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Sample records for bismuth oxide based

  1. Bismuth oxide nanorods based immunosensor for mycotoxin detection.

    Science.gov (United States)

    Solanki, Pratima R; Singh, Jay; Rupavali, Bharti; Tiwari, Sachchidanand; Malhotra, Bansi D

    2017-01-01

    We report results of the studies relating to fabrication of an efficient immunosensor based on bismuth oxide nanorods (nBi 2 O 3 ), electrophoretically deposited onto indium-tin-oxide (ITO) coated glass substrate. This immunosensor was fabricated by immobilization of anti-aflatoxin monoclonal antibodies (Ab-AFB1) and bovine serum albumin (BSA) for aflatoxin B1 detection. The structural and morphological studies of n-Bi 2 O 3 have been carried out by XRD, UV-vis spectrophotometer; SEM, AFM and FTIR. It was found that the nBi 2 O 3 provided improved sensing characteristics to the electrode interface in terms of electroactive surface area, diffusion coefficient, charge transfer rate constant and electron transfer kinetics. The results of electrochemical response studies of this BSA/Ab-AFB1/nBi 2 O 3 /ITO immunosensor revealed good linearity in the range of 1-70ngdL -1 with low detection limit of 8.715ng/dL, improved sensitivity of 1.132μA/(ng/dLcm -2 ), regression coefficient R 2 of 0.918 and reproducibility of >11 times. The association constant for the BSA/Ab-AFB1/nBi 2 O 3 /ITO immunosensor was determined as 7.318ng/dL. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Structure-Composition-Property Relationships of Complex Bismuth Oxide Based Photocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Thomas [Univ. of South Carolina, Columbia, SC (United States). Dept. of Chemistry and Biochemistry

    2014-01-08

    Development of a new family of up- and down-conversion materials based on oxtfluorides that can potentially increase photocatalytic activities of photocatalysts such as bismuth oxides and can also be used as phosphors in Al1-xGaxN-based devices and solar devices.

  3. High ionic conductivity in confined bismuth oxide-based heterostructures

    DEFF Research Database (Denmark)

    Sanna, Simone; Esposito, Vincenzo; Christensen, Mogens

    2016-01-01

    Bismuth trioxide in the cubic fluorite phase (δ-Bi2O3) exhibits the highest oxygen ionic conductivity. In this study, we were able to stabilize the pure -Bi2O3 at low temperature with no addition of stabilizer but only by engineering the interface, using highly coherent heterostructures made...... of alternative layers of δ-Bi2O3 and Yttria Stabilized Zirconia (YSZ), deposited by pulsed laser deposition. The resulting [δ-Bi2O3=YSZ] heterostructures are found to be stable over a wide temperature range (500-750 °C) and exhibits stable high ionic conductivity over a long time comparable to the value...

  4. High ionic conductivity in confined bismuth oxide-based heterostructures

    Directory of Open Access Journals (Sweden)

    Simone Sanna

    2016-12-01

    Full Text Available Bismuth trioxide in the cubic fluorite phase (δ-Bi2O3 exhibits the highest oxygen ionic conductivity. In this study, we were able to stabilize the pure δ-Bi2O3 at low temperature with no addition of stabilizer but only by engineering the interface, using highly coherent heterostructures made of alternative layers of δ-Bi2O3 and Yttria Stabilized Zirconia (YSZ, deposited by pulsed laser deposition. The resulting [δ-Bi2O3/YSZ] heterostructures are found to be stable over a wide temperature range (500-750 °C and exhibits stable high ionic conductivity over a long time comparable to the value of the pure δ-Bi2O3, which is approximately two orders of magnitude higher than the conductivity of YSZ bulk.

  5. High ionic conductivity in confined bismuth oxide-based heterostructures

    DEFF Research Database (Denmark)

    Sanna, Simone; Esposito, Vincenzo; Christensen, Mogens

    2016-01-01

    Bismuth trioxide in the cubic fluorite phase (δ-Bi2O3) exhibits the highest oxygen ionic conductivity. In this study, we were able to stabilize the pure -Bi2O3 at low temperature with no addition of stabilizer but only by engineering the interface, using highly coherent heterostructures made...... of alternative layers of δ-Bi2O3 and Yttria Stabilized Zirconia (YSZ), deposited by pulsed laser deposition. The resulting [δ-Bi2O3=YSZ] heterostructures are found to be stable over a wide temperature range (500-750 °C) and exhibits stable high ionic conductivity over a long time comparable to the value...... of the pure δ-Bi2O3, which is approximately two orders of magnitude higher than the conductivity of YSZ bulk....

  6. Hydrothermal synthesis of bismuth germanium oxide

    Science.gov (United States)

    Boyle, Timothy J.

    2016-12-13

    A method for the hydrothermal synthesis of bismuth germanium oxide comprises dissolving a bismuth precursor (e.g., bismuth nitrate pentahydrate) and a germanium precursor (e.g., germanium dioxide) in water and heating the aqueous solution to an elevated reaction temperature for a length of time sufficient to produce the eulytite phase of bismuth germanium oxide (E-BGO) with high yield. The E-BGO produced can be used as a scintillator material. For example, the air stability and radioluminescence response suggest that the E-BGO can be employed for medical applications.

  7. Facile solvothermal synthesis of a graphene nanosheet-bismuth oxide composite and its electrochemical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huanwen [Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Hu Zhongai, E-mail: zhongai@nwnu.edu.c [Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Chang Yanqin; Chen Yanli; Lei Ziqiang; Zhang Ziyu; Yang Yuying [Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

    2010-12-01

    This work demonstrates a novel and facile route for preparing graphene-based composites comprising of metal oxide nanoparticles and graphene. A graphene nanosheet-bismuth oxide composite as electrode materials of supercapacitors was firstly synthesized by thermally treating the graphene-bismuth composite, which was obtained through simultaneous solvothermal reduction of the colloidal dispersions of negatively charged graphene oxide sheets in N,N-dimethyl formamide (DMF) solution of bismuth cations at 180 {sup o}C. The morphology, composition, and microstructure of the composites together with pure graphite oxide, and graphene were characterized using powder X-ray diffraction (XRD), FT-IR, field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), thermogravimetry and differential thermogravimetry (TG-DTG). The electrochemical behaviors were measured by cyclic voltammogram (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The specific capacitance of 255 F g{sup -1} (based on composite) is obtained at a specific current of 1 A g{sup -1} as compared with 71 F g{sup -1} for pure graphene. The loaded-bismuth oxide achieves a specific capacitance as high as 757 F g{sup -1} even at 10 A g{sup -1}. In addition, the graphene nanosheet-bismuth oxide composite electrode exhibits the excellent rate capability and well reversibility.

  8. Study of multiphasic molybdate-based catalysts. II. Synergy effect between bismuth molybdates and mixed iron and cobalt molybdates in mild oxidation of propene

    Energy Technology Data Exchange (ETDEWEB)

    Millet, J.M.M.; Ponceblanc, H.; Coudurier, G.; Vedrine, J.C. (Institut de Recherches sur la Catalyse, Villeurbanne (France)); Herrmann, J.M. (Laboratoire de Photocatalyse, Ecully (France))

    1993-08-01

    Results are reported concerning the synergy effect observed in the oxidation of propene to acrolein over bismuth and mixed iron and cobalt molybdates. The pure bismuth, iron, and cobalt molybdates and mixed cobalt and iron molybdates (solid solutions) have been prepared and individually tested as catalysts. Mechanical mixtures of these phases have been prepared and tested as catalysts. All the catalysts have been characterized before and after the catalytic reaction by several techniques such as ESR, XPS, EDX-STEM, TEM, XRD, and Moessbauer and UV spectroscopies. The synergy effect observed is tentatively explained as due to the deposition on the large bismuth molybdate particles of smaller mixed iron and cobalt molybdate particles with spreading of the bismuth molybdate over the latter particles. It is proposed that the Fe[sub x]Co[sub 1-x]MoO[sub 4] phase plays the role of the fast electron conducting material which enhances the electron mobility and the efficiency of the redox mechanism, the active and selective phase being the overlying bismuth molybdate compounds. 27 refs., 5 figs., 7 tabs.

  9. Study of bismuth molybdenum oxidic catalysts for methanol oxidation to formaldehyde

    International Nuclear Information System (INIS)

    Khokhler, R.Ya.; Kurina, L.N.; Kudrina, N.V.

    1982-01-01

    Phase composition and catalytic properties of bismuth molybdenum oxidic system in reaction of methanol oxidation are studied at temperature of 280-350 deg. Increase of selectivity according to formaldehyde is connected with formation of MoO 3 solid solution in bismuth molybdate Bi 2 O 3 x3MoO 3

  10. Oxygen surface exchange kinetics of erbia-stabilized bismuth oxide

    NARCIS (Netherlands)

    Yoo, C.-Y.; Boukamp, Bernard A.; Bouwmeester, Henricus J.M.

    2011-01-01

    The surface oxygen exchange kinetics of bismuth oxide stabilized with 25 mol% erbia (BE25) has been studied in the temperature and pO2 ranges 773–1,023 K and 0.1– 0.95 atm, respectively, using pulse-response 18O–16O isotope exchange measurements. The results indicate that BE25 exhibits a

  11. Formic Acid Oxidation at Platinum-Bismuth Clusters

    DEFF Research Database (Denmark)

    Lovic, J. D.; Stevanovic, S. I.; Tripkovic, D. V.

    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...

  12. Current and potential applications of bismuth-based drugs.

    Science.gov (United States)

    Keogan, Donal M; Griffith, Darren M

    2014-09-23

    : Bismuth compounds have been used extensively as medicines and in particular for the treatment of gastrointestinal ailments. In addition to bismuth's well known gastroprotective effects and efficacy in treating H. pylori infection it also has broad anti-microbial, anti-leishmanial and anti-cancer properties. Aspects of the biological chemistry of bismuth are discussed and biomolecular targets associated with bismuth treatment are highlighted. This review strives to provide the reader with an up to date account of bismuth-based drugs currently used to treat patients and discuss potential medicinal applications of bismuth drugs with reference to recent developments in the literature. Ultimately this review aims to encourage original contributions to this exciting and important field.

  13. Synthesis of bismuth (III oxide films based anodes for electrochemical degradation of reactive blue 19 and crystal violet

    Directory of Open Access Journals (Sweden)

    Petrović Milica M.

    2014-01-01

    Full Text Available The Bi2O3 films-based anodes were synthesized by electrodeposition of Bi on stainless steel substrate at constant current density and during different deposition times, fallowed by calcination, forming Bi2O3. The thickness of the films was determined by two methods: the observation under the microscope and by calculation from mass difference. Electrochemical proceses at the anodes were ivestigated by linear sweep voltammetry. At the anodes obtained within 2, 5, 10 and 15 minutes of deposition, two dyes, namely: Reactive Blue 19 and Crystal Violet, were decolorized by oxidation with •OH radical, generated from H2O2 decomposition at the anodes. Decoloration times of the anodes varied, and the shortest one was achieved with the anode obtained during 5 minutes of deposition, with the film thickness of 2.5±0.3 μm. The optimal H2O2 concentration for the dyes degradation was found to be 10 mmol dm-3. [Projekat Ministarstva nauke Republike Srbije, br. ТR 34008

  14. Optical Properties of Bismuth Tellurite Based Glass

    Science.gov (United States)

    Oo, Hooi Ming; Mohamed-Kamari, Halimah; Wan-Yusoff, Wan Mohd Daud

    2012-01-01

    A series of binary tellurite based glasses (Bi2O3)x (TeO2)100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO). The Fourier transform infrared spectroscopy (FTIR) results show the bonding of the glass sample and the optical band gap, Eopt decreases while the refractive index increases when the ion Bi3+ content increases. PMID:22605999

  15. Optical Properties of Bismuth Tellurite Based Glass

    Directory of Open Access Journals (Sweden)

    Hooi Ming Oo

    2012-04-01

    Full Text Available A series of binary tellurite based glasses (Bi2O3x (TeO2100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO. The Fourier transform infrared spectroscopy (FTIR results show the bonding of the glass sample and the optical band gap, Eopt decreases while the refractive index increases when the ion Bi3+ content increases.

  16. Microstructure and electrical properties of bismuth and bismuth oxide deposited by magnetron sputtering UBM

    International Nuclear Information System (INIS)

    Otalora B, D. M.; Dussan, A.; Olaya F, J. J.

    2015-01-01

    In this work, bismuth (Bi) and bismuth oxide (Bi 2 O 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 2 O 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 2 O 3 and Bi, respectively. (Author)

  17. Oxidative Dehydrogenation of n-Butenes to 1,3-Butadiene over Bismuth Molybdate and Ferrite Catalysts: A Review

    KAUST Repository

    Hong, Eunpyo

    2015-11-02

    1,3-Butadiene, an important raw material for a variety of chemical products, can be produced via the oxidative dehydrogenation (ODH) of n-butenes over multicomponent oxide catalysts based on bismuth molybdates and ferrites. In this review, the basic concept, reaction mechanism, and catalysts typically used in an ODH reaction are discussed. © 2015, Springer Science+Business Media New York.

  18. Monte Carlo simulations for dose enhancement in cancer treatment using bismuth oxide nanoparticles implanted in brain soft tissue.

    Science.gov (United States)

    Taha, Eslam; Djouider, Fathi; Banoqitah, Essam

    2018-03-26

    The objective of this work is to study the dosimetric performances of bismuth oxide nanoparticles implanted in tumors in cancer radiotherapy. GEANT4 based Monte Carlo numerical simulations were performed to assess dose enhancement distributions in and around a 1 × 1 × 1 cm 3 tumor implanted with different concentrations of bismuth oxide and irradiated with low energies 125 I, 131 Cs, and 103 Pd radioactive sources. Dose contributions were considered from photoelectrons, Auger electrons, and characteristic X-rays. Our results show the dose enhancement increased with increasing both bismuth oxide concentration in the target and photon energy. A dose enhancement factor up to 18.55 was obtained for a concentration of 70 mg/g of bismuth oxide in the tumor when irradiated with 131 Cs source. This study showed that bismuth oxide nanoparticles are innovative agents that could be potentially applicable to in vivo cancer radiotherapy due to the fact that they induce a highly localized energy deposition within the tumor.

  19. Bismuth oxide film: a promising room-temperature quantum spin Hall insulator

    Science.gov (United States)

    Wang, Ya-Ping; Li, Sheng-Shi; Ji, Wei-Xiao; Zhang, Chang-Wen; Li, Ping; Wang, Pei-Ji

    2018-03-01

    Two-dimensional (2D) bismuth films have attracted extensive attention due to their nontrivial band topology and tunable electronic properties for achieving dissipationless transport devices. The experimental observation of quantum transport properties, however, are rather challenging, limiting their potential application in nanodevices. Here, we predict, based on first-principles calculations, an alternative 2D bismuth oxide, BiO, as an excellent topological insulator (TI), whose intrinsic bulk gap reaches up to 0.28 eV. Its nontrivial topology is confirmed by topological invariant Z 2 and time-reversal symmetry protected helical edge states. The appearance of topological phase is robust against mechanical strain and different levels of oxygen coverage in BiO. Since the BiO is naturally stable against surface oxidization and degradation, these results enrich the topological materials and present an alternative way to design topotronics devices at room temperature.

  20. 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.

  1. 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.

  2. Improved proton CT imaging using a bismuth germanium oxide scintillator

    Science.gov (United States)

    Tanaka, Sodai; Nishio, Teiji; Tsuneda, Masato; Matsushita, Keiichiro; Kabuki, Shigeto; Uesaka, Mitsuru

    2018-02-01

    Range uncertainty is among the most formidable challenges associated with the treatment planning of proton therapy. Proton imaging, which includes proton radiography and proton computed tomography (pCT), is a useful verification tool. We have developed a pCT detection system that uses a thick bismuth germanium oxide (BGO) scintillator and a CCD camera. The current method is based on a previous detection system that used a plastic scintillator, and implements improved image processing techniques. In the new system, the scintillation light intensity is integrated along the proton beam path by the BGO scintillator, and acquired as a two-dimensional distribution with the CCD camera. The range of a penetrating proton is derived from the integrated light intensity using a light-to-range conversion table, and a pCT image can be reconstructed. The proton range in the BGO scintillator is shorter than in the plastic scintillator, so errors due to extended proton ranges can be reduced. To demonstrate the feasibility of the pCT system, an experiment was performed using a 70 MeV proton beam created by the AVF930 cyclotron at the National Institute of Radiological Sciences. The accuracy of the light-to-range conversion table, which is susceptible to errors due to its spatial dependence, was investigated, and the errors in the acquired pixel values were less than 0.5 mm. Images of various materials were acquired, and the pixel-value errors were within 3.1%, which represents an improvement over previous results. We also obtained a pCT image of an edible chicken piece, the first of its kind for a biological material, and internal structures approximately one millimeter in size were clearly observed. This pCT imaging system is fast and simple, and based on these findings, we anticipate that we can acquire 200 MeV pCT images using the BGO scintillator system.

  3. 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.

  4. Growth of Li doped bismuth oxide nanorods and its electrochemical performance for the determination of L-cysteine

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Yong, E-mail: yongwen1982@163.com [School of Civil Engineering and Architecture, Xinjiang University (China); Pei, Li-zhai; Wei, Tian [chool of Materials Science and Engineering, Anhui University of Technology (China)

    2017-05-15

    Li doped bismuth oxide nanorods have been prepared using sodium bismuthate and Li acetate. X-ray diffraction (XRD) pattern shows that the nanorods are composed of monoclinic Bi{sub 2}O{sub 4} and cubic LiBi{sub 12}O{sub 18.50} phases. Scanning electron microscopy (SEM) observation shows that the nanorods have the length and diameter of 1-5 μm and 50-350 nm, respectively. The formation of the Li doped bismuth oxide nanorods is closely relative to the hydrothermal conditions. The electrochemical performance for the determination of L-cysteine based on a Li doped bismuth oxide nanorods modified glassy carbon electrode (GCE) has been developed. The CV peak current increases obviously and linearly with increasing the scan rate. Under the optimal conditions, Li doped bismuth oxide nanorods modified GCE exhibits good analytical performance with good reproducibility and stability. The linear range of L-cysteine is 0.0001-2 mM and the detection limit is 0.36 μM and 0.17 μM for cvp1 and cvp2, respectively. (author)

  5. Growth of Li doped bismuth oxide nanorods and its electrochemical performance for the determination of L-cysteine

    International Nuclear Information System (INIS)

    Wen, Yong; Pei, Li-zhai; Wei, Tian

    2017-01-01

    Li doped bismuth oxide nanorods have been prepared using sodium bismuthate and Li acetate. X-ray diffraction (XRD) pattern shows that the nanorods are composed of monoclinic Bi 2 O 4 and cubic LiBi 12 O 18.50 phases. Scanning electron microscopy (SEM) observation shows that the nanorods have the length and diameter of 1-5 μm and 50-350 nm, respectively. The formation of the Li doped bismuth oxide nanorods is closely relative to the hydrothermal conditions. The electrochemical performance for the determination of L-cysteine based on a Li doped bismuth oxide nanorods modified glassy carbon electrode (GCE) has been developed. The CV peak current increases obviously and linearly with increasing the scan rate. Under the optimal conditions, Li doped bismuth oxide nanorods modified GCE exhibits good analytical performance with good reproducibility and stability. The linear range of L-cysteine is 0.0001-2 mM and the detection limit is 0.36 μM and 0.17 μM for cvp1 and cvp2, respectively. (author)

  6. Bismuth Oxide Nanoparticles in the Stratosphere

    Science.gov (United States)

    Rietmeijer, Frans J. M.; Mackinnon, Ian D. R.

    1997-01-01

    Platey grains of cubic Bi2O3, alpha-Bi2O3, and Bi2O(2.75), nanograins were associated with chondritic porous interplanetary dust particles W7029C1, W7029E5, and 2011C2 that were collected in the stratosphere at 17-19 km altitude. Similar Bi oxide nanograins were present in the upper stratosphere during May 1985. These grains are linked to the plumes of several major volcanic eruptions during the early 1980s that injected material into the stratosphere. The mass of sulfur from these eruptions is a proxy for the mass of stratospheric Bi from which we derive the particle number densities (p/cu m) for "average Bi2O3 nanograins" due to this volcanic activity and those necessary to contaminate the extraterrestrial chondritic porous interplanetary dust particles via collisional sticking. The match between both values supports the idea that Bi2O3 nanograins of volcanic origin could contaminate interplanetary dust particles in the Earth's stratosphere.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  8. Bismuth-based electrochemical stripping analysis

    Science.gov (United States)

    Wang, Joseph

    2004-01-27

    Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

  9. Photoconductivity in Transition Metal Doped Bismuth Germanium Oxide

    Science.gov (United States)

    Newkirk, Nolan M.; McCullough, J. S.; Martin, J. J.

    1999-10-01

    Bismuth germanium oxide (BGO) is a photorefractive material that has potential for a number of applications. We are investigating the possibility of tailoring it for specific uses by doping with 3d-ions. . Anti-site bismuth is a native defect in melt-grown BGO. This amphoteric defect dominates the photo-response of undoped BGO and plays a role in transition metal doped samples. The majority of the 3d-ions go into the tetrahedrally bonded Ge-site; thus, Cr would be expected to be in a 4+ state. Instead, it gives up an electron to the anti-site Bi and is in a 5+ state. Strongly persistent photorefractive gratings are observed in BGO:Cr. Photoconductivity measurements were performed on undoped BGO, BGO:V, and BGO:Cr before and after the samples were exposed to 442 nm light. The photoconductivity response roughly matched the optical absorption spectra of the samples. The exposed samples showed additional photo-induced absorption bands and much stronger photocurrents in the same spectral regions. The exposure to blue light appears to convert Cr from the 5+ state to the 4+state.

  10. Radiopacity and histological assessment of Portland cement plus bismuth oxide.

    Science.gov (United States)

    Coutinho-Filho, Tauby; De-Deus, Gustavo; Klein, Leila; Manera, Gisele; Peixoto, Carla; Gurgel-Filho, Eduardo Diogo

    2008-12-01

    The present study evaluated the subcutaneous connective tissue reactions and the radiopacity of MTA, Portland cement (PC), and Portland cement plus bismuth oxide (BO). Forty rats were divided into 5 groups (n = 8 per group): A1: Control (empty capsule); A2: Pro-Root MTA; A3: PC; A4: PC + BO 1:1; and A5: PC + BO 2:1. Polyethylene tubes were filled with the test materials and standardized radiographic images were taken. Histological evaluation was done after 7 and 60 days. Student t test and Fisher's test were used in the statistical analysis (P A4 > A5 > A3. No differences were found for the tissue response in the 2 experimental periods. A positive correlation between BO concentration and radiopacity of PC was determined. The histological evaluation suggests that all studied materials were biocompatible at 7 and 60 days.

  11. Bismuth-Based Quadruple Therapy with Bismuth Subcitrate, Metronidazole, Tetracycline and Omeprazole in the Eradication of Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Raymond Lahaie

    2001-01-01

    Full Text Available BACKGROUND: A previous study showed that 14 days of qid bismuth-based triple therapy with tetracycline 500 mg, metronidazole 250 mg and colloidal bismuth subcitrate 120 mg resulted in excellent Helicobacter pylori eradication rates (89.5%. The present study looked at a shorter treatment period by adding omeprazole and by reducing the dose of tetracycline.

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

    Science.gov (United States)

    Hernandez-Delgadillo, Rene; Velasco-Arias, Donaji; Martinez-Sanmiguel, Juan Jose; Diaz, David; Zumeta-Dube, Inti; Arevalo-Niño, Katiushka; Cabral-Romero, Claudio

    2013-01-01

    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 aqueous colloidal Bi2O3 nanoparticles. PMID:23637533

  13. Intrinsic stress of bismuth oxide thin films: effect of vapour chopping and air ageing

    International Nuclear Information System (INIS)

    Patil, R B; Puri, R K; Puri, V

    2008-01-01

    Bismuth oxide thin films of thickness 1000 A 0 have been prepared by thermal oxidation (in air) of vacuum evaporated bismuth thin films (on glass substrate) at different oxidation temperatures and duration. Both the vapour chopped and nonchopped bismuth oxide thin films showed polycrystalline and polymorphic structure. The monoclinic bismuth oxide was found to be predominant in both the cases. The effect of vapour chopping and air exposure for 40 days on the intrinsic stress of bismuth oxide thin films has been studied. The vapour chopped films showed low (3.92 - 4.80 x 10 9 N/m 2 ) intrinsic stress than those of nonchopped bismuth oxide thin films (5.77 - 6.74 x 10 9 N/m 2 ). Intrinsic stress was found to increase due to air ageing. The effect of air ageing on the vapour chopped films was found low. The vapour chopped films showed higher packing density. Higher the packing density, lower the film will age. The process of chopping vapour flow creates films with less inhomogenety i.e. a low concentration of flaws and non-planar defects which results in lower intrinsic stress

  14. Theoretical Investigation of Bismuth-Based Semiconductors for Photocatalytic Applications

    KAUST Repository

    Laradhi, Shaikhah

    2017-11-01

    Converting solar energy to clean fuel has gained remarkable attention as an emerged renewable energy resource but optimum efficiency in photocatalytic applications has not yet been reached. One of the dominant factors is designing efficient photocatalytic semiconductors. The research reveals a theoretical investigation of optoelectronic properties of bismuth-based metal oxide and oxysulfide semiconductors using highly accurate first-principles quantum method based on density functional theory along with the range-separated hybrid HSE06 exchange-correlation functional. First, bismuth titanate compounds including Bi12TiO20, Bi4Ti3O12, and Bi2Ti2O7 were studied in a combined experimental and theoretical approach to prove its photocatalytic activity under UV light. They have unique bismuth layered structure, tunable electronic properties, high dielectric constant and low electron and effective masses in one crystallographic direction allowing for good charge separation and carrier diffusion properties. The accuracy of the investigation was determined by the good agreement between experimental and theoretical values. Next, BiVO4 with the highest efficiency for oxygen evolution was investigated. A discrepancy between the experimental and theoretical bandgap was reported and inspired a systematic study of all intrinsic defects of the material and the corresponding effect on the optical and transport properties. A candidate defective structure was proposed for an efficient photocatalytic performance. To overcome the carrier transport limitation, a mild hydrogen treatment was also introduced. Carrier lifetime was enhanced due to a significant reduction of trap-assisted recombination, either via passivation of deep trap states or reduction of trap state density. Finally, an accurate theoretical approach to design a new family of semiconductors with enhanced optoelectronic properties for water splitting was proposed. We simulated the solid solutions Bi1−xRExCuOS (RE = Y, La

  15. Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide.

    Science.gov (United States)

    Saliba, E; Abbassi-Ghadi, S; Vowles, R; Camilleri, J; Hooper, S; Camilleri, J

    2009-04-01

    To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement. The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests. Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement. Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.

  16. 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

  17. Simultaneous removal of Cr(VI) and phenol contaminants using Z-scheme bismuth oxyiodide/reduced graphene oxide/bismuth sulfide system under visible-light irradiation.

    Science.gov (United States)

    Chen, Acong; Bian, Zhaoyong; Xu, Jie; Xin, Xin; Wang, Hui

    2017-12-01

    An all-solid-state Z-scheme system containing Bi-based semiconductors bismuth oxyiodide (BiOI) and bismuth sulfide (Bi 2 S 3 ) was constructed on reduced graphene oxide (rGO) sheets through an electrostatic self-assembly method to simultaneously remove aqueous Cr(VI) and phenol. In this Z-scheme that mimicked natural photosynthesis, photoinduced electrons in the conduction band (CB) of BiOI were transferred through rGO and reacted with photoinduced holes in the valence band (VB) of Bi 2 S 3 , which significantly increased its photocatalytic activity. The reduction and oxidation reactions were performed on Bi 2 S 3 and BiOI photocatalysts, respectively. Furthermore, complex contaminants of coexisting heavy metal Cr(VI) and organic phenol were treated using the system under visible-light irradiation. Results showed that Cr(VI) reduction and phenol oxidation were achieved efficiently with optimum reductive and oxidative efficiencies up to 73% and 95% under visible-light irradiation, respectively. This work provided a promising method of simultaneously removing heavy metals and organic pollutants by using a Z-scheme system with enhanced photocatalytic activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Oxidation mechanism of T91 steel in liquid lead-bismuth eutectic: with consideration of internal oxidation

    Science.gov (United States)

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

    2016-01-01

    Clarification of the microscopic events that occur during oxidation is of great importance for understanding and consequently controlling the oxidation process. In this study the oxidation product formed on T91 ferritic/martensitic steel in oxygen saturated liquid lead-bismuth eutectic (LBE) at 823 K was characterized at the nanoscale using focused-ion beam and transmission electron microscope. An internal oxidation zone (IOZ) under the duplex oxide scale has been confirmed and characterized systematically. Through the microscopic characterization of the IOZ and the inner oxide layer, the micron-scale and nano-scale diffusion of Cr during the oxidation in LBE has been determined for the first time. The micron-scale diffusion of Cr ensures the continuous advancement of IOZ and inner oxide layer, and nano-scale diffusion of Cr gives rise to the typical appearance of the IOZ. Finally, a refined oxidation mechanism including the internal oxidation and the transformation of IOZ to inner oxide layer is proposed based on the discussion. The proposed oxidation mechanism succeeds in bridging the gap between the existing models and experimental observations. PMID:27734928

  19. In situ electron beam irradiated rapid growth of bismuth nanoparticles in bismuth-based glass dielectrics at room temperature

    International Nuclear Information System (INIS)

    Singh, Shiv Prakash; Karmakar, Basudeb

    2011-01-01

    In this study, in situ control growth of bismuth nanoparticles (Bi 0 NPs) was demonstrated in bismuth-based glass dielectrics under an electron beam (EB) irradiation at room temperature. The effects of EB irradiation were investigated in situ using transmission electron microscopy (TEM), selected-area electron diffraction and high-resolution transmission electron microscopy. The EB irradiation for 2–8 min enhanced the construction of bismuth nanoparticles with a rhombohedral structure and diameter of 4–9 nm. The average particle size was found to increase with the irradiation time. Bismuth metal has a melting point of 271 °C and this low melting temperature makes easy the progress of energy induced structural changes during in situ TEM observations. This is a very useful technique in nano-patterning for integrated optics and other applications.

  20. Synthesis of binary bismuth-cadmium oxide nanorods with sensitive electrochemical sensing performance

    International Nuclear Information System (INIS)

    Wen, Yong; Pei, Lizhai; Wei, Tian

    2017-01-01

    Binary bismuth-cadmium oxide nanorods have been synthesized by a simple hydrothermal process without templates and additives. X-ray diffraction and high-resolution transmission electron microscopy reveal that the nanorods possess single crystalline tetragonal Bi 2 CdO 4 phase. Scanning electron microscopy and transmission electron microscopy images show that the length and diameter of the nanorods are 20-300 nm and 5-10 μm, respectively. The formation of the binary bismuth-cadmium oxide nanorods is closely related to the hydrothermal parameters. The electrochemical sensing performance of the binary bismuth-cadmium oxide nanorods has been investigated using the nanorods as glassy carbon electrode modifiers. The detection limit is 0.19 μM with a linear range of 0.0005-2 mM. The nanorod-modified glassy carbon electrode exhibits good electrocatalytic activity toward L-cysteine and great application potential for electrochemical sensors.

  1. Synthesis of binary bismuth-cadmium oxide nanorods with sensitive electrochemical sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Yong [Xinjiang Univ., Xinjiang (China). School of Civil Engineering and Architecture; Pei, Lizhai; Wei, Tian [Anhui Univ. of Technology, Anhui (China). School of Materials Science and Engineering

    2017-07-15

    Binary bismuth-cadmium oxide nanorods have been synthesized by a simple hydrothermal process without templates and additives. X-ray diffraction and high-resolution transmission electron microscopy reveal that the nanorods possess single crystalline tetragonal Bi{sub 2}CdO{sub 4} phase. Scanning electron microscopy and transmission electron microscopy images show that the length and diameter of the nanorods are 20-300 nm and 5-10 μm, respectively. The formation of the binary bismuth-cadmium oxide nanorods is closely related to the hydrothermal parameters. The electrochemical sensing performance of the binary bismuth-cadmium oxide nanorods has been investigated using the nanorods as glassy carbon electrode modifiers. The detection limit is 0.19 μM with a linear range of 0.0005-2 mM. The nanorod-modified glassy carbon electrode exhibits good electrocatalytic activity toward L-cysteine and great application potential for electrochemical sensors.

  2. Quantitative 3D Determination of Radiosensitization by Bismuth-Based Nanoparticles.

    Science.gov (United States)

    Alqathami, Mamdooh; Blencowe, Anton; Geso, Moshi; Ibbott, Geoffrey

    2016-03-01

    The nanoparticle-induced dose enhancement effect has been shown to improve the therapeutic efficacy of ionizing radiation in external beam radiotherapy. Whereas previous studies have focused on gold nanoparticles (AuNPs), no quantitative studies have been conducted to investigate the potential superiority of other high atomic number (Z) nanomaterials such as bismuth-based nanoparticles. The aims of this study were to experimentally validate and quantify the dose enhancement properties of commercially available bismuth-based nanoparticles (bismuth oxide (Bi2O3-NPs) and bismuth sulfide (Bi2S3-NPs)), and investigate their potential superiority over AuNPs in terms of radiation dose enhancement. Phantom cuvettes doped with and without nanoparticles where employed for measuring radiation dose enhancement produced from the interaction of radiation with metal nanoparticles. Novel 3D phantoms were employed to investigate the 3D spatial distribution of ionising radiation dose deposition. The phantoms were irradiated with kilovoltage and megavoltage X-ray beams and optical absorption changes were measured using a spectrophotometer and optical CT scanner. The radiation dose enhancement factors (DEFs) obtained for 50 nm diameter Bi2O3-NPs and AuNPs were 1.90 and 1.77, respectively, for 100 kV energy and a nanoparticle concentration of 0.5 mM. In addition, the DEFs of 5 nm diameter Bi2S3-NPs and AuNPs were determined to be 1.38 and 1.51, respectively, for 150 kV energy and a nanoparticle concentration of 0.25 mM. The results demonstrate that both bismuth-based nanoparticles can enhance the effects of radiation. For 6 MV energy the DEFs for all the investigated nanoparticles were lower (< 15%) than with kilovoltage energy.

  3. Preparation of Bismuth- and Thallium-Based Cuprate Superconductors

    Science.gov (United States)

    1991-10-01

    erage work period (29); early symptoms of thallium - poisoning include hair loss. Safety considerations in handling thallium compounds should include... Thallium -Based Cuprate Superconductors by S. A. Sunshine and T. A. Vanderah Chemistry Division, Research Department Naval Weapons Center, China Lake, CA...Technical Report #2 10/90-9/91 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Preparation of Bismuth- and Thallium -Based Cuprate Suoerconductors NOOO14-91 WX

  4. Influence of bismuth loading in polystyrene-based plastic scintillators for low energy gamma spectroscopy

    International Nuclear Information System (INIS)

    Bertrand, G.H.V.; Sguerra, F.; Dehe-Pittance, C.; Carrel, F.; Coulon, R.; Normand, S.; Barat, E.; Dautremer, T.; Montagu, T.; Hamel, M.

    2014-01-01

    This article presents the synthesis and the blend of bismuth complexes in polystyrene based plastic scintillators. A specific design has enabled the fabrication of a scintillator loaded with up to 17 wt% of bismuth. Tri-carboxylate and tri-aryl bismuth compounds were used to explore and understand the influence of bismuth loading on the two main criteria of plastic scintillation: light yield and detection efficiency of γ-rays. For gamma radiation with an energy ≤200 keV, bismuth loaded scintillators demonstrate the ability to produce a photoelectric peak (total absorption peak) in pulse height spectra. The increase of interactions due to bismuth doping was quantified and fitted with standard models. Finally the performance of our bismuth loaded scintillators was evaluated to be better than that of a commercial lead loaded counterpart. (authors)

  5. Preparation of Bismuth Oxide Photocatalyst and Its Application in White-light LEDs

    Directory of Open Access Journals (Sweden)

    Yen-Chang Chu

    2013-01-01

    Full Text Available Bismuth oxide photocatalysts were synthesized and coated on the front surface of phosphor-converted white light-emitting diodes to produce a safe and environmentally benign lighting source. Bismuth oxide photocatalyst powders were synthesized with a spray pyrolysis method at 500°C, 600°C, 700°C, and 800°C. Using the absorption spectrum in the blue and UV regions of the bismuth oxide photocatalysts, the blue light and UV leakage problems of phosphor-converted white LEDs can be significantly reduced. The experimental results showed that bismuth oxide photocatalyst synthesized at 700°C exhibited the most superior spectrum inhibiting ability. The suppressed ratio reached 52.33% in the blue and UV regions from 360 to 420 nm. Related colorimetric parameters and the photocatalyst decomposition ability of fabricated white-light LEDs were tested. The CIE chromaticity coordinates (x,y were (0.349, 0.393, and the correlated color temperature was 4991 K. In addition, the coating layer of photocatalyst can act as an air purifier and diffuser to reduce glare. A value of 66.2±0.60 ppmv of molecular formaldehyde gas can be decomposed in 120 mins.

  6. Studying Impact of Different Precipitating Agents on Crystal Structure, Morphology and Photocatalytic Activity of Bismuth Oxide

    Directory of Open Access Journals (Sweden)

    Yayuk Astuti

    2017-10-01

    How to Cite: Astuti, Y., Arnelli, Pardoyo, Fauziyah, A., Nurhayati, S., Wulansari, A.D., Andianingrum, R., Widiyandari, H., Bhaduri, G.A. (2017. Studying Impact of Different Precipitating Agents on Crystal Structure, Morphology and Photocatalytic Activity of Bismuth Oxide. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (3: 478-484 (doi:10.9767/bcrec.12.3.1144.478-484

  7. Dynamic spatial structure of spontaneous beams in photorefractive bismuth sillicon oxide

    DEFF Research Database (Denmark)

    Buchhave, Preben; Lyuksyutov, S.; Vasnetsov, M.

    1996-01-01

    We report the domain structure of spontaneously occurring beams (subharmonics) in photorefractive bismuth silicon oxide with an applied electric field from 1 to 6 kV/cm and a running grating. The subharmonic beams are generated in a pattern of domains that evolve dynamically as they move through...

  8. Porous structure of oxide bismuth-molybdenum catalysts applied to silica gel

    International Nuclear Information System (INIS)

    Mikhajlenko, E.L.; Tarasova, D.V.; Razumova, N.V.

    1982-01-01

    A study was made on the formation of porous structure of oxide bismuth-molybdenum catalysts applied to silica gel. It has been shown that the structure and phase composition of the catalysts are determined by an initial state of a carrier. When a stabilized zol is used as a carrier its purification during the synthesis takes place as a result of the sodium ion interaction with molybdenum and bismuth ions with the formation of NaBi(MoO 4 ) 2 phase. The change in the catalyst structure during heat treatment is specified by the carrier caking in the presence of the Bi 2 (MoO 4 ) 3 fusible phase

  9. Methylene blue photocatalysis in the presence of bismuth oxide under UV and solar light irradiation

    Directory of Open Access Journals (Sweden)

    Vanessa Rocha Liberatti

    2014-05-01

    Full Text Available Bismuth oxide (Bi2O3, an n-type semiconductor has been satisfactorily investigated for photocatalytic organic contaminant remediation. The Bi2O3 was prepared by solution combustion synthesis (SCS using as the oxidizing bismuth nitrate in acidic medium and urea as fuel. The influence of the type of synthesis on the photocatalytic properties of the oxide formed was investigated by XRD. From the diffractograms was verified that the materials obtained are predominantly of Bi2O3 crystals, it is possible to identify a sample with two crystalline phases, monoclinic (α-Bi2O3 and tetragonal (β-Bi2O3, and the other with only the monoclinic (α-Bi2O3. The two-phase oxide showed higher photocatalytic activity for discoloration of methylene blue under UV irradiation (60.59% and under sunlight (61.64% in 664 nm, followed kinetic law of pseudo-first order.

  10. High temperature superconducting material: Bismuth strontium calcium copper oxide. (Latest citations from the Aerospace database). Published Search

    International Nuclear Information System (INIS)

    1993-11-01

    The bibliography contains citations concerning the development, fabrication, and analysis of a high temperature superconducting material based on bismuth-strontium-calcium-copper-oxides (Bi-Sr-Ca-Cu-O). Topics include the physical properties, structural and compositional analysis, magnetic field and pressure effects, and noble metal dopings of Bi-Sr-Ca-Cu-O based systems. The highest transition temperature recorded to date for this material was 120 degrees Kelvin. Fabrication methods and properties of Bi-Sr-Ca-Cu-O films and ceramics are also considered. (Contains 250 citations and includes a subject term index and title list.)

  11. Dental discoloration caused by bismuth oxide in MTA in the presence of sodium hypochlorite.

    Science.gov (United States)

    Marciano, Marina Angélica; Duarte, Marco Antonio Hungaro; Camilleri, Josette

    2015-12-01

    The aim of this research was to analyse the dental discolouration caused by mineral trioxide aggregate (MTA) induced by bismuth oxide and also assess the colour stability of other dental cements. Bismuth oxide, calcium tungstate and zirconium oxide were placed in contact with sodium hypochlorite for 24 h after which they were dried and photographed. Phase analyses were performed by X-ray diffraction (XRD) of radiopacifiers before and after immersion in sodium hypochlorite. Furthermore, teeth previously immersed in water or sodium hypochlorite were filled with MTA Angelus, Portland cement (PC), PC with 20 % zirconium oxide, PC with 20 % calcium tungstate and Biodentine. Teeth were immersed for 28 days in Hank's balanced salt solution after which they were sectioned and characterized using scanning electron microscopy (SEM) with energy-dispersive mapping and stereomicroscopy. Bismuth oxide in contact with sodium hypochlorite exhibited a change in colour from light yellow to dark brown. XRD analysis demonstrated peaks for radiopacifier and sodium chloride in samples immersed in sodium hypochlorite. The SEM images of the dentine to material interface showed alteration in material microstructure for MTA Angelus and Biodentine with depletion in calcium content in the material. The energy-dispersive maps showed migration of radiopacifier and silicon in dentine. MTA Angelus in contact with a tooth previously immersed in sodium hypochlorite resulted in colour alteration at the cement/dentine interface. MTA Angelus should not be used after irrigation with sodium hypochlorite as this will result in tooth discoloration.

  12. 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.

  13. Pharmacokinetics of metronidazole, tetracycline and bismuth in healthy volunteers after oral administration of compound tablets containing a combination of metronidazole, tetracycline hydrochloride and bismuth oxide.

    Science.gov (United States)

    Wu, Y; Ding, L; Huang, N-Y; Wen, A-D; Liu, B; Li, W-B

    2015-02-01

    To eradicate Helicobacter pylori in human pylorus and to heal duodenal ulcers, recently, a new formulation of combination tablets containing metronidazole 125 mg, tetracycline hydrochloride 125 mg and bismuth oxide 40 mg has been developed. To investigate the pharmacokinetics of metronidazole, tetracycline and bismuth in healthy Chinese volunteers after oral administration of the test formulation. A one-sequence, 3-period study was conducted in 12 Chinese healthy volunteers (6 male, 6 female). Volunteers each received single low dose (1 tablet) under fed condition in period 1, single high dose (3 tablets) under fasted condition in period 2, and single high dose (3 tablets) and multiple doses (3 tablets at once, 4 times daily for 7 consecutive days) under fed condition in period 3. Blood samples were collected and determined over 48 h in every period. After single high dose administration under fed condition, the C max of metronidazole, tetracycline and bismuth were 6.833 ± 0.742 μg/mL, 0.8513 ± 0.1253 μg/mL and 3.32 ± 1.89 ng/mL, respectively. The C max and AUC 0-48 of metronidazole increased in proportion to the doses within the tested dose range, but tetracycline and bismuth did not. Food caused 10% and 80% decrease of the C max for metronidazole and bismuth, respectively, but did not affect tetracycline. No gender effect was found on the pharmacokinetics of the 3 ingredients. In the steady state, the C av of metronidazole, tetracycline and bismuth were 20.75 ± 3.52 μg/mL, 1.900 ± 0.243 μg/mL and 5.61 ± 1.34 ng/mL, respectively. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Assessment of color stability of white mineral trioxide aggregate angelus and bismuth oxide in contact with tooth structure.

    Science.gov (United States)

    Marciano, Marina Angélica; Costa, Reginaldo Mendonça; Camilleri, Josette; Mondelli, Rafael Francisco Lia; Guimarães, Bruno Martini; Duarte, Marco Antonio Hungaro

    2014-08-01

    Dental discoloration with use of materials containing bismuth oxide has been reported. It is postulated that the discoloration is a result of chemical interaction of bismuth oxide with dentin. The aim of the study was to analyze dental color alteration and the chemical interaction of bismuth oxide with the main components present in composite (methacrylate) and in dentin (collagen). Fifty bovine teeth were prepared and filled with white mineral trioxide aggregate (MTA) Angelus, Portland cement (PC) with 20% zirconium oxide, or PC with 20% calcium tungstate and then sealed with composite. Triple antibiotic paste and unfilled samples were the positive and negative controls, respectively. The specimens were stored in separate flasks immersed in tap water at 37°C with ambient light blocked out. The color assessment was performed with a spectrophotometer at different intervals, namely before filling and 24 hours, 15 days, and 30 days after filling. The color change and the luminosity were calculated. The statistical analysis was performed by using nonparametric Kruskal-Wallis and Dunn tests (P bismuth oxide, zirconium oxide, and calcium tungstate with collagen and methacrylate was assessed by placing the materials in contact, followed by color assessment. The analysis of color change values showed that all the materials presented color alteration after the evaluated periods. Statistically higher luminosity was verified for PC/20% zirconium oxide in comparison with white MTA Angelus (P Bismuth oxide exhibited a color change when in contact with collagen. The color of white MTA Angelus was altered in contact with dental structures. Collagen, which is present in dentin matrix, reacted with bismuth oxide, resulting in a grayish discoloration. The use of an alternative radiopacifier to replace bismuth in white MTA is indicated. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. The fabrication and thermal properties of bismuth-aluminum oxide nanothermometers.

    Science.gov (United States)

    Wang, Chiu-Yen; Chen, Shih-Hsun; Tsai, Ping-Hsin; Chiou, Chung-Han; Hsieh, Sheng-Jen

    2017-01-27

    Bismuth (Bi) nanowires, well controlled in length and diameter, were prepared by using an anodic aluminum oxide (AAO) template-assisted molding injection process with a high cooling rate. A high performance atomic layer deposition (ALD)-capped bismuth-aluminum oxide (Bi-Al 2 O 3 ) nanothermometer is demonstrated that was fabricated via a facile, low-cost and low-temperature method, including AAO templated-assisted molding injection and low-temperature ALD-capped processes. The thermal behaviors of Bi nanowires and Bi-Al 2 O 3 nanocables were studied by in situ heating transmission electron microscopy. Linear thermal expansion of liquid Bi within native bismuth oxide nanotubes and ALD-capped Bi-Al 2 O 3 nanocables were evaluated from 275 °C to 700 °C and 300 °C to 1000 °C, respectively. The results showed that the ALD-capped Bi-Al 2 O 3 nanocable possesses the highest working temperature, 1000 °C, and the broadest operation window, 300 °C-1000 °C, of a thermal-expanding type nanothermometer. Our innovative approach provides another way of fabricating core-shell nanocables and to further achieve sensing local temperature under an extreme high vacuum environment.

  16. 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.

  17. Progress in bismuth vanadate photoanodes for use in solar water oxidation.

    Science.gov (United States)

    Park, Yiseul; McDonald, Kenneth J; Choi, Kyoung-Shin

    2013-03-21

    Harvesting energy directly from sunlight as nature accomplishes through photosynthesis is a very attractive and desirable way to solve the energy challenge. Many efforts have been made to find appropriate materials and systems that can utilize solar energy to produce chemical fuels. One of the most viable options is the construction of a photoelectrochemical cell that can reduce water to H(2) or CO(2) to carbon-based molecules. Bismuth vanadate (BiVO(4)) has recently emerged as a promising material for use as a photoanode that oxidizes water to O(2) in these cells. Significant advancement in the understanding and construction of efficient BiVO(4)-based photoanode systems has been made within a short period of time owing to various newly developed ideas and approaches. In this review, the crystal and electronic structures that are closely related to the photoelectrochemical properties of BiVO(4) are described first, and the photoelectrochemical properties and limitations of BiVO(4) are examined. Subsequently, the latest efforts toward addressing these limitations in order to improve the performances of BiVO(4)-based photoanodes are discussed. These efforts include morphology control, formation of composite structures, composition tuning, and coupling oxygen evolution catalysts. The discussions and insights provided in this review reflect the most recent approaches and directions for general photoelectrode developments and they will be directly applicable for the understanding and improvement of other photoelectrode systems.

  18. Development of disposable bulk-modified screen-printed electrode based on bismuth oxide for stripping chronopotentiometric analysis of lead (II) and cadmium (II) in soil and water samples

    Energy Technology Data Exchange (ETDEWEB)

    Kadara, Rashid O. [Cranfield Health, Cranfield University, Silsoe, Bedfordshire MK45 4DT (United Kingdom); School of Science and Technology, Nottingham Trent University, Clifton Campus, Nottinghamshire NG11 8NS (United Kingdom)], E-mail: kayusee2001@yahoo.co.uk; Tothill, Ibtisam E. [Cranfield Health, Cranfield University, Silsoe, Bedfordshire MK45 4DT (United Kingdom)

    2008-08-08

    A bulk-modified screen-printed carbon electrode characterised for metal ion detection is presented. Bismuth oxide (Bi{sub 2}O{sub 3}) was mixed with graphite-carbon ink to obtain the modified electrode. The best composition was 2% Bi{sub 2}O{sub 3} (wt%) in the graphite-carbon ink. The modified electrode with onboard screen-printed carbon counter and silver-silver chloride pseudo-reference electrodes exhibited good performance in the electrochemical measurement of lead (II) and cadmium (II). The electrode displayed excellent linear behaviour in the concentration range examined (20-300 {mu}g L{sup -1}) with limits of detection of 8 and 16 {mu}g L{sup -1} for both lead (II) and cadmium (II), respectively. The analytical utility of the modified electrode was illustrated by the stripping chronopotentiometric determinations of lead (II) in soil extracts and wastewater samples.

  19. Development of disposable bulk-modified screen-printed electrode based on bismuth oxide for stripping chronopotentiometric analysis of lead (II) and cadmium (II) in soil and water samples

    International Nuclear Information System (INIS)

    Kadara, Rashid O.; Tothill, Ibtisam E.

    2008-01-01

    A bulk-modified screen-printed carbon electrode characterised for metal ion detection is presented. Bismuth oxide (Bi 2 O 3 ) was mixed with graphite-carbon ink to obtain the modified electrode. The best composition was 2% Bi 2 O 3 (wt%) in the graphite-carbon ink. The modified electrode with onboard screen-printed carbon counter and silver-silver chloride pseudo-reference electrodes exhibited good performance in the electrochemical measurement of lead (II) and cadmium (II). The electrode displayed excellent linear behaviour in the concentration range examined (20-300 μg L -1 ) with limits of detection of 8 and 16 μg L -1 for both lead (II) and cadmium (II), respectively. The analytical utility of the modified electrode was illustrated by the stripping chronopotentiometric determinations of lead (II) in soil extracts and wastewater samples

  20. First proof of bismuth oxide nanoparticles as efficient radiosensitisers on highly radioresistant cancer cells.

    Science.gov (United States)

    Stewart, Callum; Konstantinov, Konstantin; McKinnon, Sally; Guatelli, Susanna; Lerch, Michael; Rosenfeld, Anatoly; Tehei, Moeava; Corde, Stéphanie

    2016-11-01

    This study provides the first proof of the novel application of bismuth oxide as a radiosensitiser. It was shown that on the highly radioresistant 9L gliosarcoma cell line, bismuth oxide nanoparticles sensitise to both kilovoltage (kVp) or megavoltage (MV) X-rays radiation. 9L cells were exposed to a concentration of 50μg.mL -1 of nanoparticle before irradiation at 125kVp and 10MV. Sensitisation enhancement ratios of 1.48 and 1.25 for 125kVp and 10MV were obtained in vitro, respectively. The radiation enhancement of the nanoparticles is postulated to be a combination of the high Z nature of the bismuth (Z=83), and the surface chemistry. Monte Carlo simulations were performed to elucidate the physical interactions between the incident radiation and the nanoparticle. The results of this work show that Bi 2 O 3 nanoparticles increase the radiosensitivity of 9L gliosarcoma tumour cells for both kVp and MV energies. Monte Carlo simulations demonstrate the advantage of a platelet morphology. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  1. Study of the bismuth oxide concentration required to provide Portland cement with adequate radiopacity for endodontic use.

    Science.gov (United States)

    Bueno, Carlos Eduardo da Silveira; Zeferino, Eduardo Gregatto; Manhães, Luiz Roberto Coutinho; Rocha, Daniel Guimarães Pedro; Cunha, Rodrigo Sanches; De Martin, Alexandre Sigrist

    2009-01-01

    The purpose of this study was to determine the ideal concentration of bismuth oxide in white Portland cement to provide it with sufficient radiopacity for use as an endodontic material (ADA specification #57). 2-mm thick standardized test specimens of white MTA and of white Portland cement, as controls, and of white Portland cement with the experimental addition of 5%, 10%, 15%, 20%, 25% or 30% of bismuth oxide were radiographed and compared with various thicknesses of pure aluminum, using optic density to determine the observed grayscale levels of radiopacity in a scale ranging from 0 to 255. The data was submitted to ANOVA (pPortland cement with 0%, 5%, 10%, 15%, 20%, 25% and 30% of bismuth oxide presented mean readings of 63.3, 95.7, 110.7, 142.7, 151.3, 161.0 and 180.0 respectively. MTA presented a mean reading of 157.3. The readings of MTA and white Portland cement with 15% bismuth oxide did not differ significantly from the reading observed for a thickness of 4 mm of aluminum (145.3), which is considered ideal for a test specimen by ADA specification #57 (2 mm above the thickness of the test specimen). White MTA and white Portland cement with 15% bismuth oxide presented the radiopacity required for an endodontic cement.

  2. Bismuth Sodium Titanate Based Materials for Piezoelectric Actuators

    Science.gov (United States)

    Reichmann, Klaus; Feteira, Antonio; Li, Ming

    2015-01-01

    The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized. PMID:28793724

  3. Bismuth Sodium Titanate Based Materials for Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    Klaus Reichmann

    2015-12-01

    Full Text Available The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized.

  4. Bismuth Sodium Titanate Based Materials for Piezoelectric Actuators.

    Science.gov (United States)

    Reichmann, Klaus; Feteira, Antonio; Li, Ming

    2015-12-04

    The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized.

  5. Nucleation and growth of lead oxide particles in liquid lead-bismuth eutectic.

    Science.gov (United States)

    Gladinez, Kristof; Rosseel, Kris; Lim, Jun; Marino, Alessandro; Heynderickx, Geraldine; Aerts, Alexander

    2017-10-18

    Liquid lead-bismuth eutectic (LBE) is an important candidate to become the primary coolant of future, generation IV, nuclear fast reactors and Accelerator Driven System (ADS) concepts. One of the main challenges with the use of LBE as a coolant is to avoid its oxidation which results in solid lead oxide (PbO) precipitation. The chemical equilibria governing PbO formation are well understood. However, insufficient kinetic information is currently available for the development of LBE-based nuclear technology. Here, we report the results of experiments in which the nucleation, growth and dissolution of PbO in LBE during temperature cycling are measured by monitoring dissolved oxygen using potentiometric oxygen sensors. The metastable region, above which PbO nucleation can occur, has been determined under conditions relevant for the operation of LBE cooled nuclear systems and was found to be independent of setup geometry and thus thought to be widely applicable. A kinetic model to describe formation and dissolution of PbO particles in LBE is proposed, based on Classical Nucleation Theory (CNT) combined with mass transfer limited growth and dissolution. This model can accurately predict the experimentally observed changes in oxygen concentration due to nucleation, growth and dissolution of PbO, using the effective interfacial energy of a PbO nucleus in LBE as a fitting parameter. The results are invaluable to evaluate the consequences of oxygen ingress in LBE cooled nuclear systems under normal operating and accidental conditions and form the basis for the development of cold trap technology to avoid PbO formation in the primary reactor circuit.

  6. Structural Dynamics and Evolution of Bismuth Electrodes during Electrochemical Reduction of CO 2 in Imidazolium-Based Ionic Liquid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Medina-Ramos, Jonnathan [Chemical; Lee, Sang Soo [Chemical; Fister, Timothy T. [Chemical; Hubaud, Aude A. [Chemical; Sacci, Robert L.; Mullins, David R.; DiMeglio, John L. [Department; Pupillo, Rachel C. [Department; Velardo, Stephanie M. [Department; Lutterman, Daniel A.; Rosenthal, Joel [Department; Fenter, Paul [Chemical

    2017-09-14

    Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM), and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM]+) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF6 and TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi2O3) and metallic bismuth (Bi0) and that the reduction of oxidized bismuth species to Bi0 is fully achieved under potentials at which CO2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO2 reduction near -1.75 V vs Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM]+ solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates that extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. In contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO2 reduction. Overall, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM]+-based

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

    DEFF Research Database (Denmark)

    Schuh, Kirsten; Kleist, Wolfgang; Høj, Martin

    2014-01-01

    Hydrothermal synthesis has been used as a soft chemical method to prepare bismuth molybdate catalysts for the selective oxidation of propylene to acrolein. All obtained samples displayed a plate-like morphology, but their individual aspect ratios varied with the hydrothermal synthesis conditions...... 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 at 550...

  8. Effect of Bismuth Oxide on the Microstructure and Electrical Conductivity of Yttria Stabilized Zirconia

    Directory of Open Access Journals (Sweden)

    Liwei Liu

    2016-03-01

    Full Text Available Bismuth oxide (Bi2O3-doped yttria-stabilized zirconia (YSZ were prepared via the solid state reaction method. X-ray diffraction and electron diffraction spectroscopy results indicate that doping with 2 mol% Bi2O3 and adding 10 mol% yttria result in a stable zirconia cubic phase. Adding Bi2O3 as a dopant increases the density of zirconia to above 96%, while reducing its normal sintering temperature by approximately 250 °C. Moreover, electrical impedance analyses show that adding Bi2O3 enhances the conductivity of zirconia, improving its capability as a solid electrolyte for intermediate or even lower temperatures.

  9. An acclerator-based installation of small power with the lead-bismuth coolant

    Energy Technology Data Exchange (ETDEWEB)

    Gorshkov, V.T.; Yefimov, E.I.; Novikova, N.N. [Research and Development Bereau, Podolsk (Russian Federation)] [and others

    1995-10-01

    The structure of the accelerator-based installation is described that includes the subcritical reactor-blanket with power 15 MW(h) cooled with lead-bismuth, the lead-bismuth flow target where a beam of {alpha}-particle is injected, the equipment of a primary and secondary curcuits. Some results of calculations and estimations are discussed that have been carried out to justify the target and blanket constructions. Some main characteristics of the installation are presented.

  10. Different bismuth-based therapies for eradicating Helicobacter pylori: Randomized clinical trial of efficacy and safety.

    Science.gov (United States)

    Gokcan, Hale; Oztas, Erkin; Onal, Ibrahim Koral

    2016-02-01

    Bismuth salts are used for treating dyspepsia, and they exert antibacterial effects on Helicobacter pylori. This study aimed to compare the efficacy and safety of three bismuth-containing combination regimens for H. pylori eradication in a Turkish population. In this single-center study, 149 patients, who were diagnosed with H. pylori infection with urea breath test and histopathological examination, were randomized to receive the following therapies for 14 days: (1) bismuth-containing clarithromycin-based triple therapy (CBS-LAC), (2) bismuth-containing levofloxacin-based triple therapy (CBS-LAL), and (3) bismuth-containing quadruple therapy (BCQT). Eradication rates were evaluated six weeks after the treatment by performing intention to treat (ITT) and per protocol (PP) analyses. In addition, data on side effect profiles and patient compliance were collected. PP and ITT analyses showed that eradication rates were 86% and 81.1%, respectively, with BCQT; 68.3% and 66.7%, respectively, with CBS-LAL therapy; and 65.3% and 59.3%, respectively, with CBS-LAC therapy. Eradication rates obtained using PP and ITT analyses were statistically significant for all the regimens. Addition of bismuth to standard triple and levofloxacin-based regimen did not show an acceptable increase in eradication rates. Therefore, BCQT may be preferred for the first-line treatment of H. pylori infection. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  11. Synthesis of Bismuth Oxide Thin Films Deposited by Reactive Magnetron Sputtering

    International Nuclear Information System (INIS)

    Iljinas, A.; Burinskas, S.; Dudonis, J.

    2011-01-01

    In this work Bi 2 O 3 thin films were deposited onto the Si (111) and soda lime glass substrates by the reactive direct current magnetron sputtering system using pure Bi as a sputtering target. The dependences of electro-optical characteristics of the films on the substrate type and temperature were investigated. Transmittance and reflectance of the Bi 2 O 3 films were measured with ultraviolet and visible light spectrometer. It was found that the substrate temperature during deposition has a very strong influence on the phase components of thin films. The results indicate that the direct allowed transitions dominate in the films obtained in this work. For the direct allowed transitions the band gap energy is found to be about 1.98 eV and 2.2 eV. The reflectance of thin bismuth oxide film depends on the substrate. Small transparency of thin films grown on glass is more related to large reflectance than absorption. The reflectance spectra of the bismuth oxide thin films deposited on the Si substrates show higher quality of optical characteristics compared to the samples deposited on glass substrates. (author)

  12. Elastic Behavior of Borate Glasses Containing Lead and Bismuth Oxides

    Directory of Open Access Journals (Sweden)

    Mehrdad Khanisanij

    2014-01-01

    Full Text Available PbO and Bi2O3 binary borate glasses with different compositions, (MOX(B2O31−X (M = Pb, Bi, have been characterized and ultrasonic velocity as well as density is taken into account. In addition, the results have been compared with those of Ag, K, and Li oxide borate glasses from others. The ultrasonic velocities (both longitudinal and transverse and density for (PbOX(B2O31−X and (Bi2O3X(B2O31−X have been measured accurately and elastic moduli as well as hardness and Poisson’s ratio was determined. It has been demonstrated that density and ultrasonic velocities are enhanced by increasing PbO and Bi2O3 molar fraction with different values for each borate glass composition. However, the enhancement of ultrasonic velocities did not carry on continuously and after reaching a maximum point, they fell down dramatically. Both PbO and Bi2O3 showed almost similar glass improvement in case of density, ultrasonic velocity, and elastic moduli.

  13. Tribochemistry of Bismuth and Bismuth Salts for Solid Lubrication.

    Science.gov (United States)

    Gonzalez-Rodriguez, Pablo; van den Nieuwenhuijzen, Karin J H; Lette, Walter; Schipper, Dik J; Ten Elshof, Johan E

    2016-03-23

    One of the main trends in the past decades is the reduction of wastage and the replacement of toxic compounds in industrial processes. Some soft metallic particles can be used as nontoxic solid lubricants in high-temperature processes. The behavior of bismuth metal particles, bismuth sulfide (Bi2S3), bismuth sulfate (Bi2(SO4)3), and bismuth oxide (Bi2O3) as powder lubricants was studied in a range of temperatures up to 580 °C. The mechanical behavior was examined using a high-temperature pin-on-disc setup, with which the friction force between two flat-contact surfaces was recorded. The bismuth-lubricated surfaces showed low coefficients of friction (μ ≈ 0.08) below 200 °C. Above the melting temperature of the metal powder at 271 °C, a layer of bismuth oxide developed and the friction coefficient increased. Bismuth oxide showed higher friction coefficients at all temperatures. Bismuth sulfide exhibited partial oxidation upon heating but the friction coefficient decreased to μ ≈ 0.15 above 500 °C, with the formation of bismuth oxide-sulfate, while some bismuth sulfate remained. All surfaces were studied by X-ray diffraction (XRD), confocal microscopy, high-resolution scanning electron microscopy (HR-SEM), and energy-dispersive X-ray spectroscopy (EDS). This study reveals how the partial oxidation of bismuth compounds at high temperatures affects their lubrication properties, depending on the nature of the bismuth compound.

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

    International Nuclear Information System (INIS)

    Pendleton, P.; Taylor, D.

    1976-01-01

    Propene + 18 0 2 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 [ 16 0] acrolein content of the total acrolein formed and the proportion of 16 0 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)

  15. 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

    2015-01-01

    A series of bismuth molybdate catalysts with relatively high surface area was prepared via mild hydrothermal synthesis. Variation of the pH value and Bi/Mo ratio during the synthesis allowed tuning of the crystalline Bi-Mo oxide phases, as determined by X-ray diffraction (XRD) and Raman spectrosc...

  16. Incorporation of thiosemicarbazide in Amberlite IRC-50 for separation of astatine from α-irradiated bismuth oxide

    International Nuclear Information System (INIS)

    Roy, Kamalika; Basu, S.; Ramaswami, A.; Nayak, Dalia; Lahiri, Susanta

    2004-01-01

    A chelating resin was synthesized by incorporating thiosemicarbazide into Amberlite IRC-50, a weakly acidic polymer. Astatine radionuclides produced by α-irradiating bismuth oxide were separated using the newly synthesized chelating resin. The resin showed high selectivity for astatine. The adsorbed astatine was recovered using 0.1 M EDTA at pH∼10

  17. 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.

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

    International Nuclear Information System (INIS)

    Ueda, W.; Moro-oka, Y.; Ikawa, T.

    1981-01-01

    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 18 O 2 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 Bi 3+ ; catalyst particles are composed of a shell of bismuth molybdates and a core of MMoO 4 . 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 Bi 3+

  19. Recent Advances in Bismuth-Based Nanomaterials for Photoelectrochemical Water Splitting.

    Science.gov (United States)

    Bhat, Swetha S M; Jang, Ho Won

    2017-08-10

    In recent years, bismuth-based nanomaterials have drawn considerable interest as potential candidates for photoelectrochemical (PEC) water splitting owing to their narrow band gaps, nontoxicity, and low costs. The unique electronic structure of bismuth-based materials with a well-dispersed valence band comprising Bi 6s and O 2p orbitals offers a suitable band gap to harvest visible light. This Review presents significant advancements in exploiting bismuth-based nanomaterials for solar water splitting. An overview of the different strategies employed and the new ideas adopted to improve the PEC performance of bismuth-based nanomaterials are discussed. Morphology control, the construction of heterojunctions, doping, and co-catalyst loading are several approaches that are implemented to improve the efficiency of solar water splitting. Key issues are identified and guidelines are suggested to rationalize the design of efficient bismuth-based materials for sunlight-driven water splitting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. 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.

  1. 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.

  2. Electrical characterization of strontium titanate borosilicate glass ceramics system with bismuth oxide addition using impedance spectroscopy

    International Nuclear Information System (INIS)

    Thakur, O.P.; Kumar, Devendra; Parkash, Om; Pandey, Lakshman

    2003-01-01

    The ac electrical data, measured in the frequency range 0.1 kHz-1 MHz, were used to study the electrical response of strontium titanate borosilicate glass ceramic system with bismuth oxide addition. Complex plane plots from these electrical data for various glass ceramic samples reveal contributions from simultaneously operating polarization mechanisms to overall dielectric behavior. The complex modulus (M * ) representation of electrical data for various glass ceramic samples were found to be more informative. Equivalent circuit models, which represent the electrical behavior of glass ceramic samples, were determined using complex non-linear least square (CNLS) fitting. An attempt has been made to understand the dielectric behavior of various glass ceramics in terms of contributions arising from different polarization processes occurring at glassy matrix, crystalline phases, glass to crystal interface region and blocking electrodes. Glass ceramics containing SrTiO 3 and TiO 2 (rutile) phases show thermally stable dielectric behavior

  3. Optical and electrical properties of thin films of bismuth ferric oxide

    International Nuclear Information System (INIS)

    Cardona R, D.

    2014-01-01

    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 Fe 2 O 3 ) 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 BiFeO 3 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 BiFeO 3 composition. These samples showed a secondary phase (Bi 2 5FeO 4 0 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-Fe 2 O 3 ) 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)

  4. Crystal structure and electrical properties of gadolinia doped bismuth oxide nanoceramic powders

    Energy Technology Data Exchange (ETDEWEB)

    Ar Latin-Small-Letter-Dotless-I , M. [Physics Department, Faculty of Sciences, Erciyes University, Kayseri (Turkey); Tasc Latin-Small-Letter-Dotless-I oglu, I.; Alt Latin-Small-Letter-Dotless-I ndal, S. [Physics Department, Faculty of Arts and Sciences, Gazi University, Ankara (Turkey); Uslu, I.; Aytimur, A. [Department of Chemistry Education, Gazi University, Ankara (Turkey); Karaaslan, T. [Physics Department, Faculty of Sciences, Erciyes University, Kayseri (Turkey); Kocyigit, S., E-mail: sergas_29@hotmail.com [Department of Chemistry Education, Gazi University, Ankara (Turkey)

    2012-10-15

    A novel method of fabrication of gadolinia doped bismuth oxide nanoceramic via the sol-gel technique is reported. Their thermal, structural and morphological properties are described by measurements of Differential Thermal Analysis/Thermal Gravimetry, X-ray Powder Diffraction and Scanning Electron Microscopy. The samples have stable high ion conductive face centered cubic {delta}-phase nanocrystalline structure. The electrical measurements of the nanoceramic powders were carried out in the temperature range of (689-1091 K) using 4-point probe technique. There is a transition between two distinct regions at 720 Degree-Sign C, which can be attributed to the order-disorder transition. This observation is supported by the differential thermal analysis measurements. The experimental results show that the value of conductivity increases with increasing temperature over linear parts characterized by two different activation energies. The conductivity data over whole measured temperature range were fitted to the Arrhenius equations of conductivity and it shows two linear regions with different slopes which correspond to low-temperature range (689-975 K) and high-temperature range (999-1091 K). The values of E{sub a1} and E{sub a2} were obtained from the slopes of ln {sigma}{sub DC} versus q/kT plot as 1.25 eV and 2.81 eV for low-temperature range and high-temperature range, respectively. -- Highlights: Black-Right-Pointing-Pointer Gadolinia doped bismuth oxide nanoceramic were produced via the sol-gel technique. Black-Right-Pointing-Pointer Structural characterizations were carried out by XRD and SEM techniques. Black-Right-Pointing-Pointer Thermal and electrical properties were evaluated by DTA/TG and 4-point probe. Black-Right-Pointing-Pointer Crystallite size was calculated using Scherrer equation. Black-Right-Pointing-Pointer The dislocation density, the microstrain and unit cell volume were calculated.

  5. Bismuth and polonium

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    Bismuth and polonium are the only elements in their respective chemical series that form cations. The lighter elements in both groups only form anions. Bismuth has trivalent and pentavalent oxidation states, but the latter is relatively unstable with respect to formation of the oxide. Polonium exhibits a range of oxidation states, with the divalent and tetravalent states forming the cations Po 2+ and PoO 2+ in aqueous solution. In aqueous solution, polonium(IV) forms the oxoanion PoO 2+ . Levy, Danford and Agron conducted X-ray diffraction studies of bismuth(III) solutions and established a structure for the hexameric species, Bi 6 (OH) 12 6+ . The reported data for the solubility constants of polymeric species of bismuth (III) are listed in this chapter. The stability and solubility constants derived at 25 C for zero ionic strength have been used to create a predominance speciation diagram for bismuth(III).

  6. Bismuth Subsalicylate

    Science.gov (United States)

    Pink Bismuth® ... Bismuth subsalicylate is used to treat diarrhea, heartburn, and upset stomach in adults and children 12 years of age and older. Bismuth subsalicylate is in a class of medications called ...

  7. Ex vivo assessment of genotoxicity and cytotoxicity in murine fibroblasts exposed to white MTA or white Portland cement with 15% bismuth oxide.

    Science.gov (United States)

    Zeferino, E G; Bueno, C E S; Oyama, L M; Ribeiro, D A

    2010-10-01

    To evaluate whether white mineral trioxide aggregate (MTA) or white Portland cement with 15% bismuth oxide were able to induce genetic damage and cellular death ex vivo. Aliquots of 1 × 10(4) murine fibroblasts were incubated at 37 °C for 3 h with MTA (white) or white Portland cement with 15% bismuth oxide, at final concentrations ranging from 10 to 1000 μg mL(-1) individually. Data of three independent repeats from the comet assay and the trypan blue exclusion test were assessed by the one-way anova followed by Tukey's test. Mineral trioxide aggregate or Portland cement containing bismuth oxide did not produce genotoxic effects with respect to the single-cell gel (comet) assay data for all concentrations evaluated. Furthermore, no cytotoxicity was observed for MTA or Portland cement. White MTA or white Portland cement containing 15% bismuth oxide were not genotoxic and cytotoxic. © 2010 International Endodontic Journal.

  8. 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.

  9. Effect of bismuth oxide on white mineral trioxide aggregate: chemical characterization and physical properties.

    Science.gov (United States)

    Grazziotin-Soares, R; Nekoofar, M H; Davies, T E; Bafail, A; Alhaddar, E; Hübler, R; Busato, A L S; Dummer, P M H

    2014-06-01

    To assess the effect of bismuth oxide (Bi2 O3 ) on the chemical characterization and physical properties of White mineral trioxide aggregate (MTA) Angelus. Commercially available White MTA Angelus and White MTA Angelus without Bi2 O3 provided by the manufacturer especially for this study were subjected to the following tests: Rietveld X-ray diffraction analysis (XRD), energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), compressive strength, Vickers microhardness test and setting time. Chemical analysis data were reported descriptively, and physical properties were expressed as means and standard deviations. Data were analysed using Student's t-test and Mann-Whitney U test (P = 0.05). Calcium silicate peaks were reduced in the diffractograms of both hydrated materials. Bismuth particles were found on the surface of White MTA Angelus, and a greater amount of particles characterized as calcium hydroxide was observed by visual examination on White MTA without Bi2 O3 . The material without Bi2 O3 had the shortest final setting time (38.33 min, P = 0.002), the highest Vickers microhardness mean value (72.35 MPa, P = 0.000) and similar compressive strength results (P = 0.329) when compared with the commercially available White MTA Angelus containing Bi2 O3 . The lack of Bi2 O3 was associated with an increase in Vickers microhardness, a reduction in final setting time, absence of Bi2 O3 peaks in diffractograms, as well as a large amount of calcium and a morphology characteristic of calcium hydroxide in EDX/SEM analysis. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  10. Investigation of gamma ray shielding efficiency and mechanical performances of concrete shields containing bismuth oxide as an environmentally friendly additive

    Science.gov (United States)

    Yao, Ya; Zhang, Xiaowen; Li, Mi; Yang, Rong; Jiang, Tianjiao; Lv, Junwen

    2016-10-01

    Concrete has a proven ability to attenuate gamma rays and neutrons without compromising structural property; therefore, it is widely used as the primary shielding material in many nuclear facilities. Recently, there is a tendency toward using various additives to enhance the shielding properties of these concrete mixtures. However, most of these additives being used either pose hygiene hazards or require special handling processes. It would be ideal if environmentally friendly additives were available for use. The bismuth oxide (Bi2O3) additive shows promise in various shielding applications due to its proven radiation attenuation ability and environmentally friendly nature. To the best of our knowledge, however, Bi2O3 has never been used in concrete mixtures. Therefore, for this research, we fabricated the Bi2O3-based concrete mixtures by adding Bi2O3 powder in the ordinary concrete mixture. Concrete mixtures with lead oxide (PbO) additives were used for comparison. Radiation shielding parameters like the linear attenuation coefficients (LAC) of all these concrete mixtures showing the effects of the Bi2O3 additions are presented. The mechanical performances of concrete mixtures incorporated with Bi2O3 additive were also investigated. It suggested that the concrete mixture containing 25% Bi2O3 powder (B5 in this study) provided the best shielding capacity and mechanical performance among other mixes. It has a significant potential for application as a structural concrete where radiological protection capability is required.

  11. Catalyst free, base free microwave irradiated synthesis of aryl nitrites from potassium aryltrifluoroborates and bismuth nitrate

    Science.gov (United States)

    Al-Masum, Mohammad; Welch, Rebecca L.

    2014-01-01

    A mixture of bismuth nitrate pentahydrate and potassium aryltrifluoroborate in toluene under microwave heating at 120 °C for 20 min provides an interesting and mild reaction protocol for the synthesis of aryl nitrite. The conversion to aryl nitrites from aryltrifluoroborates without transition metal catalyst and base in high yields is remarkable. PMID:25242828

  12. 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.

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

    Science.gov (United States)

    Marciano, Marina Angélica; Garcia, Roberto Brandão; Cavenago, Bruno Cavalini; Minotti, Paloma Gagliardi; Midena, Raquel Zanin; Guimarães, Bruno Martini; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro

    2014-01-01

    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. 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 (pPortland 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.

  14. Bismuth oxide decorated graphene oxide nanocomposites synthesized via sonochemical assisted hydrothermal method for adsorption of cationic organic dyes.

    Science.gov (United States)

    Das, Trupti R; Patra, Santanu; Madhuri, Rashmi; Sharma, Prashant K

    2018-01-01

    Bismuth oxide decorated graphene oxide (Bi 2 O 3 @GO) nanocomposites were successfully synthesized by sonochemical method followed by hydrothermal treatment. The structural, morphology/microstructure and functional groups were investigated through X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared (FTIR) spectroscopy, respectively. In the FESEM and TEM studies, well dispersed Bi 2 O 3 nanoparticles of size 3-5nm were found uniformly distributed throughout the surface and edges of GO sheets. The HRTEM measurements on the Bi 2 O 3 nanoparticle decorated graphene oxide shows imaged lattice spacing of 3.2Å corresponding to (111) plane of Bi 2 O 3 which confirms the successful synthesis of bismuth oxide decorated graphene oxide (Bi 2 O 3 @GO) nanocomposite. The synthesized nanocomposite was employed for adsorption and removal of cationic organic dyes like RhB from industrial wastewater. The effect of various parameters, viz., contact time, temperature, pH and amount of adsorbent on the adsorption capability as well as dye removal capacity of the adsorbent was studied in detail. Under optimized conditions, like, contact time (65min), amount of adsorbent (5mg), temperature (35°) and pH (4), the adsorption capacity of GO and Bi 2 O 3 @GO were recorded and the percentage of removal was found to be 64% and 80.7% for GO and Bi 2 O 3 @GO, respectively. The Bi 2 O 3 @GO nanocomposite shows higher adsorption capacity (320mg/g) as compare to only GO (224mg/g). The adsorption isotherm follows both the Temkin as well as Langmuir isotherm having heat of sorption 65.88 with Langmuir constant of 13.13 corresponding to the complete monolayer coverage of 387.44mg/g. The adsorption kinetics also follow, both pseudo first order and intraparticle diffusion model with adsorption capacity of 84.91mg/g and intra particle diffusion rate constant of 10.53mg/g min 1/2 for Bi 2 O 3 @GO

  15. Chemical composition, radiopacity, and biocompatibility of Portland cement with bismuth oxide.

    Science.gov (United States)

    Hwang, Yun-Chan; Lee, Song-Hee; Hwang, In-Nam; Kang, In-Chol; Kim, Min-Seok; Kim, Sun-Hun; Son, Ho-Hyun; Oh, Won-Mann

    2009-03-01

    This study compared the chemical constitution, radiopacity, and biocompatibility of Portland cement containing bismuth oxide (experimental cement) with those of Portland cement and mineral trioxide aggregate (MTA). The chemical constitution of materials was determined by scanning electron microscopy and energy-dispersive X-ray analysis. The radiopacity of the materials was determined using the ISO/6876 method. The biocompatibility of the materials was tested by MTT assay and tissue reaction. The constitution of all materials was similar. However, the Portland cement and experimental cement were more irregular and had a larger particle size than MTA. The radiopacity of the experimental cement was similar to MTA. The MTT assay revealed MTA to have slightly higher cell viability than the other materials. However, there were no statistically significant differences between the materials, with the exception of MTA at 24 h. There was no significant difference in the tissue reaction between the experimental groups. These results suggest that the experimental cement may be used as a substitute for MTA.

  16. Hyaluronic acid-functionalized bismuth oxide nanoparticles for computed tomography imaging-guided radiotherapy of tumor.

    Science.gov (United States)

    Du, Fengyi; Lou, Jiaming; Jiang, Rong; Fang, Zhengzou; Zhao, Xuefen; Niu, Yuanyuan; Zou, Shenqiang; Zhang, Miaomiao; Gong, Aihua; Wu, Chaoyang

    2017-01-01

    The inherent radioresistance and inaccuracy of localization of tumors weaken the clinical implementation effectiveness of radiotherapy. To overcome these limitations, hyaluronic acid-functionalized bismuth oxide nanoparticles (HA-Bi 2 O 3 NPs) were synthesized by one-pot hydrothermal method for target-specific computed tomography (CT) imaging and radiosensitization of tumor. After functionalization with hyaluronic acid, the Bi 2 O 3 NPs possessed favorable solubility in water and excellent biocompatibility and were uptaken specifically by cancer cells overexpressing CD44 receptors. The as-prepared HA-Bi 2 O 3 NPs exhibited high X-ray attenuation efficiency and ideal radiosensitivity via synergizing X-rays to induce cell apoptosis and arrest the cell cycle in a dose-dependent manner in vitro. Remarkably, these properties offered excellent performance in active-targeting CT imaging and enhancement of radiosensitivity for inhibition of tumor growth. These findings demonstrated that HA-Bi 2 O 3 NPs as theranostic agents exhibit great promise for CT imaging-guided radiotherapy in diagnosis and treatment of tumors.

  17. Hydrothermal synthesis and crystal structure of a new lithium copper bismuth oxide, LiCuBiO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Kumada, Nobuhiro, E-mail: kumada@yamanashi.ac.jp [Center for Crystal Science and Technology, University of Yamanashi, Miyamae-cho 7-32, Kofu 400-8511 (Japan); Nakamura, Ayumi [Center for Crystal Science and Technology, University of Yamanashi, Miyamae-cho 7-32, Kofu 400-8511 (Japan); Miura, Akira [Center for Crystal Science and Technology, University of Yamanashi, Miyamae-cho 7-32, Kofu 400-8511 (Japan); Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060-8628 (Japan); Takei, Takahiro [Center for Crystal Science and Technology, University of Yamanashi, Miyamae-cho 7-32, Kofu 400-8511 (Japan); Azuma, Masaki; Yamamoto, Hajime [Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku Yokohama, Kanagawa 226-8503 (Japan); Magome, Eisuke; Moriyoshi, Chikako; Kuroiwa, Yoshihiro [Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8526 (Japan)

    2017-01-15

    A new lithium copper bismuth oxide, LiCuBiO{sub 4} was prepared by hydrothermal reaction using NaBiO{sub 3}0.1*4H{sub 2}O. The crystal structural model of this compound was refined by using synchrotron X-ray powder diffraction data. This bismuthate has the LiCuSbO{sub 4} related structure with the orthorhombic cell (Space group: Pnma) of a=10.9096(9), b=5.8113(5) and c=5.0073(4) Å, and the final R-factors were R{sub wp}=4.84 and R{sub p}=3.58%. This compound is the first example of a lithium copper bismuthate containing Bi{sup 5+}. An antiferromagnetic ordering of Cu{sup 2+} moment was observed at 6 K. - Graphical abstract: In the crystal structure of LiCuBiO{sub 4} all metal atoms are coordinated octahedrally by six O atoms and LiO{sub 6} and CuO{sub 6} octahedra form the one-dimensional chains by edge-sharing along the b-axis. The LiO{sub 6} and CuO{sub 6} chains form the layer by face-sharing in the bc plane. The Bi atoms are placed in that interlayer and BiO{sub 6} octahedra are edge-sharing with LiO{sub 6} and CuO{sub 6} octahedra. - Highlights: • A new lithium copper bismuth oxide, LiCuBiO{sub 4} is prepared by hydrothermal reaction. • The crystal structure of LiCuBiO{sub 4} is closely related with that of LiCuSbO{sub 4}. • This new compound exhibits an antiferromagnetic ordering of Cu{sup 2+} moment at 6 K.

  18. Design of a new nanocomposite between bismuth nanoparticles and graphene oxide for development of electrochemical sensors.

    Science.gov (United States)

    Bindewald, Eduardo H; Schibelbain, Arthur F; Papi, Maurício A P; Neiva, Eduardo G C; Zarbin, Aldo J G; Bergamini, Márcio F; Marcolino-Júnior, Luiz H

    2017-10-01

    This study describes a new route for preparation of a nanocomposite between graphene oxide (GO) and bismuth nanoparticles (BiNPs) and its evaluation as modifier electrode for development of electrochemical sensors. BiNPs were synthesized under ultrasound conditions using Bi(NO 3 ) 3 as metal precursor and ascorbic acid (AA) as reducing agent/passivating. Some experimental parameters of BiNPs synthesis such as Bi 3+ :AA molar ratio and reaction time were conducted aiming the best voltammetric performance of the sensor. Glassy carbon electrodes (GCE) were modified by drop-casting with the BiNPs dispersions and anodic stripping voltammetry measurements were performed and revealed an improvement in the sensitivityfor determination of Cd(II) and Pb(II) compared to an unmodified electrode. The best electrochemical response was obtained for a BiNPs synthesis with Bi 3+ :AA molar ratio of 1:6 and reaction time of 10min, which yielded Bi metallic nanoparticles with average size of 5.4nm confirmed by XRD and TEM images, respectively. GO was produced by graphite oxidation using potassium permanganate and exfoliated with an ultrasound tip. GO-BiNPs nanocomposite was obtained by a simple mixture of GO and BiNPs dispersions in water and kept under ultrasonic bath for 1h. GCE were modified with a nanocomposite suspension containing 0.3 and 1.5mgmL -1 of GO and BiNPs in water, respectively. Under optimized conditions, the proposed nanocomposite was evaluated on the voltammetric determination of Pb (II) and Cd (II), leading to a linear response range between 0.1 and 1.4μmolL -1 for both cations, with limit of detection of 30 and 27nmolL -1 , respectively. These results indicate the great potential of the GO-BiNPs nanocomposite for improving the sensitivity of voltammetric procedures. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Evaluation of a carbon paste electrode modified with Strontium substituted bismuth and titanium oxide nanoparticles in the toxic metal chromium (VI determination potentiometric method

    Directory of Open Access Journals (Sweden)

    Atefeh Badri

    2016-09-01

    Full Text Available Strontium substituted bismuth and titanium oxide nanoparticles with aurivillius morphology synthesized by chemical co-precipitation method and were characterized using XRD. The nanopartcles were used in the composition of the carbon paste to improve conductivity and transduction of chemical signal to electrical signal. A procedure for the determination of chromium is described based on pre-concentration of the dichromate anion at a carbon paste electrode modified. A novel potentiometric Cr6+carbon paste electrode incorporating Strontium substituted bismuth and titanium oxide nanoparticles (SSBTO. Ina acetate buffer solution of pH 5, the sensor displays a rapid and linear response for Cr6+ over the concentration range 1.0×10-5 to 1.0×10-1mol L-1 M with an anionic slope of 54.8± 0.2 mV decade ’ and a detection limit of the order of0.002 /µg ml ‘. The sensor is used for determination of Cr6+ by direct monitoring of Cr6+.The average recoveries of Cr6+at concentration levels of 0.5~40 pg/ml ’is 98.3. The electrode has a short response time (<6s and can be used for at least twenty days without any considerable divergence in potentials and the working pH range was 4.5-6.5. The proposed electrode was successfully used as an indicator for potentiometric determination of Cr6+in water sample.

  20. Systematics of c-axis phonons in the thallium- and bismuth-based cuprate superconductors

    NARCIS (Netherlands)

    Tsvetkov, A.A.; Dulic, Diana; Marel, D. van der; Damascelli, A.; Kaljushnaia, G.A.; Gorina, J.I.; Senturina, N.N.; Kolesnikov, N.N.; Ren, Z.F.; Wang, J.H.; Menovsky, A.A.; Palstra, T.T.M.

    1999-01-01

    We present grazing incidence reflectivity measurements in the far-infrared region at temperatures above and below Tc for a series of thallium- (Tl2Ba2CuO6, Tl2Ba2CaCu2O8) and bismuth- (Bi2Sr2CuO6, Bi2Sr2CaCu2O8, and Bi2-xPbxSr2CaCu2O8) based cuprate superconductors. From the spectra, which are

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

    International Nuclear Information System (INIS)

    Manaila, R.; Ionescu, N.I.; Caldararu, M.

    1980-01-01

    Complex Bi-Mo oxide catalysts supported on amorphous SiO 2 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 MoO 3 . The Fe 2 (MoO 4 ) 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 0 C induced also the transition of the metastable modification β-NiMoO 4 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)

  2. Hydrogen Treatment and FeOOH overlayer: Effective approaches for enhancing the photoelectrochemical water oxidation performance of bismuth vanadate thin films

    DEFF Research Database (Denmark)

    Singh, Aadesh P.; Saini, Nishant; Mehta, Bodh R.

    2018-01-01

    The water oxidation capability of the promising photoanode bismuth vanadate (BiVO4) is hampered by poor bulk electron transport and by high rates of charge recombination at the semiconductor/electrolyte interface. Here, we demonstrate that a dual modification of BiVO4 by: (i) annealing in a hydro......The water oxidation capability of the promising photoanode bismuth vanadate (BiVO4) is hampered by poor bulk electron transport and by high rates of charge recombination at the semiconductor/electrolyte interface. Here, we demonstrate that a dual modification of BiVO4 by: (i) annealing...

  3. Using nanostructured conductive carbon tape modified with bismuth as the disposable working electrode for stripping analysis in paper-based analytical devices.

    Science.gov (United States)

    Feng, Qiu-Mei; Zhang, Qing; Shi, Chuan-Guo; Xu, Jing-Juan; Bao, Ning; Gu, Hai-Ying

    2013-10-15

    Low cost disposable working electrodes are specifically desired for practical applications of electrochemical detection considering maturity of electrochemical stations and data collection protocols. In this paper double-sided conductive adhesive carbon tape with nanostructure was applied to fabricate disposable working electrodes. Being supported by indium tin oxide glass, the prepared carbon tape electrodes were coated with bismuth film for stripping analysis of heavy metal ions. By integrating the bismuth modified electrodes with paper-based analytical devices, we were able to differentiate Zn, Cd and Pb ions with the sample volume of around 15 μL. After the optimization of parameters, including modification of bismuth film and the area of the electrodes, etc., Pb ions could be measured in the linear range from 10 to 500 μg/L with the detection limit of 2 μg/L. Our experimental results revealed that the disposable modified electrodes could be used to quantify migrated lead from toys with the results agreed well with that using atomic absorption spectrometry. Although bismuth modification and stripping analysis could be influenced by the low conductivity of the carbon tape, the low cost disposable carbon tape electrodes take the advantages of large-scaled produced double-sided carbon tape, including its reproducible nanostructure and scaled-up fabrication process. In addition, the preparation of disposable electrodes avoids time-consuming pretreatment and experienced operation. This study implied that the carbon tape might be an alternative candidate for practical applications of electrochemical detection. © 2013 Elsevier B.V. All rights reserved.

  4. Investigation of iron-bismuth-molybdenum catalysts

    International Nuclear Information System (INIS)

    Ven'yaminov, S.A.; Barannik, G.B.; Pitaeva, A.N.; Sazonova, N.N.; Plyasova, L.M.

    1977-01-01

    The catalytic properties of an oxide iron-bismuth-molybdenum system in reactions of oxidative ammonolysis of propylene and oxidative dehydrogenation of butene-1 are investigated. It is shown that catalysts containing double molybdate of bismuth and iron (the X-phase) exhibit an increased catalytic activity as compared with bismuth molybdate (Bi 2 O 3 x3MoO 3 ). Preliminary reduction of such specimens increases their activity and selectivity in subsequent work under conditions of a stationary course of the oxidation reaction. The activity and selectivity of catalysts containing only bismuth molybdate and iron molybdate are due to the additivity of the properties of the separate molybdates

  5. Synergy Effects of the Mixture of Bismuth Molybdate Catalysts with SnO2/ZrO2/MgO in Selective Propene Oxidation and the Connection between Conductivity and Catalytic Activity

    DEFF Research Database (Denmark)

    Le, Minh Thang; Do, Van Hung; Truong, Duc Duc

    2016-01-01

    Bismuth molybdate catalysts have been used for partial oxidation and ammoxidation of light hydrocarbons since the 1950s. In particular, there is the synergy effect (the enhancement of the catalytic activity in the catalysts mixed from different components) in different phases of bismuth molybdate...... for the question: does the electrical conductivity influence the catalytic activity (which has been previously proposed by some authors). In this work, highly conductive materials (SnO2, ZrO2) and nonconductive materials (MgO) are added to beta bismuth molybdates (beta-Bi2Mo2O9) using mechanical mixing...... of these mixtures showed that the addition of 10% mol SnO2 to beta bismuth molybdate resulted in the highest activity while the addition of nonconductive MgO could not increase the catalytic activity. This shows that there may be a connection between conductivity and catalytic activity in the mixtures of bismuth...

  6. Evaluating X-ray absorption of nano-bismuth oxide ointment for decreasing risks associated with X-ray exposure among operating room personnel and radiology experts

    Directory of Open Access Journals (Sweden)

    M. Rashidi

    2015-12-01

      Conclusion: It seems that due to higher atomic number and lower toxicity, Bi2O3 nanoparticles have better efficiency in X-ray absorbtion, comparing to the lead. Cream and ointment of bismuth oxide nanoparticles can be used as X-ray absorbant for different professions such as physicians, dentists, radiology experts, and operating room staff and consequently increase health and safety of these employees.

  7. High Photon-to-Current Conversion in Solar Cells Based on Light-Absorbing Silver Bismuth Iodide.

    Science.gov (United States)

    Zhu, Huimin; Pan, Mingao; Johansson, Malin B; Johansson, Erik M J

    2017-06-22

    Here, a lead-free silver bismuth iodide (AgI/BiI 3 ) with a crystal structure with space group R3‾ m is investigated for use in solar cells. Devices based on the silver bismuth iodide deposited from solution on top of TiO 2 and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) as a hole-transport layer are prepared and the photovoltaic performance is very promising with a power conversion efficiency over 2 %, which is higher than the performance of previously reported bismuth-halide materials for solar cells. Photocurrent generation is observed between 350 and 700 nm, and the maximum external quantum efficiency is around 45 %. The results are compared to solar cells based on the previously reported material AgBi 2 I 7 , and we observe a clearly higher performance for the devices with the new silver and bismuth iodides composition and different crystal structure. The X-ray diffraction spectrum of the most efficient silver bismuth iodide material shows a hexagonal crystal structure with space group R3‾ m, and from the light absorption spectrum we obtain an indirect band gap energy of 1.62 eV and a direct band gap energy of 1.85 eV. This report shows the possibility for finding new structures of metal-halides efficient in solar cells and points out new directions for further exploration of lead-free metal-halide solar cells. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  8. Nano-scaled top-down of bismuth chalcogenides based on electrochemical lithium intercalation

    International Nuclear Information System (INIS)

    Chen Jikun; Zhu Yingjie; Chen Nuofu; Liu Xinling; Sun Zhengliang; Huang Zhenghong; Kang Feiyu; Gao Qiuming; Jiang Jun; Chen Lidong

    2011-01-01

    A two-step method has been used to fabricate nano-particles of layer-structured bismuth chalcogenide compounds, including Bi 2 Te 3 , Bi 2 Se 3 , and Bi 2 Se 0.3 Te 2.7 , through a nano-scaled top-down route. In the first step, lithium (Li) atoms are intercalated between the van der Waals bonded quintuple layers of bismuth chalcogenide compounds by controllable electrochemical process inside self-designed lithium ion batteries. And in the second step, the Li intercalated bismuth chalcogenides are subsequently exposed to ethanol, in which process the intercalated Li atoms would explode like atom-scaled bombs to exfoliate original microscaled powder into nano-scaled particles with size around 10 nm. The influence of lithium intercalation speed and amount to three types of bismuth chalcogenide compounds are compared and the optimized intercalation conditions are explored. As to maintain the phase purity of the final nano-particle product, the intercalation lithium amount should be well controlled in Se contained bismuth chalcogenide compounds. Besides, compared with binary bismuth chalcogenide compound, lower lithium intercalation speed should be applied in ternary bismuth chalcogenide compound.

  9. The Relationship Between Structural and Catalytic Activity of α and γ-Bismuth-Molybdate Catalysts for Partial Oxidation of Propylene to Acrolein

    Science.gov (United States)

    Fansuri, H.; Pham, G. H.; Wibawanta, S.; Zhang, D. K.; French, David

    Bismuth-molybdate catalysts are known to be effective for catalytic partial oxidation of propylene to acrolein. Their properties and the kinetics and reaction mechanisms for acrolein production have been extensively studied, especially in their basic forms, such as α, β, and γ-bismuth-molybdate. Although the reaction mechanisms have been reported widely in the literature, a general agreement has not been reached, especially from a catalyst-structure point of view. The present contribution reports an effort to understand the structural changes of α and γ-bismuth-molybdate catalysts at varying temperatures as examined using high temperature XRD and to relate the catalyst performance (activity and selectivity) for propylene partial oxidation to acrolein. The XRD analysis was performed at temperature between 250 and 450°C in ambient atmosphere and the Rietveld refinement method was used to extract unit cell parameters. The results showed a distinct similarity between the shapes of the thermal expansion of the catalysts and their activity and selectivity curves, indicating a significant role that the catalyst interatomic structure plays in the overall reaction mechanism.

  10. Synthesis of mesoporous bismuth-impregnated aluminum oxide for arsenic removal: Adsorption mechanism study and application to a lab-scale column.

    Science.gov (United States)

    Zhu, Ningyuan; Qiao, Jun; Ye, Yanfang; Yan, Tingmei

    2018-04-01

    High mobility and toxicity of arsenic [As (III)] limit its removal from an aquatic environment and pose a threat to human health. In this work, batch adsorption experiments were conducted to investigate the adsorption capacity of bismuth-impregnated aluminum oxide (BiAl). Continuous application of As (III) removal was achieved via a lab-scale column reactor. Bismuth impregnation decreased the specific surface area of aluminum oxide and affected its pore size distribution. However, because of its abundant and well-proportioned mesoporous character, it also enhanced its adsorption capacity through the surface complexation of As (III). Batch adsorption experiments demonstrated a suitable Freundlich model and a fitted pseudo-second-kinetic model for As (III) adsorption. The main mechanism was chemisorption with both bismuth and aluminum atoms; however, physisorption also contributed to arsenic adsorption at the initial stage of the reaction. The Adams-Bohart model better described the breakthrough curves than the Thomas model. BiAl exhibited efficient As (III) adsorption over a wide pH range and could be applied to As (III) removal from wastewater. A high As (III) removal efficiency (91.6%) was obtained at an initial As (III) concentration of 5 mg L -1 at a flow rate of 1 mL min -1 . This study indicates the potential for the practical application of BiAl in As (III) removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. 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)

  12. Bismuth oxyiodide incorporated reduced graphene oxide nanocomposite material as an efficient photocatalyst for visible light assisted degradation of organic pollutants

    Science.gov (United States)

    Vinoth, R.; Babu, S. Ganesh; Ramachandran, R.; Neppolian, B.

    2017-10-01

    Herein, Bismuth oxyiodide (BiOI) - reduced graphene oxide (rGO) photocatalysts were prepared via simple hydrothermal method. The BiOI-rGO photocatalyst exhibited high crystallinity with tetragonal phase of BiOI. In addition, the electronic interaction between rGO sheet and BiOI reduced the band-gap value from 1.86 eV of bare BiOI to 1.51 eV of BiOI-rGO (6 wt%) photocatalyst. More interestingly, the rGO showed a strong influence on tailoring the morphology of BiOI to different nanostructures with different rGO loading (wt%), which further reflected differences in the photocatalytic activity. A significant quenching in the photoluminescence intensity of rGO supported BiOI photocatalyst confirmed the effective suppression of electron-hole pair recombination. The optimized rGO (4 wt%) loaded BiOI photocatalyst significantly improved the photocatalytic activity (∼85%) towards the degradation of methyl orange (MO) dye compared to that of pristine BiOI (∼29%). Thus, around three folds enhancement in the photocatalytic activity of BiOI-rGO (4 wt%) catalyst was mainly attributed to ultrafast separation of electron-hole pairs and rapid transportation of carriers by rGO support. The superior photocatalytic activity demonstrated by this newly synthesized BiOI-rGO photocatalyst makes it's a potential candidate for environmental remediation process.

  13. 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.

  14. Simultaneous solution-based generation and characterization of crystalline bismuth thin film by femtosecond laser spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liangdong; Keszler, Douglas A.; Fang, Chong, E-mail: Chong.Fang@oregonstate.edu [Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003 (United States); Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331-6507 (United States); Saha, Sumit; Liu, Weimin; Wang, Yanli [Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003 (United States)

    2015-08-10

    We demonstrate generation and characterization of crystalline bismuth thin film from triphenyl bismuth in methanol. Upon ultraviolet (267 nm) femtosecond laser irradiation of the solution, a thin film of elemental bismuth forms on the inner side of the sample cuvette, confirmed by detection of the coherent A{sub 1g} optical phonon mode of crystalline bismuth at ∼90 cm{sup −1}. Probe pulses at 267 and 400 nm are used to elucidate the excited state potential energy surface and photochemical reaction coordinate of triphenyl bismuth in solution with femtosecond resolution. The observed phonon mode blueshifts with increasing irradiation time, likely due to the gradual thickening of nascent bismuth thin film to ∼80 nm in 90 min. From transient absorption with the 400 nm probe, we observe a dominant ∼4 ps decay time constant of the excited-state absorption signal, which is attributed to a characteristic metal-ligand bond-weakening/breaking intermediate enroute to crystalline metallic thin film from the solution precursor molecules. Our versatile optical setup thus opens an appealing avenue to characterize the laser-induced crystallization process in situ and prepare high-quality thin films and nanopatterns directly from solution phase.

  15. Synthesis and characterization of bismuth telluride based nanostructured thermoelectric composite materials

    Science.gov (United States)

    Keshavarz Khorasgani, Mohsen

    Thermoelectric (TE) materials and devices are attractive in solid-state energy conversion applications such as waste heat recovery, air-conditioning, and refrigeration. Since the 1950's lots of unremitting efforts have been made to enhance the efficiency of energy conversion in TE materials (i. e. improving the figure of merit (ZT)), however, most of commercial bulk TE materials still suffer from low efficiency with ZTs around unity. To enhance the performance of bismuth telluride based TE alloys, we have developed composite TE materials, based on the idea that introducing more engineered interfaces in the bulk TE materials may lead to thermal conductivity reduction due to increased phonon scattering by these interfaces. In this approach it is expected that the electronic transport properties of the material are not effectively affected. Consequently, ZT enhancement can be achieved. In this dissertation we will discuss synthesis and characterization of two types of bismuth telluride based bulk composite TE materials. The first type is engineered to contain the presence of coherent interfaces between phases in the material resulting from different mixtures of totally miscible compounds with similar composition. The second type includes the nanocomposites with embedded foreign nano-particles in which the matrix and the particles are delimited by incoherent interfaces. The synthesis procedure, micro- and nano-structures as well as thermoelectric properties of these composites will be presented. In our study on the composites with coherent interfaces, we produced a series of different composites of p-type bismuth antimony telluride alloys and studied their microstructure and thermoelectric properties. Each composite consists of two phases that were obtained in powder form by mechanical alloying. Mixed powders in various proportions of the two different phases were consolidated by hot extrusion to obtain each bulk composite. The minimum grain size of bulk composites as

  16. Effectiveness of ranitidine bismuth citrate and proton pump inhibitor based triple therapies of Helicobacter pylori in Turkey

    Directory of Open Access Journals (Sweden)

    Mustafa Iscan

    2011-09-01

    Full Text Available Background : Helicobacter pylori infection is the main cause of gastritis, gastroduodenal ulcer disease, MALT lymphoma, and adenocarcinoma of the stomach. The reported prevalence of H. pylori in the adult population in Turkey is 67.6%–81.3%. A national meta-analysis showed that the average H. pylori eradication rate with proton pump inhibitor-based triple regimens in Turkey had decreased from 84% in 1997 to 55.3% in 2004, suggesting a need to evaluate alternative regimens. Materials and methods : The study was a prospective, single-center trial with a parallel group design. After the selection procedure, consecutive out-patients were assigned to one of six study groups using random sampling numbers. All patients received amoxicillin 1,000 mg b.i.d. and clarithromycin 500 mg b.i.d. along with ranitidine bismuth citrate 400 mg b.i.d., or omeprazole 20 mg b.i.d., or lansoprazole 30 mg b.i.d., or rabeprazole 20 mg b.i.d., or pantoprazole 40 mg b.i.d., or esomeprazole 40 mg b.i.d. for 14 days. Results : When we look at the eradication rates of the treatment groups, only two groups (ranitidine bismuth citrate and rabeprazole groups had eradication rates greater than 80%, both at intention to treat and per protocol analyses. The other four groups (omeprazole, lansoprazole, pantoprazole, and esomeprazole groups showed statistically significant lower eradication rates both at intention to treat (between 57.6 and 66.7% and per protocol (between 60.3 and 72.1% analyses when compared with ranitidine bismuth citrate and rabeprazole groups (p<.05. Conclusion : Ranitidine bismuth citrate and/or rabeprazole based triple therapies must be preferred for the first-line treatment of H. pylori infection.

  17. An ecotoxicological study on tin- and bismuth-catalysed PDMS based coatings containing a surface-active polymer.

    Science.gov (United States)

    Pretti, Carlo; Oliva, Matteo; Mennillo, Elvira; Barbaglia, Martina; Funel, Marco; Reddy Yasani, Bhaskar; Martinelli, Elisa; Galli, Giancarlo

    2013-12-01

    Novel films were prepared by condensation curing reaction of a poly(dimethyl siloxane) (PDMS) matrix with bismuth neodecanoate and dibutyltin diacetate catalysts. An ecotoxicological study was performed on the leachates of the coatings using the bacterium Vibrio fischeri, the unicellular alga Dunaliella tertiolecta, the crustacean Artemia salina and the fish Sparus aurata (larvae) as testing organisms. A copper-based self-polishing commercial paint was also tested as reference. The results showed that the tin-catalysed coatings and the copper paint were highly toxic against at least two of the four test organisms, whereas bismuth-catalysed coatings did not show any toxic effect. Moreover, the same biological assessment was also carried out on PDMS coatings containing a surface-active fluorinated polymer. The toxicity of the entire polymeric system resulted only from the tin catalyst used for the condensation curing reaction, as the bismuth catalysed coatings incorporating the surface-active polymer remained atoxic toward all the tested organisms. © 2013 Elsevier Inc. All rights reserved.

  18. 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 ...

  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. Synthesis of bismuth sulfide/reduced graphene oxide composites and their electrochemical properties for lithium ion batteries

    International Nuclear Information System (INIS)

    Zhang, Zhian; Zhou, Chengkun; Huang, Lei; Wang, Xiwen; Qu, Yaohui; Lai, Yanqing; Li, Jie

    2013-01-01

    Graphical abstract: The Bi 2 S 3 /reduced graphene oxide composites were synthesized by a one-pot hydrothermal route and exhibited an extraordinary capacity of 1073.1 mAh g −1 with excellent cycling stability and high rate capability as anode material of lithium ion battery. The enhancement in the electrochemical performance could be attributed to the introduction of RGO sheets that not only buffer the large volume changes during the alloy/dealloy reaction of Li and Bi, but also provide a highly conductive network for rapid electron transport in electrode during electrochemical reaction. -- Highlights: •Bi 2 S 3 /RGO composites were in situ prepared by one-pot hydrothermal route. •The Bi 2 S 3 nanoparticles are homogeneous dispersion on the RGO sheets. •Bi 2 S 3 /RGO exhibits excellent cycling stability and high rate capability. •This work will also of interest for supercapacitor and solar cells. -- Abstract: A simple one-pot hydrothermal route was developed to synthesize bismuth sulfide/reduced graphene oxide composites (Bi 2 S 3 /RGO composites) in this work. The morphology and crystalline structure of the obtained products were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high resolution transmission electron microscopy (HRTEM). The results of Raman spectra and Fourier transform infrared (FTIR) spectra demonstrated that graphite oxide (GO) sheets were in situ reduced to a certain extent. Transmission electron microscopy (TEM) observation indicated that the Bi 2 S 3 nanoparticles, with a size of 80–100 nm in length, are anchored on RGO sheets. Electrochemical tests show the Bi 2 S 3 /RGO composite exhibits an extraordinary capacity of 1073.1 mAh g −1 with excellent cycling stability and high rate capability compared to pure Bi 2 S 3 particles prepared by a similar route in the absence of GO. The enhancement in the electrochemical performance could be attributed to the introduction of RGO sheets

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

    International Nuclear Information System (INIS)

    Al-Alas, Ahlam; Beg, Saba; Al-Areqi, Niyazi A.S.

    2012-01-01

    Samples of the BICDVOX system, formulated as Bi 4 Cd x V 2−x O 11−(3x/2)−δ 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 5+ by Cd 2+ exhibited different phase transitions upon varying composition. For compositions with x ≤ 0.05, two successive transitions; α↔β↔γ are evident, while the β↔γ transition exists in the composition range 0.05 4+ → V 5+ re–oxidation results in increased defect trapping effects in the system at higher temperatures. -- Highlights: ► γ-Stabilized BICDVOX at lower dopant concentrations. ► Good oxide-ion conductivity at lower temperatures. ► High temperature-vanadium reduction with lower dopant concentrations.

  2. Evaluation of a Net Dose-Reducing Organ-Based Tube Current Modulation Technique: Comparison With Standard Dose and Bismuth-Shielded Acquisitions.

    Science.gov (United States)

    Lambert, Jack W; Gould, Robert G

    2016-06-01

    The purpose of this study was to compare the dose and image noise associated with two methods of radiation dose reduction to the superficial anterior organs: bismuth shielding and a net dose-reducing organ-based tube current modulation TCM technique. Three scanning modes-the reference dose, bismuth-shielded, and organ dose-modulated modes-were evaluated. With the use of an anthropomorphic phantom, surface doses to the eye, thyroid, and female breast were measured using optically stimulated luminescence detectors. A CT dose index (CTDI) phantom was used to compare doses with the overall phantom volume in the different modes. The dose to the anterior surface was reduced by 35%, 42%, and 37% in the head, neck, and chest regions, respectively, when the bismuth-shielded scanning mode was used, whereas surface dose reductions of 20%, 34%, and 38%, respectively, were noted for the organ-based TCM scanning mode. The CTDI-type dose was reduced by 13%, 14%, and 17% in the head, neck, and chest regions, respectively, when the bismuth-shielded mode was used, whereas dose reductions of 9%, 18%, and 20%, respectively, were observed for the organ-based TCM mode. Anterior image noise increased by 0.1, 9.5, and 0.7 HU in the head, neck, and chest regions, respectively, when the bismuth-shielded mode was used. These findings compared with increases in image noise of 0.1, 0.5, and 0.6 HU, respectively, for the organ-based TCM mode. The implementation of organ-based TCM reduces the net tube current per rotation, so no body region receives increased radiation exposure. The use of this method allows the dose to the anterior surface to be reduced to an extent similar to that observed with the use of the bismuth shield, yet it does not produce the image quality degradation associated with bismuth shielding.

  3. Enhanced thermoelectric properties of metal film on bismuth telluride-based materials

    International Nuclear Information System (INIS)

    Chao, Wen Hsuan; Chen, Yi Ray; Tseng, Shih Chun; Yang, Ping Hsing; Wu, Ren Jye; Hwang, Jenn Yeu

    2014-01-01

    Diffusion barriers have a significant influence on the reliability and life time of thermoelectric modules. Although nickel is commonly used as a diffusion barrier in commercial thermoelectric modules, several studies have verified that Ni migrates to bismuth telluride-based material during high temperature cycles and causes a loss in efficacy. In this paper, the influence of metal layers coated to p-type and n-type Bi 2 Te 3 on the interface characterization and thermoelectric property is studied using a RF magnetron sputtering. The findings from this study demonstrate the structural and thermoelectric properties of p-type and n-type Bi 2 Te 3 coated with different metal layers. The crystalline phase and compositional change of the interface between the Bi 2 Te 3 materials and the metal layers were determined using an X-ray diffractometer and scanning electron microscopy with energy dispersive spectroscopy. Formation of NiTe was observed in the sample of Ni/p-type Bi 2 Te 3 based films post-annealed in an N 2 atmosphere at 200 °C. In contrast, no Co x Te y was formed in the sample of Co/p-type Bi 2 Te 3 based films post-annealed at 200 °C. For as-deposited Ni/p-type and n-type Bi 2 Te 3 based legs, the Ni slightly diffused into the Bi 2 Te 3 based legs. A similar phenomenon also occurred in the as-deposited Co/p-type and n-type Bi 2 Te 3 based legs. The Seebeck coefficients of the Co contacts on the Bi 2 Te 3 based material displayed better behavior than those of the Ni contacts on the Bi 2 Te 3 based legs. Thus Co could be a suitable diffusion barrier for bulk Bi 2 Te 3 based material. The observed effects on the thermoelectric and structural properties of metal/Bi 2 Te 3 based material are crucial for understanding the interface between the diffusion barrier and thermoelectric materials. - Highlights: • Interface characterization of metal coated to p-type and n-type Bi 2 Te 3 is studied. • We examined the phase transformation of metal/Bi 2 Te 3 based films

  4. Spark plasma sintered bismuth telluride-based thermoelectric materials incorporating dispersed boron carbide

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.R., E-mail: hugo.williams@leicester.ac.uk [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Ambrosi, R.M. [Space Research Centre, Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Chen, K. [School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Friedman, U. [Department of Engineering, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Ning, H.; Reece, M.J. [School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Robbins, M.C.; Simpson, K. [European Thermodynamics Ltd., 8 Priory Business Park, Wistow Road, Kibworth LE8 0R (United Kingdom); Stephenson, K. [European Space Agency, ESTEC TEC-EP, Keplerlaan 1, 2201AZ Noordwijk (Netherlands)

    2015-03-25

    Highlights: • Nano-B{sub 4}C reinforced Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} p-type thermoelectric produced by SPS. • Addition of B{sub 4}C up to 0.2 vol% to SPS’d material has little effect on zT. • Vickers hardness improved by 27% by adding 0.2 vol% B{sub 4}C. • Fracture toughness of SPS material: K{sub IC} = 0.80 MPa m{sup 1/2} by SEVNB. • Mechanical properties much better than commercial directionally solidified material. - Abstract: The mechanical properties of bismuth telluride based thermoelectric materials have received much less attention in the literature than their thermoelectric properties. Polycrystalline p-type Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} materials were produced from powder using spark plasma sintering (SPS). The effects of nano-B{sub 4}C addition on the thermoelectric performance, Vickers hardness and fracture toughness were measured. Addition of 0.2 vol% B{sub 4}C was found to have little effect on zT but increased hardness by approximately 27% when compared to polycrystalline material without B{sub 4}C. The K{sub IC} fracture toughness of these compositions was measured as 0.80 MPa m{sup 1/2} by Single-Edge V-Notched Beam (SEVNB). The machinability of polycrystalline materials produced by SPS was significantly better than commercially available directionally solidified materials because the latter is limited by cleavage along the crystallographic plane parallel to the direction of solidification.

  5. Monte Carlo simulations of radioactive waste encapsulated by bisphenol-A polycarbonate and effect of bismuth-III oxide filler material

    Science.gov (United States)

    Özdemir, Tonguç

    2017-06-01

    Radioactive waste generated from the nuclear industry and non-power applications should carefully be treated, conditioned and disposed according to the regulations set by the competent authority(ies). Bisphenol-a polycarbonate (BPA-PC), a very widely used polymer, might be considered as a potential candidate material for low level radioactive waste encapsulation. In this work, the dose rate distribution in the radioactive waste drum (containing radioactive waste and the BPA-PC polymer matrix) was determined using Monte Carlo simulations. Moreover, the change of mechanical properties of BPA-PC was estimated and their variation within the waste drum was determined for the periods of 15, 30 and 300 years after disposal to the final disposal site. The change of the dose rate within the waste drum with different contents of bismuth-III oxide were also simulated. It was concluded that addition of bismuth-III oxide filler decreases the dose delivered to the polymeric matrix due to photoelectric effect.

  6. [Ten-day Sequential Therapy versus Bismuth Based Quadruple Therapy as Second Line Treatment for Helicobacter pylori Infection].

    Science.gov (United States)

    Kim, Sung Bum; Lee, Si Hyung; Kim, Kyeong Ok; Jang, Byung Ik; Kim, Tae Nyeun

    2015-11-01

    Ten-day sequential therapy has been evaluated as the first line therapy for Helicobacter pylori eradication but studies on sequential therapy as a second line therapy is lacking. The aim of this study was to compare the efficacy of 10-day sequential therapy and quadruple therapy as second line treatment for H. pylori eradication after failure of standard triple therapy. Patients who did not respond to standard triple therapy for H. pylori eradication were assigned to either 10-day sequential or bismuth based quadruple therapy as second line treatment from January 2009 to December 2014 at Yeungnam University Medical Center. Post treatment H. pylori status was determined by rapid urease test, giemsa staining, or (13)C-urea breath test. Eradication rate and side effects of both therapies were compared. A total of 158 H. pylori infected patients were included and 70 patients were treated by bismuth based quadruple therapy and 88 patients by 10-day sequential therapy. Age and sex were not significantly different between the two groups. Eradication rate was 84.3% (59/70) in quadruple group and 56.8% (50/88) in sequential group. Side effects occurred significantly higher in quadruple group than sequential group (27.1% vs. 11.4%, p=0.011). For second line H. pylori eradication after failure of standard triple therapy, bismuth based quadruple therapy showed significantly higher H. pylori eradication rate than 10-day sequential therapy. Further prospective studies are needed to evaluate the efficacy of 10-day sequential therapy as a second line H. pylori eradication treatment.

  7. Preparation of bismuth telluride based thermoelectric nanomaterials via low-energy ball milling and their property characterizations

    Science.gov (United States)

    Robinson, Christopher A.

    Thermoelectric materials are able to convert energy between heat and electricity with no moving parts, making them very appealing for power generation purposes. This is particularly appealing since many forms of energy generation lose energy to waste heat. The Livermore National Laboratory estimates that up to 55% of the energy created in traditional power plants is lost through heat generation [1]. As greenhouse gas emissions become a more important issue, large sources of waste like this will need to be harnessed. Adoption of these materials has been limited due to the cost and efficiency of current technology. Bismuth telluride based alloys have a dimensionless figure of merit, a measure of efficiency, near one at room temperature, which makes it the best current material. In order to compete with other forms of energy generation, this needs to be increased to three or higher [2]. Recently, improvements in performance have come in the form of random nanostructured materials [3]. Bulk bismuth telluride is subjected to particle size reduction via high-energy ball milling in order to scatter phonons between grains. This reduces the lattice thermal conductivity which in turn increases the performance of the material. In this work, we investigate the use of low-energy ball milling as a method of creating nanoparticles of n-type and p-type Bi2Te3 alloys for thermoelectric applications. Optimization of parameters such as milling containers, milling media, contamination and milling time has resulted in creating 15nm particles of bismuth telluride alloys. After creating solid pellets of the resulting powders via hot pressing, the material's thermal and electrical conductivities as well as Seebeck coefficients were measured. The ZT of n-type Bi2Te2.7Se3 created using this method is 0.32, while the p-type Bi0.5Sb1.5Te3 exhibits a higher ZT of 1.24, both at room temperature.

  8. Electrodeposition and characterization of manganese-bismuth system from chloride based acidic bath

    Energy Technology Data Exchange (ETDEWEB)

    Benfedda, B., E-mail: baya_pg@yahoo.f [Laboratoire de Physique et Chimie des Materiaux (LPCM), Universite M. Mammeri de Tizi-Ouzou (Algeria); Benbrahim, N.; Kadri, A. [Laboratoire de Physique et Chimie des Materiaux (LPCM), Universite M. Mammeri de Tizi-Ouzou (Algeria); Chainet, E. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces (LEPMI), ENSEEG, 1130 rue de la piscine, B.P. 75, 38402 Saint Martin d' Heres, Grenoble (France); Charlot, F.; Coindeau, S. [C.M.T.C., Grenoble I.N.P. Bat Phelma Campus, Domaine Universitaire, B.P. 75, 1260 rue de la piscine, 38402 Saint Martin d' Heres (France)

    2011-01-01

    In this work, Mn-Bi system has been successfully electrodeposited on Cu/Si substrates from aqueous ammonium chloride containing electrolyte. A thermodynamic study of the electrolysis bath highlights the possible formation of manganese complexes (MnCl{sup +}, MnCl{sub 2},MnCl{sub 3}{sup -}) and bismuth complexes (BiCl{sup 2+},BiCl{sub 2}{sup +}, BiCl{sub 3},BiCl{sub 4}{sup -},BiCl{sub 5}{sup 2-},BiCl{sub 6}{sup 3-}). The mechanism process involving Mn and Bi electrodeposition is investigated by cyclic voltammetry. Mn-Bi films can be grown under potentiostatic control. The physico-chemical, morphological and structural characterizations of the deposits were carried out by scanning electron microscopy (SEM) and X-rays analysis (XRD). The results reveal a granular surface quality and a heterogeneous chemical composition of the films. The energy dispersive spectroscopy (EDS) analysis reveals the presence of manganese and bismuth peaks whose relative intensities vary according to the imposed potential and the position on the sample. The X-rays diffraction analysis showed three different crystalline phases: {alpha}-manganese (body centred cubic system), {gamma}-manganese (body centred tetragonal system) and bismuth (rhombohedral system).

  9. 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...

  10. 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 surfa...... to acrolein at temperatures relevant for industrial applications (360 degrees C)....

  11. Melanin-gamma rays assistants for bismuth oxide nanoparticles synthesis at room temperature for enhancing antimicrobial, and photocatalytic activity.

    Science.gov (United States)

    El-Batal, Ahmed I; El-Sayyad, Gharieb S; El-Ghamry, Abbas; Agaypi, Kerolos M; Elsayed, Mohamed A; Gobara, Mohamed

    2017-08-01

    Melanin pigment has been deemed as a natural photoprotector with strong hydrophobicity. It allured considerable compatibility with many applications in medicine, food, and nanotechnology. Penicillium chrysogenium has been devoted to the green synthesis of melanin whereby optimizing its culture and environmental conditions. The impacts of alternative economic L-tyrosine natural sources (unprecedented alternate origins) and gamma radiation were pledged for the potential growing of the pigment. Herein, notable increases in melanin yield (6.4mg/ml; much higher than nonoptimized one by 40 folds) was obtained by optimizing the culture, and environmental requirements [potato starch (3.0%), yeast extract (5.0%), copper sulfate (0.2mM), 0.25% L-tyrosine, 0.1% L-glycine, and 0.1% Tween 20 at pH5.0, and 30°C for 7.0days using 180.0rpm shaking speed]. The addition of banana's peel (2.0%) has been led to increase the melanin production up to (8.3mg/ml; much higher than optimized one by 1.29 folds). It stimulated the induced enzymes, (i.e., tyrosinase) because it contained significant amounts of L-tyrosine, dopamine, and L-DOPA as resources for melanin biosynthesis. Then irradiated P. chrysogenium (2.5kGy) induced the pigment yield to 10.3mg/ml; much higher than optimized one by (1.61 folds). On the other hand, we tailored a methodology involved the product of melanin and gamma rays (25.0kGy) to an eco-friendly synthesis of Bismuth oxide nanoparticles (BiONPs) at the room temperature. Melanin under such alkaline condition functioning as simultaneously hydrolyzes, photoprotection of the Bi seeds, and stabilizer against the uncontrolled growth and the free radicals attack. Whereas the gamma irradiation induced the room temperature condensation reaction to occur, a novel mechanism proposal was discussed. BiONPs were characterized by UV-Vis., DLS, XRD, SEM, EDX, and FTIR. DLS and XRD calculations with TEM analysis exhibited the mean diameter of BiONPs was 29.82nm. Moreover, the as

  12. Optical and electrical properties of thin films of bismuth ferric oxide; Propiedades opticas y electricas de peliculas delgadas de oxido de bismuto ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Cardona R, D.

    2014-07-01

    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 Fe{sub 2}O{sub 3}) 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 BiFeO{sub 3} 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 BiFeO{sub 3} composition. These samples showed a secondary phase (Bi{sub 2}5FeO{sub 4}0 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-Fe{sub 2}O{sub 3}) 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)

  13. A multicenter, randomized, prospective study of 14-day ranitidine bismuth citrate- vs. lansoprazole-based triple therapy for the eradication of Helicobacter pylori in dyspeptic patients.

    Science.gov (United States)

    Avşar, Erol; Tiftikçi, Arzu; Poturoğlu, Sule; Erzin, Yusuf; Kocakaya, Ozan; Dinçer, Dinç; Yıldırım, Bulut; Güliter, Sefa; Türkay, Cansel; Yılmaz, Uğur; Onuk, Mehmet Derya; Bölükbaş, Cengiz; Ellidokuz, Ender; Bektaş, Ahmet; Taşan, Güralp; Aytuğ, Necip; Ateş, Yüksel; Kaymakoğlu, Sabahattin

    2013-01-01

    Proton-pump inhibitor and ranitidine bismuth citrate-based triple regimens are the two recommended first line treatments for the eradication of Helicobacter pylori. We aimed to compare the effectiveness and tolerability of these two treatments in a prospective, multicentric, randomized study. Patients with dyspeptic complaints were recruited from 15 study centers. Presence of Helicobacter pylori was investigated by both histology and rapid urease test. The patients were randomized to either ranitidine bismuth citrate 400 mg bid plus amoxicillin 1 g bid plus clarithromycin 500 mg bid (n=149) or lansoprazole 30 mg bid plus amoxicillin 1 g bid plus clarithromycin 500 mg bid (n=130) treatment arm for 14 days. Adverse events have been recorded during the treatment phase. A 13 C urea breath test was performed 6 weeks after termination of treatment to assess the efficacy of the therapy. Eradication rate was calculated by intention-to-treat and per-protocol analysis. Two hundred seventy-nine patients (123 male, 156 female) were eligible for randomization. In per-protocol analysis (n=247), Helicobacter pylori was eradicated with ranitidine bismuth citrate- and lansoprazole-based regimens in 74,6% and 69,2% of cases, respectively (p>0,05). Intention-to-treat analysis (n=279) revealed that eradication rates were 65,1% and 63,6% in ranitidine bismuth citrate and in lansoprazole-based regimens, respectively (p>0,05). Both regimes were well-tolerated, and no serious adverse event was observed during the study. Ranitidine bismuth citrate-based regimen is at least as effective and tolerable as the classical proton-pump inhibitor-based regimen, but none of the therapies could achieve the recommendable eradication rate.

  14. A new bismuth-based coordination polymer as an efficient visible light responding photocatalyst under white LED irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ya-Jing; Zheng, Yue-Qing, E-mail: zhengyueqing@nbu.edu.cn; Wang, Jin-Jian; Zhou, Lin-Xia

    2017-02-15

    A new bismuth-based polymer, [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O (H{sub 2}pydc=pyridine-2,5-dicarboxylic acid, bpe=trans-bis(4-pyridyl) ethylene) has been hydrothermally synthesized. Transient photocurrent response and electrochemical impedance spectroscopy studies indicate that the synthesized polymer with efficient charge separation and transportation can be used as a potential photocatalyst. So we use it for the degradation of rhodamine B (RhB) dye wastewater under visible light. The comparative study on commercial Bi{sub 2}O{sub 3} shows [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O has the higher photocatalytic performance, with the degradation rate of 97% and 2% within 100 min for [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O and commercial Bi{sub 2}O{sub 3} respectively. Additionally, the five cycle reproducibility results of [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O implies that it can be used as a stable photocatalyst. - Graphical abstract: We report a new 1D coordination polymer [Hbpe][Bi(Hpydc){sub 2}(pydc)]·H{sub 2}O by a facile hydrothermal method. The Bi-CP shows good photoelectric property and photocatalytic activity for RhB degradation under visible white LED lamp irradiation. And the stability of the visible-light-responsive bismuth-based coordination polymer has also been examined. - Highlights: • A new Bi(III) coordination polymer is hydrothermally synthesized. • The Bi-CP shows good photoelectric and photocatalytic properties. • Bi-CP shows higher activity than the commercial Bi{sub 2}O{sub 3} for RhB degradation.

  15. Measurement system for nuclear safeguards based on bismuth-germanate scintillators

    International Nuclear Information System (INIS)

    Moss, C.E.; Dowdy, E.J.; Evans, A.E.; Hamm, M.E.; Lucas, M.C.; Shunk, E.R.

    1983-01-01

    To determine gamma-ray flux spectra, with high efficiency as the foremost objective, we constructed a system that uses bismuth-germanage scintillators as sensors. The system, consisting of eight scintillators and a LeCroy 3500 data acquisition system, has been calibrated and characterized from 0.06 to 8.29 MeV. By fitting the calibration spectra with a function containing 17 parameters, we were able to construct theoretical response functions, which we then used to obtain the gamma-ray flux spectra at multiple space points resulting from a variety of radioactive objects of interest in nuclear safeguards. The results of our procedure agree with calculated values to within less than 10%. 6 figures

  16. [Levofloxacin-based triple therapy versus bismuth-based quadruple therapy in the treatment of Helicobacter pylori as the rescue therapy: a meta analysis].

    Science.gov (United States)

    Zhang, M; Chen, C Y; Wang, X T; Lyu, B

    2017-05-01

    Objective: To evaluate the efficacy of levofloxacin-based triple therapy and bismuth-based quadruple therapy in the treatment of Helicobacter pylori (Hp) infection as rescue regimens. Methods: Related randomized controlled trials assessing the efficacy and safety of levofloxacin-based triple therapy eradicating Hp as salvage treatment were retrieved from Pubmed, Cochrane Library, SPRINGER, VIP database, WanFang database and CKNI database. The literature quality was evaluated by the improved Jadad criterion. RevMan5.3 sofeware was applied to data analysis. The mergment model was chosen on the basis of the outcome of the heterogeneity tests and original data was pooled for meta-analysis. Publication bias assessed with funnel plots. Results: Ultimately seventeen literatures were included for meta-analysis, the analysis showed that the eradication rate of levofloxacin-based triple therapy was higher comparing to the bismuth-based quadruple therapy but the difference was not statistically significant(77.0% vs 68.7%, OR =1.52, 95% CI 0.96-2.42, P =0.34). In European countries, levofloxacin-based triple therapy was more effective than quadruple therapy(80.6% vs 68.5%, OR =2.18, 95% CI 1.25-3.81, P bismuth-based quadruple therapy, levofloxacin-based triple therapy has higher eradication rate, compliance rate and lesser side effects, so we recommend it as a second-line rescue therapy after front-line Hp eradication failure. The optimal second-line alternative scheme might differ among countries depending on quinolone resistance.

  17. Time zero determination for FEL pump-probe studies based on ultrafast melting of bismuth

    Directory of Open Access Journals (Sweden)

    S. W. Epp

    2017-09-01

    Full Text Available A common challenge for pump-probe studies of structural dynamics at X-ray free-electron lasers (XFELs is the determination of time zero (T0—the time an optical pulse (e.g., an optical laser arrives coincidently with the probe pulse (e.g., a XFEL pulse at the sample position. In some cases, T0 might be extracted from the structural dynamics of the sample's observed response itself, but generally, an independent robust method is required or would be superior to the inferred determination of T0. In this paper, we present how the structural dynamics in ultrafast melting of bismuth can be exploited for a quickly performed, reliable and accurate determination of T0 with a precision below 20 fs and an overall experimental accuracy of 50 fs to 150 fs (estimated. Our approach is potentially useful and applicable for fixed-target XFEL experiments, such as serial femtosecond crystallography, utilizing an optical pump pulse in the ultraviolet to near infrared spectral range and a pixelated 2D photon detector for recording crystallographic diffraction patterns in transmission geometry. In comparison to many other suitable approaches, our method is fairly independent of the pumping wavelength (UV–IR as well as of the X-ray energy and offers a favorable signal contrast. The technique is exploitable not only for the determination of temporal characteristics of the experiment at the interaction point but also for investigating important conditions affecting experimental control such as spatial overlap and beam spot sizes.

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

    International Nuclear Information System (INIS)

    Beznosov, A.V.; Pinaev, S.S.; Muraviev, E.V.; Romanov, P.V.

    2005-01-01

    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·m 2 for steels and 5,0x10 -6 - 5,0x10 -5 Ohm·m 2 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)

  19. Effects of simvastain and enamel matrix derivative on Portland cement with bismuth oxide-induced growth and odontoblastic differentiation in human dental pulp cells.

    Science.gov (United States)

    Lee, So-Youn; Min, Kyung-San; Choi, Gi-Woon; Park, Jae-Hong; Park, Sang-Hyuk; Lee, Sang-Im; Kim, Eun-Cheol

    2012-03-01

    We previously reported that bismuth oxide containing Portland cement (BPC) showed similar biocompatibility to Portland cement (PC) in periodontal ligament cells. However, the bioactivity of simvastatin and Emdogain (Biora AB, Malmö, Sweden) on BPC was not reported. The aim of this study was to evaluate the effects of simvastatin and Emdogain on BPC compared with mineral trioxide aggregate (MTA) in human dental pulp cells (HDPCs). Cell growth was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay. Differentiation was evaluated by alkaline phosphatase (ALP) activity, alizarin red staining, and reverse-transcriptase polymerase chain reaction. The cell growth of HDPCs exposed to Emdogain and simvastatin plus BPC was superior to those administered BPC alone and similar to those that received MTA for 14 days. The simvastatin and Emdogain groups increased the odontogenic potential of the BPC group with respect to ALP activity, mineralization nodules, messenger RNA expression of ALP, osteopontin, osteocalcin, Runx2, and osterix. These results suggest that simvastatin and Emdogain improved cell growth and the differentiation of the BPC group in HDPCs and may be useful ingredients in BPC as pulp-capping material. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Marion, E-mail: marion.roy@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Martinelli, Laure, E-mail: laure.martinelli@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Ginestar, Kevin, E-mail: kevin.ginestar@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Favergeon, Jérôme, E-mail: jerome.favergeon@utc.fr [Laboratoire Roberval, UMR 7337, Université de Technologie de Compiègne, Centre de Recherche de Royallieu, CS 60319, 60203 Compiègne Cedex (France); Moulin, Gérard [Laboratoire Roberval, UMR 7337, Université de Technologie de Compiègne, Centre de Recherche de Royallieu, CS 60319, 60203 Compiègne Cedex (France)

    2016-01-15

    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{sup −9} and 5 10{sup −4} g kg{sup −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{sup −1} K{sup −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. - Highlights: • 10 austenitic steels and Ni rich alloys were tested in LBE at 520 °C with dissolved oxygen content between 10{sup -9} and 5 10{sup -4} wt%. • It is shown that only thermodynamics cannot explain the Ni rich alloys corrosion behaviour in LBE. • The role of oxygen on corrosion behaviour in LBE was highlighted. • An equilibrium line was defined above which only oxidation has occurred on 316L: RTln[O](wt%) = -57584/T(K)-55.876T(K)+254546. • 18Cr-15Ni-3.7Si, 21Cr-11Ni-1.6Si and 14Cr-25Ni-3.5Al

  1. 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)

    Jayasinghe, R.; Tsuji, L.J.S.; Gough, W.A.; Karagatzides, J.D.; Perera, D.; Nieboer, E.

    2004-01-01

    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

  2. Structure-activity relationships of carbon-supported platinum-bismuth and platinum-antimony oxidation catalysts

    CSIR Research Space (South Africa)

    Maphoru, MV

    2017-04-01

    Full Text Available Compositional and morphological studies on supported platinum are important for the improvement and expanded use of catalysts for oxidative coupling reactions. Nanocomposites consisting of 5% Pt supported on activated carbon and promoted with 5% Bi...

  3. Refining method for bismuth nitrate

    International Nuclear Information System (INIS)

    Shibata, Shigeyuki.

    1997-01-01

    The present invention concerns a method of separating and removing α ray emitting nuclides present in an aqueous solution of bismuth nitrate by an industrially convenient method. A nitric acid concentration in the aqueous solution of bismuth nitrate in which α ray emitting nuclides are dissolved is lowered to coprecipitate the bismuth oxynitrate and the α ray emitting nuclides. The coprecipitation materials are separated from the aqueous solution of bismuth nitrate to separate the α ray emitting nuclides dissolved in the aqueous solution of bismuth nitrate thereby refining the aqueous solution of bismuth nitrate. (T.M.)

  4. Effectiveness of ranitidine bismuth citrate and proton pump inhibitor ...

    African Journals Online (AJOL)

    Effectiveness of ranitidine bismuth citrate and proton pump inhibitor based triple therapies of Helicobacter pylori in Turkey. ... Results: When we look at the eradication rates of the treatment groups, only two groups (ranitidine bismuth citrate and rabeprazole groups) had eradication rates greater than 80%, both at intention to ...

  5. 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...

  6. Determination of trace amounts of lead and cadmium using a bismuth/glassy carbon composite electrode.

    Science.gov (United States)

    Hwang, Gil-Ho; Han, Won-Kyu; Hong, Seok-Jun; Park, Joon-Shik; Kang, Sung-Goon

    2009-02-15

    We examined the use of a bismuth-glassy carbon (Bi/C) composite electrode for the determination of trace amounts of lead and cadmium. Incorporated bismuth powder in the composite electrode was electrochemically dissolved in 0.1M acetate buffer (pH 4.5) where nanosized bismuth particles were deposited on the glassy carbon at the reduction potential. The anodic stripping voltammetry on the Bi/C composite electrode exhibited well-defined, sharp and undistorted peaks with a favorable resolution for lead and cadmium. Comparing a non-oxidized Bi/C composite electrode with an in-situ plated bismuth film electrode, the Bi/C composite electrode exhibited superior performance due to its much larger surface area. The limit of detection was 0.41 microg/L for lead and 0.49 microg/L for cadmium. Based on this study, we are able to conclude that various types of composite electrodes for electroanalytical applications can be developed with a prudent combination of electrode materials.

  7. 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.

  8. Synthesis and characterization of Bi{sub 31}Cr{sub 5}O{sub 61.5}, a new bismuth chromium oxide, potential mixed-ionic-electronic conductor for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Colmont, Marie; Drache, Michel; Roussel, Pascal [Universite Lille Nord de France, Unite de Catalyse et de Chimie du Solide (UCCS), CNRS UMR 8181, 59655 Villeneuve d' Ascq Cedex (France)

    2010-11-01

    Single crystals, as well as pure powder of the new bismuth chromate, Bi{sub 31}Cr{sub 5}O{sub 61.5} were synthesized by slow cooling of a mixture of Bi{sub 2}O{sub 3}-Cr{sub 2}O{sub 3} and then fully structurally characterized using X-ray diffraction. It crystallizes in the monoclinic space group P2{sub 1}/n with unit cell parameters a = 23.5794(8), b = 11.6189(4), c = 24.3629(8) A and {beta} = 108.02(1) , Z = 4. The final conventional agreement factors converged to R = 0.0540 and wR = 0.0561 for 27520 independent reflections. The +VI chromium oxidation state was proved by thermogravimetric and magnetic measurements. The structure can be described by the association of isolated CrO{sub 4} tetrahedra surrounded by 11 or 12 Bi atoms forming truncated or not cuboctahedra. The stability of both pure powder sample and pressed sintered pellets was studied at elevated temperature by X-ray diffraction and by dilatometry previously to ionic conductivity measurements done by impedance spectroscopy. (author)

  9. High-Performance Red-Light Photodetector Based on Lead-Free Bismuth Halide Perovskite Film.

    Science.gov (United States)

    Tong, Xiao-Wei; Kong, Wei-Yu; Wang, You-Yi; Zhu, Jin-Miao; Luo, Lin-Bao; Wang, Zheng-Hua

    2017-06-07

    In this study, we developed a sensitive red-light photodetector (RLPD) based on CsBi 3 I 10 perovskite thin film. This inorganic, lead-free perovskite was fabricated by a simple spin-coating method. Device analysis reveals that the as-assembled RLPD was very sensitive to 650 nm light, with an on/off ratio as high as 10 5 . The responsivity and specific detectivity of the device were estimated to be 21.8 A/W and 1.93 × 10 13 Jones, respectively, which are much better than those of other lead halide perovskite devices. In addition, the device shows a fast response (rise time: 0.33 ms; fall time: 0.38 ms) and a high external quantum efficiency (4.13 × 10 3 %). It is also revealed that the RLPD has a very good device stability even after storage for 3 months under ambient conditions. In summary, we suggest that the CsBi 3 I 10 perovskite photodetector developed in this study may have potential applications in future optoelectronic systems.

  10. Fabrication of Thermoelectric Sensor and Cooling Devices Based on Elaborated Bismuth-Telluride Alloy Thin Films

    Directory of Open Access Journals (Sweden)

    Abdellah Boulouz

    2014-01-01

    Full Text Available The principal motivation of this work is the development and realization of smart cooling and sensors devices based on the elaborated and characterized semiconducting thermoelectric thin film materials. For the first time, the details design of our sensor and the principal results are published. Fabrication and characterization of Bi/Sb/Te (BST semiconducting thin films have been successfully investigated. The best values of Seebeck coefficient (α(T at room temperature for Bi2Te3, and (Bi1−xSbx2Te3 with x = 0.77 are found to be −220 µV/K and +240 µV/K, respectively. Fabrication and evaluation of performance devices are reported. 2.60°C of cooling of only one Peltier module device for an optimal current of Iopt=2.50 mA is obtained. The values of temperature measured by infrared camera, by simulation, and those measured by the integrated and external thermocouple are reported. A sensitivity of the sensors of 5 mV Torr−1 mW−1 for the pressure sensor has been found with a response time of about 600 ms.

  11. 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)

  12. Development of lead-bismuth coolant technology for nuclear device

    International Nuclear Information System (INIS)

    Kamata, Kin-ya; Kitano, Teruaki; Ono, Mikinori

    2004-01-01

    Liquid lead-bismuth is a promising material as a future fast reactor coolant or an intensive neutron source material for accelerator driven transmutation system (ADS). To develop nuclear plants and their installations using lead-bismuth coolant for practical use, both coolant technologies, inhabitation process of steels and quality control of coolant, and total operation system for liquid lead-bismuth plants are required. Based on the experience of liquid metal coolant, Mitsui Engineering and Shipbuilding Co., Ltd. (MES) has completed the liquid lead-bismuth forced circulation loop and has acquired various engineering data on main components including economizer. As a result of tis operation, MES has developed key technologies of lead-bismuth coolant such as controlling of oxygen content in lead-bismuth and a purification of lead-bismuth coolant. MES participated in the national project, ''The Development of Accelerator Driven Transmutation System'', together with JAERI (Japan Atomic Energy Research Institute) and started corrosion test for beam window of ADS. (author)

  13. Post-CMOS FinFET integration of bismuth telluride and antimony telluride thin-film-based thermoelectric devices on SoI substrate

    KAUST Repository

    Aktakka, Ethem Erkan

    2013-10-01

    This letter reports, for the first time, heterogeneous integration of bismuth telluride (Bi2Te3) and antimony telluride (Sb 2Te3) thin-film-based thermoelectric ffect transistors) via a characterized TE-film coevaporationand shadow-mask patterning process using predeposition surface treatment methods for reduced TE-metal contact resistance. As a demonstration vehicle, a 2 × 2 mm2-sized integrated planar thermoelectric generator (TEG) is shown to harvest 0.7 μ W from 21-K temperature gradient. Transistor performance showed no significant change upon post-CMOS TEG integration, indicating, for the first time, the CMOS compatibility of the Bi2Te3 and Sb2Te3 thin films, which could be leveraged for realization of high-performance integrated micro-TE harvesters and coolers. © 2013 IEEE.

  14. Surface oxygen exchange properties of bismuth oxide-based solid electrolytes and electrode materials

    NARCIS (Netherlands)

    Boukamp, Bernard A.; Vinke, I.C.; de Vries, K.J.; Burggraaf, A.J.

    1989-01-01

    The surface oxygen exchange coefficient, ks, has been measured for the solid solution (Bi2O3)0.75(Er2O3)0.25 and (Bi2O3)0.6(Tb2O3)0.4 (abbreviated BE25 and BT40), using gas-phase 18O exchange techniques. The activation enth alpy of ks amounts to ΔE=110 kJ/molforBT40 andΔE=130 kJ/molforBE25. The

  15. Characteristics of Honeycomb-Type Oxygen Generator with Electrolyte Based on Doped Bismuth Oxide

    Science.gov (United States)

    Chen, Yu-Wen; Liu, Yi-Xin; Wang, Sea-Fue; Devasenathipathy, Rajkumar

    2018-03-01

    An oxygen generator using Y-doped Bi2O3 as electrolyte to transport oxygen ions has been developed, having honeycomb-type structure with dimensions of 40 mm × 35 mm × 30 mm and consisting of 13 × 12 channels. External wire circuitry for the channels arrayed using parallel, series, and hybrid connection was evaluated to achieve the best oxygen separation efficiency. It was observed that the oxygen generator with hybrid connection facilitated evolution of oxygen at maximum of 117 sccm and high purity > 99.9% at 550°C under current flow of 14 A. Addition of 5 wt.% silane and 3 wt.% glass-ceramic powder to the Ag slurry used at both electrodes not only increased the coverage of the metal electrode on the ceramic substrate during dip coating but also prevented cracking at the electrode layer of the module under stress from the electric field and temperature during high-temperature operation, thus reducing the decay rate of the oxygen generator in durability testing.

  16. 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 mixture with Bi/Mo ratio = 1.3 consisting of γ- and α-phase, exhibits the highest activity. Less homogeneous ‘artificial mixtures’ exhibit reduced synergy effects when compared to homogeneous ‘in situ mixtures’....

  17. THORIUM DISPERSION IN BISMUTH

    Science.gov (United States)

    Bryner, J.S.

    1961-07-01

    The growth of thorium bismutaide particles, which are formed when thorium is suspended in liquid bismuth, is inhibited when the liquid metal suspension is being flowed through a reactor and through a heat exchanger in sequence. It involves the addition of as little as 1 part by weight of tellurium to 100 parts of thorium. This addition is sufficient to inhibit particle growth and agglomeration.

  18. Bismuth toxicity in patients treated with bismuth iodoform paraffin packs.

    Science.gov (United States)

    Atwal, A; Cousin, G C S

    2016-01-01

    Bismuth is a heavy metal used in bismuth iodoform paraffin paste (BIPP) antiseptic dressings and in a number of other medical preparations. It can be absorbed systemically and cause toxicity. We report 2 cases of such neurotoxicity after it was used in operations on the jaws. Copyright © 2015. Published by Elsevier Ltd.

  19. Tribochemistry of Bismuth and Bismuth Salts for Solid Lubrication

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.; van den Nieuwenhuijzen, Karin Jacqueline Huberta; Lette, W.; Schipper, Dirk J.; ten Elshof, Johan E.

    2016-01-01

    One of the main trends in the past decades is the reduction of wastage and the replacement of toxic compounds in industrial processes. Some soft metallic particles can be used as nontoxic solid lubricants in high-temperature processes. The behavior of bismuth metal particles, bismuth sulfide

  20. Potential containment materials for liquid-lead and lead-bismuth eutectic spallation neutron source

    International Nuclear Information System (INIS)

    Park, J.J.; Butt, D.P.; Beard, C.A.

    1997-11-01

    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 P O 2 = 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

  1. MO-F-CAMPUS-I-04: Patient Eye-Lens Dose Reduction in Routine Brain CT Examinations Using Organ-Based Tube Current Modulation and In-Plane Bismuth Shielding

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Hui-Yu; Liao, Ying-Lan [Chang Gung University, Taoyun, Taiwan (China); Chang Gung University / Chang Gung Memorial Hospital, Taoyun, Taiwan (China); Lai, Nan-Ku; Chen, Tou-Rong [Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chung Shan Medical University, Taichung, Taiwan (China); Chen, Jun-Rong [Chang Gung University / Chang Gung Memorial Hospital, Taoyun, Taiwan (China)

    2015-06-15

    Purpose: The purpose of this study is to assess eye-lens dose for patients who underwent brain CT examinations using two dose reduction Methods: organ-based tube current modulation (OBTCM) and in-plane bismuth shielding method. Methods: This study received institutional review board approval; written informed consent to participate was obtained from all patients. Ninety patients who underwent the routine brain CT examination were randomly assigned to three groups, ie. routine, OBTCM, and bismuth shield. The OBTCM technique reduced the tube current when the X-ray tube rotates in front of patients’ eye-lens region. The patients in the bismuth shield group were covered one-ply bismuth shield in the eyes’ region. Eye-lens doses were measured using TLD-100H chips and the total effective doses were calculated using CT-Expo according to the CT scanning parameters. The surface doses for patients at off-center positions were assessed to evaluate the off-centering effect. Results: Phantom measurements indicates that OBTCM technique could reduced by 26% to 28% of the surface dose to the eye lens, and increased by 25% of the surface dose at the opposed incident direction at the angle of 180°. Patients’ eye-lens doses were reduced 16.9% and 30.5% dose of bismuth shield scan and OBTCM scan, respectively compared to the routine scan. The eye-lens doses were apparently increased when the table position was lower than isocenter. Conclusion: Reducing the dose to the radiosensitive organs, such as eye lens, during routine brain CT examinations could lower the radiation risks. The OBTCM technique and in-plane bismuth shielding could be used to reduce the eye-lens dose. The eye-lens dose could be effectively reduced using OBTCM scan without interfering the diagnostic image quality. Patient position relative the CT gantry also affects the dose level of the eye lens. This study was supported by the grants from the Ministry of Science and Technology of Taiwan (MOST103-2314-B-182

  2. Coating compositions comprising bismuth-alloyed zinc

    DEFF Research Database (Denmark)

    2008-01-01

    The present application discloses (i) a coating composition comprising a particulate zinc-based alloyed material, said material comprising 0.05-0.7% by weight of bismuth (Bi), the D50 of the particulate material being in the range of 2.5-30 µm; (ii) a coated structure comprising a metal structure......, wherein the material comprises 0.05-0.7%(w/w) of bismuth (Bi), and wherein the D50 of the particulate material is in the range of 2.5-30 µm; (iv) a composite powder consisting of at least 25%(w/w) of the particulate zinc-based alloyed material, the rest being a particulate material consisting of zinc...

  3. A guide to the influence of bismuth on lead/acid battery performance

    Science.gov (United States)

    Koop, M. J.; Rand, D. A. J.; Culpin, B.

    A review is given of the literature that deals with the influence of bismuth on the microstructure, oxygen/hydrogen evolution kinetics and anodic corrosion of lead and lead alloys with regard to their performance in lead/acid batteries. Analysis shows that there is considerable disagreement as to the effect of bismuth on lead microstructure. For example, the various investigators report an increase, a decrease, or negligible change in grain size. In general, it is concluded that the oxygen overpotential on PbO 2 is lowered in the presence of bismuth. The effect is enhanced as the bismuth content is increased. It is postulated that the behaviour results from the formation of a mixed oxide, PbO 2·BiO x. By contrast, cathodic hydrogen evolution is reported widely to be largely unaffected by bismuth. Nevertheless, there is evidence that the reaction is particularly sensitive to the surface characteristics of electrodes and that these features can induce either a suppression or an enhancement of the hydrogen-gassing rate. Many studies have shown that bismuth accelerates the anodic corrosion of lead alloys, especially at high concentrations of bismuth. At 0.1 wt.% bismuth and below, the effect on the corrosion rate is negligible. The authors of this discussion are of the opinion that much of the conflicting evidence in the areas reported is caused by spurious differences in grain structure that are introduced by variations in sample preparation, rather than by the action of bismuth itself. In battery-related tests, bismuth has usually been found to exert little influence on performance, but there is some suggestion that cycle life is increased. The present body of knowledge is insufficient to confirm the correctness of any currently specified maximum level for bismuth with respect to a given battery design.

  4. A miniaturized bismuth-based sensor to evaluate the marine organism Styela plicata bioremediation capacity toward heavy metal polluted seawater.

    Science.gov (United States)

    Colozza, Noemi; Gravina, Maria Flavia; Amendola, Luca; Rosati, Modesto; Akretche, Djamal Eddine; Moscone, Danila; Arduini, Fabiana

    2017-04-15

    Cadmium and lead are highly toxic heavy metals which cause a severe worldwide pollution. In addition to the toxic effect produced by the direct exposure, they can be bioconcentrated and accumulated in living organisms, including humans. Herein, a miniaturized and disposable electrochemical sensor was improved for the simultaneous detection of cadmium and lead ions to study the bioremediation of polluted seawater in presence of the filter-feeding marine organism Styela plicata. A screen-printed electrode modified in situ with a bismuth film was selected using the anodic stripping analysis as detection technique. This sensor was coupled with a portable potentiostat and the detection of cadmium and lead ions was carried out by Square Wave Anodic Stripping Voltammetry, allowing the simultaneous detection of both heavy metals at ppb level (LOD=0.3ppb for lead, 1.5ppb for cadmium). This analytical tool was then applied to assess the bioremediation capacity of S. plicata through a bioremediation experiment, in which the organism has been exposed to seawater artificially polluted with 1000ppb of Cd 2+ and Pb 2+ . The matrix effect of both seawater and acid digested biological samples was evaluated. A bioconcentration phenomenon was observed for both heavy metals through the analysis of S. plicata tissues. In details, Pb 2+ resulted to be about 2.5 times more bioconcentrated than Cd 2+ , giving an effective bioremediation level in seawater of 13% and 40% for Cd 2+ and Pb 2+ , respectively. Thus, our results demonstrate the capability of S. plicata to bioremediate Cd 2+ and Pb 2+ polluted seawater as well as the suitability of the electrochemical sensor for contaminated marine environment monitoring and bioremediation evaluation. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Takahashi, Minoru; Sekimoto, Hiroshi

    2003-03-01

    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

  6. Adsorption and condensation of bismuth on tungsten

    International Nuclear Information System (INIS)

    Radon, T.; Sidorski, Z.

    1979-01-01

    The bismuth-tungsten system was studied by means of field emission microscopy. The average work function changes induced by the bismuth adsorption were measured for different amounts of adsorbed bismuth. It was found that the adsorption of bismuth changes the work function of tungsten only slightly. The penetration of bismuth into the tungsten substrate was observed. The growth of bismuth single crystals was studied when bismuth was deposited with a rate of about 6 monolayers per minute onto the tungsten substrate and kept at 470 K. Bismuth single crystals with two-fold symmetry occurred most often on the (100) tungsten planes. On the (111) tungsten plane bismuth crystals with three-fold symmetry were observed. An explanation of the observed phenomena is proposed. (Auth.)

  7. Nano crystalline Bi{sub 2}(VO{sub 5}) phases in lithium bismuth borate glasses containing mixed vanadium-nickel oxides

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Arti, E-mail: artidabhur@gmail.com; Khasa, S.; Dahiya, M. S. [Department of Physics, Deenbandhu Chhotu Ram University of Science and Technology, Murthal, India-131039 (India); Agarwal, A. [Department of Applied Physics, G. J. University of Science and Technology, Hisar, India-125001 (India)

    2016-05-23

    Glass composition 7V{sub 2}O{sub 5}·23Li{sub 2}O·20Bi{sub 2}O{sub 3}·50B{sub 2}O{sub 3} and x(2NiO·V{sub 2}O{sub 5})·(30-x)Li{sub 2}O·20Bi{sub 2}O{sub 3}·50B{sub 2}O{sub 3}, x=0, 2, 5, 7 and 10, were produced by conventional melt quenching technique. The quenched amorphous glass samples were annealed at temperatures 400°C and 500°C for 6 hours. The Bi{sub 2}(VO{sub 5}) crystallite were grown in all prepared glass matrix. Tn vanadium lithium bismuth borate glass (annealed), the some phrase of V{sub 2}O{sub 5}-crystal were observed along with the nano crystalline Bi{sub 2}(VO{sub 5}) phase. The sharp peaks in FTTR spectra of all annealed compositions were also compatible with the XRD diffraction peaks of the system under investigation. Average crystalline size (D) of the Bi{sub 2}(VO{sub 5}) nano-crystallite was ~30 nm for samples annealed at 400°C and ~42 nm for samples annealed at 500°C. Lattice parameter and the lattice strain for all the samples was also calculated corresponding to the (113) plane of Bi{sub 2}(VO{sub 5}) crystallite.

  8. Development of highly sensitive electrochemical genosensor based on multiwalled carbon nanotubes-chitosan-bismuth and lead sulfide nanoparticles for the detection of pathogenic Aeromonas.

    Science.gov (United States)

    Fernandes, António Maximiano; Abdalhai, Mandour H; Ji, Jian; Xi, Bing-Wen; Xie, Jun; Sun, Jiadi; Noeline, Rasoamandrary; Lee, Byong H; Sun, Xiulan

    2015-01-15

    In this paper, we reported the construction of new high sensitive electrochemical genosensor based on multiwalled carbon nanotubes-chitosan-bismuth complex (MWCNT-Chi-Bi) and lead sulfide nanoparticles for the detection of pathogenic Aeromonas. Lead sulfide nanoparticles capped with 5'-(NH2) oligonucleotides thought amide bond was used as signalizing probe DNA (sz-DNA) and thiol-modified oligonucleotides sequence was used as fixing probe DNA (fDNA). The two probes hybridize with target Aeromonas DNA (tDNA) sequence (fDNA-tDNA-szDNA). The signal of hybridization is detected by differential pulse voltammetry (DPV) after electrodeposition of released lead nanoparticles (PbS) from sz-DNA on the surface of glass carbon electrode decorated with MWCNT-Chi-Bi, which improves the deposition and traducing electrical signal. The optimization of incubation time, hybridization temperature, deposition potential, deposition time and the specificity of the probes were investigated. Our results showed the highest sensibility to detect the target gene when compared with related biosensors and polymerase chain reaction (PCR). The detection limit for this biosensor was 1.0×10(-14) M. We could detect lower than 10(2) CFU mL(-1) of Aeromonas in spiked tap water. This method is rapid and sensitive for the detection of pathogenic bacteria and would become a potential application in biomedical diagnosis, food safety and environmental monitoring. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Substutited molybdates of bismuth on a basis of Bi13Mo5O34±δ: production and properties

    Directory of Open Access Journals (Sweden)

    Z. A. Mikhailovskaya

    2014-11-01

    Full Text Available The present work is devoted to the investigation of the methods of a synthesis and properties of the one of the most interesting one-dimensional oxygen –ion conductors, the Bi13Mo5O34±δ –based complex oxides. The general compositions of these bismuth molybdates are Bi13Mo5-хMeхO34-δ, and Bi13-yMeyMo5O34-δ, with Me = Mg, Ca, Sr, Ba (IIA group and Co, Fe, Ni (Fe triade. The samples have been synthesized using conventional ceramic technology. The powders and pellets of the bismuth molybdates were studied by X-Ray diffraction, scanning electron microscopy, laser dispersion, dilatometry, atom absorption and inductively-coupled plasma atomic emission spectrometry. Electrical conductivity has been studied using impedance spectroscopy method.

  10. Study of the redox properties of bismuth-molybdate and uranium-antimonate catalysts

    International Nuclear Information System (INIS)

    Paz-Pujalt, G.R.

    1985-01-01

    The oxidation/reduction properties of various bismuth molybdates, molybdenum trioxide, bismuth oxide, uranium antimonate, and iron antimonate have been studied in an effort to correlate them to their catalytic properties. The temperature at which γ-phase bismuth molybdate is prereduced plays an important role in the behavior the catalyst exhibits under reoxidation conditions. The overall behavior of γ-phase bismuth molybdate under catalytic conditions may be divided into two temperature regimes: below 360 0 C the catalyst shows a higher rate of propylene adsorption than product desorption, and above 360 0 C where produced desorption is dominant. This temperature is the same at which the Arrhenius plot for the reaction has a break. Several reduction of γ-bismuth molybdate results in the formation of clusters of bismuth metal and crystallites of molybdenum dioxide. This is irreversible. The reoxidation of the bismuth molybdate catalysts shows the presence of two oxygen incorporation temperatures. The ratios of the areas under these peaks are not the same for the three catalysts. Uranium antimonate shows a lesser degree of lattice oxygen participation. During several reduction the catalyst decomposes partially and an excess of antimony is evident. The isothermal reduction profiles of the catalysts permitted their classification into either of two reduction models: (A) α-, β-, γ-phase bismuth molybdates, molybdenum trioxide, bismuth oxide, and the equimolar mixture follow the nucleation model, (B) uranium antimonate, and iron antimonate following the shrinking sphere model. These models have been correlated to certain characteristics of these catalysts. Group A catalysts show a high degree of lattice oxygen participation (migration of bulk oxygen to surface nuclei). In contrast in group B catalysts only a few layers of oxygen are peeled off during catalysis

  11. Preliminary study on nano- and micro-composite sol-gel based alumina coatings on structural components of lead-bismuth eutectic cooled fast breeder reactors

    International Nuclear Information System (INIS)

    Dou, Peng; Kasada, Ryuta

    2011-01-01

    In order to protect the structural components of lead-bismuth eutectic cooled fast breeder reactors from liquid metal corrosion, Al 2 O 3 nano- and micro-composite coatings were developed using an improved sol-gel process, which includes dipping specimens in a sol-gel solution dispersed with fine α-Al 2 O 3 powders prepared by mechanical milling. Accelerated corrosion tests were conducted on coated specimens in liquid lead-bismuth eutectic at 500 o C under dynamic conditions. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses revealed that the coatings are composed of α-Al 2 O 3 and they are about 10 μm thick. After the corrosion tests, no spallation occurred on the coatings, and neither Pb nor Bi penetrated into the coatings, which indicates that the coatings possess an enhanced dynamic LBE corrosion resistance to lead-bismuth eutectic corrosion. The nano-structured composite particles integrated into the coatings play an important role in achieving such superior lead-bismuth eutectic corrosion resistance.

  12. 21 CFR 73.1162 - Bismuth oxychloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The color additive bismuth oxychloride is a synthetically prepared white or nearly white amorphous or finely...

  13. 21 CFR 73.2162 - Bismuth oxychloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bismuth oxychloride. 73.2162 Section 73.2162 Food... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and specifications. (1) The color additive bismuth oxychloride shall conform in identity and specifications to the...

  14. Electrochemical immunosensor based on bismuth nanocomposite film and cadmium ions functionalized titanium phosphates for the detection of anthrax protective antigen toxin.

    Science.gov (United States)

    Sharma, Mukesh K; Narayanan, J; Upadhyay, Sanjay; Goel, Ajay K

    2015-12-15

    Bacillus anthracis is a bioterrorism agent classified by the Centers for Disease Control and Prevention (CDC). Herein, a novel electrochemical immunosensor for the sensitive, specific and easy detection of anthrax protective antigen (PA) toxin in picogram concentration was developed. The immunosensor consists of (i) a Nafion-multiwall carbon nanotubes-bismuth nanocomposite film modified glassy carbon electrodes (BiNPs/Nafion-MWCNTs/GCE) as a sensing platform and (ii) titanium phosphate nanoparticles-cadmium ion-mouse anti-PA antibodies (TiP-Cd(2+)-MαPA antibodies) as signal amplification tags. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), thermogravimmetric analysis (TGA), Fourier transform-infra red spectroscopy (FT-IR), zeta-potential analysis, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were employed to characterize the synthesized TiP nanoparticles and modified electrode surfaces. The immunosensing performance of BiNPs/Nafion-MWCNTs/GCE was evaluated based on sandwich immunoassay protocol. A square wave voltammetry (SWV) scan from -1.2 to -0.3 V in HAc-NaAc buffer solution (pH 4.6) without stripping process was performed to record the electrochemical responses at -0.75 V corresponding to high content of Cd(2+) ions loaded in TiP nanoparticles for the measurement of PA toxin. Under optimal conditions, the currents increased with increasing PA toxin concentrations in spiked human serum samples and showed a linear range from 0.1 ng/ml to 100 ng/ml. The limit of detection of developed immunosensor was found to be 50 pg/ml at S/N=3. The total time of analysis was 35 min. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. 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.

  16. Bismuth Passivation Technique for High-Resolution X-Ray Detectors

    Science.gov (United States)

    Chervenak, James; Hess, Larry

    2013-01-01

    The Athena-plus team requires X-ray sensors with energy resolution of better than one part in 3,000 at 6 keV X-rays. While bismuth is an excellent material for high X-ray stopping power and low heat capacity (for large signal when an X-ray is stopped by the absorber), oxidation of the bismuth surface can lead to electron traps and other effects that degrade the energy resolution. Bismuth oxide reduction and nitride passivation techniques analogous to those used in indium passivation are being applied in a new technique. The technique will enable improved energy resolution and resistance to aging in bismuth-absorber-coupled X-ray sensors. Elemental bismuth is lithographically integrated into X-ray detector circuits. It encounters several steps where the Bi oxidizes. The technology discussed here will remove oxide from the surface of the Bi and replace it with nitridized surface. Removal of the native oxide and passivating to prevent the growth of the oxide will improve detector performance and insulate the detector against future degradation from oxide growth. Placing the Bi coated sensor in a vacuum system, a reduction chemistry in a plasma (nitrogen/hydrogen (N2/H2) + argon) is used to remove the oxide and promote nitridization of the cleaned Bi surface. Once passivated, the Bi will perform as a better X-ray thermalizer since energy will not be trapped in the bismuth oxides on the surface. A simple additional step, which can be added at various stages of the current fabrication process, can then be applied to encapsulate the Bi film. After plasma passivation, the Bi can be capped with a non-diffusive layer of metal or dielectric. A non-superconducting layer is required such as tungsten or tungsten nitride (WNx).

  17. 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.

  18. Investigation of iron-bismuth-molybdenum catalysts

    International Nuclear Information System (INIS)

    Ven'yaminov, S.A.; Pitaeva, A.N.; Barannik, G.B.; Plyasova, L.M.; Maksimovskaya, R.I.; Kustova, G.N.

    1977-01-01

    Using the methods of roentgenography, derivatography, EPR-and infrared-spectroscopy, the phase composition of an iron-bismut molybdenum system is investigated. It is shown that the method of introducing iron additives substantially affects the phase composition of the system. Interaction of a mixture of bismuth and iron hydroxides with a molybdic acid solution results in the formation of bismuth and iron molybdates. If iron hydroxide reacts with previously synthesized bismuth molybdate, a compound containing bismuth, molybdenum, and iron (the X-phase) is formed in the specimens along with the bismuth and iron molybdates

  19. A new supramolecular based liquid solid microextraction method for preconcentration and determination of trace bismuth in human blood serum and hair samples by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Kahe, Hadi; Chamsaz, Mahmoud

    2016-11-01

    A simple and reliable supramolecule-aggregated liquid solid microextraction method is described for preconcentration and determination of trace amounts of bismuth in water as well as human blood serum and hair samples. Catanionic microstructures of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants, dissolved in deionized water/propanol, are used as a green solvent to extract bismuth (III)-diethyldithiocarbamate complexes by dispersive microextraction methodology. The extracted solid phase is easily removed and dissolved in 50 μL propanol for subsequent measurement by electrothermal atomic absorption spectrometry (ET-AAS). The procedure benefits the merits of supramolecule aggregates' properties and dispersive microextraction technique using water as the main component of disperser solvent, leading to direct interaction with analyte. Phase separation behavior of extraction solvent and different parameters influencing the extraction efficiency of bismuth ion such as salt concentration, pH, centrifugation time, amount of chelating agent, SDS:CTAB mole ratio, and solvent amounts were thoroughly optimized. Under the optimal experimental conditions, the calibration curve was linear in the range of 0.3-6 μg L -1 Bi (III) with a limit of detection (LOD) of 0.16 μg L -1 (S/N = 3). The relative standard deviations (RSD) of determination were obtained to be 5.1 and 6.2 % for 1 and 3 μg L -1 of Bi (III), respectively. The developed method was successfully applied as a sensitive and accurate technique for determination of bismuth ion in human blood serum, hair samples, and a certified reference material.

  20. Temperature gradient compatibility tests of some refractory metals and alloys in bismuth and bismuth--lithium solutions

    International Nuclear Information System (INIS)

    DiStefano, J.R.; Cavin, O.B.

    1976-11-01

    Quartz, T-111, and Mo thermal-convection loop tests were conducted at temperatures up to 700 0 C (100 0 C ΔT) to determine the compatibility of several refractory metals/alloys with bismuth and bismuth-lithium solutions for molten salt breeder reactor applications. Methods of evaluation included weight change measurements, metallographic examination, chemical and electron microprobe analysis, and mechanical properties tests. Molybdenum, T-111, and TA--10 percent W appear to be the most promising containment materials, while niobium and iron-based alloys are unacceptable

  1. Microwave-induced Bismuth Salts-mediated Synthesis of Molecules of Medicinal Interests.

    Science.gov (United States)

    Bandyopadhyay, Debasish; Chavez, Ashlee; Banik, Bimal K

    2017-01-01

    Bismuth salts-mediated reactions have become a powerful tool for the synthesis of diverse medicinally-significant compounds because of their low-toxicity (non-toxic) and Lewis acidic capacity. In fact, LD50 of bismuth nitrate is lower than table salt. On the other hand, microwave-induced chemical synthesis is considered as a major greener route in modern chemistry. A total of 139 publications (including a few authentic web links) have been reviewed mainly to discuss bismuth salts-induced electrophilic aromatic substitution, protection-deprotection chemistry of carbonyl compounds, enamination, oxidation, carbohydrate chemistry, hydrolysis, addition-elimination route, Paal-Knorr reaction, Clauson-kaas synthesis, Michael addition, aza-Michael addition, Hantzsch reaction, Biginelli reaction, Ferrier rearrangement, Pechmann condensation, Diels-Alder and aza-Diels- Alder reactions, as well as effects of microwave irradiation in a wide range of chemical transformations. Bismuth salts-mediated reactions are developed for the synthesis of diverse organic molecules of medicinal significance. Reactions conducted with bismuth salts are environmentally benign, economical, rapid and high yielding. Microwave irradiation has accelerated these reactions significantly. It is believed that bismuth salts released corresponding acids in the media during the reaction. However, a coordination of bismuth salt to the electronegative atom is also observed in the NMR study. Bismuth has much less control (less attractive forces) over anions (for example, halides, nitrate, sulfate and triflates) compared to alkali metals. Therefore, it forms weak bond with electronegative atoms more readily and facilitates the reactions significantly. Many products obtained via bismuth salts-mediated reactions are medicinally active or intermediate for the synthesis of biologically active molecules including antifungal, anti-parasitic, anticancer and antibacterial agents, as well as agents to prevent

  2. A study on structural stability of bismuth titanate with lanthanum ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 3. A study on structural stability of bismuth titanate with lanthanum ... In addition, the enlarged region of Bi 4f, Bi 4d, Ti 2p, La 3d and O 1s of doping sample was clearly seen after deconvolution. Based on binding energy position, it can be unambiguously stated ...

  3. New Er{sup 3+} doped antimony oxide based glasses: Thermal analysis, structural and spectral properties

    Energy Technology Data Exchange (ETDEWEB)

    Ouannes, K. [Faculté des Sciences et de la Technologie, Université de Biskra, BP 145 RP, 07000, Biskra (Algeria); Lebbou, K., E-mail: kheirreddine.lebbou@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622, Villeurbanne (France); Walsh, Brian-M. [NASA Langley Research Center, Hampton, VA, 23681 (United States); Poulain, M. [UMR 6226- Verres et Céramiques – Campus de Beaulieu, Université de Rennes1, 35042, Rennes (France); Alombert-Goget, G.; Guyot, Y. [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622, Villeurbanne (France)

    2015-11-15

    The novel oxide glass compositions based on Sb{sub 2}O{sub 3} are elaborated and characterized, in the system (90-X)Sb{sub 2}O{sub 3}–10Na{sub 2}O–XBi{sub 2}O{sub 3} (SNB). We are interested in bismuth rates incorporated into the glass, its effect on the different physical properties that have been measured, and especially, in radiative and spectroscopic properties of erbium doped SNB glasses. Differential scanning calorimeter (DSC) measurements show an improvement of the stability factor,ΔT, of the glasses, which can indicate a reinforcement of the network. Both FTIR and Raman spectra have also been considered in terms of bismuth influence. As a function of composition, we have principally measured optical absorption, visible and infrared emission, and lifetime. The Judd–Ofelt parameters measured from the absorption spectra have been used to calculate the radiative lifetime (τ{sub r}) and the stimulated emission cross section. The spectroscopic quality factor χ = Ω{sub 4}/Ω{sub 6} = 0.73, low phonon energy of ∼600–700 cm{sup −1}, a reduced quenching effect, and a high quantum efficiency of 90% for the 1.53 μm measured emission, by pumping at 980 nm, are in favor of promising laser applications. - Highlights: • Glass belonging to Er-doped Sb{sub 2}O{sub 3}–Na{sub 2}O–Bi{sub 2}O{sub 3} (SNB) system are elaborated and characterized. • The intensity parameters Ωt were obtained via the Judd–Ofelt theory. • The optical properties were studied as a function of glass composition.

  4. A comparison of core perturbation by coolant loss between sodium and lead-bismuth cooled reactor

    International Nuclear Information System (INIS)

    Kim, Yong Nam; Kim, Jong Kyung; Park, Won Seok

    2003-01-01

    This study performs a comparative analysis of the core perturbation caused by coolant loss between sodium and lead-bismuth eutectic. Considering the Zr-based and the U-based fuel in a 1,000MWth class reactor for TRU incineration, we investigate which coolant shows better performance for negative coolant loss reactivity in each case of fuel type. The calculation results show that in the case of U-based fuel, sodium gives rise to more positive coolant loss reactivity than lead-bismuth. However, when the Zr-based (U-free) fuel is considered, sodium offers negative coolant loss reactivity, whereas lead-bismuth makes the coolant loss reactivity positive. It is recommended to employ sodium coolant for the fertile-free fueled core and lead-bismuth for the core with fertile nuclides

  5. Bismuth-Induced Inactivation of Ferric Uptake Regulator from Helicobacter pylori.

    Science.gov (United States)

    He, Xiaojun; Liao, Xiangwen; Li, Hongyan; Xia, Wei; Sun, Hongzhe

    2017-12-18

    Ferric uptake regulator (Fur) of Helicobacter pylori is a global regulator that is important for bacterial colonization and survival within the gastric mucosa. H. pylori Fur (HpFur) is unique in its ability to regulate gene expression in both metal-bound (holo-Fur) and metal-free (apo-Fur) forms. Bismuth-based drugs are widely used for the treatment of H. pylori infection. However, the mechanism of action of bismuth drug was not fully understood. Recently, it has been reported that bismuth drugs could interfere with the bacterial ferric uptake pathway and inhibit bacterial growth, implying intrinsic correlation between bismuth drug and bacterial iron metabolism. Herein, we demonstrate that Bi(III) binds to HpFur protein specifically at the physiologically important S1 site, which further leads to protein oligomerization and loss of DNA binding capability. The targeting of HpFur by bismuth drugs significantly reduced transcription levels of its regulated genes, which are crucial for bacterial physiology and metabolism. Our studies present direct evidence that perturbation of iron metabolism in H. pylori by bismuth might serve as one of the mechanisms for the antimicrobial activity of bismuth drugs.

  6. Aspects of the magmatic geochemistry of bismuth

    Science.gov (United States)

    Greenland, L.P.; Gottfried, D.; Campbell, E.Y.

    1973-01-01

    Bismuth has been determined in 74 rocks from a differentiated tholeiitic dolerite, two calc-alkaline batholith suites and in 66 mineral separates from one of the batholiths. Average bismuth contents, weighted for rock type, of the Great Lake (Tasmania) dolerite, the Southern California batholith and the Idaho batholith are, 32, 50 and 70 ppb respectively. All three bodies demonstrate an enrichment of bismuth in residual magmas with magmatic differentiation. Bismuth is greatly enriched (relative to the host rock) in the calcium-rich accessory minerals, apatite and sphene, but other mineral analyses show that a Bi-Ca association is of little significance to the magmatic geochemistry of bismuth. Most of the bismuth, in the Southern California batholith at least, occurs in a trace mineral phase (possibly sulfides) present as inclusions in the rock-forming minerals. ?? 1973.

  7. Water oxidation by amorphous cobalt-based oxides: volume activity and proton transfer to electrolyte bases.

    Science.gov (United States)

    Klingan, Katharina; Ringleb, Franziska; Zaharieva, Ivelina; Heidkamp, Jonathan; Chernev, Petko; Gonzalez-Flores, Diego; Risch, Marcel; Fischer, Anna; Dau, Holger

    2014-05-01

    Water oxidation in the neutral pH regime catalyzed by amorphous transition-metal oxides is of high interest in energy science. Crucial determinants of electrocatalytic activity were investigated for a cobalt-based oxide film electrodeposited at various thicknesses on inert electrodes. For water oxidation at low current densities, the turnover frequency (TOF) per cobalt ion of the bulk material stayed fully constant for variation of the thickness of the oxide film by a factor of 100 (from about 15 nm to 1.5 μm). Thickness variation changed neither the nanostructure of the outer film surface nor the atomic structure of the oxide catalyst significantly. These findings imply catalytic activity of the bulk hydrated oxide material. Nonclassical dependence on pH was observed. For buffered electrolytes with pKa values of the buffer base ranging from 4.7 (acetate) to 10.3 (hydrogen carbonate), the catalytic activity reflected the protonation state of the buffer base in the electrolyte solution directly and not the intrinsic catalytic properties of the oxide itself. It is proposed that catalysis of water oxidation occurs within the bulk hydrated oxide film at the margins of cobalt oxide fragments of molecular dimensions. At high current densities, the availability of a proton-accepting base at the catalyst-electrolyte interface controls the rate of water oxidation. The reported findings may be of general relevance for water oxidation catalyzed at moderate pH by amorphous transition-metal oxides. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Iodine Gas Trapping using Granular Porous Bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Hwan; Shin, Jin Myeong; Park, Jang Jin; Park, Geun Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yim, Mansung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    {sup 129}I is a radionuclide with a very long half-life of 1.57 Χ 10{sup 7} years and has negative health effects to the human body. Therefore, the emission of {sup 129}I into the air is closely regulated by the Environmental Protection Agency (EPA). Many methods for trapping gaseous {sup 129}I have been developed thus far, including wet scrubbing and adsorption using silver loaded zeolites. Although wet scrubbing can effectively remove iodine, it suffers from corrosion of the vessel due to high concentration of the scrubbing solution. Silver loaded zeolites also show effectiveness in capturing {sup 129}I gas, yet weak thermal stability of physisorbed iodine remains a challenge. We studied a novel and facile method to trap iodine gas using bismuth. Granular bismuth having many pores was synthesized using bismuth nitrate and polyvinyl alcohol as a bismuth precursor and pore forming agent, respectively. Reaction of iodine and our samples resulted in an iodine capturing capacity of more than 2 times that of the commercial grade silver exchanged zeolite (AgX). Granular porous bismuths synthesized using bismuth nitrate and PVA show a promising performance in capturing iodine gas. The use of bismuth in trapping {sup 129}I gas can reduce the process cost as bismuth is cheap. Further study is going on to improve the mechanical property of granular porous bismuths for their easy handling.

  9. Recent advances in bioinorganic chemistry of bismuth.

    Science.gov (United States)

    Li, Hongyan; Sun, Hongzhe

    2012-04-01

    Bismuth has been used in medicine for over two centuries for the treatment of various diseases, in particular for gastrointestinal disorders, owing to its antimicrobial activity. Recent structural characterization of bismuth drugs provides an insight into assembly and pharmacokinetic pathway of the drugs. Mining potential protein targets inside the pathogen via metallomic/metalloproteomic approach and further characterization on the interactions of bismuth drugs with these targets laid foundation in understanding the mechanism of action of bismuth drugs. Such studies would be beneficial in rational design of new potential drugs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. BISMUTH PHOSPHATE CARRIER PROCESS FOR Pu RECOVERY

    Science.gov (United States)

    Finzel, T.G.

    1959-02-01

    An improvement in the bismuth phosphate carrier precipitation process for recovering plutonium is described. It has been found that a more granular and more easily filterable carrier precipitiite is formed if the addition of the bismuth and phosphate ions is effected by first adding 9/10 of the bismuth ions necessary, then slowly adding all of the source of the phosphate ions to be incorporated in the precipitate, while digesting at 75 C and afterwards incorporating the remainder of the total bismuth ions necessary

  11. Photoreductive generation of amorphous bismuth nanoparticles using polysaccharides--bismuth-cellulose nanocomposites.

    Science.gov (United States)

    Breitwieser, Doris; Kriechbaum, Margit; Ehmann, Heike M A; Monkowius, Uwe; Coseri, Sergiu; Sacarescu, Liviu; Spirk, Stefan

    2015-02-13

    A simple and highly reproducible synthesis of amorphous bismuth nanoparticles incorporated into a polysaccharide matrix using a photoreduction process is presented. As precursor for the generation of the Bi nanoparticles, organosoluble triphenylbismuth is used. The precursor is dissolved in toluene and mixed with a hydrophobic organosoluble polysaccharide, namely trimethylsilyl cellulose (TMSC) with high DSSi. The solution is subjected to UV exposure, which induces the homolytic cleavage of the bismuth-carbon bond in BiPh3 resulting in the formation of Bi(0) and phenyl radicals. The aggregation of the Bi atoms can be controlled in the TMSC matrix and yields nanoparticles of around 20 nm size as proven by TEM. The phenyl radicals undergo recombination to form small organic molecules like benzene and biphenyl, which can be removed from the nanocomposite after lyophilization and exposure to high vacuum. Finally, the TMSC matrix is converted to cellulose after exposure to HCl vapors, which remove the trimethylsilyl groups from the TMSC derivative. Although TMSC is converted to cellulose, the formed TMS-OH is not leaving the nanocomposite but reacts instead with surface oxide layer of the Bi nanoparticles to form silylated Bi nanoparticles as proven by TEM/EDX. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 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.

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

    Science.gov (United States)

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

    2016-01-22

    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.

  14. Aggregation and hydrolysis reactions of bismuth alkoxides

    International Nuclear Information System (INIS)

    Whitmire, K.H.; Jones, C.M.; Burkart, M.D.; Hutchinson, J.C.; McKnight, A.L.

    1992-01-01

    This paper reports that new bismuth alkoxide and oxo-alkoxide complexes have been prepared from the salt metathesis reaction of NaOR with BiCl 3 . When R = CH(CF 3 ) 2 , the product is [Bi(μ-OR)(OR) 2 (THF)] 2 . similar work with R = C 6 F 5 has not yielded a simple alkoxide, but complexes of formulation NaBi 3 (μ 3 -O)(OR) 8 (THF), NaBi 4 (μ 3 -O) 2 (OR) 9 (THF) 2 , Na 2 Bi 4 (μ 3 -O) 2 (OR) 10 and Bi 6 (μ 3 -OR)(μ 3 -O) 4 [μ 3 -OBI(OR) 4 ] 3 have been observed. The reaction of BiPh 3 with HOC 6 F 5 , however, did produce the desired alkoxide which has been characterized as [Bi(OR) 2 (μ-OR)(toluene)] 2 and [Bi(OR) 2 (μ-OR)(toluene)] 2 · 2 toluene. The reaction of this alkoxide with NaOC 6 F 5 led to the production of Bi 6 (μ 3 -O) 2 (μ 4 -O)(OR) 12 and NaBi 3 (μ 3 -O)(OR) 8 (THF) 3 . Reaction of BiPh 3 with HOC 6 F 5 in THF led to the formation of Bi 6 (μ 3 -OR)(μ 3 -O) 4 [μ 3 -OBi(OR) 4 ] 3 (THF) 2 . Surprisingly the reaction of BiEt 3 and HOR (R = C 6 F 5 or Ph) displaced only one Et group to give [Et 2 Bi(μ-OR)] oo which exist as infinite chain polymers with alternating Bi-O-Bi backbones. These spiral chains form chiral helices in the crystal lattice. The discovery of high T C superconducting copper oxide phases containing bismuth, lead and thallium has led to this investigation

  15. Ranitidine bismuth citrate: A review

    Directory of Open Access Journals (Sweden)

    N Chiba

    2001-01-01

    Full Text Available Recognition of the relationship between Helicobacter pylori infection and the development of gastroduodenal disease has increased greatly in recent years. To avoid complications of H pylori infection, such as the development of recurrent duodenal and gastric ulcers, effective therapies are required for eradication of the infection. This article reviews ranitidine bismuth citrate (RBC, a novel complex of ranitidine, bismuth and citrate, which was developed specifically for the purpose of eradicating H pylori. Dual therapy with RBC in combination with clarithromycin for 14 days yields eradication rates of 76%. Triple therapy bid for one week with a proton pump inhibitor, clarithromycin and either amoxicillin or a nitroimidazole (tinidazole or metronidazole is advocated as the treatment of choice for H pylori eradication. Analogous regimens with RBC in place of proton pump inhibitors show effective eradication rates in comparative studies and with pooled data. RBC, used alone or in combination with other antibiotics, appears to be a safe and effective drug for the treatment of H pylori infection. Bismuth levels do not appear to rise to toxic levels.

  16. Oxidatively generated base damage to cellular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Cadet, Jean [Laboratoire ' Lesions des Acides Nucleiques' , SCIB-UMR-E no.3 - CEA/UJF, Institut nano-sciences et Cryogenie, CEA/Grenoble, F-38054 Grenoble Cedex 9 (France); Departement de Medecine Nucleaire et Radiobiologie, Faculte de medecine de des sciences de la sante, Universite de Sherbrooke, Sherbrooke, Quebec, J1H 5N4 (Canada); Douki, Thierry; Ravanat, Jean-Luc [Laboratoire ' Lesions des Acides Nucleiques' , SCIB-UMR-E no.3 - CEA/UJF, Institut nano-sciences et Cryogenie, CEA/Grenoble, F-38054 Grenoble Cedex 9 (France)

    2010-07-01

    Search for the formation of oxidatively base damage in cellular DNA has been a matter of debate for more than 40 years due to the lack of accurate methods for the measurement of the lesions. HPLC associated with either tandem mass spectrometry (MS/MS) or electrochemical detector (ECD) together with optimized DNA extraction conditions constitutes a relevant analytical approach. This has allowed the accurate measurement of oxidatively generated single and clustered base damage in cellular DNA following exposure to acute oxidative stress conditions mediated by ionizing radiation. UVA light and one-electron oxidants. In this review the formation of 11 single base lesions that is accounted for by reactions of singlet oxygen, hydroxyl radical or high intensity UVC laser pulses with nucleobases is discussed on the basis of the mechanisms available from model studies. In addition several clustered lesions were found to be generated in cellular DNA as the result of one initial radical hit on either a vicinal base or the 2-deoxyribose. Information on nucleo-base modifications that are formed upon addition of reactive aldehydes arising from the breakdown of lipid hydroperoxides is also provided. (authors)

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

    Science.gov (United States)

    Stefik, Morgan

    2016-07-07

    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. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

    Davis, C.B.; Shieh, A. S.

    2000-01-01

    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

  19. Element Distribution in the Oxygen-Rich Side-Blow Bath Smelting of a Low-Grade Bismuth-Lead Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xiao, Hui; Chen, Lin; Chen, Wei; Liu, Weifeng; Zhang, Duchao

    2018-03-01

    Oxygen-rich side-blow bath smelting (OSBS) technology offers an efficient method for processing complex bismuth-lead concentrates; however, the element distributions in the process remain unclear. This work determined the distributions of elements, i.e., bismuth, lead, silver, copper, arsenic and antimony, in an industrial-scale OSBS process. The feed, oxidized slag and final products were collected from the respective sampling points and analyzed. For the oxidative smelting process, 65% of bismuth and 76% of silver in the concentrate report to the metal alloy, whereas less lead reports to the metal ( 31%) than the oxidized slag ( 44%). Approximately 50% of copper enters the matte, while more than 63% of arsenic and antimony report to the slag. For the reductive smelting process, less than 4.5% of bismuth, lead, silver and copper in the oxidized slag enter the reduced slag, indicating high recoveries of these metal values.

  20. Efficacy of 7-Day and 14-Day Bismuth-Containing Quadruple Therapy and 7-Day and 14-Day Moxifloxacin-Based Triple Therapy as Second-Line Eradication for Helicobacter pylori Infection

    Science.gov (United States)

    Lee, Seong tae; Lee, Dong Ho; Lim, Ji Hyun; Kim, Nayoung; Park, Young Soo; Shin, Cheol Min; Jo, Hyun Jin; Song, In sung

    2015-01-01

    Background/Aims Bismuth-containing quadruple and moxifloxacin-based triple regimens are recommended as second-line therapy for Helicobacter pylori infection. The aim of this study was to compare the efficacy of each regimen. Methods From August 2004 to October 2012, a total of 949 patients (mean age, 54.32±12.08 years; male, 49.4%) who failed H. pylori eradication with a standard triple regimen were included. Patients treated with a bismuth-containing quadruple regimen for 7 and 14 days were designated as 7-BMT and 14-BMT, respectively, and those treated with a moxifloxacin-based triple regimen for 7 and 14 days were designated as 7-MA and 14-MA, respectively. H. pylori eradication was confirmed using the 13C-urea breath test, rapid urease test or histology. Results The eradication rates by 7-BMT, 14-BMT, 7-MA, and 14-MA were 66.4% (290/437), 71.1% (113/159), 53.1% (51/96), and 73.5% (189/257), respectively, by intention-to-treat analysis (ITT) and 76.5% (284/371), 83.8% (109/130), 55.6% (50/90), and 80.6% (187/232), respectively, by per-protocol analysis (PP). The eradication rates were higher in 14-BMT than 7-BMT by the ITT and PP analyses (p=0.277 and p=0.082, respectively). The 14-BMT and 14-MA treatments showed similar efficacies by ITT and PP (p=0.583 and p=0.443, respectively). Conclusions The 7-BMT, 14-BMT, and 14-MA treatments showed similar and suboptimal efficacies. In both regimens, extending the duration of treatment may be reasonable considering the high level of antibiotic resistance in Korea. PMID:25071068

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

    International Nuclear Information System (INIS)

    Babitsky, Nicolay A.; Leshok, Darya Y.; Mikhaleva, Natalia S.; Kuzubov, Aleksandr A.; Zhereb, Vladimir P.; Kirik, Sergei D.

    2015-01-01

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

  2. Indium Tin Oxide Resistor-Based Nitric Oxide Microsensors

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Gonzalez, Jose M., III; Liu, Chung-Chiun

    2012-01-01

    A sensitive resistor-based NO microsensor, with a wide detection range and a low detection limit, has been developed. Semiconductor microfabrication techniques were used to create a sensor that has a simple, robust structure with a sensing area of 1.10 0.99 mm. A Pt interdigitated structure was used for the electrodes to maximize the sensor signal output. N-type semiconductor indium tin oxide (ITO) thin film was sputter-deposited as a sensing material on the electrode surface, and between the electrode fingers. Alumina substrate (250 m in thickness) was sequentially used for sensor fabrication. The resulting sensor was tested by applying a voltage across the two electrodes and measuring the resulting current. The sensor was tested at different concentrations of NO-containing gas at a range of temperatures. Preliminary results showed that the sensor had a relatively high sensitivity to NO at 450 C and 1 V. NO concentrations from ppm to ppb ranges were detected with the low limit of near 159 ppb. Lower NO concentrations are being tested. Two sensing mechanisms were involved in the NO gas detection at ppm level: adsorption and oxidation reactions, whereas at ppb level of NO, only one sensing mechanism of adsorption was involved. The NO microsensor has the advantages of high sensitivity, small size, simple batch fabrication, high sensor yield, low cost, and low power consumption due to its microsize. The resistor-based thin-film sensor is meant for detection of low concentrations of NO gas, mainly in the ppb or lower range, and is being developed concurrently with other sensor technology for multispecies detection. This development demonstrates that ITO is a sensitive sensing material for NO detection. It also provides crucial information for future selection of nanostructured and nanosized NO sensing materials, which are expected to be more sensitive and to consume less power.

  3. Crystal growth of bismuth tungstate

    Energy Technology Data Exchange (ETDEWEB)

    De L' Eprevier, A. G.; Shukla, V. N.; Payne, D. A.

    1979-01-01

    Bi/sub 2/WO/sub 6/ is a polar material in the bismuth titanate family, Bi/sub 2/M/sub n-1/R/sub n/0/sub 3n+3/. Additions of NaF to a Na/sub 2/WO/sub 4/ - WO/sub 3/ flux yielded large single crystals up to 0.8 mm thick, which were free of inclusions. Total impurities were less than 500 ppM, and the crystals were single domain.

  4. Aluminium bismuthate nanorods and the electrochemical performance for detection of tartaric acid

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei@ahut.edu.cn [Key Lab of Materials Science and Processing of Anhui Province, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Wei, T.; Lin, N.; Fan, C.G. [Key Lab of Materials Science and Processing of Anhui Province, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Yang, Zao, E-mail: yangzao888@tom.com [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064 (China)

    2016-09-15

    Aluminium bismuthate nanorods had been synthesized by a facile hydrothemral method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed that the lengh and diameter were 2–10 μm and 50–200 nm, respectively. X-ray diffraction (XRD) and high-resolution TEM (HRTEM) showed that the nanorods were composed of single crystalline orthorhombic Al{sub 4}Bi{sub 2}O{sub 9} phase. The aluminium bismuthate nanorods could be explained by the nucleation and crystalline growth process based on the products obtained from different hydrothermal conditions. Aluminium bismuthate nanorods modified glassy carbon electrode (GCE) was fabricated for the electrochemical detection of tartaric acid (TA) in neutral solution. A pair of semi-reversible redox peaks located at −0.08 V and −0.53 V, respectively were observed. The current intensity of the cyclic voltammogram (CV) peak increased linearly obviously with increasing the scan rate and TA concentration. The detection limit and linear range were 0.64 μM and 0.001–2 mM, respectively with the correlation coefficient of 0.995. The aluminium bismuthate nanorods modified GCE had good reproducibility and stability for the detection of TA. - Highlights: • Aluminium bismuthate nanorods were synthesized by a facile hydrothermal process. • The size of aluminium bismuthate nanorods could be controlled by growth conditions. • Aluminium bismuthate nanorods showed good electrochemical performance for the detection of tartaric acid. • Aluminium bismuthate nanorods modified GCE had good reproducibility and stability.

  5. 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.

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

    International Nuclear Information System (INIS)

    Jagdale, Pravin; Castellino, Micaela; Marrec, Françoise; Rodil, Sandra E.; Tagliaferro, Alberto

    2014-01-01

    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 3 ) in acetone (CH 3 -CO-CH 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.

  7. Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

    2012-04-01

    The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

  8. 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

  9. Radio-sensitization of animals by bismuth

    International Nuclear Information System (INIS)

    Pierotti, T.; Verain, A.

    1969-01-01

    Digestive absorption of bismuth by animals leads to radio-sensitization. This effect is very marked when the X-rays used are centered on the absorption line of bismuth. This work has involved the use of more than 2000 C3H/JAX mice, and has shown that a maximum lethal effect, with respect to the standard, occurs for bismuth sub-nitrate doses of the order of 3 g/kg and for exposures of 700 R. For stronger or weaker doses, the sensitization effect is less marked. (authors) [fr

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

    International Nuclear Information System (INIS)

    Martynov, P.N.; Ivanov, K.D.

    1998-01-01

    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)

  11. Bismuth Telluride and Its Alloys as Materials for Thermoelectric Generation

    Directory of Open Access Journals (Sweden)

    H. Julian Goldsmid

    2014-03-01

    Full Text Available Bismuth telluride and its alloys are widely used as materials for thermoelectric refrigeration. They are also the best materials for use in thermoelectric generators when the temperature of the heat source is moderate. The dimensionless figure of merit, ZT, usually rises with temperature, as long as there is only one type of charge carrier. Eventually, though, minority carrier conduction becomes significant and ZT decreases above a certain temperature. There is also the possibility of chemical decomposition due to the vaporization of tellurium. Here we discuss the likely temperature dependence of the thermoelectric parameters and the means by which the composition may be optimized for applications above room temperature. The results of these theoretical predictions are compared with the observed properties of bismuth telluride-based thermoelements at elevated temperatures. Compositional changes are suggested for materials that are destined for generator modules.

  12. Transmucosal penetration of bismuth particles in the human stomach.

    Science.gov (United States)

    Nwokolo, C U; Lewin, J F; Hudson, M; Pounder, R E

    1992-01-01

    Electron microscopic examination of upper gastrointestinal biopsies with x-ray microanalysis was used to detect electron-dense particles of bismuth in the mucosa of the upper gastrointestinal tract, 30-60 minutes after oral dosing with either tripotassium dicitrato bismuthate [De-Noltab; Brocades (Great Britain) Ltd., Weybridge, UK; five patients] or bismuth salicylate (Pepto-Bismol; Richardson Vicks Ltd., Egham, UK; five patients), or without dosing (two patients). Transmucosal penetration of bismuth particles was observed in the gastric antral mucosa of all patients who had been dosed with tripotassium dicitrato bismuthate, but there was no penetration after oral dosing with bismuth salicylate. Persorption of bismuth particles through the gastric mucosa to the vascular endothelium provides an explanation for the rapid rise of plasma bismuth concentration observed only after oral dosing with tripotassium dicitrato bismuthate.

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

    International Nuclear Information System (INIS)

    Fazio, C.; Benamati, G.; Martini, C.; Palombarini, G.

    2001-01-01

    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

  14. Electrical resistivity of fast neutron irradiated bismuth

    International Nuclear Information System (INIS)

    Quelard, G.

    1975-01-01

    The production and recovery of fast neutron radiation damage in bismuth, at 20K has been studied by means of electrical resistivity. Results are independent of crystallographic orientation and indicate a creation of carriers during irradiation [fr

  15. 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.

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

    International Nuclear Information System (INIS)

    Flores-Castañeda, M.; Camps, E.; Camacho-López, M.; Muhl, S.

    2015-01-01

    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

  17. Crystallization of bismuth borate glasses

    International Nuclear Information System (INIS)

    Bajaj, Anu; Khanna, Atul

    2009-01-01

    Bismuth borate glasses with Bi 2 O 3 concentration of 20-66 mol% were prepared by melt quenching and devitrified by heat treatment above their glass transition temperatures. All glasses show a strong tendency towards crystallization on annealing that increases with Bi 2 O 3 concentration. The crystalline phases formed on devitrification were characterized by FTIR absorption spectroscopy and DSC measurements. Our studies reveal that phases produced in glasses are strongly determined by initial glass composition and the two most stable crystalline phases are: Bi 3 B 5 O 12 and Bi 4 B 2 O 9 . The metastable BiBO 3 phase can also be formed by devitrification of glass with 50 mol% of Bi 2 O 3 . This phase is, however, unstable and decomposes into Bi 3 B 5 O 12 and Bi 4 B 2 O 9 on prolonged heat treatment.

  18. 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.

  19. Bismuth Silver Oxysulfide for Photoconversion Applications: Structural and Optoelectronic Properties

    KAUST Repository

    Baqais, Amal Ali Abdulallh

    2017-09-18

    Single-phase bismuth silver oxysulfide, BiAgOS, was prepared by a hydrothermal method. Its structural, morphological and optoelectronic properties were investigated and compared with bismuth copper oxysulfide (BiCuOS). Rietveld refinement of the powder X-ray diffraction (XRD) measurements revealed that the BiAgOS and BiCuOS crystals have the same structure as ZrSiCuAs: the tetragonal space group P4/nmm. X-ray photoelectron spectroscopy (XPS) analyses confirmed that the BiAgOS has a high purity, in contrast with BiCuOS, which tends to have Cu vacancies. The Ag has a monovalent oxidation state, whereas Cu is present in the oxidation states of +1 and +2 in the BiCuOS system. Combined with experimental measurements, density functional theory calculations employing the range-separated hybrid HSE06 exchange-correlation functional with spin-orbit coupling quantitatively elucidated photophysical properties such as ab-sorption coefficients, effective masses and dielectric constants. BiCuOS and BiAgOS were found to have indirect bandgaps of 1.1 and 1.5 eV, respectively. Both possess high dielectric constants and low electron and hole effective masses. Therefore, these materials are expected to have high exciton dissociation capabilities and excellent carrier diffusion properties. This study reveals that BiAgOS is a promising candidate for photoconversion applications.

  20. 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…

  1. State-of-the-art Sn2+-based ternary oxides as photocatalysts for water splitting: electronic structures and optoelectronic properties

    KAUST Repository

    Noureldine, Dalal

    2016-09-19

    Developing visible light responsive metal oxide photocatalysts is a challenge that must be conquered to achieve high efficiency for water splitting or hydrogen evolution reactions. Valence band engineering is possible by forming ternary oxides using the combination of a metal cation with an s2d10 electronic configuration and a transition metal oxide with a d0 configuration. Many (Sn2+, Bi3+, Pb2+)-based ternary metal oxide photocatalysts have been reported for hydrogen and/or oxygen evolution under visible irradiation. Sn2+-based materials have attracted particular attention because tin is inexpensive, abundant and more environmentally friendly than lead or bismuth. In this review, we provide a fruitful library for Sn2+-based photocatalysts that have been reported to evolve hydrogen using sacrificial reagents, including SnNb2O6, Sn2Nb2O7, SnTaxNb2−xO6, SnTa2O6, Sn2Ta2O7, SnWO4 (α and β phases), SnSb2O6·nH2O, and Sn2TiO4. The synthesis method used in the literature and the resultant morphology and crystal structure of each compound are discussed. The density functional theory (DFT) calculations of the electronic structure and density of states are provided, and the consequent optoelectronic properties such as band gap, nature of the bandgap, dielectric constant, and effective masses are summarized. This review will help highlight the main challenges for Sn2+-based materials.

  2. Comparison of Second-Line Quadruple Therapies with or without Bismuth for Helicobacter pylori Infection.

    Science.gov (United States)

    Jheng, Guang-Hong; Wu, I-Chen; Shih, Hsiang-Yao; Wu, Meng-Chieh; Kuo, Fu-Chen; Hu, Huang-Ming; Liu, Chung-Jung; Hsu, Wen-Hung; Hu, Chi-Tan; Bair, Ming-Jong; Kuo, Chao-Hung; Wu, Deng-Chyang; Hsu, Ping-I

    2015-01-01

    The bismuth-based quadruple regimen has been applied in Helicobacter pylori rescue therapy worldwide. The non-bismuth-based quadruple therapy or "concomitant therapy" is an alternative option in first-line eradication but has not been used in second-line therapy. Discovering a valid regimen for rescue therapy in bismuth-unavailable countries is important. We conducted a randomized controlled trial to compare the efficacies of the standard quadruple therapy and a modified concomitant regimen. One hundred and twenty-four patients were randomly assigned into two groups: RBTM (rabeprozole 20 mg bid., bismuth subcitrate 120 mg qid, tetracycline 500 mg qid, and metronidazole 250 mg qid) and RATM (rabeprozole 20 mg bid., amoxicillin 1 g bid., tetracycline 500 mg qid, and metronidazole 250 mg qid) for 10 days. The eradication rate of the RBTM and RATM regimen was 92.1% and 90.2%, respectively, in intention-to-treat analysis. Patients in both groups had good compliance (~96%). The overall incidence of adverse events was higher in the RATM group (42.6% versus 22.2%, P = 0.02), but only seven patients (11.5%) experienced grades 2-3 events. In conclusion, both regimens had good efficacy, compliance, and acceptable side effects. The 10-day RATM treatment could be an alternative rescue therapy in bismuth-unavailable countries.

  3. Methodology for the effective stabilization of tin-oxide-based oxidation/reduction catalysts

    Science.gov (United States)

    Jordan, Jeffrey D. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Leighty, Bradley D. (Inventor); Watkins, Anthony N. (Inventor); Schryer, Jacqueline L. (Inventor); Oglesby, Donald M. (Inventor); Gulati, Suresh T. (Inventor); Summers, Jerry C. (Inventor)

    2011-01-01

    The invention described herein involves a novel approach to the production of oxidation/reduction catalytic systems. The present invention serves to stabilize the tin oxide reducible metal-oxide coating by co-incorporating at least another metal-oxide species, such as zirconium. In one embodiment, a third metal-oxide species is incorporated, selected from the group consisting of cerium, lanthanum, hafnium, and ruthenium. The incorporation of the additional metal oxide components serves to stabilize the active tin-oxide layer in the catalytic process during high-temperature operation in a reducing environment (e.g., automobile exhaust). Moreover, the additional metal oxides are active components due to their oxygen-retention capabilities. Together, these features provide a mechanism to extend the range of operation of the tin-oxide-based catalyst system for automotive applications, while maintaining the existing advantages.

  4. Determination of Lung-to-Blood Absorption Rates for Lead and Bismuth which are Appropriate for Radon Progeny

    International Nuclear Information System (INIS)

    Marsh, J.W.; Birchall, A.

    1999-01-01

    The ICRP Publication 66 Human Respiratory Tract Model (HRTM) treats clearance as a competitive process between absorption into blood and particle transport to the gastrointestinal tract and lymphatics. The ICRP recommends default absorption rates for lead and bismuth in ICRP Publication 71 but states that the values are not appropriate for short-lived radon progeny. This paper describes an evaluation of published data from volunteer experiments to estimate the absorption half-times of lead and bismuth that are appropriate for short-lived radon progeny. The absorption half-time for lead was determined to be 10±2 h, based on 212 Pb lung and blood retention data from several studies. The absorption half-time for bismuth was estimated to be about 13 h, based on 212 Bi urinary excretion data from one experiment and the ICRP biokinetic model for bismuth as a decay product of lead. (author)

  5. Bismuth alloy potting seals aluminum connector in cryogenic application

    Science.gov (United States)

    Flower, J. F.; Stafford, R. L.

    1966-01-01

    Bismuth alloy potting seals feedthrough electrical connector for instrumentation within a pressurized vessel filled with cryogenic liquids. The seal combines the transformation of high-bismuth content alloys with the thermal contraction of an external aluminum tube.

  6. Enhanced piezoelectric properties and excellent thermal stabilities of cobalt-modified Aurivillius-type calcium bismuth titanate (CaBi4Ti4O15)

    International Nuclear Information System (INIS)

    Zhao, Tian-Long; Wang, Chun-Ming; Wang, Chun-Lei; Wang, Yi-Ming; Dong, Shuxiang

    2015-01-01

    Highlights: • Cobalt oxide modified CBT-based ceramics were prepared and investigated in detail. • XRPD analysis revealed Co ions enter into B-site of CBT-based ceramics. • CBT-Co4 ceramics show the enhanced d 33 of 14 pC/N and T c of 782 °C. • CBT-Co4 ceramics present the improved high-temperature resistivity. • Thermal depoling behavior indicates CBT-Co4 ceramics exhibit good thermal stability. - Abstract: Bismuth layer-structured ferroelectric (BLSF) calcium bismuth titanate (CaBi 4 Ti 4 O 15 , CBT) piezoelectric ceramics with 0.0–1.0 wt.% cobalt oxide (Co 2 O 3 ) have been prepared via a conventional solid-state reaction method. Microstructural morphology and electrical properties of cobalt oxide-modified CBT ceramics were investigated in detail. X-ray powder diffraction (XRPD) analysis revealed that the cobalt oxide-modified CBT ceramics have a pure four-layer Aurivillius-type structure. The piezoelectric properties of CBT ceramics were significantly enhanced by cobalt oxide modifications. The piezoelectric coefficient d 33 and Curie temperature T c of 0.2 wt.% cobalt oxide-modified CBT ceramics (CBT-Co4) are 14 pC/N and 782 °C, respectively. The DC resistivity and thermal depoling behavior at elevated temperature indicated that the CBT-Co4 ceramics exhibit good thermal stability, demonstrating that the CBT-Co4 ceramics are potential materials for high temperature piezoelectric applications.

  7. Liquid Bismuth Propellant Flow Sensor

    Science.gov (United States)

    Polzin, Kurt A.; Stanojev, B. J.; Korman, V.

    2007-01-01

    Quantifying the propellant mass flow rate in liquid bismuth-fed electric propulsion systems has two challenging facets. First, the flow sensors must be capable of providing a resolvable measurement at propellant mass flow rates on the order of 10 mg/see with and uncertainty of less that 5%. The second challenge has to do with the fact that the materials from which the flow sensors are fabricated must be capable of resisting any of the corrosive effects associated with the high-temperature propellant. The measurement itself is necessary in order to properly assess the performance (thrust efficiency, Isp) of thruster systems in the laboratory environment. The hotspot sensor[I] has been designed to provide the bismuth propellant mass flow rate measurement. In the hotspot sensor, a pulse of thermal energy (derived from a current pulse and associated joule heating) is applied near the inlet of the sensor. The flow is "tagged" with a thermal feature that is convected downstream by the flowing liquid metal. Downstream, a temperature measurement is performed to detect a "ripple" in the local temperature associated with the passing "hotspot" in the propellant. By measuring the time between the upstream generation and downstream detection of the thermal feature, the flow speed can be calculated using a "time of flight" analysis. In addition, the system can be calibrated by measuring the accumulated mass exiting the system as a-function of time and correlating this with the time it takes the hotspot to convect through the sensor. The primary advantage of this technique is that it doesn't depend on an absolute measurement of temperature but, instead, relies on the observation of thermal features. This makes the technique insensitive to other externally generated thermal fluctuations. In this paper, we describe experiments performed using the hotspot flow sensor aimed at quantifying the resolution of the sensor technology. Propellant is expelled onto an electronic scale to

  8. Studies on bismuth carboxylates—synthesis and characterization of ...

    Indian Academy of Sciences (India)

    1. Introduction. A large number of bismuth compounds are clinically active against Helicobacter pylori and other gastroin- testinal disorders.1–2 Prominent among these are bis- muth subsalicylate (trade name Pepto-Bismol), col- loidal bismuth subcitrate (CBS, trade name De-Nol) and ranitidine bismuth citrate (trade name ...

  9. Short report: evaluation of Helicobacter pylori eradication with bismuth sucralfate

    NARCIS (Netherlands)

    Reijers, M. H.; Noach, L. A.; Tytgat, G. N.

    1994-01-01

    In a pilot study we have evaluated the clinical efficacy of bismuth sucralfate to eradicate H. pylori. Ten consecutive patients with chronic dyspepsia and H. pylori associated gastritis were treated with bismuth sucralfate (220 mg bismuth per tablet, 4 tablets per day for 4 weeks). If a 14C urea

  10. 21 CFR 520.1204 - Kanamycin, bismuth subcarbonate, activated attapulgite.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Kanamycin, bismuth subcarbonate, activated... § 520.1204 Kanamycin, bismuth subcarbonate, activated attapulgite. (a) Specifications—(1) Each 5 milliliters (mL) of suspension contains 100 milligrams (mg) kanamycin (as the sulfate), 250 mg bismuth...

  11. Ni-Based Solid Oxide Cell Electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Holtappels, Peter

    2013-01-01

    This paper is a critical review of the literature on nickel-based electrodes for application in solid oxide cells at temperature from 500 to 1000 _C. The applications may be fuel cells or electrolyser cells. The reviewed literature is that of experimental results on both model electrodes...... and practical composite cermet electrodes. A substantially longer three-phase boundary (TPB) can be obtained per unit area of cell in such a composite of nickel and electrolyte material, provided that two interwoven solid networks of the two solid and one gaseous phases are obtained to provide a three...... such as milling and sintering. The various electrode properties are deeply related to these parameters, but also much related to the atomic scale structure of the Ni-electrolyte interface, which in turn is affected by segregation of electrolyte components and impurities as well as poisons in the gas phase...

  12. Bismuth centred magnetic perovskite: A projected multiferroic

    International Nuclear Information System (INIS)

    Kundu, Asish K.; Seikh, Md. Motin; Nautiyal, Pranjal

    2015-01-01

    In recent time substantial attention has been initiated to understand the physics behind multiferroism and to design new multiferroic materials. BiMnO 3 and BiFeO 3 are the well-studied Bi-centred multiferroic oxides. BiMnO 3 is a ferromagnetic–ferroelectric (metastable) phase and require drastic conditions to synthesize. However, lanthanum substituted BiMnO 3 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 La 0.5 Bi 0.5 MnO 3 perovskite with various substitutions at different levels. A few of these perovskites are found to be of practical importance e.g. La 0.5 Bi 0.5 Mn 0.67 Co 0.33 O 3 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 6s 2 lone pair of Bi 3+ 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

  13. Oxygen holes and hybridization in the bismuthates

    Science.gov (United States)

    Khazraie, Arash; Foyevtsova, Kateryna; Elfimov, Ilya; Sawatzky, George A.

    2018-02-01

    Motivated by the recently renewed interest in the superconducting bismuth perovskites, we investigate the electronic structure of the parent compounds A BiO3 (A = Sr, Ba) using ab initio methods and tight-binding (TB) modeling. We use the density functional theory (DFT) in the local density approximation (LDA) to understand the role of various interactions in shaping the A BiO3 band structure near the Fermi level. It is established that interatomic hybridization involving Bi-6 s and O-2 p orbitals plays the most important role. Based on our DFT calculations, we derive a minimal TB model and demonstrate that it can describe the properties of the band structure as a function of lattice distortions, such as the opening of a charge gap with the onset of the breathing distortion and the associated condensation of holes onto a1 g-symmetric molecular orbitals formed by the O-2 pσ orbitals on collapsed octahedra. We also derive a single band model involving the hopping of an extended molecular orbital involving both Bi-6 s and a linear combination of six O-2 p orbitals which provides a very good description of the dispersion and band gaps of the low energy scale bands straddling the chemical potential.

  14. Glass-like carbon, pyrolytic graphite or nanostructured carbon for electrochemical sensing of bismuth ion?

    Directory of Open Access Journals (Sweden)

    Jadranka Milikić

    2016-06-01

    Full Text Available Different carbon electrodes were explored for application in electroanalysis, namely for sensing of bismuth ion as model analyte. Carbon materials tested included glassy carbon, basal and edge plane pyrolytic graphite, as well as nanostructured carbonized polyaniline prepared in the presence of 3,5-dinitrosalicylic acid. Bismuth ion was chosen as model analyte as protocol for its detection and quantifications is still to be determined. Herein, anodic stripping voltammetry was used with study of effect of several parameters such as scan rate and deposition time. Electrode based on carbonized polyaniline showed the highest activity for bismuth ion sensing in terms of the highest current densities recorded both in a laboratory and in real sample, while basal plane pyrolytic graphite electrode gave the lowest limit of detection.

  15. Electron donating and acid-base properties of cerium oxide and its mixed oxides with alumina

    International Nuclear Information System (INIS)

    Sugunan, S.; Jalaja, J.M.

    1994-01-01

    The electron donating properties of cerium oxide activated at 300, 500 and 800 degC and of its mixed oxides with alumina were examined based on the adsorption of electron acceptors exhibiting different electron affinities. The surface acidity/basicity of the oxides was determined by titrimetry; the H 0,max values are given. The limit of electron transfer from the oxide surface lies within the region of 1.77 and 2.40 eV in terms of the electron affinity of the electron acceptor. Cerium oxide promotes the electron donor nature of alumina while leaving the limit of electron transfer unchanged. 2 tabs., 4 figs., 13 refs

  16. 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 - others: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: 1.308, year: 2015

  17. 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.

  18. 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

  19. Hyperfine splitting in lithium-like bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Lochmann, Matthias; Froemmgen, Nadja; Hammen, Michael; Will, Elisa [Universitaet Mainz (Germany); Andelkovic, Zoran; Kuehl, Thomas; Litvinov, Yuri; Winters, Danyal; Sanchez, Rodolfo [GSI Helmholtzzentrum, Darmstadt (Germany); Botermann, Benjamin; Noertershaeuser, Wilfried [Technische Universitaet Darmstadt (Germany); Bussmann, Michael [Helmholtzzentrum Dresden-Rossendorf (Germany); Dax, Andreas [CERN, Genf (Switzerland); Hannen, Volker; Joehren, Raphael; Vollbrecht, Jonas; Weinheimer, Christian [Universitaet Muenster (Germany); Geppert, Christopher [Universitaet Mainz (Germany); GSI Helmholtzzentrum, Darmstadt (Germany); Stoehlker, Thomas [GSI Helmholtzzentrum, Darmstadt (Germany); Universitaet Heidelberg (Germany); Thompson, Richard [Imperial College, London (United Kingdom); Volotka, Andrey [Technische Universitaet Dresden (Germany); Wen, Weiqiang [IMP Lanzhou (China)

    2013-07-01

    High-precision measurements of the hyperfine splitting values on Li- and H-like bismuth ions, combined with precise atomic structure calculations allow us to test QED-effects in the regime of the strongest magnetic fields that are available in the laboratory. Performing laser spectroscopy at the experimental storage ring (ESR) at GSI Darmstadt, we have now succeeded in measuring the hyperfine splitting in Li-like bismuth. Probing this transition has not been easy because of its extremely low fluorescence rate. Details about this challenging experiment will be given and the achieved experimental accuracy are presented.

  20. Bismuth salicylate for diarrhea in children

    Science.gov (United States)

    Goldman, Ran D.

    2013-01-01

    Abstract Question Recently, I had a visit from a 5-year-old patient who had been given bismuth subsalicylate for a diarrheal illness by a local family physician during a trip to South America. Is this a practice we should encourage? Answer Research from developing countries has found the use of bismuth subsalicylate to be effective in shortening the duration of diarrheal illness. Despite these findings, its limited effectiveness and concerns about it potentially causing Reye syndrome, compliance, and cost are the key reasons it is not routinely recommended for children. PMID:23946025

  1. Infrared spectra of U.S. automobile original finishes (post - 1989). VIII: In situ identification of bismuth vanadate using extended range FT-IR spectroscopy, Raman spectroscopy, and X-ray fluorescence spectrometry.

    Science.gov (United States)

    Suzuki, Edward M

    2014-03-01

    Chrome Yellow (PbCrO4 ·xPbSO4 ) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO4 ·nBi2 MoO6 , n = 0-2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT-IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far-infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO4 , and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these. © 2013 American Academy of Forensic Sciences.

  2. Bismuth Subgallate Toxicity in the Age of Online Supplement Use.

    Science.gov (United States)

    Sampognaro, Paul; Vo, Kathy T; Richie, Megan; Blanc, Paul D; Keenan, Kevin

    2017-11-01

    Bismuth salts have been used to treat gastroenterological disorders and are readily available over-the-counter and via the internet. Even though generally considered safe, bismuth compounds can cause a syndrome of subacute, progressive encephalopathy when taken in large quantities. We present the case of woman who developed progressive encephalopathy, aphasia, myoclonus, and gait instability after chronically ingesting large amounts of bismuth subgallate purchased from a major online marketing website to control symptoms of irritable bowel syndrome. After extensive neurological work-up, elevated bismuth levels in her blood, urine, and cerebrospinal fluid confirmed the diagnosis of bismuth-related neurotoxicity. She improved slowly following cessation of exposure. This case highlights bismuth subgallate as a neurotoxic bismuth formulation and reminds providers of the potential for safety misconceptions of positively reviewed online supplements.

  3. A scanning electron microscopy study of bismuth and phosphate phases in bismuth phosphate process waste at Hanford

    International Nuclear Information System (INIS)

    Reynolds, J.G.; Page, J.S.; Cooke, G.A.; John Pestovich

    2015-01-01

    This study characterizes major bismuth and phosphate-bearing phases in Hanford radioactive waste from the bismuth phosphate process using scanning electron microscopy with energy dispersive spectroscopy. Large bismuth phases displayed lath morphology and consisted of sodium, iron, bismuth, and phosphorus. The majority of the bismuth and phosphate observed was in small particulate (<2 µm in diameter) containing sodium, phosphorus, iron, and nickel. Additionally, phosphorus was included in a sodium-aluminum-phosphate lath-shaped species. Characterization of these waste types is of particular importance since they may have the bounding particle properties for designing waste mixing and transport processes used during treatment. (author)

  4. Influence of sintering parameters in the ferroelectric properties os strontium bismuth tantalate samples obtained by oxide mixture; Estudo da influencia dos parametros de sinterizacao nas propriedades ferroeletricas de amostras de tantalato de bismuto - estroncio obtidas por mistura de oxidos

    Energy Technology Data Exchange (ETDEWEB)

    Souza, R.R. de; Pereira, A.S.; Sousa, V.C., E-mail: ricson.souza@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Egea, J.R.J. [Instituto de Ceramica y Vidrio (ICV/CSIC), Madrid (Spain)

    2012-07-01

    The family of compounds layered-type perovskite, know as Aurivilius presents great alternative not only by the absence of lead in the composition, but because the polarization retention, replacing PZT in FeRAM devices. The strontium bismuth tantalate (SrBi{sub 2}Ta{sub 2}O{sub 9}) or SBT is ferroelectric material that has attracted considerable interest, since it has high fatigue resistance, supporting high hysteresis loops, with the change in polarization.Checking polarization and depolarization currents stimulated by temperature it is possible to obtain, for example, information about the nature of charges and about the activation energy for the process of dielectric relaxation. For analysis of ferroelectric properties of this compound, it is essential to obtain specimens with a relative density around 95%. Thus, it is important the optimization of the sintering process in order to obtain a ceramic body with a high densification. The influence of sintering parameters to obtain SrBi{sub 2}Ta{sub 2}O{sub 9} in the polarization properties and in the microstructure of sintered samples was investigated by thermostimulated currents and electronic microscopy, respectively. Results show that variation of these parameters may cause changes in the ferroelectric properties of the material. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Bányász, I., E-mail: banyasz@sunserv.kfki.hu [Department of Crystal Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Zolnai, Z.; Fried, M.; Lohner, T. [Research Institute for Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Berneschi, S.; Righini, G.C. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); “Enrico Fermi” Center for Study and Research, Piazza del Viminale 2, 00184 Roma (Italy); Pelli, S.; Nunzi-Conti, G. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)

    2013-07-15

    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. Er{sup 3+}-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{sup +} 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{sup +} 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.

  6. Nano lead oxide and epdm composite for development of polymer based radiation shielding material: Gamma irradiation and attenuation tests

    Science.gov (United States)

    Özdemir, T.; Güngör, A.; Akbay, I. K.; Uzun, H.; Babucçuoglu, Y.

    2018-03-01

    It is important to have a shielding material that is not easily breaking in order to have a robust product that guarantee the radiation protection of the patients and radiation workers especially during the medical exposure. In this study, nano sized lead oxide (PbO) particles were used, for the first time, to obtain an elastomeric composite material in which lead oxide nanoparticles, after the surface modification with silane binding agent, was used as functional material for radiation shielding. In addition, the composite material including 1%, 5%, 10%, 15% and 20% weight percent nano sized lead oxide was irradiated with doses of 81, 100 and 120 kGy up to an irradiation period of 248 days in a gamma ray source with an initial dose rate of 21.1 Gy/h. Mechanical, thermal properties of the irradiated materials were investigated using DSC, DMA, TGA and tensile testing and modifications in thermal and mechanical properties of the nano lead oxide containing composite material via gamma irradiation were reported. Moreover, effect of bismuth-III oxide addition on radiation attenuation of the composite material was investigated. Nano lead oxide and bismuth-III oxide particles were mixed with different weight ratios. Attenuation tests have been conducted to determine lead equivalent values for the developed composite material. Lead equivalent thickness values from 0.07 to 0.65 (2-6 mm sample thickness) were obtained.

  7. Sustainable selective oxidations using ceria-based materials

    NARCIS (Netherlands)

    Beckers, J.; Rothenberg, G.

    2010-01-01

    This Perspective covers sustainable oxidation processes using doped cerias, ceria-supported catalysts and ceria-based mixed oxides. Firstly, we consider the general properties of ceria-based catalysts. We outline the advantages of the ceria redox cycle, and explain the dynamic behaviour of these

  8. Magnetoreflection studies of ion implanted bismuth

    International Nuclear Information System (INIS)

    Nicolini, C.; Chieu, T.C.; Dresselhaus, M.S.; Massachusetts Inst. of Tech., Cambridge; Dresselhaus, G.

    1982-01-01

    The effect of the implantation of Sb ions on the electronic structure of the semimetal bismuth is studied by the magnetoreflection technique. The results show long electronic mean free paths and large implantation-induced increases in the band overlap and L-point band gap. These effects are opposite to those observed for Bi chemically doped with Sb. (author)

  9. On excitation of acoustic plasmons in bismuth

    International Nuclear Information System (INIS)

    Babkin, G.I.; Kravchenko, V.Ya.

    1977-01-01

    The amplitude of the transverse electromagnetic wave penetrating through a bismuth plate under conditions of existence of an acoustic plasma wave is calculated. Two wave coupling mechanisms due to the anisotropy of the carrier spectrum and the carrier drift in the magnetic field of the wave are considered. In the latter case, a wave of double frequency penetrates through the plate

  10. 21 CFR 73.2110 - Bismuth citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bismuth citrate. 73.2110 Section 73.2110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... paragraph (c)(1), effective April 27, 2010. For the convenience of the user, the revised text is set forth...

  11. Preparation and characterization of nanostructured copper bismuth ...

    Indian Academy of Sciences (India)

    Thin films of copper bismuth diselenide were prepared by chemical bath deposition technique onto glass substrate below 60°C. The deposition parameters such as time, temperature of deposition and pH of the solution, were optimized. The set of films having different elemental compositions was prepared by varying Cu/Bi ...

  12. Bismuth phosphates as intermediate temperature proton conductors

    DEFF Research Database (Denmark)

    Huang, Yunjie; Christensen, Erik; Shuai, Qin

    2017-01-01

    Proton conducting electrolyte materials operational in the intermediate temperature range of 200-400 °C are of special interest for applications in fuel cells and water electrolysers. Bismuth phosphates in forms of polycrystalline powders and amorphous glasses are synthesized and investigated...

  13. 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

  14. Cytotoxic Effect of Lipophilic Bismuth Dimercaptopropanol Nanoparticles on Epithelial Cells.

    Science.gov (United States)

    Rene, Hernandez-Delgadillo; Badireddy, Appala Raju; José, Martínez-Sanmiguel Juan; Francisco, Contreras-Cordero Juan; Israel, Martinez-Gonzalez Gustavo; Isela, Sánchez-Nájera Rosa; Chellam, Shankararaman; Claudio, Cabral-Romero

    2016-01-01

    Bismuth nanoparticles have many interesting properties to be applied in biomedical and medicinal sectors, however their safety in humans have not been comprehensively investigated. The objective of this research was to determine the cytotoxic effect of bismuth dimercaptopropanol nanoparticles (BisBAL NPs) on epithelial cells. The nanoparticles are composed of 18.7 nm crystallites on average and have a rhombohedral structure, agglomerating into chains-like or clusters of small nanoparticles. Based on MTT viability assay and fluorescence microscopy, cytotoxicity was not observed on monkey kidney cells after growing with 5 µM of BisBAL NPs for 24 h. Employing same techniques, identical results were obtained with human epithelial cells (HeLa), showing a not strain-dependent phenomenon. The absence of toxic effects on epithelial cells growing with BisBAL NPs was corroborated with long-time experiments (24-72 hrs.), showing no difference in comparison with growing control (cells without nanoparticles). Further, genotoxicity assays, comet assay and fluorescent microscopy and electrophoresis in bromide-stained agarose gel revealed no damage to genomic DNA of MA104 cells after 24 h. of exposition to BisBAL NPs. Finally, the effect of bismuth nanoparticles on protein synthesis was studied in cells growing with BisBAL NPs for 24 h. SDS-PAGE assays showed no difference between treated and untreated cells, suggesting that BisBAL NPs did not interfere with protein synthesis. Hence BisBAL NPs do not appear to exert cytotoxic effects suggesting their biological compatibility with epithelial cells.

  15. High temperature oxidation behavior of TiAl-based intermetallics

    International Nuclear Information System (INIS)

    Stroosnijder, M.F.; Sunderkoetter, J.D.; Haanappel, V.A.C.

    1996-01-01

    TiAl-based intermetallic compounds have attracted considerable interest as structural materials for high-temperature applications due to their low density and substantial mechanical strength at high temperatures. However, one major drawback hindering industrial application arises from the insufficient oxidation resistance at temperatures beyond 700 C. In the present contribution some general aspects of high temperature oxidation of TiAl-based intermetallics will be presented. This will be followed by a discussion of the influence of alloying elements, in particular niobium, and of the effect of nitrogen in the oxidizing environment on the high temperature oxidation behavior of such materials

  16. Mucosa protectives: sucralfate and colloidal bismuth subcitrate in peptic ulcer disease

    NARCIS (Netherlands)

    Tytgat, G. N.; Nio, C. Y.

    1987-01-01

    Mucosa protective drugs are thought to have an important role in the treatment of both duodenal (DU) and gastric ulcer (GU) disease by means of correcting the disturbed defensive factors. Sucralfate as well as colloidal bismuth subcitrate (CBS) form a layer on the ulcer base and in this way protect

  17. Poly(ethylene oxide)–Poly(propylene oxide)-Based Copolymers for ...

    African Journals Online (AJOL)

    Amphiphilic poly(ethylene oxide)–poly(propylene oxide) (PEO–PPO)-based copolymers are thermoresponsive materials having aggregation properties in aqueous medium. As hydrosolubilizers of poorly water-soluble drugs and improved stability of sensitive agents, these materials have been investigated for improvement ...

  18. Synthesis of polyether-based block copolymers based on poly(propylene oxide) and terephthalates

    NARCIS (Netherlands)

    van der Schuur, J.M.; Feijen, Jan; Gaymans, R.J.

    2005-01-01

    Poly(propylene oxide) (PPO) is a low reactive telechelic polyether and the synthesis of high molecular weight poly(propylene oxide)-based block copolymers was studied. The poly(propylene oxide) used was end capped with 20 wt % ethylene oxide and had a molecular weight of 2300 g/mol (ultra-low monol

  19. Bismuth pyrochlore thin films for dielectric energy storage

    International Nuclear Information System (INIS)

    Michael, Elizabeth K.; Trolier-McKinstry, Susan

    2015-01-01

    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/cm 3 , while bismuth zinc tantalate exhibited a recoverable energy storage density of 60.7 ± 2.0 J/cm 3 . 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/cm 3

  20. Adsorption of volatile polonium and bismuth species on metals in various gas atmospheres. Pt. I. Adsorption of volatile polonium and bismuth on gold

    Energy Technology Data Exchange (ETDEWEB)

    Maugeri, Emilio Andrea; Neuhausen, Joerg; Dressler, Rugard; Piguet, David; Voegele, Alexander; Schumann, Dorothea [Paul Scherrer Institut (PSI), Villigen (Switzerland). Lab. for Radiochemistry; Eichler, Robert [Paul Scherrer Institut (PSI), Villigen (Switzerland). Lab. for Radiochemistry; Bern Univ. (Switzerland). Dept. for Chemistry and Biochemistry; Rijpstra, Kim [Ghent Univ., Zwijnaarde (Belgium). Center for Molecular Modeling (CMM); Cottenier, Stefaan [Ghent Univ., Zwijnaarde (Belgium). Center for Molecular Modeling (CMM); Ghent Univ., Zwijnaarde (Belgium). Dept. of Materials Science and Engineering

    2016-07-01

    Polonium isotopes are considered the most hazardous radionuclides produced during the operation of accelerator driven systems (ADS) when lead-bismuth eutectic (LBE) is used as the reactor coolant and as the spallation target material. In this work the use of gold surfaces for capturing polonium from the cover gas of the ADS reactor was studied by thermochromatography. The results show that gaseous monoatomic polonium, formed in dry hydrogen, is adsorbed on gold at 1058 K. Its adsorption enthalpy was calculated as -250±7 kJ mol{sup -1}, using a Monte Carlo simulation code. Highly volatile polonium species that were observed in similar experiments in fused silica columns in the presence of moisture in both inert and reducing gas were not detected in the experiments studying adsorption on gold surfaces. PoO{sub 2} is formed in both dry and moist oxygen, and its interaction with gold is characterized by transport reactions. The interaction of bismuth, present in large amounts in the atmosphere of the ADS, with gold was also evaluated. It was found that bismuth has a higher affinity for gold, compared to polonium, in an inert, reducing, and oxidizing atmosphere. This fact must be considered when using gold as a material for filtering polonium in the cover gas of ADS.

  1. Anionic Conducting Oxide Ceramics

    National Research Council Canada - National Science Library

    Dunn, Bruce

    1998-01-01

    This program has emphasized the interrelationships among synthesis, microstructure and properties for oxygen ion conducting ceramics based on copper-substituted bismuth vanadate (Bi V Cu O ), known as BICUVOX...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, R.S.; Dhankhar, Sunil; Punia, R., E-mail: rajeshpoonia13@gmail.com; Nanda, Kirti; Kishore, N.

    2014-02-25

    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 TeO{sub 4} structural units into TeO{sub 3} units with increase in bismuth content. • B{sub 2}O{sub 3} exists in the both BO{sub 3} trigonal and BO{sub 4} tetrahedral structural units. -- Abstract: Tellurium oxide based quaternary glasses in the system TeO{sub 2}⋅B{sub 2}O{sub 3}⋅Bi{sub 2}O{sub 3}⋅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 Bi{sub 2}O{sub 3} content. Theoretical calculations of crystalline volume (V{sub c}) have also been made. The glass transition temperature (T{sub g}) has been determined using differential scanning calorimetry (DSC) and its value is observed to decrease with increase in Bi{sub 2}O{sub 3} content. IR and Raman spectra of the present glass system indicate that ZnO acts as network modifier and exists in ZnO{sub 4} units. TeO{sub 2} exists as TeO{sub 3}, TeO{sub 4}, and TeO{sub 6} structural units and the number of TeO{sub 4} groups decreases with increase in bismuth content except for the glass sample with x = 5, which shows maximum number of TeO{sub 4} structural units among all other studied glass samples and transformation of some of TeO{sub 4} structural units into TeO{sub 3} structural units is observed with increase in bismuth content. Bismuth plays the role of network modifier with BiO{sub 6} octahedral structural units for glass samples with x = 5, 10, and 15, whereas, exists in network forming BiO{sub 3} pyramidal structural units for glass sample with x = 20. B{sub 2}O{sub 3} exists in the form of BO{sub 3} trigonal and BO{sub 4} tetrahedral structural units. The transmittance of the present glasses is observed to be very high (up to 95

  3. Flexible Sensory Platform Based on Oxide-based Neuromorphic Transistors.

    Science.gov (United States)

    Liu, Ning; Zhu, Li Qiang; Feng, Ping; Wan, Chang Jin; Liu, Yang Hui; Shi, Yi; Wan, Qing

    2015-12-11

    Inspired by the dendritic integration and spiking operation of a biological neuron, flexible oxide-based neuromorphic transistors with multiple input gates are fabricated on flexible plastic substrates for pH sensor applications. When such device is operated in a quasi-static dual-gate synergic sensing mode, it shows a high pH sensitivity of ~105 mV/pH. Our results also demonstrate that single-spike dynamic mode can remarkably improve pH sensitivity and reduce response/recover time and power consumption. Moreover, we find that an appropriate negative bias applied on the sensing gate electrode can further enhance the pH sensitivity and reduce the power consumption. Our flexible neuromorphic transistors provide a new-concept sensory platform for biochemical detection with high sensitivity, rapid response and ultralow power consumption.

  4. Ultrathin bismuth nanosheets from in situ topotactic transformation for selective electrocatalytic CO2 reduction to formate.

    Science.gov (United States)

    Han, Na; Wang, Yu; Yang, Hui; Deng, Jun; Wu, Jinghua; Li, Yafei; Li, Yanguang

    2018-04-03

    Electrocatalytic carbon dioxide reduction to formate is desirable but challenging. Current attention is mostly focused on tin-based materials, which, unfortunately, often suffer from limited Faradaic efficiency. The potential of bismuth in carbon dioxide reduction has been suggested but remained understudied. Here, we report that ultrathin bismuth nanosheets are prepared from the in situ topotactic transformation of bismuth oxyiodide nanosheets. They process single crystallinity and enlarged surface areas. Such an advantageous nanostructure affords the material with excellent electrocatalytic performance for carbon dioxide reduction to formate. High selectivity (~100%) and large current density are measured over a broad potential, as well as excellent durability for >10 h. Its selectivity for formate is also understood by density functional theory calculations. In addition, bismuth nanosheets were coupled with an iridium-based oxygen evolution electrocatalyst to achieve efficient full-cell electrolysis. When powered by two AA-size alkaline batteries, the full cell exhibits impressive Faradaic efficiency and electricity-to-formate conversion efficiency.

  5. Oxidative Degradation and Stabilisation of Mineral Oil-Based Lubricants

    Science.gov (United States)

    Aguilar, G.; Mazzamaro, G.; Rasberger, M.

    Thermally induced hydrocarbon oxidation is a self-accelerating autoxidation process and is divided into 'low'-, 30-120°C, and 'high'-, >120°C, temperature phases. The first has four stages - induction of radical chain reactions, propagation, branching and then termination. Mechanisms of these processes are described and discussed. Differences in hydrocarbon reactivity are related to molecular structure. For hydrocarbon oxidation >120°C, the first stage is the same as low-temperature oxidation but with reduced selectivity and increased reactivity; second, the oxidation phase becomes diffusion controlled as hydrocarbon viscosities increase from progressive polycondensation of higher molecular weight products, causing varnish and sludge formation. Base oil oxidation stabilities depend upon their derivation, whether solvent neutral, hydrocracked or synthetic, and their response to antioxidant treatment. Lubricant oxidation control focuses on radical scavengers and hydroperoxide decomposers and their synergistic mixtures.

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

    International Nuclear Information System (INIS)

    Biswal, Jasmine B.; Garje, Shivram S.; Nuwad, Jitendra; Pillai, C.G.S.

    2013-01-01

    Two different phase pure materials (Bi 2 S 3 and Bi 2 P 4 O 13 ) have been prepared under different conditions using the same single source precursors. Solvothermal decomposition of the complexes, Bi(S 2 P(OR) 2 ) 3 [where, R=Methyl (Me) (1), Ethyl (Et) (2), n-Propyl (Pr n ) (3) and iso-Propyl (Pr 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 2 P 4 O 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 2 P 4 O 13 thin films were also carried out. - Graphical abstract: Solvothermal decomposition of bismuth(III) dialkyldithiophosphates in ethylene glycol gave Bi 2 S 3 nanoparticles, whereas aerosol assisted chemical vapor deposition of these single source precursors deposited Bi 2 P 4 O 13 thin films. Display Omitted - Highlights: • Preparation of phase pure orthorhombic Bi 2 S 3 nanorods and monoclinic Bi 2 P 4 O 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 2 P 4 O 13 thin films. • Bi 2 S 3 nanorods and Bi 2 P 4 O 13 thin films using same single source precursors

  7. Nonproportionality in the scintillation light yield of bismuth germanate

    Science.gov (United States)

    Gentile, T. R.; Bales, M. J.; Breuer, H.; Chupp, T. E.; Coakley, K. J.; Cooper, R. L.; Nico, J. S.; O`Neill, B.

    2015-06-01

    We present measurements of nonproportionality in the scintillation light yield of bismuth germanate (BGO) for gamma-rays with energies between 6 keV and 662 keV. The scintillation light was read out by avalanche photodiodes (APDs) with both the BGO crystals and APDs operated at a temperature of ≈ 90 K. Data were obtained using radioisotope sources to illuminate both a single BGO crystal in a small test cryostat and a 12-element detector in a neutron radiative beta-decay experiment. In addition one datum was obtained in a 4.6 T magnetic field based on the bismuth K x-ray escape peak produced by a continuum of background gamma rays in this apparatus. These measurements and comparison to prior results were motivated by an experiment to study the radiative decay mode of the free neutron. The combination of data taken under different conditions yields a reasonably consistent picture for BGO nonproportionality that should be useful for researchers employing BGO detectors at low gamma ray energies.

  8. Supramolecular water oxidation with rubda-based catalysts

    KAUST Repository

    Richmond, Craig J.

    2014-11-05

    Extremely slow and extremely fast new water oxidation catalysts based on the Rubda (bda = 2,2′-bipyri-dine-6,6′-dicarboxylate) systems are reported with turnover frequencies in the range of 1 and 900 cycless"1, respectively. Detailed analyses of the main factors involved in the water oxidation reaction have been carried out and are based on a combination of reactivity tests, electrochemical experiments, and DFT calculations. These analyses give a convergent interpretation that generates a solid understanding of the main factors involved in the water oxidation reaction, which in turn allows the design of catalysts with very low energy barriers in all the steps involved in the water oxidation catalytic cycle. We show that for this type of system p-stacking interactions are the key factors that influence reactivity and by adequately controlling them we can generate exceptionally fast water oxidation catalysts.

  9. Combined isovalent alloying gallium arsenide with bismuth and indium

    International Nuclear Information System (INIS)

    Vorob'eva, V.V.; Zushinskaya, O.V.; Novikov, S.V.; Savel'ev, I.G.; Chaldyshev, V.V.

    1989-01-01

    Electric conductivity and the Hall effect at 77 and 300K of gallium arsenide epitaxial films grown from the melted solution with bismuth and indium additions at 77 and 300K. Different mechanisms of bismuth and indium effect on the ensamble of defects and background addition in gallium arsenide, are established. Bismuth effect is conditioned by the change of liquid phase properties, and indium effect is conditioned by the processes taking place in a crystal. The experimental results have shown that the mutual alloying of gallium arsenide with indium and bismuth in the process of liquid-phase epitaxy ensures high electrophysical film properties

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

    International Nuclear Information System (INIS)

    Aziz, Sidek Hj. Abd.; Ahmad, Hamezan; Wahab, Zaidan A.; Sulaiman, Zainal Abidin; Talib, Zainal Abidin; Shaari, A. Halim; Senin, H. B.

    2007-01-01

    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

  11. Active Oxidation of a UHTC-Based CMC

    Science.gov (United States)

    Glass, David E.; Splinter, Scott C.

    2012-01-01

    The active oxidation of ceramic matrix composites (CMC) is a severe problem that must be avoided for multi-use hypersonic vehicles. Much work has been performed studying the active oxidation of silicon-based CMCs such as C/SiC and SiC-coated carbon/carbon (C/C). Ultra high temperature ceramics (UTHC) have been proposed as a possible material solution for high-temperature applications on hypersonic vehicles. However, little work has been performed studying the active oxidation of UHTCs. The intent of this paper is to present test data indicating an active oxidation process for a UHTC-based CMC similar to the active oxidation observed with Si-based CMCs. A UHTC-based CMC was tested in the HyMETS arc-jet facility (or plasma wind tunnel, PWT) at NASA Langley Research Center, Hampton, VA. The coupon was tested at a nominal surface temperature of 3000 F (1650 C), with a stagnation pressure of 0.026 atm. A sudden and large increase in surface temperature was noticed with negligible increase in the heat flux, indicative of the onset of active oxidation. It is shown that the surface conditions, both temperature and pressure, fall within the region for a passive to active transition (PAT) of the oxidation.

  12. Solar Water Splitting and Nitrogen Fixation with Layered Bismuth Oxyhalides.

    Science.gov (United States)

    Li, Jie; Li, Hao; Zhan, Guangming; Zhang, Lizhi

    2017-01-17

    precisely channeling their migration from the bulk to the surface along the different directions, thus enabling more electrons to reach the surface for water splitting and nitrogen fixation. Simultaneously, their oxygen termination feature and the strain differences between interlayers and intralayers render the easy generation of surface oxygen vacancies (OVs) that afford Lewis-base and unsaturated-unsaturated sites for nitrogen activation. With these rationales as the guideline, we can obtain striking visible-light hydrogen- and ammonia-evolving rates without using any noble-metal cocatalysts. Then we show how to utilize IEF and OV based strategies to improve the solar water splitting and nitrogen fixation performances of bismuth oxyhalide photocatalysts. Finally, we highlight the challenges remaining in using bismuth oxyhalides for solar hydrogen and ammonia syntheses, and the prospect of further development of this research field. We believe that our mechanistic insights could serve as a blueprint for the design of more efficient solar water splitting and nitrogen fixation systems, and layered bismuth oxyhalides might open up new photocatalyst paradigm for such two solar chemical syntheses.

  13. "Chemical contraction" in rubidium-bismuth melts

    Science.gov (United States)

    Khairulin, R. A.; Abdullaev, R. N.; Stankus, S. V.

    2017-10-01

    The density and thermal expansion of liquid rubidium and rubidium-bismuth alloy containing 25.0 at % Bi were measured by the gamma-ray attenuation technique at temperatures from liquidus to 1000 K. The results of this study were compared with the data obtained by other authors. The molar volume of the Rb75Bi25 melt strongly deviates from the additivity rule for ideal solutions.

  14. Synthesis, structure and electrical properties of Mg-, Ni-codoped bismuth niobates

    Directory of Open Access Journals (Sweden)

    M. S. Koroleva

    2017-12-01

    Full Text Available Mg-, Ni-codoped bismuth niobates Bi1.6Mg0.8-xNixNb1.6O7-δ (x = 0; 0.2; 0.4; 0.6; 0.8 were obtained by conventional solid-state reaction method. It was shown that the Mg atoms are distributed at the Nb sites while the Ni atoms are distributed over the Bi- and the Nb-sites, according to the results of comparison of pycnometric and X-ray density of the Bi1.6Mg0.4Ni0.4Nb1.6O7-δ pyrochlore. In this case, about 15–20% of the vacancies are formed at the Bi sites. The obtained compounds are stable up to their melting point based on the DSC analysis data. Real dielectric permittivity ε' of the Bi1.6Mg0.8-xNixNb1.6O7-δ samples decreases from 80 to 65 with the temperature decrease from 25 to 700 °C and practically does not depend on frequency in the range of 1–1000 kHz. Oxides Bi1.6Mg0.8-xNixNb1.6O7-δ behave like insulators up to 280 °C, their conductivity increases with temperature (Ea,dc ≈ 1.3 eV, dc and with the Ni content at a given temperature.

  15. Polyurethane networks based on poly (ethylene oxide)

    International Nuclear Information System (INIS)

    Zulfiqar, S.; Quddos, A.

    1993-01-01

    A wide range of infinite urethane polymer networks were prepared from poly (ethylene glycol) (PEG) and hexamethylene disocyanate (HMDI) using 1,1,1, tris (hydroxymethyl) ethane (THME) as crosslinking agent. Differential scanning calorimetry showed that the hydrate formation depends quantitatively upon the weight fraction on poly(ethylene oxide) in the gel. It has been shown that the crosslinked polyurethanes crystallize only with definite ranges of chain length between the knots. In this range with the increase of the degree of crosslinking and crystallinity on the swelling character of the polymeric materials has also been discussed. (author)

  16. Oxide-based thin film transistors for flexible electronics

    Science.gov (United States)

    He, Yongli; Wang, Xiangyu; Gao, Ya; Hou, Yahui; Wan, Qing

    2018-01-01

    The continuous progress in thin film materials and devices has greatly promoted the development in the field of flexible electronics. As one of the most common thin film devices, thin film transistors (TFTs) are significant building blocks for flexible platforms. Flexible oxide-based TFTs are well compatible with flexible electronic systems due to low process temperature, high carrier mobility, and good uniformity. The present article is a review of the recent progress and major trends in the field of flexible oxide-based thin film transistors. First, an introduction of flexible electronics and flexible oxide-based thin film transistors is given. Next, we introduce oxide semiconductor materials and various flexible oxide-based TFTs classified by substrate materials including polymer plastics, paper sheets, metal foils, and flexible thin glass. Afterwards, applications of flexible oxide-based TFTs including bendable sensors, memories, circuits, and displays are presented. Finally, we give conclusions and a prospect for possible development trends. Project supported in part by the National Science Foundation for Distinguished Young Scholars of China (No. 61425020), in part by the National Natural Science Foundation of China (No. 11674162).

  17. 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

  18. Piezoelectric Zinc Oxide Based MEMS Acoustic Sensor

    Directory of Open Access Journals (Sweden)

    Aarti Arora

    2008-04-01

    Full Text Available An acoustic sensors exhibiting good sensitivity was fabricated using MEMS technology having piezoelectric zinc oxide as a dielectric between two plates of capacitor. Thin film zinc oxide has structural, piezoelectric and optical properties for surface acoustic wave (SAW and bulk acoustic wave (BAW devices. Oxygen effficient films are transparent and insulating having wide applications for sensors and transducers. A rf sputtered piezoelectric ZnO layer transforms the mechanical deflection of a thin etched silicon diaphragm into a piezoelectric charge. For 25-micron thin diaphragm Si was etched in tetramethylammonium hydroxide solution using bulk micromachining. This was followed by deposition of sandwiched structure composed of bottom aluminum electrode, sputtered 3 micron ZnO film and top aluminum electrode. A glass having 1 mm diameter hole was bonded on backside of device to compensate sound pressure in side the cavity. The measured value of central capacitance and dissipation factor of the fabricated MEMS acoustic sensor was found to be 82.4pF and 0.115 respectively, where as the value of ~176 pF was obtained for the rim capacitance with a dissipation factor of 0.138. The response of the acoustic sensors was reproducible for the devices prepared under similar processing conditions under different batches. The acoustic sensor was found to be working from 30Hz to 8KHz with a sensitivity of 139µV/Pa under varying acoustic pressure.

  19. Enhanced piezoelectric properties and excellent thermal stabilities of cobalt-modified Aurivillius-type calcium bismuth titanate (CaBi{sub 4}Ti{sub 4}O{sub 15})

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Tian-Long [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Wang, Chun-Ming, E-mail: wangcm@sdu.edu.cn [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Wang, Chun-Lei; Wang, Yi-Ming [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Dong, Shuxiang [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2015-11-15

    Highlights: • Cobalt oxide modified CBT-based ceramics were prepared and investigated in detail. • XRPD analysis revealed Co ions enter into B-site of CBT-based ceramics. • CBT-Co4 ceramics show the enhanced d{sub 33} of 14 pC/N and T{sub c} of 782 °C. • CBT-Co4 ceramics present the improved high-temperature resistivity. • Thermal depoling behavior indicates CBT-Co4 ceramics exhibit good thermal stability. - Abstract: Bismuth layer-structured ferroelectric (BLSF) calcium bismuth titanate (CaBi{sub 4}Ti{sub 4}O{sub 15}, CBT) piezoelectric ceramics with 0.0–1.0 wt.% cobalt oxide (Co{sub 2}O{sub 3}) have been prepared via a conventional solid-state reaction method. Microstructural morphology and electrical properties of cobalt oxide-modified CBT ceramics were investigated in detail. X-ray powder diffraction (XRPD) analysis revealed that the cobalt oxide-modified CBT ceramics have a pure four-layer Aurivillius-type structure. The piezoelectric properties of CBT ceramics were significantly enhanced by cobalt oxide modifications. The piezoelectric coefficient d{sub 33} and Curie temperature T{sub c} of 0.2 wt.% cobalt oxide-modified CBT ceramics (CBT-Co4) are 14 pC/N and 782 °C, respectively. The DC resistivity and thermal depoling behavior at elevated temperature indicated that the CBT-Co4 ceramics exhibit good thermal stability, demonstrating that the CBT-Co4 ceramics are potential materials for high temperature piezoelectric applications.

  20. Second-line bismuth-containing quadruple therapy for Helicobacter pylori eradication and impact of diabetes.

    Science.gov (United States)

    Kim, Sung Eun; Park, Moo In; Park, Seun Ja; Moon, Won; Kim, Jae Hyun; Jung, Kyoungwon; Kim, Hae Koo; Lee, Young Dal

    2017-02-14

    To investigate Helicobacter pylori ( H . pylori ) eradication rates using second-line bismuth-containing quadruple therapy and to identify predictors of eradication failure. This study included 636 patients who failed first-line triple therapy and received 7 d of bismuth-containing quadruple therapy between January 2005 and December 2015. We retrospectively demonstrated H . pylori eradication rates with respect to the year of therapy as well as demographic and clinical factors. H . pylori eradication was confirmed by a 13 C-urea breath test or a rapid urease test at least 4 wk after the completion of bismuth-based quadruple therapy: proton pump inhibitor, metronidazole, bismuth, and tetracycline. The overall eradication rates by intention-to-treat analysis and per-protocol analysis were 73.9% (95%CI: 70.1%-77.4%) and 94.5% (95%CI: 92.4%-96.5%), respectively. Annual eradication rates from 2005 to 2015 were 100.0%, 92.9%, 100.0%, 100.0%, 100.0%, 97.4%, 100.0%, 93.8%, 84.4%, 98.9%, and 92.5%, respectively, by per-protocol analysis. A multivariate analysis showed that diabetes mellitus (OR = 3.99, 95%CI: 1.56-10.20, P = 0.004) was associated with H . pylori eradication therapy failure. The second-line bismuth-containing quadruple therapy for H . pylori infection is still effective in Korea, and diabetes mellitus is suggested to be a risk factor for eradication failure.

  1. INTENSITY- AND TIME COURSE-BASED CLASSIFICATIONS OF OXIDATIVE STRESSES

    Directory of Open Access Journals (Sweden)

    Volodymyr Lushchak

    2015-05-01

    Full Text Available In living organisms, production of reactive oxygen species (ROS is counterbalanced by their elimination and/or prevention of formation which in concert can typically maintain a steady-state (stationary ROS level. However, this balance may be disturbed and lead to elevated ROS levels and enhanced damage to biomolecules. Since 1985, when H. Sies first introduced the definition of oxidative stress, this area has become one of the hot topics in biology and, to date, many details related to ROS-induced damage to cellular components, ROS-based signaling, cellular responses and adaptation have been disclosed. However, some basal oxidative damage always occurs under unstressed conditions, and in many experimental studies it is difficult to show definitely that oxidative stress is indeed induced by the stressor. Therefore, usually researchers experience substantial difficulties in the correct interpretation of oxidative stress development. For example, in many cases an increase or decrease in the activity of antioxidant and related enzymes are interpreted as evidences of oxidative stress. Careful selection of specific biomarkers (ROS-modified targets may be very helpful. To avoid these sorts of problems, I propose several classifications of oxidative stress based on its time-course and intensity. The time-course classification includes acute and chronic stresses. In the intensity based classification, I propose to discriminate four zones of function in the relationship between “Dose/concentration of inducer” and the measured “Endpoint”: I – basal oxidative stress zone (BOS; II – low intensity oxidative stress (LOS; III – intermediate intensity oxidative stress (IOS; IV – high intensity oxidative stress (HOS. The proposed classifications may be helpful to describe experimental data where oxidative stress is induced and systematize it based on its time course and intensity. Perspective directions of investigations in the field include

  2. New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

    Directory of Open Access Journals (Sweden)

    Daily Rodríguez-Padrón

    2017-09-01

    Full Text Available Polysaccharides from natural sources and iron precursors were applied to develop new bio-nanocomposites by mechanochemical milling processes. The proposed methodology was demonstrated to be advantageous in comparison with other protocols for the synthesis of iron oxide based nanostructures. Additionally, mechanochemistry has enormous potential from an environmental point-of-view since it is able to reduce solvent issues in chemical syntheses. The catalytic activity of the obtained nanocatalysts was investigated in both the oxidation of benzyl alcohol to benzaldehyde and in the alkylation of toluene with benzyl chloride. The microwave-assisted oxidation of benzyl alcohol reached 45% conversion after 10 min. The conversion of the alkylation of toluene in both microwave-assisted and conventional heating methods was higher than 99% after 3 min and 30 min, respectively. The transformation of benzyl alcohol and toluene into valuable product in both the oxidation and alkylation reaction reveals a potential method for the valorization of lignocellulosic biomass.

  3. Optical Properties of Chemical Bath Deposited Bismuth Fluoride (Bif ...

    African Journals Online (AJOL)

    Thin films of bismuth fluoride (Bif3) were deposited using chemical bath deposition technique from chemical baths containing solutions of bismuth nitrate (EDTA) and potassium bromide with EDTA as complexing agent in slightly acidic medium. The films were characterized using Fourier transform infrared (FTIR) ...

  4. Bismuth-silver mineralization in the Sergozerskoe gold occurrence

    Directory of Open Access Journals (Sweden)

    Kalinin A. A.

    2017-03-01

    Full Text Available Bismuth-silver mineralization attendant to gold mineralization in the Sergozerskoe gold occurrence has been studied in detail. Bi-Ag mineralization is connected with diorite porphyry dykes, which cut volcanic-sedimentary Lopian complexes of the Strel'ninsky greenstone belt – hornblendite and actinolite-chlorite amphibolites, biotite and bi-micaceous gneisses. Distribution of Bi-Ag mineralization similar to gold mineralization is controlled by 80 m thick zone of silicification. Bi minerals are found in brecciated diorite porphyry. Bismuth-silver mineralization includes native metals (bismuth, electrum, silver, tellurides (hedleyite, hessite, selenides (ikunolite, sulfides and sulfosalts of Bi and Ag (matildite, lillianite, eckerite, jalpaite, prustite, acanthite, a few undiagnosed minerals. All Bi and Ag minerals associate with galena. Composition of mineralization evolved from early to late stages of development, depending on intensity of rock alteration. The earliest Bi-Ag minerals were native bismuth and hedleyite formed dissemination in galena, and electrum with 30-45 mass.% Au. Later native bismuth was partly substituted by silver and bismuth sulfosalts and bismuth sulfides. The latest minerals were low-temperature silver sulfides eckerite, jalpaite, and acanthite, which were noted only in the most intensively altered rocks. As soon as the process of formation of Bi-Ag mineralization is the same as formation of gold, findings of bismuth-silver mineralization can serve as a positive exploration sign for gold in the region.

  5. Use of a Soluble Anode in Electrodeposition of Thick Bismuth Telluride Layers

    Science.gov (United States)

    Maas, M.; Diliberto, S.; de Vaulx, C.; Azzouz, K.; Boulanger, C.

    2014-10-01

    Integration of thermoelectric devices within an automotive heat exchanger could enable conversion of lost heat into electrical energy, contributing to improved total output from the engine. For this purpose, synthesis of thick bismuth telluride (Bi2Te3) films is required. Bismuth telluride has been produced by an electrochemical method in nitric acid with a sacrificial bismuth telluride anode as the source of cations. The binary layer grows on the working electrode while the counter-electrode, a Bi2Te3 disk obtained by high frequency melting, is oxidized to BiIII and TeIV. This process leads to auto-regeneration of the solution without modification of its composition. The thickness of films deposited by use of the Bi2Te3 anode was approximately 10 times that without. To demonstrate the utility of a soluble anode in electrochemical deposition, we report characterization of the composition and morphology of the films obtained under different experimental conditions. Perfectly dense and regular Bi2Te3 films (˜400 μm) with low internal stress and uniform composition across the cross-section were prepared. Their thermoelectric properties were assessed.

  6. Effect of Bismuth Breast Shielding on Radiation Dose and Image Quality in Coronary CT Angiography

    Science.gov (United States)

    Einstein, Andrew J.; Elliston, Carl D.; Groves, Daniel W.; Cheng, Bin; Wolff, Steven D.; Pearson, Gregory D. N.; Peters, M. Robert; Johnson, Lynne L.; Bokhari, Sabahat; Johnson, Gary W.; Bhatia, Ketan; Pozniakoff, Theodore; Brenner, David J.

    2011-01-01

    Background Coronary computed tomographic angiography (CCTA) is associated with high radiation dose to the female breasts. Bismuth breast shielding offers the potential to significantly reduce dose to the breasts and nearby organs, but the magnitude of this reduction and its impact on image quality and radiation dose have not been evaluated. Methods Radiation doses from CCTA to critical organs were determined using metal-oxide-semiconductor field-effect transistors positioned in a customized anthropomorphic whole-body dosimetry verification phantom. Image noise and signal were measured in regions of interest (ROIs) including the coronary arteries. Results With bismuth shielding, breast radiation dose was reduced 46–57% depending on breast size and scanning technique, with more moderate dose reduction to the heart, lungs, and esophagus. However, shielding significantly decreased image signal (by 14.6 HU) and contrast (by 28.4 HU), modestly but significantly increased image noise in ROIs in locations of coronary arteries, and decreased contrast-to-noise ratio by 20.9%.. Conclusions While bismuth breast shielding can significantly decrease radiation dose to critical organs, it is associated with an increase in image noise, decrease in contrast-to-noise, and changes tissue attenuation characteristics in the location of the coronary arteries. PMID:22068687

  7. Functional disruption of peroxiredoxin by bismuth antiulcer drugs attenuates Helicobacter pylori survival.

    Science.gov (United States)

    Chang, Yuen-Yan; Cheng, Tianfan; Yang, Xinming; Jin, Lijian; Sun, Hongzhe; Li, Hongyan

    2017-07-01

    Bismuth drugs have been used clinically to treat infections from Helicobacter pylori, a pathogen that is strongly related to gastrointestinal diseases even stomach cancer. Despite extensive studies, the mechanisms of action of bismuth drugs are not fully understood. Alkyl hydroperoxide reductase subunit C (AhpC) is the most abundant 2-cysteine peroxiredoxin, crucial for H. pylori survival in the host by defense of oxidative stress. Herein we show that a Bi(III) antiulcer drug (CBS) binds to the highly conserved cysteine residues (Cys49 and Cys169) with a dissociation constant (K d ) of Bi(III) to AhpC of 3.0 (±1.0) × 10 -24 M. Significantly the interaction of CBS with AhpC disrupts the peroxiredoxin and chaperone activities of the enzyme both in vitro and in bacterial cells, leading to attenuated bacterial survival. Moreover, using a home-made fluorescent probe, we demonstrate that Bi(III) also perturbs AhpC relocation between the cytoplasm and membrane region in decomposing the exogenous ROS. Our study suggests that disruption of redox homeostasis by bismuth drugs via interaction with key enzymes such as AhpC contributes to their antimicrobial activity.

  8. Heat capacity, enthalpy and entropy of bismuth niobate and bismuth tantalate

    Czech Academy of Sciences Publication Activity Database

    Hampl, M.; Strejc, A.; Sedmidubský, D.; Růžička, K.; Hejtmánek, Jiří; Leitner, J.

    2006-01-01

    Roč. 179, - (2006), s. 77-80 ISSN 0022-4596 Institutional research plan: CEZ:AV0Z10100521 Keywords : heat capacity * heat of formation * heat content * bismuth perovskite Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.107, year: 2006

  9. Segmented Thermoelectric Oxide-based Module

    DEFF Research Database (Denmark)

    Le, Thanh Hung; Linderoth, Søren

    for a more stable high temperature material. In this study, thermoelectric properties from 300 to 1200 K of Ca0.9Y0.1Mn1-xFexO3 for 0 ≤ x ≤ 0.25 were systematically investigated in term of Y and Fe co-doping at the Ca- and Mn-sites, respectively. It was found that with increasing the content of Fe doping......, the Seebeck coefficient of Ca0.9Y0.1Mn1-xFexO3 tended to increase, while the tendency towards the electrical conductivity was more complicated. Thermal conductivity of the Fe-doped samples showed a lower value than that of the non-doped sample. The maximum dimensionless figure-of-merit, zT was found......Since 1990s, oxide thermoelectrics have been considered as promising thermoelectric (TE) materials due to their non-toxicity, low-cost, and chemical stability at high temperatures. Studied results show great potential for applications in thermoelectric power generator (TEG) at high temperature...

  10. Magnetoviscoelastic characteristics of superparamagnetic oxides (Fe, Ni) based ferrofluids

    Science.gov (United States)

    Katiyar, Ajay; Dhar, Purbarun; Nandi, Tandra; Das, Sarit K.

    2017-08-01

    Ferrofluids have been popular among the academic and scientific communities owing to their intelligent physical characteristics under external stimuli and are in fact among the first nanotechnology products to be employed in real world applications. However, studies on the magnetoviscoelastic behavior of concentrated ferrofluids, especially of superparamagnetic oxides of iron and nickel are rare. The present article comprises the formulation of magneto-colloids utilizing the three various metal oxides nanoparticles viz. Iron (II, III) oxide (Fe3O4), Iron (III) oxide (Fe2O3) and Nickel oxide (NiO) in oil. Iron (II, III) oxide based colloids demonstrate high magnetoviscous characteristics over the other oxides based colloids under external magnetic fields. The maximum magnitude of yield stress and viscosity is found to be 3.0 kPa and 2.9 kPa.s, respectively for iron (II, III) oxide based colloids at 2.6 vol% particle concentration and 1.2 T magnetic field. Experimental investigations reveal that the formulated magneto-nanocolloids are stable, even in high magnetic fields and almost reversible when exposed to rising and drop of magnetic fields of the same magnitude. Observations also reveal that the elastic behavior dominates over the viscous behavior with enhanced relaxation and creep characteristics under the magnetic field. The effect of temperature on viscosity and yield stress of magneto-nanocolloids under magnetic fields has also been discussed. Thus, the present findings have potential applications in various fields such as electromagnetic clutch and brakes of automotive, damping, sealing, optics, nanofinishing etc.

  11. Screen-printed electrodes made of a bismuth nanoparticle porous carbon nanocomposite applied to the determination of heavy metal ions

    International Nuclear Information System (INIS)

    Niu, Pengfei; Gich, Martí; Roig, Anna; Fernández-Sánchez, César; Navarro- Hernández, Carla; Fanjul-Bolado, Pablo

    2016-01-01

    This work reports on the simplified fabrication and on the characterization of bismuth-based screen-printed electrodes (SPEs) for use in heavy metal detection. A nanocomposite consisting of bismuth nanoparticles and amorphous carbon was synthesized by a combined one-step sol-gel and pyrolysis process and milled down to a specific particle size distribution as required for the preparation of an ink formulation to be used in screen printing. The resulting electrochemical devices were applied to the detection of Pb(II) and Cd(II) ions in water samples. The porous structure of carbon and the high surface area of the bismuth nanoparticles allow for the detection of Pb(II) and Cd(II) at concentration levels below 4 ppb. The application of the SPEs was demonstrated by quantifying these ions in tap drinking water and wastewater collected from an influent of an urban wastewater treatment plant. (author)

  12. High cure rate of Helicobacter pylori infection using tripotassium dicitrato bismuthate, furazolidone and clarithromycin triple therapy for 1 week

    NARCIS (Netherlands)

    Xiao, S. D.; Liu, W. Z.; Hu, P. J.; Xia, D. H.; Tytgat, G. N.

    1999-01-01

    When metronidazole is used in bismuth-based or proton pump inhibitor-based triple therapy, the cure rate of Helicobacter pylori is usually high. However, metronidazole-resistant H. pylori strains, which are increasing in frequency, are a major cause of failed H. pylori eradication. To evaluate the

  13. Charge transport in metal oxide nanocrystal-based materials

    Science.gov (United States)

    Runnerstrom, Evan Lars

    There is probably no class of materials more varied, more widely used, or more ubiquitous than metal oxides. Depending on their composition, metal oxides can exhibit almost any number of properties. Of particular interest are the ways in which charge is transported in metal oxides: devices such as displays, touch screens, and smart windows rely on the ability of certain metal oxides to conduct electricity while maintaining visible transparency. Smart windows, fuel cells, and other electrochemical devices additionally rely on efficient transport of ionic charge in and around metal oxides. Colloidal synthesis has enabled metal oxide nanocrystals to emerge as a relatively new but highly tunable class of materials. Certain metal oxide nanocrystals, particularly highly doped metal oxides, have been enjoying rapid development in the last decade. As in myriad other materials systems, structure dictates the properties of metal oxide nanocrystals, but a full understanding of how nanocrystal synthesis, the processing of nanocrystal-based materials, and the structure of nanocrystals relate to the resulting properties of nanocrystal-based materials is still nascent. Gaining a fundamental understanding of and control over these structure-property relationships is crucial to developing a holistic understanding of metal oxide nanocrystals. The unique ability to tune metal oxide nanocrystals by changing composition through the introduction of dopants or by changing size and shape affords a way to study the interplay between structure, processing, and properties. This overall goal of this work is to chemically synthesize colloidal metal oxide nanocrystals, process them into useful materials, characterize charge transport in materials based on colloidal metal oxide nanocrystals, and develop ways to manipulate charge transport. In particular, this dissertation characterizes how the charge transport properties of metal oxide nanocrystal-based materials depend on their processing and

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

    NARCIS (Netherlands)

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

    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

  15. An evaluated neutronic data file for bismuth

    International Nuclear Information System (INIS)

    Guenther, P.T.; Lawson, R.D.; Meadows, J.W.; Smith, A.B.; Smith, D.L.; Sugimoto, M.; Howerton, R.J.

    1989-11-01

    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

  16. An evaluated neutronic data file for bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, P.T.; Lawson, R.D.; Meadows, J.W.; Smith, A.B.; Smith, D.L.; Sugimoto, M. (Argonne National Lab., IL (USA)); Howerton, R.J. (Lawrence Livermore National Lab., CA (USA))

    1989-11-01

    A comprehensive evaluated neutronic data file for bismuth, extending from 10{sup {minus}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.

  17. Quantum oscillations of conductivity in bismuth wires

    International Nuclear Information System (INIS)

    Condrea, Elena

    2011-01-01

    Measurements of the resistance of bismuth nanowires with several diameters and different quality reveal oscillations on the dependence of resistance under uniaxial strain at T = 4.2 K. Amplitude of oscillations is significant (38 %) at helium temperature and becomes smearing at T = 77 K. Observed oscillations originate from quantum size effect. A simple evaluation of period of oscillations allows us to identify the groups of carriers involved in transport. Calculated periods of 42.2 and 25.9 nm satisfy approximately the ratio 2:1 for two experimentally observed sets of oscillations from light and heavy electrons.

  18. Nitrous oxide-based techniques versus nitrous oxide-free techniques for general anaesthesia.

    Science.gov (United States)

    Sun, Rao; Jia, Wen Qin; Zhang, Peng; Yang, KeHu; Tian, Jin Hui; Ma, Bin; Liu, Yali; Jia, Run H; Luo, Xiao F; Kuriyama, Akira

    2015-11-06

    Nitrous oxide has been used for over 160 years for the induction and maintenance of general anaesthesia. It has been used as a sole agent but is most often employed as part of a technique using other anaesthetic gases, intravenous agents, or both. Its low tissue solubility (and therefore rapid kinetics), low cost, and low rate of cardiorespiratory complications have made nitrous oxide by far the most commonly used general anaesthetic. The accumulating evidence regarding adverse effects of nitrous oxide administration has led many anaesthetists to question its continued routine use in a variety of operating room settings. Adverse events may result from both the biological actions of nitrous oxide and the fact that to deliver an effective dose, nitrous oxide, which is a relatively weak anaesthetic agent, needs to be given in high concentrations that restrict oxygen delivery (for example, a common mixture is 30% oxygen with 70% nitrous oxide). As well as the risk of low blood oxygen levels, concerns have also been raised regarding the risk of compromising the immune system, impaired cognition, postoperative cardiovascular complications, bowel obstruction from distention, and possible respiratory compromise. To determine if nitrous oxide-based anaesthesia results in similar outcomes to nitrous oxide-free anaesthesia in adults undergoing surgery. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014 Issue 10); MEDLINE (1966 to 17 October 2014); EMBASE (1974 to 17 October 2014); and ISI Web of Science (1974 to 17 October 2014). We also searched the reference lists of relevant articles, conference proceedings, and ongoing trials up to 17 October 2014 on specific websites (http://clinicaltrials.gov/, http://controlled-trials.com/, and http://www.centerwatch.com). We included randomized controlled trials (RCTs) comparing general anaesthesia where nitrous oxide was part of the anaesthetic technique used for the induction or maintenance of general

  19. 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)

    Tian, Ye; Jiang, Lianjun; Zhang, Xuejun; Deng, Yangbao; Deng, Shuguang

    2014-01-01

    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)

  20. Bismuth-ceramic nanocomposites through ball milling and liquid crystal synthetic methods

    Science.gov (United States)

    Dellinger, Timothy Michael

    Three methods were developed for the synthesis of bismuth-ceramic nanocomposites, which are of interest due to possible use as thermoelectric materials. In the first synthetic method, high energy ball milling of bismuth metal with either MgO or SiO2 was found to produce nanostructured bismuth dispersed on a ceramic material. The morphology of the resulting bismuth depended on its wetting behavior with respect to the ceramic: the metal wet the MgO, but did not wet on the SiO2. Differential Scanning Calorimetry measurements on these composites revealed unusual thermal stability, with nanostructure retained after multiple cycles of heating and cooling through the metal's melting point. The second synthesis methodology was based on the use of lyotropic liquid crystals. These mixtures of water and amphiphilic molecules self-assemble to form periodic structures with nanometer-scale hydrophilic and hydrophobic domains. A novel shear mixing methodology was developed for bringing together reactants which were added to the liquid crystals as dissolved salts. The liquid crystals served to mediate synthesis by acting as nanoreactors to confine chemical reactions within the nanoscale domains of the mesophase, and resulted in the production of nanoparticles. By synthesizing lead sulfide (PbS) and bismuth (Bi) particles as proof-of-concept, it was shown that nanoparticle size could be controlled by controlling the dimensionality of the nanoreactors through control of the liquid crystalline phase. Particle size was shown to decrease upon going from three-dimensionally percolating nanoreactors, to two dimensional sheet-like nanoreactors, to one dimensional rod-like nanoreactors. Additionally, particle size could be controlled by varying the precursor salt concentration. Since the nanoparticles did not agglomerate in the liquid crystal immediately after synthesis, bismuth-ceramic nanocomposites could be prepared by synthesizing Bi nanoparticles and mixing in SiO2 particles which

  1. Nanomaterials-based electrochemical sensors for nitric oxide

    International Nuclear Information System (INIS)

    Dang, Xueping; Hu, Hui; Wang, Shengfu; Hu, Shengshui

    2015-01-01

    Electrochemical sensing has been demonstrated to represent an efficient way to quantify nitric oxide (NO) in challenging physiological environments. A sensing interface based on nanomaterials opens up new opportunities and broader prospects for electrochemical NO sensors. This review (with 141 refs.) gives a general view of recent advances in the development of electrochemical sensors based on nanomaterials. It is subdivided into sections on (i) carbon derived nanomaterials (such as carbon nanotubes, graphenes, fullerenes), (ii) metal nanoparticles (including gold, platinum and other metallic nanoparticles); (iii) semiconductor metal oxide nanomaterials (including the oxides of titanium, aluminum, iron, and ruthenium); and finally (iv) nanocomposites (such as those formed from carbon nanomaterials with nanoparticles of gold, platinum, NiO or TiO 2 ). The various strategies are discussed, and the advances of using nanomaterials and the trends in NO sensor technology are outlooked in the final section. (author)

  2. Recrystallization characteristics of oxide dispersion strengthened nickel-base alloys

    Science.gov (United States)

    Hotzler, R. K.; Glasgow, T. K.

    1980-01-01

    Electron microscopy was employed to study the process of recrystallization in two oxide dispersion strengthened (ODS) mechanically alloyed nickel-base alloys, MA 754 and MA 6000E. MA 754 contained both fine, uniformly dispersed particles and coarser oxides aligned along the working direction. Hot rolled MA 754 had a grain size of 0.5 microns and high dislocation densities. After partial primary recrystallization, the fine grains transformed to large elongated grains via secondary (or abnormal) grain growth. Extruded and rolled MA 6000E contained equiaxed grains of 0.2 micron diameter. Primary recrystallization occurring during working eliminated virtually all dislocations. Conversion from fine to coarse grains was triggered by gamma prime dissolution; this was also a process of secondary or abnormal grain growth. Comparisons were made to conventional and oxide dispersion strengthened nickel-base alloys.

  3. Magnetoviscoelastic characteristics of superparamagnetic oxides (Fe, Ni) based ferrofluids

    International Nuclear Information System (INIS)

    Katiyar, Ajay; Dhar, Purbarun; Nandi, Tandra; Das, Sarit K.

    2017-01-01

    Highlights: • The magnetoviscous effect in ferrofluids in the presence of magnetic field is investigated. • Oxides of Fe and Ni are dispersed in oil to formulate the ferrofluids. • Drastic enhancement in the yield stress and viscosity under the magnetic field is observed for Fe 3 O 4 -based ferrofluids. • Viscoelastic properties of the formulated ferrofluids demonstrate the strong function of magnetic field. • The increase in temperature reduces the magneto-viscous effect in ferrofluids under the magnetic field. - Abstract: Ferrofluids have been popular among the academic and scientific communities owing to their intelligent physical characteristics under external stimuli and are in fact among the first nanotechnology products to be employed in real world applications. However, studies on the magnetoviscoelastic behavior of concentrated ferrofluids, especially of superparamagnetic oxides of iron and nickel are rare. The present article comprises the formulation of magneto-colloids utilizing the three various metal oxides nanoparticles viz. Iron (II, III) oxide (Fe 3 O 4 ), Iron (III) oxide (Fe 2 O 3 ) and Nickel oxide (NiO) in oil. Iron (II, III) oxide based colloids demonstrate high magnetoviscous characteristics over the other oxides based colloids under external magnetic fields. The maximum magnitude of yield stress and viscosity is found to be 3.0 kPa and 2.9 kPa.s, respectively for iron (II, III) oxide based colloids at 2.6 vol% particle concentration and 1.2 T magnetic field. Experimental investigations reveal that the formulated magneto-nanocolloids are stable, even in high magnetic fields and almost reversible when exposed to rising and drop of magnetic fields of the same magnitude. Observations also reveal that the elastic behavior dominates over the viscous behavior with enhanced relaxation and creep characteristics under the magnetic field. The effect of temperature on viscosity and yield stress of magneto-nanocolloids under magnetic fields has

  4. Magnetoviscoelastic characteristics of superparamagnetic oxides (Fe, Ni) based ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Katiyar, Ajay, E-mail: ajay_k@ric.drdo.in [Research and Innovation Centre (DRDO), IIT Madras Research Park, Chennai 600113 (India); Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Dhar, Purbarun [Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 (India); Nandi, Tandra [Defence Materials and Stores Research and Development Establishment (DRDO), G.T. Road, Kanpur 208013 (India); Das, Sarit K. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 (India)

    2017-08-15

    Highlights: • The magnetoviscous effect in ferrofluids in the presence of magnetic field is investigated. • Oxides of Fe and Ni are dispersed in oil to formulate the ferrofluids. • Drastic enhancement in the yield stress and viscosity under the magnetic field is observed for Fe{sub 3}O{sub 4}-based ferrofluids. • Viscoelastic properties of the formulated ferrofluids demonstrate the strong function of magnetic field. • The increase in temperature reduces the magneto-viscous effect in ferrofluids under the magnetic field. - Abstract: Ferrofluids have been popular among the academic and scientific communities owing to their intelligent physical characteristics under external stimuli and are in fact among the first nanotechnology products to be employed in real world applications. However, studies on the magnetoviscoelastic behavior of concentrated ferrofluids, especially of superparamagnetic oxides of iron and nickel are rare. The present article comprises the formulation of magneto-colloids utilizing the three various metal oxides nanoparticles viz. Iron (II, III) oxide (Fe{sub 3}O{sub 4}), Iron (III) oxide (Fe{sub 2}O{sub 3}) and Nickel oxide (NiO) in oil. Iron (II, III) oxide based colloids demonstrate high magnetoviscous characteristics over the other oxides based colloids under external magnetic fields. The maximum magnitude of yield stress and viscosity is found to be 3.0 kPa and 2.9 kPa.s, respectively for iron (II, III) oxide based colloids at 2.6 vol% particle concentration and 1.2 T magnetic field. Experimental investigations reveal that the formulated magneto-nanocolloids are stable, even in high magnetic fields and almost reversible when exposed to rising and drop of magnetic fields of the same magnitude. Observations also reveal that the elastic behavior dominates over the viscous behavior with enhanced relaxation and creep characteristics under the magnetic field. The effect of temperature on viscosity and yield stress of magneto

  5. Study of point defects in bismuth

    International Nuclear Information System (INIS)

    Bois, P.

    1987-03-01

    Single crystalline samples of bismuth, pure and n or p - doped by adding tellurium or tin, were electron irradiated at low temperature (4.2 K and 20 K). In the energy range 0.7 - 2.5 MeV, a displacement threshold energy of 13 eV and an athermal recombination volume of 150 atomic volumes were determined. Joint measurements of resistivity, magnetotransport and positron annihilation enabled to precised the nature of the annealing stages: 40-50 K, free migration of interstitials; 90-120 K long range migration of vacancy. Point defects have according to their nature a different effect on the electronic properties of bismuth: isolated Frenkel pairs are globally donnors with a charge of + 0.16 e- and the vacancy is donnor, which seems to attribute to it a negative formation volume. A simple model with non-deformating bands is no longer sufficient to explain the behaviour under irradiation: one has to take into account an acceptor level with a charge of - 0,27 e-, linked to the cascade-type defects and resonating with the valence band. It's position in the band overlap and it's width (8 meV) could be precised. In first approximation this coupling with less mobile carriers does not affect the simple additive rule which exists for relaxation times. Some yet obscure magnetic properties seem to be linked to this defect level [fr

  6. PHYSICAL-CHEMICAL PROPERTIES OF BISMUTH AND BISMUTH OXIDES: SYNTHESIS, CHARACTERIZATION AND APPLICATIONS

    Directory of Open Access Journals (Sweden)

    CLAUDIA MILENA BEDOYA HINCAPIÉ

    2012-01-01

    Full Text Available Las propiedades físico-químicas del bismuto y sus óxidos han sido objeto de estudio en las dos últimas décadas. Como resultado de estas investigaciones, estos materiales se han logrado crecer en diferentes estructuras cristalográficas y con dimensiones micro y nanométricas, utilizando diferentes técnicas (pulverización catódica, depósito por laser pulsado, método hidrotérmico, etc. Las dimensiones alcanzadas han permitido obtener películas delgadas, nanotubos, nanoesferas y nanohilos, con los cuales se han desarrollado dispositivos entre los que se destacan detectores de metales pesados, filtros ópticos y sensores de campo magnético. Debido al auge que han tomado estos materiales en los últimos años, en este documento se realizó una revisión bibliográfica de algunas técnicas empleadas para procesar materiales basados en bismuto en forma nanométrica, y algunas de sus aplicaciones tecnológicas.

  7. Palladium-catalyzed air-based oxidative coupling of arylboronic acids with H-phosphine oxides leading to aryl phosphine oxides.

    Science.gov (United States)

    Fu, Tingting; Qiao, Hongwei; Peng, Zhimin; Hu, Gaobo; Wu, Xueji; Gao, Yuxing; Zhao, Yufen

    2014-05-14

    We present a novel and highly efficient methodology that allows for the construction of C-P bonds via the palladium-catalyzed air-based oxidative coupling of various commercially available arylboronic acids with easily oxidized H-phosphine oxides leading to valuable aryl phosphine oxides, particularly triarylphosphine oxides, with the use of air as the green oxidant, broad substrate applicability and good to excellent yields. The described catalytic system should be an efficient complement to the Chan-Lam type reaction and be useful in synthetic programs.

  8. Reduced-graphene-oxide-and-strontium-titanate-based double

    Indian Academy of Sciences (India)

    Microwave-absorbing materials based on reduced graphene oxide (r-GO)/ strontium titanate were prepared by embedding in epoxy matrix. R-GO and strontium titanate were synthesized and characterized before composite fabrication. Microstructures of the constituent elements were studied by scanning electron ...

  9. Reduced-graphene-oxide-and-strontium-titanate-based double ...

    Indian Academy of Sciences (India)

    Microwave-absorbing materials based on reduced graphene oxide (r-GO)/ strontium titanate were prepared by embedding in epoxy matrix. R-GO and strontium titanate were synthesized and characterized before composite fabrication. Microstructures of the constituent elements were studied by scanning electron ...

  10. Preparation and characterization of iron oxide and hydroxide based nanomaterials

    Science.gov (United States)

    Carbajal Franco, Guillermo

    Iron (Fe) oxides and hydroxides are common and abundant materials. They exhibit diverse crystal structures, properties and phenomena by virtue of which they find a wide range of scientific and technological applications. Controlled growth and manipulation of the specific structure and electronic behavior to meet the requirements of a given application is a challenging problem in view of many possible phases and composition of the resulting materials. The preparation method and experimental conditions will, therefore, significantly affect the properties and performance of Fe oxides and hydroxides. The goal of the project is to obtain Fe-based oxide/hydroxide catalytic materials and to derive a comprehensive understanding of the microstructure and electronic properties. The obvious relevance of the work it to optimize conditions to produce high quality Fe- based nanomaterials capable of dissociating the water molecules and produce hydrogen. The present approach to synthesize Fe oxides and hydroxides is based on a chemical route involving Fe-containing compounds. First step involved is the precipitation of Fe hydroxide/oxide particles from iron salts in an aqueous and non-aqueous media. The resultant precipitates consist of agglomerated nanoparticles. The size of the resulting Fe oxide and hydroxide nanoparticle depends on the concentration of the original solutions. After precipitation, a weak organic acid is added to obtain different concentrations. The samples were obtained at different intervals of time. Structure modification and dispersion of nanoparticles have been achieved and correlated with the concentration of the organic acid. It is demonstrated that the microstructure can be controlled in order to tune the materials' electronic behavior. In addition, the incorporation of various metal ions into the host matrix is explored in order to control the structure and electronic properties. The results are presented and discussed in detail in this dissertation.

  11. Oxidative dehydrogenation of ethane on rare-earth oxide-based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Buyevskaya, O.; Baerns, M. [Institut fuer Angewandte Chemie Berlin-Adlershof e.V., Berlin (Germany)

    1998-12-31

    Results on the oxidative dehydrogenation of ethane on rare-earth oxide (REO) based catalysts (Na-P-Sm-O, Sm-Sr(Ca)-O, La-Sr-O and Nd-Sr-O) are described. Oxygen adsorption was found to be a key factor which determines the activity of this type of catalysts. Continuous flow experiments in the presence of catalysts which reveal strong oxygen adsorption showed that the reaction mixture is ignited resulting in an enhanced heat generation at the reactor inlet. The heat produced by the oxidative reactions was sufficient under the conditions chosen for the endothermic thermal pyrolysis which takes place preferentially in the gas phase. Ignition of the reaction mixture is an important catalyst function. Contrary to non-catalytic oxidative dehydrogenation, reaction temperatures above 700 C could be achieved without significant external heat input. Ethylene yields of up to 34-45% (S=66-73%) were obtained on REO-based catalysts under non-isothermal conditions (T{sub max}=810-865 C) at contact times in the order of 30 to 40 ms. (orig.)

  12. HgO/I as an Efficient Reagent for the Oxidative Aromatization of ...

    African Journals Online (AJOL)

    NJD

    reported for the aromatization of them, such as bismuth nitrate ... celite,19 microwave-assisted with FeCl3.SiO2,. 20 bismuth(III) chloride supported onto wet HZSM-5 zeolite,21 selenium dioxide,22 iodobenzene diacetate,23 iodoxy benzoic acid (IBA),24 ... oxidation of sulfide to sulfoxides32 and dimerization of anilines.

  13. Joining of Half-Heusler and Bismuth Tellurides for Segmented Thermoelectric Generators

    DEFF Research Database (Denmark)

    Ngan, Pham Hoang; Han, Li; Christensen, Dennis Valbjørn

    2018-01-01

    Segmented generators where the p- or n-type legs are formed by joining materials in series enables each material to operate in their most efficient temperature range. Here, we have fabricated and characterized segmented thermoelectric p- and n-type legs based on bismuth tellurides and half......-Heusler alloys p-type Hf0.5Zr0.5CoSn0.2Sb0.8 and n-type Ti0.6Hf0.4NiSn. A two-step process was introduced to join the half-Heusler to the bismuth tellurides to form a segmented structure which was then characterized for its thermoelectric and structural properties. The output power generation was characterized...

  14. Structural investigation of Zn doped sodium bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, V., E-mail: vijetabhatia0712@gmail.com; Kumar, D. [Department of Physics, Punjabi University Patiala (India); Singh, D.; Singh, S. P. [Department of Physics, SGGSW University, Fatehgarh Sahib (India)

    2016-05-06

    A series of Bismuth Borate Oxide Glass samples with composition x(ZnO):(15-x)Na{sub 2}O:15Bi{sub 2}O{sub 3}:70B{sub 2}O{sub 3} (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 BO{sub 3} & BO{sub 4} structural units) have been observed.

  15. Measurement of oxidatively generated base damage in cellular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Cadet, Jean, E-mail: jean.cadet@cea.fr [Laboratoire ' Lesions des Acides Nucleiques' , SCIB-UMR-E no3 (CEA/UJF), FRE CNRS 3200, Departement de Recherche Fondamentale sur la Matiere Condensee, CEA/Grenoble, F-38054 Grenoble Cedex 9 (France); Douki, Thierry; Ravanat, Jean-Luc [Laboratoire ' Lesions des Acides Nucleiques' , SCIB-UMR-E no3 (CEA/UJF), FRE CNRS 3200, Departement de Recherche Fondamentale sur la Matiere Condensee, CEA/Grenoble, F-38054 Grenoble Cedex 9 (France)

    2011-06-03

    This survey focuses on the critical evaluation of the main methods that are currently available for monitoring single and complex oxidatively generated damage to cellular DNA. Among chromatographic methods, HPLC-ESI-MS/MS and to a lesser extent HPLC-ECD which is restricted to a few electroactive nucleobases and nucleosides are appropriate for measuring the formation of single and clustered DNA lesions. Such methods that require optimized protocols for DNA extraction and digestion are sensitive enough for measuring base lesions formed under conditions of severe oxidative stress including exposure to ionizing radiation, UVA light and high intensity UVC laser pulses. In contrast application of GC-MS and HPLC-MS methods that are subject to major drawbacks have been shown to lead to overestimated values of DNA damage. Enzymatic methods that are based on the use of DNA repair glycosylases in order to convert oxidized bases into strand breaks are suitable, even if they are far less specific than HPLC methods, to deal with low levels of single modifications. Several other methods including immunoassays and {sup 32}P-postlabeling methods that are still used suffer from drawbacks and therefore are not recommended. Another difficult topic is the measurement of oxidatively generated clustered DNA lesions that is currently achieved using enzymatic approaches and that would necessitate further investigations.

  16. Manganese oxides-based composite electrodes for supercapacitors

    Science.gov (United States)

    Su, Dongyun; Ma, Jun; Huang, Mingyu; Liu, Feng; Chen, Taizhou; Liu, Chao; Ni, Hongjun

    2017-06-01

    In recent, nanostructured transition metal oxides as a new class of energy storage materials have widely attracted attention due to its excellent electrochemical performance for supercapacitors. The MnO2 based transition metal oxides and their composite electrode materials were focused in the review for supercapacitor applications. The researches on different nanostructures of manganese oxides such as Nano rods, Nano sheets, nanowires, nanotubes and so on have been discovered in recent years, together with brief explanations of their properties. Research on enhancing materials’ properties by designing combination of different materials on the micron or Nano scale is too limited, and therefore we discuss the effects of different components’ sizes and their synergy on the performance. Moreover, the low-cost and large-scale fabrication of flexible supercapacitors with high performance (high energy density and cycle stability) have been pointed out and studied.

  17. Nanotubes from Oxide-Based Misfit Family: The Case of Calcium Cobalt Oxide.

    Science.gov (United States)

    Panchakarla, Leela S; Lajaunie, Luc; Ramasubramaniam, Ashwin; Arenal, Raul; Tenne, Reshef

    2016-06-28

    Misfit layered compounds (MLCs) have generated significant interest in recent years as potential thermoelectric materials. MLC nanotubes could reveal behavior that is entirely different from the bulk material. Recently, new chemical strategies were exploited for the synthesis of nanotubular forms of chalcogenide-based MLCs, which are promising candidates for thermoelectric materials. However, analogous synthesis of oxide-based MLC nanotubes has not been demonstrated until now. Here, we report a chemical strategy for synthesis of cobalt-oxide-based misfit nanotubes. A combination of high-resolution (scanning) transmission electron microscopy (including image simulations), spatially resolved electron energy-loss spectroscopy, electron diffraction, and density functional theory (DFT) calculations is used to discover the formation of a phase within these nanotubes that differs significantly from bulk calcium cobaltite MLCs. Furthermore, DFT calculations show that this phase is semiconducting with a band gap in excess of 1 eV, unlike bulk calcium cobaltite MLCs, which are known to be metallic. Through systematic experiments, we propose a formation mechanism for these nanotubes that could also apply more generally to realizing other oxide-based MLC nanotubes.

  18. Mechanism-Based Design of Green Oxidation Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rybak-Akimova, Elena [Tufts Univ., Medford, MA (United States)

    2015-03-16

    situation. Growing families of synthetic iron complexes that resemble active sites of metalloenzymes produce metal-based intermediates (rather than hydroxyl radicals) in reactions with oxygen donors. These complexes are very promising for selective oxygen and peroxide activation. In order to understand the mechanisms of metal-based small molecule activation, kinetically competent metal-oxygen intermediates must be identified. One of the grand challenges identified by the Department of Energy workshop "Catalysis for Energy" is understanding mechanisms and dynamics of catalyzed reactions. The research summarized herein focuses on detailed characterization of the formation and reactivity of various iron-peroxo- and iron-oxo intermediates that are involved in catalysis. Rates of rapid reactions were studied at low temperatures by a specialized technique termed cryogenic stopped-flow spectrophotometry. These measurements identified reaction conditions which favor the formation of catalytically competent oxidants. Chemical structures of reactive complexes was determined, and new, efficient catalysts for hydrocarbon oxidation were synthesized. Importantly, these catalysts are selective, they promote oxidation of hydrocarbons at a specific site. The catalysts are also efficient and robust, hundreds of cycles of substrate oxidation occur within minutes at room temperature. Furthermore, they enable utilization of environmentally friendly oxidants, such as hydrogen peroxide, which produces water as the only byproduct. Mechanistic insights uncovered the role of various acid-containing additives in catalytic oxidations. Proton delivery to the active catalytic sites facilitated oxidations, similarly to the catalytic pathways in metal-containing enzymes. Under certain conditions, two metals in one complex can act in concert, modeling the reactivity of a bacterial enzyme which converts methane into methanol. In related studies, a family of nickel complexes that react with carbon dioxide at

  19. Origin of broad NIR photoluminescence in bismuthate glass and Bi-doped glasses at room temperature

    International Nuclear Information System (INIS)

    Peng, Mingying; Zollfrank, Cordt; Wondraczek, Lothar

    2009-01-01

    Bi-doped glasses with broadband photoluminescence in the near-infrared (NIR) spectral range are presently receiving significant consideration for potential applications in telecommunications, widely tunable fiber lasers and spectral converters. However, the origin of NIR emission remains disputed. Here, we report on NIR absorption and emission properties of bismuthate glass and their dependence on the melting temperature. Results clarify that NIR emission occurs from the same centers as it does in Bi-doped glasses. The dependence of absorption and NIR emission of bismuthate glasses on the melting temperature is interpreted as thermal dissociation of Bi 2 O 3 into elementary Bi. Darkening of bismuthate glass melted at 1300 deg. C is due to the agglomeration of Bi atoms. The presence of Bi nanoparticles is confirmed by transmission electron microscopy, high-resolution energy dispersive x-ray spectroscopy and element distribution mapping. By adding antimony oxide as an oxidation agent to the glass, NIR emission centers can be eliminated and Bi 3+ is formed. By comparing with atomic spectral data, absorption bands at ∼320 , ∼500 , 700 , 800 and 1000 nm observed in Bi-doped glasses are assigned to Bi 0 transitions 4 S 3/2 → 2 P 3/2 , 4 S 3/2 → 2 P 1/2 , 4 S 3/2 → 2 D 5/2 , 4 S 3/2 → 2 D 3/2 (2) and 4 S 3/2 → 2 D 3/2 (1), respectively, and broadband NIR emission is assigned to the transition 2 D 3/2 (1)→ 4 S 3/2 .

  20. Corrosion study of the graphene oxide and reduced graphene oxide-based epoxy coatings

    Science.gov (United States)

    Ghauri, Faizan Ali; Raza, Mohsin Ali; Saad Baig, Muhammad; Ibrahim, Shoaib

    2017-12-01

    This work aims to determine the effect of graphene oxide (GO) and reduced graphene oxide (rGO) incorporation as filler on the corrosion protection ability of epoxy coatings in saline media. GO was derived from graphite powder following modified Hummers’ method, whereas rGO was obtained after reduction of GO with hydrazine solution. About 1 wt.% of GO or rGO were incorporated in epoxy resin by solution mixing process followed by ball milling. GO and rGO-based epoxy composite coatings were coated on mild steel substrates using film coater. The coated samples were characterized by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests after 1 and 24 h immersion in 3.5% NaCl. The results suggested that GO-based epoxy composite coatings showed high impedance and low corrosion rate.

  1. Grain boundary effects on the mechanical properties of bismuth nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Burek, Michael J.; Jin, Sumin; Leung, Michael C.; Jahed, Zeinab; Wu, Janet [Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1 (Canada); Budiman, Arief Suriadi [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tamura, Nobumichi; Kunz, Martin [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Tsui, Ting Y., E-mail: tttsui@uwaterloo.ca [Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1 (Canada)

    2011-06-15

    Cylindrical bismuth nanopillars with diameters between 130 and 1100 nm were fabricated by electron beam lithography and electroplating. The microstructure of the electrodeposited bismuth was established to be polycrystalline with a wide distribution of grains from {approx}0.1 to 1 {mu}m in size. A clear transition in the mechanism governing the plastic deformation of bismuth nanopillars is observed as the nanopillar size becomes comparable with the average grain size of 280 nm. In larger nanopillar specimens, where the average grain size is much smaller than the nanopillar diameter, deformation is dominated by grain boundary-mediated mechanisms. When the bismuth nanopillar diameter approaches the average grain size the deformation behavior transitions to a mechanism dominated by dislocation dynamics. This transition is identified by post-compression scanning electron microscopy, strain rate sensitivity, and average flow stresses.

  2. Microstructures and oxidation behavior of some Molybdenum based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Pratik Kumar [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The advent of Ni based superalloys revolutionized the high temperature alloy industry. These materials are capable of operating in extremely harsh environments, comprising of temperatures around 1050 C, under oxidative conditions. Demands for increased fuel efficiency, however, has highlighted the need for materials that can be used under oxidative conditions at temperatures in excess of 1200 C. The Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that melt in the 1250 - 1450 C, resulting in softening of the alloys above 1000 C. Therefore, recent research directions have been skewed towards exploring and developing newer alloy systems. This thesis comprises a part of such an effort. Techniques for rapid thermodynamic assessments were developed and applied to two different systems - Mo-Si alloys with transition metal substitutions (and this forms the first part of the thesis) and Ni-Al alloys with added components for providing high temperature strength and ductility. A hierarchical approach towards alloy design indicated the Mo-Ni-Al system as a prospective candidate for high temperature applications. Investigations on microstructures and oxidation behavior, under both isothermal and cyclic conditions, of these alloys constitute the second part of this thesis. It was seen that refractory metal systems show a marked microstructure dependence of oxidation.

  3. Relationships among oxidation-reduction and acid-base properties of the actinides in high oxidation states

    International Nuclear Information System (INIS)

    Morss, L.R.

    1992-01-01

    The first chemical identification of plutonium, its subsequent isolation on the macroscopic scale, and more recent chemical separation schemes were achieved by taking advantage of the differences among the oxidation states of uranium, neptunium, and plutonium. Many acid-base properties modify the relative stabilities of oxidation states of the actinides. In the solid state, strongly basic compounds such as Cs 2 O yield complex oxides with oxidation states of Np(VII), Pu(VI), and Am(VI) whereas more acidic compounds such as CsF yield complex fluorides with lower oxidation states. In aqueous solution, high basicity and strongly covalent complexes favor high oxidation states. In nonaqueous solvent systems, high acidity generally favors low oxidation states. This paper elucidates and attempts to interpret the effects of these acid-base properties in a systematic fashion

  4. Studies on bismuth carboxylates—synthesis and characterization of ...

    Indian Academy of Sciences (India)

    synthesis and characterization of a new structural form of bismuth(III) dipicolinate ... 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 ...

  5. Synthesis, structural and property studies of bismuth containing perovskites

    OpenAIRE

    Chen, Wei-tin

    2009-01-01

    Several bismuth-containing transition metal perovskites that are of interest as potential multiferroic materials have been synthesised and studied. These materials have been structurally characterised and their physical properties have been examined at varying temperatures and pressures. The new series of substituted bismuth ferrite perovskites BixCa1-xFeO3, where x = 0.4 - 1.0, has been prepared. A disordered cubic phase (x = 0.4 - 0.67) and the coexistence of rhombohedral ...

  6. Effectiveness of Second through Sixth Line Salvage Helicobacter pylori Treatment: Bismuth Quadruple Therapy is Almost Always a Reasonable Choice.

    Science.gov (United States)

    Shaikh, Tahir; Fallone, Carlo A

    2016-01-01

    Aim. There is a paucity of data on the efficacy of empiric H. pylori treatment after multiple treatment failures. The aim of this study is to examine the efficacy of empiric salvage therapy as a second through sixth line treatment. Methods. In this single gastroenterology center prospective study in Montreal, Canada, patients with failed H. pylori treatment were offered empiric salvage therapy based on the patients' previous antibiotic exposure. Enrollment occurred after 1-5 previous failed attempts and eradication determined at least 4 weeks after completion of treatment. Results. 205 treatments were attempted in 175 patients using 7 different regimens. Eradication was achieved in 154 attempts (PP = 81% (154/191), ITT = 75% (154/205)). Bismuth quadruple therapy (BQT) had higher eradication success (PP = 91% (102/112), ITT = 84% (102/121)) when compared to all PPI triple therapies combined (PP = 66% (49/74), absolute risk reduction (ARR): 25% (95% CI: 13-37), ITT = 62% (49/79), ARR: 22% (95% CI: 10-35), and p bismuth and tetracycline exposure had a lower proportion of eradication compared to patients without such an exposure (PP: 60% (6/10) versus 95% (94/99), ARR: 35% (95% CI: 11-64), and p bismuth quadruple regimen is superior to triple therapies and is effective for second through fifth line empirical treatment (≥85% PP, ≥70% ITT). Successful eradication is significantly lower with BQT if a similar bismuth based regimen was used in the past.

  7. Synthesis and characterization of superconducting bismuthates

    International Nuclear Information System (INIS)

    Tang, Horngyi.

    1991-01-01

    A new electrosynthetic technique for low-temperature crystal growth of superconducting bismuthates was developed, and its utility demonstrated by growing various high-quality BiO 3 crystals. The crystals of Ba 1-x K x BiO 3 and Ba 1-x Rb x BiO 3 display their T c onset at 31.8k and 28k, respectively, using SQUID magnetometry. The structure of a KBiO 3 x H 2 O single crystal determined by single crystal x-ray diffraction confirms previous results from powder samples that it is isostructural with KSbO 3 . The crystals of Ba 1-x Cs x BiO 3 do not show superconductivity to 4k. Chemical vapor-transport experiments leading to the fabrication of MoS 2 /WSe 2 junctions were also performed and are described in detail

  8. Two-band induced superconductivity in single-layer graphene and topological insulator bismuth selenide

    Science.gov (United States)

    Talantsev, E. F.; Crump, W. P.; Tallon, J. L.

    2018-01-01

    Proximity-induced superconductivity in single-layer graphene (SLG) and in topological insulators represent almost ideal examples of superconductivity in two dimensions. Fundamental mechanisms governing superconductivity in the 2D limit are of central interest for modern condensed-matter physics. To deduce fundamental parameters of superconductor/graphene/superconductor and superconductor/bismuth selenide/superconductor junctions we investigate the self-field critical currents in these devices using the formalism of the Ambegaokar–Baratoff model. Our central finding is that the induced superconducting state in SLG and bismuth selenide each exhibits gapping on two superconducting bands. Based on recent results obtained on ultra-thin films of natural superconductors, including single-atomic layer of iron selenide, double and triple atomic layers of gallium, and several atomic layer tantalum disulphide, we conclude that a two-band induced superconducting state in SLG and bismuth selenide is part of a wider, more general multiple-band phenomenology of currently unknown origin.

  9. Strongly Enhanced Photovoltaic Performance and Defect Physics of Air-Stable Bismuth Oxyiodide (BiOI).

    Science.gov (United States)

    Hoye, Robert L Z; Lee, Lana C; Kurchin, Rachel C; Huq, Tahmida N; Zhang, Kelvin H L; Sponseller, Melany; Nienhaus, Lea; Brandt, Riley E; Jean, Joel; Polizzotti, James Alexander; Kursumović, Ahmed; Bawendi, Moungi G; Bulović, Vladimir; Stevanović, Vladan; Buonassisi, Tonio; MacManus-Driscoll, Judith L

    2017-09-01

    Bismuth-based compounds have recently gained increasing attention as potentially nontoxic and defect-tolerant solar absorbers. However, many of the new materials recently investigated show limited photovoltaic performance. Herein, one such compound is explored in detail through theory and experiment: bismuth oxyiodide (BiOI). BiOI thin films are grown by chemical vapor transport and found to maintain the same tetragonal phase in ambient air for at least 197 d. The computations suggest BiOI to be tolerant to antisite and vacancy defects. All-inorganic solar cells (ITO|NiO x |BiOI|ZnO|Al) with negligible hysteresis and up to 80% external quantum efficiency under select monochromatic excitation are demonstrated. The short-circuit current densities and power conversion efficiencies under AM 1.5G illumination are nearly double those of previously reported BiOI solar cells, as well as other bismuth halide and chalcohalide photovoltaics recently explored by many groups. Through a detailed loss analysis using optical characterization, photoemission spectroscopy, and device modeling, direction for future improvements in efficiency is provided. This work demonstrates that BiOI, previously considered to be a poor photocatalyst, is promising for photovoltaics. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Exchange Bias Effects in Iron Oxide-Based Nanoparticle Systems

    Science.gov (United States)

    Phan, Manh-Huong; Alonso, Javier; Khurshid, Hafsa; Lampen-Kelley, Paula; Chandra, Sayan; Stojak Repa, Kristen; Nemati, Zohreh; Das, Raja; Iglesias, Óscar; Srikanth, Hariharan

    2016-01-01

    The exploration of exchange bias (EB) on the nanoscale provides a novel approach to improving the anisotropic properties of magnetic nanoparticles for prospective applications in nanospintronics and nanomedicine. However, the physical origin of EB is not fully understood. Recent advances in chemical synthesis provide a unique opportunity to explore EB in a variety of iron oxide-based nanostructures ranging from core/shell to hollow and hybrid composite nanoparticles. Experimental and atomistic Monte Carlo studies have shed light on the roles of interface and surface spins in these nanosystems. This review paper aims to provide a thorough understanding of the EB and related phenomena in iron oxide-based nanoparticle systems, knowledge of which is essential to tune the anisotropic magnetic properties of exchange-coupled nanoparticle systems for potential applications. PMID:28335349

  11. Biomedical application of hierarchically built structures based on metal oxides

    Science.gov (United States)

    Korovin, M. S.; Fomenko, A. N.

    2017-12-01

    Nowadays, the use of hierarchically built structures in biology and medicine arouses much interest. The aim of this work is to review and summarize the available literature data about hierarchically organized structures in biomedical application. Nanoparticles can serve as an example of such structures. Medicine holds a special place among various application methods of similar systems. Special attention is paid to inorganic nanoparticles based on different metal oxides and hydroxides, such as iron, zinc, copper, and aluminum. Our investigations show that low-dimensional nanostructures based on aluminum oxides and hydroxides have an inhibitory effect on tumor cells and possess an antimicrobial activity. At the same time, it is obvious that the large-scale use of nanoparticles by humans needs to thoroughly study their properties. Special attention should be paid to the study of nanoparticle interaction with living biological objects. The numerous data show that there is no clear understanding of interaction mechanisms between nanoparticles and various cell types.

  12. Development and Testing of an Americium/Lanthanide Separation Flowsheet Using Sodium Bismuthate

    Energy Technology Data Exchange (ETDEWEB)

    Jack Law; Bruce Mincher; Troy Garn; Mitchell Greenhalgh; Nicholas Schmitt; Veronica Rutledge

    2014-04-01

    The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. A separation process amenable to process scale-up remains elusive. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series this separation is challenging ; however, higher oxidation states of americium can be prepared using sodium bismuthate and separated via solvent extraction using diamylamylphosphonate (DAAP) extraction. Among the other trivalent metals only Ce is also oxidized and extracted. Due to the long-term instability of Am(VI) , the loaded organic phase is readily selectively stripped to partition the actinide to a new acidic aqueous phase. Batch extraction distribution ratio measurements were used to design a flowsheet to accomplish this separation. Additionally, crossflow filtration was investigated as a method to filter the bismuthate solids from the feed solution prior to extraction. Results of the filtration studies, flowsheet development work and flowsheet performance testing using a centrifugal contactor are detailed.

  13. Selenide-Based Electrocatalysts and Scaffolds for Water Oxidation Applications

    KAUST Repository

    Xia, Chuan

    2015-11-05

    Selenide-based electrocatalysts and scaffolds on carbon cloth are successfully fabricated and demonstrated for enhanced water oxidation applications. A max­imum current density of 97.5 mA cm−2 at an overpotential of a mere 300 mV and a small Tafel slope of 77 mV dec−1 are achieved, suggesting the potential of these materials to serve as advanced oxygen evolution reaction catalysts.

  14. Bismuth(III) volatilization and immobilization by filamentous fungus Aspergillus clavatus during aerobic incubation.

    Science.gov (United States)

    Boriová, Katarína; Urík, Martin; Bujdoš, Marek; Matúš, Peter

    2015-02-01

    As with many metals, bismuth can be accumulated or transformed by microorganisms. These interactions affect microbial consortia and bismuth environmental behaviour, mobility, and toxicity. Recent research focused specifically on bismuth anaerobic transformation by bacteria and archaea has inspired the evaluation of the mutual interactions between bismuth and filamentous fungi as presented in this article. The Aspergillus clavatus fungus proved resistant to adverse effects from bismuth contamination in culture medium with up to a concentration of 195 µmol L(-1) during static 15- and 30-day cultivation. The examined resistance mechanism includes biosorption to the fungal surface and biovolatilization. Pelletized fungal biomass has shown high affinity for dissolved bismuth(III). Bismuth biosorption was rapid, reaching equilibrium after 50 min with a 0.35 mmol g(-1) maximum sorption capacity as calculated from the Langmuir isotherm. A. clavatus accumulated ≤70 µmol g(-1) of bismuth after 30 days. Preceding isotherm study implications that most accumulated bismuth binds to cell wall suggests that biosorption is the main detoxification mechanism. Accumulated bismuth was also partly volatilized (≤1 µmol) or sequestrated in the cytosol or vacuoles. Concurrently, ≤1.6 µmol of bismuth remaining in solution was precipitated by fungal activity. These observations indicate that complex mutual interactions between bismuth and filamentous fungi are environmentally significant regarding bismuth mobility and transformation.

  15. Advances in Base-Free Oxidation of Bio-Based Compounds on Supported Gold Catalysts

    Directory of Open Access Journals (Sweden)

    Robert Wojcieszak

    2017-11-01

    Full Text Available The oxidation of bio-based molecules in general, and of carbohydrates and furanics in particular, is a highly attractive process. The catalytic conversion of renewable compounds is of high importance. Acids and other chemical intermediates issued from oxidation processes have many applications related, especially, to food and detergents, as well as to pharmaceutics, cosmetics, and the chemical industry. Until now, the oxidation of sugars, furfural, or 5-hydroxymethylfurfural has been mainly conducted through biochemical processes or with strong inorganic oxidants. The use of these processes very often presents many disadvantages, especially regarding products separation and selectivity control. Generally, the oxidation is performed in batch conditions using an appropriate catalyst and a basic aqueous solution (pH 7–9, while bubbling oxygen or air through the slurry. However, there is a renewed interest in working in base-free conditions to avoid the production of salts. Actually, this gives direct access to different acids or diacids without laborious product purification steps. This review focuses on processes applying gold-based catalysts, and on the catalytic properties of these systems in the base-free oxidation of important compounds: C5–C6 sugars, furfural, and 5-hydroxymethylfurfural. A better understanding of the chemical and physical properties of the catalysts and of the operating conditions applied in the oxidation reactions is essential. For this reason, in this review we put emphasis on these most impacting factors.

  16. Fundamental study on reaction of lead-bismuth eutectic and sodium. Identification of reaction products and examination of reaction behavior

    International Nuclear Information System (INIS)

    Saito, Jun-ichi; Hirakawa, Yasushi

    2003-09-01

    A simplified secondary sodium cooling system utilizing lead-bismuth eutectic as an intermediate coolant has been selected as one of candidate systems for the 'Feasibility Studies on Commercialized Fast Reactor System'. In this study, fundamental reaction experiments have been performed to understand a reaction behavior between sodium and lead-bismuth. In order to identify the reaction products and to elucidate a reaction process, sampling and X-ray diffraction analysis of the reaction products are carried out. Following results are obtained. (1) The principal reaction products which formed in sodium and lead-bismuth ternary system are BiNa 3 and Pb 4 Na 15 intermetallic compounds. These two reaction products are identified irrespective of either primary sample content or sampling temperature. (2) Pb 3 Na intermetallic compound is identified in the reaction products for the first time. (3) The principal reaction product which formed in sodium and bismuth binary system is BiNa 3 intermetallic compound. (4) The reaction products which formed in sodium and lead binary system consist of various intermetallic compounds of sodium and lead system. Single phase of an intermetallic compound can not be obtained in this system. Based on these X-ray diffraction analyses, reaction process models of formation and dissolution are proposed. (author)

  17. Surface Preparation and Deposited Gate Oxides for Gallium Nitride Based Metal Oxide Semiconductor Devices

    Science.gov (United States)

    Long, Rathnait D.; McIntyre, Paul C.

    2012-01-01

    The literature on polar Gallium Nitride (GaN) surfaces, surface treatments and gate dielectrics relevant to metal oxide semiconductor devices is reviewed. The significance of the GaN growth technique and growth parameters on the properties of GaN epilayers, the ability to modify GaN surface properties using in situ and ex situ processes and progress on the understanding and performance of GaN metal oxide semiconductor (MOS) devices are presented and discussed. Although a reasonably consistent picture is emerging from focused studies on issues covered in each of these topics, future research can achieve a better understanding of the critical oxide-semiconductor interface by probing the connections between these topics. The challenges in analyzing defect concentrations and energies in GaN MOS gate stacks are discussed. Promising gate dielectric deposition techniques such as atomic layer deposition, which is already accepted by the semiconductor industry for silicon CMOS device fabrication, coupled with more advanced physical and electrical characterization methods will likely accelerate the pace of learning required to develop future GaN-based MOS technology.

  18. Promising iron oxide-based magnetic nanoparticles in biomedical engineering.

    Science.gov (United States)

    Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh; Vo, Toi Van; Lee, Beom-Jin

    2012-12-01

    For the past few decades biomedical engineering has imprinted its significant impact on the map of science through its wide applications on many other fields. An important example obviously proving this fact is the versatile application of magnetic nanoparticles in theranostics. Due to preferable properties such as biocompatibility, non-toxicity compared to other metal derivations, iron oxide-based magnetic nanoparticles was chosen to be addressed in this review. Aim of this review is to give the readers a whole working window of these magnetic nanoparticles in the current context of science. Thus, preparation of magnetic iron oxide nanoparticles with the so-far techniques, methods of characterizing the nanoparticles as well as their most recent biomedical applications will be stated.

  19. Thermal neutron detectors based on complex oxide crystals

    CERN Document Server

    Ryzhikov, V; Volkov, V; Chernikov, V; Zelenskaya, O

    2002-01-01

    The ways of improvement of spectrometric quality of CWO and GSO crystals have been investigated with the aim of their application in thermal neutron detectors based on radiation capture reactions. The efficiency of the neutron detection by these crystals was measured, and the obtained data were compared with the results for sup 6 LiI(Tl) crystals. It is shown that the use of complex oxide crystals and neutron-absorption filters for spectrometry of thermal and resonance neutrons could be a promising method in combination with computer data processing. Numerical calculations are reported for spectra of gamma-quanta due to radiation capture of the neutrons. To compensate for the gamma-background lines, we used a crystal pair of heavy complex oxides with different sensitivity to neutrons.

  20. A composite structure based on reduced graphene oxide and metal oxide nanomaterials for chemical sensors

    Directory of Open Access Journals (Sweden)

    Vardan Galstyan

    2016-10-01

    Full Text Available A hybrid nanostructure based on reduced graphene oxide and ZnO has been obtained for the detection of volatile organic compounds. The sensing properties of the hybrid structure have been studied for different concentrations of ethanol and acetone. The response of the hybrid material is significantly higher compared to pristine ZnO nanostructures. The obtained results have shown that the nanohybrid is a promising structure for the monitoring of environmental pollutants and for the application of breath tests in assessment of exposure to volatile organic compounds.

  1. [Determination of trace bismuth in iron, steel and alloy by hydride generation-atomic fluorimetry].

    Science.gov (United States)

    Liu, Q

    2000-02-01

    With the aid of hydride generation-atomic fluorimetry, an analysis method by adding thiosemicarbazide-ascorbic acid and phosphoric acid to eliminate the interference of matrix has been developed for the determination of trace bismuth in iron, steel and alloy. The detection limit is Bi = 0.02 microgram.g-1 (3 sigma, n = 11, sample amount 0.2000 g). The method has been applied to determine trace arsenic in middle and low alloy steel, ferro and nickel-based superalloy, nickel-based superalloy, cobalt-based superalloy, copper alloy with satisfactory results.

  2. Selective propene oxidation on mixed metal oxide catalysts

    International Nuclear Information System (INIS)

    James, David William

    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 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 'Sb 2 O 5 ' and FeSbO 4 , and a significant difference between these and the Sb 2 O 3 and Sb 2 O 4 phases, implying that the mixed oxide catalyst has a surface mainly comprised of Sb 5+ . The lack of reactivity of Sb 2 O 4 implies a similarity of the surface with

  3. Mixed conductivity in erbia-stabilized bismuth oxide

    NARCIS (Netherlands)

    Vinke, I.C.; Vinke, I.C.; Boukamp, Bernard A.; de Vries, K.J.; de Vries, Karel Jan; Burggraaf, Anthonie; Burggraaf, A.J.

    1992-01-01

    The mixed conducting solid solution 0.75Bi2O3−0.25Tb4O7 (BT40) was studied by impedance techniques using ionically blocking electrodes. These measurements confirmed the p-type electronic conductivity suggested in literature. In air at temperatures between 600 and 900 K the ionic transference number

  4. 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.

  5. Thin film bismuth iron oxides useful for piezoelectric devices

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    Zrodnikov, A.V.; Chitaykin, V.I.; Gromov, B.F.; Grigoryv, O.G.; Dedoul, A.V.; Toshinsky, G.I.; Dragunov, Yu.G.; Stepanov, V.S.

    2000-01-01

    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)

  7. 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.

  8. 75 FR 34360 - Listing of Color Additives Exempt From Certification; Bismuth Citrate; Confirmation of Effective...

    Science.gov (United States)

    2010-06-17

    .... FDA-2008-C-0098] Listing of Color Additives Exempt From Certification; Bismuth Citrate; Confirmation... final rule amended the color additive regulations by increasing the permitted use level of bismuth... permitted use level of bismuth citrate as a color additive in cosmetics intended for coloring hair on the...

  9. 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 the...

  10. 75 FR 14491 - Listing of Color Additives Exempt From Certification; Bismuth Citrate

    Science.gov (United States)

    2010-03-26

    .... FDA-2008-C-0098] Listing of Color Additives Exempt From Certification; Bismuth Citrate AGENCY: Food... amending the color additive regulations to increase the permitted use level of bismuth citrate as a color..., Alexandria, VA 22314. The petition proposed to amend the color additive regulations in Sec. 73.2110 Bismuth...

  11. The inhibitory effect of colloidal bismuth hydroxide gel on Escherichia coli O157:H7 and on the activity of Shiga toxins.

    Science.gov (United States)

    Subils, Tomás; Casabonne, Cecilia; Balagué, Claudia

    2014-12-04

    Shiga toxin-producing Escherichia coli (STEC) is the causative agent of hemolytic uremic syndrome (HUS). Colloidal bismuth hydroxide gel (CBHG) is an anti-diarrheal and antisecretory compound, which does not inhibit gastrointestinal motility and reaches an in vivo gut concentration of 10.8 mg/ml of bismuth. Its action on bacteria has not been studied. We analyzed its inhibitory effects on STEC, as well as the deactivation of the Shiga toxin (Stx) and its ability to block the spread of genes encoding Stx. We determined a minimum inhibitory concentration and bactericidal concentration for the STEC O157:H7 strain (EDL933), with CBHG and Chobet® bismuth cream with pectin (CBCHP). We analyzed its effect on Stx by means of cytotoxicity assay and ELISA, as well as its effect on the free 933 W Stx phage. Effect on the EDL933 strain: CBHG: MIC 10 mg/ml of bismuth. MIC 6 mg/ml and MBC 15 mg/ml of bismuth. Effect on EDL933 virulence factors: significant decrease in active Stx and 933 W Stx phage titer. ELISA did not find significant differences with treatment. The results obtained may be useful in the development of new therapeutic strategies based on the use of CBHG to prevent or improve the prognosis of HUS, as it can be used to control STEC infections.

  12. Sensitive electrochemical detection of nitric oxide based on AuPt and reduced graphene oxide nanocomposites.

    Science.gov (United States)

    Liu, Zhonggang; Forsyth, Heidi; Khaper, Neelam; Chen, Aicheng

    2016-06-20

    Since nitric oxide (NO) plays a critical role in many biological processes, its precise detection is essential toward an understanding of its specific functions. Here we report on a facile and environmentally compatible strategy for the construction of an electrochemical sensor based on reduced graphene oxide (rGO) and AuPt bimetallic nanoparticles. The prepared nanocomposites were further employed for the electroanalysis of NO using differential pulse voltammetry (DPV) and amperometric methods. The dependence of AuPt molar ratios on the electrochemical performance was investigated. Through the combination of the advantages of the high conductivity from rGO and highly electrocatalytic activity from AuPt bimetallic nanoparticles, the AuPt-rGO based NO sensor exhibited a high sensitivity of 7.35 μA μM(-1) and a low detection limit of 2.88 nM. Additionally, negligible interference from common ions or organic molecules was observed, and the AuPt-rGO modified electrode demonstrated excellent stability. Moreover, this optimized electrochemical sensor was practicable for efficiently monitoring the NO released from rat cardiac cells, which were stimulated by l-arginine (l-arg), showing that stressed cells generated over 10 times more NO than normal cells. The novel sensor developed in this study may have significant medical diagnostic applications for the prevention and monitoring of disease.

  13. Performance limitations of polymer electrolytes based on ethylene oxide polymers

    International Nuclear Information System (INIS)

    Buriez, Olivier; Han, Yong Bong; Hou, Jun; Kerr, John B.; Qiao, Jun; Sloop, Steven E.; Tian, Minmin; Wang, Shanger

    1999-01-01

    Studies of polymer electrolyte solutions for lithium-polymer batteries are described. Two different salts, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium trifluoromethanesulfonate (LiTf), were dissolved in a variety of polymers. The structures were all based upon the ethylene oxide unit for lithium ion solvation and both linear and comb-branch polymer architectures have been examined. Conductivity, salt diffusion coefficient and transference number measurements demonstrate the superior transport properties of the LiTFSI salt over LiTf. Data obtained on all of these polymers combined with LiTFSI salts suggest that there is a limit to the conductivity achievable at room temperature, at least for hosts containing ethylene oxide units. The apparent conductivity limit is 5 x 10-5 S/cm at 25 C. Providing that the polymer chain segment containing the ethylene oxide units is at least 5-6 units long there appears to be little influence of the polymer framework to which the solvating groups are attached. To provide adequate separator function, the mechanical properties may be disconnected from the transport properties by selection of an appropriate architecture combined with an adequately long ethylene oxide chain. For both bulk and interfacial transport of the lithium ions, conductivity data alone is insufficient to understand the processes that occur. Lithium ion transference numbers and salt diffusion coefficients also play a major role in the observed behavior and the transport properties of these polymer electrolyte solutions appear to be quite inadequate for ambient temperature performance. At present, this restricts the use of such systems to high temperature applications. Several suggestions are given to overcome these obstacles

  14. Bismuth X-ray absorber studies for TES microcalorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Sadleir, J.E. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States) and University of Illinois Physics Department, Urbana, IL 61801 (United States)]. E-mail: sadleir@milkyway.gsfc.nasa.gov; Bandler, S.R. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brekosky, R.P. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Chervenak, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Figueroa-Feliciano, E. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Finkbeiner, F. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Iyomoto, N. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelley, R.L. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kilbourne, C.A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); King, J.M. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Porter, F.S. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Robinson, I.K. [University of Illinois Physics Department, Urbana, IL 61801 (United States); Saab, T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Talley, D.J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2006-04-15

    Bismuth's large atomic number and low carrier density makes it an attractive X-ray absorber material for microcalorimeters. Bismuth's long Fermi wavelength and long mean free paths have motivated much interest in the fabrication of high quality bismuth films to study quantum size effects. Despite such incentives, fabrication of high quality bismuth films has proven difficult, and measured properties of such films are highly variable in the literature. Implementing a bismuth deposition process for TES (superconducting Transition Edge Sensor) device fabrication presents additional challenges particularly at interfaces due to the inherent granularity and surface roughness of its films, its low melting point, and its tendency to diffuse and form undesired intermetallic phases. We report observations of Bi-Cu and Bi-Au diffusion in our devices correlating with large shifts in T{sub c} (superconducting transition temperature). Using SEM and in situ R vs T annealing experiments we have been able to study these diffusion processes and identify their activation temperatures.

  15. Controlled synthesis of bismuth oxyiodide toward optimization of photocatalytic performance

    International Nuclear Information System (INIS)

    Liao, Chenxing; Ma, Zhijun; Chen, Xiaofeng; He, Xin; Qiu, Jianrong

    2016-01-01

    Highlights: • Different bismuth oxyiodide was synthesized. • The hollow Bi 4 O 5 I 2 microspheres was obtained. • Formation mechanism of the hollow structure was discussed in detail. - Abstract: A new investigation on the variation rule of the structure, morphology, chemical composition and photocatalytic performance of bismuth oxyiodide synthesized by solvothermal method as a function of reaction conditions was performed here. The composition and morphology of the product could be determined by X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The results revealed that the particle size together with content of iodide in bismuth oxyiodide decrease with the increase of the concentration of reaction precursors. Hollow Bi 4 O 5 I 2 microsphere with specific surface area as high as 120.88 m 2 g −1 can be easily synthesized when the concentration of the reaction precursors finally increased to 62.5 mM. Photocatalytic water purification performance of the as-prepared samples was evaluated by using Rhodamine B (RhB) as a model contaminant. The results revealed that the hollow Bi 4 O 5 I 2 exhibited the best performance among all the bismuth oxyodide synthesized here for the degradation of RhB under visible light irradiation. Meanwhile, the formation mechanism of the hierarchical hollow structure of bismuth oxyiodide was investigated by the dissolution-recrystallization mechanism.

  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. Study on Zinc Oxide-Based Electrolytes in Low-Temperature Solid Oxide Fuel Cells.

    Science.gov (United States)

    Xia, Chen; Qiao, Zheng; Feng, Chu; Kim, Jung-Sik; Wang, Baoyuan; Zhu, Bin

    2017-12-28

    Semiconducting-ionic conductors have been recently described as excellent electrolyte membranes for low-temperature operation solid oxide fuel cells (LT-SOFCs). In the present work, two new functional materials based on zinc oxide (ZnO)-a legacy material in semiconductors but exceptionally novel to solid state ionics-are developed as membranes in SOFCs for the first time. The proposed ZnO and ZnO-LCP (La/Pr doped CeO₂) electrolytes are respectively sandwiched between two Ni 0.8 Co 0.15 Al 0.05 Li-oxide (NCAL) electrodes to construct fuel cell devices. The assembled ZnO fuel cell demonstrates encouraging power outputs of 158-482 mW cm -2 and high open circuit voltages (OCVs) of 1-1.06 V at 450-550 °C, while the ZnO-LCP cell delivers significantly enhanced performance with maximum power density of 864 mW cm -2 and OCV of 1.07 V at 550 °C. The conductive properties of the materials are investigated. As a consequence, the ZnO electrolyte and ZnO-LCP composite exhibit extraordinary ionic conductivities of 0.09 and 0.156 S cm -1 at 550 °C, respectively, and the proton conductive behavior of ZnO is verified. Furthermore, performance enhancement of the ZnO-LCP cell is studied by electrochemical impedance spectroscopy (EIS), which is found to be as a result of the significantly reduced grain boundary and electrode polarization resistances. These findings indicate that ZnO is a highly promising alternative semiconducting-ionic membrane to replace the electrolyte materials for advanced LT-SOFCs, which in turn provides a new strategic pathway for the future development of electrolytes.

  18. Enhancement of the thermoelectric performance of oxygen substituted bismuth telluride

    Science.gov (United States)

    Van Quang, Tran; Kim, Miyoung

    2017-12-01

    We carried out first-principles calculations based on density functional theory and the semi-classical Boltzmann transport theory to study the effect of oxygen substitution on the electronic structure and thermoelectric properties of bismuth telluride. The newly formed compound, Bi2O2Te, is found to be a narrow bandgap semiconductor with the bandgap of Eg = 0.13 eV. The presence of a flat band close to the valence band maximum gives rise to a steep slope of density of states near Fermi energy, leading to a significant enhancement of the Seebeck coefficient. As a result, the thermoelectric power factor of Bi2O2Te is significantly improved by controlling the carrier concentration, and the maximum power factor increased with temperature. Assuming the experiment-thermal conductivity, Bi2O2Te exhibits a high figure of merit of ZT ˜1.27 around 600 K for the p-type doping, which matches or exceeds ZT of the state-of-the-art thermoelectric materials in this temperature range. This suggests that Bi2O2Te with p-type doping is a new promising material for use in the moderate-temperature thermoelectric energy conversion.

  19. 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.

  20. Iron oxide-based nanomagnets in nanomedicine: fabrication and applications

    Directory of Open Access Journals (Sweden)

    Meng Meng Lin

    2010-02-01

    Full Text Available Iron oxide-based nanomagnets have attracted a great deal of attention in nanomedicine over the past decade. Down to the nanoscale, superparamagnetic iron oxide nanoparticles can only be magnetized in the presence of an external magnetic field, which makes them capable of forming stable colloids in a physio-biological medium. Their superparamagnetic property, together with other intrinsic properties, such as low cytotoxicity, colloidal stability, and bioactive molecule conjugation capability, makes such nanomagnets ideal in both in-vitro and in-vivo biomedical applications. In this review, a chemical, physical, and biological synthetic approach to prepare iron oxide-based nanomagnets with different physicochemical properties was illustrated and compared. The growing interest in iron oxide-based nanomagnets with multifunctionalities was explored in cancer diagnostics and treatment, focusing on their combined roles in a magnetic resonance contrast agent, hyperthermia, and magnetic force assisted drug delivery. Iron oxides as magnetic carriers in gene therapy were reviewed with a focus on the sophisticated design and construction of magnetic vectors. Finally, the iron oxide-based nanomagnet also represents a very promising tool in particle/cell interfacing in controlling cellular functionalities, such as adhesion, proliferation, differentiation, and cell patterning, in stem cell therapy and tissue engineering applications. Meng Meng Lin received a BSc in biotechnology at the University of Hong Kong, China in 2004 and an MSc in biomedical nanotechnology at Newcastle University, UK, in 2005. She is currently working toward her PhD at the Institute of Science and Technology in Medicine, Keele University, UK. She was a visiting student at the Royal Institute of Technology, Sweden, in 2006. Her research interests include nanoparticles preparation, cell/nanomaterials interface, and cancer-oriented drug delivery. Hyung-Hwan Kim received an MSc degree in

  1. Elaboration of aluminum oxide-based graphite containing castables

    Science.gov (United States)

    Zhou, Ningsheng

    The aim of this work was set to develop effective and practicable new methods to incorporate natural flake graphite (FG) into the Al2O 3 based castables for iron and steel making applications. Three approaches, viz. micro-pelletized graphite (PG), crushed briquette of Al2O3-graphite (BAG) and TiO2 coated graphite (CFG), have been developed to insert flake graphite into Al2O 3 rich Al2O3-SiC based and Al2O 3-MgO based castables. These approaches were put into effect as countermeasures against the problems caused by FG in order: (1) to agglomerate the FG powders so as to decrease the specific surface area; (2) to diminish the density difference by using crushed carbon bonded compact of oxide-FG mixture; (3) to modify the surface of the flake graphite by forming hydrophilic coating; (4) to control the dispersion state of the graphite in the castable to maintain enough bonding strength; and (5) to use appropriate antioxidants to inhibit the oxidation of FG. The whole work was divided into two stages. In stage one, Al2O 3-SiC-C castables were dealt with to compare 4 modes of inserting graphite, i.e., by PG, BAG, CFG and FG. Overall properties were measured, all in correlation with graphite amount and incorporating mode. In stage two, efforts were made to reduce water demand in the Al2O3-MgO castables system. For this purpose, the matrix portion of the castable mixes was extracted and a coaxial double cylinder viscometer was adopted to investigate rheological characteristics of the matrix slurries vs. 4 kinds of deflocculants, through which the best deflocculant and its appropriate amount were found. Efforts were then made to add up to 30% MgO into the castables, using a limited amount of powders (antioxidants, Si, SiC, B4C and ZrB2, were added respectively or in combination. Overall properties of the castables, were investigated in correlation with MgO amount and graphite and antioxidant packages. Optimization work on oxidation and slag resistance was pursued. Finally

  2. Electrical Characteristics of MnO2 Doped Bismuth Borate Glass Systems

    Science.gov (United States)

    Nissar, Umair; Ahmad, Javed; Rana, Anwar Manzoor; Bukhari, S. H.; Jamil, M. T.; Khan, J. Alam; Shakeel, R.; Nadeem, M. Y.

    2018-02-01

    Transparent glasses have a large number of applications in the industry of electronics as well as optical devices. xMnO2-(25- x) Bi2O3-75H3BO3 (0 ≤ x ≤ 1.5 mol.%) transparent glasses have been prepared via melt-quench technique and characterized using dc electrical measurements, and by analyzing x-ray diffraction and Fourier transform infrared (FTIR) spectra. These characteristics were examined to understand the role of modifier oxides, i.e., Bi2O3 and MnO2 in the B2O3 glass network. Adding MnO2 into a glass network causes structural changes, which are responsible for any variations in electrical characteristics of bismuth borate glasses. Manganese bismuth borate glasses (MBBG) show Ohmic conduction at low fields; however, glasses with higher manganese content seem to conduct through bulk limited Poole-Frenkel mechanism. FTIR spectroscopy analyses depict the presence of BO3 and BO4 groups along with B-O-B and Bi-O-Bi bonding vibrations. Glasses with higher MnO2 content also show Mn-O bond vibrations. The reduction of BO4 groups and increase of BO3 units lead to the formation of non-bridging oxygens (NBOs) which are responsible for the variations in the electrical properties of these glasses.

  3. Powder of a copper oxide superconductor precursor, fabrication process and use for the preparation of superconducting oxide

    International Nuclear Information System (INIS)

    Dehaudt, P.

    1990-01-01

    The precursor powder comprises at least a copper compound (hydroxide, oxide and hydroxynitrates), at least a rare earth and/or yttrium compound (nitrates, hydroxides and hydroxynitrates) or bismuth oxide and at least an alkaline earth nitrate. It can be prepared by atomization drying of a suspension a copper precipitate or coprecipitate and other elements of the superconducting oxide in solution [fr

  4. Electrochemical oxidation of organic carbonate based electrolyte solutions at lithium metal oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, R.; Novak, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The oxidative decomposition of carbonate based electrolyte solutions at practical lithium metal oxide composite electrodes was studied by differential electrochemical mass spectrometry. For propylene carbonate (PC), CO{sub 2} evolution was detected at LiNiO{sub 2}, LiCoO{sub 2}, and LiMn{sub 2}O{sub 4} composite electrodes. The starting point of gas evolution was 4.2 V vs. Li/Li{sup +} at LiNiO{sub 2}, whereas at LiCoO{sub 2} and LiMn{sub 2}O{sub 4}, CO{sub 2} evolution was only observed above 4.8 V vs. Li/Li{sup +}. In addition, various other volatile electrolyte decomposition products of PC were detected when using LiCoO{sub 2}, LiMn{sub 2}O4, and carbon black electrodes. In ethylene carbonate / dimethyl carbonate, CO{sub 2} evolution was only detected at LiNiO{sub 2} electrodes, again starting at about 4.2 V vs. Li/Li{sup +}. (author) 3 figs., 2 refs.

  5. Nanoarchitectures in dye-sensitized solar cells: metal oxides, oxide perovskites and carbon-based materials.

    Science.gov (United States)

    Shaikh, Jasmin S; Shaikh, Navajsharif S; Mali, Sawanta S; Patil, Jyoti V; Pawar, Krishna K; Kanjanaboos, Pongsakorn; Hong, Chang Kook; Kim, J H; Patil, Pramod S

    2018-03-15

    Dye-sensitized solar cells (DSSCs) have aroused great interest and been regarded as a potential renewable energy resource among the third-generation solar cell technologies to fulfill the 21 st century global energy demand. DSSCs have notable advantages such as low cost, easy fabrication process and being eco-friendly in nature. The progress of DSSCs over the last 20 years has been nearly constant due to some limitations, like poor long-term stability, narrow absorption spectrum, charge carrier transportation and collection losses and poor charge transfer mechanism for regeneration of dye molecules. The main challenge for the scientific community is to improve the performance of DSSCs by using different approaches, like finding new electrode materials with suitable nanoarchitectures, dyes in composition with promising semiconductors and metal quantum dot fluorescent dyes, and cost-effective hole transporting materials (HTMs). This review focuses on DSSC photo-physics, which includes charge separation, effective transportation, collection and recombination processes. Different nanostructured materials, including metal oxides, oxide perovskites and carbon-based composites, have been studied for photoanodes, and counter electrodes, which are crucial to achieve DSSC devices with higher efficiency and better stability.

  6. 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.

  7. Melting and solidification of bismuth inclusions in aluminium

    DEFF Research Database (Denmark)

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

    1995-01-01

    Supercooling of crystalline bismuth inclusions in aluminium crystals has been observed and studied with different techniques: x-ray diffraction, in situ Rutherford backscattering/channelling spectrometry and transmission electron microscopy. The results of the measurements with different experime......Supercooling of crystalline bismuth inclusions in aluminium crystals has been observed and studied with different techniques: x-ray diffraction, in situ Rutherford backscattering/channelling spectrometry and transmission electron microscopy. The results of the measurements with different...... 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...

  8. Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation

    Science.gov (United States)

    Liu, Mingzhao; Nam, Chang-Yong; Zhang, Lihua

    2015-01-01

    Here a seedless and template-free technique is demonstrated to scalably grow bismuth nanowires, through thermal evaporation in high vacuum at RT. Conventionally reserved for the fabrication of metal thin films, thermal evaporation deposits bismuth into an array of vertical single crystalline nanowires over a flat thin film of vanadium held at RT, which is freshly deposited by magnetron sputtering or thermal evaporation. By controlling the temperature of the growth substrate the length and width of the nanowires can be tuned over a wide range. Responsible for this novel technique is a previously unknown nanowire growth mechanism that roots in the mild porosity of the vanadium thin film. Infiltrated into the vanadium pores, the bismuth domains (~ 1 nm) carry excessive surface energy that suppresses their melting point and continuously expels them out of the vanadium matrix to form nanowires. This discovery demonstrates the feasibility of scalable vapor phase synthesis of high purity nanomaterials without using any catalysts. PMID:26709727

  9. Bismuth distribution in InSb/Bi epitaxial layers

    International Nuclear Information System (INIS)

    Lantsov, A.F.; Akchurin, R.Kh.; Zinov'ev, V.G.

    1981-01-01

    Bismuth distribution in epitaxial layers of InSb/Bi, prepared by liquid-phase epitaxy (LPE) on InSb sublayers, is studied. The solution-melt, crystallization is carried out from the compositions corresponded to the cross sections InSb-Bi, InSb-InBi and InSb-In 2 Bi of ternary system In-Sb-Bi and changed in the limits, determined by the state diagram liquidus in the temperature range from 220 to 450 deg C. The temperature dependence of the coefficients of bismuth distribution in epitaxial layers of InSb(Bi) is specified. The dependence of bismuth concentration on the composition of initial liquid phase is established [ru

  10. Green Emission of Tellurite Based Glass Containing Erbium Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Azlan Muhammad Noorazlan

    2015-01-01

    Full Text Available Investigation on green emission and spectral intensity of tellurite based glass containing erbium oxide NPs is one of the crucial issues. Tellurite based glass containing erbium oxide NPs with the composition of {[(TeO20.70(B2O30.30]0.7(ZnO0.3}0.95(Er2O30.05 has been prepared by using conventional melt-quenching method. The structural and optical properties of the glass sample were characterized by using XRD, FTIR, UV-Vis absorption, and PL spectroscopy. The amorphous structural arrangement was proved through XRD method. The formation of TeO3 and BO3 units was revealed by FTIR analysis. Five transition states of excitation were shown in UV-Vis spectra which arise from the ground state 4I15/2 to the excited states 4G11/2 + 2H9/2 + 4F5/2 + 4F7/2 + 2H11/2 + 4S3/2 + 4F9/2 + 4I9/2 + 4I11/2. The intensity parameters Ωt (t=2, 4, 6 are calculated and follow the trend of Ω2>Ω4>Ω6. Broad green emission at 559 nm under 385 nm excitation was obtained.

  11. Nanostructured Titanium Oxide Film- And Membrane-Based Photocatalysis For Water Treatment

    Science.gov (United States)

    Titanium Oxide (TiO2) photocatalysis, one of the ultraviolet (UV)-based advanced oxidation technologies (AOTs) and nanotechnologies (AONs), has attracted great attention for the development of efficient water treatment and purification systems due to the effectiveness ...

  12. Effect of the Different High Volume Fraction of SiC Particles on the Junction of Bismuthate Glass-SiCp/Al Composite

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2018-01-01

    Full Text Available The in-house developed bismuthate glass and the SiCp/Al composites with different volume fractions of SiC particles (namely, 60 vol.%, 65 vol.%, 70 vol.%, and 75 vol.% were jointed by vacuum hot-pressing process. The novel material can be used for the space mirror. The SiCp is an abbreviation for SiC particle. Firstly, the SiCp/Al composites with different vol.% of SiC particle were manufactured by using infiltration process. In order to obtain a stable bonding interface, the preoxide layers were fabricated on the surfaces of these composites for reacting with the bismuthate glass. The coefficient of thermal expansion (CTE was carried out for characterizing the difference between the composites and bismuthate glass. The sealing quality of the composites and the bismuthate glass was quantified by using shear strength testing. The optical microstructures showed the particles were uniformly distributed in the Al matrix. The SEM image shows that a smooth oxidation layer was generated on the SiCp/Al composite. The CTE testing result indicated that the higher the vol.% of the particles in the composite, the lower the CTE value. The shear strength testing result disclosed that SiCp/Al composite with relatively low CTE value was favorable to obtain a bonding interface with high strength.

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

    International Nuclear Information System (INIS)

    Zhao Yue; Liu Hong; Liu Jin; Hu Chenguo; Wang Jiyang

    2010-01-01

    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.

  14. Optical properties of bismuth-doped silica fibres in the temperature range 300 — 1500 K

    International Nuclear Information System (INIS)

    Dvoretskii, D A; Bufetov, Igor' A; Vel'miskin, V V; Zlenko, Alexander S; Khopin, V F; Semjonov, S L; Guryanov, Aleksei N; Denisov, L K; Dianov, Evgenii M

    2012-01-01

    The visible and near-IR absorption and luminescence bands of bismuth-doped silica and germanosilicate fibres have been measured for the first time as a function of temperature. The temperature-dependent IR luminescence lifetime of a bismuth-related active centre associated with silicon in the germanosilicate fibre has been determined. The Bi 3+ profile across the silica fibre preform is shown to differ markedly from the distribution of IR-emitting bismuth centres associated with silicon. The present results strongly suggest that the IR-emitting bismuth centre comprises a lowvalence bismuth ion and an oxygen-deficient glass network defect. (optical fibres, lasers and amplifiers. properties and applications)

  15. Influence of reaction conditions on formation of ionic liquid-based nanostructured Bi2O3 as an efficient visible-light-driven photocatalyst

    Science.gov (United States)

    Bagheri, Mozhgan; Heydari, Mojgan; Vaezi, Mohammad Reza

    2018-01-01

    In this study, nanostructured bismuth oxide was synthesized based on the chemical reaction of bismuth nitrate and NaOH in the ionic liquid 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) under ultrasonic irradiation. The effect of sodium hydroxide with a different molar ratio of NaOH to bismuth in the range of 3-10 was investigated. The results of fourier-transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) showed that NaOH has a critical role in the formation of pure α-Bi2O3. So, at high concentrations of NaOH (NaOH:Bi ≥ 7.5), the chloride anion from the ionic liquid cannot be entered into the crystalline structure of bismuth oxide, which resulted in the formation of pure bismuth oxide, while at lower concentrations of NaOH (NaOH:Bi ≤ 5), Bi3O4Cl was formed with a layered structure. The XRD results revealed that the synthesized α-Bi2O3 has a monoclinic structure and scanning electron microscopy (SEM) images showed that the sample consists of needle like particles with an average thickness of 50 nm. The ionic liquid has an important role in the prevention of an agglomeration of particles in the Bi2O3 sample. The photocatalytic activity of the synthesized Bi2O3 was investigated to study the degradation of malachite green dye as a model pollutant under visible light. The effects of various parameters such as the pH, concentration of the dye, and the catalyst on the degradation of malachite green were also investigated.

  16. Microscopic and voltammetric properties of lustrous bismuth deposits

    OpenAIRE

    Krolicka, Agnieszka; Bobrowski, Andrzej; Pamuła, Elżbieta

    2010-01-01

    A comparison of lustrous bismuth films, plated at glassy carbon, platinum and gold supports, is presented. The voltammetric performance of preplated bismuth film electrodes was tested using 50 μg/L In(III) and 50 μg/L Pb(II) solutions in 0.1 M acetic buffer in square wave and differential pulse modes. The influence of support material, plating solution concentration and storing conditions on the voltammetric response of BiFEs is discussed. The results of microscopic examination...

  17. Modelling of the partial oxidation of {alpha}, {beta}-unsaturated aldehydes on Mo-V-oxides based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, H.; Petzoldt, J.C.; Stein, B.; Weimer, C.; Gaube, J.W. [Technische Univ. Darmstadt (Germany). Inst. fuer Chemische Technologie

    1998-12-31

    A kinetic model based on the Mars-van Krevelen mechanism that allows to describe the microkinetics of the heterogeneously catalysed partial oxidation of {alpha}, {beta}-unsaturated aldehydes is presented. This conversion is represented by a network, composed of the oxidation of the {alpha}, {beta}-unsaturated aldehyde towards the {alpha}, {beta}-unsaturated carboxylic acid and the consecutive oxidation of the acid as well as the parallel reaction of the aldehyde to products of deeper oxidation. The reaction steps of aldehyde respectively acid oxidation and catalyst reoxidation have been investigated separately in transient experiments. The combination of steady state and transient experiments has led to an improved understanding of the interaction of the catalyst with the aldehyde and the carboxylic acids as well as to a support of the kinetic model assumptions. (orig.)

  18. Superparamagnetic Iron Oxide Nanoparticle-Based Delivery Systems for Biotherapeutics

    Science.gov (United States)

    Mok, Hyejung; Zhang, Miqin

    2014-01-01

    Introduction Superparamagnetic iron oxide nanoparticle (SPION)-based carrier systems have many advantages over other nanoparticle-based systems. They are biocompatible, biodegradable, facilely tunable, and superparamagnetic and thus controllable by an external magnetic field. These attributes enable their broad biomedical applications. In particular, magnetically-driven carriers are drawing considerable interest as an emerging therapeutic delivery system because of their superior delivery efficiency. Area covered This article reviews the recent advances in use of SPION-based carrier systems to improve the delivery efficiency and target specificity of biotherapeutics. We examine various formulations of SPION-based delivery systems, including SPION micelles, clusters, hydrogels, liposomes, and micro/nanospheres, as well as their specific applications in delivery of biotherapeutics. Expert opinion Recently, biotherapeutics including therapeutic cells, proteins and genes have been studied as alternative treatments to various diseases. Despite the advantages of high target specificity and low adverse effects, clinical translation of biotherapeutics has been hindered by the poor stability and low delivery efficiency compared to chemical drugs. Accordingly, biotherapeutic delivery systems that can overcome these limitations are actively pursued. SPION-based materials can be ideal candidates for developing such delivery systems because of their excellent biocompatibility and superparamagnetism that enables long-term accumulation/retention at target sites by utilization of a suitable magnet. In addition, synthesis technologies for production of finely-tuned, homogeneous SPIONs have been well developed, which may promise their rapid clinical translation. PMID:23199200

  19. Polonium release from an ATW burner system with liquid lead-bismuth coolant

    International Nuclear Information System (INIS)

    Li, N.; Yefimov, E.; Pankratov, D.

    1998-04-01

    The authors analyzed polonium release hazards in a conceptual pool-type ATW burner with liquid lead-bismuth eutectic (LBE) coolant. Simplified quantitative models are used based on experiments and real NPP experience. They found little Po contamination outside the burner under normal operating conditions with nominal leakage from the gas system. In sudden gas leak and/or coolant spill accidents, the P contamination level can reach above the regulation limit but short exposure would not lead to severe health consequences. They are evaluating and developing mitigation methods

  20. Extension of the calibration of an NE-213 liquid scintillator based pulse height response spectrometer up to 18 MeV neutron energy and leakage spectrum measurements on bismuth at 8 MeV and 18 MeV neutron energies

    International Nuclear Information System (INIS)

    Fenyvesi, A.; Valastyan, I.; Olah, L.; Csikai, J.; Plompen, A.; Jaime, R.; Loevestam, G.; Semkova, V.

    2011-01-01

    Monoenergetic neutrons were produced at the Van de Graaff accelerator of the EC-JRC-Institute for Reference Materials and Measurements (IRMM, Geel, Belgium). An air-jet cooled D 2 -gas target (1.2 bar, ΔE d = 448 keV) was bombarded with E d =4976 keV deuterons to produce neutrons up to E n = 8 MeV energy via the D(d,n) 3 He reaction. Higher energy neutrons up to E n = 18 MeV were produced via the T(d,n) 4 He reaction by bombarding a TiT target with E d =1968 keV deuterons. Pulse height spectra were measured at different neutron energies from E n = 8 MeV up to E n = 18 MeV with the NE-213 liquid scintillator based Pulse Height Response Spectrometer (PHRS) of UD-IEP. The energy calibration of the PHRS system has been extended up to E n = 18 MeV. Pulse height spectra induced by gamma photons have been simulated by the GRESP7 code. Neutron induced pulse height spectra have been simulated by the NRESP7 and MCNP-POLIMI codes. Comparison of the results of measurements and simulations enables the improvement of the parameter set of the function used by us to describe the light output dependence of the resolution of the PHRS system at light outputs of L > 2 light units. Also, it has been shown that the derivation method for unfolding neutron spectra from measured pulse height spectra performs well when relative measurements are done up to E n = 18 MeV neutron energy. For matrix unfolding purposes, the NRESP7 code has to be preferred to calculate the pulse height response matrix of the PHRS system. Leakage spectra of neutrons behind bismuth slabs of different thicknesses have been measured with the PHRS system by using monoenergetic neutrons. The maximum slab thickness was d = 14 cm. Simulations of the measurements have been carried out with the MCNP-4c code. The necessary nuclear cross-sections were taken from the from the ENDF/B-VII and JEFF.3.1 data libraries. For both libraries, the agreement of measured and simulated neutron spectra is good for the 5 MeV ≤ En ≤ 18

  1. Writable electrochemical energy source based on graphene oxide

    Science.gov (United States)

    Wei, Di

    2015-10-01

    Graphene oxide (GO) was mainly used as raw material for various types of reduced graphene oxide (rGO) as a cost effective method to make graphene like materials. However, applications of its own unique properties such as extraordinary proton conductivity and super-permeability to water were overlooked. Here GO based battery-like planar energy source was demonstrated on arbitrary insulating substrate (e.g. polymer sheet/paper) by coating PEDOT, GO ink and rGO on Ag charge collectors. Energy from such GO battery depends on its length and one unit cell with length of 0.5 cm can generate energy capacity of 30 Ah/L with voltage up to 0.7 V when room temperature ionic liquid (RTIL) is added. With power density up to 0.4 W/cm3 and energy density of 4 Wh/L, GO battery was demonstrated to drive an electrochromic device. This work is the first attempt to generate decent energy using the fast transported water molecules inside GO. It provides very safe energy source that enables new applications otherwise traditional battery technology can not make including building a foldable energy source on paper and platform for futuristic wearable electronics. A disposable energy source made of GO was also written on a plastic glove to demonstrate wearability.

  2. A Structurally Based Viscosity Model for Oxide Melts

    Science.gov (United States)

    Zhang, Guo-Hua; Chou, Kuo-Chih; Mills, Ken

    2014-04-01

    A structurally based viscosity model is proposed to represent the viscosity of oxide melts as functions of both temperature and composition; The oxide melts cover the following constituents: Li2O, Na2O, K2O, MgO, CaO, SrO, BaO, FeO, MnO, Al2O3, SiO2, CaF2, TiO2, Fe2O3, and P2O5. The model describes the slag structure in terms of the various forms of oxygen ions which are classified according to the metal cations they bond with. Approximate methods for calculating the concentrations of these oxygen ions are proposed and are then used to describe the effect of melt structure on viscosity. The model provides a good description of the variations in viscosity with composition and temperature. The measured viscosities were compared with values calculated with the model, and the current model was found to provide reliable estimates of viscosities of slags used in various industrial processes ( e.g., blast furnace, basic oxygen steelmaking, ladle refining, continuous casting of steel, coal gasification, and electroslag remelting).

  3. Charge transport in metal oxide nanocrystal-based materials

    OpenAIRE

    Runnerstrom, Evan Lars

    2016-01-01

    There is probably no class of materials more varied, more widely used, or more ubiquitous than metal oxides. Depending on their composition, metal oxides can exhibit almost any number of properties. Of particular interest are the ways in which charge is transported in metal oxides: devices such as displays, touch screens, and smart windows rely on the ability of certain metal oxides to conduct electricity while maintaining visible transparency. Smart windows, fuel cells, and other electrochem...

  4. A physiologically based kinetic model for bacterial sulfide oxidation

    NARCIS (Netherlands)

    Klok, J.B.M.; Graaff, de C.M.; Bosch, van den P.L.F.; Boelee, N.C.; Keesman, K.J.; Janssen, A.J.H.

    2013-01-01

    In the biotechnological process for hydrogen sulfide removal from gas streams, a variety of oxidation products can be formed. Under natron-alkaline conditions, sulfide is oxidized by haloalkaliphilic sulfide oxidizing bacteria via flavocytochrome c oxidoreductase. From previous studies, it was

  5. Magnetic composites based on hybrid spheres of aluminum oxide and superparamagnetic nanoparticles of iron oxides

    International Nuclear Information System (INIS)

    Braga, Tiago P.; Vasconcelos, Igor F.; Sasaki, Jose M.; Fabris, J.D.; Oliveira, Diana Q.L. de; Valentini, Antoninho

    2010-01-01

    Materials containing hybrid spheres of aluminum oxide and superparamagnetic nanoparticles of iron oxides were obtained from a chemical precursor prepared by admixing chitosan and iron and aluminum hydroxides. The oxides were first characterized with scanning electron microscopy, X-ray diffraction, and Moessbauer spectroscopy. Scanning electron microscopy micrographs showed the size distribution of the resulting spheres to be highly homogeneous. The occurrence of nano-composites containing aluminum oxides and iron oxides was confirmed from powder X-ray diffraction patterns; except for the sample with no aluminum, the superparamagnetic relaxation due to iron oxide particles were observed from Moessbauer spectra obtained at 298 and 110 K; the onset six line-spectrum collected at 20 K indicates a magnetic ordering related to the blocking relaxation effect for significant portion of small spheres in the sample with a molar ratio Al:Fe of 2:1.

  6. Fano resonance in anodic aluminum oxide based photonic crystals.

    Science.gov (United States)

    Shang, Guo Liang; Fei, Guang Tao; Zhang, Yao; Yan, Peng; Xu, Shao Hui; Ouyang, Hao Miao; Zhang, Li De

    2014-01-08

    Anodic aluminum oxide based photonic crystals with periodic porous structure have been prepared using voltage compensation method. The as-prepared sample showed an ultra-narrow photonic bandgap. Asymmetric line-shape profiles of the photonic bandgaps have been observed, which is attributed to Fano resonance between the photonic bandgap state of photonic crystal and continuum scattering state of porous structure. And the exhibited Fano resonance shows more clearly when the sample is saturated ethanol gas than air-filled. Further theoretical analysis by transfer matrix method verified these results. These findings provide a better understanding on the nature of photonic bandgaps of photonic crystals made up of porous materials, in which the porous structures not only exist as layers of effective-refractive-index material providing Bragg scattering, but also provide a continuum light scattering state to interact with Bragg scattering state to show an asymmetric line-shape profile.

  7. Photothermally Driven Refreshable Microactuators Based on Graphene Oxide Doped Paraffin.

    Science.gov (United States)

    Hou, Sichao; Wang, Miao; Guo, Shouwu; Su, Ming

    2017-08-09

    Actuators based on phase change materials (paraffin) can simultaneously produce large stroke length and large force due to thermal expansion, but the low thermal conductivity of paraffin requires high power input and long actuation time. The graphene oxide (GO) doped paraffin dynamic actuator addresses the key challenges in the design of thermal phase change actuators: Thermal conductivity and light absorbing are increased, and the response time is reduced compared to the standard phase change actuator designed with metal heating resistors. The thermal properties of GO-paraffin composites with varied loading amount are characterized to confirm the optimal loading amount of 1.0%. A multicell phase change actuator was integrated into a digital micromirror controlled optical system. A series of photothermally driven refreshable patterns were generated and confirmed with infrared imaging.

  8. Hydrogen Gas Sensors Based on Semiconductor Oxide Nanostructures

    Directory of Open Access Journals (Sweden)

    Yongming Hu

    2012-04-01

    Full Text Available Recently, the hydrogen gas sensing properties of semiconductor oxide (SMO nanostructures have been widely investigated. In this article, we provide a comprehensive review of the research progress in the last five years concerning hydrogen gas sensors based on SMO thin film and one-dimensional (1D nanostructures. The hydrogen sensing mechanism of SMO nanostructures and some critical issues are discussed. Doping, noble metal-decoration, heterojunctions and size reduction have been investigated and proved to be effective methods for improving the sensing performance of SMO thin films and 1D nanostructures. The effect on the hydrogen response of SMO thin films and 1D nanostructures of grain boundary and crystal orientation, as well as the sensor architecture, including electrode size and nanojunctions have also been studied. Finally, we also discuss some challenges for the future applications of SMO nanostructured hydrogen sensors.

  9. Method for evaluation of doses from ingestion of polonium, bismuth and lead as natural radioactive material(NORM)

    International Nuclear Information System (INIS)

    Pena, Vanessa; Puerta, Anselmo; Morales, Javier

    2013-01-01

    In this work was carried out an evaluation of dose from ingestion of radioactive daughters of radon (lead, bismuth and polonium), taking into account ages from three months up to adult men, using the new model of the human alimentary tract HATM and methodology of calculating doses proposed by the ICRP publication 103, which allows the estimation of dose based on the concentration of the radionuclide present in the diet or in the water of consumption

  10. Multiscale mechanics of graphene oxide and graphene based composite films

    Science.gov (United States)

    Cao, Changhong

    The mechanical behavior of graphene oxide is length scale dependent: orders of magnitude different between the bulk forms and monolayer counterparts. Understanding the underlying mechanisms plays a significant role in their versatile application. A systematic multiscale mechanical study from monolayer to multilayer, including the interactions between layers of GO, can provide fundamental support for material engineering. In this thesis, an experimental coupled with simulation approach was used to study the multiscale mechanics of graphene oxide (GO) and the methods developed for GO study are proved to be applicable also to mechanical study of graphene based composites. GO is a layered nanomaterial comprised of hierarchical units whose characteristic dimension lies between monolayer GO (0.7 nm - 1.2 nm) and bulk GO papers (≥ 1 mum). Mechanical behaviors of monolayer GO and GO nanosheets (10 nm- 100 nm) were comprehensively studied this work. Monolayer GO was measured to have an average strength of 24.7 GPa,, orders of magnitude higher than previously reported values for GO paper and approximately 50% of the 2D intrinsic strength of pristine graphene. The huge discrepancy between the strength of monolayer GO and that of bulk GO paper motivated the study of GO at the intermediate length scale (GO nanosheets). Experimental results showed that GO nanosheets possess high strength in the gigapascal range. Molecular Dynamic simulations showed that the transition in the failure behavior from interplanar fracture to intraplanar fracture was responsible for the huge strength discrepancy between nanometer scale GO and bulk GO papers. Additionally, the interfacial shear strength between GO layers was found to be a key contributing factor to the distinct mechanical behavior among hierarchical units of GO. The understanding of the multiscale mechanics of GO is transferrable in heterogeneous layered nanomaterials, such as graphene-metal oxide based anode materials in Li

  11. Zinc oxide based dye sensitized solar cell using eosin – Y as ...

    African Journals Online (AJOL)

    A zinc oxide based Dye sensitized Solar Cell (DSSC) has been fabricated, using Eosin-Y as the dye adsorbed on a nanocrystalline zinc oxide - fluorine doped tin oxide electrode, for the sensitization of the large band gap semiconductor. The absorption spectrum of Eosin-Y showed high absorption of visible light between ...

  12. Study of oxidation behaviour of Zr-based bulk amorphous alloy Zr 65 ...

    Indian Academy of Sciences (India)

    The oxidation behaviour of Zr-based bulk amorphous alloy Zr65Cu17.5Ni10Al7.5 has been studied in air environment at various temperatures in the temperature range 591–684 K using a thermogravimetric analyser (TGA). The oxidation kinetics of the alloy in the amorphous phase obeys the parabolic rate law for oxidation ...

  13. 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 formation...

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

    International Nuclear Information System (INIS)

    Rajkovic, Ivan

    2008-01-01

    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.)

  15. Melting behaviour of lead and bismuth nano-particles in ...

    Indian Academy of Sciences (India)

    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 ...

  16. Tailoring the Bandgap and magnetic properties by Bismuth ...

    Indian Academy of Sciences (India)

    66

    refined with the single phase orthorhombic Pnma symmetry along with minor amount (< 2%) of Bi2O3. (nonmagnetic) impurity .The observations suggests that the solubility of Bismuth (Bi) in Nd site is lower than 15 at. % through our sol-gel processing technique. Single phase of NBiCO and the minimal change of lattice ...

  17. Crystal structure and ionic conductivity of a new bismuth tungstate,

    Indian Academy of Sciences (India)

    Unknown

    43. Dedicated to Prof J Gopalakrishnan on his 62nd birthday. *For correspondence. Crystal structure and ionic conductivity of a new bismuth tungstate,. Bi3W2O10⋅5. B MUKTHA and T N GURU ROW*. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 e-mail: ssctng@sscu.iisc.ernet.in.

  18. Poisoning effect of bismuth on modification behaviour of strontium in ...

    Indian Academy of Sciences (India)

    also be added to aluminum–magnesium alloys to counteract. ∗. Author for correspondence (saeedfarahany@gmail.com, fsaeed2@live.utm.my) the detrimental effect of sodium on hot cracking (Talbot and. Ransley 1997). Pillai and Anantharaman (1968) reported that bismuth could play a role as silicon modifier whereas ...

  19. 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.)

  20. Colloidal bismuth subcitrate in peptic ulcer--a review

    NARCIS (Netherlands)

    Tytgat, G. N.

    1987-01-01

    De-Nol (colloidal bismuth subcitrate, CBS) precipitates in an acid environment and adheres to the exudate layer covering an ulcer crater; moreover, CBS blocks pepsin activity, retards hydrogen-ion back-diffusion and stimulates prostaglandin synthesis. The average healing rate in duodenal ulcer (DU)

  1. 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

  2. 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...

  3. A Biological Approach for the Synthesis of Bismuth Nanoparticles: Using Thiolated M13 Phage as Scaffold.

    Science.gov (United States)

    Vera-Robles, L Irais; Escobar-Alarcón, Luis; Picquart, Michel; Hernández-Pozos, J Luis; Haro-Poniatowski, Emmanuel

    2016-04-05

    We report the synthesis of Bi nanoparticles (Bi NPs) using the M13 phage as scaffold. The p8 protein of the phage is functionalized with thiol groups of different lengths, and these thiolated regions act as nucleation centers for Bi(3+) ions. The size distribution, shape, and resilience to oxidation of the Bi NPs depend on the length of the thiol group used. The NPs are characterized by high resolution transmission electron microscopy, Raman, and IR spectroscopies, matrix assisted laser desorption/ionization, and optical absorption. These results show that the nanoparticles are crystalline and have a typical diameter of ∼3.0 nm. The method of preparation presented here is reproducible and implies "greener" conditions than those reported elsewhere. To the best of our knowledge, this is the first report of bismuth nanoparticles synthesized by a biomineralization method.

  4. Magneto-optical Faraday spectroscopy of completely bismuth-substituted Bi3Fe5O12 garnet thin films

    International Nuclear Information System (INIS)

    Deb, M; Popova, E; Fouchet, A; Keller, N

    2012-01-01

    We performed a magneto-optical (MO) Faraday spectroscopy study of bismuth iron garnet Bi 3 Fe 5 O 12 thin single-crystalline films with thickness from 5 to 220 nm. The Faraday rotation and ellipticity spectra were measured for photon energies ranging from 1.7 to 4.2 eV. Using a model based on two electric dipole transitions associated with tetrahedral and octahedral iron sites, we successfully reproduce the observed rotation and ellipticity spectra. The sign of both site contributions to the Faraday rotation and ellipticity spectra has been used to interpret the complex thermal dependence of the Faraday rotation and ellipticity. For a Faraday ellipticity, anomalous hysteresis loops have been observed around specific photon energies. To explain the surprising shape of hysteresis loop, a model based on the superposition of two hysteresis loops with opposite sign associated with both sites is proposed. The modelling of these hysteresis loops allows accessing the magnetic properties of each individual sublattice. Finally, we have studied the dependence of the energy level parameters on bismuth content in Yi 3-x Bi x Fe 5 O 12 garnet and on the thickness of bismuth iron garnet. Based on this analysis, we show that MO spectroscopy is a fast and non-destructive technique to determine the bi-deficiency of BIG films.

  5. Decoding nitric oxide release rates of amine-based diazeniumdiolates.

    Science.gov (United States)

    Wang, Yan-Ni; Collins, Jack; Holland, Ryan J; Keefer, Larry K; Ivanic, Joseph

    2013-08-01

    Amine-based diazeniumdiolates (NONOates) have garnered widespread use as nitric oxide (NO) donors, and their potential for nitroxyl (HNO) release has more recently been realized. While NO release rates can vary significantly with the type of amine, half-lives of seconds to days under physiological conditions, there is as yet no way to determine a priori the NO or HNO production rates of a given species, and no discernible trends have manifested other than that secondary amines produce only NO (i.e., no HNO). As a step to understanding these complex systems, here we describe a procedure for modeling amine-based NONOates in water solvent that provides an excellent correlation (R(2) = 0.94) between experimentally measured dissociation rates of seven secondary amine species and their computed NO release activation energies. The significant difference in behavior of NONOates in the gas and solvent phases is also rigorously demonstrated via explicit additions of quantum mechanical water molecules. The presented results suggest that the as-yet unsynthesized simplest amine-based NONOate, the diazeniumdiolated ammonia anion [H2N-N(O)═NO(-)], could serve as an unperturbed HNO donor. These results provide a step forward toward the accurate modeling of general NO and/or HNO donors as well as for the identification of tailored prodrug candidates.

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

    International Nuclear Information System (INIS)

    Portefaix, J.L.; Figueras, F.; Forissier, M.

    1980-01-01

    CD 2 CHCH 3 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 CD 2 CHCH 3 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-02-28

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

  8. Graphene Oxide as Reinforcement in Epoxy Based Nanocomposites.

    OpenAIRE

    Svendsen, Elizabeth Martine

    2014-01-01

    Graphene oxide has received much attention in recent years because of its many promising properties. Graphene oxide can be used to produce graphene in large quantities, and in addition graphene oxide has many promising properties itself, such as its high level of dispersion in polar solvents, and good compatibility with various polymers. Addition of nanoparticles in composite materials have been tested for many years, and in recent years carbon nanotubes have been in focus as a reinforcement....

  9. Aluminum oxide nanostructured microcantilever arrays for nanomechanical-based sensing.

    Science.gov (United States)

    Long, Zhou; Hill, Kasey; Sepaniak, Michael J

    2010-05-15

    Novel nanostructured microcantilever (MC) surfaces were developed by modifying the active side of the MCs with aluminum oxide nanoparticles (AONP) for purposes of enhancing sensitivity in nanomechanical-based sensing. Uniform layers of AONP were spin coated and chemically immobilized on the surfaces of MCs with tetramethoxysilane (TMOS) as a cross-linker. Optimization studies on MC modification were performed for better surface uniformity and higher surface area, based on scanning electron microscope (SEM) images. The AONP-modified MC array (MCA) were subsequently functionalized by being immersed in parallel configured capillaries filled with different reagents for immobilizing chemical or biological receptors onto the MC surfaces. A MCA prepared for chemical sensing was exposed to the samples made of headspace vapor of different volatile organic compounds (VOCs). The characteristic response signatures for each gas phase VOC analyte showed substantial diversity. Immersion time in the capillary and the chemical nature of the reagents used for functionalization were both optimized to achieve the highest sensitivity and long-term reproducibility in nanomechanical responses to the test analytes. A second MCA functionalized with two different immunological receptors was prepared and exposed to three biological analytes in the liquid phase, with a highly selective response obtained for each analyte. Fluorescence microscope images and FT-IR spectra were used in this work to validate the controlled, variable chemical nature of the MC surfaces.

  10. Bismuth subsalicylate nanoparticles with anaerobic antibacterial activity for dental applications

    Science.gov (United States)

    Vega-Jiménez, A. L.; Almaguer-Flores, A.; Flores-Castañeda, M.; Camps, E.; Uribe-Ramírez, M.; Aztatzi-Aguilar, O. G.; De Vizcaya-Ruiz, A.

    2017-10-01

    In recent years, nanomaterials have been used in the medical-dental field as new alternative antimicrobial agents. Bismuth subsalicylate (BSS) has been used as an antimicrobial agent, but the effect of BSS in the form of nanoparticles (BSS-nano) as a potential antimicrobial agent has not been tested, in specific against bacteria responsible for periodontal disease. The aim of this study was to evaluate the antibacterial effect of BSS-nano against oral anaerobic bacteria and to assess the safety of BSS-nano by evaluating their cytotoxicity in human gingival fibroblast (HGF-1) cells. BSS-nano were synthesized by laser ablation and were previously physico-chemically characterized using in vitro assays. The antibacterial activity was measured using the tetrazolium-based XTT assay, and cytotoxicity was determined using lactate dehydrogenase (LDH) and MTS assays in HGF-1 cells. Transmission electron microscopy of HGF-1 exposed to BSS-nano was also performed. BSS-nano was shown to have a primary size of 4-22 nm and a polygonal shape. Among the tested bacterial strains, those with a greater sensitivity to BSS-nano (highest concentration of 21.7 μg ml-1) were A. actinomycetemcomitans, C. gingivalis, and P. gingivalis. BSS-nano at a concentration of 60 μg ml-1 showed low cytotoxicity (6%) in HFG-1 cells and was mainly localized intracellularly in acidic vesicles. Our results indicate that the concentration of BSS-nano used as an effective antibacterial agent does not induce cytotoxicity in mammalian cells; thus, BSS-nano can be applied as an antibacterial agent in dental materials or antiseptic solutions.

  11. Lead-Bismuth-Eutectic Spallation Neutron Source for Nuclear Transmuter

    International Nuclear Information System (INIS)

    Gohar, Y.; Herceg, J.; Krajtl, L.; Micklich, B.; Pointer, D.; Saiveau, J.; Sofu, T.; Finck, P.

    2002-01-01

    A lead-bismuth eutectic (LBE) spallation target design concept has been developed for the subcritical multiplier (SCM) design of the accelerator-driven test facility (ADTF). The design is based on a coaxial geometrical configuration, which has been carefully analyzed and designed to achieve an optimum performance. The target design description, the results from the parametric studies, and the design analyses including neutronics, heat transfer, and hydraulics analyses are given in this paper. A detailed MCNPX geometrical model for the target has been developed to generate heating rates and nuclear responses in the structural material for the design process. The beam has a uniform distribution of 600 MeV protons and 5-MW total power. A small LBE buffer is optimized to reduce the irradiation damage in the SCM fuel elements from the scatter protons and the high-energy neutrons, to maximize the neutron yield to the SCM operation, and to provide inlet and outlet manifolds for the LBE coolant. A special attention has been given to the target window design to enhance its lifetime. The window volumetric heating is 766 W/cm 3 relative to 750 W/cm 3 in LBE for a 40-μA/cm 2 current density. The results show that the nuclear heating from the proton beam diminishes at about 32 cm along the beam axis in the LBE target material. The neutron contribution to the atomic displacement is in the range of 94 to ∼100% for the structure material outside the proton beam path. In the beam window, the neutron contribution is ∼74% and the proton beam is responsible for more than 95% of the total gas production. The proton contribution to the gas production vanishes outside the beam path. The LBE average velocity is ∼2 m/s. The heat transfer and the hydraulics analyses have been iterated to reduce the maximum temperature and the thermal stress level in the target window to enhance its operating life. (authors)

  12. Tungsten oxide proton conducting films for low-voltage transparent oxide-based thin-film transistors

    International Nuclear Information System (INIS)

    Zhang, Hongliang; Wan, Qing; Wan, Changjin; Wu, Guodong; Zhu, Liqiang

    2013-01-01

    Tungsten oxide (WO x ) electrolyte films deposited by reactive magnetron sputtering showed a high room temperature proton conductivity of 1.38 × 10 −4 S/cm with a relative humidity of 60%. Low-voltage transparent W-doped indium-zinc-oxide thin-film transistors gated by WO x -based electrolytes were self-assembled on glass substrates by one mask diffraction method. Enhancement mode operation with a large current on/off ratio of 4.7 × 10 6 , a low subthreshold swing of 108 mV/decade, and a high field-effect mobility 42.6 cm 2 /V s was realized. Our results demonstrated that WO x -based proton conducting films were promising gate dielectric candidates for portable low-voltage oxide-based devices.

  13. Structural influence of mixed transition metal ions on lithium bismuth borate glasses

    Science.gov (United States)

    Yadav, Arti; Dahiya, Manjeet S.; Hooda, A.; Chand, Prem; Khasa, S.

    2017-08-01

    Lithium bismuth borate glasses containing mixed transition metals having composition 7CoO·23Li2O·20Bi2O3·50B2O3 (CLBB), 7V2O5·23Li2O·20Bi2O3·50B2O3 (VLBB) and x(2CoO·V2O5)·(30 - x)Li2O·20Bi2O3·50B2O3 (x = 0.0 (LBB) and x = 2.0, 5.0, 7.0, 10.0 mol% (CVLBB1-4)) are synthesized via melt quench route. The synthesized compositions are investigated for their physical properties using density (D) and molar volume (Vm), thermal properties by analyzing DSC/TG thermo-graphs, structural properties using IR absorption spectra in the mid-IR range and optical properties using UV-Vis-NIR spectroscopy. The Electron Paramagnetic Resonance (EPR) spectra of vanadyl and cobalt ion have been analyzed to study compositional effects on spin-Hamiltonian parameters. The non linear variations in physical properties depict a strong structural influence of Co/V- oxides on the glassy matrix. The compositional variations in characteristic temperatures (glass transition temperature Tg, glass crystallization temperature Tp and glass melting temperature Tm) reveals that Tg for glass samples CLBB is relatively less than that of pure lithium bismuth borate (LBB) glass sample wherein Tg for sample VLBB is higher than that of LBB. The increase in Tg (as compared with LBB) with an enhanced substitution of mixed transition metal oxides (2CoO·V2O5) shows a progressive structure modification of bismuth borate matrix. These predictions are very well corroborated by corresponding compositional trends of Tp and Tm. FTIR studies reveal that Co2+& VO2+ ions lead to structural rearrangements through the conversion of three-coordinated boron into four coordinated boron and thereby reducing number of non-bridging oxygen atoms. Bismuth is found to exist in [BiO6] octahedral units only, whereas boroxol rings are not present in the glass network. The theoretical values of optical basicity (Λth) and corresponding oxide ion polarizability (αo2-) have also been calculated to investigate oxygen covalency of

  14. Outstanding visible photocatalytic activity of a new mixed bismuth titanatate material

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain); Departamento Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Profesor García González s/n, 41012 Sevilla (Spain); Sayagués, M.J.; Navío, J.A. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain); Hidalgo, M.C., E-mail: carmen.hidalgo@csic.es [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain)

    2017-02-01

    Highlights: • Photocatalyst based on bismuth titanates with high visible activity. • Its visible activity as high as UV activity of TiO{sub 2} P25 for phenol degradation. • Photocatalyst is majority of phase Bi{sub 20}TiO{sub 32} with Bi{sub 4}Ti{sub 3}O{sub 12} and amorphous TiO{sub 2}. • High visible activity due to low BG, interconnected phases and high surface area. - Abstract: In this work, a new photocatalyst based on bismuth titanates with outstanding visible photocatalytic activity was prepared by a facile hydrothermal method. The synthesised material showed visible activity as high as UV activity of commercial TiO{sub 2} P25 under the same experimental conditions for phenol degradation. A wide characterisation of the photocatalyst was performed. The material was composed of three phases; majority of Bi{sub 20}TiO{sub 32} closely interconnected to Bi{sub 4}Ti{sub 3}O{sub 12} and amorphous TiO{sub 2}. The high visible activity showed by this material could be ascribed to a combination of several features; i.e. low band gap energy value (2.1 eV), a structure allowing a good separation path for visible photogenerated electron-holes pairs and a relatively high surface area. This photocatalyst appeared as a promising material for solar and visible applications of photocatalysis.

  15. Capacity extended bismuth-antimony cathode for high-performance liquid metal battery

    Science.gov (United States)

    Dai, Tao; Zhao, Yue; Ning, Xiao-Hui; Lakshmi Narayan, R.; Li, Ju; Shan, Zhi-wei

    2018-03-01

    Li-Bi based liquid metal batteries (LMBs) have attracted interest due to their potential for solving grid scale energy storage problems. In this study, the feasibility of replacing the bismuth cathode with a bismuth-antimony alloy cathode in lithium based LMBs is investigated. The influence of the Bi:Sb ratio on voltage characteristics is evaluated via the constant current discharge method and electrochemical titration. On observing the cross section of the electrode at various stages of discharge, it is determined that both Sb and Bi form solid intermetallics with Li on the cathode. Additionally, the addition of Bi not only reduces the melting temperature of the Bi:Sb intermetallic but also actively contributes to the electrode capacity. Thereafter, a Li|LiCl-LiF|Sb-Bi liquid metal battery with 3 A h nameplate capacity, assembled and cycled at 1 C rate, is found to possess a stable capacity for over 160 cycles. The overall performance of this battery is discussed in the context of cost effectiveness, energy and coulombic efficiencies.

  16. Extended Photo-Conversion Spectrum in Low-Toxic Bismuth Halide Perovskite Solar Cells.

    Science.gov (United States)

    Johansson, Malin B; Zhu, Huimin; Johansson, Erik M J

    2016-09-01

    Lead-based perovskites show very promising properties for use in solar cells; however, the toxicity of lead is a potential inhibitor for large-scale application of these solar cells. Here, a low-toxic bismuth halide, CsBi3I10, is synthesized from solution and the optical properties and crystal structure are compared with previously reported Cs3Bi2I9 perovskite, and the photovoltaic properties are also investigated. The XRD pattern suggests that the CsBi3I10 film has a layered structure with a different dominating crystal growth direction than the Cs3Bi2I9 perovskite. A band gap of 1.77 eV is obtained for the CsBi3I10 film, which is smaller than the band gap of Cs3Bi2I9 at 2.03 eV, and an extended visible light absorption spectrum is therefore obtained. The solar cell device with CsBi3I10 shows a photocurrent up to 700 nm, and this work shows therefore the possibility for increased light absorption and higher photocurrents in solar cells based on bismuth halide perovskites.

  17. Gaseous Heterogeneous Catalytic Reactions over Mn-Based Oxides for Environmental Applications: A Critical Review.

    Science.gov (United States)

    Xu, Haomiao; Yan, Naiqiang; Qu, Zan; Liu, Wei; Mei, Jian; Huang, Wenjun; Zhao, Songjian

    2017-08-15

    Manganese oxide has been recognized as one of the most promising gaseous heterogeneous catalysts due to its low cost, environmental friendliness, and high catalytic oxidation performance. Mn-based oxides can be classified into four types: (1) single manganese oxide (MnOx), (2) supported manganese oxide (MnOx/support), (3) composite manganese oxides (MnOx-X), and (4) special crystalline manganese oxides (S-MnOx). These Mn-based oxides have been widely used as catalysts for the elimination of gaseous pollutants. This review aims to describe the environmental applications of these manganese oxides and provide perspectives. It gives detailed descriptions of environmental applications of the selective catalytic reduction of NOx with NH 3 , the catalytic combustion of volatile organic compounds, Hg 0 oxidation and adsorption, and soot oxidation, in addition to some other environmental applications. Furthermore, this review mainly focuses on the effects of structure, morphology, and modified elements and on the role of catalyst supports in gaseous heterogeneous catalytic reactions. Finally, future research directions for developing manganese oxide catalysts are proposed.

  18. Oxidation of a Commercial Nickel-Based Superalloy under Static Loading

    Science.gov (United States)

    Foss, B. J.; Hardy, M. C.; Child, D. J.; McPhail, D. S.; Shollock, B. A.

    2014-12-01

    The current demands of the aviation industry for increased gas-turbine efficiency necessitate higher turbine entry temperatures, requiring that alloys exhibit superior oxidation resistance. The synergistic effects of oxidation and mechanical stresses pose a complex issue. The purpose of the current research was to examine the effects of stress on the oxidation and oxygen transport in a commercial nickel-based superalloy. Fine grain RR1000 in both polished and shot-peened conditions was studied for classic (zero load) and statically loaded conditions using integrated two-stage isotopic tracing combined with focused-ion-beam secondary ion mass spectrometry (FIB-SIMS). Cr2O3 external oxide formed with semicontinuous TiO2 above and below. Preferential grain boundary Al2O3 internal oxide formation, γ'-dissolution, and recrystallization occurred subsurface. Oxidation mechanisms were dominated by anionic/cationic growth in the external oxide with inward oxygen transport, initially through the partially unprotective external oxide, then along internal oxide/alloy interfaces. Loading did not influence the oxidation products formed but did bring about expedited oxidation kinetics and changes to the oxide morphology. The oxygen diffusivity D {O/ * } (×10-13 cm2s-1) ranged from 0.39 for the polished alloy to 3.7 for the shot-peened condition under compressive stress. Arguably, the most significant effects took place in the subsurface regions. Increased oxidation kinetics were attributed to the development of fast cation diffusion paths as the alloy deformed by creep.

  19. Effects of cyclic stress and temperature on oxidation damage of a nickel-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Karabela, A. [Department of Mechanical and Design Engineering, University of Portsmouth, Anglesea Building, Anglesea Road, Portsmouth PO1 3DJ (United Kingdom); Zhao, L.G., E-mail: liguo.zhao@port.ac.uk [Department of Mechanical and Design Engineering, University of Portsmouth, Anglesea Building, Anglesea Road, Portsmouth PO1 3DJ (United Kingdom); Tong, J. [Department of Mechanical and Design Engineering, University of Portsmouth, Anglesea Building, Anglesea Road, Portsmouth PO1 3DJ (United Kingdom); Simms, N.J.; Nicholls, J.R. [School of Applied Sciences, Cranfield University, Cranfield, MK43 0AL (United Kingdom); Hardy, M.C. [Rolls-Royce plc, Elton Road, Derby DE24 8BJ (United Kingdom)

    2011-07-25

    Highlights: {yields} FIB shows the formation of surface oxide scales and internal micro-voids. {yields} Oxidation damage at 800 deg. C is much more severe than that at 700 deg. C and 750 deg. C. {yields} Cyclic stress enhances the extent of oxidation damage at 750 deg. C and above. {yields} Enrichment of Cr and Ti, as well as lower Ni and Co levels, in the surface oxides. {yields} Penetration of oxygen into the material and internal oxidation are evidenced. - Abstract: Oxidation damage, combined with fatigue, is a concern for nickel-based superalloys utilised as disc rotors in high pressure compressor and turbine of aero-engines. A study has been carried out for a nickel-based alloy RR1000, which includes cyclic experiments at selected temperatures (700-800 deg. C) and microscopy examination using focused ion beam (FIB). The results suggest that the major mechanism of oxidation damage consists of the formation of surface oxide scales and internal micro-voids and oxide particles beneath the oxide scales, which become more severe with the increase of temperature. Applying a cyclic stress does not change the nature of oxidation damage but tends to enhance the extent of oxidation damage for temperatures at 750 deg. C and 800 deg. C. The influence of cyclic stress on oxidation damage appears to be insignificant at 700 deg. C, indicating a combined effect of cyclic stress and temperature. Further energy-dispersive X-ray spectrometry (EDXS) analyses show the enrichment of Cr and Ti, together with lower Ni and Co levels, in the surface oxide scales, suggesting the formation of brittle Cr{sub 2}O{sub 3}, TiO{sub 2}, NiO and Co{sub 3}O{sub 4} oxides on the specimen surface. Penetration of oxygen into the material and associated internal oxidation, which leads to further material embrittlement and associated failure, are evidenced from both secondary ion imaging and EDXS analyses.

  20. Oxide characterization and hydrogen behaviors of Zr-based alloys

    International Nuclear Information System (INIS)

    Kim, Y. S.; Kim, D. J.; Kwon, S. H.; Lee, H. S.; Oh, S. J.; Yim, B. J.; Son, S. B.; Yun, S. P.

    2006-03-01

    The work scope and contents of the research are as follows : basic properties of zirconium alloys, hydrogen pick-up mechanism of zirconium alloy, effects of hydride on the corrosion behaviors of zirconium alloys, estimation on stress of oxide layer in the zirconium alloy, microstructure and characteristic of oxide in pre-hydrided zirconium alloys

  1. Semiempirical search for oxide superconductors based on bond valence sums

    International Nuclear Information System (INIS)

    Tanaka, S.; Fukushima, N.; Niu, H.; Ando, K.

    1992-01-01

    Relationships between crystal structures and electronic states of layered transition-metal oxides are analyzed in the light of bond valence sums. Correlations between the superconducting transition temperature T c and the bond-valence-sum parameters are investigated for the high-T c cuprate compounds. Possibility of making nonsuperconducting oxides superconducting is discussed. (orig.)

  2. Spectroscopic properties of 1.8 μm emission in Tm3+ doped bismuth silicate glass

    International Nuclear Information System (INIS)

    Zhao, Guoying; Tian, Ying; Wang, Xin; Fan, Huiyan; Hu, Lili

    2013-01-01

    The emission properties around 1.8 μm in Tm 3+ doped bismuth silicate glass have been investigated. Based on the obtained Raman spectroscopy and differential scanning calorimetry curves, it is found the introduced Bi 2 O 3 can efficiently reduce the phonon energy of silicate glass to 926 cm −1 . The energy gap between glass transition temperature and onset temperature of crystallization is 169 °C. The OH − content maintains lower in glass by bubbling dry O 2 during the melting process. The cut-off wavelength in mid-infrared range is as long as 5 μm. Bismuth silicate glass has high radiative transition probability of 238.80 s −1 corresponding to the Tm 3+ : 3 F 4 → 3 H 6 transition compared with conventional silicate glasses. The strongest emission at 1.8 μm with a large full width at half-maximum of 238 nm is achieved from this bismuth silicate glass doped with 0.9 mol% Tm 2 O 3 . Its fluorescence lifetime at 1.8 μm is 640 μs. - Highlights: ► The 1.8 μm fluorescence of Tm 3+ -doped bismuth silicate glass is investigated. ► The prepared glass has lower phonon energy than other typical silicate glasses. ► A broadband 1.8 μm emission with the FWHM of 238 nm is observed. ► The fluorescence lifetime of Tm 3+ : 3 F 4 level reaches 640 μs.

  3. Irradiation performance of thorium oxide based coated particle fuels

    International Nuclear Information System (INIS)

    Shiratori, Tetsuo; Itoh, Akinori; Akabori, Mitsuo; Shiba, Koreyuki; Adachi, Mamoru

    1988-11-01

    BISO coated ThO 2 particles as fertile fuel and BISO or TRISO coated (Th, U)O 2 particles as fissile fuel for a High-temperature Gas-cooled Reactor (HTGR) were irradiated to investigate particle performances in loosely-packed condition of two capsules in JRR-2 and one capsule in JMTR. Irradiation of these coated particles was achieved to a maximum fast neutron fluence of 2.22 x 10 21 neutrons/cm 2 (E > 0.18 MeV) and a maximum thermal neutron fluence of 1.35 x 10 21 neutrons/cm 2 at temperatures of 770 to 1225 deg C. And a maximum burnup of fissile particles was 2.42 % FIMA. It was found in the post-irradiation examinations that the coated particles were intact except a little of the BISO coated fissile particles, and the thorium oxide based coated particles performed well under the irradiation conditions. The data were also taken on the fission product behavior released from the fuel kernels during the irradiation. And density of the outer LTIPyC (OPyC) increased as increasing the fluence of fast neutron. As a result of the densification of the OPyC, the crushing strength of the BISO coated particles increased, otherwise the TRISO coated particles decreased. (author)

  4. Anion-based approaches to tunable functionality in oxide heterostructures

    Science.gov (United States)

    May, Steven

    2014-03-01

    The ability to control the position and composition of the anion site is emerging as a promising route to tune properties in epitaxial perovskites. This talk will focus on recent and ongoing efforts aimed at developing anion-based approaches to tailor electronic and magnetic properties in oxide films. First, I will discuss how the position of the oxygen anions can be tailored to stabilize non-bulk-like bond angles and lengths, thereby altering electronic bandwidth. Recent work on La2/3Sr1/3MnO3 will be presented in which ultrathin films under the same strain state exhibit dramatically different electronic and magnetic properties when grown on substrates with different symmetries. In the second half of the talk, I will describe efforts focused on altering the composition of the anion site. In La1/3Sr2/3FeO3-δ films, a reversible change in oxygen content leads to dramatic changes in electrical, optical, and structural properties. Finally, the synthesis of oxyfluoride ferrite and nickelate perovskite films via topotactic reactions carried out following thin film deposition will be described. This work is supported by the Office of Naval Research (N00014-11-1-0664) and the U. S. Army Research Office (W911NF-12-1-0132).

  5. Processing, characterization and properties of oxide based nanocomposites

    Science.gov (United States)

    Bhaduri, Sutapa

    The synthesis, characterization and mechanical properties of oxide based nanocomposites are reported in this dissertation. Two binary systems are studied: Alsb2Osb3-MgO and Alsb2Osb3-ZrOsb2. Alsb2Osb3-MgO was chosen because of its relatively large field of solid solubilities at a moderate temperature. On the other hand, Alsb2Osb3-ZrOsb2 was chosen because it shows minimal solid solubility of the constituents. A novel "Auto Ignition" process using suitable fuels and oxidizers was utilized in the synthesis of nanocomposites and solid solutions. Thermodynamic calculations were carried out in predicting end point adiabatic temperatures (Tsbad) for each composition in both systems. Combustion temperatures were experimentally measured by means of a data acquisition system. Characterizations of the powders were carried out by x-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive analysis (EDAX) and differential thermal analysis (DTA). Heat treatment experiments were carried out to study the grain growth behavior. A hot isostatic pressing (HIP) model was developed for the present nanoceramics. Input parameters were carefully chosen for such nanomaterials. The as-synthesized nanocrystalline powders were consolidated to near theoretical density by hot isostatic pressing (HIPing) while retaining fine grain size. The experimental results were compared with the predictions of the model. Mechanical properties, such as room temperature toughness, low temperatures well as high temperature hardness, were determined for both systems. Room temperature hardness values were (2.89-7.79) GPa and fracture toughness was between 2.7 and 5.82 MPa.msp{1/2} for various compositions in the Alsb2Osb3-MgO system. Room temperature hardness values were between 5.33 and 8.71 GPa and fracture toughness values ranged from (5.3-9.62) MPa.msp{1/2} for various compositions in the Alsb2Osb3-ZrOsb2 system. Nanoindentation experiments were carried out to further explore the room

  6. Defects and properties of cadmium oxide based transparent conductors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Kin Man, E-mail: kinmanyu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Kowloon (Hong Kong); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Detert, D. M.; Dubon, O. D. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Chen, Guibin [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department and Jiangsu Key Laboratory for Chemistry of Low Dimensional Materials, Huaiyin Normal University, Jiangsu 223300 (China); Zhu, Wei [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics and The Center for Physical Experiments, University of Science and Technology of China, Hefei, Anhui 230026 (China); Liu, Chaoping [Department of Physics and Materials Science, City University of Hong Kong, Kowloon (Hong Kong); Grankowska, S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Institute of Experimental Physics (IEP UW), Warsaw University, Warsaw (Poland); Hsu, L. [Department of Postsecondary Teaching and Learning, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Walukiewicz, Wladek [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2016-05-14

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (<200 °C), sputter deposition tends to trap both oxygen vacancies and compensating defects in the CdO film resulting in materials with high electron concentration of ∼2 × 10{sup 20}/cm{sup 3} and mobility in the range of 40–100 cm{sup 2}/V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O{sub 2} partial pressure in the sputter gas mixture results in films with resistivity from ∼4 × 10{sup −4} to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 10{sup 21 }cm{sup −3} and electron mobility higher than 120 cm{sup 2}/V s can be achieved. Thermal annealing of doped CdO films in N{sub 2} ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ∼1 eV and that the mobility of sputtered deposited CdO is limited

  7. Defects and properties of cadmium oxide based transparent conductors

    Science.gov (United States)

    Yu, Kin Man; Detert, D. M.; Chen, Guibin; Zhu, Wei; Liu, Chaoping; Grankowska, S.; Hsu, L.; Dubon, O. D.; Walukiewicz, Wladek

    2016-05-01

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (concentration of ˜2 × 1020/cm3 and mobility in the range of 40-100 cm2/V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O2 partial pressure in the sputter gas mixture results in films with resistivity from ˜4 × 10-4 to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 1021 cm-3 and electron mobility higher than 120 cm2/V s can be achieved. Thermal annealing of doped CdO films in N2 ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ˜1 eV and that the mobility of sputtered deposited CdO is limited by a background acceptor concentration of ˜5-6 × 1020/cm3. The calculations offer an insight into understanding of the effects of defects on electrical properties of undoped and doped CdO and offer a potential to use similar methods to

  8. Defects and properties of cadmium oxide based transparent conductors

    International Nuclear Information System (INIS)

    Yu, Kin Man; Detert, D. M.; Dubon, O. D.; Chen, Guibin; Zhu, Wei; Liu, Chaoping; Grankowska, S.; Hsu, L.; Walukiewicz, Wladek

    2016-01-01

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (<200 °C), sputter deposition tends to trap both oxygen vacancies and compensating defects in the CdO film resulting in materials with high electron concentration of ∼2 × 10 20 /cm 3 and mobility in the range of 40–100 cm 2 /V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O 2 partial pressure in the sputter gas mixture results in films with resistivity from ∼4 × 10 −4 to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 10 21  cm −3 and electron mobility higher than 120 cm 2 /V s can be achieved. Thermal annealing of doped CdO films in N 2 ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ∼1 eV and that the mobility of sputtered deposited CdO is limited by a background acceptor concentration of

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

    International Nuclear Information System (INIS)

    Agrinier, H.

    1961-01-01

    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) [fr

  10. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    International Nuclear Information System (INIS)

    Aleme, C.; Mourao, A. P.; Lyra, M. A.

    2014-08-01

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  11. Neutronics design for lead-bismuth cooled accelerator-driven system for transmutation of minor actinide

    International Nuclear Information System (INIS)

    Tsujimoto, Kazufumi; Sasa, Toshinobu; Nishihara, Kenji; Oigawa, Hiroyuki; Takano, Hideki

    2004-01-01

    Neutronics design study was performed for lead-bismuth cooled accelerator-driven system (ADS) to transmute minor actinides. Early study for ADS indicated two problems: a large burnup reactivity swing and a significant peaking factor. To solve these problems, effect of design parameters on neutronics characteristics were searched. The design parameters were initial plutonium loading, buffer region between spallation target and core, and zone fuel loading. Parametric survey calculations were performed considering fuel cycle consisting of burnup and recycle. The results showed that burnup reactivity swing depends on the plutonium fraction in the initial fuel loading, and the lead-bismuth buffer region and the two-zone loading were effective for solving the problems. Moreover, an optimum value for the effective multiplication factor was also evaluated using reactivity coefficients. From the result, the maximum allowable value of the effective multiplication factor for a practical ADS can be set at 0.97. Consequently, a new core concept combining the buffer region and the two-zone loading was proposed base on the results of the parametric survey. (author)

  12. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    Energy Technology Data Exchange (ETDEWEB)

    Aleme, C.; Mourao, A. P. [Centro Federal de Educacion Tecnologica de Minas Gerais, Biomedical Engineering Center, Belo Horizonte - MG (Brazil); Lyra, M. A., E-mail: carolinaaleme@gmail.com [Universidad Federal de Minas Gerais, Department of Nuclear Engineering, Av. Pdte. Antonio Carlos 6627, Pampulha, 31270-91 Belo Horizonte - MG (Brazil)

    2014-08-15

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  13. Oxidation behaviour and mechanism of a cobalt based superalloy between 1050 and 1250 °C

    Science.gov (United States)

    Liu, Longfei; Wu, Shusen; Yu, Guangming; Chen, Yang

    2013-10-01

    A new Co-base superalloy 22Co-21Ni-23Fe-29Cr-2.2Nb (Co22 for short) was developed, and the influence of a trace amount of rare earth (RE) on the oxidation resistance was investigated. Isothermal oxidation behaviour of this Co-base superalloy was investigated at 1050-1250 °C in air, analyzed with scanning electronic microscopy and X-ray diffraction. The results show that oxidation mass gain of the samples with or without RE elements obeyed secondary parabolic law, and the effect of 0.03 wt.% RE on oxidation resistance is small. The oxidation rate constant of the 0.03 wt.% RE added Co22 alloy decreases by about 6.1% to 9.0% compared to that of the Co22 alloy without RE. Oxidation at 1050-1250 °C for 100 h results in the formation of MnCr2O4, Cr2O3 and SiO2. A continuous and protective MnCr2O4 spinel layer forms as outer layer. The continuous middle oxide layer is confirmed to be Cr2O3, and the innermost layer consists of discontinuous SiO2. The outer and middle layers strongly improve oxidation resistance and oxide layer adhesion because of their continuity and compactness, and the innermost SiO2 layer forms a diffusion barrier to prevent further oxidation. Formation and growth mechanisms of oxide layers were also discussed.

  14. METHOD OF SEPARATING FISSION PRODUCTS FROM FUSED BISMUTH-CONTAINING URANIUM

    Science.gov (United States)

    Wiswall, R.H.

    1958-06-24

    A process is described for removing metal selectively from liquid metal compositions. The method effects separation of flssion product metals selectively from dilute solution in fused bismuth, which contains uraniunn in solution without removal of more than 1% of the uranium. The process comprises contacting the fused bismuth with a fused salt composition consisting of sodium, potassium and lithium chlorides, adding to fused bismuth and molten salt a quantity of bismuth chloride which is stoichiometrically required to convert the flssion product metals to be removed to their chlorides which are more stable in the fused salt than in the molten metal and are, therefore, preferentially taken up in the fused salt phase.

  15. Bismuth(III) deferiprone effectively inhibits growth of Desulfovibrio desulfuricans ATCC 27774.

    Science.gov (United States)

    Barton, Larry L; Lyle, Daniel A; Ritz, Nathaniel L; Granat, Alex S; Khurshid, Ali N; Kherbik, Nada; Hider, Robert; Lin, Henry C

    2016-04-01

    Sulfate-reducing bacteria have been implicated in inflammatory bowel diseases and ulcerative colitis in humans and there is an interest in inhibiting the growth of these sulfide-producing bacteria. This research explores the use of several chelators of bismuth to determine the most effective chelator to inhibit the growth of sulfate-reducing bacteria. For our studies, Desulfovibrio desulfuricans ATCC 27774 was grown with nitrate as the electron acceptor and chelated bismuth compounds were added to test for inhibition of growth. Varying levels of inhibition were attributed to bismuth chelated with subsalicylate or citrate but the most effective inhibition of growth by D. desulfuricans was with bismuth chelated by deferiprone, 3-hydroxy-1,2-dimethyl-4(1H)-pyridone. Growth of D. desulfuricans was inhibited by 10 μM bismuth as deferiprone:bismuth with either nitrate or sulfate respiration. Our studies indicate deferiprone:bismuth has bacteriostatic activity on D. desulfuricans because the inhibition can be reversed following exposure to 1 mM bismuth for 1 h at 32 °C. We suggest that deferiprone is an appropriate chelator for bismuth to control growth of sulfate-reducing bacteria because deferiprone is relatively nontoxic to animals, including humans, and has been used for many years to bind Fe(III) in the treatment of β-thalassemia.

  16. Bismuth uptake in the kidney as a test of absorption from the gastrointestinal tract in mice

    International Nuclear Information System (INIS)

    Renault, Henri; Rapin, J.R.; Bralet, A.-M.

    1976-01-01

    The absorption of bismuth administered per os as an insoluble salt: basic nitrate and phosphate, labeled with 206 Bi was studied. The bismuth amounts in blood and most tissues were too small to be detected. However kidneys took up a significant bismuth quantity which allowed to measure the absorption of the metal through digestive wall. Bismuth absorption from phosphate, a very insoluble salt, was much less than that which was obtained from basic nitrate; this latter is an example of partially soluble salt in the stomach [fr

  17. Nanophotonic Modulator with Bismuth Ferrite as Low-loss Switchable Material

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Zhukovsky, Sergei; Lavrinenko, Andrei

    2015-01-01

    We propose a nanophotonic waveguide modulator with bismuth ferrite as a tunable material. Due to near-zero losses in bismuth ferrite, modulation with up to 20 dB/μm extinction ratio and 12 μm propagation length is achieved.......We propose a nanophotonic waveguide modulator with bismuth ferrite as a tunable material. Due to near-zero losses in bismuth ferrite, modulation with up to 20 dB/μm extinction ratio and 12 μm propagation length is achieved....

  18. Oxide-based materials by atomic layer deposition

    Science.gov (United States)

    Godlewski, Marek; Pietruszka, Rafał; Kaszewski, Jarosław; Witkowski, Bartłomiej S.; Gierałtowska, Sylwia; Wachnicki, Łukasz; Godlewski, Michał M.; Slonska, Anna; Gajewski, Zdzisław

    2017-02-01

    Thin films of wide band-gap oxides grown by Atomic Layer Deposition (ALD) are suitable for a range of applications. Some of these applications will be presented. First of all, ALD-grown high-k HfO2 is used as a gate oxide in the electronic devices. Moreover, ALD-grown oxides can be used in memory devices, in transparent transistors, or as elements of solar cells. Regarding photovoltaics (PV), ALD-grown thin films of Al2O3 are already used as anti-reflection layers. In addition, thin films of ZnO are tested as replacement of ITO in PV devices. New applications in organic photovoltaics, electronics and optoelectronics are also demonstrated Considering new applications, the same layers, as used in electronics, can also find applications in biology, medicine and in a food industry. This is because layers of high-k oxides show antibacterial activity, as discussed in this work.

  19. Electrochemical Water-Splitting Based on Hypochlorite Oxidation

    Czech Academy of Sciences Publication Activity Database

    Minhová Macounová, Kateřina; Simic, N.; Ahlberg, E.; Krtil, Petr

    2015-01-01

    Roč. 137, č. 23 (2015), s. 7262-7265 ISSN 0002-7863 Institutional support: RVO:61388955 Keywords : electrochemistry * hypochlorite oxidation * water-splitting Subject RIV: CG - Electrochemistry Impact factor: 13.038, year: 2015

  20. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...... configurations are compared with each other. Technoeconomy is used when calculating the cost if the plants. It is found that when a solid oxide fuel cell plant is combined with a gas turbine cycle then the plant efficiency will be the highest one while if a biomass gasification plant is integrated...... with these hybrid cycles then integrated biomass gasification with solid oxide fuel cell and steam cycle will have the highest plant efficiency. The cost of solid oxide fuel cell with steam plant is found to be the lowest one with a value of about 1030$/kW....

  1. MRI based on iron oxide nanoparticles contrast agents: effect of oxidation state and architecture

    Science.gov (United States)

    Javed, Yasir; Akhtar, Kanwal; Anwar, Hafeez; Jamil, Yasir

    2017-11-01

    Iron oxide nanoparticles (IONPs) extensively employed beyond regenerative medicines to imaging disciplines because of their great constituents for magneto-responsive nano-systems. The unique superparamagnetic behavior makes IONPs very suitable for hyperthermia and imaging applications. From the last decade, versatile functionalization with surface capabilities, efficient contrast properties and biocompatibilities make IONPs an essential imaging contrast agent for magnetic resonance imaging (MRI). IONPs have shown signals for both longitudinal relaxation and transverse relaxation; therefore, negative contrast as well as dual contrast can be used for imaging in MRI. In the current review, we have focused on different oxidation state of iron oxides, i.e., magnetite, maghemite and hematite for their T1 and T2 contrast enhancement properties. We have also discussed different factors (synthesis protocols, biocompatibility, toxicity, architecture, etc.) that can affect the contrast properties of the IONPs. [Figure not available: see fulltext.

  2. Electrical Pressure Transducers Based on Graphene Oxide Polysiloxane Composites

    Directory of Open Access Journals (Sweden)

    Antonio PELUSO

    2010-12-01

    Full Text Available Exfoliated graphite oxide embedded into a polysiloxane matrix can be simply obtained by sonochemical approach. These nanocomposites show an electrical conductivity depending on the applied stress and have most of crucial characteristics of an electrical pressure transducer (absence of electrical hysteresis, prompt resistivity variation, etc.. The highest sensitivity for these electrical devices is obtained with exfoliated graphene oxide concentration just a little inferior to the percolation threshold (that is, 5.5wt.% of graphene.

  3. 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

  4. Physiochemical and optical properties of chitosan based graphene oxide bionanocomposite.

    Science.gov (United States)

    Kumar, Santosh; Koh, Joonseok

    2014-09-01

    In the present investigation an ecofriendly approach and a simple homogeneous solution casting method led to the development of biodegradable chitosan/graphene oxide bionanocomposites. The formation of bionanocomposite was confirmed by UV-vis, FT-IR, Raman spectroscopy, XRD, and further evaluated by thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The circular dichroism (CD) study of chitosan/graphene oxide revealed that the intensity of the negative transition band at wavelength of 200-222 nm decreased with the different pH of chitosan/graphene oxide solutions. It was also found that the pH conditions affect the interaction between chitosan and graphene oxide. Optical properties of chitosan/graphene oxide are evaluated by photoluminescence (PL) spectroscopy which showed blue shift at excitation wavelength of 255 nm compared to graphene oxide. These results strongly suggest that the bionanocomposite materials may open new vistas in biotechnological, biosensor and biomedical applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. 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.

  6. 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.

  7. X-ray Investigations of Liquid Bismuth-Copper Alloys

    Science.gov (United States)

    Nzali, J. Nomssi; Hoyer, W.

    2000-04-01

    Liquid copper, bismuth, and eleven bismuth-copper alloys were investigated at temperatures above the liquidus with X-ray diffraction. The experimental procedure was adjusted to reduce the effects of evaporation. The Faber-Ziman total structure factors S(Q) feature a splitting of the first maximum and negative values for Q around 1 Å -1 in a large concentration range. The results are compared to previous neutron diffraction results by Zaiss and Steeb, to square-well potential model calculations by Gopala Rao and Satpathy and to a simple segregation model. The segregation model reproduces the features qualitatively. Partial structure factors are assessed by fitting both neutron and X-ray scattering results with reverse Monte-Carlo simulation

  8. Quantum nernst effect in a bismuth single crystal

    International Nuclear Information System (INIS)

    Matsuo, M.; Endo, A.; Hatano, N.; Nakamura, H.; Shirasaki, R.; Sugihara, K.

    2009-07-01

    We calculate the phonon-drag contribution to the transverse (Nernst) thermoelectric power S yx 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 S yx is much larger than the longitudinal (Seebeck) thermoelectric power S xx can be naturally explained as the effect of the phonon drag, combined with the well-known relation between the longitudinal and the Hall resistivity ρ xx >> |ρ yx | 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)

  9. Dose reduction using Bismuth protectors in chest computed tomography

    International Nuclear Information System (INIS)

    Anaya, R.

    2012-01-01

    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.

  10. Modular Lead-Bismuth Fast Reactors in Nuclear Power

    OpenAIRE

    Georgy Toshinsky; Vladimir Petrochenko

    2012-01-01

    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...

  11. Conversion Reaction-Based Oxide Nanomaterials for Lithium Ion Battery Anodes.

    Science.gov (United States)

    Yu, Seung-Ho; Lee, Soo Hong; Lee, Dong Jun; Sung, Yung-Eun; Hyeon, Taeghwan

    2016-04-27

    Developing high-energy-density electrodes for lithium ion batteries (LIBs) is of primary importance to meet the challenges in electronics and automobile industries in the near future. Conversion reaction-based transition metal oxides are attractive candidates for LIB anodes because of their high theoretical capacities. This review summarizes recent advances on the development of nanostructured transition metal oxides for use in lithium ion battery anodes based on conversion reactions. The oxide materials covered in this review include oxides of iron, manganese, cobalt, copper, nickel, molybdenum, zinc, ruthenium, chromium, and tungsten, and mixed metal oxides. Various kinds of nanostructured materials including nanowires, nanosheets, hollow structures, porous structures, and oxide/carbon nanocomposites are discussed in terms of their LIB anode applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. A Comprehensive Review of Glucose Biosensors Based on Nanostructured Metal-Oxides

    Science.gov (United States)

    Rahman, Md. Mahbubur; Saleh Ahammad, A. J.; Jin, Joon-Hyung; Ahn, Sang Jung; Lee, Jae-Joon

    2010-01-01

    Nanotechnology has opened new and exhilarating opportunities for exploring glucose biosensing applications of the newly prepared nanostructured materials. Nanostructured metal-oxides have been extensively explored to develop biosensors with high sensitivity, fast response times, and stability for the determination of glucose by electrochemical oxidation. This article concentrates mainly on the development of different nanostructured metal-oxide [such as ZnO, Cu(I)/(II) oxides, MnO2, TiO2, CeO2, SiO2, ZrO2, and other metal-oxides] based glucose biosensors. Additionally, we devote our attention to the operating principles (i.e., potentiometric, amperometric, impedimetric and conductometric) of these nanostructured metal-oxide based glucose sensors. Finally, this review concludes with a personal prospective and some challenges of these nanoscaled sensors. PMID:22399911

  13. Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials

    International Nuclear Information System (INIS)

    Cheng Gang; Yang Hanmin; Rong Kaifeng; Lu Zhong; Yu Xianglin; Chen Rong

    2010-01-01

    Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO) 2 CO 3 ) is one of commonly used antibacterial agents against Helicobacter pylori (H. pylori). Different (BiO) 2 CO 3 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) 2 CO 3 nanostructures. The possible formation mechanism of different (BiO) 2 CO 3 nanostructures fabricated under different conditions was also discussed. - Graphical abstract: Different bismuth subcarbonate ((BiO) 2 CO 3 ) 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) 2 CO 3 nanostructures.

  14. Bismuth Oxysulfide and Its Polymer Nanocomposites for Efficient Purification

    Directory of Open Access Journals (Sweden)

    Yidong Luo

    2018-03-01

    Full Text Available The danger of toxic organic pollutants in both aquatic and air environments calls for high-efficiency purification material. Herein, layered bismuth copper oxychalcogenides, BiCuSO, nanosheets of high photocatalytic activity were introduced to the PVDF (Polyvinylidene Fluoride. The fibrous membranes provide an easy, efficient, and recyclable way to purify organic pollutant. The physical and photophysical properties of the BiCuSO and its polymer composite were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, ultraviolet-visible diffuse reflection spectroscopy (DRS, X-ray photoelectron spectroscopy (XPS, electron spin resonance (EPR. Photocatalysis of Congo Red reveals that the BiCuSO/PVDF shows a superior photocatalytic activity of a 55% degradation rate in 70 min at visible light. The high photocatalytic activity is attributed to the exposed active {101} facets and the triple vacant associates V B i ‴ V O • • V B i ‴ . By engineering the intrinsic defects on the surface of bismuth oxysulfide, high solar-driven photocatalytic activity can be approached. The successful fabrication of the bismuth oxysulfide and its polymer nanocomposites provides an easy and general approach for high-performance purification materials for various applications.

  15. Theoretical study of bismuth-doped cadmium telluride

    Science.gov (United States)

    Menendez-Proupin, E.; Rios-Gonzalez, J. A.; Pena, J. L.

    Cadmium telluride heavily doped with bismuth has been proposed as an absorber with an intermediate band for solar cells. Increase in the photocurrent has been shown recently, although the overall cell efficiency has not improved. In this work, we study the electronic structure and the formation energies of the defects associated to bismuth impurities. We have performed electronic structure calculations within generalized density functional theory, using the exchange-correlation functional HSE(w) , where the range-separation parameter w has been tuned to reproduce the CdTe bandgap. Improving upon previous reports, we have included the spin-orbit interaction, which modifies the structure of the valence band and the energy levels of bismuth. We have found that interstitial Bi (Bii) tends to occupy Cd vacancies, cadmium substitution (BiCd) creates single donor level, while tellurium substitution (BiTe) is a shallow single acceptor. We investigate the interaction between these point defects and how can they be combined to create a partially filled intermediate band. Supported by FONDECYT Grant 1130437, CONACYT-SENER SUSTENTABILIDAD ENERGETICA/project CeMIE-Sol PY-207450/25 and PY-207450/26. JARG acknowledges CONACYT fellowship for research visit. Powered@NLHPC (ECM-02).

  16. Superconductivity in the high-pressure phase of bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Philip A.C.; Semeniuk, Konstantin; Grosche, F. Malte [Department of Physics, Cavendish Laboratory, University of Cambridge (United Kingdom)

    2016-07-01

    At pressures above 27 kbar, elemental bismuth adopts a highly unusual incommensurate host-guest structure. This structure combines two distinct, interpenetrating crystal lattices and consequently lacks discrete translational symmetry. Although similar high pressure structures have been observed in other elements, their electronic properties have not been investigated in detail. The moderate pressure required to induce the host-guest phase in bismuth presents a favourable opportunity for comprehensive electrical transport studies. The high-pressure host-guest phase of bismuth, termed Bi-III, is known to be superconducting with a transition temperature of around 7 K, but the details of its superconducting and normal state properties are comparatively little explored. We report resistivity and magnetisation measurements in the Bi-III phase in fields up to 9 T and temperatures down to 120 mK. We find evidence for a strikingly high critical field and an unusual temperature dependence of the resistivity above the superconducting transition. We discuss our findings in the context of theoretical descriptions of host-guest materials.

  17. Soluble Lead and Bismuth Chalcogenidometallates: Versatile Solders for Thermoelectric Materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [Department; Son, Jae Sung [Department; School; Dolzhnikov, Dmitriy S. [Department; Filatov, Alexander S. [Department; Hazarika, Abhijit [Department; Wang, Yuanyuan [Department; Hudson, Margaret H. [Department; Sun, Cheng-Jun [Advanced; Chattopadhyay, Soma [Physical; Talapin, Dmitri V. [Department; Center

    2017-07-27

    Here we report the syntheses of largely unexplored lead and bismuth chalcogenidometallates in the solution phase. Using N2H4 as the solvent, new compounds such as K6Pb3Te6·7N2H4 were obtained. These soluble molecular compounds underwent cation exchange processes using resin chemistry, replacing Na+ or K+ by decomposable N2H5+ or tetraethylammonium cations. They also transformed into stoichiometric lead and bismuth chalcogenide nanomaterials with the addition of metal salts. Such a versatile chemistry led to a variety of composition-matched solders to join lead and bismuth chalcogenides and tune their charge transport properties at the grain boundaries. Solution-processed thin films composed of Bi0.5Sb1.5Te3 microparticles soldered by (N2H5)6Bi0.5Sb1.5Te6 exhibited thermoelectric power factors (~28 μW/cm K2) comparable to those in vacuum-deposited Bi0.5Sb1.5Te3 films. The soldering effect can also be integrated with attractive fabrication techniques for thermoelectric modules, such as screen printing, suggesting the potential of these solders in the rational design of printable and moldable thermoelectrics.

  18. Improved interface properties of GaN-based metal-oxide-semiconductor devices with thin Ga-oxide interlayers

    Science.gov (United States)

    Yamada, Takahiro; Ito, Joyo; Asahara, Ryohei; Watanabe, Kenta; Nozaki, Mikito; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

    2017-06-01

    The impact of thin Ga-oxide (GaOx) interlayers on the electrical properties of GaN-based metal-oxide-semiconductor (MOS) devices was systematically investigated. Thin thermal oxides formed at around 900 °C were found to be beneficial for improving the electrical properties of insulator/GaN interfaces, despite the fact that thermal oxidation of GaN surfaces at high temperatures proceeds by means of grain growth. Consequently, well-behaved capacitance-voltage characteristics of SiO2/GaOx/n-GaN stacked MOS capacitors with an interface state density (Dit) as low as 1.7 × 1011 cm-2 eV-1 were demonstrated. Moreover, the Dit value was further reduced for the SiO2/GaOx/GaN capacitor with a 2-nm-thick sputter-deposited GaOx interlayer. These results clearly indicate the intrinsically superior nature of the oxide/GaN interfaces and provide plausible guiding principles for fabricating high-performance GaN-MOS devices with thin GaOx interlayers.

  19. Bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 with unselectively efficient photocatalytic activity and mechanism insight

    Science.gov (United States)

    Hao, Lin; Huang, Hongwei; Guo, Yuxi; Du, Xin; Zhang, Yihe

    2017-10-01

    Fabrication of homo/hetero-junctions by coupling of wide-band gap semiconductor and narrow-band gap semiconductor is desirable as they can achieve a decent balance between photoabsorption and photo-redox ability. Herein, a n-n type bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 was developed by facilely manipulating the basicity in a one-pot hydrothermal process. Compared with BiOCl which only responds to UV light, the photo-responsive range is remarkably extended to visible region. The BiOCl/Bi12O17Cl2 phasejunctions show much higher photocatalytic activity than the single BiOCl and Bi12O17Cl2 toward degradation of methyl orange (MO) under simulated solar light. In particular, it presented a high photo-oxidation ability in degrading diverse industrial contaminants including 2,4-dichlorophenol (2,4-DCP), phenol, bisphenol A (BPA) and tetracycline hydrochloride. Based on a series of photoelectrochemical and photoluminescence measurements, the fortified photocatalytic performance of BiOCl/Bi12O17Cl2 phasejunctions was manifested to be attributed to the efficient separation and transfer efficiencies of photoinduced electron-hole pairs because of the junctional interface formed between BiOCl and Bi12O17Cl2. The study may not only furnish a high-effective photocatalyst in the application of environment purification, but also pave a path to fabricate agnate phase-junctional photocatalyst.

  20. Electrocatalysis of oxygen electrode reactions by some perovskite oxides based on lanthanum manganate

    International Nuclear Information System (INIS)

    Raj, I.A.; Rao, K.V.; Venkatesan, V.K.

    1984-01-01

    In recent years, several electrocatalyst materials based on platinum, silver, tungsten bronzes, spinels, metal chelates, etc., have been studied for use as oxygen diffusion electrodes in alkaline fuel cells, secondary metal-air batteries, and water electrolyzers. However, virtually all catalysts of commercial importance are semiconducting transition metal oxides. The various oxide catalysts that have been studied can be grouped under mixed oxides, spinels, and perovskites

  1. Tantalum oxide-based plasma-sprayed environmental barrier coatings

    Science.gov (United States)

    Weyant, Christopher M.

    Energy efficiency in gas turbine engines is linked to the high temperature capabilities of materials used in the hot section of the engine. To facilitate a significant increase in engine efficiency, tough structural ceramics have been developed that can handle the thermo-mechanical stresses that gas turbine components experience. Unfortunately, the high-temperature, high-pressure, and high-velocity combustion gases in a gas turbine contain water vapor and/or hydrogen which have been shown to volatilize the protective silica layer on silicon-based ceramics. This degradation leads to significant surface recession in ceramic gas turbine components. In order to maintain their structural integrity, an environmental barrier coating (EBC) could be used to protect ceramics from the harsh gas turbine environment. Due to its coefficient of thermal expansion and phase stability at elevated temperatures, tantalum oxide (Ta2O5) was examined as the base material for an air plasma-sprayed EBC on Si3N 4 ceramics. As-sprayed pure Ta2O5 was comprised of both low-temperature beta-Ta2O5 and high-temperature alpha-Ta 2O5 that was quenched into the structure. Residual stress measurements via X-ray diffraction determined the as-sprayed coating to be in tension and extensive vertical macrocracks were observed in the coating. Heat treatments of the pure coating led to conversion of alpha-Ta2 O5 to beta-Ta2O5, conversion of tensile stresses to compressive, localized buckling of the coating, and significant grain growth which caused microcracking in the coating. The pure coating was found to be an inadequate EBC. Al2O3 was investigated as a solid solution alloying addition designed to enhance the stability of beta-Ta2O 5, and reduce grain growth by slowing grain boundary diffusion. La 2O3 was investigated as an alloying addition designed to form second phase particles which would reduce grain growth through pinning. Al2O3 was successful at both stabilizing beta-Ta 2O5 and reducing grain

  2. Development and characterization of the oxidation behavior of various high temperature niobium based alloys

    Science.gov (United States)

    Portillo, Benedict I., II

    The oxidation response of various niobium based refractory alloys from the Nb-Mo-Si-B-X alloy system has been examined at temperatures between 700 and 1400°C in air. The development of these alloys was part of an ongoing effort to develop and discover a new materials system capable of replacing nickel based super alloys. Additions of titanium were found to provide limited oxidation resistance. A discontinuous layer of TiO2 was observed to from at temperatures above 1100°C. Alloys containing titanium additions were observed to suffer from pest oxidation at low and intermediate temperatures due to the development of Nb2O5. Poor oxidation resistance at intermediate temperatures for alloys with titanium additions was attributed to a transformation in the structure of Nb2O5 formed. Additions of chromium were observed to increase oxidation resistance through the development of a layered oxide structure containing SiO2 and CrNbO4. An intermediate oxidation layer was observed to develop along the oxide metal interface in which the solid solution was not oxidized. These alloys were found to be susceptible to pest oxidation at intermediate and low oxidation temperatures between 700 and 1000°C. Boron and molybdenum content was modified and shown to suppress pest oxidation at 700°C. Modified molybdenum content led to the development of molybdenum based primary solid solution instead of niobium. Alloys with modified molybdenum and boron content were found to have the best oxidation resistance surviving 168 hours of cyclic oxidation at 1400°C. Transient oxidation behavior was observed in thermal gravimetric results collected at 1200°C in the alloys with modified boron and molybdenum content and attributed to the preferential oxidation of Nb5Si3. Oxidation behavior was characterized by the weight change per surface area method and by thermal gravimetric analysis. Oxidation products were characterized by x-ray diffraction and scanning electron microscopy in several modes

  3. Properties of Edible Films Based on Oxidized Starch and Zein

    Directory of Open Access Journals (Sweden)

    Elizabeth Argüello-García

    2014-01-01

    Full Text Available The objective of this work was to investigate the effect of zein and film formulation on mechanical and structural properties of native (FNS, and oxidized with 2.5% (FOSA and 3.5% (FOSB banana starch. The oxidized starch showed differences from native starch due to the oxidation process, showing a decrease in lipids, proteins, and amylose. The increase of the sodium hypochlorite increased the content of carbonyl and carboxyl groups in the ranges 0.015–0.028% and 0.022–0.031%, respectively. The film obtained from FOSB displayed the highest tensile strength (5.05 MPa and satisfactory elongation value (27.1%. The zein addition caused a decrease in these mechanical properties, as well as a significant decrease in water vapour permeability (WVP. However, films from FOSA and FOSB showed higher permeability than that of the native starch. The addition of glycerol and the level of oxidation increased the films moisture. Micrographs showed that, during the oxidation process, impurities were largely eliminated from the starch granule, noting more homogeneous structures both in granules and films.

  4. Electrical characterization of graphene oxide and organic dielectric layers based on thin film transistor

    Energy Technology Data Exchange (ETDEWEB)

    Karteri, İbrahim, E-mail: ibrahimkarteri@gmail.com [Department of Materials Science And Engineering, Kahramanmaras Sutcu Imam University, Kahramanmaraş 4610 (Turkey); Karataş, Şükrü [Department of Physics, Kahramanmaras Sutcu Imam University, Kahramanmaraş 4610 (Turkey); Yakuphanoğlu, Fahrettin [Department of Physics, Fırat University, Elazıg 2310 (Turkey)

    2014-11-01

    Highlights: • We report the synthesis of graphene oxide nanosheets and electrical characterization of graphene oxide based thin film transistor. • Graphene oxide (GO) nanosheets were prepared by using modified Hummers method. • We used insulator layers which are polymethylmethacrylate (PMMA) and polyvinyl phenol (PVP) for graphene oxide based thin flim transistor. - Abstract: We have studied the electrical characteristics of graphene oxide based thin flim transistor with the polymer insulators such as polymethyl methacrylate (PMMA) and poly-4-vinylphenol (PVP). Graphene oxide (GO) nanosheets were prepared by using modified Hummers method. The structural properties of GO nanosheets were characterized with Ultraviolet Visible (UV–vis), FT-IR spectroscopy and X-rays diffraction (XRD). Graphene oxide based thin flim transistor (GO-TFT) was prepared by a spin-coating and thermal evaporation technique. The electrical characterization of GO-TFT was analyzed by output and transfer characteristics by using Keithley-4200 semiconductor characterization system (SCS). The graphene oxide based thin flim transistor devices show p-type semiconducting behavior. The mobility, threshold voltage, sub-threshold swing value and I{sub on}/I{sub off} of GO-TFT were found to be 0.105 cm{sup 2} V{sup −1} s{sup −1}, −8.7 V, 4.03 V/decade and 10, respectively.

  5. Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

    Science.gov (United States)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2015-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  6. Discovery of biomarkers for oxidative stress based on cellular metabolomics.

    Science.gov (United States)

    Wang, Ningli; Wei, Jianteng; Liu, Yewei; Pei, Dong; Hu, Qingping; Wang, Yu; Di, Duolong

    2016-07-01

    Oxidative stress has a close relationship with various pathologic physiology phenomena and the potential biomarkers of oxidative stress may provide evidence for clinical diagnosis or disease prevention. Metabolomics was employed to identify the potential biomarkers of oxidative stress. High-performance liquid chromatography-diode array detector, mass spectrometry and partial least squares discriminate analysis were used in this study. The 10, 15 and 13 metabolites were considered to discriminate the model group, vitamin E-treated group and l-glutathione-treated group, respectively. Some of them have been identified, namely, malic acid, vitamin C, reduced glutathione and tryptophan. Identification of other potential biomarkers should be conducted and their physiological significance also needs to be elaborated.

  7. Processing, Structure and High Temperature Oxidation Properties of Polymer-Derived and Hafnium Oxide Based Ceramic Systems

    Science.gov (United States)

    Terauds, Kalvis

    Demands for hypersonic aircraft are driving the development of ultra-high temperature structural materials. These aircraft, envisioned to sustain Mach 5+, are expected to experience continuous temperatures of 1200--1800°C on the aircraft surface and temperatures as high as 2800°C in combustion zones. Breakthroughs in the development of fiber based ceramic matrix composites (CMCs) are opening the door to a new class of high-tech UHT structures for aerospace applications. One limitation with current carbon fiber or silicon carbide fiber based CMC technology is the inherent problem of material oxidation, requiring new approaches for protective environmental barrier coatings (EBC) in extreme environments. This thesis focuses on the development and characterization of SiCN-HfO2 based ceramic composite EBC systems to be used as a protective layer for silicon carbide fiber based CMCs. The presented work covers three main architectures for protection (i) multilayer films, (ii) polymer-derived HfSiCNO, and (iii) composite SiCN-HfO 2 infiltration. The scope of this thesis covers processing development, material characterization, and high temperature oxidation behavior of these three SiCN-HfO2 based systems. This work shows that the SiCN-HfO 2 composite materials react upon oxidation to form HfSiO4, offering a stable EBC in streaming air and water vapor at 1600°C.

  8. Efficient enhancement of bismuth NIR luminescence by aluminum and its mechanism in bismuth doped germanate laser glass

    DEFF Research Database (Denmark)

    Wang, L.P.; Tan, L.L.; Yue, Yuanzheng

    2016-01-01

    As a new member of laser glass family, bismuth-doped glasses have received rising interests due to the application of fiber amplifiers and laser sources in the new spectral range for the next-generation optical communication system. For practical application of the glasses, it must be considered ......+ are not completely randomly distributed inside germanate glass and they prefer the residence around tetrahedral AlO4 sites....

  9. 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

  10. Rapid and Sensitive Determination of Lipid Oxidation Using the Reagent Kit Based on Spectrophotometry (FOODLABfat System

    Directory of Open Access Journals (Sweden)

    Chang Woo Kwon

    2016-01-01

    Full Text Available The reliability and availability of FOODLABfat system for determining acid value (AV and peroxide value (POV were assessed during the hydrolytic rancidification and lipid oxidation of edible oils. This reagent kit based on spectrophotometry was compared to the official methods (ISO 660 and 3960 protocols based on manual titration employing the standard mixture for the simulated oxidation models and edible oils during the thermally induced oxidation at 180°C. The linear regression line of standard mixture and the significant difference of thermally oxidized time course study determined between them showed high correlations (R2=0.998 and p<0.05 in both AVs and POVs. Considering ISO protocols with a probability of human error in manual titration, the rapidness and simplicity of the reagent kit based on spectrophotometry make it a promising alternative to monitor the lipid oxidation of edible oils and lipid-containing foods.

  11. The Study of LeachateTreatment by Using Three Advanced Oxidation Process Based Wet air Oxidation

    Directory of Open Access Journals (Sweden)

    Behroz Karimi

    2013-01-01

    Full Text Available Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put under a 10-bar pressure, at temperatures of 100, 200, and 300[degree sign] as well as three retention times of 30, 60, and 90 minutes. The sample was placed at 18 stages of leachate storage ponds in Isfahan Compost Plant with the volume of 20 liters, using three WPO, WAO methods and a combination of WAO/GAC for leachate pre-treatment. Thirty percent of pure oxygen and hydrogen peroxide were applied as oxidation agents. The COD removal efficiency in WAO method is 7.8-33.3%, in BOD is 14.7-50.6%, the maximum removal percentage (efficiency for NH4-N is 53.3% and for NO3-N is 56.4-73.9%. The removal efficiency of COD and BOD5 is 4.6%-34 and 24%-50 respectively in WPO method. Adding GAC to the reactor, the removal efficiency of all parameters was improved. The maximum removal efficiency was increased 48% for COD, 31%-43.6 for BOD5 by a combinational method, and the ratio of BOD5/COD was also increased to 90%. In this paper, WAO and WPO process was used for Leachate pre-treatment and WAO/GAC combinational process was applied for improving the organic matter removal and leachate treatment; it was also determined that the recent process is much more efficient in removing resistant organic matter.

  12. Metal oxide-based, nano-structured catalyst materials for water oxidation

    OpenAIRE

    Fekete, Monika

    2017-01-01

    Hydrogen has the potential to revolutionalise the transportation fuels market towards a greener future. (Photo)electrocatalytic water splitting into oxygen and hydrogen, at present, is one of the most promising technologies that could render large-scale hydrogen production commercially viable. One of the main challenges that has hampered the widespread use of water electrolysis techniques is the large overpotential involved in the water oxidation (anode) reaction, that accompanies the hydr...

  13. Low temperature synthesis of fluorite-type Ce-based oxides of ...

    Indian Academy of Sciences (India)

    M MALATHI

    type) Ce-based oxides of ... M Malathi et al. Figure 1. The structures of (a) Fluorite (F-type), (b) Pyrochlore (P-type) and (c) C-type oxides. the phase formation can not only depend on the relative ..... Thermal Barrier Coatings J. Alloys Compd.

  14. In situ X-ray absorption spectroscopy of transition metal based water oxidation catalysts

    NARCIS (Netherlands)

    van Oversteeg, Christina H M|info:eu-repo/dai/nl/413490483; Doan, Hoang Q; de Groot, Frank M F|info:eu-repo/dai/nl/08747610X; Cuk, Tanja

    2016-01-01

    X-ray absorption studies of the geometric and electronic structure of primarily heterogeneous Co, Ni, and Mn based water oxidation catalysts are reviewed. The X-ray absorption near edge and extended X-ray absorption fine structure studies of the metal K-edge, characterize the metal oxidation state,

  15. Calcium Oxide Supported on Monoclinic Zirconia as a Highly Active Solid Base Catalyst

    NARCIS (Netherlands)

    Frey, A.M.; Haasterecht, van T.; Jong, de K.P.; Bitter, J.H.

    2013-01-01

    Calcium oxide supported on ZrO2 is a highly active catalyst for base-catalyzed reactions such as aldol-type reactions and transesterification reactions. The role of key parameters during preparation, that is, impregnation versus precipitation, heat treatment, and metal oxide loading on the basicity

  16. Low temperature synthesis of fluorite-type Ce-based oxides of ...

    Indian Academy of Sciences (India)

    M MALATHI

    type) Ce-based oxides of compositions Ln2Ce2O7 (Ln = Pr, Nd and Eu). F-type oxides can be considered as multi-functional materials due to the deficiency of anions. Pr2Ce2O7 (PCO), Nd2Ce2O7 (NCO) and Eu2Ce2O7 (ECO) were prepared ...

  17. Base-oxidant promoted metal-free N-demethylation of arylamines

    Indian Academy of Sciences (India)

    A metal-free oxidative N-demethylation of arylamines with triethylamine as a base and tert-butyl hydroperoxide (TBHP) as oxidant is reported in this paper. The reaction is general, practical, inexpensive, non-toxic, and the method followed is environmentally benign, with moderate to good yields.

  18. Oxide-based protonic conductors: Point defects and transport properties

    DEFF Research Database (Denmark)

    Bonanos, N.

    2001-01-01

    , hydrogen pumps, fuel cells, etc. The extent to which protonic defects form depends mainly on the partial pressure of water vapour, temperature and basicity of the constituent oxides, while their mobility depends, among other factors, on the metal-oxygen bond length and bond energy. The defect equilibria...

  19. Study of YSZ-based electrochemical sensors with oxide electrodes ...

    Indian Academy of Sciences (India)

    Unknown

    decade) to CO gas was also noticed. The response to CO was decreased (– 4 mV/decade) using Au electrode. The role played by WO3 on the sensing electrode was discussed. Keywords. Gas sensors; YSZ; oxide electrode. 1. Introduction.

  20. High-temperature oxidation kinetics of sponge-based E110 cladding alloy

    Science.gov (United States)

    Yan, Yong; Garrison, Benton E.; Howell, Mike; Bell, Gary L.

    2018-02-01

    Two-sided oxidation experiments were recently conducted at 900°C-1200 °C in flowing steam with samples of sponge-based Zr-1Nb alloy E110. Although the old electrolytic E110 tubing exhibited a high degree of susceptibility to nodular corrosion and experienced breakaway oxidation rates in a relatively short time, the new sponge-based E110 demonstrated steam oxidation behavior comparable to Zircaloy-4. Sample weight gain and oxide layer thickness measurements were performed on oxidized E110 specimens and compared to oxygen pickup and oxide layer thickness calculations using the Cathcart-Pawel correlation. Our study shows that the sponge-based E110 follows the parabolic law at temperatures above 1015 °C. At or below 1015 °C, the oxidation rate was very low when compared to Zircaloy-4 and can be represented by a cubic expression. No breakaway oxidation was observed at 1000 °C for oxidation times up to 10,000 s. Arrhenius expressions are given to describe the parabolic rate constants at temperatures above 1015 °C and cubic rate constants are provided for temperatures below 1015 °C. The weight gains calculated by our equations are in excellent agreement with the measured sample weight gains at all test temperatures. In addition to the as-fabricated E110 cladding sample, prehydrided E110 cladding with hydrogen concentrations in the 100-150 wppm range was also investigated. The effect of hydrogen content on sponge-based E110 oxidation kinetics was minimal. No significant difference was found between as-fabricated and hydrided samples with regard to oxygen pickup and oxide layer thickness for hydrogen contents below 150 wppm.

  1. Hierarchical oxide-based composite nanostructures for energy, environmental, and sensing applications

    Science.gov (United States)

    Gao, Pu-Xian; Shimpi, Paresh; Cai, Wenjie; Gao, Haiyong; Jian, Dunliang; Wrobel, Gregory

    2011-02-01

    Self-assembled composite nanostructures integrate various basic nano-elements such as nanoparticles, nanofilms and nanowires toward realizing multifunctional characteristics, which promises an important route with potentially high reward for the fast evolving nanoscience and nanotechnology. A broad array of hierarchical metal oxide based nanostructures have been designed and fabricated in our research group, involving semiconductor metal oxides, ternary functional oxides such as perovskites and spinels and quaternary dielectric hydroxyl metal oxides with diverse applications in efficient energy harvesting/saving/utilization, environmental protection/control, chemical sensing and thus impacting major grand challenges in the area of materials and nanotechnology. Two of our latest research activities have been highlighted specifically in semiconductor oxide alloy nanowires and metal oxide/perovskite composite nanowires, which could impact the application sectors in ultraviolet/blue lighting, visible solar absorption, vehicle and industry emission control, chemical sensing and control for vehicle combustors and power plants.

  2. Oxidative stability of fish oil-enriched mayonnaise-based salads

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Nielsen, Nina Skall; Jacobsen, Charlotte

    2010-01-01

    The oxidative stability of fish oil-enriched mayonnaise-based salads and the influence of different vegetables in shrimp and tuna salads were evaluated. Moreover, the lipid oxidation in the presence of 1% oregano, rosemary, or thyme in fish oil-enriched tuna salad was assessed. The results obtained...... showed that the mayonnaise itself was more oxidatively stable without vegetables and tuna or shrimp, in spite of the higher oil content in mayonnaise (63 and 6.3% fish oil, respectively) compared to salads (∼24 and 2.4% fish oil, respectively). Surprisingly, the fish oil-enriched mayonnaise was only...... significantly different from the standard mayonnaise in the volatile concentration during the end of storage. In fish oil-enriched shrimp salad, asparagus had an anti-oxidative effect and shrimp a pro-oxidative effect, where the anti-oxidative effect of asparagus was strong enough to prevent the pro...

  3. In situ X-ray absorption spectroscopy of transition metal based water oxidation catalysts.

    Science.gov (United States)

    van Oversteeg, Christina H M; Doan, Hoang Q; de Groot, Frank M F; Cuk, Tanja

    2017-01-03

    X-ray absorption studies of the geometric and electronic structure of primarily heterogeneous Co, Ni, and Mn based water oxidation catalysts are reviewed. The X-ray absorption near edge and extended X-ray absorption fine structure studies of the metal K-edge, characterize the metal oxidation state, metal-oxygen bond distance, metal-metal distance, and degree of disorder of the catalysts. These properties guide the coordination environment of the transition metal oxide radical that localizes surface holes and is required to oxidize water. The catalysts are investigated both as-prepared, in their native state, and under reaction conditions, while transition metal oxide radicals are generated. The findings of many experiments are summarized in tables. The advantages of future X-ray experiments on water oxidation catalysts, which include the limited data available of the oxygen K-edge, metal L-edge, and resonant inelastic X-ray scattering, are discussed.

  4. An Efficient Glycoblotting-Based Analysis of Oxidized Lipids in Liposomes and a Lipoprotein.

    Science.gov (United States)

    Furukawa, Takayuki; Hinou, Hiroshi; Takeda, Seiji; Chiba, Hitoshi; Nishimura, Shin-Ichiro; Hui, Shu-Ping

    2017-10-05

    Although widely occurring lipid oxidation, which is triggered by reactive oxygen species (ROS), produces a variety of oxidized lipids, practical methods to efficiently analyze oxidized lipids remain elusive. Herein, it is shown that the glycoblotting platform can be used to analyze oxidized lipids. Analysis is based on the principle that lipid aldehydes, one of the oxidized lipid species, can be captured selectively, enriched, and detected. Moreover, 3-methyl-1-p-tolyltriazene (MTT) methylates phosphoric and carboxylic acids, and this MTT-mediated methylation is, in combination with conventional tandem mass spectrometry (MS/MS) analysis, an effective method for the structural analysis of oxidized lipids. By using three classes of standards, liposomes, and a lipoprotein, it is demonstrated that glycoblotting represents a powerful approach for focused lipidomics, even in complex macromolecules. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Thermal stabilities of electromechanical properties in cobalt-modified strontium bismuth titanate (SrBi{sub 4}Ti{sub 4}O{sub 15})

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qian; Cao, Zhao-Peng; Wang, Chun-Ming, E-mail: wangcm@sdu.edu.cn; Fu, Qing-Wei; Yin, De-Fu; Tian, Hu-He

    2016-07-25

    Bismuth layer-structured ferroelectric (BLSF) strontium bismuth titanate (SrBi{sub 4}Ti{sub 4}O{sub 15}, SBT) ceramic oxides with B-site cobalt substitutions have been synthesized using conventional solid–state reaction. The dielectric, piezoelectric, and ferroelectric properties of cobalt-modified SBT are investigated in detail. The results indicate that cobalt is very effective in promoting the piezoelectric performance of SBT. The SBT modified with 3 mol% Co{sup 3+} (SBT-3Co) exhibits the optimized piezoelectric properties, with a piezoelectric constant d{sub 33} of 28 pC/N, which is the highest value among the modified SBT-based piezoelectric ceramics ever reported. The temperature-dependent electrical impedance, resonance frequencies, and electromechanical coupling factors (k{sub p} and k{sub t}) reveal that the cobalt-modified SBT ceramics have good thermal stabilities of electromechanical properties up to 300 °C. These results demonstrate that the cobalt-modified SBT ceramics are promising materials for high temperature piezoelectric sensors applications. - Graphical abstract: The manuscript deals with the thermal stabilities of piezoelectric properties of cobalt-modified SrBi{sub 4}Ti{sub 4}O{sub 15} (SBT) ceramics. The 3 mol% Co{sup 3+} modified SBT (SBT-3Co) ceramics exhibit a piezoelectric constant d{sub 33} of 28 pC/N and a Curie temperature T{sub c} of 528 °C. The SBT-3Co ceramics have good thermal stabilities of electromechanical properties up to 300 °C. - Highlights: • A high level of piezoelectric performance (d{sub 33}∼28 pC/N)is obtained. • High Curie temperature (T{sub c}∼528 °C) is acquired for the optimal composition. • The SBT-3Co exhibits good thermal stabilities of electromechanical properties. • The Co-modified SrBi{sub 4}Ti{sub 4}O{sub 15} is promising as high temperature piezoelectric material.

  6. A first principle study on electronic property of bismuth nano tubes

    International Nuclear Information System (INIS)

    Su Changrong; Li Jiaming

    2002-01-01

    A first principle molecular dynamics with density functional theory and ultra-soft pseudopotential has been performed on the bismuth nano tubes. The strain energies are found to follow the classical 1/R 2 strain law. The bismuth nano tubes are expected as semi-conductor with the band gaps around 0.7-0.8 eV

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 (BiFeO 3 ) 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. - Highlights: • Bismuth ferrite was synthesized by solution evaporation method. • The effect of different annealing atmosphere on magnetic properties was studied. • The magnetic properties dramatically increased in case of Oxygen annealing. • The influence of crystalline size on magnetic properties was studied. • The magnetization was decreased as the temperature and crystallite size increased.

  8. Method of Creating Micro-scale Silver Telluride Grains Covered with Bismuth Nanoparticles

    Science.gov (United States)

    Kim, Hyun-Jung (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Park, Yeonjoon (Inventor); Lee, Kunik (Inventor)

    2014-01-01

    Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.

  9. Effects of In Vitro Antibiotic Resistance on Treatment: Bismuth-Containing Regimens

    Directory of Open Access Journals (Sweden)

    Naoki Chiba

    2000-01-01

    Full Text Available Bismuth compounds remain useful for Helicobacter pylori eradication therapy. These include colloidal bismuth subcitrate (CBS, bismuth subsalicylate (BSS and, most recently, ranitidine bismuth citrate (RBC. CBS appears to prevent the development of imidazole resistance when coadministered with nitroimidazoles. Traditional triple therapy with bismuth, metronidazole and tetracycline or amoxicillin (BMT/A only partially overcomes metronidazole resistance. However, the addition of a PPI to bismuth triple therapy largely overcomes established metronidazole resistance if treatment is given for at least one week or more. When RBC rather than PPI is used with clarithromycin, this dual regimen appears to be more effective in preventing the development of secondary clarithromycin resistance. The triple combination of RBC, metronidazole and clarithromycin appears to be effective against metronidazole resistant strains of H pylori. Thus, overall, there is some evidence that bismuth compounds may prevent the development of antibiotic resistance and that existing antibiotic resistance may at least be partially overcome in vitro and in vivo. With the growing emergence of H pylori resistance to metronidazole and clarithromycin, further research to clarify the role of bismuth compounds is required.

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

    NARCIS (Netherlands)

    Kokorian, J; Engelen, Johannes Bernardus Charles; de Vries, Jeroen; Nazeer, H.; Woldering, L.A.; Abelmann, Leon

    2013-01-01

    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

  11. Cladding oxidation model development based on diffusion equations and a simulation of the monoclinic-tetragonal phase transformation of zirconia during transient oxidation

    Science.gov (United States)

    He, Xiaoqiang; Yu, Hongxing; Jiang, Guangming; Dang, Gaojian; Wu, Dan; Zhang, Yu

    2014-08-01

    Zircaloy cladding oxidation is mostly represented by parabolic rate correlation. But the correlation approach is not suitable for long-term isothermal oxidation [4] or oxidation occurs under steam starvation conditions [5] and cannot obtain the detailed oxygen distribution which impacts the detailed mechanical behavior. To obtain the detailed oxygen distribution, a multi-phase diffusion problem with moving boundaries was introduced to simulate the cladding oxidation [9,10]. However, the hysteresis phenomenon related to the coexistence of monoclinic-tetragonal phases of zirconia which are very important to model the cladding oxidation during a LOCA, is not analyzed. In this study, a cladding oxidation model based on diffusion equations in the temperature range from 923 K to 2098 K which contains β-Zr, α-Zr, monoclinic-ZrO2, tetragonal-ZrO2, and cubic-ZrO2 is developed and the detailed oxygen distribution in the cladding could be obtained. It showed that the simulations of short-term and long-term isothermal oxidation, transient oxidation, and oxidation under steam starvation conditions were reasonable through comparing with the experimental data. We found that our model can give a reasonable simulation of the hysteresis phenomenon of monoclinic-tetragonal phase transformation during transient oxidation as well as a much better simulation of the hypothetical LOCA transient oxidation experiments [11] in ORNL than that by the code based on the parabolic rate correlation. This indicates that the developed model can accurately simulate the cladding oxidation during a LOCA transient.

  12. Pollution Control Meets Sustainability: Structure-Activity Studies on New Iron Oxide-Based CO Oxidation Catalysts.

    Science.gov (United States)

    Schoch, Roland; Bauer, Matthias

    2016-08-09

    A new class of catalysts for the oxidation of CO based on iron oxide as a biocompatible, earth-abundant and non-toxic metal is presented. The catalytic activities achieved with these catalysts provide promising milestones towards the substitution of noble metals in CO oxidation catalysts. The catalysts can be obtained by using iron core-shell nanoparticle precursors. The metal used for the shell material determines whether the iron core is integrated in or isolated from the support. The active iron site is effectively integrated into the γ-Al2 O3 support if an aluminum shell is present in the core-shell precursor. When the metal used for the shell is different from the support, an isolated structure is formed. Using this directed synthesis approach, different iron oxide species can be obtained and their structural differences are linked to distinct catalytic activities, as demonstrated by combined in-depth analytical studies using XRD, X-ray absorption spectroscopy (XAS), UV/Vis, and Brunauer-Emmett-Teller (BET) analysis. The key species responsible for high catalytic activity is identified as isolated tetrahedrally coordinated Fe(III) centers, whereas aggregation leads to a reduction in activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Effects of p-substituents on electrochemical CO oxidation by Rh porphyrin-based catalysts.

    Science.gov (United States)

    Yamazaki, Shin-ichi; Yamada, Yusuke; Takeda, Sahori; Goto, Midori; Ioroi, Tsutomu; Siroma, Zyun; Yasuda, Kazuaki

    2010-08-21

    Electrochemical CO oxidation by several carbon-supported rhodium tetraphenylporphyrins with systematically varied meso-substituents was investigated. A quantitative analysis revealed that the p-substituents on the meso-phenyl groups significantly affected CO oxidation activity. The electrocatalytic reaction was characterized in detail based on the spectroscopic and X-ray structural results as well as electrochemical analyses. The difference in the activity among Rh porphyrins is discussed in terms of the properties of p-substituents along with a proposed reaction mechanism. Rhodium tetrakis(4-carboxyphenyl)porphyrin (Rh(TCPP)), which exhibited the highest activity among the porphyrins tested, oxidized CO at a high rate at much lower potentials (means that CO is electrochemically oxidized by this catalyst when a slight overpotential is applied during the operation of a proton exchange membrane fuel cell. This catalyst exhibited little H(2) oxidation activity, in contrast to Pt-based catalysts.

  14. Factors that influence telomeric oxidative base damage and repair by DNA glycosylase OGG1

    DEFF Research Database (Denmark)

    Rhee, David B; Ghosh, Avik; Lu, Jian

    2011-01-01

    Telomeres are nucleoprotein complexes at the ends of linear chromosomes in eukaryotes, and are essential in preventing chromosome termini from being recognized as broken DNA ends. Telomere shortening has been linked to cellular senescence and human aging, with oxidative stress as a major...... contributing factor. 7,8-Dihydro-8-oxogaunine (8-oxodG) is one of the most abundant oxidative guanine lesions, and 8-oxoguanine DNA glycosylase (OGG1) is involved in its removal. In this study, we examined if telomeric DNA is particularly susceptible to oxidative base damage and if telomere-specific factors...... affect the incision of oxidized guanines by OGG1. We demonstrated that telomeric TTAGGG repeats were more prone to oxidative base damage and repaired less efficiently than non-telomeric TG repeats in vivo. We also showed that the 8-oxodG-incision activity of OGG1 is similar in telomeric and non...

  15. Optical properties of bismuth-doped silica fibres in the temperature range 300 - 1500 K

    Energy Technology Data Exchange (ETDEWEB)

    Dvoretskii, D A; Bufetov, Igor' A; Vel' miskin, V V; Zlenko, Alexander S; Khopin, V F; Semjonov, S L; Guryanov, Aleksei N; Denisov, L K; Dianov, Evgenii M

    2012-09-30

    The visible and near-IR absorption and luminescence bands of bismuth-doped silica and germanosilicate fibres have been measured for the first time as a function of temperature. The temperature-dependent IR luminescence lifetime of a bismuth-related active centre associated with silicon in the germanosilicate fibre has been determined. The Bi{sup 3+} profile across the silica fibre preform is shown to differ markedly from the distribution of IR-emitting bismuth centres associated with silicon. The present results strongly suggest that the IR-emitting bismuth centre comprises a lowvalence bismuth ion and an oxygen-deficient glass network defect. (optical fibres, lasers and amplifiers. properties and applications)

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

    DEFF Research Database (Denmark)

    Mogensen, O.E.; Trumpy, Georg

    1969-01-01

    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...... of the 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...

  17. Microcontroller based instrumentation for heater control circuit of tin oxide based hydrogen sensor

    International Nuclear Information System (INIS)

    Premalatha, S.; Krithika, P.; Gunasekaran, G.; Ramakrishnan, R.; Ramanarayanan, R.R.; Prabhu, E.; Jayaraman, V.; Parthasarathy, R.

    2015-01-01

    A thin film sensor based on tin oxide developed in IGCAR is used to monitor very low levels of hydrogen (concentration ranging from 2 ppm to 80 ppm). The heater and the sensor patterns are integrated on a miniature alumina substrate and necessary electrical leads are taken out. For proper functioning of the sensor, the heater has to be maintained at a constant temperature of 350°C. The sensor output (voltage signal) varies with H 2 concentration. In fast breeder reactors, liquid sodium is used as coolant. The sensor is used to detect water/steam leak in secondary sodium circuit. During the start up of the reactor, steam leak into sodium circuit generates hydrogen gas as a product that doesn't dissolve in sodium, but escapes to the surge tank containing argon i.e. in cover gas plenum of sodium circuit. On-line monitoring of hydrogen in cover gas is done to detect an event of water/steam leakage. The focus of this project is on the instrumentation pertaining to the temperature control for the sensor heater. The tin oxide based hydrogen sensor is embedded in a substrate which consists of a platinum heater, essentially a resistor. There is no provision of embedding a temperature sensor on the heater surface due to the physical constraints, without which maintaining a constant heater temperature is a complex task

  18. Magneto-thermal conduction and phonon anomalies across magnetic transitions in multiferroic (poly and nanocrystalline) bismuth ferrite

    International Nuclear Information System (INIS)

    Uma, S.; Philip, J.

    2014-01-01

    Bismuth ferric oxide (BFO) or bismuth ferrite is a multiferroic material with perovskite structure in which ferroelectric and antiferromagnetic orderings coexist. The magneto-electric coupling in this material makes it interesting from fundamental physics and applications points of view. As a result of complex magneto-elastic coupling and spin-glass behavior at low temperatures, the material exhibits a number of phase transitions driven by magnetic ordering. Earlier reports indicate that the primary order parameter in these transitions is not polarization but are related to magnon mode softening. In order to throw more light on the magneto-elastic and phonon related properties of this material, we measured the thermal transport properties, thermal conductivity and specific heat capacity, in the presence of an external magnetic field and compared the results with the zero field case. Results are reported for polycrystalline as well as nanocrystalline samples of BFO between 140 K and 250 K. A photopyroelectric thermal wave technique has been employed for the measurements. Anomalies in thermal properties observed at 140 K, 200 K and 240 K in polycrystalline samples as well as their changes with applied field are explained in terms of magneto-elastic and spin–phonon couplings. It is found that the transitions get less well defined and one of the transition temperatures get shifted upwards considerably as the particle sizes are reduced to nanometer scales. Particle size dependences of phonon and magnon–phonon scattering are invoked to explain these results

  19. Structural and luminescence properties of Sm3+ -doped bismuth phosphate glass for orange-red photonic applications.

    Science.gov (United States)

    Damodaraiah, S; Reddy Prasad, V; Ratnakaram, Y C

    2018-05-01

    In the present study, the effect of bismuth oxide (Bi 2 O 3 ) content on the structural and optical properties of 0.5Sm 3+ -doped phosphate glass and the effect of concentration on structural and optical properties of Sm 3+ -doped bismuth phosphate (BiP) glass were studied. Structural characterization was accomplished using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and 31 P nuclear magnetic resonance (NMR) spectroscopy. Optical properties were studied using absorption, photoluminescence and decay measurements. Using optical absorption spectra, Judd-Ofelt parameters were derived to determine the local structure and bonding in the vicinity of Sm 3+ ions. The emission spectra of Sm 3+ -doped BiP glass showed two intense emission bands, 4 G 5/2 → 6 H 7/2 (orange) and 4 G 5/2 → 6 H 9/2 (red) for which the stimulated emission cross-sections (σ e ) and branching ratios (β) were found to be higher. The quantum efficiencies were also calculated from decay measurements recorded for the 4 G 5/2 level of Sm 3+ ions. The suitable combination of Bi 2 O 3 (10 mol%) and Sm 3+ (0.5 mol%) ions in these glasses acted as an efficient lasing material and might be suitable for the development of visible orange-red photonic materials. Copyright © 2018 John Wiley & Sons, Ltd.

  20. New nitric oxide donors based on ruthenium complexes

    Directory of Open Access Journals (Sweden)

    C.N. Lunardi

    2009-01-01

    Full Text Available Nitric oxide (NO donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2- by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension.