Influence of laser alloying with boron and niobium on microstructure and properties of Nimonic 80A-alloy

NASA Astrophysics Data System (ADS)

Makuch, N.; Piasecki, A.; Dziarski, P.; Kulka, M.

2015-12-01

Ni-base superalloys were widely used in aeronautics, chemical and petrochemical industries due to their high corrosion resistance, high creep and rupture strength at high temperature. However, these alloys were not considered for applications in which conditions of appreciable mechanical wear were predominant. The diffusion boriding provided suitable protection against wear. Unfortunately, this process required long duration and high temperature. In this study, instead of the diffusion process, the laser alloying with boron and niobium was used in order to produce the hard and wear resistant layer on Nimonic 80A-alloy. The laser-alloying was carried out as a two-step process. First, the external cylindrical surface of specimens was pre-placed with a paste containing boron and niobium. Then, the pre-placed coating and the thin surface layer of the substrate were re-melted by a laser beam. The high laser beam power (P=1.56 kW) and high averaging irradiance (E=49.66 kW/cm2) provided the thick laser re-melted zone. The laser-borided layers were significantly thicker (470 μm) in comparison with the layers obtained as a consequence of the diffusion boriding. Simultaneously, the high overlapping of multiple laser tracks (86%) caused that the laser-alloyed layer was uniform in respect of the thickness. The produced layer consisted of nickel borides (Ni3B, Ni2B, Ni4B3, NiB), chromium borides (CrB, Cr2B), niobium borides (NbB2, NbB) and Ni-phase. The presence of hard borides caused the increase in microhardness up to 1000 HV in the re-melted zone. However, the measured values were lower than those-characteristic of niobium borides, chromium borides and nickel borides. The presence of the soft Ni-phase in re-melted zone was the reason for such a situation. After laser alloying, the significant increase in abrasive wear resistance was also observed. The mass wear intensity factor, as well as the relative mass loss of the laser-alloyed specimens, was over 10 times smaller in comparison with untreated Nimonic 80A-alloy.

In Situ Solid-Gas Reactivity of Nanoscaled Metal Borides from Molten Salt Synthesis.

PubMed

Gouget, Guillaume; Debecker, Damien P; Kim, Ara; Olivieri, Giorgia; Gallet, Jean-Jacques; Bournel, Fabrice; Thomas, Cyril; Ersen, Ovidiu; Moldovan, Simona; Sanchez, Clément; Carenco, Sophie; Portehault, David

2017-08-07

Metal borides have mostly been studied as bulk materials. The nanoscale provides new opportunities to investigate the properties of these materials, e.g., nanoscale hardening and surface reactivity. Metal borides are often considered stable solids because of their covalent character, but little is known on their behavior under a reactive atmosphere, especially reductive gases. We use molten salt synthesis at 750 °C to provide cobalt monoboride (CoB) nanocrystals embedded in an amorphous layer of cobalt(II) and partially oxidized boron as a model platform to study morphological, chemical, and structural evolutions of the boride and the superficial layer exposed to argon, dihydrogen (H 2 ), and a mixture of H 2 and carbon dioxide (CO 2 ) through a multiscale in situ approach: environmental transmission electron microscopy, synchrotron-based near-ambient-pressure X-ray photoelectron spectroscopy, and near-edge X-ray absorption spectroscopy. Although the material is stable under argon, H 2 triggers at 400 °C decomposition of CoB, leading to cobalt(0) nanoparticles. We then show that H 2 activates CoB for the catalysis of CO 2 methanation. A similar decomposition process is also observed on NiB nanocrystals under oxidizing conditions at 300 °C. Our work highlights the instability under reactive atmospheres of nanocrystalline cobalt and nickel borides obtained from molten salt synthesis. Therefore, we question the general stability of metal borides with distinct compositions under such conditions. These results shed light on the actual species in metal boride catalysis and provide the framework for future applications of metal borides in their stability domains.

Interlayer utilization (including metal borides) for subsequent deposition of NSD films via microwave plasma CVD on 316 and 440C stainless steels

NASA Astrophysics Data System (ADS)

Ballinger, Jared

Diamond thin films have promising applications in numerous fields due to the extreme properties of diamonds in conjunction with the surface enhancement of thin films. Biomedical applications are numerous including temporary implants and various dental and surgical instruments. The unique combination of properties offered by nanostructured diamond films that make it such an attractive surface coating include extreme hardness, low obtainable surface roughness, excellent thermal conductivity, and chemical inertness. Regrettably, numerous problems exist when attempting to coat stainless steel with diamond generating a readily delaminated film: outward diffusion of iron to the surface, inward diffusion of carbon limiting necessary surface carbon precursor, and the mismatch between the coefficients of thermal expansion yielding substantial residual stress. While some exotic methods have been attempted to overcome these hindrances, the most common approach is the use of an intermediate layer between the stainless steel substrate and the diamond thin film. In this research, both 316 stainless steel disks and 440C stainless steel ball bearings were tested with interlayers including discrete coatings and graded, diffusion-based surface enhancements. Titanium nitride and thermochemical diffusion boride interlayers were both examined for their effectiveness at allowing for the growth of continuous and adherent diamond films. Titanium nitride interlayers were deposited by cathodic arc vacuum deposition on 440C bearings. Lower temperature diamond processing resulted in improved surface coverage after cooling, but ultimately, both continuity and adhesion of the nanostructured diamond films were unacceptable. The ability to grow quality diamond films on TiN interlayers is in agreement with previous work on iron and low alloy steel substrates, and the similarly seen inadequate adhesion strength is partially a consequence of the lacking establishment of an interfacial carbide phase. Surface boriding was implemented using the novel method of microwave plasma CVD with a mixture of hydrogen and diborane gases. On 440C bearings, dual phase boride layers of Fe2B and FeB were formed which supported adhered nanostructured diamond films. Continuity of the films was not seamless with limited regions remaining uncoated potentially corresponding to delamination of the film as evidenced by the presence of tubular structures presumably composed of sp2 bonded carbon. Surface boriding of 316 stainless steel discs was conducted at various powers and pressures to achieve temperatures ranging from 550-800 °C. The substrate boriding temperature was found to substantially influence the resultant interlayer by altering the metal boride(s) present. The lowest temperatures produced an interlayer where CrB was the single detected phase, higher temperatures yielded the presence of only Fe2B, and a combination of the two phases resulted from an intermediate boriding temperature. Compared with the more common, commercialized boriding methods, this a profound result given the problems posed by the FeB phase in addition to other advantages offered by CVD processes and microwave generated plasmas in general. Indentation testing of the boride layers revealed excellent adhesion strength for all borided interlayers, and above all, no evidence of cracking was observed for a sole Fe2B phase. As with boriding of 440C bearings, subsequent diamond deposition was achieved on these interlayers with substantially improved adhesion strength relative to diamond coated TiN interlayers. Both XRD and Raman spectroscopy confirmed a nanostructured diamond film with interfacial chromium carbides responsible for enhanced adhesion strength. Interlayers consisting solely of Fe2B have displayed an ability to support fully continuous nanostructured diamond films, yet additional study is required for consistent reproduction. This is in good agreement with initial work on pack borided high alloy steels to promote diamond film surface modification. The future direction for continued research of nanostructured diamond coatings on microwave plasma CVD borided stainless steel should further investigate the adhesion of both borided interlayers and subsequent NSD films in addition to short, interrupted diamond depositions to study the interlayer/diamond film interface.

Plasma boriding of a cobalt-chromium alloy as an interlayer for nanostructured diamond growth

NASA Astrophysics Data System (ADS)

Johnston, Jamin M.; Jubinsky, Matthew; Catledge, Shane A.

2015-02-01

Chemical vapor deposited (CVD) diamond coatings can potentially improve the wear resistance of cobalt-chromium medical implant surfaces, but the high cobalt content in these alloys acts as a catalyst to form graphitic carbon. Boriding by high temperature liquid baths and powder packing has been shown to improve CVD diamond compatibility with cobalt alloys. We use the microwave plasma-enhanced (PE) CVD process to deposit interlayers composed primarily of the borides of cobalt and chromium. The use of diborane (B2H6) in the plasma feedgas allows for the formation of a robust boride interlayer for suppressing graphitic carbon during subsequent CVD of nano-structured diamond (NSD). This metal-boride interlayer is shown to be an effective diffusion barrier against elemental cobalt for improving nucleation and adhesion of NSD coatings on a CoCrMo alloy. Migration of elemental cobalt to the surface of the interlayer is significantly reduced and undetectable on the surface of the subsequently-grown NSD coating. The effects of PECVD boriding are compared for a range of substrate temperatures and deposition times and are evaluated using glancing-angle X-ray diffraction (XRD), cross-sectional scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and micro-Raman spectroscopy. Boriding of CoCrMo results in adhered nanostructured diamond coatings with low surface roughness.

Analysis of Deformation Substructures in a Notched LCF Sample Under Dwell Condition in a Ni-Based Superalloy (PREPRINT)

DTIC Science & Technology

2012-08-01

interior, and carbides and borides at the grain boundaries. Blocky carbide particles can also be seen in the grain interior (Figure 1b). The borides ...can be seen distributed (b) higher magnification image of a typical grain boundary decorated with carbide and boride particles. Bi-modal distribution

Future Directions for Selected Topics in Physics and Materials Science

DTIC Science & Technology

2012-07-12

referred to as lightides (e.g. borides , nitrides, phosphides) • Materials for energy conversion, energy storage, energy transport and energy production...Distributed nanosystems and sensors • Strategy for multilayered combinatorics • lightides ( borides , nitrides, phosphides, • New applications for...Strategy for multilayered combinatorics Lightides ( borides , nitrides, phosphides) • Energy conversion, .storage and production • Precision control

Plasma metallurgical production of nanocrystalline borides and carbides

NASA Astrophysics Data System (ADS)

Galevsky, G. V.; Rudneva, V. V.; Cherepanov, A. N.; Galevsky, S. G.; Efimova, K. A.

2016-09-01

he experience in production and study of properties of nanocrystalline borides and chromium carbides, titanium, silicon was summarized. The design and features of the vertical three-jet once-through reactor with power 150 kW, used in the plasma metallurgical production, was described. The technological, thermotechnical and resource characteristics of the reactor were identified. The parameters of borides and carbides synthesis, their main characteristics in the nanodispersed state and equipment-technological scheme of production were provided. Evaluation of engineering-and-economical performance of the laboratory and industrial levels of borides and carbides production and the state corresponding to the segment of the world market was carried out.

The Growth Behavior of Titanium Boride Layers in α and β Phase Fields of Titanium

NASA Astrophysics Data System (ADS)

Lv, Xiaojun; Hu, Lingyun; Shuang, Yajing; Liu, Jianhua; Lai, Yanqing; Jiang, Liangxing; Li, Jie

2016-07-01

In this study, the commercially pure titanium was successfully electrochemical borided in a borax-based electrolyte. The process was carried out at a constant cathodic current density of 300 mA cm-2 and at temperatures of 1123 K and 1223 K (850 °C and 950 °C) for 0.5, 1, 2, 3, and 5 hours. The growth behavior of titanium boride layers in the α phase field of titanium was compared with that in the β phase field. After boriding, the presence of both the TiB2 top layer and TiB whisker sub-layer was confirmed by the X-ray diffraction (XRD) and scanning electron microscope. The relationship between the thickness of boride layers and boriding time was found to have a parabolic character in both α and β phase fields of titanium. The TiB whiskers showed ultra-fast growth rate in the β phase field. Its growth rate constant was found to be as high as 3.2002 × 10-13 m2 s-1. Besides, the chemical resistance of the TiB2 layer on the surface of titanium substrate was characterized by immersion tests in molten aluminum.

Kinetic Investigation and Wear Properties of Fe2B Layers on AISI 12L14 Steel

NASA Astrophysics Data System (ADS)

Keddam, M.; Ortiz-Dominguez, M.; Elias-Espinosa, M.; Arenas-Flores, A.; Zuno-Silva, J.; Zamarripa-Zepeda, D.; Gomez-Vargas, O. A.

2018-03-01

In the current study, the powder-pack boriding was applied to the AISI 12L14 steel in the temperature range 1123 K to 1273 K for an exposure time between 2 and 8 hours. The produced boride layer was composed of Fe2B with a sawtooth morphology. A diffusion model based on the integral method was applied to investigate the growth kinetics of Fe2B layers. As a main result, the boron diffusion coefficients in Fe2B were estimated by considering the principle of mass balance at the (Fe2B/substrate) interface with an inclusion of boride incubation times. The value of activation energy for boron diffusion in AISI 12L14 steel was estimated as 165 kJ mol-1 and compared with other values of activation energy found in the literature. An experimental validation of the present model was made by using four different boriding conditions. Furthermore, the Rockwell-C adhesion test was employed to assess the cohesion of boride layers to the base metal. The scratch and pin-on-disc tests were also carried out to analyze the effect of boriding on wear behavior of AISI 12L14 steel.

Suppression of Boride Formation in Transient Liquid Phase Bonding of Pairings of Parent Superalloy Materials with Different Compositions and Grain Structures and Resulting Mechanical Properties

NASA Astrophysics Data System (ADS)

Steuer, Susanne; Singer, Robert F.

2014-07-01

Two Ni-based superalloys, columnar grained Alloy 247 and single-crystal PWA1483, are joined by transient liquid phase bonding using an amorphous brazing foil containing boron as a melting point depressant. At lower brazing temperatures, two different morphologies of borides develop in both base materials: plate-like and globular ones. Their ratio to each other is temperature dependent. With very high brazing temperatures, the deleterious boride formation in Alloy 247 can be totally avoided, probably because the three-phase-field moves to higher alloying element contents. For the superalloy PWA1483, the formation of borides cannot be completely avoided at high brazing temperatures as incipient melting occurs. During subsequent solidification of these areas, Chinese-script-like borides precipitate. The mechanical properties (tensile tests at room and elevated temperatures and short-term creep rupture tests at elevated temperatures) for brazed samples without boride precipitation are very promising. Tensile strengths and creep times to 1 pct strain are comparable, respectively, higher than the ones of the weaker parent material for all tested temperatures and creep conditions (from 90 to 100 pct rsp. 175 to 250 pct).

Microstructure Evolution and Composition Control during the Processing of Thin-gage Metallic Foil (Preprint)

DTIC Science & Technology

2012-02-01

the presence of somewhat randomly-distributed carbides and borides (white particles in BSE images), this grain size was comparable to that observed...pinned by carbide/ boride particles (imaging white in Figure 8c). The very fine gamma-prime precipitates likely produced during magnetron sputtering...sputtered material. First, the carbide/ boride particles were nucleated and hence located preferentially at the grain boundaries in the sputtered

Novel Routes to Tune Thermal Conductivities and Thermoelectric Properties of Materials

DTIC Science & Technology

2012-11-15

expand the possibilities of borides as functional compou nds. A series of indium-free novel TCO compounds with novel crystal structures, has...powerful methods for modification were demonstrated in the borides , silicides and oxides. Introduction: The goal of this project is to...the possibility to modify the crystal structures can expand the possibilities of borides as functional compounds. A series of indium-free novel TCO

Alloying-Element Loss during High-Temperature Processing of a Nickel-Base Superalloy (Preprint)

DTIC Science & Technology

2013-01-01

precipitates, and the fine white/gray particles are carbides and borides . ............................................. 23 Figure 2. Aluminum...comparable size, and submicron carbides and borides . A fifteen-minute heat treatment at the subsolvus temperature used in the present work (i.e...precipitates, and ~0.3 volume pct. of carbides and borides with an average diameter of ~0.3 m (Figure 1) [5, 6]. B. Procedures To establish the

Amorphous Iron Borides: Preparation, Structure and Magnetic Properties.

DTIC Science & Technology

1982-09-28

temperature. External magnetic field experiments were performed in a superconducting solenoid with both source and absor- ber at 4.2 K. The observed...D-Ai20 919 AMORPHOUS IRON BORIDES: PREPARATION STRUCTURE AND i/i MAGNETIC PROPERTIES(U) JOHNS HOPKINS UNIV LAUREL NO APPLIED PHYSICS LRB K MOORJRNI...NATIONAL BUREAU OF STANOANOS-93-A 10 AMORPHOUS IRON BORIDES: PREPARATION, STRUCTURE ~AND MAGNETIC PROPERTIES FINAL REPORT Kishin Moorjani September 1982 U

Effect of Heat Treatment on Borides Precipitation and Mechanical Properties of CoCrFeNiAl1.8Cu0.7B0.3Si0.1 High-Entropy Alloy Prepared by Arc-Melting and Laser-Cladding

NASA Astrophysics Data System (ADS)

Zhang, H.; Tang, H.; He, Y. Z.; Zhang, J. L.; Li, W. H.; Guo, S.

2017-11-01

Effects of heat treatment on borides precipitation and mechanical properties of arc-melted and laser-cladded CoCrNiFeAl1.8Cu0.7B0.3Si0.1 high-entropy alloys were comparatively studied. The arc-melted alloy contains lots of long strip borides distributed in the body-centered cubic phase, with a hardness about 643 HV0.5. Laser-cladding can effectively inhibit the boride precipitation and the laser-cladded alloy is mainly composed of a simple bcc solid solution, with a high hardness about 769 HV0.5, indicating the strengthening effect by interstitial boron atoms is greater than the strengthening by borides precipitation. Heat treatments between 800°C and 1200°C can simultaneously improve the hardness and fracture toughness of arc-melted alloys, owing to the boride spheroidization, dissolution, re-precipitation, and hence the increased boron solubility and nano-precipitation in the bcc solid solution. By contrast, the hardness of laser-cladded alloys reduce after heat treatments in the same temperature range, due to the decreased boron solubility in the matrix.

Certain physical properties of cobalt and nickel borides

NASA Technical Reports Server (NTRS)

Kostetskiy, I. I.; Lvov, S. N.

1981-01-01

The temperature dependence of the electrical resistivity, the thermal conductivity, and the thermal emf of cobalt and nickel borides were studied. In the case of the nickel borides the magnetic susceptibility and the Hall coefficient were determined at room temperature. The results are discussed with allowance for the current carrier concentration, the effect of various mechanisms of current-carrier scattering and the location of the Fermi level in relation to the 3d band.

A study on the formation of solid state nanoscale materials using polyhedral borane compounds

NASA Astrophysics Data System (ADS)

Romero, Jennifer V.

The formation of boron containing materials using a variety of methods was explored. The pyrolysis of a metal boride precursor solution can be accomplished using a one-source method by combining TiCl4, B10H 14 and CH3CN in one reaction vessel and pyrolyzing it at temperatures above 900 °C. Amorphous dark blue colored films were obtained after the pyrolysis reactions. Well-defined spherical shaped grains or particles were observed by SEM. The amorphous films generated contained titanium, however, the determination of the boron content of the films was inconclusive. This one pot method making metal boride thin films has the advantage of being able to dictate the stoichiometry of the reactants. Another part of this work represents the first report of both the use of metal boride materials and the use of a titanium-based compound for the formation of nanotubes. This method provides a facile method for generating well-formed boron-containing carbon nanotubes in a "one-pot" process through an efficient aerosol process. The formation of metal boride corrosion resistant layers was also explored. It was shown that metallic substrates can be effectively boronized using paste mixtures containing boron carbide and borax. The formation of a Fe4B 2 iron boride phase was achieved, however, this iron boride phase does not give enough corrosion protection. The formation of a corrosion resistant metal boride coating with strong adhesion was accomplished by boronization of a thermal sprayed nickel layer on the surface of steel. Surfactants were explored as possible nanoreactors in which metal boride nanoparticles could be formed to use as nanotube growth catalyst via room temperature reaction. Different surfactants were used, but none of them successfully generated very well dispersed metal boride nanoparticles. Nanoparticles with varying shapes and sizes were generated which were highly amorphous. The carboxylic acid derivative of closo-C2B 10 cages was explored as a ligand in the hydrothermal preparation of coordination polymers with zinc salts. It was found that the stability of the cage is apparently insufficient under these conditions and cage degradation was observed. Consequently, a preliminary investigation of the preparation of dipyridyl derivatives of both the closo-C2B 10 and the closo-B12 cages was performed.

Synthesis and Characterization of YB4 Ceramics

DTIC Science & Technology

2011-06-24

capa bility at temperatures above 2000°C1 with adequate mechani cal properties and oxidation resistance. Refractory metal borides based on HfB2 and ZrB2...increase in the oxidation resistance was accomplished by the addition of the Group IV VI transition metal borides , which was the result of phase...metal borides for use as materials for ultra high temper ature (UHT) applications. However, for instance, yttrium tet raboride, YB4, appears promising as

Finding the Stable Structures of WxN1-x with an ab-initio High-Throughput Approach

DTIC Science & Technology

2014-03-13

cubic boron nitride[4], carbonitrides,[5] and transition metal borides .[6, 7] Over the past several years there has been considerable theoretical...include ionic and covalent structures which seem chemically similar to W-N. These include borides , carbides, oxides, and other nitrides. In this paper we...metallic alloys, [23–27] we extended it to include over fifty new structures. These include nitrides, oxides, borides , and carbides. The important

Magnesium Aluminum Borides as Explosive Materials

DTIC Science & Technology

2011-12-20

Metal Silicides , and Metal Borides by Chemical Vapour Deposition Using Single Organometallic Precursors,” Trans. Inst. Met. Finishing, 72, 127-129...391 (2003). 62. X. Xiaojing, D. Bohua, Q. Zuanhui, and L. Yuanhui, “ Preparation and Synthesis Mechanism of Li-B Alloy,” Rare Metal Materials and...SUPPLEMENTARY NOTES 14. ABSTRACT Metal boride.; and boroo carbide Witted l’"irh Al ’I\\· ere compared co B. Mg. Al Mg:-AJ and Si a.s poteotia! fuel ad.diti

Development of high temperature stable Ohmic and Schottky contacts on n-gallium nitride

NASA Astrophysics Data System (ADS)

Khanna, Rohit

In this work the effort was made to towards develop and investigate high temperature stable Ohmic and Schottky contacts for n type GaN. Various borides and refractory materials were incorporated in metallization scheme to best attain the desired effect of minimal degradation of contacts when placed at high temperatures. This work focuses on achieving a contact scheme using different borides which include two Tungsten Borides (namely W2B, W2B 5), Titanium Boride (TiB2), Chromium Boride (CrB2) and Zirconium Boride (ZrB2). Further a high temperature metal namely Iridium (Ir) was evaluated as a potential contact to n-GaN, as part of continuing improved device technology development. The main goal of this project was to investigate the most promising boride-based contact metallurgies on GaN, and finally to fabricate a High Electron Mobility Transistor (HEMT) and compare its reliability to a HEMT using present technology contact. Ohmic contacts were fabricated on n GaN using borides in the metallization scheme of Ti/Al/boride/Ti/Au. The characterization of the contacts was done using current-voltage measurements, scanning electron microscopy (SEM) and Auger Electron Spectroscopy (AES) measurements. The contacts formed gave specific contact resistance of the order of 10-5 to 10-6 Ohm-cm2. A minimum contact resistance of 1.5x10-6 O.cm 2 was achieved for the TiB2 based scheme at an annealing temperature of 850-900°C, which was comparable to a regular ohmic contact of Ti/Al/Ni/Au on n GaN. When some of borides contacts were placed on a hot plate or in hot oven for temperature ranging from 200°C to 350°C, the regular metallization contacts degraded before than borides ones. Even with a certain amount of intermixing of the metallization scheme the boride contacts showed minimal roughening and smoother morphology, which, in terms of edge acuity, is crucial for very small gate devices. Schottky contacts were also fabricated and characterized using all the five boride compounds. The barrier height obtained on n GaN was ˜0-5-0.6 eV which was low compared to those obtained by Pt or Ni. This barrier height is too low for use as a gate contact and they can only have limited use, perhaps, in gas sensors where large leakage current can be tolerated in exchange for better thermal reliability. AlGaN/GaN High Electron Mobility Transistors (HEMTs) were fabricated with Ti/Al/TiB2/Ti/Au source/drain ohmic contacts and a variety of gate metal schemes (Pt/Au, Ni/Au, Pt/TiB2/Au or Ni/TiB 2/Au) and were subjected to long-term annealing at 350°C. By comparison with companion devices with conventional Ti/Al/Pt/Au ohmic contacts and Pt/Au gate contacts, the HEMTs with boride-based ohmic metal and either Pt/Au, Ni/Au or Ni/TiB2/Au gate metal showed superior stability of both source-drain current and transconductance after 25 days aging at 350°C. The need for sputter deposition of the borides causes' problem in achieving significantly lower specific contact resistance than with conventional schemes deposited using e-beam evaporation. The borides also seem to be, in general, good getters for oxygen leading to sheet resistivity issues. Ir/Au Schottky contacts and Ti/Al/Ir/Au ohmic contacts on n-type GaN were investigated as a function of annealing temperature and compared to their more common Ni-based counterparts. The Ir/Au ohmic contacts on n-type GaN with n˜1017 cm-3 exhibited barrier heights of 0.55 eV after annealing at 700°C and displayed less intermixing of the contact metals compared to Ni/Au. A minimum specific contact resistance of 1.6 x 10-6 O.cm2 was obtained for the ohmic contacts on n-type GaN with n˜1018 cm-3 after annealing at 900°C. The measurement temperature dependence of contact resistance was similar for both Ti/Al/Ir/Au and Ti/Al/Ni/Au, suggesting the same transport mechanism was present in both types of contacts. The Ir-based ohmic contacts displayed superior thermal aging characteristics at 350°C. Auger Electron Spectroscopy showed that Ir is a superior diffusion barrier at these moderate temperatures than Ni.

Fabrication and Characterization of Plasma Electrolytic Borocarburized Layers on Q235 Low-Carbon Steel at Different Discharge Voltages

NASA Astrophysics Data System (ADS)

Wang, Bin; Wu, Jie; Jin, Xiaoyue; Wu, Xiaoling; Wu, Zhenglong; Xue, Wenbin

The influence of applied voltage on the plasma electrolytic borocarburizing (PEB/C) layer of Q235 low-carbon steel in high-concentration borax solution was investigated. XRD and XPS spectra of PEB/C layer confirmed that the modified boride layer mainly consisted of Fe2B phase, and the FeB phase only exists in the loose top layer. The applied voltage on Q235 steel played a key role in determining the properties of hardened layers. The thickness and microhardness of boride layers increased with the increase of the applied voltage, which led to superior corrosion and wear resistances of Q235 low-carbon steel. The diffusion coefficient (D) of boride layer at 280, 300 and 330V increased with borocarburizing temperature and ranged from 0.062×10-12m2/s to 0.462×10-12m2/s. The activation energy (Q) of boride layer growth during PEB/C treatment was only 52.83kJṡmol-1, which was much lower than that of the conventional boriding process.

Niobium boride layers deposition on the surface AISI D2 steel by a duplex treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kon, O., E-mail: okon42@htotmail.com; Pazarlioglu, S.; Sen, S.

2015-03-30

In this paper, we investigated the possibility of deposition of niobium boride layers on the surface of AISI D2 steel by a duplex treatment. At the first step of duplex treatment, boronizing was performed on AISI D2 steel samples at 1000{sup o}C for 2h and then pre-boronized samples niobized at 850°C, 900°C and 950°C using thermo-reactive deposition method for 1–4 h. The presence of the niobium boride layers such as NbB, NbB{sub 2} and Nb{sub 3}B{sub 4} and also iron boride phases such as FeB, Fe{sub 2}B were examined by X-ray diffraction analysis. Scanning electron microscope (SEM) and micro-hardness measurementsmore » were realized. Experimental studies showed that the depth of the coating layers increased with increasing temperature and times and also ranged from 0.42 µm to 2.43 µm, depending on treatment time and temperature. The hardness of the niobium boride layer was 2620±180 HV{sub 0.005}.« less

Crystal structure and phase stability of tungsten borides

NASA Astrophysics Data System (ADS)

Li, Quan; Zhou, Dan; Ma, Yanming; Chen, Changfeng

2013-03-01

We address the longstanding and controversial issue of ground-state structures of technically important tungsten borides using a first-principles structural search method via a particle-swarm optimization (PSO) algorithm. We have explored a large set of stable chemical compositions (convex hull) and clarified the ground-state structures for a wide range of boron concentrations, including W2B, W3B2,WB,W2B3, WB2,W2B5, WB3, and WB4. We further assessed relative stability of various tungsten borides and compared the calculated results with previously reported experimental data. The phase diagram predicted by the presented calculations may serve as a useful guide for synthesis of a variety of tungsten borides. This work was supported by DOE Grant No. DE-FC52-06NA26274.

High Energy Advanced Thermal Storage for Spacecraft Solar Thermal Power and Propulsion Systems

DTIC Science & Technology

2011-10-12

Vol. 108, No. 6, June 1961, pp. 568-572. 38. Storms, E. and Mueller, B., "Phase Relations and Thermodynamic Properties of Transition Metal Borides ...T., and Naka, S., "Formation Process of Tungsten Borides by Solid State Reaction Between Tungsten and Amorphous Boron," Journal of Materials...Molybdenum- Borides ," Journal of Metals, September 1952, pp. 983-988. 41. Ellis, R.C., “Various Preparations of Elemental Boron,” Proceedings of the 1st

Finding the Stable Structures of N1-xWx with an Ab Initio High-Throughput Approach

DTIC Science & Technology

2015-05-26

W. These include borides , carbides, oxides, and other nitrides. We also invented many structures to mimic the random pattern of vacancies on both the...structures. These include nitrides, oxides, borides , and carbides, as well as supercells of standard structures with atoms removed to mimic the random patter...1930). [15] R. Kiessling and Y. H. Liu, Thermal stability of the chromium, iron, and tungsten borides in streaming ammonia and the existence of a new

Molten Boron Phase-Change Thermal Energy Storage to Augment Solar Thermal Propulsion Systems

DTIC Science & Technology

2011-07-13

Thermodynamic Properties of Transition Metal Borides . I. The Molybdenum-boron system and Elemental Boron," Journal of Physical Chemistry, Vol. 81...February 1977, pp. 318-324. 38Itoh, H., Matsudaira, T., and Naka, S., "Formation Process of Tungsten Borides by Solid State Reaction Between Tungsten...Molybdenum-Boron and Some Properties of The Molybdenum- Borides ," Journal of Metals, September 1952, pp. 983-988. 40Stout, N. D., Mar, R. W., and Boo, W. O

Effects of Tungsten Addition on the Microstructure and Corrosion Resistance of Fe-3.5B Alloy in Liquid Zinc

PubMed Central

Liu, Xin; Wang, Mengmeng; Yin, Fucheng; Ouyang, Xuemei; Li, Zhi

2017-01-01

The effects of tungsten addition on the microstructure and corrosion resistance of Fe-3.5B alloys in a liquid zinc bath at 520 °C were investigated by means of scanning electron microscopy, X-ray diffraction and electron probe micro-analysis. The microstructure evolution in different alloys is analyzed and discussed using an extrapolated Fe-B-W ternary phase diagram. Experimental results show that there are three kinds of borides, the reticular (Fe, W)2B, the rod-like (Fe, W)3B and flower-like FeWB. The addition of tungsten can refine the microstructure and improve the stability of the reticular borides. Besides, it is beneficial to the formation of the metastable (Fe, W)3B phase. The resultant Fe-3.5B-11W (wt %) alloy possesses excellent corrosion resistance to liquid zinc. When tungsten content exceeds 11 wt %, the formed flower-like FeWB phase destroys the integrity of the reticular borides and results in the deterioration of the corrosion resistance. Also, the corrosion failure resulting from the spalling of borides due to the initiation of micro-cracks in the grain boundary of borides is discussed in this paper. PMID:28772759

Non-Contact Tabletop Mechanical Testing of Ultra-High Temperature Ceramics

DTIC Science & Technology

2012-05-01

class of refractory materials including transition metal borides , carbides and nitrides e.g. ZrB2l HfB2) ZrC, HfC, TaC, HfN and ZrN. They recently...ike oxidizing atmospheres, at very high temperatures Refractory borides like ZrB2 and HfB2 have extremely high melting temperatures (over 3000°C...But borides are very poor in oxidation resistance, due to the nature of thär oxides Non-protective ZrCfe or Hf02 and volatile liquid B203. Addition

Dislocation Decorrelation and Relationship to Deformation Microtwins during Creep of a Gamma’ Precipitate Strengthened Ni-based Superalloy

DTIC Science & Technology

2011-11-01

Deformation is highly localized around stress concentrators such as carbides, borides and serrated grain boundaries, which act as sources of a/2h110i...highly localized around stress concentrators such as carbides, borides and serrated grain boundaries, which act as sources of a/2h110i matrix-type...phase at different thicknesses. 7328 R.R. Unocic et al. / Acta Materialia 59 (2011) 7325–7339 the image. A number of carbide and/or boride phases are

Beta cell device using icosahedral boride compounds

DOEpatents

Aselage, Terrence L.; Emin, David

2002-01-01

A beta cell for converting beta-particle energies into electrical energy having a semiconductor junction that incorporates an icosahedral boride compound selected from B.sub.12 As.sub.2, B.sub.12 P.sub.2, elemental boron having an .alpha.-rhombohedral structure, elemental boron having a .beta.-rhombohedral structure, and boron carbides of the chemical formula B.sub.12-x C.sub.3-x, where 0.15

Nano-Disperse Borides and Carbides: Plasma Technology Production, Specific Properties, Economic Evaluation

NASA Astrophysics Data System (ADS)

Galevskii, G. V.; Rudneva, V. V.; Galevskii, S. G.; Tomas, K. I.; Zubkov, M. S.

2016-04-01

The experience of production and study on properties of nano-disperse chromium and titanium borides and carbides, and silicon carbide has been generalized. The structure and special service aspects of utilized plasma-metallurgical complex equipped with a three-jet direct-flow reactor with a capacity of 150 kW have been outlined. Processing, heat engineering and service life characteristics of the reactor are specified. The synthesis parameters of borides and carbides, as well as their basic characteristics in nano-disperse condition and their production flow diagram are outlined. Engineering and economic performance of synthesizing borides in laboratory and industrial conditions is assessed, and the respective segment of the international market as well. The work is performed at State Siberian Industrial University as a project part of the State Order of Ministry of Science and Education of the Russian Federation No. 11.1531/2014/K.

The effect of boriding on wear resistance of cold work tool steel

NASA Astrophysics Data System (ADS)

Anzawa, Y.; Koyama, S.; Shohji, I.

2017-05-01

Recently, boriding has attracted extensive attention as surface stiffening processing of plain steel. In this research, the influence of processing time on the formation layer of cold work tool steel (KD11MAX) by Al added fused salt bath was examined. In addition, in order to improve the abrasion resistance of KD11MAX, the effect of the treatment of boronization on the formation layer has been investigated. Boriding were performed in molten borax which contained about 10 mass% Al at processing time of 1.8 ~ 7.2 ks (processing temperature of 1303 K). As a result of the examination, the hardness of the boriding layer becomes about 1900 HV when the processing time of 3.6 ks. Also the abrasion resistance has improved remarkably. Furthermore, it was revealed that the formation layer was boronized iron from the Vickers hardness and analysis of the X-ray diffraction measurement.

Metal Immiscibility Route to Synthesis of Ultrathin Carbides, Borides, and Nitrides.

PubMed

Wang, Zixing; Kochat, Vidya; Pandey, Prafull; Kashyap, Sanjay; Chattopadhyay, Soham; Samanta, Atanu; Sarkar, Suman; Manimunda, Praveena; Zhang, Xiang; Asif, Syed; Singh, Abhisek K; Chattopadhyay, Kamanio; Tiwary, Chandra Sekhar; Ajayan, Pulickel M

2017-08-01

Ultrathin ceramic coatings are of high interest as protective coatings from aviation to biomedical applications. Here, a generic approach of making scalable ultrathin transition metal-carbide/boride/nitride using immiscibility of two metals is demonstrated. Ultrathin tantalum carbide, nitride, and boride are grown using chemical vapor deposition by heating a tantalum-copper bilayer with corresponding precursor (C 2 H 2 , B powder, and NH 3 ). The ultrathin crystals are found on the copper surface (opposite of the metal-metal junction). A detailed microscopy analysis followed by density functional theory based calculation demonstrates the migration mechanism, where Ta atoms prefer to stay in clusters in the Cu matrix. These ultrathin materials have good interface attachment with Cu, improving the scratch resistance and oxidation resistance of Cu. This metal-metal immiscibility system can be extended to other metals to synthesize metal carbide, boride, and nitride coatings. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kinetics and Tribological Characterization of Pack-Borided AISI 1025 Steel

NASA Astrophysics Data System (ADS)

Gómez-Vargas, O. A.; Keddam, M.; Ortiz-Domínguez, M.

2017-03-01

In this present study, the AISI 1025 steel was pack-borided in the temperature range of 1,123-1,273 K for different treatment times ranging from 2 to 8 h. A diffusion model was suggested to estimate the boron diffusion coefficients in the Fe2B layers. As a result, the boron activation energy for the AISI 1025 steel was estimated as 174.36 kJ/mol. This value of energy was compared with the literature data. To extend the validity of the present model, other additional boriding conditions were considered. The boride layers formed on the AISI 1025 steel were characterized by the following experimental techniques: scanning electron microscopy, X-ray diffraction analysis and the Daimler-Benz Rockwell-C indentation technique. Finally, the scratch and pin-on-disc tests for wear resistance were achieved using an LG Motion Ltd and a CSM tribometer, respectively, under dry sliding conditions.

Ceramic material suitable for repair of a space vehicle component in a microgravity and vacuum environment, method of making same, and method of repairing a space vehicle component

NASA Technical Reports Server (NTRS)

Riedell, James A. (Inventor); Easler, Timothy E. (Inventor)

2009-01-01

A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium diboride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

Effect of borides on hot deformation behavior and microstructure evolution of powder metallurgy high borated stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Xuan

To investigate borides effect on the hot deformation behavior and microstructure evolution of powder metallurgy high borated stainless steel, hot compression tests at the temperatures of 950– 1150 °C and the strain rates of 0.01– 10 s{sup −1} were performed. Flow stress curves indicated that borides increased the material's stress level at low temperature but the strength was sacrificed at temperatures above 1100 °C. A hyperbolic-sine equation was used to characterize the dependence of the flow stress on the deformation temperature and strain rate. The hot deformation activation energy and stress exponent were determined to be 355 kJ/mol and 3.2,more » respectively. The main factors leading to activation energy and stress exponent of studied steel lower than those of commercial 304 stainless steel were discussed. Processing maps at the strains of 0.1, 0.3, 0.5, and 0.7 showed that flow instability mainly concentrated at 950– 1150 °C and strain rate higher than 0.6 s{sup −1}. Results of microstructure illustrated that dynamic recrystallization was fully completed at both high temperature-low strain rate and low temperature-high strain rate. In the instability region cracks were generated in addition to cavities. Interestingly, borides maintained a preferential orientation resulting from particle rotation during compression. - Highlights: •The decrement of activation energy was affected by boride and boron solution. •The decrease of stress exponent was influenced by composition and Cottrell atmosphere. •Boride represented a preferential orientation caused by particle rotation.« less

On the Correlation between Morphology of alpha and Its Crystallographic Orientation Relationship with TiB and Beta in Boron Containing Ti-5Al-5Mo-5V-3Cr-0.5Fe Alloy (Preprint)

DTIC Science & Technology

2012-01-01

submitted to Metallurgical Transactions. This document contains color. 14. ABSTRACT While the role of borides on the microstructure of titanium...Ohio, U.S.A. Abstract While the role of borides on the microstructure of titanium alloys has been discussed in many previous reports, this paper...morphology of  precipitates nucleating from boride precipitates present in the  matrix of a titanium alloy; and (b) to investigate the role of presence or

Thermodynamic modelling of phase equilibrium in system Ti-B-Si-C, synthesis and phases composition of borides and carbides layers on titanic alloyVT-1 at electron beam treatment in vacuum

NASA Astrophysics Data System (ADS)

Smirnyagina, N. N.; Khaltanova, V. M.; Lapina, A. E.; Dasheev, D. E.

2017-01-01

Composite layers on the basis of carbides and borides the titan and silicon on titanic alloy VT-1 are generated at diffused saturation in vacuum. Formation in a composite of MAX phase Ti3SiC2 is shown. Thermodynamic research of phase equilibrium in systems Ti-Si-C and Ti-B-C in the conditions of high vacuum is executed. The thermodynamics, formation mechanisms of superfirm layers borides and carbides of the titan and silicon are investigated.

Effect of mechanical activation on jell boronizing treatment of the AISI 4140

NASA Astrophysics Data System (ADS)

Yılmaz, S. O.; Karataş, S.

2013-06-01

The article presents the effect of mechanical activation on the growth kinetics of boride layer of boronized AISI 4140 steel. The samples were boronized by ferroboron + (SiO2-Na2O) powders for 873-1173 K temperature and 2, 4, 6 and 8 h times, respectively. The morphology and types of borides formed on the surface of AISI 4140 steel substrate were analyzed. Layer growth kinetics were analyzed by measuring the extent of penetration of FeB and Fe2B sublayers as function of treatment time and temperature in the range of 873-1173 K. High diffusivity was obtained by creating a large number of defects through mechanical activation in the form of nanometer sized crystalline particles through the repeated fracturing and cold-welding of the powder particles, and a depth of 100 μm was found in the specimen borided by the 2 h MA powders, for 4 h and 1073 K, where 2000-2350 HV were measured. Consequently, the application conditions of boronizing were improved by usage of mechanical activation. The preferred Fe2B boride without FeB could be formed in the boride layer under 973 K boronizing temperature by mechanically activated by ferroboron + sodium silicate powder mixture due to the decrease of the activation energy.

Yttria Nanoparticle Reinforced Commercially Pure (CP) Titanium

DTIC Science & Technology

2011-09-01

nanoparticles as well as titanium boride (TiB) reinforcements were produced through gas atomization. After consolidation and extrusion, room temperature...pure FE iron O oxygen Ti titanium TiB titanium boride TYS tensile yield strength UTS ultimate tensile strength wt% weight percent Y2O3

Growth kinetics of borided layers: Artificial neural network and least square approaches

NASA Astrophysics Data System (ADS)

Campos, I.; Islas, M.; Ramírez, G.; VillaVelázquez, C.; Mota, C.

2007-05-01

The present study evaluates the growth kinetics of the boride layer Fe 2B in AISI 1045 steel, by means of neural networks and the least square techniques. The Fe 2B phase was formed at the material surface using the paste boriding process. The surface boron potential was modified considering different boron paste thicknesses, with exposure times of 2, 4 and 6 h, and treatment temperatures of 1193, 1223 and 1273 K. The neural network and the least square models were set by the layer thickness of Fe 2B phase, and assuming that the growth of the boride layer follows a parabolic law. The reliability of the techniques used is compared with a set of experiments at a temperature of 1223 K with 5 h of treatment time and boron potentials of 2, 3, 4 and 5 mm. The results of the Fe 2B layer thicknesses show a mean error of 5.31% for the neural network and 3.42% for the least square method.

Selection of peptides binding to metallic borides by screening M13 phage display libraries.

PubMed

Ploss, Martin; Facey, Sandra J; Bruhn, Carina; Zemel, Limor; Hofmann, Kathrin; Stark, Robert W; Albert, Barbara; Hauer, Bernhard

2014-02-10

Metal borides are a class of inorganic solids that is much less known and investigated than for example metal oxides or intermetallics. At the same time it is a highly versatile and interesting class of compounds in terms of physical and chemical properties, like semiconductivity, ferromagnetism, or catalytic activity. This makes these substances attractive for the generation of new materials. Very little is known about the interaction between organic materials and borides. To generate nanostructured and composite materials which consist of metal borides and organic modifiers it is necessary to develop new synthetic strategies. Phage peptide display libraries are commonly used to select peptides that bind specifically to metals, metal oxides, and semiconductors. Further, these binding peptides can serve as templates to control the nucleation and growth of inorganic nanoparticles. Additionally, the combination of two different binding motifs into a single bifunctional phage could be useful for the generation of new composite materials. In this study, we have identified a unique set of sequences that bind to amorphous and crystalline nickel boride (Ni3B) nanoparticles, from a random peptide library using the phage display technique. Using this technique, strong binders were identified that are selective for nickel boride. Sequence analysis of the peptides revealed that the sequences exhibit similar, yet subtle different patterns of amino acid usage. Although a predominant binding motif was not observed, certain charged amino acids emerged as essential in specific binding to both substrates. The 7-mer peptide sequence LGFREKE, isolated on amorphous Ni3B emerged as the best binder for both substrates. Fluorescence microscopy and atomic force microscopy confirmed the specific binding affinity of LGFREKE expressing phage to amorphous and crystalline Ni3B nanoparticles. This study is, to our knowledge, the first to identify peptides that bind specifically to amorphous and to crystalline Ni3B nanoparticles. We think that the identified strong binding sequences described here could potentially serve for the utilisation of M13 phage as a viable alternative to other methods to create tailor-made boride composite materials or new catalytic surfaces by a biologically driven nano-assembly synthesis and structuring.

Synthesis of Binary Transition Metal Nitrides, Carbides and Borides from the Elements in the Laser-Heated Diamond Anvil Cell and Their Structure-Property Relations

PubMed Central

Friedrich, Alexandra; Winkler, Björn; Juarez-Arellano, Erick A.; Bayarjargal, Lkhamsuren

2011-01-01

Transition metal nitrides, carbides and borides have a high potential for industrial applications as they not only have a high melting point but are generally harder and less compressible than the pure metals. Here we summarize recent advances in the synthesis of binary transition metal nitrides, carbides and borides focusing on the reaction of the elements at extreme conditions generated within the laser-heated diamond anvil cell. The current knowledge of their structures and high-pressure properties like high-(p,T) stability, compressibility and hardness is described as obtained from experiments. PMID:28824101

Directionally Solidified Eutectic Ceramics for Multifunctional Aerospace Applications

DTIC Science & Technology

2013-01-01

eutectic materials development through a new initiative entitled Boride Eutectic Project. These results first time organize and populate materials...property databases, and utilize an iterative feedback routine to constantly improve the design process of the boride eutectics LaB6-MeB2 (Me = Zr, Hf, Ti

Superabrasive boride and a method of preparing the same by mechanical alloying and hot pressing

DOEpatents

Cook, Bruce A.; Harringa, Joel L.; Russell, Alan M.

2002-08-13

A ceramic material which is an orthorhombic boride of the general formula: AlMgB.sub.14 :X, with X being a doping agent. The ceramic is a superabrasive, and in most instances provides a hardness of 40 GPa or greater.

Theoretical and Experimental Investigations on the Mechanism of Carbothermal Reduction of Zirconia (Preprint)

DTIC Science & Technology

2012-08-01

Properties. Abyss Books, Washington, D.C., 2002. 2. G. Montel, A. Lebugle and H. Pastor. "Manufacture of Materials Containing Refractory Borides ...and ZrO2," International Journal of Refractory Metals and Hard Materials, 17, 235-43 (1999). 10. A.W. Weimer, Carbide, nitride and boride

Adhesive and Cohesive Strength in FeB/Fe2B Systems

NASA Astrophysics Data System (ADS)

Meneses-Amador, A.; Blancas-Pérez, D.; Corpus-Mejía, R.; Rodríguez-Castro, G. A.; Martínez-Trinidad, J.; Jiménez-Tinoco, L. F.

2018-05-01

In this work, FeB/Fe2B systems were evaluated by the scratch test. The powder-pack boriding process was performed on the surface of AISI M2 steel. The mechanical parameters, such as yield stress and Young's modulus of the boride layer, were obtained by the instrumented indentation technique. Residual stresses produced on the boride layer were estimated by using the x-ray diffraction (XRD) technique. The scratch test was performed in order to evaluate the cohesive/adhesive strength of the FeB/Fe2B coating. In addition, a numerical evaluation of the scratch test on boride layers was performed by the finite element method. Maximum principal stresses were related to the failure mechanisms observed by the experimental scratch test. Shear stresses at the interfaces of the FeB/Fe2B/substrate system were also evaluated. Finally, the results obtained provide essential information about the effect of the layer thickness, the residual stresses, and the resilience modulus on the cohesive/adhesive strength in FeB/Fe2B systems.

The Effects of Borides on the Mechanical Properties of TLPB Repaired Inconel 738 Superalloy

NASA Astrophysics Data System (ADS)

Wei, J.; Ye, Y.; Sun, Z.; Zou, G.; Bai, H.; Wu, A.; Liu, L.

2017-10-01

The transient liquid phase diffusion bonding (TLPB) method was used to repair an artificial crack in Inconel 738, which was notched by a femtosecond laser. Mixed ratios of BNi-1a:DF-4B were investigated at the bonding temperature of 1373 K (1100 °C) for 2 to 36 hours. The effect of borides on the mechanical properties of TLPB repaired joints was studied through analysis of the microstructure, fracture path, and morphology observations. The borides formation, morphology, distribution, and joints strength were studied in detail. The results showed that the diffusion of B can either increase or decrease the joint strength, depending on its distribution and morphology. The amount of large blocky Ni-B compounds in the precipitate zone were reduced with increasing holding time, which resulted in an increase in joint strength. Nevertheless, further increasing the holding time led to a decrease in joint strength because of the formation of continuous acicular borides in the diffusion-affected zone. The fracture modes of TLPB joints were also discussed on the basis of the microstructure and fractography.

Micro-Abrasion Wear Resistance of Borided 316L Stainless Steel and AISI 1018 Steel

NASA Astrophysics Data System (ADS)

Reséndiz-Calderon, C. D.; Rodríguez-Castro, G. A.; Meneses-Amador, A.; Campos-Silva, I. E.; Andraca-Adame, J.; Palomar-Pardavé, M. E.; Gallardo-Hernández, E. A.

2017-11-01

The 316L stainless steel has high corrosion resistance but low tribological performance. In different industrial sectors (biomedical, chemical, petrochemical, and nuclear engineering), improvement upon wear resistance of 316L stainless steel components using accessible and inexpensive methods is critical. The AISI 1018 steel is widely used in industry, but its tribological performance is not the best among steels. Therefore, in this study the behavior of the borided 316L stainless steel and 1018 steel is evaluated under micro-abrasion wear. The boriding was carried out at 1223 K over 6 h of exposure time, resulting in a biphase layer composed of FeB/Fe2B phases. In order to evaluate Fe2B phase with no influence from FeB phase, AISI 1018 steel samples were borided at 1273 K for over 20 min and then diffusion annealed at 1273 K over 2 h to obtain a Fe2B mono-phase layer. Micro-abrasion wear resistance was evaluated by a commercial micro-abrasion testing rig using a mix of F-1200 SiC particles with deionized water as abrasive slurry. The obtained wear rates for FeB and Fe2B phases and for the 316L stainless steel were compared. Wear resistance of 316L stainless steel increases after boriding. The wear mechanisms for both phases and for the stainless steel were identified. Also, transient conditions for rolling and grooving abrasion were determined for the FeB and Fe2B phases.

Surface decoration through electrostatic interaction leading to enhanced reactivity: Low temperature synthesis of nanostructured chromium borides (CrB and CrB{sub 2})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menaka,; Kumar, Bharat; Kumar, Sandeep

The present study describes a novel low temperature route at ambient pressure for the synthesis of nanocrystalline chromium borides (CrB and CrB{sub 2}) without using any flux or additives. The favorable and intimate mixing of nanoparticles of chromium acetate (Cr source) and boron forms an active chromium–boron precursor which decomposes at much lower temperature (400 °C) to form CrB (which is ∼1000 °C less than the known ambient pressure synthesis). The chromium acetate nanoparticles (∼5 nm) decorate the larger boron particles (150–200 nm) due to electrostatic interactions resulting from opposing surface charges of boron (zeta potential:+48.101 mV) and chromium acetatemore » (zeta potential:−4.021 mV) in ethanolic medium and is evident in the TEM micrographs. The above method leads to the formation of pure CrB film like structure at 400 °C and nanospheres (40–60 nm) at 600 °C. Also, chromium diboride (CrB{sub 2}) nanoparticles (25 nm) could be obtained at 1000 °C. - Graphical abstract: Variation of surface charge of reactants, precursor and the products, chromium borides (CrB and CrB{sub 2}). Highlights: ► Novel borothermal reduction process for synthesis of chromium boride. ► Significant lowering of reaction temperature to obtain nanocrystalline chromium boride. ► Enhanced reactivity due to appropriate surface interactions.« less

Investigation of diffusional interaction between P91 grade ferritic steel and Fe-15 wt.%B alloy and study of kinetics of boride formation at high temperature

NASA Astrophysics Data System (ADS)

Rai, Arun Kumar; Vijayashanthi, N.; Tripathy, H.; Hajra, R. N.; Raju, S.; Murugesan, S.; Saroja, S.

2017-11-01

In the present study, the feasibility of employing the indigenously developed ferroboron alloy (Fe-15 wt.%B) as an alternate neutron shield material in combination with 9Cr-based ferritic steel (P91) clad in future Indian fast breeder reactors (FBR), has been investigated from a metallurgical perspective. Towards this goal, a series of diffusion couple experiments have been conducted at three different temperatures namely, 600, 700 and 800 °C for time durations up to 5000 h. The thickness of interaction layer has been monitored using standard metallographic procedures. The experiments revealed that ferroboron/P91 combination exhibited a tendency to form complex intermetallic borides at the interface. The structural and microstructural characterization of the interface confirmed that the reaction layer consists predominantly of borides of Fe and Cr of type FeB, Fe2B, (Fe,Cr)2B and (Fe,Cr)B. The measured variation of interaction layer thickness as a function of time and temperature have been modelled in terms of diffusion mediated interaction. The growth kinetics of borided layer has followed the parabolic law at each temperature, and the apparent activation energy for boride layer formation is found to be of the order of 115 kJ mol-1. This indicates that the kinetics of boriding could be governed by diffusion of B into the P91 matrix. Based on the findings of present study, an extrapolative estimate of the clad attack thickness at 550 °C for 60 years of operating time has been made and it turns out to be 210 ± 15 μm, which is less than the clad thickness of FBR shielding subassembly (4 mm) [1]. Thus, this study confirms that at testing temperatures from 550 to 600 °C, the ferroboron/P91 steel combination can be safely employed for shielding subassembly applications in fast reactors.

Kinetics of electrolysis current reversal boriding of tool steels in a boron-containing oxychloride melt based on CaCl2

NASA Astrophysics Data System (ADS)

Chernov, Ya. B.; Filatov, E. S.

2017-08-01

The kinetics of thermal diffusion boriding in a melt based on calcium chloride with a boron oxide additive is studied using reversed current. The main temperature, concentration, and current parameters of the process are determined. The phase composition of the coating is determined by a metallographic method.

Search for New Superconductors for Energy and Power Applications

DTIC Science & Technology

2014-10-21

superconductors, borides , carbides, silicides, and chalcogenides. In addition, a number of thin film systems have been explored: A15s, superlattices, arrays of...YBa2Cu3O7 Bi2Se3 Eu-Si-C ErRh4B4 Bi2Sr2CaCu2O8 (UD, OD) Sb2Se3 V-Si-C (Ga,Mn)As CuO ZrSe2 Sm-Si-C Hf(FeCo)P Y1-xCaxCrO3 Fe-Te-Se BORIDES Hf-Fe-C-P...Physics, Warsaw, Poland Table III New superconductors, discovered by UCSD MURI team. BORIDES Tc (K) Nb0.9Zr0.1B 11.2 ZrNbxB 9.0 ZrVxB 9.0

Silicon carbide sintered body manufactured from silicon carbide powder containing boron, silicon and carbonaceous additive

NASA Technical Reports Server (NTRS)

Tanaka, Hidehiko

1987-01-01

A silicon carbide powder of a 5-micron grain size is mixed with 0.15 to 0.60 wt% mixture of a boron compound, i.e., boric acid, boron carbide (B4C), silicon boride (SiB4 or SiB6), aluminum boride, etc., and an aluminum compound, i.e., aluminum, aluminum oxide, aluminum hydroxide, aluminum carbide, etc., or aluminum boride (AlB2) alone, in such a proportion that the boron/aluminum atomic ratio in the sintered body becomes 0.05 to 0.25 wt% and 0.05 to 0.40 wt%, respectively, together with a carbonaceous additive to supply enough carbon to convert oxygen accompanying raw materials and additives into carbon monoxide.

Method of boronizing transition metal surfaces

DOEpatents

Koyama, Koichiro; Shimotake, Hiroshi

1983-01-01

A method is presented for preparing a boride layer on a transition metal substrate for use in corrosive environments or as a harden surface in machine applications. This method is particularly useful in treating current collectors for use within a high temperature and corrosive electrochemical cell environment. A melt of a alkali metal boride tetrafluoride salt including such as KF to lower its melting point is prepared including a dissolved boron containing material, for instance NiB, MnB.sub.2, or CrB.sub.2. A transition metal to be coated is immersed in the melt at a temperature of no more than 700.degree. C. and a surface boride layer of that transition metal is formed within a period of about 24 hours on the substrate surface.

Subminiature eddy current transducers for studying boride coatings

NASA Astrophysics Data System (ADS)

Dmitriev, S. F.; Ishkov, A. V.; Malikov, V. N.; Sagalakov, A. M.

2016-07-01

Strengthening of parts and units of machines, increased reliability and longer service life is an important task of modern mechanical engineering. The main objects of study in the work were selected steel 65G and 50HGA, wear-resistant boride coatings ternary system Fe-B-Fe n B which were investigated by scanning electron microscopy and eddy-current nondestructive methods.

Demonstration of Shear Localization in Ultrafine Grained Tungsten Alloys via Powder Metallurgy Processing Route

DTIC Science & Technology

2012-09-01

of a di-tungsten boride (W2B) phase was not detected in the nW-B sample, but the low concentration of boron may have made this phase undetectable by...Split Hopkinson Bar UFG ultrafine grained W2B di-tungsten boride XRD x-ray diffraction NO. OF NO. OF COPIES ORGANIZATION COPIES

Slater-Pauling behavior within quaternary intermetallic borides of the Ti{sub 3}Co{sub 5}B{sub 2} structure-type

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burghaus, Jens; Dronskowski, Richard, E-mail: drons@HAL9000.ac.rwth-aachen.d; Miller, Gordon J.

2009-10-15

First-principles, density-functional studies of several intermetallic borides of the general type M{sub 2}M'Ru{sub 5-n}Rh{sub n}B{sub 2} (n=0-5; M=Sc, Ti, Nb; M'=Fe, Co) show that the variation in saturation magnetic moment with valence-electron count follows a Slater-Pauling curve, with a maximum moment occurring typically at 66 valence electrons. The magnetic moments in these compounds occur primarily from the 3d electrons of the magnetically active M' sites, with some contribution from the Ru/Rh sites via magnetic polarization. Electronic DOS curves reveal that a rigid-band approach is a reasonable approximation for the estimation of saturation moments and the analysis of orbital interactions inmore » this family of complex borides. COHP analyses of the M'-M' orbital interactions indicate optimized interactions in the minority spin states for Co-containing phases, but strong bonding interactions remaining in Fe-containing phases. - Graphical abstract: Theoretically determined (spin-polarized LMTO-GGA) local magnetic moments as a function of the chemical valence Z for various intermetallic borides.« less

Superplastic behavior of two ultrahigh boron steels

NASA Astrophysics Data System (ADS)

Jiménez, J. A.; González-Doncel, G.; Acosta, P.; Ruano, O. A.

1994-06-01

The high-temperature deformation behavior of two ultrahigh boron steels containing 2.2 pct and 4.9 pct B was investigated. Both alloys were processed via powder metallurgy involving gas atomization and hot isostatic pressing (hipping) at various temperatures. After hipping at 700 °C, the Fe-2.2 pct B alloy showed a fine microstructure consisting of l- µm grains and small elongated borides (less than 1 µm) . At 1100 °C, a coarser microstructure with rounded borides was formed. This alloy was superplastic at 850 °C with stress exponents of about two and tensile elongations as high as 435 pct. The microstructure of the Fe-4.9 pct B alloy was similar to that of the Fe-2.2 pct B alloy showing, in addition, coarse borides. This alloy also showed low stress exponent values but lacked high tensile elongation (less than 65 pct), which was attributed to the presence of stress accumulation at the interface between the matrix and the large borides. A change in the activation energy value at the α-γ transformation temperature was seen in the Fe-2.2 pct B alloy. The plastic flow data were in agreement with grain boundary sliding and slip creep models.

Friction and wear of radiofrequency-sputtered borides, silicides, and carbides

NASA Technical Reports Server (NTRS)

Brainard, W. A.; Wheeler, D. R.

1978-01-01

The friction and wear properties of several refractory compound coatings were examined. These compounds were applied to 440 C bearing steel surfaces by radiofrequency (RF) sputtering. The refractory compounds were the titanium and molybdenum borides, the titanium and molybdenum silicides, and the titanium, molybdenum, and boron carbides. Friction testing was done with a pin-on-disk wear apparatus at loads from 0.1 to 5.0 newtons. Generally, the best wear properties were obtained when the coatings were bias sputtered onto 440 C disks that had been preoxidized. Adherence was improved because of the better bonding of the coatings to the iron oxide formed during preoxidation. As a class the carbides provided wear protection to the highest loads. Titanium boride coatings provided low friction and good wear properties to moderate loads.

Low temperature InP /Si wafer bonding using boride treated surface

NASA Astrophysics Data System (ADS)

Huang, Hui; Ren, Xiaomin; Wang, Wenjuan; Song, Hailan; Wang, Qi; Cai, Shiwei; Huang, Yongqing

2007-04-01

An approach for InP /Si wafer bonding based on boride-solution treatment was presented. The bonding energy is higher than the InP fracture energy by annealing at 280°C. An In0.53Ga0.47As/InP multiple-quantum-well (MQW) structure grown on InP was transferred onto Si substrate via the bonding process. X-ray diffraction and photoluminescence reveal that crystal quality of the bonded MQW was preserved. A thin B2O3-POx-SiO2 oxide layer of about 28nm thick at the bonding interface was detected. X-ray photoelectron spectroscopy and Raman analyses indicate that the formation of oxygen bridging bonds by boride treatment is responsible for the strong fusion obtained at such low temperature.

Method of boronizing transition metal surfaces

DOEpatents

Koyama, Koichiro; Shimotake, Hiroshi.

1983-08-16

A method is presented for preparing a boride layer on a transition metal substrate for use in corrosive environments or as a harden surface in machine applications. This method is particularly useful in treating current collectors for use within a high temperature and corrosive electrochemical cell environment. A melt of a alkali metal boride tetrafluoride salt including such as KF to lower its melting point is prepared including a dissolved boron containing material, for instance NiB, MnB[sub 2], or CrB[sub 2]. A transition metal to be coated is immersed in the melt at a temperature of no more than 700 C and a surface boride layer of that transition metal is formed within a period of about 24 hours on the substrate surface. 4 figs.

Taguchi Analysis on the Effect of Process Parameters on Densification During Spark Plasma Sintering of HfB2-20SiC (Preprint)

DTIC Science & Technology

2011-11-01

30 kN pressure and heating rate of 100 K/min. Introduction Boride , carbides and nitrides of the group IVB and VB transition metals are considered...10. Sciti D., Silvestroni L., Nygren M. Spark plasma sintering of Zr- and Hf- borides with decreasing amounts of MoSi2 as sintering aid Journal of

Phase identification in boron-containing powder metallurgy steel using EBSD in combination with EPMA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Ming-Wei, E-mail: mwwu@ntut.edu.tw; Cai, Wen-Zhang

2016-03-15

Boron (B) is extensively used to induce liquid phase sintering (LPS) in powder metallurgy (PM) steels and thereby increase the densification. The alloying elements in B-containing PM steels affect the boride phase, stability of the boride, the temperature of liquid formation, and the progress of LPS. However, the boride phase has not been systematically identified yet. The main objective of this study was to clarify the influences of alloying elements, including C, Cr, and Ni, on the boride phases using electron backscatter diffraction (EBSD) in combination with electron probe microanalysis (EPMA). Network structures consisting of ferrite, Fe{sub 2}B boride, andmore » Fe{sub 3}C carbide were extensively observed in the Fe–0.4B–0.5C steel. The portions of Fe{sub 2}B were sufficiently larger than those of Fe{sub 3}C, and Fe{sub 3}C was mostly distributed at the interfaces between ferrite and Fe{sub 2}B. Adding 1.5 wt.% Cr or 1.8 wt.% Ni to Fe–0.4B–0.5C steel completely changes the Fe{sub 2}B and Fe{sub 3}C phases to a M{sub 3}(B,C) phase, where M represents the metallic elements, including Fe, Cr, Mo, and Ni. Furthermore, Cr, Mo, B, and C atoms tend to concentrate on the M{sub 3}(B,C) phase, but Ni atoms do not. - Highlights: • Network structures consisting of ferrite, Fe{sub 2}B boride, and Fe{sub 3}C carbide were extensively observed in the Fe–0.4B–0.5C steel. • Adding 1.5 wt.% Cr or 1.8 wt.% Ni to Fe–0.4B–0.5C steel completely transforms the Fe{sub 2}B and Fe{sub 3}C phases to a M{sub 3}(B,C) phase. • Cr, Mo, B, and C atoms tend to concentrate on the M{sub 3}(B,C) phase, but Ni atoms do not.« less

Multifunctional Ceramic Nanostructured Coatings

DTIC Science & Technology

2010-12-01

silicon carbide composites // J. Europ. Cer. Soc. − 2004. − Vol. 24. − P. 2169−2179. 22. Yu. P. Udalov, E. E. Valova, S. S. Ordanian. Fabrication and...by the titanium and tungsten borides and carbides . The analysis was done using the X-ray and electron-optical methods. This information expands our...coating compositions should be based on limited solubility materials. Such systems include carbides , nitrides, borides and silicides based on

Structure of superhard tungsten tetraboride: A missing link between MB2 and MB12 higher borides

PubMed Central

Lech, Andrew T.; Turner, Christopher L.; Mohammadi, Reza; Tolbert, Sarah H.; Kaner, Richard B.

2015-01-01

Superhard metals are of interest as possible replacements with enhanced properties over the metal carbides commonly used in cutting, drilling, and wear-resistant tooling. Of the superhard metals, the highest boride of tungsten—often referred to as WB4 and sometimes as W1–xB3—is one of the most promising candidates. The structure of this boride, however, has never been fully resolved, despite the fact that it was discovered in 1961—a fact that severely limits our understanding of its structure–property relationships and has generated increasing controversy in the literature. Here, we present a new crystallographic model of this compound based on refinement against time-of-flight neutron diffraction data. Contrary to previous X-ray–only structural refinements, there is strong evidence for the presence of interstitial arrangements of boron atoms and polyhedral bonding. The formation of these polyhedra—slightly distorted boron cuboctahedra—appears to be dependent upon the defective nature of the tungsten-deficient metal sublattice. This previously unidentified structure type has an intermediary relationship between MB2 and MB12 type boride polymorphs. Manipulation of the fractionally occupied metal and boron sites may provide insight for the rational design of new superhard metals. PMID:25733870

Analysis of boron carbides' electronic structure

NASA Technical Reports Server (NTRS)

Howard, Iris A.; Beckel, Charles L.

1986-01-01

The electronic properties of boron-rich icosahedral clusters were studied as a means of understanding the electronic structure of the icosahedral borides such as boron carbide. A lower bound was estimated on bipolaron formation energies in B12 and B11C icosahedra, and the associated distortions. While the magnitude of the distortion associated with bipolaron formation is similar in both cases, the calculated formation energies differ greatly, formation being much more favorable on B11C icosahedra. The stable positions of a divalent atom relative to an icosahedral borane was also investigated, with the result that a stable energy minimum was found when the atom is at the center of the borane, internal to the B12 cage. If incorporation of dopant atoms into B12 cages in icosahedral boride solids is feasible, novel materials might result. In addition, the normal modes of a B12H12 cluster, of the C2B10 cage in para-carborane, and of a B12 icosahedron of reduced (D sub 3d) symmetry, such as is found in the icosahedral borides, were calculated. The nature of these vibrational modes will be important in determining, for instance, the character of the electron-lattice coupling in the borides, and in analyzing the lattice contribution to the thermal conductivity.

Electrochemical Corrosion Behavior of Spray-Formed Boron-Modified Supermartensitic Stainless Steel

NASA Astrophysics Data System (ADS)

Zepon, Guilherme; Nogueira, Ricardo P.; Kiminami, Claudio S.; Botta, Walter J.; Bolfarini, Claudemiro

2017-04-01

Spray-formed boron-modified supermartensitic stainless steel (SMSS) grades are alloys developed to withstand severe wear conditions. The addition of boron to the conventional chemical composition of SMSS, combined with the solidification features promoted by the spray forming process, leads to a microstructure composed of low carbon martensitic matrix reinforced by an eutectic network of M2B-type borides, which considerably increases the wear resistance of the stainless steel. Although the presence of borides in the microstructure has a very beneficial effect on the wear properties of the alloy, their effect on the corrosion resistance of the stainless steel was not comprehensively evaluated. The present work presents a study of the effect of boron addition on the corrosion resistance of the spray-formed boron-modified SMSS grades by means of electrochemical techniques. The borides fraction seems to have some influence on the repassivation kinetics of the spray-formed boron-modified SMSS. It was shown that the Cr content of the martensitic matrix is the microstructural feature deciding the corrosion resistance of this sort of alloys. Therefore, if the Cr content in the alloy is increased to around 14 wt pct to compensate for the boron consumed by the borides formation, the corrosion resistance of the alloy is kept at the same level of the alloy without boron addition.

A Crossover from High Stiffness to High Hardness: The Case of Osmium and Its Borides

NASA Astrophysics Data System (ADS)

Bian, Yongming; Liu, Xiaomei; Li, Anhu; Liang, Yongcheng

2016-09-01

Transition-metal light-element compounds are currently raising great expectations for hard and superhard materials. Using the widely attracting osmium (Os) and its borides (OsB, Os2B3 and OsB2) as prototypes, we demonstrate by first-principles calculations that heavy transition metals, which possess high stiffness but low hardness, can be converted into highly hard materials by incorporating of light elements to form compounds. Such a crossover is a manifestation that the underlying sources of high stiffness and high hardness are fundamentally different. The stiffness is related to elastic deformation that is closely associated with valence electron density, whereas the hardness depends strongly on plastic deformation that is determined by bonding nature. Therefore, the incorporation of light atoms into transition metal should be a valid pathway of designing hard and superhard materials. This strategy is in principle also applicable to other transition-metal borides, carbides, and nitrides.

Investigation of the structure and properties of boron-containing coatings obtained by electron-beam treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krivezhenko, Dina S., E-mail: dinylkaa@yandex.ru; Drobyaz, Ekaterina A., E-mail: ekaterina.drobyaz@yandex.ru; Bataev, Ivan A., E-mail: ivanbataev@ngs.ru

2015-10-27

An investigation of surface-hardened materials obtained by cladding with an electron beam injected into the air atmosphere was carried out. Structural investigations of coatings revealed that an increase in boron carbide concentration in a saturating mixture contributed to a rise of a volume fraction of iron borides in coatings. The maximum hardened depth reached 2 mm. Hardened layers were characterized by the formation of heterogeneous structure which consisted of iron borides and titanium carbides distributed uniformly in the eutectic matrix. Areas of titanium boride conglomerations were detected. It was found that an increase in the boron carbide content led to anmore » enhancement in hardness of the investigated materials. Friction testing against loosely fixed abrasive particles showed that electron-beam cladding of powder mixtures containing boron carbides, titanium, and iron in air atmosphere allowed enhancing a resistance of materials hardened in two times.« less

Thermodynamical and thermoelectric properties of boron doped YPd{sub 3} and YRh{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dwivedi, Shalini; Sharma, Yamini, E-mail: sharma.yamini62@gmail.com; Sharma, Ramesh

2016-05-23

The structural, electronic, thermal, and optical properties of borides of cubic non-magnetic YX{sub 3} (X=Rh, Pd) compounds and their borides which crystallize in the AuCu{sub 3} structure have been studied using the density functional theory (DFT). The flat bands in the vicinity of E{sub F} which are associated with superconductivity appear in YPd{sub 3} and YRh{sub 3} band structures. However, the B s-states enhance the flat band only in YRh{sub 3}B. The optical properties clearly show that boron insertion modifies the absorption and transmittance. The YX{sub 3} alloys and their borides exhibit valuable changes in the thermopower and ZT. Itmore » is observed that the properties of the Y-X intermetallics change significantly for the Y-Rh and Y-Pd alloys and the presence of single boron atom modifies the properties to a great extent.« less

Magnetization Analysis of Magnesium Boride Wires

NASA Astrophysics Data System (ADS)

Cave, J. R.; Zhu, W.

2006-03-01

Cycled applied field magnetization curves contain a wealth of information on critical current density and flux pinning that is not commonly exploited. Detailed magnetization data for magnesium boride wire cores have been analyzed for critical state model consistency. The iron-sheathed silicon nitride doped magnesium boride wires were prepared from pure magnesium and boron powders with nano-scale silicon nitride additions (MgB2-x(Si3N4)x/7 with x = 0 - 0.4). A subsequent short annealing heat treatment, 800 degrees C and of 1 hour duration in Argon, was applied to create the desired phase. Magnetization critical current densities were up to ˜340 kA/cm2 at 5K and 1T. Major and minor loop analysis will be described, for field sweeps up to 3 tesla at fixed temperatures and for temperature sweeps from 5K to 45K in fixed fields, with respect to parameters describing the critical state model.

Investigation of the structure and properties of boron-containing coatings obtained by electron-beam treatment

NASA Astrophysics Data System (ADS)

Krivezhenko, Dina S.; Drobyaz, Ekaterina A.; Bataev, Ivan A.; Chuchkova, Lyubov V.

2015-10-01

An investigation of surface-hardened materials obtained by cladding with an electron beam injected into the air atmosphere was carried out. Structural investigations of coatings revealed that an increase in boron carbide concentration in a saturating mixture contributed to a rise of a volume fraction of iron borides in coatings. The maximum hardened depth reached 2 mm. Hardened layers were characterized by the formation of heterogeneous structure which consisted of iron borides and titanium carbides distributed uniformly in the eutectic matrix. Areas of titanium boride conglomerations were detected. It was found that an increase in the boron carbide content led to an enhancement in hardness of the investigated materials. Friction testing against loosely fixed abrasive particles showed that electron-beam cladding of powder mixtures containing boron carbides, titanium, and iron in air atmosphere allowed enhancing a resistance of materials hardened in two times.

Crystal structures and compressibility of novel iron borides Fe{sub 2}B{sub 7} and Fe{sub x}B{sub 50} synthesized at high pressure and high temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bykova, E., E-mail: elena.bykova@uni-bayreuth.de; Laboratory of Crystallography, University of Bayreuth, D-95440 Bayreuth; Gou, H.

2015-10-15

We present here a detailed description of the crystal structures of novel iron borides, Fe{sub 2}B{sub 7} and Fe{sub x}B{sub 50} with various iron content (x=1.01(1), 1.04(1), 1.32(1)), synthesized at high pressures and high temperatures. As revealed by high-pressure single-crystal X-ray diffraction, the structure of Fe{sub 2}B{sub 7} possesses short incompressible B–B bonds, which make it as stiff as diamond in one crystallographic direction. The volume compressibility of Fe{sub 2}B{sub 7} (the bulk modulus K{sub 0}= 259(1.8) GPa, K{sub 0}′= 4 (fixed)) is even lower than that of FeB{sub 4} and comparable with that of MnB{sub 4}, known for highmore » bulk moduli among 3d metal borides. Fe{sub x}B{sub 50} adopts the structure of the tetragonal δ-B, in which Fe atoms occupy an interstitial position. Fe{sub x}B{sub 50} does not show considerable anisotropy in the elastic behavior. - Graphical abstract: Crystal structures of novel iron borides, Fe{sub 2}B{sub 7} and Fe{sub x}B{sub 50} (x=1.01(1), 1.04(1), 1.32(1)). - Highlights: • Novel iron borides, Fe{sub 2}B{sub 7} and Fe{sub x}B{sub 50}, were synthesized under HPHT conditions. • Fe{sub 2}B{sub 7} has a unique orthorhombic structure (space group Pbam). • Fe{sub 2}B{sub 7} possesses short incompressible B–B bonds that results in high bulk modulus. • Fe{sub x}B{sub 50} adopts the structure of the tetragonal δ-B composed of B{sub 12} icosahedra. • In Fe{sub x}B{sub 50} intraicosahedral bonds are stiffer than intericosahedral ones.« less

Radiopacifier Particle Size Impacts the Physical Properties of Tricalcium Silicate–based Cements

PubMed Central

Saghiri, Mohammad Ali; Gutmann, James L.; Orangi, Jafar; Asatourian, Armen; Sheibani, Nader

2016-01-01

Introduction The aim of this study was to evaluate the impact of radiopaque additive, bismuth oxide, particle size on the physical properties, and radiopacity of tricalcium silicate–based cements. Methods Six types of tricalcium silicate cement (CSC) including CSC without bismuth oxide, CSC + 10% (wt%) regular bismuth oxide (particle size 10 μm), CSC + 20% regular bismuth oxide (simulating white mineral trioxide aggregate [WMTA]) as a control, CSC + 10% nano bismuth oxide (particle size 50–80 nm), CSC + 20% nano-size bismuth oxide, and nano WMTA (a nano modification of WMTA comprising nanoparticles in the range of 40–100 nm) were prepared. Twenty-four samples from each group were divided into 4 groups and subjected to push-out, surface microhardness, radiopacity, and compressive strength tests. Data were analyzed by 1-way analysis of variance with the post hoc Tukey test. Results The push-out and compressive strength of CSC without bismuth oxide and CSC with 10% and 20% nano bismuth oxide were significantly higher than CSC with 10% or 20% regular bismuth oxide (P < .05). The surface micro-hardness of CSC without bismuth oxide and CSC with 10% regular bismuth oxide had the lowest values (P < .05). The lowest radiopacity values were seen in CSC without bismuth oxide and CSC with 10% nano bismuth oxide (P < .05). Nano WMTA samples showed the highest values for all tested properties (P < .05) except for radiopacity. Conclusions The addition of 20% nano bismuth oxide enhanced the physical properties of CSC without any significant changes in radiopacity. Regular particle-size bismuth oxide reduced the physical properties of CSC material for tested parameters. PMID:25492489

The effect of melt refining upon inclusions in aluminum

NASA Astrophysics Data System (ADS)

Simensen, C. J.

1982-03-01

A series of aluminum melts has been refined with respect to inclusions by use of ALCOA 469, FILD, or SNIF. The content and size distribution of inclusions in the original-and the refined melts-have been measured by use of neutron activation (oxygen content), gas chromatography (carbide content), sedimentation analysis, and dissolution of metal in hydrochloric acid and subsequent analysis of oxides by means of a Coulter Counter. All the units tested have a beneficial effect and decrease the inclusion content, but the number of analyses are too few to make general conclusions. However, for melts cleaned by use of SNIF, it was found that oxides larger than 50 μm in cross section and borides larger than 20 μm in diameter were removed, while the smaller borides were agglomerated only. The effect of FILD and ALCOA 469 upon the melt tested was removal of borides larger than 5-10 μ m and oxides larger than 15μm in diameter, respectively.

Interfacial reactions in borsic/Ti-3Al-2-1/2V composite

NASA Technical Reports Server (NTRS)

Rao, V. B.; Houska, C. R.; Unnam, J.; Brewer, W. D.; Tenney, D. R.

1979-01-01

The paper provides a detailed X-ray characterization of a borsic/Ti-3Al-2-1/2V composite, and to correlate the relative intensities of the reaction products with the mechanical properties. Based on X-ray integrated intensity data two stages of interface reactions were identified: during the first stage there is a simultaneous interdiffusion of Si, C, and Ti atoms at the filament/matrix interface resulting in the formation of Ti5Si3, TiSi and small amounts of TiSi2 and TiC. The second stage is associated with considerable TiSi2 and boride formation. It appears that the alpha-phase of Ti is more reactive in forming silicides and borides than the beta-phase. The silicide intensities and the reaction zone thicknesses are shown to be directly related to the reduction of the ultimate tensile strength by thermal degradation, and the results indicate that silicide reaction products are as detrimental to strength as the borides.

A Simple Kinetic Model for the Growth of Fe2B Layers on AISI 1026 Steel During the Powder-pack Boriding

NASA Astrophysics Data System (ADS)

Flores-Rentería, M. A.; Ortiz-Domínguez, M.; Keddam, M.; Damián-Mejía, O.; Elias-Espinosa, M.; Flores-González, M. A.; Medina-Moreno, S. A.; Cruz-Avilés, A.; Villanueva-Ibañez, M.

2015-02-01

This work focused on the determination of boron diffusion coefficient through the Fe2B layers on AISI 1026 steel using a mathematical model. The suggested model solves the mass balance equation at the (Fe2B/substrate) interface. This thermochemical treatment was carried out in the temperature range of 1123-1273 K for a treatment time ranging from 2 to 8 h. The generated boride layers were characterized by different experimental techniques such as light optical microscopy, scanning electron microscopy, XRD analysis and the Daimler-Benz Rockwell-C indentation technique. As a result, the boron activation energy for AISI 1026 steel was estimated as 178.4 kJ/mol. Furthermore, this kinetic model was validated by comparing the experimental Fe2B layer thickness with the predicted one at a temperature of 1253 K for 5 h of treatment. A contour diagram relating the layer thickness to the boriding parameters was proposed to be used in practical applications.

Amorphous nickel boride membrane on a platinum-nickel alloy surface for enhanced oxygen reduction reaction.

PubMed

He, Daping; Zhang, Libo; He, Dongsheng; Zhou, Gang; Lin, Yue; Deng, Zhaoxiang; Hong, Xun; Wu, Yuen; Chen, Chen; Li, Yadong

2016-08-09

The low activity of the oxygen reduction reaction in polymer electrolyte membrane fuel cells is a major barrier for electrocatalysis, and hence needs to be optimized. Tuning the surface electronic structure of platinum-based bimetallic alloys, a promising oxygen reduction reaction catalyst, plays a key role in controlling its interaction with reactants, and thus affects the efficiency. Here we report that a dealloying process can be utilized to experimentally fabricate the interface between dealloyed platinum-nickel alloy and amorphous nickel boride membrane. The coating membrane works as an electron acceptor to tune the surface electronic structure of the platinum-nickel catalyst, and this composite catalyst composed of crystalline platinum-nickel covered by amorphous nickel boride achieves a 27-times enhancement in mass activity relative to commercial platinum/carbon at 0.9 V for the oxygen reduction reaction performance. Moreover, this interactional effect between a crystalline surface and amorphous membrane can be readily generalized to facilitate the 3-times higher catalytic activity of commercial platinum/carbon.

Influence of heat treatment on microstructure and hot crack susceptibility of laser-drilled turbine blades made from Rene 80

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osterle, W.; Krause, S.; Moelders, T.

2008-11-15

Turbine components from conventionally cast nickel-base alloy Rene 80 show different hot cracking susceptibilities depending on their heat treatment conditions leading to slightly different microstructures. Electron probe micro-analysis, focused ion beam technique and analytical transmission electron microscopy were applied to reveal and identify grain boundary precipitates and the {gamma}-{gamma}'-microstructure. The distribution of borides along grain boundaries was evaluated statistically by quantitative metallography. The following features could be correlated with an increase of cracking susceptibility: i) Increasing grain size, ii) increasing fraction of grain boundaries with densely spaced borides, iii) lack of secondary {gamma}'-particles in matrix channels between the coarse cuboidalmore » {gamma}'-precipitates. The latter feature seems to be responsible for linking-up of cracked grain boundary precipitates which occurred as an additional cracking mechanism after one heat treatment, whereas decohesion at the boride-matrix-interface in the heat affected zone of laser-drilled holes was observed for both heat treatments.« less

Method of making an icosahedral boride structure

DOEpatents

Hersee, Stephen D.; Wang, Ronghua; Zubia, David; Aselage, Terrance L.; Emin, David

2005-01-11

A method for fabricating thin films of an icosahedral boride on a silicon carbide (SiC) substrate is provided. Preferably the icosahedral boride layer is comprised of either boron phosphide (B.sub.12 P.sub.2) or boron arsenide (B.sub.12 As.sub.2). The provided method achieves improved film crystallinity and lowered impurity concentrations. In one aspect, an epitaxially grown layer of B.sub.12 P.sub.2 with a base layer or substrate of SiC is provided. In another aspect, an epitaxially grown layer of B.sub.12 As.sub.2 with a base layer or substrate of SiC is provided. In yet another aspect, thin films of B.sub.12 P.sub.2 or B.sub.12 As.sub.2 are formed on SiC using CVD or other vapor deposition means. If CVD techniques are employed, preferably the deposition temperature is above 1050.degree. C., more preferably in the range of 1100.degree. C. to 1400.degree. C., and still more preferably approximately 1150.degree. C.

Microstructure and mechanical properties of Ni and Fe-base boride-dispersion-strengthened microcrystalline alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wade, C.S.; Park, H.G.; Hoagland, R.G.

This paper considers the relation between microstructure and mechanical properties of two Ni-base and two Fe-base Boride-Dispersion-Strengthened Microcrystalline (BDSM) alloys. In these very fine grained materials the borides were primarily Cr, Mo, and MoFe in a fcc matrix in three of the alloys, and a bcc in one of the Fe-base alloys. Strength data and resistance to stress corrosion cracking are reported and, in the latter case, extraordinary resistance to SCC in NaCl, Na{sub 2}S{sub 2}O{sub 3} and boiling MgCl{sub 2} environments was observed in every case. The fcc BDSM alloys also demonstrated excellent thermal stability in terms of strengthmore » and fracture roughness up to 1000 C. The bcc alloy suffered severe loss of toughness. The fracture mode involved ductile rupture in all alloys and they display a reasonably linear correlation between K{sub Ic} and the square root of particle spacing.« less

Magnetic properties and magnetic hardening mechansim of Pt-Co-B alloys

NASA Technical Reports Server (NTRS)

Qiu, Ning; Flanagan, F.; Wittig, James E.

1994-01-01

The intrinsic coercivity is found to be maximized in the Pt42Co45B13 ternary alloy which is undercooled and rapidly solidified (quenched using a 70 m/s wheel speed after undercooling), and then annealed (800 C for 2400 min). The same alloy, processed at slower cooling rates and annealed in the same way, has a much larger scale microstructure and a much lower resulting magnetic coercivity. The microstructure which would optimize the coercitvity of this coercivity of this ternary alloy is a completely ordered L1(sub zero) Pt-Co matrix with a submicron magnetic single-domion Co-boride precipitate. The L1(sub zero) phase is highly anistropic magnetically while the Co-boride precipate is somewhat less so. Annealing treatments designed to produced single-domain Co-boride precipitates enhance the coercivity. This suggests that the refined microstructures is responsible for the high coercivities found in the rapidly solidified and annealed alloy. The magnetic domain wall thickness for a Co-boride precipitate is determined from both experimental observation and theoretical calculation in order to evaluate its influence on the coercivity of the alloy. The effects of the pinning of domain walls and the barrier to the nucleation of reverse domains on the coercivity are discussed. Both microstrucutral analysis and theoretical calculation indicate that the high coercivities in the Pt42Co45B13 alloy are due to the difficult nucleation of reverse magnetic domains.

Bismuth oxyfluoride @ CMK-3 nanocomposite as cathode for lithium ion batteries

NASA Astrophysics Data System (ADS)

Ni, Dan; Sun, Wang; Xie, Liqiang; Fan, Qinghua; Wang, Zhenhua; Sun, Kening

2018-01-01

Bismuth oxyfluoride impregnated CMK-3 nanocomposite is synthesized by a facile nanocasting approach. Mesoporous carbon CMK-3 can suppress the aggregation and growth of bismuth oxyfluoride particles and offer rapid electron and Li ion passageways. Bismuth oxyfluoride nanoparticles are embedded in the mesoporous channels with particle size less than 20 nm. The bismuth oxyfluoride@CMK-3 nanocomposite maintains 148 mA h g-1 after 40 cycles with the capacity from both the bismuth oxyfluoride and the functional groups on the mesoporous carbon. The hybrid with confined bismuth oxyfluoride nanoparticles, conductive carbon network, and oxygen functional groups on the carbon matrix exhibits higher capacity and cycling stability than bulk bismuth oxyfluoride particles when used as lithium ion batteries cathode.

Bismuth Subgallate Toxicity in the Age of Online Supplement Use.

PubMed

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.

Electroplating of the superconductive boride MgB2 from molten salts

NASA Astrophysics Data System (ADS)

Abe, Hideki; Yoshii, Kenji; Nishida, Kenji; Imai, Motoharu; Kitazawa, Hideaki

2005-02-01

An electroplating technique of the superconductive boride MgB2 onto graphite substrates is reported. Films of MgB2 with a thickness of tens micrometer were fabricated on the planar and curved surfaces of graphite substrates by means of electrolysis on a mixture of magnesium chloride, potassium chloride, sodium chloride, and magnesium borate fused at 600 °C under an Ar atmosphere. The electrical resistivity and magnetization measurements revealed that the electroplated MgB2 films undergo a superconducting transition with the critical temperature (Tc) of 36 K.

Fine structure of the K X-ray absorption spectra of titanium in some hydrides, borides, and silicides (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vainshtein, �. E.; Zhurakovskii, E. A.

1959-08-01

X-ray spectral analyses confirmed the hypothesis on the metal-like state of hydrogen in tithnium hydrides. Experiments with titunium borides and silicides indicate the special character and degree of the 3d--level participation in the metallic'' bond between the atoms of various complexes. The structure of metalloid elements becomes more complicated with an increase in the specific number of boron and silicon atoms and the bond between the atoms tends to become covalent. (R.V.J.)

History of ``NANO''-Scale VERY EARLY Solid-State (and Liquid-State) Physics/Chemistry/Metallurgy/ Ceramics; Interstitial-Alloys Carbides/Nitrides/Borides/...Powders and Cermets, Rock Shocks, ...

NASA Astrophysics Data System (ADS)

Maiden, Colin; Siegel, Edward

History of ``NANO'': Siegel-Matsubara-Vest-Gregson[Mtls. Sci. and Eng. 8, 6, 323(`71); Physica Status Solidi (a)11,45(`72)] VERY EARLY carbides/nitrides/borides powders/cermets solid-state physics/chemistry/metallurgy/ ceramics FIRST-EVER EXPERIMENTAL NANO-physics/chemistry[1968 ->Physica Status Solidi (a)11,45(`72); and EARLY NANO-``physics''/NANO-``chemistry'' THEORY(after: Kubo(`62)-Matsubara(`60s-`70s)-Fulde (`65) [ref.: Sugano[Microcluster-Physics, Springer('82 `98)

Spectroscopic Characterization of Extracellular Polymeric Substances from Escherichia coli and Serratia marcescens: Suppression using Sub-Inhibitory Concentrations of Bismuth Thiols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Badireddy, Appala R.; Korpol, Bhoom Reddy; Chellam, Shankararaman

2008-10-21

Free and capsular EPS produced by Escherichia coli and Serratia marcescens were characterized in detail using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Total EPS production decreased upon treatment with sub-inhibitory concentrations of lipophilic bismuth thiols (bismuth dimercaptopropanol, BisBAL; bismuth ethanedithiol, BisEDT; and bismuth pyrithione, BisPYR), BisBAL being most effective. Bismuth thiols also influenced acetylation and carboxylation of polysaccharides in EPS from S. marcescens. Extensive homology between EPS samples in the presence and absence of bismuth was observed with proteins, polysaccharides, and nucleic acids varying predominantly only in the total amount expressed. Secondmore » derivative analysis of the amide I region of FTIR spectra revealed decreases in protein secondary structures in the presence of bismuth thiols. Hence, anti-fouling properties of bismuth thiols appear to originate in their ability to suppress O-acetylation and protein secondary structures in addition to total EPS secretion.« less

SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE

DOEpatents

Watt, G.W.

1958-08-19

An tmproved method is described for separating plutonium hydroxide from bismuth hydroxide. The end product of the bismuth phosphate processes for the separation amd concentration of plutonium is a inixture of bismuth hydroxide amd plutonium hydroxide. It has been found that these compounds can be advantageously separated by treatment with a reducing agent having a potential sufficient to reduce bismuth hydroxide to metalltc bisinuth but not sufficient to reduce the plutonium present. The resulting mixture of metallic bismuth and plutonium hydroxide can then be separated by treatment with a material which will dissolve plutonium hydroxide but not metallic bismuth. Sodiunn stannite is mentioned as a preferred reducing agent, and dilute nitric acid may be used as the separatory solvent.

METHOD OF MAKING UO$sub 2$-Bi SLURRIES

DOEpatents

Hahn, H.T.

1960-05-24

A process is given of preparing an easily dispersible slurry of uranium dioxide in bismuth. A mixture of bismuth oxide, uranium, and bismuth are heated in a capsule to a temperature over the melting point of bismuth oxide. The amount of bismuth oxide used is less than that stoichiometrically required because the oxygen in the capsule also enters into the reaction.

Synthesis and Characterization of Low-Cost Superhard Transition-Metal Borides

NASA Astrophysics Data System (ADS)

Kaner, Richard

2013-06-01

The increasing demand for high-performance cutting and forming tools, along with the shortcomings of traditional tool materials such as diamond (unable to cut ferrous materials), cubic boron nitride (expensive) and tungsten carbide (relatively-low hardness), has motivated the search for new superhard materials for these applications. This has led us to a new class of superhard materials, dense refractory transition-metal borides, which promise to address some of the existing problems of conventional superhard materials. For example, we have synthesized rhenium diboride (ReB2) using arc melting at ambient pressure. This superhard material has demonstrated an excellent electrical conductivity and superior mechanical properties, including a Vickers hardness of 48.0 GPa (under an applied load of 0.49 N). To further increase the hardness and lower the materials costs, we have begun exploring high boron content metal borides including tungsten tetraboride (WB4) . We have synthesized WB4 by arc melting and studied its hardness and high-pressure behavior. With a similar Vickers hardness (43.3 GPa under a load of 0.49 N) and bulk modulus (326-339 GPa) to ReB2, WB4 offers a lower cost alternative and has the potential to be used in cutting tools. To further enhance the hardness of this superhard metal, we have created the binary and ternary solid solutions of WB4 with Cr, Mn and Ta, the results of which show a hardness increase of up to 20 percent. As with other metals, these metallic borides can be readily cut and shaped using electric discharge machining (EDM).

Microstructure of Vacuum-Brazed Joints of Super-Ni/NiCr Laminated Composite Using Nickel-Based Amorphous Filler Metal

NASA Astrophysics Data System (ADS)

Ma, Qunshuang; Li, Yajiang; Wu, Na; Wang, Juan

2013-06-01

Vacuum brazing of super-Ni/NiCr laminated composite and Cr18-Ni8 stainless steel was carried out using Ni-Cr-Si-B amorphous filler metal at 1060, 1080, and 1100 °C, respectively. Microstructure and phase constitution were investigated by means of optical and scanning electron microscopy, energy-dispersive spectroscopy, x-ray diffraction, and micro-hardness tester. When brazed at 1060-1080 °C, the brazed region can be divided into two distinct zones: isothermally solidified zone (ISZ) consisting of γ-Ni solid solution and athermally solidified zone (ASZ) consisting of Cr-rich borides. Micro-hardness of the Cr-rich borides formed in the ASZ was as high as 809 HV50 g. ASZ decreased with increase of the brazing temperature. Isothermal solidification occurred sufficiently at 1100 °C and an excellent joint composed of γ-Ni solid solution formed. The segregation of boron from ISZ to residual liquid phase is the reason of Cr-rich borides formed in ASZ. The formation of secondary precipitates in diffusion-affected zone is mainly controlled by diffusion of B.

Microstructure and High Temperature Mechanical Property of Fe-Cr-B Based Metal/Ceramic Composite Manufactured by Metal Injection Molding Process

NASA Astrophysics Data System (ADS)

Lee, Kee-Ahn; Gwon, Jin-Han; Yoon, Tae-Sik

2018-03-01

This study investigated the microstructure and the room and high temperature mechanical properties of Fe-Cr-B alloy manufactured by metal injection molding. In addition, hot isostatic pressing was performed to increase the density of the material, and a comparison of properties was made. Microstructural observation confirmed a bi-continuous structure composed of a three-dimensional network of α-Fe phase and (Cr,Fe)2B phase. The HIPed specimen featured a well-formed adhesion between the α-Fe phase and boride, and the number of fine pores was significantly reduced. The tensile results confirmed that the HIPed specimen (RT to 900 °C) had higher strengths compared to the as-sintered specimen, and the change of elongation starting from 700 °C was significantly greater in the HIPed specimen. Fractography suggested that cracks propagated mostly along the interface between the α-Fe matrix and boride in the as-sintered specimen, while direct fracture of boride was observed in addition to interface separation in the HIPed specimen.

Bismuth-doped optical fibres: A new breakthrough in near-IR lasing media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dianov, Evgenii M

Recent results demonstrate that bismuth-doped optical fibres have considerable potential as near-IR active lasing media. This paper examines bismuth-doped fibres intended for the fabrication of fibre lasers and optical amplifiers and reviews recent results on the luminescence properties of various types of bismuth-doped fibres and the performance of bismuth-doped fibre lasers and optical amplifiers for the spectral range 1150 - 1550 nm. Problems are discussed that have yet to be solved in order to improve the efficiency of the bismuth lasers and optical amplifiers. (optical fibres, lasers and amplifiers. properties and applications)

Chemical structure of bismuth compounds determines their gastric ulcer healing efficacy and anti-Helicobacter pylori activity.

PubMed

Sandha, G S; LeBlanc, R; Van Zanten, S J; Sitland, T D; Agocs, L; Burford, N; Best, L; Mahoney, D; Hoffman, P; Leddin, D J

1998-12-01

The recognition of the role of Helicobacter pylori in the pathogenesis of peptic ulcer disease has led to renewed interest in bismuth pharmacology since bismuth compounds have both anti-Helicobacter pylori and ulcer healing properties. The precise chemical structure of current bismuth compounds is not known. This has hindered the development of new and potentially more efficacious formulations. We have created two new compounds, 2-chloro-1,3-dithia-2-bismolane (CDTB) and 1,2-[bis(1,3-dithia-2-bismolane)thio]ethane (BTBT), with known structure. In a rat model of gastric ulceration, BTBT was comparable to, and CDTB was significantly less effective than colloidal bismuth subcitrate in healing cryoprobe-induced ulcers. However, both BTBT and CDTB inhibited H. pylori growth in vitro at concentrations <1/10 that of colloidal bismuth subcitrate. The effects on ulcer healing are not mediated by suppression of acid secretion, pepsin inhibition, or prostaglandin production. Since all treated animals received the same amount of elemental bismuth, it appears that the efficacy of bismuth compounds varies with compound structure and is not simply dependent on the delivery of bismuth ion. Because the structure of the novel compounds is known, our understanding of the relationship of bismuth compound structure and to biologic activity will increase. In the future it may be possible to design other novel bismuth compounds with more potent anti-H. pylori and ulcer healing effects.

Electrically conductive containment vessel for molten aluminum

DOEpatents

Holcombe, C.E.; Scott, D.G.

1984-06-25

The present invention is directed to a containment vessel which is particularly useful in melting aluminum. The vessel of the present invention is a multilayered vessel characterized by being electrically conductive, essentially nonwettable by and nonreactive with molten aluminum. The vessel is formed by coating a tantalum substrate of a suitable configuration with a mixture of yttria and particulate metal 10 borides. The yttria in the coating inhibits the wetting of the coating while the boride particulate material provides the electrical conductivity through the vessel. The vessel of the present invention is particularly suitable for use in melting aluminum by ion bombardment.

Electrically conductive containment vessel for molten aluminum

DOEpatents

Holcombe, Cressie E.; Scott, Donald G.

1985-01-01

The present invention is directed to a containment vessel which is particularly useful in melting aluminum. The vessel of the present invention is a multilayered vessel characterized by being electrically conductive, essentially nonwettable by and nonreactive with molten aluminum. The vessel is formed by coating a tantalum substrate of a suitable configuration with a mixture of yttria and particulate metal borides. The yttria in the coating inhibits the wetting of the coating while the boride particulate material provides the electrical conductivity through the vessel. The vessel of the present invention is particularly suitable for use in melting aluminum by ion bombardment.

Phase equilibrium in system Ti-Si-C-B and synthesis of MAX phase layers in vacuum under the influence of electron beam

NASA Astrophysics Data System (ADS)

Smirnyagina, N. N.; Khaltanova, V. M.; Dasheev, D. E.; Lapina, A. E.

2017-05-01

Composite layers on the basis of carbides and borides the titan and silicon on titanic alloy VТ-1 are generated at diffused saturation by electron beam treatment in vacuum. Formation in a composite of MAX phase Ti3SiC2 is shown. Thermodynamic research of phase equilibrium in systems Ti-Si-C and Ti-B-C in the conditions of high vacuum is executed. The thermodynamics, formation mechanisms of superfirm layers borides and carbides of the titan and silicon are investigated.

Brazing Inconel 625 Using Two Ni/(Fe)-Based Amorphous Filler Foils

NASA Astrophysics Data System (ADS)

Chen, Wen-Shiang; Shiue, Ren-Kae

2012-07-01

For MBF-51 filler, the brazed joint consists of interfacial grain boundary borides, coarse Nb6Ni16Si7, and Ni/Cr-rich matrix. In contrast, the VZ-2106 brazed joint is composed of interfacial Nb6Ni16Si7 precipitates as well as grain boundary borides, coarse Nb6Ni16Si7, and Ni/Cr/Fe-rich matrix. The maximum tensile strength of 443 MPa is obtained from the MBF-51 brazed specimen. The tensile strengths of VZ-2106 brazed joints are approximately 300 MPa. Both amorphous filler foils demonstrate potential in brazing IN-625 substrate.

Mineral resource of the month: bismuth

USGS Publications Warehouse

Carlin, James F.

2006-01-01

Bismuth compounds are most known for their soothing effects on the stomach, wounds and sores. These properties make the compounds an essential part of many medicinal and cosmetic preparations, which until 1930 accounted for about 90 percent of the bismuth used. The subsequent development of low-melting alloys and chemical catalysts containing bismuth, as well as its use as an additive to casting alloys, has resulted in a wider variety of industrial applications for bismuth.

Effect of bismuth subcitrate on amphibian gastroduodenal bicarbonate secretion.

PubMed Central

Shorrock, C J; Crampton, J R; Gibbons, L C; Rees, W D

1989-01-01

The ulcer healing and cytoprotective properties of colloidal bismuth (De-Nol) are well established although its mode of action is unclear. We have examined the action of bismuth subcitrate, the active ingredient of De-Nol, on gastroduodenal bicarbonate secretion by isolated amphibian mucosa. Addition of bismuth subcitrate (10(-6) to 10(-4) M) to the luminal solution produced a dose dependent increase in bicarbonate secretion from both gastric and duodenal mucosae without a change in transmucosal potential difference. The magnitude of this stimulation was greater for gastric than duodenal mucosae at all dose ranges. A second bismuth salt, bismuth oxynitrate, produced similar increases in bicarbonate secretion from gastric mucosae. Pretreatment of gastric mucosa with the cyclooxygenase inhibitor, indomethacin (10(-5) and 10(-4) M), did not abolish the secretory response to bismuth subcitrate. Similar treatment with the chloride transport inhibitor, 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS) (10(-3) M) prevented the secretory response to bismuth subcitrate. PMID:2788112

PROCESS OF COATING METALS WITH BISMUTH OR BISMUTH-BASE ALLOYS

DOEpatents

Beach, J.G.

1958-01-28

A method is described for producing coatings of bismuth or bismuth alloys on a metal base. This is accomplished by electrodepositing the bismuth from an aqueous solution of BiCl/sub 3/, and by making the metal base alternately the cathode and the anode, the cathode periods being twice as long as the anode periods. In one embodiment a nickel coating is first electrodeposited in a known way, and this nickel plated piece is tae base upon which tae bismuth is deposited by the process of this patent. The coated piece is then heat treated to produce a homogeneous Ni--Bi alloy by diffusion.

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

Code of Federal Regulations, 2014 CFR

2014-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS 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...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS 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...

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

Code of Federal Regulations, 2011 CFR

2011-07-01

...-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...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS 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...

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

Code of Federal Regulations, 2010 CFR

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...

BISMUTH PHOSPHATE CARRIER PROCESS FOR Pu RECOVERY

DOEpatents

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

Bursting at the Seams: Rippled Monolayer Bismuth on NbSe 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Alan; Adamo, Carolina; Jia, Shuang

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant closemore » to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe 2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.« less

Bursting at the Seams: Rippled Monolayer Bismuth on NbSe 2

DOE PAGES

Fang, Alan; Adamo, Carolina; Jia, Shuang; ...

2018-04-13

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant closemore » to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe 2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.« less

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

NASA Astrophysics Data System (ADS)

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

2011-12-01

A two-step method has been used to fabricate nano-particles of layer-structured bismuth chalcogenide compounds, including Bi2Te3, Bi2Se3, and Bi2Se0.3Te2.7, 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.

Bioavailability and chronic toxicity of bismuth citrate to earthworm Eisenia andrei exposed to natural sandy soil.

PubMed

Omouri, Zohra; Hawari, Jalal; Fournier, Michel; Robidoux, Pierre Yves

2018-01-01

The present study describes bioavailability and chronic effects of bismuth to earthworms Eisenia andrei using OECD reproduction test. Adult earthworms were exposed to natural sandy soil contaminated artificially by bismuth citrate. Average total concentrations of bismuth in soil recovered by HNO 3 digestion ranged from 75 to 289mg/kg. Results indicate that bismuth decreased significantly all reproduction parameters of Eisenia andrei at concentrations ≥ 116mg/kg. However, number of hatched cocoons and number of juveniles seem to be more sensitive than total number of cocoons, as determined by IC 50 ; i.e., 182, 123 and > 289mg/kg, respectively. Bismuth did not affect Eisenia andrei growth and survival, and had little effect on phagocytic efficiency of coelomocytes. The low immunotoxicity effect might be explained by the involvement of other mechanisms i.e. bismuth sequestered by metal-binding compounds. After 28 days of exposure bismuth concentrations in earthworms tissue increased with increasing bismuth concentrations in soil reaching a stationary state of 21.37mg/kg dry tissue for 243mg Bi/kg dry soil total content. Data indicate also that after 56 days of incubation the average fractions of bismuth available extracted by KNO 3 aqueous solution in soil without earthworms varied from 0.0051 to 0.0229mg/kg, while in soil with earthworms bismuth concentration ranged between 0.310-1.347mg/kg dry soil. We presume that mucus and chelating agents produced by earthworms and by soil or/and earthworm gut microorganisms could explain this enhancement, as well as the role of dermal and ingestion routes of earthworms uptake to soil contaminant. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis, Structure, and Properties of Refractory Hard-Metal Borides

NASA Astrophysics Data System (ADS)

Lech, Andrew Thomas

As the limits of what can be achieved with conventional hard compounds, such as tungsten carbide, are nearing reach, super-hard materials are an area of increasing industrial interest. The refractory hard metal borides, such as ReB2 and WB4, offer an increasingly attractive alternative to diamond and cubic boron nitride as a next-generation tool material. In this Thesis, a thorough discussion is made of the progress achieved by our laboratory towards understanding the synthesis, structure, and properties of these extremely hard compounds. Particular emphasis is placed on structural manipulation, solid solution formation, and the unique crystallographic manifestations of what might also be called "super-hard metals".

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

ERIC Educational Resources Information Center

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…

Hydrothermal synthesis of bismuth germanium oxide

DOEpatents

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.

Bismuth, Metronidazole, and Tetracycline

MedlinePlus

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

Thermodynamics Calculation and Experimental Study on Separation of Bismuth from a Bismuth Glance Concentrate Through a Low-Temperature Molten Salt Smelting Process

NASA Astrophysics Data System (ADS)

Yang, Jian-Guang; He, De-Wen; Tang, Chao-Bo; Chen, Yong-Ming; Sun, Ya-Hui; Tang, Mo-Tang

2011-08-01

The main purpose of this study is to characterize and separate bismuth from a bismuth glance concentrate through a low-temperature, sulfur-fixing smelting process. This article reports on a study conducted on the optimization of process parameters, such as Na2CO3 and zinc oxide wt pct in charging, smelting temperature, smelting duration on the bismuth yield, resultant crude bismuth grade, and sulfur-fixing rate. A maximum bismuth recovery of 97.31 pct, crude bismuth grade of 96.93 pct, and 98.23 pct sulfur-fixing rate are obtained when a charge (containing 63.50 wt pct of Na2CO3 and 22.50 wt pct of bismuth glance, as well as 5 pct in excess of the stoichiometric requirement of zinc oxide dosage) is smelted at 1000 K (727 °C) for 150 minutes. This smelting operation is free from atmospheric pollution because zinc oxide is used as the sulfur-fixing agent, which can capture sulfur from bismuth sulfide and form the more thermodynamic-stable compound, zinc sulfide. The solid residue is subjected to a mineral dressing operation to obtain suspension, which is filtered to produce a cake, representing the solid particles of zinc sulfide. Based on the results of the chemical content analysis of the as-resultant zinc sulfide, more than 93 pct zinc sulfide can be recovered, and the recovered zinc sulfide grade can reach 60.20 pct. This material can be sold as zinc sulfide concentrate or roasted to be regenerated as zinc oxide.

Facile formation of metallic bismuth/bismuth oxide heterojunction on porous carbon with enhanced photocatalytic activity.

PubMed

Zhang, Liping; Ghimire, Pramila; Phuriragpitikhon, Jenjira; Jiang, Baojiang; Gonçalves, Alexandre A S; Jaroniec, Mietek

2018-03-01

Bismuth/bismuth oxide heterojunction on porous carbon (Bi 0 /Bi 2 O 3 @C) was successfully prepared by a surfactant-assisted sol-gel method. This composite photocatalyst was fabricated by depositing Bi 2 O 3 and metallic bismuth nanoparticles (NPs) on porous carbon sheets. Bi NPs were created by in-situ reduction of Bi 2 O 3 with amorphous carbon. During the synthesis, bismuth and carbon precursors were mixed in different ratios, resulting in distinct amounts of metallic bismuth in the composites. The composites showed large specific surface area and pore volume as well as strong light absorption ability due to the existing carbon. In addition, the plasmonic bismuth NPs were found to behave as a noble metal, which is able to generate hot charge carriers under visible light irradiation. Photocatalytic performance of the Bi 0 /Bi 2 O 3 @C composites was investigated by degradation of methylene blue. It turned out that the composites showed much higher efficiency as compared to bare Bi 2 O 3 , which may be attributed to the synergistic effects of porous structures, improved optical absorption, and surface plasmon resonance. Copyright © 2017 Elsevier Inc. All rights reserved.

Glutathione and multidrug resistance protein transporter mediate a self-propelled disposal of bismuth in human cells

PubMed Central

Hong, Yifan; Lai, Yau-Tsz; Chan, Godfrey Chi-Fung; Sun, Hongzhe

2015-01-01

Glutathione and multidrug resistance protein (MRP) play an important role on the metabolism of a variety of drugs. Bismuth drugs have been used to treat gastrointestinal disorder and Helicobacter pylori infection for decades without exerting acute toxicity. They were found to interact with a wide variety of biomolecules, but the major metabolic pathway remains unknown. For the first time (to our knowledge), we systematically and quantitatively studied the metabolism of bismuth in human cells. Our data demonstrated that over 90% of bismuth was passively absorbed, conjugated to glutathione, and transported into vesicles by MRP transporter. Mathematical modeling of the system reveals an interesting phenomenon. Passively absorbed bismuth consumes intracellular glutathione, which therefore activates de novo biosynthesis of glutathione. Reciprocally, sequestration by glutathione facilitates the passive uptake of bismuth and thus completes a self-sustaining positive feedback circle. This mechanism robustly removes bismuth from both intra- and extracellular space, protecting critical systems of human body from acute toxicity. It elucidates the selectivity of bismuth drugs between human and pathogens that lack of glutathione, such as Helicobacter pylori, opening new horizons for further drug development. PMID:25737551

Intense 2.7 µm emission and structural origin in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass.

PubMed

Guo, Yanyan; Li, Ming; Hu, Lili; Zhang, Junjie

2012-01-15

The 2.7 μm emission properties in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass were investigated in the present Letter. An intense 2.7 μm emission in Er3+-doped bismuthate glass was observed. It is found that Er3+-doped bismuthate glass possesses high spontaneous transition probability A (65.26 s(-1)) and large 2.7 μm emission cross section σ(em) (9.53×10(-21) cm2) corresponding to the stimulated emission of Er3+:4I11/2→4I13/2 transition. The emission characteristic and energy transfer process upon excitation of a conventional 980 nm laser diode in bismuthate glass were analyzed. Additionally, the structure of bismuthate glass was analyzed by the Raman spectrum. The advantageous spectroscopic characteristics of Er3+ single-doped bismuthate glass together with the prominent thermal property indicate that bismuthate glass might become an attractive host for developing solid-state lasers around 2.7 μm.

Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm

PubMed Central

Hernandez-Delgadillo, Rene; Velasco-Arias, Donaji; Diaz, David; Arevalo-Niño, Katiushka; Garza-Enriquez, Marianela; De la Garza-Ramos, Myriam A; Cabral-Romero, Claudio

2012-01-01

Background and methods Despite continuous efforts, the increasing prevalence of resistance among pathogenic bacteria to common antibiotics has become one of the most significant concerns in modern medicine. Nanostructured materials are used in many fields, including biological sciences and medicine. While some bismuth derivatives has been used in medicine to treat vomiting, nausea, diarrhea, and stomach pain, the biocidal activity of zerovalent bismuth nanoparticles has not yet been studied. The objective of this investigation was to analyze the antimicrobial activity of bismuth nanoparticles against oral bacteria and their antibiofilm capabilities. Results Our results showed that stable colloidal bismuth nanoparticles had 69% antimicrobial activity against Streptococcus mutans growth and achieved complete inhibition of biofilm formation. These results are similar to those obtained with chlorhexidine, the most commonly used oral antiseptic agent. The minimal inhibitory concentration of bismuth nanoparticles that interfered with S. mutans growth was 0.5 mM. Conclusion These results suggest that zerovalent bismuth nanoparticles could be an interesting antimicrobial agent to be incorporated into an oral antiseptic preparation. PMID:22619547

The Effects of Bismuth Oxide on Microstructures and Magnetic Properties of Mn-Mg-Al Ferrites

NASA Astrophysics Data System (ADS)

Nekouee, Kh. A.; Rahimi, A. H.; Haghighi, M. Alineghad; Ehsani, N.

2018-04-01

In the present paper, the effects of bismuth oxide as an additive on microstructure and magnetic properties of Mg0.9Mn0.1Al0.4Fe1.6O4 were investigated. Mg-Mn-Al ferrite powders were prepared by the conventional solid state synthesis method. Two different amounts of bismuth oxide (2.5 wt.% and 5 wt.%) were utilized as the sintering aid and their microstructure and physical properties were compared to those of the sample without additives. X-ray diffraction (XRD) analysis indicated that crystal lattice distortion due to the microstructural constraints as the result from incorporation of bismuth oxide into the microstructure was developed by adding bismuth oxide. XRD Rietveld refinement was used to define the cation distribution and to refine the lattice parameter and oxygen parameter for the sample without bismuth oxide as (Mg0.16Mn0.02Al0.15Fe0.77)A(Mg0.74Mn0.08Al0.25Fe0.83)BO4 and 8.3308 Å and 0.2542, respectively. Microstructure studies show that a bismuth rich liquid phase forms during the sintering at 1250°C, which enhances the densification of sintered bodies up to 13% (a relative density of 93%). Magnetization of sintered samples were increased from 21.1 emu/g to 26.2 emu/g upon addition of 2.5 wt.% bismuth oxide and then decreased to 24.9 emu/g when 5 wt.% bismuth oxide was added.

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

PubMed Central

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

Structural, electronic and thermal properties of super hard ternary boride, WAlB

NASA Astrophysics Data System (ADS)

Rajpoot, Priyanka; Rastogi, Anugya; Verma, U. P.

2018-04-01

A first principle study of the structural, electronic and thermal properties of Tungsten Aluminum Boride (WAlB) using full-potential linearized augmented plane wave (FP-LAPW) in the frame work of density function theory (DFT) have been calculated. The calculated equilibrium structural parameters are in excellent agreement with available experimental results. The calculated electronic band structure reveals that WAlB is metallic in nature. The quasi-harmonic Debye model is applied to study of the temperature and pressure effect on volume, Debye temperature, thermal expansion coefficient and specific heat at constant volume and constant pressure. To the best of our knowledge theoretical investigation of these properties of WAlB is reported for the first time.

Infiltration processing of boron carbide-, boron-, and boride-reactive metal cermets

DOEpatents

Halverson, Danny C.; Landingham, Richard L.

1988-01-01

A chemical pretreatment method is used to produce boron carbide-, boron-, and boride-reactive metal composites by an infiltration process. The boron carbide or other starting constituents, in powder form, are immersed in various alcohols, or other chemical agents, to change the surface chemistry of the starting constituents. The chemically treated starting constituents are consolidated into a porous ceramic precursor which is then infiltrated by molten aluminum or other metal by heating to wetting conditions. Chemical treatment of the starting constituents allows infiltration to full density. The infiltrated precursor is further heat treated to produce a tailorable microstructure. The process at low cost produces composites with improved characteristics, including increased toughness, strength.

Structural, electronic, vibrational and optical properties of Bin clusters

NASA Astrophysics Data System (ADS)

Liang, Dan; Shen, Wanting; Zhang, Chunfang; Lu, Pengfei; Wang, Shumin

2017-10-01

The neutral, anionic and cationic bismuth clusters with the size n up to 14 are investigated by using B3LYP functional within the regime of density functional theory and the LAN2DZ basis set. By analysis of the geometries of the Bin (n = 2-14) clusters, where cationic and anionic bismuth clusters are largely similar to those of neutral ones, a periodic effect by adding units with one to four atoms into smaller cluster to form larger cluster is drawn for the stable structures of bismuth clusters. An even-odd alteration is shown for the properties of the clusters, such as the calculated binding energies and dissociation energies, as well as frontier orbital energies, electron affinities, ionization energies. All the properties indicate that the Bi4 cluster is the most possible existence in bismuth-containing materials, which supports the most recent experiment. The orbital compositions, infrared and Raman activities and the ultraviolet absorption of the most possible tetramer bismuth cluster are given in detail to reveal the periodic tendency of adding bismuth atoms and the stability of tetramer bismuth cluster.

Extreme Pressure Synergistic Mechanism of Bismuth Naphthenate and Sulfurized Isobutene Additives

NASA Astrophysics Data System (ADS)

Xu, Xin; Hu, Jianqiang; Yang, Shizhao; Xie, Feng; Guo, Li

A four-ball tester was used to evaluate the tribological performances of bismuth naphthenate (BiNap), sulfurized isobutene (VSB), and their combinations. The results show that the antiwear properties of BiNap and VSB are not very visible, but they possess good extreme pressure (EP) properties, particularly sulfur containing bismuth additives. Synergistic EP properties of BiNap with various sulfur-containing additives were investigated. The results indicate that BiNap exhibits good EP synergism with sulfur-containing additives. The surface analytical tools, such as X-ray photoelectron spectrometer (XPS) scanning electron microscope (SEM) and energy dispersive X-ray (EDX), were used to investigate the topography, composition contents, and depth profile of some typical elements on the rubbing surface. Smooth topography of wear scar further confirms that the additive showed good EP capacities, and XPS and EDX analyzes indicate that tribochemical mixed protective films composed of bismuth, bismuth oxides, sulfides, and sulfates are formed on the rubbing surface, which improves the tribological properties of lubricants. In particular, a large number of bismuth atoms and bismuth sulfides play an important role in improving the EP properties of oils.

The Quantitative Significance of Nondestructive Evaluation of Graphite and Ceramic Materials.

DTIC Science & Technology

NONDESTRUCTIVE TESTING), (* GRAPHITE , (*BORIDES, NONDESTRUCTIVE TESTING), (*REFRACTORY MATERIALS, NONDESTRUCTIVE TESTING), DEFECTS(MATERIALS), TENSILE PROPERTIES, RADIOGRAPHY, ULTRASONIC PROPERTIES, DENSITY.

High-Temperature Syntheses of New, Thermally-Stable Chemical Compounds.

DTIC Science & Technology

SYNTHESIS(CHEMISTRY), HEAT RESISTANT PLASTICS, NITRILES, FLUORINE COMPOUNDS, COMPLEX COMPOUNDS, NITROGEN, SULFIDES, ORGANOMETALLIC COMPOUNDS, ORGANOBORANES, BORIDES, SPINEL, CARBIDES, NITRIDES, SILICIDES .

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

NASA Astrophysics Data System (ADS)

Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

2017-11-01

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth, and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. We show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

DOE PAGES

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; ...

2017-11-08

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

Localization and Related Phenomena in Multiply Connected Nanostructured Inverse Opal Bismuth

NASA Astrophysics Data System (ADS)

Bleiweiss, Michael; Saygi, Salih; Amirzadeh, Jafar; Datta, Timir; Lungu, Anca; Yin, Ming; Palm, Eric; Brandt, Bruce; Iqbal, Zafar

2001-03-01

The nanostructures were fabricated by pressure infiltration of bismuth into porous artificial opal and were characterized using SEM, EDX and XRD. These structures form a regular three-dimensional network in which the bismuth regions percolate in all directions between the close packed spheres of SiO_2. The sizes of the conducting regions are of the order of tens of nanometers. The static magnetic properties of both bismuth inverse opal and bulk bismuth were studied using a SQUID magnetometer. Transport measurements, including Hall, were done using standard ac four and six probe techniques in fields up to 17 T* and temperatures between 4.2 and 150 K. The results of these measurements, including the observation of localization phenomena, will be discussed. Comparisons will be made with published results on bismuth nanowires. *Performed at the National High Magnetic Field Lab (NHMFL) FSU, Tallahassee, FL. Partially supported by a grant from NASA.

Hydrothermal synthesis of nanocubes of sillenite type compounds for photovoltaic applications and solar energy conversion of carbon dioxide to fuels

DOEpatents

Subramanian, Vaidyanathan; Murugesan, Sankaran

2014-04-29

The present invention relates to formation of nanocubes of sillenite type compounds, such as bismuth titanate, i.e., Bi.sub.12TiO.sub.20, nanocubes, via a hydrothermal synthesis process, with the resulting compound(s) having multifunctional properties such as being useful in solar energy conversion, environmental remediation, and/or energy storage, for example. In one embodiment, a hydrothermal method is disclosed that transforms nanoparticles of TiO.sub.2 to bismuth titanate, i.e., Bi.sub.12TiO.sub.20, nanocubes, optionally loaded with palladium nanoparticles. The method includes reacting titanium dioxide nanotubes with a bismuth salt in an acidic bath at a temperature sufficient and for a time sufficient to form bismuth titanate crystals, which are subsequently annealed to form bismuth titanate nanocubes. After annealing, the bismuth titanate nanocubes may be optionally loaded with nano-sized metal particles, e.g., nanosized palladium particles.

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

PubMed

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.

B Layers and Adhesion on Armco Iron Substrate

NASA Astrophysics Data System (ADS)

Elias-Espinosa, M.; Ortiz-Domínguez, M.; Keddam, M.; Flores-Rentería, M. A.; Damián-Mejía, O.; Zuno-Silva, J.; Hernández-Ávila, J.; Cardoso-Legorreta, E.; Arenas-Flores, A.

2014-08-01

In this work, a kinetic model was suggested to evaluate the boron diffusion coefficient in the Fe2B layers grown on the Armco iron substrate by the powder-pack boriding. This thermochemical treatment was carried out in the temperature range of 1123-1273 K for treatment times ranging from 2 to 8 h. The boron diffusion coefficient in the Fe2B layers was estimated by solving the mass balance equation at the (Fe2B/substrate) interface with an inclusion of boride incubation time. To validate the present model, the simulated value of Fe2B layer thickness was compared with the experimental value obtained at 1253 K for a treatment time of 5 h. The morphology of Fe2B layers was observed by SEM and optical microscopy. Metallographic studies showed that the boride layer has a saw-tooth morphology in all the samples. The layer thickness measurements were done with the help of MSQ PLUS software. The Fe2B phase was identified by x-ray diffraction method. Finally, the adherence of Fe2B layers on the Armco iron substrate was qualitatively evaluated by using the Daimler-Benz Rockwell-C indentation technique. In addition, the estimated value of boron activation energy was compared to the literature data.

A Simple, General Synthetic Route toward Nanoscale Transition Metal Borides.

PubMed

Jothi, Palani R; Yubuta, Kunio; Fokwa, Boniface P T

2018-04-01

Most nanomaterials, such as transition metal carbides, phosphides, nitrides, chalcogenides, etc., have been extensively studied for their various properties in recent years. The similarly attractive transition metal borides, on the contrary, have seen little interest from the materials science community, mainly because nanomaterials are notoriously difficult to synthesize. Herein, a simple, general synthetic method toward crystalline transition metal boride nanomaterials is proposed. This new method takes advantage of the redox chemistry of Sn/SnCl 2 , the volatility and recrystallization of SnCl 2 at the synthesis conditions, as well as the immiscibility of tin with boron, to produce crystalline phases of 3d, 4d, and 5d transition metal nanoborides with different morphologies (nanorods, nanosheets, nanoprisms, nanoplates, nanoparticles, etc.). Importantly, this method allows flexibility in the choice of the transition metal, as well as the ability to target several compositions within the same binary phase diagram (e.g., Mo 2 B, α-MoB, MoB 2 , Mo 2 B 4 ). The simplicity and wide applicability of the method should enable the fulfillment of the great potential of this understudied class of materials, which show a variety of excellent chemical, electrochemical, and physical properties at the microscale. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Corrosion and wear behaviors of boronized AISI 316L stainless steel

NASA Astrophysics Data System (ADS)

Kayali, Yusuf; Büyüksaǧiş, Aysel; Yalçin, Yılmaz

2013-09-01

In this study, the effects of a boronizing treatment on the corrosion and wear behaviors of AISI 316L austenitic stainless steel (AISI 316L) were examined. The corrosion behavior of the boronized samples was studied via electrochemical methods in a simulation body fluid (SBF) and the wear behavior was examined using the ball-on-disk wear method. It was observed that the boride layer that formed on the AISI 316L surface had a flat and smooth morphology. Furthermore, X-ray diffraction analyses show that the boride layer contained FeB, Fe2B, CrB, Cr2B, NiB, and Ni2B phases. Boride layer thickness increased with an increasing boronizing temperature and time. The boronizing treatment also increased the surface hardness of the AISI 316L. Although there was no positive effect of the coating on the corrosion resistance in the SBF medium. Furthermore, a decrease in the friction coefficient was recorded for the boronized AISI 316L. As the boronizing temperature increased, the wear rate decreased in both dry and wet mediums. As a result, the boronizing treatment contributed positively to the wear resistance by increasing the surface hardness and by decreasing the friction coefficient of the AISI 316L.

I Situ Surface X-Ray Diffraction Studies of Electrochemically Deposited Monolayers

NASA Astrophysics Data System (ADS)

Yee, Dennis

1995-01-01

In situ x-ray diffraction has been used to determine the detailed atomic structure of electrochemically deposited lead, thallium, and bismuth monolayers on the silver (111) electrode surface. A review of our previously published lead and thallium monolayer results and the first in situ surface x-ray crystallographic study of the bismuth monolayer structure is presented. The crystallographic analysis of the bismuth Bragg rod intensities and the interference between the bismuth Bragg rod and silver crystal truncation rod scattering were used to determine the detailed atomic structure of the bismuth on silver (111) system at the liquid-solid interface. Our previous in situ x-ray diffraction studies showed that the bismuth monolayer lattice is rectangular and uniaxially incommensurate with the underlying hexagonal silver surface. A crystallographic analysis of the measured structure factor magnitudes reveals that the monolayer forms chains of atoms on the silver surface, similar to the bulk Bi(110)_{rh} plane, with a near neighbor distance of 3.12 +/- 0.01 A and a bond angle of 93 +/- 1^circ, consistent with the bulk Bi(110) _{rh} plane values. The crystallographic refinement also shows that the bismuth monolayer atoms are anisotropically disordered with a rms disorder of 0.25 +/- 0.03 A in the incommensurate direction and 0.09 +/- 0.03 A rms in the commnensurate direction. The interference between the Bi(20) Bragg rod and the Ag(10L)_ {h} crystal truncation rod scattering reveals that one set of bismuth atoms is registered near the bridge sites of the silver (111) surface while another set is registered near the 3-fold hollow sites. In addition, the Bi-Ag d-spacing (3.1 +/- 0.1 A) is found to be consistent with the bulk bismuth near neighbor distance. The bismuth z-direction rms disorder (1.01 +/- 0.08 A) is found to be dominated by the roughness of the underlying silver (sigma_{Ag} = 0.9 +/- 0.1 A rms). Using the estimated bismuth-bismuth spring constant of 1.41 +/- 0.07 eV/A^2 from our measured bismuth two-dimensional compressibility, two simple models are used to try and understand the origin of the anisotropic disorder. A simple two-dimensional isotropic thermal fluctuation model shows that thermal fluctuations are not large enough to account for all of the measured excess disorder in the incommensurate direction. A simple one-dimensional Frenkel-Kontorova model shows that the substrate-induced disorder can account for the anisotropic disorder, assuming a substrate sinusoidal potential strength of 0.35 +/- 0.02 eV.

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

PubMed

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 Leishmaniosis and Chagas' diseases. Bismuth salts are able to (i) generate mineral acids in the reaction media and (ii) coordinate with electronegative atoms to facilitate the reaction. When the reagents and the catalyst (bismuth salt) are subjected to microwave irradiation, microwave passes through the (glass) walls of the reaction vessel and heat only the reactants avoiding local overheating at the wall of the vessel. Accordingly, the possibility of side reaction and subsequent by-product formation are reduced abruptly which in turn increases the yield of the desired product. The extreme rapidity with excellent yield of the product can be rationalized as a synergistic effect of the bismuth salts and microwave irradiation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Reactive magnetron sputtering deposition of bismuth tungstate onto titania nanoparticles for enhancing visible light photocatalytic activity

NASA Astrophysics Data System (ADS)

Ratova, Marina; Kelly, Peter J.; West, Glen T.; Tosheva, Lubomira; Edge, Michele

2017-01-01

Titanium dioxide - bismuth tungstate composite materials were prepared by pulsed DC reactive magnetron sputtering of bismuth and tungsten metallic targets in argon/oxygen atmosphere onto anatase and rutile titania nanoparticles. The use of an oscillating bowl placed beneath the two magnetrons arranged in a co-planar closed field configuration enabled the deposition of bismuth tungstate onto loose powders, rather than a solid substrate. The atomic ratio of the bismuth/tungsten coatings was controlled by varying the power applied to each target. The effect of the bismuth tungstate coatings on the phase, optical and photocatalytic properties of titania was investigated by X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) surface area measurements, transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy and an acetone degradation test. The latter involved measurements of the rate of CO2 evolution under visible light irradiation of the photocatalysts, which indicated that the deposition of bismuth tungstate resulted in a significant enhancement of visible light activity, for both anatase and rutile titania particles. The best results were achieved for coatings with a bismuth to tungsten atomic ratio of 2:1. In addition, the mechanism by which the photocatalytic activity of the TiO2 nanoparticles was enhanced by compounding it with bismuth tungstate was studied by microwave cavity perturbation. The results of these tests confirmed that such enhancement of the photocatalytic properties is due to more efficient photogenerated charge carrier separation, as well as to the contribution of the intrinsic photocatalytic properties of Bi2WO6.

Bismuth-induced Raman modes in GaP 1– xBi x

DOE PAGES

Christian, Theresa M.; Fluegel, Brian; Beaton, Daniel A.; ...

2016-09-02

Here, dilute bismide semiconductor alloys are a promising material platform for optoelectronic devices due to drastic impacts of bismuth on the electronic structure of the alloy. At the same time, the details of bismuth incorporation in the lattice are not fully understood. In this work, we conduct Raman scattering spectroscopy on GaP 1- xBi x epilayers grown by molecular beam epitaxy (MBE) and identify several bismuth-related Raman features including gap vibration modes at 296, 303, and 314 cm -1. This study paves the way for more detailed analysis of the local symmetry at bismuth incorporation sites in the dilute bismidemore » alloy regime.« less

Investigation on gas sensing properties of Ag doped BiFeO3

NASA Astrophysics Data System (ADS)

Bagwaiya, Toshi; Khade, Poonam; Reshi, Hilal Ahmad; Bhattacharya, Shovit; Shelke, Vilas; Kaur, Manmeet; Debnath, A. K.; Muthe, K. P.; Gadkari, S. C.

2018-04-01

Bismuth ferrite (BFO) and Ag substituted Bismuth ferrite with perovskite structure have been synthesized using sol-gel method and investigated for their gas sensing properties. Single phase and rhombohedral crystal structure of the samples were confirmed from XRD pattern. Oxidation state of the elements is confirmed using X-Ray Photoelectron Spectroscopy (XPS). Since Ag substituted Bismuth ferrite exhibited pronounced response to H2S gas as compared to other gases, H2S gas sensing properties of Bismuth ferrite (BFO) and Ag substituted Bismuth ferrite were investigated in detail. Bi0.9Ag0.1FeO3 (BAFO) exhibits enhanced sensitivity, quick response and selectivity towards H2S as compared to BFO.

METHOD OF SEPARATING FISSION PRODUCTS FROM FUSED BISMUTH-CONTAINING URANIUM

DOEpatents

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.

Design of cemented tungsten carbide and boride-containing shields for a fusion power plant

NASA Astrophysics Data System (ADS)

Windsor, C. G.; Marshall, J. M.; Morgan, J. G.; Fair, J.; Smith, G. D. W.; Rajczyk-Wryk, A.; Tarragó, J. M.

2018-07-01

Results are reported on cemented tungsten carbide (cWC) and boride-containing composite materials for the task of shielding the centre column of a superconducting tokamak power plant. The shield is based on five concentric annular shells consisting of cWC and water layers of which the innermost cWC shield can be replaced with boride composites. Sample materials have been fabricated changing the parameters of porosity P, binder alloy fraction f binder and boron weight fraction f boron. For the fabricated materials, and other hypothetical samples with chosen parameters, Monte Carlo studies are made of: (i) the power deposition into the superconducting core, (ii) the fast neutron and gamma fluxes and (iii) the attenuation coefficients through the shield for the deposited power and neutron and gamma fluxes. It is shown that conventional Co-based cWC binder alloy can be replaced with a Fe–Cr alloy (92 wt.% Fe, 8 wt.% Cr), which has lower activation than cobalt with minor changes in shield performance. Boride-based composite materials have been prepared and shown to give a significant reduction in power deposition and flux, when placed close to the superconducting core. A typical shield of cemented tungsten carbide with 10 wt.% of Fe–8Cr binder and 0.1% porosity has a power reduction half-length of 0.06 m. It is shown that the power deposition increases by 4.3% for every 1% additional porosity, and 1.7% for every 1 wt.% additional binder. Power deposition decreased by 26% for an initial 1 wt.% boron addition, but further increases in f boron showed only a marginal decrease. The dependences of power deposited in the core, the maximum neutron and gamma fluxes on the core surface, and the half attenuation distances through the shield have been fitted to within a fractional percentage error by analytic functions of the porosity, metallic binder alloy and boron weight fractions.

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

DOE PAGES

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.; ...

2017-09-12

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO 2 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 (TBAPF 6 or TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi 2O 3) and metallic bismuth (Bi 0), and that the reduction of oxidized bismuth speciesmore » to Bi 0 is fully achieved under potentials at which CO 2 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 CO 2 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 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 CO 2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. By contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO 2 reduction. In conclusion, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM] + based electrolytes, including the reduction of bismuth oxide to bismuth metal, changes in roughness and near-surface viscosity.« less

Enhancement of bismuth antibacterial activity with lipophilic thiol chelators.

PubMed Central

Domenico, P; Salo, R J; Novick, S G; Schoch, P E; Van Horn, K; Cunha, B A

1997-01-01

The antibacterial properties of bismuth are greatly enhanced when bismuth is combined with certain lipophilic thiol compounds. Antibacterial activity was enhanced from 25- to 300-fold by the following seven different thiols, in order of decreasing synergy: 1,3-propanedithiol, dimercaprol (BAL), dithiothreitol, 3-mercapto-2-butanol, beta-mercaptoethanol, 1-monothioglycerol, and mercaptoethylamine. The dithiols produced the greatest synergy with bismuth at optimum bismuth-thiol molar ratios of from 3:1 to 1:1. The monothiols were generally not as synergistic and required molar ratios of from 1:1 to 1:4 for optimum antibacterial activity. The most-active mono- or dithiols were also the most soluble in butanol. The intensity of the yellow formed by bismuth-thiol complexes reflected the degree of chelation and correlated with antibacterial potency at high molar ratios. The bismuth-BAL compound (BisBAL) was active against most bacteria, as assessed by broth dilution, agar diffusion, and agar dilution analyses. Staphylococci (MIC, 5 to 7 microM Bi3+) and Helicobacter pylori (MIC, 2.2 microM) were among the most sensitive bacteria. Gram-negative bacteria were sensitive (MIC, < 17 microM). Enterococci were relatively resistant (MIC, 63 microM Bi3+). The MIC range for anaerobes was 15 to 100 microM Bi3+, except for Clostridium difficile (MIC, 7.5 microM). Bactericidal activity averaged 29% above the MIC. Bactericidal activity increased with increasing pH and/or increasing temperature. Bismuth-thiol solubility, stability, and antibacterial activity depended on pH and the bismuth-thiol molar ratio. BisBAL was stable but ineffective against Escherichia coli at pH 4. Activity and instability (reactivity) increased with increasing alkalinity. BisBAL was acid soluble at a molar ratio of greater than 3:2 and alkaline soluble at a molar ratio of less than 2:3. In conclusion, certain lipophilic thiol compounds enhanced bismuth antibacterial activity against a broad spectrum of bacteria. The activity, solubility, and stability of BisBAL were strongly dependent on the pH, temperature, and molar ratio. Chelation of bismuth with certain thiol agents enhanced the solubility and lipophilicity of this cationic heavy metal, thereby significantly enhancing its potency and versatility as an antibacterial agent. PMID:9257744

Etude des mecanismes de formation des microstructures lors du brasage isotherme de superalliages a base de nickel

NASA Astrophysics Data System (ADS)

Ruiz-Vargas, Jose

This thesis reports theoretical and experimental investigations carried out to understand the mechanisms of microstructure formation during isothermal brazing, produced by brazing Inconel 625 and MC2 nickel-based superalloys with filler metal BNi-2. Firstly, studies were made on pure Ni to interpret microstructure's formation with simplified alloy chemistry. Microstructure formation have been studied when varying time at constant temperature (isothermal kinetics), but also when varying temperature for constant hold time (isochronal kinetics). The chemical composition and crystallography of the present phases have been identified, with the following results : (i) the fraction of dissolved base metal has been found proportional to the initial thickness of the brazing alloy, so that the composition of the liquid remains homogeneous with a precise initial equilibrium composition during the whole brazing process, (ii) the melting of the joint occurs in two steps : at lower temperature, it involves only partially melting, and boron diffusion in pure Ni leads to the precipitation of fine Ni3B borides at the interface ; in a second stage, at higher temperature, melting is complete and thermodynamic equilibrium requires significant dissolution of nickel, which also involves the dissolution of part of borides already formed. Secondly, nickel plating technique was used on Inconel 625 nickel-based superalloy. A thin layer of Ni with varying thickness, has been electrodeposited to observe the gradual dissolution of Inconel and microstructural features formation due to the presence of superalloy alloying elements. It has been observed that the nickel coating does not prevent precipitation in the base metal as boron diffuse rapidly through the coating width. In the intermediate nickel plating width, fragile precipitates of nickel borides have been observed, because the contribution of Inconel alloying elements to the melt was very limited. In absence of nickel plating on the superalloy, the formation of Nb and Cr-Mo borides phase has been observed. Efforts have been made to evaluate the accuracy of Boron measurement by energy dispersion X-ray spectroscopy (EDS) in the MC2 superalloy and BNi-2 filler metal. The most accurate method to quantify Boron using EDS is by composition difference. A precision of 5 at.% has been reached when using optimized data acquisition and post processing schemes. Ultimately, Electron Backscatter Diffraction (EBSD) combined with localized EDS analysis has been proven invaluable in conclusively identifying micrometer sized boride precipitates ; thus further improving the characterization of brazed Ni-based superalloys.

Plasma enhanced chemical vapor deposition of metalboride interfacial layers as diffusion barriers for nanostructured diamond growth on cobalt containing alloys CoCrMo and WC-Co

NASA Astrophysics Data System (ADS)

Johnston, Jamin M.

This work is a compilation of theory, finite element modeling and experimental research related to the use of microwave plasma enhanced chemical vapor deposition (MPECVD) of diborane to create metal-boride surface coatings on CoCrMo and WC-Co, including the subsequent growth of nanostructured diamond (NSD). Motivation for this research stems from the need for wear resistant coatings on industrial materials, which require improved wear resistance and product lifetime to remain competitive and satisfy growing demand. Nanostructured diamond coatings are a promising solution to material wear but cannot be directly applied to cobalt containing substrates due to graphite nucleation. Unfortunately, conventional pre-treatment methods, such as acid etching, render the substrate too brittle. Thus, the use of boron in a MPECVD process is explored to create robust interlayers which inhibit carbon-cobalt interaction. Furthermore, modeling of the MPECVD process, through the COMSOL MultiphysicsRTM platform, is performed to provide insight into plasma-surface interactions using the simulation of a real-world apparatus. Experimental investigation of MPECVD boriding and NSD deposition was conducted at surface temperatures from 700 to 1100 °C. Several well-adhered metal-boride surface layers were formed: consisting of CoB, CrB, WCoB, CoB and/or W2CoB2. Many of the interlayers were shown to be effective diffusion barriers against elemental cobalt for improving nucleation and adhesion of NSD coatings; diamond on W2CoB2 was well adhered. However, predominantly WCoB and CoB phase interlayers suffered from diamond film delamination. Metal-boride and NSD surfaces were evaluated using glancing-angle x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), cross-sectional scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), micro-Raman spectroscopy, nanoindentation, scratch testing and epoxy pull testing. COMSOL MultiphysicsRTM was used to construct a representation of the MPECVD chamber. Relevant material properties, boundary conditions and adjustable parameters were applied to match the actual experimental set-up. Despite approximations, simulations for the surface temperature and surface accumulation matched well with experimental data. The combination of data from CoCrMo, WC-Co and modeling of the MPECVD process confirms that the use of boron to create metal-boride interlayers is applicable for subsequent nanostructured diamond coatings and that the surface temperature and deposition thickness can be predicted using finite element modeling.

Deposition and characterization of aluminum magnesium boride thin film coatings

NASA Astrophysics Data System (ADS)

Tian, Yun

Boron-rich borides are a special group of materials possessing complex structures typically comprised of B12 icosahedra. All of the boron-rich borides sharing this common structural unit exhibit a variety of exceptional physical and electrical properties. In this work, a new ternary boride compound AlMgB14, which has been extensively studied in bulk form due to its novel mechanical properties, was fabricated into thin film coatings by pulsed laser deposition (PLD) technology. The effect of processing conditions (laser operating modes, vacuum level, substrate temperature, and postannealing, etc.) on the composition, microstructure evolution, chemical bonding, and surface morphology of AlMgB14 thin film coatings has been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectrometry; the mechanical, electrical, and optical properties of AlMgB14 thin films have been characterized by nanoindentation, four-point probe, van der Pauw Hall measurement, activation energy measurement, and UV-VIS-NIR spectrophotometer. Experimental results show that AlMgB14 films deposited in the temperature range of 300 K - 873 K are amorphous. Depositions under a low vacuum level (5 x 10-5 Torr) can introduce a significant amount of C and O impurities into AlMgB14 films and lead to a complex oxide glass structure. Orthorhombic AlMgB14 phase cannot be obtained by subsequent high temperature annealing. By contrast, the orthorhombic AlMgB 14 crystal structure can be attained via high temperature-annealing of AlMgB14 films deposited under a high vacuum level (< 3 x 10-6 Torr), accompanied by strong texture formation. Low vacuum level-as deposited AlMgB14 films have low hardness (10 GPa), but high vacuum level-as deposited AlMgB14 films exhibit an extremely high hardness (45 GPa - 51 GPa), and the higher deposition temperature results in still higher hardness. Furthermore, a very low friction coefficient (0.04 - 0.05) has been observed for high vacuum level-as deposited AlMgB14 films, which could be ascribed to the in situ formation of a surface self-lubricating layer. Unlike most boron-rich boride films, high vacuum level-as deposited AlMgB14 films also possess a low n-type electrical resistivity, which is a consequence of high carrier concentration and moderate carrier mobility. The operative electrical transport mechanism and doping behavior for high vacuum level-as deposited AlMgB14 films are discussed in detail in this thesis.

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2010 CFR

2010-04-01

... amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture... 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...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO 2 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 (TBAPF 6 or TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi 2O 3) and metallic bismuth (Bi 0), and that the reduction of oxidized bismuth speciesmore » to Bi 0 is fully achieved under potentials at which CO 2 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 CO 2 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 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 CO 2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. By contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO 2 reduction. In conclusion, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM] + based electrolytes, including the reduction of bismuth oxide to bismuth metal, changes in roughness and near-surface viscosity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.

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 undermore » 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 electrolytes, including the reduction of bismuth oxide to bismuth metal and changes in roughness and near-surface viscosity.« less

Separation of bismuth from gram amounts of thallium and silver by cation-exchange chromatography in nitric acid.

PubMed

Meintjies, E; Strelow, F W; Victor, A H

1987-04-01

Traces and small amounts of bismuth can be separated from gram amounts of thallium and silver by successively eluting these elements with 0.3M and 0.6M nitric acid from a column containing 13 ml (3 g) of AG50W-X4, a cation-exchanger (100-200 mesh particle size) with low cross-linking. Bismuth is retained and can be eluted with 0.2M hydrobromic acid containing 20% v/v acetone, leaving many other trace elements absorbed. Elution of thallium is quite sharp, but silver shows a small amount of tailing (less than 1 gmg/ml silver in the eluate) when gram amounts are present, between 20 and 80 mug of silver appearing in the bismuth fraction. Relevant elution curves and results for the analysis of synthetic mixtures containing between 50 mug and 10 mg of bismuth and up to more than 1 g of thallium and silver are presented, as well as results for bismuth in a sample of thallium metal and in Merck thallium(I) carbonate. As little as 0.01 ppm of bismuth can be determined when the separation is combined with electrothermal atomic-absorption spectrometry.

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

PubMed

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.

Study of the structure, dielectric and ferroelectric behavior of BaBi4+δTi4O15 ceramics

NASA Astrophysics Data System (ADS)

Khokhar, Anita; Goyal, Parveen K.; Thakur, O. P.; Sreenivas, K.

2016-05-01

The structure and ferroelectric properties of excess bismuth doped barium bismuth titanate BaBi4+δTi4O15 (δ = 2 - 10 wt.%)) ceramics prepared by solid-state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of a single phase material with a change in the orthorhombic distortion with varying excess of bismuth content. There is no change in the phase transition temperature (Tm) while the relaxor behaviour has been modified significantly with excess of bismuth doping. Saturated hysteresis loops with high remnant polarization (Pr ~ 12.5 µC/cm2), low coercive fields (Ec ~ 26 kV/cm) are measured and a high piezoelectric coefficient (d33 ~ 29 pC/N) is achieved in poled BaBi4Ti4O15 ceramics prepared with up to 8 wt.% of excess bismuth oxide. The improvement in the ferroelectric properties with increase in the excess bismuth content in BaBi4Ti4O15 ceramics has been explained in terms of changing oxygen vacancy concentration and structural relaxation. Tunable ferroelectric materials can be obtained by manipulating the doping amount of excess bismuth.

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

PubMed Central

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

2008-01-01

AIM: To assess the safety of bismuth used in Helicobacter pylori (H pylori) eradication therapy regimens. METHODS: We conducted a systematic review and meta-analysis. MEDLINE and EMBASE were searched (up to October 2007) to identify randomised controlled trials comparing bismuth with placebo or no treatment, or bismuth salts in combination with antibiotics as part of eradication therapy with the same dose and duration of antibiotics alone or, in combination, with acid suppression. Total numbers of adverse events were recorded. Data were pooled and expressed as relative risks with 95% confidence intervals (CI). RESULTS: We identified 35 randomised controlled trials containing 4763 patients. There were no serious adverse events occurring with bismuth therapy. There was no statistically significant difference detected in total adverse events with bismuth [relative risk (RR) = 1.01; 95% CI: 0.87-1.16], specific individual adverse events, with the exception of dark stools (RR = 5.06; 95% CI: 1.59-16.12), or adverse events leading to withdrawal of therapy (RR = 0.86; 95% CI: 0.54-1.37). CONCLUSION: Bismuth for the treatment of H pylori is safe and well-tolerated. The only adverse event occurring significantly more commonly was dark stools. PMID:19109870

A novel structure photonic crystal fiber based on bismuth-oxide for optical parametric amplification

NASA Astrophysics Data System (ADS)

Jin, Cang; Yuan, Jinhui; Yu, Chongxiu

2010-11-01

The heavy metal oxide glasses containing bismuth such as bismuth sesquioxide show unique high refractive index. In addition, the bismuth-oxide based glass does not include toxic elements such as Pb, As, Se, Te, and exhibits well chemical, mechanical and thermal stability. Hence, it is used to fabricate high nonlinear fiber for nonlinear optical application. Although the bismuth-oxide based high nonlinear fiber can be fusion-spliced to conventional silica fibers and have above advantages, yet it suffers from large group velocity dispersion because of material chromatic dispersion which restricts its utility. In regard to this, the micro-structure was introduced to adjust the dispersion of bismuth-oxide high nonlinear fiber in the 1550nm wave-band. In this paper, a hexagonal solid-core micro-structure is developed to balance its dispersion and nonlinearity. Our simulation and calculation results show that the bismuth-oxide based photonic crystal fiber has near zero dispersion around 1550nm where the optical parametric amplification suitable wavelength is. Its dispersion slop in the communication wavelength range is also relatively flat. Moreover, both nonlinear coefficient and model filed distribution were simulated, respectively.

METHOD OF PREPARING URANIUM, THORIUM, OR PLUTONIUM OXIDES IN LIQUID BISMUTH

DOEpatents

Davidson, J.K.; Robb, W.L.; Salmon, O.N.

1960-11-22

A method is given for forming compositions, as well as the compositions themselves, employing uranium hydride in a liquid bismuth composition to increase the solubility of uranium, plutonium and thorium oxides in the liquid bismuth. The finely divided oxide of uranium, plutonium. or thorium is mixed with the liquid bismuth and uranium hydride, the hydride being present in an amount equal to about 3 at. %, heated to about 5OO deg C, agitated and thereafter cooled and excess resultant hydrogen removed therefrom.

Direct synthesis of magnesium borohydride

DOEpatents

Ronnebro, Ewa Carin Ellinor [Kennewick, WA; Severa, Godwin [Honolulu, HI; Jensen, Craig M [Kailua, HI

2012-04-03

A method is disclosed for directly preparing an alkaline earth metal borohydride, i.e. Mg(BH.sub.4).sub.2, from the alkaline earth metal boride MgB.sub.2 by hydrogenating the MgB.sub.2 at an elevated temperature and pressure. The boride may also be doped with small amounts of a metal chloride catalyst such as TiCl.sub.3 and/or NiCl.sub.2. The process provides for charging MgB.sub.2 with high pressure hydrogen above at least 70 MPa while simultaneously heating the material to about 350.degree. C. to about 400.degree. C. The method is relatively simple and inexpensive and provides a reversible hydride compound having a hydrogen capacity of at least 11 wt %.

The low-lying quartet electronic states of group 14 diatomic borides XB (X = C, Si, Ge, Sn, Pb)

NASA Astrophysics Data System (ADS)

Pontes, Marcelo A. P.; de Oliveira, Marcos H.; Fernandes, Gabriel F. S.; Da Motta Neto, Joaquim D.; Ferrão, Luiz F. A.; Machado, Francisco B. C.

2018-04-01

The present work focuses in the characterization of the low-lying quartet electronic and spin-orbit states of diatomic borides XB, in which X is an element of group 14 (C, Si, Ge, Sn, PB). The wavefunction was obtained at the CASSCF/MRCI level with a quintuple-ζ quality basis set. Scalar relativistic effects were also taken into account. A systematic and comparative analysis of the spectroscopic properties for the title molecular series was carried out, showing that the (1)4Π→X4Σ- transition band is expected to be measurable by emission spectroscopy to the GeB, SnB and PbB molecules, as already observed for the lighter CB and SiB species.

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 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 crystalline, odorless powder consisting principally of BiOCl. (2) Color additive mixtures for drug use made...

Bismuth doping effect on crystal structure and photodegradation activity of Bi-TiO2 nanoparticles

NASA Astrophysics Data System (ADS)

Wu, Ming-Chung; Chang, Yin-Hsuan; Lin, Ting-Han

2017-04-01

The bismuth precursor is adopted as dopant to synthesize bismuth doped titanium dioxide nanoparticles (Bi-TiO2 NPs) with sol-gel method following by the thermal annealing treatment. We systematically developed a series of Bi-TiO2 NPs at several calcination temperatures and discovered the corresponding crystal structure by varying the bismuth doping concentration. At a certain 650 °C calcination temperature, the crystal structure of bismuth titanate (Bi2Ti2O7) is formed when the bismuth doping concentration is as high as 10.0 mol %. The photocatalytic activity of Bi-TiO2 NPs is increased by varying the doping concentration at the particular calcination temperature. By the definition X-ray diffraction (XRD) structural identification, a phase diagram of Bi-TiO2 NPs in doping concentration versus calcination temperature is provided. It can be useful for further study in the crystal structure engineering and the development of photocatalyst.

Ultrasonication of Bismuth Telluride Nanocrystals Fabricated by Solvothermal Method

NASA Technical Reports Server (NTRS)

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

2006-01-01

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

Adaptive statistical iterative reconstruction and bismuth shielding for evaluation of dose reduction to the eye and image quality during head CT

NASA Astrophysics Data System (ADS)

Kim, Myeong Seong; Choi, Jiwon; Kim, Sun Young; Kweon, Dae Cheol

2014-03-01

There is a concern regarding the adverse effects of increasing radiation doses due to repeated computed tomography (CT) scans, especially in radiosensitive organs and portions thereof, such as the lenses of the eyes. Bismuth shielding with an adaptive statistical iterative reconstruction (ASIR) algorithm was recently introduced in our clinic as a method to reduce the absorbed radiation dose. This technique was applied to the lens of the eye during CT scans. The purpose of this study was to evaluate the reduction in the absorbed radiation dose and to determine the noise level when using bismuth shielding and the ASIR algorithm with the GE DC 750 HD 64-channel CT scanner for CT of the head of a humanoid phantom. With the use of bismuth shielding, the noise level was higher in the beam-hardening artifact areas than in the revealed artifact areas. However, with the use of ASIR, the noise level was lower than that with the use of bismuth alone; it was also lower in the artifact areas. The reduction in the radiation dose with the use of bismuth was greatest at the surface of the phantom to a limited depth. In conclusion, it is possible to reduce the radiation level and slightly decrease the bismuth-induced noise level by using a combination of ASIR as an algorithm process and bismuth as an in-plane hardware-type shielding method.

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth...-tin-bismuth forming operations' process wastewater shall not exceed the following values: (a) Rolling... monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth...-tin-bismuth forming operations' process wastewater shall not exceed the following values: (a) Rolling... monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES). Except as...-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following values... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES). Except as...-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following values... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

Myoclonic encephalopathy due to bismuth salts: treatment with dimercaprol and analysis of CSF transmitters.

PubMed

Molina, J A; Calandre, L; Bermejo, F

1989-03-01

Two cases of myoclonic encephalopathy due to bismuth salts intoxication are reported. In both, treatment with dimercaprol led to clinical recovery. This therapy was shown to enhance bismuth clearance. We also present data on the CSF metabolites dopamine, norepinephrine and serotonin of one patient.

PRODUCTION OF PLUTONIUM FLUORIDE FROM BISMUTH PHOSPHATE PRECIPITATE CONTAINING PLUTONIUM VALUES

DOEpatents

Brown, H.S.; Bohlmann, E.G.

1961-05-01

A process is given for separating plutonium from fission products present on a bismuth phosphate carrier. The dried carrier is first treated with hydrogen fluoride at between 500 and 600 deg C whereby some fission product fluorides volatilize away from plutonium tetrafluoride, and nonvolatile fission product fluorides are formed then with anhydrous fluorine at between 400 and 500 deg C. Bismuth and plutonium distill in the form of volatile fluorides away from the nonvolatile fission product fluorides. The bismuth and plutonium fluorides are condensed at below 290 deg C.

Multi-elemental bio-imaging of rat tissue from a study investigating the bioavailability of bismuth from shotgun pellets.

PubMed

Urgast, Dagmar S; Ellingsen, Dag G; Berlinger, Balázs; Eilertsen, Einar; Friisk, Grete; Skaug, Vidar; Thomassen, Yngvar; Beattie, John H; Kwun, In-Sook; Feldmann, Jörg

2012-07-01

In recent years, bismuth has been promoted as a "green element" and is used as a substitute for the toxic lead in ammunition and other applications. However, the bioavailability and toxicity of bismuth is still not very well described. Following a hunting accident with bismuth-containing shots, a bioavailability study of bismuth from metal pellets inoculated into rat limb muscles was carried out. Bismuth could be found in urine and blood of the animals. Bio-imaging using laser ablation ICP-MS of thin sections of the tissue around the metal implant was carried out to find out more about the distribution of the metal diffusing into the tissue. Two laser ablation systems with different ablation cell designs were compared regarding their analytical performance. Low concentrations of bismuth showing a non-symmetrical pattern were detected in the tissue surrounding the metal implant. This was partly an artefact from cutting the thin sections but also bio-mobilisation of the metals of the implant could be seen. An accumulation of zinc around the implant was interpreted as a marker of inflammation. Challenges regarding sample preparation for laser ablation and bio-imaging of samples of diverse composition became apparent during the analysis.

Enhanced detection of quantum dots labeled protein by simultaneous bismuth electrodeposition into microfluidic channel.

PubMed

Medina-Sánchez, Mariana; Miserere, Sandrine; Cadevall, Miquell; Merkoçi, Arben

2016-02-01

In this study, we propose an electrochemical immunoassay into a disposable microfluidic platform, using quantum dots (QDs) as labels and their enhanced detection using bismuth as an alternative to mercury electrodes. CdSe@ZnS QDs were used to tag human IgG as a model protein and detected through highly sensitive stripping voltammetry of the dissolved metallic component (cadmium in our case). The modification of the screen printed carbon electrodes (SPCEs) was done by a simple electrodeposition of bismuth that was previously mixed with the sample containing QDs. A magneto-immunosandwich assay was performed using a micromixer. A magnet placed at its outlet in order to capture the magnetic beads used as solid support for the immunoassay. SPCEs were integrated at the end of the channel as detector. Different parameters such as bismuth concentration, flow rate, and incubation times, were optimized. The LOD for HIgG in presence of bismuth was 3.5 ng/mL with a RSD of 13.2%. This LOD was about 3.3-fold lower than the one obtained without bismuth. Furthermore, the sensitivity of the system was increased 100-fold respect to experiments carried out with classical screen-printed electrodes, both in presence of bismuth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Viability of Bismuth as a Green Substitute for Lead in Jacketed .357 Magnum Revolver Bullets

NASA Astrophysics Data System (ADS)

Jenkins, Joel

In seeking to develop environmentally friendly lead-free non-toxic bullets, the research ballistically evaluated the performance of copper-jacketed handgun bullets containing a pure bismuth core. The lead was first removed from 140 grain Hornady(TM) XTPRTM bullets of 38 caliber (.357 diameter) by melting. The empty jackets were then refilled with pure bismuth, including the forming of a correctly sized hollow-point cavity. Due to the lower density of bismuth as compared to lead, the bismuth-cored bullets consistently weighed 125 gains. Conveniently this allowed direct comparison to commercially available 125 grain Hornady(TM) XTPRTM lead-cored bullets of 38 caliber. Both bismuth-cored and lead-cored versions of the 125 grain bullets had identical nose dimensions and jacket material, the only dimensional difference being the bullet length below the cannelure. Shooting took place at an outdoor range using a 357 Magnum Ruger(TM) SP101RTM revolver with 3" barrel as the test weapon. FBI protocols were followed when firing through clothing, wallboard, plywood, steel plates and laminated glass. Wound paths and bullets were captured in ballistic gelatin, with data collected for velocity, penetration, expansion, and weight retention. Bismuth compared favorably with lead in all but the laminated glass test, where it under penetrated due to jacket separation.

Microstructural characterization of Ni-based self-fluxing alloy after selective surface-engineering using diode laser

NASA Astrophysics Data System (ADS)

Chun, Eun-Joon; Park, Changkyoo; Nishikawa, Hiroshi; Kim, Min-Su

2018-06-01

The microstructural characterization of thermal-sprayed Ni-based self-fluxing alloy (Metco-16C®) after laser-assisted homogenization treatment was performed. To this end, a high-power diode laser system was used. This supported the real-time control of the target homogenization temperature at the substrate surface. Non-homogeneities of the macrosegregation of certain elements (C and Cu) and the local concentration of Cr-based carbides and borides in certain regions in the as-sprayed state could be enhanced with the application of homogenization. After homogenization at 1423 K, the hardness of the thermal-sprayed layer was found to have increased by 1280 HV from the as-sprayed state (750 HV). At this homogenization temperature, the microstructure of the thermal-sprayed layer consisted of a lamellar structuring of the matrix phase (austenite and Ni3Si) with fine (<5 μm) carbides and borides (the rod-like phase of Cr5B3, the lumpy phase of M23C6, and the extra-fine phase of M7C3). Despite the formation of several kinds of carbides and borides during homogenization at 1473 K, the lowest hardness level was found to be less than that of the as-sprayed state, because of the liquid-state homogenization treatment without formation of lamellar structuring between austenite and Ni3Si.

[Geochemical distribution of dissolved bismuth in the Yellow Sea and East China Sea].

PubMed

Wu, Xiao-Dan; Song, Jin-Ming; Wu, Bin; Li, Xue-Gang

2014-01-01

Occurrence level, geochemical distribution of dissolved bismuth and its coupling relationship to eco-environment were investigated in the Yellow Sea and East China Sea to explore the source and influencing factors. The results showed that the concentration of dissolved bismuth was within the range of 0-0. 029 microg x L(-1) at the surface and 0.001-0.189 microg x L(-1) at the bottom, with the averages of 0.008 and 0.016 microg x L(-1), respectively. Horizontally, low value of dissolved bismuth exhibited the bidirectional extension feature, indicating that it could trace the path of Changjiang Diluted Water. High value of dissolved bismuth was observed where the Subei Costal Current and Yellow Sea Warm Current flowed and the Changjiang Diluted Water and Zhejiang-Fujian Coastal Current met, suggesting that it was controlled by the cycle of current system. Vertically, the coastal water was fully mixed by water convection and eddy mixing, and was divided from the stratified water by strong tidal front, which blocked the transport of dissolved bismuth to the open sea. Thus, the concentration in front area was significantly higher than that in the open sea. Diurnal variation of dissolved bismuth was related to the hydrodynamic conditions (tide, suspension and thermocline) instead of the environmental factors (temperature and salinity). Positive relationship to SPM (suspended particulate matter) clarified that bismuth was prone to release from solid phase to liquid phase. Furthermore, conditions with temperature ranging 22-27 degrees C, salinity ranging 28-31 and pH ranging 7.9-8.1 were shown to be optimal for the release process.

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS... pretreatment standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process... (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS... pretreatment standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process... (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS). Except as... standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process wastewater... million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010 0.005 (b...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS... pretreatment standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process... (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS). Except as... standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process wastewater... million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010 0.005 (b...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 73 [Docket No. 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...

Method of Creating Micro-scale Silver Telluride Grains Covered with Bismuth Nanoparticles

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Lee, Kunik (Inventor); Kim, Hyun-Jung (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (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.

The cytotoxicity of organobismuth compounds with certain molecular structures can be diminished by replacing the bismuth atom with an antimony atom in the molecules.

PubMed

Kohri, Kumiko; Yoshida, Eiko; Yasuike, Shuji; Fujie, Tomoya; Yamamoto, Chika; Kaji, Toshiyuki

2015-06-01

Organic-inorganic hybrid molecules, which are composed of an organic structure and metal(s), are indispensable for synthetic chemical reactions; however, their toxicity has been incompletely understood. In the present study, we discovered two cytotoxic organobismuth compounds whose cytotoxicity diminished upon replacement of the intramolecular bismuth atom with an antimony atom. The intracellular accumulation of the organobismuth compounds was much higher than that of the organoantimony compounds with the corresponding organic structures. We also showed that both the organic structure and bismuth atom are required for certain organobismuth compounds to exert their cytotoxic effect, suggesting that the cytotoxicity of such a compound is a result of an interaction between the organic structure and the bismuth atom. The present data suggest that organobismuth compounds with certain molecular structures exhibit cytotoxicity via an interaction between the molecular structure and the bismuth atom, and this cytotoxicity can be diminished by replacing the bismuth atom with an antimony atom, resulting in lower intracellular accumulation.

NASA research on refractory compounds.

NASA Technical Reports Server (NTRS)

Gangler, J. J.

1971-01-01

The behavior and properties of the refractory carbides, nitrides, and borides are being investigated by NASA as part of its research aimed at developing superior heat resistant materials for aerospace applications. Studies of the zirconium-carbon-oxygen system show that zirconium oxycarbides of different compositions and lattice parameters can be formed between 1500 C and 1900 C and are stable below 1500 C. More applied studies show that hot working generally improves the microstructure and therefore the strength of TiC and NbC. Sintering studies on UN indicate that very high densities can be achieved. Hot pressing of cermets of HfN and HfC produces good mechanical properties for high temperature bearing applications. Attempts to improve the impact resistance of boride composites by the addition of a nickel or carbon yarn were not overly successful.

Ceramic fibers from Si-B-C polymer precursors

NASA Technical Reports Server (NTRS)

Riccitiello, S. R.; Hsu, M. S.; Chen, T. S.

1993-01-01

Non-oxide ceramics such as silicon carbide (SiC), silicon nitride (Si3N4), and silicon borides (SiB4, SiB6) have thermal stability, oxidation resistance, hardness, and varied electrical properties. All these materials can be prepared in a fiber form from a suitable polymer precursor. The above mentioned fibers, when tested over a temperature range from 25 to 1400 C, experience degradation at elevated temperatures. Past work in ceramic materials has shown that the strength of ceramics containing both carbides and borides is sustained at elevated temperatures, with minimum oxidation. The work presented here describes the formation of ceramic fibers containing both elements, boron and silicon, prepared via the polymer precursor route previously reported by the authors, and discusses the fiber mechanical properties that are retained over the temperature range studied.

Low-cost industrially available molybdenum boride and carbide as "platinum-like" catalysts for the hydrogen evolution reaction in biphasic liquid systems.

PubMed

Scanlon, Micheál D; Bian, Xiaojun; Vrubel, Heron; Amstutz, Véronique; Schenk, Kurt; Hu, Xile; Liu, BaoHong; Girault, Hubert H

2013-02-28

Rarely reported low-cost molybdenum boride and carbide microparticles, both of which are available in abundant quantities due to their widespread use in industry, adsorb at aqueous acid-1,2-dichloroethane interfaces and efficiently catalyse the hydrogen evolution reaction in the presence of the organic electron donor - decamethylferrocene. Kinetic studies monitoring biphasic reactions by UV/vis spectroscopy, and further evidence provided by gas chromatography, highlight (a) their superior rates of catalysis relative to other industrially significant transition metal carbides and silicides, as well as a main group refractory compound, and (b) their highly comparable rates of catalysis to Pt microparticles of similar dimensions. Insight into the catalytic processes occurring for each adsorbed microparticle was obtained by voltammetry at the liquid-liquid interface.

Ternary ceramic thermal spraying powder and method of manufacturing thermal sprayed coating using said powder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogli, Evelina; Sherman, Andrew J.; Glasgow, Curtis P.

The invention describes a method for producing ternary and binary ceramic powders and their thermal spraying capable of manufacturing thermal sprayed coatings with superior properties. Powder contain at least 30% by weight ternary ceramic, at least 20% by weight binary molybdenum borides, at least one of the binary borides of Cr, Fe, Ni, W and Co and a maximum of 10% by weight of nano and submicro-sized boron nitride. The primary crystal phase of the manufactured thermal sprayed coatings from these powders is a ternary ceramic, while the secondary phases are binary ceramics. The coatings have extremely high resistance againstmore » corrosion of molten metal, extremely thermal shock resistance and superior tribological properties at low and at high temperatures.« less

Design of Wear-Resistant Austenitic Steels for Selective Laser Melting

NASA Astrophysics Data System (ADS)

Lemke, J. N.; Casati, R.; Lecis, N.; Andrianopoli, C.; Varone, A.; Montanari, R.; Vedani, M.

2018-03-01

Type 316L stainless steel feedstock powder was modified by alloying with powders containing carbide/boride-forming elements to create improved wear-resistant austenitic alloys that can be readily processed by Selective Laser Melting. Fe-based alloys with high C, B, V, and Nb contents were thus produced, resulting in a microstructure that consisted of austenitic grains and a significant amount of hard carbides and borides. Heat treatments were performed to modify the carbide distribution and morphology. Optimal hard-phase spheroidization was achieved by annealing the proposed alloys at 1150 °C for 1 hour followed by water quenching. The total increase in hardness of samples containing 20 pct of C/B-rich alloy powder was of 82.7 pct while the wear resistance could be increased by a factor of 6.

Helicobacter pylori second-line rescue therapy with levofloxacin- and bismuth-containing quadruple therapy, after failure of standard triple or non-bismuth quadruple treatments.

PubMed

Gisbert, J P; Romano, M; Gravina, A G; Solís-Muñoz, P; Bermejo, F; Molina-Infante, J; Castro-Fernández, M; Ortuño, J; Lucendo, A J; Herranz, M; Modolell, I; Del Castillo, F; Gómez, J; Barrio, J; Velayos, B; Gómez, B; Domínguez, J L; Miranda, A; Martorano, M; Algaba, A; Pabón, M; Angueira, T; Fernández-Salazar, L; Federico, A; Marín, A C; McNicholl, A G

2015-04-01

The most commonly used second-line Helicobacter pylori eradication regimens are bismuth-containing quadruple therapy and levofloxacin-containing triple therapy, both offering suboptimal results. Combining bismuth and levofloxacin may enhance the efficacy of rescue eradication regimens. To evaluate the efficacy and tolerability of a second-line quadruple regimen containing levofloxacin and bismuth in patients whose previous H. pylori eradication treatment failed. This was a prospective multicenter study including patients in whom a standard triple therapy (PPI-clarithromycin-amoxicillin) or a non-bismuth quadruple therapy (PPI-clarithromycin-amoxicillin-metronidazole, either sequential or concomitant) had failed. Esomeprazole (40 mg b.d.), amoxicillin (1 g b.d.), levofloxacin (500 mg o.d.) and bismuth (240 mg b.d.) was prescribed for 14 days. Eradication was confirmed by (13) C-urea breath test. Compliance was determined through questioning and recovery of empty medication envelopes. Incidence of adverse effects was evaluated by questionnaires. 200 patients were included consecutively (mean age 47 years, 67% women, 13% ulcer). Previous failed therapy included: standard clarithromycin triple therapy (131 patients), sequential (32) and concomitant (37). A total of 96% took all medications correctly. Per-protocol and intention-to-treat eradication rates were 91.1% (95%CI = 87-95%) and 90% (95%CI = 86-94%). Cure rates were similar regardless of previous (failed) treatment or country of origin. Adverse effects were reported in 46% of patients, most commonly nausea (17%) and diarrhoea (16%); 3% were intense but none was serious. Fourteen-day bismuth- and levofloxacin-containing quadruple therapy is an effective (≥90% cure rate), simple and safe second-line strategy in patients whose previous standard triple or non-bismuth quadruple (sequential or concomitant) therapies have failed. © 2015 John Wiley & Sons Ltd.

Effect of absorption recovery in bismuth-doped silica glass at 1450 nm on soliton grouping in fiber laser

PubMed Central

Gumenyuk, R.; Melkumov, M. A.; Khopin, V. F.; Dianov, E. M.; Okhotnikov, O. G.

2014-01-01

Saturable absorption in bismuth-doped glasses was found to have a noticeable influence on soliton interaction and group formation. This phenomenon, observed in 1450 nm mode-locked bismuth-doped fiber laser, shows the distinct feature of the multiple pulse regime, which appears as a stationary pulse group whose length can be spread over the whole cavity length by variation of the pump power and polarization. Pulse positioning within the ensemble depends on the saturation fluence and the relatively fast recovery dynamics of bismuth fiber. PMID:25391808

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jena, Puru; Kandalam, Anil K.; Christian, Theresa M.

Gallium phosphide bismide (GaP1-xBix) epilayers with bismuth fractions from 0.9% to 3.2%, as calculated from lattice parameter measurements, were studied with Rutherford backscattering spectrometry (RBS) to directly measure bismuth incorporation. The total bismuth fractions found by RBS were higher than expected from the lattice parameter calculations. Furthermore, in one analyzed sample grown by molecular beam epitaxy at 300 degrees C, 55% of incorporated bismuth was found to occupy interstitial sites. We discuss implications of this high interstitial incorporation fraction and its possible relationship to x-ray diffraction and photoluminescence measurements of GaP0.99Bi0.01.

Study of the structure, dielectric and ferroelectric behavior of BaBi{sub 4+δ}Ti{sub 4}O{sub 15} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khokhar, Anita, E-mail: mails4anita@gmail.com, E-mail: goyalphy@gmail.com; Goyal, Parveen K., E-mail: mails4anita@gmail.com, E-mail: goyalphy@gmail.com; Sreenivas, K.

2016-05-23

The structure and ferroelectric properties of excess bismuth doped barium bismuth titanate BaBi{sub 4+δ}Ti{sub 4}O{sub 15} (δ = 2 - 10 wt.%)) ceramics prepared by solid-state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of a single phase material with a change in the orthorhombic distortion with varying excess of bismuth content. There is no change in the phase transition temperature (T{sub m}) while the relaxor behaviour has been modified significantly with excess of bismuth doping. Saturated hysteresis loops with high remnant polarization (P{sub r} ~ 12.5  µC/cm{sup 2}), low coercive fields (E{sub c} ~ 26 kV/cm) aremore » measured and a high piezoelectric coefficient (d{sub 33} ~ 29 pC/N) is achieved in poled BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics prepared with up to 8 wt.% of excess bismuth oxide. The improvement in the ferroelectric properties with increase in the excess bismuth content in BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics has been explained in terms of changing oxygen vacancy concentration and structural relaxation. Tunable ferroelectric materials can be obtained by manipulating the doping amount of excess bismuth.« less

The efficacy of ranitidine bismuth citrate, amoxicillin and doxycycline or tetracycline regimens as a first line treatment for Helicobacter pylori eradication.

PubMed

Akyildiz, Murat; Akay, Sinan; Musoglu, Ahmet; Tuncyurek, Muge; Aydin, Ahmet

2009-01-01

The eradication rates of Helicobacter pylori (H. pylori) clearly decreased with standard PPI-based triple therapies. To assess the efficacy of two different triple therapies consisting of ranitidine bismuth citrate-amoxicillin-doxycycline and ranitidine bismuth citrate-amoxicillin-tetracycline combinations as a first line treatment option. One hundred and fifteen consecutive dyspeptic patients in whom H. pylori infection was diagnosed for the first time were enrolled in this study. The patients were randomized into two groups. Group 1 (n=57) was assigned to receive a 14-day triple therapy consisting of ranitidine bismuth citrate 400 mg (b.i.d.), amoxicillin 1 g (b.i.d) and doxycycline 100 mg (b.i.d.). Group 2 (n=58) was assigned to receive a 14-day triple therapy consisting of ranitidine bismuth citrate 400 mg (b.i.d.), amoxicillin 1 g (b.i.d.) and tetracycline 500 mg (q.i.d.). The eradication was achieved in 45.7% (21/46) and 40.8% (20/49) of the patients in group 1 and group 2, according to per protocol analysis. The intention-to-treat eradication rates were 36.8% (21/57) and 34.5% (20/58) in group 1 and group 2, respectively. Two-week therapy with neither ranitidine bismuth citrate-amoxicillin-doxycycline nor ranitidine bismuth citrate-amoxicillin-tetracycline is adequately effective for H. pylori eradication as a first line therapy.

Electronic Structure Properties and a Bonding Model of Thermoelectric Half-Heusler and Boride Phases

NASA Astrophysics Data System (ADS)

Simonson, Jack William

Half-Heusler alloys MNiSn and MCoSb (M = Ti, Zr, Hf) and layered boride intermetallics with structure types YCrB4 and Er 3CrB7 were designed, synthesized, and characterized. The thermoelectric properties of these two classes of alloys were measured from room temperature to 1100 K with the intent of indirectly studying their electronic structure properties and gauging not only their suitability but that of related alloys for high temperature thermoelectric power generation. In the case of the half-Heusler alloys, transition metals were substituted to both the M and Ni/Co sites to study the resultant modifications of the d-orbital-rich portion of the electronic structure near the Fermi energy. This modification and subsequent pinning of the Fermi energy within the gap is discussed herein in terms of first principles electronic structure calculations from the literature. In the half-Heusler alloys, it was found that substitution of transition metals invariably led to a decrease in the thermopower, while the resistivity typically maintained its semiconducting trend. On the other hand, Sn doping in MCoSb type alloys -- a dopant that has been known for some time to be efficient -- was shown to result in high ZT at temperatures in excess of 1000 K. Moreover, the band gaps of the transition metal-doped alloys measured in this work offer insight into the discrepancy between the predicted and measured band gaps in the undoped parent compositions. In the case of the layered boride alloys, on the other hand, few electronic calculations have been published, thus prompting the generalization of a well-known electron counting rule -- which is typically used to study molecular organometallics, boranes, and metallocenes -- to predict the trends in the densities of states of crystalline solids that possess the requisite deltahedral bonding geometry. In accordance with these generalized electronic counting rules, alloys of the form RMB4 (R = Y, Gd, Ho; M = Cr, Mo, W) were measured to be n-type semiconductors with band gaps ranging from 0.15 eV to 0.25 eV. These alloys exhibited thermoelectric power factors comparable with those of other potential boride thermoelectric materials reported in the literature. Furthermore, as a result of the procedure developed for precision synthesis of boron-rich intermetallics and the improved understanding of bonding trends, layered borides of several previously overlooked structure-types were synthesized and screened for superconductivity. Consequently, alloys of the MoB4 phase were discovered to be superconducting when doped with Nb or Ti. Electrical resistivity measurements of superconducting transitions between 6 and 8 K in these materials were confirmed via magnetic susceptibility measurements and x-ray diffraction. Structural measurements indicated opposite trends in lattice modification than those reported for the superconducting transition metal diborides.

Synthesis of cross-linked chitosan modified with the glycine moiety for the collection/concentration of bismuth in aquatic samples for ICP-MS determination.

PubMed

Oshita, Koji; Noguchi, Osamu; Oshima, Mitsuko; Motomizu, Shoji

2007-10-01

A chelating resin, cross-linked chitosan modified with the glycine moiety (glycine-type chitosan resin), was developed for the collection and concentration of bismuth in aquatic samples for ICP-MS measurements. The adsorption behavior of bismuth and 55 elements on glycine-type chitosan resin was systematically examined by passing a sample solution containing 56 elements through a mini-column packed with the resin (wet volume; 1 ml). After eluting the elements adsorbed on the resin with nitric acid, the eluates were measured by ICP-MS. The glycine-type chitosan resin could adsorb several cations by a chelating mechanism and several oxoanions by an anion-exchange mechanism. Especially, the resin could adsorb almost 100% Bi(III) over a wide pH region from pH 2 to 6. Bismuth could be strongly adsorbed at pH 3, and eluted quantitatively with 10 ml of 3 M nitric acid. A column pretreatment method with the glycine-type chitosan resin was used prior to removal of high concentrations of matrices in a seawater sample and the preconcentration of trace bismuth in river water samples for ICP-MS measurements. The column pretreatment method was also applied to the determination of bismuth in real samples by ICP-MS. The LOD of bismuth was 0.1 pg ml(-1) by 10-fold column preconcentration for ICP-MS measurements. The analytical results for bismuth in sea and river water samples by ICP-MS were 22.9 +/- 0.5 pg ml(-1) (RSD, 2.2%) and 2.08 +/- 0.05 pg ml(-1) (RSD, 2.4%), respectively.

Electronic bandstructure of semiconductor dilute bismide structures

NASA Astrophysics Data System (ADS)

Erucar, T.; Nutku, F.; Donmez, O.; Erol, A.

2017-02-01

In this work electronic band structure of dilute bismide GaAs/GaAs1-xBix quantum well structures with 1.8% and 3.75% bismuth compositions have been investigated both experimentally and theoretically. Photoluminescence (PL) measurements reveal that effective bandgap of the samples decreases approximately 65 meV per bismuth concentration. Temperature dependence of the effective bandgap is obtained to be higher for the sample with higher bismuth concentration. Moreover, both asymmetric characteristic at the low energy tail of the PL and full width at half maximum (FWHM) of PL peak increase with increasing bismuth composition as a result of increased Bi related defects located above valence band (VB). In order to explain composition dependence of the effective bandgap quantitatively, valence band anti-crossing (VBAC) model is used. Bismuth composition and temperature dependence of effective bandgap in a quantum well structure is modeled by solving Schrödinger equation and compared with experimental PL data.

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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

2018-06-01

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.

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of effluent... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of effluent... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

Build-up enhancement of photoluminescence from phenylazomethine bismuth dendrimer using Bi(OTf)3

NASA Astrophysics Data System (ADS)

Kambe, Tetsuya; Imaoka, Shotaro; Imaoka, Takane; Yamamoto, Kimihisa

2018-05-01

Metal assembly to a dendrimer can provide various functionalities based on the branched structure. Here, we researched assembly phenomena of bismuth salts in the phenylazomethine dendrimer and achieved enhancement of emission intensity per metal unit by using Bi(OTf)3. This enhancement suggested increasing of Bi-N coordination bonds derived from the bismuth units in the dendrimer.

Computational chemistry calculations of stability for bismuth nanotubes, fullerene-like structures and hydrogen-containing nanostructures.

PubMed

Kharissova, Oxana V; Osorio, Mario; Vázquez, Mario Sánchez; Kharisov, Boris I

2012-08-01

Using molecular mechanics (MM+), semi-empirical (PM6) and density functional theory (DFT) (B3LYP) methods we characterized bismuth nanotubes. In addition, we predicted the bismuth clusters {Bi(20)(C(5V)), Bi(24)(C(6v)), Bi(28)(C(1)), B(32)(D(3H)), Bi(60)(C(I))} and calculated their conductor properties.

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

NASA Astrophysics Data System (ADS)

Dasika, Vaishno D.; Krivoy, E. M.; Nair, H. P.; Maddox, S. J.; Park, K. W.; Jung, D.; Lee, M. L.; Yu, E. T.; Bank, S. R.

2014-12-01

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

Composition for radiation shielding

DOEpatents

Kronberg, J.W.

1994-08-02

A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

Topological Insulator State in Thin Bismuth Films Subjected to Plane Tensile Strain

NASA Astrophysics Data System (ADS)

Demidov, E. V.; Grabov, V. M.; Komarov, V. A.; Kablukova, N. S.; Krushel'nitskii, A. N.

2018-03-01

The results of experimental examination of galvanomagnetic properties of thin bismuth films subjected to plane tensile strain resulting from the difference in thermal expansion coefficients of the substrate material and bismuth are presented. The resistivity, the magnetoresistance, and the Hall coefficient were studied at temperatures ranging from 5 to 300 K in magnetic fields as strong as 0.65 T. Carrier densities were calculated. A considerable increase in carrier density in films thinner than 30 nm was observed. This suggests that surface states are more prominent in thin bismuth films on mica substrates, while the films themselves may exhibit the properties of a topological insulator.

Oxidation mechanism of formic acid on the bismuth adatom-modified Pt(111) surface.

PubMed

Perales-Rondón, Juan Victor; Ferre-Vilaplana, Adolfo; Feliu, Juan M; Herrero, Enrique

2014-09-24

In order to improve catalytic processes, elucidation of reaction mechanisms is essential. Here, supported by a combination of experimental and computational results, the oxidation mechanism of formic acid on Pt(111) electrodes modified by the incorporation of bismuth adatoms is revealed. In the proposed model, formic acid is first physisorbed on bismuth and then deprotonated and chemisorbed in formate form, also on bismuth, from which configuration the C-H bond is cleaved, on a neighbor Pt site, yielding CO2. It was found computationally that the activation energy for the C-H bond cleavage step is negligible, which was also verified experimentally.

Composition for radiation shielding

DOEpatents

Kronberg, James W.

1994-01-01

A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

Bismuth oxyhalide nanomaterials: layered structures meet photocatalysis

NASA Astrophysics Data System (ADS)

Li, Jie; Yu, Ying; Zhang, Lizhi

2014-07-01

In recent years, layered bismuth oxyhalide nanomaterials have received more and more interest as promising photocatalysts because their unique layered structures endow them with fascinating physicochemical properties; thus, they have great potential photocatalytic applications for environment remediation and energy harvesting. In this article, we explore the synthesis strategies and growth mechanisms of layered bismuth oxyhalide nanomaterials, and propose design principles of tailoring a layered configuration to control the nanoarchitectures for high efficient photocatalysis. Subsequently, we focus on their layered structure dependent properties, including pH-related crystal facet exposure and phase transformation, facet-dependent photoactivity and molecular oxygen activation pathways, so as to clarify the origin of the layered structure dependent photoreactivity. Furthermore, we summarize various strategies for modulating the composition and arrangement of layered structures to enhance the photoactivity of nanostructured bismuth oxyhalides via internal electric field tuning, dehalogenation effect, surface functionalization, doping, plasmon modification, and heterojunction construction, which may offer efficient guidance for the design and construction of high-performance bismuth oxyhalide-based photocatalysis systems. Finally, we highlight some crucial issues in engineering the layered-structure mediated properties of bismuth oxyhalide photocatalysts and provide tentative suggestions for future research on increasing their photocatalytic performance.

NEUTRONIC REACTOR FUEL COMPOSITION

DOEpatents

Thurber, W.C.

1961-01-10

Uranium-aluminum alloys in which boron is homogeneously dispersed by adding it as a nickel boride are described. These compositions have particular utility as fuels for neutronic reactors, boron being present as a burnable poison.

Anomalous stress response of ultrahard WB n compounds

DOE PAGES

Li, Quan; Zhou, Dan; Zheng, Weitao; ...

2015-10-29

Boron-rich tungsten borides are premier prototypes of a new class of ultrahard compounds. Here, we show by first-principles calculations that their stress-strain relations display surprisingly diverse and anomalous behavior under a variety of loading conditions. Most remarkable is the dramatically changing bonding configurations and deformation modes with rising boron concentration in WB n (n=2, 3, 4), resulting in significantly different stress responses and unexpected indentation strength variations. This novel phenomenon stems from the peculiar structural arrangements in tungsten borides driven by boron’s ability to form unusually versatile bonding states. Our results elucidate the intriguing deformation mechanisms that define a distinctmore » type of ultrahard material. Here, these new insights underscore the need to explore unconventional structure-property relations in a broad range of transition-metal light-element compounds.« less

X-Ray photoelectron spectroscopy study of radiofrequency-sputtered titanium, carbide, molybdenum carbide, and titanium boride coatings and their friction properties

NASA Technical Reports Server (NTRS)

Brainard, W. A.; Wheeler, D. R.

1977-01-01

Radiofrequency sputtered coatings of titanium carbide, molybdenum carbide and titanium boride were tested as wear resistant coatings on stainless steel in a pin on disk apparatus. X-ray photoelectron spectroscopy (XPS) was used to analyze the sputtered films with regard to both bulk and interface composition in order to obtain maximum film performance. Significant improvements in friction behavior were obtained when properly biased films were deposited on deliberately preoxidized substrates. XPS depth profile data showed thick graded interfaces for bias deposited films even when adherence was poor. The addition of 10 percent hydrogen to the sputtering gas produced coatings with thin poorly adherent interfaces. Results suggest that some of the common practices in the field of sputtering may be detrimental to achieving maximum adherence and optimum composition for these refractory compounds.

Electronic, structural and magnetic studies of niobium borides of group 8 transition metals, Nb2MB2 (M=Fe, Ru, Os) from first principles calculations

NASA Astrophysics Data System (ADS)

Touzani, Rachid St.; Fokwa, Boniface P. T.

2014-03-01

The Nb2FeB2 phase (U3Si2-type, space group P4/mbm, no. 127) is known for almost 50 years, but until now its magnetic properties have not been investigated. While the synthesis of Nb2OsB2 (space group P4/mnc, no. 128, a twofold superstructure of U3Si2-type) with distorted Nb-layers and Os2-dumbbells was recently achieved, "Nb2RuB2" is still not synthesized and its crystal structure is yet to be revealed. Our first principles density functional theory (DFT) calculations have confirmed not only the experimental structures of Nb2FeB2 and Nb2OsB2, but also predict "Nb2RuB2" to crystalize with the Nb2OsB2 structure type. According to chemical bonding analysis, the homoatomic B-B interactions are optimized and very strong, but relatively strong heteroatomic M-B, B-Nb and M-Nb bonds (M=Fe, Ru, Os) are also found. These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of these ternary borides. The density-of-states at the Fermi level predicts metallic behavior, as expected, from metal-rich borides. Analysis of possible magnetic structures concluded preferred antiferromagnetic ordering for Nb2FeB2, originating from ferromagnetic interactions within iron chains and antiferromagnetic exchange interactions between them.

Specific features of thermal and magnetic properties of Yb B50 at low temperatures

NASA Astrophysics Data System (ADS)

Novikov, V. V.; Zhemoedov, N. A.; Matovnikov, A. V.; Mitroshenkov, N. V.; Popova, E. A.; Tolstosheev, A. K.; Malkin, B. Z.; Bud'ko, S. L.

2018-05-01

Heat capacity, thermal expansion, and magnetization of ytterbium boride Yb B50 were studied at temperatures 0.6-300 K, 5-300 K, and 2-300 K, respectively. We revealed two smooth peaks at about 4.0 and 60 K in the temperature dependence of the heat capacity. A comparison with the heat capacity of the diamagnetic isostructural boride Lu B50 shows that these anomalies can be attributed to excitations in the ytterbium sublattice (Schottky anomalies). A scheme for splitting of the ground F 7 /2 2 multiplet of Y b3 + ions in the crystal field is proposed. Reliability of the proposed crystal-field energies of the Y b3 + ions is confirmed by the analysis of temperature dependencies of magnetic susceptibility and magnetization in applied magnetic fields up to 55 kOe. A clear anisotropy of the thermal expansion and a negative expansion within a wide temperature range (40-185 K) were observed. Assuming that this anomaly of the thermal expansion in higher borides is caused by the specific thermal evolution of a crystal lattice observed earlier, in particular, in Lu B50 , and the interaction of rare-earth ions with lattice strains, we have determined phenomenological Grüneisen parameters which characterize effects due to thermal transitions of Y b3 + ions between the ground and excited states. A phase transition of Yb B50 to any magnetically ordered state was not observed down to the lowest temperatures of experiments.

Fusion welding of a modern borated stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robino, C.V.; Cieslak, M.J.

1997-01-01

Experiments designed to assess the fabrication and service weldability of 304B4A borated stainless steel were conducted. Welding procedures and parameters for manual gas tungsten arc (GTA) welding, autogenous electron beam (EB) welding and filler-added EB welding were developed and found to be similar to those for austenitic stainless steels. Following the procedure development, four test welds were produced and evaluated by microstructural analysis and Charpy impact testing. Further samples were used for determination of the postweld heat treatment (PWHT) response of the welds. The fusion zone structure of welds in this alloy consists of primary austenite dendrites with an interdendriticmore » eutectic-like austenite/boride constituent. Welds also show an appreciable partially molten zone that consists of the austenite/boride eutectic surrounding unmelted austenite islands. The microstructure of the EB welds was substantially finer than that of the GTA welds, and boride coarsening was not observed in the solid state heat-affected zone (HAZ) of either weld type. The impact toughness of as-welded samples was found to be relatively poor, averaging less than 10 J for both GTA and EB welds. For fusion zone notched GTA and EB samples and centerline notched EB samples, fracture generally occurred along the boundary between the partially molten and solid-state regions of the HAZ. The results of the PWHT study were very encouraging, with typical values of the impact energy for HAZ notched samples approaching 40 J, or twice the minimum code-acceptable value.« less

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the degree of... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the degree of... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

Heat-Pipe Bismuth Laser; Examination of Laser Action at 4722A in Bismuth Vapor

DTIC Science & Technology

1976-11-01

11, 15(1975). of Type 6p 3 -6p 2 7s in the Bismuth Atomic Spectrum in Intermediate Coupling," Acta Physica Polonica A47, 231(1975). 19. A.N. Nesmeyanov...Calculated Transit n Probabilities and Lifetimes for the First Excited Configuration np (n+l)s in the Neutral As, Sb and Bi Atoms, " Physica Scripta

Using quality control to limit bismuth in copper cathodes

NASA Astrophysics Data System (ADS)

Serrano, John R.; Berger, Dennis; Bridges, Bill

1994-10-01

This article describes quality-control work at Phelps Dodge, undertaken as part of ISO 9003 certification, to better identify and prevent the contamination of copper cathodes by bismuth. It also overviews the implementation of a production control system as well as associated training designed to minimize the possibility of bismuth-contaminated copper progressing beyond the cathode stage to other areas of manufacturing or distribution.

Radiation dose reduction to the breast in thoracic CT: Comparison of bismuth shielding, organ-based tube current modulation, and use of a globally decreased tube current

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Jia; Duan Xinhui; Christner, Jodie A.

2011-11-15

Purpose: The purpose of this work was to evaluate dose performance and image quality in thoracic CT using three techniques to reduce dose to the breast: bismuth shielding, organ-based tube current modulation (TCM) and global tube current reduction. Methods: Semi-anthropomorphic thorax phantoms of four different sizes (15, 30, 35, and 40 cm lateral width) were used for dose measurement and image quality assessment. Four scans were performed on each phantom using 100 or 120 kV with a clinical CT scanner: (1) reference scan; (2) scan with bismuth breast shield of an appropriate thickness; (3) scan with organ-based TCM; and (4)more » scan with a global reduction in tube current chosen to match the dose reduction from bismuth shielding. Dose to the breast was measured with an ion chamber on the surface of the phantom. Image quality was evaluated by measuring the mean and standard deviation of CT numbers within the lung and heart regions. Results: Compared to the reference scan, dose to the breast region was decreased by about 21% for the 15-cm phantom with a pediatric (2-ply) shield and by about 37% for the 30, 35, and 40-cm phantoms with adult (4-ply) shields. Organ-based TCM decreased the dose by 12% for the 15-cm phantom, and 34-39% for the 30, 35, and 40-cm phantoms. Global lowering of the tube current reduced breast dose by 23% for the 15-cm phantom and 39% for the 30, 35, and 40-cm phantoms. In phantoms of all four sizes, image noise was increased in both the lung and heart regions with bismuth shielding. No significant increase in noise was observed with organ-based TCM. Decreasing tube current globally led to similar noise increases as bismuth shielding. Streak and beam hardening artifacts, and a resulting artifactual increase in CT numbers, were observed for scans with bismuth shields, but not for organ-based TCM or global tube current reduction. Conclusions: Organ-based TCM produces dose reduction to the breast similar to that achieved with bismuth shielding for both pediatric and adult phantoms. However, organ-based TCM does not affect image noise or CT number accuracy, both of which are adversely affected by bismuth shielding. Alternatively, globally decreasing the tube current can produce the same dose reduction to the breast as bismuth shielding, with a similar noise increase, yet without the streak artifacts and CT number errors caused by the bismuth shields. Moreover, globally decreasing the tube current reduces the dose to all tissues scanned, not simply to the breast.« less

Disturbed oxidative metabolism in organic brain syndrome caused by bismuth in skin creams.

PubMed

Krüger, G; Thomas, D J; Weinhardt, F; Hoyer, S

1976-09-04

Two patients are described with an organic brain syndrome thought to be due to bismuth (Bi) absorbed from a skin cream. Both patients had intellectual impairment and memory loss punctuated by periods of confusion, tremulousness, clumsiness, difficulty in walking, and myoclonic jerks. A similar clinical picture has been reported from Australia and France in patients taking insoluble bismuth salts by mouth. Bi was found in cerebral venous blood in both patients and in the cerebrospinal fluid in one. It is suggested that bismuth can cross the blood/brain barrier and disturb oxidative cerebral metabolism, because increased lactate production was found with decreased consumption of oxygen and glucose and lowered cerebral blood-flow.

Dual-modality, fluorescent, PLGA encapsulated bismuth nanoparticles for molecular and cellular fluorescence imaging and computed tomography

NASA Astrophysics Data System (ADS)

Swy, Eric R.; Schwartz-Duval, Aaron S.; Shuboni, Dorela D.; Latourette, Matthew T.; Mallet, Christiane L.; Parys, Maciej; Cormode, David P.; Shapiro, Erik M.

2014-10-01

Reports of molecular and cellular imaging using computed tomography (CT) are rapidly increasing. Many of these reports use gold nanoparticles. Bismuth has similar CT contrast properties to gold while being approximately 1000-fold less expensive. Herein we report the design, fabrication, characterization, and CT and fluorescence imaging properties of a novel, dual modality, fluorescent, polymer encapsulated bismuth nanoparticle construct for computed tomography and fluorescence imaging. We also report on cellular internalization and preliminary in vitro and in vivo toxicity effects of these constructs. 40 nm bismuth(0) nanocrystals were synthesized and encapsulated within 120 nm Poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles by oil-in-water emulsion methodologies. Coumarin-6 was co-encapsulated to impart fluorescence. High encapsulation efficiency was achieved ~70% bismuth w/w. Particles were shown to internalize within cells following incubation in culture. Bismuth nanocrystals and PLGA encapsulated bismuth nanoparticles exhibited >90% and >70% degradation, respectively, within 24 hours in acidic, lysosomal environment mimicking media and both remained nearly 100% stable in cytosolic/extracellular fluid mimicking media. μCT and clinical CT imaging was performed at multiple X-ray tube voltages to measure concentration dependent attenuation rates as well as to establish the ability to detect the nanoparticles in an ex vivo biological sample. Dual fluorescence and CT imaging is demonstrated as well. In vivo toxicity studies in rats revealed neither clinically apparent side effects nor major alterations in serum chemistry and hematology parameters. Calculations on minimal detection requirements for in vivo targeted imaging using these nanoparticles are presented. Indeed, our results indicate that these nanoparticles may serve as a platform for sensitive and specific targeted molecular CT and fluorescence imaging.Reports of molecular and cellular imaging using computed tomography (CT) are rapidly increasing. Many of these reports use gold nanoparticles. Bismuth has similar CT contrast properties to gold while being approximately 1000-fold less expensive. Herein we report the design, fabrication, characterization, and CT and fluorescence imaging properties of a novel, dual modality, fluorescent, polymer encapsulated bismuth nanoparticle construct for computed tomography and fluorescence imaging. We also report on cellular internalization and preliminary in vitro and in vivo toxicity effects of these constructs. 40 nm bismuth(0) nanocrystals were synthesized and encapsulated within 120 nm Poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles by oil-in-water emulsion methodologies. Coumarin-6 was co-encapsulated to impart fluorescence. High encapsulation efficiency was achieved ~70% bismuth w/w. Particles were shown to internalize within cells following incubation in culture. Bismuth nanocrystals and PLGA encapsulated bismuth nanoparticles exhibited >90% and >70% degradation, respectively, within 24 hours in acidic, lysosomal environment mimicking media and both remained nearly 100% stable in cytosolic/extracellular fluid mimicking media. μCT and clinical CT imaging was performed at multiple X-ray tube voltages to measure concentration dependent attenuation rates as well as to establish the ability to detect the nanoparticles in an ex vivo biological sample. Dual fluorescence and CT imaging is demonstrated as well. In vivo toxicity studies in rats revealed neither clinically apparent side effects nor major alterations in serum chemistry and hematology parameters. Calculations on minimal detection requirements for in vivo targeted imaging using these nanoparticles are presented. Indeed, our results indicate that these nanoparticles may serve as a platform for sensitive and specific targeted molecular CT and fluorescence imaging. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01405g

Group III-nitride thin films grown using MBE and bismuth

DOEpatents

Kisielowski, Christian K.; Rubin, Michael

2002-01-01

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

Group III-nitride thin films grown using MBE and bismuth

DOEpatents

Kisielowski, Christian K.; Rubin, Michael

2000-01-01

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

Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide

DOE PAGES

Lee, Yeseul; Lo, Shih -Han; Chen, Changqiang; ...

2014-05-02

Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23–27μW cm –1 K –2 at temperatures above 400 K. The addition of small amounts (~0.25 mol%) of antimony generates extensive nanoscale precipitates, whereasmore » comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. As a result, the corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.« less

Targeted nanoparticles for enhanced X-ray radiation killing of multidrug-resistant bacteria.

PubMed

Luo, Yang; Hossain, Mainul; Wang, Chaoming; Qiao, Yong; An, Jincui; Ma, Liyuan; Su, Ming

2013-01-21

This paper describes a nanoparticle enhanced X-ray irradiation based strategy that can be used to kill multidrug resistant (MDR) bacteria. In the proof-of-concept experiment using MDR Pseudomonas aeruginosa (P. aeruginosa) as an example, polyclonal antibody modified bismuth nanoparticles are introduced into bacterial culture to specifically target P. aeruginosa. After washing off uncombined bismuth nanoparticles, the bacteria are irradiated with X-rays, using a setup that mimics a deeply buried wound in humans. Results show that up to 90% of MDR P. aeruginosa are killed in the presence of 200 μg ml(-1) bismuth nanoparticles, whereas only ∼6% are killed in the absence of bismuth nanoparticles when exposed to 40 kVp X-rays for 10 min. The 200 μg ml(-1) bismuth nanoparticles enhance localized X-ray dose by 35 times higher than the control with no nanoparticles. In addition, no significant harmful effects on human cells (HeLa and MG-63 cells) have been observed with 200 μg ml(-1) bismuth nanoparticles and 10 min 40 kVp X-ray irradiation exposures, rendering the potential for future clinical use. Since X-rays can easily penetrate human tissues, this bactericidal strategy has the potential to be used in effectively killing deeply buried MDR bacteria in vivo.

Microstructure and Mechanical Properties of Tin-Bismuth Solder Reinforced by Aluminum Borate Whiskers

NASA Astrophysics Data System (ADS)

Wang, Jun; Wei, Hongmei; He, Peng; Lin, Tiesong; Lu, Fengjiao

2015-10-01

Tin-bismuth solder has emerged as a promising lead-free alternative to tin-lead solder, especially for low-temperature packaging applications. However, the intrinsic brittleness of tin-bismuth solder alloy, aggravated by the coarse bismuth-rich phase and the thick interfacial intermetallic layer, notably limits the mechanical performance of the bonded joints. In this work, the microstructure and mechanical performance of solder joints were improved by adding 3.2 vol.% aluminum borate whiskers to the tin-bismuth solder alloy. This whisker-reinforced composite solder was fabricated through a simple process. Typically, 25- μm to 75- μm tin-bismuth particles were mixed with a small amount of aluminum borate whiskers with diameter of 0.5 μm to 1.5 μm and length of 5 μm to 15 μm. The addition of whiskers restrained the formation of coarse brittle bismuth-rich phase and decreased the lamellar spacing from 0.84 μm to 7.94 μm to the range of 0.22 μm to 1.80 μm. Moreover, the growth rate of the interfacial intermetallic layer during the remelting treatment decreased as well. The joint shear strength increased from 19.4 MPa to 24.7 MPa, and only declined by 4.9% (average, -5.9% to 15.8%) after the tenth remelting, while the shear strength of the joint without whiskers declined by 31.5% (average, 10.1-44.1%). The solder alloy was reinforced because of their high strength and high modulus and also the refinement effect on the solder alloy microstructure.

CONCENTRATION AND DECONTAMINATION OF SOLUTIONS CONTAINING PLUTONIUM VALUES BY BISMUTH PHOSPHATE CARRIER PRECIPITATION METHODS

DOEpatents

Seaborg, G.T.; Thompson, S.G.

1960-08-23

A process is given for isolating plutonium present in the tetravalent state in an aqueous solution together with fission products. First, the plutonium and fission products are coprecipitated on a bismuth phosphate carrier. The precipitate obtained is dissolved, and the plutonium in the solution is oxidized to the hexavalent state (with ceric nitrate, potassium dichromate, Pb/ sub 3/O/sub 4/, sodium bismuthate and/or potassium dichromate). Thereafter a carrier for fission products is added (bismuth phosphate, lanthanum fluoride, ceric phosphate, bismuth oxalate, thorium iodate, or thorium oxalate), and the fission-product precipitation can be repeated with one other of these carriers. After removal of the fission-product-containing precipitate or precipitates. the plutonium in the supernatant is reduced to the tetravalent state (with sulfur dioxide, hydrogen peroxide. or sodium nitrate), and a carrier for tetravalent plutonium is added (lanthanum fluoride, lanthanum hydroxide, lanthanum phosphate, ceric phosphate, thorium iodate, thorium oxalate, bismuth oxalate, or niobium pentoxide). The plutonium-containing precipitate is then dissolved in a relatively small volume of liquid so as to obtain a concentrated solution. Prior to dissolution, the bismuth phosphate precipitates first formed can be metathesized with a mixture of sodium hydroxide and potassium carbonate and plutonium-containing lanthanum fluorides with alkali-metal hydroxide. In the solutions formed from a plutonium-containing lanthanum fluoride carrier the plutonium can be selectively precipitated with a peroxide after the pH was adjusted preferably to a value of between 1 and 2. Various combinations of second, third, and fourth carriers are discussed.

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

PubMed

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 < .05). The interaction of the 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 < .05). The teeth filled with white MTA Angelus demonstrated a grayish discoloration with evident dentin staining. 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.

The physical and mechanical metallurgy of advanced O+BCC titanium alloys

NASA Astrophysics Data System (ADS)

Cowen, Christopher John

This thesis comprises a systematic study of the microstructural evolution, phase transformation behavior, elevated-temperature creep behavior, room-temperature and elevated-temperature tensile behavior, and room-temperature fatigue behavior of advanced titanium-aluminum-niobium (Ti-Al-Nb) alloys with and without boron additions. The specific alloys studied were: Ti-5A1-45Nb (at%), Ti-15Al-33Nb (at%), Ti-15Al-33Nb-0.5B (at%), Ti-15Al-33Nb-5B (at%), Ti-21Al-29Nb (at%), Ti-22Al-26Nb (at%), and Ti-22Al-26Nb-5B (at%). The only alloy composition that had been previously studied before this thesis work began was Ti-22Al-26Nb (at%). Publication in peer-reviewed material science journals of the work performed in this thesis has made data available in the scientific literature that was previously non-existent. The knowledge gap for Ti-Al-Nb phase equilibria over the compositional range of Ti-23Al-27Nb (at%) to Ti-12Al-38Nb (at%) that existed before this work began was successfully filled. The addition of 5 at% boron to the Ti-15Al-33Nb alloy produced 5-9 volume percent boride phase needles within the microstructure. The chemical composition of the boride phase measured by electron microprobe was determined to be approximately B 2TiNb. The lattice parameters of the boride phase were simulated through density functional theory calculations by collaborators at the Air Force Research Laboratory based on the measured composition. Using the simulated lattice parameters, electron backscatter diffraction kikuchi patterns and selected area electron diffraction patterns obtained from the boride phase were successfully indexed according to the space group and site occupancies of the B27 orthorhombic crystal structure. This suggests that half the Ti (c) Wyckoff positions are occupied by Ti atoms and the other half are occupied by Nb atoms in the boride phase lattice. Creep deformation behavior is the main focus of this thesis and in particular understanding the dominant creep deformation mechanisms as a function of stress, temperature, and strain rate. Microstructure-creep relationships for Ti-Al-Nb-xB alloys were developed with the understanding gained. A rule-of-mixtures empirical model based on constituent phase volume fractions and strain rates was developed to predict the minimum creep rates of two-phase O+BCC microstructures. The most innovative results of this thesis were produced through the development of an in-situ creep testing methodology. The creep deformation evolution was chronicled in-situ during high temperature creep experiments, while creep displacement versus time data was simultaneously obtained. The in-situ experiments revealed that prior-BCC grain boundaries were the locus of damage accumulation during creep deformation. A methodology that allows in-situ observation of surface creep deformation as a function of creep displacement has yet to be presented in the literature.

Acute Esophageal Necrosis: A Case of Black Esophagus Associated with Bismuth Subsalicylate Ingestion

PubMed Central

Mankal, Pavan; Judeh, Hani; Kim, Sang

2014-01-01

We present a case of acute esophageal necrosis (AEN) likely caused by chronic use of bismuth subsalicylate, an active ingredient in over-the-counter Pepto-Bismol®, which contains 220 g of salicylic acid in each 30 mL quantity. While aspirin is known to cause gastritis and gastric ulcers, this is the first case, to our knowledge, reporting AEN after chronic bismuth subsalicylate use. PMID:26157851

URANIUM BISMUTHIDE DISPERSION IN MOLTEN METAL

DOEpatents

Teitel, R.J.

1959-10-27

The formation of intermetallic bismuth compounds of thorium or uranium dispersed in a liquid media containing bismuth and lead is described. A bismuthide of uranium dispersed in a liquid metal medium is formed by dissolving uranium in composition of lead and bismuth containing less than 80% lead and lowering the temperature of the composition to a temperature below the point at which the solubility of uranium is exceeded and above the melting point of the composition.

PURIFICATION OF PLUTONIUM USING A CERIUM PRECIPITATE AS A CARRIER FOR FISSION PRODUCTS

DOEpatents

Faris, B.F.; Olson, C.M.

1961-07-01

Bismuth phosphate carrier precipitation processes are described for the separation of plutonium from fission products wherein in at least one step bismuth phosphate is precipitated in the presence of hexavalent plutonium thereby carrying a portion of the fission products from soluble plu tonium values. In this step, a cerium phosphate precipitate is formed in conjunction with the bismuth phosphate precipitate, thereby increasing the amount of fission products removed from solution.

Bismuth interstitial impurities and the optical properties of GaP 1- x - yBi xN y

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, Theresa M.; Beaton, Daniel A.; Perkins, John D.

Two distinctive regimes of behavior are observed from GaP 1-x-y Bi x N y alloys with x < 2.4%, y < 3.4% grown by molecular beam epitaxy. These regimes are correlated with abundant bismuth interstitial impurities that are encouraged or suppressed according to the sample growth temperature, with up to 55% of incorporated bismuth located interstitially. When bismuth interstitials are present, radiative recombination arises at near-band-edge localized states rather than from impurity bands and deep state luminescence. Finally, this change demonstrates a novel strategy for controlling luminescence in isoelectronic semiconductor alloys and is attributed to a disruption of carrier transfermore » processes.« less

Preparation of bismuth titanate/calcium alginate composite bead and its photocatalytic degradation of dye pollutants

NASA Astrophysics Data System (ADS)

Gan, Huihui; Dong, Nanyang; Lu, Linxiao; Fu, Yan; Zhang, Huining; Qian, Yongxin; Zhang, Kefeng; Jin, Huixia

2017-08-01

In this study, the bismuth titanate/calcium alginate composite bead was synthesized by immobilizing bismuth titanate Bi4Ti3O12 particles into 1.5% sodium alginate (SA) matrix. The Bi4Ti3O12 particles were characterized by X-ray diffraction (XRD). The photocatalytic activity for the degradation of dye Rhodamine B in solution by as-prepared bismuth titanate/calcium alginate composite bead was investigated. The as-prepared composite beads CA/BTO-700 exhibited best photocatalytic efficiency for the degradation of RhB compared with CA/BTO-800 and CA/BTO-900 under simulated solar light. After 4 cycles in photocatalytic degradation of RhB, the degradation rate of the CA/BTO-700 nearly remained unchanged.

Bismuth interstitial impurities and the optical properties of GaP 1- x - yBi xN y

DOE PAGES

Christian, Theresa M.; Beaton, Daniel A.; Perkins, John D.; ...

2017-10-10

Two distinctive regimes of behavior are observed from GaP 1-x-y Bi x N y alloys with x < 2.4%, y < 3.4% grown by molecular beam epitaxy. These regimes are correlated with abundant bismuth interstitial impurities that are encouraged or suppressed according to the sample growth temperature, with up to 55% of incorporated bismuth located interstitially. When bismuth interstitials are present, radiative recombination arises at near-band-edge localized states rather than from impurity bands and deep state luminescence. Finally, this change demonstrates a novel strategy for controlling luminescence in isoelectronic semiconductor alloys and is attributed to a disruption of carrier transfermore » processes.« less

Magnetism and structural chemistry of ternary borides RE2MB 6 ( RE = rare earth, M = Ru, Os)

NASA Astrophysics Data System (ADS)

Hiebl, K.; Rogl, P.; Nowotny, H.

1984-10-01

The magnetic behavior of the ternary borides RE2RuB 6 and RE2OsB 6 ( RE = Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) was studied in the temperature range 1.5 K < T < 1100 K. All compounds crystallize with the Y 2ReB 6-type structure and are characterized by direct RE- RE contacts and the formation of planar infinite two-dimensional rigid boron nets. The magnetic properties reveal a typical Van Vleck paramagnetism of free RE3+-ions at temperatures higher than 200 K with ferromagnetic interaction in the low-temperature range T < 55 K. The ferromagnetic ordering temperatures vary with the De Gennes factor. There is no indication for a magnetic contribution from the Ru(Os)-sublattice. Above 1.8 K none of the samples were found to be superconducting.

Electronic structure and mechanical properties of osmium borides, carbides and nitrides from first principles

NASA Astrophysics Data System (ADS)

Liang, Yongcheng; Zhao, Jianzhi; Zhang, Bin

2008-06-01

The stabilities, mechanical properties and electronic structures of osmium boride (OsB), carbide (OsC) and nitride (OsN), in the tungsten carbide (WC), rocksalt (NaCl), cesium chloride (CsCl) and zinc blende (ZnS) structures respectively, are systematically predicted by calculations from first-principles. Only four phases, namely, OsB(WC), OsB(CsCl), OsC(WC), and OsC(ZnS), are mechanically stable, and none is a superhard compound, contrary to previous speculation. Most importantly, we find that the changing trends of bulk modulus and shear modulus are completely different for OsB, OsC and OsN in same hexagonal WC structure, which indicates that the underlying sources of hardness and incompressibility are fundamentally different: the former is determined by bonding nature while the latter is closely associated with valence electron density.

The Influence of Nano-Scale Silicon Nitride Additions on the Physical and Magnetic Properties of Iron Sheathed Magnesium Boride Wires

NASA Astrophysics Data System (ADS)

Zhu, W.; Cave, J.

2006-03-01

The enhancement of flux line pinning in magnesium boride wires is a critical issue for their future applications in devices and machines. It is well known that small size dopants can significantly influence the current densities of these materials. Here, the influence of nanometric (<30nm) silicon nitride on physical properties and current density is presented. The iron-sheathed powder in tube wires were prepared using pure magnesium and boron powders with silicon nitride additions. The wires were rolled flat and treated at up to 900 degrees C in flowing argon. SEM and XRD were used to identify phases and microstructures. Magnetization critical currents, up to several 100 of thousands A/cm2, at various temperatures and fields (5K - 20K and up to 3 tesla) show that there are competing mechanisms from chemical and flux pinning effects.

Magnetic and magnetothermal studies of iron boride (FeB) nanoparticles

NASA Astrophysics Data System (ADS)

Hamayun, M. Asif; Abramchuk, Mykola; Alnasir, Hisham; Khan, Mohsin; Pak, Chongin; Lenhert, Steven; Ghazanfari, Lida; Shatruk, Michael; Manzoor, Sadia

2018-04-01

We report magnetic and magnetothermal properties of iron boride (FeB) nanoparticles prepared by surfactant-assisted ball milling of arc-melted bulk ingots of this binary alloy. Size-dependent magnetic properties were used to identify the transition to the single domain limit and calculate the anisotropy and exchange stiffness constants for this system. Extended milling is seen to produce coercivity enhancement and exchange bias of up to 270 Ôe at room temperature. The magnetothermal properties were investigated by measuring the response of single domain FeB nanoparticles to externally applied ac magnetic fields. All investigated particle sizes show a significant heating response, demonstrating their potential as candidates for magnetically induced hyperthermia. FeB nanoparticles were encapsulated into lipophilic domains of liposomes as evidenced by TEM. Exposure of HeLa cells to these liposomes did not affect cell viability, suggesting the biocompatibility of these new magnetic nanomaterials.

Identification of delamination failure of boride layer on common Cr-based steels

NASA Astrophysics Data System (ADS)

Taktak, Sukru; Tasgetiren, Suleyman

2006-10-01

Adhesion is an important aspect in the reliability of coated components. With low-adhesion of interfaces, different crack paths may develop depending on the local stress field at the interface and the fracture toughness of the coating, substrate, and interface. In the current study, an attempt has been made to identify the delamination failure of coated Cr-based steels by boronizing. For this reason, two commonly used steels (AISI H13, AISI 304) are considered. The steels contain 5.3 and 18.3 wt.% Cr, respectively. Boriding treatment is carried out in a slurry salt bath consisting of borax, boric acid, and ferrosilicon at a temperature range of 800 950 °C for 3, 5, and 7 h. The general properties of the boron coating are obtained by mechanical and metallographic characterization tests. For identification of coating layer failure, some fracture toughness tests and the Daimler-Benz Rockwell-C adhesion test are used.

Bismuth-based electrochemical stripping analysis

DOEpatents

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.

Bismuth Nephrotoxicity: Report of a Case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gryboski, Joyce D.; Gotoff, Samuel P.

1961-12-28

A case of renal poisoning by bismuth thioglycolate is reported which demonstrates the nephrotoxicity of bismuth compounds in the pediatric age group. For treatment of warts the patient received a relatively small amount of bismuth thioglycollate (1.3 mg/kg body wt), and although the symptomatology was mild, the degree of azotemia was severe. Evidence of both tubular and glomerular damage was present, the former reflected by fixed urinary specific gravity and minimal glycosuria in the presence of a normal blood sugar, and the latter by azotemia and mild proteinuria. Backward diffusion of creatinine through damaged tubular epithelium probably contributed to themore » observed elevated plasma creatinine value, and the presence of a high anion content of serum probably represented retained phosphate, sulfate, and organic acids. The observed maculopapular rash probably corresponded to the socalled erythema of the ninth day, described previously as a rare manifestation of bismuth toxicity. The therapy employed was that for acute renal failure, but chelating agents, which are potential nephrotoxins, were not employed because of the known rapid excretion of bismuth thioglycollate. Rehydration was carried out, and electrolyte and protein intake was limited until diuresis was well established and the blood urea nitrogen had begun to fall. To avoid hyperkalemia, potassium restriction was carried out. Normal renal function was restored within a month after the onset of renal injury. It is suggested that the degree of sensitivity to the metal was related to the age of the patient and to the structural maturity of the kidney, for all cases of bismuth nephropathy reported the past 15 yr have occurred in the pediatric age group, children less than 3 yr being the most severely affected.« less

Bismuth Passivation Technique for High-Resolution X-Ray Detectors

NASA Technical Reports Server (NTRS)

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).

Liquid Bismuth Feed System for Electric Propulsion

NASA Technical Reports Server (NTRS)

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.

Dual-modality, fluorescent, PLGA encapsulated bismuth nanoparticles for molecular and cellular fluorescence imaging and computed tomography.

PubMed

Swy, Eric R; Schwartz-Duval, Aaron S; Shuboni, Dorela D; Latourette, Matthew T; Mallet, Christiane L; Parys, Maciej; Cormode, David P; Shapiro, Erik M

2014-11-07

Reports of molecular and cellular imaging using computed tomography (CT) are rapidly increasing. Many of these reports use gold nanoparticles. Bismuth has similar CT contrast properties to gold while being approximately 1000-fold less expensive. Herein we report the design, fabrication, characterization, and CT and fluorescence imaging properties of a novel, dual modality, fluorescent, polymer encapsulated bismuth nanoparticle construct for computed tomography and fluorescence imaging. We also report on cellular internalization and preliminary in vitro and in vivo toxicity effects of these constructs. 40 nm bismuth(0) nanocrystals were synthesized and encapsulated within 120 nm Poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles by oil-in-water emulsion methodologies. Coumarin-6 was co-encapsulated to impart fluorescence. High encapsulation efficiency was achieved ∼70% bismuth w/w. Particles were shown to internalize within cells following incubation in culture. Bismuth nanocrystals and PLGA encapsulated bismuth nanoparticles exhibited >90% and >70% degradation, respectively, within 24 hours in acidic, lysosomal environment mimicking media and both remained nearly 100% stable in cytosolic/extracellular fluid mimicking media. μCT and clinical CT imaging was performed at multiple X-ray tube voltages to measure concentration dependent attenuation rates as well as to establish the ability to detect the nanoparticles in an ex vivo biological sample. Dual fluorescence and CT imaging is demonstrated as well. In vivo toxicity studies in rats revealed neither clinically apparent side effects nor major alterations in serum chemistry and hematology parameters. Calculations on minimal detection requirements for in vivo targeted imaging using these nanoparticles are presented. Indeed, our results indicate that these nanoparticles may serve as a platform for sensitive and specific targeted molecular CT and fluorescence imaging.

Separation of Californium from other Actinides

DOEpatents

Mailen, J C; Ferris, L M

1973-09-25

A method is provided for separating californium from a fused fluoride composition containing californium and at least one element selected from the group consisting of plutonium, americium, curium, uranium, thorium, and protactinium which comprises contacting said fluoride composition with a liquid bismuth phase containing sufficient lithium or thorium to effect transfer of said actinides to the bismuth phase and then contacting the liquid bismuth phase with molten LiCl to effect selective transfer of californium to the chloride phase.

PLUTONIUM CARRIER METATHESIS WITH ORGANIC REAGENT

DOEpatents

Thompson, S.G.

1958-07-01

A method is described for converting a plutonium containing bismuth phosphate carrier precipitate Into a compositton more readily soluble in acid. The method consists of dissolving the bismuth phosphate precipitate in an aqueous solution of alkali metal hydroxide, and adding one of a certaia group of organic compounds, e.g., polyhydric alcohols or a-hydrorycarboxylic acids. The mixture is then heated causiing formation of a bismuth hydroxide precipitate containing plutonium which may be readily dissolved in nitric acid for further processing.

OPTICAL FIBRES AND FIBREOPTIC SENSORS: Bismuth-ring-doped fibres

NASA Astrophysics Data System (ADS)

Zlenko, Aleksandr S.; Akhmetshin, Ural G.; Dvoirin, Vladislav V.; Bogatyrev, Vladimir A.; Firstov, Sergei V.

2009-11-01

A new process for bismuth doping of optical fibres is proposed in which the dopant is introduced into a thin layer surrounding the fibre core. This enables bismuth stabilisation in the silica glass, with no limitations on the core composition. In particular, the GeO2 content of the fibre core in this study is 16 mol %. Spectroscopic characterisation of such fibres and optical gain measurements suggest that the proposed approach has considerable potential for laser applications.

Piezoelectric and Electrostrictive Materials for Transducer Applications. Volume 1.

DTIC Science & Technology

1988-03-01

3 Composites for Hydrophone Applications ...................... 2 2.3.1 Lead Bismuth Titanate Ferrate Compositions ................. 2 2.3.2...external variables are considered. 2.3 0:3 Composites for Hydrophone Applications 2.3.1 Lead Bismuth Titanate Ferrate Compositions the-"Following up...34" Even for doped samples however, the best results were obtained at the 50% bismuth ferrate composition. 0.. W* . - ’ w-w~-,wn~ , 7WI W W PP7W-w7WnM

Effect of Discharge Time on Plasma Electrolytic Borocarbonitriding of Pure Iron

NASA Astrophysics Data System (ADS)

Jin, Xiaoyue; Wu, Jie; Wang, Bin; Yang, Xuan; Chen, Lin; Qu, Yao; Xue, Wenbin

The plasma electrolytic borocarbonitriding (PEB/C/N) process on pure iron was carried out in 25% borax solution with glycerine and carbamide additives under different discharge time at 360V. The morphology and structure of PEB/C/N hardened layers were analyzed by SEM and XRD. The hardness profiles of hardened layers were measured by microhardness test. Corrosion behavior of PEB/C/N layers was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Their wear performance was carried out using a pin-disc friction and wear tester under dry sliding test. The PEB/C/N samples mainly consisted of α-Fe, Fe2B, Fe3C, FeN, FeB, Fe2O3 and Fe4N phases, and the Fe2B phase was the dominant phase in the boride layer. It was found that the thickness of boride layer increased with the discharge time and reached 14μm after 60min treatment. The microhardness of the boride layer was up to 2100HV, which was much higher than that of the bare pure iron (about 150HV). After PEB/C/N treatment, the corrosion resistance of pure iron was slightly improved. The friction coefficient of PEB/C/N treated pure iron decreased to 0.129 from 0.556 of pure iron substrate. The wear rate of the PEB/C/N layer after 60min under dry sliding against ZrO2 ball was only 1/10 of that of the bare pure iron. The PEB/C/N treatment is an effective way to improve the wear behavior of pure iron.

Correlation between structural stability of LiBH4 and cation electronegativity in metal borides: an experimental insight for catalyst design.

PubMed

Cai, Weitong; Yang, Yuanzheng; Tao, Pingjun; Ouyang, Liuzhang; Wang, Hui

2018-04-03

Nanosized metal borides MBx (M = Mg, Ti, Fe, Si) are found to play an important role in enhancing the hydrogen storage performance of LiBH4 in this work. The hydrogen storage behavior and mechanism of these modified systems are investigated through TPD-MS, XRD, FTIR and SEM characterization methods. By introducing these metal borides into LiBH4 through ball milling, the systems display three dehydrogenation stages disclosing their similarity and distinction. The 1st stage starts at 190 °C, the 2nd stage ranges from 280 °C to 400 °C and the 3rd stage ends at 550 °C with a peak at round 440 °C similar to that of pristine LiBH4. Distinguishing features exist at the 2nd stage revealing the effectiveness of MBx in an order of MgB2 < TiB2 < FeB < SiB4. Significantly, reversibility up to 9.7 wt% is achieved from LiBH4 with assistance of SiB4. The catalytic effect of MBx is influenced by the Pauling electronegativity of M in MBx and the interfacial contact characteristic between LiBH4 and MBx. The larger electronegativity leads to an enhanced catalytic effect and consequently lower temperature at the major stage. In contrast to the components in the solid state, the molten LiBH4 promotes a catalytic effect due to a superior interfacial contact. These results provide an insight into designing high-performance catalysts applied to LiBH4 as a hydrogen storage material.

Boron-Based Hydrogen Storage: Ternary Borides and Beyond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vajo, John J.

DOE continues to seek reversible solid-state hydrogen materials with hydrogen densities of ≥11 wt% and ≥80 g/L that can deliver hydrogen and be recharged at moderate temperatures (≤100 °C) and pressures (≤100 bar) enabling incorporation into hydrogen storage systems suitable for transportation applications. Boron-based hydrogen storage materials have the potential to meet the density requirements given boron’s low atomic weight, high chemical valance, and versatile chemistry. However, the rates of hydrogen exchange in boron-based compounds are thus far much too slow for practical applications. Although contributing to the high hydrogen densities, the high valance of boron also leads to slowmore » rates of hydrogen exchange due to extensive boron-boron atom rearrangements during hydrogen cycling. This rearrangement often leads to multiple solid phases occurring over hydrogen release and recharge cycles. These phases must nucleate and react with each other across solid-solid phase boundaries leading to energy barriers that slow the rates of hydrogen exchange. This project sought to overcome the slow rates of hydrogen exchange in boron-based hydrogen storage materials by minimizing the number of solid phases and the boron atom rearrangement over a hydrogen release and recharge cycle. Two novel approaches were explored: 1) developing matched pairs of ternary borides and mixed-metal borohydrides that could exchange hydrogen with only one hydrogenated phase (the mixed-metal borohydride) and only one dehydrogenated phase (the ternary boride); and 2) developing boranes that could release hydrogen by being lithiated using lithium hydride with no boron-boron atom rearrangement.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sitler, Steven J.; Raja, Krishnan S.; Charit, Indrajit

Solid solutions of HfB 2-ZrB 2 mixtures were prepared by high-energy ball milling of diboride and additive powders followed by spark plasma sintering (SPS). A mixture of stoichiometric 1:1 HfB 2-ZrB 2 borides was the base composition to which Hf, Zr, Ta, LaB 6 or Gd 2O 3 was added. Hf, Zr and Ta were added in order to bring the boron-to-metal ratio down to 1.86, rendering the boride as MeB 1.86. In the case of LaB 6 and Gd 2O 3, 1.8 mol% was added. Electroanalytical behavior of hydrogen evolution reactions was evaluated in 1 M H 2SO 4more » and 1 M NaOH solutions. The LaB 6 additive material showed Tafel slopes of 125 and 90 mV/decade in acidic and alkaline solutions respectively. The Hf and Zr rich samples showed Tafel slopes of about 120 mV/decade in both electrolytes. The over potentials of hydrogen evolution reactions (at 10 mA/cm 2) in the alkaline solution were about 100 mV lower than those in acidic solution. The metal-rich diborides and addition of LaB 6 showed better hydrogen evolution reaction (HER) activities than the base 1:1 HfB 2-ZrB 2 stoichiometric diboride solid solution. Furthermore, the higher activity of metal-rich borides could be attributed to the increased electron population at the d-orbitals of the metal shown by band structure modeling calculations using the Density Functional Theory approach.« less

Effect of bismuth doping on the structural and magnetic properties of zinc-ferrite nanoparticles prepared by a microwave combustion method

NASA Astrophysics Data System (ADS)

Shoushtari, Morteza Zargar; Emami, Akram; Ghahfarokhi, Seyed Ebrahim Mosavi

2016-12-01

In this study, we examine the bismuth doping effect on the structural, magnetic and microstructural properties of zinc-ferrite nanoparticles (ZnFe2-xBixO4 with x=0.0, 0.02, 0.04, 0.06, 0.1, 0.15) which have been prepared by a microwave combustion method. The structural, morphological and electromagnetic properties and also Curie temperature of the samples were examined by x-ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), vibrating sample magnetometer (VSM), and LCR meter, respectively. In order to measure the energy band gap, the FTIR spectra of the samples were also considered. The XRD patterns of the samples revealed that all of them are ZnFe2O4 structure and no additional peak was observed in their patterns. This implied that the samples were single-phase up to bismuth solubility of 0.15 in Zinc-Ferrite. The results of XRD patterns also showed that the value lattice parameter increases with increasing the bismuth doping. The FESEM results revealed an ascending trend in the size of the nanoparticles. Also considering the VSM results characterized that an increasing the bismuth doping leads to lower the saturation magnetization. The Curie temperatures of the samples were reduced as a result of increasing the amount of bismuth.

Li3PO4 Matrix Enables a Long Cycle Life and High Energy Efficiency Bismuth-Based Battery.

PubMed

Sun, Chuan-Fu; Hu, Junkai; Wang, Peng; Cheng, Xi-Yuan; Lee, Sang Bok; Wang, YuHuang

2016-09-14

Bismuth is a lithium-ion battery anode material that can operate at an equilibrium potential higher than graphite and provide a capacity twice as high as that of Li4Ti5O12, making it intrinsically free from lithium plating that may cause catastrophic battery failure. However, the potential of bismuth is hampered by its inferior cyclability (limited to tens of cycles). Here, we propose an "ion conductive solid-state matrix" approach to address this issue. By homogeneously confining bismuth nanoparticles in a solid-state γ-Li3PO4 matrix that is electrochemically formed in situ, the resulting composite anode exhibits a reversible capacity of 280 mA hours per gram (mA h/g) at a rate of 100 mA/g and a record cyclability among bismuth-based anodes up to 500 cycles with a capacity decay rate of merely 0.071% per cycle. We further show that full-cell batteries fabricated from this composite anode and commercial LiFePO4 cathode deliver a stable cell voltage of ∼2.5 V and remarkable energy efficiency up to 86.3%, on par with practical batteries (80-90%). This work paves a way for harnessing bismuth-based battery chemistry for the design of high capacity, safer lithium-ion batteries to meet demanding applications such as electric vehicles.

Ranitidine bismuth citrate and ranitidine do not affect gastric emptying of a radio-labelled liquid meal.

PubMed Central

Parikh, R; Sweetland, J; Forster, E R; Bedding, A W; Farr, S J; Smith, J T

1994-01-01

Ranitidine bismuth citrate, a new chemical entity which is a salt complex of ranitidine and bismuth citrate, is being developed for the treatment of relapse of benign gastric and duodenal ulcer and eradication of Helicobacter pylori. The aim of the present study was to establish whether ranitidine bismuth citrate (800 mg) or ranitidine hydrochloride (300 mg) have any effect on gastric emptying of a liquid meal using gamma scintigraphy. On three separate occasions, each of twelve subjects received a single oral tablet of 800 mg ranitidine bismuth citrate, 300 mg ranitidine hydrochloride or placebo in random order. Thirty minutes after dosing each subject was given 375 ml of 99mTc-DTPA (diethylene triaminepentaacetic acid) labelled Clinifeed-ISO. The primary endpoint was the time to 50% gastric emptying (t50%). The proportion of the meal remaining was summarised by weighted mean proportion of the meal remaining in the stomach over 0-60 min and 0-180 min, separately. No differences were observed for t50%, weighted mean 0-60 min, and weighted mean 0-180 min between any two treatments. In man, we have detected no significant effect of single oral doses of ranitidine bismuth citrate 800 mg or ranitidine hydrochloride 300 mg on the rate of gastric emptying of a liquid meal when compared with placebo. PMID:7888296

How reliable are environmental data on 'orphan' elements? The case of bismuth concentrations in surface waters.

PubMed

Filella, Montserrat

2010-01-01

Like all elements of the periodic table, bismuth is ubiquitously distributed throughout the environment as a result of natural processes and human activities. It is present as Bi(III) in environmental, biological and geochemical samples. Although bismuth and its compounds are considered to be non-toxic to humans, its increasing use as a replacement for lead has highlighted how little is known about its environmental and ecotoxicological behaviour. In this first critical review paper on the existing information on bismuth occurrence in natural waters, 125 papers on fresh and marine waters have been collated. Although the initial objective of this study was to establish the range of the typical concentrations of total dissolved bismuth in natural waters, this proved impossible to achieve due to the wide, and hitherto unexplained, dispersion of published data. Since analytical limitations might be one of the reasons underlying value dispersion, new analytical methods published since 2000--intended to be applied to natural waters--have also been reviewed. Disappointingly, the detection limits of the bulk of them are well above those required; they are thus of limited usefulness. Analysis of the existing information on bismuth in secondary references (i.e., books, review chapters) and on its chemical speciation in seawater revealed that the uncritical reproduction of old data is a widespread practice.

Bismuth-Silicon and Bismuth-Polyurethane Composite Shields for Breast Protection in Chest Computed Tomography Examinations

PubMed Central

Mehnati, Parinaz; Arash, Mehran; Akhlaghi, Parisa

2018-01-01

The article aims at constructing protective composite shields for breasts in chest computed tomography and investigating the effects of applying these new bismuth composites on dose and image quality. Polyurethane and silicon with 5% of bismuth were fabricated as a protective shield. At first, their efficiency in attenuating the X-ray beam was investigated by calculating the total attenuation coefficients at diagnostic energy range. Then, a physical chest phantom was scanned without and with these shields at tube voltage of 120 kVp, and image parameters together with dose values were studied. The results showed that these two shields have great effects on attenuating the X-ray beam, especially for lower energies (<40 kV), and in average, the attenuation coefficients of bismuth-polyurethane composite are higher in this energy range. The maximum relative differences between the average Hounsfield units (HUs) and noises of images without and with shield for both composites in 13 regions of interest were 4.5% and 15.7%, respectively. Moreover, primary investigation confirmed the ability of both shields (especially polyurethane-bismuth composite) in dose reduction. Comparing these two composites regarding the amount of dose reduction, the changes in HU and noise, and attenuation coefficients in diagnostic energy range, it seems that polyurethane composite is more useful for dose reduction, especially for higher tube voltages. PMID:29628636

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

NASA Technical Reports Server (NTRS)

Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline;

Thermodynamics of Pb17Li-bismuth interactions

NASA Astrophysics Data System (ADS)

Hubberstey, Peter; Sample, Tony

1994-09-01

Thermodynamic calculations of the PbBiLi ternary system have been completed to rationalise the formation of solid Li 3Bi on reaction of liquid Pb17Li with bismuth. At 723 K, the bismuth activity in equilibrium with liquid Pi17Li and solid Li 3Bi is calculated to be 9.50 × 10 -4; this can be correlated to a solubility of 2.09 × 10 -1 mol% Bi(2520 wppm). The corresponding bismuth activity in equilibrium with liquid Pb17Li and solid LiBi is 5.04 × 10 -2 (an extrapolated value as LiBi decomposes peritectically at 688 K). The minimum lithium content of PbLi alloys required to react with unit activity bismuth to form Li 3Bi at 723 K is calculated to be ˜ 1.8 mol% Li. The dominance of Li 3Bi in the PbBiLi system is attributed to its extreme stability as evidenced by both its high melting point (1418 K) and free energy of formation [ ΔGf0(Li 3Bi, c 723 K) = 212.8 kJ mol -1].

Pairing from dynamically screened Coulomb repulsion in bismuth

NASA Astrophysics Data System (ADS)

Ruhman, Jonathan; Lee, Patrick A.

2017-12-01

Recently, Prakash et al. have discovered bulk superconductivity in single crystals of bismuth, which is a semimetal with extremely low carrier density. At such low density, we argue that conventional electron-phonon coupling is too weak to be responsible for the binding of electrons into Cooper pairs. We study a dynamically screened Coulomb interaction with effective attraction generated on the scale of the collective plasma modes. We model the electronic states in bismuth to include three Dirac pockets with high velocity and one hole pocket with a significantly smaller velocity. We find a weak-coupling instability, which is greatly enhanced by the presence of the hole pocket. Therefore we argue that bismuth is the first material to exhibit superconductivity driven by retardation effects of Coulomb repulsion alone. By using realistic parameters for bismuth we find that the acoustic plasma mode does not play the central role in pairing. We also discuss a matrix element effect, resulting from the Dirac nature of the conduction band, which may affect Tc in the s -wave channel without breaking time-reversal symmetry.

Photovoltaic cell

DOEpatents

Gordon, Roy G.; Kurtz, Sarah

1984-11-27

In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

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

NASA Astrophysics Data System (ADS)

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; Swanberg, Erik L.; Tillotson, Thomas M.; Payne, Stephen A.; Hurlbut, Charles R.

2015-04-01

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

POLONIUM SEPARATION PROCESS

DOEpatents

Karraker, D.G.

1959-07-14

A liquid-liquid extraction process is presented for the recovery of polonium from lead and bismuth. According to the invention an acidic aqueous chloride phase containing the polonium, lead, and bismuth values is contacted with a tributyl phosphate ether phase. The polonium preferentially enters the organic phase which is then separated and washed with an aqueous hydrochloric solution to remove any lead or bismuth which may also have been extracted. The now highly purified polonium in the organic phase may be transferred to an aqueous solution by extraction with aqueous nitric acid.

METHOD FOR REMOVING CONTAMINATION FROM PRECIPITATES

DOEpatents

Stahl, G.W.

1959-01-01

An improvement in the bismuth phosphate carrier precipitation process is presented for the recovery and purification of plutonium. When plutonium, in the tetravalent state, is carried on a bismuth phosphate precipitate, amounts of centain of the fission products are carried along with the plutonium. The improvement consists in washing such fission product contaminated preeipitates with an aqueous solution of ammonium hydrogen fluoride. since this solution has been found to be uniquely effective in washing fission production contamination from the bismuth phosphate precipitate.

University of Maryland MRSEC - News: Featured

Science.gov Websites

state at surface of bismuth selenide Completed device MRSEC research, published in NanoLetters ASAP in and M. S. Fuhrer, "Insulating behavior in ultrathin bismuth selenide field effect transistors

PROCESS USING BISMUTH PHOSPHATE AS A CARRIER PRECIPITATE FOR FISSION PRODUCTS AND PLUTONIUM VALUES

DOEpatents

Finzel, T.G.

1959-03-10

A process is described for separating plutonium from fission products carried therewith when plutonium in the reduced oxidation state is removed from a nitric acid solution of irradiated uranium by means of bismuth phosphate as a carrier precipitate. The bismuth phosphate carrier precipitate is dissolved by treatment with nitric acid and the plutonium therein is oxidized to the hexavalent oxidation state by means of potassium dichromate. Separation of the plutonium from the fission products is accomplished by again precipitating bismuth phosphate and removing the precipitate which now carries the fission products and a small percentage of the plutonium present. The amount of plutonium carried in this last step may be minimized by addition of sodium fluoride, so as to make the solution 0.03N in NaF, prior to the oxidation and prccipitation step.

Isotopic generator for bismuth-212 and lead-212 based on radium

DOEpatents

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

1985-01-30

Disclosed are method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

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

DOE PAGES

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; ...

2015-01-09

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

Simultaneous quantitative analysis of arsenic, bismuth, selenium, and tellurium in soil samples using multi-channel hydride-generation atomic fluorescence spectrometry.

PubMed

Wang, Fang; Zhang, Gai

2011-03-01

The basic principles and the application of hydride-generation multi-channel atomic fluorescence spectrometry (HG-MC-AFS) in soil analysis are described. It is generally understood that only one or two elements can be simultaneously detected by commonly used one- or two-channel HG-AFS. In this work, a new sample-sensitive and effective method for the analysis of arsenic, bismuth, tellurium, and selenium in soil samples by simultaneous detection using HG-MC-AFS was developed. The method detection limits for arsenic, bismuth, tellurium, and selenium are 0.19 μg/g, 0.10 μg/g, 0.11 μg/g, and 0.08 μg/g, respectively. This method was successfully applied to the simultaneous determination of arsenic, bismuth, tellurium, and selenium in soil samples.

Isotopic generator for bismuth-212 and lead-212 from radium

DOEpatents

Atcher, Robert W.; Friedman, Arnold M.; Hines, John

1987-01-01

A method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

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

PubMed Central

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

2017-01-01

AIM To investigate Helicobacter pylori (H. pylori) eradication rates using second-line bismuth-containing quadruple therapy and to identify predictors of eradication failure. METHODS 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 13C-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. RESULTS 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. CONCLUSION 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. PMID:28246480

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

PubMed

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 (p<0.05) and the Ryan-Einot-Gabriel-Welch and Quiot test (REGWQ) for multiple comparison of the means. White Portland 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.

Comparison of analytical performances of inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry for trace analysis of bismuth and bismuth oxide

NASA Astrophysics Data System (ADS)

Medvedev, Nickolay S.; Shaverina, Anastasiya V.; Tsygankova, Alphiya R.; Saprykin, Anatoly I.

2018-04-01

The paper presents а comparison of analytical performances of inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) for trace analysis of high purity bismuth and bismuth oxide. Matrix effects in the ICP-MS and ICP-AES methods were studied as a function of Bi concentration, ICP power and nebulizer flow rate. For ICP-MS the strong dependence of the matrix effects versus the atomic mass of analytes was observed. For ICP-AES the minimal matrix effects were achieved for spectral lines of analytes with low excitation potentials. The optimum degree of sample dilution providing minimum values of the limits of detection (LODs) was chosen. Both methods let us to reach LODs from n·10-7 to n·10-4 wt% for more than 50 trace elements. For most elements the LODs of ICP-MS were lower in comparison to ICP-AES. Validation of accuracy of the developed techniques was performed by "added-found" experiments and by comparison of the results of ICP-MS and ICP-AES analysis of high-purity bismuth oxide.

Short-term static corrosion tests in lead-bismuth

NASA Astrophysics Data System (ADS)

Soler Crespo, L.; Martín Muñoz, F. J.; Gómez Briceño, D.

2001-07-01

Martensitic steels have been proposed to be used as structural materials and as spallation target window in hybrid systems devoted to the transmutation of radioactive waste of long life and high activity. However, their compatibility with lead-bismuth in the operating conditions of these systems depends on the existence of a protective layer such as an oxide film. The feasibility of forming and maintaining an oxide layer or maintaining a pre-oxidised one has been studied. Martensitic steel F82Hmod. (8% Cr) has been tested in lead-bismuth under static and isothermal conditions at 400°C and 600°C. In order to study the first stages of the interaction between the steel and the eutectic, short-term tests (100 and 665 h) have been carried out. Pre-oxidised and as-received samples have been tested in atmospheres with different oxidant potential. For low oxygen concentration in lead-bismuth due to unexpected oxygen consumption in the experimental device, dissolution of as-received F82Hmod. occurs and pre-oxidation does not prevent the material dissolution. For high oxygen concentration, the pre-oxidation layer seems to improve the feasibility of protecting stainless steels controlling the oxygen potential of lead-bismuth with a gas phase.

Content and distribution of arsenic, bismuth, lithium and selenium in mineral and synthetic fertilizers and their contribution to soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senesi, N.; Polemio, M.; Lorusso, L.

1979-01-01

Concentrations of arsenic, bismuth, lithium and selenium were determined by atomic absorption spectrophotometry in 32 samples of commercial fertilizers from various manufacturers and distributors. Arsenic and lithium were detected in all investigated samples, bismuth in 50% of samples and selenium only in two samples. Arsenic content ranged from 2 to 321 ppM; lithium varied from 5 to 0.1 ppM; bismuth was always lower than 0.5 ppM; selenium was detectable at the levels of 10 and 13 ppM. Fertilizers made from rock phosphates contained trace element amounts generally higher than those derived from rock carbonates, synthetic nitrogen fertilizers and potassium sulphate.more » Additions of trace elements from fertilizers applied at common rates to cultivated soils are tabulated and discussed on the basis of the natural soil reserves and toxicity levels for plants. Whereas applications of bismuth resulted always very low to influence the usual soil content and plant uptakes and selenium was only rarely present in fertilizers, lithium and moreover arsenic additions by fertilizers could influence the trace element status in soil, overcoming occasionally the toxicity levels for more sensitive crops.« less

Bismuth knowledge during the Renaissance strengthened by its use in Italian lustres production

NASA Astrophysics Data System (ADS)

Padeletti, G.; Fermo, P.

The knowledge of bismuth during the XV and XVI centuries represents an open question since, according to some authors, this element was confused with lead, tin and silver. On the contrary, G. Agricola (1494-1555), the pioneer of mineralogical science in Europe, in his two works (De Natura Fossilium, Lib X, 1546 and Bermannus Sive De Re Metallica Dialogus, 1528) asserts that bismuth was considered as an element distinct from the other metals at that time. This question gave rise to some interest, and von Lippmann in 1930 wrote a treatise dealing with the history of bismuth between 1400 and 1800. In this work we present the results obtained on Italian and Hispano-Moresque shards studied by means of X-ray diffraction, atomic absorption spectrometry with electrothermal atomisation, inductively coupled plasma optical emission spectrometry and scanning electron microscopy. It seems that our work could provide a new and important contribution to this debate, because we found bismuth in lustre composition of Renaissance shards produced in central Italy. Furthermore, we found that it could also be considered as a discriminating element between Italian and Hispano-Moresque productions, useful to assess their origin.

Bismuth Based Hybrid Perovskites A3Bi2 I9 (A: Methylammonium or Cesium) for Solar Cell Application.

PubMed

Park, Byung-Wook; Philippe, Bertrand; Zhang, Xiaoliang; Rensmo, Håkan; Boschloo, Gerrit; Johansson, Erik M J

2015-11-18

Low-toxic bismuth-based perovskites are prepared for the possible replacement of lead perovskite in solar cells. The perovskites have a hexagonal crystalline phase and light absorption in the visible region. A power conversion efficiency of over 1% is obtained for a solar cell with Cs3 Bi2 I9 perovskite, and it is concluded that bismuth perovskites have very promising properties for further development in solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SEPARATION OF POLONIUM, PROTACTINIUM OR MIXTURES THEREOF IN AQUEOUS SOLUTION FROM BISMUTH, LEAD, ZIRCONIUM AND/OR COLUMBIUM VALUES

DOEpatents

Van Winkle, Q.; Kraus, K.A.

1959-10-27

A process is presented for separating polonium, protactinium, or mixtures thereof in aqueous solution from bismuth, zirconium, lead, and niobium values contained in the solution. The method comprises providing hydrochloric acid in the solution in a concentration of at least 5N. contacting the aqueous solution with a substantially waterimmiscible organic solvent such as diisopropyl ketone, and separating the aqueous phase containing the bismuth, zirconium, lead, and niobium from the organic extract phase containing the polonium, protactinium, or mixture thereof.

Alkali metal for ultraviolet band-pass filter

NASA Technical Reports Server (NTRS)

Mardesich, Nick (Inventor); Fraschetti, George A. (Inventor); Mccann, Timothy A. (Inventor); Mayall, Sherwood D. (Inventor); Dunn, Donald E. (Inventor); Trauger, John T. (Inventor)

1993-01-01

An alkali metal filter having a layer of metallic bismuth deposited onto the alkali metal is provided. The metallic bismuth acts to stabilize the surface of the alkali metal to prevent substantial surface migration from occurring on the alkali metal, which may degrade optical characteristics of the filter. To this end, a layer of metallic bismuth is deposited by vapor deposition over the alkali metal to a depth of approximately 5 to 10 A. A complete alkali metal filter is described along with a method for fabricating the alkali metal filter.

DFT investigations of hydrogen storage materials

NASA Astrophysics Data System (ADS)

Wang, Gang

Hydrogen serves as a promising new energy source having no pollution and abundant on earth. However the most difficult problem of applying hydrogen is to store it effectively and safely, which is smartly resolved by attempting to keep hydrogen in some metal hydrides to reach a high hydrogen density in a safe way. There are several promising metal hydrides, the thermodynamic and chemical properties of which are to be investigated in this dissertation. Sodium alanate (NaAlH4) is one of the promising metal hydrides with high hydrogen storage capacity around 7.4 wt. % and relatively low decomposition temperature of around 100 °C with proper catalyst. Sodium hydride is a product of the decomposition of NaAlH4 that may affect the dynamics of NaAlH4. The two materials with oxygen contamination such as OH- may influence the kinetics of the dehydriding/rehydriding processes. Thus the solid solubility of OH - groups (NaOH) in NaAlH4 and NaH is studied theoretically by DFT calculations. Magnesium boride [Mg(BH4)2] is has higher hydrogen capacity about 14.9 wt. % and the decomposition temparture of around 250 °C. However one flaw restraining its application is that some polyboron compounds like MgB12H12 preventing from further release of hydrogen. Adding some transition metals that form magnesium transition metal ternary borohydride [MgaTMb(BH4)c] may simply the decomposition process to release hydrogen with ternary borides (MgaTMbBc). The search for the probable ternary borides and the corresponding pseudo phase diagrams as well as the decomposition thermodynamics are performed using DFT calculations and GCLP method to present some possible candidates.

Metallic Borides, La 2 Re 3 B 7 and La 3 Re 2 B 5 , Featuring Extensive Boron–Boron Bonding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bugaris, Daniel E.; Malliakas, Christos D.; Chung, Duck Young

We synthesized La 2Re 3B 7 and La 3Re 2B 5 in single-crystalline form from a molten La/Ni eutectic at 1000°C, in the first example of the flux crystal growth of ternary rare-earth rhenium borides. Both compounds crystallize in their own orthorhombic structure types, with La 2Re 3B 7 (space group Pcca) having lattice parameters a = 7.657(2) Å, b = 6.755(1) Å, and c = 11.617(2) Å, and La 3Re 2B 5 (space group Pmma) having lattice parameters a = 10.809(2) Å, b = 5.287(1) Å, and c = 5.747(1) Å. Furthermore, the compounds possess three-dimensional framework structures thatmore » are built up from rhenium boride polyhedra and boron-boron bonding. La 3Re 2B 5 features fairly common B 2 dumbbells, whereas La 2Re 3B 7 has unique one-dimensional subunits composed of alternating triangular B3 and trans-B4 zigzag chain fragments. Also observed in La 3Re 2B 5 is an unusual coordination of B by an octahedron of La atoms. Electronic band structure calculations predict that La 2Re 3B 7 is a semimetal, which is observed in the electrical resistivity data as measured on single crystals, with behavior obeying the Bloch-Grüneisen model and a room-temperature resistivity ρ300K of ~ 375 μΩ cm. The electronic band structure calculations also suggest that La 3Re 2B 5 is a regular metal.« less

Metallic Borides, La 2 Re 3 B 7 and La 3 Re 2 B 5 , Featuring Extensive Boron–Boron Bonding

DOE PAGES

Bugaris, Daniel E.; Malliakas, Christos D.; Chung, Duck Young; ...

2016-01-26

We synthesized La 2Re 3B 7 and La 3Re 2B 5 in single-crystalline form from a molten La/Ni eutectic at 1000°C, in the first example of the flux crystal growth of ternary rare-earth rhenium borides. Both compounds crystallize in their own orthorhombic structure types, with La 2Re 3B 7 (space group Pcca) having lattice parameters a = 7.657(2) Å, b = 6.755(1) Å, and c = 11.617(2) Å, and La 3Re 2B 5 (space group Pmma) having lattice parameters a = 10.809(2) Å, b = 5.287(1) Å, and c = 5.747(1) Å. Furthermore, the compounds possess three-dimensional framework structures thatmore » are built up from rhenium boride polyhedra and boron-boron bonding. La 3Re 2B 5 features fairly common B 2 dumbbells, whereas La 2Re 3B 7 has unique one-dimensional subunits composed of alternating triangular B3 and trans-B4 zigzag chain fragments. Also observed in La 3Re 2B 5 is an unusual coordination of B by an octahedron of La atoms. Electronic band structure calculations predict that La 2Re 3B 7 is a semimetal, which is observed in the electrical resistivity data as measured on single crystals, with behavior obeying the Bloch-Grüneisen model and a room-temperature resistivity ρ300K of ~ 375 μΩ cm. The electronic band structure calculations also suggest that La 3Re 2B 5 is a regular metal.« less

Metal-Rich Transition Metal Diborides as Electrocatalysts for Hydrogen Evolution Reactions in a Wide Range of pH

DOE PAGES

Sitler, Steven J.; Raja, Krishnan S.; Charit, Indrajit

2016-09-23

Solid solutions of HfB 2-ZrB 2 mixtures were prepared by high-energy ball milling of diboride and additive powders followed by spark plasma sintering (SPS). A mixture of stoichiometric 1:1 HfB 2-ZrB 2 borides was the base composition to which Hf, Zr, Ta, LaB 6 or Gd 2O 3 was added. Hf, Zr and Ta were added in order to bring the boron-to-metal ratio down to 1.86, rendering the boride as MeB 1.86. In the case of LaB 6 and Gd 2O 3, 1.8 mol% was added. Electroanalytical behavior of hydrogen evolution reactions was evaluated in 1 M H 2SO 4more » and 1 M NaOH solutions. The LaB 6 additive material showed Tafel slopes of 125 and 90 mV/decade in acidic and alkaline solutions respectively. The Hf and Zr rich samples showed Tafel slopes of about 120 mV/decade in both electrolytes. The over potentials of hydrogen evolution reactions (at 10 mA/cm 2) in the alkaline solution were about 100 mV lower than those in acidic solution. The metal-rich diborides and addition of LaB 6 showed better hydrogen evolution reaction (HER) activities than the base 1:1 HfB 2-ZrB 2 stoichiometric diboride solid solution. Furthermore, the higher activity of metal-rich borides could be attributed to the increased electron population at the d-orbitals of the metal shown by band structure modeling calculations using the Density Functional Theory approach.« less

Thermal properties of zirconium diboride -- transition metal boride solid solutions

NASA Astrophysics Data System (ADS)

McClane, Devon Lee

This research focuses on the thermal properties of zirconium diboride (ZrB2) based ceramics. The overall goal was to improve the understanding of how different transition metal (TM) additives influence thermal transport in ZrB2. To achieve this, ZrB2 with 0.5 wt% carbon, and 3 mol% of individual transition metal borides, was densified by hot-press sintering. The transition metals that were investigated were: Y, Ti, Hf, V, Nb, Ta, Cr, Mo, W, and Re. The room temperature thermal diffusivities of the compositions ranged from 0.331 cm2/s for nominally pure ZrB2 to 0.105 cm2/s for (Zr,Cr)B2 and converged around 0.155cm2/s at higher temperatures for all compositions. Thermal conductivities were calculated from the diffusivities, using temperature-dependent values for density and heat capacity. The electron contribution to thermal conductivity was calculated from measured electrical resistivity according to the Wiedemann-Franz law. The phonon contribution to thermal conductivity was calculated by subtracting the electron contribution from the total thermal conductivity. Rietveld refinement of x-ray diffraction data was used to determine the lattice parameters of the compositions. The decrease in thermal conductivity for individual additives correlated directly to the metallic radius of the additive. Additional strain appeared to exist for additives when the stable TM boride for that metal had different crystal symmetries than ZrB2. This research provided insight into how additives and impurities affect thermal transport in ZrB2. The research potentially offers a basis for future modeling of thermal conductivity in ultra-high temperature ceramics based on the correlation between metallic radius and the decrease in thermal conductivity.

Ten-day quadruple therapy comprising low-dose rabeprazole, bismuth, amoxicillin and tetracycline is an effective and safe first-line treatment for Helicobacter pylori infection in population with high antibiotic resistance: a prospective, multicenter, randomized, parallel-controlled clinical trial in China.

PubMed

Xie, Yong; Zhu, Zhenhua; Wang, Jiangbin; Zhang, Lingxia; Zhang, Zhenyu; Lu, Hong; Zeng, Zhirong; Chen, Shiyao; Liu, Dongsheng; Lv, Nonghua

2018-06-18

Objectives: To investigate the efficacy and safety of 10-day bismuth quadruple therapy with amoxicillin, tetracycline or clarithromycin and different doses of rabeprazole for first-line treatment of Helicobacter pylori infection. Methods: This multicenter, randomized, parallel-controlled clinical trial was conducted between March 2013 and August 2014. A total of 431 H. pylori -infected patients with duodenal ulcers were enrolled and randomized into four treatment groups (1:1:1:1) for 10 days: 1. LR-BAC Group, which received rabeprazole 10 mg b.i.d., bismuth, amoxicillin and clarithromycin; 2. LR-BAT Group, which received rabeprazole 10mg b.i.d., bismuth, amoxicillin and tetracycline; 3. HR-BAC Group, which received rabeprazole 20 mg b.i.d., and bismuth, amoxicillin and clarithromycin; and 4. HR-BAT Group, which received rabeprazole 20 mg b.i.d., bismuth, amoxicillin, tetracycline. Antimicrobial susceptibility was assessed by the E-test method. The primary outcome was H. pylori eradication at 4 weeks after the treatment. Results: The per-protocol (PP) eradication rates in the LR-BAC, LR-BAT, HR-BAC, and HR-BAT groups were 94.1%, 91.9%, 94.8% and 91.9%, respectively, while the intention-to-treat (ITT) eradication rates in those groups were 87.2%, 87.2%, 87.7% and 86%, respectively. There was no significant difference between four groups in PP analysis( P =0.799) and ITT analysis( P =0.985). The efficacies of four treatment therapy were not affected by antibiotics resistance. The adverse events in four treatment groups were similar, CNS and gastrointestinal symptoms were the most common reported. Conclusions: Bismuth-containing quadruple therapy with low-dose rabeprazole, amoxicillin and tetracycline is a good option for first-line treatment of H. pylori infection in population with high antibiotic resistance. Copyright © 2018 Xie et al.

Compact and Integrated Liquid Bismuth Propellant Feed System

NASA Technical Reports Server (NTRS)

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

2007-01-01

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

Physical and optical property studies on Bi3+ ion containing vanadium sodium borate glasses

NASA Astrophysics Data System (ADS)

Venkatesh, G.; Meera, B. N.; Eraiah, B.

2018-04-01

xBi2O3-(15-x)V2O5-45B2O3-40Na2O glasses have been prepared using melt quenching technique. Amorphous nature of the glasses is verified using powder XRD. Densities and molar volume have been determined as a function of bismuth content and interestingly both increases as a function of bismuth content. Further oxygen packing density (OPD) is found to decrease with bismuth content. The increase in the molar volume as a function of bismuth content may be due to structural changes in the glass network. The optical properties performed from the optical absorption spectra were recorded in the wavelength range 200-1100 nm using UV-Visible spectrophotometer. The theoretical optical basicity of the oxides have also been estimated. The calculated energy band gap values increases with increase in Bi2O3 content.

Evaluation of the gamma radiation shielding parameters of bismuth modified quaternary glass system

NASA Astrophysics Data System (ADS)

Kaur, Parminder; Singh, K. J.; Thakur, Sonika

2018-05-01

Glasses modified with heavy metal oxides (HMO) are an interesting area of research in the field of gamma-ray shielding. Bismuth modified lithium-zinc-borate glasses have been studied whereby bismuth oxide is added from 0 to 50 mol%. The gamma ray shielding properties of the glasses were evaluated at photon energy 662 keV with the help of XMuDat computer program by using the Hubbell and Seltzer database. Various gamma ray shielding parameters such as attenuation coefficient, shield thickness in terms of half and tenth value layer, effective atomic number have been studied in this work. A useful comparison of this glass system has been made with standard radiation shielding concretes viz. ordinary, barite and iron concrete. The glass samples containing 20 to 50 mol% bismuth oxide have shown better gamma ray shielding properties and hence have the potential to become good radiation absorbers.

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

NASA Astrophysics Data System (ADS)

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.

Identification of Nanocrystalline Inclusions in Bismuth-Doped Silica Fibers and Preforms.

PubMed

Iskhakova, Liudmila D; Milovich, Filipp O; Mashinsky, Valery M; Zlenko, Alexander S; Borisovsky, Sergey E; Dianov, Evgeny M

2016-10-01

The nature of nanocrystalline inclusions and dopant distribution in bismuth-doped silicate fibers and preforms are studied by scanning and transmission electron microscopy, and energy and wavelength-dispersive X-ray microanalysis. The core compositions are Bi:SiO2, Bi:Al2O3-SiO2, Bi:GeO2-SiO2, Bi:Al2O3-GeO2-SiO2, and Bi:P2O5-Al2O3-GeO2-SiO2. Nanocrystals of metallic Bi, Bi2O3, SiO2, GeO2, and Bi4(GeO4)3 are observed in these glasses. These inclusions can be the reason for the background optical loss in bismuth-doped optical fibers. The bismuth concentration of 0.0048±0.0006 at% is directly measured in aluminosilicate optical fibers with effective laser generation (slope efficiency of 27% at room temperature).

Stopping cross sections of He + ions in bismuth

NASA Astrophysics Data System (ADS)

Kuldeep; Jain, Animesh K.

1985-06-01

The stopping cross sections, ɛ( E), of He + ions in bismuth have been measured by Rutherford backscattering spectrometry (RBS) at incident energies ranging from E = 1.6-3.4 MeV. The energy loss of He + ions and thicknesses of the bismuth films deposited on aluminium substrates were determined from the RBS spectra at each energy for scattering angles of 130° and 165°. The film thicknesses of some of the samples were also measured by weighing and the results compared with those from RBS. Parameters for energy dependence of stopping cross section in the Varelas-Biersack interpolation formula have been obtained for bismuth from a fit to all the available experimental data. Accuracy of our method based on RBS is demonstrated by measurements on copper, for which ɛ( E) is already well studied. It is also shown that reliable ɛ( E) values may be obtained even on samples with non-uniform film thickness.

An on-line system using ion-imprinted polymer for preconcentration and determination of bismuth in seawater employing atomic fluorescence spectrometry.

PubMed

Felix, Caio S A; Silva, Darllen G; Andrade, Heloysa M C; Riatto, Valeria B; Victor, Mauricio M; Ferreira, Sergio L C

2018-07-01

This work proposes an on-line preconcentration system using ion-imprinted polymer (IIP) for determination of bismuth in seawater employing atomic fluorescence spectrometry (AFS). The polymer was synthesized using 2- (5-bromo-2-pyridylazo) -5-diethylaminophenol (Br-PADAP) for complex formation, ethylene glycol dimethacrylate (EGDMA), cross-linking reagent and methacrylic acid (AMA) reagents, used as the functional monomer, 2,2-azobisisobutyronitrile was used as the radical initiator. The polymer was characterized employing the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The determination of bismuth was performed employing hydride generation atomic fluorescence spectrometry (HG AFS) and the experimental conditions were optimized using a Box Behnken design involving the factors sample pH, eluent concentration and sodium tetrahydroborate concentration. So, using the optimized conditions the system allows the determination of bismuth with limits of detection and quantification of 26 and 88 ng L -1 , a preconcentration factor of 19.8. All these parameters were determined using a sample volume of 25 mL. The precision expressed as relative standard deviation (RSD%) was 3.7% for a bismuth(III) solution of concentration 0.25 µg L -1 . The system proposed was applied for the determination of bismuth in four seawater samples collected in Salvador City, Bahia State, Brazil. The concentrations obtained varied from 0.38 to 0.45 μg L -1 . The accuracy was evaluated by addition/recovery test, and the recoveries found varied from 92% to 101%. Copyright © 2018 Elsevier B.V. All rights reserved.

Bismuth silicate glass containing heavy metal oxide as a promising radiation shielding material

NASA Astrophysics Data System (ADS)

Elalaily, Nagia A.; Abou-Hussien, Eman M.; Saad, Ebtisam A.

2016-12-01

Optical and FTIR spectroscopic measurements and electron paramagnetic resonance (EPR) properties have been utilized to investigate and characterize the given compositions of binary bismuth silicate glasses. In this work, it is aimed to study the possibility of using the prepared bismuth silicate glasses as a good shielding material for γ-rays in which adding bismuth oxide to silicate glasses causes distinguish increase in its density by an order of magnitude ranging from one to two more than mono divalent oxides. The good thermal stability and high density of the bismuth-based silicate glass encourage many studies to be undertaken to understand its radiation shielding efficiency. For this purpose a glass containing 20% bismuth oxide and 80% SiO2 was prepared using the melting-annealing technique. In addition the effects of adding some alkali heavy metal oxides to this glass, such as PbO, BaO or SrO, were also studied. EPR measurements show that the prepared glasses have good stability when exposed to γ-irradiation. The changes in the FTIR spectra due to the presence of metal oxides were referred to the different housing positions and physical properties of the respective divalent Sr2+, Ba2+ and Pb2+ ions. Calculations of optical band gap energies were presented for some selected glasses from the UV data to support the probability of using these glasses as a gamma radiation shielding material. The results showed stability of both optical and magnetic spectra of the studied glasses toward gamma irradiation, which validates their irradiation shielding behavior and suitability as the radiation shielding candidate materials.

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

PubMed

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.

Role of intestinal microbiota in transformation of bismuth and other metals and metalloids into volatile methyl and hydride derivatives in humans and mice.

PubMed

Michalke, Klaus; Schmidt, Annette; Huber, Britta; Meyer, Jörg; Sulkowski, Margareta; Hirner, Alfred V; Boertz, Jens; Mosel, Frank; Dammann, Philip; Hilken, Gero; Hedrich, Hans J; Dorsch, Martina; Rettenmeier, Albert W; Hensel, Reinhard

2008-05-01

The present study shows that feces samples of 14 human volunteers and isolated gut segments of mice (small intestine, cecum, and large intestine) are able to transform metals and metalloids into volatile derivatives ex situ during anaerobic incubation at 37 degrees C and neutral pH. Human feces and the gut of mice exhibit highly productive mechanisms for the formation of the toxic volatile derivative trimethylbismuth [(CH(3))(3)Bi] at rather low concentrations of bismuth (0.2 to 1 mumol kg(-1) [dry weight]). An increase of bismuth up to 2 to 14 mmol kg(-1) (dry weight) upon a single (human volunteers) or continuous (mouse study) administration of colloidal bismuth subcitrate resulted in an average increase of the derivatization rate from approximately 4 pmol h(-1) kg(-1) (dry weight) to 2,100 pmol h(-1) kg(-1) (dry weight) in human feces samples and from approximately 5 pmol h(-1) kg(-1) (dry weight) to 120 pmol h(-1) kg(-1) (dry weight) in mouse gut samples, respectively. The upshift of the bismuth content also led to an increase of derivatives of other elements (such as arsenic, antimony, and lead in human feces or tellurium and lead in the murine large intestine). The assumption that the gut microbiota plays a dominant role for these transformation processes, as indicated by the production of volatile derivatives of various elements in feces samples, is supported by the observation that the gut segments of germfree mice are unable to transform administered bismuth to (CH(3))(3)Bi.

Inadvertent exaggerated anticoagulation following use of bismuth subsalicylate in an enterally fed patient receiving warfarin therapy.

PubMed

Bingham, Angela L; Brown, Rex O; Dickerson, Roland N

2013-12-01

We report a case of an inadvertent increase in the international normalized ratio (INR) after the addition of bismuth subsalicylate for the treatment of diarrhea in an enterally fed patient receiving warfarin therapy. A 56-year-old Caucasian female presented to the trauma intensive care unit (ICU) with multiple lower extremity fractures. Warfarin was initiated for deep vein thrombosis prophylaxis due to the patient's inability to ambulate. The target INR was 2-3. Continuous intragastric enteral feeding was withheld 1 hour before and 1 hour after intragastric administration of warfarin. Bismuth subsalicylate 30 mL every 4 hours was prescribed for diarrhea. Within 3 days after starting bismuth subsalicylate therapy, the patient's INR increased from 2.56 to 3.54 and minor bleeding was noted from the patient's tracheostomy site. No significant change in warfarin dosage, variability in vitamin K intake, or medications that potentially alter warfarin metabolism were present during the unexpected rise in INR. When the bismuth subsalicylate was discontinued, the patient's INR stabilized into the target range on the same warfarin dose given at the time of the supratherapeutic INR. Salicylate displaces warfarin from plasma protein binding sites and may result in a significant increase in INR secondary to redistribution of warfarin to the free active form. Evaluation of this case report using the Drug Interaction Probability Scale and Naranjo Adverse Drug Reaction Probability Scale yielded scores consistent with a probable adverse drug interaction. Bismuth subsalicylate exaggerates warfarin's anticoagulant response and its concurrent use during warfarin therapy should be avoided.

Spin Hall effect and Landau spectrum of Dirac electrons in bismuth

NASA Astrophysics Data System (ADS)

Fuseya, Yuki

2015-03-01

Bismuth has played an important role in solid-state physics. Many key phenomena were first discovered in bismuth, such as diamagnetism, Seebeck, Nernst, Shubnikov-de Haas, and de Haas-van Alphen effects. These phenomena result from particular electronic states of bismuth. The strong spin-orbit interaction (~ 1.5eV) causes strong spin-dependent interband couplings resulting in an anomalous spin magnetic moment. We investigate the spin Hall effect and the angular dependent Landau spectrum of bismuth paying special attention to the effect of the anomalous spin magnetic moment. It is shown that the spin Hall insulator is possible and there is a fundamental relationship between the spin Hall conductivity and orbital diamagnetism in the insulating state of the Dirac electrons. Based on this theoretical finding, the magnitude of spin Hall conductivity is estimated for bismuth by that of orbital susceptibility. The magnitude of spin Hall conductivity turns out to be as large as 104Ω-1 cm-1, which is about 100 times larger than that of Pt. It is also shown that the ratio of the Zeeman splitting to the cyclotron energy, which reflects the effect of crystalline spin-orbit interaction, for holes at the T-point can be larger than 1.0 (the maximum of previous theories) and exhibit strong angular dependence, which gives a possible solution to the long-standing mystery of holes at the T-point. In collaboration with Masao Ogata, Hidetoshi Fukuyama, Zengwei Zhu, Benoît Fauqué, Woun Kang, and Kamran Behnia. Supported by JSPS (KAKENHI 24244053, 25870231, and 13428660).

Boride Formation Induced by pcBN Tool Wear in Friction-Stir-Welded Stainless Steels

NASA Astrophysics Data System (ADS)

Park, Seung Hwan C.; Sato, Yutaka S.; Kokawa, Hiroyuki; Okamoto, Kazutaka; Hirano, Satoshi; Inagaki, Masahisa

2009-03-01

The wear of polycrystalline cubic boron nitride (pcBN) tool and its effect on second phase formation were investigated in stainless steel friction-stir (FS) welds. The nitrogen content and the flow stress were analyzed in these welds to examine pcBN tool wear. The nitrogen content in stir zone (SZ) was found to be higher in the austenitic stainless steel FS welds than in the ferritic and duplex stainless steel welds. The flow stress of austenitic stainless steels was almost 1.5 times larger than that of ferritic and duplex stainless steels. These results suggest that the higher flow stress causes the severe tool wear in austenitic stainless steels, which results in greater nitrogen pickup in austenitic stainless steel FS welds. From the microstructural observation, a possibility was suggested that Cr-rich borides with a crystallographic structure of Cr2B and Cr5B3 formed through the reaction between the increased boron and nitrogen and the matrix during FS welding (FSW).

Transition metal carbides, nitrides and borides, and their oxygen containing analogs useful as water gas shift catalysts

DOEpatents

Thompson, Levi T.; Patt, Jeremy; Moon, Dong Ju; Phillips, Cory

2003-09-23

Mono- and bimetallic transition metal carbides, nitrides and borides, and their oxygen containing analogs (e.g. oxycarbides) for use as water gas shift catalysts are described. In a preferred embodiment, the catalysts have the general formula of M1.sub.A M2.sub.B Z.sub.C O.sub.D, wherein M1 is selected from the group consisting of Mo, W, and combinations thereof; M2 is selected from the group consisting of Fe, Ni, Cu, Co, and combinations thereof; Z is selected from the group consisting of carbon, nitrogen, boron, and combinations thereof; A is an integer; B is 0 or an integer greater than 0; C is an integer; O is oxygen; and D is 0 or an integer greater than 0. The catalysts exhibit good reactivity, stability, and sulfur tolerance, as compared to conventional water shift gas catalysts. These catalysts hold promise for use in conjunction with proton exchange membrane fuel cell powered systems.

Ultra High Temperature Ceramics' Processing Routes and Microstructures Compared

NASA Technical Reports Server (NTRS)

Gusman, Michael; Stackpoole, Mairead; Johnson, Sylvia; Gasch, Matt; Lau, Kai-Hung; Sanjurjo, Angel

2009-01-01

Ultra High Temperature Ceramics (UHTCs), such as HfB2 and ZrB2 composites containing SiC, are known to have good thermal shock resistance and high thermal conductivity at elevated temperatures. These UHTCs have been proposed for a number of structural applications in hypersonic vehicles, nozzles, and sharp leading edges. NASA Ames is working on controlling UHTC properties (especially, mechanical properties, thermal conductivity, and oxidation resistance) through processing, composition, and microstructure. In addition to using traditional methods of combining additives to boride powders, we are preparing UHTCs using coat ing powders to produce both borides and additives. These coatings and additions to the powders are used to manipulate and control grain-boundary composition and second- and third-phase variations within the UHTCs. Controlling the composition of high temperature oxidation by-products is also an important consideration. The powders are consolidated by hot-pressing or field-assisted sintering (FAS). Comparisons of microstructures and hardness data will be presented.

A superconducting battery material: Lithium gold boride (LiAu3B)

NASA Astrophysics Data System (ADS)

Aydin, Sezgin; Şimşek, Mehmet

2018-04-01

The superconducting and potential cathode material properties of ternary boride of LiAu3B have been investigated by density functional first principles. The Li-concentration effects on the actual electronic and structural properties, namely the properties of LixAu9B3 (x = 0, 1, 2) sub-systems are studied. It is remarkably shown that the existence of Li-atoms has no considerable effect on the structural properties of Au-B skeleton in LiAu3B. Then, it can be offered as a potential cathode material for Li-ion batteries with the very small volume deviation of 0.42%, and the suitable average open circuit voltage of ∼1.30 V. Furthermore, the vibrational and superconducting properties such as electron-phonon coupling constant (λ) and critical temperature (Tc) of LiAu3B are studied. The calculated results suggest that LiAu3B should be a superconductor with Tc ∼5.8 K, also.

SEPARATION OF FISSION PRODUCTS FROM PLUTONIUM BY PRECIPITATION

DOEpatents

Seaborg, G.T.; Thompson, S.G.; Davidson, N.R.

1959-09-01

Fission product separation from hexavalent plutonium by bismuth phosphate precipitation of the fission products is described. The precipitation, according to this invention, is improved by coprecipitating ceric and zirconium phosphates (0.05 to 2.5 grams/liter) with the bismuth phosphate.

METHOD FOR RECOVERING PLUTONIUM VALUES FROM SOLUTION USING A BISMUTH HYDROXIDE CARRIER PRECIPITATE

DOEpatents

Faris, B.F.

1961-04-25

Carrier precipitation processes for separating plutonium values from aqueous solutions are described. In accordance with the invention a bismuth hydroxide precipitate is formed in the plutonium-containing solution, thereby carrying plutonium values from the solution.

Fabrication of Nanovoid-Imbedded Bismuth Telluride with Low Dimensional System

NASA Technical Reports Server (NTRS)

Chu, Sang-Hyon (Inventor); Choi, Sang H. (Inventor); Kim, Jae-Woo (Inventor); Park, Yeonjoon (Inventor); Elliott, James R. (Inventor); King, Glen C. (Inventor); Stoakley, Diane M. (Inventor)

2013-01-01

A new fabrication method for nanovoids-imbedded bismuth telluride (Bi--Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi--Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.

Ion mobility and transport properties of bismuth fluoride-containing solid solutions with tysonite-type structure

NASA Astrophysics Data System (ADS)

Kavun, V. Ya.; Uvarov, N. F.; Slobodyuk, A. B.; Merkulov, E. B.; Polyantsev, M. M.

2018-07-01

The ion mobility and conductivity of solid solutions with tysonite-type structure obtained by doping bismuth trifluoride with lead (II) fluoride, and zirconium and bismuth oxides have been studied using 19F NMR, X-ray diffraction analysis, and impedance spectroscopy. The types of ionic motions in the fluoride sublattice of the synthesized solid solutions in the temperature range 150-450 K have been determined and the energy of their activation has been estimated. Due to high ionic conductivity, above 10-2 S/cm at 570 K, these solid solutions can be considered as superionic conductors.

Preparation of Ferroelectric Thin Films of Bismuth Layer Structured Compounds

NASA Astrophysics Data System (ADS)

Watanabe, Hitoshi; Mihara, Takashi; Yoshimori, Hiroyuki; Araujo, Carlos

1995-09-01

Ferroelectric thin films of bismuth layer structured compounds, SrBi2Ta2O9, SrBi2Nb2O9, SrBi4Ti4O15 and their solid solutions, were formed onto a sputtered platinum layer on a silicon substrate using spin-on technique and metal-organic decomposition (MOD) method. X-ray diffraction (XRD) analysis and some electrical measurements were performed on the prepared thin films. XRD results of SrBi2(Ta1- x, Nb x)2O9 films (0≤x≤1) showed that niobium ions substitute for tantalum ions in an arbitrary ratio without any change of the layer structure and lattice constants. Furthermore, XRD results of SrBi2 xTa2O9 films (0≤x≤1.5) indicated that the formation of the bismuth layer structure does not always require an accurate bismuth content. The layer structure was formed above 50% of the stoichiometric bismuth content in the general formula. SrBi2(Ta1- x, Nb x)2O9 films with various Ta/Nb ratios have large enough remanent polarization for nonvolatile memory application and have shown high fatigue resistance against 1011 cycles of full switching of the remanent polarization. Mixture films of the three compounds were also investigated.

Facile synthesis of light harvesting semiconductor bismuth oxychloride nano photo-catalysts for efficient removal of hazardous organic pollutants

PubMed Central

Seddigi, Zaki S.; Baig, Umair; Ahmed, Saleh A.; Abdulaziz, M. A.; Danish, Ekram Y.; Khaled, Mazen M.; Lais, Abul

2017-01-01

In the present work, bismuth oxychloride nanoparticles–a light harvesting semiconductor photocatalyst–were synthesized by a facile hydrolysis route, with sodium bismuthate and hydroxylammonium chloride as the precursor materials. The as-synthesized semiconductor photocatalysts were characterized using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy, X-ray photoelectron spectroscopy and Photoluminescence spectroscopy techniques. The crystal structure, morphology, composition, and optical properties of these facile synthesized bismuth oxychloride nanoparticles (BiOCl NPs) were compared to those of traditional bismuth oxychloride. In addition, the photocatalytic performance of facile-synthesized BiOCl NPs and traditional BiOCl, as applied to the removal of hazardous organic dyes under visible light illumination, is thoroughly investigated. Our results reveal that facile-synthesized BiOCl NPs display strong UV-Vis light adsorption, improved charge carrier mobility and an inhibited rate of charge carrier recombination, when compared to traditional BiOCl. These enhancements result in an improved photocatalytic degradation rate of hazardous organic dyes under UV-Vis irradiance. For instance, the facile-synthesized BiOCl NPs attained 100% degradation of methylene blue and methyl orange dyes in approximately 30 mins under UV-Vis irradiation, against 55% degradation for traditional BiOCl under similar experimental conditions. PMID:28245225

Facile synthesis of light harvesting semiconductor bismuth oxychloride nano photo-catalysts for efficient removal of hazardous organic pollutants.

PubMed

Seddigi, Zaki S; Gondal, Mohammed A; Baig, Umair; Ahmed, Saleh A; Abdulaziz, M A; Danish, Ekram Y; Khaled, Mazen M; Lais, Abul

2017-01-01

In the present work, bismuth oxychloride nanoparticles-a light harvesting semiconductor photocatalyst-were synthesized by a facile hydrolysis route, with sodium bismuthate and hydroxylammonium chloride as the precursor materials. The as-synthesized semiconductor photocatalysts were characterized using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy, X-ray photoelectron spectroscopy and Photoluminescence spectroscopy techniques. The crystal structure, morphology, composition, and optical properties of these facile synthesized bismuth oxychloride nanoparticles (BiOCl NPs) were compared to those of traditional bismuth oxychloride. In addition, the photocatalytic performance of facile-synthesized BiOCl NPs and traditional BiOCl, as applied to the removal of hazardous organic dyes under visible light illumination, is thoroughly investigated. Our results reveal that facile-synthesized BiOCl NPs display strong UV-Vis light adsorption, improved charge carrier mobility and an inhibited rate of charge carrier recombination, when compared to traditional BiOCl. These enhancements result in an improved photocatalytic degradation rate of hazardous organic dyes under UV-Vis irradiance. For instance, the facile-synthesized BiOCl NPs attained 100% degradation of methylene blue and methyl orange dyes in approximately 30 mins under UV-Vis irradiation, against 55% degradation for traditional BiOCl under similar experimental conditions.

Dismantling and chemical characterization of spent Peltier thermoelectric devices for antimony, bismuth and tellurium recovery.

PubMed

Balva, Maxime; Legeai, Sophie; Garoux, Laetitia; Leclerc, Nathalie; Meux, Eric

2017-04-01

Major uses of thermoelectricity concern refrigeration purposes, using Peltier devices, mainly composed of antimony, bismuth and tellurium. Antimony was identified as a critical raw material by EU and resources of bismuth and tellurium are not inexhaustible, so it is necessary to imagine the recycling of thermoelectric devices. That for, a complete characterization is needed, which is the aim of this work. Peltier devices were manually dismantled in three parts: the thermoelectric legs, the alumina plates on which remain the electrical contacts and the silicone paste used to connect the plates. The characterization was performed using five Peltier devices. It includes mass balances of the components, X-ray diffraction analysis of the thermoelectric legs and elemental analysis of each part of the device. It appears that alumina represents 45% of a Peltier device in weight. The electrical contacts are mainly composed of copper and tin, and the thermoelectric legs of bismuth, tellurium and antimony. Thermoelectric legs appear to be Se-doped Bi 2 Te 3 and (Bi 0,5 Sb 1,5 )Te 3 for n type and p type semiconductors, respectively. This work shows that Peltier devices can be considered as a copper ore and that thermoelectric legs contain high amounts of bismuth, tellurium and antimony compared to their traditional resources.

Exploring reaction pathways in the hydrothermal growth of phase-pure bismuth ferrites

NASA Astrophysics Data System (ADS)

Goldman, Abby R.; Fredricks, Jeremy L.; Estroff, Lara A.

2017-06-01

Phase-pure bismuth ferrites (BiFeO3 and Bi2Fe4O9) are grown using hydrothermal synthesis. In addition to varying the KOH, bismuth, and iron salt concentrations to tune which crystalline phases are formed, we identified that a 48 h, pre-furnace, room temperature reaction is critical for the formation of phase-pure BiFeO3. To understand the reaction pathways leading to the different bismuth ferrite phases, we investigate the changes in composition of the intermediate products as a function of reagent concentrations and room temperature reaction times. During the syntheses that included a room temperature reaction, Bi25FeO40 is formed in the intermediate products, and BiFeO3 is the majority phase of the final products. The BiFeO3 crystals grown using this method are clusters of faceted subunits. These results indicate that forming Bi25FeO40 is a productive route to the formation of BiFeO3. Bi2Fe4O9 is formed via an alternate reaction pathway that proceeded via an amorphous precursor. This improved understanding of how hydrothermal synthesis can be used to control the phase-purity and morphology of bismuth ferrites opens doors to explore the multiferroic properties of BiFeO3 with complex morphologies.

Bismuth-embedded SBA-15 mesoporous silica for radioactive iodine capture and stable storage

NASA Astrophysics Data System (ADS)

Yang, Jae Hwan; Cho, Yong-Jun; Shin, Jin Myeong; Yim, Man-Sung

2015-10-01

Efficient capture and stable storage of the long-lived iodine-129 (129I), released as off-gas from nuclear fuel reprocessing, have been of significant concern in the waste management field. In this study, bismuth-embedded SBA-15 mesoporous silica was firstly applied for iodine capture and storage. SBA-15 was functionalized with thiol (-SH) groups, followed by bismuth adsorption with Bi-S bonding, which was thermally treated to form Bi2S3 within SBA-15. The bismuth-embedded SBA-15s demonstrated high iodine loading capacities (up to 540 mg-I/g-sorbent), which benefitted from high surface area and porosity of SBA-15 as well as the formation of thermodynamically stable BiI3 compound. Iodine physisorption was effectively suppressed due to the large pores present in SBA-15, resulting in chemisorption as a main mechanism for iodine confinement. Furthermore, a chemically durable iodine-bearing material was made with a facile post-sorption process, during which the iodine-incorporated phase was changed from BiI3 to chemically durable Bi5O7I. Thus, our results showed that both efficient capture and stabilization of 129I would be possible with the bismuth-embedded SBA-15, in contrast to other sorbents mainly focused on iodine capture.

The physical properties of accelerated Portland cement for endodontic use.

PubMed

Camilleri, J

2008-02-01

To investigate the physical properties of a novel accelerated Portland cement. The setting time, compressive strength, pH and solubility of white Portland cement (Lafarge Asland; CEM 1, 52.5 N) and accelerated Portland cement (Proto A) produced by excluding gypsum from the manufacturing process (Aalborg White) and a modified version with 4 : 1 addition of bismuth oxide (Proto B) were evaluated. Proto A set in 8 min. The compressive strength of Proto A was comparable with that of Portland cement at all testing periods (P > 0.05). Additions of bismuth oxide extended the setting time and reduced the compressive strength (P < 0.05). Both cements and storage solution were alkaline. All cements tested increased by >12% of their original weight after immersion in water for 1 day with no further absorption after 28 days. Addition of bismuth oxide increased the water uptake of the novel cement (P < 0.05). The setting time of Portland cement can be reduced by excluding the gypsum during the last stage of the manufacturing process without affecting its other properties. Addition of bismuth oxide affected the properties of the novel cement. Further investigation on the effect that bismuth oxide has on the properties of mineral trioxide aggregate is thus warranted.

The Nature of the Microstructure and Interface Boundary Formation in Directionally Solidified Ceramic Boride Composites

DTIC Science & Technology

2011-05-01

failure resistance, which results from their different microplasticity (microbrittleness) and relaxation ability. In order to evaluate the... microplasticity (microbrittleness) in the series of isomorphic hexaborides produced by zone melting we have plotted a number of statistical curves that show

Ultracapacitor current collector

DOEpatents

Jerabek, Elihu Calfin; Mikkor, Mati

2001-10-16

An ultracapacitor having two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. At least one of the current collectors comprises a conductive metal substrate coated with a metal nitride, carbide or boride coating.

Hydrothermal synthesis of barium strontium titanate and bismuth titanate materials

NASA Astrophysics Data System (ADS)

Xu, Huiwen

Hydrothermal processing facilitates the synthesis of crystalline ceramic materials of varying composition or complex crystal structure. The present work can be divided into two parts. First is to study the low temperature hydrothermal synthesis of bismuth titanate. Second is to study both thermodynamic and kinetic aspects of the hydrothermally synthesized barium strontium titanate. A chelating agent was used to form a Bi-Ti gel precursor. By hydrothermally treating the Bi-Ti gel, crystalline bismuth titanate has been synthesized at 160°C for the first time. Microstructural evolution during the low temperature synthesis of bismuth titanate can be divided into two stages, including condensation of Bi-Ti gel particles and crystallization of bismuth titanate. Crystallization of bismuth titanate occurred by an in situ transformation mechanism at an early stage followed by a dissolution-reprecipitation mechanism. Phase separation was observed in hydrothermally synthesized barium strontium titanate (BST). By hydrothermally treating BST powders between 250°C--300°C, an asymmetrical miscibility gap was found in the BaTiO3-SrTiO 3 system at low temperatures (T ≤ 320°C). A subregular solid solution model was applied to calculate the equilibrium compositions and the Gibbs free energy of formation of BST solid solution at low temperatures (T ≤ 320°C). The Gibbs free energy of formation of Sr-rich BST phase is larger than that of Ba-rich BST phase. Kinetic studies of single phase BST solid solution at 80°C show that, compared to the BaTiO3 or Ba-rich BST, SrTiO3 and Sr-rich BST powders form at lower reaction rates.

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.

PubMed

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.

Probing the local structure of crystalline NaBiO3·XH2O and its acidified derivatives

NASA Astrophysics Data System (ADS)

Kozma, Karoly; Surta, T. Wesley; Molina, Pedro I.; Lyubinetsky, Igor; Stoxen, Wynn; Byrne, Nicole M.; Dolgos, Michelle; Nyman, May

2018-07-01

Sodium bismuthate is a commercially available, inexpensive, non-toxic and very potent inorganic oxidant and photocatalyst. It is one of the important reagents for oxidative separation of Am3+ from the chemically similar lanthanide ions, for its recovery or safe disposal from reprocessed nuclear fuel. While the structure of NaBiO3 has been described from powder and neutron diffraction; the structure of NaBiO3·XH2O, the manufactured form of sodium bismuthate, is currently unknown. Herein, we describe the structure of NaBiO3·XH2O (X = 3) using pair distribution function (PDF) analysis of X-ray total scattering data. In our proposed structure model, NaBiO3·3H2O is similar to NaBiO3, but with turbostratic disorder in the stacking direction of the alternating Bi-O and Na-O layers. We propose locations for the lattice water, and its role in creating turbostratic disorder. We also used PDF to describe the structural evolution of sodium bismuthate upon exposure to nitric acid, the conditions employed in for nuclear fuel reprocessing. We supported the proposed model for pristine NaBiO3·3H2O and its acidified derivatives by a variety of techniques including thermogravimetry, powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). By employing both surface and bulk techniques, we hypothesize that the bismuth reduced to Bi3+ upon aqueous acid exposure remains in the lattice, rather than completely dissolving and/or depositing on the surface, as prior suggested. Using pretreated acidified sodium bismuthate samples, we delineated the effects of acid strength vs. bismuthate structure/composition on Ce3+ to Ce4+ oxidation efficacy.

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

PubMed

Marciano, Marina Angélica; Estrela, Carlos; Mondelli, Rafael Francisco Lia; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro

2013-01-01

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<0.05). The cements in which bismuth oxide was added showed radiopacity corresponding to the ISO recommendations (>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.

Pressed boride cathodes

NASA Technical Reports Server (NTRS)

Wolski, W.

1985-01-01

Results of experimental studies of emission cathodes made from lanthanum, yttrium, and gadolinium hexaborides are presented. Maximum thermal emission was obtained from lanthanum hexaboride electrodes. The hexaboride cathodes operated stably under conditions of large current density power draw, at high voltages and poor vacuum. A microtron electron gun with a lanthanum hexaboride cathode is described.

Thermophysical and Electronic Properties Information Analysis Center (TEPIAC): A Continuing Systematic Program on Tables of Thermophysical and Electronic Properties of Materials.

DTIC Science & Technology

1977-02-01

oxides and their mixtures, arsenides, borides, bromides , carbides , chlorides , fluoride s, nitride s, phosphides, silicides , sulfides , tellurides...ivity of alkali elements (lithium , sodium , potassium , rubi- dium , ces ium , and francium) and contains recomme nded reference values generated

Molecular Modeling of High-Temperature Oxidation of Refractory Borides

DTIC Science & Technology

2008-02-01

generate the classical potential, we adopt the van Beest , Kramer and van Santen (BKS) parameterization for Si-O interactions, but fit B-O and Si-B...seminar at Department of Aerospace and Mechanical Engineering, University of Notre Dame, March 20, 2007. 6 Los Alamos National Lab Physics & Theoretical

Picture of the Week: Making the (reactive) case for explosives science

Science.gov Websites

: small organisms, big impacts Biocrusts: small organisms, big impacts View on Flickr Bismuth and tin on the rocks Bismuth and tin on the rocks View on Flickr Need to Know: Van Allen Belts Need to Know: Van

CONCENTRATION PROCESS FOR PLUTONIUM IONS, IN AN OXIDATION STATE NOT GREATER THAN +4, IN AQUEOUS ACID SOLUTION

DOEpatents

Seaborg, G.T.; Thompson, S.G.

1960-06-14

A process for concentrating plutonium is given in which plutonium is first precipitated with bismuth phosphate and then, after redissolution, precipitated with a different carrier such as lanthanum fluoride, uranium acetate, bismuth hydroxide, or niobic oxide.

ADSORPTION-BISMUTH PHOSPHATE METHOD FOR SEPARATING PLUTONIUM

DOEpatents

Russell, E.R.; Adamson, A.W.; Boyd, G.E.

1960-06-28

A process is given for separating plutonium from uranium and fission products. Plutonium and uranium are adsorbed by a cation exchange resin, plutonium is eluted from the adsorbent, and then, after oxidation to the hexavalent state, the plutonium is contacted with a bismuth phosphate carrier precipitate.

Preventing bacterial growth on implanted device with an interfacial metallic film and penetrating X-rays.

PubMed

An, Jincui; Sun, An; Qiao, Yong; Zhang, Peipei; Su, Ming

2015-02-01

Device-related infections have been a big problem for a long time. This paper describes a new method to inhibit bacterial growth on implanted device with tissue-penetrating X-ray radiation, where a thin metallic film deposited on the device is used as a radio-sensitizing film for bacterial inhibition. At a given dose of X-ray, the bacterial viability decreases as the thickness of metal film (bismuth) increases. The bacterial viability decreases with X-ray dose increases. At X-ray dose of 2.5 Gy, 98% of bacteria on 10 nm thick bismuth film are killed; while it is only 25% of bacteria are killed on the bare petri dish. The same dose of X-ray kills 8% fibroblast cells that are within a short distance from bismuth film (4 mm). These results suggest that penetrating X-rays can kill bacteria on bismuth thin film deposited on surface of implant device efficiently.

Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation

PubMed Central

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

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

NASA Astrophysics Data System (ADS)

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

2013-01-01

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

Alkali-metal induced band structure deformation investigated by angle-resolved photoemission spectroscopy and first-principles calculations

NASA Astrophysics Data System (ADS)

Ito, S.; Feng, B.; Arita, M.; Someya, T.; Chen, W.-C.; Takayama, A.; Iimori, T.; Namatame, H.; Taniguchi, M.; Cheng, C.-M.; Tang, S.-J.; Komori, F.; Matsuda, I.

2018-04-01

Alkali-metal adsorption on the surface of materials is widely used for in situ surface electron doping, particularly for observing unoccupied band structures by angle-resolved photoemission spectroscopy (ARPES). However, the effects of alkali-metal atoms on the resulting band structures have yet to be fully investigated, owing to difficulties in both experiments and calculations. Here, we combine ARPES measurements on cesium-adsorbed ultrathin bismuth films with first-principles calculations of the electronic charge densities and demonstrate a simple method to evaluate alkali-metal induced band deformation. We reveal that deformation of bismuth surface bands is directly correlated with vertical charge-density profiles at each electronic state of bismuth. In contrast, a change in the quantized bulk bands is well described by a conventional rigid-band-shift picture. We discuss these two aspects of the band deformation holistically, considering spatial distributions of the electronic states and cesium-bismuth hybridization, and provide a prescription for applying alkali-metal adsorption to a wide range of materials.

System Analysis for Decay Heat Removal in Lead-Bismuth Cooled Natural Circulated Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takaaki Sakai; Yasuhiro Enuma; Takashi Iwasaki

2002-07-01

Decay heat removal analyses for lead-bismuth cooled natural circulation reactors are described in this paper. A combined multi-dimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural circulation reactors. For the preliminary study, transient analysis has been performed for a 100 MWe lead-bismuth-cooled reactor designed by Argonne National Laboratory (ANL). In addition, decay heat removal characteristics of a 400 MWe lead-bismuth-cooled natural circulation reactor designed by Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. PRACS (Primary Reactor Auxiliary Cooling System) is prepared for the JNC's concept to get sufficient heatmore » removal capacity. During 2000 sec after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 Centigrade, because the buoyancy force in a primary circulation path is temporary reduced. However, the natural circulation is recovered by the PRACS system and the out let temperature decreases successfully. (authors)« less

System Analysis for Decay Heat Removal in Lead-Bismuth-Cooled Natural-Circulation Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakai, Takaaki; Enuma, Yasuhiro; Iwasaki, Takashi

2004-03-15

Decay heat removal analyses for lead-bismuth-cooled natural-circulation reactors are described in this paper. A combined multidimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural-circulation reactors. For the preliminary study, transient analysis has been performed for a 300-MW(thermal) lead-bismuth-cooled reactor designed by Argonne National Laboratory. In addition, decay heat removal characteristics of a 400-MW(electric) lead-bismuth-cooled natural-circulation reactor designed by the Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. The primary reactor auxiliary cooling system (PRACS) is prepared for the JNC concept to get sufficient heat removal capacity. During 2000 smore » after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 deg. C because the buoyancy force in a primary circulation path is temporarily reduced. However, the natural circulation is recovered by the PRACS system, and the outlet temperature decreases successfully.« less

Quantum Effects in Inverse Opal Structures

NASA Astrophysics Data System (ADS)

Bleiweiss, Michael; Datta, Timir; Lungu, Anca; Yin, Ming; Iqbal, Zafar; Palm, Eric; Brandt, Bruce

2002-03-01

Properties of bismuth inverse opals and carbon opal replicas were studied. The bismuth nanostructures were fabricated by pressure infiltration into porous artificial opal, while the carbon opal replicas were created via CVD. These structures form a regular three-dimensional network in which the bismuth and carbon regions percolate in all directions between the close packed spheres of SiO_2. The sizes of the conducting regions are of the order of tens of nanometers. Static susceptibility of the bismuth inverse opal showed clear deHaas-vanAlphen oscillations. Transport measurements, including Hall, were done using standard ac four and six probe techniques in fields up to 17 T* and temperatures between 4.2 and 200 K. Observations of Shubnikov-deHaas oscillations in magnetoresistance, one-dimensional weak localization, quantum Hall and other effects will be discussed. *Performed at the National High Magnetic Field Lab (NHMFL) FSU, Tallahassee, FL. This work was partially supported by grants from DARPA-nanothermoelectrics, NASA-EPSCOR and the USC nanocenter.

Melt Convection Effects in the Bridgman Crystal Growth of an Alloy Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Simpson James E.; Garimella, Suresh V.; deGroh, Henry C., III; Abbaschian, Reza

1998-01-01

The solidification of a dilute bismuth-tin alloy under Bridgman crystal growth conditions is investigated in support of NASA's MEPHISTO space shuttle flight experiment. Computations are performed in two-dimensions with a uniform grid. The simulation includes the species-concentration, temperature and flow fields, as well as conduction in the ampoule. Fully transient simulations have been performed; no simplifying steady state approximations are used. Results are obtained under microgravity conditions for pure bismuth, and Bismuth-0.1 at.% Sn and Bi-1.0 at.% Sn alloys. The concentration dependence of the melting temperature is neglected; the solid/liquid interface temperature is assumed to be the melting temperature of pure bismuth for all cases studied. For the Bi-1.0 at.% Sn case the results indicate that a secondary convective cell, driven by solutal gradients, forms near the interface. The magnitude of the velocities in this cell increases with time; this causes increasing solute segregation at the liquid/solid interface.

Dynamic behavior of pump light radiation induced photo-bleaching effect on BAC-Si in bismuth/erbium co-doped optical fibers

NASA Astrophysics Data System (ADS)

Ding, Mingjie; Luo, Yanhua; Wen, Jianxiang; Peng, Gang-Ding

2018-02-01

Ultra-wide emission in bismuth doped optical fiber has been extremely studied for the development of the laser and amplifier working at near infrared band. In our homemade bismuth/erbium co-doped optical fiber, bismuth active center associated with silica (BAC-Si) has been found that when pumping at its resonant wavelength at 830 nm the NIR emission could be partially bleached. In addition, a self-recovery process has been observed at room temperature. However, the exact mechanism is still unclear. In this work, we have investigated the photo-bleaching effect on the BAC-Si via the pump power, pump wavelength and temperature dependence. Based on analyzing the result using stretched exponential function, it shows that the bleaching effect on BAC-Si has a strong link with the excitation process of Bi ion in BAC-Si. A potential energy curve model is used to illustrate the BAC-Si photo-bleaching process.

Volume and Surface Properties of a Bismuth-Containing Separating Nickel Melt

NASA Astrophysics Data System (ADS)

Filippov, K. S.

2017-11-01

The influence of a bismuth impurity on the properties of solid and liquid alloys in the concentration range that obeys Henry's law is considered. The structural and physicochemical properties, specifically, the density and the surface tension, of real melts are studied on relatively pure metals. The changes in the properties of the melts are estimated from changes in the temperature dependences of the density and the surface tension upon heating and cooling and in the concentration dependences of these parameters at a constant temperature. These dependences exhibit a correlation between the volume and surface properties of the melts: the density and the surface tension increase or decrease simultaneously. The introduction of bismuth in the nickel melt is accompanied by the appearance of a relatively strong compression effect (i.e., a decrease in the melt volume). At a certain bismuth content in the melt, the compression effect weakens because of the appearance of an excess phase or its associates and melt separation.

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

PubMed

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.

Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

NASA Astrophysics Data System (ADS)

Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

2017-06-01

p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p-n modules of bismuth telluride without any doping process.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Hui-Yu; Liao, Ying-Lan; Chang Gung University / Chang Gung Memorial Hospital, Taoyun, Taiwan

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-plymore » 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-182-009-MY2), and Chang Gung Memorial Hospital (CMRPD1C0682)« less

A bismuth activation counter for high sensitivity pulsed 14 MeV neutrons

NASA Astrophysics Data System (ADS)

Burns, E. J. T.; Thacher, P. D.; Hassig, G. J.; Decker, R. D.; Romero, J. A.; Barrett, K. P.

2011-08-01

We have built a fast neutron bismuth activation counter that measures activation counts from pulsed 14-MeV neutron generators for incident neutron fluences between 30 and 300 neutrons/cm2 at 15.2 cm (6 in.). The activation counter consists of a large bismuth germanate (BGO) detector surrounded by a bismuth metal shield in front of and concentric with the cylindrical detector housing. The 14 MeV neutrons activate the 2.6-millisecond (ms) isomer in the shield and the detector by the reaction 209Bi (n,2nγ) 208mBi. The use of millisecond isomers and activation counting times minimizes the background from other activated materials and the environment. In addition to activation, the bismuth metal shields against other outside radiation sources. We have tested the bismuth activation counter, simultaneously, with two data acquisition systems (DASs) and both give similar results. The two-dimensional (2D) DAS and three dimensional (3D) DAS both consist of pulse height analysis (PHA) systems that can be used to discriminate against gamma radiations below 300 keV photon energy, so that the detector can be used strictly as a counter. If the counting time is restricted to less than 25 ms after the neutron pulse, there are less than 10 counts of background for single pulse operation in all our operational environments tested so far. High-fluence neutron generator operations are restricted by large dead times and pulse height saturation. When we operate our 3D DAS PHA system in list mode acquisition (LIST), real-time corrections to dead time or live time can be made on the scale of 1 ms time windows or dwell times. The live time correction is consistent with nonparalyzable models for dead time of 1.0±0.2 μs for our 3D DAS and 1.5±0.3 μs for our 2D DAS dominated by our fixed time width analog to digital converters (ADCs). With the same solid angle, we have shown that the bismuth activation counter has a factor of 4 increase in sensitivity over our lead activation counter, because of higher counts and negligible backgrounds.

14 day sequential therapy versus 10 day bismuth quadruple therapy containing high-dose esomeprazole in the first-line and second-line treatment of Helicobacter pylori: a multicentre, non-inferiority, randomized trial.

PubMed

Liou, Jyh-Ming; Chen, Chieh-Chang; Fang, Yu-Jen; Chen, Po-Yueh; Chang, Chi-Yang; Chou, Chu-Kuang; Chen, Mei-Jyh; Tseng, Cheng-Hao; Lee, Ji-Yuh; Yang, Tsung-Hua; Chiu, Min-Chin; Yu, Jian-Jyun; Kuo, Chia-Chi; Luo, Jiing-Chyuan; Hsu, Wen-Feng; Hu, Wen-Hao; Tsai, Min-Horn; Lin, Jaw-Town; Shun, Chia-Tung; Twu, Gary; Lee, Yi-Chia; Bair, Ming-Jong; Wu, Ming-Shiang

2018-05-29

Whether extending the treatment length and the use of high-dose esomeprazole may optimize the efficacy of Helicobacter pylori eradication remains unknown. To compare the efficacy and tolerability of optimized 14 day sequential therapy and 10 day bismuth quadruple therapy containing high-dose esomeprazole in first-line therapy. We recruited 620 adult patients (≥20 years of age) with H. pylori infection naive to treatment in this multicentre, open-label, randomized trial. Patients were randomly assigned to receive 14 day sequential therapy or 10 day bismuth quadruple therapy, both containing esomeprazole 40 mg twice daily. Those who failed after 14 day sequential therapy received rescue therapy with 10 day bismuth quadruple therapy and vice versa. Our primary outcome was the eradication rate in the first-line therapy. Antibiotic susceptibility was determined. ClinicalTrials.gov: NCT03156855. The eradication rates of 14 day sequential therapy and 10 day bismuth quadruple therapy were 91.3% (283 of 310, 95% CI 87.4%-94.1%) and 91.6% (284 of 310, 95% CI 87.8%-94.3%) in the ITT analysis, respectively (difference -0.3%, 95% CI -4.7% to 4.4%, P = 0.886). However, the frequencies of adverse effects were significantly higher in patients treated with 10 day bismuth quadruple therapy than those treated with 14 day sequential therapy (74.4% versus 36.7% P < 0.0001). The eradication rate of 14 day sequential therapy in strains with and without 23S ribosomal RNA mutation was 80% (24 of 30) and 99% (193 of 195), respectively (P < 0.0001). Optimized 14 day sequential therapy was non-inferior to, but better tolerated than 10 day bismuth quadruple therapy and both may be used in first-line treatment in populations with low to intermediate clarithromycin resistance.

Tin-silver-bismuth solders for electronics assembly

DOEpatents

Vianco, Paul T.; Rejent, Jerome A.

1995-01-01

A lead-free solder alloy for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

Tin-silver-bismuth solders for electronics assembly

DOEpatents

Vianco, P.T.; Rejent, J.A.

1995-08-08

A lead-free solder alloy is disclosed for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

Burnout current density of bismuth nanowires

NASA Astrophysics Data System (ADS)

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

2008-05-01

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

Electromagnetic Pumps for Liquid Metal-Fed Electric Thrusters

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Markusic, Thomas E.

2007-01-01

Prototype designs of two separate pumps for use in electric propulsion systems with liquid lithium and bismuth propellants are presented. Both pumps are required to operate at elevated temperatures, and the lithium pump must additionally withstand the corrosive nature of the propellant. Compatibility of the pump materials and seals with lithium and bismuth were demonstrated through proof-of-concept experiments followed by post-experiment visual inspections. The pressure rise produced by the bismuth pump was found to be linear with input current and ranged from 0-9 kPa for corresponding input current levels of 0-30 A, showing good quantitative agreement with theoretical analysis.

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

NASA Astrophysics Data System (ADS)

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).

Solid-state reaction synthesis for mixed-phase Eu3+-doped bismuth molybdate and its luminescence properties

NASA Astrophysics Data System (ADS)

Liang, Danyang; Ding, Yu; Wang, Nan; Cai, Xiaomeng; Li, Jia; Han, Linyu; Wang, Shiqi; Han, Yuanyuan; Jia, Guang; Wang, Liyong

2017-09-01

A method for mixed-phase bismuth molybdate doped with Eu3+ ions was developed by solid-state reaction assisting with polyvinyl alcohol (PVA). The results of powder X-ray diffraction showed a mixed-phase structure and the microscopical characterization technology revealed the formation process with the addition of PVA. As a structure inducer, the PVA molecules played a vital role in the formation of phase structure. The as-obtained Eu3+-doped bismuth molybdates were also characterized by using different spectroscopic techniques including FTIR and photoluminescence (PL). The results show that doping concentration, PVA addition and calcination temperature affect photoluminescence properties remarkably.

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2013 CFR

2013-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1); (ii) For coloring externally applied cosmetics, only those diluents listed in § 73.1001(b) and, in...

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2012 CFR

2012-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1); (ii) For coloring externally applied cosmetics, only those diluents listed in § 73.1001(b) and, in...

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2014 CFR

2014-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1); (ii) For coloring externally applied cosmetics, only those diluents listed in § 73.1001(b) and, in...

Bismuth-based oxide semiconductors: Mild synthesis and practical applications

NASA Astrophysics Data System (ADS)

Timmaji, Hari Krishna

In this dissertation study, bismuth based oxide semiconductors were prepared using 'mild' synthesis techniques---electrodeposition and solution combustion synthesis. Potential environmental remediation and solar energy applications of the prepared oxides were evaluated. Bismuth vanadate (BiVO4) was prepared by electrodeposition and solution combustion synthesis. A two step electrosynthesis strategy was developed and demonstrated for the first time. In the first step, a Bi film was first electrodeposited on a Pt substrate from an acidic BiCl3 medium. Then, this film was anodically stripped in a medium containing hydrolyzed vanadium precursor, to generate Bi3+, and subsequent BiVO4 formation by in situ precipitation. The photoelectrochemical data were consistent with the in situ formation of n-type semiconductor films. In the solution combustion synthesis procedure, BiVO4 powders were prepared using bismuth nitrate pentahydrate as the bismuth precursor and either vanadium chloride or vanadium oxysulfate as the vanadium precursor. Urea, glycine, or citric acid was used as the fuel. The effect of the vanadium precursor on the photocatalytic activity of combustion synthesized BiVO 4 was evaluated in this study. Methyl orange was used as a probe to test the photocatalytic attributes of the combustion synthesized (CS) samples, and benchmarked against a commercial bismuth vanadate sample. The CS samples showed superior activity to the commercial benchmark sample, and samples derived from vanadium chloride were superior to vanadium oxysulfate counterparts. The photoelectrochemical properties of the various CS samples were also studied and these samples were shown to be useful both for environmental photocatalytic remediation and water photooxidation applications. Silver bismuth tungstate (AgBiW2O8) nanoparticles were prepared for the first time by solution combustion synthesis by using silver nitrate, bismuth nitrate, sodium tungstate as precursors for Ag, Bi, and W respectively and urea as the fuel. The photocatalytic activity of these nanoparticles was superior to a sample prepared by solid-state synthesis. The combustion-synthesized particles were subsequently modified with Pt catalyst islands using a photodeposition technique and then used for the photo-generation of syngas (CO + H2). Formic acid was used in these experiments for in situ generation of CO2 and its subsequent reduction to CO. In the absence of Pt modification, H2 was not obtained. These results were compared with those obtained with acetic acid in place of formic acid, and finally the mechanistic pathways for syngas and methane photogeneration are presented.

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

NASA Technical Reports Server (NTRS)

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 much as to cause cracks in the body or cause the bond between parts to delaminate. Those parts that will carry the current pulse must be electrically conductive while the sensor body must be an electrical insulator. Generally, the material choices as well as the sensor design must aid to preserve the integrity of the thermal feature to obtain accurate measurements. The present aim is to also incorporate, into the sensor body, an active heating arrangement based on ceramic heater technology similar to that used in semiconductor manufacturing.

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

PubMed Central

Li, Xiaoqiang

2018-01-01

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. PMID:29675118

Dietary intake of barium, bismuth, chromium, lithium, and strontium in a Spanish population (Canary Islands, Spain).

PubMed

González-Weller, Dailos; Rubio, Carmen; Gutiérrez, Ángel José; González, Gara Luis; Caballero Mesa, José María; Revert Gironés, Consuelo; Burgos Ojeda, Antonio; Hardisson, Arturo

2013-12-01

The aim of this study was to analyze barium, bismuth, chromium, lithium, and strontium contents in food and beverages consumed by the population of the Canary Islands (Spain) as well as determine dietary intake of these metals in the archipelago as a whole and in its individual islands. To this end, 440 samples were analyzed by ICP-OES and GFAAS. Barium concentrations ranged from 5.210 ± 2.117 mg/kg in nuts to 0.035 ± 0.043 mg/L in water. Viscera exhibited the highest levels of bismuth (38.07 ± 36.80 mg/kg). The cold meat and sausages group stood out for its high chromium concentrations (0.494 ± 0.257 mg/kg). The highest concentration of lithium and strontium came out in nuts (8.761 ± 5.368 mg/kg and 9.759 ± 5.181 mg/kg, respectively). The total intakes of barium, bismuth, chromium, lithium, and strontium were 0.685, 1.274, 0.087, 3.674, and 1.923 mg/day, respectively. Cereals turned out to contribute most to the dietary intake of barium, bismuth, chromium, and lithium in the Canary Islands, while fruit contributes most to the strontium intake. We also performed a metal intake study by age and sex of the population and compared the outcome with data from other regions, both national and international.

Sensitive voltammetric determination of lead released from ceramic dishes by using of bismuth nanostructures anchored on biochar.

PubMed

Agustini, Deonir; Mangrich, Antonio Salvio; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2015-09-01

A simple and sensitive electroanalytical method was developed for determination of nanomolar levels of Pb(II) based on the voltammetric stripping response at a carbon paste electrode modified with biochar (a special charcoal) and bismuth nanostructures (nBi-BchCPE). The proposed methodology was based on spontaneous interactions between the highly functionalized biochar surface and Pb(II) ions followed by reduction of these ions into bismuth nanodots which promote an improvement on the stripping anodic current. The experimental procedure could be summarized in three steps: including an open circuit pre-concentration, reduction of accumulated lead ions at the electrode surface and stripping step under differential pulse voltammetric conditions (DPAdSV). SEM images revealed dimensions of bismuth nanodots ranging from 20 nm to 70 nm. The effects of main parameters related to biochar, bismuth and operational parameters were examined in detail. Under the optimal conditions, the proposed sensor has exhibited linear range from 5.0 to 1000 nmol L(-1) and detection limit of 1.41 nmol L(-1) for Pb(II). The optimized method was successfully applied for determination of Pb(II) released from overglaze-decorated ceramic dishes. Results obtained were compared with those given by inductively coupled plasma optical emission spectroscopy (ICP-OES) and they are in agreement at 99% of confidence level. Copyright © 2015. Published by Elsevier B.V.

Valley polarization in bismuth

NASA Astrophysics Data System (ADS)

Fauque, Benoit

2013-03-01

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

Halloysite nanotubes as a solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction for the determination of bismuth in water samples using high-resolution continuum source graphite-furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Krawczyk-Coda, Magdalena

2017-03-01

In this research, a simple, accurate, and inexpensive preconcentration procedure was developed for the determination of bismuth in water samples, using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS). During the preconcentration step, halloysite nanotubes (HNTs) were used as a solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction (USA DMSPE). The influence of the pH of the sample solution, amount of HNTs, and extraction time, as well as of the main parameters of HR CS GFAAS, on absorbance was investigated. The limit of detection was 0.005 μg L- 1. The preconcentration factor achieved for bismuth was 32. The relative standard deviation (RSD) was 4%. The accuracy of this method was validated by analyses of NIST SRM 1643e (Trace elements in water) and TMDA-54.5 (A high level fortified sample for trace elements) certified reference materials. The measured bismuth contents in these certified reference materials were in satisfactory agreement with the certified values according to the t-test for a 95% confidence level. The proposed method has been successfully applied to the determination of bismuth in five different real water samples (seawater, lake water, river water, stream water and rain water).

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

PubMed

Wang, Bin; Qu, Shengguan; Li, Xiaoqiang

2018-01-01

The in-house developed bismuthate glass and the SiC p /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 SiC p /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 SiC p /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 SiC p /Al composite with relatively low CTE value was favorable to obtain a bonding interface with high strength.

Effect of bismuth subcitrate and sucralfate on rat duodenal and human gastric bicarbonate secretion in vivo.

PubMed Central

Shorrock, C J; Garner, A; Hunter, A H; Crampton, J R; Rees, W D

1990-01-01

Acid and alkali secretion have been examined together with prostaglandin E2 production in response to two mucosal protective drugs, colloidal bismuth subcitrate and sucralfate. Doses of colloidal bismuth subcitrate in the therapeutic range (120 and 1200 mg) had no effect on alkali secretion or luminal PGE2 output when perfused into the stomach of human volunteers. Similarly, in the anaesthetised rat, neither gastric acid nor duodenal alkali secretions were influenced by iv (12 mg/kg) or topical (120 mg/ml) administration of colloidal bismuth subcitrate. In contrast, perfusion of the human stomach with 1 g sucralfate stimulated bicarbonate output by 50%, a response which was unaffected by indomethacin (25 mg/h). A rise of 64% in gastric PGE2 output after sucralfate was, however, prevented by indomethacin pretreatment. Alkali secretion by rat duodenum was also increased by sucralfate but the response depended on the basal secretory rate. Low basal secretors (less than 3 mumol) showed a 75% stimulation whereas rats with high basal secretory rates (greater than 3 mumol) showed no significant response. All duodenal preparations regardless of basal secretory rate showed a stimulation of bicarbonate output with topical PGE2. The results suggest that enhancement of gastroduodenal bicarbonate secretion may play a role in the protective action of sucralfate but is unlikely to explain mucosal protection by colloidal bismuth subcitrate. PMID:2318428

Third order nonlinear optical properties of bismuth zinc borate glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shanmugavelu, B.; Ravi Kanth Kumar, V. V., E-mail: ravi.phy@pondiuni.edu.in; Kuladeep, R.

2013-12-28

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

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Bismuth oxychloride. 73.2162 Section 73.2162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF... subpart as safe in color additive mixtures for coloring externally applied drugs. (b) Specifications. The...

Ultrathin Lutetium Oxide Film as an Epitaxial Hole-Blocking Layer for Crystalline Bismuth Vanadate Water Splitting Photoanodes

DOE PAGES

Zhang, Wenrui; Yan, Danhua; Tong, Xiao; ...

2018-01-08

Here a novel ultrathin lutetium oxide (Lu 2O 3) interlayer is integrated with crystalline bismuth vanadate (BiVO4) thin film photoanodes to facilitate carrier transport through atomic-scale interface control. The epitaxial Lu 2O 32O 3

Stabilized Alkali-Metal Ultraviolet-Band-Pass Filters

NASA Technical Reports Server (NTRS)

Mardesich, Nick; Fraschetti, George A.; Mccann, Timothy; Mayall, Sherwood D.; Dunn, Donald E.; Trauger, John T.

1995-01-01

Layers of bismuth 5 to 10 angstrom thick incorporated into alkali-metal ultraviolet-band-pass optical filters by use of advanced fabrication techniques. In new filters layer of bismuth helps to reduce surface migration of sodium. Sodium layer made more stable and decreased tendency to form pinholes by migration.

Bismuth pyrochlore-based thin films for dielectric energy storage

NASA Astrophysics Data System (ADS)

Michael, Elizabeth K.

The drive towards the miniaturization of electronic devices has created a need for dielectric materials with large energy storage densities. These materials, which are used in capacitors, are a critical component in many electrical systems. Here, the development of dielectric energy storage materials for pulsed power applications, which require materials with the ability to accumulate a large amount of energy and then deliver it to the system rapidly, is explored. The amount of electrostatic energy that can be stored by a material is a function of the induced polarization and the dielectric breakdown strength of the material. An ideal energy storage dielectric would possess a high relative permittivity, high dielectric breakdown strength, and low loss tangent under high applied electric fields. The bismuth pyrochlores are a compositionally tunable family of materials that meet these requirements. Thin films of cubic pyrochlore bismuth zinc niobate, bismuth zinc tantalate, and bismuth zinc niobate tantalate, were fabricated using a novel solution chemistry based upon the Pechini method. This solution preparation is advantageous because it avoids the use of teratogenic solvents, such as 2-methoxyethanol. Crystalline films fabricated using this solution chemistry had very small grains that were approximately 27 nm in lateral size and 35 nm through the film thickness. Impedance measurements found that the resistivity of the grain boundaries was two orders of magnitude higher than the resistivity of the grain interior. The presence of many resistive grain boundaries impeded conduction through the films, resulting in high breakdown strengths for these materials. In addition to high breakdown strengths, this family of materials exhibited moderate relative permittivities of 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. 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/cm3. Intermediate compositions of bismuth zinc niobate tantalate were explored to maximize the energy storage density of the substitutional solid solution. At an optimized concentration of ten mole percent tantalum, the maximum recoverable 10 kHz energy storage density was ˜66.9 +/- 2.4 J/cm3. These films of bismuth zinc niobate tantalate (Bi1.5Zn0.9Nb1.35Ta0.15O 6.9) sustained a maximum field of 5.5 MV/cm at 10 kHz, and demonstrated a relative permittivity of 122 +/- 4. The films maintained a high energy storage density above 20 J/cm3 though temperatures of 200°C. The second major objective of this work was to integrate complex oxides processed at temperatures below 350°C onto flexible polyimide substrates for potential use in flexible energy storage applications. Nanocomposite films consisting of a nanocrystalline fluorite related to delta-bismuth oxide in an amorphous matrix were prepared by reducing the citric acid concentration of the precursor solution, relative to the crystalline films. These solutions were batched with the composition Bi1.5Zn0.9Nb 1.35Ta0.15O6.9. The nanocomposite had a relative permittivity of 50 +/- 2 and dielectric losses on the order of 0.03 +/- 0.01. For measurement frequencies of 1 kHz and 10 kHz, the nanocomposite demonstrated a breakdown strength of 3.8 MV/cm, and a room-temperature energy storage density of approximately 40.2 +/- 1.7 J/cm3. To determine the suitability of the nanocomposite films for use in flexible applications, free-standing flexible nanocomposite films underwent repetitive compressive and tensile bending around a minimum bend diameter of 7 mm, which corresponded to a strain of 0.10%. After bending the films 30,000 times, the energy storage density of the films was unchanged, indicating that nanocomposite bismuth zinc niobate tantalate films may be suitable for flexible energy storage applications. To demonstrate the broader applicability of the nanocomposite approach to developing energy storage dielectrics at low processing temperatures, films of nanocomposite lead titanate, Pb1.1TiO3.1, were deposited using an inverted mixing order solution preparation, and annealed at a maximum temperature of 400°C. X-ray diffraction indicated the presence of nanocrystalline ordering, and transmission electron microscopy confirmed the nucleation of isolated nanocrystals of lead oxide in an amorphous lead titanate matrix. (Abstract shortened by UMI.).

Lithium Borides - High Energy Materials

DTIC Science & Technology

2000-02-28

1993. 99, 7983. (32) Pulay P.; Hamilton. T. P. J. Chem. Phys. 1988, 88. 4926 . (33) Frisch. M. J.: Trucks. G. W.; Schlegel. H. B.: Gill, P. M. W...25] P.V. Sudhakar, K. Lammertsma, J. Chem. Phys. 99 (1993) 7929. [26] M.J. van der Woerd, K. Lammertsma, B.J. Duke, H.F. Schaefer , III, J

Grain Refinement and Texture Mitigation in Low Boron Containing TiAl-Alloys

NASA Astrophysics Data System (ADS)

Hecht, Ulrike; Witusiewicz, Victor T.

2017-12-01

Controlling the grain size and texture of lamellar TiAl-alloys is essential for well-balanced creep and fatigue properties. Excellent refinement and texture mitigation are achieved in aluminum lean alloys by low boron additions of 0.2 at.%. This amount is sufficient to promote in situ formation of ultrafine borides during the last stages of body centered cubic (BCC) solidification. The borides subsequently serve as nucleation sites for hexagonal close packed (HCP) during the BCC-HCP phase transformation. Bridgman solidification experiments with alloy Ti-43Al-8Nb-0.2C-0.2B were performed under a different growth velocity, i.e., cooling rate, to evaluate the HCP grain size distribution and texture. For slow-to-moderate cooling rates, about 65% of HCP grains are randomly oriented, despite the pronounced texture of the parent BCC phase resulting from directional solidification. For high cooling rates, obtained by quenching, texture mitigation is less pronounced. Only 28% of the HCP grains are randomly oriented, the majority being crystallographic variants of the Burgers orientation relationship.

An XPS study of the adherence of refractory carbide, silicide, and boride RF-sputtered wear-resistant coatings. [X-ray Photoelectron Spectroscopy of steel surfaces

NASA Technical Reports Server (NTRS)

Brainard, W. A.; Wheeler, D. R.

1978-01-01

Radio frequency sputtering was used to deposit refractory carbide, silicide, and boride coatings on 440-C steel substrates. Both sputter etched and pre-oxidized substrates were used and the films were deposited with and without a substrate bias. The composition of the coatings was determined as a function of depth by X-ray photoelectron spectroscopy combined with argon ion etching. Friction and wear tests were conducted to evaluate coating adherence. In the interfacial region there was evidence that bias may produce a graded interface for some compounds. Biasing, while generally improving bulk film stoichiometry, can adversely affect adherence by removing interfacial oxide layers. Oxides of all film constituents except carbon and iron were present in all cases but the iron oxide coverage was only complete on the preoxidized substrates. The film and iron oxides were mixed in the MoSi2 and Mo2C films but layered in the Mo2B5 films. In the case of mixed oxides, preoxidation enhanced film adherence. In the layered case it did not.

Boronization and Carburization of Superplastic Stainless Steel and Titanium-Based Alloys

PubMed Central

Matsushita, Masafumi

2011-01-01

Bronization and carburization of fine-grain superplastic stainless steel is reviewed, and new experimental results for fine grain Ti88.5Al4.5V3Fe2Mo2 are reported. In superplastic duplex stainless steel, the diffusion of carbon and boron is faster than in non-superplastic duplex stainless steel. Further, diffusion is activated by uniaxial compressive stress. Moreover, non-superplastic duplex stainless steel shows typical grain boundary diffusion; however, inner grain diffusion is confirmed in superplastic stainless steel. The presence of Fe and Cr carbides or borides is confirmed by X-ray diffraction, which indicates that the diffused carbon and boron react with the Fe and Cr in superplastic stainless steel. The Vickers hardness of the carburized and boronized layers is similar to that achieved with other surface treatments such as electro-deposition. Diffusion of boron into the superplastic Ti88.5Al4.5V3Fe2Mo2 alloy was investigated. The hardness of the surface exposed to boron powder can be increased by annealing above the superplastic temperature. However, the Vickers hardness is lower than that of Ti boride. PMID:28824144

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

DOEpatents

Krumhansl, James L; Nenoff, Tina M

2013-02-26

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

Electrolytic Polishing and Etching Techniques for Preparing Specimens of Bismuth and Antimony and Their Alloys: Materials and Structures.

DTIC Science & Technology

Electrolytic polishing was performed in a solution of methyl alcohol, sulphuric acid , hydrocloric acid and ethylene glycol. Etching was done...electrolytically in a 5 percent chromic acid solution. Use of these techniques has permitted detailed studies of the microstructures of bismuth-antimony single

Bismuth(III) trifluoromethanesulfonate catalyzed ring opening reaction of mono epoxy oleochemicals to form keto and diketo derivatives

USDA-ARS?s Scientific Manuscript database

Using a catalytic system, methyl oleate is transformed into long chain keto and diketo derivatives via an epoxide route. Methyl 9(10)-oxooctadecanoate and methyl 9,10-dioxooctadecanoate were made by a ring opening reaction of epoxidized methyl oleate using bismuth triflate catalyst. Lower reaction t...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

SEPARATION OF FISSION PRODUCT VALUES FROM THE HEXAVALENT PLUTONIUM BY CARRIER PRECIPITATION

DOEpatents

Davies, T.H.

1959-12-15

An improved precipitation of fission products on bismuth phosphate from an aqueous mineral acid solution also containing hexavalent plutonium by incorporating, prior to bismuth phosphate precipitation, from 0.05 to 2.5 grams/ liter of zirconium phosphate, niobium oxide. and/or lanthanum fluoride is described. The plutonium remains in solution.

The effects of EF-Ts and bismuth on EF-Tu in Helicobacter pylori: implications for an elegant timing for the introduction of EF-Ts in the elongation and EF-Tu as a potential drug target.

PubMed

Wang, Dongxian; Luo, Benping; Shan, Weiran; Hao, Mingcong; Sun, Xuesong; Ge, Ruiguang

2013-06-01

Helicobacter pylori is a common human pathogen responsible for various gastric diseases. Bismuth can effectively inhibit the growth of this bacterium and is commonly recommended for the treatment of the related diseases. Translation elongation factors EF-Tu and EF-Ts are two important components of the protein translation system. EF-Ts has inhibitory effects on the GTPase activity of EF-Tu and enhances GDP release, a hint that careful timing for the introduction of EF-Ts in the elongation should be accomplished to prevent the complete inhibition of the elongation process. Bismuth inhibits the chaperone activity of EF-Tu, and has opposite effects on the elongation activity: inhibitory effects on the intrinsic GTPase activity and stimulation of GDP release. The present work deepens our understanding of the bacterial elongation process as mediated by EF-Tu and EF-Ts and extends our knowledge about the inhibitory effects of bismuth-based drugs against Helicobacter pylori.

Oxide layer stability in lead-bismuth at high temperature

NASA Astrophysics Data System (ADS)

Martín, F. J.; Soler, L.; Hernández, F.; Gómez-Briceño, D.

2004-11-01

Materials protection by 'in situ' oxidation has been studied in stagnant lead-bismuth, with different oxygen levels (H 2/H 2O ratios of 0.3 and 0.03), at temperatures from 535 °C to 600 °C and times from 100 to 3000 h. The materials tested were the martensitic steels F82Hmod, EM10 and T91 and the austenitic stainless steels, AISI 316L and AISI 304L. The results obtained point to the existence of an apparent threshold temperature above which corrosion occurs and the formation of a protective and stable oxide layer is not possible. This threshold temperature depends on material composition, oxygen concentration in the liquid lead-bismuth and time. The threshold temperature is higher for the austenitic steels, especially for the AISI 304L, and it increases with the oxygen concentration in the lead-bismuth. The oxide layer formed disappear with time and, after 3000 h all the materials, except AISI 304L, suffer corrosion, more severe for the martensitic steels and at the highest temperature tested.

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

NASA Astrophysics Data System (ADS)

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.

Electromagnetic Pumps for Conductive-Propellant Feed Systems

NASA Technical Reports Server (NTRS)

Markusic, Thomas E.; Polzin, Kurt A.; Dehoyos, Amado

2005-01-01

Prototype electromagnetic pumps for use with lithium and bismuth propellants were constructed and tested. Such pumps may be used to pressurize future electric propulsion liquid metal feed systems, with the primary advantages being the compactness and simplicity versus alternative pressurization technologies. Design details for two different pumps are described: the first was designed to withstand (highly corrosive) lithium propellant, and t he second was designed to tolerate the high temperature required to pump liquid bismuth. Both qualitative and quantitative test results are presented. Open-loop tests demonstrated the capability of each device to electromagnetically pump its design propellant (lithium or bismuth). A second set of tests accurately quantified the pump pressure developed as a function of current. These experiments, which utilized a more easily handled material (gallium), demonstrated continuously-adjustable pump pressure levels ranging from 0-100 Torr for corresponding input current levels of 0-75 A. While the analysis and testing in this study specifically targeted lithium and bismuth propellants, the underlying design principles should be useful in implementing liquid metal pumps in any conductive-propellant feed system.

ANION EXCHANGE METHOD FOR SEPARATION OF METAL VALUES

DOEpatents

Hyde, E.K.; Raby, B.A.

1959-02-10

A method is described for selectively separating radium, bismuth, poloniums and lead values from a metallic mixture of thc same. The mixture is dissolved in aqueous hydrochloric acid and the acidity is adjusted to between 1 to 2M in hydrochloric acid to form the anionic polychloro complexes of polonium and bismuth. The solution is contacted with a first anion exchange resin such as strong base quaternary ammonia type to selectively absorb the polonium and bismuth leaving the radium and lead in the effluent. The effluent, after treatment in hydrochloric acid to increase the hydrochloric acid concentration to 6M is contacted with a second anion exchange iesin of the same type as the above to selectively adsorb the lead leaving the radium in the effluent. Radium is separately recovered from the effluent from the second exchange column. Lead is stripped from the loaded resin of the second column by treatment with 3M hydrochloric acid solution. The loaded resin of the first column is washed with 8M hydrochloric acid solution to recover bismuth and then treated with strong nitric acid solution to recover polonium.

Atomic Layer Deposition of Bismuth Vanadates for Solar Energy Materials.

PubMed

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.

Time-resolved spectroscopy and optical gain of silica-based fibers co-doped with Bi, Al and/or Ge, P, and Ti

NASA Astrophysics Data System (ADS)

Firstov, S. V.; Bufetov, I. A.; Khopin, V. F.; Umnikov, A. A.; Guryanov, A. N.; Dianov, E. M.

2009-04-01

The optical properties of optical fibers based on silica glass doped with bismuth and co-doped with aluminum oxides and/or germanium, phosphorus, and titanium oxides are studied. The optical loss and luminescence spectra of optical fibers substantially depend on the core composition. The gain spectra of single-mode optical fibers are measured in the IR range. It is demonstrated that the phosphorus-germanium-silicate optical fiber doped with bismuth exhibits a broad gain band (1270-1520 nm) when pumped at a wavelength of 1230 nm. It is also shown that the bismuth-aluminosilicate optical fibers additionally doped with Ge or Ti at about 1 at % have the gain spectra that are significantly narrower than the IR luminescence spectra (in contrast to the fibers that do not contain Ge and Ti). The intensity decay curves of the IR luminescence in such fibers indicate the presence of both short-lived (with the lifetime τ≤4 μs) and long-lived (τ ˜ 1 ms) energy levels in the bismuth active centers.

Bismuth Oxysulfide and Its Polymer Nanocomposites for Efficient Purification

PubMed Central

Luo, Yidong; Qiao, Lina; Wang, Huanchun; Lan, Shun; Shen, Yang; Lin, Yuanhua; Nan, Cewen

2018-01-01

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 VBi‴VO••VBi‴. 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. PMID:29562701

Synthesis and Characterisation of Reduced Graphene Oxide/Bismuth Composite for Electrodes in Electrochemical Energy Storage Devices.

PubMed

Wang, Jiabin; Zhang, Han; Hunt, Michael R C; Charles, Alasdair; Tang, Jie; Bretcanu, Oana; Walker, David; Hassan, Khalil T; Sun, Yige; Šiller, Lidija

2017-01-20

A reduced graphene oxide/bismuth (rGO/Bi) composite was synthesized for the first time using a polyol process at a low reaction temperature and with a short reaction time (60 °C and 3 hours, respectively). The as-prepared sample is structured with 20-50 nm diameter bismuth particles distributed on the rGO sheets. The rGO/Bi composite displays a combination of capacitive and battery-like charge storage, achieving a specific capacity value of 773 C g -1 at a current density of 0.2 A g -1 when charged to 1 V. The material not only has good power density but also shows moderate stability in cycling tests with current densities as high as 5 A g -1 . The relatively high abundance and low price of bismuth make this rGO/Bi material a promising candidate for use in electrode materials in future energy storage devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Light-Induced Surface Reactions at the Bismuth Vanadate/Potassium Phosphate Interface.

PubMed

Favaro, Marco; Abdi, Fatwa F; Lamers, Marlene; Crumlin, Ethan J; Liu, Zhi; van de Krol, Roel; Starr, David E

2018-01-18

Bismuth vanadate has recently drawn significant research attention as a light-absorbing photoanode due to its performance for photoelectrochemical water splitting. In this study, we use in situ ambient pressure X-ray photoelectron spectroscopy with "tender" X-rays (4.0 keV) to investigate a polycrystalline bismuth vanadate (BiVO 4 ) electrode in contact with an aqueous potassium phosphate (KPi) solution at open circuit potential under both dark and light conditions. This is facilitated by the creation of a 25 to 30 nm thick electrolyte layer using the "dip-and-pull" method. We observe that under illumination bismuth phosphate forms on the BiVO 4 surface leading to an increase of the surface negative charge. The bismuth phosphate layer may act to passivate surface states observed in photoelectrochemical measurements. The repulsive interaction between the negatively charged surface under illumination and the phosphate ions in solution causes a shift in the distribution of ions in the thin aqueous electrolyte film, which is observed as an increase in their photoelectron signals. Interestingly, we find that such changes at the BiVO 4 /KPi electrolyte interface are reversible upon returning to dark conditions. By measuring the oxygen 1s photoelectron peak intensities from the phosphate ions and liquid water as a function of time under dark and light conditions, we determine the time scales for the forward and reverse reactions. Our results provide direct evidence for light-induced chemical modification of the BiVO 4 /KPi electrolyte interface.

An evaluation of in-plane shields during thoracic CT.

PubMed

Foley, S J; McEntee, M F; Rainford, L A

2013-08-01

The object of this study was to compare organ dose and image quality effects of using bismuth and barium vinyl in-plane shields with standard and low tube current thoracic CT protocols. A RANDO phantom was scanned using a 64-slice CT scanner and three different thoracic protocols. Thermoluminescent dosemeters were positioned in six locations to record surface and absorbed breast and lung doses. Image quality was assessed quantitatively using region of interest measurements. Scanning was repeated using bismuth and barium vinyl in-plane shields to cover the breasts and the results were compared with standard and reduced dose protocols. Dose reductions were most evident in the breast, skin and anterior lung when shielding was used, with mean reductions of 34, 33 and 10 % for bismuth and 23, 18 and 11 % for barium, respectively. Bismuth was associated with significant increases in both noise and CT attenuation values for all the three protocols, especially anteriorly and centrally. Barium shielding had a reduced impact on image quality. Reducing the overall tube current reduced doses in all the locations by 20-27 % with similar increases in noise as shielding, without impacting on attenuation values. Reducing the overall tube current best optimises dose with minimal image quality impact. In-plane shields increase noise and attenuation values, while reducing anterior organ doses primarily. Shielding remains a useful optimisation tool in CT and barium is an effective alternative to bismuth especially when image quality is of concern.

Overcoming Limitations in Semiconductor Alloy Design

NASA Astrophysics Data System (ADS)

Christian, Theresa Marie

Inorganic semiconductors provide an astonishingly versatile, robust, and efficient platform for optoelectronic energy conversion devices. However, conventional alloys and growth regimes face materials challenges that restrict the full potential of these devices. Novel alloy designs based on isoelectronic co-doping, metamorphic growth and controllable atomic ordering offer new pathways to practical and ultra-high-efficiency optoelectronic devices including solar cells and light-emitting diodes. Abnormal isoelectronic alloys of GaP1-xBix, GaP 1-x-yBixNy, and GaAs1-xBix with unprecedented bismuth incorporation fractions and crystalline quality are explored in this thesis research. Comparative studies of several GaP1-xBix and GaP1-x-yBixNy alloys demonstrate that the site-specific incorporation of bismuth during epitaxial growth is sensitive to growth temperature and has dramatic effects on carrier transfer processes in these alloys. Additionally, distinctive bismuth-related localized states are spectrally identified for the first time in samples of GaAs1-xBix grown by laser-assisted epitaxial growth. These results address fundamental questions about the nature of bismuth-bismuth inter-impurity interactions. Finally, a metamorphic growth strategy for a novel light-emitting diode (LED) design is also discussed. This work utilized direct-bandgap AlxIn1-xP active layers with atomic ordering-based electron confinement to improve emission in the yellow and green spectral regions, where incumbent technologies are least effective, and demonstrated the feasibility of non-lattice-matched LED active materials for visible light emission.

Two basic bismuth nitrates: [Bi6O6(OH)2](NO3)4 · 2H2O with superior photodegradation activity for rhodamine B and [Bi6O5(OH)3](NO3)5 · 3H2O with ultrahigh adsorption capacity for methyl orange

NASA Astrophysics Data System (ADS)

Pang, Jiawei; Han, Qiaofeng; Liu, Weiqi; Shen, Zichen; Wang, Xin; Zhu, Junwu

2017-11-01

A novel basic bismuth nitrate, [Bi6O6(OH)2](NO3)4·2H2O (denoted as BiON-4N), was easily obtained at room temperature in the existence of 2-methoxyethanol (CH3OCH2CH2OH; 2ME) with a pH value ranging from 4.5 to 7.0. The morphology of BiON-4N could be easily tailored by changing the variety and amount of bases like urea, hexamethylenetetramine (HMTA), NaOH and NH3·H2O. When the solution pH was decreased lower than 4.5, another basic bismuth nitrate, [Bi6O5(OH)3](NO3)5·3H2O (denoted as BiON-5N), could be synthesized. Among those, BiON-4N nanoparticles obtained with 40 mmol of HMTA exhibited superior photocatalytic activity for rhodamine B (RhB) degradation with an efficiency of 100% within 4 min of UV light irradiation, which was much higher than that of commercial TiO2 (P25). The excellent photocatalytic performance of BiON-4N was mainly attributed to higher surface area (13.1 m2 g-1) in comparison with other basic bismuth nitrates. Furthermore, the as-prepared BiON-5N revealed excellent adsorption performance for the anions like methyl orange (MO) and K2Cr2O7, and especially for MO, the maximum adsorption capacity arrived up to 730 mg g-1, which should be relevant to highly positively charged surface. This work provides a new strategy for developing bismuth-based nanomaterials in the big bismuth family as potential photocatalyst and adsorbent for the removal of dyes and contaminants.

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

PubMed Central

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

2006-01-01

AIM: To evaluate the bioequivalence of ranitidine and bismuth derived from two compound preparations. METHODS: The bioavailability was measured in 20 healthy male Chinese volunteers following a single oral dose (equivalent to 200 mg of ranitidine and 220 mg of bismuth) of the test or reference products in the fasting state. Then blood samples were collected for 24 h. Plasma concentrations of ranitidine and bismuth were analyzed by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax, AUC(0-t) and AUC(0-infinity) were tested for bioequivalence using ANOVA and Schuirmann two-one sided t-test. Tmax was analyzed by Wilcoxon’s test. RESULTS: Various pharmacokinetic parameters of ranitidine derived from the two compound preparations, including Cmax, AUC(0-t), AUC(0-infinity), Tmax and T1/2, were nearly consistent with previous observations. These parameters derived from test and reference drug were as follows: Cmax (0.67 ± 0.21 vs 0.68 ± 0.22 mg/L), AUC(0-t) (3.1 ± 0.6 vs 3.0 ± 0.7 mg/L per hour), AUC(0-infinity) (3.3 ± 0.6 vs 3.2 ± 0.8 mg/L per hour), Tmax (2.3 ± 0.9 vs 2.1 ± 0.9 h) and T1/2 (2.8 ± 0.3 vs 3.1 ± 0.4 h). In addition, double-peak absorption profiles of ranitidine were found in some Chinese volunteers. For bismuth, those parameters derived from test and reference drug were as follows: Cmax (11.80 ± 7.36 vs 11.40 ± 6.55 μg/L), AUC(0-t) (46.65 ± 16.97 vs 47.03 ± 21.49 μg/L per hour), Tmax (0.50 ± 0.20 vs 0.50 ± 0.20 h) and T1/2 (10.2 ± 2.3 vs 13.0 ± 6.9 h). Ninety percent of confidence intervals for the test/reference ratio of Cmax, AUC(0-t) and AUC(0-infinity) derived from both ranitidine and bismuth were found within the bioequivalence acceptable range of 80%-125%. No significant difference was found in Tmax derived from both ranitidine and bismuth. CONCLUSION: The two compound preparations are bioequivalent and may be prescribed interchangeably. PMID:16718762

Pt-B System Revisited: Pt2B, a New Structure Type of Binary Borides. Ternary WAl12-Type Derivative Borides.

PubMed

Sologub, Oksana; Salamakha, Leonid; Rogl, Peter; Stöger, Berthold; Bauer, Ernst; Bernardi, Johannes; Giester, Gerald; Waas, Monika; Svagera, Robert

2015-11-16

On the basis of a detailed study applying X-ray single-crystal and powder diffraction, differential scanning calorimetry, and scanning electron microscopy analysis, it was possible to resolve existing uncertainties in the Pt-rich section (≥65 atom % Pt) of the binary Pt-B phase diagram above 600 °C. The formation of a unique structure has been observed for Pt2B [X-ray single-crystal data: space group C2/m, a = 1.62717(11) nm, b = 0.32788(2) nm, c = 0.44200(3) nm, β = 104.401(4)°, RF2 = 0.030]. Within the homogeneity range of "Pt3B", X-ray powder diffraction phase analysis prompted two structural modifications as a function of temperature. The crystal structure of "hT-Pt3B" complies with the hitherto reported structure of anti-MoS2 [space group P63/mmc, a = 0.279377(2) nm, c = 1.04895(1) nm, RF = 0.075, RI = 0.090]. The structure of the new "[Formula: see text]T-Pt3B" is still unknown. The formation of previously reported Pt∼4B has not been confirmed from binary samples. Exploration of the Pt-rich section of the Pt-Cu-B system at 600 °C revealed a new ternary compound, Pt12CuB6-y [X-ray single-crystal data: space group Im3̅, a = 0.75790(2) nm, y = 3, RF2 = 0.0129], which exhibits the filled WAl12-type structure accommodating boron in the interstitial trigonal-prismatic site 12e. The isotypic platinum-aluminum-boride was synthesized and studied. The solubility of copper in binary platinum borides has been found to attain ∼7 atom % Cu for Pt2B but to be insignificant for "[Formula: see text]T-Pt3B". The architecture of the new Pt2B structure combines puckered layers of boron-filled and empty [Pt6] octahedra (anti-CaCl2-type fragment) alternating along the x axis with a double layer of boron-semifilled [Pt6] trigonal prisms interbedded with a layer of empty tetrahedra and tetragonal pyramids (B-deficient α-T[Formula: see text]I fragment). Assuming boron vacancies ordering (space group R3), the Pt12CuB6-y structure exhibits serpentine-like columns of edge-connected boron-filled [Pt6] trigonal prisms running infinitely along the z axis and embedding the icosahedrally coordinated Cu atom. Pt2B, (Pt1-yCuy)2B (y = 0.045), and Pt12CuB6-y (y = 3) behave metallically, as revealed by temperature-dependent electrical resistivity measurements.

Investigation of crystal growth in zero gravity environment and investigation of metallic whiskers

NASA Technical Reports Server (NTRS)

Davis, J. H.; Lal, R. B.; Walter, H. U.; Castle, J. G., Jr.

1972-01-01

Theoretical and experimental work reported relates to the effects of near-zero gravity on growths of crystals and metallic whiskers during Skylab and Apollo flight experiments. Studies on growth and characterization of candidate materials for flight experiments cover indium-bismuth compounds, bismuth single crystals, gallium arsenide films and single crystals, and cadmium whiskers.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krumhansl, James L; Nenoff, Tina M

2015-01-06

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

Bismuth Titanate Fabricated by Spray-on Deposition and Microwave Sintering For High-Temperature Ultrasonic Transducers.

PubMed

Searfass, Clifford T; Pheil, C; Sinding, K; Tittmann, B R; Baba, A; Agrawal, D K

2016-01-01

Thick films of ferroelectric bismuth titanate (Bi4Ti3O12) have been fabricated by spray-on deposition in conjunction with microwave sintering for use as high-temperature ultrasonic transducers. The elastic modulus, density, permittivity, and conductivity of the films were characterized. Electro-mechanical properties of the films were estimated with a commercial d33 meter which gave 16 pC/N. This value is higher than typically reported for bulk bismuth titanate; however, these films withstand higher field strengths during poling which is correlated with higher d33 values. Films were capable of operating at 650 °C for roughly 5 min before depoling and can operate at 600 °C for at least 7 days.

Effect of Immersion Time on Corrosion Behavior of Single-Phase Alloy and Nanocomposite Bismuth Telluride-Based Thermoelectrics in NaCl Solution

NASA Astrophysics Data System (ADS)

Keshavarz, Mohsen K.; Fattah-Alhosseini, Arash

2018-05-01

The corrosiveness of bismuth telluride-based thermoelectric materials (n-type single-phase alloy and a nanocomposite with MoS2 nanoinclusions), in 0.1 molar solution of sodium chloride (NaCl), was investigated. The electrochemical impedance spectroscopy curves obtained after 1, 24, 48 and 72 h immersion time revealed the enhancement of the corrosion resistance of the nanocomposite specimen in a 0.1 molar NaCl solution in comparison with the single-phase bismuth telluride-based alloys, and the passivity increased by immersion time up to 72 h. The nanocomposite sample with submicron grains provided suitable nucleation sites for passive film nucleation that led to higher protective behavior.

Fast oxygen diffusion in bismuth oxide probed by quasielastic neutron scattering

DOE PAGES

Mamontov, Eugene

2016-09-24

In this paper, we present the first, to our knowledge, study of solid state oxygen translational diffusion by quasielastic neutron scattering. Such studies in the past might have been precluded by relatively low diffusivities of oxygen anions in the temperature range amenable to neutron scattering experiments. To explore the potential of the quasielastic scattering technique, which can deduce atomic diffusion jump length of oxygen anions through the momentum transfer dependence of the scattering signal, we have selected the fastest known oxygen conductor, bismuth oxide. Finally, we have found the oxygen anion jump length in excellent agreement with the nearest oxygen-vacancymore » distance in the anion sublattice of the fluorite-related structure of bismuth oxide.« less

Study of iron structure stability in high temperature molten lead-bismuth eutectic with oxygen injection using molecular dynamics simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arkundato, Artoto; Su'ud, Zaki; Sudarko

2014-09-30

Corrosion of structural materials in high temperature molten lead-bismuth eutectic is a major problem for design of PbBi cooled reactor. One technique to inhibit corrosion process is to inject oxygen into coolant. In this paper we study and focus on a way of inhibiting the corrosion of iron using molecular dynamics method. For the simulation results we concluded that effective corrosion inhibition of iron may be achieved by injection 0.0532 wt% to 0.1156 wt% oxygen into liquid lead-bismuth. At this oxygen concentration the structure of iron material will be maintained at about 70% in bcc crystal structure during interaction withmore » liquid metal.« less

Bismuth Infusion of ABS Enables Additive Manufacturing of Complex Radiological Phantoms and Shielding Equipment.

PubMed

Ceh, Justin; Youd, Tom; Mastrovich, Zach; Peterson, Cody; Khan, Sarah; Sasser, Todd A; Sander, Ian M; Doney, Justin; Turner, Clark; Leevy, W Matthew

2017-02-24

Radiopacity is a critical property of materials that are used for a range of radiological applications, including the development of phantom devices that emulate the radiodensity of native tissues and the production of protective equipment for personnel handling radioactive materials. Three-dimensional (3D) printing is a fabrication platform that is well suited to creating complex anatomical replicas or custom labware to accomplish these radiological purposes. We created and tested multiple ABS (Acrylonitrile butadiene styrene) filaments infused with varied concentrations of bismuth (1.2-2.7 g/cm³), a radiopaque metal that is compatible with plastic infusion, to address the poor gamma radiation attenuation of many mainstream 3D printing materials. X-ray computed tomography (CT) experiments of these filaments indicated that a density of 1.2 g/cm³ of bismuth-infused ABS emulates bone radiopacity during X-ray CT imaging on preclinical and clinical scanners. ABS-bismuth filaments along with ABS were 3D printed to create an embedded human nasocranial anatomical phantom that mimicked radiological properties of native bone and soft tissue. Increasing the bismuth content in the filaments to 2.7 g/cm³ created a stable material that could attenuate 50% of 99m Technetium gamma emission when printed with a 2.0 mm wall thickness. A shielded test tube rack was printed to attenuate source radiation as a protective measure for lab personnel. We demonstrated the utility of novel filaments to serve multiple radiological purposes, including the creation of anthropomorphic phantoms and safety labware, by tuning the level of radiation attenuation through material customization.

[The high fermentative capacity of colonic bacteria in the origin of flatulence and its sensibility to bismuth subsalicylate].

PubMed

León-Barúa, Raúl; Alvarez De Roig, Maritza; Roig-Arosemena, Javier; Berendson-Seminario, Roberto; Torres-Zevallos, Hernando

2007-01-01

Using a previously described technique, "in vitro" determinations were carried out for faecal fermentation (FF): basal faecal fermentation (BFF), i.e, only with faeces, with faeces and lactulose (LFF) and with faeces, lactulose and bismuth subsalicylate (BiLFF) in 34 patients with flatulence. The media+d.s. of the difference between the LFFand BFF levels (LFF-BFF) in patients with flatulence was significant and markedly higher than the respective media +d.s. in 30 normal control patients previously studied (9.1+4.7 vs. 3.9+3.2 ml gas/24 hrs; p<0.000001 respectively). And, although FF was reduced by adding bismuth salicylate in only 24% (70.6%) of the patients with flatulence but not in the remaining 10 (29.4%), in total the media+d.s. of the differences between the levels BiLFF and BFF (BiLFFBFF) was significantly lower that the media+d.s. of the differences between the LFF and BFF levels (LFF-BFF) (6.0+4.2 vs 9.1+4.7 ml gas/24 hrs; p<0.01 respectively). These results confirm that: 1) The fermentative capacity of the colonic bacteriae is most likely to be abnormally intense in peoples with flatulence and 2) Bismuth subsalicylate can be useful in the control of excessive colonic fermentation and flatulence; they raise, furthermore, the interesting possibility that we may have found the way to predict when the use of bismuth subsalicylate could be effective in the treatment of a patient with flatulence.

Modulation of magnetic interaction in Bismuth ferrite through strain and spin cycloid engineering

NASA Astrophysics Data System (ADS)

Yadav, Rama Shanker; Reshi, Hilal Ahmad; Pillai, Shreeja; Rana, D. S.; Shelke, Vilas

2016-12-01

Bismuth ferrite, a widely studied room temperature multiferroic, provides new horizons of multifunctional behavior in phase transited bulk and thin film forms. Bismuth ferrite thin films were deposited on lattice mismatched LaAlO3 substrate using pulsed laser deposition technique. X-ray diffraction confirmed nearly tetragonal (T-type) phase of thin film involving role of substrate induced strain. The film thickness of 56 nm was determined by X-ray reflectivity measurement. The perfect coherence and epitaxial nature of T- type film was observed through reciprocal space mapping. The room temperature Raman measurement of T-type bismuth ferrite thin film also verified phase transition with appearance of only few modes. In parallel, concomitant La and Al substituted Bi1-xLaxFe0.95Al0.05O3 (x = 0.1, 0.2, 0.3) bulk samples were synthesized using solid state reaction method. A structural phase transition into orthorhombic (Pnma) phase at x = 0.3 was observed. The structural distortion at x = 0.1, 0.2 and phase transition at x = 0.3 substituted samples were also confirmed by changes in Raman active modes. The remnant magnetization moment of 0.199 emu/gm and 0.28 emu/gm were observed for x = 0.2 and 0.3 bulk sample respectively. The T-type bismuth ferrite thin film also showed high remnant magnetization of around 20emu/cc. The parallelism in magnetic behavior between T-type thin film and concomitant La and Al substituted bulk samples is indication of modulation, frustration and break in continuity of spiral spin cycloid.

"Chemical contraction" in rubidium-bismuth melts

NASA Astrophysics Data System (ADS)

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.

THORIUM DISPERSION IN BISMUTH

DOEpatents

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.

Silver Ink For Jet Printing

NASA Technical Reports Server (NTRS)

Vest, R. W.; Singaram, Saraswathi

1989-01-01

Metallo-organic ink containing silver (with some bismuth as adhesion agent) applied to printed-circuit boards and pyrolized in air to form electrically conductive patterns. Ink contains no particles of silver, does not have to be mixed during use to maintain homogeneity, and applied to boards by ink-jet printing heads. Consists of silver neodecanoate and bismuth 2-ethylhexanoate dissolved in xylene and/or toluene.

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

DOE PAGES

Hoye, Robert L. Z.; Lee, Lana C.; Kurchin, Rachel C.; ...

2017-07-17

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. Themore » 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. In conclusion, this work demonstrates that BiOI, previously considered to be a poor photocatalyst, is promising for photovoltaics.« less

Explanation of the conductivity minimum in tin- and tellurium-doped bismuth

NASA Astrophysics Data System (ADS)

Roy, Arpita; Banerjee, Dipali; Bhattacharya, Ramendranarayan

1995-01-01

The presence of a minimum observed in the variation of conductivity of bismuth with impurity concentrations at a constant temperature (4.2 K) has remained unexplained for a long time. An attempt to explain this anomalous behavior is reported here. In order to do so, a calculation has been made to find the change in the number of free carriers in bismuth with the addition of impurities (donors or acceptors). The calculation has been made using simple parabolic bands. It is known that when tin or tellurium atoms are added as impurities to bismuth all of the atoms are ionized. It has been found here that the number of free carriers initially shows a slow rate of decrease (for donors) or a slow rate of increase (for acceptors) as the impurity concentration is increased, as long as the impurity concentration is small, i.e., as long as the shift of the Fermi level is small. For a higher impurity concentration the number of carriers increases at a rate equal to that of the impurity concentration. This finding, combined with the scattering by impurity ions, could explain the anomalous behavior satisfactorily.

Soluble Lead and Bismuth Chalcogenidometallates: Versatile Solders for Thermoelectric Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hao; Son, Jae Sung; Dolzhnikov, Dmitriy S.

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 solderedmore » 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.« less

Tin, Bismuth, and Tin-Bismuth Alloy Electrodeposition from Chlorometalate Salts in Deep Eutectic Solvents.

PubMed

Vieira, Luciana; Burt, Jennifer; Richardson, Peter W; Schloffer, Daniel; Fuchs, David; Moser, Alwin; Bartlett, Philip N; Reid, Gillian; Gollas, Bernhard

2017-06-01

The electrodeposition of tin, bismuth, and tin-bismuth alloys from Sn II and Bi III chlorometalate salts in the choline chloride/ethylene glycol (1:2 molar ratio) deep eutectic solvent was studied on glassy carbon and gold by cyclic voltammetry, rotating disc voltammetry, and chronoamperometry. The Sn II -containing electrolyte showed one voltammetric redox process corresponding to Sn II /Sn 0 . The diffusion coefficient of [SnCl 3 ] - , detected as the dominating species by Raman spectroscopy, was determined from Levich and Cottrell analyses. The Bi III -containing electrolyte showed two voltammetric reduction processes, both attributed to Bi III /Bi 0 . Dimensionless current/time transients revealed that the electrodeposition of both Sn and Bi on glassy carbon proceeded by 3D-progressive nucleation at a low overpotential and changed to instantaneous at higher overpotentials. The nucleation rate of Bi on glassy carbon was considerably smaller than that of Sn. Elemental Sn and Bi were electrodeposited on Au-coated glass slides from their respective salt solutions, as were Sn-Bi alloys from a 2:1 Sn II /Bi III solution. The biphasic Sn-Bi alloys changed from a Bi-rich composition to a Sn-rich composition by making the deposition potential more negative.

Theoretical study of bismuth-doped cadmium telluride

NASA Astrophysics Data System (ADS)

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).

Glass composite waste forms for iodine confined in bismuth-embedded SBA-15

NASA Astrophysics Data System (ADS)

Yang, Jae Hwan; Park, Hwan Seo; Ahn, Do-Hee; Yim, Man-Sung

2016-11-01

The aim of this study was to stabilize bismuth-embedded SBA-15 that captured iodine gas by fabrication of monolithic waste forms. The iodine containing waste was mixed with Bi2O3 (a stabilizing additive) and low-temperature sintering glass followed by pelletizing and the sintering process to produce glass composite materials. Iodine volatility during the sintering process was significantly affected by the ratio of Bi2O3 and the glass composition. It was confirmed that BiI3, the main iodine phase within bismuth-embedded SBA-15, was effectively transformed to the mixed phases of Bi5O7I and BiOI. The initial leaching rates of iodine from the glass composite waste forms ranged 10-3-10-2 g/m2 day, showing the stability of the iodine phases encapsulated by the glassy networks. It was also observed that common groundwater anions (e.g., chloride, carbonate, sulfite, and fluoride) elevated the iodine leaching rate by anion exchange reactions. The present results suggest that the glass composite waste form of bismuth-embedded SBA-15 could be a candidate material for stable storage of 129I.

Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials

NASA Astrophysics Data System (ADS)

Cheng, Gang; Yang, Hanmin; Rong, Kaifeng; Lu, Zhong; Yu, Xianglin; Chen, Rong

2010-08-01

Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO) 2CO 3) is one of commonly used antibacterial agents against Helicobacter pylori ( H. pylori). Different (BiO) 2CO 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) 2CO 3 nanostructures. The possible formation mechanism of different (BiO) 2CO 3 nanostructures fabricated under different conditions was also discussed.

Bismuth molybdate thick films as ethanol sensor

NASA Astrophysics Data System (ADS)

Jain, Kiran; Kumar, Vipin; Gupta, H. P.; Rastogi, A. C.

2003-10-01

Ethanol sensitivity of bismuth molybdate thick films and sintered pellets were investigated. Sintered pellets were prepared by traditional ceramic processing. Thick films were prepared by metallorganic decomposition process. Ethanol gas sensitivity was measured at various temperatures and concentrations. Thick films of alpha phase bismuth molybdate prepared by spray pyrolysis showed a very fast response to ethanol detection. The response time for the bulk samples is about 40 sec which decreased to about 6 sec for thick films at an operating temperature of 300°C. An extremely low level approximately 10 ppm detection and fast response makes this technique ideal for sensor element fabrication for detection and estimation of alcohol in breath-analyzer. Unlike SnO2, the resistance of these sensors is not affected by humidity at the operating temperature.

Role of Bismuth in the Electrokinetics of Silicon Photocathodes for Solar Rechargeable Vanadium Redox Flow Batteries.

PubMed

Flox, Cristina; Murcia-López, Sebastián; Carretero, Nina M; Ros, Carles; Morante, Juan R; Andreu, Teresa

2018-01-10

The ability of crystalline silicon to photoassist the V 3+ /V 2+ cathodic reaction under simulated solar irradiation, combined with the effect of bismuth have led to important electrochemical improvements. Besides the photovoltage supplied by the photovoltaics, additional decrease in the onset potentials, high reversibility of the V 3+ /V 2+ redox pair, and improvement in the electrokinetics were attained thanks to the addition of bismuth. In fact, Bi 0 deposition has shown to slightly decrease the photocurrent, but the significant enhancement in the charge transfer, reflected in the overall electrochemical performance clearly justifies its use as additive in a photoassisted system for maximizing the efficiency of solar charge to battery. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxygen content and Tc of Ba 0.6K 0.4BiO 3-δ

NASA Astrophysics Data System (ADS)

Idemoto, Yasushi; Iwata, Yoshiki; Fueki, Kazuo

1992-10-01

The single phase of Ba 1- xK xBiO 3-δ with x=0.316∼0.514 was prepared by adding an excess amount of KO 2 to the starting materials and by washing the products with ethanol. In the case of Ba 0.6K 0.4BiO 3-δ, superconductivity appeared when the bismuth valence was higher than +4.2 and the highest Tc was attained at around a bismuth valence of +4.3. Tc decreased with the increase in bismuth valence above +4.3. A high temperature X-ray diffraction study revealed that the lattice constant increases by the thermal expansion below 400°C but the increase becomes remarkable above 400°C owing to evaporation of potassium and deoxygenation.

Structural and optical characterization of bismuth sulphide nanorods

NASA Astrophysics Data System (ADS)

Shah, N. M.; Poria, K. C.

2017-05-01

In this work Bismuth sulfide (Bi2S3) nanorods with a high order of crystallinity is synthesized via hydrothermal method from aqueous solution of Bismuth Nitrate Pentahydrate and elemental Sulphur using Triethanolamine (TEA) as capping agent. The microstructures of Bi2S3 nanorods were investigated by X-ray diffraction (XRD) analysis. The positions and relative intensities of all the peaks in XRD pattern are in good agreement with those of the orthorhombic crystal structure of Bi2S3. TEM images shows that synthesized Bi2S3 has morphology of nanorods while selected area electron diffraction pattern indicates single crystalline nature. The analysis of diffuse reflectance (DR) spectrum of as synthesized Bi2S3 using Kubelka - Munk theory suggests direct energy band gap of 1.5 eV.

Formation and possible growth mechanism of bismuth nanowires on various substrates

NASA Astrophysics Data System (ADS)

Volkov, V. T.; Kasumov, A. Yu.; Kasumov, Yu. A.; Khodos, I. I.

2017-08-01

In this work, we report results of a study of bismuth nanowires growth on various substrates, including Fe, Ni, Co, W, Pt, Au thin films on oxidized Si, Si (111), oxidized Si (100), and fused quartz. The nanowires (NW) were prepared by RF diode sputtering of Bi onto a substrate heated to about 200 °C. The structure of the wires was studied by a scanning and transmission electron microscopy. The NWs are monocrystalline up to a length of several micrometers and possess a very thin (less than 2 nm) oxide layer. A major influence of the substrate type on the quantity and the length of the obtained nanowires is observed. Based on the above studies, we propose a possible mechanism of a bismuth nanowire growth.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.

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

PREFACE: The 16th International Symposium on Boron, Borides and Related Materials (ISBB 2008)

NASA Astrophysics Data System (ADS)

Tanaka, Takaho

2009-07-01

This volume of Journal of Physics: Conference Series contains invited and contributed peer-reviewed papers that were presented at the 16th International Symposium on Boron, Borides and Related Materials (ISBB 2008), which was held on 7-12 September 2008, at Kunibiki Messe, Matsue, Japan. This triennial symposium has a half-century long history starting from the 1st meeting in 1959 at Asbury Park, New Jersey. We were very pleased to organize ISBB 2008, which gathered chemists, physicists, materials scientists as well as diamond and high-pressure researchers. This meeting had a strong background in the boron-related Japanese research history, which includes the discovery of superconductivity in MgB2 and development of Nd-Fe-B hard magnets and of YB66 soft X-ray monochromator. The scope of ISBB 2008 spans both basic and applied interdisciplinary research that is centered on boron, borides and related materials, and the collection of articles defines the state of the art in research on these materials. The topics are centered on: 1. Preparation of new materials (single crystals, thin films, nanostructures, ceramics, etc) under normal or extreme conditions. 2. Crystal structure and chemical bonding (new crystal structures, nonstoichiometry, defects, clusters, quantum-chemical calculations). 3. Physical and chemical properties (band structure, phonon spectra, superconductivity; optical, electrical, magnetic, emissive, mechanical properties; phase diagrams, thermodynamics, catalytic activity, etc) in a wide range of temperatures and pressures. 4. Applications and prospects (thermoelectric converters, composites, ceramics, coatings, etc) There were a few discoveries of new materials, such as nanomaterials, and developments in applications. Many contributions were related to 4f heavy Fermion systems of rare-earth borides. Exotic mechanisms of magnetism and Kondo effects have been discussed, which may indicate another direction of development of boride. Two special sessions, 'Boron chemistry' and 'Superconductivity', were also held at the symposium. The session on Boron chemistry was planned to honor the scientific work in boron chemistry of Professor J Bauer on the occasion of his retirement. Many recent results were discussed in the session, and Professor Bauer himself introduced novel rare-earth-boron-carbon compounds RE10B7C10 (RE = Gd - Er) in his lecture. In the latter session, on the basis of recent discoveries of superconductivity in MgB2 and in β-boron under high pressure, the superconductivity of boron and related materials was discussed and the superconductivity of boron-doped diamond was also addressed. More than 120 participants from 16 countries attended the ISBB 2008, and active presentations (22 invited, 33 oral and 68 posters) and discussions suggest that research on boron and borides is entering a new phase of development. This volume contains 46 articles from 52 submitted manuscripts. The reviewers were invited not only from symposium participants but also from specialists worldwide, and they did a great job of evaluating and commenting on the submitted manuscripts to maintain the highest quality standard of this volume. Recent discoveries of superconductivity in boron under high pressure, synthesis of a new allotrope of boron and of various boron and boride nanostructures will lead this highly interdisciplinary field of science, which will further grow and gain attention in terms of both basic and applied research. In this context, we are very much looking forward to the next symposium, which will be held in Istanbul, Turkey, in 2011, organized by Professor Onuralp Yucel, Istanbul Technical University. Turkey currently has the world highest share of borate production and is expected to be involved more in boron-related research. Acknowledgements We gratefully acknowledge the style improvement by Dr K Iakoubovskii, and sincerely thank Shimane Prefecture and Matsue City for their financial support. The symposium was also supported by Tokyo University of Science, Suwa and foundations including, the Kajima Foundation, Foundation for Promotion of Material Science and Technology of Japan and Nippon Sheet Glass Foundation for Materials Science and Engineering, as well as companies including JFE Steel Corporation, Shincron Co, Ltd, Toyo Kohan Co, Ltd, Fukuda Metal Foil and Powder Co, Ltd, Japan New Metals Co, Ltd, H C Starck Ltd and Fritsch Japan Co, Ltd. Editors Chair Takaho Tanaka (National Institute for Materials Science, Japan) Vice chairs Koun Shirai (Osaka University, Japan) Kaoru Kimura (The University of Tokyo, Japan) Ken-ichi Takagi (Tokyo City University, Japan) Touetsu Shishido (Tohoku University, Japan) Shigeru Okada (Kokushikan University) Hideaki Itoh (Nagoya University,Japan) Katsumitsu Nakamura (Nihon University, Japan) Organizing committee of ISBB 2008 K Takagi Chairman (Tokyo City University) T Tanaka Program Committee Chairman (National Institute for Materials Science) K Kimura Secretary (The University of Tokyo) J Akimitsu (Aoyama University)K Shirai (Osaka University) H Itoh (Nagoya University)T Shishido (Tohoku University) K Nakamura (Nihon University)K Soga (Tokyo University of Science) K Nishiyama (Tokyo University of Science, Suwa)M Takeda (Nagaoka University of Technology) S Okada (Kokushikan University)Y Yamazaki (Toyo Kohan Co, Ltd) International Scientific Committee 0f ISBB (2008-2011) K Takagi Chairman (Japan) B Albert (Germany) J-F Halet (France) M Takeda (Japan) M Antadze (Georgia) H Hillebrecht (Germany) T Tanaka (Japan) J Bauer (France) W Jung (Germany) R Telle (Germany) I Boustani (Germany) K Kimura (Japan) M Trenary (USA) D Emin (USA) T Mori (Japan) O Tsagareishvili (Georgia) M Engler (Germany) P D Ownby (USA) H Werheit (Germany) N Frage (Israel) P Rogl (Austria) G Will (Germany) Yu Grin (Germany) S Shalamberidze (Georgia) O Yucel (Turkey) V N Gurin (Russia) N Shitsevalova (Ukraine) G Zhang (China)

Thermal emission property of solid solution Gd{sub 1-x}Nd{sub x}B{sub 6} (x=0, 0.6, 0.8)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xing Zhang, Jiu; Hong Bao, Li; Lin Zhou, Shen, E-mail: zjiuxing@bjut.edu.cn, E-mail: Baolihong_10@yahoo.com.cn, E-mail: zhoushenlin@emails.bjut.edu.cn

2011-07-01

In this paper, to further explore the excellent emission properties of rare earth boride cathode, herein we present the synthesis, characterization and properties of polycrystalline Nd{sub 1-x}Gd{sub x}B{sub 6} (x = 0, 0.6, 0.8) bulk via arc plasma and reactive SPS. (author)

Process research into metallic pipe wear of hot chamber die casting machines and methods ofincreasing wear resistance

NASA Astrophysics Data System (ADS)

Mukhametzyanova, G. F.; Kolesnikov, MS; Mukhametzyanov, I. R.; Astatshenko, V. I.

2017-09-01

The kinetics and reasons for metallic pipe wear of hot chamberzinc alloy die casting machines are established.Increasing metallic pipe wear components wear resistance is being achieved by means of die steelДИ - 22 with electroslag remelting modification and electron-beamremelting modification and after the processes of nitriding and boriding besides.

Nb2OsB2, with a new twofold superstructure of the U3Si2 type: Synthesis, crystal chemistry and chemical bonding

NASA Astrophysics Data System (ADS)

Mbarki, Mohammed; Touzani, Rachid St.; Fokwa, Boniface P. T.

2013-07-01

The new ternary metal-rich boride, Nb2OsB2, was synthesized by arc-melting the elements in a water-cooled copper crucible under an argon atmosphere. The compound was characterized from single-crystal X-ray data and EDX measurements. It crystallizes as a new superstructure (space group P4/mnc, no. 128) of the tetragonal U3Si2-structure type with lattice parameters a=5.922(1) Å and c=6.879(2) Å. All of the B atoms are involved in B2 dumbbells with B-B distances of 1.89(4) Å. Structure relaxation using VASP (Vienna ab intio Simulation Package) has confirmed the space group and the lattice parameters. According to electronic structure calculations (TB-LMTO-ASA), the homoatomic B-B interactions are optimized and very strong, but relatively strong heteroatomic Os-B, Nb-B and Nb-Os bonds are also found: These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of this new phase. The density of state at the Fermi level predicts metallic behavior, as expected, from this metal-rich boride.

The use of surface layer with boron in friction pairs lubricated by engine oils

NASA Astrophysics Data System (ADS)

Szczypiński-Sala, W.; Lubas, J.

2016-09-01

The aim of the present work is to determine the influence of surface layers with boron and engine oil on the processes of friction and wear in friction pairs. The ring samples with borided surface layer cooperated under test conditions with counterparts made with CuPb30 and AlSn20 bearing alloys. During the tests, the friction pairs were lubricated with 15W/40 Lotos mineral oil and 5W/40 Lotos synthetic oil. The lubrication of friction area with Lotos mineral oil causes the reduction of the friction force, the temperature in the friction area and the wear of the bearing alloys under study, whereas the lubrication with Lotos synthetic oil reduces the changes in the geometrical structure of the cooperating friction pair elements. Lubrication of the friction area in the start-up phase of the friction pair by mineral oil causes faster stabilization of the friction conditions in the contact area than in the cause of lubrication of the friction pair by synthetic oil. The intensity of wear of the AlSn20 bearing alloy cooperating with the borided surface layer is three times smaller than the intensity of use of the CuPb30 alloy bearing.

Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Crx(Rh1-yRuy)7-xB3 (x=0.88-1; y=0-1) with Th7Fe3-type structure

NASA Astrophysics Data System (ADS)

Misse, Patrick R. N.; Mbarki, Mohammed; Fokwa, Boniface P. T.

2012-08-01

Powder samples and single crystals of the new complex boride series Crx(Rh1-yRuy)7-xB3 (x=0.88-1; y=0-1) have been synthesized by arc-melting the elements under purified argon atmosphere on a water-cooled copper crucible. The products, which have metallic luster, were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX measurements. Within the whole solid solution range the hexagonal Th7Fe3 structure type (space group P63mc, no. 186, Z=2) was identified. Single-crystal structure refinement results indicate the presence of chromium at two sites (6c and 2b) of the available three metal Wyckoff sites, with a pronounced preference for the 6c site. An unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors in the solid solution: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region.

On the transferability of electron density in binary vanadium borides VB, V3B4 and VB2.

PubMed

Terlan, Bürgehan; Akselrud, Lev; Baranov, Alexey I; Borrmann, Horst; Grin, Yuri

2015-12-01

Binary vanadium borides are suitable model systems for a systematic analysis of the transferability concept in intermetallic compounds due to chemical intergrowth in their crystal structures. In order to underline this structural relationship, topological properties of the electron density in VB, V3B4 and VB2 reconstructed from high-resolution single-crystal X-ray diffraction data as well as derived from quantum chemical calculations, are analysed in terms of Bader's Quantum Theory of Atoms in Molecules [Bader (1990). Atoms in Molecules: A Quantum Theory, 1st ed. Oxford: Clarendon Press]. The compounds VB, V3B4 and VB2 are characterized by a charge transfer from the metal to boron together with two predominant atomic interactions, the shared covalent B-B interactions and the polar covalent B-M interactions. The resembling features of the crystal structures are well reflected by the respective B-B interatomic distances as well as by ρ(r) values at the B-B bond critical points. The latter decrease with an increase in the corresponding interatomic distances. The B-B bonds show transferable electron density properties at bond critical points depending on the respective bond distances.

High effective atomic number polymer scintillators for gamma ray spectroscopy

DOEpatents

Cherepy, Nerine Jane; Sanner, Robert Dean; Payne, Stephen Anthony; Rupert, Benjamin Lee; Sturm, Benjamin Walter

2014-04-15

A scintillator material according to one embodiment includes a bismuth-loaded aromatic polymer having an energy resolution at 662 keV of less than about 10%. A scintillator material according to another embodiment includes a bismuth-loaded aromatic polymer having a fluor incorporated therewith and an energy resolution at 662 keV of less than about 10%. Additional systems and methods are also presented.

REMOVAL OF CERTAIN FISSION PRODUCT METALS FROM LIQUID BISMUTH COMPOSITIONS

DOEpatents

Dwyer, O.E.; Howe, H.E.; Avrutik, E.R.

1959-11-24

A method is described for purifying a solution of urarium in liquid bismuth containing at least one metal from the group consisting of selenium, tellurium, palladium, ruthenium, rhodium, niobium, and zirconium. The solution is contacted with zinc in an inert atmosphere to form a homogeneous melt, a solid zinc phase is formed, and the zinc phase containing the metal is separated from the melt.

[Quadruple regimens using domestically manufactured drugs in gastritis and duodenal ulcer patients for Helicobacter pylori eradication: a perspective, multicenter, randomized controlled trial].

PubMed

Gao, Wen; Hu, Fulian; Cheng, Hong; Wang, Huahong; Yang, Yunsheng; Liang, Hao; Zhang, Shutian; Meng, Fandong; Cui, Meihua; Wei, Hong; Sheng, Jianqiu; An, Hejuan J; Jiang, Bo; Chen, Ye; Li, Yanqing; Zuo, Xiuli; Gong, Jun; Zhao, Ping; Dong, Lei; Wang, Bangmao; Jiang, Kai; Zhang, Guiying; Li, Jiansheng; Zhao, Ye; Gao, Hengjun; Yang, Li

2016-01-26

To observe the effects and safety of quadruple regimens including domestically manufactured rabeprazole used as first line/initial therapy for Helicobacter pylori(H.pylori) eradication in gastritis and duodenal ulcer patients, and to investigate the effects of extended use of bismuth after the quadruple therapy on eradication of H. pylori. From January to August 2013, 430 patients with chronic gastritis or duodenal ulcer who were confirmed as H. pylori positive in gastroscopy for upper gastrointestinal symptoms were enrolled from 12 centers in China for initial treatment using quadruple regimens for H. pylori eradication. The study was a prospective, multicenter, randomized double-blinded double-dummy parallel-controlled clinical trial. The 310 chronic gastritis patients were divided into 2 groups: group A1 was given quadruple regime (rabeprazole+ amoxicillin+ clarithromycin+ bismuth potassium citrate) for 10 days followed by bismuth-placebo for 21 days; group A2 was given the quadruple regimen for 10 days and then bismuth potassium citrate for 21 days. The duodenal ulcer patients were given the quadruple for 10 days, then rabeprazole for 14 days. All the patients took (13)C urea breath test to detect H. pylori 28 days after medicine withdrawal. Altogether 428 cases were enrolled and 404 completed the trial. The total eradication rate in the chronic gastritis patients was 85.1% (262/308, intention-to-treat (ITT)analysis), which was 81.7% (125/153, ITT) in the A1 group and 88.4% (137/155, ITT) in the A2 group; the eradication rate in the duodenal ulcer patients was 85.8% (103/120, ITT). No severe adverse effects were reported. The symptoms (pain, burning sensation, reflux, belching, nausea, and vomiting) improvement status was similar among A1 and A2 groups. The quadruple regimen using rabeprazole manufactured in China and administered for 10 days as first line/initial therapy in chronic gastritis and duodenal ulcer patients could achieve good H. pylori eradication rate. The extended use of bismuth after 10-day quadruple regimen might further improve the eradication rate. The regimens containing proton-pump inhibitor and bismuth may be well tolerated and safe in clinical application.

Advantages of Moxifloxacin and Levofloxacin-based triple therapy for second-line treatments of persistent Helicobacter pylori infection: a meta analysis.

PubMed

Li, Yuqin; Huang, Xiayue; Yao, Linhua; Shi, Ruihua; Zhang, Guoxin

2010-07-01

The main aim of this meta-analysis was to compare the efficacy and safety of clarithromycin and second-generation fluoroquinolone-based triple therapy vs. bismuth-based quadruple therapy for the treatment of persistent Helicobacter pylori infection. A systematic literature search was conducted for articles and abstracts from 1981 to March 2009 using Medline, PubMed, EMBase, Google Scholar and CNKI (Chinese), Wanfang (Chinese) digital database and recent Digestive Disease Week, United European Gastroenterology Week, and European Helicobacter Study Group conferences were also performed. Boolean operators (NOT, AND, OR) were used in succession to narrow and widen the search. Sixteen articles and four abstracts met the inclusion criteria, and were included in the meta-analysis by using Review Manager 4.2.8. The eradication rates demonstrated that clarithromycin-based triple therapy is inferior to bismuth-based quadruple therapy (OR = 0.53, 95% CI: 0.35-0.80, P = 0.002). Thirteen RCTs compared levofloxacin-based triple therapy vs. bismuth-based quadruple therapy, the eradication rates of the two regimens were shown to have no significant difference (OR = 1.43, 95% CI: 0.82-2.51, P = 0.21). But the eradication rates demonstrated superiority of the 10-day levofloxacin-based triple therapy over 7-day bismuth-based quadruple therapy (OR = 4.79, 95% CI: 2.95-7.79, P < 0.00001). Levofloxacin-based triple therapy was better tolerated than bismuth-based quadruple therapy with lower rates of side effects (OR = 0.41, 95% CI: 0.27-0.61, P < 0.0001), and lower rates of discontinuation of therapy due to adverse events (OR = 0.13, 95% CI: 0.06-0.33, P < 0.0001). Furthermore, our meta-analysis suggested that the eradication rates of the moxifloxacin-based triple therapy has a slight superiority to bismuth-based quadruple therapy, but there was no significant difference between them. Second-generation fluoroquinolone-based triple therapy can be suggested as the regimen of choice for rescue therapy in the eradication of persistent H. pylori infection especially 10-day levofloxacin-based triple therapy.

Shielding properties of lead-free protective clothing and their impact on radiation doses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlattl, Helmut; Zankl, Maria; Eder, Heinrich

2007-11-15

The shielding properties of two different lead-free materials--tin and a compound of 80% tin and 20% bismuth--for protective clothing are compared with those of lead for three typical x-ray spectra generated at tube voltages of 60, 75, and 120 kV. Three different quantities were used to compare the shielding capability of the different materials: (1) Air-kerma attenuation factors in narrow-beam geometry, (2) air-kerma attenuation factors in broad-beam geometry, and (3) ratios of organ and effective doses in the human body for a whole-body irradiation with a parallel beam directed frontally at the body. The thicknesses of tin (0.45 mm) andmore » the tin/bismuth compound (0.41 mm) to be compared against lead correspond to a lead equivalence value of 0.35 mm for the 75 kV spectrum. The narrow-beam attenuation factors for 0.45 mm tin are 54% and 32% lower than those for 0.35 mm lead for 60 and 120 kV; those for 0.41 mm tin/bismuth are 12% and 32% lower, respectively. The decrease of the broad-beam air-kerma attenuation factors compared to lead is 74%, 46%, and 41% for tin and 42%, 26%, and 33% for tin/bismuth and the spectra at 60, 75, and 120 kV, respectively. Therefore, it is recommended that the characterization of the shielding potential of a material should be done by measurements in broad-beam geometry. Since the secondary radiation that is mainly responsible for the shielding reduction in broad-beam geometry is of low penetrability, only more superficially located organs receive significantly enhanced doses. The increase for the dose to the glandular breast tissue (female) compared to being shielded by lead is 143%, 37%, and 45% when shielded by tin, and 35%, 15%, and 39% when shielded by tin/bismuth for 60, 75, and 120 kV, respectively. The effective dose rises by 60%, 6%, and 38% for tin, and 14%, 3% and, 35% for tin/bismuth shielding, respectively.« less

Bismuth Propellant Feed System Development at NASA-MSFC

NASA Technical Reports Server (NTRS)

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 more detailed flow sensor calibration will be performed to accurately quantify the flow monitoring capabilities. This effort is funded under a Technology Innovation Program (TIP) award from NASA-MSFC's Technology Transfer office and performed under SAA8-061060.

[Protective effect of compound bismuth and magnesium granules on aspirin-induced gastric mucosal injury in rats].

PubMed

Mu, F H; Hu, F L; Wei, H; Zhang, Y Y; Yang, G B; Lei, X Y; Yang, Y P; Sun, W N; Cui, M H

2016-02-01

To investigate the protective effect of compound bismuth and magnesium granules on aspirin-induced gastric mucosal injury in rats and its possible mechanism. Acute gastric mucosal injury model was developed with intraperitoneal injection of aspirin in Wistar rats. The rats were divided into normal control group, injury group, sucralfate protection group, compound bismuth and magnesium granules protection group and its herbal components protection group(each group 12 rats). In the protection groups, drugs as mentioned above were administered by gavage before treated with intraperitoneal injection of aspirin. To evaluate the extent of gastric mucosal injury and the protective effect of drugs, gastric mucosal lesion index, gastric mucosal blood flow, content of gastric mucosal hexosamine, prostaglandins (PG), nitric oxide(NO), tumor necrosis factor (TNF), and interleukin (IL) -1, 2, 8 were measured in each group, and histological changes were observed by gross as well as under microscope and electron microscope. Contents of hexosamine, NO, and PG in all the protection groups were significantly higher than those in the injury group (all P<0.01), and content of NO in the compound bismuth and magnesium granules group was significantly higher than that in the sucralfate group ((11.29±0.51) vs(10.80±0.36)nmol/ml, P<0.05). The gastric mucosal lesion index, contents of TNF, and IL-1, 2, 8 were significantly lower in all the protection groups than in the injury group (all P<0.01), and contents of IL-2 and IL-8 in the compound bismuth and magnesium granules group were significantly lower than those in the sucralfate group ((328.17±6.56) vs(340.23±8.05)pg/ml, P<0.01; (170.82±7.31) vs(179.31±7.80)pg/ml, P<0.05). Tissue injury and inflammatory reaction in all the protection groups were obviously mitigated compared with the injury group. Compound bismuth and magnesium granules and its herbal components may have significant protective effect on aspirin-induced gastric mucosal injury.

Second-line rescue triple therapy with levofloxacin after failure of non-bismuth quadruple "sequential" or "concomitant" treatment to eradicate H. pylori infection.

PubMed

Gisbert, Javier P; Molina-Infante, Javier; Marin, Alicia C; Vinagre, Gemma; Barrio, Jesus; McNicholl, Adrian Gerald

2013-06-01

Non-bismuth quadruple "sequential" and "concomitant" regimens, including a proton pump inhibitor (PPI), amoxicillin, clarithromycin and a nitroimidazole, are increasingly used as first-line treatments for Helicobacter pylori infection. Eradication with rescue regimens may be challenging after failure of key antibiotics such as clarithromycin and nitroimidazoles. To evaluate the efficacy and tolerability of a second-line levofloxacin-containing triple regimen (PPI-amoxicillin-levofloxacin) in the eradication of H. pylori after non-bismuth quadruple-containing treatment failure. prospective multicenter study. in whom a non-bismuth quadruple regimen, administered either sequentially (PPI + amoxicillin for 5 days followed by PPI + clarithromycin + metronidazole for 5 more days) or concomitantly (PPI + amoxicillin + clarithromycin + metronidazole for 10 days) had previously failed. levofloxacin (500 mg b.i.d.), amoxicillin (1 g b.i.d.) and PPI (standard dose b.i.d.) for 10 days. eradication was confirmed with (13)C-urea breath test 4-8 weeks after therapy. Compliance and tolerance: compliance was determined through questioning and recovery of empty medication envelopes. Incidence of adverse effects was evaluated by means of a questionnaire. 100 consecutive patients were included (mean age 50 years, 62% females, 12% peptic ulcer and 88% dyspepsia): 37 after "sequential", and 63 after "concomitant" treatment failure. All patients took all medications correctly. Overall, per-protocol and intention-to-treat H. pylori eradication rates were 75.5% (95% CI 66-85%) and 74% (65-83%). Respective intention-to-treat cure rates for "sequential" and "concomitant" failure regimens were 74.4% and 71.4%, respectively. Adverse effects were reported in six (6%) patients; all of them were mild. Ten-day levofloxacin-containing triple therapy constitutes an encouraging second-line strategy in patients with previous non-bismuth quadruple "sequential" or "concomitant" treatment failure.

Helicobacter pylori first-line and rescue treatments in the presence of penicillin allergy.

PubMed

Gisbert, Javier P; Barrio, Jesús; Modolell, Inés; Molina-Infante, Javier; Aisa, Angeles Perez; Castro-Fernández, Manuel; Rodrigo, Luis; Cosme, Angel; Gisbert, Jose Luis; Fernández-Bermejo, Miguel; Marcos, Santiago; Marín, Alicia C; McNicholl, Adrián G

2015-02-01

Helicobacter pylori eradication is a challenge in penicillin allergy. To assess the efficacy and safety of first-line and rescue treatments in patients allergic to penicillin. Prospective multicenter study. Patients allergic to penicillin were given a first-line treatment comprising (a) 7-day omeprazole-clarithromycin-metronidazole and (b) 10-day omeprazole-bismuth-tetracycline-metronidazole. Rescue treatments were as follows: (a) bismuth quadruple therapy; (b) 10-day PPI-clarithromycin-levofloxacin; and (c) 10-day PPI-clarithromycin-rifabutin. Eradication was confirmed by (13)C-urea breath test. Compliance was determined through questioning and recovery of empty medication envelopes. Adverse effects were evaluated by questionnaires. In total, 267 consecutive treatments were included. (1) First-line treatment: Per-protocol and intention-to-treat eradication rates with omeprazole-clarithromycin-metronidazole were 59 % (62/105; 95 % CI 49-62 %) and 57 % (64/112; 95 % CI 47-67 %). Respective figures for PPI-bismuth-tetracycline-metronidazole were 75 % (37/49; 95 % CI 62-89 %) and 74 % (37/50; 95 % CI (61-87 %) (p < 0.05). Compliance with treatment was 94 and 98 %, respectively. Adverse events were reported in 14 % with both regimens (all mild). (2) Second-line treatment: Intention-to-treat eradication rate with omeprazole-clarithromycin-levofloxacin was 64 % both after triple and quadruple failure; compliance was 88-100 %, with 23-29 % adverse effects (all mild). (3) Third-/fourth-line treatment: Intention-to-treat eradication rate with PPI-clarithromycin-rifabutin was 22 %. In allergic to penicillin patients, a first-line treatment with a bismuth-containing quadruple therapy (PPI-bismuth-tetracycline-metronidazole) seems to be a better option than the triple PPI-clarithromycin-metronidazole regimen. A levofloxacin-based regimen (together with a PPI and clarithromycin) represents a second-line rescue option in the presence of penicillin allergy.

Determination of silver, antimony, bismuth, copper, cadmium and indium in ores, concentrates and related materials by atomic-absorption spectrophotometry after methyl isobutyl ketone extraction as iodides.

PubMed

Donaldson, E M; Wang, M

1986-03-01

Methods for determining ~ 0.2 mug g or more of silver and cadmium, ~ 0.5 mug g or more of copper and ~ 5 mug g or more of antimony, bismuth and indium in ores, concentrates and related materials are described. After sample decomposition and recovery of antimony and bismuth retained by lead and calcium sulphates, by co-precipitation with hydrous ferric oxide at pH 6.20 +/- 0.05, iron(III) is reduced to iron(II) with ascorbic acid, and antimony, bismuth, copper, cadmium and indium are separated from the remaining matrix elements by a single methyl isobutyl ketone extraction of their iodides from ~2M sulphuric acid-0.1M potassium iodide. The extract is washed with a sulphuric acid-potassium iodide solution of the same composition to remove residual iron and co-extracted zinc, and the extracted elements are stripped from the extract with 20% v v nitric acid-20% v v hydrogen peroxide. Alternatively, after the removal of lead sulphate by filtration, silver, copper, cadmium and indium can be extracted under the same conditions and stripped with 40% v v nitric acid-25% v v hydrochloric acid. The strip solutions are treated with sulphuric and perchloric acids and ultimately evaporated to dry ness. The individual elements are determined in a 24% v v hydrochloric acid medium containing 1000 mug of potassium per ml by atomic-absorption spectrophotometry with an air-acetylene flame. Tin, arsenic and molybdenum are not co-extracted under the conditions above. Results obtained for silver, antimony, bismuth and indium in some Canadian certified reference materials by these methods are compared with those obtained earlier by previously published methods.

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

PubMed

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 (p<0.05). The results showed an increase of the pH level after 15 days, followed by a slight increase after 30 days and a decrease after 60 days. There were no significant statistical differences among the groups (p>0.05). 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). 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.

First-line treatment of Helicobacter pylori in Lebanon: Comparison of bismuth-containing quadruple therapy versus 14-days sequential therapy.

PubMed

Tarhini, Mahdi; Fayyad-Kazan, Mohammad; Fayyad-Kazan, Hussein; Mokbel, Mahmoud; Nasreddine, Mohammad; Badran, Bassam; Kchour, Ghada

2018-04-01

Helicobacter Pylori (H. Pylori) is the most common cause of peptic ulcer disease (PUD) and represents a strong risk factor for gastric cancer. Treatment of H. Pylori is, therefore, a persistent need to avoid serious medical complications. Resistance to antibiotics remains to be the major challenge for H. Pylori eradication. In this study, we determined the prevalence of H. pylori infection and evaluated H. pylori eradication efficacy of bismuth-containing quadruple therapy (Pylera) versus 14-days sequential therapy in treatment naïve-Lebanese patients. 1030 patients, showing symptoms of peptic ulcer (PU) and gastritis, underwent 14 C-Urea Breath Test and esophagogastroduodenoscopy to examine H. Pylori infection and gastrointestinal disorders. Among the H. Pylori-positive patients 60 individuals were randomly selected, separated into two groups (each consisting of 30 patients) and treated with either bismuth-containing quadruple therapy or 14-days sequential therapy. We show that of the 1050 patients tested: 46.2% were H. pylori-positive, 55% had gastritis, 46.2% had both gastritis and H. pylori infection, 8.8% had gastritis but no H. pylori infection, 44.9% had neither gastritis nor H. pylori infection. Following the 14-days sequential therapy, the eradication rate was significantly higher than that obtained upon using bismuth-containing quadruple therapy [80% (24/30) versus 50% (15/30), χ 2  = 5.93, P = 0.015]. In conclusion, we determined H. pylori and gastritis prevalence among Lebanese PU-patients and showed that 14-days sequential therapy is more efficient than bismuth-containing quadruple therapy in terms of H. Pylori-eradication. Published by Elsevier Ltd.

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

NASA Astrophysics Data System (ADS)

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.

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.

PubMed

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.

Berberine containing quadruple therapy for initial Helicobacter pylori eradication: An open-label randomized phase IV trial.

PubMed

Zhang, Di; Ke, Li; Ni, Zhen; Chen, Yu; Zhang, Lin-Hui; Zhu, Shao-Hua; Li, Chan-Juan; Shang, Lei; Liang, Jie; Shi, Yong-Quan

2017-08-01

Due to increasing antimicrobial resistance, a bismuth-based quadruple regimen has been recommended as an alternative first-line therapy for Helicobacter pylori (H pylori) eradication. However, different results are varied greatly and the availability of bismuth was limited in some countries. We assessed the efficacy and safety of 14-day berberine-containing quadruple therapy as an alternative regimen for H pylori eradication. In a randomized, open-label, non-inferiority, phase IV trial between November 25, 2014, and October 15, 2015, 612 treatment-naive patients were randomly assigned to 14-day berberine-containing (n = 308) or 14-day bismuth-containing (n = 304) quadruple therapy. The primary outcomes were eradication rates determined by the C urea breath test (C-UBT) 28 days after the end of treatment. The secondary outcomes were adverse events and compliance. The baseline demographic data including age, gender, body mass index (BMI), general condition and severity score were not statistically different in both groups. The eradication rates in bismuth and berberine groups were 86.4% (266/308) and 90.1% (274/304) in intention-to-treat (ITT) analysis (P = .149), and 89.6% (266/297) and 91.3% (273/299) in per-protocol (PP) analysis (P = .470), respectively. No statistically significant difference was found in the overall incidence of adverse events between both groups (35.7% vs 28.6%, P = .060). Both regimens achieved the recommended efficacy for H pylori eradication. The berberine-containing quadruple regimen was not inferior to bismuth-containing quadruple regimen and can be recommended as an alternative regimen for H pylori eradication in the local region.

Peculiarities of electron density distribution in bismuth chalcogenides, iron pnictides, cuprates and related unconventional superconductors

NASA Astrophysics Data System (ADS)

Orlov, V. G.; Sergeev, G. S.

2018-05-01

With the aim to reveal the origin of instabilities in the electron subsystem of unconventional superconductors, such as stripes or nematic symmetry breaking, electron band structure calculations were performed for a number of bismuth chalcogenides, bismuth oxide, iron pnictides, as well as for Bi2Sr2CaCu2O8, YBa2Cu3O7 and La2CuO4. It was found that bond critical points in the electron density distribution ρ(r) of all the studied compounds were characterized by positive sign of electron density Laplacian evidencing on depletion of electron charge from the area of bond critical points. A correlation was found between the Tc and the value of electron density Laplacian in the strongest bond critical points of superconductors and related substances.

[The direct AAS determination of micro elements in hair and nail by base-digestion].

PubMed

Ju, Hong-fang

2002-08-01

The study of micro elements is more and more extensively, and people can gain some informations by the level of micro elements in tissue. This paper tempts to dissolve hair or nail in 2 mol.L-1 NaOH and determinate nine micro elements including calcium, zinc, iron, manganese, nickel, cadmium, copper, lead and bismuth in them by base-digestion with FAAS and GFAAS. It shows that the measured value of these elements is coincident with reference articles reported, except bismuth. The elements' percent recoveries are 90.0%-110.8%. The result also shows that the level of zinc and copper in hair are higher than in nail, and the level of bismuth, cadmium and iron in hair are lower than in nail, but the level of micro elements in hair and in nail are not correlative.

Optical characteristics of bismuth sulfide (Bi2S3) thin films.

NASA Astrophysics Data System (ADS)

Mahmoud, S.; Eid, A. H.; Omar, H.

Thin films of bismuth sulfide (Bi2S3) were grown by two deposition techniques, by thermal evaporation and by chemical deposition. The thermally deposited reactions consisted in depositing the individual elements, namely bismuth and sulfur, sequentially from a tungsten boat source and allowing the layers to interdiffuse to form the compound during the heat-treatment. The chemical deposition was based on the reaction between the triethanolamine compex of Bi3+ ions and thiourea in basic media. Scanning electron microscope and X-ray diffraction analysis were made on as-deposited and on annealed films to determine their structure. The different electronic transitions and the optical constants are determined from the transmision and reflection data of these thin films for normal incidence. The optical gaps of Bi2S3 films show a remarkable dependence on the preparation method.

Evaluation of gamma-ray attenuation properties of bismuth borate glass systems using Monte Carlo method

NASA Astrophysics Data System (ADS)

Tarim, Urkiye Akar; Ozmutlu, Emin N.; Yalcin, Sezai; Gundogdu, Ozcan; Bradley, D. A.; Gurler, Orhan

2017-11-01

A Monte Carlo method was developed to investigate radiation shielding properties of bismuth borate glass. The mass attenuation coefficients and half-value layer parameters were determined for different fractional amounts of Bi2O3 in the glass samples for the 356, 662, 1173 and 1332 keV photon energies. A comparison of the theoretical and experimental attenuation coefficients is presented.

Marine Chemistry in the People’s Republic of China.

DTIC Science & Technology

1984-08-01

Eh, Fe, Al, Mn, Cu, Pb, Zn, Cd, Hg, Cr, and also the sedimentation rate by Pb- 210 method. (2) The effects of flow rate, eddy diffusion, axial length of...sediments, distribution, determination, radium-226, uranium-238, radon-222, polonium - 210 , bismuth- 210 , lead-206, particulates, adsorption, polonium ...sediments, distribution, radium-226, uranium-238, radon-222, polonium - 210 , bismuth- 210 , lead-206, particulates, adsorption, polonium , dating, Zhujiang

Synthesis & characterization of Bi7.38Ce0.62O12.3 and its optical and electrocatalytic property

NASA Astrophysics Data System (ADS)

Padmanaban, A.; Dhanasekaran, T.; Kumar, S. Praveen; Gnanamoorthy, G.; Stephen, A.; Narayanan, V.

2017-05-01

Bismuth cerium oxide was synthesized by thermal decomposition method. The material was characterized by X-ray diffraction technique, DRS UV-Vis, Raman spectral methods and FE-SEM. The electrocatalytic sensing activity of bismuth cerium oxide modified GCE toward 4-nitrophenol exhibits better activity than the bare GCE. The modified electrode shows higher anodic current response with lower potential.

Design of alumina forming FeCrAl steels for lead or lead-bismuth cooled fast reactors

NASA Astrophysics Data System (ADS)

Lim, Jun; Hwang, Il Soon; Kim, Ji Hyun

2013-10-01

Iron-chromium-aluminum alloys containing 15-20 wt.% Cr and 4-6 wt.% Al have shown excellent corrosion resistance in the temperature range up to 600 °C or higher in liquid lead and lead-bismuth eutectic environments by the formation of protective Al2O3 layers. However, the higher Cr and Al concentrations in ferritic alloys could be problematic because of severe embrittlement in the manufacturing process as well as in service, caused by the formation of brittle phases. For this reason, efforts worldwide have so far mainly focused on the development of aluminizing surface treatments. However, aluminizing surface treatments have major disadvantages of cost, processing difficulties and reliability issues. In this study, a new FeCrAl alloy is proposed for structural materials in lead and lead-bismuth cooled nuclear applications. The alloy design relied on corrosion experiments in high temperature lead and lead-bismuth eutectic environments and computational thermodynamic calculations using the commercial software, JMatPro. The design of new alloys has focused on the optimization of Cr and Al levels for the formation of an external Al2O3 layer which can provide excellent oxidation and corrosion resistance in liquid lead alloys in the temperature range 300-600 °C while still retaining workable mechanical properties.

Flow injection-hydride generation atomic absorption spectrometric determination of selenium, arsenic and bismuth.

PubMed

Zhang, Yanlin; Adeloju, Samuel B

2008-08-15

A simple and robust flow injection system which permits low sample and reagent consumption is described for rapid and reliable hydride generation atomic absorption spectrometric determination of selenium, arsenic and bismuth. The system, which composed of one peristaltic pump and one four channel solenoid valve, used water as the carrier streams for both sample and NaBH(4) solution. Rapid off-line pre-reduction of the analytes was achieved by using hydroxylamine hydrochloride for selenium and a mixture of potassium iodide and ascorbic acid for arsenic and bismuth. Transition metal interference was eliminated with the addition of thiourea and EDTA into the NaBH(4) solution and significant sensitivity enhancement was observed for selenium in the presence of thiourea in the reductant solution. Under optimised conditions, the method achieved detection limits of 0.2 ng mL(-1) for Se, 0.5 ng mL(-1) for As and 0.3 ng mL(-1) for Bi. The method was very reproducible, achieving relative standard deviations of 6.3% for Se, 3.6% for As and 4.7% for Bi, and has a sample throughput of 360 h(-1). Successful application of the method to the quantification of selenium, arsenic and bismuth in a certified reference river sediment sample is reported.

Color stability of white mineral trioxide aggregate in contact with hypochlorite solution.

PubMed

Camilleri, Josette

2014-03-01

One of the uses of white mineral trioxide aggregate (MTA) is as an apical barrier in immature teeth. Although this treatment has been reported to have high success rates, a number of cases of discoloration have been noted. The aim of this research was to investigate the color stability of white MTA in contact with various solutions used in endodontics. The change in color of white MTA after immersion in water, sodium hypochlorite, or hydrogen peroxide was assessed by viewing the color change on digital photographs and also by using a spectrophotometer. White MTA, white Portland cement, and bismuth oxide were assessed. The changes in the material after immersion in the different solutions were assessed by x-ray diffraction analysis and Fourier transform infrared spectroscopy. Immersion of white MTA and bismuth oxide in sodium hypochlorite resulted in the formation of a dark brown discoloration. This change was not observed in Portland cement. X-ray diffraction analysis and Fourier transform infrared analysis displayed the reduction of sodium hypochlorite in contact with bismuth oxide and MTA to sodium chloride. Contact of white MTA and other bismuth-containing materials with sodium hypochlorite solution should be avoided. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Liquid Bismuth Propellant Management System for the Very High Specific Impulse Thruster with Anode Layer

NASA Technical Reports Server (NTRS)

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

2007-01-01

Two prototype bismuth propellant feed systems were constructed and operated in conjunction with a propellant vaporizer. One system provided bismuth to a vaporizer using gas pressurization but did not include a means to measure the flow rate. The second system incorporated an electromagnetic pump to provide fine control of the hydrostatic pressure and a new type of in-line flow sensor that was developed for accurate, real-time measurement of the mass flow rate. High-temperature material compatibility was a driving design requirement for the pump and flow sensor, leading to the selection of Macor for the main body of both components. Posttest inspections of both components revealed no degradation of the material. The gas pressurization system demonstrated continuous pressure control over a range from zero to 200 torr. In separate proof-of-concept experiments, the electromagnetic pump produced a linear pressure rise as a function of current that compared favorably with theoretical pump pressure predictions, producing a pressure rise of 10 kPa at 30 A. Preliminary flow sensor operation indicated a bismuth flow rate of 6 mg/s with an uncertainty of plus or minus 6%. An electronics suite containing a real-time controller was successfully used to control the entire system, simultaneously monitoring all power supplies and performing data acquisition duties.

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

PubMed

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.

Tin, Bismuth, and Tin–Bismuth Alloy Electrodeposition from Chlorometalate Salts in Deep Eutectic Solvents

PubMed Central

Vieira, Luciana; Burt, Jennifer; Richardson, Peter W.; Schloffer, Daniel; Fuchs, David; Moser, Alwin; Bartlett, Philip N.; Reid, Gillian

2017-01-01

Abstract The electrodeposition of tin, bismuth, and tin–bismuth alloys from SnII and BiIII chlorometalate salts in the choline chloride/ethylene glycol (1:2 molar ratio) deep eutectic solvent was studied on glassy carbon and gold by cyclic voltammetry, rotating disc voltammetry, and chronoamperometry. The SnII‐containing electrolyte showed one voltammetric redox process corresponding to SnII/Sn0. The diffusion coefficient of [SnCl3]−, detected as the dominating species by Raman spectroscopy, was determined from Levich and Cottrell analyses. The BiIII‐containing electrolyte showed two voltammetric reduction processes, both attributed to BiIII/Bi0. Dimensionless current/time transients revealed that the electrodeposition of both Sn and Bi on glassy carbon proceeded by 3D‐progressive nucleation at a low overpotential and changed to instantaneous at higher overpotentials. The nucleation rate of Bi on glassy carbon was considerably smaller than that of Sn. Elemental Sn and Bi were electrodeposited on Au‐coated glass slides from their respective salt solutions, as were Sn–Bi alloys from a 2:1 SnII/BiIII solution. The biphasic Sn–Bi alloys changed from a Bi‐rich composition to a Sn‐rich composition by making the deposition potential more negative. PMID:28638772

Vapor pressure and evaporation rate of certain heat-resistant compounds in a vacuum at high temperatures

NASA Technical Reports Server (NTRS)

Bolgar, A. S.; Verkhoglyadova, T. S.; Samsonov, G. V.

1985-01-01

The vapor pressure and evaporation rate of borides of titanium, zirconium, and chrome; and of strontium and carbides of titanium, zirconium, and chrome, molybdenum silicide; and nitrides of titanium, niobium, and tantalum in a vacuum were studied. It is concluded that all subject compounds evaporate by molecular structures except AlB sub 12' which dissociates, losing the aluminum.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erdemir, Ali; Eryilmaz, Osman Levent; Urgen, Mustafa

A nanocomposite coating and method of making and using the coating. The nanocomposite coating is disposed on a base material, such as a metal or ceramic; and the nanocomposite consists essentially of a matrix of an alloy selected from the group of Cu, Ni, Pd, Pt and Re which are catalytically active for cracking of carbon bonds in oils and greases and a grain structure selected from the group of borides, carbides and nitrides.

LINER FOR EXTRUSION BILLET CONTAINERS

DTIC Science & Technology

Shrink-fit assembly device for buildup of ceramic-coated liner and sleeve assemblies was tested and modified to develop desired temperatures and...preliminary evaluation of suitability for extrusion liner use. Procedures were developed for welding short, hollow ceramic cylinders of high-strength metal...carbides and borides to form a ceramic extrusion liner of suitable length. Disassembly tooling for rapid separation of shrink-fitted sleeves from a worn

Correlation between thermodynamical stabilities of metal borohydrides and cation electronegativites: First-principles calculations and experiments

NASA Astrophysics Data System (ADS)

Nakamori, Yuko; Miwa, Kazutoshi; Ninomiya, Akihito; Li, Haiwen; Ohba, Nobuko; Towata, Shin-Ichi; Züttel, Andreas; Orimo, Shin-Ichi

2006-07-01

The thermodynamical stabilities for the series of metal borohydrides M(BH4)n ( M=Li , Na, K, Cu, Mg, Zn, Sc, Zr, and Hf; n=1-4 ) have been systematically investigated by first-principles calculations. The results indicated that an ionic bonding between Mn+ cations and [BH4]- anions exists in M(BH4)n , and the charge transfer from Mn+ cations to [BH4]- anions is a key feature for the stability of M(BH4)n . A good correlation between the heat of formation ΔHboro of M(BH4)n and the Pauling electronegativity of the cation χP can be found, which is represented by the linear relation, ΔHboro=248.7χP-390.8 in the unit of kJ/mol BH4 . In order to confirm the predicted correlation experimentally, the hydrogen desorption reactions were studied for M(BH4)n ( M=Li , Na, K, Mg, Zn, Sc, Zr, and Hf), where the samples of the later five borohydrides were mechanochemically synthesized. The thermal desorption analyses indicate that LiBH4 , NaBH4 , and KBH4 desorb hydrogen to hydride phases. Mg(BH4)2 , Sc(BH4)3 , and Zr(BH4)4 show multistep desorption reactions through the intermediate phases of hydrides and/or borides. On the other hand, Zn(BH4)2 desorbs hydrogen and borane to elemental Zn due to instabilities of Zn hydride and boride. A correlation between the desorption temperature Td and the Pauling electronegativity χP is observed experimentally and so χP is an indicator to approximately estimate the stability of M(BH4)n . The enthalpy change for the desorption reaction, ΔHdes , is estimated using the predicted ΔHboro and the reported data for decomposed product, ΔHhyd/boride . The estimated ΔHdes show a good correlation with the observed Td , indicating that the predicted stability of borohydride is experimentally supported. These results are useful for exploring M(BH4)n with appropriate stability as hydrogen storage materials.

Complete titanium substitution by boron in a tetragonal prism: exploring the complex boride series Ti(3-x)Ru(5-y)Ir(y)B(2+x) (0 ≤ x ≤ 1 and 1 < y < 3) by experiment and theory.

PubMed

Fokwa, Boniface P T; Hermus, Martin

2011-04-18

Polycrystalline samples and single crystals of four members of the new complex boride series Ti(3-x)Ru(5-y)Ir(y)B(2+x) (0 ≤ x ≤ 1 and 1 < y < 3) were synthesized by arc-melting the elements in a water-cooled copper crucible under an argon atmosphere. The new silvery phases were structurally characterized by powder and single-crystal X-ray diffraction as well as energy- and wavelength-dispersive X-ray spectroscopy analyses. They crystallize with the tetragonal Ti(3)Co(5)B(2) structure type in space group P4/mbm (No. 127). Tetragonal prisms of Ru/Ir atoms are filled with titanium in the boron-poorest phase (Ti(3)Ru(2.9)Ir(2.1)B(2)). Gradual substitution of titanium by boron then results in the successive filling of this site by a Ti/B mixture en route to the complete boron occupation, leading to the boron-richest phase (Ti(2)Ru(2.8)Ir(2.2)B(3)). Furthermore, both ruthenium and iridium share two sites in these structures, but a clear Ru/Ir site preference is found. First-principles density functional theory calculations (Vienna ab initio simulation package) on appropriate structural models (using a supercell approach) have provided more evidence on the stability of the boron-richest and -poorest phases, and the calculated lattice parameters corroborate very well with the experimentally found ones. Linear muffin-tin orbital atomic sphere approximation calculations further supported these findings through crystal orbital Hamilton population bonding analyses, which also show that the Ru/Ir-B and Ru/Ir-Ti heteroatomic interactions are mainly responsible for the structural stability of these compounds. Furthermore, some stable and unstable phases of this complex series could be predicted using the rigid-band model. According to the density of states analyses, all phases should be metallic conductors, as was expected from these metal-rich borides.

Thermoelctric Properties of Bi and Bismuth Telluride Composites

NASA Astrophysics Data System (ADS)

Huber, Tito E.; Calcao, Ricky

1998-03-01

It has been suggested that microengineering traditional thermoelectric materials into composites may leadto asignificant improvement in their thermoelectric performance. One approach for the fabrication of nanostructured materials is the utilization of nanochannel insulators as a matrix for the synthesis of dense composites using high pressure injection of the melt. We will discuss the synthesis and structural properties of oriented Bi and Bismuth Telluride wire arrays prepared with this technique. Funded by the Army Research Office.

Bismuth oxide nanotubes-graphene fiber-based flexible supercapacitors.

PubMed

Gopalsamy, Karthikeyan; Xu, Zhen; Zheng, Bingna; Huang, Tieqi; Kou, Liang; Zhao, Xiaoli; Gao, Chao

2014-08-07

Graphene-bismuth oxide nanotube fiber as electrode material for constituting flexible supercapacitors using a PVA/H3PO4 gel electrolyte is reported with a high specific capacitance (Ca) of 69.3 mF cm(-2) (for a single electrode) and 17.3 mF cm(-2) (for the whole device) at 0.1 mA cm(-2), respectively. Our approach opens the door to metal oxide-graphene hybrid fibers and high-performance flexible electronics.

Synthesis of Bi2S3 quantum dots for sensitized solar cells by reverse SILAR

NASA Astrophysics Data System (ADS)

Singh, Navjot; Sharma, J.; Tripathi, S. K.

2016-05-01

Quantum Dot Sensitized Solar cells (QDSSC) have great potential to replace silicon-based solar cells. Quantum dots of various materials and sizes could be used to convert most of the visible light into the electrical current. This paper put emphasis on the synthesis of Bismuth Sulphide quantum dots and selectivity of the anionic precursor by Successive Ionic Layer Adsorption Reaction (SILAR). Bismuth Sulfide (Bi2S3) (group V - Vi semiconductor) is strong contestant for cadmium free solar cells due to its optimum band gap for light harvesting. Optical, structural and electrical measurements are reported and discussed. Problem regarding the choice of precursor for anion extraction is discussed. Band gap of the synthesized quantum dots is 1.2 eV which does not match with the required energy band gap of bismuth sulfide that is 1.7eV.

Coexistence of Topological Edge State and Superconductivity in Bismuth Ultrathin Film.

PubMed

Sun, Hao-Hua; Wang, Mei-Xiao; Zhu, Fengfeng; Wang, Guan-Yong; Ma, Hai-Yang; Xu, Zhu-An; Liao, Qing; Lu, Yunhao; Gao, Chun-Lei; Li, Yao-Yi; Liu, Canhua; Qian, Dong; Guan, Dandan; Jia, Jin-Feng

2017-05-10

Ultrathin freestanding bismuth film is theoretically predicted to be one kind of two-dimensional topological insulators. Experimentally, the topological nature of bismuth strongly depends on the situations of the Bi films. Film thickness and interaction with the substrate often change the topological properties of Bi films. Using angle-resolved photoemission spectroscopy, scanning tunneling microscopy or spectroscopy and first-principle calculation, the properties of Bi(111) ultrathin film grown on the NbSe 2 superconducting substrate have been studied. We find the band structures of the ultrathin film is quasi-freestanding, and one-dimensional edge state exists on Bi(111) film as thin as three bilayers. Superconductivity is also detected on different layers of the film and the pairing potential exhibits an exponential decay with the layer thicknesses. Thus, the topological edge state can coexist with superconductivity, which makes the system a promising platform for exploring Majorana Fermions.

High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED

NASA Astrophysics Data System (ADS)

Ullmann, Johannes; Andelkovic, Zoran; Brandau, Carsten; Dax, Andreas; Geithner, Wolfgang; Geppert, Christopher; Gorges, Christian; Hammen, Michael; Hannen, Volker; Kaufmann, Simon; König, Kristian; Litvinov, Yuri A.; Lochmann, Matthias; Maaß, Bernhard; Meisner, Johann; Murböck, Tobias; Sánchez, Rodolfo; Schmidt, Matthias; Schmidt, Stefan; Steck, Markus; Stöhlker, Thomas; Thompson, Richard C.; Trageser, Christian; Vollbrecht, Jonas; Weinheimer, Christian; Nörtershäuser, Wilfried

2017-05-01

Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209Bi82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron-nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209Bi82+,80+ with a precision that is improved by more than an order of magnitude. Even though this quantity is believed to be largely insensitive to nuclear structure and therefore the most decisive test of QED in the strong magnetic field regime, we find a 7-σ discrepancy compared with the theoretical prediction.

High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED.

PubMed

Ullmann, Johannes; Andelkovic, Zoran; Brandau, Carsten; Dax, Andreas; Geithner, Wolfgang; Geppert, Christopher; Gorges, Christian; Hammen, Michael; Hannen, Volker; Kaufmann, Simon; König, Kristian; Litvinov, Yuri A; Lochmann, Matthias; Maaß, Bernhard; Meisner, Johann; Murböck, Tobias; Sánchez, Rodolfo; Schmidt, Matthias; Schmidt, Stefan; Steck, Markus; Stöhlker, Thomas; Thompson, Richard C; Trageser, Christian; Vollbrecht, Jonas; Weinheimer, Christian; Nörtershäuser, Wilfried

2017-05-16

Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209 Bi 82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron-nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209 Bi 82+,80+ with a precision that is improved by more than an order of magnitude. Even though this quantity is believed to be largely insensitive to nuclear structure and therefore the most decisive test of QED in the strong magnetic field regime, we find a 7-σ discrepancy compared with the theoretical prediction.