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Sample records for zirconium iodides

  1. Equations of state for crystalline zirconium iodide: The role of dispersion

    NASA Astrophysics Data System (ADS)

    Rossi, Matthew L.; Taylor, Christopher D.

    2013-02-01

    We present the first-principle equations of state of several zirconium iodides, ZrI2, ZrI3, and ZrI4, computed using density functional theory methods that apply various methods for introducing the dispersion correction. Iodides formed due to reaction of molecular or atomic iodine with zirconium and zircaloys are of particular interest due to their application to the cladding material used in the fabrication of nuclear fuel rods. Stress corrosion cracking (SCC), associated with fission product chemistry with the clad material, is a major concern in the life cycle of nuclear fuels, as many of the observed rod failures have occurred due to pellet-cladding chemical interactions (PCCI) [A. Atrens, G. Dannhäuser, G. Bäro, Stress-corrosion-cracking of zircaloy-4 cladding tubes, Journal of Nuclear Materials 126 (1984) 91-102; P. Rudling, R. Adamson, B. Cox, F. Garzarolli, A. Strasser, High burn-up fuel issues, Nuclear Engineering and Technology 40 (2008) 1-8]. A proper understanding of the physical properties of the corrosion products is, therefore, required for the development of a comprehensive SCC model. In this particular work, we emphasize that, while existing modeling techniques include methods to compute crystal structures and associated properties, it is important to capture intermolecular forces not traditionally included, such as van der Waals (dispersion) correction. Furthermore, crystal structures with stoichiometries favoring a high I:Zr ratio are found to be particularly sensitive, such that traditional density functional theory approaches that do not incorporate dispersion incorrectly predict significantly larger volumes of the lattice. This latter point is related to the diffuse nature of the iodide electron cloud.

  2. Zirconium

    USGS Publications Warehouse

    Bedinger, G.M.

    2013-01-01

    Zirconium is the 20th most abundant element in the Earth’s crust. It occurs in a variety of rock types and geologic environments but most often in igneous rocks in the form of zircon (ZrSiO4). Zircon is recovered as a coproduct of the mining and processing of heavy mineral sands for the titanium minerals ilmenite and rutile. The sands are formed by the weathering and erosion of rock containing zircon and titanium heavy minerals and their subsequent concentration in sedimentary systems, particularly in coastal environments. A small quantity of zirconium, less than 10 kt/a (11,000 stpy), compared with total world production of 1.4 Mt (1.5 million st) in 2012, was derived from the mineral baddeleyite (ZrO2), produced from a single source in Kovdor, Russia.

  3. Potassium Iodide

    MedlinePlus

    ... iodide you should take or give to your child depends on your age or your child's age. If potassium iodide is taken by a ... you should take yourself or give to your child. Ask your doctor, pharmacist, or public official if ...

  4. Methyl iodide

    Integrated Risk Information System (IRIS)

    Methyl iodide ; CASRN 74 - 88 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effe

  5. Cesium iodide alloys

    DOEpatents

    Kim, H.E.; Moorhead, A.J.

    1992-12-15

    A transparent, strong CsI alloy is described having additions of monovalent iodides. Although the preferred iodide is AgI, RbI and CuI additions also contribute to an improved polycrystalline CsI alloy with outstanding multispectral infrared transmittance properties. 6 figs.

  6. PLUTONIUM-ZIRCONIUM ALLOYS

    DOEpatents

    Schonfeld, F.W.; Waber, J.T.

    1960-08-30

    A series of nuclear reactor fuel alloys consisting of from about 5 to about 50 at.% zirconium (or higher zirconium alloys such as Zircaloy), balance plutonium, and having the structural composition of a plutonium are described. Zirconium is a satisfactory diluent because it alloys readily with plutonium and has desirable nuclear properties. Additional advantages are corrosion resistance, excellent fabrication propenties, an isotropie structure, and initial softness.

  7. Hydrogen iodide decomposition

    DOEpatents

    O'Keefe, Dennis R.; Norman, John H.

    1983-01-01

    Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.2 is returned to a reactor operating in accordance with the Bunsen equation to create more HI.

  8. SEPARATING HAFNIUM FROM ZIRCONIUM

    DOEpatents

    Lister, B.A.J.; Duncan, J.F.

    1956-08-21

    A dilute aqueous solution of zirconyl chloride which is 1N to 2N in HCl is passed through a column of a cation exchange resin in acid form thereby absorbing both zirconium and associated hafnium impurity in the mesin. The cation exchange material with the absorbate is then eluted with aqueous sulfuric acid of a O.8N to 1.2N strength. The first portion of the eluate contains the zirconium substantially free of hafnium.

  9. 21 CFR 172.375 - Potassium iodide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium iodide. 172.375 Section 172.375 Food and... Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be safely used in accordance with the following prescribed conditions: (a) Potassium iodide may be safely...

  10. Catalytic determination of molybdenum(VI) by means of an iodide ion-selective electrode and a landolt-type hydrogen peroxide-iodide reaction.

    PubMed

    Kataoka, M; Nishimura, K; Kambara, T

    1983-12-01

    A trace amount of molybdenum(VI) can be determined by using its catalytic effect on the oxidation of iodide to iodine by hydrogen peroxide in acidic medium. Addition of ascorbic acid added to the reaction mixture produces the Landolt effect, i.e., the iodine produced by the indicator reaction is reduced immediately by the ascorbic add. Hence the concentration of iodide begins to decrease once all the ascorbic acid has been consumed. The induction period is measured by monitoring the concentration of iodide ion with an iodide ion-selective electrode. The reciprocal of the induction period varies linearly with the concentration of molybdenum(VI). The most suitable pH and concentrations of hydrogen peroxide and potassium iodide are found to be 1.5, 5 and 10mM, respectively. An appropriate amount of ascorbic acid is added to the reaction mixture according to the concentration of molybdenum(VI) in the sample solution. A calibration graph with good proportionality is obtained for the molybdenum(VI) concentration range from 0.1 to 160 muM. Iron(III), vanadium(IV), zirconium(IV), tungsten(VI), copper(II) and chromium(VI) interfere, but iron(III) and copper(II) can be masked with EDTA.

  11. ZIRCONIUM-CLADDING OF THORIUM

    DOEpatents

    Beaver, R.J.

    1961-11-21

    A method of cladding thorium with zirconium is described. The quality of the bond achieved between thorium and zirconium by hot-rolling is improved by inserting and melting a thorium-zirconium alloy foil between the two materials prior to rolling. (AEC)

  12. Zirconium and hafnium

    USGS Publications Warehouse

    Jones, James V.; Piatak, Nadine M.; Bedinger, George M.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. Most zirconium is consumed in the form of the main ore mineral zircon (ZrSiO4, or as zirconium oxide or other zirconium chemicals. Zirconium and hafnium are both refractory lithophile elements that have nearly identical charge, ionic radii, and ionic potentials. As a result, their geochemical behavior is generally similar. Both elements are classified as incompatible because they have physical and crystallochemical properties that exclude them from the crystal lattices of most rock-forming minerals. Zircon and another, less common, ore mineral, baddeleyite (ZrO2), form primarily as accessory minerals in igneous rocks. The presence and abundance of these ore minerals in igneous rocks are largely controlled by the element concentrations in the magma source and by the processes of melt generation and evolution. The world’s largest primary deposits of zirconium and hafnium are associated with alkaline igneous rocks, and, in one locality on the Kola Peninsula of Murmanskaya Oblast, Russia, baddeleyite is recovered as a byproduct of apatite and magnetite mining. Otherwise, there are few primary igneous deposits of zirconium- and hafnium-bearing minerals with economic value at present. The main ore deposits worldwide are heavy-mineral sands produced by the weathering and erosion of preexisting rocks and the concentration of zircon and other economically important heavy minerals, such as ilmenite and rutile (for titanium), chromite (for chromium), and monazite (for rare-earth elements) in sedimentary systems, particularly in coastal environments. In coastal deposits, heavy-mineral enrichment occurs where sediment is repeatedly reworked by wind, waves, currents, and tidal processes. The resulting heavy-mineral-sand deposits, called placers or paleoplacers, preferentially form at relatively low latitudes on passive continental margins and supply 100 percent of

  13. The iodide space in rabbit brain

    PubMed Central

    Ahmed, Nawal; Van Harreveld, A.

    1969-01-01

    1. The iodide space in rabbit brain varies greatly depending on the conditions under which it is determined. 2. When 131I- only is used the iodide space 4 hr after administration of the marker is of the order of 2%. The iodide content of the cerebrospinal fluid (c.s.f.) is about 1% of that of the serum. 3. Depression of the active iodide transport by perchlorate increases the space to 8·2% and the iodide content of the c.s.f. to 26% of that of the serum. 4. The active iodide transport can also be depressed by saturation with unlabelled iodide. Up to a serum iodide concentration of 5 mM the space determined after 5 hr remained constant at 2·7%. The iodide space grew when the serum iodide content was enhanced from 5 to 20 mM, to become constant at a value of 10·6% on further increase of the serum iodide (up to 50 mM). The iodide content of the c.s.f. increased in a similar manner as the space with the iodide concentration of the serum to about 1/3 of the serum concentration. The iodide space of the muscle was independent of the plasma iodide content. 5. From 4 to 8 hr after administration of 131I- alone or with unlabelled iodide (to a serum concentration of 15 mM) the iodide space remained relatively constant. 6. When 131I- was administered in the fluid with which the ventricles were perfused an iodide space of about 7% was attained after about 5 hr. 7. In experiments in which 131I- was administered intravenously and the sink action of the c.s.f. was eliminated by perfusion of the ventricles with a perfusate containing as much 131I- as the plasma, the iodide space was 10·2%. When in addition active iodide transport was depressed by perchlorate the space increased to 16·8%. 8. Intravenous administration of labelled and unlabelled iodide (to a serum concentration of 20-40 mM) and ventricle perfusion with the same concentration of 131I- and unlabelled iodide as in the plasma yielded an iodide space of 20·8%. In similar experiments the iodide concentration of the

  14. Electroless deposition process for zirconium and zirconium alloys

    DOEpatents

    Donaghy, R. E.; Sherman, A. H.

    1981-08-18

    A method is disclosed for preventing stress corrosion cracking or metal embrittlement of a zirconium or zirconium alloy container that is to be coated on the inside surface with a layer of a metal such as copper, a copper alloy, nickel, or iron and used for holding nuclear fuel material as a nuclear fuel element. The zirconium material is etched in an etchant solution, desmutted mechanically or ultrasonically, oxidized to form an oxide coating on the zirconium, cleaned in an aqueous alkaline cleaning solution, activated for electroless deposition of a metal layer and contacted with an electroless metal plating solution. This method provides a boundary layer of zirconium oxide between the zirconium container and the metal layer. 1 fig.

  15. Electroless deposition process for zirconium and zirconium alloys

    DOEpatents

    Donaghy, Robert E.; Sherman, Anna H.

    1981-01-01

    A method is disclosed for preventing stress corrosion cracking or metal embrittlement of a zirconium or zirconium alloy container that is to be coated on the inside surface with a layer of a metal such as copper, a copper alloy, nickel, or iron and used for holding nuclear fuel material as a nuclear fuel element. The zirconium material is etched in an etchant solution, desmutted mechanically or ultrasonically, oxidized to form an oxide coating on the zirconium, cleaned in an aqueous alkaline cleaning solution, activated for electroless deposition of a metal layer and contacted with an electroless metal plating solution. This method provides a boundary layer of zirconium oxide between the zirconium container and the metal layer.

  16. IODIDE DEFICIENCY, THYROID HORMONES, AND NEURODEVELOPMENT

    EPA Science Inventory

    ABSTRACT BODY: Iodide is an essential nutrient for thyroid hormone synthesis. Severe iodide insufficiency during early development is associated with cognitive deficits. Environmental contaminants can perturb the thyroid axis and this perturbation may be more acute under conditio...

  17. 21 CFR 184.1634 - Potassium iodide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

  18. 21 CFR 184.1634 - Potassium iodide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

  19. 21 CFR 582.5634 - Potassium iodide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium iodide. 582.5634 Section 582.5634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c...

  20. 21 CFR 184.1634 - Potassium iodide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium... reacting hydriodic acid (HI) with potassium bicarbonate (KHCO3). (b) The ingredient meets the...

  1. 21 CFR 184.1634 - Potassium iodide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

  2. 21 CFR 184.1634 - Potassium iodide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

  3. 21 CFR 582.5634 - Potassium iodide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium iodide. 582.5634 Section 582.5634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c...

  4. Auger recombination in sodium iodide

    NASA Astrophysics Data System (ADS)

    McAllister, Andrew; Kioupakis, Emmanouil; Åberg, Daniel; Schleife, André

    2014-03-01

    Scintillators are an important tool used to detect high energy radiation - both in the interest of national security and in medicine. However, scintillator detectors currently suffer from lower energy resolutions than expected from basic counting statistics. This has been attributed to non-proportional light yield compared to incoming radiation, but the specific mechanism for this non-proportionality has not been identified. Auger recombination is a non-radiative process that could be contributing to the non-proportionality of scintillating materials. Auger recombination comes in two types - direct and phonon-assisted. We have used first-principles calculations to study Auger recombination in sodium iodide, a well characterized scintillating material. Our findings indicate that phonon-assisted Auger recombination is stronger in sodium iodide than direct Auger recombination. Computational resources provided by LLNL and NERSC. Funding provided by NA-22.

  5. SEPARATING HAFNIUM FROM ZIRCONIUM

    DOEpatents

    Lister, B.A.J.; Duncan, J.F.; Hutcheon, J.M.

    1956-08-21

    Substantially complete separation of zirconium from hafnium may be obtained by elution of ion exchange material, on which compounds of the elements are adsorbed, with an approximately normal solution of sulfuric acid. Preferably the acid concentration is between 0.8 N amd 1.2 N, amd should not exceed 1.5 N;. Increasing the concentration of sulfate ion in the eluting solution by addition of a soluble sulfate, such as sodium sulfate, has been found to be advantageous. The preferred ion exchange materials are sulfonated polystyrene resins such as Dowex 50,'' and are preferably arranged in a column through which the solutions are passed.

  6. ZIRCONIUM PHOSPHATE ADSORPTION METHOD

    DOEpatents

    Russell, E.R.; Adamson, A.S.; Schubert, J.; Boyd, G.E.

    1958-11-01

    A method is presented for separating plutonium values from fission product values in aqueous acidic solution. This is accomplished by flowing the solutlon containing such values through a bed of zirconium orthophosphate. Any fission products adsorbed can subsequently be eluted by washing the column with a solution of 2N HNO/sub 3/ and O.lN H/sub 3/PO/sub 4/. Plutonium values may subsequently be desorbed by contacting the column with a solution of 7N HNO/sub 3/ .

  7. Strontium Iodide Radiation Instrumentation (SIRI)

    NASA Astrophysics Data System (ADS)

    Mitchell, Lee J.; Phlips, Bernard F.; Woolf, Richard S.; Finne, Theodore T.; Johnson, W. Neil; Jackson, Emily G.

    2017-08-01

    The Strontium Iodide Radiation Instrumentation (SIRI) is designed to space-qualify new gamma-ray detector technology for space-based astrophysical and defense applications. This new technology offers improved energy resolution, lower power consumption and reduced size compared to similar systems. The SIRI instrument consists of a single europiumdoped strontium iodide (SrI2:Eu) scintillation detector. The crystal has an energy resolution of 3% at 662 keV compared to the 6.5% of traditional sodium iodide and was developed for terrestrial-based weapons of mass destruction (WMD) detection. SIRI's objective is to study the internal activation of the SrI2:Eu material and measure the performance of the silicon photomultiplier (SiPM) readouts over a 1-year mission. The combined detector and readout measure the gammaray spectrum over the energy range of 0.04 - 4 MeV. The SIRI mission payoff is a space-qualified compact, highsensitivity gamma-ray spectrometer with improved energy resolution relative to previous sensors. Scientific applications in solar physics and astrophysics include solar flares, Gamma Ray Bursts, novae, supernovae, and the synthesis of the elements. Department of Defense (DoD) and security applications are also possible. Construction of the SIRI instrument has been completed, and it is currently awaiting integration onto the spacecraft. The expected launch date is May 2018 onboard STPSat-5. This work discusses the objectives, design details and the STPSat-5 mission concept of operations of the SIRI spectrometer.

  8. Iodide uptake by negatively charged clay interlayers?

    PubMed

    Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

    2015-09-01

    Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI(aq)) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Modification in band gap of zirconium complexes

    SciTech Connect

    Sharma, Mayank, E-mail: mayank30134@gmail.com; Singh, J.; Chouhan, S.

    2016-05-06

    The optical properties of zirconium complexes with amino acid based Schiff bases are reported here. The zirconium complexes show interesting stereo chemical features, which are applicable in organometallic and organic synthesis as well as in catalysis. The band gaps of both Schiff bases and zirconium complexes were obtained by UV-Visible spectroscopy. It was found that the band gap of zirconium complexes has been modified after adding zirconium compound to the Schiff bases.

  10. SEPARATION OF HAFNIUM FROM ZIRCONIUM

    DOEpatents

    Overholser, L.B.; Barton, C.J. Sr.; Ramsey, J.W.

    1960-05-31

    The separation of hafnium impurities from zirconium can be accomplished by means of organic solvent extraction. The hafnium-containing zirconium feed material is dissolved in an aqueous chloride solution and the resulting solution is contacted with an organic hexone phase, with at least one of the phases containing thiocyanate. The hafnium is extracted into the organic phase while zirconium remains in the aqueous phase. Further recovery of zirconium is effected by stripping the onganic phase with a hydrochloric acid solution and commingling the resulting strip solution with the aqueous feed solution. Hexone is recovered and recycled by means of scrubbing the onganic phase with a sulfuric acid solution to remove the hafnium, and thiocyanate is recovered and recycled by means of neutralizing the effluent streams to obtain ammonium thiocyanate.

  11. Refractive Index of Sodium Iodide

    SciTech Connect

    Jellison Jr, Gerald Earle; Boatner, Lynn A; Ramey, Joanne Oxendine

    2012-01-01

    The refractive index of sodium iodide, an important scintillator material that is widely used for radiation detection, is based on a single measurement made by Spangenberg at one wavelength using the index-matching liquid immersion method (Z. Kristallogr., 57, 494-534 (1923)). In the present paper, we present new results for the refractive index of sodium iodide as measured by the minimum deviation technique at six wavelengths between 436 nm (n=1.839 0.002) and 633 nm (n=1.786 0.002). These 6 measurements can be fit to a Sellmeier model, resulting in a 2 of 1.02, indicating a good fit to the data. In addition,more » we report on ellipsometry measurements, which suggest that the near-surface region of the air sensitive NaI crystal seriously degrades, even in a moisture-free environment, resulting in a significantly lower value of the refractive index near the surface. First-principles theoretical calculations of the NaI refractive index that agree with the measured values within 0.025-0.045 are also presented and discussed.« less

  12. Iodide handling by the thyroid epithelial cell.

    PubMed

    Nilsson, M

    2001-01-01

    Iodination of thyroglobulin, the key event in the synthesis of thyroid hormone, is an extracellular process that takes place inside the thyroid follicles at the apical membrane surface that faces the follicular lumen. The supply of iodide involves two steps of TSH-regulated transport, basolateral uptake and apical efflux, that imprint the polarized phenotype of the thyroid cell. Iodide uptake is generated by the sodium/iodide symporter present in the basolateral plasma membrane. A candidate for the apical iodide-permeating mechanism is pendrin, a chloride/iodide transporting protein recently identified in the apical membrane. In physiological conditions, transepithelial iodide transport occurs without intracellular iodination, despite the presence of large amounts of thyroglobulin and thyroperoxidase inside the cells. The reason is that hydrogen peroxide, serving as electron acceptor in iodide-protein binding and normally produced at the apical cell surface, is rapidly degraded by cytosolic glutathione peroxidase once it enters the cells. Iodinated thyroglobulin in the lumen stores not only thyroid hormone but iodine incorporated in iodotyrosine residues as well. After endocytic uptake and degradation of thyroglobulin, intracellular deiodination provides a mechanism for recycling of iodide to participate in the synthesis of new thyroid hormone at the apical cell surface.

  13. 21 CFR 172.375 - Potassium iodide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be..., will not result in daily ingestion of the additive so as to provide a total amount of iodine in excess...

  14. 21 CFR 172.375 - Potassium iodide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be safely used in accordance with the...

  15. 21 CFR 172.375 - Potassium iodide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be..., will not result in daily ingestion of the additive so as to provide a total amount of iodine in excess...

  16. 21 CFR 582.5634 - Potassium iodide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c... salt as a source of dietary iodine in accordance with good manufacturing or feeding practice. ...

  17. 21 CFR 582.5634 - Potassium iodide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c... salt as a source of dietary iodine in accordance with good manufacturing or feeding practice. ...

  18. 21 CFR 582.5634 - Potassium iodide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c... salt as a source of dietary iodine in accordance with good manufacturing or feeding practice. ...

  19. 21 CFR 172.375 - Potassium iodide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be...

  20. Fine-grained zirconium-base material

    DOEpatents

    Van Houten, G.R.

    1974-01-01

    A method is described for making zirconium with inhibited grain growth characteristics, by the process of vacuum melting the zirconium, adding 0.3 to 0.5% carbon, stirring, homogenizing, and cooling. (Official Gazette)

  1. Ablation Resistant Zirconium and Hafnium Ceramics

    NASA Technical Reports Server (NTRS)

    Bull, Jeffrey (Inventor); White, Michael J. (Inventor); Kaufman, Larry (Inventor)

    1998-01-01

    High temperature ablation resistant ceramic composites have been made. These ceramics are composites of zirconium diboride and zirconium carbide with silicon carbide, hafnium diboride and hafnium carbide with silicon carbide and ceramic composites which contain mixed diborides and/or carbides of zirconium and hafnium. along with silicon carbide.

  2. Iodide Protects Heart Tissue from Reperfusion Injury

    PubMed Central

    Iwata, Akiko; Morrison, Michael L.; Roth, Mark B.

    2014-01-01

    Iodine is an elemental nutrient that is essential for mammals. Here we provide evidence for an acute therapeutic role for iodine in ischemia reperfusion injury. Infusion of the reduced form, iodide, but not the oxidized form iodate, reduces heart damage by as much as 75% when delivered intravenously following temporary loss of blood flow but prior to reperfusion of the heart in a mouse model of acute myocardial infarction. Normal thyroid function may be required because loss of thyroid activity abrogates the iodide benefit. Given the high degree of protection and the high degree of safety, iodide should be explored further as a therapy for reperfusion injury. PMID:25379708

  3. Mercuric iodide light detector and related method

    DOEpatents

    Iwanczyk, J.S.; Barton, J.B.; Dabrowski, A.J.; Schnepple, W.F.

    1986-09-23

    Apparatus and method for detecting light involve applying a substantially uniform electrical potential difference between first and second spaced surfaces of a body of mercuric iodide, exposing the first surface to light and measuring an electrical current passed through the body in response to the light. The mercuric iodide may be substantially monocrystalline and the potential may be applied between a substantially transparent conductive layer at the first surface and a second conductive layer at the second surface. In a preferred embodiment, the detector is coupled to a scintillator for passage of light to the mercuric iodide in response to ionizing radiation incident on the scintillator. 7 figs.

  4. Mercuric iodide light detector and related method

    DOEpatents

    Iwanczyk, Jan S.; Barton, Jeff B.; Dabrowski, Andrzej J.; Schnepple, Wayne F.

    1986-01-01

    Apparatus and method for detecting light involve applying a substantially uniform electrical potential difference between first and second spaced surfaces of a body of mercuric iodide, exposing the first surface to light and measuring an electrical current passed through the body in response to the light. The mercuric iodide may be substantially monocrystalline and the potential may be applied between a substantially transparent conductive layer at the first surface and a second conductive layer at the second surface. In a preferred embodiment, the detector is coupled to a scintillator for passage of light to the mercuric iodide in response to ionizing radiation incident on the scintillator.

  5. PROCESS OF DISSOLVING ZIRCONIUM ALLOYS

    DOEpatents

    Shor, R.S.; Vogler, S.

    1958-01-21

    A process is described for dissolving binary zirconium-uranium alloys where the uranium content is about 2%. In prior dissolution procedures for these alloys, an oxidizing agent was added to prevent the precipitation of uranium tetrafluoride. In the present method complete dissolution is accomplished without the use of the oxidizing agent by using only the stoichiometric amount or slight excess of HF required by the zirconium. The concentration of the acid may range from 2M to 10M and the dissolution is advatageously carried out at a temperature of 80 deg C.

  6. Zirconium tetrachloride revisited

    DOE PAGES

    Borjas Nevarez, Rosendo; Balasekaran, Samundeeswari Mariappan; Kim, Eunja; ...

    2018-02-19

    We present that zirconium tetrachloride, ZrCl 4, is a strategic material with wide-ranging applications. Until now, only one crystallographic study on ZrCl 4has been reported [Krebs (1970).Z. Anorg. Allg. Chem.378, 263–272] and that was more than 40 years ago. The compound used for the previous determination was prepared from ZrO 2 and Cl 2–CCl 4, and single-crystal X-ray diffraction (SCXRD) studies on ZrCl 4 obtained from Zr metal have not yet been reported. In this context, we prepared ZrCl 4 from the reaction of Zr metal and Cl 2 gas in a sealed tube and investigated its structure at 100,more » 150, 200, 250, and 300 K. At 300 K, the SCXRD analysis indicates that ZrCl 4 crystallizes in the orthorhombic space group Pca2 1 [a= 6.262 (9),b= 7.402 (11),c= 12.039 (17) Å, andV= 558.0 (14) Å 3] and consists of infinite zigzag chains of edge-sharing ZrCl 6 octahedra. This chain motif is similar to that observed previously in ZrCl 4, but the structural parameters and space group differ. Finally, in the temperature range 100–300 K, no phase transformation was identified, while elongation of intra-chain Zr...Zr [3.950 (1) Å at 100 K and 3.968 (5) Å at 300 K] and inter-chain Cl...Cl [3.630 (3) Å at 100 K and 3.687 (9) Å at 300 K] distances occurred.« less

  7. 21 CFR 520.763a - Dithiazanine iodide tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dithiazanine iodide tablets. 520.763a Section 520... iodide tablets. (a) Chemical name. 3-Ethyl-2-[5-(3-ethyl - 2 - benzothiazolinylidene) - 1,3 - pentadienyl]-benzothiazolium iodide. (b) Specifications. Dithiazanine iodide tablets contain 10 milligrams, 50 milligrams, 100...

  8. SEPARATION PROCESS FOR ZIRCONIUM AND COMPOUNDS THEREOF

    DOEpatents

    Crandall, H.W.; Thomas, J.R.

    1959-06-30

    The separation of zirconium from columbium, rare earths, yttrium and the alkaline earth metals, such mixtures of elements occurring in zirconium ores or neutron irradiated uranium is described. According to the invention a suitable separation of zirconium from a one normal acidic aqueous solution containing salts, nitrates for example, of tetravalent zirconium, pentavalent columbium, yttrium, rare earths in the trivalent state and alkaline earths can be obtained by contacting the aqueous solution with a fluorinated beta diketonc alone or in an organic solvent solution, such as benzene, to form a zirconium chelate compound. When the organic solvent is present the zirconium chelate compound is directly extracted; otherwise it is separated by filtration. The zirconium may be recovered from contacting the organic solvent solution containing the chelated compound by back extraction with either an aqueous hydrofluoric acid or an oxalic acid solution.

  9. Recovery of anhydrous hydrogen iodide

    DOEpatents

    O'Keefe, Dennis R.; McCorkle, Jr., Kenneth H.; de Graaf, Johannes D.

    1982-01-01

    Relatively dry hydrogen iodide can be recovered from a mixture of HI, I.sub.2 and H.sub.2 O. After the composition of the mixture is adjusted so that the amounts of H.sub.2 O and I.sub.2 do not exceed certain maximum limits, subjection of the mixture to superatmospheric pressure in an amount equal to about the vapor pressure of HI at the temperature in question causes distinct liquid phases to appear. One of the liquid phases contains HI and not more than about 1 weight percent water. Often the adjustment in the composition will include the step of vaporization, and the distinct layers appear following the increase in pressure of the vapor mixture. Adjustment in the composition may also include the addition of an extraction agent, such as H.sub.3 PO.sub.4, and even though the adjusted composition mixture contains a significant amount of such an agent, the creation of the distinct liquid phases is not adversely affected.

  10. A perchlorate sensitive iodide transporter in frogs

    PubMed Central

    Carr, Deborah L.; Carr, James A.; Willis, Ray E.; Pressley, Thomas A.

    2008-01-01

    Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater 125I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na+/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na+-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na+/iodide symporter in Xenopus laevis, as well as Rana catesbeiana. PMID:18275962

  11. Iodide transport: implications for health and disease

    PubMed Central

    2014-01-01

    Disorders of the thyroid gland are among the most common conditions diagnosed and managed by pediatric endocrinologists. Thyroid hormone synthesis depends on normal iodide transport and knowledge of its regulation is fundamental to understand the etiology and management of congenital and acquired thyroid conditions such as hypothyroidism and hyperthyroidism. The ability of the thyroid to concentrate iodine is also widely used as a tool for the diagnosis of thyroid diseases and in the management and follow up of the most common type of endocrine cancers: papillary and follicular thyroid cancer. More recently, the regulation of iodide transport has also been the center of attention to improve the management of poorly differentiated thyroid cancer. Iodine deficiency disorders (goiter, impaired mental development) due to insufficient nutritional intake remain a universal public health problem. Thyroid function can also be influenced by medications that contain iodide or interfere with iodide metabolism such as iodinated contrast agents, povidone, lithium and amiodarone. In addition, some environmental pollutants such as perchlorate, thiocyanate and nitrates may affect iodide transport. Furthermore, nuclear accidents increase the risk of developing thyroid cancer and the therapy used to prevent exposure to these isotopes relies on the ability of the thyroid to concentrate iodine. The array of disorders involving iodide transport affect individuals during the whole life span and, if undiagnosed or improperly managed, they can have a profound impact on growth, metabolism, cognitive development and quality of life. PMID:25009573

  12. PROCESS OF PREPARING ZIRCONIUM OXYCHLORIDE

    DOEpatents

    Wilhelm, H.A.; Andrews, M.L.

    1960-06-28

    A process is given for preparing zirconyl chloride by mixing solid zirconyl chloride octahydrate and solid zirconium tetrachloride at room temperature whereby both chlorides are converted to zirconyl chloride trinydrate and hydrogen chloride is formed and volatilized by the reaction heat.

  13. Congenital hypothyroidism from complete iodide transport defect: long-term evolution with iodide treatment.

    PubMed Central

    Albero, R.; Cerdan, A.; Sanchez Franco, F.

    1987-01-01

    Hypothyroidism from iodide transport deficiency is a rare disease, especially when found in two affected siblings. Treatment with high doses of iodide has been recommended, but no long term results have been reported. Two siblings with congenital hypothyroidism due to total failure to transport iodide have been followed up during twelve and a half years of treatment with oral potassium iodide. Iodine doses varied between 10.3 and 22 mg/day, and serum total iodine concentrations between 100 and 210 micrograms/dl. Total triiodothyronine (T3), thyroxine (T4) and free T4 were in the normal range during the time of study. Basal thyroid stimulating hormones (TSH) and maximum TSH response to thyrotrophin releasing hormone (TRH) were also in the range of normal values. These data along with clinical findings confirmed the potential usefulness of iodine in hypothyroidism due to complete iodide transport defect. PMID:3451231

  14. Demonstration of Iodide Transport Defect but Normal Iodide Organification in Nonfunctioning Nodules of Human Thyroid Glands

    PubMed Central

    Field, James B.; Larsen, P. Reed; Yamashita, Kamejiro; Mashiter, Keith; Dekker, Andrew

    1973-01-01

    Benign and malignant nodules in human thyroid glands, which did not concentrate iodide in vivo, were also unable to accumulate iodide in vitro. The mean thyroid-to-medium ratio (T/M) in seven benign nodules was 0.8±0.2 compared with 7±2 in adjacent normal thyroid tissue. In four malignant thyroid nodules, the mean T/M was 0.5±0.1 compared with 11±4 in adjacent normal thyroid. Despite the inability of such nodules to concentrate iodide, iodide organification was present but was only one-half to one-third as active as in surrounding normal thyroid. Thyroid-stimulating hormone (TSH) increased iodide organification equally in both benign nodules and normal thyroid although it had no effect in three of the four malignant lesions. The reduction in organification is probably related to the absence of iodide transport, since incubation of normal thyroid slices with perchlorate caused similar diminution in iodide incorporation but no change in the response to TSH. Monoiodotyrosine (MIT) and di-iodotyrosine (DIT) accounted for most of the organic iodide in both the nodules and normal tissue. The MIT/DIT ratio was similar in normal and nodule tissue. The normal tissue contained much more inorganic iodide than the nodules, consistent with the absence of the iodide trap in the latter tissue. The thyroxine content of normal thyroid was 149±17 μg/g wet wt and 18±4 μg/g wet wt in the nodules. The transport defect in the nodules was not associated with any reduction in total, Na+-K+- or Mg++-activated ATPase activities or the concentration of ATP. Basal adenylate cyclase was higher in nodules than normal tissue. Although there was no difference between benign and malignant nodules, the response of adenylate cyclase to TSH was greater in the benign lesions. These studies demonstrate that nonfunctioning thyroid nodules, both benign and malignant, have a specific defect in iodide transport that accounts for their failure to accumulate radioactive iodide in vivo. In benign

  15. Zirconium Phosphate Supported MOF Nanoplatelets.

    PubMed

    Kan, Yuwei; Clearfield, Abraham

    2016-06-06

    We report a rare example of the preparation of HKUST-1 metal-organic framework nanoplatelets through a step-by-step seeding procedure. Sodium ion exchanged zirconium phosphate, NaZrP, nanoplatelets were judiciously selected as support for layer-by-layer (LBL) assembly of Cu(II) and benzene-1,3,5-tricarboxylic acid (H3BTC) linkers. The first layer of Cu(II) is attached to the surface of zirconium phosphate through covalent interaction. The successive LBL growth of HKUST-1 film is then realized by soaking the NaZrP nanoplatelets in ethanolic solutions of cupric acetate and H3BTC, respectively. The amount of assembled HKUST-1 can be readily controlled by varying the number of growth cycles, which was characterized by powder X-ray diffraction and gas adsorption analyses. The successful construction of HKUST-1 on NaZrP was also supported by its catalytic performance for the oxidation of cyclohexene.

  16. Method for preparing hydrous zirconium oxide gels and spherules

    DOEpatents

    Collins, Jack L.

    2003-08-05

    Methods for preparing hydrous zirconium oxide spherules, hydrous zirconium oxide gels such as gel slabs, films, capillary and electrophoresis gels, zirconium monohydrogen phosphate spherules, hydrous zirconium oxide spherules having suspendable particles homogeneously embedded within to form a composite sorbent, zirconium monohydrogen phosphate spherules having suspendable particles of at least one different sorbent homogeneously embedded within to form a composite sorbent having a desired crystallinity, zirconium oxide spherules having suspendable particles homogeneously embedded within to form a composite, hydrous zirconium oxide fiber materials, zirconium oxide fiber materials, hydrous zirconium oxide fiber materials having suspendable particles homogeneously embedded within to form a composite, zirconium oxide fiber materials having suspendable particles homogeneously embedded within to form a composite and spherules of barium zirconate. The hydrous zirconium oxide spherules and gel forms prepared by the gel-sphere, internal gelation process are useful as inorganic ion exchangers, catalysts, getters and ceramics.

  17. Scintillator handbook with emphasis on cesium iodide

    NASA Technical Reports Server (NTRS)

    Tidd, J. L.; Dabbs, J. R.; Levine, N.

    1973-01-01

    This report provides a background of reasonable depth and reference material on scintillators in general. Particular attention is paid to the cesium iodide scintillators as used in the High Energy Astronomy Observatory (HEAO) experiments. It is intended especially for use by persons such as laboratory test personnel who need to obtain a working knowledge of these materials and their characteristics in a short time.

  18. 21 CFR 184.1265 - Cuprous iodide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the following specific limitations: Category of food Maximum treatment level in food Functional use... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cuprous iodide. 184.1265 Section 184.1265 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  19. Potassium iodide capsule treatment of feline sporotrichosis.

    PubMed

    Reis, Erica G; Gremião, Isabella D F; Kitada, Amanda A B; Rocha, Raphael F D B; Castro, Verônica S P; Barros, Mônica B L; Menezes, Rodrigo C; Pereira, Sandro A; Schubach, Tânia M P

    2012-06-01

    Sporotrichosis is a mycosis caused by Sporothrix schenckii. The most affected animal is the cat; it has played an important role in the zoonotic transmission of this disease, especially in Rio de Janeiro, Brazil, since 1998. In order to evaluate the treatment of feline sporotrichosis with potassium iodide, an observational cohort was conducted in 48 cats with sporotrichosis at Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz. All cats received potassium iodide capsules, 2.5 mg/kg to 20 mg/kg q24h. The cure rate was 47.9%, treatment failure was 37.5%, treatment abandonment was 10.4% and death was 4.2%. Clinical adverse effects were observed in 52.1% of the cases. Thirteen cats had a mild increase in hepatic transaminase levels during the treatment, six of them presented clinical signs suggestive of hepatotoxicity. Compared to previous studies with itraconazole and iodide in saturated solution, potassium iodide capsules are an alternative for feline sporotrichosis treatment.

  20. Developments in mercuric iodide gamma ray imaging

    SciTech Connect

    Patt, B.E.; Beyerle, A.G.; Dolin, R.C.

    A mercuric iodide gamma-ray imaging array and camera system previously described has been characterized for spatial and energy resolution. Based on this data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criterion for the new camera will be presented. 2 refs., 7 figs.

  1. 21 CFR 184.1265 - Cuprous iodide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the following specific limitations: Category of food Maximum treatment level in food Functional use... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Cuprous iodide. 184.1265 Section 184.1265 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  2. Barium iodide and strontium iodide crystals andd scintillators implementing the same

    DOEpatents

    Payne, Stephen A; Cherepy, Nerine J; Hull, Giulia E; Drobshoff, Alexander D; Burger, Arnold

    2013-11-12

    In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, wherein a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu.sup.2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.

  3. DISSOLUTION OF ZIRCONIUM-CONTAINING FUEL ELEMENTS

    DOEpatents

    Horn, F.L.

    1961-12-12

    Uranium is recovered from spent uranium fuel elements containing or clad with zirconium. These fuel elements are placed in an anhydrous solution of hydrogen fluoride and nitrogen dioxide. Within this system uranium forms a soluble complex and zirconium forms an insoluble complex. The uranium can then be separated, treated, and removed from solution as uranium hexafluoride. (AEC)

  4. Method of making crack-free zirconium hydride

    DOEpatents

    Sullivan, Richard W.

    1980-01-01

    Crack-free hydrides of zirconium and zirconium-uranium alloys are produced by alloying the zirconium or zirconium-uranium alloy with beryllium, or nickel, or beryllium and scandium, or nickel and scandium, or beryllium and nickel, or beryllium, nickel and scandium and thereafter hydriding.

  5. Atomic force microscopy of lead iodide crystal surfaces

    NASA Astrophysics Data System (ADS)

    George, M. A.; Azoulay, M.; Jayatirtha, H. N.; Biao, Y.; Burger, A.; Collins, W. E.; Silberman, E.

    1994-03-01

    Atomic force microscopy (AFM) was used to characterize the surface of lead iodide crystals. The high vapor pressure of lead iodide prohibits the use of traditional high resolution surface study techniques that require high vacuum conditions. AFM was used to image numerous insulating surface in various ambients, with very little sample preparation techniques needed. Freshly cleaved and modified surfaces, including, chemical and vacuum etched, and air aged surfaces, were examined. Both intrinsic and induced defects were imaged with high resolution. The results were compared to a similar AFM study of mercuric iodide surfaces and it was found that, at ambient conditions, lead iodide is significantly more stable than mercuric iodide.

  6. Separation of Zirconium and Hafnium: A Review

    NASA Astrophysics Data System (ADS)

    Xu, L.; Xiao, Y.; van Sandwijk, A.; Xu, Q.; Yang, Y.

    Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium. This paper provides an overview of the processes for separating hafnium from zirconium. The separation processes are roughly classified into hydro- and pyrometallurgical routes. The current dominant zirconium production route involves pyrometallurgical ore cracking, multi-step hydrometallurgical liquid-liquid extraction for hafnium removal and the reduction of zirconium tetrachloride to the pure metal by the Kroll process. The lengthy hydrometallurgical Zr-Hf separation operations leads to high production cost, intensive labour and heavy environmental burden. Using a compact pyrometallurgical separation method can simplify the whole production flowsheet with a higher process efficiency. The known separation methods are discussed based on the following reaction features: redox characteristics, volatility, electrochemical properties and molten salt extraction. The commercially operating extractive distillation process is a significant advance in Zr-Hf separation technology but it suffers from high process maintenance cost. The recently developed new process based on molten salt-metal equilibrium for Zr-Hf separation shows a great potential for industrial application, which is compact for nuclear grade zirconium production starting from crude ore. In the present paper, the available separation technologies are compared. The advantages and disadvantages as well as future directions of research and development for nuclear grade zirconium production are discussed.

  7. URANIUM DECONTAMINATION WITH RESPECT TO ZIRCONIUM

    DOEpatents

    Vogler, S.; Beederman, M.

    1961-05-01

    A process is given for separating uranium values from a nitric acid aqueous solution containing uranyl values, zirconium values and tetravalent plutonium values. The process comprises contacting said solution with a substantially water-immiscible liquid organic solvent containing alkyl phosphate, separating an organic extract phase containing the uranium, zirconium, and tetravalent plutonium values from an aqueous raffinate, contacting said organic extract phase with an aqueous solution 2M to 7M in nitric acid and also containing an oxalate ion-containing substance, and separating a uranium- containing organic raffinate from aqueous zirconium- and plutonium-containing extract phase.

  8. Optical diagnostics of mercuric iodide crystal growth

    NASA Astrophysics Data System (ADS)

    Burger, A.; Morgan, S. H.; Silberman, E.; Nason, D.

    Two optical methods were recently developed for in situ monitoring of the growth process of mercuric iodide crystals. The first method uses resonance fluorescence spectroscopy (RFS) for the determination of iodine vapor present in the growth ampule, which is an important parameter in determining the stoichiometry, and therefore the quality of the crystals. The second method, Reflectance Spectroscopy Thermometry (RST) measures the crystal face temperature with a percent accuracy of plus or minus 1.5 C.

  9. Optical diagnostics of mercuric iodide crystal growth

    NASA Astrophysics Data System (ADS)

    Burger, Arnold; Morgan, Steven H.; Silberman, Enrique; Nason, Donald

    1991-12-01

    Two optical methods were recently developed for in situ monitoring of the growth process of mercuric iodide crystals. The first method uses resonance fluorescence spectroscopy (RFS) for the determination of iodine vapor present in the growth ampule, which is an important parameter in determining the stoichiometry, and therefore the quality of the crystals. The second method, reflectance spectroscopy thermometry (RST) measures the crystal face temperature with a present accuracy of +/- 1.5 degree(s)C.

  10. Production of nuclear grade zirconium: A review

    NASA Astrophysics Data System (ADS)

    Xu, L.; Xiao, Y.; van Sandwijk, A.; Xu, Q.; Yang, Y.

    2015-11-01

    Zirconium is an ideal material for nuclear reactors due to its low absorption cross-section for thermal neutrons, whereas the typically contained hafnium with strong neutron-absorption is very harmful for zirconium as a fuel cladding material. This paper provides an overview of the processes for nuclear grade zirconium production with emphasis on the methods of Zr-Hf separation. The separation processes are roughly classified into hydro- and pyrometallurgical routes. The known pyrometallurgical Zr-Hf separation methods are discussed based on the following reaction features: redox characteristics, volatility, electrochemical properties and molten salt-metal equilibrium. In the present paper, the available Zr-Hf separation technologies are compared. The advantages and disadvantages as well as future directions of research and development for nuclear grade zirconium production are discussed.

  11. Oxidized zirconium on ceramic; Catastrophic coupling.

    PubMed

    Ozden, V E; Saglam, N; Dikmen, G; Tozun, I R

    2017-02-01

    Oxidized zirconium (Oxinium™; Smith & Nephew, Memphis, TN, USA) articulated with polyethylene in total hip arthroplasty (THA) appeared to have the potential to reduce wear dramatically. The thermally oxidized metal zirconium surface is transformed into ceramic-like hard surface that is resistant to abrasion. The exposure of soft zirconium metal under hard coverage surface after the damage of oxidized zirconium femoral head has been described. It occurred following joint dislocation or in situ succeeding disengagement of polyethylene liner. We reported three cases of misuse of Oxinium™ (Smith & Nephew, Memphis, TN, USA) heads. These three cases resulted in catastrophic in situ wear and inevitable failure although there was no advice, indication or recommendation for this use from the manufacturer. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. METHOD OF IMPROVING CORROSION RESISTANCE OF ZIRCONIUM

    DOEpatents

    Shannon, D.W.

    1961-03-28

    An improved intermediate rinse for zirconium counteracts an anomalous deposit that often results in crevices and outof-the-way places when ordinary water is used to rinse away a strong fluoride etching solution designed to promote passivation of the metal. The intermediate rinse, which is used after the etching solution and before the water, is characterized by a complexing agent for fluoride ions such as aluminum or zirconium nitrates or chlorides.

  13. DISSOLUTION OF ZIRCONIUM AND ALLOYS THEREFOR

    DOEpatents

    Swanson, J.L.

    1961-07-11

    The dissolution of zirconium cladding in a water solution of ammonium fluoride and ammonium nitrate is described. The method finds particular utility in processing spent fuel elements for nuclear reactors. The zirconium cladding is first dissolved in a water solution of ammonium fluoride and ammonium nitrate; insoluble uranium and plutonium fiuorides formed by attack of the solvent on the fuel materiai of the fuel element are then separated from the solution, and the fuel materiai is dissolved in another solution.

  14. THE ANALYSIS OF URANIUM-ZIRCONIUM ALLOYS

    SciTech Connect

    Milner, G.W.C.; Skewies, A.F.

    1953-03-01

    A satisfactory procedure is described for the analysis of uranium-zirconium alloys containing up to 25% zirconium. It is based on the separation of the zirconium from the uranium by dissolving the cupferron complex of the former element into chloroform. After the evaporation of the solvent from the combined organic extracts, the residue is ignited to zirconium oxide. The latter is then re-dissolved and zirconium is separated from other elements co-extracted in the solvent extraction procedure by precipitation with mandelic acid. The zirconium mandelate is finally ignited to oxide at 960 deg C. The uranium is separated from the aqueous solutionmore » remaining from the cupferron extraction by precipitating with tannin at a pH of 8; the precipitate being removed by filtration and then ignited a t 800 deg C. The residue is dissolved in nitric acid and the uranium is finally determined by precipitating as ammonium diuranate and then igniting to U{sub 3}O{sub 8}. (auth)« less

  15. IMPROVEMENT OF THE EXTRACTION SEPARATION OF URANIUM AND ZIRCONIUM USING ZIRCONIUM-MASKING REAGENTS (in German)

    SciTech Connect

    Kyrs, M.; Caletka, R.; Selucky, P.

    1963-12-01

    The masking capacities of a series of reagents were studied in the zirconium extraction with tributyl phosphate solution in the presence of nitric acid. It was established that with many reagents an improvement of the separation of uranium from zirconium could be obtained. The efficiency of the reagents increases in the series tannin, oxalic acid, tiron, pyrogallol, and Arsenazo I. (tr-auth)

  16. Copper Mediated Fluorination of Aryl Iodides

    PubMed Central

    Fier, Patrick S.; Hartwig, John F.

    2012-01-01

    The synthesis of aryl fluorides has been a topic of considerable interest because of the importance of aryl fluorides in pharmaceuticals, agrochemicals and materials. The stability, reactivity and biological properties of aryl fluorides can be distinct from those of the corresponding arenes. Methods for the synthesis of aryl fluorides, however, are limited. We report the conversion of a diverse set of aryl iodides to the corresponding aryl fluorides. This reaction occurs with a cationic copper reagent and silver fluoride. Preliminary results suggest this reaction is enabled by a facile reductive elimination from a cationic aryl copper(III) fluoride. PMID:22709145

  17. The addition of iodine to tetramethylammonium iodide

    USGS Publications Warehouse

    Foote, H.W.; Fleischer, M.

    1953-01-01

    The system tetramethylammonium iodide-iodine-toluene has been studied by the solubility method at 6 and at 25??. The compounds (CH3)4NI3, (CH3)4NI5 and (CH3)4NI11 were found to be stable phases at both temperatures. In addition, the compound (CH3)4NI10 was found at 6?? and the compound (CH3)4NI9 at 25??. The dissociation pressures of the compounds at these temperatures were calculated from the solubility data.

  18. Taming the Reactivity of Glycosyl Iodides To Achieve Stereoselective Glycosidation.

    PubMed

    Gervay-Hague, Jacquelyn

    2016-01-19

    Although glycosyl iodides have been known for more than 100 years, it was not until the 21st century that their full potential began to be harnessed for complex glycoconjugate synthesis. Mechanistic studies in the late 1990s probed glycosyl iodide formation by NMR spectroscopy and revealed important reactivity features embedded in protecting-group stereoelectronics. Differentially protected sugars having an anomeric acetate were reacted with trimethylsilyl iodide (TMSI) to generate the glycosyl iodides. In the absence of C-2 participation, generation of the glycosyl iodide proceeded by inversion of the starting anomeric acetate stereochemistry. Once formed, the glycosyl iodide readily underwent in situ anomerization, and in the presence of excess iodide, equilibrium concentrations of α- and β-iodides were established. Reactivity profiles depended upon the identity of the sugar and the protecting groups adorning it. Consistent with the modern idea of disarmed versus armed sugars, ester protecting groups diminished the reactivity of glycosyl iodides and ether protecting groups enhanced the reactivity. Thus, acetylated sugars were slower to form the iodide and anomerize than their benzylated analogues, and these disarmed glycosyl iodides could be isolated and purified, whereas armed ether-protected iodides could only be generated and reacted in situ. All other things being equal, the β-iodide was orders of magnitude more reactive than the thermodynamically more stable α-iodide, consistent with the idea of in situ anomerization introduced by Lemieux in the mid-20th century. Glycosyl iodides are far more reactive than the corresponding bromides, and with the increased reactivity comes increased stereocontrol, particularly when forming α-linked linear and branched oligosaccharides. Reactions with per-O-silylated glycosyl iodides are especially useful for the synthesis of α-linked glycoconjugates. Silyl ether protecting groups make the glycosyl iodide so reactive

  19. Production of Molecular Iodine and Tri-iodide in the Frozen Solution of Iodide: Implication for Polar Atmosphere.

    PubMed

    Kim, Kitae; Yabushita, Akihiro; Okumura, Masanori; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Blaszczak-Boxe, Christopher S; Min, Dae Wi; Yoon, Ho-Il; Choi, Wonyong

    2016-02-02

    The chemistry of reactive halogens in the polar atmosphere plays important roles in ozone and mercury depletion events, oxidizing capacity, and dimethylsulfide oxidation to form cloud-condensation nuclei. Among halogen species, the sources and emission mechanisms of inorganic iodine compounds in the polar boundary layer remain unknown. Here, we demonstrate that the production of tri-iodide (I3(-)) via iodide oxidation, which is negligible in aqueous solution, is significantly accelerated in frozen solution, both in the presence and the absence of solar irradiation. Field experiments carried out in the Antarctic region (King George Island, 62°13'S, 58°47'W) also showed that the generation of tri-iodide via solar photo-oxidation was enhanced when iodide was added to various ice media. The emission of gaseous I2 from the irradiated frozen solution of iodide to the gas phase was detected by using cavity ring-down spectroscopy, which was observed both in the frozen state at 253 K and after thawing the ice at 298 K. The accelerated (photo-)oxidation of iodide and the subsequent formation of tri-iodide and I2 in ice appear to be related with the freeze concentration of iodide and dissolved O2 trapped in the ice crystal grain boundaries. We propose that an accelerated abiotic transformation of iodide to gaseous I2 in ice media provides a previously unrecognized formation pathway of active iodine species in the polar atmosphere.

  20. Artefacts in multimodal imaging of titanium, zirconium and binary titanium–zirconium alloy dental implants: an in vitro study

    PubMed Central

    Schöllchen, Maximilian; Aarabi, Ghazal; Assaf, Alexandre T; Rendenbach, Carsten; Beck-Broichsitter, Benedicta; Semmusch, Jan; Sedlacik, Jan; Heiland, Max; Fiehler, Jens; Siemonsen, Susanne

    2017-01-01

    Objectives: To analyze and evaluate imaging artefacts induced by zirconium, titanium and titanium–zirconium alloy dental implants. Methods: Zirconium, titanium and titanium–zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard protocols were used for each modality. For MRI, line–distance profiles were plotted to quantify the accuracy of size determination. For CT and CBCT, six shells surrounding the implant were defined every 0.5 cm from the implant surface and histogram parameters were determined for each shell. Results: While titanium and titanium–zirconium alloy induced extensive signal voids in MRI owing to strong susceptibility, zirconium implants were clearly definable with only minor distortion artefacts. For titanium and titanium–zirconium alloy, the MR signal was attenuated up to 14.1 mm from the implant. In CT, titanium and titanium–zirconium alloy resulted in less streak artefacts in comparison with zirconium. In CBCT, titanium–zirconium alloy induced more severe artefacts than zirconium and titanium. Conclusions: MRI allows for an excellent image contrast and limited artefacts in patients with zirconium implants. CT and CBCT examinations are less affected by artefacts from titanium and titanium–zirconium alloy implants compared with MRI. The knowledge about differences of artefacts through different implant materials and image modalities might help support clinical decisions for the choice of implant material or imaging device in the clinical setting. PMID:27910719

  1. Artefacts in multimodal imaging of titanium, zirconium and binary titanium-zirconium alloy dental implants: an in vitro study.

    PubMed

    Smeets, Ralf; Schöllchen, Maximilian; Gauer, Tobias; Aarabi, Ghazal; Assaf, Alexandre T; Rendenbach, Carsten; Beck-Broichsitter, Benedicta; Semmusch, Jan; Sedlacik, Jan; Heiland, Max; Fiehler, Jens; Siemonsen, Susanne

    2017-02-01

    To analyze and evaluate imaging artefacts induced by zirconium, titanium and titanium-zirconium alloy dental implants. Zirconium, titanium and titanium-zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard protocols were used for each modality. For MRI, line-distance profiles were plotted to quantify the accuracy of size determination. For CT and CBCT, six shells surrounding the implant were defined every 0.5 cm from the implant surface and histogram parameters were determined for each shell. While titanium and titanium-zirconium alloy induced extensive signal voids in MRI owing to strong susceptibility, zirconium implants were clearly definable with only minor distortion artefacts. For titanium and titanium-zirconium alloy, the MR signal was attenuated up to 14.1 mm from the implant. In CT, titanium and titanium-zirconium alloy resulted in less streak artefacts in comparison with zirconium. In CBCT, titanium-zirconium alloy induced more severe artefacts than zirconium and titanium. MRI allows for an excellent image contrast and limited artefacts in patients with zirconium implants. CT and CBCT examinations are less affected by artefacts from titanium and titanium-zirconium alloy implants compared with MRI. The knowledge about differences of artefacts through different implant materials and image modalities might help support clinical decisions for the choice of implant material or imaging device in the clinical setting.

  2. Phase 2 Methyl Iodide Deep-Bed Adsorption Tests

    SciTech Connect

    Soelberg, Nick; Watson, Tony

    2014-09-01

    Nuclear fission produces fission products (FPs) and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methylmore » iodide adsorption test plan. This report summarizes the second phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during the second half of Fiscal Year (FY) 2014. Test results continue to show that methyl iodide adsorption using AgZ can achieve total iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) above 1,000, until breakthrough occurred. However, mass transfer zone depths are deeper for methyl iodide adsorption compared to diatomic iodine (I2) adsorption. Methyl iodide DFs for the Ag Aerogel test adsorption efficiencies were less than 1,000, and the methyl iodide mass transfer zone depth exceeded 8 inches. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.« less

  3. Removal efficiency of water purifier and adsorbent for iodine, cesium, strontium, barium and zirconium in drinking water.

    PubMed

    Sato, Itaru; Kudo, Hiroaki; Tsuda, Shuji

    2011-01-01

    The severe incident of Fukushima Daiichi Nuclear Power Station has caused radioactive contamination of environment including drinking water. Radioactive iodine, cesium, strontium, barium and zirconium are hazardous fission products because of the high yield and/or relatively long half-life. In the present study, 4 pot-type water purifiers and several adsorbents were examined for the removal effects on these elements from drinking water. Iodide, iodate, cesium and barium were removed by all water purifiers with efficiencies about 85%, 40%, 75-90% and higher than 85%, respectively. These efficiencies lasted for 200 l, which is near the recommended limits for use of filter cartridges, without decay. Strontium was removed with initial efficiencies from 70% to 100%, but the efficiencies were slightly decreased by use. Zirconium was removed by two models, but hardly removed by the other models. Synthetic zeolite A4 efficiently removed cesium, strontium and barium, but had no effect on iodine and zirconium. Natural zeolite, mordenite, removed cesium with an efficiency as high as zeolite A4, but the removal efficiencies for strontium and barium were far less than those of zeolite A4. Activated carbon had little removal effects on these elements. In case of radioactive contamination of tap water, water purifiers may be available for convenient decontamination of drinking water in the home.

  4. Evaluating iodide recycling inhibition as a novel molecular initiating event for thyroid axis disruption

    EPA Science Inventory

    The enzyme iodotyrosine deiodinase (dehalogenase, IYD) catalyzes iodide recycling and promotes iodide retention in thyroid follicular cells. Loss of function or chemical inhibition of IYD reduces available iodide for thyroid hormone synthesis, which leads to hormone insufficiency...

  5. Zirconium: biomedical and nephrological applications.

    PubMed

    Lee, David B N; Roberts, Martin; Bluchel, Christian G; Odell, Ross A

    2010-01-01

    Recent years have witnessed a rapid increase in the use of zirconium (Zr)-containing compounds in artificial internal organs. Examples include dental implants and other restorative practices, total knee and hip replacement, and middle-ear ossicular chain reconstruction. In nephrological practice, Zr-containing sorbents have been used in hemofiltration, hemodialysis, peritoneal dialysis, and in the design and construction of wearable artificial kidneys. Zr compounds continue to be widely and extensively used in deodorant and antiperspirant preparations. In the public health arena, Zr compounds have been studied or used in controlling phosphorus pollution and in the reclamation of poison and bacteria-contaminated water. Experimental and clinical studies support the general consensus that Zr compounds are biocompatible and exhibit low toxicity. Reports on possible Zr-associated adverse reactions are rare and, in general, have not rigorously established a cause-and-effect relationship. Although publications on the use of Zr compounds have continued to increase in recent years, reports on Zr toxicity have virtually disappeared from the medical literature. Nevertheless, familiarity with, and continued vigilant monitoring of, the use of these compounds are warranted. This article provides an updated review on the biomedical use of Zr compounds.

  6. 40 CFR 721.9973 - Zirconium dichlorides (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Zirconium dichlorides (generic). 721... Substances § 721.9973 Zirconium dichlorides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as zirconium dichlorides (PMNs P...

  7. Processing fissile material mixtures containing zirconium and/or carbon

    DOEpatents

    Johnson, Michael Ernest; Maloney, Martin David

    2013-07-02

    A method of processing spent TRIZO-coated nuclear fuel may include adding fluoride to complex zirconium present in a dissolved TRIZO-coated fuel. Complexing the zirconium with fluoride may reduce or eliminate the potential for zirconium to interfere with the extraction of uranium and/or transuranics from fission materials in the spent nuclear fuel.

  8. Zirconium diselenite microstructures, formation and mechanism

    NASA Astrophysics Data System (ADS)

    Naik, Chandan C.; Salker, A. V.

    2018-04-01

    In this work, a series of microstructures of zirconium diselenite (Zr(SeO3)2) has been prepared via a simple precipitation method at room temperature without adding any organic surfactants. Phase purity of the sample has been checked by X-ray Diffraction. From the SEM, FESEM, and TEM images spheroid nanoparticles to the starfish-like structure of zirconium diselenite are detected. The morphological evolution processes were investigated carefully following time-dependent experiments and a growth mechanism has been proposed. Two different crystal growth processes, the oriented attachment process accompanying the Ostwald ripening process were held responsible for the formation of a structure resembling starfish having four arms.

  9. Epitaxial Electrodeposition of Methylammonium Lead Iodide Perovskites

    DOE PAGES

    Koza, Jakub A.; Hill, James C.; Demster, Ashley C.; ...

    2015-12-16

    Here, an electrochemical/chemical route is introduced to deposit both textured and epitaxial films of methylammonium lead iodide (MAPbI 3) perovskites. The perovskite films are produced by chemical conversion of lead dioxide films that have been electrodeposited as either textured or epitaxial films onto [111]-textured Au and [100] and [111] single-crystal Au substrates. The epitaxial relationships for the MAPbI 3 films are MAPbI 3(001)[010]∥PbO 2(100)<001> and MAPbI 3(110)[111]∥PbO 2(100)<001> regardless of the Au substrate orientation, because the in-plane order of the converted film is controlled by the epitaxial PbO 2 precursor film. The textured and epitaxial MAPbI 3 films both havemore » trap densities lower than and photoluminescence intensities higher than those of polycrystalline films produced by spin coating.« less

  10. Homology of pendrin, sodium-iodide symporter and apical iodide transporter.

    PubMed

    Benvenga, Salvatore; Guarneri, Fabrizio

    2018-06-01

    We observed local homology between human pendrin and sodium/iodide symporter (NIS), that was absent in the NIS-homologous sodium/monocarboxylate transporter or apical iodide transporter (AIT) which, however, does not transport iodide. Thus, we analyzed the full proteins. They shared 63 identical and 66 similar residues (overall homology 14.4%, but 21% when omitting intervening sequences of 15 or more residues). Pendrin was more homologous to NIS (25%) than AIT (20%), particularly in the STAS domain (sulfate transporter and antisigma factor antagonist). Homology was concentrated in 11 segments, with 3/11 involving the STAS domain. In 9/11, homology was greater with NIS (45-58.3%) than with AIT (8.3-42.3%); in 4 of these 9 segments, homology was comparable to or greater than that between NIS and AIT (8.3-52.6%). Pendrin residues which are mutated in Pendred's syndrome are identical to those in the aligned position of NIS and AIT. Hypothyroidism-associated pendrin mutations almost always fall within 4/11 segments. These are the first data that show homology between pendrin and NIS, and topographic relationships between pendrin mutations and the hypothyroid phenotype of PDS.

  11. Barium iodide and strontium iodide crystals and scintillators implementing the same

    DOEpatents

    Payne, Stephen A.; Cherepy, Nerine J.; Hull, Giulia E.; Drobshoff, Alexander D.; Burger, Arnold

    2016-11-29

    In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV, where the strontium iodide material is characterized by a volume not less than 1 cm.sup.3. In another embodiment, a scintillator optic includes europium-doped strontium iodide providing at least 50,000 photons per MeV, where the europium in the crystal is primarily Eu.sup.2+, and the europium is present in an amount greater than about 1.6%. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, where a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 and 1.0, the scintillator optic is a crystal that provides at least 50,000 scintillation photons per MeV and energy resolution of less than about 5% at 662 keV, and the crystal has a volume of 1 cm.sup.3 or more; the scintillator optic contains more than about 2% europium.

  12. Flavonoid Rutin Increases Thyroid Iodide Uptake in Rats

    PubMed Central

    Lima Gonçalves, Carlos Frederico; de Souza dos Santos, Maria Carolina; Ginabreda, Maria Gloria; Soares Fortunato, Rodrigo; Pires de Carvalho, Denise; Freitas Ferreira, Andrea Claudia

    2013-01-01

    Thyroid iodide uptake through the sodium-iodide symporter (NIS) is not only an essential step for thyroid hormones biosynthesis, but also fundamental for the diagnosis and treatment of different thyroid diseases. However, part of patients with thyroid cancer is refractory to radioiodine therapy, due to reduced ability to uptake iodide, which greatly reduces the chances of survival. Therefore, compounds able to increase thyroid iodide uptake are of great interest. It has been shown that some flavonoids are able to increase iodide uptake and NIS expression in vitro, however, data in vivo are lacking. Flavonoids are polyhydroxyphenolic compounds, found in vegetables present in human diet, and have been shown not only to modulate NIS, but also thyroperoxidase (TPO), the key enzyme in thyroid hormones biosynthesis, besides having antiproliferative effect in thyroid cancer cell lines. Therefore, we aimed to evaluate the effect of some flavonoids on thyroid iodide uptake in Wistar rats in vivo. Among the flavonoids tested, rutin was the only one able to increase thyroid iodide uptake, so we decided to evaluate the effect of this flavonoid on some aspects of thyroid hormones synthesis and metabolism. Rutin led to a slight reduction of serum T4 and T3 without changes in serum thyrotropin (TSH), and significantly increased hypothalamic, pituitary and brown adipose tissue type 2 deiodinase and decreased liver type 1 deiodinase activities. Moreover, rutin treatment increased thyroid iodide uptake probably due to the increment of NIS expression, which might be secondary to increased response to TSH, since TSH receptor expression was increased. Thus, rutin might be useful as an adjuvant in radioiodine therapy, since this flavonoid increased thyroid iodide uptake without greatly affecting thyroid function. PMID:24023911

  13. METHOD AND ALLOY FOR BONDING TO ZIRCONIUM

    DOEpatents

    McCuaig, F.D.; Misch, R.D.

    1960-04-19

    A brazing alloy can be used for bonding zirconium and its alloys to other metals, ceramics, and cermets, and consists of 6 to 9 wt.% Ni, 6 to 9 wn~.% Cr, Mo, or W, 0 to 7.5 wt.% Fe, and the balance Zr.

  14. Superconductivity in zirconium-rhodium alloys

    NASA Technical Reports Server (NTRS)

    Zegler, S. T.

    1969-01-01

    Metallographic studies and transition temperature measurements were made with isothermally annealed and water-quenched zirconium-rhodium alloys. The results clarify both the solid-state phase relations at the Zr-rich end of the Zr-Rh alloy system and the influence upon the superconducting transition temperature of structure and composition.

  15. International strategic minerals inventory summary report; zirconium

    USGS Publications Warehouse

    Towner, R.R.

    1992-01-01

    Zircon, a zirconium silicate, is currently the most important commercial zirconium-bearing mineral. Baddeleyite, a natural form of zirconia, is less important but has some specific end uses. Both zircon and baddeleyite occur in hard-rock and placer deposits, but at present all zircon production is from placer deposits. Most baddeleyite production is from hard-rock deposits, principally as a byproduct of copper and phosphate-rock mining. World zirconium resources in identified, economically exploitable deposits are about 46 times current production rates. Of these resources, some 71 percent are in South Africa, Australia, and the United States. The principal end uses of zirconium minerals are in ceramic applications and as refractories, abrasives, and mold linings in foundries. A minor amount, mainly of zircon, is used for the production of hafnium-free zirconium metal, which is used principally for sheathing fuel elements in nuclear reactors and in the chemical-processing industry, aerospace engineering, and electronics. Australia and South Africa are the largest zircon producers and account for more than 70 percent of world output; the United States and the Soviet Union account for another 20 percent. South Africa accounts for almost all the world's production of baddeleyite, which is about 2 percent of world production of contained zirconia. Australia and South Africa are the largest exporters of zircon. Unless major new deposits are developed in countries that have not traditionally produced zircon, the pattern of world production is unlikely to change by 2020. The proportions, however, of production that come from existing producing countries may change somewhat.

  16. Cesium iodide crystals fused to vacuum tube faceplates

    NASA Technical Reports Server (NTRS)

    Fleck, H. G.

    1964-01-01

    A cesium iodide crystal is fused to the lithium fluoride faceplate of a photon scintillator image tube. The conventional silver chloride solder is then used to attach the faceplate to the metal support.

  17. Chloride, bromide and iodide scintillators with europium

    SciTech Connect

    Zhuravleva, Mariya; Yang, Kan

    A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has beenmore » studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.« less

  18. Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer—A Review

    PubMed Central

    Gonçalves, Carlos F. L.; de Freitas, Mariana L.; Ferreira, Andrea C. F.

    2017-01-01

    Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer. PMID:28604619

  19. Engineering and design properties of thallium-doped sodium iodide and selected properties of sodium-doped cesium iodide

    NASA Technical Reports Server (NTRS)

    Forrest, K.; Haehner, C.; Heslin, T.; Magida, M.; Uber, J.; Freiman, S.; Hicho, G.; Polvani, R.

    1984-01-01

    Mechanical and thermal properties, not available in the literature but necessary to structural design, using thallium doped sodium iodide and sodium doped cesium iodide were determined to be coefficient of linear thermal expansion, thermal conductivity, thermal shock resistance, heat capacity, elastic constants, ultimate strengths, creep, hardness, susceptibility to subcritical crack growth, and ingot variation of strength. These properties were measured for single and polycrystalline materials at room temperature.

  20. Hydrogen peroxide inhibits iodide influx and enhances iodide efflux in cultured FRTL-5 rat thyroid cells.

    PubMed

    Sugawara, M; Yamaguchi, D T; Lee, H Y; Yanagisawa, K; Murakami, S; Summer, C N; Johnson, D G; Levin, S R

    1990-05-01

    This study describes the effects of hydrogen peroxide on the two iodide transport systems, I influx and I efflux, in the cultured FRTL-5 rat thyroid cells. I influx was measured by the amount of I taken up by the cells during incubation with Na125I and NaI for 7 min, and I efflux was measured by calculating the rate of 125I release from the 125I-loaded cells in the presence and absence of 5 mmol/l H2O2. Exposure to greater than 100 mumol/l H2O2 for 40 min caused a significant inhibition of I influx; the inhibition was reversible and non-competitive with iodide. Thyroid Na+K+ ATPase activity, a major mechanism to drive I influx, decreased by 40% after the cells were exposed to 5 mmol/l H2O2 for 10 min. H2O2 enhanced I efflux only when Ca2+ was present in the medium. The mechanism of an enhanced I efflux by H2O2 appears to be mediated through the elevation of free cytosolic Ca2+ concentration. Our data indicate that H2O2 can affect I transport by inhibiting I influx and enhancing I efflux.

  1. Structure and interstitial iodide migration in hybrid perovskite methylammonium lead iodide

    NASA Astrophysics Data System (ADS)

    Minns, J. L.; Zajdel, P.; Chernyshov, D.; van Beek, W.; Green, M. A.

    2017-05-01

    Hybrid perovskites form an emerging family of exceptional light harvesting compounds. However, the mechanism underpinning their photovoltaic effect is still far from understood, which is impeded by a lack of clarity on their structures. Here we show that iodide ions in the methylammonium lead iodide migrate via interstitial sites at temperatures above 280 K. This coincides with temperature dependent static distortions resulting in pseudocubic local symmetry. Based on bond distance analysis, the migrating and distorted iodines are at lengths consistent with the formation of I2 molecules, suggesting a 2I--->I2+2e- redox couple. The actual formula of this compound is thus (CH3NH3)PbI3-2x(I2)x where x~0.007 at room temperature. A crucial feature of the tetragonal structure is that the methylammonium ions do not sit centrally in the A-site cavity, but disordered around two off-centre orientations that facilitate the interstitial ion migration via a gate opening mechanism.

  2. Optical response of mixed methylammonium lead iodide and formamidinium tin iodide perovskite thin films

    DOE PAGES

    Ghimire, Kiran; Zhao, Dewei; Yan, Yanfa; ...

    2017-07-13

    Here, mixed tin (Sn) and lead (Pb) based perovskite thin films have been prepared by solution processing combining methylammonium lead iodide (MAPbI 3) and formamidinium tin iodide (FASnI 3) precursors. Optical response in the form of complex dielectric function (ε = ε 1 + iε 2) spectra and absorption coefficient (α) spectra of (FASnI 3) 1-x(MAPbI 3) x based perovskite films have been extracted over a spectral range 0.74 to 5.89 eV using spectroscopic ellipsometry. Absorption band edge energy changes as a function of composition for films including FASnI 3, MAPbI 3, and mixed x = 0.20, 0.35, 0.40, andmore » 0.6 (FASnI 3) 1-x(MAPbI 3) x perovskites. (FASnI 3) 0.60(MAPbI 3) 0.4 is found to have the minimum absorption band edge energy near ~1.2 eV.« less

  3. METHOD OF MAKING DELTA ZIRCONIUM HYDRIDE MONOLITHIC MODERATOR PIECES

    DOEpatents

    Vetrano, J.B.

    1962-01-23

    A method is given for preparing large, sound bodies of delta zirconium hydride. The method includes the steps of heating a zirconium body to a temperature of not less than l000 deg C, providing a hydrogen atmosphere for the zirconium body at a pressure not greater than one atmosphere, reducing the temperature slowly to 800 deg C at such a rate that cracks do not form while maintaining the hydrogen pressure substantially constant, and cooling in an atmosphere of hydrogen. (AEC)

  4. Intercalation chemistry of zirconium 4-sulfophenylphosphonate

    NASA Astrophysics Data System (ADS)

    Svoboda, Jan; Zima, Vítězslav; Melánová, Klára; Beneš, Ludvík; Trchová, Miroslava

    2013-12-01

    Zirconium 4-sulfophenylphosphonate is a layered material which can be employed as a host for the intercalation reactions with basic molecules. A wide range of organic compounds were chosen to represent intercalation ability of zirconium 4-sulfophenylphosphonate. These were a series of alkylamines from methylamine to dodecylamine, 1,4-phenylenediamine, p-toluidine, 1,8-diaminonaphthalene, 1-aminopyrene, imidazole, pyridine, 4,4‧-bipyridine, poly(ethylene imine), and a series of amino acids from glycine to 6-aminocaproic acid. The prepared compounds were characterized by powder X-ray diffraction, thermogravimetry analysis and IR spectroscopy and probable arrangement of the guest molecules in the interlayer space of the host is proposed based on the interlayer distance of the prepared intercalates and amount of the intercalated guest molecules.

  5. Accelerated degradation of methyl iodide by agrochemicals.

    PubMed

    Zheng, Wei; Papiernik, Sharon K; Guo, Mingxin; Yates, Scott R

    2003-01-29

    The fumigant methyl iodide (MeI, iodomethane) is considered a promising alternative to methyl bromide (MeBr) for soil-borne pest control in high-cash-value crops. However, the high vapor pressure of MeI results in emissions of a significant proportion of the applied mass into the ambient air, and this may lead to pollution of the environment. Integrating the application of certain agrochemicals with soil fumigation provides a novel approach to reduce excessive fumigant emissions. This study investigated the potential for several agrochemicals that are commonly used in farming operations, including fertilizers and nitrification inhibitors, to transform MeI in aqueous solution. The pseudo-first-order hydrolysis half-life (t(1/2)) of MeI was approximately 108 d, while the transformation of MeI in aqueous solutions containing selected agrochemicals was more rapid, with t(1/2) < 100 d (t(1/2) < 0.5 d in some solutions containing nitrification inhibitors). The influence of these agrochemicals on the rate of MeI degradation in soil was also determined. Adsorption to soil apparently reduced the availability of some nitrification inhibitors in the soil aqueous phase and lowered the degradation rate in soil. In contrast, addition of the nitrification inhibitors thiourea and allylthiourea to soil significantly accelerated the degradation of MeI, possibly due to soil surface catalysis. The t(1/2) of MeI was <20 h in thiourea- and allylthiourea-amended soil, considerably less than that in unamended soil (t(1/2) > 300 h).

  6. Manufacturing process to reduce large grain growth in zirconium alloys

    DOEpatents

    Rosecrans, P.M.

    1984-08-01

    It is an object of the present invention to provide a procedure for desensitizing zirconium-based alloys to large grain growth (LGG) during thermal treatment above the recrystallization temperature of the alloy. It is a further object of the present invention to provide a method for treating zirconium-based alloys which have been cold-worked in the range of 2 to 8% strain to reduce large grain growth. It is another object of the present invention to provide a method for fabricating a zirconium alloy clad nuclear fuel element wherein the zirconium clad is resistant to large grain growth.

  7. Evaluation of a Zirconium Recycle Scrubber System

    SciTech Connect

    Spencer, Barry B.; Bruffey, Stephanie H.

    2017-04-01

    A hot-cell demonstration of the zirconium recycle process is planned as part of the Materials Recovery and Waste Forms Development (MRWFD) campaign. The process treats Zircaloy® cladding recovered from used nuclear fuel with chlorine gas to recover the zirconium as volatile ZrCl4. This releases radioactive tritium trapped in the alloy, converting it to volatile tritium chloride (TCl). To meet regulatory requirements governing radioactive emissions from nuclear fuel treatment operations, the capture and retention of a portion of this TCl may be required prior to discharge of the off-gas stream to the environment. In addition to demonstrating tritium removal from amore » synthetic zirconium recycle off-gas stream, the recovery and quantification of tritium may refine estimates of the amount of tritium present in the Zircaloy cladding of used nuclear fuel. To support these objectives, a bubbler-type scrubber was fabricated to remove the TCl from the zirconium recycle off-gas stream. The scrubber was fabricated from glass and polymer components that are resistant to chlorine and hydrochloric acid solutions. Because of concerns that the scrubber efficiency is not quantitative, tests were performed using DCl as a stand-in to experimentally measure the scrubbing efficiency of this unit. Scrubbing efficiency was ~108% ± 3% with water as the scrubber solution. Variations were noted when 1 M NaOH scrub solution was used, values ranged from 64% to 130%. The reason for the variations is not known. It is recommended that the equipment be operated with water as the scrubbing solution. Scrubbing efficiency is estimated at 100%.« less

  8. ELECTROLYTIC CLADDING OF ZIRCONIUM ON URANIUM

    DOEpatents

    Wick, J.J.

    1959-09-22

    A method is presented for coating uranium with zircoalum by rendering the uranium surface smooth and oxidefree, immersing it in a molten electrolytic bath in NaCI, K/sub 2/ZrF/sub 6/, KF, and ZrO/sub 2/, and before the article reaches temperature equilibrium with the bath, applying an electrolyzing current of 60 amperes per square dectmeter at approximately 3 volts to form a layer of zirconium metal on the uranium.

  9. The pathogenesis of iodide mumps: A case report.

    PubMed

    Zhang, Guilian; Li, Tao; Wang, Heying; Liu, Jiao

    2017-11-01

    Iodide mumps is an uncommon condition, induced by iodide-containing contrast, and is characterized by a rapid, painless enlargement of the bilateral or unilateral salivary gland. At present, the pathogenesis of iodide mumps is not yet clear. It may be related to an idiosyncratic reaction, a toxic accumulation of iodine in the gland duct, or renal function damage leading to an iodine excretion disorder. This paper reports the clinical manifestations and magnetic resonance imaging results of one case of iodide mumps, which occurred after digital subtraction angiography. A 66-year-old Chinese man presented to our department with a 1-month speech barrier and 1 day of vomiting. He had the history of high blood sugar, the history of high blood pressure and the history of Vitiligo. He had no history of allergies and had never previously received iodide-containing contrast. His renal function and other laboratory examinations were normal. During the digital subtraction angiography (DSA), the patient received approximately 130 mL of nonionic contrast agent (iodixanol). Five hours postsurgery, the patient experienced bilateral parotid enlargement with no other discomfort, such as pain, fever, skin redness, itching, hives, nausea, vomiting, or respiratory abnormalities. We thought the diagnosis was iodide mumps. Intravenous dexamethasone (5 mg) was administered. 20 hours post-DSA, after which the bilateral parotid shrunk. By 4 days postsurgery, the patient's bilateral parotid had recovered completely. We found no obvious abnormal sequence signal in diffusion magnetic resonance imaging or the corresponding apparent diffusion coefficient. Our findings suggest that vasogenic edema may play an important role in the pathogenesis of iodide mumps. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  10. Fluorometric determination of zirconium in minerals

    USGS Publications Warehouse

    Alford, W.C.; Shapiro, L.; White, C.E.

    1951-01-01

    The increasing use of zirconium in alloys and in the ceramics industry has created renewed interest in methods for its determination. It is a common constituent of many minerals, but is usually present in very small amounts. Published methods tend to be tedious, time-consuming, and uncertain as to accuracy. A new fluorometric procedure, which overcomes these objections to a large extent, is based on the blue fluorescence given by zirconium and flavonol in sulfuric acid solution. Hafnium is the only element that interferes. The sample is fused with borax glass and sodium carbonate and extracted with water. The residue is dissolved in sulfuric acid, made alkaline with sodium hydroxide to separate aluminum, and filtered. The precipitate is dissolved in sulfuric acid and electrolysed in a Melaven cell to remove iron. Flavonol is then added and the fluorescence intensity is measured with a photo-fluorometer. Analysis of seven standard mineral samples shows excellent results. The method is especially useful for minerals containing less than 0.25% zirconium oxide.

  11. From Zirconium Nanograins to Zirconia Nanoneedles

    PubMed Central

    Zalnezhad, E.; Hamouda, A. M. S.; Jaworski, J.; Do Kim, Young

    2016-01-01

    Combinations of three simple techniques were utilized to gradually form zirconia nanoneedles from zirconium nanograins. First, a physical vapor deposition magnetron sputtering technique was used to deposit pure zirconium nanograins on top of a substrate. Second, an anodic oxidation was applied to fabricate zirconia nanotubular arrays. Finally, heat treatment was used at different annealing temperatures in order to change the structure and morphology from nanotubes to nanowires and subsequently to nanoneedles in the presence of argon gas. The size of the pure zirconium nanograins was estimated to be approximately 200–300 nm. ZrO2 nanotubular arrays with diameters of 70–120 nm were obtained. Both tetragonal and monoclinic ZrO2 were observed after annealing at 450 °C and 650 °C. Only a few tetragonal peaks appeared at 850 °C, while monoclinic ZrO2 was obtained at 900 °C and 950 °C. In assessing the biocompatibility of the ZrO2 surface, the human cell line MDA-MB-231 was found to attach and proliferate well on surfaces annealed at 850 °C and 450 °C; however, the amorphous ZrO2 surface, which was not heat treated, did not permit extensive cell growth, presumably due to remaining fluoride. PMID:27623486

  12. METHOD OF PRODUCING HAFNIUM-FREE "CRYSTAL-BAR" ZIRCONIUM FROM A CRUDE SOURCE OF ZIRCONIUM

    SciTech Connect

    Newnham, I.E.

    1959-05-01

    Production of Hf-free crystal-bar Zr is described. The crude source of Zr is carbided with carbon in a graphite resistance furnace, then treated with iodide to form ZrI/sub 4/. The ZrI/sub 4/ plus iodide impurities is heated with Zr powder in an evacuated vessel to 500 C. This causes ZrI/sub 3/ to form and be separated from the more volatile HfI/sub 4/ and AlI/sub 3/ which deposit on the condenserlid. The ZrI/sub 3/ is further separated from iodides of Fe, and V by heating to 350 C to re-form ZrI/sub 4/. The morevolatile ZrI/sub 4/ then is collected in puremore » form on another condenser-lid from which it can be removed and reduced to Zr. (T.R.H.)« less

  13. Development of Self-Healing Zirconium-Silicide Coatings for Improved Performance Zirconium-Alloy Fuel Cladding

    SciTech Connect

    Sridharan, Kumar; Mariani, Robert; Bai, Xianming

    Zirconium-alloy fuel claddings have been used successfully in Light Water Reactors (LWR) for over four decades. However, under high temperature accident conditions, zirconium-alloys fuel claddings exhibit profuse exothermic oxidation accompanied by release of hydrogen gas due to the reaction with water/steam. Additionally, the ZrO 2 layer can undergo monoclinic to tetragonal to cubic phase transformations at high temperatures which can induce stresses and cracking. These events were unfortunately borne out in the Fukushima-Daiichi accident in in Japan in 2011. In reaction to such accident, protective oxidation-resistant coatings for zirconium-alloy fuel claddings has been extensively investigated to enhance safety margins inmore » accidents as well as fuel performance under normal operation conditions. Such surface modification could also beneficially affect fuel rod heat transfer characteristics. Zirconium-silicide, a candidate coating material, is particularly attractive because zirconium-silicide coating is expected to bond strongly to zirconium-alloy substrate. Intermetallic compound phases of zirconium-silicide have high melting points and oxidation of zirconium silicide produces highly corrosion resistant glassy zircon (ZrSiO 4) and silica (SiO 2) which possessing self-healing qualities. Given the long-term goal of developing such coatings for use with nuclear reactor fuel cladding, this work describes results of oxidation and corrosion behavior of bulk zirconium-silicide and fabrication of zirconium-silicide coatings on zirconium-alloy test flats, tube configurations, and SiC test flats. In addition, boiling heat transfer of these modified surfaces (including ZrSi 2 coating) during clad quenching experiments is discussed in detail.« less

  14. Study on gold concentrate leaching by iodine-iodide

    NASA Astrophysics Data System (ADS)

    Wang, Hai-xia; Sun, Chun-bao; Li, Shao-ying; Fu, Ping-feng; Song, Yu-guo; Li, Liang; Xie, Wen-qing

    2013-04-01

    Gold extraction by iodine-iodide solution is an effective and environment-friendly method. In this study, the method using iodine-iodide for gold leaching is proved feasible through thermodynamic calculation. At the same time, experiments on flotation gold concentrates were carried out and encouraging results were obtained. Through optimizing the technological conditions, the attained high gold leaching rate is more than 85%. The optimum process conditions at 25°C are shown as follows: the initial iodine concentration is 1.0%, the iodine-to-iodide mole ratio is 1:8, the solution pH value is 7, the liquid-to-solid mass ratio is 4:1, the leaching time is 4 h, the stirring intensity is 200 r/mim, and the hydrogen peroxide consumption is 1%.

  15. Phase 1 Methyl Iodide Deep-Bed Adsorption Tests

    SciTech Connect

    Soelberg, Nick; Watson, Tony

    2014-08-22

    Nuclear fission results in the production of fission products (FPs) and activation products including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent [Jubin 2012b]. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing hasmore » progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the first phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during Fiscal Year (FY) 2013 and early FY-2014. Testing has been performed to address questions posed in the test plan, and followed the testing outline in the test plan. Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide reacts when in contact with the AgZ sorbent, and not significantly in the gas flow upstream of the sorbent. The reaction(s) enable separation of the iodine from the organic moiety, so that the iodine can chemisorb onto the sorbent. The organic moiety can form other compounds, some of which are organic compounds that are detected and can be tentatively identified using GC-FID and GCMS. Test results also show that other gas constituents (NOx and/or H2O) can affect the methyl iodide reactions. With NOx and H2O present in the gas stream, the majority of uncaptured iodine exiting iodine-laden sorbent beds is in the form of I2 or HI

  16. Standard free energy of formation of iron iodide

    NASA Technical Reports Server (NTRS)

    Khandkar, A.; Tare, V. B.; Wagner, J. B., Jr.

    1983-01-01

    An experiment is reported where silver iodide is used to determine the standard free energy of formation of iron iodide. By using silver iodide as a solid electrolyte, a galvanic cell, Ag/AgI/Fe-FeI2, is formulated. The standard free energy of formation of AgI is known, and hence it is possible to estimate the standard free energy of formation of FeI2 by measuring the open-circuit emf of the above cell as a function of temperature. The free standard energy of formation of FeI2 determined by this method is -38784 + 24.165T cal/mol. It is estimated that the maximum error associated with this method is plus or minus 2500 cal/mol.

  17. Thyroid effects of iodine and iodide in potable water

    NASA Technical Reports Server (NTRS)

    Bull, Richard J.; Thrall, Karla D.; Sherer, Todd T.

    1991-01-01

    Experiments are reviewed which examine the comparative toxicological effects of iodide (I) and iodine (I2) when used to disinfect drinking water. References are made to a subchronic study in rats, a comparison of the distribution of radiolabeled I and I2, and a demonstration of thyroxine formation in the gastrointestinal tract. The results of the study of the rats are examined in detail; the findings show that I and I2 have opposite effects on the concentrations of thyroid hormones in blood. Iodide slightly decreases circulating thyroxine, while I2 significantly increases the thyroxine concentrations, decreases triiodothyronine levels, and does not change the weight of the thyroid gland. The related effects of I2 ingestion are set forth in detail and are shown to be unique to I2 contamination. Iodine can counteract the effects of iodide and should therefore be used as a disinfectant in drinking water.

  18. NEUTRON REACTOR FUEL ELEMENT UTILIZING ZIRCONIUM-BASE ALLOYS

    DOEpatents

    Saller, H.A.; Keeler, J.R.; Szumachowski, E.R.

    1957-11-12

    This patent relates to clad fuel elements for use in neutronic reactors and is drawn to such a fuel element which consists of a core of fissionable material, comprised of an alloy of zirconium and U/sup 235/ enriched uranium, encased in a jacket of a binary zirconium-tin alloy in which the tin content ranges between 1 and 15% by weight.

  19. [The clinical application of zirconium-dioxide-ceramics. Case report].

    PubMed

    Somfai, Dóra; Zsigmond, Ágnes; Károlyházy, Katalin; Kispély, Barbara; Hermann, Péter

    2015-12-01

    Due to its outstanding physical, mechanical and esthetic properties, zirconium-dioxide is one of the most popular non-metal denture, capable of surpassing PFM in most cases. The recent advances of CAD/CAM technology makes it a good alternitve. Here we show the usefulness of zirconium-dioxide in everyday dental practice through three case reports.

  20. 40 CFR 721.10602 - Lead niobium titanium zirconium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... as specified in § 721.90 (a)(4), (b)(4), and (c)(4) (Where N=8, and 8 is an aggregate of releases for the following substances: Lead strontium titanium zirconium oxide (PMN P-11-270; CAS No. 61461-40-3... strontium titanium tungsten oxide (PMN P-11-272; CAS No. 1262279-30-0); Lanthanum lead titanium zirconium...

  1. 40 CFR 721.10602 - Lead niobium titanium zirconium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... as specified in § 721.90 (a)(4), (b)(4), and (c)(4) (Where N=8, and 8 is an aggregate of releases for the following substances: Lead strontium titanium zirconium oxide (PMN P-11-270; CAS No. 61461-40-3... strontium titanium tungsten oxide (PMN P-11-272; CAS No. 1262279-30-0); Lanthanum lead titanium zirconium...

  2. 40 CFR 721.10598 - Lead strontium titanium zirconium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Lead strontium titanium zirconium... Specific Chemical Substances § 721.10598 Lead strontium titanium zirconium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lead strontium...

  3. 40 CFR 721.10598 - Lead strontium titanium zirconium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Lead strontium titanium zirconium... Specific Chemical Substances § 721.10598 Lead strontium titanium zirconium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lead strontium...

  4. PROCESS FOR DISSOLVING BINARY URANIUM-ZIRCONIUM OR ZIRCONIUM-BASE ALLOYS

    DOEpatents

    Jonke, A.A.; Barghusen, J.J.; Levitz, N.M.

    1962-08-14

    A process of dissolving uranium-- zirconium and zircaloy alloys, e.g. jackets of fuel elements, with an anhydrous hydrogen fluoride containing from 10 to 32% by weight of hydrogen chloride at between 400 and 450 deg C., preferably while in contact with a fluidized inert powder, such as calcium fluoride is described. (AEC)

  5. Zirconium fluoride glass - Surface crystals formed by reaction with water

    NASA Technical Reports Server (NTRS)

    Doremus, R. H.; Bansal, N. P.; Bradner, T.; Murphy, D.

    1984-01-01

    The hydrated surfaces of a zirconium barium fluoride glass, which has potential for application in optical fibers and other optical elements, were observed by scanning electron microscopy. Crystalline zirconium fluoride was identified by analysis of X-ray diffraction patterns of the surface crystals and found to be the main constituent of the surface material. It was also found that hydrated zirconium fluorides form only in highly acidic fluoride solutions. It is possible that the zirconium fluoride crystals form directly on the glass surface as a result of its depletion of other ions. The solubility of zirconium fluoride is suggested to be probably much lower than that of barium fluoride (0.16 g/100 cu cm at 18 C). Dissolution was determined to be the predominant process in the initial stages of the reaction of the glass with water. Penetration of water into the glass has little effect.

  6. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    DOEpatents

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  7. Cherenkov and Scintillation Properties of Cubic Zirconium

    NASA Technical Reports Server (NTRS)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  8. METHOD FOR DISSOLVING ZIRCONIUM-URANIUM COMPOSITIONS

    DOEpatents

    Gens, T.A.

    1961-07-18

    A method is descrioed for treating a zirconium-- uranium composition to form a stable solution from which uranium and other values may be extracted by contacting the composition with at least a 4 molar aqueous solution of ammonium fluoride at a temperature of about 100 deg C, adding a peroxide, in incremental amounts, to the heated solution throughout the period of dissolution until all of the uranium is converted to soluble uranyl salt, adding nitric acid to the resultant solution to form a solvent extraction feed solution to convert the uranyl salt to a solvent extractable state, and thereafter recovering the uranium and other desired values from the feed solution by solvent extraction.

  9. Physical property measurements of doped cesium iodide crystals

    NASA Technical Reports Server (NTRS)

    Synder, R. S.; Clotfelter, W. N.

    1974-01-01

    Mechanical and thermal property values are reported for crystalline cesium iodide doped with sodium and thallium. Young's modulus, bulk modulus, shear modulus, and Poisson's ratio were obtained from ultrasonic measurements. Young's modulus and the samples' elastic and plastic behavior were also measured under tension and compression. Thermal expansion and thermal conductivity were the temperature dependent measurements that were made.

  10. 21 CFR 520.763a - Dithiazanine iodide tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Dithiazanine iodide tablets. 520.763a Section 520.763a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763a Dithiazanine...

  11. 21 CFR 520.763b - Dithiazanine iodide powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Dithiazanine iodide powder. 520.763b Section 520.763b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

  12. 21 CFR 520.763a - Dithiazanine iodide tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Dithiazanine iodide tablets. 520.763a Section 520.763a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763a Dithiazanine...

  13. 21 CFR 520.763 - Dithiazanine iodide oral dosage forms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Dithiazanine iodide oral dosage forms. 520.763 Section 520.763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763...

  14. 21 CFR 520.763 - Dithiazanine iodide oral dosage forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Dithiazanine iodide oral dosage forms. 520.763 Section 520.763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763...

  15. 21 CFR 520.763b - Dithiazanine iodide powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Dithiazanine iodide powder. 520.763b Section 520.763b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

  16. 21 CFR 520.763a - Dithiazanine iodide tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Dithiazanine iodide tablets. 520.763a Section 520.763a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763a Dithiazanine...

  17. 21 CFR 520.763 - Dithiazanine iodide oral dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Dithiazanine iodide oral dosage forms. 520.763 Section 520.763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763...

  18. 21 CFR 520.763 - Dithiazanine iodide oral dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dithiazanine iodide oral dosage forms. 520.763 Section 520.763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763...

  19. 21 CFR 520.763 - Dithiazanine iodide oral dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Dithiazanine iodide oral dosage forms. 520.763 Section 520.763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763...

  20. 21 CFR 520.763b - Dithiazanine iodide powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Dithiazanine iodide powder. 520.763b Section 520.763b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

  1. 21 CFR 520.763a - Dithiazanine iodide tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Dithiazanine iodide tablets. 520.763a Section 520.763a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763a Dithiazanine...

  2. 21 CFR 520.763b - Dithiazanine iodide powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dithiazanine iodide powder. 520.763b Section 520.763b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

  3. 21 CFR 520.763b - Dithiazanine iodide powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Dithiazanine iodide powder. 520.763b Section 520.763b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.763b Dithiazanine...

  4. Processing α-mercuric iodide by zone refining

    NASA Astrophysics Data System (ADS)

    Burger, A.; Morgan, S. H.; Henderson, D. O.; Biao, Y.; Zhang, K.; Silberman, E.; Nason, D.; van den Berg, L.; Ortale-Baccash, C.; Cross, E.

    1993-03-01

    An investigation is being conducted on zone refining α-mercuric iodide. Analytical studies using differential scanning calorimetry and anion chromatography indicate that impurities are accumulated mainly at the end where zone travel terminates. Early results indicate that single crystals can be readily grown from zone-refined material.

  5. Palladium-Catalyzed Direct C–H Arylation of Cyclic Enaminones with Aryl Iodides

    PubMed Central

    Yu, Yi-Yun; Bi, Lei

    2013-01-01

    A ligand-free method for the Pd-catalyzed direct arylation of cyclic enaminones using aryl iodides was developed. This method can be applied to a wide range of cyclic enaminones and aryl iodides with excellent C5-regioselectivity. Using widely available aryl iodides, the generality of this transformation provides easy access to a variety of 3-arylpiperidine structural motifs. PMID:23750615

  6. 40 CFR 415.510 - Applicability; description of the potassium iodide production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... potassium iodide production subcategory. 415.510 Section 415.510 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Potassium Iodide Production Subcategory § 415.510 Applicability; description of the potassium iodide production subcategory. The provisions of this subpart are applicable to discharges...

  7. 40 CFR 415.510 - Applicability; description of the potassium iodide production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... potassium iodide production subcategory. 415.510 Section 415.510 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Potassium Iodide Production Subcategory § 415.510 Applicability; description of the potassium iodide production subcategory. The provisions of this subpart are applicable to discharges...

  8. 40 CFR 415.510 - Applicability; description of the potassium iodide production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... potassium iodide production subcategory. 415.510 Section 415.510 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Potassium Iodide Production Subcategory § 415.510 Applicability; description of the potassium iodide production subcategory. The provisions of this subpart are applicable to discharges...

  9. 40 CFR 415.510 - Applicability; description of the potassium iodide production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... potassium iodide production subcategory. 415.510 Section 415.510 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Potassium Iodide Production Subcategory § 415.510 Applicability; description of the potassium iodide production subcategory. The provisions of this subpart are applicable to discharges...

  10. 40 CFR 415.510 - Applicability; description of the potassium iodide production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... potassium iodide production subcategory. 415.510 Section 415.510 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Potassium Iodide Production Subcategory § 415.510 Applicability; description of the potassium iodide production subcategory. The provisions of this subpart are applicable to discharges...

  11. Development of a mercuric iodide solid state spectrometer for X-ray astronomy

    NASA Technical Reports Server (NTRS)

    Vallerga, J.

    1983-01-01

    Mercuric iodide detectors, experimental development for astronomical use, X ray observations of the 1980 Cygnus X-1 High State, astronomical had X ray detectors in current use, detector development, balloon flight of large area (1500 sq cm) Phoswich detectors, had X ray telescope design, shielded mercuric iodide background measurement, Monte Carlo analysis, measurements with a shielded mercuric iodide detector are discussed.

  12. Regulation of Iodide Uptake in Placental Primary Cultures

    PubMed Central

    Burns, R.; O'Herlihy, C.; Smyth, P.P.A.

    2013-01-01

    Background Maintenance of adequate iodide supply to the developing fetus is dependent not only on maternal dietary iodine intake but also on placental iodide transport. The objective of this study was to examine the effects of different pregnancy-associated hormones on the uptake of radioiodide by the placenta and to determine if iodide transporter expression is affected by hormone incubation. Methods Primary cultures of placental trophoblast cells were established from placentas obtained at term from pre-labor caesarean sections. They were pre-incubated with 17β-estradiol, prolactin, oxytocin, human chorionic gonadotropin (hCG) and progesterone either singly or in combination over 12 h with 125I uptake being measured after 6 h. RNA was isolated from placental trophoblasts and real-time RT-PCR performed using sodium iodide symporter (NIS) and pendrin (PDS) probes. Results Significant dose response increments in 125I uptake by trophoblast cells (p < 0.01) were observed following incubation with hCG (60% increase), oxytocin (45% increase) and prolactin (32% increase). Although progesterone (50-200 ng/ml) and 17β-estradiol (1,000-15,000 pg/ml) alone produced no significant differences in uptake, they facilitated increased uptake when combined with prolactin or oxytocin, with a combination of all four hormones producing the greatest increase (82%). Increased 125I uptake was accompanied by corresponding increments in NIS mRNA (ratio 1.52) compared to untreated control cells. No significantly increased expression levels of PDS were observed. Conclusions Pregnancy-associated hormones, particularly oxytocin and hCG, have a role in promoting placental iodide uptake which may protect the fetus against iodine deficiency. PMID:24783055

  13. FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

    SciTech Connect

    Soelberg, Nicholas Ray; Watson, Tony Leroy

    2015-09-30

    Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO 3 and increased NO 2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reducedmore » silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO 2, very low H 2O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I 2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.« less

  14. METHOD OF PREPARING SINTERED ZIRCONIUM METAL FROM ITS HYDRIDES

    DOEpatents

    Angier, R.P.

    1958-02-11

    The invention relates to the preparation of metal shapes from zirconium hydride by powder metallurgical techniques. The zirconium hydride powder which is to be used for this purpose can be prepared by rendering massive pieces of crystal bar zirconium friable by heat treatment in purified hydrogen. This any then be ground into powder and powder can be handled in the air without danger of it igniting. It may then be compacted in the normal manner by being piaced in a die. The compact is sintered under vacuum conditions preferably at a temperature ranging from 1200 to 1300 deg C and for periods of one to three hours.

  15. SEPARATION OF URANIUM FROM ZIRCONIUM AND NIOBIUM BY SOLVENT EXTRACTION

    DOEpatents

    Voiland, E.E.

    1958-05-01

    A process for separation of the uranium from zirconium and/or niobium values contained in 3 to 7M aqueous nitric acid solutions is described. This is accomplished by adding phosphoric acid anions to the nitric acid solution containing the uranium, zirconium, and/or niobium in an amount sufficient to make the solution 0.05 to 0.2M in phosphate ion and contacting the solution with an organic water-immiscible solvent such as MEK, whereby the uranyl values are taken up by the extract phase while the zirconium and niobium preferentially remain in the aqueous raffinate.

  16. RECOVERY OF URANIUM FROM ZIRCONIUM-URANIUM NUCLEAR FUELS

    DOEpatents

    Gens, T.A.

    1962-07-10

    An improvement was made in a process of recovering uranium from a uranium-zirconium composition which was hydrochlorinated with gsseous hydrogen chloride at a temperature of from 350 to 800 deg C resulting in volatilization of the zirconium, as zirconium tetrachloride, and the formation of a uranium containing nitric acid insoluble residue. The improvement consists of reacting the nitric acid insoluble hydrochlorination residue with gaseous carbon tetrachloride at a temperature in the range 550 to 600 deg C, and thereafter recovering the resulting uranium chloride vapors. (AEC)

  17. Direct vapor/solid synthesis of mercuric iodide using compounds of mercury and iodine

    DOEpatents

    Skinner, Nathan L.

    1990-01-01

    A process is disclosed for producing high purity mercuric iodide by passing a gaseous source of a mercuric compound through a particulate bed of a low vapor pressure iodide compound which is maintained at an elevated temperature which is the lower of either: (a) just below the melting or volatilization temperature of the iodide compound (which ever is lower); or (b) just below the volatilization point of the other reaction product formed during the reaction; to cause the mercuric compound to react with the iodide compound to form mercuric iodide which then passes as a vapor out of the bed into a cooler condensation region.

  18. PRECIPITATION OF ZIRCONIUM AND FLUORIDE IONS FROM SOLUTIONS

    DOEpatents

    Newby, B.J.

    1963-06-11

    A process is given for removing zirconium and fluorine ions from aqueous solutions also containing uranium(VI). The precipitation is carried out with sodium formate, and the uranium remains in solution. (AEC)

  19. Process for massively hydriding zirconium--uranium fuel elements

    DOEpatents

    Katz, N.H.

    1973-12-01

    A method is described of hydriding uranium-zirconium alloy by heating the alloy in a vacuum, introducing hydrogen and maintaining an elevated temperature until occurrence of the beta--delta phase transformation and isobarically cooling the composition. (Official Gazette)

  20. Zirconium Hydride Space Power Reactor design.

    NASA Technical Reports Server (NTRS)

    Asquith, J. G.; Mason, D. G.; Stamp, S.

    1972-01-01

    The Zirconium Hydride Space Power Reactor being designed and fabricated at Atomics International is intended for a wide range of potential applications. Throughout the program a series of reactor designs have been evaluated to establish the unique requirements imposed by coupling with various power conversion systems and for specific applications. Current design and development emphasis is upon a 100 kilowatt thermal reactor for application in a 5 kwe thermoelectric space power generating system, which is scheduled to be fabricated and ground tested in the mid 70s. The reactor design considerations reviewed in this paper will be discussed in the context of this 100 kwt reactor and a 300 kwt reactor previously designed for larger power demand applications.

  1. Purification and deposition of silicon by an iodide disproportionation reaction

    DOEpatents

    Wang, Tihu; Ciszek, Theodore F.

    2002-01-01

    Method and apparatus for producing purified bulk silicon from highly impure metallurgical-grade silicon source material at atmospheric pressure. Method involves: (1) initially reacting iodine and metallurgical-grade silicon to create silicon tetraiodide and impurity iodide byproducts in a cold-wall reactor chamber; (2) isolating silicon tetraiodide from the impurity iodide byproducts and purifying it by distillation in a distillation chamber; and (3) transferring the purified silicon tetraiodide back to the cold-wall reactor chamber, reacting it with additional iodine and metallurgical-grade silicon to produce silicon diiodide and depositing the silicon diiodide onto a substrate within the cold-wall reactor chamber. The two chambers are at atmospheric pressure and the system is open to allow the introduction of additional source material and to remove and replace finished substrates.

  2. CHARACTERISTICS OF ANODIC AND CORROSION FILMS ON ZIRCONIUM

    SciTech Connect

    Misch, R.D.

    1960-05-01

    Zirconium anodizes similarly to tungsten in respect to the change of interference colors with applied voltage. However, the oxide layer on tungsten cannot reach as great a thickness. Hafnium does not anodize in the same way as zirconium but is similar to tantalum. By measuring the interference color and capacitative thicknesses on zirconium (Grades I and III) and a 2.5 wt.% tin ailoy, the film was found to grow less rapidly in terms of capacitance than in terms of iaterference colors. This was interpreted to mean that cracks develop in the oxide as it thickens. The effect was most pronouncedmore » on Grade III zirconium and least pronounced on the tin alloy. The reduction in capacitative thickness was especially noticeable when white oxide appeared. Comparative measurements on Grade I zirconium and 2.5 wt.% tin alloy indicated that the thickness of the oxide film on the tin alloy (after 16 hours in water) increased more rapidly with temperature than the film on zirconium. Tin is believed to act in ways to counteract the tendency of the oxide to form cracks, and to produce vacancies which promote ionic diffusion. (auth)« less

  3. Nanoindentation study of bulk zirconium hydrides at elevated temperatures

    SciTech Connect

    Cinbiz, Mahmut Nedim; Balooch, Mehdi; Hu, Xunxiang

    Here, the mechanical properties of zirconium hydrides was studied using nano-indentation technique at a temperature range of 25 – 400 °C. Temperature dependency of reduced elastic modulus and hardness of δ- and ε-zirconium hydrides were obtained by conducting nanoindentation experiments on the bulk hydride samples with independently heating capability of indenter and heating stage. The reduced elastic modulus of δ-zirconium hydride (H/Zr ratio =1.61) decreased from ~113 GPa to ~109 GPa while temperature increased from room temperature to 400°C. For ε-zirconium hydrides (H/Zr ratio=1.79), the reduced elastic modulus decreased from 61 GPa to 54 GPa as temperature increased from roommore » temperature to 300 °C. Whereas, hardness of δ-zirconium hydride significantly decreased from 4.1 GPa to 2.41 GPa when temperature increased from room temperature to 400 °C. Similarly, hardness of ε-zirconium hydride decreased from 3.06 GPa to 2.19 GPa with temperature increase from room temperature to 300°C.« less

  4. Nanoindentation study of bulk zirconium hydrides at elevated temperatures

    DOE PAGES

    Cinbiz, Mahmut Nedim; Balooch, Mehdi; Hu, Xunxiang; ...

    2017-08-02

    Here, the mechanical properties of zirconium hydrides was studied using nano-indentation technique at a temperature range of 25 – 400 °C. Temperature dependency of reduced elastic modulus and hardness of δ- and ε-zirconium hydrides were obtained by conducting nanoindentation experiments on the bulk hydride samples with independently heating capability of indenter and heating stage. The reduced elastic modulus of δ-zirconium hydride (H/Zr ratio =1.61) decreased from ~113 GPa to ~109 GPa while temperature increased from room temperature to 400°C. For ε-zirconium hydrides (H/Zr ratio=1.79), the reduced elastic modulus decreased from 61 GPa to 54 GPa as temperature increased from roommore » temperature to 300 °C. Whereas, hardness of δ-zirconium hydride significantly decreased from 4.1 GPa to 2.41 GPa when temperature increased from room temperature to 400 °C. Similarly, hardness of ε-zirconium hydride decreased from 3.06 GPa to 2.19 GPa with temperature increase from room temperature to 300°C.« less

  5. Quercetin as colorimetric reagent for determination of zirconium

    USGS Publications Warehouse

    Grimaldi, F.S.; White, C.E.

    1953-01-01

    Methods described in the literature for the determination of zirconium are generally designed for relatively large amounts of this element. A good procedure using colorimetric reagent for the determination of trace amounts is desirable. Quercetin has been found to yield a sensitive color reaction with zirconium suitable for the determination of from 0.1 to 50?? of zirconium dioxide. The procedure developed involves the separation of zirconium from interfering elements by precipitation with p-dimethylaminoazophenylarsonic acid prior to its estimation with quercetin. The quercetin reaction is carried out in 0.5N hydrochloric acid solution. Under the operating conditions it is indicated that quercetin forms a 2 to 1 complex with zirconium; however, a 2 to 1 and a 1 to 1 complex can coexist under special conditions. Approximate values for the equilibrium constants of the complexes are K1 = 0.33 ?? 10-5 and K2 = 1.3 ?? 10-9. Seven Bureau of Standards samples of glass sands and refractories were analyzed with excellent results. The method described should find considerable application in the analysis of minerals and other materials for macro as well as micro amounts of zirconium.

  6. Growth of mercuric iodide single crystals from dimethylsulfoxide

    DOEpatents

    Carlston, Richard C.

    1976-07-13

    Dimethylsulfoxide is used as a solvent for the growth of red mercuric iodide (HgI.sub.2) crystals for use in radiation detectors. The hygroscopic property of the solvent allows controlled amounts of water to enter into the solvent phase and diminish the large solubility of HgI.sub.2 so that the precipitating solid collects as well-defined euhedral crystals which grow into a volume of several cc.

  7. Infrared attenuation of thallium bromo-iodide fibers

    NASA Technical Reports Server (NTRS)

    Magilavy, B.; Goebel, J.

    1986-01-01

    Analysis of attenuation measurements in the near infrared of an unclad fiber of Thallium Bromo-Iodide (Th(Br,I)), a polycrystalline thallium halide, is presented. A general overview is given of the properties of fiber optics. Two groups of attenuation measurements, for the region 1.2 to 3.4 and for 3 to 11 microns, respectively, are presented, analyzed, and compared with those of two other groups of researchers.

  8. Photochemical versus biological production of methyl iodide during Meteor 55

    NASA Astrophysics Data System (ADS)

    Richter, U.; Wallace, D.

    2003-04-01

    The flux of methyl iodide from sea to air represents the largest flux of iodine from the ocean to the atmosphere. Surface water concentrations and hence fluxes are particularly high in tropical regions. This flux may be responsible for the enrichment of iodine in the marine aerosol and may contribute to important processes in the marine boundary layer, including particle formation. Methyl iodide is commonly referred to as a biogenic gas, with both macroalgae and phytoplankton identified as important sources. On the other hand experimental and field data have shown the importance of photochemical production that is not necessarily associated directly with biological activity. During the Meteor cruise 55 along 11°N in the tropical Atlantic Ocean, a series of experiments were conducted to examine the biological vs. photochemical production of methyl iodide. A total of eight separate experiments were conducted. Production of CH3I in quartz glass flasks during 24 hour incubations (dark and natural sunlight) was measured under three experimental treatments: untreated seawater, filtered seawater (0.1 um pore size filter to exclude most phytoplankton and bacteria), and seawater that was poisoned with mercuric chloride. There were two clear findings from these experiments: (1) methyl iodide production was significantly higher in all the incubations that were exposed to the light than in the dark incubations; (2) there was no significant difference between CH3I production under the three experimental treatments. These results argue very strongly for the primary importance of photochemical production of CH3I as opposed to biogenic production at least for the tropical open ocean surface waters. Further experiments are required to investigate the reactants involved, their sources, the wavelength and depth dependence of production, etc. as well as (possibly related) sink processes.

  9. Zirconium behaviour during electrorefining of actinide-zirconium alloy in molten LiCl-KCl on aluminium cathodes

    NASA Astrophysics Data System (ADS)

    Meier, R.; Souček, P.; Malmbeck, R.; Krachler, M.; Rodrigues, A.; Claux, B.; Glatz, J.-P.; Fanghänel, Th.

    2016-04-01

    A pyrochemical electrorefining process for the recovery of actinides from metallic nuclear fuel based on actinide-zirconium alloys (An-Zr) in a molten salt is being investigated. In this process actinides are group-selectively recovered on solid aluminium cathodes as An-Al alloys using a LiCl-KCl eutectic melt at a temperature of 450 °C. In the present study the electrochemical behaviour of zirconium during electrorefining was investigated. The maximum amount of actinides that can be oxidised without anodic co-dissolution of zirconium was determined at a selected constant cathodic current density. The experiment consisted of three steps to assess the different stages of the electrorefining process, each of which employing a fresh aluminium cathode. The results indicate that almost a complete dissolution of the actinides without co-dissolution of zirconium is possible under the applied experimental conditions.

  10. Layer Protecting the Surface of Zirconium Used in Nuclear Reactors.

    PubMed

    Ashcheulov, Petr; Skoda, Radek; Skarohlíd, Jan; Taylor, Andrew; Fendrych, Frantisek; Kratochvílová, Irena

    2016-01-01

    Zirconium alloys have very useful properties for nuclear facilities applications having low absorption cross-section of thermal electrons, high ductility, hardness and corrosion resistance. However, there is also a significant disadvantage: it reacts with water steam and during this (oxidative) reaction it releases hydrogen gas, which partly diffuses into the alloy forming zirconium hydrides. A new strategy for surface protection of zirconium alloys against undesirable oxidation in nuclear reactors by polycrystalline diamond film has been patented- Czech patent 305059: Layer protecting the surface of zirconium alloys used in nuclear reactors and PCT patent: Layer for protecting surface of zirconium alloys (Patent Number: WO2015039636-A1). The zirconium alloy surface was covered by polycrystalline diamond layer grown in plasma enhanced chemical vapor deposition apparatus with linear antenna delivery system. Substantial progress in the description and understanding of the polycrystalline diamond/ zirconium alloys interface and material properties under standard and nuclear reactors conditions (irradiation, hot steam oxidation experiments and heating-quenching cycles) was made. In addition, process technology for the deposition of protective polycrystalline diamond films onto the surface of zirconium alloys was optimized. Zircaloy2 nuclear fuel pins were covered by 300 nm thick protective polycrystalline diamond layer (PCD) using plasma enhanced chemical vapor deposition apparatus with linear antenna delivery system. The polycrystalline diamond layer protects the zirconium alloy surface against undesirable oxidation and consolidates its chemical stability while preserving its functionality. PCD covered Zircaloy2 and standard Zircaloy2 pins were for 30 min. oxidized in 1100°C hot steam. Under these conditions α phase of zirconium changes to β phase (more opened for oxygen/hydrogen diffusion). PCD anticorrosion protection of Zircaloy nuclear fuel assemblies can

  11. Identification of Potential Sodium Iodide Symporter (NIS) Inhibitors in ToxCast Phase1_v2 Chemical Library Using in vitro Radioactive Iodide Uptake (RAIU) Assay

    EPA Science Inventory

    Identification of Potential Sodium Iodide Symporter (NIS) Inhibitors in ToxCast Phase1_v2 Chemical Library Using in vitro Radioactive Iodide Uptake (RAIU) Assay Jun Wang1,2, Daniel R. Hallinger2, Ashley S. Murr2, Angela R. Buckalew1, Tammy E. Stoker2, Susan C. Laws21Oak Ridge In...

  12. Hydrogen peroxide inhibits iodide uptake and iodine organification in cultured porcine thyroid follicles.

    PubMed

    Fukayama, H; Murakami, S; Nasu, M; Sugawara, M

    1991-01-01

    We investigated the effect of hydrogen peroxide on the process of thyroid hormone formation in a physiologic culture system of porcine thyroid follicles that we recently established. Porcine thyroid follicles cultured in medium containing 1 mU/mL TSH were exposed to 0 to 500 microM hydrogen peroxide in the presence of 0.1 microCi carrier-free Na125 and sodium iodide for 2 h. Iodide uptake and iodine organification were measured in this incubation system. The kinetics of iodide uptake were used to explain the action of hydrogen peroxide. In addition, cAMP content and Na+,K(+)-ATPase activity (an enzyme necessary for iodide uptake) were measured to investigate the mechanism of hydrogen peroxide action. Hydrogen peroxide at concentrations of 100, 200, and 500 microM inhibited iodide uptake in a dose-dependent manner. Iodide organification was inhibited only when the concentration of hydrogen peroxide was greater than 200 microM. The kinetics of iodide uptake indicated that hydrogen peroxide was a noncompetitive inhibitor with iodide. Inhibition of iodide uptake and iodine organification by hydrogen peroxide were not mediated by alteration of cAMP content of Na+,K(+)-ATPase activity, since exposure to even 500 microM hydrogen peroxide did not change these parameters in the follicle when compared with those of control samples. Our results suggest that the iodide transport system in the thyroid follicle is inhibited at 200 microM hydrogen peroxide or greater.

  13. Laccase-catalyzed oxidation of iodide and formation of organically bound iodine in soils.

    PubMed

    Seki, Miharu; Oikawa, Jun-ichi; Taguchi, Taro; Ohnuki, Toshihiko; Muramatsu, Yasuyuki; Sakamoto, Kazunori; Amachi, Seigo

    2013-01-02

    Laccase oxidizes iodide to molecular iodine or hypoiodous acid, both of which are easily incorporated into natural soil organic matter. In this study, iodide sorption and laccase activity in 2 types of Japanese soil were determined under various experimental conditions to evaluate possible involvement of this enzyme in the sorption of iodide. Batch sorption experiment using radioactive iodide tracer ((125)I(-)) revealed that the sorption was significantly inhibited by autoclaving (121 °C, 40 min), heat treatment (80 and 100 °C, 10 min), γ-irradiation (30 kGy), N(2) gas flushing, and addition of reducing agents and general laccase inhibitors (KCN and NaN(3)). Interestingly, very similar tendency of inhibition was observed in soil laccase activity, which was determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a substrate. The partition coefficient (K(d): mL g(-1)) for iodide and specific activity of laccase in soils (Unit g(-1)) showed significant positive correlation in both soil samples. Addition of a bacterial laccase with an iodide-oxidizing activity to the soils strongly enhanced the sorption of iodide. Furthermore, the enzyme addition partially restored iodide sorption capacity of the autoclaved soil samples. These results suggest that microbial laccase is involved in iodide sorption on soils through the oxidation of iodide.

  14. Understanding the Irradiation Behavior of Zirconium Carbide

    SciTech Connect

    Motta, Arthur; Sridharan, Kumar; Morgan, Dane

    2013-10-11

    Zirconium carbide (ZrC) is being considered for utilization in high-temperature gas-cooled reactor fuels in deep-burn TRISO fuel. Zirconium carbide possesses a cubic B1-type crystal structure with a high melting point, exceptional hardness, and good thermal and electrical conductivities. The use of ZrC as part of the TRISO fuel requires a thorough understanding of its irradiation response. However, the radiation effects on ZrC are still poorly understood. The majority of the existing research is focused on the radiation damage phenomena at higher temperatures (>450{degree}C) where many fundamental aspects of defect production and kinetics cannot be easily distinguished. Little is known aboutmore » basic defect formation, clustering, and evolution of ZrC under irradiation, although some atomistic simulation and phenomenological studies have been performed. Such detailed information is needed to construct a model describing the microstructural evolution in fast-neutron irradiated materials that will be of great technological importance for the development of ZrC-based fuel. The goal of the proposed project is to gain fundamental understanding of the radiation-induced defect formation in zirconium carbide and irradiation response by using a combination of state-of-the-art experimental methods and atomistic modeling. This project will combine (1) in situ ion irradiation at a specialized facility at a national laboratory, (2) controlled temperature proton irradiation on bulk samples, and (3) atomistic modeling to gain a fundamental understanding of defect formation in ZrC. The proposed project will cover the irradiation temperatures from cryogenic temperature to as high as 800{degree}C, and dose ranges from 0.1 to 100 dpa. The examination of this wide range of temperatures and doses allows us to obtain an experimental data set that can be effectively used to exercise and benchmark the computer calculations of defect properties. Combining the examination of radiation

  15. PROCESS OF RECOVERING ZIRCONIUM VALUES FROM HAFNIUM VALUES BY SOLVENT EXTRACTION WITH AN ALKYL PHOSPHATE

    DOEpatents

    Peppard, D.F.

    1960-02-01

    A process of separating hafnium nitrate from zirconium nitrate contained in a nitric acid solution by selectively. extracting the zirconium nitrate with a water-immiscible alkyl phosphate is reported.

  16. Zirconium oxide surface passivation of crystalline silicon

    NASA Astrophysics Data System (ADS)

    Wan, Yimao; Bullock, James; Hettick, Mark; Xu, Zhaoran; Yan, Di; Peng, Jun; Javey, Ali; Cuevas, Andres

    2018-05-01

    This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited zirconium oxide (ZrOx). The optimum layer thickness and activation annealing conditions are determined to be 20 nm and 300 °C for 20 min. Cross-sectional transmission electron microscopy imaging shows an approximately 1.6 nm thick SiOx interfacial layer underneath an 18 nm ZrOx layer, consistent with ellipsometry measurements (˜20 nm). Capacitance-voltage measurements show that the annealed ZrOx film features a low interface defect density of 1.0 × 1011 cm-2 eV-1 and a low negative film charge density of -6 × 1010 cm-2. Effective lifetimes of 673 μs and 1.1 ms are achieved on p-type and n-type 1 Ω cm undiffused c-Si wafers, respectively, corresponding to an implied open circuit voltage above 720 mV in both cases. The results demonstrate that surface passivation quality provided by ALD ZrOx is consistent with the requirements of high efficiency silicon solar cells.

  17. A STUDY OF THE STABILITY OF ZIRCONIUM AND HAFNIUM TETRAHALIDES ON HITTING A HOT SURFACE IN VACUUM (in Russian)

    SciTech Connect

    Tsirel'nikov, V.I.; Komissarova, L.N.; Spitsyn, V.I.

    1962-09-01

    The decomposition coefficients of the chlorides, bromides, and iodides of Zr and Hf were determined as a function of the temperature of a hot surface. The tetrahalides were carefully purified in an inert atmosphere of argon. The halide compound in a quartz ampoule was heated by a removable heater. The vapors passed through a capillary opening and struck a tungsten foil 0.5 mm thick and 12 to 15 mm wide. The Mo foil was heated electrically to control the surface temperature which was measured by an optical pyrometer. The tetrahalide decomposed according to the following reaction: Me(Hal)/sub 4/ yields Memore » + 2(Hal)/sub 2/. The lower halides dissociated completely to metal and free halides, since the temperature was >600 deg C. The Mo backing was dissolved in nitric acid, and the unsupported metal deposit of Zr or Hf was weighed, The decomposition coefficient was calcuweight of metal evaporated. Zrl/sub 4/ decomposed completely (100%) at 1500 deg C, while only 96% of the HfI/sub 4/ was decomposed at this temperature. The ZrBr/sub 4/ and HfBr/sub 4/ were decomposed by 68 and 61% respectively. The ZrCl/sub 4/ and HfCl/sub 4/ were stable at l500 deg C (5% of the ZrCl/sub 4/ was decomposed at l500 deg C). In all cases, the hafnium halide was more stable than the zirconium halide, especially in the case of the iodides. The decomposition was directly proportional to the temperature of the molybdenum target. (TTT)« less

  18. Atomic layer deposition of zirconium silicate films using zirconium tetrachloride and tetra-n-butyl orthosilicate

    NASA Astrophysics Data System (ADS)

    Kim, Won-Kyu; Kang, Sang-Woo; Rhee, Shi-Woo; Lee, Nae-In; Lee, Jong-Ho; Kang, Ho-Kyu

    2002-11-01

    Atomic layer chemical vapor deposition of zirconium silicate films with a precursor combination of ZrCl4 and tetra-n-butyl orthosilicate (TBOS) was studied for high dielectric gate insulators. The effect of deposition conditions, such as deposition temperature, pulse time for purge and precursor injection on the deposition rate per cycle, and composition of the film were studied. At 400 °C, the growth rate saturated to 1.35 Å/cycle above 500 sccm of the argon purge flow rate. The growth rate, composition ratio ((Zr/Zr+Si)), and impurity contents (carbon and chlorine) saturated with the increase of the injection time of ZrCl4 and TBOS and decreased with the increased deposition temperature from 300 to 500 °C. The growth rate, composition ratio, carbon, and chlorine contents of the Zr silicate thin films deposited at 500 °C were 1.05 Å/cycle, 0.23, 1.1 at. %, and 2.1 at. %, respectively. It appeared that by using only zirconium chloride and silicon alkoxide sources, the content of carbon and chlorine impurities could not be lowered below 1%. It was also found that the incorporation rate of metal from halide source was lower than alkoxide source.

  19. Atomic layer deposition of zirconium silicate films using zirconium tetra-tert-butoxide and silicon tetrachloride

    NASA Astrophysics Data System (ADS)

    Kim, Won-Kyu; Kang, Sang-Woo; Rhee, Shi-Woo

    2003-09-01

    A new precursor combination (SiCl4 and Zr(OtC4H9)4) was used to deposit Zr silicate with Zr(OtC4H9)4 as a zirconium source and oxygen source at the same time. SiCl4 and Zr(OtC4H9)4 have higher vapor pressures than their counterpart, ZrCl4 and tetra-n-butyl orthosilicate (TBOS), and it was expected that the cycle time would be shorter. The deposition temperature of the new combination was about 150 °C lower than that of ZrCl4 and TBOS. The film was zirconium rich while it was silicon rich with ZrCl4 and TBOS. Growth rate (nm/cycle), composition ratio [Zr/(Zr+Si)], and chlorine impurity were decreased with increasing deposition temperature from 125 to 225 °C. The composition ratio of the film deposited at 225 °C was 0.53 and the chlorine content was about 0.4 at. %. No carbon was detected by x-ray photoelectron spectroscopy.

  20. Mechanical properties of zirconium alloys and zirconium hydrides predicted from density functional perturbation theory

    DOE PAGES

    Weck, Philippe F.; Kim, Eunja; Tikare, Veena; ...

    2015-10-13

    Here, the elastic properties and mechanical stability of zirconium alloys and zirconium hydrides have been investigated within the framework of density functional perturbation theory. Results show that the lowest-energy cubic Pn-3m with combining macron]m polymorph of δ-ZrH 1.5 does not satisfy all the Born requirements for mechanical stability, unlike its nearly degenerate tetragonal P4 2/ mcm polymorph. Elastic moduli predicted with the Voigt–Reuss–Hill approximations suggest that mechanical stability of α-Zr, Zr-alloy and Zr-hydride polycrystalline aggregates is limited by the shear modulus. According to both Pugh's and Poisson's ratios, α-Zr, Zr-alloy and Zr-hydride polycrystalline aggregates can be considered ductile. The Debyemore » temperatures predicted for γ-ZrH, δ-ZrH 1.5 and ε-ZrH 2 are θ D = 299.7, 415.6 and 356.9 K, respectively, while θ D = 273.6, 284.2, 264.1 and 257.1 K for the α-Zr, Zry-4, ZIRLO and M5 matrices, i.e. suggesting that Zry-4 possesses the highest micro-hardness among Zr matrices.« less

  1. Inhibition of Ice Growth and Recrystallization by Zirconium Acetate and Zirconium Acetate Hydroxide

    PubMed Central

    Mizrahy, Ortal; Bar-Dolev, Maya; Guy, Shlomit; Braslavsky, Ido

    2013-01-01

    The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs), present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA) was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH), on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications. PMID:23555701

  2. Effects of Excess Fluoride and Iodide on Thyroid Function and Morphology.

    PubMed

    Jiang, Yaqiu; Guo, Xiujuan; Sun, Qiuyan; Shan, Zhongyan; Teng, Weiping

    2016-04-01

    Exposure to high levels of iodide in Cangzhou, Shandong Province, China has been associated with increased incidence of thyroid disease; however, whether fluoride can affect the thyroid remains controversial. To investigate the effects of excess fluoride, we evaluated thyroid gland structure and function in rats exposed to fluoride and iodide, either alone or in combination. Five-week-old Wistar rats (n = 160 total) were randomly divided into eight groups: three groups that were given excess fluoride (15, 30, or 60 ppm F); one group given excess iodide (1200 μg/L I); three groups given excess iodide plus fluoride (1200 μg/L I plus 15, 30, or 60 ppm F); and one control group. The serum concentrations of the thyroid hormones TT3 and TT4 on day 150 were significantly reduced for certain fluoride groups; however, no significant differences were observed in concentrations for the pituitary hormone TSH among any groups. Hematoxylin and eosin staining revealed that iodide causes an increase in the areas of the colloid lumens and a decrease in the diameters of epithelial cells and nuclei; however, fluoride causes an increase in nuclear diameters. The damage to follicular epithelial cells upon fluoride or iodide treatment was easily observed by transmission electron microscopy, but the effects were most dramatic upon treatment with both fluoride and iodide. These results suggest that iodide causes the most damage but that fluoride can promote specific changes in the function and morphology of the thyroid, either alone or in combination with iodide.

  3. Optical properties and surface morphology studies of palladium contacts on mercuric iodide single crystals

    NASA Astrophysics Data System (ADS)

    George, M. A.; Azoulay, M.; Burger, A.; Biao, Y.; Silberman, E.; Nason, D.

    1993-04-01

    Palladium is chemically suitable for electric contacts on mercuric iodide detectors for photon and nuclear radiation detection, so the understanding of palladium contacts is important for fundamental and practical scientific purposes. A study has been conducted on the surface morphology of evaporated contacts using atomic force microscopy (AFM) and optical transmission and reflection. Evaporated palladium coatings are typically nonuniform and may deposit selectively on mercuric iodide surface defects. Reflection measurements show that coating thickness and surface treatment affect intensity, position, and shape of a reflected peak characteristic of the mercuric iodide structure. Results indicate that the band gap energy in the surface of the mercuric iodide is lowered by palladium contacts.

  4. Iodine/iodide-free dye-sensitized solar cells.

    PubMed

    Yanagida, Shozo; Yu, Youhai; Manseki, Kazuhiro

    2009-11-17

    Dye-sensitized solar cells (DSSCs) are built from nanocrystalline anatase TiO(2) with a 101 crystal face (nc-TiO(2)) onto which a dye is absorbed, ruthenium complex sensitizers, fluid I(-)/I(3)(-) redox couples with electrolytes, and a Pt-coated counter electrode. DSSCs have now reached efficiencies as high as 11%, and G24 Innovation (Cardiff, U.K.) is currently manufacturing them for commercial use. These devices offer several distinct advantages. On the basis of the electron lifetime and diffusion coefficient in the nc-TiO(2) layer, DSSCs maintain a diffusion length on the order of several micrometers when the dyed-nc-TiO(2) porous layer is covered by redox electrolytes of lithium and/or imidazolium iodide and their polyiodide salts. The fluid iodide/iodine (I(-)/I(3)(-)) redox electrolytes can infiltrate deep inside the intertwined nc-TiO(2) layers, promoting the mobility of the nc-TiO(2) layers and serving as a hole-transport material of DSSCs. As a result, these materials eventually give a respectable photovoltaic performance. On the other hand, fluid I(-)/I(3)(-) redox shuttles have certain disadvantages: reduced performance control and long-term stability and incompatibility with some metallic component materials. The I(-)/I(3)(-) redox shuttle shows a significant loss in short circuit current density and a slight loss in open circuit voltage, particularly in highly viscous electrolyte-based DSSC systems. Iodine can also act as an oxidizing agent, corroding metals, such as the grid metal Ag and the Pt mediator on the cathode, especially in the presence of water and oxygen. In addition, the electrolytes (I(-)/I(3)(-)) can absorb visible light (lambda = approximately 430 nm), leading to photocurrent loss in the DSSC. Therefore, the introduction of iodide/iodine-free electrolytes or hole-transport materials (HTMs) could lead to cost-effective alternatives to TiO(2) DSSCs. In this Account, we discuss the iodide/iodine-free redox couple as a substitute for the

  5. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under this...

  6. 40 CFR 721.10089 - Modified salicylic acid, zirconium complex (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified salicylic acid, zirconium... Specific Chemical Substances § 721.10089 Modified salicylic acid, zirconium complex (generic). (a) Chemical... as modified salicylic acid, zirconium complex (PMN P-00-552) is subject to reporting under this...

  7. 40 CFR 471.90 - Applicability; description of the zirconium-hafnium forming subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... zirconium-hafnium forming subcategory. 471.90 Section 471.90 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Zirconium-Hafnium Forming Subcategory § 471.90 Applicability; description of the zirconium-hafnium forming subcategory. This subpart applies to discharges of pollutants to waters of the...

  8. 40 CFR 421.330 - Applicability: Description of the primary zirconium and hafnium subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... primary zirconium and hafnium subcategory. 421.330 Section 421.330 Protection of Environment ENVIRONMENTAL... CATEGORY Primary Zirconium and Hafnium Subcategory § 421.330 Applicability: Description of the primary zirconium and hafnium subcategory. The provisions of this subpart are applicable to discharges resulting...

  9. Strontium iodide gamma ray spectrometers for planetary science (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Prettyman, Thomas H.; Rowe, Emmanuel; Butler, Jarrhett; Groza, Michael; Burger, Arnold; Yamashita, Naoyuki; Lambert, James L.; Stassun, Keivan G.; Beck, Patrick R.; Cherepy, Nerine J.; Payne, Stephen A.; Castillo-Rogez, Julie C.; Feldman, Sabrina M.; Raymond, Carol A.

    2016-09-01

    Gamma rays produced passively by cosmic ray interactions and by the decay of radioelements convey information about the elemental makeup of planetary surfaces and atmospheres. Orbital missions mapped the composition of the Moon, Mars, Mercury, Vesta, and now Ceres. Active neutron interrogation will enable and/or enhance in situ measurements (rovers, landers, and sondes). Elemental measurements support planetary science objectives as well as resource utilization and planetary defense initiatives. Strontium iodide, an ultra-bright scintillator with low nonproportionality, offers significantly better energy resolution than most previously flown scintillators, enabling improved accuracy for identification and quantification of key elements. Lanthanum bromide achieves similar resolution; however, radiolanthanum emissions obscure planetary gamma rays from radioelements K, Th, and U. The response of silicon-based optical sensors optimally overlaps the emission spectrum of strontium iodide, enabling the development of compact, low-power sensors required for space applications, including burgeoning microsatellite programs. While crystals of the size needed for planetary measurements (>100 cm3) are on the way, pulse-shape corrections to account for variations in absorption/re-emission of light are needed to achieve maximum resolution. Additional challenges for implementation of large-volume detectors include optimization of light collection using silicon-based sensors and assessment of radiation damage effects and energetic-particle induced backgrounds. Using laboratory experiments, archived planetary data, and modeling, we evaluate the performance of strontium iodide for future missions to small bodies (asteroids and comets) and surfaces of the Moon and Venus. We report progress on instrument design and preliminary assessment of radiation damage effects in comparison to technology with flight heritage.

  10. Development of mercuric iodide uncooled x ray detectors and spectrometers

    NASA Technical Reports Server (NTRS)

    Iwanczyk, Jan S.

    1990-01-01

    The results obtained in the development of miniature, lowpower, light weight mercuric iodide, HgI2, x ray spectrometers for future space missions are summarized. It was demonstrated that HgI2 detectors can be employed in a high resolution x ray spectrometer, operating in a scanning electron microscope. Also, the development of HgI2 x ray detectors to augment alpha backscattering spectrometers is discussed. These combination instruments allow for the identification of all chemical elements, with the possible exception of hydrogen, and their respective concentrations. Additionally, further investigations of questions regarding radiation damage effects in the HgI2 x ray detectors are reported.

  11. Temperature dependent energy levels of methylammonium lead iodide perovskite

    NASA Astrophysics Data System (ADS)

    Foley, Benjamin J.; Marlowe, Daniel L.; Sun, Keye; Saidi, Wissam A.; Scudiero, Louis; Gupta, Mool C.; Choi, Joshua J.

    2015-06-01

    Temperature dependent energy levels of methylammonium lead iodide are investigated using a combination of ultraviolet photoemission spectroscopy and optical spectroscopy. Our results show that the valence band maximum and conduction band minimum shift down in energy by 110 meV and 77 meV as temperature increases from 28 °C to 85 °C. Density functional theory calculations using slab structures show that the decreased orbital splitting due to thermal expansion is a major contribution to the experimentally observed shift in energy levels. Our results have implications for solar cell performance under operating conditions with continued sunlight exposure and increased temperature.

  12. The production and photoelectron spectrum of thiazyl iodide. NSI

    NASA Astrophysics Data System (ADS)

    Allaf, A. W.; Matti, G. Y.; Suffolk, R. J.; Watts, J. D.

    1989-02-01

    The previously unknown molecule thiazyl iodide, NSI, has been prepared and studied by HeI photoelectron and low-resolution infrared spectroscopy. It has been produced by an on-line process using thiazyl chloride, NSCl, as precursor. The observed photoelectron spectrum has been rationalised using ab initio molecular-orbital calculations. The first ionisation energy is 10.06±0.05 eV, assigned to a largely non-bonding orbital with major components on nitrogen and iodine. Gas-phase infrared spectra yield a value for ν 1 of 1295 cm -1.

  13. Process for electroless deposition of metals on zirconium materials

    DOEpatents

    Donaghy, Robert E.

    1978-01-01

    A process for the electroless deposition of a metal layer on an article comprised of zirconium or a zirconium alloy is disclosed. The article is activated in an aged aqueous solution comprising from about 10 to about 20 grams per liter ammonium bifluoride and from about 0.75 to about 2 grams per liter of sulfuric acid. The solution is aged by immersion of pickled zirconium in the solution for at least about 10 minutes. The loosely adhering film formed on the article in the activating step is removed and the article is contacted with an electroless plating solution containing the metal to be deposited on the article upon sufficient contact with the article.

  14. Process for electrolytic deposition of metals on zirconium materials

    DOEpatents

    Donaghy, Robert E.

    1979-01-30

    A process for the electrolytic deposition of a metal layer on an article comprised of zirconium or a zirconium alloy is disclosed. The article is activated in an aged aqueous solution comprising from about 10 to about 20 grams per liter ammonium bifluoride and from about 0.75 to about 2 grams per liter of sulfuric acid. The solution is aged by immersion of pickled zirconium in the solution for at least about 10 minutes. The loosely adhering film formed on the article in the activating step is removed and the article is contacted with an electrolytic plating solution containing the metal to be deposited on the article in the presence of an electrode receiving current.

  15. METHOD OF FABRICATING A URANIUM-ZIRCONIUM HYDRIDE REACTOR CORE

    DOEpatents

    Weeks, I.F.; Goeddel, W.V.

    1960-03-22

    A method is described of evenly dispersing uranlum metal in a zirconium hydride moderator to produce a fuel element for nuclear reactors. According to the invention enriched uranium hydride and zirconium hydride powders of 200 mesh particle size are thoroughly admixed to form a mixture containing 0.1 to 3% by weight of U/sup 235/ hydride. The mixed powders are placed in a die and pressed at 100 tons per square inch at room temperature. The resultant compacts are heated in a vacuum to 300 deg C, whereby the uranium hydride deoomposes into uranium metal and hydrogen gas. The escaping hydrogen gas forms a porous matrix of zirconium hydride, with uramum metal evenly dispersed therethrough. The advantage of the invention is that the porosity and uranium distribution of the final fuel element can be more closely determined and controlled than was possible using prior methods of producing such fuel ele- ments.

  16. Extractive separation of uranium and zirconium sulfates by amines

    SciTech Connect

    Schroetterova, D.; Nekovar, P.; Mrnka, M.

    1992-04-01

    This paper describes an amine extraction process for zirconium and uranium separation. The behaviour of an extraction system containing uranium (VI) sulfate, zirconium (IV) sulfate, 0.2 and 0.5 M sulfuric acid (as the original aqueous phase), tertiary amine tri-n-lauryl- amine or primary amine Primene JMT in benzene (as the original organic phase) is discussed on the basis of equilibrium data. The measured dependences show that the degree of extraction of zirconium at the sulfuric acid concentration of 0.5 M and above is only slightly affected by a presence of uranium in solution. From this surprising behaviour it follows that zirconiummore » may be employed for the displacement of uranium from the organic phase. This effect is more pronounced with the primary amine Primene JMT than with TLA. 29 refs., 4 figs., 1 tab.« less

  17. Thermochemistry of amorphous and crystalline zirconium and hafnium silicates.

    NASA Astrophysics Data System (ADS)

    Ushakov, S.; Brown, C. E.; Navrotsky, Alexandra; Boatner, L. A.; Demkov, A. A.; Wang, C.; Nguyen, B.-Y.

    2003-03-01

    Calorimetric investigation of amorphous and crystalline zirconium and hafnium silicates was performed as part of a research program on thermochemistry of alternative gate dielectrics. Amorphous hafnium and zirconium silicates with varying SiO2 content were synthesized by a sol-gel process. Crystalline zirconium and hafnium silicates (zircon and hafnon) were synthesized by solid state reaction at 1450 °C from amorphous gels and grown as single crystals from flux. High temperature oxide melt solution calorimetry in lead borate (2PbO.B2O3) solvent at 800 oC was used to measure drop solution enthalpies for amorphous and crystalline zirconium and hafnium silicates and corresponding oxides. Applying appropriate thermochemical cycles, formation enthalpy of crystalline ZrSiO4 (zircon) from binary oxides (baddeleite and quartz) at 298 K was calculated as -23 +/-2 kJ/mol and enthalpy difference between amorphous and crystalline zirconium silicate (vitrification enthalpy) was found to be 61 +/-3 kJ/mol. Crystallization onset temperatures of amorphous zirconium and hafnium silicates, as measured by differential scanning calorimetry (DSC), increased with silica content. The resulting crystalline phases, as characterized by X-ray diffraction (XRD), were tetragonal HfO2 and ZrO2. Critical crystallite size for tetragonal to monoclinic transformation of HfO2 in the gel was estimated as 6 +/-2 nm from XRD data Crystallization enthalpies per mole of hafnia and zirconia in gels decrease slightly together with crystallite size with increasing silica content, for example from -22 to -15 +/-1 kJ per mol of HfO2 crystallized at 740 and 1006 °C from silicates with 10 and 70 mol Applications of thermal analyses and solution calorimetry techniques together with first-principles density functional calculations to estimate interface and surface energies are discussed.

  18. Relationship of dietary iodide and drinking water disinfectants to thyroid function in experimental animals.

    PubMed Central

    Revis, N W; McCauley, P; Holdsworth, G

    1986-01-01

    The importance of dietary iodide on the reported hypothyroid effect of drinking water disinfectants on thyroid function was investigated. Previous studies have also showed differences in the relative sensitivity of pigeons and rabbits to chlorinated water. Pigeons and rabbits were exposed for 3 months to diets containing high (950 ppb) or low (300 ppb) levels of iodide and to drinking water containing two levels of chlorine. Results showed that the high-iodide diet prevented the hypothyroid effect observed in pigeons given the low-iodide diet and chlorinated drinking water. Similar trends were observed in rabbits exposed to the same treatment; however, significant hypothyroid effects were not observed in this animal model. The factor associated with the observed effect of dietary iodide on the chlorine-induced change in thyroid function is unknown, as is the relative sensitivity of rabbits and pigeons to the effect of chlorine. Several factors may explain the importance of dietary iodide and the relative sensitivity of these species. For example, the iodine formed by the known reaction of chlorine with iodide could result in a decrease in the plasma level of iodide because of the relative absorption rates of iodide and iodine in the intestinal tract, and the various types and concentrations of chloroorganics (metabolites) formed in the diet following the exposure of various dietary constituents to chlorine could affect the thyroid function. The former factor was investigated in the present studies. Results do not confirm a consistent, significant reduction in the plasma level of iodide in rabbits and pigeons exposed to chlorinated water and the low-iodide diet. The latter factor is being investigated. PMID:3816728

  19. In-situ stabilization of radioactive zirconium swarf

    DOEpatents

    Hess, Clay C.

    1999-01-01

    The method for treating ignitable cutting swarf in accordance with the present invention involves collecting cutting swarf in a casting mold underwater and injecting a binder mixture comprising vinyl ester styrene into the vessel to fill void volume; and form a mixture comprising swarf and vinyl ester styrene; and curing the mixture. The method is especially useful for stabilizing the ignitable characteristics of radioactive zirconium cutting swarf, and can be used to solidify zirconium swarf, or other ignitable finely divided material, underwater. The process could also be performed out of water with other particulate wastes.

  20. In-situ stabilization of radioactive zirconium swarf

    DOEpatents

    Hess, C.C.

    1999-08-31

    The method for treating ignitable cutting swarf in accordance with the present invention involves collecting cutting swarf in a casting mold underwater and injecting a binder mixture comprising vinyl ester styrene into the vessel to fill void volume; and form a mixture comprising swarf and vinyl ester styrene; and curing the mixture. The method is especially useful for stabilizing the ignitable characteristics of radioactive zirconium cutting swarf, and can be used to solidify zirconium swarf, or other ignitable finely divided material, underwater. The process could also be performed out of water with other particulate wastes. 6 figs.

  1. Synthesis and nonstoichiometry of the zirconium trihalides

    SciTech Connect

    Daake, R.L.; Corbett, J.D.

    1978-05-01

    The synthesis of ZrX/sub 3/ (X = Cl, Br, I) by reaction of the corresponding tetrahalides with ZrCl, ZrBr, or ZrI/sub 1.8/ in sealed tantalum tubing gives high-purity, single-phase products, thereby avoiding problems of the relatively low reactivity of and contamination by zirconium powder reductant used previously. Phase limits for the three trihalides established by isopiestic equilibration with the adjoining phases are 2.94 (2) less than or equal to Cl:Zr less than or equal to 3.03 (2) (440/sup 0/C), 2.87 (2) less than or equal to Br:Zr less than or equal to 3.23 (2) (435/sup 0/C), and 2.83 (5) (775/supmore » 0/C) less than or equal to I:Zr less than or equal to 3.43 (5) (475/sup 0/C). The hexagonal lattice constants for the bromide phase (Guinier techniques) decrease linearly with increasing bromide content across the entire range without the development of any additional lines. The variation of the c dimension for ZrI/sub 3/ (and HfI/sub 3/) on oxidation is in the opposite direction, and in this case extra lines from a presumed superlattice structure developed toward the upper limit. The structural implications of these results are considered. The reported structure for ..cap alpha..-ZrCl/sub 3/, an unusual BiI/sub 3/-type variant, was based on a misassigned ZrCl powder pattern and therefore appears to be in error. 25 references.« less

  2. Efficient Use and Recycling of the Micronutrient Iodide in Mammals

    PubMed Central

    Rokita, Steven E.; Adler, Jennifer M.; McTamney, Patrick M.; Watson, James A.

    2010-01-01

    Daily ingestion of iodide alone is not adequate to sustain production of the thyroid hormones, tri- and tetraiodothyronine. Proper maintenance of iodide in vivo also requires its active transport into the thyroid and its salvage from mono- and diiodotyrosine that are formed in excess during hormone biosynthesis. The enzyme iodotyrosine deiodinase responsible for this salvage is unusual in its ability to catalyze a reductive dehalogenation reaction dependent on a flavin cofactor, FMN. Initial characterization of this enzyme was limited by its membrane association, difficult purification and poor stability. The deiodinase became amenable to detailed analysis only after identification and heterologous expression of its gene. Site-directed mutagenesis recently demonstrated that cysteine residues are not necessary for enzymatic activity in contrast to precedence set by other reductive dehalogenases. Truncation of the N-terminal membrane anchor of the deiodinase has provided a soluble and stable source of enzyme sufficient for crystallographic studies. The structure of an enzyme•substrate co-crystal has become invaluable for understanding the origins of substrate selectivity and the mutations causing thyroid disease in humans. PMID:20167242

  3. Crystal growth and scintillation properties of strontium iodide scintillators

    SciTech Connect

    van Loef, Edgar; Wilson, Cody; Cherepy, Nerine

    2009-06-01

    Single crystals of SrI{sub 2}:Eu and SrI{sub 2}:Ce/Na were grown from anhydrous iodides by the vertical Bridgman technique in evacuated silica ampoules. Growth rates were of the order of 5-30 mm/day. Radioluminescence spectra of SrI{sub 2}:Eu and SrI{sub 2}:Ce/Na exhibit a broad band due to Eu{sup 2+} and Ce{sup 3+} emission, respectively. The maximum in the luminescence spectrum of SrI{sub 2}:Eu is found at 435 nm. The spectrum of SrI{sub 2}:Ce/Na exhibits a doublet peaking at 404 and 435 nm attributed to Ce{sup 3+} emission, while additional impurity - or defected - related emission is present at approximately 525 nm.more » The strontium iodide scintillators show very high light yields of up to 120,000 photons/MeV, have energy resolutions down to 3% at 662 keV (Full Width Half Maximum) and exhibit excellent light yield proportionality with a standard deviation of less than 5% between 6 and 460 keV.« less

  4. Modulation of Sodium Iodide Symporter in Thyroid Cancer

    PubMed Central

    Lakshmanan, Aparna; Scarberry, Daniel

    2015-01-01

    Radioactive iodine (RAI) is a key therapeutic modality for thyroid cancer. Loss of RAI uptake in thyroid cancer inversely correlates with patient’s survival. In this review, we focus on the challenges encountered in delivering sufficient doses of I-131 to eradicate metastatic lesions without increasing the risk of unwanted side effects. Sodium iodide symporter (NIS) mediates iodide influx, and NIS expression and function can be selectively enhanced in thyroid cells by thyroid-stimulating hormone. We summarize our current knowledge of NIS modulation in normal and cancer thyroid cells, and we propose that several reagents evaluated in clinical trials for other diseases can be used to restore or further increase RAI accumulation in thyroid cancer. Once validated in preclinical mouse models and clinical trials, these reagents, mostly small-molecule inhibitors, can be readily translated into clinical practice. We review available genetically engineered mouse models of thyroid cancer in terms of their tumor development and progression as well as their thyroid function. These mice will not only provide important insights into the mechanisms underlying the loss of RAI uptake in thyroid tumors but will also serve as preclinical animal models to evaluate the efficacy of candidate reagents to selectively increase RAI uptake in thyroid cancers. Taken together, we anticipate that the optimal use of RAI in the clinical management of thyroid cancer is yet to come in the near future. PMID:25234361

  5. Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

    PubMed Central

    Wiwanitkit, Viroj

    2011-01-01

    The recent nuclear disaster at Japan has raised global concerns about effects of radioactive leakage in the environment, associated hazards, and how they can be prevented. In this article, we have tried to explain about the guidelines laid down by World Health Organization for a potassium iodide prophylaxis following a nuclear disaster, and its mechanism of action in preventing thyroid cancer. Data was collected mainly from the studies carried out during the Chernobyl disaster of Russia in 1986 and the hazardous effects especially on the thyroid gland were studied. It was seen that radioactive iodine leakage from the nuclear plants mainly affected the thyroid gland, and especially children were at a higher risk at developing the cancers. Potassium Iodide prophylaxis can be administered in order to prevent an increase in the incidence of thyroid cancers in the population of an area affected by a nuclear disaster. However, one has to be cautious while giving it, as using it without indication has its own risks. PMID:21731865

  6. Hydrogen pickup mechanism of zirconium alloys

    NASA Astrophysics Data System (ADS)

    Couet, Adrien

    Although the optimization of zirconium based alloys has led to significant improvements in hydrogen pickup and corrosion resistance, the mechanisms by which such alloy improvements occur are still not well understood. In an effort to understand such mechanisms, a systematic study of the alloy effect on hydrogen pickup is conducted, using advanced characterization techniques to rationalize precise measurements of hydrogen pickup. The hydrogen pick-up fraction is accurately measured for a specially designed set of commercial and model alloys to investigate the effects of alloying elements, microstructure and corrosion kinetics on hydrogen uptake. Two different techniques to measure hydrogen concentrations were used: a destructive technique, Vacuum Hot Extraction, and a non-destructive one, Cold Neutron Prompt Gamma Activation Analysis. The results indicate that hydrogen pickup varies not only from alloy to alloy but also during the corrosion process for a given alloy. For instance Zircaloy type alloys show high hydrogen pickup fraction and sub-parabolic oxidation kinetics whereas ZrNb alloys show lower hydrogen pickup fraction and close to parabolic oxidation kinetics. Hypothesis is made that hydrogen pickup result from the need to balance charge during the corrosion reaction, such that the pickup of hydrogen is directly related to (and indivisible of) the corrosion mechanism and decreases when the rate of electron transport or oxide electronic conductivity sigmao xe through the protective oxide increases. According to this hypothesis, alloying elements (either in solid solution or in precipitates) embedded in the oxide as well as space charge variations in the oxide would impact the hydrogen pick-up fraction by modifying sigmaox e, which drives oxidation and hydriding kinetics. Dedicated experiments and modelling were performed to assess and validate these hypotheses. In-situ electrochemical impedance spectroscopy (EIS) experiments were performed on Zircaloy-4 tubes

  7. Zirconium determination by cooling curve analysis during the pyroprocessing of used nuclear fuel

    NASA Astrophysics Data System (ADS)

    Westphal, B. R.; Price, J. C.; Bateman, K. J.; Marsden, K. C.

    2015-02-01

    An alternative method to sampling and chemical analyses has been developed to monitor the concentration of zirconium in real-time during the casting of uranium products from the pyroprocessing of used nuclear fuel. The method utilizes the solidification characteristics of the uranium products to determine zirconium levels based on standard cooling curve analyses and established binary phase diagram data. Numerous uranium products have been analyzed for their zirconium content and compared against measured zirconium data. From this data, the following equation was derived for the zirconium content of uranium products:

  8. Effects of Radiation and Temperature on Iodide Sorption by Surfactant-Modified Bentonite

    SciTech Connect

    Choung, Sungwook; Kim, Min Kyung; Yang, Jungseok

    2014-08-04

    Bentonite, which is used as an engineered barrier in geological repositories, is ineffective for sorbing anionic radionuclides because of its negatively charged surface. This study modified raw bentonite using a cationic surfactant (i.e., hexadecyltrimethylammonium [HDTMA]-Br) to improve its sorption capability for radioactive iodide. The effects of temperature and radiation on the iodide sorption of surfactant-modified bentonite (SMB) were evaluated under alkaline pH condition similar to that found in repository environments. Different amounts of surfactant, equivalent to the 50, 100, and 200% cation-exchange capacity of the bentonite, were used to produce the HDTMA-SMB for iodide sorption. The sorption reaction of themore » SMB with iodide reached equilibrium rapidly within 10 min regardless of temperature and radiation conditions. The rate of iodide sorption increased as the amount of the added surfactant was increased and nonlinear sorption behavior was exhibited. However, high temperature and γ-irradiation (60Co) resulted in significantly (~2–10 times) lower iodide Kd values for the SMB. The results of Fourier transform infrared spectroscopy analysis suggested that the decrease in iodide sorption may be caused by weakened physical electrostatic force between the HDTMA and iodide, and by the surfactant becoming detached from the SMB during the heating and irradiation processes.« less

  9. Oxygen-hydrogen fuel cell with an iodine-iodide cathode - A concept

    NASA Technical Reports Server (NTRS)

    Javet, P.

    1970-01-01

    Fuel cell uses a porous cathode through which is fed a solution of iodine in aqueous iodide solution, the anode is a hydrogen electrode. No activation polarization appears on the cathode because of the high exchange-current density of the iodine-iodide electrode.

  10. Fabrication of efficient low-bandgap perovskite solar cells by combining formamidinium tin iodide with methylammonium lead iodide

    DOE PAGES

    Liao, Weiqiang; Zhao, Dewei; Yu, Yue; ...

    2016-09-13

    Mixed tin (Sn)-lead (Pb) perovskites with high Sn content exhibit low bandgaps suitable for fabricating the bottom cell of perovskite-based tandem solar cells. In this work, we report on the fabrication of efficient mixed Sn-Pb perovskite solar cells using precursors combining formamidinium tin iodide (FASnI 3) and methylammonium lead iodide (MAPbI 3). The best-performing cell fabricated using a (FASnI 3) 0.6(MAPbI 3) 0.4 absorber with an absorption edge of ~1.2 eV achieved a power conversion efficiency (PCE) of 15.08 (15.00)% with an open-circuit voltage of 0.795 (0.799) V, a short-circuit current density of 26.86(26.82) mA/cm 2, and a fill factormore » of 70.6(70.0)% when measured under forward (reverse) voltage scan. In conclusion, the average PCE of 50 cells we have fabricated is 14.39 ± 0.33%, indicating good reproducibility.« less

  11. Development of a Screening Approach to Detect Thyroid Disrupting Chemicals that Inhibit the Human Sodium/Iodide Symporter (NIS)

    EPA Science Inventory

    Thyroid hormone synthesis requires active iodide uptake mediated by the sodium/iodide symporter (NIS). Monovalent anions, such as the environmental contaminant perchlorate, have been well characterized as competitive inhibitors of NIS, yet limited information exists for more stru...

  12. Dose-Response Analysis of Developmental Iodide Deficiency: Reductions in Thyroid Hormones and Impaired Hippocampal Synaptic Transmission

    EPA Science Inventory

    Iodide is an essential nutrient for thyroid hormone synthesis and severe iodide deficiency (ID) during early development is associated with neurological impairments. Several environmental contaminants can perturb the thyroid axis and this perturbation may be more acute under cond...

  13. New iodide-based molten salt systems for high temperature molten salt batteries

    NASA Astrophysics Data System (ADS)

    Fujiwara, Syozo; Kato, Fumio; Watanabe, Syouichiro; Inaba, Minoru; Tasaka, Akimasa

    Novel multi-component molten salt systems containing iodides, LiF-LiBr-LiI, LiF-NaBr-LiI, and LiF-LiCl-LiBr-LiI, were investigated for use as electrolytes in high temperature molten salt batteries to improve the discharge rate-capability. The iodide-based molten salts showed higher ionic conductivity (∼3 S cm -1 at 500 °C) than conventional LiCl-KCl, and had low enough melting points (below 400 °C) that can be used in practical high temperature molten salt batteries. The iodide-based salts showed instability at temperatures higher than 280 °C in dried air. The decomposition mechanism of iodide-based molten salts was discussed, and it was found that elimination of oxygen from the environment is effective to stabilize the iodide-based molten salts at high temperatures.

  14. A comparison between the gastric and salivary concentration of iodide, pertechnetate, and bromide in man

    PubMed Central

    Harden, R. McG.; Alexander, W. D.; Shimmins, J.; Chisholm, D.

    1969-01-01

    The concentration of iodide (I−) and pertechnetate (TcO4−) and bromide (Br−) has been measured simultaneously in gastric juice and parotid saliva. The combined gastric and salivary clearance for iodide and pertechnetate is more than twice the clearance of these ions by the thyroid gland. The concentration of the ions was in the order I−>TcO4−>Br− in both gastric juice and saliva. Differences exist between the secretion of iodide, pertechnetate, and bromide. Bromide, in contrast to iodide and pertechnetate, was found to be more concentrated in gastric juice than in saliva. The ratio of the iodide to pertechnetate clearance was greater in gastric juice than in saliva. PMID:5358585

  15. Controllable deposition of regular lead iodide nanoplatelets and their photoluminescence at room temperature

    NASA Astrophysics Data System (ADS)

    Kong, Weimin; Li, Guohui; Liang, Qiangbing; Ji, Xingqi; Li, Gang; Ji, Ting; Che, Tao; Hao, Yuying; Cui, Yanxia

    2018-03-01

    In this work, the synthesis of regular single crystalline lead iodide nanoplatelets are carried out based on the physical vapor phase deposition method. Different lead iodide nanoplatelets are obtained by tuning the location of the mica substrate along with the temperature of the tube furnace. The rules of size, thickness, density of the lead iodide nanoplatelets at varied deposition conditions are analyzed according to the crystal growth principles. It was claimed in literature that the photoluminescence of lead iodide could be obtained only at a low temperature (lower than 200 K). Here, at room temperature, we successfully obtained the photoluminescence spectra of the prepared lead iodide nanoplatelets, which possess two apparent peaks due to the biexcitons and the inelastic scattering of excitons, respectively. Our present study contributes to the development of nanoscaled high performance optoelectronic devices.

  16. Superoxide Production by a Manganese-Oxidizing Bacterium Facilitates Iodide Oxidation

    PubMed Central

    Li, Hsiu-Ping; Daniel, Benjamin; Creeley, Danielle; Grandbois, Russell; Zhang, Saijin; Xu, Chen; Ho, Yi-Fang; Schwehr, Kathy A.; Kaplan, Daniel I.; Santschi, Peter H.; Hansel, Colleen M.

    2014-01-01

    The release of radioactive iodine (i.e., iodine-129 and iodine-131) from nuclear reprocessing facilities is a potential threat to human health. The fate and transport of iodine are determined primarily by its redox status, but processes that affect iodine oxidation states in the environment are poorly characterized. Given the difficulty in removing electrons from iodide (I−), naturally occurring iodide oxidation processes require strong oxidants, such as Mn oxides or microbial enzymes. In this study, we examine iodide oxidation by a marine bacterium, Roseobacter sp. AzwK-3b, which promotes Mn(II) oxidation by catalyzing the production of extracellular superoxide (O2−). In the absence of Mn2+, Roseobacter sp. AzwK-3b cultures oxidized ∼90% of the provided iodide (10 μM) within 6 days, whereas in the presence of Mn(II), iodide oxidation occurred only after Mn(IV) formation ceased. Iodide oxidation was not observed during incubations in spent medium or with whole cells under anaerobic conditions or following heat treatment (boiling). Furthermore, iodide oxidation was significantly inhibited in the presence of superoxide dismutase and diphenylene iodonium (a general inhibitor of NADH oxidoreductases). In contrast, the addition of exogenous NADH enhanced iodide oxidation. Taken together, the results indicate that iodide oxidation was mediated primarily by extracellular superoxide generated by Roseobacter sp. AzwK-3b and not by the Mn oxides formed by this organism. Considering that extracellular superoxide formation is a widespread phenomenon among marine and terrestrial bacteria, this could represent an important pathway for iodide oxidation in some environments. PMID:24561582

  17. Superoxide production by a manganese-oxidizing bacterium facilitates iodide oxidation.

    PubMed

    Li, Hsiu-Ping; Daniel, Benjamin; Creeley, Danielle; Grandbois, Russell; Zhang, Saijin; Xu, Chen; Ho, Yi-Fang; Schwehr, Kathy A; Kaplan, Daniel I; Santschi, Peter H; Hansel, Colleen M; Yeager, Chris M

    2014-05-01

    The release of radioactive iodine (i.e., iodine-129 and iodine-131) from nuclear reprocessing facilities is a potential threat to human health. The fate and transport of iodine are determined primarily by its redox status, but processes that affect iodine oxidation states in the environment are poorly characterized. Given the difficulty in removing electrons from iodide (I(-)), naturally occurring iodide oxidation processes require strong oxidants, such as Mn oxides or microbial enzymes. In this study, we examine iodide oxidation by a marine bacterium, Roseobacter sp. AzwK-3b, which promotes Mn(II) oxidation by catalyzing the production of extracellular superoxide (O2(-)). In the absence of Mn(2+), Roseobacter sp. AzwK-3b cultures oxidized ∼90% of the provided iodide (10 μM) within 6 days, whereas in the presence of Mn(II), iodide oxidation occurred only after Mn(IV) formation ceased. Iodide oxidation was not observed during incubations in spent medium or with whole cells under anaerobic conditions or following heat treatment (boiling). Furthermore, iodide oxidation was significantly inhibited in the presence of superoxide dismutase and diphenylene iodonium (a general inhibitor of NADH oxidoreductases). In contrast, the addition of exogenous NADH enhanced iodide oxidation. Taken together, the results indicate that iodide oxidation was mediated primarily by extracellular superoxide generated by Roseobacter sp. AzwK-3b and not by the Mn oxides formed by this organism. Considering that extracellular superoxide formation is a widespread phenomenon among marine and terrestrial bacteria, this could represent an important pathway for iodide oxidation in some environments.

  18. Electrochemical quantification of iodide ions in synthetic urine using silver nanoparticles: a proof-of-concept.

    PubMed

    Toh, Her Shuang; Tschulik, Kristina; Batchelor-McAuley, Christopher; Compton, Richard G

    2014-08-21

    Typical urinary iodide concentrations range from 0.3 μM to 6.0 μM. The conventional analytical method is based on the Sandell-Kolthoff reaction. It involves the toxic reagent, arsenic acid, and a waiting time of 30 minutes for the iodide ions to reduce the cerium(iv) ions. In the presented work, an alternative fast electrochemical method based on a silver nanoparticle modified electrode is proposed. Cyclic voltammetry was performed with a freshly modified electrode in presence of iodide ions and the voltammetric peaks corresponding to the oxidation of silver to silver iodide and the reverse reaction were recorded. The peak height of the reduction signal of silver iodide was used to plot a calibration line for the iodide ions. Two calibration plots for the iodide ions were obtained, one in 0.1 M sodium nitrate (a chloride-ion free environment to circumvent any interference from the other halides) and another in synthetic urine (which contains 0.2 M KCl). In both of the calibration plots, linear relationships were found between the reduction peak height and the iodide ion concentration of 0.3 μM to 6.0 μM. A slope of 1.46 × 10(-2) A M(-1) and a R(2) value of 0.999 were obtained for the iodide detection in sodium nitrate. For the synthetic urine experiments, a slope of 3.58 × 10(-3) A M(-1) and a R(2) value of 0.942 were measured. A robust iodide sensor with the potential to be developed into a point-of-care system has been validated.

  19. Linking loss of sodium-iodide symporter expression to DNA damage

    SciTech Connect

    Lyckesvärd, Madeleine Nordén; Department of Medical Chemistry and Cell Biology, University of Gothenburg, Göteborg; Kapoor, Nirmal

    Radiotherapy of thyroid cancer with I-131 is abrogated by inherent loss of radioiodine uptake due to loss of sodium iodide symporter (NIS) expression in poorly differentiated tumor cells. It is also known that ionizing radiation per se down-regulates NIS (the stunning effect), but the mechanism is unknown. Here we investigated whether loss of NIS-mediated iodide transport may be elicited by DNA damage. Calicheamicin, a fungal toxin that specifically cleaves double-stranded DNA, induced a full scale DNA damage response mediated by the ataxia-telangiectasia mutated (ATM) kinase in quiescent normal thyrocytes. At sublethal concentrations (<1 nM) calicheamicin blocked NIS mRNA expression andmore » transepithelial iodide transport as stimulated by thyrotropin; loss of function occurred at a much faster rate than after I-131 irradiation. KU-55933, a selective ATM kinase inhibitor, partly rescued NIS expression and iodide transport in DNA-damaged cells. Prolonged ATM inhibition in healthy cells also repressed NIS-mediated iodide transport. ATM-dependent loss of iodide transport was counteracted by IGF-1. Together, these findings indicate that NIS, the major iodide transporter of the thyroid gland, is susceptible to DNA damage involving ATM-mediated mechanisms. This uncovers novel means of poor radioiodine uptake in thyroid cells subjected to extrinsic or intrinsic genotoxic stress. - Highlights: • DNA damage inhibits polarized iodide transport in normal thyroid cells. • Down-regulation of NIS expression is mediated by activation of the ATM kinase. • Long-term ATM inhibition also represses NIS-mediated iodide transport. • IGF-1 rescues NIS expression and iodide transport in DNA-damaged cells.« less

  20. Surface characterization of anodized zirconium for biomedical applications

    NASA Astrophysics Data System (ADS)

    Sanchez, A. Gomez; Schreiner, W.; Duffó, G.; Ceré, S.

    2011-05-01

    Mechanical properties and corrosion resistance of zirconium make this material suitable for biomedical implants. Its good in vivo performance is mainly due to the presence of a protective oxide layer that minimizes corrosion rate, diminishes the amount of metallic ions released to the biological media and facilitates the osseointegration process. Since the implant surface is the region in contact with living tissues, the characteristics of the surface film are of great interest. Surface modification is a route to enhance both biocompatibility and corrosion resistance of permanent implant materials. Anodizing is presented as an interesting process to modify metal surfaces with good reproducibility and independence of the geometry. In this work the surface of zirconium before and after anodizing in 1 mol/L phosphoric acid solution at a fixed potential between 3 and 30 V, was characterized by means of several surface techniques. It was found that during anodization the surface oxide grows with an inhomogeneous coverage on zirconium surface, modifying the topography. The incorporation of P from the electrolyte to the surface oxide during the anodizing process changes the surface chemistry. After 30 days of immersion in Simulated Body Fluid (SBF) solution, Ca-P rich compounds were present on anodized zirconium.

  1. Direct synthesis of zirconium powder by magnesium reduction

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Won; Yun, Jung-Yeul; Yoon, Sung-Won; Wang, Jei-Pil

    2013-05-01

    The direct synthesis of zirconium powder has been conducted through an analysis of the chemical reaction between evaporated ZrCl4 and molten magnesium over a range of reduction temperatures, concentration of hydrochloric acid, and stirring time. The observed results indicated that the purity of zirconium powder increased with increased stirring time, and Mg and MgCl2 were removed by 10 wt% of hydrochloric acid solution. The pure zirconium powder was obtained by stirring again for 5 h using 5 wt% of hydrochloric acid solution. It was noted that the mean particle size increased when the reaction temperature was increased, and the size of the powder at 1,123 K and 1,173 K was found to be 10 μm and 15 μm, respectively. In addition, the purity of the powder was also improved with temperature, and its purity finally reached up to 99.5% at 1,250 K. Overall, pure zirconium powder was obtained after a stirring stage for 5 hours using 5 wt% of hydrochloric acid solution.

  2. Method for calcining nuclear waste solutions containing zirconium and halides

    DOEpatents

    Newby, Billie J.

    1979-01-01

    A reduction in the quantity of gelatinous solids which are formed in aqueous zirconium-fluoride nuclear reprocessing waste solutions by calcium nitrate added to suppress halide volatility during calcination of the solution while further suppressing chloride volatility is achieved by increasing the aluminum to fluoride mole ratio in the waste solution prior to adding the calcium nitrate.

  3. Mineral resource of the month: zirconium and hafnium

    USGS Publications Warehouse

    Gambogi, Joseph

    2007-01-01

    Zirconium and hafnium are corrosion-resistant metals that are grouped in the same family as titanium on the periodic table. The two elements commonly occur in oxide and silicate minerals and have significant economic importance in everything from ink, ceramics and golf shoes to nuclear fuel rods.

  4. Nanophase Nickel-Zirconium Alloys for Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram; Whitacre, jay; Valdez, Thomas

    2008-01-01

    Nanophase nickel-zirconium alloys have been investigated for use as electrically conductive coatings and catalyst supports in fuel cells. Heretofore, noble metals have been used because they resist corrosion in the harsh, acidic fuel cell interior environments. However, the high cost of noble metals has prompted a search for less-costly substitutes. Nickel-zirconium alloys belong to a class of base metal alloys formed from transition elements of widely different d-electron configurations. These alloys generally exhibit unique physical, chemical, and metallurgical properties that can include corrosion resistance. Inasmuch as corrosion is accelerated by free-energy differences between bulk material and grain boundaries, it was conjectured that amorphous (glassy) and nanophase forms of these alloys could offer the desired corrosion resistance. For experiments to test the conjecture, thin alloy films containing various proportions of nickel and zirconium were deposited by magnetron and radiofrequency co-sputtering of nickel and zirconium. The results of x-ray diffraction studies of the deposited films suggested that the films had a nanophase and nearly amorphous character.

  5. Manufacturing process to reduce large grain growth in zirconium alloys

    DOEpatents

    Rosecrans, Peter M.

    1987-01-01

    A method of treating cold-worked zirconium alloys to reduce large grain gth during thermal treatment at temperatures above the recrystallization temperature of the alloy comprising heating the cold-worked alloy between about 1300.degree.-1350.degree. F. for 1 to 3 hours prior to treatment above its recrystallization temperature.

  6. Project Overview: Inhibition of the Sodium-Iodide Symporter by Perchlorate: Evaluation of Lifestage Sensitivity Using PBPK Modeling

    EPA Science Inventory

    Perchlorate (ClO4-) competitively inhibits uptake of iodide by the sodium-iodide symporter (NIS) in laboratory animals and humans. NIS is found in many tissues, but is primarily responsible for sequestering iodide into the thyroid, enabling biosynthesis of thyroid hormones. The N...

  7. Strontium and barium iodide high light yield scintillators

    NASA Astrophysics Data System (ADS)

    Cherepy, Nerine J.; Hull, Giulia; Drobshoff, Alexander D.; Payne, Stephen A.; van Loef, Edgar; Wilson, Cody M.; Shah, Kanai S.; Roy, Utpal N.; Burger, Arnold; Boatner, Lynn A.; Choong, Woon-Seng; Moses, William W.

    2008-02-01

    Europium-doped strontium and barium iodide are found to be readily growable by the Bridgman method and to produce high scintillation light yields. SrI2(Eu ) emits into the Eu2+ band, centered at 435nm, with a decay time of 1.2μs and a light yield of ˜90000photons/MeV. It offers energy resolution better than 4% full width at half maximum at 662keV, and exhibits excellent light yield proportionality. BaI2(Eu ) produces >30000photons/MeV into the Eu2+ band at 420nm (<1μs decay). An additional broad impurity-mediated recombination band is present at 550nm (>3μs decay), unless high-purity feedstock is used.

  8. Crystal Structure of Hydrazinium Iodide by Neutron Diffraction

    DOE PAGES

    Campbell, Eric V.; Wang, Xiaoping; Miller, Joel S.

    2017-10-31

    The structure of hydrazinium iodide, [H 5N 2] +·I -, at 100 K has monoclinic (P2 1/n) symmetry from single crystal neutron diffraction with a = 7.4599(7) Å, b = 5.3185(6) Å, c = 10.1628(11) Å, β = 103.150(10)°, V = 392.64(7) Å 3, Z = 4. The refinement converged to R = 0.0575, wR 2 = 0.1602, S = 1.022. Data for the crystal structure was collected on the SNS TOPAZ single-crystal time-of-flight Laue diffractometer. The compound has a one-dimensional structure which displays N–H···N hydrogen bonding. Finally, accurate intra- and intermolecular N–H distances have been determined.

  9. Crystal Structure of Hydrazinium Iodide by Neutron Diffraction

    SciTech Connect

    Campbell, Eric V.; Wang, Xiaoping; Miller, Joel S.

    The structure of hydrazinium iodide, [H 5N 2] +·I -, at 100 K has monoclinic (P2 1/n) symmetry from single crystal neutron diffraction with a = 7.4599(7) Å, b = 5.3185(6) Å, c = 10.1628(11) Å, β = 103.150(10)°, V = 392.64(7) Å 3, Z = 4. The refinement converged to R = 0.0575, wR 2 = 0.1602, S = 1.022. Data for the crystal structure was collected on the SNS TOPAZ single-crystal time-of-flight Laue diffractometer. The compound has a one-dimensional structure which displays N–H···N hydrogen bonding. Finally, accurate intra- and intermolecular N–H distances have been determined.

  10. Radiative efficiency of lead iodide based perovskite solar cells

    PubMed Central

    Tvingstedt, Kristofer; Malinkiewicz, Olga; Baumann, Andreas; Deibel, Carsten; Snaith, Henry J.; Dyakonov, Vladimir; Bolink, Henk J.

    2014-01-01

    The maximum efficiency of any solar cell can be evaluated in terms of its corresponding ability to emit light. We herein determine the important figure of merit of radiative efficiency for Methylammonium Lead Iodide perovskite solar cells and, to put in context, relate it to an organic photovoltaic (OPV) model device. We evaluate the reciprocity relation between electroluminescence and photovoltaic quantum efficiency and conclude that the emission from the perovskite devices is dominated by a sharp band-to-band transition that has a radiative efficiency much higher than that of an average OPV device. As a consequence, the perovskite have the benefit of retaining an open circuit voltage ~0.14 V closer to its radiative limit than the OPV cell. Additionally, and in contrast to OPVs, we show that the photoluminescence of the perovskite solar cell is substantially quenched under short circuit conditions in accordance with how an ideal photovoltaic cell should operate. PMID:25317958

  11. Shear Bond Strength of Orthodontic Brackets Bonded to Zirconium Crowns

    PubMed Central

    Mehmeti, Blerim; Azizi, Bleron; Kelmendi, Jeta; Iljazi-Shahiqi, Donika; Alar, Željko

    2017-01-01

    Background An increasing demand for esthetic restorations has resulted in an increased use of all-ceramic restorations, such as zirconium. However, one of the challenges the orthodontist must be willing to face is how to increase bond strength between the brackets and various ceramic restorations.Bond strength can beaffected bybracket type, by the material that bracketsaremade of, and their base surface design or retention mode. ​ Aim: of this study was to perform a comparative analysis of the shear bond strength (SBS) of metallic and ceramic orthodontic brackets bonded to all-zirconium ceramic surfaces used for prosthetic restorations, and also to evaluate the fracture mode of these two types of orthodontic brackets. Material and methods Twenty samples/semi-crowns of all-zirconium ceramic, on which orthodontic brackets were bonded, 10 metallic and 10 ceramic polycrystalline brackets, were prepared for this research. SBS has been testedby Universal Testing Machine, with a load applied using a knife edged rod moving at a fixed rate of 1 mm/min, until failure occurred. The force required to debond the brackets was recorded in Newton, then SBS was calculated to MPa. In addition, the samples were analyzed using a digital camera magnifier to determine Adhesive Remnant Index (ARI). Statistical data were processed using t-test, and the level of significance was set at α = 0.05. Results Higher shear bond strength values were observed in metallic brackets bonded to zirconium crowns compared tothoseof ceramic brackets, with a significant difference. During the test, two of the ceramic brackets were partially or totally damaged. Conclusion Metallic brackets, compared to ceramic polycrystalline brackets, seemed tocreate stronger adhesion with all-zirconium surfaces due to their better retention mode. Also, ceramic brackets showed higher fragility during debonding. PMID:28827846

  12. Shear Bond Strength of Orthodontic Brackets Bonded to Zirconium Crowns.

    PubMed

    Mehmeti, Blerim; Azizi, Bleron; Kelmendi, Jeta; Iljazi-Shahiqi, Donika; Alar, Željko; Anić-Milošević, Sandra

    2017-06-01

    An increasing demand for esthetic restorations has resulted in an increased use of all-ceramic restorations, such as zirconium. However, one of the challenges the orthodontist must be willing to face is how to increase bond strength between the brackets and various ceramic restorations.Bond strength can beaffected bybracket type, by the material that bracketsaremade of, and their base surface design or retention mode. ​: A im: of this study was to perform a comparative analysis of the shear bond strength (SBS) of metallic and ceramic orthodontic brackets bonded to all-zirconium ceramic surfaces used for prosthetic restorations, and also to evaluate the fracture mode of these two types of orthodontic brackets. Twenty samples/semi-crowns of all-zirconium ceramic, on which orthodontic brackets were bonded, 10 metallic and 10 ceramic polycrystalline brackets, were prepared for this research. SBS has been testedby Universal Testing Machine, with a load applied using a knife edged rod moving at a fixed rate of 1 mm/min, until failure occurred. The force required to debond the brackets was recorded in Newton, then SBS was calculated to MPa. In addition, the samples were analyzed using a digital camera magnifier to determine Adhesive Remnant Index (ARI). Statistical data were processed using t-test, and the level of significance was set at α = 0.05. Higher shear bond strength values were observed in metallic brackets bonded to zirconium crowns compared tothoseof ceramic brackets, with a significant difference. During the test, two of the ceramic brackets were partially or totally damaged. Metallic brackets, compared to ceramic polycrystalline brackets, seemed tocreate stronger adhesion with all-zirconium surfaces due to their better retention mode. Also, ceramic brackets showed higher fragility during debonding.

  13. A passive ozone sampler based on a reaction with iodide.

    PubMed

    Yanagisawa, Y

    1994-02-01

    A new passive sampler for ozone and its simple analytical system have been developed. Because it is small and sensitive, the sampler can be used for determining personal exposures to ozone and oxidants and for multilocation measurements. The sampler consists of an electrode, a spacer, and several layers of membrane filters and Teflon meshes. The electrode is a carbon paper disk coated with nylon-6 polymer and potassium iodide. The membrane filters are used to remove interferences. A sampling rate of ozone is controlled by the spacer and Teflon meshes. Iodine is liberated by an oxidation reaction of potassium iodide with ozone. The iodine is stabilized by forming a charge transfer complex with nylon-6 and is accumulated in the nylon-6 layer. The amount of iodine, which is proportional to the level of ozone exposure, is quantified by constant current coulometry. The discharge time of a galvanic battery is measured using the electrode as a positive electrode and a zinc plate as a counter electrode. A time-weighted average concentration of ozone is derived from the discharge time after exposing the electrode to ozone. The effects of various environmental conditions on the sampler's performance were investigated. The results indicated that the sampler showed a linear response to ozone exposure up to 1,450 parts per billion for every hour of use (ppb.hour). The minimum detectable exposure was about 400 ppb.hour. The effects of surface wind velocity, temperature, and humidity were small. However, a relative humidity below 20% resulted in an underestimation of the ozone concentration. Because the electrode requires no pretreatment and the analytical method is very simple, this method is suitable for large-scale studies of personal exposures to ozone and oxidants using multilocation measurements.

  14. Testing iodized activated carbon filters with non-radioactive methyl iodide. Final report

    SciTech Connect

    Deitz, V.R.; Romans, J.B.

    1980-05-30

    Iodized carbons, impregnated with KIx(KI + xI2), were evaluated for trapping methyl iodide-127. In this method the complete effluent of the carbon is sampled and analyzed continuously. In contrast, the RDT-M16 test procedure counts the carbon and the back-up beds for the accumulated 131 species and no information is obtained for the interaction of the large amount of carrier methyl iodide-127 with the iodized charcoal. The test apparatus to measure the penetration of methyl iodide-127 is described and the calibration procedures are detailed. Results are given for the penetration of methyl iodide-127 through new activated carbons, carbons in service, andmore » exhausted carbons withdrawn from service. The reduction in trapping efficiency with service is accompanied by the development of a maximum in the concentration of methyl iodide-127 during the air purge after the dose period. This behavior has escaped notice with methyl iodide-131 due to the way that test is made. The chromatographic holdup of methyl iodide-127 by carbons in service, together with the subsequent slow desorption step, could result in a dilution of the penetration iodine to acceptable levels under some conditions encountered in plant filter operations.« less

  15. In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats.

    PubMed

    Alayoubi, Alaadin; Sullivan, Ryan D; Lou, Hao; Patel, Hemlata; Mandrell, Timothy; Helms, Richard; Almoazen, Hassan

    2016-06-01

    The objective of this study was to evaluate the transdermal efficiency of iodide microemulsion in treating iodine deficiency using rats as an animal model. Animals were fed either iodine-deficient diet (20 μg/kg iodide) or control diet (200 μg/kg iodide) over a 17-month period. At month 14, iodide microemulsion was applied topically in iodine-deficient group and physiological evaluations of thyroid gland functions were characterized by monitoring the thyroid hormones (T3, T4), thyroid-stimulating hormone (TSH), iodide ion excretion in urine, and the overall rat body weights in both groups. Moreover, morphological evaluations of thyroid gland before and after treatment were performed by ultrasound imaging and through histological assessment. Prior to microemulsion treatment, the levels of T3, T4, and TSH in iodine-deficient group were statistically significant as compared to that in the control group. The levels of T3 and T4 increased while TSH level decreased significantly in iodine-deficient group within the first 4 weeks of treatment. After treatment, iodide concentration in urine increased significantly. There was no statistical difference in weight between the two groups. Ultrasound imaging and histological evaluations showed evidence of hyperplasia in iodine-deficient group. Topical iodide microemulsion has shown a promising potential as a novel delivery system to treat iodine deficiency.

  16. Development of w/o microemulsion for transdermal delivery of iodide ions.

    PubMed

    Lou, Hao; Qiu, Ni; Crill, Catherine; Helms, Richard; Almoazen, Hassan

    2013-03-01

    The objective of this study was to develop a water-in-oil (w/o) microemulsion which can be utilized as a transdermal delivery for iodide ions. Several w/o microemulsion formulations were prepared utilizing Span 20, ethanol, Capryol 90®, and water. The selected formulations had 5%, 10%, 15%, 20%, and a maximum of 23% w/w water content. Potassium iodide (KI) was incorporated in all formulations at 5% w/v. Physicochemical characterizations were conducted to evaluate the structure and stability. These studies included: mean droplet size, pH, viscosity, conductivity, and chemical stability tests. In vitro human skin permeation studies were conducted to evaluate the diffusion of the iodide ion through human skin. The w/o microemulsion formulations were stable and compatible with iodide ions with water content ranging from 5% to 23% w/w. The addition of KI influenced the physicochemical properties of microemulsion as compared to blank microemulsion formulations. In vitro human skin permeation studies indicated that selected formulations improved iodide ion diffusion significantly as compared to control (KI solution; P value<0.05). Iodide ions were entrapped within the aqueous core of w/o microemulsion. Span 20, ethanol and Capryol 90 protected the iodide ions against oxidation and formed a stable microemulsion. It is worth to note that according to Hofmeister series, iodide ions tend to lower the interfacial tension between water and oil and consequently enhance overall stability. This work illustrates that microemulsion system can be utilized as a vehicle for the transdermal administration of iodide.

  17. Iron-catalyzed 1,2-addition of perfluoroalkyl iodides to alkynes and alkenes.

    PubMed

    Xu, Tao; Cheung, Chi Wai; Hu, Xile

    2014-05-05

    Iron catalysis has been developed for the intermolecular 1,2-addition of perfluoroalkyl iodides to alkynes and alkenes. The catalysis has a wide substrate scope and high functional-group tolerance. A variety of perfluoroalkyl iodides including CF3 I can be employed. The resulting perfluoroalkylated alkyl and alkenyl iodides can be further functionalized by cross-coupling reactions. This methodology provides a straightforward and streamlined access to perfluoroalkylated organic molecules. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Palladium-catalyzed Heck-type cross-couplings of unactivated alkyl iodides.

    PubMed

    McMahon, Caitlin M; Alexanian, Erik J

    2014-06-02

    A palladium-catalyzed, intermolecular Heck-type coupling of alkyl iodides and alkenes is described. This process is successful with a variety of primary and secondary unactivated alkyl iodides as reaction partners, including those with hydrogen atoms in the β position. The mild catalytic conditions enable intermolecular C-C bond formations with a diverse set of alkyl iodides and alkenes, including substrates containing base- or nucleophile-sensitive functionality. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Nuclear-grade zirconium prepared by combining combustion synthesis with molten-salt electrorefining technique

    NASA Astrophysics Data System (ADS)

    Li, Hui; Nersisyan, Hayk H.; Park, Kyung-Tae; Park, Sung-Bin; Kim, Jeong-Guk; Lee, Jeong-Min; Lee, Jong-Hyeon

    2011-06-01

    Zirconium has a low absorption cross-section for neutrons, which makes it an ideal material for use in nuclear reactor applications. However, hafnium typically contained in zirconium causes it to be far less useful for nuclear reactor materials because of its high neutron-absorbing properties. In the present study, a novel effective method has been developed for the production of hafnium-free zirconium. The process includes two main stages: magnesio-thermic reduction of ZrSiO 4 under a combustion mode, to produce zirconium silicide (ZrSi), and recovery of hafnium-free zirconium by molten-salt electrorefining. It was found that, depending on the electrorefining procedure, it is possible to produce zirconium powder with a low hafnium content: 70 ppm, determined by ICP-AES analysis.

  20. Anticorrosive Behavior and Porosity of Tricationic Phosphate and Zirconium Conversion Coating on Galvanized Steel

    NASA Astrophysics Data System (ADS)

    Velasquez, Camilo S.; Pimenta, Egnalda P. S.; Lins, Vanessa F. C.

    2018-05-01

    This work evaluates the corrosion resistance of galvanized steel treated with tricationic phosphate and zirconium conversion coating after painting, by using electrochemical techniques, accelerated and field corrosion tests. A non-uniform and heterogeneous distribution of zirconium on the steel surface was observed due to preferential nucleation of the zirconium on the aluminum-rich sites on the surface of galvanized steel. The long-term anti-corrosion performance in a saline solution was better for the phosphate coating up to 120 days. The coating capacitance registered a higher increase for the zirconium coatings than the phosphate coatings up to 120 days of immersion. This result agrees with the higher porosity of zirconium coating in relation to the phosphate coating. After 3840 h of accelerated corrosion test, and after 1 year of accelerated field test, zirconium-treated samples showed an average scribe delamination length higher than the phosphate-treated samples.

  1. Anticorrosive Behavior and Porosity of Tricationic Phosphate and Zirconium Conversion Coating on Galvanized Steel

    NASA Astrophysics Data System (ADS)

    Velasquez, Camilo S.; Pimenta, Egnalda P. S.; Lins, Vanessa F. C.

    2018-04-01

    This work evaluates the corrosion resistance of galvanized steel treated with tricationic phosphate and zirconium conversion coating after painting, by using electrochemical techniques, accelerated and field corrosion tests. A non-uniform and heterogeneous distribution of zirconium on the steel surface was observed due to preferential nucleation of the zirconium on the aluminum-rich sites on the surface of galvanized steel. The long-term anti-corrosion performance in a saline solution was better for the phosphate coating up to 120 days. The coating capacitance registered a higher increase for the zirconium coatings than the phosphate coatings up to 120 days of immersion. This result agrees with the higher porosity of zirconium coating in relation to the phosphate coating. After 3840 h of accelerated corrosion test, and after 1 year of accelerated field test, zirconium-treated samples showed an average scribe delamination length higher than the phosphate-treated samples.

  2. Overcoming the crystallization and designability issues in the ultrastable zirconium phosphonate framework system

    PubMed Central

    Zheng, Tao; Yang, Zaixing; Gui, Daxiang; Liu, Zhiyong; Wang, Xiangxiang; Dai, Xing; Liu, Shengtang; Zhang, Linjuan; Gao, Yang; Chen, Lanhua; Sheng, Daopeng; Wang, Yanlong; Diwu, Juan; Wang, Jianqiang; Zhou, Ruhong; Chai, Zhifang; Albrecht-Schmitt, Thomas E.; Wang, Shuao

    2017-01-01

    Metal-organic frameworks (MOFs) based on zirconium phosphonates exhibit superior chemical stability suitable for applications under harsh conditions. These compounds mostly exist as poorly crystallized precipitates, and precise structural information has therefore remained elusive. Furthermore, a zero-dimensional zirconium phosphonate cluster acting as secondary building unit has been lacking, leading to poor designability in this system. Herein, we overcome these challenges and obtain single crystals of three zirconium phosphonates that are suitable for structural analysis. These compounds are built by previously unknown isolated zirconium phosphonate clusters and exhibit combined high porosity and ultrastability even in fuming acids. SZ-2 possesses the largest void volume recorded in zirconium phosphonates and SZ-3 represents the most porous crystalline zirconium phosphonate and the only porous MOF material reported to survive in aqua regia. SZ-2 and SZ-3 can effectively remove uranyl ions from aqueous solutions over a wide pH range, and we have elucidated the removal mechanism. PMID:28555656

  3. Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89

    SciTech Connect

    Bhatt, Nikunj B.; Pandya, Darpan N.; Xu, Jide

    The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. We report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. And while both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. The differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimizationmore » is necessary to enhance 89Zr chelation.« less

  4. Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89

    PubMed Central

    Xu, Jide; Tatum, David; Magda, Darren

    2017-01-01

    The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. Herein we report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. While both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. Differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimization is necessary to enhance 89Zr chelation. PMID:28575044

  5. Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89.

    PubMed

    Bhatt, Nikunj B; Pandya, Darpan N; Xu, Jide; Tatum, David; Magda, Darren; Wadas, Thaddeus J

    2017-01-01

    The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. Herein we report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. While both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. Differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimization is necessary to enhance 89Zr chelation.

  6. Evaluation of macrocyclic hydroxyisophthalamide ligands as chelators for zirconium-89

    DOE PAGES

    Bhatt, Nikunj B.; Pandya, Darpan N.; Xu, Jide; ...

    2017-06-02

    The development of bifunctional chelators (BFCs) for zirconium-89 immuno-PET applications is an area of active research. We report the synthesis and evaluation of octadentate hydroxyisophthalamide ligands (1 and 2) as zirconium-89 chelators. And while both radiometal complexes could be prepared quantitatively and with excellent specific activity, preparation of 89Zr-1 required elevated temperature and an increased reaction time. 89Zr-1 was more stable than 89Zr-2 when challenged in vitro by excess DTPA or serum proteins and in vivo during acute biodistribution studies. The differences in radiometal complex stability arise from structural changes between the two ligand systems, and suggest further ligand optimizationmore » is necessary to enhance 89Zr chelation.« less

  7. Provisional Peer-Reviewed Toxicity Values for Rubidium Compounds (Rubidium Iodide)

    EPA Science Inventory

    This is a PPRTV for Rubidium Compounds submitted to the Superfund Program.This assessment supports multiple isomers (see related links) and this page is about the chemical rubidium iodide, CASRN 7790-29-6.

  8. SEPARATION OF PLUTONIUM IONS FROM SOLUTION BY ADSORPTION ON ZIRCONIUM PYROPHOSPHATE

    DOEpatents

    Stoughton, R.W.

    1961-01-31

    A method is given for separating plutonium in its reduced, phosphate- insoluble state from other substances. It involves contacting a solution containing the plutonium with granular zirconium pyrophosphate.

  9. Distribution coefficients of rare earth ions in cubic zirconium dioxide

    NASA Astrophysics Data System (ADS)

    Romer, H.; Luther, K.-D.; Assmus, W.

    1994-08-01

    Cubic zirconium dioxide crystals are grown with the skull melting technique. The effective distribution coefficients for Nd(exp 3+), Sm(exp 3+) and Er(sup 3+) as dopants are determined experimentally as a function of the crystal growth velocity. With the Burton-Prim-Slichter theory, the equilibrium distribution coefficients can be calculated. The distribution coefficients of all other trivalent rare earth ions can be estimated by applying the correlation towards the ionic radii.

  10. Translucency and Strength of High Translucency Monolithic Zirconium Oxide Materials

    DTIC Science & Technology

    2016-05-17

    Zirconium-Oxide Materials presented at/published to the Journal of General Dentistry with MDWI 41-108, and has been assigned local file #16208. 2...PUBLISHED/PRESENTED. D 11a. PUBLICATION/JOURNAL (list intended publication/journal.) General Dentistry D 11b. PUBLISHED ABSTRACT (List intended...the most esthetic full veneer restorative material in dentistry for many years. In the mid-1900’s, dental materials researchers began marketing and

  11. Zirconium as a Structural Material for Naval Systems

    DTIC Science & Technology

    1985-03-29

    case with the technologically critical chemical elements chromium and cobalt, for example, from a military perspective. The case, therefore, for...By adding small amounts of tin, iron, nickel, and chromium , the impurities were effectively bound or coalesced within the metal and the corrosion...and nitrogen from the atmosphere, embrittling the weld. The techniques used for zirconium welding are gas tungsten arc welding ( GTAW ), tungsten inert

  12. Electrochemical Study of Corrosion Phenomena in Zirconium Alloys

    DTIC Science & Technology

    2005-06-01

    required reaction rates [1.1]. Based predominantly on this fact, zirconium alloys were chosen to sheath, or clad, the fuel. With the increasing demand...cathode or anode. As the oxidation and reduction reactions occur, a galvanic cell is developed. The electrons on the anode are released from the metallic...matrix as the ions are released into the aqueous solution in the initial half-cell reaction . The second half-cell reaction , taking place on the

  13. Synthesis of zirconium oxynitride in air under DC electric fields

    SciTech Connect

    Morisaki, Nobuhiro; Tokunaga, Tomoharu; Sasaki, Katsuhiro

    We synthesized zirconium oxynitride from yttria-stabilized zirconia (YSZ) in air by applying DC electric fields that produced a controlled electric current in the specimen. When YSZ was heated under an applied DC electric field, the electric current of the specimen steeply increased at a critical temperature, called a flash event, during flash sintering. By keeping the electric current of the specimen constant during the flash event and then holding the specimen at the critical temperature, YSZ was transformed into zirconium oxynitride under the optimal conditions of 50 V/cm, 500 mA, and 1000 °C. We confirmed that zirconium oxynitride formed using high-resolution transmission electronmore » microscopy, electron energy-loss spectroscopy, and energy-dispersive spectrometry. To convert oxides to nitrides, reducing conditions are necessary to form excess oxygen vacancies. Our technique produced the strong reducing conditions necessary to form nitrides from the oxides by delivering a controlled electric current to the specimen.« less

  14. Ferrier rearrangement promoted by an electrochemically generated zirconium catalyst.

    PubMed

    Stevanović, Dragana; Pejović, Anka; Damljanović, Ivan; Minić, Aleksandra; Bogdanović, Goran A; Vukićević, Mirjana; Radulović, Niko S; Vukićević, Rastko D

    2015-04-30

    In situ generated zirconium catalyst from a sacrificial zirconium anode was successfully applied to promote Ferrier rearrangement of 3,4,5-tri-O-acetyl-D-glucal and 6-deoxy-3,4-di-O-acetyl-L-glucal (3,4-di-O-acetyl-L-rhamnal) in the presence of three thiols and eleven thiophenols as nucleophiles. A simple constant current electrolysis (20 mA, 0.4 F mol(-1)) of an acetonitrile solution of lithium perchlorate (0.1 M) containing the corresponding glycal and S-nucleophiles, using a zirconium anode and a platinum cathode resulted in the successful synthesis of the corresponding 2,3-unsaturated peracetylated thioglycosides (with an average anomer ratio α/β=4.129 in the case of peracetylated D-glucal and 8.740 in the case of L-rhamnal). The same procedure proved to be appropriate in synthesizing dihydropyran derivatives ('C-glycosides') using allyltrimethylsilane as the nucleophile (only 'α-anomers' were obtained). All new compounds were fully characterized by spectral data, whereas single-crystal X-ray analysis was performed for two thioglycosides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Permeation of iodide from iodine-enriched yeast through porcine intestine.

    PubMed

    Ryszka, Florian; Dolińska, Barbara; Zieliński, Michał; Chyra, Dagmara; Dobrzański, Zbigniew

    2013-01-01

    Iodine deficiency is a common phenomenon, threatening the whole global human population. Recommended daily intake of iodine is 150 μg for adults and 250 μg for pregnant and breastfeeding women. About 50% of human population can be at risk of moderate iodine deficiency. Due to this fact, increased iodine supplementation is recommended, through intake of iodized mineral water and salt iodization. The aim of this study was to investigate permeation and absorption of iodide from iodine bioplex (experimental group) in comparison with potassium iodide (controls). Permeation and absorption processes were investigated in vitro using a porcine intestine. The experimental model was based on a standard Franz diffusion cell (FD-Cell). The iodine bioplex was produced using Saccharomyces cerevisiae yeast and whey powder: iodine content - 388 μg/g, total protein - 28.5%, total fat - 0.9%., glutamic acid - 41.2%, asparaginic acid - 29.4%, lysine - 24.8%; purchased from: F.Z.N.P. Biochefa, Sosnowiec, Poland. Potassium iodide was used as controls, at 388 μg iodine concentration, which was the same as in iodine-enriched yeast bioplex. A statistically significant increase in iodide permeation was observed for iodine-enriched yeast bioplex in comparison with controls - potassium iodide. After 5h the total amount of permeated iodide from iodine-enriched yeast bioplex was 85%, which is ~ 2-fold higher than controls - 37%. Iodide absorption was by contrast statistically significantly higher in controls - 7.3%, in comparison with 4.5% in experimental group with iodine-enriched yeast bioplex. Presented results show that iodide permeation process dominates over absorption in case of iodine-enriched yeast bioplex.

  16. Chloride, bromide and iodide scintillators with europium doping

    SciTech Connect

    Zhuravleva, Mariya; Yang, Kan

    A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has beenmore » studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.« less

  17. History and current status of strontium iodide scintillators

    SciTech Connect

    Cherepy, Nerine J.; Beck, Patrick R.; Payne, Stephen A.

    Eu-doped strontium iodide single crystal growth has reached maturity and prototype SrI 2(Eu)-based gamma ray spectrometers provide detection performance advantages over standard detectors. SrI 2(Eu) offers a high, proportional light yield of >80,000 photons/MeV. Energy resolution of <3% at 662 keV with 1.5” x 1.5” SrI2(Eu) crystals is routinely achieved, by employing either a small taper at the top of the crystal or a digital readout technique. These methods overcome light-trapping, in which scintillation light is re-absorbed and re-emitted in Eu 2+-doped crystals. As a result, its excellent energy resolution, lack of intrinsic radioactivity or toxicity, and commercial availability makemore » SrI 2(Eu) the ideal scintillator for use in handheld radioisotope identification devices. A 6-lb SrI 2(Eu) radioisotope identifier is described.« less

  18. In situ nucleophilic substitutional growth of methylammonium lead iodide polycrystals.

    SciTech Connect

    Acik, Muge; Alam, Todd M.; Guo, Fangmin

    2017-01-01

    Methylammonium lead iodide (MAPbIx) perovskites are organic-inorganic semiconductors that serve as the light-harvesting component of the photovoltaics, and are desirable with their long diffusion length yielding power conversion efficiencies of ≥22%. Conventional techniques grow perovskites by spin coating precursors on an oxide or a polymer substrate followed by annealing, however, use of high boiling point solvents and high temperatures hinder device stability and performance. Through a one-step, acid-catalyzed nucleophilic-substitutional crystal growth in polar protic solvents, we show evidence for the substrate- and annealing- free production of MAPbIx polycrystals that are metallic-lead-free with negligibly small amount of PbI2 precipitation (<10%). Onmore » the basis of this chemical composition, we have devised an in situ growth of highly air (upto ~1.5 months) and thermally-stable (≤300°C), tetragonal-phased, variable-sized polycrystals (~100 nm-10 μm) amendable for large-area deposition, and ultimately, large-scale manufacturing. This method is encouraging for stable optoelectronic devices, and leads to energy-efficient and low-cost processing.« less

  19. History and current status of strontium iodide scintillators

    DOE PAGES

    Cherepy, Nerine J.; Beck, Patrick R.; Payne, Stephen A.; ...

    2017-09-15

    Eu-doped strontium iodide single crystal growth has reached maturity and prototype SrI 2(Eu)-based gamma ray spectrometers provide detection performance advantages over standard detectors. SrI 2(Eu) offers a high, proportional light yield of >80,000 photons/MeV. Energy resolution of <3% at 662 keV with 1.5” x 1.5” SrI2(Eu) crystals is routinely achieved, by employing either a small taper at the top of the crystal or a digital readout technique. These methods overcome light-trapping, in which scintillation light is re-absorbed and re-emitted in Eu 2+-doped crystals. As a result, its excellent energy resolution, lack of intrinsic radioactivity or toxicity, and commercial availability makemore » SrI 2(Eu) the ideal scintillator for use in handheld radioisotope identification devices. A 6-lb SrI 2(Eu) radioisotope identifier is described.« less

  20. Substitutional Growth of Methylammonium Lead Iodide Perovskites in Alcohols

    DOE PAGES

    Acik, Muge; Alam, Todd M.; Guo, Fangmin; ...

    2017-09-29

    Methylammonium lead iodide (MAPbI 3) perovskites are organic–inorganic semiconductors with long carrier diffusion lengths serving as the light-harvesting component in optoelectronics. Through a substitutional growth of MAPbI 3 catalyzed by polar protic alcohols, evidence is shown in this paper for their substrate- and annealing-free production and use of toxic solvents and high temperature is prevented. The resulting variable-sized crystals (≈100 nm–10 µm) are found to be tetragonally single-phased in alcohols and precipitated as powders that are metallic-lead-free. A comparatively low MAPbI 3 yield in toluene supports the role of alcohol polarity and the type of solvent (protic vs aprotic). Themore » theoretical calculations suggest that overall Gibbs free energy in alcohols is lowered due to their catalytic impact. Based on this alcohol-catalyzed approach, MAPbI 3 is obtained, which is chemically stable in air up to ≈1.5 months and thermally stable (≤300 °C). Finally, this method is amendable to large-scale manufacturing and ultimately can lead to energy-efficient, low-cost, and stable devices.« less

  1. Slow hot carrier cooling in cesium lead iodide perovskites

    NASA Astrophysics Data System (ADS)

    Shen, Qing; Ripolles, Teresa S.; Even, Jacky; Ogomi, Yuhei; Nishinaka, Koji; Izuishi, Takuya; Nakazawa, Naoki; Zhang, Yaohong; Ding, Chao; Liu, Feng; Toyoda, Taro; Yoshino, Kenji; Minemoto, Takashi; Katayama, Kenji; Hayase, Shuzi

    2017-10-01

    Lead halide perovskites are attracting a great deal of interest for optoelectronic applications such as solar cells, LEDs, and lasers because of their unique properties. In solar cells, heat dissipation by hot carriers results in a major energy loss channel responsible for the Shockley-Queisser efficiency limit. Hot carrier solar cells offer the possibility to overcome this limit and achieve energy conversion efficiency as high as 66% by extracting hot carriers. Therefore, fundamental studies on hot carrier relaxation dynamics in lead halide perovskites are important. Here, we elucidated the hot carrier cooling dynamics in all-inorganic cesium lead iodide (CsPbI3) perovskite using transient absorption spectroscopy. We observe that the hot carrier cooling rate in CsPbI3 decreases as the fluence of the pump light increases and the cooling is as slow as a few 10 ps when the photoexcited carrier density is 7 × 1018 cm-3, which is attributed to phonon bottleneck for high photoexcited carrier densities. Our findings suggest that CsPbI3 has a potential for hot carrier solar cell applications.

  2. Re-entrant relaxor ferroelectricity of methylammonium lead iodide

    DOE PAGES

    Guo, Haiyan; Liu, Peixue; Zheng, Shichao; ...

    2016-09-24

    In this paper, we have performed a piezoresponse force microscopy (PFM) study on methylammonium lead iodide (MAPbI 3) thin films in normal (non-resonance, non-band-excitation) contact mode. In contrast to the ferroelectric Pb 0.76Ca 0.24TiO 3 (PCT) control sample, a typical ferroelectric response was not observed. However, a nonlinear electric field dependence of the local PFM amplitude was found in MAPbI 3, similar to PCT. An analysis combining results on structure, dielectric dispersion, and weak ferroelectricity demonstrates that MAPbI 3 is actually a re-entrant relaxor ferroelectric which, upon cooling, enters into a relaxor phase below its ferroelectric phase transition at ~327more » K, due to the balance between the long range ferroelectric order and structural methylammonium group orientational disorder. The ferroelectricity at room temperature is compromised due to the re-entrant relaxor behavior, causing the poor polarization retention or weak ferroelectricity. Finally, our findings essentially conciliate the conflicting experimental results on MAPbI 3's ferroelectricity and are beneficial both for basic understanding as well as for device applications.« less

  3. The Impact of Iodide-Mediated Ozone Deposition and ...

    EPA Pesticide Factsheets

    The air quality of many large coastal areas in the United States is affected by the confluence of polluted urban and relatively clean marine airmasses, each with distinct atmospheric chemistry. In this context, the role of iodide-mediated ozone (O3) deposition over seawater and marine halogen chemistry accounted for in both the lateral boundary conditions and coastal waters surrounding the continental U.S. is examined using the Community Multiscale Air Quality (CMAQ) model. Several nested simulations are conducted in which these halogen processes are implemented separately in the continental U.S. and hemispheric CMAQ domains, the latter providing lateral boundary conditions for the former. Overall, it is the combination of these processes within both the continental U.S. domain and from lateral boundary conditions that lead to the largest reductions in modeled surface O3 concentrations. Predicted reductions in surface O3 concentrations occur mainly along the coast where CMAQ typically has large overpredictions. These results suggest that a realistic representation of halogen processes in marine regions can improve model prediction of O3 concentrations near the coast. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and

  4. Lead iodide perovskite light-emitting field-effect transistor

    PubMed Central

    Chin, Xin Yu; Cortecchia, Daniele; Yin, Jun; Bruno, Annalisa; Soci, Cesare

    2015-01-01

    Despite the widespread use of solution-processable hybrid organic–inorganic perovskites in photovoltaic and light-emitting applications, determination of their intrinsic charge transport parameters has been elusive due to the variability of film preparation and history-dependent device performance. Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-effect transistors. Field-effect carrier mobility is found to increase by almost two orders of magnitude below 200 K, consistent with phonon scattering-limited transport. Under balanced ambipolar carrier injection, gate-dependent electroluminescence is also observed from the transistor channel, with spectra revealing the tetragonal to orthorhombic phase transition. This demonstration of CH3NH3PbI3 light-emitting field-effect transistors provides intrinsic transport parameters to guide materials and solar cell optimization, and will drive the development of new electro-optic device concepts, such as gated light-emitting diodes and lasers operating at room temperature. PMID:26108967

  5. A selective iodide ion sensor electrode based on functionalized ZnO nanotubes.

    PubMed

    Ibupoto, Zafar Hussain; Khun, Kimleang; Willander, Magnus

    2013-02-04

    In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10-6 to 1 × 10-1 M) and excellent sensitivity of -62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10-7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples.

  6. A Selective Iodide Ion Sensor Electrode Based on Functionalized ZnO Nanotubes

    PubMed Central

    Ibupoto, Zafar Hussain; Khun, Kimleang; Willander, Magnus

    2013-01-01

    In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion sensor exhibited a linear response over a wide range of concentrations (1 × 10−6 to 1 × 10−1 M) and excellent sensitivity of −62 ± 1 mV/decade. The detection limit of the proposed sensor was found to be 5 × 10−7 M. The effects of pH, temperature, additive, plasticizer and stabilizer on the potential response of iodide ion selective electrode were also studied. The proposed iodide ion sensor demonstrated a fast response time of less than 5 s and high selectivity against common organic and the inorganic anions. All the obtained results revealed that the iodide ion sensor based on functionalized ZnO nanotubes may be used for the detection of iodide ion in environmental water samples, pharmaceutical products and other real samples. PMID:23385412

  7. Iodide-ion-induced oscillations of the ferroin-catalyzed Belousov—Zhabotinskii reaction

    NASA Astrophysics Data System (ADS)

    Melicherčík, Milan; Treindl, Ľudovít

    1992-08-01

    Contrary to "classical" Belousov—Zhabotinskii (BZ) oscillatory systems, consisting of malonic acid, Ce(IV)—Ce(III) or Mn(III)—Mn(II) redox catalyst and KBrO 3 in solutions of H 2SO 4, where in an interval of added iodide initial concentrations 10 -4 mol dm -3 < [I -] 0 < 10 -3 mol dm -3 the oscillations have the same frequency and amplitude as in the absence of iodide, the effect of added iodide on the ferroin-catalyzed BZ system with methyl ester of 3-oxobutanoic acid leads to an increase in the number of oscillations and in the time of their duration. The dependence of this effect on substrate, bromate, iodide, sulfuric acid and ferroin concentrations has been studied. The observations may be explained by a mechanism involving direct reduction of ferroin by iodide, oxidation of iodide to iodate by bromate with a bromide production and eventual faster bromination and iodination of methyl ester of 3-oxobutanoic acid in relation to malonic acid.

  8. Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

    DOE PAGES

    Adamic, M. L.; Lister, T. E.; Dufek, E. J.; ...

    2015-03-25

    This paper presents an evaluation of an alternate method for preparing environmental samples for 129I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Furthermore, precipitated silver iodide samples are usually mixed with niobium or silver powdermore » prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.« less

  9. Perchlorate and iodide in whole blood samples from infants, children, and adults in Nanchang, China.

    PubMed

    Zhang, Tao; Wu, Qian; Sun, Hong Wen; Rao, Jia; Kannan, Kurunthachalam

    2010-09-15

    Perchlorate, ClO(4)(-), interferes with iodide (I(-)) uptake by the sodium-iodide symporter (NIS) and thereby affects thyroid hormone production in the body. Studies have reported human exposures to perchlorate based on measurements in urine, but little is known about the levels in blood. In this study, we determined concentrations of perchlorate, iodide, and other anions (e.g., chlorate [ClO(3)(-)], bromate [BrO(3)(-)], bromide [Br(-)]) in 131 whole blood samples collected from Chinese donors aged 0.4 to 90 yr, in Nanchang, China. Perchlorate, iodide, and bromide were detected in all of the samples analyzed, whereas chlorate was found in only 27% of the samples and bromate was found in only 2%. The mean (range) concentrations of perchlorate, iodide, and bromide were 2.68 (0.51-10.5), 42.6 (1.58-812), and 2120 (1050-4850) ng/mL, respectively. Perchlorate levels in blood from Nanchang adults were 10-fold greater than levels that have been previously reported for U.S. adults. The iodide/perchlorate molar ratio ranged from 3.05 to 15.3 for all age groups, and the ratio increased with age (r = 0.732, p < 0.01). Perchlorate and bromide concentrations decreased significantly with age, whereas iodide concentrations increased with age. No significant gender-related differences in blood perchlorate, iodide, or bromide levels were found. A significant negative correlation was found between the concentrations of perchlorate and iodide in blood. Exposure doses of perchlorate were estimated for infants, toddlers, children, adolescents, and adults based on the measured concentrations in blood, using a simple pharmacokinetic model. The mean exposure doses of perchlorate for our age groups ranged from 1.12 (adults) to 2.22 μg/kg bw/day (infants), values higher than the United States Environmental Protection Agency's (USEPA) reference dose (RfD: 0.7 μg/kg bw/day). This is the first study on perchlorate and iodide levels in whole blood from infants, toddlers, children, adolescents

  10. A glucose bio-battery prototype based on a GDH/poly(methylene blue) bioanode and a graphite cathode with an iodide/tri-iodide redox couple.

    PubMed

    Wang, Jen-Yuan; Nien, Po-Chin; Chen, Chien-Hsiao; Chen, Lin-Chi; Ho, Kuo-Chuan

    2012-07-01

    A glucose bio-battery prototype independent of oxygen is proposed based on a glucose dehydrogenase (GDH) bioanode and a graphite cathode with an iodide/tri-iodide redox couple. At the bioanode, a NADH electrocatalyst, poly(methylene blue) (PMB), which can be easily grown on the electrode (screen-printed carbon paste electrode, SPCE) by electrodeposition, is harnessed and engineered. We find that carboxylated multi-walled carbon nanotubes (MWCNTs) are capable of significantly increasing the deposition amount of PMB and thus enhancing the PMB's electrocatalysis of NADH oxidation and the glucose bio-battery's performance. The choice of the iodide/tri-iodide redox couple eliminates the dependence of oxygen for this bio-battery, thus enabling the bio-battery with a constant current-output feature similar to that of the solar cells. The present glucose bio-battery prototype can attain a maximum power density of 2.4 μW/cm(2) at 25 °C. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  11. Hybrid Dion-Jacobson 2D Lead Iodide Perovskites.

    PubMed

    Mao, Lingling; Ke, Weijun; Pedesseau, Laurent; Wu, Yilei; Katan, Claudine; Even, Jacky; Wasielewski, Michael R; Stoumpos, Constantinos C; Kanatzidis, Mercouri G

    2018-03-14

    The three-dimensional hybrid organic-inorganic perovskites have shown huge potential for use in solar cells and other optoelectronic devices. Although these materials are under intense investigation, derivative materials with lower dimensionality are emerging, offering higher tunability of physical properties and new capabilities. Here, we present two new series of hybrid two-dimensional (2D) perovskites that adopt the Dion-Jacobson (DJ) structure type, which are the first complete homologous series reported in halide perovskite chemistry. Lead iodide DJ perovskites adopt a general formula A'A n-1 Pb n I 3 n+1 (A' = 3-(aminomethyl)piperidinium (3AMP) or 4-(aminomethyl)piperidinium (4AMP), A = methylammonium (MA)). These materials have layered structures where the stacking of inorganic layers is unique as they lay exactly on top of another. With a slightly different position of the functional group in the templating cation 3AMP and 4AMP, the as-formed DJ perovskites show different optical properties, with the 3AMP series having smaller band gaps than the 4AMP series. Analysis on the crystal structures and density functional theory (DFT) calculations suggest that the origin of the systematic band gap shift is the strong but indirect influence of the organic cation on the inorganic framework. Fabrication of photovoltaic devices utilizing these materials as light absorbers reveals that (3AMP)(MA) 3 Pb 4 I 13 has the best power conversion efficiency (PCE) of 7.32%, which is much higher than that of the corresponding (4AMP)(MA) 3 Pb 4 I 13 .

  12. 40 CFR 721.10152 - Oxirane, substituted silylmethyl-, hydrolysis products with alkanol zirconium(4+) salt and silica...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-, hydrolysis products with alkanol zirconium(4+) salt and silica, acetates (generic). 721.10152 Section 721... Oxirane, substituted silylmethyl-, hydrolysis products with alkanol zirconium(4+) salt and silica... zirconium(4+) salt and silica, acetates (PMN P-07-674) is subject to reporting under this section for the...

  13. Use of an iodide-specific electrode to study lactoperoxidase-catalyzed iodination of l-tyrosine.

    PubMed

    Threatte, R M; Fregly, M J; Field, F P; Jones, P K

    1979-12-01

    An in vitro method employing an iodide-specific electrode for monitoring lactoperoxidase-catalyzed iodination is described. The method utilized lactoperoxidase, potassium iodide, and a glucose--glucose oxidase system for the generation of hydrogen peroxide and l-tyrosine. As iodination of l-tyrosine proceeded, the free iodide concentration in solution decreased and was monitored by an iodide-specific electrode. The iodide electrode was reliable when compared to a 131I-method for measuring free iodide changes in solution. Increasing concentrations of resorcinol, a well-known inhibitor of thyroid peroxidase-catalyzed iodination, in the reaction mixture resulted in graded inhibition of the initial rate of lactoperoxidase-catalyzed l-tyrosine iodination. This in vitro system can be used to assess inhibitory activity of various antithyroid substances.

  14. Zirconium carbide as an electrocatalyst for the chromous-chromic redox couple

    NASA Technical Reports Server (NTRS)

    Gahn, R. F.; Reid, M. A.; Yang, C. Y. (Inventor)

    1981-01-01

    Zirconium carbide is used as a catalyst in a REDOX cell for the oxidation of chromous ions to chromic ions and for the reduction of chromic ions to chromous ions. The zirconium carbide is coated on an inert electronically conductive electrode which is present in the anode fluid of the cell.

  15. 21 CFR 700.16 - Use of aerosol cosmetic products containing zirconium.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Use of aerosol cosmetic products containing zirconium. 700.16 Section 700.16 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... and other organs of experimental animals. When used in aerosol form, some zirconium will reach the...

  16. Lithium aluminate/zirconium material useful in the production of tritium

    DOEpatents

    Cawley, W.E.; Trapp, T.J.

    1984-10-09

    A composition is described useful in the production of tritium in a nuclear reactor. Lithium aluminate particles are dispersed in a matrix of zirconium. Tritium produced by the reactor of neutrons with the lithium are absorbed by the zirconium, thereby decreasing gas pressure within capsules carrying the material.

  17. Lithium aluminate/zirconium material useful in the production of tritium

    DOEpatents

    Cawley, William E.; Trapp, Turner J.

    1984-10-09

    A composition is described useful in the production of tritium in a nuclear eactor. Lithium aluminate particles are dispersed in a matrix of zirconium. Tritium produced by the reactor of neutrons with the lithium are absorbed by the zirconium, thereby decreasing gas pressure within capsules carrying the material.

  18. Lithium aluminate/zirconium material useful in the production of tritium

    DOEpatents

    Cawley, W.E.; Trapp, T.J.

    A composition is described useful in the production of tritium in a nuclear reactor. Lithium aluminate particles are dispersed in a matrix of zirconium. Tritium produced by the reactor of neutrons with the lithium are absorbed by the zirconium, thereby decreasing gas pressure within capsules carrying the material.

  19. 21 CFR 700.16 - Use of aerosol cosmetic products containing zirconium.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Use of aerosol cosmetic products containing... SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.16 Use of aerosol cosmetic products containing zirconium. (a) Zirconium-containing complexes have been used as an ingredient...

  20. 21 CFR 700.16 - Use of aerosol cosmetic products containing zirconium.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Use of aerosol cosmetic products containing... SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.16 Use of aerosol cosmetic products containing zirconium. (a) Zirconium-containing complexes have been used as an ingredient...

  1. 21 CFR 700.16 - Use of aerosol cosmetic products containing zirconium.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Use of aerosol cosmetic products containing... SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.16 Use of aerosol cosmetic products containing zirconium. (a) Zirconium-containing complexes have been used as an ingredient...

  2. Iodide Residues in Milk Vary between Iodine-Based Teat Disinfectants.

    PubMed

    French, Elizabeth A; Mukai, Motoko; Zurakowski, Michael; Rauch, Bradley; Gioia, Gloria; Hillebrandt, Joseph R; Henderson, Mark; Schukken, Ynte H; Hemling, Thomas C

    2016-07-01

    Majority of iodine found in dairy milk comes from the diet and teat disinfection products used during milking process. The objective of this study was to evaluate the effects of 4 iodine-based teat dips on milk iodide concentrations varying in iodine level (0.25% vs. 0.5%, w/w), normal low viscosity dip versus barrier dip, and application method (dip vs. spray) to ensure safe iodine levels in dairy milk when these products are used. The iodine exposure study was performed during a 2-wk period. The trial farm was purged of all iodine-based disinfection products for 21 d during a prestudy "washout period," which resulted in baseline milk iodide range of 145 to 182 ppb. During the experiment, iodine-based teat dips were used as post-milking teat disinfectants and compared to a non-iodine control disinfectant. Milk iodide residue levels for each treatment was evaluated from composited group samples. Introduction of different iodine-based teat disinfectants increased iodide residue content in milk relative to the control by between 8 and 29 μg/L when averaged across the full trial period. However, residues levels for any treatment remained well below the consumable limit of 500 μg/L. The 0.5% iodine disinfectant increased milk iodide levels by 20 μg/L more compared to the 0.25% iodine. Compared to dip-cup application, spray application significantly increased milk iodide residue by 21 μg/L and utilized approximately 23% more teat dip. This carefully controlled study demonstrated an increase in milk iodide concentrations from iodine disinfectants, but increases were small and within acceptable limits. © 2016 Institute of Food Technologists®

  3. A simple spectrophotometric method for determination of zirconium or hafnium in selected molybdenum-base alloys

    NASA Technical Reports Server (NTRS)

    Dupraw, W. A.

    1972-01-01

    A simple analytical procedure is described for accurately and precisely determining the zirconium or hafnium content of molybdenum-base alloys. The procedure is based on the reaction of the reagent Arsenazo III with zirconium or hafnium in strong hydrochloric acid solution. The colored complexes of zirconium or hafnium are formed in the presence of molybdenum. Titanium or rhenium in the alloy have no adverse effect on the zirconium or hafnium complex at the following levels in the selected aliquot: Mo, 10 mg; Re, 10 mg; Ti, 1 mg. The spectrophotometric measurement of the zirconium or hafnium complex is accomplished without prior separation with a relative standard deviation of 1.3 to 2.7 percent.

  4. Efficient One-Pot Synthesis of Colloidal Zirconium Oxide Nanoparticles for High-Refractive-Index Nanocomposites.

    PubMed

    Liu, Chao; Hajagos, Tibor Jacob; Chen, Dustin; Chen, Yi; Kishpaugh, David; Pei, Qibing

    2016-02-01

    Zirconium oxide nanoparticles are promising candidates for optical engineering, photocatalysis, and high-κ dielectrics. However, reported synthetic methods for the colloidal zirconium oxide nanoparticles use unstable alkoxide precursors and have various other drawbacks, limiting their wide application. Here, we report a facile one-pot method for the synthesis of colloidally stable zirconium oxide nanoparticles. Using a simple solution of zirconium trifluoroacetate in oleylamine, highly stable zirconium oxide nanoparticles have been synthesized with high yield, following a proposed amidization-assisted sol-gel mechanism. The nanoparticles can be readily dispersed in nonpolar solvents, forming a long-term stable transparent solution, which can be further used to fabricate high-refractive-index nanocomposites in both monolith and thin-film forms. In addition, the same method has also been extended to the synthesis of titanium oxide nanoparticles, demonstrating its general applicability to all group IVB metal oxide nanoparticles.

  5. Minimalistic Liquid-Assisted Route to Highly Crystalline α-Zirconium Phosphate.

    PubMed

    Cheng, Yu; Wang, Xiaodong Tony; Jaenicke, Stephan; Chuah, Gaik-Khuan

    2017-08-24

    Zirconium phosphates have potential applications in areas of ion exchange, catalysis, photochemistry, and biotechnology. However, synthesis methodologies to form crystalline α-zirconium phosphate (Zr(HPO 4 ) 2 ⋅H 2 O) typically involve the use of excess phosphoric acid, addition of HF or oxalic acid and long reflux times or hydrothermal conditions. A minimalistic sustainable route to its synthesis has been developed by using only zirconium oxychloride and concentrated phosphoric acid to form highly crystalline α-zirconium phosphate within hours. The morphology can be changed from platelets to rod-shaped particles by fluoride addition. By varying the temperature and time, α-zirconium phosphate with particle sizes from nanometers to microns can be obtained. Key features of this minimal solvent synthesis are the excellent yields obtained with high atom economy under mild conditions and ease of scalability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. The Deformation Mechanism of Fatigue Behaviour in a N36 Zirconium Alloy

    NASA Astrophysics Data System (ADS)

    Wang, Yingzhu

    2018-05-01

    Zirconium alloys are widely used as claddings in nuclear reactor. A N36 zirconium alloy has been deformed into a sheet with highly texture according to the result of electron back scatter diffraction test. Then this N36 zirconium alloy sheet has been cut into small beam samples with 12 x 3 x 3 mm3 in size. In this experiment, a three-point bending test was carried out to investigate the fatigue behaviour of N36 zirconium alloy. Cyclic loadings were applied on the top middle of the beam samples. The region of interest (ROI) is located at the middle bottom of the front face of the beam sample where slip band was observed in deformed beam sample due to strain concentration by using scanning electron microscopy. Twinning also plays an important role to accommodate the plastic deformation of N36 zirconium alloy in fatigue, which displays competition with slip.

  7. Ternary cobalt-molybdenum-zirconium coatings for alternative energies

    NASA Astrophysics Data System (ADS)

    Yar-Mukhamedova, Gulmira; Ved', Maryna; Sakhnenko, Nikolay; Koziar, Maryna

    2017-11-01

    Consistent patterns for electrodeposition of Co-Mo-Zr coatings from polyligand citrate-pyrophosphate bath were investigated. The effect of both current density amplitude and pulse on/off time on the quality, composition and surface morphology of the galvanic alloys were determined. It was established the coating Co-Mo-Zr enrichment by molybdenum with current density increasing up to 8 A dm-2 as well as the rising of pulse time and pause duration promotes the content of molybdenum because of subsequent chemical reduction of its intermediate oxides by hydrogen ad-atoms. It was found that the content of the alloying metals in the coating Co-Mo-Zr depends on the current density and on/off times extremely and maximum Mo and Zr content corresponds to the current density interval 4-6 A dm-2, on-/off-time 2-10 ms. Chemical resistance of binary and ternary coatings based on cobalt is caused by the increased tendency to passivity and high resistance to pitting corrosion in the presence of molybdenum and zirconium, as well as the acid nature of their oxides. Binary coating with molybdenum content not less than 20 at.% and ternary ones with zirconium content in terms of corrosion deep index are in a group ;very proof;. It was shown that Co-Mo-Zr alloys exhibits the greatest level of catalytic properties as cathode material for hydrogen electrolytic production from acidic media which is not inferior a platinum electrode. The deposits Co-Mo-Zr with zirconium content 2-4 at.% demonstrate high catalytic properties in the carbon(II) oxide conversion. This confirms the efficiency of materials as catalysts for the gaseous wastes purification and gives the reason to recommend them as catalysts for red-ox processes activating by oxygen as well as electrode materials for red-ox batteries.

  8. Lamellar zirconium phosphates to host metals for catalytic purposes.

    PubMed

    Ballesteros-Plata, Daniel; Infantes-Molina, Antonia; Rodríguez-Aguado, Elena; Braos-García, Pilar; Rodríguez-Castellón, Enrique

    2018-02-27

    In the present study a porous lamellar zirconium phosphate heterostructure (PPH) formed from zirconium(iv) phosphate expanded with silica galleries (P/Zr molar ratio equal to 2 and (Si + Zr)/P equal to 3) was prepared to host noble metals. Textural and structural characterization of PPH-noble metal materials was carried out in order to elucidate the location and dispersion of the metallic particles and the properties of the resulting material to be used in catalytic processes. In the present paper, their activity in the catalytic hydrodeoxygenation (HDO) reaction of dibenzofuran (DBF) was evaluated. X-ray diffraction (XRD), solid state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) evidenced that the structure of the pillared zirconium phosphate material was not modified by the incorporation of Pt and Pd. Moreover, transmission electron microscopy (TEM) showed a different dispersion of the noble metal. The acidity of the resulting PPH-noble metal materials also changed, although in all cases the acidity was of weak nature, and the incorporation of noble metals affected Brønsted acid sites as observed from 31 P NMR spectra. In general, the textural, structural and acidic properties of the resulting materials suggest that PPH can be considered a good candidate to be used as a catalytic support. Thus, the catalytic results of the PPH-noble metal samples indicated that the Pd sample showed a stable behavior probably ascribed to a high dispersion of the active phase. However, the Pt sample suffered from fast deactivation. The selectivity to the reaction products was strongly dependent on the noble metal employed.

  9. Stable iodide doping induced by photonic curing for carbon nanotube transparent conductive films

    NASA Astrophysics Data System (ADS)

    Wachi, Atsushi; Nishikawa, Hiroyuki; Zhou, Ying; Azumi, Reiko

    2018-06-01

    Doping has become crucial for achieving stable and high-performance conductive transparent carbon nanotube (CNT) films. In this study, we systematically investigate the doping effects of a few materials including alkali metal iodides, nonmetal iodide, and metals. We demonstrate that photonic curing can enhance the doping effects, and correspondingly improve the conductivity of CNT films, and that such iodides have better doping effects than metals. In particular, doping with a nonmetal compound (NH4I) shows the largest potential to improve the conductivity of CNT films. Typically, doping with metal iodides reduces the sheet resistance (R S) of CNT films with 70–80% optical transmittances at λ = 550 nm from 600–2400 to 250–440 Ω/square, whereas doping with NH4I reduces R S to 57 and 84 Ω/square at 74 and 84% optical transmittances, respectively. Interestingly, such a doped CNT film exhibits only a slight increase in sheet resistance under an extreme environment of high temperature (85 °C) and high relative humidity (85%) for 350 h. The results suggest that photonic-curing-induced iodide doping is a promising approach to producing high-performance conductive transparent CNT films.

  10. Catalytic spectrophotometric determination of iodide in pharmaceutical preparations and edible salt.

    PubMed

    El-Ries, M A; Khaled, Elmorsy; Zidane, F I; Ibrahim, S A; Abd-Elmonem, M S

    2012-02-01

    The catalytic effect of iodide on the oxidation of four dyes: viz. variamine blue (VB), methylene blue (MB), rhodamine B (RB), and malachite green (MG) with different oxidizing agents was investigated for the kinetic spectrophotometric determination of iodide. The above catalyzed reactions were monitored spectrophotometrically by following the change in dye absorbances at 544, 558, 660, or 617 nm for the VB, RB, MB, or MG catalyzed reactions, respectively. Under optimum conditions, iodide can be determined within the concentration levels 0.064-1.27 µg mL(-1) for VB method, 3.20-9.54 µg mL(-1) for RB method, 5.00-19.00 µg mL(-1) for the MB method, and 6.4-19.0 µg mL(-1) for the MG one, with detection limit reaching 0.004 µg mL(-1) iodide. The reported methods were highly sensitive, selective, and free from most interference. Applying the proposed procedures, trace amounts of iodide in pharmaceutical and edible salt samples were successfully determined without separation or pretreatment steps. Copyright © 2011 John Wiley & Sons, Ltd.

  11. The value of iodide as a parameter in the chemical characterisation of groundwaters

    NASA Astrophysics Data System (ADS)

    Lloyd, J. W.; Howard, K. W. F.; Pacey, N. R.; Tellam, J. H.

    1982-06-01

    Brackish and saline groundwaters can severely constrain the use of fresh groundwaters. Their chemical characterisation is important in understanding the hydraulic conditions controlling their presence in an aquifer. Major ions are frequently of limited value but minor ions can be used. Iodide in groundwater is particularly significant in many environments due to the presence of soluble iodine in aquifer matrix materials. Iodide is found in groundwaters in parts of the English Chalk aquifer in concentrations higher than are present in modern seawater. Its presence is considered as a indication of groundwater residence and is of use in the characterisation of fresh as well as saline waters. Under certain circumstances modern seawater intrusion into aquifers along English estuaries produces groundwaters which are easily identified due to iodide enrichment from estuarine muds. In other environments iodide concentrations are of value in distinguishing between groundwaters in limestones and shaly gypsiferous rocks as shown by a study in Qatar, while in an alluvial aquifer study in Peru iodide has been used to identify groundwaters entering the aquifer from adjacent granodiorites.

  12. The chemistry of PET imaging with zirconium-89.

    PubMed

    Dilworth, Jonathan R; Pascu, Sofia I

    2018-04-23

    This Tutorial Review aims to provide an overview of the use of zirconium-89 complexes in biomedical imaging. Over the past decade there have been many new papers in this field, ranging from chemistry through to preclinical and clinical applications. Here we attempt to summarise the main developments that have occurred in this period. The primary focus is on coordination chemistry but other aspects such as isotope production, isotope properties, handling and radiochemical techniques and characterisation of cold and labelled complexes are included. Selected results from animal and human clinical studies are presented in the context of the stabilities and properties of the labelled bioconjugates.

  13. METHOD FOR ANNEALING AND ROLLING ZIRCONIUM-BASE ALLOYS

    DOEpatents

    Picklesimer, M.L.

    1959-07-14

    A fabrication procedure is presented for alpha-stabilized zirconium-base alloys, and in particular Zircaloy-2. The alloy is initially worked at a temperature outside the alpha-plus-beta range (810 to 970 deg ), held at a temperature above 970 deg C for 30 minutes and cooled rapidly. The alloy is then cold-worked to reduce the size at least 20% and annealed at a temperature from 700 to 810 deg C. This procedure serves both to prevent the formation of stringers and to provide a randomly oriented crystal structure.

  14. Impedance spectroscopy of water soluble resin modified by zirconium sulphate

    NASA Astrophysics Data System (ADS)

    Joseph, Anandraj; Joshi, Girish M.

    2018-04-01

    We successfully modified water soluble resin polyvinyl alcohol (PVA) by loading zirconium sulphate (ZrSO4). We demonstrated the measurement of electrical properties by using impedance analyser across frequency range (10 Hz-1 MHz) and the temperature range of (30°C to 150°C). The impedance spectroscopy demonstrates decrease in bulk resistance as a function of temperature loading of zirconia 2.5 wt. %. Increase in AC (10-5 S/cm and DC conductivity (10- 2 S/m) observed due to ionic contribution of zirconia. However, the electrical properties of PVA/ZrSO4 composite useful to develop battery electrolyte applications.

  15. Simultaneous detection of iodine and iodide on boron doped diamond electrodes.

    PubMed

    Fierro, Stéphane; Comninellis, Christos; Einaga, Yasuaki

    2013-01-15

    Individual and simultaneous electrochemical detection of iodide and iodine has been performed via cyclic voltammetry on boron doped diamond (BDD) electrodes in a 1M NaClO(4) (pH 8) solution, representative of typical environmental water conditions. It is feasible to compute accurate calibration curve for both compounds using cyclic voltammetry measurements by determining the peak current intensities as a function of the concentration. A lower detection limit of about 20 μM was obtained for iodide and 10 μM for iodine. Based on the comparison between the peak current intensities reported during the oxidation of KI, it is probable that iodide (I(-)) is first oxidized in a single step to yield iodine (I(2)). The latter is further oxidized to obtain IO(3)(-). This technique, however, did not allow for a reasonably accurate detection of iodate (IO(3)(-)) on a BDD electrode. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Real-Time Observation of Organic Cation Reorientation in Methylammonium Lead Iodide Perovskites.

    PubMed

    Bakulin, Artem A; Selig, Oleg; Bakker, Huib J; Rezus, Yves L A; Müller, Christian; Glaser, Tobias; Lovrincic, Robert; Sun, Zhenhua; Chen, Zhuoying; Walsh, Aron; Frost, Jarvist M; Jansen, Thomas L C

    2015-09-17

    The introduction of a mobile and polarized organic moiety as a cation in 3D lead-iodide perovskites brings fascinating optoelectronic properties to these materials. The extent and the time scales of the orientational mobility of the organic cation and the molecular mechanism behind its motion remain unclear, with different experimental and computational approaches providing very different qualitative and quantitative description of the molecular dynamics. Here we use ultrafast 2D vibrational spectroscopy of methylammonium (MA) lead iodide to directly resolve the rotation of the organic cations within the MAPbI3 lattice. Our results reveal two characteristic time constants of motion. Using ab initio molecular dynamics simulations, we identify these as a fast (∼300 fs) "wobbling-in-a-cone" motion around the crystal axis and a relatively slow (∼3 ps) jump-like reorientation of the molecular dipole with respect to the iodide lattice. The observed dynamics are essential for understanding the electronic properties of perovskite materials.

  17. Mechanistic aspects of ingested chlorine dioxide on thyroid function: impact of oxidants on iodide metabolism.

    PubMed Central

    Bercz, J P; Jones, L L; Harrington, R M; Bawa, R; Condie, L

    1986-01-01

    Toxicological studies dealing with recent findings of health effects of drinking water disinfectants are reviewed. Experiments with monkeys and rodents indicate that the biological activity of ingested disinfectants is expressed via their chemical interaction with the mucosal epithelia, secretory products, and nutritional contents of the alimentary tract. Evidence exists that a principal partner of this redox interaction is the iodide of nutritional origin that is ubiquitous in the gastrointestinal tract. Thus the observation that subchronic exposure to chlorine dioxide (ClO2) in drinking water decreases serum thyroxine levels in mammalian species can be best explained with changes produced in the chemical form of the bioavailable iodide. Ongoing and previously reported mechanistic studies indicate that oxidizing agents such as chlorine-based disinfectants oxidize the basal iodide content of the gastrointestinal tract. The resulting reactive iodine species readily attaches to organic matter by covalent bonding. Evidence suggests that the extent to which such iodinated organics are formed is proportional to the magnitude of the electromotive force and stoichiometry of the redox couple between iodide and the disinfectant. Because the extent of thyroid uptake of the bioavailable iodide does not decrease during ClO2 ingestion, it seems that ClO2 does not cause iodide deficiency of sufficient magnitude to account for the decrease in hormonogenesis. Absorption of one or more of iodinated molecules, e.g., nutrients, hormones, or cellular constituents of the alimentary tract having thyromimetic or thyroid inhibitory properties, is a better hypothesis for the effects seen. Images FIGURE 1. a FIGURE 1. b FIGURE 1. c PMID:3816729

  18. Multicompartmental model for iodide, thyroxine, and triiodothyronine metabolism in normal and spontaneously hyperthyroid cats

    SciTech Connect

    Hays, M.T.; Broome, M.R.; Turrel, J.M.

    A comprehensive multicompartmental kinetic model was developed to account for the distribution and metabolism of simultaneously injected radioactive iodide (iodide*), T3 (T3*), and T4 (T4*) in six normal and seven spontaneously hyperthyroid cats. Data from plasma samples (analyzed by HPLC), urine, feces, and thyroid accumulation were incorporated into the model. The submodels for iodide*, T3*, and T4* all included both a fast and a slow exchange compartment connecting with the plasma compartment. The best-fit iodide* model also included a delay compartment, presumed to be pooling of gastrosalivary secretions. This delay was 62% longer in the hyperthyroid cats than in themore » euthyroid cats. Unexpectedly, all of the exchange parameters for both T4 and T3 were significantly slowed in hyperthyroidism, possibly because the hyperthyroid cats were older. None of the plasma equivalent volumes of the exchange compartments of iodide*, T3*, or T4* was significantly different in the hyperthyroid cats, although the plasma equivalent volume of the fast T4 exchange compartments were reduced. Secretion of recycled T4* from the thyroid into the plasma T4* compartment was essential to model fit, but its quantity could not be uniquely identified in the absence of multiple thyroid data points. Thyroid secretion of T3* was not detectable. Comparing the fast and slow compartments, there was a shift of T4* deiodination into the fast exchange compartment in hyperthyroidism. Total body mean residence times (MRTs) of iodide* and T3* were not affected by hyperthyroidism, but mean T4* MRT was decreased 23%. Total fractional T4 to T3 conversion was unchanged in hyperthyroidism, although the amount of T3 produced by this route was increased nearly 5-fold because of higher concentrations of donor stable T4.« less

  19. Zirconium: The material of the future in modern implantology.

    PubMed

    Kubasiewicz-Ross, Paweł; Dominiak, Marzena; Gedrange, Tomasz; Botzenhart, Ute U

    2017-01-01

    The authors present the contemporary state of knowledge concerning alternative materials for dental implantology. First of all, factors influencing osseointegration are stated. The most important factors seem to be the type of implant surface. Among the numerous parameters describing them, the most important are: average roughness and porous density. Some studies proved that materials with comparable surface roughness provide similar osseointegration. In modern implantology titanium is the material still considered as a "gold standard". However, aesthetic features of titanium still bear several disadvantages, especially in the case of periodontium with a thin biotype in the anterior, aesthetic sensitive area of the jaw. If a titanium implant is used in such a case, the mucosa at the implant's neck may become grayish and, consequently limits the success of the overall treatment. That was the reason for seeking alternative materials to manufacture dental implants. Initiated by general medicine, mainly orthopedics, the search led to the discovery of zirconium dioxide used in dental implantology. A small number of complications, good chemical parameters, anticorrosion, mechanical strength, elasticity module close to the one of steel, and especially biocompatibility made zirconium a perfect material for this purpose, although this material presents several problems in achieving optimal roughness. In this overview one of the probable methods, a process of partial synterization, is presented.

  20. Extensive Bone Reaction From Catastrophic Oxidized Zirconium Wear.

    PubMed

    Cassar-Gheiti, Adrian J; Collins, Dennis; McCarthy, Tom

    2016-01-01

    The use of alternative bearing surfaces for total hip arthroplasty has become popular to minimize wear and increase longevity, especially in young patients. Oxidized zirconium (Oxinium; Smith & Nephew, Memphis, Tennessee) femoral heads were introduced in the past decade for use in total hip arthroplasty. The advantages of oxidized zirconium include less risk of fracture compared with traditional ceramic heads. This case report describes a patient with a history of bilateral avascular necrosis of the femoral head after chemotherapy for acute lymphoblastic leukemia. Nonoperative management of avascular necrosis failed, and the patient was treated with bilateral total hip arthroplasty. The patient was followed at regular intervals and had slow eccentric polyethylene wear during a 10-year period. After 10 years, the patient had accelerated wear, with femoral and acetabular bone changes as a result of Oxinium and ultrahigh-molecular-weight polyethylene wear during a 6-month period. This article highlights the unusual accelerated bone changes that occurred as a result of Oxinium wear particles. Copyright 2016, SLACK Incorporated.

  1. Wear Analysis in THA Utilizing Oxidized Zirconium and Crosslinked Polyethylene

    PubMed Central

    Garvin, Kevin L.; Mangla, Jimmi; Murdoch, Nathan; Martell, John M.

    2008-01-01

    Oxidized zirconium, a material with a ceramic surface on a metal substrate, and highly cross-linked polyethylene are two materials developed to reduce wear. We measured in vivo femoral head penetration in patients with these advanced bearings. We hypothesized the linear wear rates would be lower than those published for cobalt-chrome and standard polyethylene. We retrospectively reviewed a select series of 56 THAs in a relatively young, active patient population utilizing oxidized zirconium femoral heads and highly cross-linked polyethylene acetabular liners. Femoral head penetration was determined using the Martell computerized edge-detection method. All patients were available for 2-year clinical and radiographic followup. True linear wear was 4 μm/year (95% confidence intervals, ± 59 μm/year). The early wear rates in this cohort of relatively young, active patients were low and we believe justify the continued study of these alternative bearing surfaces. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18946711

  2. Reaction of Titanium and Zirconium Particles in Cylindrical Explosive Charges

    NASA Astrophysics Data System (ADS)

    Frost, David; Cairns, Malcolm; Goroshin, Samuel; Zhang, Fan

    2007-06-01

    The critical conditions for the reaction of high melting-point metallic particles (Ti, Zr) dispersed during the detonation of long cylindrical explosive charges have been investigated experimentally. The charges consisted of packed beds of either spherical titanium particles (with diameters of 35, 90, or 215 μm; AP&C, Inc.) or nonspherical zirconium particles (250 -- 500 μm or 500 -- 600 μm, Atlantic Equipment Eng., NJ) saturated with sensitized liquid nitromethane. For the titanium particles, a threshold particle diameter exists, above which self-sustained particle reaction is not observed, although some particle reaction occurs immediately behind the detonation front then rapidly quenches. For the smallest particles, the proportion of the conical particle cloud that reacts increases with charge diameter, suggesting that the reaction initiation is a competition between particle heating and expansion cooling of the products. For zirconium particles, no critical conditions exist; particle ignition was observed for all particle and charge diameters tested. In this case, interaction of the high pressure detonation wave with the particles is sufficient to initiate reaction at the particle surface after a delay time (˜ 10's μs), which is much less than the time required for thermal equilibration of the particles.

  3. Aqueous sodium borohydride induced thermally stable porous zirconium oxide for quick removal of lead ions

    PubMed Central

    Nayak, Nadiya B.; Nayak, Bibhuti B.

    2016-01-01

    Aqueous sodium borohydride (NaBH4) is well known for its reducing property and well-established for the development of metal nanoparticles through reduction method. In contrary, this research paper discloses the importance of aqueous NaBH4 as a precipitating agent towards development of porous zirconium oxide. The boron species present in aqueous NaBH4 play an active role during gelation as well as phase separated out in the form of boron complex during precipitation, which helps to form boron free zirconium hydroxide [Zr(OH)4] in the as-synthesized condition. Evolved in-situ hydrogen (H2) gas-bubbles also play an important role to develop as-synthesized loose zirconium hydroxide and the presence of intra-particle voids in the loose zirconium hydroxide help to develop porous zirconium oxide during calcination process. Without any surface modification, this porous zirconium oxide quickly adsorbs almost hundred percentages of toxic lead ions from water solution within 15 minutes at normal pH condition. Adsorption kinetic models suggest that the adsorption process was surface reaction controlled chemisorption. Quick adsorption was governed by surface diffusion process and the adsorption kinetic was limited by pore diffusion. Five cycles of adsorption-desorption result suggests that the porous zirconium oxide can be reused efficiently for removal of Pb (II) ions from aqueous solution. PMID:26980545

  4. Capture of Tritium Released from Cladding in the Zirconium Recycle Process

    SciTech Connect

    Spencer, Barry B.; Walker, T. B.; Bruffey, S. H.

    2016-08-31

    Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-based cladding and could be released from the cladding when themore » solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using nonradioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.« less

  5. Capture of Tritium Released from Cladding in the Zirconium Recycle Process

    SciTech Connect

    Spencer, Barry B.; Walker, T. B.; Bruffey, Stephanie H.

    2016-08-31

    This report is issued as the first revision to FCRD-MRWFD-2016-000297. Zirconium may be recovered from the Zircaloy® cladding of used nuclear fuel (UNF) for recycle or to reduce the quantities of high-level waste destined for a geologic repository. Recovery of zirconium using a chlorination process is currently under development at the Oak Ridge National Laboratory. The approach is to treat the cladding with chlorine gas to convert the zirconium in the alloy (~98 wt % of the alloy mass) to zirconium tetrachloride. A significant fraction of the tritium (0–96%) produced in nuclear fuel during irradiation may be found in zirconium-basedmore » cladding and could be released from the cladding when the solid matrix is destroyed by the chlorination reaction. To prevent uncontrolled release of radioactive tritium to other parts of the plant or to the environment, a method to recover the tritium may be required. The focus of this effort was to (1) identify potential methods for the recovery of tritium from the off-gas of the zirconium recycle process, (2) perform scoping tests on selected recovery methods using non-radioactive gas simulants, and (3) select a process design appropriate for testing on radioactive gas streams generated by the engineering-scale zirconium recycle demonstrations on radioactive used cladding.« less

  6. Effect of hydrogenation conditions on the microstructure and mechanical properties of zirconium hydride

    NASA Astrophysics Data System (ADS)

    Muta, Hiroaki; Nishikane, Ryoji; Ando, Yusuke; Matsunaga, Junji; Sakamoto, Kan; Harjo, Stefanus; Kawasaki, Takuro; Ohishi, Yuji; Kurosaki, Ken; Yamanaka, Shinsuke

    2018-03-01

    Precipitation of brittle zirconium hydrides deteriorate the fracture toughness of the fuel cladding tubes of light water reactor. Although the hydride embrittlement has been studied extensively, little is known about physical properties of the hydride due to the experimental difficulties. In the present study, to elucidate relationship between mechanical properties and microstructure, two δ-phase zirconium hydrides and one ε-phase zirconium hydride were carefully fabricated considering volume changes at the metal-to-hydride transformation. The δ-hydride that was fabricated from α-zirconium exhibits numerous inner cracks due to the large volume change. Analyses of the neutron diffraction pattern and electron backscatter diffraction (EBSD) data show that the sample displays significant stacking faults in the {111} plane and in the pseudo-layered microstructure. On the other hand, the δ-hydride sample fabricated from β-zirconium at a higher temperature displays equiaxed grains and no cracks. The strong crystal orientation dependence of mechanical properties were confirmed by indentation test and EBSD observation. The δ-hydride hydrogenated from α-zirconium displays a lower Young's modulus than that prepared from β-zirconium. The difference is attributed to stacking faults within the {111} plane, for which the Young's modulus exhibits the highest value in the perpendicular direction. The strong influence of the crystal orientation and dislocation density on the mechanical properties should be considered when evaluating hydride precipitates in nuclear fuel cladding.

  7. A review of recent measurements of optical and thermal properties of α-mercuric iodide

    NASA Astrophysics Data System (ADS)

    Burger, A.; Morgan, S. H.; Silberman, E.; Nason, D.; Cheng, A. Y.

    1992-11-01

    The band gap energy of α-mercuric iodide was measured recently at elevated temperatures using optical absorption and reflection methods. In addition, reflection spectral measurements indicate that the temperature dependence of the exciton peak can provide a means of measuring, in a nondisturbing and remote manner, the local surface temperature of an α-mercuric iodide crystal during its growth from the vapor. Recent measurements of the thermal diffusivity and thermal expansion tensors have confirmed the anisotropy of this material and have implications for growth morphology and the generation of lattice defects.

  8. Iodide Ion Pairing with Highly Charged Ruthenium Polypyridyl Cations in CH3CN.

    PubMed

    Swords, Wesley B; Li, Guocan; Meyer, Gerald J

    2015-05-04

    A series of three highly charged cationic ruthenium(II) polypyridyl complexes of the general formula [Ru(deeb)3-x(tmam)x](PF6)2x+2, where deeb is 4,4'-diethyl ester-2,2'-bipyridine and tmam is 4,4'-bis[(trimethylamino)methyl]-2,2'-bipyridine, were synthesized and characterized and are referred to as 1, 2, or 3 based on the number of tmam ligands. Crystals suitable for X-ray crystallography were obtained for the homoleptic complex 3, which was found to possess D3 symmetry over the entire ruthenium complex. The complexes displayed visible absorption spectra typical of metal-to-ligand charge-transfer (MLCT) transitions. In acetonitrile, quasi-reversible waves were assigned to Ru(III/II) electron transfer, with formal reduction potentials that shifted negative as the number of tmam ligands was increased. Room temperature photoluminescence was observed in acetonitrile with quantum yields of ϕ ∼ 0.1 and lifetimes of τ ∼ 2 μs. The spectroscopic and electrochemical data were most consistent with excited-state localization on the deeb ligand for 1 and 2 and on the tmam ligand for 3. The addition of tetrabutylammonium iodide to the complexes dissolved in a CH3CN solution led to changes in the UV-vis absorption spectra consistent with ion pairing. A Benesi-Hildebrand-type analysis of these data revealed equilibrium constants that increased with the cationic charge 1 < 2 < 3 with K = 4000, 4400, and 7000 M(-1). (1)H NMR studies in CD3CN also revealed evidence for iodide ion pairs and indicated that they occur predominantly with iodide localization near the tmam ligand(s). The diastereotopic H atoms on the methylene carbon that link the amine to the bipyridine ring were uniquely sensitive to the presence of iodide; analysis revealed that an iodide "binding pocket" exists wherein iodide forms an adduct with the 3 and 3' bipyridyl H atoms and the quaternized amine. The MLCT excited states were efficiently quenched by iodide. Time-resolved photoluminescence measurements of

  9. Effects of Perchlorate on Thyroidal Uptake of Iodide with Corresponding Hormonal Changes

    DTIC Science & Technology

    2000-07-01

    with iodide for uptake at this iodide-concentrating step (Goldman and Stanbury, 1973), potentially leading to hypothyroidism . As a result perchlorate...TSH can result in increased thyroid weight, goiter and hypothyroidism (Fukuda et al., 1975; Gerber et al., 1981). The objective of this study was to...2000) "• Canine T3 kits ( canine T3 calibrators batch # C3D3-8, expired July 31, 1999; 1251 canine T 3 batch #, TC32, expired July 31, 1999; canine T3

  10. Tetrabutylammonium Iodide-Promoted Thiolation of Oxindoles Using Sulfonyl Chlorides as Sulfenylation Reagents.

    PubMed

    Zhao, Xia; Wei, Aoqi; Lu, Xiaoyu; Lu, Kui

    2017-08-01

    3-Sulfanyloxindoles were synthesised by triphenylphosphine-mediated transition-metal-free thiolation of oxindoles using sulfonyl chlorides as sulfenylation reagents. The above reaction was promoted by iodide anions, which was ascribed to the in situ conversion of sulfenyl chlorides into the more reactive sulfenyl iodides. Moreover, the thiolation of 3-aryloxindoles was facilitated by bases. The use of a transition-metal-free protocol, readily available reagents, and mild reaction conditions make this protocol more practical for preparing 3-sulfanyloxindoles than traditional methods.

  11. The BLI-3/TSP-15/DOXA-1 Dual Oxidase Complex Is Required for Iodide Toxicity in Caenorhabditis elegans

    PubMed Central

    Xu, Zhaofa; Luo, Jintao; Li, Yu; Ma, Long

    2014-01-01

    Iodine is an essential trace element for life. Iodide deficiency can lead to defective biosynthesis of thyroid hormones and is a major cause of hypothyroidism and mental retardation. Excess iodide intake, however, has been linked to different thyroidal diseases. How excess iodide causes harmful effects is not well understood. Here, we found that the nematode Caenorhabditis elegans exhibits developmental arrest and other pleiotropic defects when exposed to excess iodide. To identify the responsible genes, we performed a forward genetic screen and isolated 12 mutants that can survive in excess iodide. These mutants define at least four genes, two of which we identified as bli-3 and tsp-15. bli-3 encodes the C. elegans ortholog of the mammalian dual oxidase DUOX1 and tsp-15 encodes the tetraspanin protein TSP-15, which was previously shown to interact with BLI-3. The C. elegans dual oxidase maturation factor DOXA-1 is also required for the arresting effect of excess iodide. Finally, we detected a dramatically increased biogenesis of reactive oxygen species in animals treated with excess iodide, and this effect can be partially suppressed by bli-3 and tsp-15 mutations. We propose that the BLI-3/TSP-15/DOXA-1 dual oxidase complex is required for the toxic pleiotropic effects of excess iodide. PMID:25480962

  12. Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

    ERIC Educational Resources Information Center

    Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

    2016-01-01

    A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

  13. Direct synthesis of alkenyl iodides via indium-catalyzed iodoalkylation of alkynes with alcohols and aqueous HI.

    PubMed

    Wu, Chao; Wang, Zheng; Hu, Zhan; Zeng, Fei; Zhang, Xing-Yu; Cao, Zhong; Tang, Zilong; He, Wei-Min; Xu, Xin-Hua

    2018-05-02

    A convenient and efficient indium-catalyzed approach to synthesize alkenyl iodides has been developed through direct iodoalkylation of alkynes with alcohols and aqueous HI under mild conditions. This catalytic protocol offers an attractive approach for the synthesis of a diverse range of alkenyl iodides in good to excellent yields.

  14. Thermodynamic Analysis and Growth of Zirconium Carbide by Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Wei, Sun; Hua, Hao Zheng; Xiang, Xiong

    Equilibrium calculations were used to optimize conditions for the chemical vapor deposition of zirconium carbide from zirconium halide + CxHy+H2+Ar system. The results show the CVD-ZrC phase diagram is divided into ZrC+C, ZrC and ZrC+Zr zones by C, Zr generating lines. For the same mole of ZrCl4 reactant, it needs higher concentration of CH4 to generate single ZrC phase than that of C3H6. Using these calculations as a guide, single-phase cubic zirconium carbide coatings were deposited onto graphite substrate.

  15. Isomerization of Cyclooctadiene to Cyclooctyne with a Zinc/Zirconium Heterobimetallic Complex.

    PubMed

    Butler, Michael J; White, Andrew J P; Crimmin, Mark R

    2016-06-06

    Reaction of a zinc/zirconium heterobimetallic complex with 1,5-cyclooctadiene (1,5-COD) results in slow isomerization to 1,3-cyclooctadiene (1,3-COD), along with the formation of a new complex that includes a cyclooctyne ligand bridging two metal centers. While analogous magnesium/zirconium and aluminum/zirconium heterobimetallic complexes are competent for the catalytic isomerization of 1,5-COD to 1,3-COD, only in the case of the zinc species is the cyclooctyne adduct observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Isomerization of Cyclooctadiene to Cyclooctyne with a Zinc/Zirconium Heterobimetallic Complex

    PubMed Central

    Butler, Michael J.; White, Andrew J. P.

    2016-01-01

    Abstract Reaction of a zinc/zirconium heterobimetallic complex with 1,5‐cyclooctadiene (1,5‐COD) results in slow isomerization to 1,3‐cyclooctadiene (1,3‐COD), along with the formation of a new complex that includes a cyclooctyne ligand bridging two metal centers. While analogous magnesium/zirconium and aluminum/zirconium heterobimetallic complexes are competent for the catalytic isomerization of 1,5‐COD to 1,3‐COD, only in the case of the zinc species is the cyclooctyne adduct observed. PMID:27071992

  17. PHYSICAL PROPERTIES OF ZIRCONIUM NITRIDE IN THE HOMOGENEITY REGION (in Ukrainian)

    SciTech Connect

    Samsonov, G.V.; Verkhoglyadova, T.S.

    1962-01-01

    The x-ray method was used to determine the homogeneity region of zirconium nitride as 40 to 50 at.% (9.5 to 13.3% by weight) of nitrogen. It is also shown that part of the ionic bond in the zirconium nitride lattice increases with a decrease in the nitrogen content in this region, this increase being higher than in the homogeneity region of titunium nitride due to the smaller degree of unfilling of the electron d-shell of the zirconium atom in comparison with that of the titanium atom. (auth)

  18. Reactivity of zirconium basic sulfate in the reactions with carbonate, oxalate, and phosphate reagents

    SciTech Connect

    Nekhamkin, L.G.; Kondrashova, I.A.; Kerina, V.R.

    1987-08-20

    The reactivity of zirconium basic sulfate is determined by the possibility of replacement of oxo- and hydroxo-ligands and decreases with increasing temperature of its precipitation. The interaction of the less reactive zirconium basic sulfate with carbonate and oxalate reagents occurs at 25/sup 0/C without any change in basicity and that with phosphate reagents occurs with a decrease in it, up to the formation of a monophosphate with basicity about 20%. In the interaction of the more reactive zirconium basic sulfate, obtained without heating, oxo- and hydroxo groups can be entirely replaced by acido-ligands with the formation of unhydrolyzed compounds.

  19. Analysis of iodide and iodate in Lake Mead, Nevada using a headspace derivatization gas chromatography-mass spectrometry.

    PubMed

    Dorman, James W; Steinberg, Spencer M

    2010-02-01

    We report here a derivatization headspace method for the analysis of inorganic iodine in water. Samples from Lake Mead, the Las Vegas Wash, and from Las Vegas tap water were examined. Lake Mead and the Las Vegas Wash contained a mixture of both iodide and iodate. The average concentration of total inorganic iodine (TII) for Lake Mead was approximately 90 nM with an iodide-to-iodate ratio of approximately 1. The TII concentration (approximately 160 nM) and the ratio of iodide to iodate were higher for the Las Vegas Wash (approximately 2). The TII concentration for tap water was close to that of Lake Mead (approximately 90 nM); however, tap water contained no detectable iodide as a result of ozonation and chlorine treatment which converts all of the iodide to iodate.

  20. Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process.

    PubMed

    Sun, Zhuyu; Zhang, Chaojie; Zhao, Xiaoyun; Chen, Jing; Zhou, Qi

    2017-05-05

    N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k 1 ) of 0.60±0.03min -1 . Hydrated electrons (e aq - ) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO 2 - ) were formed as the main intermediate products, which completely converted to formate (HCOO - ), ammonium (NH 4 + ) and nitrogen (N 2 ). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of NNO bond under the attack of e aq - . The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO 2 - , thus effectively reducing the secondary pollution. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Effect of Excess Iodide Intake on Salivary Glands in a Swiss Albino Mice Model

    PubMed Central

    Ross, Gloria Romina; Fabersani, Emanuel; Russo, Matías; Gómez, Alba; Japaze, Hugo; González, Silvia Nelina

    2017-01-01

    Iodine is an important micronutrient required for nutrition. Excess iodine has adverse effects on thyroid, but there is not enough information regarding its effect on salivary glands. In addition to food and iodized salt, skin disinfectants and maternal nutritional supplements contain iodide, so its intake could be excessive during pregnancy, lactation, and infancy. The aim of this work was to evaluate the effect of excess iodide ingestion on salivary glands during mating, gestation, lactation, and postweaning period in mouse. During assay, mice were allocated into groups: control and treatment groups (received distilled water with NaI 1 mg/mL). Water intake, glandular weight, and histology were analyzed. Treatment groups showed an increase in glandular weight and a significantly (p < 0.05) higher water intake than control groups. Lymphocyte infiltration was observed in animals of treatment groups, while there was no infiltration in glandular sections of control groups. Results demonstrated that a negative relationship could exist between iodide excess and salivary glands. This work is novel evidence that high levels of iodide intake could induce mononuclear infiltration in salivary glands. These results should be considered, especially in pregnant/lactating women, to whom a higher iodine intake is usually recommended. PMID:29250546

  2. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Dithiazanine iodide and piperazine citrate suspension. 520.763c Section 520.763c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

  3. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Dithiazanine iodide and piperazine citrate suspension. 520.763c Section 520.763c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

  4. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Dithiazanine iodide and piperazine citrate suspension. 520.763c Section 520.763c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

  5. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Dithiazanine iodide and piperazine citrate suspension. 520.763c Section 520.763c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

  6. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dithiazanine iodide and piperazine citrate suspension. 520.763c Section 520.763c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS...

  7. Evolution of Iodoplumbate Complexes in Methylammonium Lead Iodide Perovskite Precursor Solutions

    DOE PAGES

    Sharenko, Alexander; Mackeen, Cameron; Jewell, Leila; ...

    2017-02-02

    Here in this study we investigate the local structure present in single-step precursor solutions of methylammonium lead iodide (MAPbI 3) perovskite as a function of organic and inorganic precursor ratio, as well as with hydriodic acid (HI), using X-ray absorption spectroscopy. An excess of organic precursor as well as the use of HI as a processing additive has been shown to lead to the formation of smooth, continuous, pinhole free MAPbI 3 films, whereas films produced from precursor solutions containing molar equivalents of methylammonium iodide (MAI) and PbI 2 lead to the formation of a discontinuous, needlelike morphology. We nowmore » show that as the amount of excess MAI in the precursor solution is increased, the iodide coordination of iodoplumbate complexes present in solution increases. The use of HI results in a similar increase in iodide coordination. We therefore offer insight into how solution chemistry can be used to control MAPbI 3 thin film morphology by revealing a strong correlation between the lead coordination chemistry in precursor solutions and the surface coverage and morphology of the resulting MAPbI 3 film.« less

  8. Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry

    PubMed Central

    Küpper, Frithjof C.; Carpenter, Lucy J.; McFiggans, Gordon B.; Palmer, Carl J.; Waite, Tim J.; Boneberg, Eva-Maria; Woitsch, Sonja; Weiller, Markus; Abela, Rafael; Grolimund, Daniel; Potin, Philippe; Butler, Alison; Luther, George W.; Kroneck, Peter M. H.; Meyer-Klaucke, Wolfram; Feiters, Martin C.

    2008-01-01

    Brown algae of the Laminariales (kelps) are the strongest accumulators of iodine among living organisms. They represent a major pump in the global biogeochemical cycle of iodine and, in particular, the major source of iodocarbons in the coastal atmosphere. Nevertheless, the chemical state and biological significance of accumulated iodine have remained unknown to this date. Using x-ray absorption spectroscopy, we show that the accumulated form is iodide, which readily scavenges a variety of reactive oxygen species (ROS). We propose here that its biological role is that of an inorganic antioxidant, the first to be described in a living system. Upon oxidative stress, iodide is effluxed. On the thallus surface and in the apoplast, iodide detoxifies both aqueous oxidants and ozone, the latter resulting in the release of high levels of molecular iodine and the consequent formation of hygroscopic iodine oxides leading to particles, which are precursors to cloud condensation nuclei. In a complementary set of experiments using a heterologous system, iodide was found to effectively scavenge ROS in human blood cells. PMID:18458346

  9. Preparation and Luminescence Thermochromism of Tetranuclear Copper(I)-Pyridine-Iodide Clusters

    ERIC Educational Resources Information Center

    Parmeggiani, Fabio; Sacchetti, Alessandro

    2012-01-01

    A simple and straightforward synthesis of a tetranuclear copper(I)-pyridine-iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the…

  10. Evolution of Iodoplumbate Complexes in Methylammonium Lead Iodide Perovskite Precursor Solutions

    SciTech Connect

    Sharenko, Alexander; Mackeen, Cameron; Jewell, Leila

    Here in this study we investigate the local structure present in single-step precursor solutions of methylammonium lead iodide (MAPbI 3) perovskite as a function of organic and inorganic precursor ratio, as well as with hydriodic acid (HI), using X-ray absorption spectroscopy. An excess of organic precursor as well as the use of HI as a processing additive has been shown to lead to the formation of smooth, continuous, pinhole free MAPbI 3 films, whereas films produced from precursor solutions containing molar equivalents of methylammonium iodide (MAI) and PbI 2 lead to the formation of a discontinuous, needlelike morphology. We nowmore » show that as the amount of excess MAI in the precursor solution is increased, the iodide coordination of iodoplumbate complexes present in solution increases. The use of HI results in a similar increase in iodide coordination. We therefore offer insight into how solution chemistry can be used to control MAPbI 3 thin film morphology by revealing a strong correlation between the lead coordination chemistry in precursor solutions and the surface coverage and morphology of the resulting MAPbI 3 film.« less

  11. Mechanisms of Exchange Reactions of Primary and Secondary Alkyl Iodides with Elementary Iodine

    SciTech Connect

    Bujake, John E.; Pratt, M. W. T.; Noyes, Richard M.

    1961-04-01

    Several primary and secondary alkyl iodides exchange thermally with I/ sup 131/ in hexachlorobutadiene between 130 and 200 deg . If the solutions are saturated with oxygen at one atmosphere, rates of exchange fit the kinetic expression k/sub b/STARI! STAl/sub 2/!1/2. Degassed solutions always exchange faster than oxygen saturated ones, but methyl, ethyl, and n-propyl iodides show the same kinetics as with oxygen. Exchange rates of degassed isopropyl and neopentyl iodides also show contributions from a k/sub a/STARI! term. Exchange in degassed ethylene dichloride is 3 to 4 times as fast as in degassed hexachlorobutadiene. Activation energies for k/sub b/more » are usually about 27 to 31 kcal/mole. Effects of substitution on alpha carbon are illustrated by the rate sequence methyl < ethyl < i-propyl = sec-butyl. Effects of substitution on beta carbon are illustrated by the rate sequence ethyl < npropyl>> neopentyl. Since the rates of exchange of methyl, ethyl, and i-propyl iodides vary in the opposite direction from the sequence for bimolecular nucleophilic substitution, the explanation proposed suggests that for nucleophilic substitution the effect of added methyl groups on an alpha carbon is a steric hindrance to solvation by solvent dipoles rather than a steric hindrance to the group attacking the carbon atom itself.« less

  12. Determination of iodine in bread and fish using the iodide ion-selective electrode

    SciTech Connect

    Steiner, J.B.

    The purpose of this study was to assess the potential for use of the ion-selective electrode (ISE) as a method for measuring the iodine content in bread and fish. Ashing methods, sample preparation and electrode responses were evaluated. The iodine values obtained using the iodide electrode were compared to iodine values obtained by the arsenic-cerium method (As-Ce). Ashing methods were used in preparing bread and haddock for iodine analysis by the ISE. The values were compared to unashed samples measured by the ISE. Electrode response to iodide was examined by varying the sample pH, measuring electrode equilibrium times, and comparingmore » direct measurement in ppm to iodide values obtained by the method of known addition. Oyster reference tissue with a known iodine concentration was used to determine rates of recovery. For the As-Ce procedure, an alkaline dry ash for two hour followed by colorimetric analysis at 320 nm was recommended. The study showed that the pre-treatment of bread and fish was necessary for ISE measurement. The iodine values obtained by the ISE in the analysis of oyster reference tissue, haddock and bread were not in agreement with their corresponding As-Ce values. Further work needs to be done to determine an ashing procedure that has minimal iodide loss an/or develop sample treatments that will improve the reliability and precision of iodine values obtained using the ion-selective electrode.« less

  13. Kinetics and Mechanism of Iodide Oxidation by Iron(III): A Clock Reaction Approach

    ERIC Educational Resources Information Center

    Bauer, Jurica; Tomisic, Vladislav; Vrkljan, Petar B. A.

    2008-01-01

    A simple method for studying the kinetics of a chemical reaction is described and the significance of reaction orders in deducing reaction mechanisms is demonstrated. In this student laboratory experiment, oxidation of iodide by iron(III) ions in an acidic medium is transformed into a clock reaction. By means of the initial rates method, it is…

  14. Mercuric iodide medical imagers for low-exposure radiography and fluoroscopy

    NASA Astrophysics Data System (ADS)

    Zentai, George; Partain, Larry; Pavlyuchkova, Raisa; Proano, Cesar; Breen, Barry N.; Taieb, A.; Dagan, Ofer; Schieber, Michael; Gilboa, Haim; Thomas, Jerry

    2004-05-01

    Photoconductive polycrystalline mercuric iodide deposited on flat panel thin film transistor (TFT) arrays is being developed for direct digital X-ray detectors that can perform both radiographic and fluoroscopic medical imaging. The mercuric iodide is either vacuum deposited by Physical Vapor Deposition (PVD) or coated onto the array by a wet Particle-In-Binder (PIB) process. The PVD deposition technology has been scaled up to the 20 cm x 25 cm size required in common medical imaging applications. A TFT array with a pixel pitch of 127 microns is used for these imagers. Arrays of 10 cm x 10 cm size have been used to evaluate performance of mercuric iodide imagers. Radiographic and fluoroscopic images of diagnostic quality at up to 15 pulses per second were demonstrated. As we previously reported, the resolution is limited to the TFT array Nyquist frequency of ~3.9 lp/mm (127 micron pixel pitch). Detective Quantum Efficiency (DQE) has been measured as a function of spatial frequency for these imagers. The DQE is lower than the theoretically calculated value due to some additional noise sources of the electronics and the array. We will retest the DQE after eliminating these noise sources. Reliability and stress testing was also began for polycrystalline mercuric iodide PVD and PIB detectors. These are simplified detectors based upon a stripe electrode or circular electrode structure. The detectors were stressed under various voltage bias, temperature and time conditions. The effects of the stress tests on the detector dark current and sensitivity were determined.

  15. Iodide-catalyzed synthesis of N-nitrosamines via C-N cleavage of nitromethane.

    PubMed

    Zhang, Jie; Jiang, Jiewen; Li, Yuling; Wan, Xiaobing

    2013-11-15

    An iodide-catalyzed process to synthesize N-nitrosamines has been developed using TBHP as the oxidant. The mild catalytic system succeeded in cleaving the carbon-nitrogen bond in nitromethane. This methodology uses commercially available, inexpensive catalysts and oxidants and has a wide substrate scope and operational simplicity.

  16. Corrosion of iron by iodide-oxidizing bacteria isolated from brine in an iodine production facility.

    PubMed

    Wakai, Satoshi; Ito, Kimio; Iino, Takao; Tomoe, Yasuyoshi; Mori, Koji; Harayama, Shigeaki

    2014-10-01

    Elemental iodine is produced in Japan from underground brine (fossil salt water). Carbon steel pipes in an iodine production facility at Chiba, Japan, for brine conveyance were found to corrode more rapidly than those in other facilities. The corroding activity of iodide-containing brine from the facility was examined by immersing carbon steel coupons in "native" and "filter-sterilized" brine samples. The dissolution of iron from the coupons immersed in native brine was threefold to fourfold higher than that in the filter-sterilized brine. Denaturing gradient gel electrophoresis analyses revealed that iodide-oxidizing bacteria (IOBs) were predominant in the coupon-containing native brine samples. IOBs were also detected in a corrosion deposit on the inner surface of a corroded pipe. These results strongly suggested the involvement of IOBs in the corrosion of the carbon steel pipes. Of the six bacterial strains isolated from a brine sample, four were capable of oxidizing iodide ion (I(-)) into molecular iodine (I(2)), and these strains were further phylogenetically classified into two groups. The iron-corroding activity of each of the isolates from the two groups was examined. Both strains corroded iron in the presence of potassium iodide in a concentration-dependent manner. This is the first report providing direct evidence that IOBs are involved in iron corrosion. Further, possible mechanisms by which IOBs corrode iron are discussed.

  17. The Reaction between Iron(II) Iodide and Potassium Dichromate(VI) in Acidified Aqueous Solution

    ERIC Educational Resources Information Center

    Talbot, Christopher

    2013-01-01

    This "Science note" teaching lesson explores the possible reaction between the ions in a reaction mixture consisting of iron(II) iodide and potassium dichromate(VI) in acidified aqueous solution. The electrode potentials will be used to deduce any spontaneous reactions under standard thermodynamic conditions (298 K, 1 bar (approximately…

  18. Fretting wear behavior of zirconium alloy in B-Li water at 300 °C

    NASA Astrophysics Data System (ADS)

    Zhang, Lefu; Lai, Ping; Liu, Qingdong; Zeng, Qifeng; Lu, Junqiang; Guo, Xianglong

    2018-02-01

    The tangential fretting wear of three kinds of zirconium alloys tube mated with 304 stainless steel (SS) plate was investigated. The tests were conducted in an autoclave containing 300 °C pressurized B-Li water for tube-on-plate contact configuration. The worn surfaces were examined with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and 3D microscopy. The cross-section of wear scar was examined with transmission electron microscope (TEM). The results indicated that the dominant wear mechanism of zirconium alloys in this test condition was delamination and oxidation. The oxide layer on the fretted area consists of outer oxide layer composed of iron oxide and zirconium oxide and inner oxide layer composed of zirconium oxide.

  19. Calcification of MC3T3-E1 cells on titanium and zirconium.

    PubMed

    Umezawa, Takayuki; Chen, Peng; Tsutsumi, Yusuke; Doi, Hisashi; Ashida, Maki; Suzuki, Shoichi; Moriyama, Keiji; Hanawa, Takao

    2015-01-01

    To confirm similarity of hard tissue compatibility between titanium and zirconium, calcification of MC3T3-E1 cells on titanium and zirconium was evaluated in this study. Mirror-polished titanium (Ti) and zirconium (Zr) disks and zirconium-sputter deposited titanium (Zr/Ti) were employed in this study. The surface of specimens were characterized using scanning electron microscopy and X-ray diffraction. Then, the cellular proliferation, differentiation and calcification of MC3T3-E1 cells on specimens were investigated. The surface of Zr/Ti was much smoother and cleaner than those of Ti and Zr. The proliferation of the cell was the same among three specimens, while the differentiation and calcification on Zr/Ti were faster than those on Ti and Zr. Therefore, Ti and Zr showed the identical hard tissue compatibility according to the evaluation with MC3T3-E1 cells. Sputter deposition may improve cytocompatibility.

  20. About structural phase state of coating based on zirconium oxide formed by microplasma oxidation method

    NASA Astrophysics Data System (ADS)

    Gubaidulina, Tatiana A.; Sergeev, Viktor P.; Kuzmin, Oleg S.; Fedorischeva, Marina V.; Kalashnikov, Mark P.

    2017-12-01

    The oxide-ceramic coating based of zirconium oxide is formed by the method of microplasma oxidation. The producing modes of the oxide layers on E110 zirconium alloy are under testing. It was found that using microplasma treatment of E110 zirconium in aluminosilicate electrolyte makes possible the formation of porous oxide-ceramic coatings based on zirconium alloyed by aluminum and niobium. The study is focused on the modes how to form heat-shielding coatings with controlled porosity and minimal amount of microcracks. The structural-phase state of the coating is studied by X-ray diffraction analysis and scanning electron microscopy (SEM). It was found that the ratio of the monoclinic and tetragonal phases changes with the change occurring in the coating formation modes.

  1. Synthesis, microstructure and dielectric properties of zirconium doped barium titanate

    SciTech Connect

    Kumar, Rohtash; School of Physical Sciences, Jawaharlal Nehru University, New Delhi; Asokan, K.

    2016-05-23

    We report on synthesis, microstructural and relaxor ferroelectric properties of Zirconium(Zr) doped Barium Titanate (BT) samples with general formula Ba(Ti{sub 1-x}Zr{sub x})O{sub 3} (x=0.20, 0.35). These lead-free ceramics were prepared by solid state reaction route. The phase transition behavior and temperature dependent dielectric properties and composition dependent ferroelectric properties were investigated. XRD analysis at room temperature confirms phase purity of the samples. SEM observations revealed retarded grain growth with increasing Zr mole fraction. Dielectric properties of BZT ceramics is influenced significantly by small addition of Zr mole fraction. With increasing Zr mole fraction, dielectric constant decreases while FWHM and frequencymore » dispersion increases. Polarization vs electric field hysteresis measurements reveal ferroelectric relaxor phase at room temperature. The advantages of such substitution maneuvering towards optimizing ferroelectric properties of BaTiO{sub 3} are discussed.« less

  2. Titanium-Zirconium-Nickel Alloy Inside Marshall's Electrostatic Levitator (ESL)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This Photo, which appeared on the July cover of `Physics Today', is of the Electrostatic Levitator (ESL) at NASA's Marshall Space Flight Center (MSFC). The ESL uses static electricity to suspend an object (about 3-4 mm in diameter) inside a vacuum chamber allowing scientists to record a wide range of physical properties without the sample contracting the container or any instruments, conditions that would alter the readings. Once inside the chamber, a laser heats the sample until it melts. The laser is then turned off and the sample cools, changing from a liquid drop to a solid sphere. In this particular shot, the ESL contains a solid metal sample of titanium-zirconium-nickel alloy. Since 1977, the ESL has been used at MSFC to study the characteristics of new metals, ceramics, and glass compounds. Materials created as a result of these tests include new optical materials, special metallic glasses, and spacecraft components.

  3. Titanium-Zirconium-Nickel Alloy Inside Marshall's Electrostatic Levitator (ESL)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This is a close-up of a sample of titanium-zirconium-nickel alloy inside the Electrostatic Levitator (ESL) vacuum chamber at NASA's Marshall Space Flight Center (MSFC). The ESL uses static electricity to suspend an object (about 3-4 mm in diameter) inside a vacuum chamber allowing scientists to record a wide range of physical properties without the sample contracting the container or any instruments, conditions that would alter the readings. Once inside the chamber, a laser heats the sample until it melts. The laser is then turned off and the sample cools, changing from a liquid drop to a solid sphere. Since 1977, the ESL has been used at MSFC to study the characteristics of new metals, ceramics, and glass compounds. Materials created as a result of these tests include new optical materials, special metallic glasses, and spacecraft components.

  4. Defect kinetics and resistance to amorphization in zirconium carbide

    NASA Astrophysics Data System (ADS)

    Zheng, Ming-Jie; Szlufarska, Izabela; Morgan, Dane

    2015-02-01

    To better understand the radiation response of zirconium carbide (ZrC), and in particular its excellent resistance to amorphization, we have used density functional theory methods to study the kinetics of point defects in ZrC. The migration barriers and recombination barriers of the simple point defects are calculated using the ab initio molecular dynamics simulation and the nudged elastic band method. These barriers are used to estimate C and Zr interstitial and vacancy diffusion and Frenkel pair recombination rates. A significant barrier for C Frenkel pair recombination is found but it is shown that a large concentration of C vacancies reduces this barrier dramatically, allowing facile healing of radiation damage. The mechanisms underlying high resistance to amorphization of ZrC were analyzed from the perspectives of structural, thermodynamic, chemical and kinetic properties. This study provides insights into the amorphization resistance of ZrC as well as a foundation for understanding general radiation damage in this material.

  5. Iodine from bacterial iodide oxidization by Roseovarius spp. inhibits the growth of other bacteria.

    PubMed

    Zhao, Dan; Lim, Choon-Ping; Miyanaga, Kazuhiko; Tanji, Yasunori

    2013-03-01

    Microbial activities in brine, seawater, or estuarine mud are involved in iodine cycle. To investigate the effects of the microbiologically induced iodine on other bacteria in the environment, a total of 13 bacteria that potentially participated in the iodide-oxidizing process were isolated from water or biofilm at a location containing 131 μg ml(-1) iodide. Three distinct strains were further identified as Roseovarius spp. based on 16 S rRNA gene sequences after being distinguished by restriction fragment length polymorphism analysis. Morphological characteristics of these three Roseovarius spp. varied considerably across and within strains. Iodine production increased with Roseovarius spp. growth when cultured in Marine Broth with 200 μg ml(-1) iodide (I(-)). When 10(6) CFU/ml Escherichia coli, Pseudomonas aeruginosa, and Bacillus pumilus were exposed to various concentrations of molecular iodine (I(2)), the minimum inhibitory concentrations (MICs) were 0.5, 1.0, and 1.0 μg ml(-1), respectively. However, fivefold increases in the MICs for Roseovarius spp. were obtained. In co-cultured Roseovarius sp. IOB-7 and E. coli in Marine Broth containing iodide (I(-)), the molecular iodine concentration was estimated to be 0.76 μg ml(-1) after 24 h and less than 50 % of E. coli was viable compared to that co-cultured without iodide. The growth inhibition of E. coli was also observed in co-cultures with the two other Roseovarius spp. strains when the molecular iodine concentration was assumed to be 0.52 μg ml(-1).

  6. Mechanism of iodide-dependent catalatic activity of thyroid peroxidase and lactoperoxidase.

    PubMed

    Magnusson, R P; Taurog, A; Dorris, M L

    1984-01-10

    Mechanisms that have been proposed for peroxidase-catalyzed iodination require the utilization of 1 mol of H2O2 for organic binding of 1 mol of iodide. When we measured the stoichiometry of this reaction using thyroid peroxidase or lactoperoxidase at pH 7.0, we consistently obtained a ratio less than 1.0. This was shown to be attributable to catalase-like activity of these enzymes, resulting in unproductive cleavage of H2O2. This catalatic activity was completely iodide-dependent. To elucidate the mechanism of the iodide-dependent catalatic activity, the effects of various agents were investigated. The major observations may be summarized as follows: 1) The catalatic activity was inhibited in the presence of an iodine acceptor such as tyrosine. 2) The pseudohalide, SCN-, could not replace I- as a promoter of catalatic activity. 3) The inhibitory effects of the thioureylene drugs, methimazole and carbimazole, on the iodide-dependent catalatic activity were very similar to those reported previously for thyroid peroxidase-catalyzed iodination. 4) High concentrations of I- inhibited the catalatic activity of thyroid peroxidase and lactoperoxidase in a manner similar to that described previously for peroxidase-catalyzed iodination. On the basis of these observations and other findings, we have proposed a scheme which offers a possible explanation for iodide-dependent catalatic activity of thyroid peroxidase and lactoperoxidase. Compound I of the peroxidases is represented as EO, and oxidation of I- by EO is postulated to form enzyme-bound hypoiodite, represented in our scheme as [EOI]-. We suggest that the latter can react with H2O2 in a catalase-like reaction, with evolution of O2. We postulate further that the same form of oxidized iodine is also involved in iodination of tyrosine, oxidation of thioureylene drugs, and oxidation of I-, and that inhibition of catalatic activity by these agents occurs through competition with H2O2 for oxidized iodine.

  7. Translucency and Strength of High-Translucency Monolithic Zirconium-Oxide Materials

    DTIC Science & Technology

    2016-05-12

    APPROV~, Col Drew W. Fallis Dean, Air Force Postgraduate Dental School r UNIFORMED SERVICES UNIVERSITY OF THE HEALTH SCIENCES AIR FORCE...POSTGRADUATE DENTAL SCHOOL 2450 Pepperrell Street Lackland AFB Texas, 78236-5345 http://www.usuhs.mil "The author hereby certifies that the use of any...Translucency Monolithic Zirconium-Oxide Materials Abstract Dental materials manufacturers have developed more translucent monolithic zirconium oxide

  8. Mechanical resistance of zirconium implant abutments: A review of the literature

    PubMed Central

    Vaquero-Aguilar, Cristina; Torres-Lagares, Daniel; Jiménez-Melendo, Manuel; Gutiérrez-Pérez, José L.

    2012-01-01

    The increase of aesthetic demands, together with the successful outcome of current implants, has renewed interest in the search for new materials with enough mechanical properties and better aesthetic qualities than the materials customarily used in implanto-prosthetic rehabilitation. Among these materials, zirconium has been used in different types of implants, including prosthetic abutments. The aim of the present review is to analyse current scientific evidence supporting the use of this material for the above mentioned purposes. We carried out the review of the literature published in the last ten years (2000 through 2010) of in vitro trials of dynamic and static loading of zirconium abutments found in the databases of Medline and Cochrane using the key words zirconium abutment, fracture resistance, fracture strength, cyclic loading. Although we have found a wide variability of values among the different studies, abutments show favourable clinical behaviour for the rehabilitation of single implants in the anterior area. Such variability may be explained by the difficulty to simulate daily mastication under in vitro conditions. The clinical evidence, as found in our study, does not recommend the use of implanto-prosthetic zirconium abutments in the molar area. Key words: Zirconium abutment, zirconium implant abutment, zirconia abutment, fracture resistance, fracture strength, cyclic loading. PMID:22143702

  9. Overcoming the crystallization and designability issues in the ultrastable zirconium phosphonate framework system

    DOE PAGES

    Zheng, Tao; Yang, Zaixing; Gui, Daxiang; ...

    2017-05-30

    Metal-organic frameworks (MOFs) based on zirconium phosphonates exhibit superior chemical stability suitable for applications under harsh conditions. These compounds mostly exist as poorly crystallized precipitates, and precise structural information has therefore remained elusive. Furthermore, a zero-dimensional zirconium phosphonate cluster acting as secondary building unit has been lacking, leading to poor designability in this system. We overcome these challenges and obtain single crystals of three zirconium phosphonates that are suitable for structural analysis. Furthermore, these compounds are built by previously unknown isolated zirconium phosphonate clusters and exhibit combined high porosity and ultrastability even in fuming acids. SZ-2 possesses the largest voidmore » volume recorded in zirconium phosphonates and SZ-3 represents the most porous crystalline zirconium phosphonate and the only porous MOF material reported to survive in aqua regia. SZ-2 and SZ-3 can effectively remove uranyl ions from aqueous solutions over a wide pH range, and we have elucidated the removal mechanism.« less

  10. Comparison of Zirconium Phosphonate-Modified Surfaces for Immobilizing Phosphopeptides and Phosphate-Tagged Proteins.

    PubMed

    Forato, Florian; Liu, Hao; Benoit, Roland; Fayon, Franck; Charlier, Cathy; Fateh, Amina; Defontaine, Alain; Tellier, Charles; Talham, Daniel R; Queffélec, Clémence; Bujoli, Bruno

    2016-06-07

    Different routes for preparing zirconium phosphonate-modified surfaces for immobilizing biomolecular probes are compared. Two chemical-modification approaches were explored to form self-assembled monolayers on commercially available primary amine-functionalized slides, and the resulting surfaces were compared to well-characterized zirconium phosphonate monolayer-modified supports prepared using Langmuir-Blodgett methods. When using POCl3 as the amine phosphorylating agent followed by treatment with zirconyl chloride, the result was not a zirconium-phosphonate monolayer, as commonly assumed in the literature, but rather the process gives adsorbed zirconium oxide/hydroxide species and to a lower extent adsorbed zirconium phosphate and/or phosphonate. Reactions giving rise to these products were modeled in homogeneous-phase studies. Nevertheless, each of the three modified surfaces effectively immobilized phosphopeptides and phosphopeptide tags fused to an affinity protein. Unexpectedly, the zirconium oxide/hydroxide modified surface, formed by treating the amine-coated slides with POCl3/Zr(4+), afforded better immobilization of the peptides and proteins and efficient capture of their targets.

  11. Overcoming the crystallization and designability issues in the ultrastable zirconium phosphonate framework system

    SciTech Connect

    Zheng, Tao; Yang, Zaixing; Gui, Daxiang

    Metal-organic frameworks (MOFs) based on zirconium phosphonates exhibit superior chemical stability suitable for applications under harsh conditions. These compounds mostly exist as poorly crystallized precipitates, and precise structural information has therefore remained elusive. Furthermore, a zero-dimensional zirconium phosphonate cluster acting as secondary building unit has been lacking, leading to poor designability in this system. We overcome these challenges and obtain single crystals of three zirconium phosphonates that are suitable for structural analysis. Furthermore, these compounds are built by previously unknown isolated zirconium phosphonate clusters and exhibit combined high porosity and ultrastability even in fuming acids. SZ-2 possesses the largest voidmore » volume recorded in zirconium phosphonates and SZ-3 represents the most porous crystalline zirconium phosphonate and the only porous MOF material reported to survive in aqua regia. SZ-2 and SZ-3 can effectively remove uranyl ions from aqueous solutions over a wide pH range, and we have elucidated the removal mechanism.« less

  12. Analysis of the influence of the macro- and microstructure of dental zirconium implants on osseointegration: a minipig study.

    PubMed

    Mueller, Cornelia Katharina; Solcher, Philipp; Peisker, Andrè; Mtsariashvilli, Maia; Schlegel, Karl Andreas; Hildebrand, Gerhard; Rost, Juergen; Liefeith, Klaus; Chen, Jiang; Schultze-Mosgau, Stefan

    2013-07-01

    It was the aim of this study to analyze the influence of implant design and surface topography on the osseointegration of dental zirconium implants. Six different implant designs were tested in the study. Nine or 10 test implants were inserted in the frontal skull in each of 10 miniature pigs. Biopsies were harvested after 2 and 4 months and subjected to microradiography. No significant differences between titanium and zirconium were found regarding the microradiographically detected bone-implant contact (BIC). Cylindric zirconium implants showed a higher BIC at the 2-month follow-up than conic zirconium implants. Among zirconium implants, those with an intermediate Ra value showed a significantly higher BIC compared with low and high Ra implants 4 months after surgery. Regarding osseointegration, titanium and zirconium showed equal properties. Cylindric implant design and intermediate surface roughness seemed to enhance osseointegration. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.

    PubMed

    Gong, Tingting; Zhang, Xiangru

    2013-11-01

    The dissolved iodine species that dominate aquatic systems are iodide, iodate and organo-iodine. These species may undergo transformation to one another and thus affect the formation of iodinated disinfection byproducts during disinfection of drinking waters or wastewater effluents. In this study, a fast, sensitive and accurate method for determining these iodine species in waters was developed by derivatizing iodide and iodate to organic iodine and measuring organic iodine with a total organic iodine (TOI) measurement approach. Within this method, organo-iodine was determined directly by TOI measurement; iodide was oxidized by monochloramine to hypoiodous acid and then hypoiodous acid reacted with phenol to form organic iodine, which was determined by TOI measurement; iodate was reduced by ascorbic acid to iodide and then determined as iodide. The quantitation limit of organo-iodine or sum of organo-iodine and iodide or sum of organo-iodine, iodide and iodate was 5 μg/L as I for a 40 mL water sample (or 2.5 μg/L as I for an 80 mL water sample, or 1.25 μg/L as I for a 160 mL water sample). This method was successfully applied to the determination of iodide, iodate and organo-iodine in a variety of water samples, including tap water, seawater, urine and wastewater. The recoveries of iodide, iodate and organo-iodine were 91-109%, 90-108% and 91-108%, respectively. The concentrations and distributions of iodine species in different water samples were obtained and compared. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Radioactive iodide (131 I-) excretion profiles in response to potassium iodide (KI) and ammonium perchlorate (NH4ClO4) prophylaxis.

    PubMed

    Harris, Curtis; Dallas, Cham; Rollor, Edward; White, Catherine; Blount, Benjamin; Valentin-Blasini, Liza; Fisher, Jeffrey

    2012-08-01

    Radioactive iodide ((131)I-) protection studies have focused primarily on the thyroid gland and disturbances in the hypothalamic-pituitary-thyroid axis. The objective of the current study was to establish (131)I- urinary excretion profiles for saline, and the thyroid protectants, potassium iodide (KI) and ammonium perchlorate over a 75 hour time-course. Rats were administered (131)I- and 3 hours later dosed with either saline, 30 mg/kg of NH(4)ClO(4) or 30 mg/kg of KI. Urinalysis of the first 36 hours of the time-course revealed that NH(4)ClO(4) treated animals excreted significantly more (131)I- compared with KI and saline treatments. A second study followed the same protocol, but thyroxine (T(4)) was administered daily over a 3 day period. During the first 6-12 hour after (131)I- dosing, rats administered NH(4)ClO(4) excreted significantly more (131)I- than the other treatment groups. T(4) treatment resulted in increased retention of radioiodide in the thyroid gland 75 hour after (131)I- administration. We speculate that the T(4) treatment related reduction in serum TSH caused a decrease synthesis and secretion of thyroid hormones resulting in greater residual radioiodide in the thyroid gland. Our findings suggest that ammonium perchlorate treatment accelerates the elimination rate of radioiodide within the first 24 to 36 hours and thus may be more effective at reducing harmful exposure to (131)I- compared to KI treatment for repeated dosing situations. Repeated dosing studies are needed to compare the effectiveness of these treatments to reduce the radioactive iodide burden of the thyroid gland.

  15. Concept Feasibility Report for Electroplating Zirconium onto Uranium Foil - Year 2

    SciTech Connect

    Coffey, Greg W.; Meinhardt, Kerry D.; Joshi, Vineet V.

    2015-03-01

    The Fuel Fabrication Capability within the U.S. High Performance Research Reactor Conversion Program is funded through the National Nuclear Security Administration (NNSA) NA-26 (Office of Material Management and Minimization). An investigation was commissioned to determine the feasibility of using electroplating techniques to apply a coating of zirconium onto depleted uranium/molybdenum alloy (U-10Mo). Electroplating would provide an alternative method to the existing process of hot roll-bonding zirconium foil onto the U-10Mo fuel foil during the fabrication of fuel elements for high-performance research reactors. The objective of this research was to develop a reproducible and scalable plating process that will produce amore » uniform, 25 μm thick zirconium metal coating on U-10Mo foil. In previous work, Pacific Northwest National Laboratory (PNNL) established a molten salt electroplating apparatus and protocol to plate zirconium metal onto molybdenum foil (Coffey 2015). During this second year of the research, PNNL furthered this work by moving to the U-10Mo alloy system (90 percent uranium:10 percent molybdenum). The original plating apparatus was disassembled and re-assembled in a laboratory capable of handling low-level radioactive materials. Initially, the work followed the previous year’s approach, and the salt bath composition was targeted at the eutectic composition (LiF:NaF:ZrF4 = 26:37:37 mol%). Early results indicated that the formation of uranium fluoride compounds would be problematic. Other salt bath compositions were investigated in order to eliminate the uranium fluoride production (LiF:NaF = 61:39 mol% and LiF:NaF:KF = 46.5:11.5:42 mol% ). Zirconium metal was used as the crucible for the molten salt. Three plating methods were used—isopotential, galvano static, and pulsed plating. The molten salt method for zirconium metal application provided high-quality plating on molybdenum in PNNL’s previous work. A key advantage of this approach is

  16. Removal of bromide and iodide anions from drinking water by silver-activated carbon aerogels.

    PubMed

    Sánchez-Polo, M; Rivera-Utrilla, J; Salhi, E; von Gunten, U

    2006-08-01

    The aim of this study is to analyze the use of Ag-doped activated carbon aerogels for bromide and iodide removal from drinking water and to study how the activation of Ag-doped aerogels affects their behavior. It has been observed that the carbonization treatment and activation process of Ag-doped aerogels increased the surface area value ( [Formula: see text] ), whereas the volume of meso-(V(2)) and macropores (V(3)) decreased slightly. Chemical characterization of the materials revealed that carbonization and especially activation process considerably increased the surface basicity of the sample. Original sample (A) presented acidic surface properties (pH(PZC)=4.5) with 21% surface oxygen, whereas the sample that underwent activation showed mainly basic surface chemical properties (pH(PZC)=9.5) with only 6% of surface oxygen. Carbonization and especially, activation process considerable increased the adsorption capacity of bromide and iodide ions. This would mainly be produced by (i) an increase in the microporosity of the sample, which increases Ag-adsorption sites available to halide anions, and (ii) a rise of the basicity of the sample, which produces an increase in attractive electrostatic interactions between the aerogel surface, positively charged at the working pH (pH(solution)iodide was studied under dynamic conditions using waters from Lake Zurich. Results obtained showed that the carbonization and activation processes increased the adsorptive capacity of the aerogel sample. However, results showed that the adsorption capacity of the aerogel samples studied was considerably lower in water from Lake Zurich. Results showed X(0.02) (amount adsorbed to initial breakthrough) values of 0.1 and 4.3 mg/g for chloride anion and dissolved organic carbon (DOC), respectively, during bromide adsorption process in water from Lake Zurich

  17. Thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring.

    PubMed

    Liang, Xue; Feng, Yanni; Lin, Laixiang; Abeysekera, Iruni Roshanie; Iqbal, Umar; Wang, Tingting; Wang, Ying; Yao, Xiaomei

    2018-05-01

    Our aim was to investigate thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring. Depending on their iodide intake, the pregnant rats were randomly divided into three groups: normal iodide intake (NI), 10 times high iodide intake (10 HI) and 100 times high iodide intake (100 HI) groups. Iodine concentration in the urine and maternal milk; iodine content and mitochondrial superoxide production; expression of TRα1, TRβ1, NIS and Dio1 in both the thyroid and mammary glands were all measured. The offspring were exposed to different iodide-containing water (NI, 10 HI and 100 HI) from weaning to postnatal day 180 (PN180). Serum thyroid hormone levels were measured in both maternal rats and their offspring. Iodine concentration in the urine and maternal milk, as well as iodine content in the thyroid and mammary glands was significantly increased in both the 10 HI and 100 HI groups (p < .05). In the 100 HI group of maternal rats, low FT3 levels, high FT4, TPOAb and TgAb levels were detected. In addition, an increased mitochondrial superoxide production and decreased expression of TRα1, TRβ1, NIS and Dio1 in the thyroid and mammary glands was found (p < .05). A positive staining of CD4 + that co-localized with TRβ1 in the infiltrated cells within the thyroid follicles was observed. At PN180 in the offspring, the FT3 and FT4 levels showed a significant decrease, while the levels of serum TSH, TPOAb and TgAb were significantly increased in both 10 HI and 100 HI groups (p < .05). In maternal rats, although normal thyroid function can be maintained following 10 HI, thyroiditis can be induced following 100 HI on lactation days 7, 14, and 21. In the offspring at PN180, hypothyroidism complicated with thyroiditis can occur in both the 10 HI and 100 HI groups. Copyright © 2018 Elsevier GmbH. All rights reserved.

  18. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility.

    PubMed

    Li, H F; Zhou, F Y; Li, L; Zheng, Y F

    2016-04-19

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)). Among the Zr-Ru alloy series, Zr-1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr-Ru alloy system as therapeutic devices under MRI diagnostics environments.

  19. Bioactivity and biocompatibility of hydroxyapatite-based bioceramic coatings on zirconium by plasma electrolytic oxidation.

    PubMed

    Aktuğ, Salim Levent; Durdu, Salih; Yalçın, Emine; Çavuşoğlu, Kültigin; Usta, Metin

    2017-02-01

    In the present work, hydroxyapatite (HAP)-based plasma electrolytic oxide (PEO) coatings were produced on zirconium at different current densities in a solution containing calcium acetate and β-calcium glycerophosphate by a single step. The phase structure, surface morphology, functional groups, thickness and roughness of the coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), eddy current method and surface profilometer, respectively. The phases of cubic-zirconia, calcium zirconate and HAP were detected by XRD. The amount of HAP and calcium zirconate increased with increasing current density. The surface of the coatings was very porous and rough. Moreover, bioactivity and biocompatibility of the coatings were analyzed in vitro immersion simulated body fluid (SBF) and MTT (3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide) assay, hemolysis assay and bacterial formation. The apatite-forming ability of the coatings was evaluated after immersion in SBF up to 28days. After immersion, the bioactivity of HAP-based coatings on zirconium was greater than the ones of uncoated zirconium and zirconium oxide-based surface. The bioactivity of PEO surface on zirconium was significantly improved under SBF conditions. The bacterial adhesion of the coatings decreased with increasing current density. The bacterial adhesion of the coating produced at 0.370A/cm 2 was minimum compared to uncoated zirconium coated at 0.260 and 0.292A/cm 2 . The hemocompatibility of HAP-based surfaces was improved by PEO. The cell attachment and proliferation of the PEO coatings were better than the one of uncoated zirconium according to MTT assay results. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility

    PubMed Central

    Li, H.F.; Zhou, F.Y.; Li, L.; Zheng, Y.F.

    2016-01-01

    In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co–Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10−6 cm3·g−1–1.29 × 10−6 cm3·g−1 for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti–6Al–4V, ~3.5 × 10−6 cm3·g−1, CP Ti and Ti–6Al–7Nb, ~3.0 × 10−6 cm3·g−1), and one-sixth that of Co–Cr alloys (Co–Cr–Mo, ~7.7 × 10−6 cm3·g−1). Among the Zr–Ru alloy series, Zr–1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr–Ru alloy system as therapeutic devices under MRI diagnostics environments. PMID:27090955

  1. Efficacy of propidium iodide and FUN-1 stains for assessing viability in basidiospores of Rhizopogon roseolus.

    PubMed

    Fernández-Miranda, Elena; Majada, Juan; Casares, Abelardo

    2017-01-01

    The use of spores in applications of ectomycorrhizal fungi requires information regarding spore viability and germination, especially in genera such as Rhizopogon with high rates of spore dormancy. The authors developed a protocol to assess spore viability of Rhizopogon roseolus using four vital stains to quantify spore viability and germination and to optimize storage procedures. They showed that propidium iodide is an excellent stain for quantifying nonviable spores. Observing red fluorescent intravacuolar structures following staining with 2-chloro-4-(2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene)-1-phenylquinolinium iodide (FUN-1) can help identify viable spores that are activated. At 6 mo and 1 y, the spores kept in a water suspension survived better than those left within intact, dry gasterocarps. Our work highlights the importance of temperature, nutrients, and vitamins for maturation and germination of spores of R. roseolus during 1 y of storage.

  2. A study of the homogeneity and deviations from stoichiometry in mercuric iodide

    NASA Astrophysics Data System (ADS)

    Burger, A.; Morgan, S.; He, C.; Silberman, E.; van den Berg, L.; Ortale, C.; Franks, L.; Schieber, M.

    1990-01-01

    We have been able to determine the deviations from stoichiometry of mercuric iodide (HgI 2) by using differential scanning calorimetry (DSC). Mercury excess or iodine deficiency in mercuric iodide can be evaluated from the eutectic melting of α-Hgl 2-Hg 2I 2 at 235 °C, which appears as an additional peak in DSC thermograms. I 2 excess can be found from the existence of the I 2-α-HgI 2 eutectic melting at 103°C. An additional DSC peak appears in some samples around 112°C, that could be explained by the presence of iodine inclusions. Using resonance fluorescence spectroscopy (RFS) we have been able to determine the presence of free I 2 that is released by samples during the heating at 120 °C (crystal growth temperature), thus giving additional support to the above DSC results.

  3. Lymphocutaneous Sporotrichosis Treated with Potassium Iodide with Development of Subclinical Hypothyroidism: Wolff-Chaikoff Effect?

    PubMed

    Arora, Pooja; Raihan, M; Kubba, Asha; Gautam, Ram K

    2017-01-01

    Sporotrichosis is a subcutaneous mycotic infection caused by Sporothrix schenckii that is acquired by traumatic implantation. The diagnosis is established by demonstration of fungal elements on histopathology and culture. Potassium iodide, azole antifungals, and terbinafine are the treatment options available. In this article, we report a 60-year-old female with lymphocutaneous sporotrichosis that responded well to potassium iodide. However, subclinical hypothyroidism (Wolff-Chaikoff effect) was encountered as a side effect of therapy which was managed with thyroxine replacement. Knowledge about the Wolff-Chaikoff effect (WCE) is important for the dermatologist and reinforces the need for screening and monitoring of thyroid stimulating hormone (TSH) in patients where long duration therapy is being planned.

  4. Growth of mercuric iodide (HgI2) for nuclear radiation detectors

    NASA Technical Reports Server (NTRS)

    Vandenberg, L.; Schnepple, W. F.

    1988-01-01

    Mercuric iodide is a material used for the fabrication of the sensing element in solid state X-ray and gamma ray detecting instruments. The operation of the devices is determined to a large degree by the density of structural defects in the single crystalline material used in the sensing element. Since there were strong indications that the quality of the material was degraded by the effects of gravity during the growth process, a research and engineering program was initiated to grow one or more crystals of mercuric iodide in the reduced gravity environment of space. A special furnace assembly was designed which could be accommodated in a Spacelab rack, and at the same time made it possible to use the same growth procedures and controls used when growing a crystal on the ground. The space crystal, after the flight, was subjected to the same evaluation methods used for earth-grown crystals, so that comparisons could be made.

  5. Normal Auger spectra of iodine in gas phase alkali iodide molecules

    NASA Astrophysics Data System (ADS)

    Hu, Zhengfa; Caló, Antonio; Kukk, Edwin; Aksela, Helena; Aksela, Seppo

    2005-06-01

    Molecular normal Auger electron spectra following the iodine 4d ionization in gas-phase alkali iodides were investigated both experimentally and theoretically. The Auger electron spectra for LiI, NaI and KI were recorded using electron impact, and for RbI by using photo-excitation. These Auger spectra were analyzed in detail and compared to the referenced normal Auger spectra of HI [L. Karlsson, S. Svensson, P. Baltzer, M. Carlsson-Göthe, M.P. Keane, A. Naves de Brito, N. Correia, B. Wannberg, J. Phys. B 22 (1989) 3001]. An energy shift toward higher kinetic energy and a narrowing in linewidth are observed in the Auger spectra series revealing the effect of the changing environment from covalently bonded HI to ionic alkali iodide compounds. The experimental results are also compared with the theoretical ab initio calculations and with the Auger spectra of I -, computed with the multiconfiguration Hartree-Fock (MCHF) method.

  6. Synthesis, spectral, and anti-microbial studies of thioiminium iodides and amine hydrochlorides.

    PubMed

    Britto, Sebastian; Renaud, Philippe; Nallu, Maruthai

    2014-01-01

    To avoid the undesired deprotonation during the addition of organolithium and organomagnesium reagents to ketones, the thioiminium salts, easily prepared from lactams and amides are converted into 2,2-disubstituted and 2-monosubstituted amines by reaction with simple nucleophiles such as organocerium and organocopper reagents. The reaction of thioiminium iodides with organocerium reagents derived by transmetalation of corresponding lithium reagents with anhydrous cerium(III) chloride has been investigated. These thioiminium iodides act as good electrophiles and accept alkylceriums towards bisaddition. The newly synthesized amines have been characterized by 1H and 13C NMR, IR and mass spectra. The amines have been converted into their hydrochlorides and characterized by COSY. These hydrochlorides have been subjected to antimicrobial screening with clinically isolated microorganisms, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi and Candida albicans. The hydrochlorides show quite good activity against these bacteria and fungus. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Fast iodide-SAD phasing for high-throughput membrane protein structure determination.

    PubMed

    Melnikov, Igor; Polovinkin, Vitaly; Kovalev, Kirill; Gushchin, Ivan; Shevtsov, Mikhail; Shevchenko, Vitaly; Mishin, Alexey; Alekseev, Alexey; Rodriguez-Valera, Francisco; Borshchevskiy, Valentin; Cherezov, Vadim; Leonard, Gordon A; Gordeliy, Valentin; Popov, Alexander

    2017-05-01

    We describe a fast, easy, and potentially universal method for the de novo solution of the crystal structures of membrane proteins via iodide-single-wavelength anomalous diffraction (I-SAD). The potential universality of the method is based on a common feature of membrane proteins-the availability at the hydrophobic-hydrophilic interface of positively charged amino acid residues with which iodide strongly interacts. We demonstrate the solution using I-SAD of four crystal structures representing different classes of membrane proteins, including a human G protein-coupled receptor (GPCR), and we show that I-SAD can be applied using data collection strategies based on either standard or serial x-ray crystallography techniques.

  8. In vitro assessment of artifacts induced by titanium, titanium-zirconium and zirconium dioxide implants in cone-beam computed tomography.

    PubMed

    Sancho-Puchades, Manuel; Hämmerle, Christoph H F; Benic, Goran I

    2015-10-01

    The aim of this study was to test whether or not the intensity of artifacts around implants in cone-beam computed tomography (CBCT) differs between titanium, titanium-zirconium and zirconium dioxide implants. Twenty models of a human mandible, each containing one implant in the single-tooth gap position 45, were cast in dental stone. Five test models were produced for each of the following implant types: titanium 4.1 mm diameter (Ti4.1 ), titanium 3.3 mm diameter (Ti3.3 ), titanium-zirconium 3.3 mm diameter (TiZr3.3 ) and zirconium dioxide 3.5-4.5 mm diameter (ZrO3.5-4.5 ) implants. For control purposes, three models without implants were produced. Each model was scanned using a CBCT device. Gray values (GV) were recorded at eight circumferential positions around the implants at 0.5 mm, 1 mm and 2 mm from the implant surface (GVT est ). GV were assessed in the corresponding volumes of interest (VOI) in the control models without implants (GVC ontrol ). Differences of gray values (ΔGV) between GVT est and GVC ontrol were calculated as percentages. One-way ANOVA and post hoc tests were applied to detect differences between implant types. Mean ΔGV for ZrO3.5-4.5 presented the highest absolute values, generally followed by TiZr3.3 , Ti4.1 and Ti3.3 implants. The differences of ΔGV between ZrO3.5-4.5 and the remaining groups were statistically significant in the majority of the VOI (P ≤ 0.0167). ΔGV for TiZr3.3 , Ti4.1 and Ti3.3 implants did not differ significantly in the most VOI. For all implant types, ΔGV showed positive values buccally, mesio-buccally, lingually and disto-lingually, whereas negative values were detected mesially and distally. Zirconium dioxide implants generate significantly more artifacts as compared to titanium and titanium-zirconium implants. The intensity of artifacts around zirconium dioxide implants exhibited in average the threefold in comparison with titanium implants. © 2014 John Wiley & Sons A/S. Published by John Wiley

  9. Photoelectron spectroscopy of color centers in negatively charged cesium iodide nanocrystals

    NASA Astrophysics Data System (ADS)

    Sarkas, Harry W.; Kidder, Linda H.; Bowen, Kit H.

    1995-01-01

    We present the photoelectron spectra of negatively charged cesium iodide nanocrystals recorded using 2.540 eV photons. The species examined were produced using an inert gas condensation cluster ion source, and they ranged in size from (CsI)-n=13 to nanocrystal anions comprised of 330 atoms. Nanocrystals showing two distinct types of photoemission behavior were observed. For (CsI)-n=13 and (CsI)-n=36-165, a plot of cluster anion photodetachment threshold energies vs n-1/3 gives a straight line extrapolating (at n-1/3=0, i.e., n=∞) to 2.2 eV, the photoelectric threshold energy for F centers in bulk cesium iodide. The linear extrapolation of the cluster anion data to the corresponding bulk property implies that the electron localization in these gas-phase nanocrystals is qualitatively similar to that of F centers in extended alkali halide crystals. These negatively charged cesium iodide nanocrystals are thus shown to support embryonic forms of F centers, which mature with increasing cluster size toward condensed phase impurity centers. Under an alternative set of source conditions, nanocrystals were produced which showed significantly lower photodetachment thresholds than the aforementioned F-center cluster anions. For these species, containing 83-131 atoms, a plot of their cluster anion photodetachment threshold energies versus n-1/3 gives a straight line which extrapolates to 1.4 eV. This value is in accord with the expected photoelectric threshold energy for F' centers in bulk cesium iodide, i.e., color centers with two excess electrons in a single defect site. These nanocrystals are interpreted to be the embryonic F'-center containing species, Cs(CsI)-n=41-65.

  10. Mechanism of action of additives in chemical vapor generation of hydrogen selenide: Iodide and thiocyanate

    NASA Astrophysics Data System (ADS)

    Pitzalis, Emanuela; Onor, Massimo; Spiniello, Roberto; Braz, Carlos Eduardo Mendes; D'Ulivo, Alessandro

    2018-07-01

    The chemical vapor generation of H2Se has been investigated in the presence and in the absence of either NaI or NaSCN as additives (0.5 mol L-1), in HClO4 media (0.1-5.0 mol L-1) and using a low concentration of NaBH4 (0.02 mol L-1). The enhancement of generation efficiency of H2Se produced by iodide and thiocyanate was measured by a continuous flow reaction system coupled with a miniature argon‑hydrogen diffusion flame and atomic absorption detection. The chemifold of the continuous flow reactor was designed in order to change the mixing sequence and the interaction time of the reagents. By this way it has been possible to evaluate the contribution of additive‑selenium and additive-borane species to the mechanism producing the increase of generation efficiency of H2Se. Both the iodide complexes of selenium and borane contribute to enhance generation efficiency of H2Se, whereas the thiocyanate complexes of selenium rather than thiocyanate-borane complexes play a major role in the enhancement of the efficiency. At elevated acidities (2 < [H+] < 5 mol L-1), only thiocyanate continues to maintain its properties to increase H2Se generation efficiency while iodide causes a marked signal depression unless its addition is performed after the starting of SeIV- [BH4-] reaction with an appropriate time delay. Both iodide and thiocyanate caused marked depression of H2Se generation when NaBH4 was replaced by the amine boranes, NH3-BH3 and tert-ButylNH2-BH3.

  11. The Ketene-Surrogate Coupling: Catalytic Conversion of Aryl Iodides to Aryl Ketenes via Ynol Ethers**

    PubMed Central

    Zhang, Wenhan; Ready, Joseph M.

    2014-01-01

    tert-Butoxyacetylene is shown to undergo Sonogashira coupling with aryl iodides to yield aryl-substituted tert-butyl ynol ethers. These intermediates participate in a [1,5]-hydride shift, which results in the extrusion of isobutylene and the generation of aryl ketenes. The ketenes are trapped in situ with multiple nucleophiles or undergoelectrocyclic ring closure to yield hydroxynaphthalenes and quinolines. PMID:24975840

  12. Crystal growth and characterization of europium doped lithium strontium iodide scintillator as an ionizing radiation detector

    NASA Astrophysics Data System (ADS)

    Uba, Samuel

    High performance detectors used in the detection of ionizing radiation is critical to nuclear nonproliferation applications and other radiation detectors applications. In this research we grew and tested Europium doped Lithium Strontium Iodide compound. A mixture of lithium iodide, strontium iodide and europium iodide was used as the starting materials for this research. Congruent melting and freezing temperature of the synthesized compound was determined by differential scanning calorimetry (DSC) using a Setaram Labsys Evo DSC-DTA instrument. The melting temperatures were recorded at 390.35°C, 407.59°C and freezing temperature was recorded at 322.84°C from a graph of heat flow plotted against temperature. The synthesized material was used as the charge for the vertical Bridgeman growth, and a 6.5 cm and 7.7cm length boule were grown in a multi-zone transparent Mullen furnace. A scintillating detector of thickness 2.53mm was fabricated by mechanical lapping in mineral oil, and scintillating response and timing were obtained to a cesium source using CS-137 isotope. An energy resolution (FWHM over peak position) of 12.1% was observed for the 662keV full absorption peak. Optical absorption in the UV-Vis wavelength range was recorded for the grown crystal using a U-2900 UV/VIS Spectrophotometer. Absorption peaks were recorded at 194nm, 273nm, and 344nm from the absorbance spectrum, various optical parameters such as absorption coefficient, extinction coefficient, refractive index, and optical loss were derived. The optical band gap energy was calculated using Tauc relation expression at 1.79eV.

  13. Evaluation of respiratory parameters in rats and rabbits exposed to methyl iodide.

    PubMed

    DeLorme, Michael P; Himmelstein, Mathew W; Kemper, Raymond A; Kegelman, Thomas A; Gargas, Michael L; Kinzell, John H

    2009-05-01

    Laboratory animals exposed to methyl iodide (MeI) have previously demonstrated lesions of the olfactory epithelium that were associated with local metabolism in the nasal tissues. Interactions of MeI in the nasal passage may, therefore, alter systemic toxicokinetics. The current study used unrestrained plethysmographs to determine the MeI effect on the breathing frequency and minute volume (MV) in rats and rabbits. Groups of 4 rats each were exposed to 0, 25, or 100 ppm and groups of 4 rabbits each were exposed to 0 and 20 ppm MeI for 6 h. Breathing frequency and MV were measured and recorded during the exposure. Blood samples were collected for inorganic serum iodide and the globin adduct S-methylcysteine (SMC) as biomarkers of systemic kinetics immediately following exposure. No significant reductions in breathing frequency were observed for either rats or rabbits. Significant changes in minute volume were demonstrated by both rats and rabbits; however, the changes observed in rats were not concentration dependent. The MeI-induced changes in MV resulted in significant differences in the total volume of test substance atmosphere inhaled over the 6-h period. Rats demonstrated a concentration-dependent increase in both inorganic serum iodide and SMC. Rabbits exposed to 20 ppm MeI demonstrated a significant increase of inorganic serum iodide; SMC was also increased but was not statistically significant. The results of this study are consistent with previous kinetic studies with MeI, and the data presented here can be integrated into a computational fluid dynamics physiologically based pharmacokinetic model for both rats and rabbits.

  14. High Chloride Doping Levels Stabilize the Perovskite Phase of Cesium Lead Iodide.

    PubMed

    Dastidar, Subham; Egger, David A; Tan, Liang Z; Cromer, Samuel B; Dillon, Andrew D; Liu, Shi; Kronik, Leeor; Rappe, Andrew M; Fafarman, Aaron T

    2016-06-08

    Cesium lead iodide possesses an excellent combination of band gap and absorption coefficient for photovoltaic applications in its perovskite phase. However, this is not its equilibrium structure under ambient conditions. In air, at ambient temperature it rapidly transforms to a nonfunctional, so-called yellow phase. Here we show that chloride doping, particularly at levels near the solubility limit for chloride in a cesium lead iodide host, provides a new approach to stabilizing the functional perovskite phase. In order to achieve high doping levels, we first co-deposit colloidal nanocrystals of pure cesium lead chloride and cesium lead iodide, thereby ensuring nanometer-scale mixing even at compositions that potentially exceed the bulk miscibility of the two phases. The resulting nanocrystal solid is subsequently fused into a polycrystalline thin film by chemically induced, room-temperature sintering. Spectroscopy and X-ray diffraction indicate that the chloride is further dispersed during sintering and a polycrystalline mixed phase is formed. Using density functional theory (DFT) methods in conjunction with nudged elastic band techniques, low-energy pathways for interstitial chlorine diffusion into a majority-iodide lattice were identified, consistent with the facile diffusion and fast halide exchange reactions observed. By comparison to DFT-calculated values (with the PBE exchange-correlation functional), the relative change in band gap and the lattice contraction are shown to be consistent with a Cl/I ratio of a few percent in the mixed phase. At these incorporation levels, the half-life of the functional perovskite phase in a humid atmosphere increases by more than an order of magnitude.

  15. A fluorescence turn-on sensor for iodide based on a thymine-Hg(II)-thymine complex.

    PubMed

    Ma, Boling; Zeng, Fang; Zheng, Fangyuan; Wu, Shuizhu

    2011-12-23

    Iodide plays a vital role in many biological processes, including neurological activity and thyroid function. Due to its physiological relevance, a method for the rapid, sensitive, and selective detection of iodide in food, pharmaceutical products, and biological samples such as urine is of great importance. Herein, we demonstrate a novel and facile strategy for constructing a fluorescence turn-on sensor for iodide based on a T-Hg(II)-T complex (T=thymine). A fluorescent anthracene-thymine dyad (An-T) was synthesized, the binding of which to a mercury(II) ion lead to the formation of a An-T-Hg(II)-T-An complex, thereby quenching the fluorescent emission of this dyad. In this respect, the dyad An-T constituted a fluorescence turn-off sensor for mercury(II) ions in aqueous media. More importantly, it was found that upon addition of iodide, the mercury(II) ion was extracted from the complex due to the even stronger binding between mercury(II) ions and iodide, leading to the release of the free dyad and restoration of the fluorescence. By virtue of this fluorescence quenching and recovery process, the An-T-Hg(II)-T-An complex constitutes a fluorescence turn-on sensor for iodide with a detection limit of 126 nM. Moreover, this sensor is highly selective for iodide over other common anions, and can be used in the determination of iodide in drinking water and biological samples such as urine. This strategy may provide a new approach for sensing some other anions. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Grotthuss Transport of Iodide in EMIM/I3 Ionic Crystal.

    PubMed

    McDaniel, Jesse G; Yethiraj, Arun

    2018-01-11

    Highly ionic environments can mediate unusual chemical reactions that would otherwise be considered impossible based on chemical intuition. For example, the formation of a chemical bond between two iodide anions to form a divalent polyiodide anion is seemingly prohibited due to Coulombic repulsion. Using ab initio molecular dynamics simulations, we show that in the 1-ethyl-3-methylimidazolium (EMIM)/I 3 ionic crystal, the reactive formation of divalent and even trivalent polyiodide anions occurs with extremely small energetic barriers, due to the electrostatic field of the ionic lattice. A practical consequence of this anomalous reactivity is that iodide anions are efficiently transported within the crystal through a "Grotthuss-exchange" mechanism involving bond-breaking and forming events. We characterize two distinct transport pathways, involving both I 4 2- and I 7 3- intermediates, with fast transport of iodide resulting from the release of an I - anion on the opposite side of the intermediate species from the initial bond formation. The ordered cation arrangement in the crystal provides the necessary electrostatic screening for close approach of anions, suggesting a new counterintuitive approach to obtain high ionic conductivity. This new design principle could be used to develop better solid-state electrolytes for batteries, fuel cells, and supercapacitors.

  17. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    PubMed

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  18. Ab initio calculation of transport properties between PbSe quantum dots facets with iodide ligands

    NASA Astrophysics Data System (ADS)

    Wang, B.; Patterson, R.; Chen, W.; Zhang, Z.; Yang, J.; Huang, S.; Shrestha, S.; Conibeer, G.

    2018-01-01

    The transport properties between Lead Selenide (PbSe) quantum dots decorated with iodide ligands has been studied using density functional theory (DFT). Quantum conductance at each selected energy levels has been calculated along with total density of states and projected density of states. The DFT calculation is carried on using a grid-based planar augmented wave (GPAW) code incorporated with the linear combination of atomic orbital (LCAO) mode and Perdew Burke Ernzerhof (PBE) exchange-correlation functional. Three iodide ligand attached low index facets including (001), (011), (111) are investigated in this work. P-orbital of iodide ligand majorly contributes to density of state (DOS) at near top valence band resulting a significant quantum conductance, whereas DOS of Pb p-orbital shows minor influence. Various values of quantum conductance observed along different planes are possibly reasoned from a combined effect electrical field over topmost surface and total distance between adjacent facets. Ligands attached to (001) and (011) planes possess similar bond length whereas it is significantly shortened in (111) plane, whereas transport between (011) has an overall low value due to newly formed electric field. On the other hand, (111) plane with a net surface dipole perpendicular to surface layers leading to stronger electron coupling suggests an apparent increase of transport probability. Apart from previously mentioned, the maximum transport energy levels located several eVs (1 2 eVs) from the edge of valence band top.

  19. Mercuric iodide detector systems for identifying substances by x-ray energy dispersive diffraction

    SciTech Connect

    Iwanczyk, J.S.; Patt, B.E.; Wang, Y.J.

    The use of mercuric iodide arrays for energy-dispersive x-ray diffraction (EDXRD) spectroscopy is now being investigated by the authors for inspection of specific crystalline powders in substances ranging from explosives to illicit drugs. Mercuric iodide has been identified as the leading candidate for replacing the Ge detectors previously employed in the development of this technique because HgI{sub 2} detectors: operate at or near room temperature; without the bulky apparatus associated with cryogenic cooling; and offer excellent spectroscopy performance with extremely high efficiency. Furthermore, they provide the practicality of constructing optimal array geometries necessary for these measurements. Proof of principle experimentsmore » have been performed using a single-HgI{sub 2} detector spectrometer. An energy resolution of 655 eV (FWHM) has been obtained for 60 keV gamma line from an {sup 241}Am source. The EDXRD signatures of various crystalline powdered compounds have been measured and the spectra obtained show the excellent potential of mercuric iodide for this application.« less

  20. Iodide, bromide, and ammonium in hydraulic fracturing and oil and gas wastewaters: environmental implications.

    PubMed

    Harkness, Jennifer S; Dwyer, Gary S; Warner, Nathaniel R; Parker, Kimberly M; Mitch, William A; Vengosh, Avner

    2015-02-03

    The expansion of unconventional shale gas and hydraulic fracturing has increased the volume of the oil and gas wastewater (OGW) generated in the U.S. Here we demonstrate that OGW from Marcellus and Fayetteville hydraulic fracturing flowback fluids and Appalachian conventional produced waters is characterized by high chloride, bromide, iodide (up to 56 mg/L), and ammonium (up to 420 mg/L). Br/Cl ratios were consistent for all Appalachian brines, which reflect an origin from a common parent brine, while the I/Cl and NH4/Cl ratios varied among brines from different geological formations, reflecting geogenic processes. There were no differences in halides and ammonium concentrations between OGW originating from hydraulic fracturing and conventional oil and gas operations. Analysis of discharged effluents from three brine treatment sites in Pennsylvania and a spill site in West Virginia show elevated levels of halides (iodide up to 28 mg/L) and ammonium (12 to 106 mg/L) that mimic the composition of OGW and mix conservatively in downstream surface waters. Bromide, iodide, and ammonium in surface waters can impact stream ecosystems and promote the formation of toxic brominated-, iodinated-, and nitrogen disinfection byproducts during chlorination at downstream drinking water treatment plants. Our findings indicate that discharge and accidental spills of OGW to waterways pose risks to both human health and the environment.

  1. Reactions of vitamin A with acceptors of electrons. Interactions with iodine and the formation of iodide

    PubMed Central

    Lucy, J. A.; Lichti, F. Ulrike

    1969-01-01

    1. The reactions of retinol and retinoic acid with iodine were investigated since knowledge of the chemical reactions of vitamin A with acceptors of electrons may shed light on its biochemical mode of action. 2. Colloidal retinol, but not retinoic acid, reacts with iodine to yield a blue–green complex that rapidly decomposes, giving iodide and an unknown species with λmax. at 870mμ. 3. In addition, both retinol and retinoic acid reduce iodine to iodide by a reaction that does not involve an intermediate coloured complex; this reaction appears to yield unstable carbonium ion derivatives of the vitamin. 4. The presence of water greatly facilitates the production of iodide from vitamin A and iodine. 5. Possible chemical pathways involved in these reactions are discussed. 6. It is suggested that the chemical properties of retinol and retinoic acid that underlie their biochemical behaviour might be apparent only when the molecules are at a lipid–water interface, and that vitamin A might be expected to react with a number of different electron acceptors in vivo. PMID:5801297

  2. The oxidation of reduced nicotinamide nucleotides by hydrogen peroxide in the presence of lactoperoxidase and thiocyanate, iodide or bromide

    PubMed Central

    McC. Hogg, D.; Jago, G. R.

    1970-01-01

    Lactoperoxidase (EC 1.11.1.7) catalysed the oxidation of NADH by hydrogen peroxide in the presence of either thiocyanate, iodide or bromide. In the presence of thiocyanate, net oxidation of thiocyanate occurred simultaneously with the oxidation of NADH, but in the presence of iodide or bromide, only the oxidation of NADH occurred to a significant extent. In the presence of thiocyanate or bromide, NADH was oxidized to NAD+ but in the presence of iodide, an oxidation product with spectral and chemical properties distinct from NAD+ was formed. Thiocyanate, iodide and bromide appeared to function in the oxidation of NADH by themselves being oxidized to products which in turn oxidized NADH, rather than by activating the enzyme. Iodine, which oxidized NADH non-enzymically, appeared to be an intermediate in the oxidation of NADH in the presence of iodide. NADPH was oxidized similarly under the same conditions. An assessment was made of the rates of these oxidation reactions, together with the rates of other lactoperoxidase-catalysed reactions, at physiological concentrations of thiocyanate, iodide and bromide. The results indicated that in milk and saliva the oxidation of thiocyanate to a bacterial inhibitor was likely to predominate over the oxidation of NADH. PMID:4317722

  3. Activation of the Nrf2-Keap 1 Pathway in Short-Term Iodide Excess in Thyroid in Rats

    PubMed Central

    Liang, Xue

    2017-01-01

    Wistar rats were randomly divided into groups of varying iodide intake: normal iodide; 10 times high iodide; and 100 times high iodide on Days 7, 14, and 28. Insignificant changes were observed in thyroid hormone levels (p > 0.05). Urinary iodine concentration and iodine content in the thyroid glands increased after high consumption of iodide from NI to 100 HI (p < 0.05). The urinary iodine concentration of the 100 HI group on Days 7, 14, and 28 was 60–80 times that of the NI group. The mitochondrial superoxide production and expressions of Nrf2, Srx, and Prx 3 all significantly increased, while Keap 1 significantly decreased in the 100 HI group when compared to the NI or 10 HI group on Days 7, 14, and 28 (p < 0.05). Immunofluorescence staining results showed that Nrf2 was localized in the cytoplasm in NI group. Although Nrf2 was detected in both cytoplasm and nucleus in 10 HI and 100 HI groups, a stronger positive staining was found in the nucleus. We conclude that the activation of the Nrf2-Keap 1 antioxidative defense mechanism may play a crucial role in protecting thyroid function from short-term iodide excess in rats. PMID:28133506

  4. Gadolinium-hydrogen ion exchange of zirconium phosphate

    NASA Technical Reports Server (NTRS)

    Liu, D. C.; Power, J. L.

    1972-01-01

    The Gd(+3)/H(+) ion exchange on a commercial zirconium phosphate ion exchanger was investigated in chloride, sulfate, and phosphate solutions of Gd(+3) at gadolinium concentrations of 0.001 to 1 millimole per cc and in the pH range of 0 to 3.5. Relatively low Gd(+3) capacities, in the range of 0.01 to 0.1 millimole per g of ion exchanger were found at room temperature. A significant difference in Gd(+3) sorption was observed, depending on whether the ion exchanger was converted from initial conditions of greater or lesser Gd(+3) sorption than the specific final conditions. Correlations were found between decrease in Gd(+3) capacity and loss of exchanger phosphate groups due to hydrolysis during washing and between increase in capacity and treatment with H3PO4. Fitting of the experimental data to ideal ion exchange equilibrium expressions indicated that each Gd(+3) ion is sorbed on only one site of the ion exchanger. The selectivity quotient was determined to be 2.5 + or - 0.4 at room temperature on gadolinium desorption in chloride solutions.

  5. Revisiting Zirconium: New Abundance Determinations with Improved Oscillator Strengths

    NASA Astrophysics Data System (ADS)

    Burris, Debra L.; Jones, M.; Nichols, R.

    2006-12-01

    The element Zirconium is produced via neutron capture (n-capture). It resides in the mass range where there is uncertainty about the production mechanism at early time. The rapid n-capture process (r-process) was believed to be responsible for the production, but no study (Burris et al 2000, Gilroy et al 1988 and others) has been able to successfully use the r-process to reproduce the abundance signature for elements in this mass range for metal-poor halo stars. It has been suggested (Sneden and Cowan 2003) that there may be an undiscovered component to the r-process. New transition probabilities for Zr II have been reported by Malcheva et al (2006). We utilize these values to make new abundance determinations for Zr in the Sun and the metal-poor halo star BD +17 3248. This work is supported in part by the AAS Small Grant Program, the Arkansas Space Grant Consortium and the UCA Undergraduate Research Council.

  6. Iron state in iron nanoparticles with and without zirconium

    NASA Astrophysics Data System (ADS)

    Filippov, V. P.; Khasanov, A. M.; Lauer, Yu. A.

    2017-11-01

    Mössbauer and X-ray methods are used for investigations of structure, stability and characteristics of pure-iron grain and two iron-zirconium alloys such as Fe + 5 wt.% Zr and Fe + 10 wt.% Zr. The used powder was ground for 24 h in a SPEX Model 8000 mill shaker. Complex nanoparticles are found, which change their properties under milling. Mössbauer spectral parameters are obtained for investigated materials. Milling results in formation of nanosized particles with two states of iron atoms: one main part is pure α-Fe and another part of iron atoms displaced in grain boundaries or defective zones in which hyperfine magnetic splitting decrease to ˜ 30.0 T. In alloys with Zr three iron states are formed in each alloy, main part of iron is in the form of α-Fe and another two states depend on the concentration of Zr and represent iron in grain boundaries with Zr atoms in nearest neighbor. The changing of iron states is discussed.

  7. Structural evolution of zirconium carbide under ion irradiation

    NASA Astrophysics Data System (ADS)

    Gosset, D.; Dollé, M.; Simeone, D.; Baldinozzi, G.; Thomé, L.

    2008-02-01

    Zirconium carbide is one of the candidate materials to be used for some fuel components of the high temperature nuclear reactors planned in the frame of the Gen-IV project. Few data exist regarding its behaviour under irradiation. We have irradiated ZrC samples at room temperature with slow heavy ions (4 MeV Au, fluence from 10 11 to 5 × 10 15 cm -2) in order to simulate neutron irradiations. Grazing incidence X-Ray diffraction (GIXRD) and transmission electron microscopy (TEM) analysis have been performed in order to study the microstructural evolution of the material versus ion fluence. A high sensitivity to oxidation is observed with the formation of zirconia precipitates during the ion irradiations. Three damage stages are observed. At low fluence (<10 12 cm -2), low modifications are observed. At intermediate fluence, high micro-strains appear together with small faulted dislocation loops. At the highest fluence (>10 14 cm -2), the micro-strains saturate and the loops coalesce to form a dense dislocation network. No other structural modification is observed. The material shows a moderate cell parameter increase, corresponding to a 0.6 vol.% swelling, which saturates around 10 14 ions/cm 2, i.e., a few Zr dpa. As a result, in spite of a strong covalent bonding component, ZrC seems to have a behaviour under irradiation close to cubic metals.

  8. Bioconjugation of zirconium uridine monophosphate: application to myoglobin direct electrochemistry.

    PubMed

    Qiao, Yuanbiao; Jian, Fangfang; Bai, Qian

    2008-03-14

    Porous nano-granule of zirconium uridine monophosphate, Zr(UMP)2.H2O is, for the first time, synthesized under mild experimental conditions and applied to the bioconjugation of myoglobin (Mb) to realize its direct electron transfer. UV-vis and resonance Raman spectroscopies prove that Mb in the Zr(UMP)2.H2O film maintains its secondary structure similar to the native state. The conjugation film of the Mb-Zr(UMP)2.H2O on the glassy carbon (GC) electrode gives a well-defined and quasi-reversible cyclic voltammogram, which reflects the direct electron transfer of the heme Fe III/Fe II couple of Mb. On the basis of the satisfying bioelectrocatalysis of the nano-conjugation of Mb and genetic substrate, a kind of mediator-free biosensor for H2O2 is developed. The linear range for H2O2 detection is estimated to be 3.92-180.14 microM. The apparent Michaelis-Menten constant (Km) and the detection limit based on the signal-to-noise ratio of 3 are found to be 196.1 microM and 1.52 microM, respectively. Both the apparent Michaelis-Menten constant and the detection limit herein are much lower than currently reported values from other Mb films. This kind of sensor possesses excellent stability, long-term life (more than 20 days) and good reproducibility.

  9. Zirconium Phosphate Nanoplatelet Potential for Anticancer Drug Delivery Applications.

    PubMed

    González, Millie L; Ortiz, Mayra; Hernández, Carmen; Cabán, Jennifer; Rodríguez, Axel; Colón, Jorge L; Báez, Adriana

    2016-01-01

    Zirconium phosphate (ZrP) nanoplatelets can intercalate anticancer agents via an ion exchange reaction creating an inorganic delivery system with potential for cancer treatment. ZrP delivery of anticancer agents inside tumor cells was explored in vitro. Internalization and cytotoxicity of ZrP nanoplatelets were studied in MCF-7 and MCF-10A cells. DOX-loaded ZrP nanoplatelets (DOX@ZrP) uptake was assessed by confocal (CLSM) and transmission electron microscopy (TEM). Cytotoxicity to MCF-7 and MCF-10A cells was determined by the MTT assay. Reactive Oxy- gen Species (ROS) production was analyzed by fluorometric assay, and cell cycle alterations and induction of apoptosis were analyzed by flow cytometry. ZrP nanoplatelets were localized in the endosomes of MCF-7 cells. DOX and ZrP nanoplatelets were co-internalized into MCF-7 cells as detected by CLSM. While ZrP showed limited toxicity to MCF-7 cells, DOX@ZrP was cytotoxic at an IC₅₀ similar to that of free DOX. Meanwhile, DOX lC₅₀ was significantly lower than the equivalent concentration of DOX@ZrP in MCF-10A cells. ZrP did not induce apoptosis in both cell lines. DOX and DOX@ZrP induced significant oxidative stress in both cell models. Results suggest that ZrP nanoplatelets are promising as carriers of anticancer agents into cancer cells.

  10. Reaction of Titanium and Zirconium Particles in Cylindrical Explosive Charges

    NASA Astrophysics Data System (ADS)

    Frost, David L.; Cairns, Malcolm; Goroshin, Samuel; Zhang, Fan

    2007-12-01

    The critical conditions for the reaction of particles of the transition metals titanium (Ti) and zirconium (Zr) dispersed during the detonation of long cylindrical explosive charges have been investigated experimentally. The charges consisted of packed beds of either spherical Ti particles or irregularly shaped Zr particles saturated with sensitized liquid nitromethane. For the Ti particles, a threshold particle diameter exists of 65±25 μm, above which self-sustained particle reaction is not observed for charge diameters up to 49 mm, although some particle reaction occurs immediately behind the detonation front then rapidly quenches. For the smallest particles (40 μm), the proportion of the conical particle cloud that reacts increases with charge diameter, suggesting that the reaction is a competition between particle heating and expansion cooling of the products. For 375 and 550 μm Zr particles, particle ignition was observed for 19 and 41 mm dia charges. In this case, interaction of the detonation wave with the particles is sufficient to initiate reaction at the particle surface after a delay time (˜5 μs), which is much less than the time required for thermal equilibration of the particles.

  11. Synthesis and Characterization of Zirconium Substituted Cobalt Ferrite Nanopowders

    DOE PAGES

    Rus, S. F.; Vlazan, P.; Herklotz, A.

    2016-01-01

    Nanocrystalline ferrites; CoFe 2O 4 (CFO) and CoFe 1.9Zr 0.1O 4 (CFZO) have been synthesized through chemical coprecipitation method. Moreover, the role played by the zirconium ions in improving the magnetic and structural properties is analyzed. X-ray diffraction revealed a single-phase cubic spinel structure for both materials, where the crystallite size increases and the lattice parameter decreases with substitution of Zr. The average sizes of the nanoparticles are estimated to be 16-19 nm. These sizes are small enough to achieve the suitable signal to noise ratio in the high density recording media. An increase in the saturation magnetization with themore » substitution of Zr suggests the preferential occupation of Zr 4+ ions in the tetrahedral sites. A decrease in the coercivity values indicates the reduction of magneto-crystalline anisotropy. We investigated spinel ferrites can be used also in recoding media due to the large value of coercivity 1000 Oe which is comparable to those of hard magnetic materials.« less

  12. Transport property correlations for the niobium-1% zirconium alloy

    NASA Astrophysics Data System (ADS)

    Senor, David J.; Thomas, J. Kelly; Peddicord, K. L.

    1990-10-01

    Correlations were developed for the electrical resistivity (ρ), thermal conductivity ( k), and hemispherical total emittance (ɛ) of niobium-1% zirconium as functions of temperature. All three correlations were developed as empirical fits to experimental data. ρ = 5.571 + 4.160 × 10 -2(T) - 4.192 × 10 -6(T) 2 μΩcm , k = 13.16( T) 0.2149W/ mK, ɛ = 6.39 × 10 -2 + 4.98 × 10 -5( T) + 3.62 × 10 -8( T) 2 - 7.28 × 10 -12( T) 3. The relative standard deviation of the electrical resistivity correlation is 1.72% and it is valid over the temperature range 273 to 2700 K. The thermal conductivity correlation has a relative standard deviation of 3.24% and is valid over the temperature range 379 to 1421 K. The hemispherical total emittance correlation was developed for smooth surface materials only and represents a conservative estimate of the emittance of the alloy for space reactor fuel element modeling applications. It has a relative standard deviation of 9.50% and is valid over the temperature range 755 to 2670 K.

  13. A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

    PubMed

    Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

    2014-02-01

    Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.

  14. Hopping conduction in zirconium oxynitrides thin film deposited by reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Guo, Jie; Zhan, Guanghui; Liu, Jingquan; Yang, Bin; Xu, Bin; Feng, Jie; Chen, Xiang; Yang, Chunsheng

    2015-10-01

    Zirconium oxynitrides thin film thermometers were demonstrated to be useful temperature sensors. However, the basic conduction mechanism of zirconium oxynitrides films has been a long-standing issue, which hinders the prediction and optimization of their ultimate performance. In this letter, zirconium oxynitrides films were grown on sapphire substrates by magnetron sputtering and their electric transport mechanism has been systemically investigated. It was found that in high temperatures region (>150 K) the electrical conductivity was dominated by thermal activation for all samples. In the low temperatures range, while Mott variable hopping conduction (VRH) was dominated the transport for films with relatively low resistance, a crossover from Mott VRH conduction to Efros-Shklovskii (ES) VRH was observed for films with relatively high resistance. This low temperature crossover from Mott to ES VRH indicates the presence of a Coulomb gap (~7 meV). These results demonstrate the competing and tunable conduction mechanism in zirconium oxynitrides thin films, which would be helpful for optimizing the performance of zirconium oxynitrides thermometer.

  15. Zirconium-based alloys, nuclear fuel rods and nuclear reactors including such alloys, and related methods

    DOEpatents

    Mariani, Robert Dominick

    2014-09-09

    Zirconium-based metal alloy compositions comprise zirconium, a first additive in which the permeability of hydrogen decreases with increasing temperatures at least over a temperature range extending from 350.degree. C. to 750.degree. C., and a second additive having a solubility in zirconium over the temperature range extending from 350.degree. C. to 750.degree. C. At least one of a solubility of the first additive in the second additive over the temperature range extending from 350.degree. C. to 750.degree. C. and a solubility of the second additive in the first additive over the temperature range extending from 350.degree. C. to 750.degree. C. is higher than the solubility of the second additive in zirconium over the temperature range extending from 350.degree. C. to 750.degree. C. Nuclear fuel rods include a cladding material comprising such metal alloy compositions, and nuclear reactors include such fuel rods. Methods are used to fabricate such zirconium-based metal alloy compositions.

  16. Sodium/iodide symporter: a key transport system in thyroid cancer cell metabolism.

    PubMed

    Filetti, S; Bidart, J M; Arturi, F; Caillou, B; Russo, D; Schlumberger, M

    1999-11-01

    The recent cloning of the gene encoding the sodium/iodide symporter (NIS) has enabled better characterization of the molecular mechanisms underlying iodide transport, thus opening the way to clarifying its role in thyroid diseases. Several studies, at both the mRNA and the protein expression levels, have demonstrated that TSH, the primary regulator of iodide uptake, upregulates NIS gene expression and NIS protein abundance, both in vitro and in vivo. However, other factors, including iodide, retinoic acid, transforming growth factor-beta, interleukin-1alpha and tumour necrosis factor alpha, may participate in the regulation of NIS expression. Investigation of NIS mRNA expression in different thyroid tissues has revealed increased levels of expression in Graves' disease and toxic adenomas, whereas a reduction or loss of NIS transcript was detected in differentiated thyroid carcinomas, despite the expression of other specific thyroid markers. NIS mRNA was also detected in non-thyroid tissues able to concentrate radioiodine, including salivary glands, stomach, thymus and breast. The production of specific antibodies against the NIS has facilitated study of the expression of the symporter protein. Despite of the presence of high levels of human (h)NIS mRNA, normal thyroid glands exhibit a heterogeneous expression of NIS protein, limited to the basolateral membrane of the thyrocytes. By immunohistochemistry, staining of hNIS protein was stronger in Graves' and toxic adenomas and reduced in thyroid carcinomas. Measurement of iodide uptake by thyroid cancer cells is the cornerstone of the follow-up and treatment of patients with thyroid cancer. However, radioiodide uptake is found only in about 67% of patients with persistent or recurrent disease. Several studies have demonstrated a decrease in or a loss of NIS expression in primary human thyroid carcinomas, and immunohistochemical studies have confirmed this considerably decreased expression of the NIS protein in thyroid

  17. Temperature dependence of chloride, bromide, iodide, thiocyanate and salicylate transport in human red cells

    PubMed Central

    Dalmark, Mads; Wieth, Jens Otto

    1972-01-01

    1. The temperature dependence of the steady-state self-exchange of chloride between human red cells and a plasma-like electrolyte medium has been studied by measuring the rate of 36Cl- efflux from radioactively labelled cells. Between 0 and 10° C the rate increased by a factor of eight corresponding to an Arrhenius activation energy of 33 kcal/mole. 2. The rate of chloride exchange decreased significantly in experiments where 95% of the chloride ions in cells and medium were replaced by other monovalent anions of a lyotropic series. The rate of chloride self-exchange was increasingly reduced by bromide, bicarbonate, nitrate, iodide, thiocyanate, and salicylate. The latter aromatic anion was by far the most potent inhibitor, reducing the rate of chloride self-exchange to 0·2% of the value found in a chloride medium. 3. The temperature sensitivity of the chloride self-exchange was not affected significantly by the anionic inhibitors. The Arrhenius activation energies of chloride exchange were between 30 and 40 kcal/mole in the presence of the six inhibitory anions mentioned above. 4. The rate of self-exchange of bromide, thiocyanate, and iodide between human red cells and media was determined after washing and labelling cells in media containing 120 mM bromide, thiocyanate, or iodide respectively. The rate of self-exchange of the three anions were 12, 3, and 0·4% of the rate of chloride self-exchange found in the chloride medium. 5. The Arrhenius activation energies of the self-exchange of bromide, iodide, and thiocyanate were all between 29 and 37 kcal/mole, the same magnitude as found for the self-exchange of chloride. 6. Although approximately 40% of the intracellular iodide and salicylate ions appeared to be adsorbed to intracellular proteins, the rate of tracer anion efflux followed first order kinetics until at least 98% of the intracellular anions had been exchanged. 7. The self-exchange of salicylate across the human red cell membrane occurred by a

  18. Geologic structure of Gofitsky deposit of titanium and zirconium and perspectives of the reserve base of titanium and zirconium in Russia

    NASA Astrophysics Data System (ADS)

    Kukhmazov, Iskander

    2016-04-01

    With the fall of the Soviet Union, all the mining deposits of titanium and zirconium appeared outside of Russian Federation. Therefore the studying of deposits of titanium and zirconium in Russia is very important nowadays. There is a paradoxical situation in the country: in spite of possible existence of national mineral resource base of Ti-Zr material, which can cover needs of the country, Russia is the one of the largest buyers of imported Ti-Zr material in the world. Many deposits are not mined, and those which are in the process of mining have poor reserves. Demand for this raw material is very great not only for Russia, but also for the world in general. Today there is a scarcity of zircon around the world and it will only increase through time. Therefore prices of products of titanium and zirconium also increase. Consequently Russian deposits of titanium and zirconium with higher content than foreign may become competitive. Russia is forced to buy raw materials (zirconium and titanium production) from former Soviet Union countries at prices higher than the world's and thus incur huge losses, including customs charges. Russia should create its own mineral resource base of Ti-Zr. Studied titanium-zirconium deposits of Stavropol region may become the basis for the south part of Russia. At first, Beshpagirsky deposit should be pointed out. It has large reserves of ore sands with high content of Ti-Zr. A combination of favorable geographical position of the area with developed industrial infrastructure makes it very beneficial as an object for high priority development. Gofitsky deposit should be pointed out as well. Its sands have a wide areal distribution and a high content of titanium and zirconium. Chokrak, Karagan-Konksk and Sarmatian sediments of the Miocene of Gofitsky deposit are productive for titanium and zirconium placers within Stavropol region of Russia. Gofitsky deposit was evaluated from financial and economic point of view and the following data

  19. Structural studies of degradation process of zirconium dioxide tetragonal phase induced by grinding with dental bur

    NASA Astrophysics Data System (ADS)

    Piosik, A.; Żurowski, K.; Pietralik, Z.; Hędzelek, W.; Kozak, M.

    2017-11-01

    Zirconium dioxide has been widely used in dental prosthetics. However, the improper mechanical treatment can induce changes in the microstructure of zirconium dioxide. From the viewpoint of mechanical properties and performance, the phase transitions of ZrO2 from the tetragonal to the monoclinic phase induced by mechanical processing, are particularly undesirable. In this study, the phase transitions of yttrium stabilized zirconium dioxide (Y-TZP) induced by mechanical treatment are investigated by the scanning electron microscopy (SEM), atomic force microscopy (AFM) and powder diffraction (XRD). Mechanical stress was induced by different types of drills used presently in dentistry. At the same time the surface temperature was monitored during milling using a thermal imaging camera. Diffraction analysis allowed determination of the effect of temperature and mechanical processing on the scale of induced changes. The observed phase transition to the monoclinic phase was correlated with the methods of mechanical processing.

  20. A novel ultrasonication method in the preparation of zirconium impregnated cellulose for effective fluoride adsorption.

    PubMed

    Barathi, M; Kumar, A Santhana Krishna; Rajesh, N

    2014-05-01

    In the present work, we propose for the first time a novel ultrasound assisted methodology involving the impregnation of zirconium in a cellulose matrix. Fluoride from aqueous solution interacts with the cellulose hydroxyl groups and the cationic zirconium hydroxide. Ultrasonication ensures a green and quick alternative to the conventional time intensive method of preparation. The effectiveness of this process was confirmed by comprehensive characterization of zirconium impregnated cellulose (ZrIC) adsorbent using Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectrometry (EDX) and X-ray diffraction (XRD) studies. The study of various adsorption isotherm models, kinetics and thermodynamics of the interaction validated the method. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Theoretical stusy of the reaction between 2,2',4' - trihydroxyazobenzene-5-sulfonic acid and zirconium

    USGS Publications Warehouse

    Fletcher, Mary H.

    1960-01-01

    Zirconium reacts with 2,2',4'-trihydroxyazobenzene-5-sulfonic acid in acid solutions to Form two complexes in which the ratios of dye to zirconium are 1 to 1 and 2 to 1. Both complexes are true chelates, with zirconium acting as a bridge between the two orthohydroxy dye groups. Apparent equilibrium constants for the reactions to form each of the complexes are determined. The reactions are used as a basis for the determination of the active component in the dye and a graphical method for the determination of reagent purity is described. Four absorption spectra covering the wave length region from 350 to 750 mu are given, which completely define the color system associated with the reactions in solutions where the hydrochloric acid concentration ranges from 0.0064N to about 7N.

  2. Determination of fluoride in water - A modified zirconium-alizarin method

    USGS Publications Warehouse

    Lamar, W.L.

    1945-01-01

    A convenient, rapid colorimetric procedure using the zirconium-alizarin indicator acidified with sulfuric acid for the determination of fluoride in water is described. Since this acid indicator is stable indefinitely, it is more useful than other zirconium-alizarin reagents previously reported. The use of sulfuric acid alone in acidifying the zirconium-alizarin reagent makes possible the maximum suppression of the interference of sulfate. Control of the pH of the samples eliminates errors due to the alkalinity of the samples. The fluoride content of waters containing less than 500 parts per million of sulfate and less than 1000 p.p.m. of chloride may be determined within a limit of 0.1 p.p.m. when a 100-ml. sample is used.

  3. Corrosion Behavior of Zirconium Treated Mild Steel with and Without Organic Coating: a Comparative Study

    NASA Astrophysics Data System (ADS)

    Ghanbari, Alireza; Attar, Mohammadreza Mohammadzade

    2014-10-01

    In this study, the anti-corrosion performance of phosphated and zirconium treated mild steel (ZTMS) with and without organic coating was evaluated using AC and DC electrochemical techniques. The topography and morphology of the zirconium treated samples were studied using atomic force microscopy (AFM) and field emission scanning electron microscope (FE-SEM) respectively. The results revealed that the anti-corrosion performance of the phosphate layer was superior to the zirconium conversion layer without an organic coating due to very low thickness and porous nature of the ZTMS. Additionally, the corrosion behavior of the organic coated substrates was substantially different. It was found that the corrosion protection performance of the phosphate steel and ZTMS with an organic coating is in the same order.

  4. Aqueous photochemical reactions of chloride, bromide, and iodide ions in a diode-array spectrophotometer. Autoinhibition in the photolysis of iodide ions.

    PubMed

    Kalmár, József; Dóka, Éva; Lente, Gábor; Fábián, István

    2014-03-28

    The aqueous photoreactions of three halide ions (chloride, bromide and iodide) were studied using a diode array spectrophotometer to drive and detect the process at the same time. The concentration and pH dependences of the halogen formation rates were studied in detail. The experimental data were interpreted by improving earlier models where the cage complex of a halogen atom and an electron has a central role. The triiodide ion was shown to exert a strong inhibiting effect on the reaction sequence leading to its own formation. An assumed chemical reaction between the triiodide ion and the cage complex interpreted the strong autoinhibition effect. It is shown that there is a real danger of unwanted interference from the photoreactions of halide ions when halide salts are used as supporting electrolytes in spectrophotometric experiments using a relatively high intensity UV light source.

  5. Bayesian model selection validates a biokinetic model for zirconium processing in humans

    PubMed Central

    2012-01-01

    Background In radiation protection, biokinetic models for zirconium processing are of crucial importance in dose estimation and further risk analysis for humans exposed to this radioactive substance. They provide limiting values of detrimental effects and build the basis for applications in internal dosimetry, the prediction for radioactive zirconium retention in various organs as well as retrospective dosimetry. Multi-compartmental models are the tool of choice for simulating the processing of zirconium. Although easily interpretable, determining the exact compartment structure and interaction mechanisms is generally daunting. In the context of observing the dynamics of multiple compartments, Bayesian methods provide efficient tools for model inference and selection. Results We are the first to apply a Markov chain Monte Carlo approach to compute Bayes factors for the evaluation of two competing models for zirconium processing in the human body after ingestion. Based on in vivo measurements of human plasma and urine levels we were able to show that a recently published model is superior to the standard model of the International Commission on Radiological Protection. The Bayes factors were estimated by means of the numerically stable thermodynamic integration in combination with a recently developed copula-based Metropolis-Hastings sampler. Conclusions In contrast to the standard model the novel model predicts lower accretion of zirconium in bones. This results in lower levels of noxious doses for exposed individuals. Moreover, the Bayesian approach allows for retrospective dose assessment, including credible intervals for the initially ingested zirconium, in a significantly more reliable fashion than previously possible. All methods presented here are readily applicable to many modeling tasks in systems biology. PMID:22863152

  6. Solid-phase zirconium and fluoride species in alkaline zircaloy cladding waste at Hanford.

    PubMed

    Reynolds, Jacob G; Huber, Heinz J; Cooke, Gary A; Pestovich, John A

    2014-08-15

    The United States Department of Energy Hanford Site, near Richland, Washington, USA, processed plutonium between 1944 and 1987. Fifty-six million gallons of waste of various origins remain, including waste from removing zircaloy fuel cladding using the so-called Zirflex process. The speciation of zirconium and fluoride in this waste is important because of the corrosivity and reactivity of fluoride as well as the (potentially) high density of Zr-phases. This study evaluates the solid-phase speciation of zirconium and fluoride using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Two waste samples were analyzed: one waste sample that is relatively pure zirconium cladding waste from tank 241-AW-105 and another that is a blend of zirconium cladding wastes and other high-level wastes from tank 241-C-104. Villiaumite (NaF) was found to be the dominant fluoride species in the cladding waste and natrophosphate (Na7F[PO4]2 · 19H2O) was the dominant species in the blended waste. Most zirconium was present as a sub-micron amorphous Na-Zr-O phase in the cladding waste and a Na-Al-Zr-O phase in the blended waste. Some zirconium was present in both tanks as either rounded or elongated crystalline needles of Na-bearing ZrO2 that are up to 200 μm in length. These results provide waste process planners the speciation data needed to develop disposal processes for this waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Zirconium and hafnium in the southeastern Atlantic States

    USGS Publications Warehouse

    Mertie, J.B.

    1958-01-01

    The principal source of zirconium and hafnium is zircon, though a minor source is baddeleyite, mined only in Brazil. Zircon is an accessory mineral in igneous, metamorphic, and sedimentary rocks, but rarely occurs in hardrock in minable quantities. The principal sources of zircon are therefore alluvial deposits, which are mined in many countries of five continents. The principal commercial deposits in the United States are in Florida, though others exist elsewhere in the southeastern Coastal Plain. The evidence indicates that conditions for the accumulation of workable deposits of heavy minerals were more favorable during the interglacial stages of the Pleistocene epoch than during Recent time. Therefore detrital ores of large volume and high tenor are more likely to be found in the terrace deposits than along the present beaches. Other concentrations of heavy minerals, however, are possible at favored sites close to the Fall Line where the Tuscaloosa formation rests upon the crystalline rocks of the Piedmont province. A score of heavy and semiheavy minerals occur in the detrital deposits of Florida, but the principal salable minerals are ilmenite, leucoxene, rutile, and zircon, though monazite and staurolite are saved at some mining plants. Commercial deposits of heavy minerals are generally required to have a tenor of 4 percent, though ores with a lower tenor can be mined at a profit if the content of monazite is notably high. The percentages of zircon in the concentrates ranges from 10 to 16 percent, and in eastern Florida from 13 to 15 percent. Thus the tenor in zircon of the ore-bearing sands ranges from 0.4 to 0.6 percent. The content of hafnium in zircon is immaterial for many uses, but for some purposes very high or very low tenors in hafnium are required. Alluvial zircon cannot be separated into such varieties, which, if needed, must be obtained from sources in bedrock. It thus becomes necessary to determine the Hf : Zr ratios in zircon from many kinds of

  8. Bonding of sapphire to sapphire by eutectic mixture of aluminum oxide and zirconium oxide

    NASA Technical Reports Server (NTRS)

    Deluca, J. J. (Inventor)

    1975-01-01

    Bonding of an element comprising sapphire, ruby or blue sapphire to another element of such material with a eutectic mixture of aluminum oxide and zirconium oxide is discussed. The bonding mixture may be applied in the form of a distilled water slurry or by electron beam vapor deposition. In one embodiment the eutectic is formed in situ by applying a layer of zirconium oxide and then heating the assembly to a temperature above the eutectic temperature and below the melting point of the material from which the elements are formed. The formation of a sapphire rubidium maser cell utilizing eutectic bonding is shown.

  9. Zirconium-modified materials for selective adsorption and removal of aqueous arsenic

    DOEpatents

    Zhao, Hongting; Moore, Robert C.

    2004-11-30

    A method, composition, and apparatus for removing contaminant species from an aqueous medium comprising: providing a material to which zirconium has been added, the material selected from one or more of zeolites, cation-exchangeable clay minerals, fly ash, mesostructured materials, activated carbons, cellulose acetate, and like porous and/or fibrous materials; and contacting the aqueous medium with the material to which zirconium has been added. The invention operates on all arsenic species in the form of arsenate, arsenite and organometallic arsenic, with no pretreatment necessary (e.g., oxidative conversion of arsenite to arsenate).

  10. The role of hydrogen in zirconium alloy corrosion

    NASA Astrophysics Data System (ADS)

    Ensor, B.; Lucente, A. M.; Frederick, M. J.; Sutliff, J.; Motta, A. T.

    2017-12-01

    Hydrogen enters zirconium metal as a result of the corrosion process and forms hydrides when present in quantities above the solubility limit at a given temperature. Zircaloy-4 coupons of different thicknesses (0.4 mm-2.3 mm) but identical chemistry and processing were corroded in autoclave at 360 °C for various times up to 2800 days. Coupons were periodically removed and weighed to determine weight gain, which allows follow of the corrosion kinetics. Coupon thickness differences resulted in different volumetric concentrations of hydrogen, as quantified using hot vacuum extraction. The thinnest coupons, having the highest concentration of hydrogen, demonstrated acceleration in their corrosion kinetics and shorter transition times when compared to thicker coupons. Furthermore, it was seen that the post-transition corrosion rate was increased with increasing hydrogen concentration. Corrosion rates increased only after the terminal solid solubility (TSS) was exceeded for hydrogen in Zircaloy-4 at 360 °C. Therefore, it is hypothesized that the corrosion acceleration is caused by the formation of hydrides. Scanning electron microscope (SEM) examinations of fractured oxide layers demonstrate the oxide morphology changed with hydrogen content, with more equiaxed oxide grains in the high hydrogen samples than in those with lower hydrogen content. Additionally, locations of advanced oxide growth were correlated with locations of hydrides in the metal. A hypothesis is proposed to explain the accelerated corrosion due to the presence of the hydrides, namely that the metal, locally, is less able to accommodate oxide growth stresses and this leads to earlier loss of oxide protectiveness in the form of more frequent oxide kinetic transitions.

  11. Nanoencapsulation of Insulin into Zirconium Phosphate for Oral Delivery Applications

    PubMed Central

    Díaz, Agustín; David, Amanda; Pérez, Riviam; González, Millie L.; Báez, Adriana; Wark, Stacey E.; Zhang, Paul; Clearfield, Abraham; Colón, Jorge L.

    2010-01-01

    The encapsulation of insulin into different kinds of materials for non-invasive delivery is an important field of study because of the many drawbacks of painful needle and syringe delivery such as physiological stress, infection, and local hypertrophy, among others.1 A stable, robust, non-toxic, and viable non-invasive carrier for insulin delivery is needed. We present a new approach for protein nanoencapsulation using layered zirconium phosphate (ZrP) nanoparticles produced without any preintercalator present. The use of ZrP without preintercalators produces a highly pure material, without any kinds of contaminants, such as the preintercalator, which can be noxious. Cytotoxicity cell viability in vitro experiments for the ZrP nanoparticles show that ZrP is not toxic, or harmful, in a biological environment, as previously reported for rats.2 Contrary to previous preintercalator-based methods, we show that insulin can be nanoencapsulated in ZrP if a highly hydrate phase of ZrP with an interlayer distance of 10.3 Å (10.3 Å-ZrP or θ-ZrP) is used as precursor. The intercalation of insulin into ZrP produced a new insulin-intercalated ZrP phase with a ca. 27 Å interlayer distance, as determined by X-ray powder diffraction, demonstrating a successful nanoencapsulation of the hormone. The in vitro release profile of the hormone after the intercalation was determined and circular dichroism was used to study the hormone stability upon intercalation and release. The insulin remains stable in the layered material, at room temperature, for a considerable amount of time, improving the shell life of the peptidic hormone. This type of materials represents a strong candidate to develop a non-invasive insulin carrier for the treatment of diabetes mellitus. PMID:20707305

  12. Improved Yttrium and Zirconium Abundances in Metal-Poor Stars

    NASA Astrophysics Data System (ADS)

    Violante, Renata; Biemont, E.; Cowan, J. J.; Sneden, C.

    2012-01-01

    Abstract We present new abundances of the lighter n-capture elements, Yttrium (Z=39) and Zirconium (Z=40) in the very metal poor, r-process rich stars BD+17 3248 and HD 221170. Very accurate abundances were obtained by use of the new transition probabilities for Y II published by Biémont et al. 2011, and Zr II by Malcheva et al. 2006, and by expanding the number of transitions employed for each element. For example, in BD+17 3248, we find log ɛπσιλον=-0.03 +/- 0.03 (σιγμα=0.15, from 23 lines) for Y II. As for Zr II, log ɛπσιλον = 0.65 +/- 0.03 (σɛγμα = 0.1, from 13 lines). The resulting abundance ratio is log ɛπσιλον [Y/Zr] = -0.68 +/- 0.05. The results for HD 221170 are in accord with those of BD+17 3248. The quantity of lines used to form the abundance means has increased significantly since the original studies of these stars, resulting in more trustworthy abundances. These observed abundance ratios are in agreement with an r-process-only value predicted from stellar models, but is under-abundant compared to an empirical model derived from direct analyses of meteoritic material. This ambiguity should stimulate further nucleosynthetic analysis to explain this abundance ratio. We would like to extend our gratitude to NSF grant AST-0908978 and the University of Texas Astronomy Department Rex G. Baker, Jr. Endowment for their financial support in this project.

  13. Rubidium and Zirconium Production in Massive AGB Stars

    SciTech Connect

    Raai, M. A. van; Lugaro, M.; Karakas, A. I.

    2008-04-06

    A recent survey of a large sample of massive Galactic asymptotic giant branch (AGB) stars shows that significant overabundances of rubidium (up to 100 times solar), but merely solar zirconium, are present in these stars. These observations can set constraints on our theoretical notion of the slow neutron capture process (the s process) in AGB stars, as well as on the rates of the neutron capture reactions involved in the production of Rb and Zr. We use the Monash nucleosynthesis code with a recently extended network to try to reproduce these observations. We present results for AGB stars of massesmore » 5, 6, and 6.5 M{center_dot} and solar metallicity. We also show results for different available choices of the neutron capture rates, as well as for the possible inclusion of a partial mixing zone (PMZ), leading to the activation of the {sup 13}C neutron source. We find increasing Rb overabundances with increasing stellar mass, as observed, but we are far from matching the highest observed Rb enhancements. Inclusion of a PMZ increases the Rb abundance, but also produces an overabundance of Zr, contrary to what is observed. Only if the third dredge up efficiency remains as high as before the onset of the superwind phase during the final few pulses of a massive AGB star, can we match the highest [Rb/Fe] ratios observed by Garcia-Hernandez et al. [l]. A better understanding of the third dredge up efficiency with decreasing envelope mass for massive AGB stars is essential for further investigation of this issue.« less

  14. 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.

  15. The visible spectrum of zirconium dioxide, ZrO2

    NASA Astrophysics Data System (ADS)

    Le, Anh; Steimle, Timothy C.; Gupta, Varun; Rice, Corey A.; Maier, John P.; Lin, Sheng H.; Lin, Chih-Kai

    2011-09-01

    The electronic spectrum of a cold molecular beam of zirconium dioxide, ZrO2, has been investigated using laser induced fluorescence (LIF) in the region from 17 000 cm-1 to 18 800 cm-1 and by mass-resolved resonance enhanced multi-photon ionization (REMPI) spectroscopy from 17 000 cm-1-21 000 cm-1. The LIF and REMPI spectra are assigned to progressions in the tilde A{^1}B_2(ν1, ν2, ν3) ← tilde X{^1}A_1(0, 0, 0) transitions. Dispersed fluorescence from 13 bands was recorded and analyzed to produce harmonic vibrational parameters for the tilde X{^1}A_1 state of ω1 = 898(1) cm-1, ω2 = 287(2) cm-1, and ω3 = 808(3) cm-1. The observed transition frequencies of 45 bands in the LIF and REMPI spectra produce origin and harmonic vibrational parameters for the tilde A{^1}B_2 state of Te = 16 307(8) cm-1, ω1 = 819(3) cm-1, ω2 = 149(3) cm-1, and ω3 = 518(4) cm-1. The spectra were modeled using a normal coordinate analysis and Franck-Condon factor predictions. The structures, harmonic vibrational frequencies, and the potential energies as a function of bending angle for the tilde A{^1}B_2 and tilde X{^1}A_1 states are predicted using time-dependent density functional theory, complete active space self-consistent field, and related first-principle calculations. A comparison with isovalent TiO2 is made.

  16. An Efficient Process for Pd-Catalyzed C–N Cross-Coupling Reactions of Aryl Iodides: Insight Into Controlling Factors

    PubMed Central

    Fors, Brett P.; Davis, Nicole R.; Buchwald, Stephen L.

    2009-01-01

    An investigation into Pd-catalyzed C–N cross-coupling reactions of aryl iodides is described. NaI is shown to have a significant inhibitory effect on these processes. By switching to a solvent system in which the iodide byproduct was insoluble, reactions of aryl iodides were accomplished with the same efficiencies as aryl chlorides and bromides. Using catalyst systems based on certain biarylphosphine ligands, aryl iodides were successfully reacted with an array of primary and secondary amines in high yields. Lastly, reactions of heteroarylamines and heteroaryliodides were also conducted in high yields. PMID:19348431

  17. Susceptibility of Escherichia coli to Bactericidal Action of Lactoperoxidase, Peroxide, and Iodide or Thiocyanate

    PubMed Central

    Thomas, Edwin L.; Aune, Thomas M.

    1978-01-01

    The bactericidal action that results from lactoperoxidase-catalyzed oxidation of iodide or thiocyanate was studied, using Escherichia coli as the test organism. The susceptibility of intact cells to bactericidal action was compared with that of cells with altered cell envelopes. Exposure to ethylenediaminetetraacetic acid, to lysozyme and ethylenediaminetetraacetic acid, or to osmotic shock were used to alter the cell envelope. Bactericidal action was greatly increased when the cells were exposed to the lactoperoxidase-peroxide-iodide system at low temperatures, low cell density, or after alteration of the cell envelope. When thiocyanate was substituted for iodide, bactericidal activity was observed only at low cell density or after osmotic shock. Low temperature and low cell density lowered the rate of destruction of peroxide by the bacteria. Therefore, competition for peroxide between the bacteria and lactoperoxidase may influence the extent of bactericidal action. Alteration of the cell envelope had only a small effect on the rate of destruction of peroxide. Instead, the increased susceptibility of these altered cells suggested that bactericidal action required permeation of a reagent through the cell envelope. In addition to altering the cell envelope, these procedures partly depleted cells of oxidizable substrates and sulfhydryl components. Adding an oxidizable substrate did not decrease the susceptibility of the altered cells. On the other hand, mild reducing agents such as sulfhydryl compounds did partly reverse bactericidal action when added after exposure of cells to the peroxidase systems. These studies indicate that alteration of the metabolism, structure, or composition of bacterial cells can greatly increase their susceptibility to peroxidase bactericidal action. PMID:348097

  18. Characterization of home-made silver sulphide based iodide selective electrode.

    PubMed

    Rajbhandari Nyachhyon, A; Yadav, A P; Manandhar, K; Pradhananga, R R

    2010-09-15

    Polycrystalline silver sulphide/silver iodide ion selective electrodes (ISEs) with four different compositions, 9:1, 2:1, 1:1, 1:9 Ag(2)S-AgI mole ratios, have been fabricated in the laboratory and characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). X-ray diffraction studies show the presence of Ag(3)SI, Ag(2)S and AgI crystalline phases in the electrode material. The electrode surfaces have been found to become smoother and lustrous with increasing percentage of silver sulphide in silver iodide. ISE 1:1, ISE 2:1 and ISE 9:1 all responded in Nernstian manner with slopes of about 60 mV/decade change in iodide ion concentration in the linear range of 1 x 10(-1) to 1 x 10(-6)M while ISE 1:9 showed sub-Nernstian behavior with slope of about 45 mV up to the concentration 1 x 10(-5)M. Two capacitive loops, one corresponding to the charge transfer process at metal electrode and the back contact and a second loop corresponding to the charge transfer process at membrane-electrolyte interface have been observed at high and low frequency ranges, respectively. Mott-Schottky analysis shows that the materials are n-type semiconductors with donor defect concentrations in the range of 5.1 x 10(14) to 2.4 x 10(19)/cm(3). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  19. Immobilization of Iodate and Iodide using Iron Oxides through Sorption and Co-precipitation at Hanford Site

    NASA Astrophysics Data System (ADS)

    Wang, G.; Qafoku, N. P.; Truex, M. J.; Strickland, C. E.; Freedman, V. L.

    2017-12-01

    Isotopes of iodine were generated during plutonium production at the U.S. Department of Energy (DOE) Hanford Site. The long half-life 129I generated during reactor operations has been released into the subsurface, resulting in several large plumes at the Hanford subsurface. We studied the interaction of iodate (IO3-) and iodide (I-) with Fe oxides. A series of batch experiments were conducted to investigate adsorption and co-precipitation of iodine species in the presence of a variety of Fe oxides, such as ferrihydrite, goethite, hematite and magnetite. In the sorption experiments, each Fe oxide was added to an artificial groundwater containing either iodate or iodide, and reacted at room temperature. The sorption batch experiments for each mineral were conducted at varied initial iodate or iodide concentrations under 3 different pH conditions (pH 5, 7, and 9). In the co-precipitation batch experiments, the initial Fe-mineral-forming solutions were prepared in artificial groundwater containing iodate or iodide. Our results indicate that both sorption and co-precipitation are viable mechanisms of the attenuation of the liquid phase iodine. Species Fe oxides could serve as hosts of iodate and iodide that are present at the Hanford subsurface.

  20. An iodine supplementation of tomato fruits coated with an edible film of the iodide-doped chitosan.

    PubMed

    Limchoowong, Nunticha; Sricharoen, Phitchan; Techawongstien, Suchila; Chanthai, Saksit

    2016-06-01

    In general, the risk of numerous thyroid cancers inevitably increases among people with iodine deficiencies. An iodide-doped chitosan (CT-I) solution was prepared for dipping tomatoes to coat the fresh surface with an edible film (1.5 μm), thereby providing iodine-rich fruits for daily intake. Characterisation of the thin film was conducted by FTIR and SEM. Stability of the CT-I film was studied via water immersion at various time intervals, and no residual iodide leached out due to intrinsic interactions between the cationic amino group of chitosan and iodide ions. Moreover, the iodide supplement exhibited no effect on the antioxidant activity of tomatoes. The iodine content in the film-coated tomato was determined by ICP-OES. The tomato coating with 1.5% (w/v) CT-I contained approximately 0.4 μg iodide per gram fresh weight. In addition, the freshness and storability of iodine-doped tomatoes were also maintained for shelf-life concerns. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A G-quadruplex based fluorescent oligonucleotide turn-on probe towards iodides detection in real samples.

    PubMed

    Li, Qian; Li, Shuaihua; Chen, Xiu; Bian, Liujiao

    2017-09-01

    A basket-type G-quadruplex (GQ) fluorescent oligonucleotide (OND) probe is designed to detect iodides dependent on thymine-Hg(II)-thymine (T-Hg(II)-T) base pairs and the intrinsic fluorescence quenching capacity of GQ. In the presence of Hg(II) ions (Hg 2+ ), the two hexachloro-fluorescein-labeled ONDs form a hairpin structure and the fluorophores are dragged close to the GQ, leading to fluorescence quenching of the probe due to photoinduced electron transfer. Upon addition of iodide anions, Hg 2+ are extracted from T-Hg(II)-T complexes which attributes to the stronger binding with iodide anions, resulting in the fluorescence recovery. Through performing the fluorescence quenching and recovery processes, this probe developed a fluorescence turn-on sensor for iodide anions determination over a linear range of 20-200nmol/L with a limit of detection of 5nmol/L. The practical use of the turn-on technology was demonstrated by its application in determination of iodides in water, food, pharmaceutical products and biological samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Re-approaching global iodine emissions: A novel parameterisation for sea-surface iodide concentrations using a machine learning approach

    NASA Astrophysics Data System (ADS)

    Sherwen, T.; Evans, M. J.; Chance, R.; Tinel, L.; Carpenter, L.

    2017-12-01

    Halogens (Cl, Br, I) in the troposphere have been shown to play a profound role in determining the concentrations of ozone and OH. Iodine, which is essentially oceanic in source, exerts its largest impacts on composition in both the marine boundary layer, and in the upper troposphere. This chemistry has only recently been implemented into global models and significant uncertainties remain, particularly regarding the magnitude of iodine emissions. Iodine emissions are dominated by the inorganic oxidation of iodide in the sea surface by ozone, which leads to release of gaseous inorganic iodine (HOI, I2). Critical for calculation of these fluxes is the sea-surface concentration of iodide, which is poorly constrained by observations. Previous parameterizations for sea-surface iodide concentration have focused on simple regressive relationships with sea surface temperature and another single oceanographic variables. This leads to differences in iodine fluxes of approximately a factor of two, and leads to substantial differences in the modelled impact of iodine on atmospheric composition. Here we use an expanded dataset of oceanic iodide observations, which incorporates new data that has been targeted at areas with poor coverage previously. A novel approach of multivariate machine learning techniques is applied to this expanded dataset to generate a model that yields improved estimates of the global sea surface iodide distribution. We then use a global chemical transport model (GEOS-Chem) to explore the impact of this new parameterisation on the atmospheric budget of iodine and its impact on tropospheric composition.

  3. Crystal Growth and Dissolution of Methylammonium Lead Iodide Perovskite in Sequential Deposition: Correlation between Morphology Evolution and Photovoltaic Performance.

    PubMed

    Hsieh, Tsung-Yu; Huang, Chi-Kai; Su, Tzu-Sen; Hong, Cheng-You; Wei, Tzu-Chien

    2017-03-15

    Crystal morphology and structure are important for improving the organic-inorganic lead halide perovskite semiconductor property in optoelectronic, electronic, and photovoltaic devices. In particular, crystal growth and dissolution are two major phenomena in determining the morphology of methylammonium lead iodide perovskite in the sequential deposition method for fabricating a perovskite solar cell. In this report, the effect of immersion time in the second step, i.e., methlyammonium iodide immersion in the morphological, structural, optical, and photovoltaic evolution, is extensively investigated. Supported by experimental evidence, a five-staged, time-dependent evolution of the morphology of methylammonium lead iodide perovskite crystals is established and is well connected to the photovoltaic performance. This result is beneficial for engineering optimal time for methylammonium iodide immersion and converging the solar cell performance in the sequential deposition route. Meanwhile, our result suggests that large, well-faceted methylammonium lead iodide perovskite single crystal may be incubated by solution process. This offers a low cost route for synthesizing perovskite single crystal.

  4. X-ray fluorescence analysis of alloy and stainless steels using a mercuric iodide detector

    NASA Technical Reports Server (NTRS)

    Kelliher, Warren C.; Maddox, W. Gene

    1988-01-01

    A mercuric iodide detector was used for the XRF analysis of a number of NBS standard steels, applying a specially developed correction method for interelemental effects. It is shown that, using this method and a good peak-deconvolution technique, the HgI2 detector is capable of achieving resolutions and count rates needed in the XRF anlysis of multielement samples. The freedom from cryogenic cooling and from power supplies necessary for an electrically cooled device makes this detector a very good candidate for a portable instrument.

  5. Index of refraction, density, and solubility of ammonium iodide solutions at high pressure.

    PubMed

    Lamelas, F J

    2013-03-07

    An asymmetric moissanite anvil cell is used to study aqueous solutions of ammonium iodide at pressures up to 10 kbar. The index of refraction is measured using the rotating Fabry-Perot technique, with an accuracy of approximately 1%. The mass density and molar volume of the solutions are estimated using the measured index values, and the molar volume is used to predict the pressure dependence of the solubility. The solubility derived from the index of refraction measurements is shown to agree with that which is determined by direct observation of the onset of crystallization.

  6. Dynamics of the Coulomb explosion of large hydrogen iodide clusters irradiated by superintense ultrashort laser pulses

    NASA Astrophysics Data System (ADS)

    Krainov, V. P.; Roshchupkin, A. S.

    2001-12-01

    Dynamics of the inner and outer above-barrier ionization and of the Coulomb explosion are calculated for large hydrogen iodide clusters irradiated by superintense ultrashort laser pulses. We have found that the Coulomb forces predominate in the expansion of these clusters in comparison with the hydrodynamic forces. The energy distribution of the iodine multiple atomic ions in laser focal volume is derived. Results of our calculations are in a good agreement with the recent experimental data of Tisch et al. [Phys. Rev. A 60, 3076 (1999)].

  7. Atypical Cutaneous Sporotrichosis in an Immunocompetent Adult: Response to Potassium Iodide.

    PubMed

    Gandhi, Nikita; Chander, Ram; Jain, Arpita; Sanke, Sarita; Garg, Taru

    2016-01-01

    Cutaneous sporotrichosis, also known as "Rose Gardener's disease," caused by dimorphic fungus Sporothrix schenkii, is usually characterized by indolent nodular or nodulo-ulcerative lesions arranged in a linear pattern. We report bizarre nonlinear presentation of Sporotrichosis, in an immunocompetent adult occurring after a visit to Amazon rain forest, speculating infection with more virulent species of Sporothrix. The diagnosis was reached with the help of periodic acid-Schiff positive yeast cells and cigar shaped bodies seen in skin biopsy along with the therapeutic response to potassium iodide.

  8. Atypical Cutaneous Sporotrichosis in an Immunocompetent Adult: Response to Potassium Iodide

    PubMed Central

    Gandhi, Nikita; Chander, Ram; Jain, Arpita; Sanke, Sarita; Garg, Taru

    2016-01-01

    Cutaneous sporotrichosis, also known as “Rose Gardener's disease,” caused by dimorphic fungus Sporothrix schenkii, is usually characterized by indolent nodular or nodulo-ulcerative lesions arranged in a linear pattern. We report bizarre nonlinear presentation of Sporotrichosis, in an immunocompetent adult occurring after a visit to Amazon rain forest, speculating infection with more virulent species of Sporothrix. The diagnosis was reached with the help of periodic acid-Schiff positive yeast cells and cigar shaped bodies seen in skin biopsy along with the therapeutic response to potassium iodide. PMID:27057047

  9. Iodide-Photocatalyzed Reduction of Carbon Dioxide to Formic Acid with Thiols and Hydrogen Sulfide.

    PubMed

    Berton, Mateo; Mello, Rossella; González-Núñez, María Elena

    2016-12-20

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO 2 capture coupled with H 2 S removal may have been relevant as a prebiotic carbon dioxide fixation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Theoretical study on the dissociation energies, ionization potentials and electron affinities of three perfluoroalkyl iodides

    NASA Astrophysics Data System (ADS)

    Cheng, Li; Shen, Zuochun; Lu, Jianye; Gao, Huide; Lü, Zhiwei

    2005-11-01

    Dissociation energies, ionization potentials and electron affinities of three perfluoroalkyl iodides, CF 3I, C 2F 5I, and i-C 3F 7I are calculated accurately with B3LYP, MP n ( n = 2-4), QCISD, QCISD(T), CCSD, and CCSD(T) methods. Calculations are performed by using large-core correlation-consistent pseudopotential basis set (SDB-aug-cc-pVTZ) for iodine atom. In all energy calculations, the zero point vibration energy is corrected. And the basis set superposition error is corrected by counterpoise method in the calculation of dissociation energy. Theoretical results are compared with the experimental values.

  11. Characteristics of the iodide/triiodide redox mediator in dye-sensitized solar cells.

    PubMed

    Boschloo, Gerrit; Hagfeldt, Anders

    2009-11-17

    Dye-sensitized solar cells (DSCs) have gained widespread interest because of their potential for low-cost solar energy conversion. Currently, the certified record efficiency of these solar cells is 11.1%, and measurements of their durability and stability suggest lifetimes exceeding 10 years under operational conditions. The DSC is a photoelectrochemical system: a monolayer of sensitizing dye is adsorbed onto a mesoporous TiO(2) electrode, and the electrode is sandwiched together with a counter electrode. An electrolyte containing a redox couple fills the gap between the electrodes. The redox couple is a key component of the DSC. The reduced part of the couple regenerates the photo-oxidized dye. The formed oxidized species diffuses to the counter electrode, where it is reduced. The photovoltage of the device depends on the redox couple because it sets the electrochemical potential at the counter electrode. The redox couple also affects the electrochemical potential of the TiO(2) electrode through the recombination kinetics between electrons in TiO(2) and oxidized redox species. This Account focuses on the special properties of the iodide/triiodide (I(-)/I(3)(-)) redox couple in dye-sensitized solar cells. It has been the preferred redox couple since the beginning of DSC development and still yields the most stable and efficient DSCs. Overall, the iodide/triiodide couple has good solubility, does not absorb too much light, has a suitable redox potential, and provides rapid dye regeneration. But what distinguishes I(-)/I(3)(-) from most redox mediators is the very slow recombination kinetics between electrons in TiO(2) and the oxidized part of the redox couple, triiodide. Certain dyes adsorbed at TiO(2) catalyze this recombination reaction, presumably by binding iodine or triiodide. The standard potential of the iodide/triiodide redox couple is 0.35 V (versus the normal hydrogen electrode, NHE), and the oxidation potential of the standard DSC-sensitizer (Ru(dcbpy)(2

  12. High Performance of Supercapacitor from PEDOT:PSS Electrode and Redox Iodide Ion Electrolyte

    PubMed Central

    Gao, Xing; Zu, Lei; Cai, Xiaomin; Li, Ce; Lian, Huiqin; Liu, Yang; Wang, Xiaodong; Cui, Xiuguo

    2018-01-01

    Insufficient energy density and poor cyclic stability is still challenge for conductive polymer-based supercapacitor. Herein, high performance electrochemical system has been assembled by combining poly (3,4-ethylenedioxythiophene) (PEDOT):poly (styrene sulfonate) (PSS) redox electrode and potassium iodide redox electrolyte, which provide the maximum specific capacity of 51.3 mAh/g and the retention of specific capacity of 87.6% after 3000 cycles due to the synergic effect through a simultaneous redox reaction both in electrode and electrolyte, as well as the catalytic activity for reduction of triiodide of the PEDOT:PSS. PMID:29772662

  13. Synthetic Studies of Antimony Sulfur Iodide and Predictions/Synthesis of New Nitrogen Containing Crystal Structures.

    DTIC Science & Technology

    1983-02-01

    Okazaki, 2 it appeared likely that well-aligned SbSI would have extremely useful piezoelectric properties. It was appreciated that a source of high purity...which often facilitate this, and may also lead to special physical effects (as with the ferroelectric behavior of SbSI). In hydroxyapatite , there are two...Fabrication of Piezoelectric Cerdmics," Ferroelectrics 41, 77-69 (1982). 3. P.E.O. Morgan, "Synthetic Studies of Antimony Sulfur Iodide," Proposal to ONR from

  14. Effect of zirconium nitride physical vapor deposition coating on preosteoblast cell adhesion and proliferation onto titanium screws.

    PubMed

    Rizzi, Manuela; Gatti, Giorgio; Migliario, Mario; Marchese, Leonardo; Rocchetti, Vincenzo; Renò, Filippo

    2014-11-01

    Titanium has long been used to produce dental implants. Problems related to its manufacturing, casting, welding, and ceramic application for dental prostheses still limit its use, which highlights the need for technologic improvements. The aim of this in vitro study was to evaluate the biologic performance of titanium dental implants coated with zirconium nitride in a murine preosteoblast cellular model. The purpose of this study was to evaluate the chemical and morphologic characteristics of titanium implants coated with zirconium nitride by means of physical vapor deposition. Chemical and morphologic characterizations were performed by scanning electron microscopy and energy dispersive x-ray spectroscopy, and the bioactivity of the implants was evaluated by cell-counting experiments. Scanning electron microscopy and energy dispersive x-ray spectroscopy analysis found that physical vapor deposition was effective in covering titanium surfaces with zirconium nitride. Murine MC-3T3 preosteoblasts were seeded onto titanium-coated and zirconium nitride-coated screws to evaluate their adhesion and proliferation. These experiments found a significantly higher number of cells adhering and spreading onto zirconium nitride-coated surfaces (P<.05) after 24 hours; after 7 days, both titanium and zirconium nitride surfaces were completely covered with MC-3T3 cells. Analysis of these data indicates that the proposed zirconium nitride coating of titanium implants could make the surface of the titanium more bioactive than uncoated titanium surfaces. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Method for making fine and ultrafine spherical particles of zirconium titanate and other mixed metal oxide systems

    DOEpatents

    Hu, Michael Z.

    2006-05-23

    Disclosed is a method for making amorphous spherical particles of zirconium titanate and crystalline spherical particles of zirconium titanate comprising the steps of mixing an aqueous solution of zirconium salt and an aqueous solution of titanium salt into a mixed solution having equal moles of zirconium and titanium and having a total salt concentration in the range from 0.01 M to about 0.5 M. A stearic dispersant and an organic solvent is added to the mixed salt solution, subjecting the zirconium salt and the titanium salt in the mixed solution to a coprecipitation reaction forming a solution containing amorphous spherical particles of zirconium titanate wherein the volume ratio of the organic solvent to aqueous part is in the range from 1 to 5. The solution of amorphous spherical particles is incubated in an oven at a temperature .ltoreq.100.degree. C. for a period of time .ltoreq.24 hours converting the amorphous particles to fine or ultrafine crystalline spherical particles of zirconium titanate.

  16. Squishy nanotraps: hybrid cellulose nanocrystal-zirconium metallogels for controlled trapping of biomacromolecules.

    PubMed

    Sheikhi, A; van de Ven, T G M

    2017-08-11

    A brick-and-mortar-like ultrasoft nanocomposite metallogel is formed by crosslinking cellulose nanocrystals (CNC) with ammonium zirconium carbonate (AZC) to trap and reconfigure dextran, a model biomacromolecule. The bricks (CNC) reinforce the metallogel, compete with dextran in reacting with AZC, and decouple long-time dextran dynamics from network formation, while the mortar (AZC) imparts bimodality to the dextran diffusion.

  17. Application of laser-induced breakdown spectroscopy to zirconium in aqueous solution

    NASA Astrophysics Data System (ADS)

    Ruas, Alexandre; Matsumoto, Ayumu; Ohba, Hironori; Akaoka, Katsuaki; Wakaida, Ikuo

    2017-05-01

    In the context of the Fukushima Dai-ichi Nuclear Power Plant (F1-NPP) decommissioning process, laser-induced breakdown spectroscopy (LIBS) has many advantages. The purpose of the present work is to demonstrate the on-line monitoring capability of the LIBS coupled with the ultra-thin liquid jet sampling method. The study focuses on zirconium in aqueous solution, considering that it is a major element in the F1-NPP fuel debris that has been subject to only a few LIBS studies in the past. The methodology of data acquisition and processing are described. In particular, two regions of interest with many high intensity zirconium lines have been observed around 350 nm in the case of the ionic lines and 478 nm in the case of atomic lines. The best analytical conditions for zirconium are different depending on the analysis of ionic lines or atomic lines. A low LOD of about 4 mg L- 1 could be obtained, showing that LIBS coupled with the ultra-thin liquid jet sampling technique is a promising alternative for more complex solutions found in the F1-NPP, namely mixtures containing zirconium.

  18. Possibilities of surface coating for thermal insulation. [zirconium dioxide, titanium dioxide, and zircon coatings

    NASA Technical Reports Server (NTRS)

    Poeschel, E.; Weisser, G.

    1979-01-01

    Calculations performed for pulsating heat sources indicate a relatively thin (200-1000 micron) coating can lower temperature both inside and on the surface of a construction material. Various coating materials (including zirconium dioxide) are discussed, together with possible thermic stresses and ways to deal with the latter.

  19. Precision of a CAD/CAM technique for the production of zirconium dioxide copings.

    PubMed

    Coli, Pierluigi; Karlsson, Stig

    2004-01-01

    The precision of a computer-aided design/manufacturing (CAD/CAM) system to manufacture zirconium dioxide copings with a predetermined internal space was investigated. Two master models were produced in acrylic resin. One was directly scanned by the Decim Reader. The Decim Producer then manufactured 10 copings from prefabricated zirconium dioxide blocks. Five copings were prepared, aiming for an internal space to the master of 45 microm. The other five copings were prepared for an internal space of 90 microm. The second test model was used to try in the copings produced. The obtained internal space of the ceramic copings was evaluated by separate measurements of the master models and inner surfaces of the copings. The master models were measured at predetermined points with an optical instrument. The zirconium dioxide copings were measured with a contact instrument at the corresponding sites measured in the masters. The first group of copings had a mean internal space to the scanned master of 41 microm and of 53 microm to the try-in master. In general, the internal space along the axial walls of the masters was smaller than that along the occlusal walls. The second group had a mean internal space of 82 microm to the scanned master and of 90 microm to the try-in master. The aimed-for internal space of the copings was achieved by the manufacturer. The CAD/CAM technique tested provided high precision in the manufacture of zirconium dioxide copings.

  20. High pressure low temperature hot pressing method for producing a zirconium carbide ceramic

    DOEpatents

    Cockeram, Brian V.

    2017-01-10

    A method for producing monolithic Zirconium Carbide (ZrC) is described. The method includes raising a pressure applied to a ZrC powder until a final pressure of greater than 40 MPa is reached; and raising a temperature of the ZrC powder until a final temperature of less than 2200.degree. C. is reached.

  1. Clinical Outcomes of Zirconium-Oxide Posts: Up-to-Date Systematic Review.

    PubMed

    Al-Thobity, Ahmad M

    2016-06-01

    The aim of this systematic review was to investigate the clinical outcomes of the use of zirconium-oxide posts in the past 20 years. The addressed question was: Do zirconium-oxide posts maintain the long-term survival rate of endodontically treated teeth? A database search was made of articles from January 1995 to December 2014; it included combinations of the following keywords: "zirconia," "zirconium oxide," "dowel/dowels," "post/posts," and "post and core." Exclusion criteria included review articles, experimental studies, case reports, commentaries, and articles published in a language other than English. Articles were reviewed by the titles, followed by the abstracts, and, finally, the full text of the selected studies. Four studies were included after filtering the selected studies according to the inclusion and exclusion criteria. In one study, the prefabricated zirconia posts with indirect glass-ceramic cores had significantly higher failure rates than other posts with direct composite cores. In two studies, no failure of the cemented posts was observed throughout the follow-up period. Due to the limited number of clinical studies, it can be concluded that the long-term success rate of prefabricated zirconium-oxide posts is unclear.

  2. Evaluation of artifacts generated by zirconium implants in cone-beam computed tomography images.

    PubMed

    Vasconcelos, Taruska Ventorini; Bechara, Boulos B; McMahan, Clyde Alex; Freitas, Deborah Queiroz; Noujeim, Marcel

    2017-02-01

    To evaluate zirconium implant artifact production in cone beam computed tomography images obtained with different protocols. One zirconium implant was inserted in an edentulous mandible. Twenty scans were acquired with a ProMax 3D unit (Planmeca Oy, Helsinki, Finland), with acquisition settings ranging from 70 to 90 peak kilovoltage (kVp) and voxel sizes of 0.32 and 0.16 mm. A metal artifact reduction (MAR) tool was activated in half of the scans. An axial slice through the middle region of the implant was selected for each dataset. Gray values (mean ± standard deviation) were measured in two regions of interest, one close to and the other distant from the implant (control area). The contrast-to-noise ratio was also calculated. Standard deviation decreased with greater kVp and when the MAR tool was used. The contrast-to-noise ratio was significantly higher when the MAR tool was turned off, except for low resolution with kVp values above 80. Selection of the MAR tool and greater kVp resulted in an overall reduction of artifacts in images acquired with low resolution. Although zirconium implants do produce image artifacts in cone-bean computed tomography scans, the setting that best controlled artifact generation by zirconium implants was 90 kVp at low resolution and with the MAR tool turned on. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Five year survival analysis of an oxidised zirconium total knee arthroplasty.

    PubMed

    Holland, Philip; Santini, Alasdair J A; Davidson, John S; Pope, Jill A

    2013-12-01

    Zirconium total knee arthroplasties theoretically have a low incidence of failure as they are low friction, hard wearing and hypoallergenic. We report the five year survival of 213 Profix zirconium total knee arthroplasties with a conforming all polyethylene tibial component. Data was collected prospectively and multiple strict end points were used. SF12 and WOMAC scores were recorded pre-operatively, at three months, at twelve months, at 3 years and at 5 years. Eight patients died and six were "lost to follow-up". The remaining 199 knees were followed up for five years. The mean WOMAC score improved from 56 to 35 and the mean SF12 physical component score improved from 28 to 34. The five year survival for failure due to implant related reasons was 99.5% (95% CI 97.4-100). This was due to one tibial component becoming loose aseptically in year zero. Our results demonstrate that the Profix zirconium total knee arthroplasty has a low medium term failure rate comparable to the best implants. Further research is needed to establish if the beneficial properties of zirconium improve long term implant survival. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. The 5-year Results of an Oxidized Zirconium Femoral Component for TKA

    PubMed Central

    Innocenti, Massimo; Carulli, Christian; Matassi, Fabrizio; Villano, Marco

    2009-01-01

    Osteolysis secondary to polyethylene wear is one of the major factors limiting long-term performance of TKA. Oxidized zirconium is a new material that combines the strength of a metal with the wear properties of a ceramic. It remains unknown whether implants with a zirconium femoral component can be used safely in TKA. To answer that question, we reviewed, at a minimum of 5 years, the clinical outcome and survivorship of a ceramic-surfaced oxidized zirconium femoral component implanted during 98 primary TKAs between April 2001 and December 2003. Survivorship was 98.7% at 7 years postoperatively. No revision was necessary and only one component failed because of aseptic loosening. Mean Knee Society score improved from 36 to 89. No adverse events were observed clinically or radiologically. These results justify pursuing the use of oxidized zirconium as an alternative bearing surface for a femoral component in TKA. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. PMID:19798541

  5. 21 CFR 700.16 - Use of aerosol cosmetic products containing zirconium.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... indicates that certain zirconium compounds have caused human skin granulomas and toxic effects in the lungs... deep portions of the lungs of users. The lung is an organ, like skin, subject to the development of granulomas. Unlike the skin, the lung will not reveal the presence of granulomatous changes until they have...

  6. Reduced-Gravity Measurements of the Effect of Oxygen on Properties of Zirconium

    NASA Technical Reports Server (NTRS)

    Zhao, J.; Lee, J.; Wunderlich, R.; Fecht, H.-J.; Schneider, S.; SanSoucie, M.; Rogers, J.; Hyers, R.

    2016-01-01

    The influence of oxygen on the thermophysical properties of zirconium is being investigated using MSL-EML (Material Science Laboratory - Electromagnetic Levitator) on ISS (International Space Station) in collaboration with NASA, ESA (European Space Agency), and DLR (German Aerospace Center). Zirconium samples with different oxygen concentrations will be put into multiple melt cycles, during which the density, viscosity, surface tension, heat capacity, and electric conductivity will be measured at various undercooled temperatures. The facility check-up of MSL-EML and the first set of melting experiments have been successfully performed in 2015. The first zirconium sample will be tested near the end of 2015. As part of ground support activities, the thermophysical properties of zirconium and ZrO were measured using a ground-based electrostatic levitator located at the NASA Marshall Space Flight Center. The influence of oxygen on the measured surface tension was evaluated. The results of this research will serve as reference data for those measured in ISS.

  7. A Selective Organic-Based Corrosion Inhibitors Containing Iodide Ion as Enhancer for Protection of Carbon Steel: A Review

    NASA Astrophysics Data System (ADS)

    Ibrahim, I. M.; Kassim, E. S. Mohd; Husin, H.; Jai, J.; Daud, M.; Hashim, M. A.

    2018-05-01

    This paper contains a review on the effect of halide ion with a selected inhibitor which is imidazole derivatives on the efficiency of corrosion inhibition. The paper first describes the mechanism of synergistic inhibition effect among halide ions enhancer with inhibitor on the steel surface. Then the paper describes the measured inhibition efficiency and summarizes the synergistic inhibition condition of imidazoline derivatives inhibitor with iodide ions. The characteristic of synergistic inhibition effect and the relationship between the amount of iodide ion consumption and the amount of organic inhibitor consumption are also discussed. It has been shown that, the synergistic effect between imidazole derivative and iodide ion is an effective method to improve the inhibitive performance in different aqueous media.

  8. Potentiation of antimicrobial photodynamic inactivation mediated by a cationic fullerene by added iodide: in vitro and in vivo studies

    PubMed Central

    Zhang, Yunsong; Dai, Tianhong; Wang, Min; Vecchio, Daniela; Chiang, Long Y; Hamblin, Michael R

    2016-01-01

    Background Antimicrobial photodynamic inactivation with fullerenes bearing cationic charges may overcome resistant microbes. Methods & results We synthesized C60-fullerene (LC16) bearing decaquaternary chain and deca-tertiary-amino groups that facilitates electron-transfer reactions via the photoexcited fullerene. Addition of the harmless salt, potassium iodide (10 mM) potentiated the ultraviolet A (UVA) or white light-mediated killing of Gram-negative bacteria Acinetobacter baumannii, Gram-positive methicillin-resistant Staphylococcus aureus and fungal yeast Candida albicans by 1–2+ logs. Mouse model infected with bioluminescent Acinetobacter baumannii gave increased loss of bioluminescence when iodide (10 mM) was combined with LC16 and UVA/white light. Conclusion The mechanism may involve photoinduced electron reduction of 1(C60>)* or 3(C60>)* by iodide producing I· or I2 followed by subsequent intermolecular electron-transfer events of (C60>)−· to produce reactive radicals. PMID:25723093

  9. Colorimetric Solid Phase Extraction for the Measurement of Total I (Iodine, Iodide, and Triiodide) in Spacecraft Drinking Water

    NASA Technical Reports Server (NTRS)

    Lipert, Robert J.; Porter, Marc D.; Siperko, Lorraine M.; Gazda, Daniel B.; Rutz, Jeff A.; Schultz, John R.; Carrizales, Stephanie M.; McCoy, J. Torin

    2009-01-01

    An experimental drinking water monitoring kit for the measurement of iodine and silver(I) was recently delivered to the International Space Station (ISS). The kit is based on Colorimetric Solid Phase Extraction (CSPE) technology, which measures the change in diffuse reflectance of indicator disks following exposure to a water sample. To satisfy additional spacecraft water monitoring requirements, CSPE has now been extended to encompass the measurement of total I (iodine, iodide, and triiodide) through the introduction of an oxidizing agent, which converts iodide and triiodide to iodine, for measurement using the same indicator disks currently being tested on ISS. These disks detect iodine, but are insensitive to iodide and triiodide. We report here the operational considerations, design, and ground-based performance of the CSPE method for total I. The results demonstrate that CSPE technology is poised to meet NASA's total I monitoring requirements.

  10. The effect of zirconium-based surface treatment on the cathodic disbonding resistance of epoxy coated mild steel

    NASA Astrophysics Data System (ADS)

    Ghanbari, A.; Attar, M. M.

    2014-10-01

    The effect of zirconium-based surface treatment on the cathodic disbonding resistance and adhesion performance of an epoxy coated mild steel substrate was investigated. The obtained data from pull-off, cathodic disbonding test and electrochemical impedance spectroscopy (EIS) indicated that the zirconium conversion layer significantly improved the adhesion strength and cathodic disbonding resistance of the epoxy coating. This may be attributed to formation of some polar zirconium compounds on the surface and increment of surface roughness, that were evident in the results of field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM), respectively.

  11. Real-Time Observation of Iodide Ion Migration in Methylammonium Lead Halide Perovskites.

    PubMed

    Li, Cheng; Guerrero, Antonio; Zhong, Yu; Gräser, Anna; Luna, Carlos Andres Melo; Köhler, Jürgen; Bisquert, Juan; Hildner, Richard; Huettner, Sven

    2017-11-01

    Organic-inorganic metal halide perovskites (e.g., CH 3 NH 3 PbI 3- x Cl x ) emerge as a promising optoelectronic material. However, the Shockley-Queisser limit for the power conversion efficiency (PCE) of perovskite-based photovoltaic devices is still not reached. Nonradiative recombination pathways may play a significant role and appear as photoluminescence (PL) inactive (or dark) areas on perovskite films. Although these observations are related to the presence of ions/defects, the underlying fundamental physics and detailed microscopic processes, concerning trap/defect status, ion migration, etc., still remain poorly understood. Here correlated wide-field PL microscopy and impedance spectroscopy are utilized on perovskite films to in situ investigate both the spatial and the temporal evolution of these PL inactive areas under external electric fields. The formation of PL inactive domains is attributed to the migration and accumulation of iodide ions under external fields. Hence, we are able to characterize the kinetic processes and determine the drift velocities of these ions. In addition, it is shown that I 2 vapor directly affects the PL quenching of a perovskite film, which provides evidence that the migration/segregation of iodide ions plays an important role in the PL quenching and consequently limits the PCE of organometal halide-based perovskite photovoltaic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Purification and Crystal Growth of Lead Iodide by Physical Vapor Transport Method

    NASA Technical Reports Server (NTRS)

    Wright, G. W.; Cole, M.; Chen, Y.-F.; Chen, K.-T.; Chen, H.; Chattopadhyay, K.; Burger, A.

    1998-01-01

    Lead iodide (PbI2) is a layered compound semiconductor being developed as room temperature x- and gamma-ray detector. Compared to the more studied material, mercuric iodide, PbI2 has a higher melting temperature and no phase transition until liquid phase which are indications of better mechanical properties. In this study, the source material was purified by the zone-refining process, and the purest section was extracted from center of the the zone-refined ingot to be grown by physical vapor transport (PVT) method. The zone-refined material and as-grown crystals were characterized by optical microscopy and differential scanning calorimetry (DSC) to reveal the surface morphology, purity and stoichiometry. The results shows that both materials are near-stoichiometric composition, with the purity of the as-grown crystals higher than zone-refined materials. The resistivity of the as-grown crystal (10" Omega-cm) was derived from current-voltage (I-V) measurement, and is 10 times higher than the zone-refined materials. Detail results will be presented and discussed.

  13. Iodine in raw and pasteurized milk of dairy cows fed different amounts of potassium iodide.

    PubMed

    Norouzian, M A

    2011-02-01

    Relation between iodine (I) intake by lactating Holstein cows and iodine concentrations in raw and pasteurized milk were investigated. Four treatment groups with eight cows assigned to each treatment were fed a basal diet containing 0.534 mg I/kg alone or supplemented with potassium iodide at 2.5, 5 or 7.5 mg/kg in 7-week period. Iodine concentrations in raw milk increased with each increase in dietary I from 162.2 ng/ml for basal diet to 534.5, 559.8 and 607.5 ng/ml when 2.5, 5 and 7.5 mg/kg was fed as potassium iodide (P < 0.05). This trend was found for blood plasma and urine iodine concentration. Iodine supplementation had no significant effect on thyroidal hormones. high-temperature short-time (HTST) pasteurization process reduced I concentration. The mean iodine content found in the milk prior to heating processing was 466.0 ± 205.0 ng/ml, whereas for the processed milk this level was 349.5 ± 172.8 ng/ml. It was concluded that iodine supplementation above of NRC recommendation (0.5 mg/kg diet DM) resulted in significant increases in iodine concentrations in milk, although the effect of heating in HTST pasteurization process on iodine concentration was not negligible.

  14. Selective capture of iodide from solutions by microrosette-like δ-Bi₂O₃.

    PubMed

    Liu, Long; Liu, Wei; Zhao, Xiaoliang; Chen, Daimei; Cai, Rongsheng; Yang, Weiyou; Komarneni, Sridhar; Yang, Dongjiang

    2014-09-24

    Radioactive iodine isotopes that are produced in nuclear power plants and used in medical research institutes could be a serious threat to the health of many people if accidentally released to the environment because the thyroid gland can absorb and concentrate them from a liquid. For this reason, uptake of iodide anions was investigated on microrosette-like δ-Bi2O3 (MR-δ-Bi2O3). The MR-δ-Bi2O3 adsorbent showed a very high uptake capacity of 1.44 mmol g(-1) by forming insoluble Bi4I2O5 phase. The MR-δ-Bi2O3 also displayed fast uptake kinetics and could be easily separated from a liquid after use because of its novel morphology. In addition, the adsorbent showed excellent selectivity for I(-) anions in the presence of large concentrations of competitive anions such as Cl(-) and CO3(2-), and could work in a wide pH range of 4-11. This study led to a new and highly efficient Bi-based adsorbent for iodide capture from solutions.

  15. Photoinduced electron transfer and solvation in iodide-doped acetonitrile clusters.

    PubMed

    Ehrler, Oli T; Griffin, Graham B; Young, Ryan M; Neumark, Daniel M

    2009-04-02

    We have used ultrafast time-resolved photoelectron imaging to measure charge transfer dynamics in iodide-doped acetonitrile clusters I(-)(CH(3)CN)(n) with n = 5-10. Strong modulations of vertical detachment energies were observed following charge transfer from the halide, allowing interpretation of the ongoing dynamics. We observe a sharp drop in the vertical detachment energy (VDE) within 300-400 fs, followed by a biexponential increase that is complete by approximately 10 ps. Comparison to theory suggests that the iodide is internally solvated and that photodetachment results in formation of a diffuse electron cloud in a confined cavity. We interpret the initial drop in VDE as a combination of expansion of the cavity and localization of the excess electron on one or two solvent molecules. The subsequent increase in VDE is attributed to a combination of the I atom leaving the cavity and rearrangement of the acetonitrile molecules to solvate the electron. The n = 5-8 clusters then show a drop in VDE of around 50 meV on a much longer time scale. The long-time VDEs are consistent with those of (CH(3)CN)(n)(-) clusters with internally solvated electrons. Although the excited-state created by the pump pulse decays by emission of a slow electron, no such decay is seen by 200 ps.

  16. AAO-CNTs electrode on microfluidic flow injection system for rapid iodide sensing.

    PubMed

    Phokharatkul, Ditsayut; Karuwan, Chanpen; Lomas, Tanom; Nacapricha, Duangjai; Wisitsoraat, Anurat; Tuantranont, Adisorn

    2011-06-15

    In this work, carbon nanotubes (CNTs) nanoarrays in anodized aluminum oxide (AAO-CNTs) nanopore is integrated on a microfluidic flow injection system for in-channel electrochemical detection of iodide. The device was fabricated from PDMS (polydimethylsiloxane) microchannel bonded on glass substrates that contains three-electrode electrochemical system, including AAO-CNTs as a working electrode, silver as a reference electrode and platinum as an auxiliary electrode. Aluminum, stainless steel catalyst, silver and platinum layers were sputtered on the glass substrate through shadow masks. Aluminum layer was then anodized by two-step anodization process to form nanopore template. CNTs were then grown in AAO template by thermal chemical vapor deposition. The amperometric detection of iodide was performed in 500-μm-wide and 100-μm-deep microchannels on the microfluidic chip. The influences of flow rate, injection volume and detection potential on the current response were optimized. From experimental results, AAO-CNTs electrode on chip offers higher sensitivity and wider dynamic range than CNTs electrode with no AAO template. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Increased expression of the sodium/iodide symporter in papillary thyroid carcinomas.

    PubMed Central

    Saito, T; Endo, T; Kawaguchi, A; Ikeda, M; Katoh, R; Kawaoi, A; Muramatsu, A; Onaya, T

    1998-01-01

    Iodide is concentrated to a much lesser extent by papillary thyroid carcinoma as compared with the normal gland. The Na+/I- symporter (NIS) is primarily responsible for the uptake of iodide into thyroid cells. Our objective was to compare NIS mRNA and protein expression in papillary carcinomas with those in specimens with normal thyroid. Northern blot analysis revealed a 2.8-fold increase in the level of NIS mRNA in specimens with papillary carcinoma versus specimens with normal thyroid. Immunoblot analysis using anti-human NIS antibody that was produced with a glutathione S-transferase fusion protein containing NIS protein (amino acids 466-522) showed the NIS protein at 77 kD. The NIS protein level was elevated in 7 of 17 cases of papillary carcinoma but was not elevated in the normal thyroid. Immunohistochemical staining revealed abundant NIS in 8 of 12 carcinomas, whereas NIS protein was barely detected in specimens with normal thyroid. Although considerable patient-to-patient variation was observed, our results indicate that NIS mRNA is elevated, and its protein tends to be more abundant, in a subset of papillary thyroid carcinomas than in normal thyroid tissue. PMID:9525971

  18. Enhancement of respiratory mucosal antiviral defenses by the oxidation of iodide.

    PubMed

    Fischer, Anthony J; Lennemann, Nicholas J; Krishnamurthy, Sateesh; Pócza, Péter; Durairaj, Lakshmi; Launspach, Janice L; Rhein, Bethany A; Wohlford-Lenane, Christine; Lorentzen, Daniel; Bánfi, Botond; McCray, Paul B

    2011-10-01

    Recent reports postulate that the dual oxidase (DUOX) proteins function as part of a multicomponent oxidative pathway used by the respiratory mucosa to kill bacteria. The other components include epithelial ion transporters, which mediate the secretion of the oxidizable anion thiocyanate (SCN(-)) into airway surface liquid, and lactoperoxidase (LPO), which catalyzes the H(2)O(2)-dependent oxidation of the pseudohalide SCN(-) to yield the antimicrobial molecule hypothiocyanite (OSCN(-)). We hypothesized that this oxidative host defense system is also active against respiratory viruses. We evaluated the activity of oxidized LPO substrates against encapsidated and enveloped viruses. When tested for antiviral properties, the LPO-dependent production of OSCN(-) did not inactivate adenovirus or respiratory syncytial virus (RSV). However, substituting SCN(-) with the alternative LPO substrate iodide (I(-)) resulted in a marked reduction of both adenovirus transduction and RSV titer. Importantly, well-differentiated primary airway epithelia generated sufficient H(2)O(2) to inactivate adenovirus or RSV when LPO and I(-) were supplied. The administration of a single dose of 130 mg of oral potassium iodide to human subjects increased serum I(-) concentrations, and resulted in the accumulation of I(-) in upper airway secretions. These results suggest that the LPO/I(-)/H(2)O(2) system can contribute to airway antiviral defenses. Furthermore, the delivery of I(-) to the airway mucosa may augment innate antiviral immunity.

  19. Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

    PubMed

    Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

    2016-01-14

    Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

  20. Potentized Mercuric chloride and Mercuric iodide enhance alpha-amylase activity in vitro.

    PubMed

    Sukul, N C; De, A; Sukul, A; Sinhababu, S P

    2002-10-01

    Mercuric chloride 30c and Mercuric iodide 30c were prepared by successive dilution in 30 steps of 1:100 followed by sonication at 20KHz for 30s at each step. Both were prepared in two media: 90% ethanol and distilled water. Three preparations of Mercuric chloride 30 in water were used: 12-month old, 1-month old and 4-day old. The controls for the water and ethanol-water preparations were pure water 30c and 90% ethanol 30c, respectively. For the three water preparations there were three matched controls of water 30c of the same ages. Each potentized substance or its control was mixed with distilled water 1:100 before testing. Hydrolysis of starch by alpha-amylase was measured by the standard procedure after incubation for 15 min at 27 degrees C. Mercuric chloride 30c and Mercuric iodide 30c in both water and aqueous ethanol media, enhanced enzyme activity significantly, compared to their respective controls. Mercuric chloride 30c, prepared in water 12 months previously, produced no significant change in the enzyme activity compared to its control. We hypothesize that the structure of the active molecule imprinted on water polymers during the process of dynamization. The specifically structured water interacts with the active sites of alpha-amylase, modifying its activity. Ethanol molecules have large non-polar part stabilizing the water structure and thus retaining activity for a longer time.

  1. Potassium iodide potentiates antimicrobial photodynamic inactivation mediated by Rose Bengal: in vitro and in vivo studies

    NASA Astrophysics Data System (ADS)

    Wen, Xiang; Zhang, Xiaoshen; Szewczyk, Grzegorz; ElHussien, Ahmed; Huang, Ying-Ying; Sarna, Tadeusz; Hamblin, Michael R.

    2018-02-01

    Rose Bengal (RB) is a halogenated xanthene dye that has been used to mediate antimicrobial photodynamic inactivation. While highly active against Gram-positive bacteria, RB is largely inactive in killing Gram-negative bacteria. We have discovered that addition of the non-toxic salt potassium iodide (100mM) potentiates green light (540nm)-mediated killing by up to six extra logs with Gramnegative bacteria Escherichia coli and Pseudomonas aeruginosa,Gram-positive methicillin resistant Staphylococcus aureus, and fungal yeast Candida albicans. The mechanism is proposed to be singlet oxygen addition to iodide anion to form peroxyiodide, which decomposes into radicals, finally forms hydrogen peroxide and molecular iodine. The effects of these different bactericidal species can be teased apart by comparing killing in three different scenarios: (1) cells+RB+KI are mixed together then illuminated with green light; (2) cells+RB are centrifuged then KI added then green light; (3) RB+KI+green light then cells added after light. We showed that KI could potentiate RBPDT in a mouse model of skin abrasions infected with bioluminescent P.aeruginosa.

  2. Investigation of the excited state iodine lifetime in the photodissociation of perfluoroalkyl iodides

    NASA Technical Reports Server (NTRS)

    Cobb, Stephen H.

    1991-01-01

    An evaluation of prospective laser materials for a space-based solar pumped laser system over the past decade has resulted in the identification of the iodine photodissociation laser as that system best suited to solar-pumped high energy operation. The active medium for the solar-pumped iodine photodissociation laser is from the family of perfluoroalkyl iodides. These lasants have the general form C(n)F(2n + 1)I, often abbreviated as RI. These iodides are known to exhibit photodissociaiton of the C-I bond when irradiated by near UV photons. The focus was on the experimental determination of the lifetime of the excited iodine atom following photodissociation of C4F9I, and also to monitor fluorescence from the iodine molecule at 500 nm to determine if I2 is being produced in the process. Photodissociation is achieved using an XeCl excimer laser with an output wavelength of 308 nm. The XeCl beam is focused into the middle of a cylindrical quartz cell containing the lasant. The laser pulse is detected with a fast risetime photomultiplier tube as it exits the cell. Other aspects of the investigation are discussed.

  3. A New Lead Iodide Perovskite based on Large Organic Cation for Solar Cell Application.

    PubMed

    Ma, Chunqing; Shen, Dong; Lo, Ming Fai; Lee, Chun-Sing

    2018-06-06

    Methylammonium (CH3NH3+) and formamidinium ((NH2)2CH+) based lead iodide perovskites are currently the two commonly used organic-inorganic lead iodide perovskites for solar cell application. Till now, there is still no alternative organic cations, which can produce perovskites with bandgaps spanning the visible spectrum (i.e. < 1.7 eV) for solar cell application. Here, a new perovskite using large propane-1,3-diammonium cation (n-Pr(NH3)22+) with a chemical structure of (n-Pr(NH3)2)0.5PbI3 is demonstrated. X-ray diffraction (XRD) result shows that the new perovskite exhibits a three-dimensional (3D), tetragonal phase. The bandgap of the new perovskite is ~ 1.6 eV, which is desirable for photovoltaic application. A (n-Pr(NH3)2)0.5PbI3 perovskite solar cell (PSC) yields a power conversion efficiency (PCE) of 5.1%. More importantly, this new perovskite is composed of larger hydrophobic cation that provides a better moisture resistance compared to CH3NH3PbI3 perovskite. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Potassium iodide as a thyroid blocker--Three Mile Island to today.

    PubMed

    Halperin, J A

    1989-05-01

    The Three Mile Island (TMI) nuclear emergency in the U.S. in March 1979 marked the first occasion when use of potassium iodide (KI) was considered for thyroid blocking of the population in the vicinity of a potentially serious release of fission products from a nuclear power reactor. In face of a demand that could not be satisfied by commercial supplies of low-dose KI drug products from the U.S. pharmaceutical industry, the Food and Drug Administration directed the manufacture and stockpiling of sufficient quantities of saturated solution of potassium iodide (SSKI) to provide protection for one million people in the event of a large-scale release of radioiodines. Although the drug was not used, the experience of producing, stockpiling, and making ready for use a large quantity of the drug resulted in significant public policy, regulatory, and logistical issues. A number of these issues have been resolved through scientific debate and consensus, development of official guidance regarding the proper role of KI in nuclear emergencies, and the approval of New Drug Applications for KI products specifically intended for thyroid blocking in nuclear emergencies. Other issues regarding broad-scale implementation of the guidelines remain today. This paper traces the history of the development and implementation of the use of KI from pre-TMI to the present.

  5. Characterization of thermally evaporated lead iodide films aimed for the detection of X-rays

    NASA Astrophysics Data System (ADS)

    Caldeira Filho, A. M.; Mulato, M.

    2011-04-01

    Some semiconductor materials such as lead iodide (PbI2) have applications in the detection of ionizing radiation at room temperature using the direct detection method. In this work we investigate lead iodide films deposited by thermal evaporation. The morphology, structure, and electric properties were investigated as a function of deposition height, i.e. the distance between evaporation-boat and substrates. The results show a morphology of vertical leaves and X-ray diffraction shows just one preferential orientation along the direction 110. Energy dispersive spectroscopy reveals that the films are not stoichiometric, with excess iodine atoms. Electrical resistivity of about 108 Ω cm was measured. This is smaller than for the bulk due to structural defects. The values of activation energy for electric transport increase from 0.52 up to 1.1 eV with decreasing deposition height, what indicates that the best film is the one deposited at the shortest distance. Exposure under X-ray mammographic energy shows a linear behavior up to 500 mR. No variation in sensibility was observed between 22 and 30 kVp.

  6. Photocatalytic hydrogen generation from hydriodic acid using methylammonium lead iodide in dynamic equilibrium with aqueous solution

    NASA Astrophysics Data System (ADS)

    Park, Sunghak; Chang, Woo Je; Lee, Chan Woo; Park, Sangbaek; Ahn, Hyo-Yong; Nam, Ki Tae

    2017-01-01

    The solar-driven splitting of hydrohalic acids (HX) is an important and fast growing research direction for H2 production. In addition to the hydrogen, the resulting chemicals (X2/X3-) can be used to propagate a continuous process in a closed cycle and are themselves useful products. Here we present a strategy for photocatalytic hydrogen iodide (HI) splitting using methylammonium lead iodide (MAPbI3) in an effort to develop a cost-effective and easily scalable process. Considering that MAPbI3 is a water-soluble ionic compound, we exploit the dynamic equilibrium of the dissolution and precipitation of MAPbI3 in saturated aqueous solutions. The I- and H+ concentrations of the aqueous solution are determined to be the critical parameters for the stabilization of the tetragonal MAPbI3 phase. Stable and efficient H2 production under visible light irradiation was demonstrated. The solar HI splitting efficiency of MAPbI3 was 0.81% when using Pt as a cocatalyst.

  7. Analysis of heterogeneous water vapor uptake by metal iodide cluster ions via differential mobility analysis-mass spectrometry

    SciTech Connect

    Oberreit, Derek; Fluid Measurement Technologies, Inc., Saint Paul, Minnesota 55110; Rawat, Vivek K.

    The sorption of vapor molecules onto pre-existing nanometer sized clusters is of importance in understanding particle formation and growth in gas phase environments and devising gas phase separation schemes. Here, we apply a differential mobility analyzer-mass spectrometer based approach to observe directly the sorption of vapor molecules onto iodide cluster ions of the form (MI){sub x}M{sup +} (x = 1-13, M = Na, K, Rb, or Cs) in air at 300 K and with water saturation ratios in the 0.01-0.64 range. The extent of vapor sorption is quantified in measurements by the shift in collision cross section (CCS) for eachmore » ion. We find that CCS measurements are sensitive enough to detect the transient binding of several vapor molecules to clusters, which shift CCSs by only several percent. At the same time, for the highest saturation ratios examined, we observed CCS shifts of up to 45%. For x < 4, cesium, rubidium, and potassium iodide cluster ions are found to uptake water to a similar extent, while sodium iodide clusters uptake less water. For x ≥ 4, sodium iodide cluster ions uptake proportionally more water vapor than rubidium and potassium iodide cluster ions, while cesium iodide ions exhibit less uptake. Measured CCS shifts are compared to predictions based upon a Kelvin-Thomson-Raoult (KTR) model as well as a Langmuir adsorption model. We find that the Langmuir adsorption model can be fit well to measurements. Meanwhile, KTR predictions deviate from measurements, which suggests that the earliest stages of vapor uptake by nanometer scale species are not well described by the KTR model.« less

  8. Copper-catalyzed direct synthesis of diaryl 1,2-diketones from aryl iodides and propiolic acids.

    PubMed

    Min, Hongkeun; Palani, Thiruvengadam; Park, Kyungho; Hwang, Jinil; Lee, Sunwoo

    2014-07-03

    Benzil derivatives such as diaryl 1,2-diketones are synthesized via the direct decarboxylative coupling reaction of aryl propiolic acids and their oxidation. The optimized conditions are that the reaction of aryl propiolic acids and aryl iodides is conducted at 140 °C for 6 h in the presence of 10 mol % CuI/Cu(OTf)2 and Cs2CO3, after which HI (aq) is added and further reacted. The method shows good functional group tolerance toward ester, aldehyde, cyano, and nitro groups. In addition, symmetrical diaryl 1,2-diketones are obtained from aryl iodides and propiolic acid in the presence of palladium and copper catalysts.

  9. Excess Iodide Induces an Acute Inhibition of the Sodium/Iodide Symporter in Thyroid Male Rat Cells by Increasing Reactive Oxygen Species

    PubMed Central

    Arriagada, Alejandro A.; Albornoz, Eduardo; Opazo, Ma. Cecilia; Becerra, Alvaro; Vidal, Gonzalo; Fardella, Carlos; Michea, Luis; Carrasco, Nancy; Simon, Felipe; Elorza, Alvaro A.; Bueno, Susan M.; Kalergis, Alexis M.

    2015-01-01

    Na+/I− symporter (NIS) mediates iodide (I−) uptake in the thyroid gland, the first and rate-limiting step in the biosynthesis of the thyroid hormones. The expression and function of NIS in thyroid cells is mainly regulated by TSH and by the intracellular concentration of I−. High doses of I− for 1 or 2 days inhibit the synthesis of thyroid hormones, a process known as the Wolff-Chaikoff effect. The cellular mechanisms responsible for this physiological response are mediated in part by the inhibition of I− uptake through a reduction of NIS expression. Here we show that inhibition of I− uptake occurs as early as 2 hours or 5 hours after exposure to excess I− in FRTL-5 cells and the rat thyroid gland, respectively. Inhibition of I− uptake was not due to reduced NIS expression or altered localization in thyroid cells. We observed that incubation of FRTL-5 cells with excess I− for 2 hours increased H2O2 generation. Furthermore, the inhibitory effect of excess I− on NIS-mediated I− transport could be recapitulated by H2O2 and reverted by reactive derived oxygen species scavengers. The data shown here support the notion that excess I− inhibits NIS at the cell surface at early times by means of a posttranslational mechanism that involves reactive derived oxygen species. PMID:25594695

  10. Constraining the sensitivity of iodide adduct chemical ionization mass spectrometry to multifunctional organic molecules using the collision limit and thermodynamic stability of iodide ion adducts

    DOE PAGES

    Lopez-Hilfiker, Felipe D.; Iyer, Siddarth; Mohr, Claudia; ...

    2016-04-06

    The sensitivity of a chemical ionization mass spectrometer (ions formed per number density of analytes) is fundamentally limited by the collision frequency between reagent ions and analytes, known as the collision limit, the ion–molecule reaction time, and the transmission efficiency of product ions to the detector. We use the response of a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) to N 2O 5, known to react with iodide at the collision limit, to constrain the combined effects of ion–molecule reaction time, which is strongly influenced by mixing and ion losses in the ion–molecule reaction drift tube. A mass spectrometric voltage scanningmore » procedure elucidates the relative binding energies of the ion adducts, which influence the transmission efficiency of molecular ions through the electric fields within the vacuum chamber. Together, this information provides a critical constraint on the sensitivity of a ToF-CIMS towards a wide suite of routinely detected multifunctional organic molecules for which no calibration standards exist. Lastly, we describe the scanning procedure and collision limit determination, and we show results from the application of these constraints to the measurement of organic aerosol composition at two different field locations.« less

  11. Water/ice phase transition: The role of zirconium acetate, a compound with ice-shaping properties

    NASA Astrophysics Data System (ADS)

    Marcellini, Moreno; Fernandes, Francisco M.; Dedovets, Dmytro; Deville, Sylvain

    2017-04-01

    Few compounds feature ice-shaping properties. Zirconium acetate is one of the very few inorganic compounds reported so far to have ice-shaping properties similar to that of ice-shaping proteins, encountered in many organisms living at low temperature. When a zirconium acetate solution is frozen, oriented and perfectly hexagonal ice crystals can be formed and their growth follows the temperature gradient. To shed light on the water/ice phase transition while freezing zirconium acetate solution, we carried out differential scanning calorimetry measurements. From our results, we estimate how many water molecules do not freeze because of their interaction with Zr cations. We estimate the colligative properties of the Zr acetate on the apparent critical temperature. We further show that the phase transition is unaffected by the nature of the base which is used to adjust the pH. Our results provide thus new hints on the ice-shaping mechanism of zirconium acetate.

  12. In Situ Enrichment of Phosphopeptides on MALDI Plates Functionalized by Reactive Landing of Zirconium(IV)–n-Propoxide Ions

    PubMed Central

    Blacken, Grady R.; Volný, Michael; Vaisar, Tomáš; Sadílek, Martin; Tureček, František

    2008-01-01

    We report substantial in situ enrichment of phosphopeptides in peptide mixtures using zirconium oxide coated plates for detection by MALDI-TOF mass spectrometry. The novel feature of this approach rests on the specific preparation of zirconium oxide coatings using reactive landing on stainless steel support of gas-phase positive ions produced by electrospray of zirconium(IV)–n-propoxide solutions in 1-propanol. Reactive landing was found to produce durable functionalized surfaces for selective phosphopeptide capture and desorption–ionization by MALDI. Enrichment factors on the order of 20–90 were achieved for several monophosphorylated peptides relative to abundant nonphosphorylated peptides in tryptic digests. We demonstrate the ability of the zirconium oxide functionalized MALDI surfaces to facilitate detection of enriched phosphopeptides in mid-femtomole amounts of α-casein digests per MALDI spot. PMID:17569507

  13. Water/ice phase transition: The role of zirconium acetate, a compound with ice-shaping properties.

    PubMed

    Marcellini, Moreno; Fernandes, Francisco M; Dedovets, Dmytro; Deville, Sylvain

    2017-04-14

    Few compounds feature ice-shaping properties. Zirconium acetate is one of the very few inorganic compounds reported so far to have ice-shaping properties similar to that of ice-shaping proteins, encountered in many organisms living at low temperature. When a zirconium acetate solution is frozen, oriented and perfectly hexagonal ice crystals can be formed and their growth follows the temperature gradient. To shed light on the water/ice phase transition while freezing zirconium acetate solution, we carried out differential scanning calorimetry measurements. From our results, we estimate how many water molecules do not freeze because of their interaction with Zr cations. We estimate the colligative properties of the Zr acetate on the apparent critical temperature. We further show that the phase transition is unaffected by the nature of the base which is used to adjust the pH. Our results provide thus new hints on the ice-shaping mechanism of zirconium acetate.

  14. Plate-shaped transformation products in zirconium-base alloys

    NASA Astrophysics Data System (ADS)

    Banerjee, S.; Dey, G. K.; Srivastava, D.; Ranganathan, S.

    1997-11-01

    Plate-shaped products resulting from martensitic, diffusional, and mixed mode transformations in zirconium-base alloys are compared in the present study. These alloys are particularly suitable for the comparison in view of the fact that the lattice correspondence between the parent β (bcc) and the product α (hcp) or γ-hydride (fct) phases are remarkably similar for different types of transformations. Crystallographic features such as orientation relations, habit planes, and interface structures associated with these transformations have been compared, with a view toward examining whether the transformation mechanisms have characteristic imprints on these experimental observables. Martensites exhibiting dislocated lath, internally twinned plate, and self-accommodating three-plate cluster morphologies have been encountered in Zr-2.5Nb alloy. Habit planes corresponding to all these morphologies have been found to be consistent with the predictions based on the invariant plane strain (IPS) criterion. Different morphologies have been found to reflect the manner in which the neighboring martensite variants are assembled. Lattice-invariant shears (LISs) for all these cases have been identified to be either {10 bar 11} α < bar 1123> α slip or twinning on {10 bar 11} α planes. Widmanstätten α precipitates, forming in a step-quenching treatment, have been shown to have a lath morphology, the α/β interface being decorated with a periodic array of < c + a> dislocations at a spacing of 8 to 10 nm. The line vectors of these dislocations are nearly parallel to the invariant lines. The α precipitates, forming in the retained β phase on aging, exhibit an internally twinned structure with a zigzag habit plane. Average habit planes for the morphologies have been found to lie near the {103} β — {113} β poles, which are close to the specific variant of the {112} β plane, which transforms into a prismatic plane of the type {1 bar 100} α . The crystallography of the

  15. Human biokinetic data and a new compartmental model of zirconium--a tracer study with enriched stable isotopes.

    PubMed

    Greiter, Matthias B; Giussani, Augusto; Höllriegl, Vera; Li, Wei Bo; Oeh, Uwe

    2011-09-01

    Biokinetic models describing the uptake, distribution and excretion of trace elements are an essential tool in nutrition, toxicology, or internal dosimetry of radionuclides. Zirconium, especially its radioisotope (95)Zr, is relevant to radiation protection due to its production in uranium fission and neutron activation of nuclear fuel cladding material. We present a comprehensive set of human data from a tracer study with stable isotopes of zirconium. The data are used to refine a biokinetic model of zirconium. Six female and seven male healthy adult volunteers participated in the study. It includes 16 complete double tracer investigations with oral ingestion and intravenous injection, and seven supplemental investigations. Tracer concentrations were measured in blood plasma and urine collected up to 100 d after tracer administration. The four data sets (two chemical tracer forms in plasma and urine) each encompass 105-240 measured concentration values above detection limits. Total fractional absorption of ingested zirconium was found to be 0.001 for zirconium in citrate-buffered drinking solution and 0.007 for zirconium oxalate solution. Biokinetic models were developed based on the linear first-order kinetic compartmental model approach used by the International Commission on Radiological Protection (ICRP). The main differences of the optimized systemic model of zirconium to the current ICRP model are (1) recycling into the transfer compartment made necessary by the observed tracer clearance from plasma, (2) different parameters related to fractional absorption for each form of the ingested tracer, and (3) a physiologically based excretion pathway to urine. The study considerably expands the knowledge on the biokinetics of zirconium, which was until now dominated by data from animal studies. The proposed systemic model improves the existing ICRP model, yet is based on the same principles and fits well into the ICRP radiation protection approach. Copyright © 2011

  16. 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.

  17. Role of endoplasmic reticulum stress-induced apoptosis in rat thyroid toxicity caused by excess fluoride and/or iodide.

    PubMed

    Liu, Hongliang; Hou, Changchun; Zeng, Qiang; Zhao, Liang; Cui, Yushan; Yu, Linyu; Wang, Lingzhi; Zhao, Yang; Nie, Junyan; Zhang, Bin; Wang, Aiguo

    2016-09-01

    Excess fluoride and iodide coexist in drinking water in many regions, but few studies have investigated the single or interactive effects on thyroid in vivo. In our study, Wistar rats were exposed to excess fluoride and/or iodide through drinking water for 2 or 8 months. The structure and function of the thyroid, cells apoptosis and the expression of inositol-requiring enzyme 1 (IRE1) pathway-related factors were analyzed. Results demonstrated that excess fluoride and/or iodide could change thyroid follicular morphology and alter thyroid hormone levels in rats. After 8 months treatment, both single and co-exposure of the two microelements could raise the thyroid cells apoptosis. However, the expressions of IRE1-related factors were only increased in fluoride-alone and the combined groups. In conclusion, thyroid structure and thyroid function were both affected by excess fluoride and/or iodide. IRE1-induced apoptosis were involved in this cytotoxic process caused by fluoride or the combination of two microelements. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Time-resolved photoelectron imaging of iodide-nitromethane (I-·CH3NO2) photodissociation dynamics.

    PubMed

    Kunin, Alice; Li, Wei-Li; Neumark, Daniel M

    2016-12-07

    Femtosecond time-resolved photoelectron spectroscopy is used to probe the decay channels of iodide-nitromethane (I - ·CH 3 NO 2 ) binary clusters photoexcited at 3.56 eV, near the vertical detachment energy (VDE) of the cluster. The production of I - is observed, and its photoelectron signal exhibits a mono-exponential rise time of 21 ± 1 ps. Previous work has shown that excitation near the VDE of the I - ·CH 3 NO 2 complex transfers an electron from iodide to form a dipole-bound state of CH 3 NO 2 - that rapidly converts to a valence bound (VB) anion. The long appearance time for the I - fragment suggests that the VB anion decays by back transfer of the excess electron to iodide, reforming the I - ·CH 3 NO 2 anion and resulting in evaporation of iodide. Comparison of the measured lifetime to that predicted by RRKM theory suggests that the dissociation rate is limited by intramolecular vibrational energy redistribution in the re-formed anion between the high frequency CH 3 NO 2 vibrational modes and the much lower frequency intermolecular I - ·CH 3 NO 2 stretch and bends, the predominant modes involved in cluster dissociation to form I - . Evidence for a weak channel identified as HI + CH 2 NO 2 - is also observed.

  19. Evaluation of iodide deficiency in the lactating rat and pup using a biologically based dose-response model

    EPA Science Inventory

    A biologically-based dose response (BBDR) model for the hypothalamic-pituitary thyroid (BPT) axis in the lactating rat and nursing pup was developed to describe the perturbations caused by iodide deficiency on the HPT axis. Model calibrations, carried out by adjusting key model p...

  20. The Impact of Iodide-Mediated Ozone Deposition and Halogen Chemistry on Surface Ozone Concentrations Across the Continental United States

    EPA Science Inventory

    The air quality of many large coastal areas in the United States is affected by the confluence of polluted urban and relatively clean marine airmasses, each with distinct atmospheric chemistry. In this context, the role of iodide-mediated ozone (O3) deposition over seawater and m...

  1. 76 FR 16770 - Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0541; FRL-8841-7] Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide); Notice of Availability AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: On March 31, 2010, EPA received a petition from...

  2. Evaluation of iodide deficiency in the lactating rat and pup using a biologically based dose response (BBDR) Model***

    EPA Science Inventory

    A biologically-based dose response (BBDR) model for the hypothalamic-pituitary thyroid (HPT) axis in the lactating rat and nursing pup was developed to describe the perturbations caused by iodide deficiency on the 1-IPT axis. Model calibrations, carried out by adjusting key model...

  3. Perfluoroalkylation of Aryl-N,N-dimethyl Hydrazones Using Hypervalent Iodine(III) Reagents or Perfluoroalkyl Iodides.

    PubMed

    Janhsen, Benjamin; Studer, Armido

    2017-11-17

    Radical trifluoromethylation of aryl N,N-dimethyl hydrazones using TBAI as an initiator and Togni's reagent as a trifluoromethyl radical source is described. Cascades proceed via electron-catalysis; this approach is generally more applicable to hydrazone perfluoroalkylation using perfluoroalkyl iodides as the radical precursors in combination with a base under visible-light initiation.

  4. Efficient Method for the Determination of the Activation Energy of the Iodide-Catalyzed Decomposition of Hydrogen Peroxide

    ERIC Educational Resources Information Center

    Sweeney, William; Lee, James; Abid, Nauman; DeMeo, Stephen

    2014-01-01

    An experiment is described that determines the activation energy (E[subscript a]) of the iodide-catalyzed decomposition reaction of hydrogen peroxide in a much more efficient manner than previously reported in the literature. Hydrogen peroxide, spontaneously or with a catalyst, decomposes to oxygen and water. Because the decomposition reaction is…

  5. Impact of humic acid on the photoreductive degradation of perfluorooctane sulfonate (PFOS) by UV/Iodide process.

    PubMed

    Sun, Zhuyu; Zhang, Chaojie; Chen, Pei; Zhou, Qi; Hoffmann, Michael R

    2017-12-15

    Iodide photolysis under UV illumination affords an effective method to produce hydrated electrons (e aq - ) in aqueous solution. Therefore, UV/Iodide photolysis can be utilized for the reductive degradation of many recalcitrant pollutants. However, the effect of naturally occurring organic matter (NOM) such as humic and fulvic acids (HA/FA), which may impact the efficiency of UV/Iodide photoreduction, is poorly understood. In this study, the UV photoreductive degradation of perfluorooctane sulfonate (PFOS) in the presence of I - and HA is studied. PFOS undergoes a relatively slow direct photoreduction in pure water, a moderate level of degradation via UV/Iodide, but a rapid degradation via UV/Iodide/HA photolysis. After 1.5 h of photolysis, 86.0% of the initial [PFOS] was degraded in the presence of both I - and HA with a corresponding defluorination ratio of 55.6%, whereas only 51.7% of PFOS was degraded with a defluorination ratio of 4.4% via UV/Iodide illumination in the absence of HA. The relative enhancement in the presence of HA in the photodegradation of PFOS can be attributed to several factors: a) HA enhances the effective generation of e aq - due to the reduction of I 2 , HOI, IO 3 - and I 3 - back to I - ; b) certain functional groups of HA (i.e., quinones) enhance the electron transfer efficiency as electron shuttles; c) a weakly-bonded association of I - and PFOS with HA increases the reaction probability; and d) absorption of UV photons by HA itself produces e aq - . The degradation and defluorination efficiency of PFOS by UV/Iodide/HA process is dependent on pH and HA concentration. As pH increases from 7.0 to 10.0, the enhancement effect of HA improves significantly. The optimal HA concentration for the degradation of 0.03 mM PFOS is 1.0 mg L -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Synthesis of formamidinium lead iodide perovskite bulk single crystal and its optical properties

    NASA Astrophysics Data System (ADS)

    Zheng, Hongge; Duan, Junjie; Dai, Jun

    2017-07-01

    Formamidinium lead iodide (FAPbI3) is a promising hybrid perovskite material for optoelectronic devices. We synthesized bulk single crystal FAPbI3 by a rapid solution crystallization method. X-ray diffraction (XRD) was performed to characterize the crystal structure. Temperature-dependent photoluminescence (PL) spectra of the bulk single crystal FAPbI3 were measured from 10 to 300 K to explain PL recombination mechanism. It shows that near band edge emission blueshifts with the temperature increasing from 10 to 120 K and from 140 K to room temperature, a sudden emission band redshift demonstrates near 140 K because of the phase transition from orthorhombic phase to cubic phase. From the temperature-dependent PL spectra, the temperature coefficients of the bandgap and thermal activation energies of FAPbI3 perovskite are fitted.

  7. Reentrant Structural and Optical Properties and Large Positive Thermal Expansion in Perovskite Formamidinium Lead Iodide.

    PubMed

    Fabini, Douglas H; Stoumpos, Constantinos C; Laurita, Geneva; Kaltzoglou, Andreas; Kontos, Athanassios G; Falaras, Polycarpos; Kanatzidis, Mercouri G; Seshadri, Ram

    2016-12-05

    The structure of the hybrid perovskite HC(NH 2 ) 2 PbI 3 (formamidinium lead iodide) reflects competing interactions associated with molecular motion, hydrogen bonding tendencies, thermally activated soft octahedral rotations, and the propensity for the Pb 2+ lone pair to express its stereochemistry. High-resolution synchrotron X-ray powder diffraction reveals a continuous transition from the cubic α-phase (Pm3‾ m, #221) to a tetragonal β-phase (P4/mbm, #127) at around 285 K, followed by a first-order transition to a tetragonal γ-phase (retaining P4/mbm, #127) at 140 K. An unusual reentrant pseudosymmetry in the β-to-γ phase transition is seen that is also reflected in the photoluminescence. Around room temperature, the coefficient of volumetric thermal expansion is among the largest for any extended crystalline solid. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A review of recent measurements of optical and thermal properties of alpha-mercuric iodide

    NASA Astrophysics Data System (ADS)

    Burger, A.; Morgan, S. H.; Silberman, E.; Nason, D.; Cheng, A. Y.

    The knowledge of the physical properties of a crystal and their relation to the nature and content of defects are essential for both applications and fundamental reasons. Alpha-mercuric iodide (alpha-HgI2) is a material which was found important applications as room temperature x ray and gamma ray detectors. Some recent thermal and optical measurements of this material, using the samples of improved crystallinity which are now available, are reviewed below. Heretofore, these properties have received less attention than the mechanical and electrical properties, particularly at elevated temperatures. In the technology of alpha-HgI2 where there is a continuing motivation to obtain larger single crystals without compromising the material quality, a better knowledge of the thermal and optical properties may lead to improvements in the processes of material purification, crystal growth, and device fabrication.

  9. Ammonia-hydrogen bromide and ammonia-hydrogen iodide complexes: anion photoelectron and ab initio studies.

    PubMed

    Eustis, S N; Whiteside, A; Wang, D; Gutowski, M; Bowen, K H

    2010-01-28

    The ammonia-hydrogen bromide and ammonia-hydrogen iodide, anionic heterodimers were studied by anion photoelectron spectroscopy. In complementary studies, these anions and their neutral counterparts were also investigated via ab initio theory at the coupled cluster level. In both systems, neutral NH(3)...HX dimers were predicted to be linear, hydrogen-bonded complexes, whereas their anionic dimers were found to be proton-transferred species of the form, (NH(4)(+)X(-))(-). Both experimentally measured and theoretically predicted vertical detachment energies (VDE) are in excellent agreement for both systems, with values for (NH(4)(+)Br(-))(-) being 0.65 and 0.67 eV, respectively, and values for (NH(4)(+)I(-))(-) being 0.77 and 0.81 eV, respectively. These systems are discussed in terms of our previous study of (NH(4)(+)Cl(-))(-).

  10. On the refractive index of sodium iodide solutions for index matching in PIV

    NASA Astrophysics Data System (ADS)

    Bai, Kunlun; Katz, Joseph

    2014-04-01

    Refractive index matching has become a popular technique for facilitating applications of modern optical diagnostic techniques, such as particle image velocimetry, in complex systems. By matching the refractive index of solid boundaries with that of the liquid, unobstructed optical paths can be achieved for illumination and image acquisition. In this research note, we extend previously provided data for the refractive index of aqueous solutions of sodium iodide (NaI) for concentrations reaching the temperature-dependent solubility limit. Results are fitted onto a quadratic empirical expression relating the concentration to the refractive index. Temperature effects are also measured. The present range of indices, 1.333-1.51, covers that of typical transparent solids, from silicone elastomers to several recently introduced materials that could be manufactured using rapid prototyping. We also review briefly previous measurements of the refractive index, viscosity, and density of NaI solutions, as well as prior research that has utilized this fluid.

  11. The Sodium/Iodide Symporter (NIS): Molecular Physiology and Preclinical and Clinical Applications

    PubMed Central

    Ravera, Silvia; Reyna-Neyra, Andrea; Ferrandino, Giuseppe; Amzel, L. Mario; Carrasco, Nancy

    2017-01-01

    Active iodide (I−) transport in both the thyroid and some extrathyroidal tissues is mediated by the N a+/I− symporter (NIS). In the thyroid, NIS-mediated I− uptake plays a pivotal role in thyroid hormone (TH) biosynthesis. THs are key during embryonic and postembryonic development and critical for cell metabolism at all stages of life. The molecular characterization of NIS in 1996 and the use of radioactive I− isotopes have led to significan advances in the diagnosis and treatment of thyroid cancer and provide the molecular basis for studies aimed at extending the use of radioiodide treatment in extrathyroidal malignancies. This review focuses on the most recent finding on I− homeostasis and I− transport deficiency-causin NIS mutations, as well as current knowledge of the structure/function properties of NIS and NIS regulatory mechanisms. We also discuss employing NIS as a reporter gene using viral vectors and stem cells in imaging, diagnostic, and therapeutic procedures. PMID:28192058

  12. Grain-Size-Limited Mobility in Methylammonium Lead Iodide Perovskite Thin Films

    SciTech Connect

    Reid, Obadiah G.; Yang, Mengjin; Kopidakis, Nikos

    2016-09-09

    We report a systematic study of the gigahertz-frequency charge carrier mobility found in methylammonium lead iodide perovskite films as a function of average grain size using time-resolved microwave conductivity and a single processing chemistry. Our measurements are in good agreement with the Kubo formula for the AC mobility of charges confined within finite grains, suggesting (1) that the surface grains imaged via scanning electron microscopy are representative of the true electronic domain size and not substantially subdivided by twinning or other defects not visible by microscopy and (2) that the time scale of diffusive transport across grain boundaries is muchmore » slower than the period of the microwave field in this measurement (-100 ps). The intrinsic (infinite grain size) minimum mobility extracted form the model is 29 +/- 6 cm2 V-1 s-1 at the probe frequency (8.9 GHz).« less

  13. Growth of single crystals of mercuric iodide (HgI/sub 2/) in spacelab III

    SciTech Connect

    Van Den Berg, L.; Schnepple, W.F.

    1981-01-01

    Continued development of a system designed to grow crystals by physical vapor transport in the environment of Spacelab III will be described, with special emphasis on simulation of expected space conditions, adjustment of crystal growth parameters, and on board observation and control of the experiment by crew members and ground personnel. A critical factor in the use of mercuric iodide for semiconductor detectors of x-rays and gamma-rays is the crystalline quality of the material. The twofold purpose of the Spacelab III experiment is therefore to grow single crystals with superior electronic properties as an indirect result of the greatly reducedmore » gravity field during the growth, and to obtain data which will lead to improved understanding of the vapor transport mechanism. The experiments planned to evaluate the space crystals, including gamma-ray diffractometry and measurements of stoichiometry, lattice dimensions, mechanical strength, luminescense, and detector performance are discussed.« less

  14. Selective nucleation of iron phthalocyanine crystals on micro-structured copper iodide.

    PubMed

    Rochford, Luke A; Ramadan, Alexandra J; Heutz, Sandrine; Jones, Tim S

    2014-12-14

    Morphological and structural control of organic semiconductors through structural templating is an efficient route by which to tune their physical properties. The preparation and characterisation of iron phthalocyanine (FePc)-copper iodide (CuI) bilayers at elevated substrate temperatures is presented. Thin CuI(111) layers are prepared which are composed of isolated islands rather than continuous films previously employed in device structures. Nucleation in the early stages of FePc growth is observed at the edges of islands rather than on the top (111) faces with the use of field emission scanning electron microscopy (FE-SEM). Structural measurements show two distinct polymorphs of FePc, with CuI islands edges nucleating high aspect ratio FePc crystallites with modified intermolecular spacing. By combining high substrate temperature growth and micro-structuring of the templating CuI(111) layer structural and morphological control of the organic film is demonstrated.

  15. Top and bottom surfaces limit carrier lifetime in lead iodide perovskite films

    DOE PAGES

    Yang, Ye; Yang, Mengjin; Moore, David T.; ...

    2017-01-23

    Carrier recombination at defects is detrimental to the performance of solar energy conversion systems, including solar cells and photoelectrochemical devices. Point defects are localized within the bulk crystal while extended defects occur at surfaces and grain boundaries. If not properly managed, surfaces can be a large source of carrier recombination. Separating surface carrier dynamics from bulk and/or grain-boundary recombination in thin films is challenging. Here, we employ transient reflection spectroscopy to measure the surface carrier dynamics in methylammonium lead iodide perovskite polycrystalline films. We find that surface recombination limits the total carrier lifetime in perovskite polycrystalline thin films, meaning thatmore » recombination inside grains and/or at grain boundaries is less important than top and bottom surface recombination. As a result, the surface recombination velocity in polycrystalline films is nearly an order of magnitude smaller than that in single crystals, possibly due to unintended surface passivation of the films during synthesis.« less

  16. Observations in eastern England of elevated methyl iodide concentrations in air of atlantic origin

    NASA Astrophysics Data System (ADS)

    Oram, D. E.; Penkett, S. A.

    Atmospheric methyl iodide (CH 3I) has been measured at a ground-based site in eastern England for two consecutive summers. Maximum values of 43.1 pptv and 28.9 pptv were recorded in 1989 and 1990, respectively. CH 3I was not detectable in the autumn and winter months. Episodes of elevated concentration persisted for periods ranging from a few hours to several days. The origin of much of the observed CH 31 would appear to be the Atlantic Ocean, indicating the presence of large source areas, possibly phytoplankton blooms, in ocean waters. If so, this work provides the first evidence of long-range transport of an important iodine-bearing species at concentrations of hemispheric significance. Estimates are made of the dry deposition velocity of CH 3I and the potential impact of elevated tropospheric levels on the human uptake of iodine.

  17. Ultrafast Extreme Ultraviolet Spectroscopy of Methylammonium Lead Iodide Perovskite for Carrier Specific Photophysics

    NASA Astrophysics Data System (ADS)

    Verkamp, Max A.; Lin, Ming-Fu; Ryland, Elizabeth S.; Benke, Kristin; Vura-Weis, Josh

    2017-06-01

    Methyl ammonium lead iodide (perovskite) is a leading candidate for next-generation solar cell devices. However, the fundamental photophysics responsible for its strong photovoltaic qualities are not fully understood. Ultrafast extreme ultraviolet (XUV) spectroscopy was used to investigate relaxation dynamics in perovskite with carrier specific signals arising from transitions from the common inner-shell level (I 4d) to the valence and conduction bands. Ultrashort (30 fs) pulses of XUV radiation in a broad spectrum (40-70 eV) were obtained using high-harmonic generation in a tabletop instrument. Transient absorption measurements with visible pump and XUV probe directly observed the dynamics of charge carriers after above-band and band-edge excitation.

  18. Tuning the band gap in hybrid tin iodide perovskite semiconductors using structural templating.

    PubMed

    Knutson, Jeremy L; Martin, James D; Mitzi, David B

    2005-06-27

    Structural distortions within the extensive family of organic/inorganic hybrid tin iodide perovskite semiconductors are correlated with their experimental exciton energies and calculated band gaps. The extent of the in- and out-of-plane angular distortion of the SnI4(2-) perovskite sheets is largely determined by the relative charge density and steric requirements of the organic cations. Variation of the in-plane Sn-I-Sn bond angle was demonstrated to have the greatest impact on the tuning of the band gap, and the equatorial Sn-I bond distances have a significant secondary influence. Extended Hückel tight-binding band calculations are employed to decipher the crystal orbital origins of the structural effects that fine-tune the band structure. The calculations suggest that it may be possible to tune the band gap by as much as 1 eV using the templating influence of the organic cation.

  19. Engaging unactivated alkyl, alkenyl and aryl iodides in visible-light-mediated free radical reactions

    NASA Astrophysics Data System (ADS)

    Nguyen, John D.; D'Amato, Erica M.; Narayanam, Jagan M. R.; Stephenson, Corey R. J.

    2012-10-01

    Radical reactions are a powerful class of chemical transformations. However, the formation of radical species to initiate these reactions has often required the use of stoichiometric amounts of toxic reagents, such as tributyltin hydride. Recently, the use of visible-light-mediated photoredox catalysis to generate radical species has become popular, but the scope of these radical precursors has been limited. Here, we describe the identification of reaction conditions under which photocatalysts such as fac-Ir(ppy)3 can be utilized to form radicals from unactivated alkyl, alkenyl and aryl iodides. The generated radicals undergo reduction via hydrogen atom abstraction or reductive cyclization. The reaction protocol utilizes only inexpensive reagents, occurs under mild reaction conditions, and shows exceptional functional group tolerance. Reaction efficiency is maintained upon scale-up and decreased catalyst loading, and the reaction time can be significantly shortened when the reaction is performed in a flow reactor.

  20. Ellipticity-dependent of multiple ionisation methyl iodide cluster using 532 nm nanosecond laser

    NASA Astrophysics Data System (ADS)

    Tang, Bin; Zhao, Wuduo; Wang, Weiguo; Hua, Lei; Chen, Ping; Hou, Keyong; Huang, Yunguang; Li, Haiyang

    2016-03-01

    The dependence of multiply charged ions on laser ellipticity in methyl iodide clusters with 532 nm nanosecond laser was measured using a time-of-flight mass spectrometer. The intensities of multiply charged ions Iq+(q = 2-4) with circularly polarised laser pulse were clearly higher than those with linearly polarised laser pulse but the intensity of single charged ions I+ was inverse. And the dependences of ions on the optical polarisation state were investigated and a flower petal and square distribution for single charged ions (I+, C+) and multiply charged ions (I2+, I3+, I4+, C2+) were observed, respectively. A theoretical calculation was also proposed to simulate the distributions of ions and theoretical results fitted well with the experimental ones. It indicated that the high multiphoton ionisation probability in the initial stage would result in the disintegration of big clusters into small ones and suppress the production of multiply charged ions.