming a continuous enhanced Cr-rich belt in the inner oxide layer next to the internal oxidation zone, which is attributed to the rapid diffusion of Cr induced by numerous non-equilibrium grain boundaries and migrating dislocations.

  19. TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

    Institute of Scientific and Technical Information of China (English)

    Eshraq Ahmed Abdullah; Abdul Halim Abdullah; Zulkarnain Zainal; Mohd Zobir Hussein; Tan Kar Ban

    2012-01-01

    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents.The synthesized product was characterized by different analytical techniques.The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants.Different kinetic,isotherm and diffusion models were chosen to describe the adsorption process.X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however,the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes.Dyes removal was found to be a function of adsorbent dosage,initial dye concentration,solution pH and temperature.The reduction of Langrnuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent.Mass transfer can be described by intra-particle diffusion at a certain stage,but it was not the rate limiting step that controlled the adsorption process.Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.

  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. MOS dosemeter using bismuth oxide (Bi2O3) and copper phthalocyanine (CuPc) polymer thick film

    International Nuclear Information System (INIS)

    A metal-oxide-silicon (MOS)-capacitor having an Ag/Bi2O3/CuPc/Ag and an MOS-transistor with Ag (gate)-Bi2O3 (gate insulator)-CuPc (semiconductor)-CdO (drain and source) structure were fabricated using screen-printing polymer thick film. The effects of gamma irradiation on the characteristics of both MOS-capacitor and MOS-transistor were investigated. The flat band voltage (VFB) of the MOS-capacitor showed a shift towards the negative gate voltage when exposed to gamma rays. The IDS-VGs characteristics displayed enhancement mode transistor for such devices. The threshold voltage was found to be 4.25 V, which displayed a linear and gradual decrease in ΔVT=0.5 V at VDS=0 V and ΔVT=1.0 V at VDS=2 V when exposed to gamma rays of dose step of 60 Gy. (authors)

  2. Efficient oxidative hydrogen peroxide production and accumulation in photoelectrochemical water splitting using a tungsten trioxide/bismuth vanadate photoanode.

    Science.gov (United States)

    Fuku, Kojiro; Sayama, Kazuhiro

    2016-04-01

    An aqueous solution of hydrogen carbonate (HCO3(-)) facilitated oxidative hydrogen peroxide (H2O2) production from water on a WO3/BiVO4 photoanode with the simultaneous production of hydrogen (H2) on a Pt cathode even at an applied voltage far lower than the theoretical electrolysis voltage (+1.77 V vs. RHE) under simulated solar light. The unprecedentedly efficient simultaneous production and accumulation of H2O2 and H2 was achieved in 2.0 M KHCO3 at low temperature, and the maximum selectivity, accumulated concentration and turnover number (TON) of H2O2 generated reached ca. 54%, more than 2 mM and 108, respectively. PMID:27009778

  3. Synergy effects between bismuth molybdate catalyst phases (Bi/Mo from 0.57 to 2) for the selective oxidation of propylene to arcrolein

    DEFF Research Database (Denmark)

    Le, Minh Thang; Well, Willy van; Stoltze, Per;

    2005-01-01

    In this work, the synergy effect between different phases of bismuth molybdate catalysts was investigated systematically. The catalysts were prepared by spray drying and had a Bi/Mo atomic between 0.57 and 2. It is found that the synergy effect is only observed in mixtures containing γ-phase. A...

  4. Formation of bismuth oxide nanowires by simultaneous templating and electrochemical adhesion of DNA on Si/SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Michael G. [School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Little, Ross; Salem, Mohamed Ali [School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Hedley, Joseph H.; Horrocks, Benjamin R. [School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Siller, Lidija, E-mail: Lidija.Siller@ncl.ac.uk [School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)

    2012-10-01

    Deoxyribonucleic acid (DNA)-templated growth of Bi/Bi{sub 2}O{sub 3} nanowires attached to the Si surface was obtained by electrochemical reduction of Bi(III) at an n-type Si electrode in aqueous Bi(NO{sub 3}){sub 3}/HNO{sub 3} at pH 2.5 with calf thymus DNA. The nanowires had a mean diameter of 5 nm and a range of lengths from 1.4 {mu}m to 6.1 {mu}m. The composition and structure of the wires were determined by atomic force microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoemission spectroscopy. The dominant component of the material is Bi{sub 2}O{sub 3} owing to the rapid re-oxidation of nanoscale Bi in the presence of air and water. Our method has the potential to construct complex architectures of Bi/Bi{sub 2}O{sub 3} nanostrucures on high quality Si substrates. - Highlights: Black-Right-Pointing-Pointer We have developed an electrochemical method to grow Bi/Bi{sub 2}O{sub 3} nanowires on silicon. Black-Right-Pointing-Pointer Bi/Bi{sub 2}O{sub 3} nanowires are templated by deoxyribonucleic acid molecules. Black-Right-Pointing-Pointer The procedure also adheres the nanowires to the electrode for characterization.

  5. 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...

  6. 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.

  7. 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.

  8. The crystal structure of baliczunicite, Bi2O(SO4)2, a new natural bismuth oxide sulfate

    DEFF Research Database (Denmark)

    Pinto, Daniela; Garavelli, Anna; Balic Zunic, Tonci

    2015-01-01

    = 14.1754(7)Å , α = 80.082(2)o, β = 88.462(2)º, γ = 89.517(2)º, V = 1052.01(8)Å3 and Z = 6. The crystal structure consists of six independent Bi sites, six S sites and 27 O sites of which three are oxo oxygen atoms not bonded to sulfur. Bismuth and S atoms are arranged close to a eutectic pattern....... The trapezoidal Bi5O39+ ions are joined along [100] with SO42- groups by means of strong bismuth-sulphate oxygen bonds, forming infinite [100] rods with composition Bi5O3(SO4)5-. One sixth of the Bi atoms do not participate in trapezoids, but form, with additional SO42- groups, rows of composition BiSO4+, also...

  9. 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)

  10. 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.

  11. Bismuth and niobium co-doped barium cobalt oxide as a promising cathode material for intermediate temperature solid oxide fuel cells

    Science.gov (United States)

    He, Shaofei; Le, Shiru; Guan, Lili; Liu, Tao; Sun, Kening

    2015-11-01

    Perovskite oxides BaBi0.05Co0.95-yNbyO3-δ (BBCNy, 0 ≤ y ≤ 0.2) are synthesized and evaluated as potential cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). Highly charged Nb5+ successfully stabilizes the cubic perovskite structure to room temperature with Nb substituting content y ≥ 0.1. The phase structure, thermal expansion behavior, electrical conductivity and electrochemical performance of BBCNy with cubic phase are systematically studied. The samples exhibit excellent chemical compatibility with GDC and have sufficiently high electrical conductivities. However, the thermal expansion coefficients of BBCNy samples are nearly twice those of the most commonly used electrolyte materials YSZ and GDC, which is a major drawback for application in IT-SOFCs. The polarization resistances of BBCNy with y = 0.10, 0.15 and 0.20 on GDC electrolyte are 0.086, 0.079 and 0.107 Ω cm2 at 700 °C, respectively. Even though the YSZ electrolyte membrane and GDC barrier layer are approximately 50 μm and 10 μm in thickness, the highest maximum power density (1.23 W cm-2) of the single cell Ni-YSZ|YSZ|GDC|BBCN0.15 is obtained at 750 °C. Good long-term stability of the single cell with BBCN0.15 cathode is also demonstrated. These results demonstrate that BBCNy perovskite oxides with cubic structure are very promising cathode materials for IT-SOFCs.

  12. Mechanosynthesis and mechanochemical treatment of bismuth doped vanadium phosphorus oxide catalysts for the partial oxidation of n-butane to maleic anhydride

    Institute of Scientific and Technical Information of China (English)

    Y H.Taufiq-Yap; Y C.Wong; Y Kamiya; W.J.Tang

    2008-01-01

    Three Bi-doped vanadyl pyrophosphate catalysts were prepared via dihydrate route(VPD method),which consisted of different preparation methods including mechanosvnthesis,mechanochemical treatment,and the conventional reflux method.The catalysts produced by the above three methods were characterized by x-ray diffraction(XRD),scanning electron microscopy(SEM),and temperature programmed reduction(TPR).Catalytic evaluation for the partial oxidation of n-butane to maleic anhydride (MA) was also carried out.The XRD patterns of all the Bi-doped catalysts showed the main peaks of pyrophosphate phase.Lower intensity peaks were observed for the mechanochemically treated Bi-doped catalyst(VPDBiMill)with two additional small DeakS corresponding to the presence of a small amount of V5+ phase.The TPR profiles showed that the highest amount of active oxygen species.i.e.V4+-O- pair,responsible for n-butane activation,was removed from VPDBiMill.Furthermore.from the catalytic test results.the graph of selectivity to MA as a function of the conversion of n-butane demonstrated that VPDBiMill was the most selective catalyst.This suggests that the mechanochemical treatment of vanadium phosphate catalyst(VPDBiMill)is a potential method to improve the catalytic properties for the partial oxidation of n-butane to maleic anhydride.

  13. Synthesis of zinc oxide varistors with a breakdown voltage of three volts using an intergranular glass phase in the bismuth-boron-oxide system

    International Nuclear Information System (INIS)

    Zinc oxide (ZnO) crystals joined by using an intergranular glass phase were investigated in order to develop surge filters for low-voltage applications and to clarify the current transport mechanism through the junction. The junctions having a ZnO/glass/ZnO sandwich structure were synthesized by using an interfacial glass phase of the Bi-B-O system. A highly nonlinear current-voltage curve was obtained for the ZnO/glass/ZnO junction with Co-doped ZnO single crystals, and the current through the junction at the breakdown voltage was proportional to the 30th power of the bias voltage. Dielectric measurements revealed that a double-sided depletion layer was formed at the interface, and the observed high nonlinearity was ascribed to the corresponding potential barrier formed at the interface

  14. 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.

  15. Single- and double energy N+ ion irradiated planar optical waveguides in Er: Tungsten–tellurite oxide glass and sillenite type Bismuth Germanate crystals working up to telecommunications wavelengths

    International Nuclear Information System (INIS)

    Ion implantation proved to be a universal technique for producing waveguides in most optical materials. Tellurite glasses are good hosts of rare-earth elements for the development of fibre and integrated optical amplifiers and lasers covering all the main telecommunication bands. Er3+-doped tellurite glasses are good candidates for the fabrication of broadband amplifiers in wavelength division multiplexing around 1.55 μm, as they exhibit large stimulated cross sections and broad emission bandwidth. Fabrication of channel waveguides in such a material via N+ ion implantation was reported recently. Sillenite type Bismuth Germanate (BGO) crystals are good nonlinear optical materials. Parameters of waveguide fabrication in both materials via implantation of MeV-energy N+ ions were optimized. First single-energy implantations at 3.5 MeV at various fluences were applied. Waveguide operation up to 1.5 μm was observed in both materials. Then double-energy implantations at a fixed upper energy of 3.5 MeV and lower energies between 2.5 and 3.1 MeV were performed to suppress leaky modes by increasing barrier width. Improvement of waveguide characteristics was found by m-line spectroscopy and spectroscopic ellipsometry

  16. 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

  17. 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.

  18. 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 ...

  19. Modelling of the oxide scale formation on Fe-Cr steel during exposure in liquid lead-bismuth eutectic in the 450-600 C temperature range

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, L.; Balbaud-Celerier, F. [CEA, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France)

    2011-06-15

    Previous studies showed that the oxidation of T91 (Fe-9Cr martensitic steel) in liquid Pb-Bi eutectic leads to the formation of a duplex oxide layer containing an inner Fe{sub 2.3}Cr{sub 0.7}O{sub 4} spinel layer and an upper magnetite layer. The magnetite layer is easily removed by the Pb-Bi flow when the oxygen concentration is low and the flow velocity is high. This phenomenon is not currently understood. The magnetite layer growth rate is limited by the iron diffusion in the oxide layer lattice. The Fe-Cr spinel layer grows in the nanometric cavities formed at the Fe-Cr spinel /T91 interface by the outwards diffusion of iron. Due to this mechanism the growth rate of the Fe-Cr spinel layer is linked to that of magnetite. A modelling of this mechanism is presented. The modelling is in agreement with the experimental data in the case of a high oxygen concentration. However, the calculated oxide scale thicknesses are systematically lower than the experimental values in the case of a low oxygen concentration when the iron diffusion only occurs via interstitials in the oxide scale. Consequently, the estimation of the iron diffusion coefficient, when diffusion occurs via interstitials, is not reliable. To have a better estimation of this iron diffusion coefficient in the Fe-Cr spinel, when diffusion occurs via interstitials, a fit is done using experimental data coming from the European DEMETRA project. Although this evaluation is only based on a fit on the experimental data, it permits to estimate the oxide layer growth kinetics in case of the formation of the described duplex oxide layer, for each oxygen concentration (leading to a vacancy and/or an interstitial diffusion), each temperature between 450 and 620 C and each hydrodynamic flow. This model shows that the hydrodynamic flow affects the corrosion rate only by the removal of the upper magnetite layer leading to an increase of the oxygen concentration at the spinel/magnetite interface. The oxidation mechanism

  20. 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.)

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. Optical, mechanical and TEM assessment of titania-doped Bi2V1−TiO$_{5.5−\\delta}$ bismuth vanadate oxides

    Indian Academy of Sciences (India)

    Gurbinder Kaur; Gary Pickrell; Vishal Kumar; Om Prakash Pandey; Kulvir Singh; Daniel Homa

    2014-12-01

    Optical, mechanical and structural behaviors have been studied for titania-doped Bi2V1−TiO$_{5.5−\\delta}$ which are used as electrolytes for intermediate temperature fuel cells. Parameters like band gap ($E_{g}$), Urbach energy ($E_{u}$), refractive index, hardness () and fracture strength () have been calculated as a function of dopant concentration, i.e. 0.05 ≤ ≤ 0.2. Furthermore, analysis of transmission electron microscopy (TEM) images for all the oxides was conducted along with line spectra of planes. Results are discussed in light of correlation of these optical and mechanical parameters to their structural properties. Band gap has also been correlated to the conductivity of these oxides. Good correlation has been obtained between them.

  6. 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)

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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)

  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. 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...

  18. 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.

  19. 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)

  20. 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.

  1. 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)

  2. 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

  3. 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…

  4. 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

  5. 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).

  6. 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

  7. 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

  8. 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)

  9. 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...

  10. 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.

  11. 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.

  12. 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)

  13. 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

  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. 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.

  16. 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.

  17. 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.

  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. 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

  20. 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

  1. 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.

  2. 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

  3. 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)

  4. 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

  5. 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.

  6. 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)

  7. 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

  8. 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.

  9. 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.

  10. 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)

  11. 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...

  12. 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...

  13. 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.

  14. 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).

  15. 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.

  16. 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.

  17. 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)

  18. 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...

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. Bismuth-doped ceria, Ce0.90Bi0.10O2: A selective and stable catalyst for clean hydrogen combustion

    NARCIS (Netherlands)

    J. Beckers; A.F. Lee; G. Rothenberg

    2009-01-01

    Bismuth-doped cerias are successfully applied as solid oxygen reservoirs in the oxidative dehydrogenation of propane. The lattice oxygen of the ceria is used to selectively combust hydrogen from the dehydrogenation mixture at 550 °C. This process has three key advantages: it shifts the dehydrogenati

  11. 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.

  12. 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

  13. Supercontinuum generation up to 2.5 μm in photonic crystal fiber made of lead-bismuth-galate glass

    International Nuclear Information System (INIS)

    In this paper we report on successful supercontinuum generation extending from the near to the mid-infrared region in the range 700–2500 nm in a micro-structured fiber made of lead-bismuth-galate glass and pumped in the femtosecond regime with a wavelength of 1540 nm. The flatness of 5 dB is observed in most of the registered spectrum 1000 – 2500 nm. The improved spectral and thermo-physical properties of this custom made lead-bismuth-galate glass against tellurite and commercially available heavy oxide SF-57 glasses are presented

  14. Coexistence and competition of surface diffusion and geometric shielding in the growth of 1D bismuth nanostructures and their ohmic contact

    International Nuclear Information System (INIS)

    We study the physical-vapor-deposition of 1D bismuth nanostructures. Bi nanowire elongating along [012] and/or [110] direction as well as anisotropic Bi nano-columns are physical-vapor-deposited successfully. The coexistence and competition of surface diffusion and geometric shielding are critical to their formation as well as growth mode transition among them. Since physical-vapor-deposition is a vacuum process, we make use of it to fabricate the ohmic contact to prevent the damage to the bismuth nanostructures brought by the etching to their thick surface oxide layer. (paper)

  15. 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...

  16. 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)....

  17. 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

  18. Analysis of single and binary phases in cerium doped sodium bismuth titanate -inorganic materials Na0.5Bi(0.5-x)CexTiO3

    International Nuclear Information System (INIS)

    The pure and cerium doped sodium bismuth titanate (NBT) inorganic powders were synthesized by solid-state reaction method. The presence of rhombohedral phase was observed in cerium doped NBT compounds. When x= 0.05 of cerium doped NBT is heat treated at 1200 degree centigrade, the compound forms single perovskite phase. The samples of x = 0.10 and 0.15 were heat treated up to 1350 degree centigrade, the binary phases with cerium and bismuth oxides were observed. The X-ray diffraction, Fourier transform infrared spectroscopy, reflectance spectra, differential thermal analysis and thermogravimetric analysis were used to analyze the various properties of samples. Moreover, the effects of cerium doping and calcining temperature on NBT samples were investigated. In this work, we present our recent results on the synthesis and characterization of cerium doped sodium bismuth titanate materials. (Author)

  19. New bismuth borophosphate Bi{sub 4}BPO{sub 10}: Synthesis, crystal structure, optical and band structure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Babitsky, Nicolay A.; Leshok, Darya Y.; Mikhaleva, Natalia S. [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation); Kuzubov, Aleksandr A., E-mail: alexkuzubov@gmail.com [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation); Institute of Physics SB RAS, Krasnoyarsk 660036 (Russian Federation); Zhereb, Vladimir P. [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation); Kirik, Sergei D., E-mail: kiriksd@yandex.ru [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation)

    2015-08-01

    New bismuth borophosphate Bi{sub 4}BPO{sub 10} 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 [Bi{sub 2}O{sub 2}]{sup 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 Bi{sub 4}BPO{sub 10}. The strips combining stacks are separated by flat triangle [BO{sub 3}]{sup 3−} -anions within stacks. Neighboring stacks are separated by tetrahedral [PO{sub 4}]{sup 3−}-anions and shifted relatively to each other. Bismuth atoms are placed in 5–7 vertex oxygen irregular polyhedra. Bi{sub 4}BPO{sub 10} 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 Bi{sub 4}BPO{sub 10} 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 Bi{sub 4}BPO{sub 10} was synthesized. • The crystal structure was determined by X-ray powder diffraction technique. • Bismuth-oxygen part [Bi{sub 4}O{sub 3}]{sup 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)

  20. Preparation of Carbon Nanotubes Supporting Bismuth Oxide Nanometer Particle and Its Catalysis on Thermal Decomposition of Ammonium Dinitramide%碳纳米管负载氧化铋的制备及催化二硝酰胺铵热分解的研究

    Institute of Scientific and Technical Information of China (English)

    李晓东; 杨燕; 杨荣杰

    2007-01-01

    采用微波辐射法制备了沉积于碳纳米管(CNTs)表面的氧化铋(Ri2O3)纳米粒子(Bi2O3/CNTs),用扫描电子显微镜(SEM)、光电子能谱(XPS)和X射线衍射(XRD)对制备的Bi2OO3CNTs纳米粒子进行了表征.研究了Bi2O3/CNTs纳米粒子对二硝酰胺铵(ADN)的催化热分解.结果表明,纳米Bi2O3均匀沉积在CNTs表面,平均粒径为8nm;添加3%Bi2O3/CNTs纳米粒子的ADN的初始热分解温度降低了12.8℃,热分解终止温度降低了29.3℃;NH4N(NO2)2→NH4NO3+N2O为ADN初始热分解的主导反应.%Carbon nanotubes (CNTs) supporting bismuth oxide ( Bi2O3 ) nanometer particle ( Bi2O3/CNTs) was prepared by the microwave radiation method. Bi2O3/CNTs nanometer particle was determined by means of scan electron microscopy ( SEM ), X-ray photoelectron spectroscopy ( XPS ) and X-ray diffraction (XRD). The catalytic property of Bi2O3/CNTs nanometer particle on thermal decomposition of ammonium dinitramide (AND) was investigated by TG and DSC. The results show that nanometer Bi2O3 was coated uniformly on the surface of CNTs. Average size of nanometer Bi2O3 is 8nm. Initial thermal decomposition temperature and ending thermal decomposition temperature of AND decrease 12.8℃ and 29.3℃, respectively when addition amount of Bi2O3/CNTs nanometer particle is 3%. NwH4N(NO2 )2→ NH4NO3 + N2O is dominant reaction of initial thermal decomposition of AND.

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. New complex bismuth oxides in the Bi{sub 2}O{sub 3}–NiO–Sb{sub 2}O{sub 5} system and their properties

    Energy Technology Data Exchange (ETDEWEB)

    Egorysheva, A.V., E-mail: anna_egorysheva@rambler.ru [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991 (Russian Federation); Ellert, O.G. [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991 (Russian Federation); Zubavichus, Y.V. [National Research Center “Kurchatov Institute”, Acad. Kurchatov sq., 1, Moscow 123182 (Russian Federation); Gajtko, O.M.; Efimov, N.N. [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991 (Russian Federation); Svetogorov, R.D.; Murzin, V.Yu. [National Research Center “Kurchatov Institute”, Acad. Kurchatov sq., 1, Moscow 123182 (Russian Federation)

    2015-05-15

    Phase equilibria in the Bi{sub 2}O{sub 3}–NiO–Sb{sub 2}O{sub 5} system have been investigated. The isothermal section of the system (650°) has been constructed. For the first time the existence of the pyrochlore structure solid solution, (Bi{sub 2−x}Ni{sub x})Ni{sub 2/3−y}Sb{sub 4/3+y}O{sub 7±δ}, x=0.1−0.35, y=0−0.1, and a new compound Bi{sub 3}Ni{sub 2/3}Sb{sub 7/3}O{sub 11} of KSbO{sub 3} structure type have been discovered. The structures and properties of these compounds were studied by XRD, XAFS, diffuse reflection spectroscopy and magnetic methods. Rietveld refinement of synchrotron radiation-based powder XRD data for pyrochlore sample of 38.43Bi{sub 2}O{sub 3}–33.0NiO–28.57Sb{sub 2}O{sub 5} composition and Bi{sub 3}Ni{sub 2/3}Sb{sub 7/3}O{sub 11} compound was performed. The best possible refinement of the positional parameters for both pyrochlore and Bi{sub 3}Ni{sub 2/3}Sb{sub 7/3}O{sub 11} structures was achieved for disordered models. Magnetic, diffuse reflection and an X-ray absorption spectroscopy study confirmed that in both compounds nickel ions are mainly in a 2+ oxidation state. According to magnetic data, Bi{sub 1.84}Ni{sub 0.16}(Ni{sub 0.63}Sb{sub 1.37})O{sub 7} pyrochlore and Bi{sub 3}Ni{sub 2/3}Sb{sub 7/3}O{sub 11} are overall paramagnetic in nature. - Graphical abstract: Isothermal section of the Bi{sub 2}O{sub 3}–NiO–Sb{sub 2}O{sub 5} system at 650 °C in air and variation of magnetic susceptibility and inverse susceptibility with temperature for Bi{sub 1.84}Ni{sub 0.79}Sb{sub 1.37}O{sub 7} pyrochlore. - Highlights: • We have constructed the isothermal section of the system Bi{sub 2}O{sub 3}–NiO–Sb{sub 2}O{sub 5}. • The boundaries of pyrochlore structure solid solution have been determined. • New Bi{sub 3}Ni{sub 2/3}Sb{sub 7/3}O{sub 11} compound of KSbO{sub 3} structure type have been discovered. • The structures were studied by means of synchrotron X-ray diffraction and XAFS. • Magnetic measurements

  6. 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...

  7. 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 ...

  8. 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.

  9. 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.

  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. Thin film bismuth iron oxides useful for piezoelectric devices

    Energy Technology Data Exchange (ETDEWEB)

    Zeches, Robert J.; Martin, Lane W.; Ramesh, Ramamoorthy

    2016-05-31

    The present invention provides for a composition comprising a thin film of BiFeO.sub.3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO.sub.3 thin film, and a second electrode in contact with the BiFeO.sub.3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.

  12. Thermodynamic Analysis and Reduction of Bismuth Oxide by Ethanol

    Science.gov (United States)

    Korkmaz, Fatih; Cetinkaya, Senol; Eroglu, Serafettin

    2016-08-01

    In this study, ethanol (C2H5OH) was used as an alternative reducing agent for Bi2O3 because ethanol is renewable, increasingly available, and low in toxicity. Thermodynamic analysis was performed to predict experimental conditions for Bi formation in the Bi2O3-C2H5OH-Ar system at Ar/C2H5OH molar ratio of 10.5. Ar was used as a carrier gas for ethanol. Bi2O3 reduction kinetics was investigated at 600 K to 800 K (327 °C to 527 °C) at Ar flow rate 85 sccm. Ar flow rate was also varied at 600 K and 800 K (327 °C and 527 °C) in order to clarify the mechanism controlling the process. Mass measurements and XRD analyses were carried out to determine the extent of reduction. Fractional conversion increased with time and temperature. Full reduction time decreased from ~180 minutes at 600 K (327 °C) to ~30 minutes at 700 K and 800 K (427 °C and 527 °C). The reduction process was external mass transfer limited ( Q a = 7.2 kJ/mole) above 700 K (427 °C). It was controlled by intrinsic chemical kinetics ( Q a = 54.7 kJ/mole) below 700 K (427 °C). In the mass-transport-controlled regime, the extent of reduction increased with flow rate as predicted by a mass-transport theory. Possible reaction pathways were discussed using the thermodynamic and experimental results.

  13. Thermodynamic Analysis and Reduction of Bismuth Oxide by Ethanol

    Science.gov (United States)

    Korkmaz, Fatih; Cetinkaya, Senol; Eroglu, Serafettin

    2016-05-01

    In this study, ethanol (C2H5OH) was used as an alternative reducing agent for Bi2O3 because ethanol is renewable, increasingly available, and low in toxicity. Thermodynamic analysis was performed to predict experimental conditions for Bi formation in the Bi2O3-C2H5OH-Ar system at Ar/C2H5OH molar ratio of 10.5. Ar was used as a carrier gas for ethanol. Bi2O3 reduction kinetics was investigated at 600 K to 800 K (327 °C to 527 °C) at Ar flow rate 85 sccm. Ar flow rate was also varied at 600 K and 800 K (327 °C and 527 °C) in order to clarify the mechanism controlling the process. Mass measurements and XRD analyses were carried out to determine the extent of reduction. Fractional conversion increased with time and temperature. Full reduction time decreased from ~180 minutes at 600 K (327 °C) to ~30 minutes at 700 K and 800 K (427 °C and 527 °C). The reduction process was external mass transfer limited (Q a = 7.2 kJ/mole) above 700 K (427 °C). It was controlled by intrinsic chemical kinetics (Q a = 54.7 kJ/mole) below 700 K (427 °C). In the mass-transport-controlled regime, the extent of reduction increased with flow rate as predicted by a mass-transport theory. Possible reaction pathways were discussed using the thermodynamic and experimental results.

  14. 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...

  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. 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...

  17. 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)

  18. 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)

  19. 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...

  20. 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.

  1. In situ bismuth-film electrode for square-wave anodic stripping voltammetric determination of tin in biodiesel

    International Nuclear Information System (INIS)

    Highlights: → A bismuth-film electrode for tin determination. → The sensor showed excellent performance. → High levels of tin were found in biodiesel samples. - Abstract: A bismuth-film electrode (BiFE) was applied in square-wave anodic stripping voltammetry (SWASV) in order to determine Sn (IV) in biodiesel samples. In situ simultaneous deposition of tin and bismuth at -1.2 V for 90 s was carried out in a supporting electrolyte containing 0.1 mol L-1 acetate buffer (pH 4.5) and 1.73 mmol L-1 caffeic acid as the complexing agent. A single well-defined anodic stripping peak was observed at -0.58 V for the oxidation of Sn to Sn (II), which was used as the analytical signal. The calibration curve was obtained in the concentration range of 0.17-7.83 μmol L-1 with the detection limit being 0.14 μmol L-1 (r = 0.9990). Repeatability and reproducibility for the measurement of the current peak were characterized by relative standard deviations of 3.6% and 4.1%, respectively, for a 5.0 μmol L-1 Sn (IV) solution (n = 10). The method was validated by comparing the results obtained with those provided by application of the atomic absorption spectroscopy technique.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. Review of liquid metal corrosion issues for potential containment materials for liquid lead and lead-bismuth eutectic spallation targets as a 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 liquid 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. In this paper, the oxidation rate of Nb-1Zr was studied based on the calculations of thickness loss resulting from oxidation. According to these calculations, it appeared that uncoated Nb-1Zr may be used for a 1-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 liquid lead-bismuth eutectic 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. (orig.)

  14. 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).

  15. 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...

  16. 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.

  17. 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.

  18. Selective propene oxidation on mixed metal oxide catalysts

    CERN Document Server

    James, D W

    2002-01-01

    Selective catalytic oxidation processes represent a large segment of the modern chemical industry and a major application of these is the selective partial oxidation of propene to produce acrolein. Mixed metal oxide catalysts are particularly effective in promoting this reaction, and the two primary candidates for the industrial process are based on iron antimonate and bismuth molybdate. Some debate exists in the literature regarding the operation of these materials and the roles of their catalytic components. In particular, iron antimonate catalysts containing excess antimony are known to be highly selective towards acrolein, and a variety of proposals for the enhanced selectivity of such materials have been given. The aim of this work was to provide a direct comparison between the behaviour of bismuth molybdate and iron antimonate catalysts, with additional emphasis being placed on the component single oxide phases of the latter. Studies were also extended to other antimonate-based catalysts, including coba...

  19. Direct Growth of Bismuth Film as Anode for Aqueous Rechargeable Batteries in LiOH, NaOH and KOH Electrolytes

    OpenAIRE

    Wenhua Zuo; Pan Xu; Yuanyuan Li; Jinping Liu

    2015-01-01

    As promising candidates for next-generation energy storage devices, aqueous rechargeable batteries are safer and cheaper than organic Li ion batteries. But due to the narrow voltage window of aqueous electrolytes, proper anode materials with low redox potential and high capacity are quite rare. In this work, bismuth electrode film was directly grown by a facile hydrothermal route and tested in LiOH, NaOH and KOH electrolytes. With low redox potential (reduction/oxidation potentials at ca. −0....

  20. Mode-locked bismuth-based erbium-doped fiber laser with stable and clean femtosecond pulses output

    Science.gov (United States)

    Harun, S. W.; Akbari, R.; Arof, H.; Ahmad, H.

    2011-06-01

    A passively mode-locked fiber ring laser is demonstrated using a 49 cm long bismuth oxide based erbium-doped fiber (Bi-EDF) and a fast semiconductor saturable absorber. Stable and clean short pulses are achieved because of these short and high nonlinear characteristics of the Bi-EDF. The laser operates at 1560 nm with a repetition rate of 8.3 MHz and a center wavelength of 1560 nm. The calibrated auto-correlator pulse trace of the laser shows a sech2 pulse shape, with an estimated pulse width of 340 fs.

  1. 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 ...

  2. 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.)

  3. 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).

  4. 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...

  5. 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

  6. 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

  7. 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

  8. 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.)

  9. 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...

  10. 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

  11. 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.

  12. Trace characterisation of tin-bismuth alloy by optical emission spectrography

    International Nuclear Information System (INIS)

    An emission spectrographic method has been developed for the determination of eighteen impurities in a tin-bismuth alloy sample. The metal alloy is converted to its oxide form and mixed with pure graphite in the ratio 2:1. 20mg of this mixture taken in a 1/4inch dia graphite electrode, is excited in nitrogen atmosphere using a 10 amp d.c. arc. The spectra of the samples are photographed using a 3.4M Ebert spectrograph with a 1180 grooves/mm grating. The concentration range covered are between 0.1ppm and 1000ppm for various elements and the precision of the method is found to be about 18 per cent. (author). 4 tabs., 6 figs

  13. Development of an oxygen sensor for molter 44.5% lead-55.5% bismuth alloy

    International Nuclear Information System (INIS)

    A potentiometric sensor for measuring oxygen activity in molter 44.5% lead-55.5% bismuth alloy is under development. Three parts form this sensor: an In/In2O3 reference electrode, a ZrO2/Y2O3 solid electrolyte, and a molybdenum working electrode. The oxygen partial pressure in the melt is calculated applying the Nernst equation to the potential difference measured by the sensor. The minimum oxygen partial pressure detected by this sensor is 10-40 bar. The sensor has been calibrated with the following metal/metal oxide mixtures: Pb-Bi/PbO, Pb/PbO, Sn/SnO2, and Bi/Bi2O3. Reproducible measurements of the oxygen pressure of PbO formation have been obtained. The sensor performance has been evaluated in 99.999% N2 and air (20% O2) environments

  14. Orogenic-type copper-gold-arsenic-(bismuth) mineralization at Flatschach (Eastern Alps), Austria

    Science.gov (United States)

    Raith, Johann G.; Leitner, Thomas; Paar, Werner H.

    2015-10-01

    Structurally controlled Cu-Au mineralization in the historic Flatschach mining district (Styria, Austria) occurs in a NE-SW to NNE-WSW oriented vein system as multiple steep-dipping calcite-(dolomite)-quartz veins in amphibolite facies metamorphic rocks (banded gneisses/amphibolites, orthogneisses, metagranitoids) of the poly-metamorphosed Austroalpine Silvretta-Seckau nappe. Vein formation postdated ductile deformation events and Eoalpine (Late Cretaceous) peak metamorphism but predated Early to Middle Miocene sediment deposition in the Fohnsdorf pull-apart basin; coal-bearing sediments cover the metamorphic basement plus the mineralized veins at the northern edge of the basin. Three gold-bearing ore stages consist of a stage 1 primary hydrothermal (mesothermal?) ore assemblage dominated by chalcopyrite, pyrite and arsenopyrite. Associated minor minerals include alloclasite, enargite, bornite, sphalerite, galena, bismuth and matildite. Gold in this stage is spatially associated with chalcopyrite occurring as inclusions, along re-healed micro-fractures or along grain boundaries of chalcopyrite with pyrite or arsenopyrite. Sericite-carbonate alteration is developed around the veins. Stage 2 ore minerals formed by the replacement of stage 1 sulfides and include digenite, anilite, "blue-remaining covellite" (spionkopite, yarrowite), bismuth, and the rare copper arsenides domeykite and koutekite. Gold in stage 2 is angular to rounded in shape and occurs primarily in the carbonate (calcite, Fe-dolomite) gangue and less commonly together with digenite, domeykite/koutekite and bismuth. Stage 3 is a strongly oxidized assemblage that includes hematite, cuprite, and various secondary Cu- and Fe-hydroxides and -carbonates. It formed during supergene weathering. Stage 1 and 2 gold consists mostly of electrum (gold fineness 640-860; mean = 725; n = 46), and rare near pure gold (fineness 930-940; n = 6). Gold in stage 3 is Ag-rich electrum (fineness 350-490, n = 12), and has a

  15. Mechanism of 1, 1-d2 propene oxidation over oxide catalysts

    International Nuclear Information System (INIS)

    CD2CHCH3 was oxidized over bismuth molybdate, tin-antimony mixed oxides and supported molybdenum and vanadium oxide catalysts. The deuterium retention is high ( > 90%) in the recovered propene. Percentage retentions of deuterium in the acrolein agree with literature data when bismuth molybdate is used as catalyst. On Sb-Sn-O and supported Mo and V oxides, no isotope effect is noticed for the abstraction of the second hydrogen from the olefin. The slow step of the reaction may therefore be different for the oxidation of propene on Bi-Mo-O and Sb-Sn-O. The ethanal produced by oxidation of CD2CHCH3 contains only minor amounts of deuterium, whatever the catalyst used. It is suggested that partial oxidation of propene to acrolein and C-C bond rupture are parallel reactions which involve different intermediates. Possible mechanisms adapted from organic chemistry are presented to explain these findings. 4 tables

  16. 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...

  17. 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...

  18. 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)

  19. 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...

  20. Synthesis and materials chemistry of bismuth tris-(di-i-propylcarbamate): deposition of photoactive Bi2O3 thin films.

    Science.gov (United States)

    Cosham, Samuel D; Hill, Michael S; Horley, Graeme A; Johnson, Andrew L; Jordan, Laura; Molloy, Kieran C; Stanton, David C

    2014-01-01

    The bismuth carbamate Bi(O2CNPr(i)2)3, a tetramer in the solid-state, has been synthesized and used to deposit mixtures of bismuth oxides by aerosol-assisted chemical vapor deposition (AACVD). The nature of the deposited oxide is a function of both temperature and run-time. Initially, δ-Bi2O3 is deposited, over which grows a thick layer of β-Bi2O3 nanowires, the latter having an increasing degree of preferred orientation at higher deposition temperatures. The photocatalytic activity of a thin film of δ-Bi2O3 for the degradation of methylene blue dye was found to be similar to that of a commercial TiO2 film on glass, while the film overcoated with β-Bi2O3 nanowires was less active. Exposure of Bi(O2CNPr(i)2)3 to controlled amounts of moist air affords the novel oxo-cluster Bi8(O)6(O2CNPr(i)2)12, whose structure has also been determined. PMID:24387747

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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)

  6. 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)

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.)

  13. 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)

  14. 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...

  15. 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.

  16. 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...

  17. 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

  18. 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.

  19. 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

  20. Optical and other spectroscopic studies of lead, zinc bismuth borate glasses doped with CuO

    Science.gov (United States)

    Rajyasree, Ch.; Vinaya Teja, P. Michael; Murthy, K. V. R.; Krishna Rao, D.

    2011-12-01

    10MO·20Bi2O3·(70-x)B2O3·xCuO [M=Pb, Zn] with x=0, 0.4 and 0.8 (wt%) glasses were synthesized by the melt-quenching technique and were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Physical parameters, like density, and spectroscopic studies (optical absorption, EPR, FTIR and photoluminescence) were used to understand the role of modifier oxide and CuO in the glass matrix. A red shift of the absorption band corresponds to 2B1g→2B2g transition of Cu2+ ions from P2 to Z4 samples and the increase of hyperfine splitting factor (A‖) from P2 to Z2 shows that with the integration of PbO by ZnO the electron density around copper ion is increased. It is also supported by the gradual increase in theoretical optical basicity values of ZnO mixed glasses, as compared to that of PbO mixed glass matrix. Reduced bismuth radicals are found in undoped and 0.4% CuO doped glasses of both the series. Analysis of the absorption and emission studies indicates that the concentration of luminescence centers of bismuth ions (Bi3+ ions in UV region) is decreased by the integration of ZnO as well as by increasing the dopant concentration. In lead series PbO4 and BiO3 units are increased from P2 to P4 and in zinc series BiO3 units are decreased from Z0 to Z4. The conductivity of the glass matrices is increased in both the series with the dopant of CuO.

  1. 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.

  2. 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.

  3. 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)

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Oxygen Transport in Liquid Lead Bismuth Eutectic Filled Cavity by Natural Convection

    International Nuclear Information System (INIS)

    This paper numerically analyzes the oxygen transport in an active oxygen controlled lead-bismuth eutectic (LBE) system. Corrosion in near wall areas and oxide-layer formations on container surfaces are included. Simulations are carried out on a simplified rectangle container. Different temperature boundary conditions are added to the container to induce pure natural-convection LBE flows. The strength of the flows is measured by the Rayleigh number (Ra). Three laminar cases: (a) heated from the bottom and cooled from the top of the container; (b) heated from the sidewalls and cooled from the top of the container; (c) one sidewall heated and the opposite wall cooled, and one fully turbulent case with one sidewall heated and the opposite sidewall cooled are selected and analyzed in detail. In each case, the characteristic velocity and oxygen diffusion time are estimated, the change of oxygen distribution with time are obtained, and the bulk concentration of oxygen and the efficiency of oxide layer formation on different liquid-solid interfaces are calculated. Based on the analysis, several conclusions are finally obtained. (authors)

  9. Effect of europium doping on mechanical properties of sodium bismuth titanate

    International Nuclear Information System (INIS)

    Through the process of sintering Eu is doped in sodium bismuth titanate (Na0.5Bi0.5TiO3 - also abbreviated as NBT) where Eu is supposed to replace Bi, making Na0.5Bi0.5-xEuxTiO3, 'x' is varied systematically from 0 to 0.08 and then the variation in mechanical properties are studied using the nanoindentation technique. With light doping concentration the elastic modulus (E) and hardness (H) are found to follow a linear relationship (with a negative slope) with the Eu doping concentration (x). Later, after certain concentration of doping a sudden recovery both in elastic modulus and hardness is observed. This is rationalized with the help of a proposed model which takes maximum solubility limit of Eu in NBT and phase segregation into account. Beyond a critical Eu concentration phase separation occurs which in turn leads to formation of three distinct phases of different composition, pure NBT, nano Eu saturated NBT and nano europium oxide. Europium oxide being of higher strength and elastic modulus balances the decreasing tendency in hardness and elastic modulus due to Eu doping in NBT and hence the bulk elastic modulus and hardness resemble with that of pure NBT. (author)

  10. 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...

  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. 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

  13. 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

  14. 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...

  15. 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

  16. 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....

  17. 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

  18. 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.

  19. Physicochemical properties of bismuth tungstate catalysts

    International Nuclear Information System (INIS)

    It is shown that in the Bi2O3-WO3 system there are formed the following compounds: 1. Bi2x3WO3=Bi(WO4)3 tsub(m)-890 deg C 2. Bi2O3x2WO3=Bi2W2O9 tsub(m)-910 deg C 3. Bi2O3xWO3=Bi2WO6 tsub(m)-1040 deg C 4. 3BiO3xWO3=Bi6WO12 tsub(m)-905 deg C In the 440-650 deg C range these compounds are characterized by endothermal maxima corresponding to dehydration and followed by exothermal maxima referred to the exothermal transition of some phases into other modifications. Increased catalytic activity is attributed to Bi2WO6 phase, activity and celectivity of which are bound with the presence of W-O octahedrons connected by the angles in the solid body volume, what leads to the growth of (W-O) tetrahonal-pyramidal centres on the surface. The concentration of such supposed active centres (W=O) reaches its maximum in Bi2WO6 phase, the least active phase Bi6WO12 having its maximum concentration of centres as W-O-W. Samples of Bi2(WO4)3 and Bi2W2O9 compositions have centres of both types. Correlation between physicochemical properties and activity shows that selective oxidation stops when Bi/W > 2, that is an active structural group of (Bi2O2)2+(WO4)2- octahedron type can exist in the catalyst containing Bi up to 57%

  20. 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

  1. 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

  2. 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.

  3. 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)

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Effect of oxidation state on Bi mineral speciation in oxidized and reduced granitoids from the Uetsu region, NE Japan

    Science.gov (United States)

    Izumino, Yuya; Maruoka, Teruyuki; Nakashima, Kazuo

    2016-06-01

    The relationship between bismuth (Bi) mineral speciation and redox state in three types of granitoids from the Uetsu region, northeast Japan is investigated. Electron microprobe analysis of Bi minerals, sphalerite, Mg-Fe-bearing carbonate minerals, and muscovite, as well as sulfur isotope analysis of sulfide minerals and microthermometric study of fluid inclusions reveal that Bi mineral speciation varies according to the redox state of the granitoids. For example, native bismuth and bismuthinite are abundant and Bi sulfosalts are rare in the lowest fS2 and fO2 mineralized zones of the reduced Iwafune granite (S-type, ilmenite-series) while Bi sulfosalts (Bi3+) are abundant and trace amounts of native bismuth (Bi0) and bismuthinite are found in the highest fS2 and fO2 mineralized zones of the oxidized Wasada granodiorite (I-type, magnetite-series). Bismuthinite is a major Bi mineral, and native bismuth and Bi sulfosalts occur in only minor amounts in the mineralized zones of the Nishitagawa granodiorite (I-type, ilmenite-series), which has intermediate fS2 and fO2 to that of the Iwafune and Wasada samples. Our study indicates that Bi mineral speciation related to granitic intrusive activity is controlled by the redox state of the magmatism, such that native bismuth is typical of reducing conditions, whereas Bi sulfosalts are typical of oxidizing conditions.

  11. Phase Relations and Defect Chemistry of Bismuth Strontium Calcium Copper Oxide Superconducting Oxides at Elevated Temperature

    Science.gov (United States)

    Hong, Byungsun

    1992-01-01

    Subsolidus phase relations in the system (Bi-Sr -Ca-Cu)-O at 800^circC were investigated via powder X-ray diffraction and electron probe microanalysis of solid-state reaction products. The only truly quaternary compound detected is the superconducting phase of n = 2 in Bi_2(Sr _{rm x}Ca_ {rm 1-x})_{ rm n+1}Cu_{rm n}O_{rm y} . The n = 2 phase is compatible with eight different binary or ternary phases. Tie lines, tie triangles, and compatibility tetrahedra involving superconducting phases were determined. The cation solubility limits of the n = 2 and n = 3 superconducting phases were established along tie lines with compatible phases via EPMA on bi- (or poly -) phasic samples prepared at 860^circ C. In each case football-shaped volumes in composition space were established as the solubility limits which bordered on the nominal compositions 2212 or 2223 with the long axis parallel to the Sr-Ca side of the quaternary but also extending toward Bi and Cu. T_{rm c} variations could be correlated with variations in Sr or (Bi+Sr) content and the length of the c-axis parameter. Via in-situ high temperature (550-650 ^circC) electrical conductivity and Seebeck coefficient measurements in Bi_ {2.1}Sr_{1.9} (Ca_{rm 1-x}Y _{rm x})Cu _2O_{rm y} , a point defect model/diagram is presented which explains the variation of thermopower with composition in the system. The reference, insulating composition should be between Bi_{2.1}Sr _{1.9}Ca_ {0.2}Y_{0.8} Cu_2O_{8.45 } and Bi_{2.1}Sr _{1.9}Ca_ {0.3}Y_{0.7} Cu_2O_{8.4 }. Y-contents higher than x = 0.8 result in a second phase. A structural phase transition from pseudo -tetragonal to orthorhombic takes place at x = 0.5, and plays a major role in determining the physical properties. Oxygen transfer from the Bi-O block to the Cu-O based perovskite block is suggested at the phase boundary of x = 0.5. Jonker analysis and oxygen pressure dependence of carrier concentration confirm p-type behavior despite the change in sign of the thermopower, and reveal a density of states-mobility product approximately an order of magnitude lower than those of other cuprate superconductors.

  12. 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...

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. A superior visible light-driven photocatalyst: Europium-doped bismuth tungstate hierarchical microspheres

    International Nuclear Information System (INIS)

    Highlights: ► The Eu/Bi2WO6 hierarchical microspheres were successfully synthesized. ► The Eu doping led to the enhanced absorbance in the visible light region. ► The Eu/Bi2WO6 composites exhibited the high visible light photocatalytic activity. - Abstract: Novel visible light-driven photocatalyst europium-doped bismuth tungstate (Eu/Bi2WO6) hierarchical microspheres has been synthesized by a hydrothermal route. The obtained products were characterized by SEM, EDX, XRD, XPS and DRS technologies. Their photocatalytic activities were determined by oxidative decomposition of Rhodamine-B (RhB) in aqueous solution under visible light irradiation. The results revealed that the europium doping greatly improved the photocatalytic efficiency of Bi2WO6 microspheres. The photodegradation reactions of RhB by Eu/Bi2WO6 composites followed the first-order kinetics. The possible reasons for Eu/Bi2WO6 composites showing higher activity than pure Bi2WO6 are mainly ascribed to the enhanced absorption in the visible region and the suppressed recombination between photogenerated electrons and holes in composite samples.

  18. Effect of V2O5 on the dc conductivity of sodium bismuth borate glasses

    International Nuclear Information System (INIS)

    Transition metal doped quaternary glass system with composition 20Na2O-30Bi2O3-(50- x)B2O3-xV2O5 (where x = 0, 0.2, 0.3, 0.5, 2.0 mol%) has been prepared by normal melt-quench technique using analytical grade Na2CO3, Bi2O3, H3BO3, V2O5 chemicals. The main objective of present study is to investigate the effect of transition metal oxide on the conductivity mechanism of ternary alkali bismuth borate glasses. Density (D) and molar volume (VM) of each glass sample was calculated using Archimedes method. Differential scanning calorimetry (DSC) measurements were carried out at a heating rate of 10K/min for the determination of glass transition temperature Tg using Q10 DSC (TA Instruments). The values of dc conductivity and activation energy for conductivity and relaxation time have been calculated for all samples using sample dimensions. (author)

  19. Influence of lanthanum doping on the dielectric, ferroelectric and relaxor behaviour of barium bismuth titanate ceramics

    Science.gov (United States)

    Kumar, Sunil; Varma, K. B. R.

    2009-04-01

    Barium lanthanum bismuth titanate (Ba1-(3/2)xLaxBi4Ti4O15, x = 0-0.4) ceramics were fabricated using the powders synthesized via the solid-state reaction route. X-ray powder diffraction analysis confirmed the above compositions to be monophasic and belonged to the m = 4 member of the Aurivillius family of oxides. The effect of the partial presence of La3+ on Ba2+ sites on the microstructure, dielectric and relaxor behaviour of BaBi4Ti4O15 (BBT) ceramics was investigated. For the compositions pertaining to x = 0.3, Tm was frequency independent. Well-developed P(polarization)-E(electric field) hysteresis loops were observed at 150 °C for all the samples and the remanent polarization (2Pr) was improved from 6.3 µC cm-2 for pure BBT to 13.4 µC cm-2 for Ba0.7La0.2Bi4Ti4O15 ceramics. Dc conductivities and associated activation energies were evaluated using impedance spectroscopy.

  20. Spectroscopic properties of bismuth-germanate glasses co-doped with erbium and holmium ions

    Science.gov (United States)

    Ragin, Tomasz; Kochanowicz, Marcin; Żmojda, Jacek; Dorosz, Dominik

    2014-05-01

    In the article an analysis of thermal and spectroscopic properties of heavy metal oxide glasses from the Bi2O3-Ga2O3- Na2O-Ge2O3 system doped with rare earth elements were presented. It has been focused on the elaboration of the glass composition in terms of low phonon energy, high transparency in the range of infrared region and high thermal stability (ΔT=160 °C) required in optical fiber technology. Fabricated glasses co-doped with Er3+/Ho3+ions under 980 nm laser diode excitation exhibit emission at 1.55 μm (Er3+: 4I 13/2 → 4I15/2) and 2.0 μm (Ho3+: 4I7 → 5I8). The emission at 2.0 μm results from the Er3+ → Ho3+energy transfer. Taking into account great thermal stability and good optical properties such as high transparency (up to 80%) or high refractive index (2.23), the fabricated bismuth-germanate glass co-doped with Er3+/Ho3+ is promising material for construction of active optical fibers operating in the range of mid-infrared.

  1. A novel tin-bismuth alloy electrode for anodic stripping voltammetric determination of zinc

    International Nuclear Information System (INIS)

    We report on a novel tin-bismuth alloy electrode (SnBiE) for the determination of trace concentrations of zinc ions by square-wave anodic stripping voltammetry without deoxygenation. The SnBiE has the advantages of easy fabrication and low cost, and does not require a pre-treatment (in terms of modification) prior to measurements. A study on the potential window of the electrode revealed a high hydrogen overvoltage though a limited anodic range due to the oxidation of tin. The effects of pH value, accumulation potential, and accumulation time were optimized with respect to the determination of trace zinc(II) at pH 5. 0. The response of the SnBiE to zinc(II) ion is linear in the 0.5-25 μM concentration range. The detection limit is 50 nM (after 60 s of accumulation). The SnBiE was applied to the determination of zinc(II) in wines and honeys, and the results were consistent with those of AAS. (author)

  2. Two Octaves Supercontinuum Generation in Lead-Bismuth Glass Based Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    Ryszard Buczynski

    2014-06-01

    Full Text Available 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. The fiber has a zero dispersion wavelength (ZDW at 1460 nm. Its dispersion is determined mainly by the first ring of holes in the cladding with a relative hole size of 0.73. Relative hole size of the remaining seven rings is 0.54, which allows single mode performance of the fiber in the infrared range and reduces attenuation of the fundamental mode. The fiber is pumped into anomalous dispersion with 150 fs pulses at 1540 nm. Observed spectrum of 700–3000 nm was generated in 2 cm of fiber with pulse energy below 4 nJ. A flatness of 5 dB was observed in 950–2500 nm range.

  3. Investigation of the oxidative ammonolysis of propylene on oxide catalysts containing molybdenum and using the response method

    International Nuclear Information System (INIS)

    The response method has been used to study the oxidative ammonolysis of propylene on MoO3 and molybdenum oxide systems containing bismuth, silicon, and phosphorous ions. The response curves obtained for ammonia, propylene, CO2, acrolein, acrylonitrile in these systems are discussed and compared with individual molybdenum trioxide. It has been shown that the modifying action of ammonia on the catalyst surfaces determines the direction of the oxidative conversion of the propylene

  4. Performance of 9% Cr steels in flowing lead-bismuth eutectic at 450 and 550 °C, and 10{sup −6} mass% dissolved oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Carsten, E-mail: carsten.schroer@kit.edu; Wedemeyer, Olaf; Novotny, Josef; Skrypnik, Aleksandr; Konys, Jürgen

    2014-12-15

    Highlights: • Accelerated oxidation follows the formation of a thin, more protective oxide scale. • Slight differences in Cr content are reflected by the oxidation rates at 450 °C. • Microstructure of the steels seems more important for oxidation at 550 °C. • Accumulation of liquid LBE at the oxide scale/steel interface may become decisive. - Abstract: Ferritic–martensitic steels with, nominally, 9 mass% chromium (Cr) were exposed to flowing lead-bismuth eutectic (LBE) in the CORRIDA loop. The experiments were performed at 450° and 550 °C, at a concentration of dissolved oxygen of the order of 10{sup −6} mass% and a flow velocity of 2 m/s. The maximum exposure time was 8000 and 20,000 h at 450° and 550 °C, respectively. Corrosion of these materials was analyzed both qualitatively and quantitatively. The steels generally show accelerated oxidation after initial formation of a thin, more protective oxide scale. At 450 °C, slight differences in Cr content are reflected by the determined oxidation rates, while, at 550 °C, the microstructure of the steels seems more important for oxidation behavior. However, processes following the accumulation of liquid LBE at the oxide scale/steel interface may, finally, become the determining factor of the overall performance.

  5. Fast synthesis of rare-earth (Pr{sup 3+}, Sm{sup 3+}, Eu{sup 3+} and Gd{sup 3+}) doped bismuth ferrite powders with enhanced magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Iorgu, A.I. [Department of Chemical Thermodynamics, “Ilie Murgulescu” Institute of Physical Chemistry, 060021 Bucharest (Romania); Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University “Politehnica” of Bucharest, 011061 Bucharest (Romania); Maxim, F., E-mail: fmaxim@icf.ro [Department of Chemical Thermodynamics, “Ilie Murgulescu” Institute of Physical Chemistry, 060021 Bucharest (Romania); Matei, C. [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University “Politehnica” of Bucharest, 011061 Bucharest (Romania); Ferreira, Liliana Pires [Centro de Física da Matéria Condensada, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Department of Physics, University of Coimbra, 3004-516 Coimbra (Portugal); Ferreira, P. [Department of Materials and Ceramics Engineering, CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Cruz, M.M. [Centro de Física da Matéria Condensada, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Berger, D., E-mail: danaberger01@yahoo.com [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University “Politehnica” of Bucharest, 011061 Bucharest (Romania)

    2015-04-25

    Highlights: • Synthesis of rare earth doped bismuth ferrite powders by combustion method. • SEM and TEM were used to investigate the morphology and size of particles. • Effect of Bi substitution with Pr, Sm, Eu and Gd on magnetic properties of powders. - Abstract: Rare-earth (Pr{sup 3+}, Sm{sup 3+}, Eu{sup 3+} and Gd{sup 3+}) doped bismuth ferrite powders were synthesized for the first time by solution combustion method, which is a fast soft chemistry route for obtaining oxide powders. The materials were investigated by X-ray diffraction, Raman spectroscopy, as well as scanning and transmission electron microscopy. A distortion from rhombohedral R3c symmetry, specific to pure bismuth ferrite, to orthorhombic symmetry was observed for all doped samples. The SEM analysis of pure and doped bismuth ferrite powders showed the formation of sintered grains, with faceted cuboids-shaped particles with different size and lower average dimension in the case of doped samples. Magnetic properties were analyzed using SQUID magnetometry, M–H hysteresis loops being measured at 10 K and 300 K. All studied pure and doped bismuth ferrite samples presented high susceptibility values for high magnetic fields indicating strong antiferromagnetic interactions, whereas the behavior at low magnetic field demonstrates the existence of ferromagnetic coupling. Compared to BiFeO{sub 3}, Bi{sub 0.9}RE{sub 0.1}FeO{sub 3} (RE = Pr, Sm, Eu and Gd) powders exhibit higher susceptibility, remanence and coercivity values, Bi{sub 0.9}Eu{sub 0.1}FeO{sub 3} sample displaying the highest remanence and coercivity at room temperature.

  6. Corrosion behavior of steels in liquid lead-bismuth with low oxygen concentrations

    International Nuclear Information System (INIS)

    Corrosion tests in pots for various steels were conducted in liquid lead-bismuth with low oxygen concentrations to elucidate corrosion behavior of steels in liquid lead-bismuth that is expected to be used for accelerator driven systems and fast reactors. The corrosion tests were performed for 3000 h under the condition of an oxygen concentration of 5x10-8 wt% at 450degC and an oxygen concentration of 3x10-9 wt% at 550degC, respectively. At 450degC, the corrosion rate of 316SS was 0.23 mm/y while it was below 0.1 mm/y for F82H, Mod.9Cr-1Mo steel, JPCA(14Cr-16Ni-2Mo), 410SS, 430SS, 2.25Cr-1Mo steel, pure iron and SX(18Cr-19Ni-5Si). Dissolution of Ni and Cr, and penetration of Pb and Bi occurred in 316SS and JPCA. Dissolution of iron and grain boundary corrosion were observed in pure iron and 2.25Cr-1Mo steel, respectively. At 550degC, the corrosion rate of 316SS reached 1.02mm/y and the corrosion rates of F82H, Mod.9Cr-1Mo steel, JPCA, 410SS, 2.25Cr-1Mo steel and pure iron were in the range between 0.1 and 1 mm/y. It was lower than 0.1 mm/y for 430SS and SX. Significant dissolution attach occurs for pure iron. Grain boundary corrosion and detachment of grains were observed in ferritic/martensitic steels. Ferritization and penetration of Pb and Bi occur over a wide range in 316SS and JPCA. It is difficult to prevent the grain boundary corrosion caused by Pb and Bi, and selective dissolution of Ni and Cr by using oxide films such as (Mn, Cr)-O and (Mn, Cr, Fe)-O formed under the condition of the low oxygen concentration at 550degC. (author)

  7. Bismuth modified physical, structural and optical properties of mid-IR transparent zinc boro-tellurite glasses

    International Nuclear Information System (INIS)

    Highlights: • Novel materials transmitting in mid-infrared spectral region. • Studied glasses may be good candidates for military and non-linear applications. • Hydrogenic excitonic model is applicable. • Transformation of TeO4 structural units into TeO3 units with increase in bismuth content. • B2O3 exists in the both BO3 trigonal and BO4 tetrahedral structural units. -- Abstract: Tellurium oxide based quaternary glasses in the system TeO2⋅B2O3⋅Bi2O3⋅ZnO have been prepared by melt quenching technique. Amorphous nature of the samples has been ascertained by X-ray Diffractogram. The values of density and molar volume increase with increase in Bi2O3 content. Theoretical calculations of crystalline volume (Vc) have also been made. The glass transition temperature (Tg) has been determined using differential scanning calorimetry (DSC) and its value is observed to decrease with increase in Bi2O3 content. IR and Raman spectra of the present glass system indicate that ZnO acts as network modifier and exists in ZnO4 units. TeO2 exists as TeO3, TeO4, and TeO6 structural units and the number of TeO4 groups decreases with increase in bismuth content except for the glass sample with x = 5, which shows maximum number of TeO4 structural units among all other studied glass samples and transformation of some of TeO4 structural units into TeO3 structural units is observed with increase in bismuth content. Bismuth plays the role of network modifier with BiO6 octahedral structural units for glass samples with x = 5, 10, and 15, whereas, exists in network forming BiO3 pyramidal structural units for glass sample with x = 20. B2O3 exists in the form of BO3 trigonal and BO4 tetrahedral structural units. The transmittance of the present glasses is observed to be very high (up to 95%) in the spectral range (λ = 2.5–6.5 μm) which is of great technological importance. The percentage value of transmittance increases with increase in Bi concentration. The Hydrogenic

  8. Understanding the Chemistry of Uncommon Americium Oxidation States for Application to Actinide/Lanthanide Separations

    Energy Technology Data Exchange (ETDEWEB)

    Leigh Martin; Bruce J. Mincher; Nicholas C. Schmitt

    2007-09-01

    A spectroscopic study of the stability of Am(V) and Am(VI) produced by oxidizing Am(III) with sodium bismuthate is presented, varying the initial americium concentration, temperature and length of the oxidation was seen to have profound effects on the resultant solutions.

  9. 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.

  10. 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

  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. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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...

  4. 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

  5. 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...

  6. 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...

  7. 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

  8. 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...

  9. 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)

  10. 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.

  11. 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.

  12. 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).

  13. Conceptual Neutronic Design of a Lead-Bismuth-Cooled Actinide Burning Reactor

    International Nuclear Information System (INIS)

    A conceptual design of a lead-bismuth-eutectic (LBE)-cooled actinide burner core with innovative streaming fuel assemblies (FAs) is described. The 1800-MW(thermal) core employs metallic, fertile-free fuel where the transuranics (plutonium plus minor actinides) are dispersed in a zirconium matrix. The core contains 157 streaming FAs that enhance neutron streaming by employing gas-filled, sealed streaming tubes at the FA periphery and center. The large reactivity excess at the beginning of life is compensated for by a system of double-entry control rods. The arrangement of top-entry and bottom-entry control rods in a staggered pattern allows the achievement of a very uniform axial power profile and a small reactivity change from control rod driveline expansion. The reactor can operate with an 18- to 24-month cycle length.Safety is provided through negative reactivity coefficients and tight neutronic coupling. The void coefficient is negative for a partially as well as a fully voided core. The effective delayed neutron fraction is 25% less than that of typical oxide-fueled fast reactors, making the requirements on reactor control performance more demanding. The Doppler coefficient is negative with a magnitude appreciably lower than the typical values of oxide fuels in sodium-cooled reactors, but comparable to the values observed in integral fast reactor (IFR) cores with metallic U-Pu-Zr fuels. The fuel thermal expansion coefficient is also negative, having a magnitude approximately equal to the Doppler coefficient. In terms of the transuranic destruction rate per MW(thermal) per effective full-power year, the design is comparable to accelerator-driven systems (ADSs). Long-lived fission products also can be transmuted, albeit at lower incineration efficiency than in ADSs

  14. 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.

  15. 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.

  16. Effect of bismuth and silver on the corrosion behavior of Sn-9Zn alloy in NaCl 3 wt.% solution

    International Nuclear Information System (INIS)

    Highlights: → Sn-9Zn-xAg-yBi as alternative for Sn-Pb solder. → Effect of silver (Ag) and bismuth (Bi) on the corrosion resistance of Sn-9Zn alloy in NaCl 3 wt%. → Bi and Ag lead to the increase of corrosion rate. → EDS and XRD analyses confirmed the oxide of zinc (ZnO and Zn5(OH)8Cl2H2O) as the major corrosion product. - Abstract: The effect of silver (Ag) and bismuth (Bi) on the corrosion resistance of Sn-9Zn alloy in NaCl 3 wt.% solution was investigated using electrochemical techniques. The results showed that the addition of Bi and Ag lead to the increase of corrosion rate and the corrosion potential Ecorr is shifted towards less noble values. After immersion, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive of spectroscopy (EDS) analysis of the corroded alloy surface revealed the nature of corrosion products. EDS and XRD analyses confirmed the oxide of zinc (ZnO and Zn5(OH)8Cl2H2O) as the major corrosion product formed on the outer surface of in the tested three solder alloys.

  17. Influence of bismuth on the structure and activity of Pt and Pd nanocatalysts for the direct electrooxidation of NaBH{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, Mario; Baranton, Steve [Laboratoire de Catalyse en Chimie Organique, Equipe Electrocatalyse, UMR 6503 CNRS, 40 avenue du recteur Pineau, F-86022 Poitiers Cedex (France); Coutanceau, Christophe, E-mail: christophe.coutanceau@univ-poitiers.f [Laboratoire de Catalyse en Chimie Organique, Equipe Electrocatalyse, UMR 6503 CNRS, 40 avenue du recteur Pineau, F-86022 Poitiers Cedex (France)

    2010-12-15

    In the past few years, borohydrides have gathered a lot of attention as an energy carrier for fuel cell application. Numerous investigations on both hydrogen generation and direct oxidation of NaBH{sub 4} have been published. Nonetheless, in our knowledge, only a few catalysts are capable to completely perform the direct oxidation of NaBH{sub 4} at low potentials without hydrogen evolution. In this work, carbon supported Pd{sub 1-x}Bi{sub x}/C and Pt{sub 1-x}Bi{sub x}/C nanocatalysts were synthesized by a 'water in oil' microemulsion method. The influence of surface modifications of Pt and Pd by Bi on the electrooxidation of sodium borohydride in alkaline media was evaluated. Physical and electrochemical methods were applied to characterize the structure and surface of the synthesized catalysts. It was verified that bismuth is present at the surface of the bimetallic catalysts and that hydrogen adsorption/desorption reactions are strongly limited on Pt and Pd surfaces with high bismuth coverage. Although the onset potential for NaBH{sub 4} oxidation on Pd{sub x}Bi{sub 1-x}/C catalysts is ca. 0.2 V higher than that for Pd/C, the presence of bismuth on palladium surface influences the reaction mechanism, limiting hydrogen evolution and oxidation in the case of Pd{sub 0.8}Bi{sub 0.2} catalyst. On Pt{sub 0.9}Bi{sub 0.1} catalyst the onset potential remains unchanged comparing to Pt/C and negligible hydrogen evolution was observed in the whole potential range where the catalyst is active. The number of exchanged electrons was calculated using the Koutecky-Levich equation and it was found that for Pt{sub 0.9}Bi{sub 0.1} catalyst, ca. 8 electrons are exchanged per BH{sub 4}{sup -} ion at low potentials. The presented results are remarkable evidencing that NaBH{sub 4} can be directly oxidized at low potentials with high energy efficiency.

  18. 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

  19. 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...

  20. Analysis of single and binary phases in cerium doped sodium bismuth titanate -inorganic materials Na{sub 0}.5Bi{sub (}0.5-x)Ce{sub x}TiO{sub 3}; Estudio de fases simples y binarias en BNT puro y dopado con cerio Na{sub 0},5Bi{sub (}0,5-x)Ce{sub x}TiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Supriya, S.; Dos Santos-Garcia, A. J.; Frutos, J. de; Fernandez-Martinez, F.

    2015-07-01

    The pure and cerium doped sodium bismuth titanate (NBT) inorganic powders were synthesized by solid-state reaction method. The presence of rhombohedral phase was observed in cerium doped NBT compounds. When x= 0.05 of cerium doped NBT is heat treated at 1200 degree centigrade, the compound forms single perovskite phase. The samples of x = 0.10 and 0.15 were heat treated up to 1350 degree centigrade, the binary phases with cerium and bismuth oxides were observed. The X-ray diffraction, Fourier transform infrared spectroscopy, reflectance spectra, differential thermal analysis and thermogravimetric analysis were used to analyze the various properties of samples. Moreover, the effects of cerium doping and calcining temperature on NBT samples were investigated. In this work, we present our recent results on the synthesis and characterization of cerium doped sodium bismuth titanate materials. (Author)

  1. Influence of lanthanum doping on the dielectric, ferroelectric and relaxor behaviour of barium bismuth titanate ceramics

    International Nuclear Information System (INIS)

    Barium lanthanum bismuth titanate (Ba1-(3/2)xLaxBi4Ti4O15, x = 0-0.4) ceramics were fabricated using the powders synthesized via the solid-state reaction route. X-ray powder diffraction analysis confirmed the above compositions to be monophasic and belonged to the m = 4 member of the Aurivillius family of oxides. The effect of the partial presence of La3+ on Ba2+ sites on the microstructure, dielectric and relaxor behaviour of BaBi4Ti4O15 (BBT) ceramics was investigated. For the compositions pertaining to x ≤ 0.1, the dielectric constant at both room temperature and in the vicinity of the temperature of the dielectric maximum (Tm) of the parent phase (BBT) increased significantly with an increase in x while Tm remained almost constant. Tm shifted towards lower temperatures accompanied by a decrease in the magnitude of the dielectric maximum (εm) with an increase in the lanthanum content (0.1 m was found to decrease with an increase in lanthanum doping, and for compositions corresponding to x ≥ 0.3, Tm was frequency independent. Well-developed P(polarization)-E(electric field) hysteresis loops were observed at 150 0C for all the samples and the remanent polarization (2Pr) was improved from 6.3 μC cm-2 for pure BBT to 13.4 μC cm-2 for Ba0.7La0.2Bi4Ti4O15 ceramics. Dc conductivities and associated activation energies were evaluated using impedance spectroscopy.

  2. Mixed-Ligand Approach to Changing the Metal Ratio in Bismuth-Transition Metal Heterometallic Precursors.

    Science.gov (United States)

    Lieberman, Craig M; Wei, Zheng; Filatov, Alexander S; Dikarev, Evgeny V

    2016-04-18

    A new series of heteroleptic bismuth-transition metal β-diketonates [BiM(hfac)3(thd)2] (M = Mn (1), Co (2), and Ni (3); hfac = hexafluoroacetylacetonate, thd = tetramethylheptanedionate) with Bi:M = 1:1 ratio have been synthesized by stoichiometric reactions between homometallic reagents [Bi(III)(hfac)3] and [M(II)(thd)2]. On the basis of analysis of the metal-ligand interactions in heterometallic structures, the title compounds were formulated as ion-pair {[Bi(III)(thd)2](+)[M(II)(hfac)3](-)} complexes. The direct reaction between homometallic reagents proceeds with a full ligand exchange between main group and transition metal centers, yielding dinuclear heterometallic molecules. In heteroleptic molecules 1-3, the Lewis acidic, coordinatively unsaturated Bi(III) centers are chelated by two bulky, electron-donating thd ligands and maintain bridging interactions with three oxygen atoms of small, electron-withdrawing hfac groups that chelate the neighboring divalent transition metals. Application of the mixed-ligand approach allows one to change the connectivity pattern within the heterometallic assembly and to isolate highly volatile precursors with the proper Bi:M = 1:1 ratio. The mixed-ligand approach employed in this work opens broad opportunities for the synthesis of heterometallic (main group-transition metal) molecular precursors with specific M:M' ratio in the case when homoleptic counterparts either do not exist or afford products with an incorrect metal:metal ratio for the target materials. Heteroleptic complexes obtained in the course of this study represent prospective single-source precursors for the low-temperature preparation of multiferroic perovskite-type oxides. PMID:27054922

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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)

  15. 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

  16. 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.

  17. 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

  18. 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”.

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. Leaching process of anode slime with high silver and bismuth%高银铋阳极泥浸出工艺研究

    Institute of Scientific and Technical Information of China (English)

    何静; 郭瑞; 蓝明艳; 王灿; 鲁君乐

    2013-01-01

      某厂高银铋阳极泥产粗铋及综合回收有价金属,工艺采用两段浸出法处理此阳极泥,第1段硫酸浸出铜,第2段盐酸浸出铋.分别考察了浸出温度、时间、液固比(质量比)、酸量及氧化剂用量对浸出率的影响.铜的浸出率(液计)96%以上,铋、锑的浸出率(渣计)均在99%以上,铅、银富集于第2段浸出渣中,铅、银渣含Pb 26.63%左右,含Ag 36.77%左右,铅和银的直收率高,分别为97.82%及98.93%.浸出过程为串级联动循环浸出,洗酸洗水均返回下一次浸出,大大地减少了废水量,环境友好.%In order to produce crude bismuth and comprehensively recovery of valuable metals from anode slime with high silver and bismuth ,The process is Two-stage leaching. The first stage is leaching of copper with sulfuric acid and the second stage is leaching of bismuth with hydrochloric acid. Studied on the relationship between the Leaching rate and the leaching temperature, time, ratio of liquid to solid(Quality), dosage of acid and oxidant.The leaching rate (Liquid) of copper is above 96%,and The leaching rate (Slag) of bismuth and antimony are all above 99 %.The lead and silver are enriched in the second stage leaching slag, which containing Pb about 26.63%,Ag about 36.77 %,the direct yield of Pb and Ag are 97.82 % and 98.93 %respectively.The process is cycle leaching, washing water and washing acid are returned to the next leaching, which greatly reduced the amount of wastewater, and good for environmental protection.

  7. Stress corrosion behavior of T91 steel in static lead-bismuth eutectic at 480 °C

    Science.gov (United States)

    Liu, Jing; Jiang, Zhizhong; Tian, Shujian; Huang, Qunying; Liu, Yuejing

    2016-01-01

    The corrosion behavior of stressed C-rings made of martensitic steel T91 was investigated through constant strain tests. The specimens with different initial hoop stresses (0 MPa, 150 MPa and 300 MPa) were exposed to static oxygen saturated lead-bismuth eutectic (LBE) at 480 °C for 500 h, 1000 h and 1500 h, respectively. The results showed that no crack was found on the outer surface of all the specimens after exposure; and the microscopic analysis showed that the specimens were covered with two oxide layers, which included a magnetite outer layer and a Fe-Cr spinel inner layer. The transformation of spinel into magnetite at the spinel/magnetite interface might be promoted by stress, which increased the difference between the thickness of the inner and outer layers. Moreover, the steel loss was estimated by the observed oxide layers; it increased rapidly when the stress was above 300 MPa, and was about 1.3 times of when the stress was absent.

  8. 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

  9. 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.

  10. Synthesis, characterization and oxide ionic conductivity of -type solid solution in bismuth oxide doped with ytterbium oxide binary system

    Indian Academy of Sciences (India)

    Esra Öztürk; Nilgun Ozpozan Kalaycioglu; Serkan Dayan; Handan Ozlu

    2013-06-01

    In this study, after doping Yb2O3 substance to -Bi2O3 substance in the range of 1% ≤ ≤ 8% in a series of different mole ratios, heat treatment was performed by applying a cascade temperature rise in the range of 700–790 °C for 48 and 120 h and new phases were obtained in the (Bi2O3)1− (Yb2O3) system. After 48 h of heat treatment at 750 °C and 120 h of heat treatment at 790 °C, mixtures containing 1–8% mole Yb2O3 formed a tetragonal phase. With the help of XRD, crystal systems and lattice parameters of the solid solutions were obtained and their characterization was carried out. Thermal measurements were made by using a simultaneous DTA/TG system. The total conductivity (T) in the -Bi2O3 doped with Yb2O3 system was measured using four-probe d.c. method.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. 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%

  16. 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%.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. Higher Americium Oxidation State Research Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-18

    The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

  8. Kinetics of the Oxidation of Bismuthinite in Oxygen-Nitrogen Atmospheres

    Science.gov (United States)

    Padilla, Rafael; Villa, Ricardo; Ruiz, Maria C.; Reddy, Ramana G.

    2011-10-01

    Bismuth is present in copper concentrates mainly as the mineral bismuthinite (Bi2S3). In some cases of smelting of concentrates, a substantial amount of bismuth can lead to contaminated copper cathodes. Thus, understanding the behavior of Bi2S3 at high temperatures is crucial to assessing the potential of bismuth removal in the pyrometallurgical process. Therefore, the oxidation of bismuthinite in mixtures of oxygen-nitrogen atmospheres was investigated using a thermogravimetric analysis technique. The results indicate that the oxidation process occurs through the following consecutive reactions: {{First stage: }}{{Bi}}_{ 2} {{S}}_{ 3} ( {{s,l}} ) + 3{{O}}2 ( {{g}} ) = 2{{Bi}}( {{l}} ) + 3{{SO}}_{ 2} ( {{g}} ) {{Second stage: }}2{{Bi}}( {{l}} ) + 3/2{{O}}2 ( {{g}} ) = {{Bi}}2 {{O}}3 ( {{s,l}} ) The kinetics of the oxidation of bismuthinite (first stage) was studied, and the model ln(1 - X) = -kapp t describes the kinetics of this reaction well. The bismuthinite oxidation dependence on oxygen partial pressure was of 0.9 order, and the intrinsic kinetic constants were obtained in the temperature range of 873 K to 1273 K (600 °C to 1000 °C), which were used to determine the activation energy of 91 kJ/mol. The results indicate that the oxidation of bismuthinite is a process controlled by chemical reactions. From this study, it can be concluded that the removal of bismuth from the Bi2S3-containing concentrates through a mechanism involving gaseous bismuth compounds is not feasible during an oxidizing roasting and/or smelting of concentrates containing Bi2S3.

  9. 从铅阳极泥中湿法提取铋、锑试验研究%Extraction of Bismuth and Antimony by Wet-process From Lead Anode Mud

    Institute of Scientific and Technical Information of China (English)

    贾辉; 王兴; 崔家友; 侯绍彬; 林浩

    2014-01-01

    Leaching of bismuth and antimony from lead anode mud oxidized at high temperature using hydrochloric acid as leaching agent ,ferric chloride as oxidant ,sodium chloride to provide more chloride ions was investigated .The effects of oxidizing temperature of lead anode mud ,hydrochloric acid concentration ,leaching temperature ,reaction time ,ratio between liquid volume and solid mass ,the amount of ferric chloride and sodium chloride on leaching of bismuth and antimony were examined . The experimental results show that the pretreatment for lead anode slime has a greater influence on the leaching of bismuth and antimony .Under the conditions of hydrochloric acid concentration of 5 mol/L ,ratio betw een liquid volume and solid mass of 5∶1 ,leaching temperature of 80 ℃ ,reaction time of 3 h ,ferric chloride concentration of 10 g/L ,sodium chloride concentration of 45 g/L ,the leaching of bismuth and antimony reach 99 .44% and 99 .69% respectively for the lead anode mud oxidized at 200 ℃ and through 200 mesh sieve .%介绍了以三氯化铁作氧化剂,氯化钠提供氯离子,用盐酸从高温氧化后的铅阳极泥中浸出铋、锑,考察了氧化温度、盐酸浓度、浸出温度、反应时间、液固体积质量比、三氯化铁和氯化钠用量对铋、锑浸出率的影响。试验结果表明:铅阳极泥预处理对铋、锑浸出率影响较大;铅阳极泥粉磨过200目筛,在氧化温度220℃、盐酸浓度5 mol/L、液固体积质量比5∶1、反应温度80℃、反应时间3 h、三氯化铁质量浓度10 g/L、氯化钠质量浓度45 g/L条件下,铋、锑浸出率分别为99.44%和99.69%,浸出效果较好。

  10. 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...

  11. 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

  12. 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.

  13. 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

  14. 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...

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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...

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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).

  7. 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

  8. 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%.

  9. 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.

  10. 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...

  11. 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

  12. 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).

  13. 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

  14. 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

  15. 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

  16. Synthesis and characterization of UV-treated Fe-doped bismuth lanthanum titanate-doped TiO2 layers in dye-sensitized solar cells

    Science.gov (United States)

    Song, Myoung Geun; Bark, Chung Wung

    2016-06-01

    Dye-sensitized solar cells (DSSCs) based on titanium dioxide (TiO2) have been extensively studied because they constitute promising low-cost alternatives to their conventional semiconductor-based counterparts. However, much of the effort aimed at achieving high conversion efficiencies has focused on dye and liquid electrolytes. In this work, we report the photovoltaic characteristics of DSSCs fabricated by mixing TiO2 with Fe-doped bismuth lanthanum titanate (Fe-BLT). These nanosized Fe-BLT powders were prepared by using a high-energy ball-milling process. In addition, we used a UV radiation-ozone (UV-O3) treatment to change the surface wettability of TiO2 from hydrophobic to hydrophilic and thereby prevented the easy separation of the Fe-BLT-mixed TiO2 from the fluorine-doped tin-oxide (FTO) coating glass.

  17. Synthesis, characterization and enhanced thermoelectric performance of structurally ordered cable-like novel polyaniline-bismuth telluride nanocomposite

    Science.gov (United States)

    Chatterjee, Krishanu; Mitra, Mousumi; Kargupta, Kajari; Ganguly, Saibal; Banerjee, Dipali

    2013-05-01

    Bismuth telluride (Bi2Te3) nanorods and polyaniline (PANI) nanoparticles have been synthesized by employing solvothermal and chemical oxidative processes, respectively. Nanocomposites, comprising structurally ordered PANI preferentially grown along the surface of a Bi2Te3 nanorods template, are synthesized using in situ polymerization. X-ray powder diffraction, UV-vis and Raman spectral analysis confirm the highly ordered chain structure of PANI on Bi2Te3 nanorods, leading to a higher extent of doping, higher chain mobility and enhancement of the thermoelectric performance. Above 380 K, the PANI-Bi2Te3 nanocomposite with a core-shell/cable-like structure exhibits a higher thermoelectric power factor than either pure PANI or Bi2Te3. At room temperature the thermal conductivity of the composite is lower than that of its pure constituents, due to selective phonon scattering by the nanointerfaces designed in the PANI-Bi2Te3 nanocable structures. The figure of merit of the nanocomposite at room temperature is comparable to the values reported in the literature for bulk polymer-based composite thermoelectric materials.

  18. Simulation considerations in lead-bismuth transmutation loops: corrosion concentration, velocity and temperature profiles of LBE loops

    International Nuclear Information System (INIS)

    Computer simulations using STAR-CD code are being implemented to describe and predict the behavior of corrosion products inside a typical lead-bismuth transmutation flow loop. A CFD code coupled to a surface reaction chemistry code CHEMKIN will be eventually employed to provide a predictive capability to the behavior of such a loop in the presence of various oxygen bulk concentrations on the surface chemistry. Work is presently concentrated on simulating flows in loops with certain imposed wall temperature conditions and a temperature dependent wall concentration for iron oxide. The results show details of the concentration profiles in the bulk flow along with velocity and temperature profiles. Another attempt is also proceeding to look at these variables distribution in various components and fittings in the loop. As an example some results are presented of a 2-D flow in a sudden expansion of the LBE as well. The results in the loop are compared with some previous obtained analytical results for the identical problem and show reasonable closeness between the two methods. The 2-D sudden expansion runs also show similar trends to experimental values obtained by previous researchers. The results are encouraging and would point to the need of performing the more complex 3-D simulations in these fittings as well as other geometrically varied shapes found in the loop

  19. Efficient water-splitting device based on a bismuth vanadate photoanode and thin-film silicon solar cells.

    Science.gov (United States)

    Han, Lihao; Abdi, Fatwa F; van de Krol, Roel; Liu, Rui; Huang, Zhuangqun; Lewerenz, Hans-Joachim; Dam, Bernard; Zeman, Miro; Smets, Arno H M

    2014-10-01

    A hybrid photovoltaic/photoelectrochemical (PV/PEC) water-splitting device with a benchmark solar-to-hydrogen conversion efficiency of 5.2% under simulated air mass (AM) 1.5 illumination is reported. This cell consists of a gradient-doped tungsten-bismuth vanadate (W:BiVO4 ) photoanode and a thin-film silicon solar cell. The improvement with respect to an earlier cell that also used gradient-doped W:BiVO4 has been achieved by simultaneously introducing a textured substrate to enhance light trapping in the BiVO4 photoanode and further optimization of the W gradient doping profile in the photoanode. Various PV cells have been studied in combination with this BiVO4 photoanode, such as an amorphous silicon (a-Si:H) single junction, an a-Si:H/a-Si:H double junction, and an a-Si:H/nanocrystalline silicon (nc-Si:H) micromorph junction. The highest conversion efficiency, which is also the record efficiency for metal oxide based water-splitting devices, is reached for a tandem system consisting of the optimized W:BiVO4 photoanode and the micromorph (a-Si:H/nc-Si:H) cell. This record efficiency is attributed to the increased performance of the BiVO4 photoanode, which is the limiting factor in this hybrid PEC/PV device, as well as better spectral matching between BiVO4 and the nc-Si:H cell. PMID:25138735

  20. Ultrasonic and optical properties and emission of Er3+/Yb3+ doped lead bismuth-germanate glass affected by Bi+/Bi2+ ions

    International Nuclear Information System (INIS)

    Rare earth doped heavy metal oxide glasses instead of silicates are interesting research area, especially, for their potential application in optoelectronics. In addition, contribution of different bismuth ionization states in photoluminescence spectra is still an open question. In this research work, [GeO2]60–[PbO]40−x–[½Bi2O3]x, glass hosts where x=0, 10, 20, 30, and 40 mol% and 0.5 wt% of Er2O3 and 1.5 wt% of Yb2O3 as doping agents were studied. The activated heavy metal oxide glass samples were synthesized by conventional melt quenching method. The optical properties were studied by refractive index, UV–visible absorption and photoluminescence (PL) measurements, and explained in terms of the Judd–Ofelt theory. The glass was also studied by ultrasonic measurements and showed that the velocity of sound is lower in Pb-rich samples. Our results also, showed that emission intensities are higher in host glasses with lower sound velocities, which is attributed mainly to multiphonon relaxation. In addition, variation of PL intensities with increase of bismuth composition was related not only to the variation of Debye temperature and refractive index; but also, to the increase of Ω6 in Pb-rich samples due to the ligand field and existence of Bi2+/Bi+ ions in Bi-rich glasses. -- Highlights: • The ultrasonic measurements on glass showed that the velocity of sound is higher in Pb-rich samples. • The PL intensity is higher in glasses with lower Debye temperature and higher refractive index. • The PL intensity is related to the multiphonon relaxation, ligand field (Ω6) and Bi2+/Bi+ ions

  1. Part I: A comparative study of bismuth-modified screen-printed electrodes for lead detection

    Energy Technology Data Exchange (ETDEWEB)

    Calvo Quintana, Josefina [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); Consorzio Interuniversitario Biostrutture e Biosistemi ' INBB' , Viale Medaglie d' Oro 305, 00136 Rome (Italy); Arduini, Fabiana, E-mail: fabiana.arduini@uniroma2.it [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); Consorzio Interuniversitario Biostrutture e Biosistemi ' INBB' , Viale Medaglie d' Oro 305, 00136 Rome (Italy); Amine, Aziz [Faculte des Sciences et Techniques, B.P.146, Mohammadia, Morocco, Rome (Italy); Punzo, Francesco; Destri, Giovanni Li [LAMSUN and CSGI at Dipartimento di Scienze Chimiche, Universita degli Studi di Catania, Viale A. Doria 6, 95125, Catania (Italy); Bianchini, Chiara [Dipartimento di Ingegneria Chimica Materiali Ambienti dell' Universita degli Studi ' La Sapienza' di Roma, via Eudossiana 18, 00184 Rome (Italy); Zane, Daniela; Curulli, Antonella [Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR,via del Castro Laurenziano 7, 00161 Rome (Italy); Palleschi, Giuseppe; Moscone, Danila [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); Consorzio Interuniversitario Biostrutture e Biosistemi ' INBB' , Viale Medaglie d' Oro 305, 00136 Rome (Italy)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer 'In situ' Bi-SPE has higher sensitivity than 'ex situ' Bi-SPE and 'Bi{sub 2}O{sub 3} bulk' SPE. Black-Right-Pointing-Pointer Electrochemical treatment of SPE before Bi film deposition allows one to reach low LOD. Black-Right-Pointing-Pointer The linearity of Pb{sup 2+} in HCl and HClO{sub 4} is greatly affected by the ionic strength. Black-Right-Pointing-Pointer Satisfactory values of the recovery percentage were obtained in drinking water samples. - Abstract: Lead determination was carried out in the frame of the European Union project Biocop ( (www.biocop.org)) using a bismuth-modified screen-printed electrode (Bi-SPE) and the stripping analysis technique. In order to choose a sensitive Bi-SPE for lead detection, an analytical comparative study of electrodes modified by Bi using 'in situ', 'ex situ' and 'bulk' procedures was carried out. On the basis of the results obtained, we confirmed that the 'in situ' procedure resulted in better analytical performances with respect to not only 'ex situ' but also to 'Bi{sub 2}O{sub 3} bulk' modified electrodes, allowing for a linear range of lead ion concentration from 0.5 to 100 {mu}g L{sup -1} and a detection limit of 0.15 {mu}g L{sup -1}. We demonstrated that, before the Bi film deposition, an oxidative electrochemical pre-treatment of the working electrode could be useful because it eliminates traces of lead in the graphite-ink, as shown with stripping measurements. It also improves the electrochemical performance of the electrodes as demonstrated with Electrochemical Impedance Spectroscopy (EIS) measurements. The influence of different analytical parameters, such as the electrolyte solution composition (acetate buffer, chloridric acid, nitric acid, perchloric acid) and the ionic strength was investigated in order to evaluate how to treat the sample before the analysis. The morphology of

  2. Structural, absorption and fluorescence spectral analysis of Pr3+ ions doped zinc bismuth borate glasses

    International Nuclear Information System (INIS)

    Highlights: → 20ZnO.xBi2O3.(79.5-x)B2O3.0.5Pr6O11 (15 ≤ x ≤ 35) glasses were prepared by melt quench technique. → The Judd-Ofelt parameters Ωλ (λ = 2, 4, 6) and other radiative properties like radiative transition probability, radiative life time, branching ratio and stimulated emission cross-section of the prepared glasses have been calculated. → The branching ratio for 3P0 → 3F2 transition of Pr3+ doped glasses is 42% and the predicted spontaneous radiative transition probability rates are fairly high. - Abstract: Glasses having composition 20ZnO.xBi2O3.(79.5 - x)B2O3.0.5Pr6O11 were prepared by melt quench technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The spectroscopic properties of these glasses were investigated by recording optical absorption and fluorescence spectra. The structural investigations of the glasses were carried out by recording the IR spectra. The optical properties of Pr3+ ions doped zinc borate glasses with varying concentration of bismuth oxide have been studied. The Judd-Ofelt intensity parameters Ωλ (λ = 2, 4, 6) and other radiative properties like radiative transition probability, radiative life time, branching ratio and stimulated emission cross-section of the prepared glasses have been calculated. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in their rare earth oxygen (RE-O) covalency. The branching ratio for 3P0 → 3F2 transition is 42% and the predicted spontaneous radiative transition probability rates are fairly high (14,347-14,607 s-1). This is beneficial for lasing emission. The stimulated emission cross-section for all the emission bands has been calculated.

  3. Investigations into Recycling Zinc from Used Metal Oxide Varistors via pH Selective Leaching: Characterization, Leaching, and Residue Analysis

    OpenAIRE

    Toni Gutknecht; Anna Gustafsson; Christer Forsgren; Christian Ekberg; Britt-Marie Steenari

    2015-01-01

    Metal oxide varistors (MOVs) are a type of resistor with significantly nonlinear current-voltage characteristics commonly used in power lines to protect against overvoltages. If a proper recycling plan is developed MOVs can be an excellent source of secondary zinc because they contain over 90 weight percent zinc oxide. The oxides of antimony, bismuth, and to a lesser degree cobalt, manganese, and nickel are also present in varistors. Characterization of the MOV showed that cobalt, nickel, and...

  4. 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

  5. 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...

  6. 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...

  7. 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...

  8. 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)

  9. Kinetic characterization of barium titanate-bismuth oxide-vanadium pentoxide glasses

    Science.gov (United States)

    Al-Syadi, Aref M.; Yousef, El Sayed; El-Desoky, M. M.; Al-Assiri, M. S.

    2014-06-01

    The glasses with the composition (80 - x)V2O5·20Bi2O3·xBaTiO3 with x = 2.5, 5, 7.5 and 10 mol % were prepared by a melting technique. The crystallization behavior and the microstructure of the glasses were investigated by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mean value of the activation energy of structural relaxation () decreased from 395 ± 3 to 369 ± 1.83 kJ/mol when BaTiO3 increased from 2.5 to 10 mol %. The activation energies obtained by the methods Kissinger and Ozawa were in the range from 213 ± 0.65 to 256 ± 1.23 kJ/mol. Different analysis methods were used to estimate the Avrami exponents. Their values range from 4.26 ± 0.6 to 2.62 ± 0.11 for the exothermic peak of the prepared glasses. Moreover, synthesized glasses-ceramic containing BaTi4O9 and Ba3TiV4O15 were estimated by using XRD.

  10. Selective oxidation of propylene to acrolein by hydrothermally synthesized bismuth molybdates

    DEFF Research Database (Denmark)

    Schuh, Kirsten; Kleist, Wolfgang; Høj, Martin;

    2014-01-01

    of nitric acid during hydrothermal synthesis enhanced both propylene conversion and acrolein yield, possibly due to a change in morphology. Formation of β-Bi2Mo2O9 was not observed under the applied conditions. In general, the catalytic performance of all samples decreased notably after calcination...

  11. Synthesis, characterization and photocatalytic performance of visible light induced bismuth oxide nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Raza, Waseem; Haque, M.M. [Department of Chemistry, Aligarh Muslim University, Aligarh, 202002 (India); Muneer, M., E-mail: m.muneer.ch@amu.ac.in [Department of Chemistry, Aligarh Muslim University, Aligarh, 202002 (India); Harada, T.; Matsumura, M. [Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, 560-8531 (Japan)

    2015-11-05

    Pure and doped Bi{sub 2}O{sub 3} nanoparticles were synthesized by sol gel method. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), UV–Visible Spectroscopy, Scanning Electron Microscopy (SEM), Thermogravimetry/Differential thermal analysis (TGA/DTA), potentiostat/galvanostat (CV), Electron-spin resonance (ESR) and Fourier transform infrared spectroscopy (FTIR). The XRD patterns of the fabricated Bi{sub 2}O{sub 3} nanoparticles exhibited only the characteristic peaks of well crystallized monoclinic α−Bi{sub 2}O{sub 3} and were in pure state. It was found that the crystallite size of doped Bi{sub 2}O{sub 3} nanoparticles decreases with increase in dopant concentration up to certain limit and then decrease. The SEM image depicts that pure and doped Bi{sub 2}O{sub 3} nanoparticles displayed nanorod like morphology; on doping the surface becomes rough. The UV–Vis absorption spectra of synthesized nanoparticles revealed that absorption edge shifts towards the longer wavelength after doping and it is highly beneficial for absorbing more visible light in the solar spectrum. FTIR spectra of doped Bi{sub 2}O{sub 3} nanoparticles showed an additional absorption band. The photocatalytic performance of the as prepared photocatalyst was evaluated by degradation of three different organic dyes as a function of irradiation time. - Highlights: • We have synthesized excellent material which can be used for waste water treatment using simple one pot sol gel method. • The characterization of Ce & Nd doped Bi{sub 2}O{sub 3} showed nanorod like uniform morphology having monoclinic phase and good structural stability. • 2% Ce doped Bi{sub 2}O{sub 3} photocatalyst exibit a high photocatalytic activity for degradation of all dyes under visible light illumination. • The effect of doped material was examined on the photocatalytic activity.

  12. Synthesis, characterization and photocatalytic performance of visible light induced bismuth oxide nanoparticle

    International Nuclear Information System (INIS)

    Pure and doped Bi2O3 nanoparticles were synthesized by sol gel method. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), UV–Visible Spectroscopy, Scanning Electron Microscopy (SEM), Thermogravimetry/Differential thermal analysis (TGA/DTA), potentiostat/galvanostat (CV), Electron-spin resonance (ESR) and Fourier transform infrared spectroscopy (FTIR). The XRD patterns of the fabricated Bi2O3 nanoparticles exhibited only the characteristic peaks of well crystallized monoclinic α−Bi2O3 and were in pure state. It was found that the crystallite size of doped Bi2O3 nanoparticles decreases with increase in dopant concentration up to certain limit and then decrease. The SEM image depicts that pure and doped Bi2O3 nanoparticles displayed nanorod like morphology; on doping the surface becomes rough. The UV–Vis absorption spectra of synthesized nanoparticles revealed that absorption edge shifts towards the longer wavelength after doping and it is highly beneficial for absorbing more visible light in the solar spectrum. FTIR spectra of doped Bi2O3 nanoparticles showed an additional absorption band. The photocatalytic performance of the as prepared photocatalyst was evaluated by degradation of three different organic dyes as a function of irradiation time. - Highlights: • We have synthesized excellent material which can be used for waste water treatment using simple one pot sol gel method. • The characterization of Ce & Nd doped Bi2O3 showed nanorod like uniform morphology having monoclinic phase and good structural stability. • 2% Ce doped Bi2O3 photocatalyst exibit a high photocatalytic activity for degradation of all dyes under visible light illumination. • The effect of doped material was examined on the photocatalytic activity

  13. Processing and Microstructural Development of Directionally-Solidified Superconducting Bismuth Strontium Calcium Copper Oxide

    Science.gov (United States)

    Chow, Hui-Meng Quek

    Ceramic rods of Bi_2Sr _2CaCu_2O _8 (2212) were directionally solidified by laser-heated float-zone growth. Longitudinal and transverse sections of boules were polished and observed by back-scattered electron imaging, and under polarized light in the optical microscope. Compositional analysis was performed by electron beam microprobe and X-ray diffraction analysis. The 2212 phase is Sr-deficient, having an actual composition of Bi_{2.5}Sr _2CaCu_{2.2} O_{y}. Plane-front growth is observed when the temperature gradient divided by the growth rate (G/R) is larger than 3 times 10^7 K-sec/cm^2 . Under these conditions, highly-textured samples of almost pure phase 2212 were obtained, and pole figures indicate that the solidification front proceeds along the (200) axis of the 2212 grains. Lower values of G/R produced dendritic growth, and varying amounts of at least four other phases were observed in a matrix of highly-textured 2212. At the lowest G/R value studied (G/R = 3.7 times 10^5 K-sec/cm ^2), no 2212 phase was observed. Measurements of the steady-state liquid zone composition indicate that it becomes progressively richer in Bi as the growth rate decreases. Boules grown at fast growth rates are multiphase and have no 2212; they show a significant amount of 2212 after annealing. The 2212 texture is highly dependent on processing path: 2212 formed from solid state reaction has a (220) preferred orientation compared to (200) texture when grown from the melt. The boules grown at fast growth rates also showed an increase in mass after annealing while no appreciable increase in mass was observed in the annealing of boules grown at moderate growth rates, thus indicating that boules grown at fast growth rates are oxygen-deficient. Compared to 2 mm diameter boules, boules of 0.6 mm diameter grown under the same conditions showed a smaller increase in mass after annealing. The Cu(I) and Cu(II) concentrations in the melt of the fast growth rate boules were estimated. Growth of fibers (300-400 μm diameter) was also initiated. Preliminary results indicate that the microstructure of the fibers is more aligned than the microstructure observed in the larger diameter boules. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.) (Abstract shortened with permission of school.).

  14. Spectroscopic properties and concentration effects on luminescence behavior of Nd3+ doped Zinc–Boro–Bismuthate glasses

    International Nuclear Information System (INIS)

    A detail investigation on laser spectroscopic properties as a function of Nd3+ ions concentration in a new heavy metal oxide based Zinc–Boro–Bismuthate glasses is reported. The Judd–Ofelt analysis indicated an enhancement in Nd–O bond covalency as well as the local asymmetry of active ions on increase in dopant concentration from 0.1 to 1.5 mol%. Based on the Judd–Ofelt intensity parameters, several radiative properties such as transition probability, radiative lifetime, branching ratio and stimulated emission cross-section of Nd3+ ions have been derived. The luminescence intensity has showed a strong increase up to 0.5 mol% Nd2O3, which then attains maximum at 1 mol% and falls down for further increase in dopant concentration. The luminescence quenching behavior at higher dopant concentration has been attributed to the hopping migration assisted energy transfer mechanism leading to the cross-relaxation among active ions. The energy transfer micro-parameters for cross-relaxation (CDA) and donor energy migration (CDD) have been derived from the luminescence decay analysis as well as spectral overlap function respectively. The high stimulated emission cross-section and smaller cross-relaxation micro-parameters along with high quantum yield from the present glasses suggests their potential for compact infrared lasers and waveguide applications. Highlights: ► Nd3+ doped heavy metal oxide based Zn–Bi-Borate glasses have been synthesized. ► Judd–Ofelt analysis has been performed in a wide concentration range. ► High stimulated emission cross-section of Nd3+ ions has been achieved. ► Fluorescence self-quenching has occurred by migration assisted energy transfer.

  15. 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

  16. 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.

  17. 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.

  18. Compatibility tests of steels in flowing liquid lead-bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Barbier, F.; Benamati, G. E-mail: benamati@brasimone.enea.it; Fazio, C.; Rusanov, A

    2001-06-01

    The behaviour of steels exposed to flowing Pb-55Bi was evaluated. The materials tested are the two austenitic steels AISI 316L and 1.4970, and the six martensitic steels Optifer IVc, T91, Batman 27, Batman 28, EP823 and EM10 which were exposed to flowing Pb-55Bi for 1000, 2000 and 3000 h and at two temperatures (573 and 743 K). The corrosion tests were conducted in the non-isothermal loop of IPPE-Obninsk under a controlled oxygen level (10{sup -6} wt%). The compatibility study showed that at a lower temperature, a very thin oxide layer (<1 {mu}m) was formed on the steels. At higher temperature, austenitic steels also exhibited a thin oxide layer sufficient to prevent their dissolution in the melt. A thicker oxide, which grew according to a parabolic law, was observed on the surface of the martensitic steels. The oxidation resistance behaviour of the martensitic steels was correlated with their alloying elements.

  19. Compatibility tests of steels in flowing liquid lead-bismuth

    Science.gov (United States)

    Barbier, F.; Benamati, G.; Fazio, C.; Rusanov, A.

    2001-06-01

    The behaviour of steels exposed to flowing Pb-55Bi was evaluated. The materials tested are the two austenitic steels AISI 316L and 1.4970, and the six martensitic steels Optifer IVc, T91, Batman 27, Batman 28, EP823 and EM10 which were exposed to flowing Pb-55Bi for 1000, 2000 and 3000 h and at two temperatures (573 and 743 K). The corrosion tests were conducted in the non-isothermal loop of IPPE-Obninsk under a controlled oxygen level (10 -6 wt%). The compatibility study showed that at a lower temperature, a very thin oxide layer (<1 μm) was formed on the steels. At higher temperature, austenitic steels also exhibited a thin oxide layer sufficient to prevent their dissolution in the melt. A thicker oxide, which grew according to a parabolic law, was observed on the surface of the martensitic steels. The oxidation resistance behaviour of the martensitic steels was correlated with their alloying elements.

  20. 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).

  1. 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

  2. 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

  3. 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.

  4. 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)

  5. 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

  6. 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.

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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)

  16. 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.

  17. 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)

  18. Growth and characterization of bismuth selenide thin films by chemical vapor deposition

    Science.gov (United States)

    Brom, Joseph E.

    Topological insulators are a recently discovered class of materials that have garnered much interest due to their unique surface states. With its relatively high band gap (0.3eV) and nearly ideal band structure, Bi2Se 3 has been a primary material of interest in the study of topological insulating behavior. However, several factors have made this study difficult. Bi2Se3 typically has a high native selenium vacancy concentration, and selenium vacancies act as donors in the material, leading to a high bulk electron concentration. The surface of Bi2Se 3 has also been shown to be susceptible to environmental doping when exposed to ambient air. Combining these two factors means that Bi2Se 3 is usually highly n-type doped, making it difficult to study the surface conducting states by transport measurements. This study investigated the use of two different chemical vapor deposition (CVD) techniques for the growth of Bi2Se3 thin films on sapphire (001): hybrid physicalchemical vapor deposition (HPCVD) and metal-organic chemical vapor deposition (MOCVD). HPCVD is a process which combines the evaporation of elemental selenium with the thermal decomposition of trimethylbismuth (TMBi). The use of elemental selenium immediately around the substrate provides a high overpressure of selenium, allowing for reduction of the selenium vacancy concentration. Bi2Se3 films grown on sapphire were epitaxial and highly oriented parallel to the substrate giving rise to narrow X-ray rocking curves (full-width-at-half-maximum=160 arcsecs for (006) reflection) and 6-fold rotational symmetry as determined by phi scans. The structural properties were consistent with deposition via a van der Waals epitaxy process. The selenium to bismuth ratio (VI/V) ratio proved important for achieving a reduced electron concentration of TMBi) dimethylselenide (DMSe) as precursors. Epitaxial Bi 2Se3 films were also produced by MOCVD on sapphire, however, the electron concentrations were generally higher (1- 3x

  19. 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

  20. 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.

  1. 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.)

  2. 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.

  3. 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)

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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)

  15. 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.

  16. 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.

  17. 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

  18. 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.

  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. STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Eric D. Wachsman; Keith L. Duncan

    2002-09-30

    A bilayer electrolyte consisting of acceptor-doped ceria (on the fuel/reducing side) and cubic-stabilized bismuth oxide (on the oxidizing side) was developed. The bilayer electrolyte that was developed showed significant improvement in open-circuit potential versus a typical ceria based SOFC. Moreover, the OCP of the bilayer cells increased as the thickness of the bismuth oxide layer increased relative to the ceria layer. Thereby, verifying the bilayer concept. Although, because of the absence of a suitable cathode (a problem we are still working assiduously to solve), we were unable to obtain power density curves, our modeling work predicts a reduction in electrolyte area specific resistance of two orders of magnitude over cubic-stabilized zirconia and projects a maximum power density of 9 W/m{sup 2} at 800 C and 0.09 W/m{sup 2} at 500 C. Towards the development of the bilayer electrolyte other significant strides were made. Among these were, first, the development of a, bismuth oxide based, oxide ion conductor with the highest conductivity (0.56 S/cm at 800 C and 0.043 S/cm at 500 C) known to date. Second, a physical model of the defect transport mechanisms and the driving forces for the ordering phenomena in bismuth oxide and other fluorite systems was developed. Third, a model for point defect transport in oxide mixed ionic-electronic conductors was developed, without the typical assumption of a uniform distribution of ions and including the effect of variable loads on the transport properties of an SOFC (with either a single or bilayer electrolyte).

  1. 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

  2. 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

  3. Assessment of the transmutation capability an accelerator driven system cooled by lead bismuth eutectic alloy

    International Nuclear Information System (INIS)

    1. PURPOSE The reduction of long-lived fission products (LLFP) and minor actinides (MA) is a key point for the public acceptability and economy of nuclear energy. In principle, any nuclear fast reactor is able to burn and transmute MA, but the amount of MA content has to be limited a few percent, having unfavourable consequences on the coolant void reactivity, Doppler effect, and delayed neutron fraction, and therefore on the dynamic behaviour and control. Accelerator Driven Systems (ADS) are instead able to safely burn and/or transmute a large quantity of actinides and LLFP, as they do not rely on delayed neutrons for control or power change and the reactivity feedbacks have very little importance during accidents. Such systems are very innovative being based on the coupling of an accelerator with a subcritical system by means of a target system, where the neutronic source needed to maintain the neutron reaction chain is produced by spallation reactions. To this end the PDS-XADS (Preliminary Design Studies on an experimental Accelerator Driven System) project was funded by the European Community in the 5th Framework Program in order both to demonstrate the feasibility of the coupling between an accelerator and a sub-critical core loaded with standard MOX fuel and to investigate the transmutation capability in order to achieve values suitable for an Industrial Scale Transmuter. This paper summarizes and compares the results of neutronic calculations aimed at evaluating the transmutation capability of cores cooled by Lead-Bismuth Eutectic alloy and loaded with assemblies based on (Pu, Am, Cm) oxide dispersed in a molybdenum metal (CERMET) or magnesia (CERCER) matrices. It also describes the constraints considered in the design of such cores and describes the thermo-mechanical behaviour of these innovative fuels along the cycle. 2. DESCRIPTION OF THE WORK: The U-free composite fuels (CERMET and CERCER) were selected for this study, being considered at European level

  4. Bismuthates: BaBiO3 and related superconducting phases

    International Nuclear Information System (INIS)

    Highlights: • BaBiO3 has the perovskite structure, but tilting of the BiO6 octahedra destroy the ideal cubic symmetry except at temperatures above 820 K. BaBiO3 is a diamagnetic semiconductor due to a CDW, which is equivalent to a Ba2Bi3+Bi5+O6 representation. • Recent calculations and experimental results confirm that there is no significant deviation from the oxidation states of 3+ and 5+. • Superconductivity with a Tc as high as 13 K occurs for BaPb1−xBixO3 phases where the 6s band is about 25% filled, and superconductivity with a Tc as high as 34 K occurs for Ba1−xKxBiO3 phases where the 6s band is about 35% filled. • These two solid solutions can have cubic, tetragonal, or orthorhombic symmetry. • However, superconductivity has only been observed when the symmetry is tetragonal. - Abstract: BaBiO3 has the perovskite structure, but tilting of the BiO6 octahedra destroy the ideal cubic symmetry except at temperatures above 820 K. BaBiO3 is a diamagnetic semiconductor due to a charge density wave (CDW), which is equivalent to a Ba2Bi3+Bi5+O6 representation. Recent calculations and experimental results confirm that there is no significant deviation from the oxidation states of 3+ and 5+. Superconductivity with a Tc as high as 13 K occurs for BaPb1−xBixO3 phases where the 6s band is about 25% filled, and superconductivity with a Tc as high as 34 K occurs for Ba1−xKxBiO3 phases where the 6s band is about 35% filled. Structures in these two solid solutions can have cubic, tetragonal, orthorhombic, or monoclinic symmetry. However, superconductivity has only been observed when the symmetry is tetragonal

  5. Selective propene oxidation on mixed metal oxide catalysts

    International Nuclear Information System (INIS)

    Selective catalytic oxidation processes represent a large segment of the modern chemical industry and a major application of these is the selective partial oxidation of propene to produce acrolein. Mixed metal oxide catalysts are particularly effective in promoting this reaction, and the two primary candidates for the industrial process are based on iron antimonate and bismuth molybdate. Some debate exists in the literature regarding the operation of these materials and the roles of their catalytic components. In particular, iron antimonate catalysts containing excess antimony are known to be highly selective towards acrolein, and a variety of proposals for the enhanced selectivity of such materials have been given. The aim of this work was to provide a direct comparison between the behaviour of bismuth molybdate and iron antimonate catalysts, with additional emphasis being placed on the component single oxide phases of the latter. Studies were also extended to other antimonate-based catalysts, including cobalt antimonate and vanadium antimonate. Reactivity measurements were made using a continuous flow microreactor, which was used in conjunction with a variety of characterisation techniques to determine relationships between the catalytic behaviour and the properties of the materials. The ratio of Fe/Sb in the iron antimonate catalyst affects the reactivity of the system under steady state conditions, with additional iron beyond the stoichiometric value being detrimental to the acrolein selectivity, while extra antimony provides a means of enhancing the selectivity by decreasing acrolein combustion. Studies on the single antimony oxides of iron antimonate have shown a similarity between the reactivity of 'Sb2O5' and FeSbO4, and a significant difference between these and the Sb2O3 and Sb2O4 phases, implying that the mixed oxide catalyst has a surface mainly comprised of Sb5+. The lack of reactivity of Sb2O4 implies a similarity of the surface with that of Sb2O3

  6. 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}.

  7. 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)

  8. 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

  9. 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

  10. Cooperative properties of single phases of complex oxide catalyst for oxidation of propylene to acrolein

    International Nuclear Information System (INIS)

    Synergetic effect of increase of acrolein yield during propylene oxidation on mechanical mixture of (α + β)CoMoO4 and MoO3, as well as CO and CO2 yield on mixture of CoMoO4 and Bi2O3·2MoO3 was revealed. It is shown that CoMoO4 generates allyl radicals, desorption of these radicals to gaseous phase is not practically observed with MoO3, bismuth molybdates and Fe2O3· Fe2O3·3MoO3

  11. Bismuth high temperature superconductors: Water processing for improved powders

    International Nuclear Information System (INIS)

    Typical solid-state synthesis routes to the Bi-2xPbxSr2Ca2Cu3Oy (Bi/Pb-2223) superconductor do not yield a material that is single phase. Contaminants include Sr-Ca-plumbates and -cuprates. In addition to being indicative of an incomplete reaction, the cuprates, in particular, tend to form in large-grained particles that resist further reaction and can be large enough to create holes in the silver cladding of superconductors drawn and rolled as part of the oxide-powder-in-tube process for manufacturing superconducting tapes. Recently, the authors have investigated the reaction of water with Bi/Pb-2223 materials. The ultimate goal of this research is to improve the microstructural and electronic properties of this superconductor. Water has been reported to destroy the superconducting properties of Bi/Pb-2223, and it has been confirmed that samples of Bi/Pb-2223 soaked in water do not display superconductivity. More importantly, it has been noted that the basic structure of the Bi/Pb-2223 compound appears to remain intact after these short exposures to water while the stronium-calcium cuprate species react quickly. This led to the discovery that superconductivity in the soaked system can be restored with a single sintering. The results of the authors' studies of the reaction of water with Bi/Pb-2223 and the microstructural and electronic effects of subsequent heat treatments will be discussed

  12. Spectroscopic study of neodymium doped lead-bismuth-borate glasses

    Science.gov (United States)

    Pasha, Altaf; Dayani, P.; Negalur, Mahesh; Swamy, Manjunatha; Abhiram, J.; Rajaramakrishna, R.

    2016-05-01

    This paper reports on different physical and optical properties of rare earth doped heavy metal oxide glasses. The glass composition of 10Bi2O3-30PbO-60B2O3-xNd2O3 where x = 0, 0.1, 0.2, 0.5 and 1 (in mol %) has been synthesized using melt-quenching technique. Refractive index measurements for these glasses were done and physical parameters were studied. Structural properties of these glasses were analysed through infrared spectra that was recorded between 1600cm-1 and 300cm-1 in transmission mode. The optical absorption spectra were recorded in the wavelength range from 300 to 700 nm. The transitions originated from ground state energy 4I9/2. The energy level analysis has been carried out by considering absorption spectral bands. The results thus obtained are comparable with reports on similar glasses, indicating that the prepared glasses may have potential laser applications.

  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. 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).