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Sample records for bromine iodides

  1. Bromine

    Czech Academy of Sciences Publication Activity Database

    Pavelka, Stanislav

    2. Weinheim : WileyVCH, 2004 - (Merian, E.; Anke, M.; Ihnat, M.; Stoeppler, M.), s. 1445-1455 ISBN 3-527-30459-2. - (3) Institutional research plan: CEZ:AV0Z5011922 Keywords : bromine * analysis * biological relevance Subject RIV: CA - Inorganic Chemistry

  2. Potassium Iodide

    Science.gov (United States)

    Potassium iodide is used to protect the thyroid gland from taking in radioactive iodine that may be released during ... the thyroid gland. You should only take potassium iodide if there is a nuclear radiation emergency and ...

  3. Bromine Safety

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, B

    2001-04-09

    The production and handling in 1999 of about 200 million kilograms of bromine plus substantial derivatives thereof by Great Lakes Chemical Corp. and Albemarle Corporation in their southern Arkansas refineries gave OSHA Occupational Injury/Illness Rates (OIIR) in the range of 0.74 to 1.60 reportable OIIRs per 200,000 man hours. OIIRs for similar industries and a wide selection of other U.S. industries range from 1.6 to 23.9 in the most recent OSHA report. Occupational fatalities for the two companies in 1999 were zero compared to a range in the U.S.of zero for all computer manufacturing to 0.0445 percent for all of agriculture, forestry and fishing in the most recent OSHA report. These results show that bromine and its compounds can be considered as safe chemicals as a result of the bromine safety standards and practices at the two companies. The use of hydrobromic acid as an electrical energy storage medium in reversible PEM fuel cells is discussed. A study in 1979 of 20 megawatt halogen working fluid power plants by Oronzio de Nora Group found such energy to cost 2 to 2.5 times the prevailing base rate at that time. New conditions may reduce this relative cost. The energy storage aspect allows energy delivery at maximum demand times where the energy commands premium rates. The study also found marginal cost and performance advantages for hydrobromic acid over hydrochloric acid working fluid. Separate studies in the late 70s by General Electric also showed marginal performance advantages for hydrobromic acid.

  4. Potassium Iodide (KI)

    Science.gov (United States)

    ... Planning Information on Specific Types of Emergencies Potassium Iodide (KI) Language: English Español (Spanish) Recommend on Facebook ... I get KI (potassium iodide)? What is Potassium Iodide (KI)? KI (potassium iodide) is a salt of ...

  5. Methyl Iodide

    Science.gov (United States)

    Methyl iodide (MeI, iodomethane, CH3I) was reported as a potential alternative to the stratospheric ozone-depleting fumigant methyl bromide (MeBr) in the mid-1990s (Sims et al., 1995; Ohr et al., 1996). It has since received significant research attention to determine its environmental fate and tran...

  6. Mercury iodide crystal growth

    Science.gov (United States)

    Cadoret, R.

    1982-01-01

    The purpose of the Mercury Iodide Crystal Growth (MICG) experiment is the growth of near-perfect single crystals of mercury Iodide (HgI2) in a microgravity environment which will decrease the convection effects on crystal growth. Evaporation and condensation are the only transformations involved in this experiment. To accomplish these objectives, a two-zone furnace will be used in which two sensors collect the temperature data (one in each zone).

  7. The sodium/iodide symporter and radio-iodide therapy

    International Nuclear Information System (INIS)

    The sodium/iodide symporter (NIS) is an intrinsic membrane protein that mediates the active transport of iodide into the thyroid and other tissues. NIS plays key roles in thyroid pathophysiology as the route by which iodide reaches the gland for thyroid hormone biosynthesis and as a means for diagnostic scintigraphic imaging and for radio-iodide therapy in hyperthyroidism and thyroid cancer. The continued molecular analysis of NIS clearly holds the potential of an even greater impact on the diagnosis and radio-iodide treatment of cancer, both in thyroid and beyond

  8. 21 CFR 184.1265 - Cuprous iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cuprous iodide. 184.1265 Section 184.1265 Food and... Substances Affirmed as GRAS § 184.1265 Cuprous iodide. (a) Cuprous iodide (copper (I) iodide, CuI, CAS Reg... with potassium iodide under slightly acidic conditions. (b) The ingredient must be of a purity...

  9. Hydrogen iodide decomposition

    Science.gov (United States)

    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.

  10. 21 CFR 172.375 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true 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...

  11. Electrochemical reaction rates in a dye sentisised solar cell - the iodide/tri-iodide redox system

    DEFF Research Database (Denmark)

    Bay, Lasse; West, Keld; Winter-Jensen, Bjørn; Jacobsen, Torben

    2006-01-01

    The electrochemical reaction rate of the redox couple iodide / tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide / tri-iodide...... layer on top of the FTO glass to lower the tri-iodide reduction rate....

  12. Mercuric iodide sensor technology

    International Nuclear Information System (INIS)

    This report describes the improvement in the performance and the manufacturing yield of mercuric iodide detectors achieved by identifying the dominant impurities, carrier traps, and processing steps limiting device performance. Theoretical studies of electron and hole transport in this material set fundamental limits on detector performance and provided a standard against which to compare experimental results. Spectroscopy techniques including low temperature photoluminescence and thermally stimulated current spectroscopy were applied to characterize the deep level traps in this material. Traps and defects that can be introduced into the detector during growth, from the contact, and during the various steps in detector fabrication were identified. Trap energy levels and their relative abundances were determined. Variations in material quality and detector performance at the micron scale were investigated to understand the distribution in electric field in large volume detectors suitable for gamma-ray spectroscopy. Surface aging and contact degradation was studied extensively by techniques including atomic force microscopy, transmission electron microscopy, and variable angle spectroscopic ellipsometry. Preferred handling and processing procedures for maximizing detector performance and yield were established. The manufacturing yield of high resolution gamma-ray detectors was improved from a few percent to more than 30%

  13. Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska

    Directory of Open Access Journals (Sweden)

    C. R. Thompson

    2014-11-01

    Full Text Available The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indications of active iodine chemistry through observed enhancements in filterable iodide, probable detection of tropospheric IO, and recently, detection of atmospheric I2. Despite decades of research, significant uncertainty remains regarding the chemical mechanisms associated with the bromine-catalyzed depletion of ozone, as well as the complex interactions that occur in the polar boundary layer due to halogen chemistry. To investigate this, we developed a zero-dimensional photochemical model, constrained with measurements from the 2009 OASIS field campaign in Barrow, Alaska. We simulated a 7 day period during late March that included a full ozone depletion event lasting 3 days and subsequent ozone recovery to study the interactions of halogen radicals under these different conditions. In addition, the effects of iodine added to our base model were investigated. While bromine atoms were primarily responsible for ODEs, chlorine and iodine were found to enhance the depletion rates and iodine was found to be more efficient per atom at depleting ozone than Br. The interaction between chlorine and bromine is complex, as the presence of chlorine can increase the recycling and production of Br atoms, while also increasing reactive bromine sinks under certain conditions. Chlorine chemistry was also found to have significant impacts on both HO2 and RO2. The results of this work highlight the need for future studies on the production mechanisms of Br2 and Cl2, as well as on the potential

  14. Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska

    Science.gov (United States)

    Thompson, C. R.; Shepson, P. B.; Liao, J.; Huey, L. G.; Apel, E. C.; Cantrell, C. A.; Flocke, F.; Orlando, J.; Fried, A.; Hall, S. R.; Hornbrook, R. S.; Knapp, D. J.; Mauldin, R. L., III; Montzka, D. D.; Sive, B. C.; Ullmann, K.; Weibring, P.; Weinheimer, A.

    2015-08-01

    The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indications of active iodine chemistry through observed enhancements in filterable iodide, probable detection of tropospheric IO, and recently, observation of snowpack photochemical production of I2. Despite decades of research, significant uncertainty remains regarding the chemical mechanisms associated with the bromine-catalyzed depletion of ozone, as well as the complex interactions that occur in the polar boundary layer due to halogen chemistry. To investigate this, we developed a zero-dimensional photochemical model, constrained with measurements from the 2009 OASIS field campaign in Barrow, Alaska. We simulated a 7-day period during late March that included a full ozone depletion event lasting 3 days and subsequent ozone recovery to study the interactions of halogen radicals under these different conditions. In addition, the effects of iodine added to our Base Model were investigated. While bromine atoms were primarily responsible for ODEs, chlorine and iodine were found to enhance the depletion rates and iodine was found to be more efficient per atom at depleting ozone than Br. The interaction between chlorine and bromine is complex, as the presence of chlorine can increase the recycling and production of Br atoms, while also increasing reactive bromine sinks under certain conditions. Chlorine chemistry was also found to have significant impacts on both HO2 and RO2, with organic compounds serving as the primary reaction partner for Cl atoms. The results of this work highlight the need for future

  15. Speciation of the bio-available iodine and bromine forms in edible seaweed by high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Romaris-Hortas, Vanessa; Bermejo-Barrera, Pilar [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain); Moreda-Pineiro, Jorge [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira, s/n. 15071, A Coruna (Spain); Moreda-Pineiro, Antonio, E-mail: antonio.moreda@usc.es [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Bioavailable iodine and bromine speciation in edible seaweed were developed. Black-Right-Pointing-Pointer In vitro dialyzability was used to assess the bioavailable fractions. Black-Right-Pointing-Pointer AEC hyphenated with inductively coupled plasma-mass spectrometry was used. Black-Right-Pointing-Pointer Iodide, MIT, DIT, bromide and bromate were found in dialyzates from edible seaweed. Black-Right-Pointing-Pointer Positive correlation between bioavailability and protein contents was found. - Abstract: A bioavailability study based on an in vitro dialyzability approach has been applied to assess the bio-available fractions of iodine and bromine species from edible seaweed. Iodide, iodate, 3-iodo-tyrosine (MIT), 3,5-diiodo-tyrosine (DIT), bromide and bromate were separated by anion exchange chromatography under a gradient elution mode (175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase, and flow rates within the 0.5-1.5 mL min{sup -1} range). Inductively coupled plasma-mass spectrometry (ICP-MS) was used as a selective detector for iodine ({sup 127}I) and bromine ({sup 79}Br). Low dialyzability ratios (within the 2.0-18% range) were found for iodine species; whereas, moderate dialyzability percentages (from 9.0 to 40%) were obtained for bromine species. Iodide and bromide were the major species found in the dialyzates from seaweed, although MIT and bromate were also found in the dialyzates from most of the seaweed samples analysed. However, DIT was only found in dialyzates from Wakame, Kombu, and NIES 09 (Sargasso) certified reference material; whereas, iodate was not found in any dialyzate. Iodine dialyzability was found to be dependent on the protein content (negative correlation), and on the carbohydrate and dietary fibre levels (positive correlation). However, bromine dialyzability was only dependent on the protein amount in seaweed (negative correlation).

  16. Speciation of the bio-available iodine and bromine forms in edible seaweed by high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: ► Bioavailable iodine and bromine speciation in edible seaweed were developed. ► In vitro dialyzability was used to assess the bioavailable fractions. ► AEC hyphenated with inductively coupled plasma-mass spectrometry was used. ► Iodide, MIT, DIT, bromide and bromate were found in dialyzates from edible seaweed. ► Positive correlation between bioavailability and protein contents was found. - Abstract: A bioavailability study based on an in vitro dialyzability approach has been applied to assess the bio-available fractions of iodine and bromine species from edible seaweed. Iodide, iodate, 3-iodo-tyrosine (MIT), 3,5-diiodo-tyrosine (DIT), bromide and bromate were separated by anion exchange chromatography under a gradient elution mode (175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase, and flow rates within the 0.5–1.5 mL min−1 range). Inductively coupled plasma-mass spectrometry (ICP-MS) was used as a selective detector for iodine (127I) and bromine (79Br). Low dialyzability ratios (within the 2.0–18% range) were found for iodine species; whereas, moderate dialyzability percentages (from 9.0 to 40%) were obtained for bromine species. Iodide and bromide were the major species found in the dialyzates from seaweed, although MIT and bromate were also found in the dialyzates from most of the seaweed samples analysed. However, DIT was only found in dialyzates from Wakame, Kombu, and NIES 09 (Sargasso) certified reference material; whereas, iodate was not found in any dialyzate. Iodine dialyzability was found to be dependent on the protein content (negative correlation), and on the carbohydrate and dietary fibre levels (positive correlation). However, bromine dialyzability was only dependent on the protein amount in seaweed (negative correlation).

  17. Two new brominated diterpenes from Laurencia decumbens

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two new brominated diterpenes, namely, laurendecumtriol and 11-deacetylpinnaterpene C, were isolated and identified from the marine red alga Laurencia decumbens. Their structures were established on the basis of various NMR spectroscopic techniques and HR-ESI-MS analyses.

  18. Bromine accumulation in acidic black colluvial soils

    Science.gov (United States)

    Cortizas, Antonio Martínez; Vázquez, Cruz Ferro; Kaal, Joeri; Biester, Harald; Casais, Manuela Costa; Rodríguez, Teresa Taboada; Lado, Luis Rodríguez

    2016-02-01

    Recent investigations showed that bromine is incorporated to soil organic matter (SOM), its content increasing with humification. But few research was done on its long-term accumulation and the role played by pedogenetic processes, as those involved in organic matter stabilization. We investigated bromine content and distribution in four deep, acidic, organic-rich, Holocene soils from an oceanic area of Western Europe. Bromine concentrations (93-778 μg g-1) in the silt + clay (area, and total estimated retention was low (6-16%). The degree of SOM bromination, expressed as the Br/C molar ratio, varied between 0.03 and 1.20 mmol Br/mol C. The ratio was highly correlated (n = 23, r2 0.88, p pool of metal-clay-stabilized organic matter.

  19. 21 CFR 582.5634 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 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....

  20. The durability of iodide sodalite

    International Nuclear Information System (INIS)

    Highlights: • Dense iodide sodalite prepared by HIP of hydrothermally synthesised powders. • Sodalite was free from leachable secondary phases. • Leach tests indicate self-arresting congruent dissolution. - Abstract: An iodide sodalite wasteform has been prepared by Hot Isostatic Pressing of powder produced by hydrothermal synthesis. The wasteform was free of leachable secondary phases which can mask leaching mechanisms. Leaching is by congruent dissolution and leach rates decrease as Si and Al accumulate in the leachate. Differential normalised leach rates are 0.005–0.01 g m−2 d−1 during the 7–14 day period. This indicates that sodalite dissolution in natural groundwater, already saturated in these elements, will be very low

  1. Iodide uptake by negatively charged clay interlayers?

    Science.gov (United States)

    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. PMID:26057987

  2. 40 CFR 721.3085 - Brominated phthalate ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated phthalate ester. 721.3085... Substances § 721.3085 Brominated phthalate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated phthalate ester (PMN P-90-581)...

  3. 40 CFR 721.9740 - Brominated triazine derivative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated triazine derivative. 721... Substances § 721.9740 Brominated triazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a brominated triazine...

  4. Iodide uptake by negatively charged clay interlayers?

    International Nuclear Information System (INIS)

    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. - Highlights: • Iodide sorption experiments were completed with a diverse array of clay minerals. • Iodide uptake trended with CEC and swamping electrolyte identity and concentration. • Results can be explained by considering the formation of ion pairs in clay interlayers

  5. Iodide, bromide, and ammonium in hydraulic fracturing and oil and gas wastewaters: environmental implications.

    Science.gov (United States)

    Harkness, Jennifer S; Dwyer, Gary S; Warner, Nathaniel R; Parker, Kimberly M; Mitch, William A; Vengosh, Avner

    2015-02-01

    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. PMID:25587644

  6. Hormonal activities of new brominated flame retardants

    Czech Academy of Sciences Publication Activity Database

    Ezechiáš, Martin; Svobodová, Kateřina; Cajthaml, Tomáš

    2012-01-01

    Roč. 87, č. 7 (2012), s. 820-824. ISSN 0045-6535 R&D Projects: GA ČR GA104/09/0694 Institutional research plan: CEZ:AV0Z50200510 Keywords : Brominated flame retardants * 2,4,6-Tribromophenol * Endocrine disruptors Subject RIV: EE - Microbiology, Virology Impact factor: 3.137, year: 2012

  7. Neutron Detection with Mercuric Iodide

    International Nuclear Information System (INIS)

    Mercuric iodide is a high-density, high-Z semiconducting material useful for gamma ray detection. This makes it convertible to a thermal neutron detector by covering it with a boron rich material and detecting the 478 keV gamma rays resulting from the 10B(n, α)7Li* reaction. However, the 374 barn thermal capture cross section of natHg, makes the detector itself an attractive absorber, and this has been exploited previously. Since previous work indicates that there are no low-energy gamma rays emitted in coincidence with the 368 keV capture gamma from the dominant 199Hg(n, γ)200Hg reaction, only the 368 keV capture gamma is seen with any efficiency a relatively thin (few mm) detector. In this paper we report preliminary measurements of neutrons via capture reactions in a bare mercuric iodide crystal and a crystal covered in 10B-loaded epoxy. The covered detector is an improvement over the bare detector because the presence of both the 478 and 368 keV gamma rays removes the ambiguity associated with the observation of only one of them. Pulse height spectra, obtained with and without lead and cadmium absorbers, showed the expected gamma rays and demonstrated that they were caused by neutrons

  8. Neutron Detection with Mercuric Iodide

    CERN Document Server

    Bell, Z A

    2003-01-01

    Mercuric iodide is a high-density, high-Z semiconducting material useful for gamma ray detection. This makes it convertible to a thermal neutron detector by covering it with a boron rich material and detecting the 478 keV gamma rays resulting from the sup 1 sup 0 B(n, alpha) sup 7 Li* reaction. However, the 374 barn thermal capture cross section of sup n sup a sup t Hg, makes the detector itself an attractive absorber, and this has been exploited previously. Since previous work indicates that there are no low-energy gamma rays emitted in coincidence with the 368 keV capture gamma from the dominant sup 1 sup 9 sup 9 Hg(n, gamma) sup 2 sup 0 sup 0 Hg reaction, only the 368 keV capture gamma is seen with any efficiency a relatively thin (few mm) detector. In this paper we report preliminary measurements of neutrons via capture reactions in a bare mercuric iodide crystal and a crystal covered in sup 1 sup 0 B-loaded epoxy. The covered detector is an improvement over the bare detector because the presence of both ...

  9. Rare, severe hypersensitivity reaction to potassium iodide

    DEFF Research Database (Denmark)

    Nielsen, Anne Sofie Korsholm; Ebbehøj, Eva; Richelsen, Bjørn

    2014-01-01

    The literature reports a large variety of adverse reactions to potassium iodide. A severe hypersensitivity reaction to potassium iodide in a 51-year-old woman with Graves' thyrotoxicosis is described. Following administration the patient developed sialadenitis, conjunctivitis, stomatitis and acne...

  10. Large area mercuric iodide photodetectors

    International Nuclear Information System (INIS)

    Results of an investigation of large area mercuric iodide (HgI2) photodetectors are reported. Different entrance contacts were studied, including semitransparent metallic films and conductive liquids. Theoretical calculations of electronic noise of these photodetectors were compared with experimental results. HgI2 photodetectors with active area up to 4 cm2 were matched with NaI(Tl) and CsI(Tl) scintillation crystals and were evaluated as gamma-radiation spectrometers. Energy resolution of 9.3% for gamma radiation of 511 keV with a CsI(Tl) scintillator and energy resolution of 9.0% for gamma radiation of 622 keV with a NaI(Tl) scintillator have been obtained

  11. Large area mercuric iodide photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Iwanczyk, J.S.; Dabrowski, A.J.; Markakis, J.M.; Ortale, C.; Schnepple, W.F.

    1984-02-01

    Results of an investigation of large area mercuric iodide (HgI/sub 2/) photodetectors are reported. Different entrance contacts were studied, including semitransparent metallic films and conductive liquids. Theoretical calculations of electronic noise of these photodetectors were compared with experimental results. HgI/sub 2/ photodetectors with active area up to 4 cm/sup 2/ were matched with NaI(Tl) and CsI(Tl) scintillation crystals and were evaluated as gamma-radiation spectrometers. Energy resolution of 9.3% for gamma radiation of 511 keV with a CsI(Tl) scintillator and energy resolution of 9.0% for gamma radiation of 622 keV with a NaI(Tl) scintillator have been obtained.

  12. Predissociation dynamics of lithium iodide

    CERN Document Server

    Schmidt, H; Stienkemeier, F; Bogomolov, A S; Baklanov, A V; Reich, D M; Skomorowski, W; Koch, C P; Mudrich, M

    2015-01-01

    The predissociation dynamics of lithium iodide (LiI) in the first excited A-state is investigated for molecules in the gas phase and embedded in helium nanodroplets, using femtosecond pump-probe photoionization spectroscopy. In the gas phase, the transient Li+ and LiI+ ion signals feature damped oscillations due to the excitation and decay of a vibrational wave packet. Based on high-level ab initio calculations of the electronic structure of LiI and simulations of the wave packet dynamics, the exponential signal decay is found to result from predissociation predominantly at the lowest avoided X-A potential curve crossing, for which we infer a coupling constant V=650(20) reciprocal cm. The lack of a pump-probe delay dependence for the case of LiI embedded in helium nanodroplets indicates fast droplet-induced relaxation of the vibrational excitation.

  13. Symproportionation versus Disproportionation in Bromine Redox Systems

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Highlights: • The disproportionation and symproportionation of bromine in different media is presented. • All the redox systems are elaborated according to the principles of the generalized approach to electrolytic redox systems (GATES/GEB). • All physicochemical knowledge is involved in the algorithm applied for this purpose. • The graphical representation of the systems is the basis of gaining the detailed physicochemical knowledge on the systems in question. -- Abstract: The paper refers to dynamic (titration) redox systems where symproportionation or disproportionation of bromine species occur. The related systems are modeled according to principles assumed in the Generalized Approach to Electrolytic Redox Systems (GATES), with Generalized Electron Balance (GEB) concept involved in the GATES/GEB software. The results obtained from calculations made with use of iterative computer programs prepared according to MATLAB computational software, are presented graphically, as 2D and 3D graphs

  14. Membrane-less hydrogen bromine flow battery

    CERN Document Server

    Braff, W A; Buie, C R

    2014-01-01

    In order for the widely discussed benefits of flow batteries for electrochemical energy storage to be applied at large scale, the cost of the electrochemical stack must come down substantially. One promising avenue for reducing stack cost is to increase the system power density while maintaining efficiency, enabling smaller stacks. Here we report on a membrane-less, hydrogen bromine laminar flow battery as a potential high power density solution. The membrane-less design enables power densities of 0.795 W cm$^{-2}$ at room temperature and atmospheric pressure, with a round-trip voltage efficiency of 92\\% at 25\\% of peak power. Theoretical solutions are also presented to guide the design of future laminar flow batteries. The high power density achieved by the hydrogen bromine laminar flow battery, along with the potential for rechargeable operation, will translate into smaller, inexpensive systems that could revolutionize the fields of large-scale energy storage and portable power systems.

  15. Brominated flame retardants and endocrine disruption

    OpenAIRE

    Vos, J G; Becher, G; Berg, van den, C.A.; Boer; Leonards, P.E.G.

    2003-01-01

    From an environmental point of view, an increasing important group of organohalogen compounds are the brominated flame retardants (BFRs), which are widely used in polymers and textiles and applied in construction materials, furniture, and electronic equipment. BFRs with the highest production volume are the polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBP-A), and hexabromocyclododecane (HBCD). Because of their persistence and low biodegradation profile, several of the PBDE ...

  16. Mercuric iodide light detector and related method

    Science.gov (United States)

    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.

  17. 21 CFR 520.763a - Dithiazanine iodide tablets.

    Science.gov (United States)

    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- -benzothiazolium iodide. (b) Specifications. Dithiazanine iodide tablets contain 10 milligrams, 50 milligrams, 100 milligrams, or 200 milligrams of...

  18. 21 CFR 520.763b - Dithiazanine iodide powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dithiazanine iodide powder. 520.763b Section 520... iodide powder. (a) Chemical name. 3-Ethyl-2- -benzothiazoliumiodide. (b) Specifications. Dithiazanine iodide powder contains 200 milligrams of dithiazanine iodide per level standard tablespoon. (c)...

  19. Reaction of bis[trialkyl(aryl)arsonium]-1,4-dihydronaphthalene iodides with mercury(2) iodide in aqueous-alcoholic solutions of potassium iodide

    International Nuclear Information System (INIS)

    Composition of mercury complex iodides, formed in the course of interaction between bis[trialkyl(aryl)arsonium]-1,4-dihydronaphthalene iodides and mercury(2) iodide in aqueous-alcoholic solution in the presence of potassium iodide excess was studied using the methods of chemical analysis, conductivity and IR spectroscopy. It was ascertained that under the conditions mentioned bisarsonium triiodomercurates are formed with the yield of 72-87%. The studies conducted confirm the potentiality of formation of mercury complex iodides of [HgI3]- composition in aqueous solutions of alkali metal iodides in the presence of some organic cations

  20. Processing. alpha. -mercuric iodide by zone refining

    Energy Technology Data Exchange (ETDEWEB)

    Burger, A.; Morgan, S.H.; Henderson, D.O.; Biao, Y.; Zhang, K.; Silberman, E. (Fisk Univ., Nashville, TN (United States). Dept. of Physics); Nason, D.; van den Berg, L.; Ortale-Baccash, C.; Cross, E. (EG and G Energy Measurements, Inc., Goleta, CA (United States). Santa Barbara Operations)

    1992-01-01

    An investigation is being conducted on zone refining {alpha}-mercuric iodide. Analytical studies using differential scanning calorimetry and anion chromatography indicate that impurities are segregated mainly at the end where zone travel terminates. Early results indicate that single crystals can be readily grown from zone refined material, and the effects of the process on the performance of radiation detectors fabricated from {alpha}-mercuric iodide are being evaluated.

  1. Iodide refining of calcium-thermal zirconium

    International Nuclear Information System (INIS)

    The possibility of high zirconium of calcium - thermal zirconium KTC-HP and metallic wastes production by iodide refining is examined. The impurities behavior is studied,the refining coefficient dependence on the impurity concentration in the initial material is determined. The impurities minimum concentration in iodide zirconium are evaluated by extrapolation.It is determined that the refining efficiency decreases in the range: Ni=Mn > Cr >F>C>N>O>Fe and aluminium and silicon removal during the iodide refining of calcium thermal zirconium is problematic. By comparison of iodide metal of KTC-HP expected quality with the specifications and the iodide zirconium purity real level obtained in the adopted practice the possibility of standard metal production of KTC-HP and metal wastes is demonstrated. The principal merit of KTC - hafnium content <0,01 mass % is preserved. Alloys melting of double or triple on the base of KTC according TS 95.2185-90 with the addition of 35...50 % of iodide zirconium by the method VDP will allow to obtain the alloys KTC-110 and KTC-125 with oxygen fraction of total mass 0,06...0,10% and hafnium content, meeting the world standards

  2. Recovery of anhydrous hydrogen iodide

    Science.gov (United States)

    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.

  3. Electrochemical reaction rates in a dye-sensitised solar cell - the iodide/tri-iodide redox system

    DEFF Research Database (Denmark)

    Bay, L.; West, K.; Winther-Jensen, B.; Jacobsen, T.

    2006-01-01

    The electrochemical reaction rate of the redox couple iodide/tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide/tri-iodide...... layer on top of the FTO glass in lowering the tri-iodide reduction rate. (c) 2005 Elsevier B.V. All rights reserved....

  4. Brominated thiophenes as precursors in the preparation of brominated and arylated anthraquinones.

    Science.gov (United States)

    Thiemann, Thies; Tanaka, Yasuko; Iniesta, Jesus

    2009-01-01

    Brominated anthraquinones can be synthesized directly from bromothiophenes when these are reacted with 1,4-naphthoquinones in the presence of meta-chloroperoxybenzoic acid. The bromoanthraquinones are versatile building blocks in the preparation of arylated anthraquinones and of extended pi-systems with interspersed anthraquinone units. PMID:19305356

  5. Brominated Thiophenes as Precursors in the Preparation of Brominated and Arylated Anthraquinones

    Directory of Open Access Journals (Sweden)

    Thies Thiemann

    2009-03-01

    Full Text Available Brominated anthraquinones can be synthesized directly from bromothiophenes when these are reacted with 1,4-naphthoquinones in the presence of meta-chloroperoxybenzoic acid. The bromoanthraquinones are versatile building blocks in the preparation of arylated anthraquinones and of extended π-systems with interspersed anthraquinone units.

  6. Brominated Thiophenes as Precursors in the Preparation of Brominated and Arylated Anthraquinones

    OpenAIRE

    Thies Thiemann; Jesus Iniesta; Yasuko Tanaka

    2009-01-01

    Brominated anthraquinones can be synthesized directly from bromothiophenes when these are reacted with 1,4-naphthoquinones in the presence of meta-chloroperoxybenzoic acid. The bromoanthraquinones are versatile building blocks in the preparation of arylated anthraquinones and of extended π-systems with interspersed anthraquinone units.

  7. Kinetics of gold dissolution in iodide solutions

    Science.gov (United States)

    Yang, Kang

    Cyanide has been used as a lixiviant for free milling gold ores for a long time. Cyanide solutions are highly toxic and their use poses long term environmental problems. Cyanidation process is efficient for oxide gold ores but it is ineffective for gold ores containing sulfides. Among the noncyanide based lixiviants, iodide has the potential of replacing cyanide due to its ability to leach gold at a wider pH range and higher rate of gold dissolution. The emerging technology of bio-oxidation is an accepted process for pretreatment of sulfide gold ores. The bio-oxidation is conducted at acidic pH which makes direct cyanidation without pH adjustment impractical. On the contrary, iodide leaching of gold from the bio-oxidized ore can be accomplished without any pH adjustment. The present study was undertaken in order to investigate the kinetics of gold dissolution in various iodide-oxidant solutions under conditions similar to those prevailing in a solution containing bio-oxidized ore. The thermodynamic study indicated that gold can be spontaneously dissolved in iodide-hydrogen peroxide, iodide-ferric ion and iodide-persulfate solutions. Dissolution of gold powder was carried out in these solutions and the results showed that the gold dissolution was dependent on solution pH, concentrations of iodide, oxidants and temperature. Gold dissolution was found to increase with decreasing pH and substantial gold dissolution could be achieved at pH ≤ 2. Increasing concentration of oxidant till an optimum oxidant/iodide molar ratio increased gold dissolution and much higher concentration of oxidant would result in a decrease in gold dissolution. With increasing iodide concentration and temperature, gold dissolution increased significantly. The activation energy data which ranged between 9.6 and 13.6 kcal/mole for various oxidants indicated that surface reaction was the rate controlling step. At higher temperatures a change in rate limiting step with passage of time was observed

  8. The BRomine, Ozone, and Mercury EXperiment (BROMEX)

    Science.gov (United States)

    Nghiem, S. V.; Shepson, P. B.; Simpson, W. R.; Perovich, D. K.; Sturm, M.; Douglas, T. A.; Rigor, I. G.; Clemente-Colon, P.; Burrows, J. P.; Richter, A.; Bottenheim, J. W.; Steffen, A.; Barber, D. G.; Kaleschke, L.; Hall, D. K.; Markus, T.; Eicken, H.; Neumann, G.

    2011-12-01

    In the decade of the 2000s, Arctic perennial (multi-year) sea ice has diminished drastically, whereas seasonal (first-year) sea ice has become the dominant ice class. This change effectively increases the overall surface salinity of the sea ice cover and in the overlying snowpack. Satellite results in 2010 and 2011 show the extent of perennial sea ice remains minimal with significant bromine explosions in the springtime. Key science questions still remain to be answered to understand the impact of the Arctic perennial sea ice reduction on low-atmospheric physical and chemical processes. Of the highest priority is to investigate the impact on bromine explosion events that lead to depletion of ozone and gaseous elementary mercury in the atmosphere. With that objective, we present the development of the BRomine, Ozone, and Mercury EXperiment in (BROMEX) in spring 2012 around Barrow, extending out to 200 km offshore and inland. In BROMEX, chemical, sea ice, snow, and ocean measurements will be made across sea ice leads both upwind and downwind areas of newly opened leads. Chemical-measurement buoys and other types of buoys will be deployed with helicopter flights to both sides of the leads. Various flight patterns of aircraft carrying ozone and bromine-measuring sensors will be used to characterize the chemical distribution over sea ice, land, and mountainous regions. Our approach will use data from multiple satellite instruments including MODIS, AMSR-E, QuikSCAT, GOME-2, SCIAMACHY, OMI, RADARSAT-2, Envisat ASAR, TerraSAR-X, TanDEM-X, SMOS, CryoSat-2 altimeter, and Oceansat-2 scatterometer. Moreover, results from recent field campaigns such as the IPY OASIS, INCATPA, CFL, SALT, and IceBridge, from sea ice and snow products generated by the U.S. Naval and National Ice Center, from NASA cryospheric observations, and from surface observation networks such as SIZONet will be utilized together with new measurements from BROMEX. Further collaborations with the international

  9. Experimental study on preparing gaseous methyl iodide by chlorotrimelthylsilane/sodium iodide

    International Nuclear Information System (INIS)

    The experiments were carried out to study the feasibility of substituting the extremely toxic dimethyl sulfate (DMS) with nontoxic reagents in preparing the gaseous methyl iodide to measure the scrubbing efficiency of iodine adsorber. The test results show that the reaction of chlorotrimelthylsilane/sodium iodide (or potassium iodide) as a iodating agent and phosphate methylesters is a good substitution method, the reaction conditions and productivity of methyl iodide can meet the requirements of both workshop and in-place tests of iodine adsorber, and the substitutes have little influence on the nuclear grade immersed activated carbon filled in the iodine adsorber. The substitution method can substitute the DMS method to prepare gaseous methyl iodide. (authors)

  10. Plasma etching of cesium iodide

    International Nuclear Information System (INIS)

    Thick films of cesium iodide (CsI) are often used to convert x-ray images into visible light. Spreading of the visible light within CsI, however, reduces the resolution of the resulting image. Anisotropic etching of the CsI film into an array of micropixels can improve the image resolution by confining light within each pixel. The etching process uses a high-density inductively coupled plasma to pattern CsI samples held by a heated, rf-biased chuck. Fluorine-containing gases such as CF4 are found to enhance the etch rate by an order of magnitude compared to Ar+ sputtering alone. Without inert-gas ion bombardment, however, the CF4 etch becomes self-limited within a few microns of depth due to the blanket deposition of a passivation layer. Using CF4+Ar continuously removes this layer from the lateral surfaces, but the formation of a thick passivation layer on the unbombarded sidewalls of etched features is observed by scanning electron microscopy. At a substrate temperature of 220 deg. C, the minimum ion-bombardment energy for etching is Ei∼50 eV, and the rate depends on Ei1/2 above 65 eV. In dilute mixtures of CF4 and Ar, the etch rate is proportional to the gas-phase density of atomic fluorine. Above 50% CF4, however, the rate decreases, indicating the onset of net surface polymer deposition. These observations suggest that anisotropy is obtained through the ion-enhanced inhibitor etching mechanism. Etching exhibits an Arrhenius-type behavior in which the etch rate increases from ∼40 nm/min at 40 deg. C to 380 nm/min at 330 deg. C. The temperature dependence corresponds to an activation energy of 0.13±0.01 eV. This activation energy is consistent with the electronic sputtering mechanism for alkali halides

  11. Formation of THMs and HANs during bromination of Microcystis aeruginosa

    Institute of Scientific and Technical Information of China (English)

    Yunzhu Pu; Lingzhao Kong; Xin Huang; Guoji Ding; Naiyun Gao

    2013-01-01

    Bromine-contained disinfectants and biocides are widely used in swimming pools,recreational waters and cooling towers.The objective of this study was to evaluate the formation of thrihalomethanes (THMs) and haloacetonitriles (HANs) and their cytotoxicity in algae solutions during free bromine disinfection.Disinfection by-products formation potential experiments were conducted using modelsolutions containing 7mg/L (as total organic carbon) Microcystis aeruginosa cells.Effects of free bromine dosage,pH and ammonia were investigated.The results showed that brominated disinfection by-products were the major products when free bromine was applied.The total THMs formed during bromination was much as that formed during chlorination,whereas HANs were elevated by using bromination instead of chlorination.Dibromoacetonitrice (C2H2NBr2) and bromoform (CHBr3) were the only detected species during free bromine disinfection.The production of C2H2NBr2 and CHBr3 increased with disinfectant dosage but decreased with dosing ammonia.CHBr3 increased with the pH changing from 5 to 9.However,C2H2NBr2 achieved the highest production at neutral pH,which was due to a joint effect of variation in hydrolysis rate and free bromine reactivity.The hydrolysis of C2H2NBr2 was basecatalytic and nearly unaffected by disinfectant.Finally,estimation of cytotoxicity of the disinfected algae solutions showed that HANs formation was responsible for the majority of toxicity.Considering its highest toxicity among the measured disinfection by-products,the elevated C2H2NBr2 should be considered when using bromine-related algaecide.

  12. New infrared spectroscopic database for bromine nitrate

    Science.gov (United States)

    Wagner, Georg; Birk, Manfred

    2016-08-01

    Fourier transform infrared measurements of bromine nitrate have been performed in the spectral region 675-1400 cm-1 at 0.014 cm-1 spectral resolution. Absorption cross sections were derived from 38 spectra covering the temperature range from 203 to 296 K and air pressure range from 0 to 190 mbar. For line-by-line analysis, further spectra were recorded at 0.00094 cm-1 spectral resolution at 223 and 293 K. The sample was synthesized from ClONO2 and Br2. Band strengths of the bands ν3 around 803 cm-1 and ν2 around 1286 cm-1 were determined from three pure BrONO2 measurements at different temperatures and pressures. Number densities in the absorption cell were derived from pressure measurements of the purified sample taking into account small amounts of impurities determined spectroscopically. Resulting band strengths are Sν3 = 2.872(52) × 10-17 cm2 molec-1 cm-1 and Sν2 = 3.63(15) × 10-17 cm2 molec-1 cm-1. Absorption cross sections of all measurements were scaled to these band strengths. Further data reduction was achieved with an interpolation scheme based on two-dimensional polynomials in ln(pressure) and temperature. The database is well-suited for remote-sensing application and should reduce the atmospheric bromine nitrate error budget substantially.

  13. Luminescent properties of calcium iodide crystals

    International Nuclear Information System (INIS)

    The influence of preparation conditions, temperature and X radiation on luminescent properties of calcium iodide scintillating crystals is studied, the results are provided. The results obtained when studying spectral characteristics of CaI2 and CaI2:H2 crystals in case of optical and X-ray excitation in the temperature range of 90-400 K, allowance made for data obtained when studying luminescent properties of calcium iodide crystals activated by Cl-, Br-, OH- and Ca2+ impurities, permit assumption that band 236 nm observed in excitation spectra of calcium iodide crystals can stem from noncontrolled hydrogen impurity. Luminescence of the crystals with the maximum in the range of 395 nm is assigned to radiation recombination of excitons localized on H- ions

  14. Adsorption of radioactive iodide by natural zeolites

    International Nuclear Information System (INIS)

    Two natural zeolites from Iranian deposits (clinoptilolite and natrolite) were characterized and their ability for adsorption of iodide from nuclear wastewaters was evaluated. The adsorption behavior was studied on natural and modified zeolites by γ-spectrometry using 131I as radiotracer. Adsorption isotherms and distribution coefficient (Kd) were measured. The results showed that clinoptilolite is a more promising zeolite for removal of iodide compared to natrolite. Furthermore, the adsorption was higher in silver, lead and thallium forms, whereas the lowest desorption was observed in lead modified zeolite. (author)

  15. The partitioning of iodides into steam

    International Nuclear Information System (INIS)

    In order to estimate the likely releases of radioactive iodine during steam generator tube rupture (SGTR) faults, it is necessary to know the relevant partition coefficients as a function of temperature and solution composition. It has been suggested previously that, under SGTR fault conditions, partitioning of free or ion-paired I- into the steam may be more extensive than that for molecular HI. This report uses available information on the partitioning of iodides and other salts to provide a means of estimating the partition coefficient of the iodide ion as a function of boric acid concentration and temperature. (author)

  16. Kinetic Isotope Effects in the Reduction of Methyl Iodide

    DEFF Research Database (Denmark)

    Holm, Torkil

    1999-01-01

    a-Deuterium kinetic isotope effects (KIE's) have been determined for the reaction of methyl iodide with a series of reducing agents. Reagents which transfer hydride ion in an SN2 reaction show small inverse or small normal KIE's. Reagents which transfer an electron to methyl iodide to produce...... methyl radical show large normal KIE's up to 20 % per a-D. Large KIE's were found for the reaction of methyl iodide with sodium, for Pd-catalyzed reaction of methyl iodide with hydrogen, for ET at a platinum cathode, for ET from benzophenone ketyl or from sodium naphthalenide, for iron catalyzed ET from...... a Grignard reagent to methyl iodide, and for reduction of methyl iodide with tributyltin hydride or with gaseous hydrogen iodide. Very small KIE's were found for electron transfer to methyl iodide from magnesium in ether or from sodium in ammonia. The reason may be that these reactions are transport...

  17. Ruthenium-Catalyzed meta-Selective C—H Bromination

    Science.gov (United States)

    Teskey, Christopher J; Lui, Andrew Y W; Greaney, Michael F

    2015-01-01

    The first example of a transition-metal-catalyzed, meta-selective C–H bromination procedure is reported. In the presence of catalytic [{Ru(p-cymene)Cl2}2], tetrabutylammonium tribromide can be used to functionalize the meta C–H bond of 2-phenylpyridine derivatives, thus affording difficult to access products which are highly predisposed to further derivatization. We demonstrate this utility with one-pot bromination/arylation and bromination/alkenylation procedures to deliver meta-arylated and meta-alkenylated products, respectively, in a single step. PMID:26288217

  18. Ruthenium-Catalyzed meta-Selective C—H Bromination

    OpenAIRE

    Teskey, Christopher J; Lui, Andrew Y W; Greaney, Michael F.

    2015-01-01

    The first example of a transition-metal-catalyzed, meta-selective C–H bromination procedure is reported. In the presence of catalytic [{Ru(p-cymene)Cl2}2], tetrabutylammonium tribromide can be used to functionalize the meta C–H bond of 2-phenylpyridine derivatives, thus affording difficult to access products which are highly predisposed to further derivatization. We demonstrate this utility with one-pot bromination/arylation and bromination/alkenylation procedures to deliver meta-arylated and...

  19. Magnetic Trapping of Cold Bromine Atoms

    CERN Document Server

    Rennick, C J; Doherty, W G; Softley, T P

    2014-01-01

    Magnetic trapping of bromine atoms at temperatures in the milliKelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br$_2$ molecules in a molecular beam. The lab-frame velocity of Br atoms is controlled by the wavelength and polarization of the photodissociation laser. Careful selection of the wavelength results in one of the pair of atoms having sufficient velocity to exactly cancel that of the parent molecule, and it remains stationary in the lab frame. A trap is formed at the null point between two opposing neodymium permanent magnets. Dissociation of molecules at the field minimum results in the slowest fraction of photofragments remaining trapped. After the ballistic escape of the fastest atoms, the trapped slow atoms are only lost by elastic collisions with the chamber background gas. The measured loss rate is consistent with estimates of the total cross section for only those collisions transferring sufficient kinetic energy to overcome the trapping potential...

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

    Science.gov (United States)

    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.

  1. Developments in mercuric iodide gamma ray imaging

    International Nuclear Information System (INIS)

    A mercuric iodide (HgI2) gamma ray imaging array and camera system previously described have been characterized for spatial and energy resolution. Based on these data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criteria for the new camera will be presented. (orig.)

  2. Developments in mercuric iodide gamma ray imaging

    Science.gov (United States)

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

    1989-11-01

    A mercuric iodide (HgI2) gamma ray imaging array and camera system previously described have been characterized for spatial and energy resolution. Based on these data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criteria for the new camera will be presented.

  3. Developments in mercuric iodide gamma ray imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

    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.

  4. Developments in mercuric iodide gamma ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Patt, B.E.; Beyerle, A.G.; Dolin, R.C.; Ortale, C. (EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations)

    1989-11-01

    A mercuric iodide (HgI{sub 2}) gamma ray imaging array and camera system previously described have been characterized for spatial and energy resolution. Based on these data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criteria for the new camera will be presented. (orig.).

  5. Scintillator handbook with emphasis on cesium iodide

    Science.gov (United States)

    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.

  6. 21 CFR 184.1634 - Potassium iodide.

    Science.gov (United States)

    2010-04-01

    ... ingredient meets the specifications of the “Food Chemicals Codex,” 3d Ed. (1981), pp. 246-247, which is... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 184.1634 Section 184.1634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  7. Iodide-trapping defect of the thyroid

    International Nuclear Information System (INIS)

    We describe a grossly hypothyroid 50-year-old woman, mentally retarded since birth. On the basis of her history of recurrent goitre, absence of 131I neck uptake and a low saliva/plasma 131I ratio, congenital hypothyroidism due to a defect of the iodide-trapping mechanism was diagnosed. Other family members studied did not have the defect

  8. Cu-catalyzed trifluoromethylation of aryl iodides with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide

    OpenAIRE

    Yuzo Nakamura; Motohiro Fujiu; Tatsuya Murase; Yoshimitsu Itoh; Hiroki Serizawa; Kohsuke Aikawa; Koichi Mikami

    2013-01-01

    The trifluoromethylation of aryl iodides catalyzed by copper(I) salt with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide and Zn dust was accomplished. The catalytic reactions proceeded under mild reaction conditions, providing the corresponding aromatic trifluoromethylated products in moderate to high yields. The advantage of this method is that additives such as metal fluoride (MF), which are indispensable to activate silyl groups for transmetallation in the corresp...

  9. Determining Of Iodide Concentration In Salt Using Iodide Ion Selective Electrode

    International Nuclear Information System (INIS)

    There are various studies about the determination of iodide or iodinate in table salt samples. Iodo metric method (5), spectrophotometric method(8), gravimetric method (2), chromatographic method (6), differential potentiometric method (3).But with ion selective electrode technicality the determination of iodide in geothermal water was only determined. So, in this work, the concentration of iodide in control table salt, iodinate table salt samples were determination, using iodide ion selective electrode . Iodide calibration graph was plotted according to the standard method, and the results of control salt samples which contain a defined concentration of iodide, and known amount of ionic strength adjustment buffer, were compatible with the assigned values. The linearity and sensitivity of method were studied, the results were 50 mg.L-1 and 0.2 mg.L-1 respectively . While, when the method applied on iodinate table salt samples which contain a amount concentration of potassium iodate (KIO3), the results were inconsistent. So, we had to convert the KIO3 to I-1 with oxidation - reduction reaction. By using convenient reduction in acidic medium . Iodate calibration graph was plotted according to the last standard method, and the results of control iodinate table salt samples were good with relative standard deviation was 3 %. (author)

  10. The metabolism and de-bromination of bromotyrosine in vivo

    NARCIS (Netherlands)

    A.R. Mani (Ali); J.C. Moreno (José C.); T.J. Visser (Theo J.); K.P. Moore (Kevin P.)

    2016-01-01

    textabstractDuring inflammation, leukocyte-derived eosinophil peroxidase catalyses the formation of hypobromous acid, which can brominate tyrosine residues in proteins to form bromotyrosine. Since eosinophils are involved in the pathogenesis of allergic reactions, such as asthma, urinary bromotyrosi

  11. Bromine number should replace FIA in gasoline olefins testing

    International Nuclear Information System (INIS)

    Fluorescent indicator adsorption (FIA) analysis, the ASTM test method proposed by the U.S. Environmental Protection Agency (EPA) for monitoring olefins in reformulated gasoline, is subject to significant bias and imprecision. This paper reports on a more accurate, environmentally pertinent measure of olefin content in reformulated gasoline is bromine number another ASTM method. Petroleum chemists should therefore work together with the EPA to select and optimize a bromine number procedure specifically designed for reformulated gasoline to replace FIA

  12. Transfer of the human sodium/iodide symporter gene enhances iodide uptake in melanoma cells

    International Nuclear Information System (INIS)

    Aim: Radioiodide therapy using 131I is effective for patients who have benign thyroid diseases or differentiated thyroid carcinoma. The transport of iodide across the cell membrane is mediated by the human sodium/iodide symporter (hNIS). To investigate the feasibility of 131I therapy for melanoma, we established melanoma cells stably expressing hNIS gene that can be modulated and studied in vivo and in vitro. Material and Methods: We transfected hNIS gene into a mouse melanoma cell line (B16) by electroporation. Iodide accumulation was assessed under various extracellular concentrations of sodium and iodide, and iodide efflux was also evaluated. Biodistribution and tumor imaging were studied using tumor-bearing mice. Results: We established a novel cell line B16-3 stably expressing the hNIS gene from B16. 125I uptake by B16-3 cells is between 6-17-fold that of B16 cells and 8-33-fold that of cell lines transduced with the eukaryotic expression vector pcDNA3 only. Iodide uptake was completely inhibited by 1mmol/L perchlorate and was dependent on external sodium and iodide concentrations. The velocity of iodide efflux from B16-3 cells was almost equal to that of FRTL-5 thyroid cells (T1/2 = 4min). In the biodistribution study using B16-3-xenografted mice, high tumor uptake of 131I was shown at 1 hour after injection, and tumor-to-normal tissue ratios were also high, except in the thyroid and stomach. However, the residual iodide in tumor lessened with time, reaching less than 3% at 24 h after injection. Conclusion: The transduction of he hNIS gene per se is sufficient to induce iodide transport in melanoma cells in vivo and in vitro. With regard to therapeutic application, however, further investigation is necessary to determine a method of maintaining radioiodide in the cells long enough to produce greater therapeutic effects

  13. Mercuric iodide X-ray camera

    Science.gov (United States)

    Patt, B. E.; del Duca, A.; Dolin, R.; Ortale, C.

    1986-02-01

    A prototype X-ray camera utilizing a 1.5- by 1.5-in., 1024-element, thin mercuric iodide detector array has been tested and evaluated. The microprocessor-based camera is portable and operates at room temperature. Events can be localized within 1-2 mm at energies below 60 keV and within 5-6 mm at energies on the order of 600 keV.

  14. Mercuric iodide x-ray camera

    International Nuclear Information System (INIS)

    A prototype x-ray camera utilizing a 1.5- by 1.5-in., 1024-element, thin mercuric iodide detector array has been tested and evaluated. The microprocessor-based camera is portable and operates at room temperature. Events can be localized within 1 to 2 mm at energies below 60 keV and within 5 to 6 mm at energies on the order of 600 keV. 5 refs., 7 figs

  15. Mercuric iodide X-ray camera

    Energy Technology Data Exchange (ETDEWEB)

    Patt, B.E.; Del Duca, A.; Dolin, R.; Ortale, C.

    1986-02-01

    A prototype x-ray camera utilizing a 1.5- by 1.5-inch, 1024-element, thin mercuric iodide detector array has been tested and evaluated. The microprocessor-based camera is portable and operates at room temperature. Events can be localized within 1-2 mm at energies below 60 keV and within 5-6 mm at energies on the order of 600 keV.

  16. Mercuric iodide x-ray camera

    Energy Technology Data Exchange (ETDEWEB)

    Patt, B.E.; Del Duca, A.; Dolin, R.; Ortale, C.

    1985-01-01

    A prototype x-ray camera utilizing a 1.5- by 1.5-in., 1024-element, thin mercuric iodide detector array has been tested and evaluated. The microprocessor-based camera is portable and operates at room temperature. Events can be localized within 1 to 2 mm at energies below 60 keV and within 5 to 6 mm at energies on the order of 600 keV. 5 refs., 7 figs.

  17. Mercuric iodide X-ray camera

    International Nuclear Information System (INIS)

    A prototype x-ray camera utilizing a 1.5- by 1.5-inch, 1024-element, thin mercuric iodide detector array has been tested and evaluated. The microprocessor-based camera is portable and operates at room temperature. Events can be localized within 1-2 mm at energies below 60 keV and within 5-6 mm at energies on the order of 600 keV

  18. Composition and properties of thallium mercury iodide

    Science.gov (United States)

    Kennedy, John H.; Schaupp, Christopher; Yang, Yuan; Zhang, Zhengming; Novinson, Thomas; Hoffard, Theresa

    1990-10-01

    Conflicting reports exist in the literature concerning the composition of thallium mercury iodide. Solid state synthesis with HgI 2 and TlI has been reported to give Tl 4HgI 6 while synthesis from solution has been reported to give Tl 2HgI 4. In this report we show that the "orange compound" precipitating from solution is actually a 1:1 mole ratio mixture of Tl 4HgI 6 and HgI 2. Pure Tl 4HgI 6, which is yellow, can be produced by heating the mixture at 100°C for several days to volatilize HgI 2 or more simply, by adding Tl(I) to a solution containing 2:1 KI:K 2HgI 4 to provide the additional iodide ions needed for Tl 4HgI 6. Tl 4HgI 6, unlike Ag 2HgI 4 and Cu 2HgI 4, has no sharp thermochromic changes and has no measurable ionic conductivity. This provides another example of the significant role the metal ion plans in determining structure and properties of metal mercury iodide compounds.

  19. Probing the tropical tropopause layer for organic and inorganic bromine

    Science.gov (United States)

    Werner, Bodo; Pfeilsticker, Klaus; Atlas, Elliot; Cheung, Ross; Chipperfield, Martyn; Colosimo, Fedele; Deutschmann, Tim; Elkins, Jim; Fahey, David; Feng, Wu; Festa, James; Gao, Ru-Shan; Hossaini, Ryan; Navarro, Maria; Raecke, Rasmus; Scalone, Lisa; Spolaor, Max; Thornberry, Troy; Tsai, Catalina; Stutz, Jochen

    2016-04-01

    Bromine chemistry impacts the levels of ozone in the upper troposphere and the stratosphere. An accurate quantitative understanding of the sources, sinks, and chemical transformation of bromine species is thus important to understand the photochemistry and budget of bromine in the tropical upper troposphere, tropopause layer and lowermost stratosphere (UT/TTL/LS). These regions are also known to serve as a gateway for delivery of ozone depleting gases to the stratosphere. CH3Br, halons, short-lived organic bromine precursors (VSLS), such as CHBr3, CH2Br2, and possibly inorganic product gases have been identified as the main bromine gases delivered to the stratosphere. However, many important details of the transport and delivery of VSLS and inorganic bromine compounds through the TTL are still uncertain. Moreover, a number of chemical processes, including the transformation of the source gases and cycling of inorganic bromine species at low ambient temperature and on ice particles are also poorly understood. The presentation reports measurements of CH4, O3, NO2, and BrO performed by different instruments and techniques during the 2013 NASA-ATTREX flights in the TTL and LS. The interpretation of our measurements is supported by chemical transport model (SLIMCAT) simulations. SLIMCAT results, in conjunction with extensive radiative transfer calculations using the Monte Carlo model McArtim, also are used to improve retrieval of O3, NO2, and BrO concentrations from limb scattered sunlight measurements made with the Differential Optical Absorption Spectroscopy (DOAS) technique during ATTREX. The chemical transport model also allows us to attribute observed concentration variations to transport and to photochemical processes. When properly accounting for the transport-related concentration variations in methane and ozone, we find that measured BrO mostly agrees with model simulations. An exception are regions where the contribution of the short-lived CH2Br2 or the

  20. Bromine pretreated chitosan for adsorption of lead (II) from water

    Indian Academy of Sciences (India)

    Rajendra Dongre; Minakshi Thakur; Dinesh Ghugal; Jostna Meshram

    2012-10-01

    Pollution by heavy metals like lead (II) is responsible for health hazards and environmental degradation. Adsorption is a prevalent method applied for removal of heavy metal pollutants from water. This study explored adsorption performances of 30% bromine pretreated chitosan for lead (II) abatement from water. Bromine pretreatment alters porosity and specific surface area of chitosan by means of physicochemical interaction with cationic sites of chitosan skeleton, besides imparting anionic alteration at amino linkages of chitosan, to remove lead (II) by chemical interactions on superfluous active sites as characterized by FTIR, SEM, DTA and elemental analysis. Lead adsorptions were studied in batch mode by varying parameters viz. pH, bromine loading, sorbent dosage, initial lead concentration, contact time and temperature. The adsorption equilibrium data was well fitted to Freundlich isotherm and maximum sorption capacity of 30% bromine pretreated chitosan sorbent was 1.755 g/kg with 85–90% lead removal efficiency. Though cost and applicability of sorbent is unproven, yet contrast to raw chitosan derivatives, activated carbons and some resins, 30% bromine pretreated chitosan endow benign and efficient lead abatement technique.

  1. Levels and trends of brominated flame retardants in the European environment

    NARCIS (Netherlands)

    Law, R.J.; Allchin, C.R.; Boer, de J.; Covaci, A.; Herzke, D.; Lepom, P.; Morris, S.; Tronczynski, J.; Wit, de C.A.

    2006-01-01

    In this paper, we review those data which have recently become available for brominated flame retardants (particularly the brominated diphenyl ethers (BDEs) and hexabromocyclododecane (HBCD)) in samples from the European environment. Environmental compartments studied comprise the atmosphere, sedime

  2. Effect of nitrogen and oxygen on radiolysis of iodide solution

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, H.; Endo, M. [Hitachi Ltd., Power and Industrial System R+D Divisions, Ibaraki (Japan)

    1996-12-01

    The effect of nitrogen and oxygen on radiolysis of iodide solution was examined. Direct decomposition of nitrogen by {gamma}-radiation produced nitric acid to decrease a water pH. This resulted in the iodine formation in the radiolysis of iodide solution. Hydrogen peroxide was produced by the radiolysis of water containing oxygen. This worked a reducing agent to suppress the formation of iodine in the radiolysis of iodide solution. In the analytical model, fourteen iodine species were considered and reaction scheme consisted in 124 reactions. The analytical model could estimate the oxidation state of iodide ions. (author) 4 figs., 4 refs.

  3. Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray...

  4. Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray spectrometers. Two...

  5. An Efficient and Facile Methodology for Bromination of Pyrimidine and Purine Nucleosides with Sodium Monobromoisocyanurate (SMBI

    Directory of Open Access Journals (Sweden)

    Roger Stromberg

    2013-10-01

    Full Text Available An efficient and facile strategy has been developed for bromination of nucleosides using sodium monobromoisocyanurate (SMBI. Our methodology demonstrates bromination at the C-5 position of pyrimidine nucleosides and the C-8 position of purine nucleosides. Unprotected and also several protected nucleosides were brominated in moderate to high yields following this procedure.

  6. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  7. Tritium and iodide diffusion through opalinus clay

    International Nuclear Information System (INIS)

    The International Mont Terri Project started in 1995 under the patronage of the Swiss National Hydrological and Geological Survey (SNHGS), and has the authorization of the Republique et Canton du Jura. The underground rock laboratory is located at the northwestern part of Switzerland (Canton Jura), in and beside the reconnaissance gallery of the Mont Terri motorway tunnel, one of the several tunnels of the A16 'Transjurane' motorway. The depth of overburden above the rock laboratory is approximately 300 meters. The project is aimed to investigate the geological, hydrogeological, geochemical and rock mechanical properties of the Opalinus Clay for assessing the feasibility and safety of a repository for radioactive waste placed in this type of host rock. One of the issues under study is radionuclide migration by diffusion through clays. As a part of this investigation, an interlaboratory comparison on small-scale diffusion experiments was carried out by three research laboratories: AEA Technology (UK), SCK-CEN (Belgium) and CIEMAT (Spain). The radionuclides investigated were tritium and iodine. This paper concerns to the methodological approach and results of the experiments undertaken by CIEMAT. The effective diffusion coefficients were measured for tritiated water and iodine (as Γ), resulting larger for tritium [(1.7±0.4)x10-11 m2/s] than for iodide [(2.7±0.3)x10-12 m2/s]. The porosity available for diffusion was calculated by using the time-lag method, but some results seemed unrealistic and showed a large variability. In general, tritium exhibited higher values of porosity than iodide (17 to 26% and 12 to 17%, respectively), which were consistent with the anion exclusion affecting the distribution of iodide into the clay pores. Copyright (2001) Material Research Society

  8. Transfer of the human sodium/iodide symporter gene enhances iodide uptake in melanoma cells

    International Nuclear Information System (INIS)

    Objective: To obtain human sodium/iodide symporter (hNIS) cDNA and to study its biological property and potential use as a therapeutic radioiodide for melanoma. Methods: hNIS gene cDNA was amplified with total RNA from human thyroid tissue by RT-PCR. The hNIS cDNA was inserted into cloning vector pUCm-T and subcloned into eukaryotic expression vector pcDNA3. The recombinant plasmid pcDNA3-hNIS was introduced into B16 cells using the electroporation technique. The uptake and efflux of iodide was examined in vitro. Results: The cloned hNIS cDNA sequence was identical to the published sequence. Two novel cell lines named B16-A containing hNIS and B16-B containing pcDNA3 only were established. The resultant cell line B16-A accumulated 17 and 19 times more radioiodide in vitro than B16 and B16-B did, respectively. However the efflux of iodide from B16-A was also rapid ( T1/2=10 min). Conclusions: Our preliminary data indicate that the transduction of the hNIS gene per se is sufficient to induce iodide transport in melanoma cells in vitro, but its T1/2 is short. With regard to therapeutic application, however, further investigation is necessary so as to develop a method of maintaining more radioiodide in the cells for long enough to produce greater therapeutic effects

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2016-02-01

    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. PMID:26745029

  11. Recent developments in thick mercuric iodide spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Hull, K.; Beyerle, A.; Lopez, B.; Markakis, J.; Ortale, C.; Schnepple, W.; van den Berg, L.

    1982-01-01

    Thick (approx. 1 cm) mercuric iodide gamma-ray detectors have been produced which show spectroscopic qualities at moderate detector biases (approx. 5 kV) comparable to those of thin spectrometers. Efficiency measurements indicate that the entire volume of the detectors is active. Spectra resolutions of less than 10% have been obtained for gamma-ray energies above 1 MeV. Short charge collection times have produced the best results. Measurement of crystal charge transport properties is discussed. A small amount of bias conditioning is necessary for best performance. Operating parameters of the detectors have been investigated.

  12. Large-area mercuric iodide photodectors

    Science.gov (United States)

    Markakis, J.; Ortale, C.; Schnepple, W.; Iwanczyk, J.; Dabrowski, A.

    1983-07-01

    The limits of the active area of mercuric iodide photodetectors imposed by the size of available crystals, electronic noise, and the uniformity of charge carrier collection are discussed. Theoretical calculations of the photodetector electronic noise are compared with the experimental results. Different entrance contacts were studied including semitransparent palladium films and conductive liquids. HgI2 photodetectors with active area up to 4 sq cm are matched with NaI(Tl) and CsI(Tl) scintillation crystals and are evaluated as gamma radiation spectrometers.

  13. Large-area mercuric iodide photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Markakis, J.; Ortale, C.; Schnepple, W.; Iwanczyk, J.; Dabrowski, A.

    1983-01-01

    This article discusses the limits of the active area of mercuric iodide photodetectors imposed by the size of available crystals, electronic noise, and the uniformity of charge carrier collection. Theoretical calculations of the photodetector electronic noise are compared with the experimental results. Different entrance contacts were studied including semitransparent palladium films and conductive liquids. HgI/sub 2/ photodetectors with active area up to 4 sq cm are matched with NaI(Tl) and CsI(Tl) scintillation crystals and are evaluated as gamma radiation spectrometers.

  14. The addition of iodine to tetramethylammonium iodide

    Science.gov (United States)

    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.

  15. Novel mercuric iodide polycrystalline nuclear particles counters

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M. [Hebrew Univ. of Jerusalem (Israel)]|[Sandia National Lab., Livermore, CA (United States); Zuck, A.; Braiman, M.; Nissenbaum, J. [Hebrew Univ. of Jerusalem (Israel)] [and others

    1996-12-31

    Polycrystalline mercuric iodide nuclear radiation detectors having areas between 0.01 to 100 cm{sup 2} and thicknesses 30 to 600 microns, have been fabricated with single, linear strip and square pixel contact. The large area detectors 10 to 600 cm{sup 2} were produced by industrial ceramic equipment while the smaller ones, about 1 cm{sup 2} area, were produced in the laboratory. The large detectors still had large leakage currents and the production process is being revised. The smaller detectors were tested and their response to lower and higher gamma energy, beta and even 100 GeV muons at CERN will be reported.

  16. Novel mercuric iodide polycrystalline nuclear particles counters

    International Nuclear Information System (INIS)

    Polycrystalline mercuric iodide nuclear radiation detectors having areas between 0.01 to 100 cm2 and thicknesses 30 to 600 microns, have been fabricated with single, linear strip and square pixel contact. The large area detectors 10 to 600 cm2 were produced by industrial ceramic equipment while the smaller ones, about 1 cm2 area, were produced in the laboratory. The large detectors still had large leakage currents and the production process is being revised. The smaller detectors were tested and their response to lower and higher gamma energy, beta and even 100 GeV muons at CERN will be reported

  17. Large-area mercuric iodide photodetectors

    International Nuclear Information System (INIS)

    This article discusses the limits of the active area of mercuric iodide photodetectors imposed by the size of available crystals, electronic noise, and the uniformity of charge carrier collection. Theoretical calculations of the photodetector electronic noise are compared with the experimental results. Different entrance contacts were studied including semitransparent palladium films and conductive liquids. HgI2 photodetectors with active area up to 4 sq cm are matched with NaI(Tl) and CsI(Tl) scintillation crystals and are evaluated as gamma radiation spectrometers

  18. Electronic and optical properties of lead iodide

    DEFF Research Database (Denmark)

    Ahuja, R.; Arwin, H.; Ferreira da Silva, A.;

    2002-01-01

    The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising...... detector material with a large technological applicability. Its band-gap energy as a function of temperature has also been measured by optical absorption. The temperature dependence has been fitted by two different relations, and a discussion of these fittings is given. ©2002 American Institute of Physics....

  19. Phase 2 Methyl Iodide Deep-Bed Adsorption Tests

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, Nick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    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 methyl 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.

  20. 21 CFR 520.763 - Dithiazanine iodide oral dosage forms.

    Science.gov (United States)

    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... Dithiazanine iodide oral dosage forms....

  1. Experimental research on performance of gaseous methyl iodide removal

    International Nuclear Information System (INIS)

    Under the circumstance of gaseous methyl iodide removal process in containment venting system, taking the deionized water and alkalescent sodium thiosulphate as absorber, the experimental researches on the performance of gaseous methyl iodide removal were carried out at different solution temperatures and concentrations. And the effects of two types of mechanisms, namely mass transfer and chemical reaction, on gaseous methyl iodide removal process were analyzed based on the experimental results. The research results show that at room temperature, the mass transfer mechanism plays a dominant role in gaseous methyl iodide removal process through the absorption of alkalescent sodium thiosulphate solution. Thus, the slow chemical reaction rate is the major factor that limits gaseous methyl iodide removal efficiency. With temperature increasing, the effect of chemical reaction is constantly enhanced in the methyl iodide removal process. However, the gas absorption process will get into an insensitive region when the reaction rate reaches to a certain point and the continuously enhancing chemical reaction rate will not greatly influence the removal efficiency. At that point, mass transfer performance becomes the major factor that limits gaseous methyl iodide removal process. The efficiency of gaseous methyl iodide removal can be further improved by necessary means of enhancing mass transfer process through increasing contact surface and so on. (authors)

  2. Dissolution of gaseous methyl iodide into aqueous sodium hydroxide solutions

    International Nuclear Information System (INIS)

    Absorption process of gaseous methyl iodide by water or sodium hydroxide solutions was investigated using a semi-flow type experimental apparatus by measuring the concentration of all measurable chemical species in both the gas and the liquid phase. The experimental temperature ranged from 288 to 311 K and the gaseous methyl iodide and aqueous sodium hydroxide concentrations were approximately 0.6 x 10-3 to 7 x 10-3 and 0 to 0.2 mol/dm3, respectively. It is estimated that the dissolution of methyl iodide into the sodium hydroxide solution proceeds according to the following steps. Step (1) Methyl iodide in air dissolves physically into the aqueous phase. Physical dissolution process obeys Henry's law. Step (2) Methyl iodide dissolved into the aqueous phase is decomposed by a base catalytic hydrolysis and produces methyl alcohol and iodide ion. The equilibrium constants of physical dissolution were obtained from the steady concentration in both the gas and the liquid phases in the semi-flow type experiment because the hydrolysis reaction rate of methyl iodide is very slow in comparison with the physical dissolution in this experimental conditions. The obtained value of the standard heat of solution of methyl iodide into water was 7.2 kcal/mol. Salting-out effect was observed when the concentration of sodium hydroxide in the absorbent was over 0.01 mol/dm3. (auth.)

  3. Iodide sensing via electrochemical etching of ultrathin gold films

    International Nuclear Information System (INIS)

    Iodide is an essential element for humans and animals and insufficient intake is still a major problem. Affordable and accurate methods are required to quantify iodide concentrations in biological and environmental fluids. A simple and low cost sensing device is presented which is based on iodide induced electrochemical etching of ultrathin gold films. The sensitivity of resistance measurements to film thickness changes is increased by using films with a thickness smaller than the electron mean free path. The underlying mechanism is demonstrated by simultaneous cyclic voltammetry experiments and resistance change measurements in a buffer solution. Iodide sensing is conducted in buffer solutions as well as in lake water with limits of detection in the range of 1 μM (127 μg L−1) and 2 μM (254 μg L−1), respectively. In addition, nanoholes embedded in the thin films are tested for suitability of optical iodide sensing based on localized surface plasmon resonance. (paper)

  4. Brominated Dioxins: Little-Known New Health Hazards - A Review

    Directory of Open Access Journals (Sweden)

    Piskorska-Pliszczyńska Jadwiga

    2014-10-01

    Full Text Available This article reviews the present state of the science concerning the polybrominated dibenzo-p-dioxins (PBDDs and dibenzofurans (PBDFs. Everywhere in the world people are exposed to anthropogenic origin chemicals. Some of them are long-lived organic compounds, which persist over the years in the environment. Persistent organic pollutants, such as organohalogen compounds, accumulate in environmental and biological compartments and have adverse effects on the health of humans and animals. Little is known about the brominated and mixed chloro/bromo dioxin and furans. Existing literature suggests that brominated dioxins and furans have similar toxicity profiles to their chlorinated analogues. The exposure data are extremely limited, showing a major data gap in estimating the potential environmental and health risk of these chemicals. The rapid increase in the use of brominated flame retardants (the main source of these pollutants has raised the level of concern over environmental and health damage from brominated dioxins and furans. It is likely that human as well as wildlife exposure to these contaminants will increase with their greater use. The findings reported here present strong evidence of the PBDDs and PBDFs as an emerging new class of contaminants.

  5. Ecotoxicity and biodegradability of new brominated flame retardants: A review

    Czech Academy of Sciences Publication Activity Database

    Ezechiáš, Martin; Covino, Stefano; Cajthaml, Tomáš

    2014-01-01

    Roč. 110, č. 2 (2014), s. 153-167. ISSN 0147-6513 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Ecotoxicity * brominated flame retardants * biodegradation * review Subject RIV: EE - Microbiology, Virology Impact factor: 2.762, year: 2014

  6. Discovery of Zinc, Selenium, Bromine, and Neodymium Isotopes

    OpenAIRE

    J.L. Gross; Claes, J.; Kathawa, J.; Thoennessen, M

    2010-01-01

    Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  7. 21 CFR 180.30 - Brominated vegetable oil.

    Science.gov (United States)

    2010-04-01

    ... “Food Chemicals Codex,” 3d Ed. (1981), pp. 40-41, which is incorporated by reference, except that free... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brominated vegetable oil. 180.30 Section 180.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  8. Discovery of zinc, selenium, bromine, and neodymium isotopes

    International Nuclear Information System (INIS)

    Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine, and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  9. Bromine provides new weapons to combat mercury emissions

    Energy Technology Data Exchange (ETDEWEB)

    Hardtke, W. [Albermarle Europe (Germany)

    2011-04-15

    Brominated powdered activated carbon has been demonstrated to capture over 90% of mercury emissions from coal fired plants, operating at high temperatures and capturing the metal in concrete-friendly, non-leaching forms to help tackle a rising global health threat. 6 refs., 5 figs.

  10. Bromine measurements in ozone depleted air over the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    J. A. Neuman

    2010-07-01

    Full Text Available In situ measurements of ozone, photochemically active bromine compounds, and other trace gases over the Arctic Ocean in April 2008 are used to examine the chemistry and geographical extent of ozone depletion in the arctic marine boundary layer (MBL. Data were obtained from the NOAA WP-3D aircraft during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC study and the NASA DC-8 aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS study. Fast (1 s and sensitive (detection limits at the low pptv level measurements of BrCl and BrO were obtained from three different chemical ionization mass spectrometer (CIMS instruments, and soluble bromide was measured with a mist chamber. The CIMS instruments also detected Br2. Subsequent laboratory studies showed that HOBr rapidly converts to Br2 on the Teflon instrument inlets. This detected Br2 is identified as active bromine and represents a lower limit of the sum HOBr + Br2. The measured active bromine is shown to likely be HOBr during daytime flights in the arctic. In the MBL over the Arctic Ocean, soluble bromide and active bromine were consistently elevated and ozone was depleted. Ozone depletion and active bromine enhancement were confined to the MBL that was capped by a temperature inversion at 200–500 m altitude. In ozone-depleted air, BrO rarely exceeded 10 pptv and was always substantially lower than soluble bromide that was as high as 40 pptv. BrCl was rarely enhanced above the 2 pptv detection limit, either in the MBL, over Alaska, or in the arctic free troposphere.

  11. Conserved charged amino acid residues in the extracellular region of sodium/iodide symporter are critical for iodide transport activity

    Directory of Open Access Journals (Sweden)

    Liang Ji-An

    2010-11-01

    Full Text Available Abstract Background Sodium/iodide symporter (NIS mediates the active transport and accumulation of iodide from the blood into the thyroid gland. His-226 located in the extracellular region of NIS has been demonstrated to be critical for iodide transport in our previous study. The conserved charged amino acid residues in the extracellular region of NIS were therefore characterized in this study. Methods Fourteen charged residues (Arg-9, Glu-79, Arg-82, Lys-86, Asp-163, His-226, Arg-228, Asp-233, Asp-237, Arg-239, Arg-241, Asp-311, Asp-322, and Asp-331 were replaced by alanine. Iodide uptake abilities of mutants were evaluated by steady-state and kinetic analysis. The three-dimensional comparative protein structure of NIS was further modeled using sodium/glucose transporter as the reference protein. Results All the NIS mutants were expressed normally in the cells and targeted correctly to the plasma membrane. However, these mutants, except R9A, displayed severe defects on the iodide uptake. Further kinetic analysis revealed that mutations at conserved positively charged amino acid residues in the extracellular region of NIS led to decrease NIS-mediated iodide uptake activity by reducing the maximal rate of iodide transport, while mutations at conserved negatively charged residues led to decrease iodide transport by increasing dissociation between NIS mutants and iodide. Conclusions This is the first report characterizing thoroughly the functional significance of conserved charged amino acid residues in the extracellular region of NIS. Our data suggested that conserved charged amino acid residues, except Arg-9, in the extracellular region of NIS were critical for iodide transport.

  12. Carrier traps and transport in mercuric iodide

    Science.gov (United States)

    Schlesinger, T. E.; Bao, X. J.; James, R. B.; Cheng, A. Y.; Ortale, C.; van den Berg, L.

    1992-11-01

    Thermally stimulated current spectroscopy (TSC) was performed on a variety of mercuric iodide samples and detectors to determine the nature and origin of deep traps in this material. It is shown that the trap type and concentration is a function of the metal overlayer employed as a contact material. The energy barrier height as well as the type (electron or hole) of barrier at the metal/semiconductor interface has also been determined by internal photoemission measurements. When polarization effects are not present, as is the case in most Pd contacted samples, the barrier height can be accurately determined by this technique. A value of 1.05 eV was measured for a hole barrier at the Pd/Hgl 2 interface.

  13. Ferroelastic Fingerprints in Methylammonium Lead Iodide Perovskite

    KAUST Repository

    Hermes, Ilka M.

    2016-02-12

    Methylammonium lead iodide (MAPbI3) perovskite materials show an outstanding performance in photovoltaic devices. However, certain material properties, especially the possible ferroic behavior, remain unclear. We observed distinct nanoscale periodic domains in the piezoresponse of MAPbI3(Cl) grains. The structure and the orientation of these striped domains indicate ferroelasticity as their origin. By correlating vertical and lateral piezoresponse force microscopy experiments performed at different sample orientations with x-ray diffraction, the preferred domain orientation was suggested to be the a1-a2-phase. The observation of these ferroelastic fingerprints appears to strongly depend on the film texture and thus the preparation route. The formation of the ferroelastic twin domains could be induced by internal strain during the cubic-tetragonal phase transition.

  14. Why does bromine square palladium off? An ab initio study of brominated palladium and its nanomorphology.

    Science.gov (United States)

    Yoo, Su-Hyun; Lee, Ji-Hwan; Delley, Bernard; Soon, Aloysius

    2014-09-14

    A first-principles description and prediction of brominated nanocrystals of Pd is presented. In particular, we conducted an extensive study of the adsorption behaviour of Br on various Pd surfaces (including both low and high Miller-index surfaces) as a function of its surface coverage. By coupling our calculated surface energies with ab initio (electrochemical) thermodynamics and the Gibbs-Wulff shape model, we find that the relative stability of the Pd surfaces is strongly modified by Br, allowing high Miller-index surfaces of Pd (namely the (210) surface) to become competitively favourable at moderate concentrations of Br. We also show that Pd nanoparticles assume a cube-like crystal shape at high concentrations of Br, exposing mainly the (100) facets with a Br surface coverage of 0.5 ML. This not only confirms and explains recent solution synthesis results, but also provides a quantitative atomic picture of the exposed surface facets, which is crucial in understanding the local surface chemistry of shape-controlled nanoparticles for better nanocatalyst design. PMID:25075669

  15. Occurrence of bromine in fluidised bed combustion of solid recovered fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vainikka, P.

    2011-12-15

    Corrosive ash species are the single most important factor limiting the electric efficiency of steam boiler plants fired with waste or biomass. Chlorine has been found to have a central role in the chemistry involved as it reduces the melting temperature of ash, forms corrosive vapour and gas species in the furnace and halogenated deposits on boiler heat transfer surfaces. In this context chlorine has been extensively researched. At the time of writing this thesis there was hardly any published data available on the occurrence of bromine (Br) in the aforementioned context. The objective of this work was to review the occurrence of bromine in solid fuels and characterise the behaviour of bromine in full-scale fluidised bed combustion. The review on the occurrence of bromine in solid fuels revealed that in anthropogenic wastes bromine is mainly found in connection to flame retarded substances. Several weight percentages of bromine can be found in plastics treated with brominated flame retardants (BFRs). Bromine is typically found some 100-200 mg kg-1 in mixed municipal solid wastes (MSW). Bromine may be enriched in fuels with high share of plastics, such as solid recovered fuel (SRF) or refuse derived fuel (RDF). Up to 2000 mg kg-1 was found as a monthly average in SRF, typical levels being 20-200 mg kg-1. Wastewater sludge from paper mills may contain bromine 20-100 mg kg-1 due the use of bromine based biocides. In other fuels bromine may be found in significant amounts in marine influenced coal deposits and peat as well as in biomass treated with brominated pesticides. In the experimental part SRF, spruce bark and wastewater sludge from a paper mill were co-fired in a full- scale bubbling fluidised bed (BFB) boiler, and the collected fuels, aerosols and waterwall deposits were analysed with the focus on the fate of bromine. Bromine was mainly found to form water soluble high vapour pressure alkali metal halides in the furnace - in the form of KBr(g) and NaBr(g) as

  16. Photoluminescence studies of impurities and defects in mercuric iodide

    International Nuclear Information System (INIS)

    The authors have studied the effects of chemical etching in potassium iodide(KI) aqueous solution, vacuum exposure and bulk heating on the photoluminescence(PL) spectra of mercuric iodide(HgI2). Different contact materials deposited onto HgI2 were also investigated, such as Pd, Cu, Al, Ni, Sn, In, Ag and Ta. These processing steps and the choice of a suitable electrode material are very important in the manufacturing of high-quality mercuric iodide nuclear detectors. Comparisons are made between the front surface photoluminescence and transmission photoluminescence spectra

  17. Electro regeneration of iodide loaded resin. Contributed Paper RD-18

    International Nuclear Information System (INIS)

    Spent resins generated in the nuclear reactor contain essentially cationic activities due to Cesium, Strontium, Cobalt, and anionic activities due to Iodide, Iodate etc with activity loading to the extent of 0.1 Cim-3 and a surface dose of the order of 5 R. It is necessary to convert the spent resin into innocuous, reusable forms. An attempt has been made to regenerate Iodide containing spent resin into OH- electrolytically by using the OH- produced at the cathode compartment of an electrolytic cell. Results show that the regeneration of the spent resin containing Iodide could be completely accomplished electrolytically more efficiently than by addition of alkali. (author)

  18. Expression of the human sodium/iodide symporter (hNIS) in xenotransplanted human thyroid carcinoma

    NARCIS (Netherlands)

    Smit, J.W.A.; Schröder - van der Elst, J.P.; Karperien, M.; Que, I.; Romijn, J.A.; Heide, van der D.

    2001-01-01

    The uptake of iodide in thyroid epithelial cells is mediated by the sodium/iodide symporter (NIS). The uptake of iodide is of vital importance for thyroid physiology and is a prerequisite for radioiodine therapy in thyroid cancer. Loss of iodide uptake due to diminished expression of the human NIS (

  19. The Effect on Sodium/Iodide Symporter and Pendrin in Thyroid Colloid Retention Developed by Excess Iodide Intake.

    Science.gov (United States)

    Chen, Xiao-Yi; Lin, Chu-Hui; Yang, Li-Hua; Li, Wang-Gen; Zhang, Jin-Wei; Zheng, Wen-Wei; Wang, Xiang; Qian, Jiang; Huang, Jia-Luan; Lei, Yi-Xiong

    2016-07-01

    It is well known that excess iodide can lead to thyroid colloid retention, a classic characteristic of iodide-induced goiter. However, the mechanism has not been fully unrevealed. Iodide plays an important role in thyroid function at multiple steps of thyroid colloid synthesis and transport among which sodium/iodide symporter (NIS) and pendrin are essential. In our study, we fed female BALB/c mice with different concentrations of high-iodine water including group A (control group, 0 μg/L), group B (1500 μg/L), group C (3000 μg/L), group D (6000 μg/L), and group E (12,000 μg/L). After 7 months of feeding, we found that excess iodide could lead to different degrees of thyroid colloid retention. Besides, NIS and pendrin expression were downregulated in the highest dose group. The thyroid iodide intake function detected by urine iodine assay and thyroidal (125)I experiments showed that the urine level of iodine increased, while the iodine intake rate decreased when the concentration of iodide used in feeding water increased (all p control group). In addition, transmission electron microscopy (TEM) indicated a reduction in the number of intracellular mitochondria of thyroid cells. Based on these findings, we concluded that the occurrence of thyroid colloid retention exacerbated by excess iodide was associated with the suppression of NIS and pendrin expression, providing an additional insight of the potential mechanism of action of excess iodide on thyroid gland. PMID:26660892

  20. Endocrine effects of some new brominated flame retardants

    Czech Academy of Sciences Publication Activity Database

    Ezechiáš, Martin; Svobodová, Kateřina; Cajthaml, Tomáš

    Praha : VŠCHT, 2012. s. 77-78. ISBN 978-80-7080-811-5. [Průmyslová ekologie /3./. 20.03.2012-23.03.2012, Hustopeče u Brna] R&D Projects: GA ČR GA104/09/0694 Institutional research plan: CEZ:AV0Z50200510 Keywords : Brominated flame retardants * Endocrine disruptors Subject RIV: EE - Microbiology, Virology

  1. Preparation and evaluation of mercuric iodide for crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, N.L.; Ortale, C.; Schieber, M.M.

    1988-01-01

    Large quantities, on the order of several hundred, of consistent, high quality mercuric iodide for crystal growth have not been commercially available. The hydrocarbon, anion, and cation impurity levels varied considerably, occasionally preventing crystal growth. This occurred even though the starting materials was from the same vendor and was subjected to the same purification treatment. This paper will describe an aqueous precipitation process of mercuric iodide preparation in batches of 3 kg using Hg(NO/sub 3/)/sub 2/ or HgCl/sub 2/and KI. Since these salts are produced in much larger quantities than mercuric iodide, more consistent quality is available. The impurity content of these batched and single crystals are compared. Some of the single crystals grown using the in-house prepared mercuric iodide have yielded a large number of spectroscopy grade nuclear radiation detectors. The influence of the major impuritites are discussed. 13 refs., 4 figs., 1 tab.

  2. Cesium iodide crystals fused to vacuum tube faceplates

    Science.gov (United States)

    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.

  3. Improved Stability of Mercuric Iodide Detectors for Anticoincidence Shields Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to utilize guard ring electrode structures and a new film growth technique to create improved polycrystalline mercuric iodide detectors for background...

  4. Kinetic determination of iodide by the oxidation reaction of benzidine with chloramine B

    International Nuclear Information System (INIS)

    Iodide catalyzed oxidation of benzidine with Chloramine B is studied for its possible application to kinetic determination of iodides. Based on the results of kinetic studies performed, optimal conditions for the catalytic reaction are revealed and a kinetic method for iodide determination is developed. The determination limit of iodide is 2x10-4 μg/ml. It was demonstrated that the proposed method can be used for the determination of iodides in water, soil, and kelp

  5. Prevention of organic iodide formation in BWR`s

    Energy Technology Data Exchange (ETDEWEB)

    Karjunen, T. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland); Laitinen, T.; Piippo, J.; Sirkiae, P. [VTT Manufacturing Technology (Finland)

    1996-12-01

    During an accident, many different forms of iodine may emerge. Organic iodides, such as methyl iodide and ethyl iodide, are relatively volatile, and thus their appearance leads to increased concentration of gaseous iodine. Since organic iodides are also relatively immune to most accident mitigation measures, such as sprays and filters, they can affect the accident source term significantly even when only a small portion of iodine is in organic form. Formation of organic iodides may not be limited by the amount of organic substances available. Excessive amounts of methane can be produced, for example, during oxidation of boron carbide, which is used in BWR`s as a neutron absorber material. Another important source is cable insulation. In a BWR, a large quantity of cables is placed below the pressure vessel. Thus a large quantity of pyrolyse gases will be produced, should the vessel fail. Organic iodides can be formed as a result of many different reactions, but at least in certain conditions the main reaction takes place between an organic radical produced by radiolysis and elemental iodine. A necessary requirement for prevention of organic iodide production is therefore that the pH in the containment water pools is kept high enough to eliminate formation of elemental iodine. In a typical BWR the suppression pool water is usually unbuffered. As a result, the pH may be dominated by chemicals introduced during an accident. If no system for adding basic chemicals is operable, the main factor affecting pool water pH may be hydrochloric acid released during cable degradation. Should this occur, the conditions could be very favorable for production of elemental iodine and, consequently, formation of organic iodides. Although high pH is necessary for iodine retention, it could have also adverse effects. High pH may, for example, accelerate corrosion of containment materials and alter the characteristics of the solid corrosion products. (author) 6 figs., 1 tab., 13 refs.

  6. Processing {alpha}-mercuric iodide by zone refining

    Energy Technology Data Exchange (ETDEWEB)

    Burger, A.; Morgan, S.H.; Henderson, D.O.; Biao, Y.; Zhang, K.; Silberman, E. [Fisk Univ., Nashville, TN (United States). Dept. of Physics; Nason, D.; van den Berg, L.; Ortale-Baccash, C.; Cross, E. [EG and G Energy Measurements, Inc., Goleta, CA (United States). Santa Barbara Operations

    1992-06-01

    An investigation is being conducted on zone refining {alpha}-mercuric iodide. Analytical studies using differential scanning calorimetry and anion chromatography indicate that impurities are segregated mainly at the end where zone travel terminates. Early results indicate that single crystals can be readily grown from zone refined material, and the effects of the process on the performance of radiation detectors fabricated from {alpha}-mercuric iodide are being evaluated.

  7. Global sea-to-air flux climatology for bromoform, dibromomethane and methyl iodide

    Directory of Open Access Journals (Sweden)

    F. Ziska

    2013-09-01

    Full Text Available Volatile halogenated organic compounds containing bromine and iodine, which are naturally produced in the ocean, are involved in ozone depletion in both the troposphere and stratosphere. Three prominent compounds transporting large amounts of marine halogens into the atmosphere are bromoform (CHBr3, dibromomethane (CH2Br2 and methyl iodide (CH3I. The input of marine halogens to the stratosphere has been estimated from observations and modelling studies using low-resolution oceanic emission scenarios derived from top-down approaches. In order to improve emission inventory estimates, we calculate data-based high resolution global sea-to-air flux estimates of these compounds from surface observations within the HalOcAt (Halocarbons in the Ocean and Atmosphere database (https://halocat.geomar.de/. Global maps of marine and atmospheric surface concentrations are derived from the data which are divided into coastal, shelf and open ocean regions. Considering physical and biogeochemical characteristics of ocean and atmosphere, the open ocean water and atmosphere data are classified into 21 regions. The available data are interpolated onto a 1°×1° grid while missing grid values are interpolated with latitudinal and longitudinal dependent regression techniques reflecting the compounds' distributions. With the generated surface concentration climatologies for the ocean and atmosphere, global sea-to-air concentration gradients and sea-to-air fluxes are calculated. Based on these calculations we estimate a total global flux of 1.5/2.5 Gmol Br yr−1 for CHBr3, 0.78/0.98 Gmol Br yr−1 for CH2Br2 and 1.24/1.45 Gmol Br yr−1 for CH3I (robust fit/ordinary least squares regression techniques. Contrary to recent studies, negative fluxes occur in each sea-to-air flux climatology, mainly in the Arctic and Antarctic regions. "Hot spots" for global polybromomethane emissions are located in the equatorial region, whereas methyl iodide emissions are enhanced in the

  8. Global sea-to-air flux climatology for bromoform, dibromomethane and methyl iodide

    Directory of Open Access Journals (Sweden)

    F. Ziska

    2013-02-01

    Full Text Available Volatile halogenated organic compounds containing bromine and iodine, which are naturally produced in the ocean, are involved in ozone depletion in both the troposphere and stratosphere. Three prominent compounds transporting large amounts of marine halogens into the atmosphere are bromoform (CHBr3, dibromomethane (CH2Br2 and methyl iodide (CH3I. The input of marine halogens to the stratosphere is based on observations and modeling studies using low resolution oceanic emission scenarios derived from top down approaches. In order to improve emission inventory estimates, we calculate data-based high resolution global sea-to-air flux estimates of these compounds from surface observations within the HalOcAt database (https://halocat.geomar.de/. Global maps of marine and atmospheric surface concentrations are derived from the data which are divided into coastal, shelf and open ocean regions. Considering physical and biogeochemical characteristics of ocean and atmosphere, the open ocean water and atmosphere data are classified into 21 regions. The available data are interpolated onto a 1° × 1° grid while missing grid values are interpolated with latitudinal and longitudinal dependent regression techniques reflecting the compounds' distributions. With the generated surface concentration climatologies for the ocean and atmosphere, global concentration gradients and sea-to-air fluxes are calculated. Based on these calculations we estimate a total global flux of 1.5/2.5 Gmol Br yr−1 for CHBr3, 0.78/0.98 Gmol Br yr−1 for CH2Br2 and 1.24/1.45 Gmol I yr−1 for CH3I (Robust Fit/Ordinary Least Square regression technique. Contrary to recent studies, negative fluxes occur in each sea-to-air flux climatology, mainly in the Arctic and Antarctic region. "Hot spots" for global

  9. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    OpenAIRE

    Tas, E.; Peleg, M.; D. U. Pedersen; Matveev, V; Pour Biazar, A.; Luria, M.

    2006-01-01

    International audience The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS) chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. ...

  10. High selectively oxidative bromination of toluene derivatives by the H2O2-HBr system

    Institute of Scientific and Technical Information of China (English)

    Jie Ju; Yu Jin Li; Jian Rong Gao; Jian Hong Jia; Liang Han; Wei Jian Sheng; Yi Xia Jia

    2011-01-01

    An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (NO2,Cl, Br, H, CH3) were high selectively brominated at the benzyl position for monobromination in CH2C12 at ice water with catalyst free. This simple but effective bromination of toluene derivatives with an aqueous H2O2-HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.

  11. A review of polytypism in lead iodide

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, P.A. [Department of Physics, Bryn Mawr College, Bryn Mawr, Pennsylvania (United States)

    2010-05-15

    Lead Iodide (PbI{sub 2}) is an important inorganic solid for both basic scientific research and possible technological applications and in this brief review we discuss the structure of PbI{sub 2}. Although the basic structure is a simple I-Pb-I layered structure with a[PbI{sub 6}]{sup 4-} near-octahedron being the basic building block, there are many ways of stacking the layers which results in many polytypes. We present 20 of the 23 entries for the structure of PbI{sub 2} from the Inorganic Structural Database and order them by polytype. This represents more than 80 years of crystallographic research in the structure of this compound. We present a simple way to view the 2H, 4H, 6H, and 6R polytypes and extend the procedure to higher-order polytypes. We note a relationship, not generally appreciated, between the distortion of the near [PbI{sub 6}]{sup 4-} octahedrons and the polytype. We suggest that the significance of vacancies has only recently been appreciated. We suggest that small discrepancies in structure determination are probably due to different distributions of vacancies and that there are, in practice, very many structures for macroscopic or even mesoscopic samples of a given polytype when vacancies are considered. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Mercuric iodide photodetectors for scintillation spectroscopy

    International Nuclear Information System (INIS)

    We have measured the responses to 137Cs (662 keV) of both a 1-inch-diam by 2-inch-thick NaI(Tl) scintillator optically coupled to a 1-inch-diam by 800-μmthick mercuric iodide (HgI2) photodetector, and a 1-cmdiam by 1-cm-thick CaWO4 scintillator coupled to a 1.3-cm-diam by 600-μm-thick HgI2 photodetector. Best spectral resolution to 137Cs was 7.8% FWHM for the NaI(Tl)-HgI2 and 12.5% FWHM for the CaWO4-HgI2 detectors; peak-to-valley ratios were 26:1 and 16:1, respectively. HgI2 detectors operate at room temperature and their use in scintillation spectroscopy presents the ultimate miniaturization of scintillation detectors, limited mainly by the size of the scintillation crystal

  13. Mercuric iodide photodetectors for scintillation spectroscopy

    International Nuclear Information System (INIS)

    We have measured the responses to 137Cs (662 keV) of both a 1-inch-diam by 2-inch-thick NaI(Tl) scintillator optically coupled to a 1-inch-diam by 800-μm-thick mercuric iodide (HgI2) photodetector, and a 1-cm-diam by 1-cm-thick CaWO4 scintillator coupled to a 1.3-cm-diam by 600-μm-thick HgI2 photodetector. Best spectral resolution to 137Cs was 7.8% FWHM for the NaI(Tl)-HgI2 and 12.5% FWHM for the CaWO4-HgI2 detectors; peak-to-valley ratios were 26:1 and 16:1, respectively. HgI2 detectors operate at room temperature and their use in scintillation spectroscopy presents the ultimate miniaturization of scintillation detectors, limited mainly by the size of the scintillation crystal

  14. Mercuric iodide photodetectors for scintillation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Markakis, J.; Dabrowski, A.; Iwanczyk, J.; Ortale, C.; Schnepple, W.

    1985-02-01

    We have measured the responses to /sup 137/Cs (662 keV) of both a 1-inch-diam by 2-inch-thick NaI(Tl) scintillator optically coupled to a 1-inch-diam by 800-..mu..mthick mercuric iodide (HgI/sub 2/) photodetector, and a 1-cmdiam by 1-cm-thick CaWO/sub 4/ scintillator coupled to a 1.3-cm-diam by 600-..mu..m-thick HgI/sub 2/ photodetector. Best spectral resolution to /sup 137/Cs was 7.8% FWHM for the NaI(Tl)-HgI/sub 2/ and 12.5% FWHM for the CaWO/sub 4/-HgI/sub 2/ detectors; peak-to-valley ratios were 26:1 and 16:1, respectively. HgI/sub 2/ detectors operate at room temperature and their use in scintillation spectroscopy presents the ultimate miniaturization of scintillation detectors, limited mainly by the size of the scintillation crystal.

  15. Mercuric iodide photodetectors for scintillation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Markakis, J.; Ortale, C.; Schnepple, W.; Iwanczyk, J.; Dabrowski, A.

    1984-01-01

    We have measured the responses to /sup 137/Cs (662 keV) of both a 1-inch-diam by 2-inch-thick NaI(Tl) scintillator optically coupled to a 1-inch-diam by 800-..mu..m-thick mercuric iodide (HgI/sub 2/) photodetector, and a 1-cm-diam by 1-cm-thick CaWO/sub 4/ scintillator coupled to a 1.3-cm-diam by 600-..mu..m-thick HgI/sub 2/ photodetector. Best spectral resolution to /sup 137/Cs was 7.8% FWHM for the NaI(Tl)-HgI/sub 2/ and 12.5% FWHM for the CaWO/sub 4/-HgI/sub 2/ detectors; peak-to-valley ratios were 26:1 and 16:1, respectively. HgI/sub 2/ detectors operate at room temperature and their use in scintillation spectroscopy presents the ultimate miniaturization of scintillation detectors, limited mainly by the size of the scintillation crystal.

  16. Posttranscriptional regulation of sodium-iodide symporter mRNA expression in the rat thyroid gland by acute iodide administration.

    Science.gov (United States)

    Serrano-Nascimento, Caroline; Calil-Silveira, Jamile; Nunes, Maria Tereza

    2010-04-01

    Iodide is an important regulator of thyroid activity. Its excess elicits the Wolff-Chaikoff effect, characterized by an acute suppression of thyroid hormone synthesis, which has been ascribed to serum TSH reduction or TGF-beta increase and production of iodolipids in the thyroid. These alterations take hours/days to occur, contrasting with the promptness of Wolff-Chaikoff effect. We investigated whether acute iodide administration could trigger events that precede those changes, such as reduction of sodium-iodide symporter (NIS) mRNA abundance and adenylation, and if perchlorate treatment could counteract them. Rats subjected or not to methylmercaptoimidazole treatment (0.03%) received NaI (2,000 microg/0.5 ml saline) or saline intraperitoneally and were killed 30 min up to 24 h later. Another set of animals was treated with iodide and perchlorate, in equimolar doses. NIS mRNA content was evaluated by Northern blotting and real-time PCR, and NIS mRNA poly(A) tail length by rapid amplification of cDNA ends-poly(A) test (RACE-PAT). We observed that NIS mRNA abundance and poly(A) tail length were significantly reduced in all periods of iodide treatment. Perchlorate reversed these effects, indicating that iodide was the agent that triggered the modifications observed. Since the poly(A) tail length of mRNAs is directly associated with their stability and translation efficiency, we can assume that the rapid decay of NIS mRNA abundance observed was due to a reduction of its stability, a condition in which its translation could be impaired. Our data show for the first time that iodide regulates NIS mRNA expression at posttranscriptional level, providing a new mechanism by which iodide exerts its autoregulatory effect on thyroid. PMID:20107044

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

    Science.gov (United States)

    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.

  18. Iodide kinetics and experimental I-131 therapy in a xenotransplanted human sodium-iodide symporter-transfected human follicular thyroid carcinoma cell line

    NARCIS (Netherlands)

    Smit, J.W.A.; Elst, van der J.P.; Karperien, M.; Que, I.; Stokkel, M.; Heide, van der D.; Romijn, J.A.

    2002-01-01

    Uptake of iodide is a prerequisite for radioiodide therapy in thyroid cancer. However, loss of iodide uptake is frequently observed in metastasized thyroid cancer, which may be explained by diminished expression of the human sodium-iodide symporter (hNIS). We studied whether transfection of hNIS int

  19. Development of crystals based in cesium iodide for application as radiation detectors

    International Nuclear Information System (INIS)

    Inorganic scintillators with fast luminescence decay time, high density and high light output have been the object of studies for application in nuclear physics, high energy physics, nuclear tomography and other fields of science and engineering. Scintillation crystals based on cesium iodide (CsI) are matters with relatively low higroscopy, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, the growth of pure CsI crystals, CsI:Br and CsI:Pb, using the Bridgman technique, is described. The concentration of the bromine doping element (Br) was studied in the range of 1,5x10-1 M to 10-2 M and the lead (Pb) in the range of 10-2 M to 5x10-4 M. To evaluate the scintillators developed, systematic measurements were carried out for luminescence emission and luminescence decay time for gamma radiation, optical transmittance assays, Vickers micro-hardness assays, determination of the doping elements distribution along the grown crystals and analysis of crystals response to the gamma radiation in the energy range of 350 keV to 1330 keV and alpha particles from a 241Am source, with energy of 5.54 MeV. It was obtained 13 ns to 19 ns for luminescence decay time for CsI:Br and CsI:Pb crystals. These results were very promising. The results obtained for micro-hardness showed a significant increase in function of the doping elements concentration, when compared to the pure CsI crystal, increasing consequently the mechanical resistance of the grown crystals. The validity of using these crystals as radiation sensors may be seen from the results of their response to gamma radiation and alpha particles. (author)

  20. Methyl Iodide Formation Under Postulated Nuclear Reactor Accident Conditions

    International Nuclear Information System (INIS)

    The formation of methyl iodide under conditions of postulated nuclear reactor accidents is discussed. Although thermodynamic calculations indicate the equilibrium methyl iodide concentrations would be quite low, calculations based on a simple kinetic scheme involving reaction between small hydrocarbon species and iodine indicate that concentrations higher than equilibrium can occur during the course of the reaction. Such calculations were performed over a wide range of initial species concentrations and a range of temperatures representative of some reactor accident situations. These calculations suggest that little methyl iodide would be expected within the core volume where temperatures are maximum. As the gas leaves the core volume and expands into the plenum region, it cools and the concentration of methyl iodide increases. At the intermediate temperatures which might characterize this region, the formation of methyl iodide from thermally induced reactions could reach its maximum rate. The gas continues to cool, however, and it is probable that by the time it leaves the plenum region it has cooled to the point where thermally induced reactions may be of little importance. Although the thermally induced reactions will become slower as the gas expands and cools, the radiation-induced reactions will not be slowed to the same extent. The gases leaving the core carry fission products and hence a radiation source is available to initiate reaction by a temperature-independent process. An investigation of the radiation chemical formation and decomposition of methyl iodide in the presence of steam suggests that radiation-induced methyl iodide formation will generally be rapid under the postulated accident situations. Thus, in the plenum region where thermal reactions have become slow, the radiation-induced reaction can still proceed and may well become the dominant factor. The same situation probably pertains as well to the containment region. (author)

  1. New insight into photo-bromination processes in saline surface waters: The case of salicylic acid

    International Nuclear Information System (INIS)

    It was shown, through a combination of field and laboratory observations, that salicylic acid can undergo photo-bromination reactions in sunlit saline surface waters. Laboratory-scale experiments revealed that the photochemical yields of 5-bromosalicylic acid and 3,5-dibromosalicylic acid from salicylic acid were always low (in the 4% range at most). However, this might be of concern since these compounds are potential inhibitors of the 20α-hydroxysteroid dehydrogenase enzyme, with potential implications in endocrine disruption processes. At least two mechanisms were involved simultaneously to account for the photo-generation of brominated substances. The first one might involve the formation of reactive brominated radical species (Br·, Br2·−) through hydroxyl radical mediated oxidation of bromide ions. These ions reacted more selectively than hydroxyl radicals with electron-rich organic pollutants such as salicylic acid. The second one might involve the formation of hypobromous acid, through a two electron oxidation of bromine ions by peroxynitrite. This reaction was catalyzed by nitrite, since these ions play a crucial role in the formation of nitric oxide upon photolysis. This nitric oxide further reacts with superoxide radical anions to yield peroxynitrite and by ammonium through the formation of N-bromoamines, probably due to the ability of N-bromoamines to promote the aromatic bromination of phenolic compounds. Field measurements revealed the presence of salicylic acid together with 5-bromosalicylic and 3,5-dibromosalicylic acid in a brackish coastal lagoon, thus confirming the environmental significance of the proposed photochemically induced bromination pathways. -- Highlights: ► Brominated derivatives of salicylic acid were detected in a brackish lagoon. ► A photochemical pathway was hypothesized to account for bromination of salicylic acid. ► Radical bromine species are partly responsible for the bromination process. ► Hypobromous acid might

  2. Molecular imaging using sodium iodide symporter (NIS)

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Je Yoel [School of Dentistry, Kyungpook National Univ., Daegu (Korea, Republic of)

    2004-04-01

    Radioiodide uptake in thyroid follicular epithelial cells, mediated by a plasma membrane transporter, sodium iodide symporter (NIS), provides a first step mechanism for thyroid cancer detection by radioiodide injection and effective radioiodide treatment for patients with invasive, recurrent, and/or metastatic thyroid cancers after total thyroidectomy. NIS gene transfer to tumor cells may significantly and specifically enhance internal radioactive accumulation of tumors following radioiodide administration, and result in better tumor control. NIS gene transfers have been successfully performed in a variety of tumor animal models by either plasmid-mediated transfection or virus (adenovirus or retrovirus)-mediated gene delivery. These animal models include nude mice xenografted with human melanoma, glioma, breast cancer of prostate cancer, rats with subcutaneous thyroid tumor implantation, as well as the rat intracranial glioma model. In these animal models, non-invasive imaging of in vivo tumors by gamma camera scintigraphy after radioiodide or technetium injection has been performed successfully, suggesting that the NIS can serve as an imaging reporter gene for gene therapy trials. In addition, the tumor killing effects of I-131, ReO4-188 and At-211 after NIS gene transfer have been demonstrated in in vitro clonogenic assays and in vivo radioiodide therapy studies, suggesting that NIS gene can also serve as a therapeutic requires a more efficient and specific system of gene delivery with better retention of radioiodide in tumor. Results thus far are, however, promising, and suggest that NIS gene transfer followed by radioiodide treatment will allow non-invasive in vivo imaging to assess the outcome of gene therapy and provide a therapeutic strategy for a variety of human diseases.

  3. Molecular imaging using sodium iodide symporter (NIS)

    International Nuclear Information System (INIS)

    Radioiodide uptake in thyroid follicular epithelial cells, mediated by a plasma membrane transporter, sodium iodide symporter (NIS), provides a first step mechanism for thyroid cancer detection by radioiodide injection and effective radioiodide treatment for patients with invasive, recurrent, and/or metastatic thyroid cancers after total thyroidectomy. NIS gene transfer to tumor cells may significantly and specifically enhance internal radioactive accumulation of tumors following radioiodide administration, and result in better tumor control. NIS gene transfers have been successfully performed in a variety of tumor animal models by either plasmid-mediated transfection or virus (adenovirus or retrovirus)-mediated gene delivery. These animal models include nude mice xenografted with human melanoma, glioma, breast cancer of prostate cancer, rats with subcutaneous thyroid tumor implantation, as well as the rat intracranial glioma model. In these animal models, non-invasive imaging of in vivo tumors by gamma camera scintigraphy after radioiodide or technetium injection has been performed successfully, suggesting that the NIS can serve as an imaging reporter gene for gene therapy trials. In addition, the tumor killing effects of I-131, ReO4-188 and At-211 after NIS gene transfer have been demonstrated in in vitro clonogenic assays and in vivo radioiodide therapy studies, suggesting that NIS gene can also serve as a therapeutic requires a more efficient and specific system of gene delivery with better retention of radioiodide in tumor. Results thus far are, however, promising, and suggest that NIS gene transfer followed by radioiodide treatment will allow non-invasive in vivo imaging to assess the outcome of gene therapy and provide a therapeutic strategy for a variety of human diseases

  4. Bayesian statistical modeling of disinfection byproduct (DBP) bromine incorporation in the ICR database.

    Science.gov (United States)

    Francis, Royce A; Vanbriesen, Jeanne M; Small, Mitchell J

    2010-02-15

    Statistical models are developed for bromine incorporation in the trihalomethane (THM), trihaloacetic acids (THAA), dihaloacetic acid (DHAA), and dihaloacetonitrile (DHAN) subclasses of disinfection byproducts (DBPs) using distribution system samples from plants applying only free chlorine as a primary or residual disinfectant in the Information Collection Rule (ICR) database. The objective of this study is to characterize the effect of water quality conditions before, during, and post-treatment on distribution system bromine incorporation into DBP mixtures. Bayesian Markov Chain Monte Carlo (MCMC) methods are used to model individual DBP concentrations and estimate the coefficients of the linear models used to predict the bromine incorporation fraction for distribution system DBP mixtures in each of the four priority DBP classes. The bromine incorporation models achieve good agreement with the data. The most important predictors of bromine incorporation fraction across DBP classes are alkalinity, specific UV absorption (SUVA), and the bromide to total organic carbon ratio (Br:TOC) at the first point of chlorine addition. Free chlorine residual in the distribution system, distribution system residence time, distribution system pH, turbidity, and temperature only slightly influence bromine incorporation. The bromide to applied chlorine (Br:Cl) ratio is not a significant predictor of the bromine incorporation fraction (BIF) in any of the four classes studied. These results indicate that removal of natural organic matter and the location of chlorine addition are important treatment decisions that have substantial implications for bromine incorporation into disinfection byproduct in drinking waters. PMID:20095529

  5. Accurate measurement of bromine contents in plastic samples by instrumental neutron activation analysis.

    Science.gov (United States)

    Kim, I J; Lee, K S; Hwang, E; Min, H S; Yim, Y H

    2013-03-26

    Accurate measurements of bromine contents in plastic samples were made by the direct comparator instrumental neutron activation analysis (INAA). Individual factors affecting the measurements were comprehensively evaluated and compensated, including the volatility loss of bromine from standard comparators, the background bromine level in the filter papers used for preparation of the standard comparators, nuclear interference, γ-ray spectral interference and the variance among replicates of the samples. Uncertainty contributions from those factors were thoroughly evaluated and included in the uncertainty budgeting of the INAA measurement. (81)Br was chosen as the target isotope, and the INAA measurements for bromine were experimentally confirmed to exhibit good linearity within a bromine content range of 10-170 μg. The established method has been applied to the analysis of eight plastic samples: four commercially available certified reference materials (CRMs) of polyethylene and polystyrene and four acrylonitrile butadiene styrene (ABS) samples prepared as the candidate reference materials (KRISS CRM 113-01-012, -013, -014 and -015). The bromine contents of the samples were calculated at three different γ-ray energies and compared, showing good agreement. The results of the four CRMs also showed good consistency with their certified values within the stated uncertainties. Finally, the bromine contents of the ABS samples were determined with expanded uncertainties (at a 95% level of confidence) between 2.5% and 5% in a bromine content range of 25-900 mg kg(-1). PMID:23498117

  6. The Evolution of a Green Chemistry Laboratory Experiment: Greener Brominations of Stilbene

    Science.gov (United States)

    McKenzie, Lallie C.; Huffman, Lauren M.; Hutchison, James E.

    2005-01-01

    The use of green metrics to compare three bromination laboratory procedures demonstrates the effectiveness of an incremental greening process for chemistry curricula. Due to this process, the bromination of alkenes can be introduced to students through the use of a safe, effective, modern practice.

  7. 40 CFR 721.775 - Brominated aromatic com-pound (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated aromatic com-pound (generic name). 721.775 Section 721.775 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.775 Brominated aromatic com-pound (generic name). (a)...

  8. Biosynthesis of brominated tyrosine metabolites by Aplysina fistularis.

    Science.gov (United States)

    Carney, J R; Rinehart, K L

    1995-07-01

    The biosynthesis of brominated tyrosine metabolites by the marine sponge Aplysina fistularis was investigated. [U-14C]-L-Tyrosine, [U-14C]-L-3-bromotyrosine, and [U-14C]-L-3,5-dibromotyrosine were incorporated into both dibromoverongiaquinol [1] and aeroplysinin-1 [2], and [methyl-14C]methionine was specifically incorporated into the O-methyl group group of 2. [Methyl-14C]-L-O-methyltyrosine, [methyl-14C]-L-3,5-dibromo-O-methyltyrosine, and several putative nitrile precursors were not incorporated into 1 or 2. PMID:7561906

  9. Future chlorine-bromine loading and ozone depletion

    Science.gov (United States)

    Prather, Michael J.; Ibrahim, Abdel Moneim; Sasaki, Toru; Stordal, Frode; Visconti, Guido

    1991-01-01

    The prediction of future ozone requires three elements: (1) a scenario for the net emissions of chemically and radiatively active trace gases from the land and oceans; (2) a global atmospheric model that projects the accumulation of these gases; and (3) a chemical transport model that describes the distribution of ozone for a prescribed atmospheric composition and climate. This chapter, of necessity, presents models for all three elements and focuses on the following: (1) atmospheric abundance of chlorine and bromine in the form of halocarbons; and (2) the associated perturbations to stratospheric ozone.

  10. Research on the phenomenon of graphitization. Crystallographic study - Study of bromine sorption

    International Nuclear Information System (INIS)

    This research thesis reports the study of the mechanism of graphitization of carbon by using X-ray diffraction analysis and the physical and chemical study of lamellar reactions between carbon and bromine. The author first presents generalities and results of preliminary studies (meaning of graphitization, presentation of the various carbon groups and classes), and then reports the study of the graphitization of compact carbons (soft carbons). More precisely, he reports the crystallographic study of partially graphitized carbons: methods and principles, experimental results and their analysis, discussion of the graphitization mechanism. In the next part, the author reports the study of bromine sorption on carbons: experimental method, isotherms of a natural graphite and of a graphitized carbon, structure of carbon-bromine complexes, isotherms of graphitizable carbons and of all other carbons, distribution of bromine layers in partially graphitized carbons, bromine sorption and Fermi level

  11. Labeling of receptor ligands with bromine radionuclides. Progress report, March 1, 1981-February 28, 1982

    International Nuclear Information System (INIS)

    In recent years there has been an interest in the use of various radioisotopes of bromine as labels for radiopharmaceuticals. Although radioisotopes of iodine have been used extensively as radiopharmaceutical labels, there are several advantages associated with the use of radiobromine as a label, due primarily to increased stability of bonds to the radiohalide and smaller steric perturbation resulting from substitution of the radiohalide. Methods of attaching radiobromine to receptor ligands with the potential of mapping estrogen receptors in mammary tumors and uteri were studied. Two ligands were studied extensively in vitro and in animal models; preliminary studies were also carried out in humans. To date, the only radioisotope of bromine used was bromine-77. In addition, a series of model compounds were labeled with bromine-77 using a recently described method for rapid bromination; the scope and limitations of this new rapid radiobromination technique were evaluated

  12. Phase 1 Methyl Iodide Deep-Bed Adsorption Tests

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Tony Watson

    2014-08-01

    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 has 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, species that

  13. Introduction of extrinsic defects into mercuric iodide during processing

    International Nuclear Information System (INIS)

    Low temperature (4.2 K) photoluminescence spectroscopy (PL) measurements were performed on mercuric iodide (HgI2) crystals which were intentionally doped with copper or silver during KI etching. PL spectra obtained after these doping experiments show specific Cu and Ag features similar to those previously observed after deposition of Cu or Ag contacts on mercuric iodide crystals. The in-diffusion of Cu or Ag into bulk HgI2 has also been confirmed a few days after doping. This diffusion introduces new recombination centers in the material. This work suggests that the processing steps used to fabricate mercuric iodide nuclear detectors can lead to the introduction of new defects which are detrimental to detector performance

  14. Introduction of extrinsic defects into mercuric iodide during processing

    Science.gov (United States)

    Hung, C.-Y.; Bao, X. J.; Schlesinger, T. E.; James, R. B.; Cheng, A. Y.; Ortale, C.; van den Berg, L.

    1993-05-01

    Low-temperature photoluminescence spectroscopy (PL) measurements were performed on mercuric iodide (HgI2) crystals which were intentionally doped with copper or silver during KI etching. PL spectra obtained after these doping experiments show specific Cu and Ag features similar to those previously observed after deposition of Cu or Ag contacts on mercuric iodide crystals. The in-diffusion of Cu or Ag into bulk HgI2 has also been confirmed a few days after doping. This diffusion introduces new recombination centers in the material. This work suggests that the processing steps used to fabricate mercuric iodide nuclear detectors can lead to the introduction of new defects which are detrimental to detector performance.

  15. Modified purification of mercuric iodide for crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, N.L.; Ortale, C.; Schieber, M.M.; van den Berg, L.

    1988-01-01

    The standard procedure used in our laboratory to purify commercially available mercuric iodide consists of a sequence of steps: (1) repeated sublimation under continous evacuation, followed by (2) melting and recrystallization, and (3) a sublimation process in a closed tube. This paper describes a modification of the standard purification sequence by adding recrystallization of the mercuric iodide in hydrochloric acid. Leaching cation impurities out of mercuric iodide powder with hydrochloric acid has been practiced before by Zaletin, (V.M. Zaletin, I.H. Nozhiua, I.N. Fomin, V.T. Shystov, and N.V. Protasov, Atomic Energy 48, 169 (1980)). Our objective for the hydrochloric acid treatment was to remove nitrates and hydrocarbons which were interfering with the vapor transport during crystal growth. Results of the procedure are presented in terms of total carbon and selected ion content of the treated and untreated material. 13 refs., 8 figs., 3 tabs.

  16. Introduction of extrinsic defects into mercuric iodide during processing

    Energy Technology Data Exchange (ETDEWEB)

    Hung, C.; Bao, X.J.; Schlesinger, T.E. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)); James, R.B. (Advanced Materials Research Division, Sandia National Laboratories, Livermore, California 94550 (United States)); Cheng, A.Y.; Ortale, C.; van den Berg, L. (EG G Energy Measurements, Incorporated, Goleta, California 93116 (United States))

    1993-05-01

    Low temperature (4.2 K) photoluminescence spectroscopy (PL) measurements were performed on mercuric iodide (HgI[sub 2]) crystals which were intentionally doped with copper or silver during KI etching. PL spectra obtained after these doping experiments show specific Cu and Ag features similar to those previously observed after deposition of Cu or Ag contacts on mercuric iodide crystals. The in-diffusion of Cu or Ag into bulk HgI[sub 2] has also been confirmed a few days after doping. This diffusion introduces new recombination centers in the material. This work suggests that the processing steps used to fabricate mercuric iodide nuclear detectors can lead to the introduction of new defects which are detrimental to detector performance.

  17. Removal efficiency of organic iodide by silver-exchanged zeolite

    International Nuclear Information System (INIS)

    The removal efficiency of radioactive organic iodide generated under accident conditions at nuclear power plants or nuclear fuel cycle processes by silver-exchanged zeolite(AgX) was experimentally evaluated. First of all, adsorption capacities of various adsorbents such as activated carbon, zeocarbon and zeolite 13X as a function of process temperature were analyzed. Optimal operating condition for the removal of methyl iodide using AgX was suggested, based on silver-exchanged amounts and adsorption temperature. The effective removal efficiency of methyl iodide by AgX was obtained at conditions that the process temperature is in the range of 150 .deg. C to 200 .deg. C and the silver exchanged amount is about 10 wt%

  18. Adsorption of Gaseous Methyl Iodide by Active Carbons

    International Nuclear Information System (INIS)

    The impregnation of active carbons is known to be a useful means of improving the ability of these carbons to retain methyl iodide which might be formed during the accidental release of fission products from a reactor. Some basic work was done on both impregnated and unimpregnated materials, which involved: (a) the texture: (b) the reaction of Mel with the impregnants; (c) the adsorption of Mel on the carbons under dry and wet conditions at different temperatures. It was found that the carbons are highly microporous. A large part of this porosity disappears on impregnation with organic amine; These impregnants react chemically with the methyl iodide, which is thereby fixed on the carbon. For carbon which is impregnated with KI, a rapid exchange reaction takes place between the methyl iodide and KI under both dry and wet conditions. Consequently most of the iodine activity can be removed from the gas. (author)

  19. Standard free energy of formation of iron iodide

    Science.gov (United States)

    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.

  20. A novel peculiar mutation in the sodium/iodide symporter gene in spanish siblings with iodide transport defect.

    Science.gov (United States)

    Kosugi, Shinji; Okamoto, Hiroomi; Tamada, Aiko; Sanchez-Franco, F

    2002-08-01

    Previously, we reported two Spanish siblings with congenital hypothyroidism due to total failure of iodide transport. These were the only cases reported to date who received long-term iodide treatment over 10 yr. We examined the sodium/iodide symporter (NIS) gene of these patients. A large deletion was observed by long and accurate PCR using primers derived from introns 2 and 7 of the NIS gene. PCR-direct sequencing revealed a deletion of 6192 bases spanning from exon 3 to intron 7 and an inverted insertion of a 431-base fragment spanning from exon 5 to intron 5 of the NIS gene. The patients were homozygous for the mutation, and their mother was heterozygous. In the mutant, deletion of exons 3-7 was suggested by analysis using programs to predict exon/intron organization, resulting in an in-frame 182-amino acid deletion from Met(142) in the fourth transmembrane domain to Gln(323) in the fourth exoplasmic loop. The mutant showed no iodide uptake activity when transfected into COS-7 cells, confirming that the mutation was the direct cause of the iodide transport defect in these patients. Further, the mutant NIS protein was synthesized, but not properly expressed, on the cell surface, but was mostly accumulated in the cytoplasm, suggesting impaired targeting to the plasma membrane. PMID:12161518

  1. Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer

    Science.gov (United States)

    Hartsough, Neal; Iwanczyk, Jan

    2009-01-01

    A film-growth process was developed for polycrystalline mercuric iodide that creates cost-effective, large-area detectors for high-energy charged-particle detection. A material, called a barrier film, is introduced onto the substrate before the normal mercuric iodide film growth process. The barrier film improves the quality of the normal film grown and enhances the adhesion between the film and the substrate. The films grown using this improved technique were found to have adequate signal-to-noise properties so that individual high-energy charged -particle interactions could be distinguished from noise, and thus, could be used to provide an anticoincidence veto function as desired.

  2. Depolymerization of Lignin in Wood with Molecular Hydrogen Iodide

    OpenAIRE

    Shevchenko, Sergey M.

    2000-01-01

    Depolymerization of lignin in wood with hydrogen iodide in a non-polar solvent is a selective, high-yield reaction that releases a diiodide of potential synthetic value into the solution. Finely milled wood (Douglas-fir, spruce, aspen, and sugarcane), was suspended in CDCl3 and treated with dry hydrogen iodide in a NMR tube. The yields and composition of the chloroform-soluble monomeric lignin depolymerization products, 1,3-diiodo-1-(4-hydroxyaryl)propanes, originated from guaiacyl (G), syrin...

  3. Algae form brominated organic compounds in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Huetteroth, A.; Putschew, A.; Jekel, M. [Tech. Univ. Berlin (Germany)

    2004-09-15

    Monitoring of organic halogen compounds, measured as adsorbable organic bromine (AOBr) revealed seasonal high concentrations of organic bromine compounds in a surface water (Lake Tegel, Berlin, Germany). Usually, in late summer, concentrations are up to five times higher than during the rest of the year. The AOBr of the lake inflows (throughout the year less then 6 {mu}g/L) were always lower then those in the lake, which indicates a production of AOBr in the lake. A correlation of the AOBr and chlorophyll-a concentration (1) in the lake provides first evidence for the influence of phototrophic organisms. The knowledge of the natural production of organohalogens is relatively recent. Up to now there are more then 3800 identified natural organohalogen compounds that have been detected in marine plants, animals, and bacteria and also in terrestrial plants, fungi, lichen, bacteria, insects, some higher animals, and humans. Halogenated organic compounds are commonly considered to be of anthropogenic origin; derived from e.g. pharmaceuticals, herbicides, fungicides, insecticides, flame retardants, intermediates in organic synthesis and solvents. Additionally they are also produced as by-products during industrial processes and by waste water and drinking water disinfection. Organohalogen compounds may be toxic, persistent and/or carcinogenic. In order to understand the source and environmental relevance of naturally produced organobromine compounds in surface waters, the mechanism of the formation was investigated using batch tests with lake water and algae cultures.

  4. Brominated dioxins and dibenzofurans in human adipose tissue. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, P.H.; Stanley, J.S.; Bauer, K.; Ayling, R.E.; Thornburg, K.R.

    1990-04-11

    The report describes the analytical efforts for the determination of polybrominated dioxins (PBDDs) and furans (PBDFs) in human adipose tissues. Data on the precision and accuracy of the method for three tetra- through hexabrominated dioxins and three tetra- through hexabrominated furans (specific 2,3,7,8-substituted isomers) were generated from the analysis of 5 unspiked and 10 spiked (5 replicates at 2 spike levels) adipose tissue samples that were included with the analysis of the FY 1987 samples. In addition, data are presented on the results of the analysis of 48 composite samples for the six specific PBDD and PBDF compounds. The targeted 2,3,7,8-substituted PBDDs and PBDFs were not detected in any of the samples except those prepared as spiked QC materials. The detection limits calculated for the tetrabromo congeners in the samples ranged from 0.46 to 8.9 pg/g (lipid basis). The detection limits for the higher brominated congeners were typically greater than that observed for the tetrabrominated compounds. There is some evidence for the presence of other brominated compounds in the adipose tissue samples. Specifically, responses were noted that correspond to the qualitative criteria for polybrominated diphenyl ethers (hexa through octabromo).

  5. Comparative environmental analysis of waste brominated plastic thermal treatments

    International Nuclear Information System (INIS)

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste

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

    Science.gov (United States)

    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...

  7. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dithiazanine iodide and piperazine citrate... § 520.763c Dithiazanine iodide and piperazine citrate suspension. (a) Specifications. Each milliliter of the drug contains 69 milligrams of dithiazanine iodide and 83 milligrams of piperazine base...

  8. Pulse radiolysis studies of the reactions of bromine atoms and dimethyl sulfoxide-bromine atom complexes with alcohols

    International Nuclear Information System (INIS)

    Dimethylsulfoxide (DMSO)-Br complexes were generated by pulse radiolysis of DMSO/bromomethane mixtures and the formation mechanism and spectral characteristics of the formed complexes were investigated in detail. The rate constant for the reaction of bromine atoms with DMSO and the extinction coefficient of the complex were obtained to be 4.6x109 M-1 s-1 and 6300 M-1 cm-1 at the absorption maximum of 430 nm. Rate constants for the reaction of bromine atoms with a series of alcohols were determined in CBrCl3 solutions applying a competitive kinetic method using the DMSO-Br complex as the reference system. The obtained rate constants were ∼108 M-1 s-1, one or two orders larger than those reported for highly polar solvents. Rate constants of DMSO-Br complexes with alcohols were determined to be ∼ 107 M-1 s-1. A comparison of the reactivities of Br atoms and DMSO-Br complexes with those of chlorine atoms and chlorine atom complexes which are ascribed to hydrogen abstracting reactants strongly indicates that hydrogen abstraction from alcohols is not the rate determining step in the case of Br atoms and DMSO-Br complexes

  9. Effects of bromination on the viscoelastic response of vinyl ester nanocomposites

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Fire, smoke and toxicity are of significant concern for composite materials used in marine applications. Bromination of vinyl ester resin imparts fire retardancy as manifested by a reduction in the amount of smoke, carbon monoxide, and corrosive combustion products. In this research, the viscoelastic properties, modulus (stiffness and damping (energy dissipation, of 1.25 and 2.5 wt. percent nanoclay and exfoliated graphite nanoplatelet (xGnP reinforced non-brominated and brominated vinyl ester have been studied over a range of temperature and frequency. Effects of frequency on the viscoelastic behavior were investigated using a Dynamic Mechanical Analyzer (DMA by sweeping the frequency over three decades: 0.01, 0.1, 1 and 10 Hz, and temperature range from 30–150°C at a step rate of 4°C per minute. Master curves were generated by time-temperature superposing the experimental data at a reference temperature. The nano reinforced composites showed a drop in initial storage modulus with bromination. Nanocomposites with 1.25 and 2.5 wt. percent graphite had the highest storage modulus among brominated specimens. Bromination was also found to significantly increase the glass transition temperature (Tg and damping for all nanocomposites. Among the brominated specimens, 1.25 wt. Percent graphite platelet reinforced vinyl ester exhibited the best viscoelastic response with high damping and glass transition temperature, along with superior storage modulus over a longer time period.

  10. Degradation of Methyl Iodide in Soil: Effects of Environmental Factors

    Science.gov (United States)

    Methyl iodide (MeI) is a promising alternative to the phased-out fumigant methyl bromide, and its environmental fate following soil fumigation is of great concern. Experiments were conducted to investigate the effect of various environmental factors on the degradation rate of MeI in soil. The chem...

  11. Enthalpies of potassium iodide dissolution in isopropanol aqueous solutions

    International Nuclear Information System (INIS)

    At 298.15 K in air-tight microcalorimeter with isothermal shell enthalpies of potassium iodide dissolution in water and in water-isopropyl alcohol mixtures (5,10,20,30,50 and 70 mol.%) are measured. Dissolution enthalpies during infinite dilution in the above-mentioned mixed solvents are determined

  12. Iodide volatility under condition relevant to PWR steam generator faults

    International Nuclear Information System (INIS)

    The evaluation of iodine volatility during steam generator tube rupture (SGTR) is hampered by three factors: (i) lack of suitable plant data under fault conditions, (ii) lack of experimental data (mainly due to the difficulty of performing experiments under the conditions required) and (iii) uncertainty in theoretical methods to extrapolate experimental data to the required conditions. This report summarises methods of estimating the volatility of hydrogen iodide and iodide salts at the required conditions of temperature and pressure. A thermodynamic method has been used to estimate HI volatility and the density correlation method for iodide salt volatility. It is assumed throughout that it is more conservative to predict higher volatility. Consideration is given to two explanations of experiments carried out at Oak Ridge National Laboratory (ORNL) on the influence of boric acid concentration and pH on the volatility of radioiodine ostensibly under SGTR conditions: (i) the results have been interpreted in terms of reactions involving volatility of iodide salt/ion-pairs and complexation by boric acid in the gas phase and (ii) the possibility is explored that the observed results are due to the influence of oxidation leading to the formation of much more volatile iodine species. (author)

  13. The contribution of anthropogenic bromine emissions to past stratospheric ozone trends: a modelling study

    Directory of Open Access Journals (Sweden)

    B.-M. Sinnhuber

    2009-04-01

    Full Text Available Bromine compounds play an important role in the depletion of stratospheric ozone. We have calculated the changes in stratospheric ozone in response to changes in the halogen loading over the past decades, using a two-dimensional (latitude/height model constrained by source gas mixing ratios at the surface. Model calculations of the decrease of total column ozone since 1980 agree reasonably well with observed ozone trends, in particular when the contribution from very short-lived bromine compounds is included. Model calculations with bromine source gas mixing ratios fixed at 1959 levels, corresponding approximately to a situation with no anthropogenic bromine emissions, show an ozone column reduction between 1980 and 2005 at Northern Hemisphere mid-latitudes of only ≈55% compared to a model run including all halogen source gases. In this sense anthropogenic bromine emissions are responsible for ≈45% of the model estimated column ozone loss at Northern Hemisphere mid-latitudes. However, since a large fraction of the bromine induced ozone loss is due to the combined BrO/ClO catalytic cycle, the effect of bromine would have been smaller in the absence of anthropogenic chlorine emissions. The chemical efficiency of bromine relative to chlorine for global total ozone depletion from our model calculations, expressed by the so called α-factor, is 64 on an annual average. This value is much higher than previously published results. Updates in reaction rate constants can explain only part of the differences in α. The inclusion of bromine from very short-lived source gases has only a minor effect on the global mean α-factor.

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

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    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 HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced 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 NO2, very low H2O 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 I2 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.

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

    International Nuclear Information System (INIS)

    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 HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced 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 NO2, very low H2O 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 I2 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.

  16. Enhancement of the carbon electrode capacitance by brominated hydroquinones

    Science.gov (United States)

    Gastol, Dominika; Walkowiak, Jedrzej; Fic, Krzysztof; Frackowiak, Elzbieta

    2016-09-01

    This paper presents supercapacitors utilizing new redox-active electrolytes with bromine species. Two sources of Br specimen were investigated, i.e. dibromodihydroxybenzene dissolved in KOH and potassium bromide dissolved in KOH with hydroxybenzene additive. KOH-activated carbon, exhibiting a well-developed porosity, was incorporated as an electrode material. The tested systems revealed a capacitance enhancement explained by Br- and partial BrO3- redox activity. The optimisation of the electrolyte concentration resulted in a capacitance value of 314 F g-1 achieved at 1.1 V voltage range. Good cyclability performance (11% capacitance loss) combined with a high capacitance value (244 F g-1) were obtained for the system operating in 0.2 mol L- 1 C6H4Br2O2 in 2 mol L-1 KOH electrolytic solution.

  17. Formation of organic iodides from containment paint ingredients caused by gamma irradiation

    International Nuclear Information System (INIS)

    The formation of volatile alkyl iodides other than methyl iodide during a serious nuclear reactor accident may have radiological significance. The hypothesis that radioactive alkyl iodides, other than methyl iodide, could form from paint solvents under the conditions of a serious nuclear accident in light water reactors (under boiling water reactor (BWR) and pressurised water reactor (PWR) conditions) was tested using stable elemental iodine, a gamma irradiator and gas chromatography equipment. It was found that methyl and isopropyl iodides were formed from the texanol ester, which is used in many modern water-based paints. Methyl, ethyl, propyl and butyl iodides were formed from a hydrocarbon solvent (white spirit) commonly used in paint products used in the past. These results suggest that further work on the formation and behaviour of the higher alkyl iodides (containing more than one carbon atom) under the conditions of a serious nuclear accident is justified. (author)

  18. A novel mutation in the sodium/iodide symporter gene in the largest family with iodide transport defect.

    Science.gov (United States)

    Kosugi, S; Bhayana, S; Dean, H J

    1999-09-01

    We previously reported nine children with an autosomally recessive form of congenital hypothyroidism due to an iodide transport defect in a large Hutterite family with extensive consanguinity living in central Canada. Since the original report, we have diagnosed congenital hypothyroidism by newborn TSH screening in 9 additional children from the family. We performed direct sequencing of the PCR products of each NIS (sodium/iodide symporter) gene exon with flanking introns amplified from genomic DNA extracted from peripheral blood cells of the patients. We identified a novel NIS gene mutation, G395R (Gly395-->Arg; GGA-->AGA), in 10 patients examined in the present study. All of the parents tested were heterozygous for the mutation, suggesting that the patients were homozygous. The mutation was located in the 10th transmembrane helix. Expression experiments by transfection of the mutant NIS complimentary DNA into COS-7 cells showed no perchlorate-sensitive iodide uptake, confirming that the mutation is the direct cause of the iodide transport defect in these patients. A patient who showed an intermediate saliva/serum technetium ratio (14.0; normal, > or = 20) and was considered to have a partial or less severe defect in the previous report (IX-24) did not have a NIS gene mutation. It is now possible to use gene diagnostics of this unique NIS mutation to identify patients with congenital hypothyroidism due to an iodide transport defect in this family and to determine the carrier state of potential parents for genetic counseling and arranging rapid and early diagnosis of their infants. PMID:10487695

  19. Preparation and evaluation of composite membranes for zinc/bromine storage batteries

    Science.gov (United States)

    Arnold, Charles, Jr.; Assink, Roger A.

    Low coulombic efficiencies of zinc/bromine redox batteries were attributed to migration of bromine and negatively charged bromine moieties through the microporous separator used to separate the catholyte from the anolyte. While it was demonstrated that improvements in coulombic efficiency can be achieved by replacing the microporous separator with a cationic ion exchange membrane, these membranes are expensive and/or not sufficiently conductive to be practicable. It was found that the rate of bromine permeation can be reduced by two orders of magnitude with minimal decreases in conductivity by impregnating commercial microporous polyethylene type separators with sulfonated polysulfone, a cationic polyelectrolyte that was developed in earlier work for other redox storage batteries.

  20. A Novel Protocol for the Regioselective Bromination of Primary Alcohols in Unprotected Carbohydrates or Glycosides

    Institute of Scientific and Technical Information of China (English)

    薛伟华; 张立芬

    2012-01-01

    The regioselective and efficient bromination of primary hydroxyl groups in unprotected carbohydrates or glycosides is successfully achieved by using (chloro-phenylthio-methylene)dimethylammoniumchloride (CPMA) in the presence of tetrabutylammonium bromide (TBAB) in dry DMF.

  1. Evaluation of carbon cryogels used as cathodes for non-flowing zinc-bromine storage cells

    Energy Technology Data Exchange (ETDEWEB)

    Ayme-Perrot, David; Walter, Serge; Gabelica, Zelimir [Groupe Securite et Ecologie Chimiques (GSEC), ENSCMu, 3 rue Alfred Werner, F-68093 Mulhouse Cedex (France); Valange, Sabine [Laboratoire de Catalyse en Chimie Organique (LACCO), ESIP, 40 Avenue du Recteur Pineau, F-86022 Poitiers Cedex (France)

    2008-01-03

    Monolithic megaloporous carbon cryogels were examined for their potential applications as cathodic electrodes in secondary zinc-bromine cells. This work investigates the possibility of using their particular macroporous texture as microscopic bromine tanks in a zinc/bromine battery. The electrochemical behaviour of a cell based upon such a Br{sub 2} electrode was studied and discussed in terms of energy yields, energy storage capability and cycle life. Good storages (over 20 Wh kg{sup -1}) could be obtained during the first 2 h of cell charging for currents between 10 and 20 mA g{sup -1}. The energy yield remains almost constant during a fairly large number of cycles, basically for weak charges (e.g. 25 C g{sup -1}). Our findings show that the good cyclability of the cathodic electrode is a consequence of the liquid state of the active bromine phase. (author)

  2. Dynamic dielectric properties and the γ transition of bromine doped polyacrylonitrile

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available Based on monitoring the γ process (the lowest temperature-relaxation in polyacrylonitrile (PAN by dynamic dielectric spectroscopy, new evidence for the formation of a charge transfer complex between bromine dopants and nitrile groups is presented. The experimental work is carried out on PAN and nitrile polymerized PAN with and without bromine doping and the effects of these factors on the γ process are measured. Nitrile polymerization results in diminishing of the γ process and in a 15% increase in its activation energy, whereas bromine doping produces splitting of the original γ process in PAN – coupled with a significant activation energy increase – and its complete disappearance in nitrile polymerized PAN. Both the splitting of the γ process and the higher activation energy reflect bromine-nitrile adduct formation..

  3. Strand breaks in plasmid DNA, natural and brominated, by low-energy X-rays

    International Nuclear Information System (INIS)

    Single- and double-strand breaks were measured in Col E1 plasmid DNA, natural and partially brominated, irradiated with monoenergetic X-rays (from a synchrotron radiation source) on both sides of the K-absorption edge for Br. The fraction of the undamaged supercoiled form decreased exponentially with the photon dose; its yield in the brominated DNA did not exhibit any energy-dependence. This result is consistent with the calculated relative contributions of photoelectric interactions with individual component atoms which show that an electron flux originating in light atoms outweighs that from bromine. However, X-rays of energy above the Br K-edge appear slightly more efficient in producing double-strand breaks. This result seems to suggest that the positive charge and submolecular effects associated with the photo-absorption in bromine play some role in damaging processes, besides the initial distribution of deposited electron energy. (author)

  4. Bromine determination by neutron activation analysis and its distribution in the atmosphere

    International Nuclear Information System (INIS)

    Bromine, one of the main participants in ozone layer destruction, is 10 to 100 times more effective than chlorine. There are two principal sources of methyl bromide emissions: the oceans and some pesticides that are used in farming. Bromine was detected in 'premium' and 'magna sin' gasolines (2.86±0.96 and 1.54±0.38 ppm, respectively) as well as in condensed water found in exhaust pipes of vehicles. In addition, samples of rainwater were also analyzed to determine atmospheric bromine concentration. In water samples Br concentrations ranging from 2.09 to 0.06 ppm were found. The techniques utilised were neutron activation analysis and high voltage electrophoresis, the latter to determine the chemical form of bromine in condensed water samples. Finally, suspended particles from rainwater were also analysed by scanning electron microscopy (SEM). (author)

  5. New insight into photo-bromination processes in saline surface waters: The case of salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tamtam, Fatima; Chiron, Serge, E-mail: serge.chiron@msem.univ-montp2.fr

    2012-10-01

    It was shown, through a combination of field and laboratory observations, that salicylic acid can undergo photo-bromination reactions in sunlit saline surface waters. Laboratory-scale experiments revealed that the photochemical yields of 5-bromosalicylic acid and 3,5-dibromosalicylic acid from salicylic acid were always low (in the 4% range at most). However, this might be of concern since these compounds are potential inhibitors of the 20{alpha}-hydroxysteroid dehydrogenase enzyme, with potential implications in endocrine disruption processes. At least two mechanisms were involved simultaneously to account for the photo-generation of brominated substances. The first one might involve the formation of reactive brominated radical species (Br{center_dot}, Br{sub 2}{center_dot}{sup -}) through hydroxyl radical mediated oxidation of bromide ions. These ions reacted more selectively than hydroxyl radicals with electron-rich organic pollutants such as salicylic acid. The second one might involve the formation of hypobromous acid, through a two electron oxidation of bromine ions by peroxynitrite. This reaction was catalyzed by nitrite, since these ions play a crucial role in the formation of nitric oxide upon photolysis. This nitric oxide further reacts with superoxide radical anions to yield peroxynitrite and by ammonium through the formation of N-bromoamines, probably due to the ability of N-bromoamines to promote the aromatic bromination of phenolic compounds. Field measurements revealed the presence of salicylic acid together with 5-bromosalicylic and 3,5-dibromosalicylic acid in a brackish coastal lagoon, thus confirming the environmental significance of the proposed photochemically induced bromination pathways. -- Highlights: Black-Right-Pointing-Pointer Brominated derivatives of salicylic acid were detected in a brackish lagoon. Black-Right-Pointing-Pointer A photochemical pathway was hypothesized to account for bromination of salicylic acid. Black

  6. Bromine as a Potential Threat to the Aquatic Environment in Areas of Mining Operations

    OpenAIRE

    Winid Bogumiła

    2013-01-01

    Fresh water normally contains limited quantities of bromine. The average content of bromine in the surface and groundwater active exchange zone generally does not exceed 200 μg/dm3 (0.2 mg/dm3). Mineralized waters, including some specific therapeutic waters, thermal waters, and brines, may contain bromides in amounts greater than in ordinary groundwater. Bromides will penetrate into groundwater and surface water due to salty groundwater inflow. In areas of mining operations, the management of...

  7. Complete Reductive Dehalogenation of Brominated Biphenyls by Anaerobic Microorganisms in Sediment

    OpenAIRE

    Bedard, Donna L.; Van Dort, Heidi M.

    1998-01-01

    We sought to determine whether microorganisms from the polychlorinated biphenyl (PCB)-contaminated sediment in Woods Pond (Lenox, Mass.) could dehalogenate brominated biphenyls. The PCB dechlorination specificities for the microorganisms in this sediment have been well characterized. This allowed us to compare the dehalogenation specificities for brominated biphenyls and chlorinated biphenyls within a single sediment. Anaerobic sediment microcosms were incubated separately at 25°C with 16 dif...

  8. Characterization and cyclic performance of membranes in hydrogen-bromine battery

    OpenAIRE

    Hugo, Yohanes

    2015-01-01

    A large renewable energy integration needs to be coupled with a low cost energy storage technology. One of the promising energy storage alternatives for the commercial market segment is the hydrogen bromine flow battery. Although the technology has been explored since 1980, the development of the hydrogen bromine flow battery system is still in the research phase due to the system complexity, the safety aspect, and technical problems. The literature review revealed that costs of the system an...

  9. Performance and Degradation of A Lithium-Bromine Rechargeable Fuel Cell Using Highly Concentrated Catholytes

    OpenAIRE

    Bai, Peng; Bazant, Martin Z.

    2016-01-01

    Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density, and higher efficiency. The cell is similar in structure to a hybrid-electrolyte Li-air battery, wh...

  10. Bromine atom production and chain propagation during springtime Arctic ozone depletion events in Barrow, Alaska

    OpenAIRE

    Thompson, Chelsea R.; Shepson, Paul B.; Liao, Jin; Huey, L. Greg; Cantrell, Chris; Flocke, Frank; Orlando, John

    2016-01-01

    Ozone depletion events (ODEs) in the Arctic are primarily controlled by a bromine radical-catalyzed destruction mechanism that depends on the efficient production and recycling of Br atoms. Numerous laboratory and modeling studies have suggested the importance of heterogeneous recycling of Br through HOBr reaction with bromide on saline surfaces. However, the gas-phase regeneration of bromine atoms through BrO-BrO radical reactions has been assumed to be an efficient, if not dominant, pa...

  11. Gaia Paradigm: A Biotic Origin Of The Polar Sunrise Arctic Bromine Explosion

    OpenAIRE

    Iudin, M.

    2008-01-01

    The main attention is given to discussion of the natural causes and regularities of the Arctic bromine pollution. We make notice of marine microbial organisms and their metabolism as a prime driving force for the elemental biogeochemical cycles. One of the important conclusions of this study is on similarity between ocean bromine concentrating as by-product of the marine microbial activities and nitrogen fixation by soil bacteria. In both cases, microbial organisms and their food webs maintai...

  12. Springtime surface ozone fluctuations at high Arctic latitudes and their possible relationship to atmospheric bromine

    Science.gov (United States)

    Oltmans, Samuel J.; Sheridan, Patrick J.; Schnell, Russell C.; Winchester, John W.

    1988-01-01

    At high Arctic stations such as Barrow, Alaska, springtime near-surface ozone amounts fluctuate between the highest and lowest values seen during the course of the year. Episodes when the surface ozone concentration is essentially zero last up to several days during this time of year. In the Arctic Gas and Aerosol Sampling Program (AGASP-I and AGASP-II) in 1983 and 1986, it was found that ozone concentrations often showed a very steep gradient in altitude with very low values near the surface. The cold temperatures, and snow-covered ground make it unlikely that the surface itself would rapidly destroy significant amounts of ozone. The AGASP aircraft measurements that found low ozone concentrations in the lowest layers of the troposphere also found that filterable excess bromine (the amount of bromine in excess of the sea salt component) in samples collected wholly or partially beneath the temperature inversion had higher bromine concentrations than other tropospheric samples. Of the four lowest ozone minimum concentrations, three of them were associated with the highest bromine enrichments. Surface measurements of excess filterable bromine at Barrow show a strong seasonal dependence with values rising dramatically early in March, then declining in May. The concentration of organic bromine gases such as bromoform rise sharply during the winter and then begin to decline after March with winter and early spring values at least three times greater than the summer minimum.

  13. Addition of bromine as a diagnostic gas to inertial confinement fusion target microspheres

    International Nuclear Information System (INIS)

    Currently, direct fuel rho r measurements on Inertial Confinement Fusion (ICF) targets by neutron activation of the argon tracer gas mixed with the DT fuel would require a 100 fold increase in neutron yield. Bromine, on the other hand, has excellent properties for neutron activation analysis at neutron yields of 10two' to 108, when present at an internal pressure of from 0.1 to 0.2 atmospheres. Bromine addition is accomplished in a 2 furnace system using the dried-gel method of microsphere production. An upper furnace operated at 15000C is separated from a lower furnace by a cooled zone. The lower furnace is filled with bromine gas and operated at approximately 12500C. The upper furnace is the glass production furnace. The cooled zone in between the upper and lower furnace is to prevent the hot bromine gas from rising into the upper furnace. The microspheres pass through the cooled zone and immediately into the 12500C bromine furnace where the bromine permeates into the spheres

  14. Photothermally induced bromination of carbon/polymer bipolar plate materials for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Martin; Franzka, Steffen [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Cappuccio, Franco; Peinecke, Volker; Heinzel, Angelika [Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Zentrum für BrennstoffzellenTechnik (ZBT), Carl-Benz-Straße 201, 47057 Duisburg (Germany); Hartmann, Nils, E-mail: nils.hartmann@uni-due.de [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)

    2015-05-01

    Graphical abstract: - Highlights: • Photothermal laser bromination of carbon/polymer materials is demonstrated. • Using a microfocused laser functionalized domains with diameters of 5 μm and 100 μm and more can be fabricated. • Bromine groups can be transformed in a variety of other chemical functionalities, i.e. amine groups. • Depending on the chemical functionality, the local chemical affinity and wettability is changed. • The routine can be applied to standard bipolar plate materials used for fuel cell applications. - Abstract: A facile photothermal procedure for direct functionalization of carbon/polymer bipolar plate materials is demonstrated. Through irradiation with a microfocused beam of an Ar{sup +}-laser at λ = 514 nm in gaseous bromine and distinct laser powers and pulse lengths local bromination of the carbon/polymer material takes place. At a 1/e spot diameter of 2.1 μm, functionalized surface areas with diameters down to 5 μm are fabricated. In complementary experiments large-area bromination is investigated using an ordinary tungsten lamp. For characterization contact angle goniometry, X-ray photoelectron spectroscopy and electron microscopy in conjunction with labeling techniques are employed. After irradiation bromine groups can easily be substituted by other chemical functionalities, e.g. azide and amine groups. This provides a facile approach in order to fabricate surface patterns and gradient structures with varying wetting characteristics. Mechanistic aspects and prospects of photothermal routines in micropatterning of carbon/polymer materials are discussed.

  15. Photothermally induced bromination of carbon/polymer bipolar plate materials for fuel cell applications

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Photothermal laser bromination of carbon/polymer materials is demonstrated. • Using a microfocused laser functionalized domains with diameters of 5 μm and 100 μm and more can be fabricated. • Bromine groups can be transformed in a variety of other chemical functionalities, i.e. amine groups. • Depending on the chemical functionality, the local chemical affinity and wettability is changed. • The routine can be applied to standard bipolar plate materials used for fuel cell applications. - Abstract: A facile photothermal procedure for direct functionalization of carbon/polymer bipolar plate materials is demonstrated. Through irradiation with a microfocused beam of an Ar+-laser at λ = 514 nm in gaseous bromine and distinct laser powers and pulse lengths local bromination of the carbon/polymer material takes place. At a 1/e spot diameter of 2.1 μm, functionalized surface areas with diameters down to 5 μm are fabricated. In complementary experiments large-area bromination is investigated using an ordinary tungsten lamp. For characterization contact angle goniometry, X-ray photoelectron spectroscopy and electron microscopy in conjunction with labeling techniques are employed. After irradiation bromine groups can easily be substituted by other chemical functionalities, e.g. azide and amine groups. This provides a facile approach in order to fabricate surface patterns and gradient structures with varying wetting characteristics. Mechanistic aspects and prospects of photothermal routines in micropatterning of carbon/polymer materials are discussed

  16. Mercuric iodide (HgI2) growth for nuclear detectors

    Science.gov (United States)

    Schnepple, W.

    1982-01-01

    The purpose of this investigation is to grow more-perfect mercuric iodide crystals in a low-gravity environment by taking advantage of diffusion-controlled growth conditions and by avoiding the problem of strain dislocations produced by the crystal's weight. This crystal has considerable practical importance as a sensitive gamma-ray detector and energy spectrometer that can operate at ambient temperature, as compared to presently available detectors that must be cooled to near liquid nitrogen temperatures. However, the performance of mercuric iodide crystals only rarely approaches the expected performance, presumably because some of the free electrical charges produced within the crystal are not collected at the electrodes, but instead remain trapped or immobilized at crystal defects. An efficient high atomic number semiconductor detector capable of operating at room temperature utilizing single HgI2 crystals offers a greater potential than existing detector technology.

  17. Development of the semiconductor detector of lead iodide

    International Nuclear Information System (INIS)

    Lead iodide (PbI2) crystal is one of the most promising semiconductor detectors to be operated at room temperature. It is a semiconductor with a wide band gap energy and high atomic numbers. The preparation of a detector crystal consists of the purification of starting material, in quartz ampoules, by zone refining technique and growth of crystals by Bridgman method. The ability to obtain high purity crystals containing a relatively low number of defects and the physical-chemistry characterization are necessary pre-requisites for the production of good quality radiation detectors. This work reports the lead iodide monocrystal purification and growth methods to obtain those crystals with appropriate characteristics for their application as radiation detectors. (author)

  18. Behaviour of organic iodides under pwr accident conditions

    International Nuclear Information System (INIS)

    Laboratory experiments were performed to study the behaviour of radioactive methyl iodide under PWR loss-of-coolant conditions. The pressure relief equipment consisted of an autoclave for simulating the primary circuit and of an expansion vessel for simulating the conditions after a rupture in the reactor coolant system. After pressure relief, the composition of the CH3sup(127/131)I-containing steam-air mixture within the expansion vessel was analysed at 80 0C over a period of 42 days. On the basis of the values measured and of data taken from the literature, both qualitative and quantitative assessments have been made as to the behaviour of radioactive methyl iodide in the event of loss-of-coolant accidents. (author)

  19. (1,2-Dicarba-closo-dodecaboranyltrimethylmethanaminium iodide

    Directory of Open Access Journals (Sweden)

    Jong-Dae Lee

    2011-08-01

    Full Text Available The title compound, [1-(CH33NCH2-1,2-C2B10H11]+·I− or C6H22B10N+·I−, was obtained by the reaction of (1,2-dicarba-closo-dodecaboranyldimethylmethanamine with methyl iodide. The asymmetric unit contains two iodide anions and two (o-carboranyltetramethylammonium cations. The bond lengths and angles in the carborane cage are within normal ranges, but the N—Cmethylene—Ccage angle is very large [120.2 (2°] because of repulsion between the carborane and tetramethylammonium units. In the crystal, ions are linked through C—H...I hydrogen bonds.

  20. Enhanced iodide sequestration by 3-biphenyl-5,6-dihydroimidazo 2,1-b thiazole in sodium/iodide sym-porter (NIS)-expressing cells

    International Nuclear Information System (INIS)

    The ability of the sodium/iodide sym-porter (NIS) to take up iodide has long provided the basis for cyto-reductive gene therapy and cancer treatment with radio-iodide. One of the major limitations of this approach is that radio-iodide retention in NIS-expressing cells is not sufficient for their destruction. We identified and characterized a small organic molecule capable of increasing iodide retention in HEK293 cells permanently transfected with human NIS cDNA (hNIS-HEK293) and in the rat thyroid-derived cell line FRTL-5. In the presence of 3-biphenyl-4'-yl-5,6-dihydroimidazo[2,1-b)thiazole (ISA1), the transmembrane iodide concentration gradient was increased up to 4.5-fold. Our experiments indicate that the imidazo-thiazole derivative acts either by inhibiting anion efflux mechanisms, or by promoting the relocation of iodide into subcellular compartments. This new compound is not only an attractive chemical tool to investigate the mechanisms of iodide flux at the cellular level, but also opens promising perspectives in the treatment of cancer after NIS gene transfer. (authors)

  1. Recovery of thallium-activated sodium iodide detectors

    International Nuclear Information System (INIS)

    A method for recovery and treatment of sodium iodide thallium activated detectors, NaI(Tl), is described. Special techniques of polishing and mounting in a dry environment (relative humidity less than 10%) are applied. The resolution was determined and compared with that obtained with a new detector and the results showed that a typical 3' phi x 3' recovered detector had a performance very similar to that of a new one. (Author)

  2. Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

    OpenAIRE

    Viroj Wiwanitkit

    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 19...

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

    OpenAIRE

    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-eff...

  4. Radiative efficiency of lead iodide based perovskite solar cells

    OpenAIRE

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

    2015-01-01

    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...

  5. Ionic transport in hybrid lead iodide perovskite solar cells

    OpenAIRE

    Eames, Christopher; Frost, Jarvist Moore; Piers R. F. Barnes; O'Regan, Brian C.; Walsh, Aron; Islam, M. Saiful

    2015-01-01

    Solar cells based on organic–inorganic halide perovskites have recently shown rapidly rising power conversion efficiencies, but exhibit unusual behaviour such as current–voltage hysteresis and a low-frequency giant dielectric response. Ionic transport has been suggested to be an important factor contributing to these effects; however, the chemical origin of this transport and the mobile species are unclear. Here, the activation energies for ionic migration in methylammonium lead iodide (CH3NH...

  6. Structural insight into iodide uptake by AFm phases.

    Science.gov (United States)

    Aimoz, Laure; Wieland, Erich; Taviot-Guého, Christine; Dähn, Rainer; Vespa, Marika; Churakov, Sergey V

    2012-04-01

    The ability of cement phases carrying positively charged surfaces to retard the mobility of (129)I, present as iodide (I(-)) in groundwater, was investigated in the context of safe disposal of radioactive waste. (125)I sorption experiments on ettringite, hydrotalcite, chloride-, carbonate- and sulfate-containing AFm phases indicated that calcium-monosulfate (AFm-SO(4)) is the only phase that takes up trace levels of iodide. The structures of AFm phases prepared by coprecipitating iodide with other anions were investigated in order to understand this preferential uptake mechanism. X-ray diffraction (XRD) investigations showed a segregation of monoiodide (AFm-I(2)) and Friedel's salt (AFm-Cl(2)) for I-Cl mixtures, whereas interstratifications of AFm-I(2) and hemicarboaluminate (AFm-OH-(CO(3))(0.5)) were observed for the I-CO(3) systems. In contrast, XRD measurements indicated the formation of a solid solution between AFm-I(2) and AFm-SO(4) for the I-SO(4) mixtures. Extended X-ray absorption fine structure spectroscopy showed a modification of the coordination environment of iodine in I-CO(3) and in I-SO(4) samples compared to pure AFm-I(2). This is assumed to be due to the introduction of stacking faults in I-CO(3) samples on one hand and due to the presence of sulfate and associated space-filling water molecules as close neighbors in I-SO(4) samples on the other hand. The formation of a solid solution between AFm-I(2) and AFm-SO(4), with a short-range mixing of iodide and sulfate, implies that AFm-SO(4) bears the potential to retard (129)I. PMID:22376086

  7. Growth of mercuric iodide single crystals from dimethylsulfoxide

    Science.gov (United States)

    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.

  8. New applications for the zinc iodide-osmium tetroxide technique.

    OpenAIRE

    Dağdeviren, A; ALP, H.; Ors, U

    1994-01-01

    The zinc iodide-osmium tetroxide (ZIO) fixation/staining method was applied for neurocytological studies and also to examine several other tissue samples including epidermal Langerhans cells, blood and bone marrow cells and lymphoid tissue. Although precise specificity cannot be attributed to the staining reaction, interesting staining patterns for different cell types were observed by using one of the ZIO staining solutions. The significance of ZIO positivity is briefly discussed.

  9. Transport of Iodide Ion in Compacted Bentonite Containing Ag2O - 12111

    International Nuclear Information System (INIS)

    Observations of the transport of iodide through compacted bentonite containing Ag2O as additive and that without additive were made. Compacted bentonite samples with densities of 1.41 g/cm3 and 1.60 g/cm3 were used in the experiment. The amount of Ag2O added to the compacted bentonite was in the range of 0.0064 ∼ 0.0468 wt/wt%. Two diffusion solutions were used: one in which iodide ion was dissolved in demineralized water (pure iodide solution), and one in which iodide ion was dissolved in 0.1 M NaCl solution (0.1 M NaCl-iodide solution). Experimental results confirmed that iodide ion was transported by the diffusion process in the compacted bentonite containing Ag2O as well as in the compacted bentonite without Ag2O. The time-lag of diffusion of iodide ion in the compacted bentonite containing Ag2O is larger than that in the compacted bentonite without Ag2O. The increase of the time-lag of diffusion was observed in pure iodide ion solution as well as in 0.1 M NaCl-iodide solution. The apparent diffusion coefficient of iodide ion in the compacted bentonite containing Ag2O was smaller than in the compacted bentonite without Ag2O. The effective diffusion coefficient decreased as the amount of Ag2O in the compacted bentonite increased. (authors)

  10. The sodium iodide symporter: its implications for imaging and therapy

    International Nuclear Information System (INIS)

    The sodium iodide symporter (NIS) is an intrinsic plasma membrane glycoprotein that mediates the active transport of iodide in the thyroid gland and a number of extrathyroidal tissues, in particular lactating mammary gland. In addition to its key function in thyroid physiology, NIS-mediated iodide accumulation allows diagnostic thyroid scintigraphy as well as therapeutic radioiodine application in benign and malignant thyroid disease. NIS therefore represents one of the oldest targets for molecular imaging and therapy. Based on the effective administration of radioiodine that has been used for over 60 years in the management of follicular cell-derived thyroid cancer, cloning and characterization of the NIS gene has paved the way for the development of a novel cytoreductive gene therapy strategy based on targeted NIS expression in thyroidal and nonthyroidal cancer cells followed by therapeutic application of 131I or alternative radionuclides, including 188Re and 211At. In addition, the possibility of direct and non-invasive imaging of functional NIS expression by 123I- and 99mTc-scintigraphy or 124I-PET-imaging allows the application of NIS as a novel reporter gene. In conclusion, the dual role of NIS as diagnostic and therapeutic gene and the detection of extra-thyroidal endogenous NIS expression in breast cancer open promising perspectives in nuclear medicine and molecular oncology for diagnostic and therapeutic application of NIS outside the thyroid gland. (orig.)

  11. Synthesis and evaluation of iodide uptake inhibitors in thyroid gland

    International Nuclear Information System (INIS)

    This work was intended to discover small organic molecules acting as iodide uptake inhibitors in thyroid cells. These compounds can indeed be derivatized into biochemical probes for further characterization of proteins involved in iodide transport mechanisms. On the long term, these inhibitors also appear as attractive drug candidates for treatment of thyroid pathologies or radioprotection against iodine isotopes. A similar strategy was adopted for both of the two inhibitor families. First, we synthesized a chemical library of around 100 analogues; we measured their IC50 against iodide uptake in FRTL-5 cells to get structure-activity relationships. Absolute configuration of stereo-genic centers was also investigated, and a preferential stereochemistry was found to be responsible for activity. From this basis, around twenty 'second-generation' analogues were synthesized by combining fragments contributing to biological activity. Biological evaluation indicated that nine were very potent inhibitors, with IC50 ≤ 6 nM and satisfying physicochemical properties required for drug candidates. Finally, one photoactivatable biotinylated probe was developed in each family and used for photoaffinity labeling. Several specifically labeled proteins are still under identification and constitute new potential therapeutic targets. (author)

  12. Growth and luminescence properties of undoped strontium iodide crystals

    International Nuclear Information System (INIS)

    Highlights: •Undoped strontium iodide crystal with high optical quality was grown using the Bridgman method. •Metal impurities distribution throughout crystal boule was determined and discussed. •Reliable optical transmission spectrum of undoped strontium iodide crystal was obtained. •Luminescence properties for broad emission band at room temperature were studied. •The room temperature broad emission band was proposed to have an origin of self-trapped exciton. -- Abstract: High optical quality undoped strontium iodide crystal grown by using the Bridgman method was characterized. Crystal growth process was described and growth technical parameters were discussed. Impurity analysis of raw materials and as-grown crystal boule indicates that it is feasible to pre-purify the raw material by zone refining or recrystallization. Luminescence properties were studied by photoluminescence, radioluminescence, fluorescence decay time, and scintillation time response. As-grown crystal shows good optical transmittance with wavelength concerned and is transparent for its large Stoke shift, 540 nm peaked broad emission, which has a fluorescence decay time 494 ns at 300 K. The broad emission range from 350 nm to 800 nm was tentatively speculated to be intrinsic and have an origin of self-trapped exciton

  13. Utilization of a Green Brominating Agent for the Spectrophotometric Determination of Pipazethate HCl in Pure Form and Pharmaceutical Preparations

    OpenAIRE

    Ayman A. Gouda

    2013-01-01

    Five simple, accurate, and sensitive spectrophotometric methods (A–E) have been described for the indirect assay of pipazethate HCl (PZT) either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C), the determination of the residual bromine ...

  14. Electrochemistry of silver iodide the capacity of the double layer at the silver iodide-water interface

    NARCIS (Netherlands)

    Lyklema, J.; Overbeek, J.Th.G.

    1961-01-01

    A method is described for obtaining differential double layer capacities on silver iodide. Especially the influence of the nature and concentration of indifferent electrolytes was investigated, viz., the nitrates of Li·, K·, Rb·, NH4·, H·, Tl·, Mg··, Ba··, Co··, Cd··, Pb··, La···, Th····, the fluori

  15. Antimycobacterial brominated metabolites from two species of marine sponges.

    Science.gov (United States)

    de Oliveira, Maria Fernanda; de Oliveira, Jaine Honorata; Galetti, Fabio C; de Souza, Ana Olívia; Silva, Célio Lopes; Hajdu, Eduardo; Peixinho, Solange; Berlinck, Roberto G

    2006-04-01

    A screening of 500 crude extracts of marine invertebrates against the growth of Mycobacterium tuberculosis H37Rv yielded MeOH extracts of the sponges Aplysina cauliformis and Pachychalina sp. with significant activity. Further bioassay-guided fractionation of both crude extracts led to the isolation of four bromine-containing metabolites. The known (+)-fistularin-3 (1) and 11-deoxyfistularin-3 (2), and the new compound 2-(3-amino-2,4-dibromo-6-hydroxyphenyl)acetic acid (3) were isolated from the sponge A. cauliformis, while the new bromotyrosine-derived 3-(3,5-dibromo-4-methoxyphenyl)-2-methoxy- N-methylpropan-1-ammonium (4) was isolated from Pachychalina sp. Compound 4 exhibited weak antimycobacterial activity while compounds 1-3 displayed activity against Mycobacterium tuberculosis H37Rv, with MICs of 7.1, 7.3 and 49 microM, respectively. Compounds 1 and 2 also exhibited low cytotoxicity against J744 macrophages, indicating that both 1 and 2 are interesting leads for the development of new anti-tuberculosis agents. PMID:16557458

  16. Excited atomic bromine energy transfer and quenching mechanisms

    Science.gov (United States)

    Johnson, Ray O.

    1993-08-01

    Pulsed and steady-state photolysis experiments have been conducted to determine the rate coefficients for collisional deactivation of the spin-orbit excited state of atomic bromine, Br((sup 2)P(sub 1/2)). Pulsed lifetime studies for quenching by Br2 and CO2 established absolute rate coefficients at room temperature of k(sub Br2) = 1.2 +/- 0.1 x 10(exp-12) and k(sub CO2) = 1.5 +/0.2 x 10(exp-11) cu cm/molecule-s. Steady-state photolysis methods were used to determine the quenching rates for the rare gases, N2, 02, H2, D2, NO, NO2, N2O, SF6, CF4, CH4, CO, CO2, COS, SO2, H2S, HBr, HC1, and HI relative to that for Br2. Quenching rate temperature dependence was examined for Br2, CO2, N2O, HCl, COS, NO, and NO2 for temperatures from 300 to 420 K. Diffusion and three body effects were examined in order to determine the slowest relative quenching rate measurable by this experimental technique.

  17. Untypical bromine corrosion in boilers co-firing biomass

    Directory of Open Access Journals (Sweden)

    A. Hernas

    2012-09-01

    Full Text Available Purpose: The aim of this study was to determine the untypical corrosion resistance of rotary air preheaters in a biomass co-fired power plant.Design/methodology/approach: The selected results of some components of regenerative rotary air preheaters in a biomass co-fired power plant are presented. The macro and microstructure of corroded components of a LUVO preheater after 3 years of service are presented. The chemical composition of corrosion products was determined by X-ray microanalysis.Findings: Data concerning toxicity and identification of PBDEs (Polibrominated diphenyl ethers in the biomass is very limited. The presented research provides information and the proposed corrosion reaction mechanism in environments containing biomass with aggressive compounds like Cl, Si, H and Br.Research limitations/implications: An extended research on PBDEs in power plant fuels is necessary to give a full assessment of the corrosion mechanism in the presented environment; obligatory classification of the co-fired biomass.Originality/value: Firstly, an assessment of the danger for boiler materials co-firing biomass containing brominated organic flame and presentation of the reaction during the corrosion process and degradation of power boiler components in the presented environment. Secondly, the highlighting of the problem that there is a need to properly select and determine the chemical composition of the biomass used.

  18. Hydrogen cycle employing calcium-bromine and electrolysis

    International Nuclear Information System (INIS)

    The Secure Transportable Autonomous Reactor (STAR) project is part of the U.S. Department of Energy's (DOE's) Nuclear Energy Research Initiative (NERI) to develop Generation IV nuclear reactors that will supply high-temperature heat at over 800 C. The NERI project goal is to develop an economical, proliferation-resistant, sustainable, nuclear-based energy supply system based on a modular-sized fast reactor that is passively safe and cooled with heavy liquid metal. STAR consists of: (1) A combined thermochemical water-splitting cycle to generate hydrogen, (2) A steam turbine cycle to generate electricity, and (3) An optional capability to produce potable water from brackish or salt water. However, there has been limited reporting on critical elements of the thermochemical cycle: (1) establishing chemical reaction kinetics and operating pressures and (2) addressing materials issues for hydrogen production. This paper reviews the thermodynamic basis for a three-stage Calcium-Bromine water-splitting cycle based on the University of Tokyo Cycle No.3 [UT-3] and discusses the further chemistry work that is required to develop an economical process including modifying UT-3 to incorporate HBr dissociation

  19. Modelling chemistry over the Dead Sea: bromine and ozone chemistry

    Directory of Open Access Journals (Sweden)

    L. Smoydzin

    2009-02-01

    Full Text Available Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs, widely known to happen in polar regions, are also likely to occur over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br levels in the Dead Sea water and the release of gas phase halogen species out of sea borne aerosol particles and their conversion to reactive halogen species. It is likely that other sources for reactive halogen compounds are needed to explain the observed concentrations for BrO and O3. To explain the chemical mechanism taking place over the Dead Sea leading to BrO levels of several pmol/mol we used the single column model MISTRA which calculates microphysics, meteorology, gas and aerosol phase chemistry. We performed pseudo Lagrangian studies by letting the model column first move over the desert which surrounds the Dead Sea region and then let it move over the Dead Sea itself. To include an additional source for gas phase halogen compounds, gas exchange between the Dead Sea water and the atmosphere is treated explicitly. Model calculations indicate that this process has to be included to explain the measurements.

  20. Modelling chemistry over the Dead Sea: bromine and ozone chemistry

    Directory of Open Access Journals (Sweden)

    R. von Glasow

    2009-07-01

    Full Text Available Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs, widely known to happen in polar regions, are also occuring over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br levels in the Dead Sea water and the release of gas phase halogen species out of sea borne aerosol particles and their conversion to reactive halogen species. It is likely that other sources for reactive halogen compounds are needed to explain the observed concentrations for BrO and O3. To explain the chemical mechanism taking place over the Dead Sea leading to BrO levels of several pmol/mol we used the one-dimensional model MISTRA which calculates microphysics, meteorology, gas and aerosol phase chemistry. We performed pseudo Lagrangian studies by letting the model column first move over the desert which surrounds the Dead Sea region and then let it move over the Dead Sea itself. To include an additional source for gas phase halogen compounds, gas exchange between the Dead Sea water and the atmosphere is treated explicitly. Model calculations indicate that this process has to be included to explain the measurements.

  1. Non-polar halogenated natural products bioaccumulated in marine samples. II. Brominated and mixed halogenated compounds.

    Science.gov (United States)

    Vetter, Walter; Jun, Wu

    2003-07-01

    Several identified and potential natural brominated bioaccumulative compounds were studied in this work. 4,6-dibromo-2-(2('),4(')-dibromo)phenoxyanisole (BC-2) previously detected in Australian marine mammals and isolated from sponges, was synthesized. Two byproducts (a tetrabromo isomer and a tribromo congener) were investigated as well. The byproducts of the synthesis were not identified in the environmental samples investigated. Previously described natural brominated compounds (BC-1, BC-2, BC-3, BC-10, BC-11, MHC-1) and anthropogenic brominated diphenyl ethers (BDE-47, BDE-99, BDE-100, BDE-154) were detected in a sample of human milk. The sample was from a woman from the Faeroe Islands who frequently consumed fish as well as whale blubber and meat. The most abundant compound originated from the natural tetrabromo phenoxyanisole BC-3 which may have a 3:1 distribution of bromine on the two phenyl units. This sample also accumulated a dibromochloroanisole, as well as a previously unknown mixed halogenated compound (MHC-X) and an unknown, most likely aromatic brominated compound. Co-elutions on a DB-5 column were found for BDE-99 and BC-11 as well as BDE-154 and the unknown brominated compound. This suggests that quantification of these two compounds has to be carried out carefully.Two samples of lower trophic level, namely Baltic cod liver and Mexican mussel tissue, were investigated as well. The cod liver samples contained BDE congeners but also abundant signals for the natural 2,3,3('),4,4('),5,5(')-heptachloro-1(')-methyl-1,2(')-bipyrrole Q1 and tribromoanisole (TBA). The mussel sample contained Q1, TBA, another halogenated anisole, BC-1, BC-2, and BC-3, as well as additional, potential natural brominated compounds in the elution range of tribromophenoxyanisoles. PMID:12738265

  2. Impact of deep convection and dehydration on bromine loading in the upper troposphere and lower stratosphere

    Directory of Open Access Journals (Sweden)

    J. Aschmann

    2011-03-01

    Full Text Available Stratospheric bromine loading due to very short-lived substances is investigated with a three-dimensional chemical transport model over a period of 21 years using meteorological input data from the European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis from 1989 to the end of 2009. Within this framework we analyze the impact of dehydration and deep convection on the amount of stratospheric bromine using an idealized and a detailed full chemistry approach. We model the two most important brominated short-lived substances, bromoform (CHBr3 and dibromomethane (CH2Br2, assuming a uniform convective detrainment mixing ratio of 1 part per trillion by volume (pptv for both species. The contribution of very short-lived substances to stratospheric bromine varies drastically with the applied dehydration mechanism and the associated scavenging of soluble species ranging from 3.4 pptv in the idealized setup up to 5 pptv using the full chemistry scheme. In the latter case virtually the entire amount of bromine originating from very short-lived source gases is able to reach the stratosphere thus rendering the impact of dehydration and scavenging on inorganic bromine in the tropopause insignificant. Furthermore, our long-term calculations show that the mixing ratios of very short-lived substances are strongly correlated to convective activity, i.e. intensified convection leads to higher amounts of very short-lived substances in the upper troposphere/lower stratosphere especially under extreme conditions like El Niño seasons. However, this does not apply to the inorganic brominated product gases whose concentrations are anti-correlated to convective activity mainly due to convective dilution and possible scavenging, depending on the applied approach.

  3. Impact of deep convection and dehydration on bromine loading in the upper troposphere and lower stratosphere

    Directory of Open Access Journals (Sweden)

    J. Aschmann

    2011-01-01

    Full Text Available Stratospheric bromine loading due to very short-lived substances is investigated with a three-dimensional chemical transport model over a period of 21 years using meteorological input data from the European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis from 1989 to the end of 2009. Within this framework we analyze the impact of dehydration and deep convection on the amount of stratospheric bromine using an idealized and a detailed full chemistry approach. We model the two most important brominated short-lived substances, bromoform (CHBr3 and dibromomethane (CH2Br2, assuming a uniform detrainment mixing ratio of 1 part per trillion by volume (pptv for both species. The contribution of very short-lived substances to stratospheric bromine varies drastically with the applied dehydration mechanism and the associated scavenging of soluble species ranging from 3.4 pptv in the idealized setup up to 5 pptv using the full chemistry scheme. In the latter case virtually the entire amount of bromine originating from very short-lived source gases is able to reach the stratosphere thus rendering the impact of dehydration and scavenging on inorganic bromine in the tropopause insignificant. Furthermore, our long-term calculations show that the mixing ratios of very short-lived substances are strongly correlated to convective activity, i.e. intensified convection leads to higher amounts of very short-lived substances in the upper troposphere/lower stratosphere especially under extreme conditions like El Niño seasons. However, this does not apply to the inorganic brominated product gases whose concentrations are anti-correlated to convective activity mainly due to convective dilution and possible scavenging, depending on the applied approach.

  4. An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

    Science.gov (United States)

    Blechschmidt, A.-M.; Richter, A.; Burrows, J. P.; Kaleschke, L.; Strong, K.; Theys, N.; Weber, M.; Zhao, X.; Zien, A.

    2016-02-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high-latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favoured the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

  5. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    Directory of Open Access Journals (Sweden)

    A. Pour Biazar

    2006-06-01

    Full Text Available The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br− present in the Dead Sea water. Further, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br. The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the positive correlation observed between BrO and O3 at low O3 concentrations, and for the jagged diurnal pattern of BrO observed in the Dead Sea area. The present study has shown that the heterogeneous decomposition of BrONO2 has the potential to greatly affect the RBS activity in areas under anthropogenic influence, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

  6. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    Directory of Open Access Journals (Sweden)

    E. Tas

    2006-01-01

    Full Text Available The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br− present in the Dead Sea water. Furthermore, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br. The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the jagged diurnal pattern of BrO observed in the Dead Sea area, and for the positive correlation observed between BrO and O3 at low O3 concentrations. The present study has shown that the heterogeneous decomposition of BrONO2 has a great potential to affect the RBS activity in areas influenced by anthropogenic emissions, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

  7. Abiotic formation of methyl iodide on synthetic birnessite: A mechanistic study

    Energy Technology Data Exchange (ETDEWEB)

    Allard, Sébastien, E-mail: s.allard@curtin.edu.au; Gallard, Hervé

    2013-10-01

    Methyl iodide is a well-known volatile halogenated organic compound that contributes to the iodine content in the troposphere, potentially resulting in damage to the ozone layer. Most methyl iodide sources derive from biological activity in oceans and soils with very few abiotic mechanisms proposed in the literature. In this study we report that synthetic manganese oxide (birnessite δ-MnO{sub 2}) can catalyze the formation of methyl iodide in the presence of natural organic matter (NOM) and iodide. Methyl iodide formation was only observed at acidic pH (4–5) where iodide is oxidized to iodine and NOM is adsorbed on δ-MnO{sub 2}. The effect of δ-MnO{sub 2}, iodide and NOM concentrations, nature of NOM and ionic strength was investigated. High concentrations of methyl iodide were formed in experiments conducted with the model compound pyruvate. The Lewis acid property of δ-MnO{sub 2} leads to a polarization of the iodine molecule, and catalyzes the reaction with natural organic matter. As manganese oxides are strong oxidants and are ubiquitous in the environment, this mechanism could significantly contribute to the global atmospheric input of iodine. Highlights: • Methyl iodide is formed when iodide, natural organic matter and MnO{sub 2} are in contact. • Iodide is oxidized to iodine by MnO{sub 2} which reacts with NOM already adsorbed on MnO{sub 2}. • High formation of methyl iodide was observed with pyruvate. • This abiotic mechanism could contribute to the input of iodine in the atmosphere. • This abiotic mechanism could impact the ozone layer in the troposphere.

  8. Abiotic formation of methyl iodide on synthetic birnessite: A mechanistic study

    International Nuclear Information System (INIS)

    Methyl iodide is a well-known volatile halogenated organic compound that contributes to the iodine content in the troposphere, potentially resulting in damage to the ozone layer. Most methyl iodide sources derive from biological activity in oceans and soils with very few abiotic mechanisms proposed in the literature. In this study we report that synthetic manganese oxide (birnessite δ-MnO2) can catalyze the formation of methyl iodide in the presence of natural organic matter (NOM) and iodide. Methyl iodide formation was only observed at acidic pH (4–5) where iodide is oxidized to iodine and NOM is adsorbed on δ-MnO2. The effect of δ-MnO2, iodide and NOM concentrations, nature of NOM and ionic strength was investigated. High concentrations of methyl iodide were formed in experiments conducted with the model compound pyruvate. The Lewis acid property of δ-MnO2 leads to a polarization of the iodine molecule, and catalyzes the reaction with natural organic matter. As manganese oxides are strong oxidants and are ubiquitous in the environment, this mechanism could significantly contribute to the global atmospheric input of iodine. Highlights: • Methyl iodide is formed when iodide, natural organic matter and MnO2 are in contact. • Iodide is oxidized to iodine by MnO2 which reacts with NOM already adsorbed on MnO2. • High formation of methyl iodide was observed with pyruvate. • This abiotic mechanism could contribute to the input of iodine in the atmosphere. • This abiotic mechanism could impact the ozone layer in the troposphere

  9. Discovery of aryl-tri-fluoroborates as potent sodium/iodide sym-porter (NIS) inhibitors

    International Nuclear Information System (INIS)

    The structure-based design of sodium/iodide sym-porter (NIS) inhibitors identified new active compounds. The organo-tri-fluoroborate shown was found to inhibit iodide uptake with an IC50 value of 0.4 μM on rat-derived thyroid cells. The biological activity is rationalized by the presence of the BF3- ion as a minimal binding motif for substrate recognition at the iodide binding site. (authors)

  10. Uptake of Iodide From Water in Atlantic Halibut Larvae (Hippoglossus Hippoglossus L.)

    DEFF Research Database (Denmark)

    Moren, Mari; Sloth, Jens Jørgen; Hamre, Kristin

    2008-01-01

    The natural diet of marine fish larvae, copepods, contain 60-350 mg I kg(-1), while live feed used in commercial hatcheries have iodine concentrations in the range of 1 mg kg(-1). Seawater is also considered to be an important source of iodine for marine fish. The question asked in this study is...... relative low levels of iodide (0-22 nM) and except for samples from one site; the levels of iodide and iodate were in agreement with previously published data. The uptake of iodide from seawater was measured by incubating Atlantic halibut larvae in water with a constant level of radioactive iodide (I-125...

  11. Expression of sodium-iodide symporter in thyroid gland tumors: immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Bondarenko O.O.

    2009-01-01

    Full Text Available One of the key moments of radioiodine therapy, and also radioisotope diagnostics of cancers of a thyroid gland is ability of their cells to accumulate iodide. This ability is provided with activity of the specific transporter – sodium-iodide symporter. Our research has shown disorders of sodium-iodide symporter immunoexpression in all tumors of thyroid gland: from overexpression and absence of plasma membrane expression in differentiated carcinomas, up to weak or actually absent in low differentiated cancers and Hurtle-cells tumors. Thus, there is a prospect of application of the sodium-iodide symporter, as the prognostic marker of thyroid cancers.

  12. Experimental studies on removal of airborne fission products methyl iodide by sprays in containment

    International Nuclear Information System (INIS)

    For reducing the amount of fission products leaked to environment under accident conditions of PWR, the experimental studies on the removal of airborne fission products methyl iodide by sprays in containment was carried out on the basis of the theoretical work in a simulation facility. Inactive methyl iodide was used for the experiment so the experiment facility was simplified. A gas chromatography was employed to measure the aerosol concentration of methyl iodide. A series of experiments on the removal of methyl iodide by sprays under different temperatures and various chemical additives has been made. The experimental results are useful for rationally selecting parameters of containment spray system of PWR

  13. Brominated skeletal components of the marine demosponges, Aplysina cavernicola and Ianthella basta: analytical and biochemical investigations.

    Science.gov (United States)

    Kunze, Kurt; Niemann, Hendrik; Ueberlein, Susanne; Schulze, Renate; Ehrlich, Hermann; Brunner, Eike; Proksch, Peter; van Pée, Karl-Heinz

    2013-04-01

    Demosponges possess a skeleton made of a composite material with various organic constituents and/or siliceous spicules. Chitin is an integral part of the skeleton of different sponges of the order Verongida. Moreover, sponges of the order Verongida, such as Aplysina cavernicola or Ianthella basta, are well-known for the biosynthesis of brominated tyrosine derivates, characteristic bioactive natural products. It has been unknown so far whether these compounds are exclusively present in the cellular matrix or whether they may also be incorporated into the chitin-based skeletons. In the present study, we therefore examined the skeletons of A. cavernicola and I. basta with respect to the presence of bromotyrosine metabolites. The chitin-based-skeletons isolated from these sponges indeed contain significant amounts of brominated compounds, which are not easily extractable from the skeletons by common solvents, such as MeOH, as shown by HPLC analyses in combination with NMR and IR spectroscopic measurements. Quantitative potentiometric analyses confirm that the skeleton-associated bromine mainly withstands the MeOH-based extraction. This observation suggests that the respective, but yet unidentified, brominated compounds are strongly bound to the sponge skeletons, possibly by covalent bonding. Moreover, gene fragments of halogenases suggested to be responsible for the incorporation of bromine into organic molecules could be amplified from DNA isolated from sponge samples enriched for sponge-associated bacteria. PMID:23595055

  14. Removal of brominated flame retardant from electrical and electronic waste plastic by solvothermal technique

    International Nuclear Information System (INIS)

    Highlights: ► A process for brominated flame retardants (BFRs) removal in plastic was established. ► The plastic became bromine-free with the structure maintained after this treatment. ► BFRs transferred into alcohol solvent were easily debrominated by metallic copper. - Abstract: Brominated flame retardants (BFRs) in electrical and electronic (E and E) waste plastic are toxic, bioaccumulative and recalcitrant. In the present study, tetrabromobisphenol A (TBBPA) contained in this type of plastic was tentatively subjected to solvothermal treatment so as to obtain bromine-free plastic. Methanol, ethanol and isopropanol were examined as solvents for solvothermal treatment and it was found that methanol was the optimal solvent for TBBPA removal. The optimum temperature, time and liquid to solid ratio for solvothermal treatment to remove TBBPA were 90 °C, 2 h and 15:1, respectively. After the treatment with various alcohol solvents, it was found that TBBPA was finally transferred into the solvents and bromine in the extract was debrominated catalyzed by metallic copper. Bisphenol A and cuprous bromide were the main products after debromination. The morphology and FTIR properties of the plastic were generally unchanged after the solvothermal treatment indicating that the structure of the plastic maintained after the process. This work provides a clean and applicable process for BFRs-containing plastic disposal.

  15. Electrochemical performance and transport properties of a Nafion membrane in a hydrogen-bromine cell environment

    Science.gov (United States)

    Baldwin, Richard S.

    1987-01-01

    The overall energy conversion efficiency of a hydrogen-bromine energy storage system is highly dependent upon the characteristics and performance of the ion-exchange membrane utilized as a half-cell separator. The electrochemical performance and transport properties of a duPont Nafion membrane in an aqueous HBr-Br2 environment were investigated. Membrane conductivity data are presented as a function of HBr concentration and temperature for the determination of ohmic voltage losses across the membrane in an operational cell. Diffusion-controlled bromine permeation rates and permeabilities are presented as functions of solution composition and temperature. Relationships between the degree of membrane hydration and the membrane transport characteristics are discussed. The solution chemistry of an operational hydrogen-bromine cell undergoing charge from 45% HBr to 5% HBr is discussed, and, based upon the experimentally observed bromine permeation behavior, predicted cell coulombic losses due to bromine diffusion through the membrane are presented as a function of the cell state-of-charge.

  16. The bromine enhancement ratio in mammalian cells in vitro and experimental mouse tumours

    International Nuclear Information System (INIS)

    Human kidney cells in culture and cells of mouse sarcoma-180 were allowed to incorporate bromine into their DNA. Cultured cells with and without incorporated BUdR were irradiated with electromagnetic radiations ranging in energy from 12 keV X-rays to 60Co γ-rays to find out whether or not there exists any energy dependence of the bromine dose enhancement ratio BER. Such a dependence should show in the immediate neighbourhood of the K-absorption edge of bromine (13.5 keV). Any influence of the Auger effect triggered in bromine by external irradiation should show by a significant increase of the BER for energies rising from slightly below to slight above the bromine K-edge. Values of D37, D0 and the extrapolation numbers of the cell survival curves served as biological endpoints. Measured values of BER ranged from 1.12-2.00 without any significant dependence on energy. A weakly pronounced peak was found for 50 kV X-rays of 26 keV mean energy. Sarcoma-180 were irradiated with 14 keV X-rays and 60C γ-rays. BUdR was administered i.v., i.p. and directly into the tumours in quantities of up to 1 ml of a 10-3M solution. (Auth.)

  17. Bromine and bromide content in soils: Analytical approach from total reflection X-ray fluorescence spectrometry.

    Science.gov (United States)

    Gallardo, Helena; Queralt, Ignasi; Tapias, Josefina; Candela, Lucila; Margui, Eva

    2016-08-01

    Monitoring total bromine and bromide concentrations in soils is significant in many environmental studies. Thus fast analytical methodologies that entail simple sample preparation and low-cost analyses are desired. In the present work, the possibilities and drawbacks of low-power total reflection X-ray fluorescence spectrometry (TXRF) for the determination of total bromine and bromide contents in soils were evaluated. The direct analysis of a solid suspension using 20 mg of fine ground soil (water soil extracts. In this case, the TXRF analysis can be directly performed by depositing 10 μL of the internal standardized soil extract sample on a quartz glass reflector in a measuring time of 1500 s. The bromide limit of detection by this approach was 10 μg L(-1). Good agreement was obtained between the TXRF results for the total bromine and bromide determinations in soils and those obtained by other popular analytical techniques, e.g. energy dispersive X-ray fluorescence spectrometry (total bromine) and ionic chromatography (bromide). As a study case, the TXRF method was applied to study bromine accumulation in two agricultural soils fumigated with a methyl bromide pesticide and irrigated with regenerated waste water. PMID:27179429

  18. Brominated Skeletal Components of the Marine Demosponges, Aplysina cavernicola and Ianthella basta: Analytical and Biochemical Investigations

    Directory of Open Access Journals (Sweden)

    Eike Brunner

    2013-04-01

    Full Text Available Demosponges possess a skeleton made of a composite material with various organic constituents and/or siliceous spicules. Chitin is an integral part of the skeleton of different sponges of the order Verongida. Moreover, sponges of the order Verongida, such as Aplysina cavernicola or Ianthella basta, are well-known for the biosynthesis of brominated tyrosine derivates, characteristic bioactive natural products. It has been unknown so far whether these compounds are exclusively present in the cellular matrix or whether they may also be incorporated into the chitin-based skeletons. In the present study, we therefore examined the skeletons of A. cavernicola and I. basta with respect to the presence of bromotyrosine metabolites. The chitin-based-skeletons isolated from these sponges indeed contain significant amounts of brominated compounds, which are not easily extractable from the skeletons by common solvents, such as MeOH, as shown by HPLC analyses in combination with NMR and IR spectroscopic measurements. Quantitative potentiometric analyses confirm that the skeleton-associated bromine mainly withstands the MeOH-based extraction. This observation suggests that the respective, but yet unidentified, brominated compounds are strongly bound to the sponge skeletons, possibly by covalent bonding. Moreover, gene fragments of halogenases suggested to be responsible for the incorporation of bromine into organic molecules could be amplified from DNA isolated from sponge samples enriched for sponge-associated bacteria.

  19. Polarized spectral complexes of optical functions of monovalent mercury iodide

    Science.gov (United States)

    Sobolev, V. V.; Sobolev, V. Val.; Anisimov, D. V.

    2015-12-01

    Spectral complexes of optical functions of monovalent mercury iodide Hg2I2 were determined for E ⊥ c and E || c polarizations in the range from 2 to 5.5 eV at 4.2 K. The permittivity and characteristic electron energy loss spectra were expanded in simple components with the determination of their main parameters, including the energy of the maximum and the oscillator strength. The calculations were performed based on known reflectance spectra. Computer programs based on Kramers-Kronig relations and the improved parameter-free method of Argand diagrams were used.

  20. Measuring Cell Death by Propidium Iodide Uptake and Flow Cytometry.

    Science.gov (United States)

    Crowley, Lisa C; Scott, Adrian P; Marfell, Brooke J; Boughaba, Jeanne A; Chojnowski, Grace; Waterhouse, Nigel J

    2016-01-01

    Propidium iodide (PI) is a small fluorescent molecule that binds to DNA but cannot passively traverse into cells that possess an intact plasma membrane. PI uptake versus exclusion can be used to discriminate dead cells, in which plasma membranes become permeable regardless of the mechanism of death, from live cells with intact membranes. PI is excited by wavelengths between 400 and 600 nm and emits light between 600 and 700 nm, and is therefore compatible with lasers and photodetectors commonly available in flow cytometers. This protocol for PI staining can be used to quantitate cell death in most modern research facilities and universities. PMID:27371595

  1. Mechanochromic and thermochromic luminescence of a copper iodide cluster.

    Science.gov (United States)

    Perruchas, Sandrine; Le Goff, Xavier F; Maron, Sébastien; Maurin, Isabelle; Guillen, François; Garcia, Alain; Gacoin, Thierry; Boilot, Jean-Pierre

    2010-08-18

    The mechanochromic and thermochromic luminescence properties of a molecular copper(I) iodide cluster formulated [Cu(4)I(4)(PPh(2)(CH(2)CH=CH(2)))(4)] are reported. Upon mechanical grinding in a mortar, its solid-state emission properties are drastically modified as well as its thermochromic behavior. This reversible phenomenon has been attributed to distortions in the crystal packing leading to modifications of the intermolecular interactions and thus of the [Cu(4)I(4)] cluster core geometry. Notably, modification of the Cu-Cu interactions seems to be involved in this phenomenon directly affecting the emissive properties of the cluster. PMID:20698644

  2. Electronic properties and Compton profiles of silver iodide

    Indian Academy of Sciences (India)

    Alpa Dashora; Ambica Marwal; K R Soni; B L Ahuja

    2010-06-01

    We have carried out an extensive study of electronic properties of silver iodide in - and -phases. The theoretical Compton profiles, energy bands, density of states and anisotropies in momentum densities are computed using density functional theories. We have also employed full-potential linearized augmented plane-wave method to derive the energy bands and the density of states. To compare our theoretical data, isotropic Compton profile measurement on -AgI using 137Cs Compton spectrometer at an intermediate resolution of 0.38 a.u. has been undertaken. The theoretical anisotropies are also interpreted on the basis of energy bands.

  3. Rutherford backscattering and Auger spectroscopy of mercuric iodide detectors

    Energy Technology Data Exchange (ETDEWEB)

    Felter, T.E.; Stulen, R.H. (Sandia National Labs., Livermore, CA (USA)); Schnepple, W.F.; Ortale, C.; Van den Berg, L. (EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations)

    1989-11-01

    Palladium contacts on mercuric iodide have been studied using Rutherford backscattering spectroscopy and Auger electron spectroscopy. Results on actual detector contacts show some intermixing of both mercury and iodine with the palladium. To investigate the role of processing variables as a possible cause of this effect we have fabricated model contacts at low temperatures (T {approx equal} 100 K) and analyzed in situ. The results demonstrated that significant interdiffusion occurs at temperatures as low as 225 K. We conclude that excessive heating during contact deposition could prove to be detrimental to device performance and that the use of cooled substrates during processing should be explored. (orig.).

  4. Low-temperature photoluminescence studies of mercuric-iodide photodetectors

    Science.gov (United States)

    James, R. B.; Bao, X. J.; Schlesinger, T. E.; Markakis, J. M.; Cheng, A. Y.; Ortale, C.

    1989-09-01

    Mercuric-iodide (HgI2 ) photodetectors with sputtered indium-tin-oxide (ITO) entrance electrodes were studied using low-temperature photoluminescence spectroscopy. The photoluminescence spectrum obtained on each photodetector was found to differ for points beneath the ITO contact and points adjacent to it, indicating that the contact fabrication process introduces new carrier traps and radiative recombination centers within the ITO-HgI2 interfacial region. In particular, a new broad band was observed in the spectra taken from points beneath the ITO electrode. Photocurrent-versus-position measurements showed that the intensity of this broad band was enhanced in regions having relatively poor photoresponse.

  5. Rutherford backscattering and Auger spectroscopy of mercuric iodide detectors

    Science.gov (United States)

    Felter, T. E.; Stulen, R. H.; Schnepple, W. F.; Ortale, C.; van den Berg, L.

    1989-11-01

    Palladium contacts on mercuric iodide have been studied using Rutherford backscattering spectroscopy and Auger electron spectroscopy. Results on actual detector contacts show some intermixing of both mercury and iodine with the palladium. To investigate the role of processing variables as a possible cause of this effect we have fabricated model contacts at low temperatures (T ≈ 100 K) and analyzed in situ. The results demonstrated that significant interdiffusion occurs at temperatures as low as 225 K. We conclude that excessive heating during contact deposition could prove to be detrimental to device performance and that the use of cooled substrates during processing should be explored.

  6. Low-temperature photoluminescence studies of mercuric-iodide photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    James, R.B. (Theoretical Division, Sandia National Laboratories, Livermore, California 94551-0969 (US)); Bao, X.J. (Theoretical Division, Sandia National Laboratories, Livermore, California 94551-0969 (US)); Schlesinger, T.E. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213); Markakis, J.M. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213); Cheng, A.Y. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213); Ortale, C. (EG G Energy Measurements, Inc., Goleta, California 93116)

    1989-09-15

    Mercuric-iodide (HgI{sub 2} ) photodetectors with sputtered indium-tin-oxide (ITO) entrance electrodes were studied using low-temperature photoluminescence spectroscopy. The photoluminescence spectrum obtained on each photodetector was found to differ for points beneath the ITO contact and points adjacent to it, indicating that the contact fabrication process introduces new carrier traps and radiative recombination centers within the ITO-HgI{sub 2} interfacial region. In particular, a new broad band was observed in the spectra taken from points beneath the ITO electrode. Photocurrent-versus-position measurements showed that the intensity of this broad band was enhanced in regions having relatively poor photoresponse.

  7. Low-temperature photoluminescence studies of mercuric-iodide photodetectors

    International Nuclear Information System (INIS)

    Mercuric-iodide (HgI2 ) photodetectors with sputtered indium-tin-oxide (ITO) entrance electrodes were studied using low-temperature photoluminescence spectroscopy. The photoluminescence spectrum obtained on each photodetector was found to differ for points beneath the ITO contact and points adjacent to it, indicating that the contact fabrication process introduces new carrier traps and radiative recombination centers within the ITO-HgI2 interfacial region. In particular, a new broad band was observed in the spectra taken from points beneath the ITO electrode. Photocurrent-versus-position measurements showed that the intensity of this broad band was enhanced in regions having relatively poor photoresponse

  8. Rutherford backscattering and Auger spectroscopy of mercuric iodide detectors

    International Nuclear Information System (INIS)

    Palladium contacts on mercuric iodide have been studied using Rutherford backscattering spectroscopy and Auger electron spectroscopy. Results on actual detector contacts show some intermixing of both mercury and iodine with the palladium. To investigate the role of processing variables as a possible cause of this effect we have fabricated model contacts at low temperatures (T ≅ 100 K) and analyzed in situ. The results demonstrated that significant interdiffusion occurs at temperatures as low as 225 K. We conclude that excessive heating during contact deposition could prove to be detrimental to device performance and that the use of cooled substrates during processing should be explored. (orig.)

  9. Temperature dependent energy levels of methylammonium lead iodide perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Benjamin J.; Marlowe, Daniel L.; Choi, Joshua J., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Sun, Keye; Gupta, Mool C., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Saidi, Wissam A. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Scudiero, Louis, E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Chemistry Department and Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164 (United States)

    2015-06-15

    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.

  10. Persistent photovoltage in methylammonium lead iodide perovskite solar cells

    OpenAIRE

    Baumann, A.; Tvingstedt, K.; Heiber, M. C.; Väth, S.; C. Momblona; H. J. Bolink; Dyakonov, V.

    2014-01-01

    We herein perform open circuit voltage decay (OCVD) measurements on methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to increase the understanding of the charge carrier recombination dynamics in this emerging technology. Optically pulsed OCVD measurements are conducted on CH3NH3PbI3 solar cells and compared to results from another type of thin-film photovoltaics, namely, the two reference polymer–fullerene bulk heterojunction solar cell devices based on P3HT:PC60BM and PTB7:PC70...

  11. Temperature dependent energy levels of methylammonium lead iodide perovskite

    International Nuclear Information System (INIS)

    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. Temperature dependent energy levels of methylammonium lead iodide perovskite

    Science.gov (United States)

    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.

  13. Human health risk associated with brominated flame-retardants (BFRs).

    Science.gov (United States)

    Lyche, Jan L; Rosseland, Carola; Berge, Gunnar; Polder, Anuschka

    2015-01-01

    The purposes of this review are to assess the human exposure and human and experimental evidence for adverse effects of brominated flame-retardants (BFRs) with specific focus on intake from seafood. The leakage of BFRs from consumer products leads to exposure of humans from fetal life to adulthood. Fish and fish products contain the highest levels of BFRs and dominate the dietary intake of frequent fish eaters in Europe, while meat, followed by seafood and dairy products accounted for the highest US dietary intake. House dust is also reported as an important source of exposure for children as well as adults. The levels of BFRs in the general North American populations are higher than those in Europe and Japan and the highest levels are detected in infants and toddlers. The daily intake via breast milk exceeds the RfD in 10% of US infants. BFRs including PBDEs, HBCDs and TBBP-A have induced endocrine-, reproductive- and behavior effects in laboratory animals. Furthermore, recent human epidemiological data demonstrated association between exposure to BFRs and similar adverse effects as observed in animal studies. Fish including farmed fish and crude fish oil for human consumption may contain substantial levels of BFRs and infants and toddlers consuming these products on a daily basis may exceed the tolerable daily intake suggesting that fish and fish oil alone represent a risk to human health. This intake comes in addition to exposure from other sources (breast milk, other food, house dust). Because potential harmful concentrations of BFRs and other toxicants occur in fish and fish products, research on a wider range of products is warranted, to assess health hazard related to the contamination of fish and fish products for human consumption. PMID:25454234

  14. Determination of bromine contents in blood and hair of workers exposed to methyl by radioactivation analysis method bromide

    International Nuclear Information System (INIS)

    The bromine contained in blood and hair samples obtained from workers exposed to methyl bromide was analyzed by nondestructive activation analysis. The samples were irradiated for 1 min in pneumatic irradiation facility of Kyoto University research reactor with an estimated thermal neutron flux density at 2 x 1013 n.cm-2.sec-1. The irradiation was counted with Ge(Li) detector. The duration of measurement of radionuclide bromine in blood and hair was 200 sec within 2 - 10 min after irradiation. The bromine content of serum sample obtained from a worker suspected of methyl bromide poisoning was found to be 412 μg/g on 13 days apart from exposure to methyl bromide. The biological half-life of bromine in this case was found to be about 16 days. Then bromine contents in serum and hair samples obtained from workers exposed to methyl bromide were found to be 1.7 and 2.6 times higher respectively than those of nonexposed workers. Any correlations of bromine contents were not observed between serum and hair samples obtained from workers exposed to methyl bromide, nor between bromine amount in the serum of workers exposed to methyl bromide and the terms exposed to it, but statistically significant positive correlation was observed between bromine amount in the hair of workers exposed to methyl bromide and the terms exposed to it. (author)

  15. Bromine-77-labeled estrogen receptor-binding radiopharmaceuticals for breast tumor imaging

    International Nuclear Information System (INIS)

    Two derivatives of 16α-bromoestradiol, both with and without an 11β-methoxy substituent, have been labeled with bromine-77 and evaluated as potential breast tumor imaging agents. Extensive characterization of these radiotracers in animal models has demonstrated their effective concentration in estrogen target tissues. Preliminary clinical studies have demonstrated the potential of radiolabeled estrogens for breast tumor imaging; however, the suboptimal decay properties of bromine-77 limit the utility of these agents in imaging studies. These results with 77-Br-labeled estrogens suggest that estrogen derivatives labeled with other radionuclides should provide enhanced image resolution with various imaging devices. Although the decay characteristics of bromine-77 are such that it is not ideally suited to imaging with conventional gamma cameras, it may be a useful radionuclide for therapeutic applications

  16. Determination by neutron activation analysis of loss of arsenic, antimony, bromine and mercury during lyophilization

    International Nuclear Information System (INIS)

    Neutron activation analysis has been used to monitor the loss of arsenic, as dimethylarsinic acid, (CH3)2AsOOH, or as sodium arsenate (Na2HAsO4.7H2O), antimony (as potassium antimony, tartrate, KSbC4O7.1/2H2O) and bromine (as bromide ion) during lyophilization of acidified and neutral aqueous synthetic and environmental samples. Losses of Sb and As ranged from zero to 60%, while losses of bromine were constant (at 91%) in acidic solutions. The variable losses of As and Sb were due solely to the presence of and partial decomposition of the (CH3)2AsOOH. Electrochemical oxidation of Br- to Br2 is responsible for the high losses of bromine. In addition losses of mercury (as methylmercuric chloride) were 1O0% in both acidic and neutral aqueous synthetic samples during lyophilization. (author)

  17. Regional variation and possible sources of brominated contaminants in breast milk from Japan

    International Nuclear Information System (INIS)

    This study focuses on the regional trends and possible sources of brominated organic contaminants accumulated in breast milk from mothers in southeastern (Okinawa) and northwestern (Hokkaido) areas of Japan. For persistent brominated flame retardants, polybrominated diphenyl ethers (PBDEs; major components, BDE-47 and BDE-153) were distributed at higher levels in mothers from Okinawa (mean, 2.1 ng/g lipid), while hexabromobenzene (HeBB) and its metabolite 1,2,4,5-tetrabromobenzene were more abundantly detected in mothers from Hokkaido (0.86 and 2.6 ng/g lipid), suggesting that there are regional differences in their exposure in Japan. We also detected naturally produced brominated compounds, one of which was identified as 2′-methoxy-2,3′,4,5′-tetrabromodiphenyl ether (2′-MeO-BDE68) at higher levels in mothers from Okinawa (0.39 ng/g lipid), while the other was identified as 3,3′,4,4′-tetrabromo-5,5′-dichloro-2,2′-dimethyl-1,1′-bipyrrole in mothers from Hokkaido (0.45 ng/g lipid). The regional variation may be caused by source differences, i.e. southern seafood for MeO-PBDEs and northern biota for halogenated bipyrroles in the Japanese coastal water. - Highlights: ► In this study, we detected brominated organic contaminants in Japanese breast milk. ► Naturally produced brominated organic contaminants were also detected. ► Northern and southern Japan showed regional differences in these contaminants. ► Exposure to the contaminants is suggested to arise from different specific sources. - Brominated organic contaminants were detected in Japanese breast milk.

  18. Nuclear detonation, thyroid cancer and potassium iodide prophylaxis.

    Science.gov (United States)

    Wiwanitkit, Viroj

    2011-04-01

    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

  19. Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

    Directory of Open Access Journals (Sweden)

    Viroj Wiwanitkit

    2011-01-01

    Full Text Available 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.

  20. Progress in tumor therapy with human sodium iodide symporter

    International Nuclear Information System (INIS)

    The sodium iodide symporter (NIS) is an intrinsic plasma membrane protein that mediates active iodide transport into the thyroid gland and several extrathyroidal tissues, in particular the lactation mammary gland. Because of the cloning characterization of NIS, its key role in thyroid pathology and physiology could be investigated. The progress would be significant if the mechanisms of NIS expression in lactating mammary gland and breast cancer are elucidated, in which more than 80% of cases express endogenous NIS. In the future, two approaches could extend the use of radioiodide treatment to thyroid cancer and nonthyroidal cancer. One is by using the main mechanisms involving tumorous transformation to treat the tumor, based on the reinducing NIS expression in thyroid and cancer. The other is based on the application of NIS as a novel cytoreductive gene therapy strategy. NIS offers the unique advantage that it can be used both as a reporter and as a therapeutic gene, so that it is possible to image, monitor, and treat the tumor with radioiodide, just as in differentiated thyroid cancer. (authors)

  1. Polymorphic copper iodide clusters: insights into the mechanochromic luminescence properties.

    Science.gov (United States)

    Benito, Quentin; Le Goff, Xavier F; Maron, Sébastien; Fargues, Alexandre; Garcia, Alain; Martineau, Charlotte; Taulelle, Francis; Kahlal, Samia; Gacoin, Thierry; Boilot, Jean-Pierre; Perruchas, Sandrine

    2014-08-13

    An in-depth study of mechanochromic and thermochromic luminescent copper iodide clusters exhibiting structural polymorphism is reported and gives new insights into the origin of the mechanochromic luminescence properties. The two different crystalline polymorphs exhibit distinct luminescence properties with one being green emissive and the other one being yellow emissive. Upon mechanical grinding, only one of the polymorphs exhibits great modification of its emission from green to yellow. Interestingly, the photophysical properties of the resulting partially amorphous crushed compound are closed to those of the other yellow polymorph. Comparative structural and optical analyses of the different phases including a solution of clusters permit us to establish a correlation between the Cu-Cu bond distances and the luminescence properties. In addition, the local structure of the [Cu4I4P4] cluster cores has been probed by (31)P and (65)Cu solid-state NMR analysis, which readily indicates that the grinding process modifies the phosphorus and copper atoms environments. The mechanochromic phenomenon is thus explained by the disruption of the crystal packing within intermolecular interactions inducing shortening of the Cu-Cu bond distances in the [Cu4I4] cluster core and eventually modification of the emissive state. These results definitely establish the role of cuprophilic interactions in the mechanochromism of copper iodide clusters. More generally, this study constitutes a step further into the understanding of the mechanism involved in the mechanochromic luminescent properties of metal-based compounds. PMID:25076411

  2. Comparison of Germanium and Sodium Iodide: In Vivo Measurement Systems

    International Nuclear Information System (INIS)

    The experience several investigators have had with lithium-drifted germanium. Ge(Li), and lithium-drifted silicon, Si (Li), counting systems for in vivo measurements is compared with conventional scintillator detector systems in similar configurations. Measurements of plutonium and americium in lungs, other organs, and wounds using coaxial and planar-drift detectors are presented. A proposed large area planar Ge(Li) lung counter system is compared to two- and four-crystal sodium iodide counters (130 cm2 by 9 mm thick) currently used for uranium and plutonium lung measurements. A large Ge(Li) detector system being employed at Battelle-Northwest Laboratory to make whole-body measurements of radionuclide deposits in humans consists of four coaxial detectors, each 40 cm3 in volume (total 160 cm3). The individual detectors are enclosed in separate cryostats but mounted in a common 30 litre liquid nitrogen dewar of the ''chicken feeder'' design. The system is compared to the standard 23 cm diameter by 10 cm thick sodium iodide scintillator in the standard chair position. (author)

  3. Interruption with the Migration of Iodide by GR(CT)

    International Nuclear Information System (INIS)

    The purpose of this study is to understand the influence of green rust on the migration of iodide. GR(CT) would be major corrosion product of iron near the seawater or saline layer in underground. The GR(CT) may play an important role in the retardation of the iodide migration in a deep geological environment due to it's anionic exchange reaction. In underground radioactive waste repository, the corrosion of iron canisters would be proceed as follows; Fe(II) and/or Fe(III) dissolved from iron containers → Fe(II)(OH)2 and/or Fe(III)(OH)3 → Green rust → Lepidocrocite or Magnetite → Goetite etc. Generally, the green rust has known to exist in environments close to the Fe(Π)/Fe(ΠΙ) transition zone or between the oxidized layer and reduced layer in the underground. As anion exchanger and strong reducer, the green rusts can affect the migration of anions, reactions involving green rusts were poorly studied in relation to the safety assessment of radioactive waste repository

  4. Nonradiometric and radiometric testing of radioiodine sorbents using methyl iodide

    International Nuclear Information System (INIS)

    A nonradiometric test of adsorbents and adsorbers with normal methyl iodide (CH3127I) is desirable. Use of methyl radioiodide (CH3131I) requires special precautions and facilities and results in bed contamination. However, first it must be established to what extent the removal of CH3127I by adsorbents is indicative of the removal of CH3131I. An experimental apparatus was built and used to simultaneously measure the penetrations of CH3I molecules and the radioisotope in CH3131I through charcoal absorbent beds. Gas chromatography with electron capture detection was used to measure CH3I. Radioiodine was measured using charcoal traps within NaI scintillation well crystals. Real time (5-min interval) radioiodine measurement provided immediate penetration results directly comparable to the real time penetrations of methyl iodide. These penetrations were compared for typical charcoal adsorbents with these impregnants: (a) 5% KI3, (b) 5% KI3 + 2% TEDA, (c) 5% TEDA, and (d) metal salts (Whetlerite). Differences between CH3I and CH3131I penetrations observed for the two iodized charcoals were attributed to isotope exchange reactions. Equivalent penetrations were observed for non-iodized adsorbents and for iodized ones at initial time. First order rates were confirmed for reactions with TEDA and for isotope exchange. This was one more confirmation of the lack of a challenge concentration effect on efficiencies at low test bed loadings. In addition to other removal mechanisms, reversible physical adsorption was observed with all charcoals

  5. Dichlorinated and Brominated Rugulovasines, Ergot Alkaloids Produced by Talaromyces wortmannii

    DEFF Research Database (Denmark)

    Soman De Medeiros, Lívia; da Silva, José Vinícius; Abreu, Lucas Magalhães;

    2015-01-01

    . Brominated rugulovasines were also detected when the microbial incubation medium was supplemented with bromine sources. Studies from 1D/2D NMR and HRMS spectroscopy data allowed the structural elucidation of the dichlorinated compounds, while tandem MS/HRMS data analysis supported the rationalization of......UHPLC-DAD-HRMS based dereplication guided the detection of new halogenated alkaloids co-produced by Talaromyces wortmannii. From the fungal growth in large scale, the epimers 2,8-dichlororugulovasines A and B were purified and further identified by means of a HPLC-SPE/NMR hyphenated system...

  6. Photochemical bromination of substituted indan-1-one derivatives: synthesis of new polybromoindan-1-one derivatives

    OpenAIRE

    KUŞ, Nermin Şimşek

    2009-01-01

    The photobromination of substituted indan derivatives was studied. Four products, 2,3-dibromo-inden-1-one (5), trans-2,3-dibromoindan-1-one (6), 2,2-dibromoindan-1,3-dione (7) and 2,2-dibromoindan-1-one (8), were obtained by the bromination of indan-1-one (4). The bromination of 2-methyl indanone (9) and 3-methyl-indanone (13) gave the corresponding monobromo, dibromo, and tribromo compounds in high yield. 4-Nitro indan (16) was tribrominated under same condition reaction. The stru...

  7. Effect of Brominated Furanones on the Formation of Biofilm by Escherichia coli on Polyvinyl Chloride Materials

    OpenAIRE

    Lianhua, Ye; Yunchao, Huang; Geng, Xu; Youquang, Zhou; Guangqiang, Zhao; Yujie, Lei

    2013-01-01

    To study the influence of brominated furanones on the biofilm (BF) formation by Escherichia coli (E. coli) on polyvinyl chloride (PVC) material, and to provide new ways of surface modification of materials to clinically prevent biomaterial centered infection. Three brominated furanones, dissolved in ethanol, furanone-1(3,4-dibromo-5-hydroxyl-furanone), furanone-2(4-bromo-5-(4-methoxypheny)-3-(methylamino)-furanone), and furanone-3(3,4-dibromo-5,5-dimethoxypheny-2(5H)-furanone) with representa...

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

    Science.gov (United States)

    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...

  9. Colorimetric sensing of iodide based on triazole-acetamide functionalized gold nanoparticles

    International Nuclear Information System (INIS)

    We have modified gold nanoparticles (AuNPs) with triazole acetamide to obtain a material for the sensitive and selective colorimetric determination of iodide. The functionalized AuNPs were prepared by a reductive single chemical step using a Cu(I)-catalyzed click reaction. The presence of iodide ions induces the aggregation of these AuNPs and results in a color change from wine-red to purple. The iodide-induced aggregation can be detected visually with bare eyes, but also by photometry. The detection limit is as low as 15 nM. The method displays excellent selectivity for iodide over other anions due to the selective interaction with the amido groups of the triazole. The method was applied to the determination of iodide in spiked lake waters. (author)

  10. Advances of radioiodine therapy of tumor induced by sodium iodide symporter gene

    International Nuclear Information System (INIS)

    As a kind of membrane protein that mainly mediates iodide transport into thyroid follicular cells, sodium iodide symporter (NIS) plays a key role in radioiodine therapy of both thyroid and other cancers. Studies show that decreased NIS expression level or intracellular localization in thyroid carcinomas lead to low iodine uptake. So NIS gene therapy is a new method to overcome this problem. To be therapeutically effective, radioiodine has to be remained in the tumor cells for sufficient long time; this is still a problem which reduces therapeutic effect. It should increase iodide retention and decrease iodide efflux in tumor cells to optimize therapeutic scheme. This article reviews the studies on advances of radioiodine therapy of tumor induced by sodium iodide symporter gene. (authors)

  11. Recovery and separation for the trace amounts of iodide in PWR spent fuel

    International Nuclear Information System (INIS)

    An separation and recovery technique for iodide in spent pressurized water reactor (PWR) fuels has been established using a SIMFUEL simulated for spent PWR fuel. The spent PWR fuels were dissolved with mixture of nitric and hydrochloric acids(80; 20 mol%) which can oxidize iodide to iodate through dissolution process. Iodide in uranium matrix and co-exist fission products was separated and recovered by organic extraction of iodine with carbon tetrachloride and by back extraction of iodide with 0.1 M NaHSO3. Recovered iodide was measured using an ion chromatograph/shielding system available for analysis of radioactive materials. In practice, a spent PWR fuel whose burnup rate was 42,261 MWd/MtU was analyzed and then the relation between the burnup and the quantity of the fission products was compared to the calculated by burnup code, Origen 2

  12. Ultrasensitive iodide detection based on the resonance light scattering of histidine-stabilized gold nanoclusters

    International Nuclear Information System (INIS)

    We have developed a novel resonance light scattering (RLS) assay for the sensitive and selective determination of iodide. It is based on the use of histidine-stabilized gold nanoclusters (His-AuNCs) which undergo fusion and aggregation in the presence of iodide. The resulting enhancement in the intensity of RLS is proportional to the concentration of iodide in the 0.01 to 8.0 μM range, and the detection limit is as low as 1.8 nM at a signal-to-noise ratio of 3. This “turn-on” method is highly selective for iodide and not interfered by other ions commonly present. It was applied to the determination of iodide in (spiked) real water samples. (author)

  13. Iodine K-edge EXAFS analysis of iodide ion-cyclodextrin inclusion complexes in aqueous solution

    International Nuclear Information System (INIS)

    We study the structure of inclusion complexes of α-, β-, γ-cyclodextrin with mono-iodide ion in aqueous solution by means of iodine K-edge EXAFS spectroscopy. The analysis is based on the assumption that two kinds of iodide ions exist in KI-cyclodextrin aqueous solution i.e. hydrated mono-iodide ions and one-one mono-iodide-cyclodextrin inclusion complexes. In KI-α-cyclodextrin system, iodine K-edge EXAFS analyse show that the average coordination number of the oxygen atoms in water molecules in the first hydration shell decreases as the fraction of included ions increases. This result suggests that dehydration process accompanies the formation of the inclusion complex. This is not found in the case of β-cyclodextrin, indicating that in this case the iodide ions are included together with the whole first hydration shell.

  14. Evaluation of optimal silver amount for the removal of methyl iodide on silver-impregnated adsorbents

    International Nuclear Information System (INIS)

    The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver-impregnated zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver impregnation amount for the removal of methyl iodide at temperatures up to 300 deg. C. The degree of adsorption efficiency of methyl iodide on silver-impregnated adsorbent is strongly dependent on impregnation amount and process temperature. A quantitative comparison of adsorption efficiencies on three adsorbents in a fixed bed was investigated. The influence of temperature, methyl iodide concentration and silver impregnation amount on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It shows that the effective impregnation ratio was about 10wt%, based on the degree of silver utilization for the removal of methyl iodide. The practical applicability of silver-impregnated zeolite for the removal of radioiodine generated from the DUPIC process was consequently proposed. (author)

  15. Synthesis of a Stable Primary-Alkyl-Substituted Selenenyl Iodide and Its Hydrolytic Conversion to the Corresponding Selenenic Acid

    OpenAIRE

    Shohei Sase; Ryo Kakimoto; Ryutaro Kimura; Kei Goto

    2015-01-01

    A primary-alkyl-substituted selenenyl iodide was successfully synthesized through oxidative iodination of a selenol with N-iodosuccinimide by taking advantage of a cavity-shaped steric protection group. The selenenyl iodide exhibited high thermal stability and remained unchanged upon heating at 100 °C for 3 h in [D8]toluene. The selenenyl iodide was reduced to the corresponding selenol by treatment with dithiothreitol. Hydrolysis of the selenenyl iodide under alkaline conditions afforded the ...

  16. 10 CFR 35.392 - Training for the oral administration of sodium iodide I-131 requiring a written directive in...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Training for the oral administration of sodium iodide I... sodium iodide I-131 requiring a written directive in quantities less than or equal to 1.22 gigabecquerels... oral administration of sodium iodide I-131 requiring a written directive in quantities less than...

  17. 10 CFR 35.394 - Training for the oral administration of sodium iodide I-131 requiring a written directive in...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Training for the oral administration of sodium iodide I... Byproduct Material-Written Directive Required § 35.394 Training for the oral administration of sodium iodide... of sodium iodide I-131 requiring a written directive in quantities greater than 1.22...

  18. 76 FR 16770 - Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide...

    Science.gov (United States)

    2011-03-25

    ... AGENCY Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide... iodide) be suspended and cancelled. The Agency is posting this petition for public comment. Following the... Earthjustice requesting that all uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency...

  19. Regioselective chlorination and bromination of unprotected anilines under mild conditions using copper halides in ionic liquids

    OpenAIRE

    Han Wang; Kun Wen; Nurbiya Nurahmat; Yan Shao; He Zhang; Chao Wei; Ya Li; Yongjia Shen; Zhihua Sun

    2012-01-01

    By using ionic liquids as solvents, the chlorination or bromination of unprotected anilines at the para-position can be achieved in high yields with copper halides under mild conditions, without the need for potentially hazardous operations such as supplementing oxygen or gaseous HCl.

  20. Regioselective chlorination and bromination of unprotected anilines under mild conditions using copper halides in ionic liquids

    Directory of Open Access Journals (Sweden)

    Han Wang

    2012-05-01

    Full Text Available By using ionic liquids as solvents, the chlorination or bromination of unprotected anilines at the para-position can be achieved in high yields with copper halides under mild conditions, without the need for potentially hazardous operations such as supplementing oxygen or gaseous HCl.

  1. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    Science.gov (United States)

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. PMID:26874310

  2. Performance and Degradation of A Lithium-Bromine Rechargeable Fuel Cell Using Highly Concentrated Catholytes

    CERN Document Server

    Bai, Peng

    2016-01-01

    Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density, and higher efficiency. The cell is similar in structure to a hybrid-electrolyte Li-air battery, where a lithium metal anode in nonaqueous electrolyte is separated from aqueous bromine catholytes by a lithium-ion conducting ceramic plate. The cell with a flat graphite electrode can discharge at a peak power density around 9mW cm-2 and in principle could provide a specific energy of 791.8 Wh kg-1, superior to most existing cathode materials and catholytes. It can also run in regenerative mode to recover the lithium metal anode and free bromine with 80-90% voltage efficiency, without any catalysts. Degradation of the sol...

  3. On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

    DEFF Research Database (Denmark)

    Mazzanti, Virginia; Cacciarini, Martina; Broman, Søren Lindbæk;

    2012-01-01

    Background: The dihydroazulene (DHA)/vinylheptafulvene (VHF) system (with two cyano groups at C1) functions as a photo-/thermoswitch. Direct ionic bromination of DHA has previously furnished a regioselective route to a 7,8-dibromide, which by elimination was converted to a 7-bromo-substituted DHA...

  4. Photothermally induced bromination of carbon/polymer bipolar plate materials for fuel cell applications

    Science.gov (United States)

    Schade, Martin; Franzka, Steffen; Cappuccio, Franco; Peinecke, Volker; Heinzel, Angelika; Hartmann, Nils

    2015-05-01

    A facile photothermal procedure for direct functionalization of carbon/polymer bipolar plate materials is demonstrated. Through irradiation with a microfocused beam of an Ar+-laser at λ = 514 nm in gaseous bromine and distinct laser powers and pulse lengths local bromination of the carbon/polymer material takes place. At a 1/e spot diameter of 2.1 μm, functionalized surface areas with diameters down to 5 μm are fabricated. In complementary experiments large-area bromination is investigated using an ordinary tungsten lamp. For characterization contact angle goniometry, X-ray photoelectron spectroscopy and electron microscopy in conjunction with labeling techniques are employed. After irradiation bromine groups can easily be substituted by other chemical functionalities, e.g. azide and amine groups. This provides a facile approach in order to fabricate surface patterns and gradient structures with varying wetting characteristics. Mechanistic aspects and prospects of photothermal routines in micropatterning of carbon/polymer materials are discussed.

  5. Bromine-82 Labelling of Human Serum Albumin, Insulin and Fibrinogen by Electrochemical Means

    International Nuclear Information System (INIS)

    The authors describe results obtained with a method using bromine-82 to label human serum albumin, fibrinogen and insulin, three organic substances of special importance in diagnostics and biological research. The method involves electrolytic bromination in an aqueous solution; this is performed in an electrolysis cell, whose anodic zone containing the substance to be labelled is partitioned from the cathodic zone by a dialysis membrane. For each of the three substances mentioned, the degree of bromination produced by a direct current (200, 200, 300 x 10-6 Å) was studied as a function of anode potential in 10-3 and 10-4 M solutions of NH4Br, the amount of bromine-labelled substance formed being checked by radio electrophoresis for various anodic potential values differing from each other by 50 mV. By immuno- electrophoresis it was ascertained that denaturation of albumin and fibrinogen only starts at anodic potential values for which the degree of labelling is already very high as compared with that yielded by chemical methods of labelling. The method here described has the advantage of rapid execution and is well suited to remote handling in a shielded zone. (author)

  6. Microbial degradation of the brominated flame retardant TBNPA by groundwater bacteria: laboratory and field study.

    Science.gov (United States)

    Balaban, Noa; Bernstein, Anat; Gelman, Faina; Ronen, Zeev

    2016-08-01

    In the present study, the biodegradation of the brominated flame retardant tribromoneopentylalcohol (TBNPA) by a groundwater enrichment culture was investigated using a dual carbon ((13)C/(12)C)- bromine ((81)Br/(79)Br) stable isotope analysis. An indigenous aerobic bacterial consortium was enriched from the polluted groundwater underlying an industrial site in the northern Negev Desert, Israel, where TBNPA is an abundant pollutant. Aerobic biodegradation was shown to be rapid, with complete debromination within a few days, whereas anaerobic biodegradation was not observed. Biodegradation under aerobic conditions was accompanied by a significant carbon isotope effect with an isotopic enrichment factor of ɛCbulk = -8.8‰ ± 1.5‰, without any detectable bromine isotope fractionation. It was found that molecular oxygen is necessary for biodegradation to occur, suggesting an initial oxidative step. Based on these results, it was proposed that H abstraction from the C-H bond is the first step of TBNPA biodegradation under aerobic conditions, and that the C-H bond cleavage results in the formation of unstable intermediates, which are rapidly debrominated. A preliminary isotopic analysis of TBNPA in the groundwater underlying the industrial area revealed that there are no changes in the carbon and bromine isotope ratio values downstream of the contamination source. Considering that anoxic conditions prevail in the groundwater of the contaminated site, the lack of isotope shifts in TBNPA indicates the lack of TBNPA biodegradation in the groundwater, in accordance with our findings. PMID:27183339

  7. Electron stimulated desorption of anions from native and brominated single stranded oligonucleotide trimers

    Energy Technology Data Exchange (ETDEWEB)

    Polska, Katarzyna; Rak, Janusz [Department of Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Bass, Andrew D.; Cloutier, Pierre; Sanche, Leon [Research Group in the Radiation Sciences, Faculty of Medicine, Universite de Sherbrooke, Sherbrooke, Quebec J1H 5N4 (Canada)

    2012-02-21

    We measured the low energy electron stimulated desorption (ESD) of anions from thin films of native (TXT) and bromine monosubstituted (TBrXT) oligonucleotide trimers deposited on a gold surface (T = thymidine, X = T, deoxycytidine (C), deoxyadenosine (A) or deoxyguanosine (G), Br = bromine). The desorption of H{sup -}, CH{sub 3}{sup -}/NH{sup -}, O{sup -}/NH{sub 2}{sup -}, OH{sup -}, CN{sup -}, and Br{sup -} was induced by 0 to 20 eV electrons. Dissociative electron attachment, below 12 eV, and dipolar dissociation, above 12 eV, are responsible for the formation of these anions. The comparison of the results obtained for the native and brominated trimers suggests that the main pathways of TBrXT degradation correspond to the release of the hydride and bromide anions. Significantly, the presence of bromine in oligonucleotide trimers blocks the electron-induced degradation of nuclobases as evidenced by a dramatic decrease in CN{sup -} desorption. An increase in the yields of OH{sup -} is also observed. The debromination yield of particular oligonucleotides diminishes in the following order: BrdU > BrdA > BrdG > BrdC. Based on these results, 5-bromo-2{sup '}-deoxyuridine appears to be the best radiosensitizer among the studied bromonucleosides.

  8. Assessment of the zinc-bromine battery for utility load leveling. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Will, F. G.; Iacovangelo, C. D.; Jackowski, J. S.; Secor, F. W.

    1978-03-15

    The technical and economic prospects of zinc-bromine batteries employing Nafion/sup R*/ fluorinated ion exchange membranes was evaluated. The applicability and performance limits of a variety of materials and concepts were explored, noval all-carbon electrode structures developed and tested in cells of up to 36 w-hr size, and a system design and cost analysis was performed.

  9. Biodegradation of brominated aromatics by cultures and laccase of Trametes versicolor

    Czech Academy of Sciences Publication Activity Database

    Uhnáková, Bronislava; Petříčková, Alena; Biedermann, David; Homolka, Ladislav; Vejvoda, Vojtěch; Bednář, P.; Papoušková, B.; Šulc, Miroslav; Martínková, Ludmila

    2009-01-01

    Roč. 76, č. 6 (2009), s. 826-832. ISSN 0045-6535 R&D Projects: GA MŠk 2B06151 Institutional research plan: CEZ:AV0Z50200510 Keywords : Brominated phenols * Tetrabromobisphenol A * Laccase Subject RIV: CE - Biochemistry Impact factor: 3.253, year: 2009

  10. Thermoelectric properties of bromine filled CoSb3 skutterudite

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Brenden R.; Crawford, Caitlin M.; McKinney, Robert W.; Parilla, Philip A.; Toberer, Eric S.

    2016-01-01

    Historically, the improved thermoelectric performance of skutterudite compounds has largely been driven by the incorporation of electropositive donors on interstitial sites. These 'rattlers' serve to optimize both electronic and thermal properties by tuning the carrier concentration and scattering phonons. In this work, we show that interstitial bromine can be incorporated into CoSb3 and assess the impact on electronic and thermal transport. In contrast to prior high pressure syntheses with iodine, interstitial bromine incorporation is achieved at ambient pressure. Transport properties are stable up to at least 375 degrees C. Bromine serves as an electronegative acceptor and can induce degenerate (>5 x 1019 cm-3) hole densities. In contrast to other p-type skutterudite compositions, bromine preserves the intrinsically high hole mobility of CoSb3 while significantly reducing the lattice thermal conductivity. The development of a stable p-type dopant for the interstitial filler site enables the development of skutterudites with both donor and acceptor interstitials to maximize phonon scattering while maintaining the high mobility of CoSb3.

  11. XAS AND XPS CHARACTERIZATION OF MERCURY BINDING ON BROMINATED ACTIVATED CARBON

    Science.gov (United States)

    Brominated powdered activated carbon sorbents have been shown to e quite effective for mercury capture when injected into the flue gas duct at coal-fired power plants and are especially useful when buring Western low-chlorine subbituminous coals. X-ray absorption spectroscopy (X...

  12. Ullmann-type coupling of brominated tetrathienoanthracene on copper and silver

    Czech Academy of Sciences Publication Activity Database

    Gutzler, R.; Cardenas, L.; Lipton-Duffin, J.; El Garah, M.; Dinca, L.E.; Szakacs, C.E.; Fu, Ch.; Gallagher, M.; Vondráček, Martin; Rybachuk, M.; Perepichka, D.F.; Rosei, F.

    2014-01-01

    Roč. 6, č. 5 (2014), 2660-2668. ISSN 2040-3364 R&D Projects: GA MŠk(CZ) LM2011029 Institutional support: RVO:68378271 Keywords : Ullmann reaction * brominated tetrathienoanthracene * high resolution photoemission * STM Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.394, year: 2014

  13. Surface characteristics of photoaligned polyimide film interfacial reacted with bromine or ethanethiol

    International Nuclear Information System (INIS)

    The surface characteristics of polyimide films containing cinnamate groups which promote the uniform alignment in adjacent liquid crystal (LC) upon photodimerization by linearly polarized ultraviolet (LPUV) lights were studied [M. Schadt, K. Schmitt, V. Koznikov, V. Chignirov, Jpn. J. Appl. Phys. 31 (1992) 2155. ]. But photoalignment methods have an image sticking problem by un-reacted photosensitive functional groups, which can be a severe defect to achieve high reliability of liquid crystal display (LCD) panels. So the un-reacted photosensitive functional groups were deactivated using bromine or ethanethiol. Bromine and ethanethiol lead to the formation of carbon-bromine or carbon-sulfur bonds from carbon-carbon double bonds. The interfacial reaction of bromine or ethanethiol on the polyimide surface has been studied using in situ X-ray photoelectron spectroscopy (XPS). The change of surface tension was observed by using a contact angle analyzer. The photoelastic modulator (PEM) was used to analyze the optical anisotropy on the polyimide surface. Also, the atomic force microscopy (AFM) was used to observe the morphology of polyimide surface [K. Rajesh, M.K. Ram, S.C. Jain, S.B. Samanta, A.V. Narliker, Thin Solid Films 325 (1998) 251.

  14. METABOLISM OF BROMINATED FLAME RETARDANTS IN HUMAN ASTROCYTES AND EFFECTS ON THYROID HORMONE HOMEOSTASIS

    Science.gov (United States)

    In this proposed study, hydroxylated PBDEs and brominated phenols likely will be formed in astrocytes as a result of cytochrome p450-mediated metabolism. Previous studies have shown that polychlorinated biphenyls (PCBs) affect the regulation of thyroid hormones at the bloo...

  15. Bromine release from blowing snow and its impact on tropospheric chemistry

    Science.gov (United States)

    Griffiths, Paul; Yang, Xin; Abraham, N. Luke; Archibald, Alexander; Pyle, John

    2016-04-01

    In the last two decades, significant depletion of boundary layer ozone (ozone depletion events, ODEs) has been observed in both Arctic and Antarctic spring. ODEs are attributed to catalytic destruction by bromine radicals (Br plus BrO), especially during bromine explosion events (BEs), when high concentrations of BrO periodically occur. The source of bromine and the mechanism that sustains the high BrO levels are still the subject of study. Recent work by Pratt et al. (2013) posits Br2 production within saline snow and sea ice which leads to sudden ODEs. Previously, Yang et al. (2008) suggested snow could provide a source of (depleted) sea-salt aerosol if wicked from the surface of ice. They suggest that rapid depletion of bromide from the aerosol will constitute a source of photochemical Bry. Given the large sea ice extent in polar regions, this may constitute a significant source of sea salt and bromine in the polar lower atmosphere. While bromine release from blowing snow is perhaps less likely to trigger sudden ODEs, it may make a contribution to regional scale processes affecting ozone levels. Currently, the model parameterisations of Yang et al. assumes that rapid release of bromine occurs from fresh snow on sea ice during periods of strong wind. The parameterisation depends on an assumed sea-salt aerosol distribution generated via sublimation of the snow above the boundary layer, as well as taking into account the salinity of the snow. In this work, we draw on recent measurements by scientists from the British Antarctic Survey during a cruise aboard the Polarstern in the southern oceans. This has provided an extensive set of measurements of the chemical and physical characteristics of blowing snow over sea ice, and of the aerosol associated with it. Based on the observations, we have developed an improved parameterisation of the release of bromine from blowing snow. The paper presents results from the simulation performed using the United Kingdom Chemistry

  16. Strawberry growers wavered over methyl iodide, feared public backlash

    Directory of Open Access Journals (Sweden)

    Julie Guthman

    2016-08-01

    Full Text Available Methyl iodide, once promoted as a suitable alternative to methyl bromide for soil fumigation in strawberry systems, was withdrawn from the market in 2012 after a contentious regulatory battle that revolved around its high toxicity. At the time of its withdrawal, Arysta LifeScience, the maker of the chemical, claimed that it was no longer economically viable. In this study, I investigated what made the chemical nonviable, with a specific focus on growers' nonadoption of it. Interviews with strawberry growers in the four top California strawberry-growing counties revealed that growers' decisions not to use it were primarily related to public disapproval, although the continued availability of methyl bromide and other fumigants played a contributing role by making adoption less urgent. The study results suggest that policies in place during the methyl bromide phaseout did not strongly encourage the development and extension of less toxic alternatives, which undermined the strawberry industry's position.

  17. Betaine potassium iodide dihydrate: a new compound of betaine

    International Nuclear Information System (INIS)

    Betaine potassium iodide dihydrate, [(CH3)3N+CH2COO-]2.KI.2H2O, BKI for short, is a new compound of the aminoacid betaine with a triclinic symmetry and the space group P1-bar at room temperature. The study of dielectric properties provided evidence for the existence of a structural phase transition occurring around 100 K. The spontaneous electric polarization is zero in both phases. A study of dielectric dispersion disclosed two relaxational modes with different relevance in the high and in the low temperature phases. The main features observed in BKI are consistently described by the Landau theory, by assuming a quadratic coupling between the primary order parameter and the electric polarization. (author). Letter-to-the-editor

  18. Incorporation of defects during processing of mercuric iodide detectors

    Science.gov (United States)

    Bao, X. J.; Schlesinger, T. E.; James, R. B.; Stulen, R. H.; Ortale, C.; Cheng, A. Y.

    1990-07-01

    The effects of chemical etching in KI solution, heating, and vacuum exposures of HgI2 were individually studied by low-temperature photoluminescence (PL) spectroscopy. Each of these processing steps is important in the manufacturing of mercuric iodide detectors and may be responsible for the incorporation of carrier traps both in the near-surface region and in the bulk. The results of etching experiments showed that the near-surface region has a different defect structure than the bulk, which appears to result from iodine deficiency. Bulk heating at 100 °C also modifies the defect structure of the crystal. Vacuum exposure has an effect similar to chemical etching, but it does not cause significant degradation of the stoichiometry for recently KI-etched specimens. These studies suggest that some features in the PL spectra of HgI2 are associated with stoichiometry of the specimens.

  19. Electronic characterization of mercuric iodide gamma ray spectrometers

    International Nuclear Information System (INIS)

    During the past four years the yield of high resolution mercuric iodide (HgI2) gamma ray spectrometers produced at EG ampersand G/EM has increased dramatically. Data is presented which demonstrates a strong correlation between starting material and spectrometer performance. Improved spectrometer yields are attributed to the method of HgI2 synthesis and to material purification procedures. Data is presented which shows that spectrometer performance is correlated with hole mobility-lifetime products. In addition, the measurement of Schottky barrier heights on HgI2 spectrometers has been performed using I-V curves and the photoelectric method. Barrier heights near 1.1 eV have been obtained using various contacts and contact deposition methods. These data suggest the pinning of the Fermi level at midgap at the HgI2 surface, probably due to surface states formed prior to contact deposition

  20. Incorporation of defects during processing of mercuric iodide detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bao, X.J.; Schlesinger, T.E. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (USA)); James, R.B.; Stulen, R.H. (Theoretical Division, Sandia National Laboratories, Livermore, California 94450 (USA)); Ortale, C.; Cheng, A.Y. (EG G Energy Measurements, Inc., Goleta, California 93116 (USA))

    1990-07-01

    The effects of chemical etching in KI solution, heating, and vacuum exposures of HgI{sub 2} were individually studied by low-temperature photoluminescence (PL) spectroscopy. Each of these processing steps is important in the manufacturing of mercuric iodide detectors and may be responsible for the incorporation of carrier traps both in the near-surface region and in the bulk. The results of etching experiments showed that the near-surface region has a different defect structure than the bulk, which appears to result from iodine deficiency. Bulk heating at 100 {degree}C also modifies the defect structure of the crystal. Vacuum exposure has an effect similar to chemical etching, but it does not cause significant degradation of the stoichiometry for recently KI-etched specimens. These studies suggest that some features in the PL spectra of HgI{sub 2} are associated with stoichiometry of the specimens.

  1. Modified purification of mercuric iodide for crystal growth

    Science.gov (United States)

    Skinner, N. L.; Ortale, C.; Schieber, M. M.; Van Den Berg, L.

    1988-06-01

    The standard procedure used in our laboratory to purify commercially available mercuric iodide (HgI 2) consists of a sequence of steps: (1) repeated sublimation under continuous evacuation, followed by (2) melting and recrystallization, and (3) a sublimation process in a closed tube. This paper describes a modification of the standard purification sequence by adding recrystallization of the HgI 2 in hydrochloric acid. Leaching cation impurities out of HgI 2 powder with hydrochloric acid has been practised before by Zaletin et al. Our objective for the hydrochloric acid treatment was to remove nitrates and hydrocarbons which were interfering with the vapor transport during crystal growth. Results of the procedure are presented in terms of total carbon and selected ion content of the treated and untreated material.

  2. Investigation of copper electrodes for mercuric iodide detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Bao, X.J.; Schlesinger, T.E. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA (USA)); James, R.B.; Stulen, R.H. (Advanced Materials Division, Sandia National Laboratories, Livermore, CA (USA)); Ortale, C.; van den Berg, L. (EG G Energy Measurements, Inc., Goleta, CA (USA))

    1990-06-15

    Copper diffusion in mercuric iodide was studied by low-temperature photoluminescence (PL) spectroscopy and Auger electron spectroscopy. A broad radiative emission band at a wavelength of about 6720 A in the PL spectra was found to be related to Cu incorporation in the crystal. PL spectra obtained from surface doping experiments indicate that Cu is a rapid diffuser in HgI{sub 2} bulk material. Auger electron spectroscopy performed as a function of depth from the crystal surface confirms the rapid bulk diffusion process of Cu in HgI{sub 2}. Fabrication of HgI{sub 2} nuclear detectors with Cu electrodes indicates that Cu is not acceptable as an electrode material, which is consistent with the fact that it diffuses easily into the bulk crystal and introduces new radiative recombination centers.

  3. Investigation of copper electrodes for mercuric iodide detector applications

    Science.gov (United States)

    Bao, X. J.; Schlesinger, T. E.; James, R. B.; Stulen, R. H.; Ortale, C.; van den Berg, L.

    1990-06-01

    Copper diffusion in mercuric iodide was studied by low-temperature photoluminescence (PL) spectroscopy and Auger electron spectroscopy. A broad radiative emission band at a wavelength of about 6720 Å in the PL spectra was found to be related to Cu incorporation in the crystal. PL spectra obtained from surface doping experiments indicate that Cu is a rapid diffuser in HgI2 bulk material. Auger electron spectroscopy performed as a function of depth from the crystal surface confirms the rapid bulk diffusion process of Cu in HgI2. Fabrication of HgI2 nuclear detectors with Cu electrodes indicates that Cu is not acceptable as an electrode material, which is consistent with the fact that it diffuses easily into the bulk crystal and introduces new radiative recombination centers.

  4. Photon recycling in lead iodide perovskite solar cells

    Science.gov (United States)

    Pazos-Outón, Luis M.; Szumilo, Monika; Lamboll, Robin; Richter, Johannes M.; Crespo-Quesada, Micaela; Abdi-Jalebi, Mojtaba; Beeson, Harry J.; Vrućinić, Milan; Alsari, Mejd; Snaith, Henry J.; Ehrler, Bruno; Friend, Richard H.; Deschler, Felix

    2016-03-01

    Lead-halide perovskites have emerged as high-performance photovoltaic materials. We mapped the propagation of photogenerated luminescence and charges from a local photoexcitation spot in thin films of lead tri-iodide perovskites. We observed light emission at distances of ≥50 micrometers and found that the peak of the internal photon spectrum red-shifts from 765 to ≥800 nanometers. We used a lateral-contact solar cell with selective electron- and hole-collecting contacts and observed that charge extraction for photoexcitation >50 micrometers away from the contacts arose from repeated recycling between photons and electron-hole pairs. Thus, energy transport is not limited by diffusive charge transport but can occur over long distances through multiple absorption-diffusion-emission events. This process creates high excitation densities within the perovskite layer and allows high open-circuit voltages.

  5. Development of mercuric iodide detectors for XAS and XRD measurements

    International Nuclear Information System (INIS)

    A prototype element for an energy dispersive detector (EDD) array was constructed using a Mercuric Iodide detector. Both detector and front end FET could be thermoelectrically cooled. Tested at SSRL, the detector had 250 eV electronic noise and 315 eV resolution at 5.9 keV. K line fluorescence spectra were collected for selected elements between Cl (2622 eV) and Zn (8638 eV). Count rate capability to 60,000 cps was demonstrated. Several detector parameters were measured, including energy linearity, resolution vs. shaping time, and detector dead time. An EXAFS (extended x-ray absorption fine structure) spectrum was recorded and compared to simultaneously collected transmission data

  6. Polarographic determination of indium and thallium iodides in phosphor tablets

    International Nuclear Information System (INIS)

    The technique of polarographic determination of indium and thallium iodides in phosphor tablets without preliminary separation of elements was developed. Mercury-dropping electrode was used as an indicator, and saturated calomel electrode was used as an auxiliary electrode. A recording of reduction currents was performed in the potential interval from -0.25 up to 1.15 V at potential sweep speed of 200 mV/min. Optimum conditions of sample acidic decomposition and polarography were presented. A solution of ethylene diamine (0.5 M), of ammonia (0.25 M) and of potassium chloride (0.05 M) served as a background electrolyte. The suggested technique allows one to determine component contents in tablets with a satisfactory accuracy. A period of one tablet analysis constitutes 1.5 h

  7. Investigation of sodium iodide hydration and dehydration in moist atmosphere

    International Nuclear Information System (INIS)

    Effect of different factors on NaI hydration and dehydration kinetics under nonequilibrium conditions is studied. NaIx2H2O solid or homogeneous solution is established to be formed at sodium iodide interaction with water vapour depending on air humidity. At low humidity water absorption is not observed. Effect of water vapour pressure, the NaI particle size, the air flux rate over a salt on the absorption rate is studied. The latter points to process rate limitation by diffusion in a gaseous phase. The NaI solution decomposition at light with iodine formation is marked. The character of NaIx2H2O dehydration depends on water vapour removing from the over-salt space. Total water removing before and after crystal hydrate thermal degradation when aqueous solution evaporation occurs, is possible. At 143 deg C the water vapour pressure over solution equals the atmospheric one

  8. Mercuric iodide crystals obtained by solvent evaporation using ethanol

    International Nuclear Information System (INIS)

    Millimeter-sized mercuric iodide crystals were fabricated by the solvent evaporation technique using pure ethanol as a solvent. Three different conditions for solution evaporation were tested: (i) in the dark at room temperature; (ii) in the presence of light at room temperature and (iii) in an oven at 40 deg. C. Morphology, structure, optical and electrical properties were investigated using several techniques. Crystals fabricated in the dark show better properties and stability than others, possibly because the larger the energy of the system, the larger the number of induced growth defects. The crystals fabricated in the dark have adequate structure for higher resistivity and activation energy close to half the optical band-gap, as desired. With proper encapsulation these crystals might be good candidates for the development of ionizing radiation sensors.

  9. Rapid sonochemical preparation of shape-selective lead iodide

    International Nuclear Information System (INIS)

    Graphical abstract: SEM morphologies of various PbI2 products obtained with the iodine concentration of 6.7 g/L and irradiation time of 1 minute at the reaction temperatures of 35 °C (a), 25 °C (b), and 15 °C (c). Highlights: ► PbI2 with various morphologies were rapidly formed at room temperature. ► We could well control the morphologies of PbI2 by changing reaction conditions. ► The PbI2 films could better resist rolling in a liquid media. -- Abstract: Lead iodide (PbI2) films/crystals with various nano/micro morphologies (e.g., Nanoflake, block and microrod) were rapidly synthesized by taking advantage of a simple sonochemical method. The PbI2 crystals with uniform nanoflake structures could be fabricated directly on lead foils with the irradiation time as short as 36 s via interfacial reaction between lead foils and elemental iodine in ethanol at ambient temperature. It was found experimentally that the morphologies of the resulting thin films/crystals could be well controlled by the adjustment of several parameters including irradiation time, reaction solvents, iodine concentration, ultrasonic power, and reaction temperature. Most importantly, the resultant PbI2 films are stable enough to resist rolling under the drastic ultrasound irradiation in a liquid media. This method is believed to be the fastest way for in situ fabrication of morphology-controlled semiconductor films on various metal substrates for subsequent applications related to the other metal iodide or metal sulfide semiconductor films.

  10. Ambient synthesis and optoelectronic properties of copper iodide semiconductor nanoparticles

    International Nuclear Information System (INIS)

    Graphical abstract: A simple chemical route to prepare crystalline γ-phase copper iodide semiconductor. Highlights: ► A new facile technique is developed to synthesize CuI semiconductor nanoparticles. ► As prepared material is highly crystalline γ-phase and visible fluorescent. ► It exhibits good electrical conductivity ∼10−4 (Ω cm)−1. ► Strong quantum confinement is observed, 22 nm size shows band gap shift of 1.7 eV. ► The γ-phase is thermodynamically more stable. -- Abstract: Electrically conducting copper iodide (CuI) nanoparticles have been synthesized at room temperature via a simple single step chemical route, using ethyl alcohol as a solvent. The resulting material was characterized by X-ray diffraction, differential scanning calorimetry, optical absorption, photoluminescence, scanning electron microscopy, energy-dispersive X-ray spectroscopy and high resolution transmission electron microscopy to assess the quality of these semiconductor nanoparticles. Thin film was deposited on copper substrate that was used to investigate temperature dependent electrical conductivity. These investigations confirm that the material is semiconductor having a negative temperature coefficient of resistivity. Thermal analysis and X-ray diffraction studies reveal that it is of low temperature γ phase. Energy-dispersive X-ray spectroscopy measurements confirm the stoichiometry of as prepared material. The shift in optical absorption edge towards lower wavelength region (Eg ∼ 4.77 eV) as compared to its bulk absorption indicates that a decrease in particle size has a significant effect. Photoluminescence peak observed at 2.90 eV is unique to its material property. These optoelectronic properties of CuI will be helpful in the development of future electronic devices

  11. Evaluation of quaternary ammonium halides for removal of methyl iodide from flowing air streams

    International Nuclear Information System (INIS)

    The quaternary ammonium halides of several tertiary amines were used as impregnants on activated carbon and were tested for methyl iodide penetration in accordance with test Method A, ASTM D3803, 1979, ''Standard Test Methods for Radio-iodine Testing of Nuclear Grade Gas Phase Adsorbents''. The results suggest that the primary removal mechanism for methyl iodide-131 is isotopic exchange with the quaternary ammonium halide. For example, a 5 wt% impregnation of each of the tetramethyl, tetraethyl, tetrapropyl and tetrabutyl ammonium iodides on activated carbon yielded percent penetrations of 0.47, 0.53, 0.78, and 0.08 respectively when tested according to Method A of ASTM D3803. A sample impregnated with 5% tetramethyl ammonium hydroxide gave a methyl iodide penetration of 64.87%, thus supporting the isotopic exchange mechanism for removal. It has been a generally held belief that the success of tertiary amines as impregnants for radioiodine removal is a result of their ability to complex with the methyl iodide. The results of the work indicates that the superiority of the tertiary amines similar to triethylene diamine and quinuclidine, when compared to their straight chain analogs, is a result of their ease in reacting with methyl iodide-127 to form the quaternary ammonium iodide followed by isotopic exchange

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

    Science.gov (United States)

    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. PMID:26288943

  13. An Investigation of Diffusion of Iodide Ion in Compacted Bentonite Containing Ag2O

    International Nuclear Information System (INIS)

    In the compacted bentonite containing Ag2O, the transport of iodide ion was investigated by Through-diffusion method. It is confirmed that Iodide ion is transported by diffusion process in the compacted bentonite containing Ag2O as well as in the compacted bentonite without Ag2O. However, the lag-time of iodide ion in the compacted bentonite containing Ag2O is larger than that in the compacted bentonite without Ag2O. The increase of the lag-time was observed in pure iodide ion solution and also in 0.1M NaCl-iodide ion solution. The apparent diffusion coefficient of iodide ion in the compacted bentonite containing Ag2O has lower value than that in the compacted bentonite without Ag2O. The effect of Ag2O on the effective diffusion coefficient was not clearly investigated in the compacted bentonite containing Ag2O while the values of effective diffusion coefficient of iodide ion in the compacted bentonite without Ag2O obtained in this study were similar to those in the compacted bentonite reported in the literature

  14. Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF

    International Nuclear Information System (INIS)

    Highlights: • Specification of an empirical factor for conversion from bromine to PBB and PBDE. • The handheld XRF device was validated for this particular application. • A very large number of over 4600 pieces of monitor housings was analysed. • The recyclable fraction mounts up to 85% for TV but only 53% of PC waste plastics. • A high percentage of pieces with bromine contents of over 50,000 ppm was obtained. - Abstract: This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television sets (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000 ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC–MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements

  15. Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF

    Energy Technology Data Exchange (ETDEWEB)

    Aldrian, Alexia, E-mail: alexia.aldrian@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Ledersteger, Alfred, E-mail: a.ledersteger@saubermacher.at [Saubermacher Dienstleistungs AG, Hans-Roth-Straße 1, 8073 Feldkirchen bei Graz (Austria); Pomberger, Roland, E-mail: roland.pomberger@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria)

    2015-02-15

    Highlights: • Specification of an empirical factor for conversion from bromine to PBB and PBDE. • The handheld XRF device was validated for this particular application. • A very large number of over 4600 pieces of monitor housings was analysed. • The recyclable fraction mounts up to 85% for TV but only 53% of PC waste plastics. • A high percentage of pieces with bromine contents of over 50,000 ppm was obtained. - Abstract: This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television sets (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000 ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC–MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements.

  16. A case study of a transported bromine explosion event in the Canadian high arctic

    Science.gov (United States)

    Zhao, X.; Strong, K.; Adams, C.; Schofield, R.; Yang, X.; Richter, A.; Friess, U.; Blechschmidt, A.-M.; Koo, J.-H.

    2016-01-01

    Ozone depletion events in the polar troposphere have been linked to extremely high concentrations of bromine, known as bromine explosion events (BEE). However, the optimum meteorological conditions for the occurrence of these events remain uncertain. On 4-5 April 2011, a combination of both blowing snow and a stable shallow boundary layer was observed during a BEE at Eureka, Canada (86.4°W, 80.1°N). Measurements made by a Multi-Axis Differential Optical Absorption Spectroscopy spectrometer were used to retrieve BrO profiles and partial columns. During this event, the near-surface BrO volume mixing ratio increased to ~20 parts per trillion by volume, while ozone was depleted to ~1 ppbv from the surface to 700 m. Back trajectories and Global Ozone Monitoring Experiment-2 satellite tropospheric BrO columns confirmed that this event originated from a bromine explosion over the Beaufort Sea. From 30 to 31 March, meteorological data showed high wind speeds (24 m/s) and elevated boundary layer heights (~800 m) over the Beaufort Sea. Long-distance transportation (~1800 km over 5 days) to Eureka indicated strong recycling of BrO within the bromine plume. This event was generally captured by a global chemistry-climate model when a sea-salt bromine source from blowing snow was included. A model sensitivity study indicated that the surface BrO at Eureka was controlled by both local photochemistry and boundary layer dynamics. Comparison of the model results with both ground-based and satellite measurements confirmed that the BEE observed at Eureka was triggered by transport of enhanced BrO from the Beaufort Sea followed by local production/recycling under stable atmospheric shallow boundary layer conditions.

  17. Spectrophotometric determination of trace quantities of iodide after separation from large quantities of bromide, chloride, or sulfate by solvent extraction

    International Nuclear Information System (INIS)

    Iodide solutions were reacted with 2,4,6-triphenylpyrylium bisulfate to yield the triphenylpyrylium iodide which was extracted with chloroform and spectrophotometrically determined. The interference from perchlorate, bromide, chloride, and sulfate ions on the iodide determination was evaluated. An analytical procedure for the determination of iodide present as the iodate was developed using sodium sulfite to reduce the iodate to iodide. The use of this method for the determination of KI in commercial iodized salt gave results comparable to those obtained by the AOAC iodometric method. (U.S.)

  18. Global atmospheric model for mercury including oxidation by bromine atoms

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-12-01

    Full Text Available Global models of atmospheric mercury generally assume that gas-phase OH and ozone are the main oxidants converting Hg0 to HgII and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate here the viability of atomic bromine (Br as an alternative Hg0 oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming gas-phase Br to be the sole Hg0 oxidant (Hg + Br model and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg + OH/O3 model. We specify global 3-D Br concentration fields based on our best understanding of tropospheric and stratospheric Br chemistry. In both the Hg + Br and Hg + OH/O3 models, we add an aqueous photochemical reduction of HgII in cloud to impose a tropospheric lifetime for mercury of 6.5 months against deposition, as needed to reconcile observed total gaseous mercury (TGM concentrations with current estimates of anthropogenic emissions. This added reduction would not be necessary in the Hg + Br model if we adjusted the Br oxidation kinetics downward within their range of uncertainty. We find that the Hg + Br and Hg + OH/O3 models are equally capable of reproducing the spatial distribution of TGM and its seasonal cycle at northern mid-latitudes. The Hg + Br model shows a steeper decline of TGM concentrations from the tropics to southern mid-latitudes. Only the Hg + Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites; the snowpack component of GEOS-Chem suggests that 40% of HgII deposited to snow in the Arctic is transferred to the ocean and land reservoirs, amounting to a net deposition flux to the Arctic of 60 Mg a−1. Summertime events of depleted Hg0 at Antarctic sites due to subsidence are much better simulated by

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

    Science.gov (United States)

    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. PMID:26319807

  20. The effect of bromination of carbon fibers on the coefficient of thermal expansion of graphite fiber-epoxy composites

    Science.gov (United States)

    Jaworske, D. A.; Maciag, C.

    1987-01-01

    To examine the effect of bromination of carbon fibers on the coefficient of thermal expansion (CTE) of carbon fiber epoxy composites, several pristine and brominated carbon fiber-epoxy composite samples were subjected to thermomechanical analysis. The CTE's of these samples were measured in the uniaxial and transverse directions. The CTE was dominated by the fibers in the uniaxial direction, while it was dominated by the matrix in the transverse directions. Bromination had no effect on the CTE of any of the composites. In addition, the CTE of fiber tow was measured in the absence of a polymer matrix, using an extension probe. The results from this technique were inconclusive.

  1. Permeability of iodide in multilamellar liposomes modeled by two compartments and a reservoir.

    Science.gov (United States)

    Schullery, S E

    1977-07-14

    A previously published rate law for the diffusion of iodide from multilamellar egg phosphatidylcholine liposomes (Schullery, S.E. (1975) Chem. Phys. Lipids 14, 49-58) is fitted to the relatively simple mathematical model of two compartments in series with a reservoir. All of the inner liposome compartments are assumed to behave as effectively one compartment in series with the liposome's outermost compartment. Based on this model, reasonable values are calculated for the fraction of the total solution trapped by liposomes which is in the outermost liposome compartment, 17%, and the permeability coefficient of iodide against isotonic, mixed iodide-chloride solution, 2-10(-9) cm/s. PMID:884087

  2. Thyroglobulin in smoking mothers and their newborns at delivery suggests autoregulation of placental iodide transport overcoming thiocyanate inhibition

    DEFF Research Database (Denmark)

    Andersen, Stine L; Backman Nøhr, Susanne; Wu, Chun S; Olsen, Jørn; Pedersen, Klaus M; Laurberg, Peter

    2013-01-01

    BACKGROUND: Placental transport of iodide is required for fetal thyroid hormone production. The sodium iodide symporter (NIS) mediates active iodide transport into the thyroid and the lactating mammary gland and is also present in placenta. NIS is competitively inhibited by thiocyanate from...... maternal smoking, but compensatory autoregulation of iodide transport differs between organs. The extent of autoregulation of placental iodide transport remains to be clarified. OBJECTIVE: To compare the impact of maternal smoking on thyroglobulin (Tg) levels in maternal serum at delivery and in cord serum......: Maternal smoking increased the degree of iodine deficiency in parallel in the mother and the fetus, as reflected by increased Tg levels. However, placental iodide transport seemed unaffected despite high thiocyanate levels, suggesting that thiocyanate-insensitive iodide transporters alternative to NIS are...

  3. Combustion and inorganic bromine emission of waste printed circuit boards in a high temperature furnace

    International Nuclear Information System (INIS)

    Highlights: ► The combustion efficiency of waste printed circuit boards (PCBs) depends on temperature, excess air factor, and high temperature zone residence time. Temperature has the most significant impact. Under the proposed condition, combustion of waste PCBs alone is quite complete within the furnace. ► High temperature prompts a more complete bromine release and conversion. When temperature is high enough, 99.9% organobrominated compounds, the potential precursors for brominated dixoins formation, are destroyed efficiently and convert to inorganic bromine in flue gas, as HBr and Br2. ► Temperature has crucial influence over the inhibition of HBr conversion to Br2, while the oxygen partial pressure plays a reverse role in the conversion to a very small extent. Increasing temperature will decrease the volume percentage ratio of Br2/HBr in flue gas greatly. ► The thermodynamic equilibrium approach of bromine conversion was investigated. The two forms of inorganic bromine in flue gas substantially reach thermodynamic equilibrium within 0.25 s. Under the proposed operating condition, the reaction of Br transfer and conversion finish. - Abstract: High temperature combustion experiments of waste printed circuit boards (PCBs) were conducted using a lab-scale system featuring a continuously-fed drop tube furnace. Combustion efficiency and the occurrence of inorganic bromine (HBr and Br2) were systematically studied by monitoring the main combustion products continuously. The influence of furnace temperature (T) was studied from 800 to 1400 °C, the excess air factor (EAF) was varied from 1.2 to 1.9 and the residence time in the high temperature zone (RTHT) was set at 0.25, 0.5, or 0.75 s. Combustion efficiency depends on temperature, EAF and RTHT; temperature has the most significant effect. Conversion of organic bromine from flame retardants into HBr and Br2 depends on temperature and EAF. Temperature has crucial influence over the ratio of HBr to Br2

  4. Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

    International Nuclear Information System (INIS)

    Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase their methyl iodide affinity, the effect of triethylenediamine impregnation was studied at 5 and 10 wt.%. The results obtained indicated that in both cases the adsorption efficiency is markedly improved by the addition of impregnant, which allows the adsorbate uptake to occur not only by physical adsorption, via non-specific interactions (as in non-impregnated carbons) but also by the specific interaction of triethylenediamine with radioactive methyl iodide. Methyl iodide retention efficiencies up to 98.1% were achieved. (author)

  5. Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, C.M.; Gonzalez, J.F.; Roman, S. [Extremadura Univ., Badajoz (Spain). Dept. de Fisica Aplicada

    2011-02-15

    Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase their methyl iodide affinity, the effect of triethylenediamine impregnation was studied at 5 and 10 wt.%. The results obtained indicated that in both cases the adsorption efficiency is markedly improved by the addition of impregnant, which allows the adsorbate uptake to occur not only by physical adsorption, via non-specific interactions (as in non-impregnated carbons) but also by the specific interaction of triethylenediamine with radioactive methyl iodide. Methyl iodide retention efficiencies up to 98.1% were achieved. (author)

  6. Production of 131-I iodide capsules in Argentina

    International Nuclear Information System (INIS)

    It is well known that 131I iodide capsules are better suited to be taken by the patient than the corresponding solution. Therefore most Pharmacopeias have monographs for 131I in both pharmaceutical forms: solution or capsules, for diagnosis but principally for therapeutic purposes. In Argentina this radiopharmaceutical has been made commercially available in November 2007. At this time Bacon Laboratories SAIC started its production, authorized by the Health and Nuclear Regulatory Authorities. 131I, in the pharmaceutical form of capsules, have evident advantages in radioprotection for the patients and the personnel involved in its administration. The intake of a 131I provokes frequently that the external part of the mouth (principally if there is a beard and/or a moustache) undergoes an external contamination. This problem is enhanced if the patient has some motor difficulties to take the glass with the solution. In this case he will need assistance from the medical or technical staff, who will receive a much greater radiation dose than in normal cases. In the capsule of 131I iodide, the solution is adsorbed on a sodium phosphate matrix. The capsule is in a plastic tube contained in an appropriate lead shielding. To take the capsule, the patient inclines the open lead shielding containing the capsule in the direction of the mouth. Once the capsule is in the mouth it is swallowed with a little portion of water. After its intake, the radiopharmaceutical is absorbed from the gastrointestinal tract. If a patient is unable to carry out the intake, the assistance by medical or technical staff is easy with practically no radiation harm, since the 131I is shielded by an adequate lead thickness. It is evident that the hands and external face of the patient are also protected since no possibility of contamination exists. The aim of this work is to present the production procedure, the packaging of the capsules and the decrease of the dose received by the involved personnel

  7. Recovery of iodide ions from geothermal water with silica with grafted alkylammonium groups

    International Nuclear Information System (INIS)

    Effect of a number of factors (time of contact and mass ratio of phases, acidity and temperature of the medium, concentrations of macro components of geothermal water) on the sorption recovery of iodide ions with 3-(octadecyldimethylammonium)propylsilica and 3-(trimethylammonium)propylsilica from aqueous solutions was studied. Sorption isotherms were discussed. The possibility of using 3-(octadecyldimethylammonium)-propylsilica for recovery of iodide ions from highly mineralized geothermal water was analyzed

  8. Activity coefficients of ferrocenium iodide in aqueous-organic salt solutions

    International Nuclear Information System (INIS)

    Values of electrode potentials were obtained by the method of potentiometric titration at 298.2 K, the standard values of emf and unified activity coefficients of ferrocenium iodide in water-acetone and water-ethanol solvents of different salt composition being calculated. It is shown that interaction of ferrocenium (Fc+) with iodide can occur with formation of two forms of complexes, i.e. [Fc+I-] and [Fc+I2]-

  9. Regioselective conversion of primary alcohols into iodides in unprotected methyl furanosides and pyranosides

    DEFF Research Database (Denmark)

    Skaanderup, Philip Robert; Poulsen, Carina Storm; Hyldtoft, Lene; Jørgensen, Malene R.; Madsen, Robert

    Two methods are described for the regioselective displacement of the primary hydroxy group in methyl glycosides with iodide. The first method is a modification of a literature procedure employing triphenylphosphine and iodine, where purification has been carried out on a reverse phase column in...... and substitution with iodide can be carried out in a one-pot process. Protection of the iodoglycosides is also described either by benzylation with benzyl trichloroacetimidate or silylation with triethylsilyl chloride....

  10. Optimization of mercuric iodide platelets growth by the polymer controlled vapor transport method

    OpenAIRE

    Fornaro L.; Mussio L.; Köncke M.; Luchini L.; Saucedo E.; Rivoir A.; Quagliata E.

    1999-01-01

    Mercuric iodide crystals in their platelet habit were grown by the polymer controlled vapor transport method. Mercuric iodide 99% in purity was sublimated at temperatures about 122 - 126 °C and vacuum conditions (10-5 mmHg), after selecting an appropriate polymer. Temperature profiles and experimental heat transfer models were determined for two growth furnaces using different insulator configurations for the cold extreme (air, ceramic wool, grilon, copper and ceramic wool). Growth conditions...

  11. Extending the C-V method of establishing MIS detector quality to mercuric iodide radiation detectors

    International Nuclear Information System (INIS)

    It has been observed that mercuric iodide capacitance measurements provide good indication about the quality of the crystal and its suitability as a room temperature radiation detector. Such capacitance / voltage measurements show a peak at low frequency. The sharpness of the peak is proportional to the quality of the crystal, and the peak is very similar to metal insulator semiconductor (MIS) capacitance curves. The paper proposes a model for the mercuric iodide capacitance. (author)

  12. Distribution of brominated compounds within the sponge Aplysina aerophoba: coupling of X-ray microanalysis with cryofixation techniques.

    Science.gov (United States)

    Turon, X; Becerro, M A; Uriz, M J

    2000-08-01

    The major secondary metabolites of the sponge Aplysina aerophoba are brominated compounds. X-ray energy dispersive microanalysis was therefore used to locate secondary metabolites via the Br signal in energy emission spectra from sponge sections. To test the reliability of this method in the face of the loss or redistribution of metabolites during processing, we compared the results obtained by conventional aldehyde fixation with those obtained by cryofixation and cryosubstitution with and without cryoembedding. Bromine appeared to be concentrated in two sponge structures, viz. fibres and spherulous cells, when cryofixed material was examined. However, X-ray microanalysis failed to demonstrate the presence of bromine in spherulous cells in chemically fixed samples, showing the need for cryotechniques to avoid the loss of compounds. Cryofixation plus cryosubstitution methods performed best regarding structural preservation and the immobilization of metabolites. The presence of bromine in the spherulous cells suggests that this cell type is the producer of the secondary metabolites, as described for other sponge species. Nevertheless, the presence of bromine in sponge fibres indicates that they can accumulate metabolic substances, although we have been unable to assess whether the chemicals are in their original form or in a modified state within the fibres. A. aerophoba has both bacterial and cyanobacterial symbionts in its mesohyl; the absence of brominated compounds in them contrasts with previous findings in other sponges with prokaryote symbionts. PMID:10955726

  13. The effect of elemental and hydrocarbon impurities on mercuric iodide gamma ray detector performance

    Science.gov (United States)

    Cross, Eilene S.; Buffleben, George; Soria, Ed; James, Ralph; Schieber, Michael; Natarajan, Raj; Gerrish, Vern

    Mercuric iodide is a room temperature semiconductor material that is used for gamma ray and x-ray radiation detection. Mercuric iodide is synthesized from mercuric chloride and potassium iodide and is then purified by a series of melts and sublimation steps and by zone refining. The mercuric iodide is grown into crystals and platelets and then fabricated into detectors. Elemental contamination may be a determining factor in the performance of these detectors. These contaminates may be present in the starting material or may be introduced during, or be unaffected by, the purification, growth or fabrication steps. Methods have been developed for the analysis of trace levels of elemental contamination. Inductively Coupled Plasma/Mass Spectroscopy (ICP/MS), Inductively Coupled Plasma/Optical Emission Spectroscopy (ICP/OES) and Gas Chromatography/Mass Spectroscopy (GC/MS) are used to determine sub ppm levels of many trace elemental impurities. Trace levels of many elemental impurities in the raw mercuric iodide are significantly reduced during the purification and zone refining processes. Though the levels of impurities are reduced, poor performing mercuric iodide detectors have contamination levels remaining or reintroduced which are higher for Ag, Al, Ca, Cu, Mg, Mn, Na, Pb and Zn than detectors with good gamma ray response. This paper will discuss the analytical methodology, the effects of purification on impurity levels, and the correlation between detector performance and impurity levels.

  14. Critical Evaluation of Acetylthiocholine Iodide and Acetylthiocholine Chloride as Substrates for Amperometric Biosensors Based on Acetylcholinesterase

    Directory of Open Access Journals (Sweden)

    Gabriel-Lucian Radu

    2013-01-01

    Full Text Available Numerous amperometric biosensors have been developed for the fast analysis of neurotoxic insecticides based on inhibition of cholinesterase (AChE. The analytical signal is quantified by the oxidation of the thiocholine that is produced enzymatically by the hydrolysis of the acetylthiocholine pseudosubstrate. The pseudosubstrate is a cation and it is associated with chloride or iodide as corresponding anion to form a salt. The iodide salt is cheaper, but it is electrochemically active and consequently more difficult to use in electrochemical analytical devices. We investigate the possibility of using acetylthiocholine iodide as pseudosubstrate for amperometric detection. Our investigation demonstrates that operational conditions for any amperometric biosensor that use acetylthiocholine iodide must be thoroughly optimized to avoid false analytical signals or a reduced sensitivity. The working overpotential determined for different screen-printed electrodes was: carbon-nanotubes (360 mV, platinum (560 mV, gold (370 mV, based on a catalytic effect of iodide or cobalt phthalocyanine (110 mV, but with a significant reduced sensitivity in the presence of iodide anions.

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

    International Nuclear Information System (INIS)

    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 decease in hormonogenesis. Absorption of one or more of iodinated molecules, e.g., nutrient, hormones, or cellular constituents of the alimentary tract having thyromimetic or thyroid inhibitory properties, is a better hypothesis for the effects seen

  16. Novel Si-tripodand functionalized ionic liquids as iodide sources for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Novel ionic liquids with iodide anions and functionalized with silicon tripodand centers have been synthesized and tested as iodide sources for dye sensitized solar cells, 1-methyl-3-(3-(trimethoxysilyl)propyl)imidazolium iodide 3a, 1-methyl-3-(3-(tris(2-methoxyethoxy)silyl)propyl)imidazolium iodide 3b, and 1-methyl-3-(3-(tris(2-(2-methoxyethoxy)ethoxy)silyl)propyl)imidazolium iodide 3c. The compounds have been proved to be thermally and electrochemically stable, as evidenced by thermogravimetry and linear sweep voltammetry on platinum. Specific conductivities at 25 °C of pure ionic liquids are of the order of 10−4 S cm−1 and show little dependence on the length of oxaethylene chains. Conductivities rise to nearly 10−2 S cm−1 for the electrolytes prepared on their bases as a result of viscosity decrease. Model dye-sensitized solar cells show appreciable conversion efficiencies, reaching a maximum value of 5.08% for the electrolyte with 3b as iodide source. Electrochemical impedance spectroscopy measurements revealed high resistance associated with electron recombination on the interface of TiO2/dye/electrolyte and important contribution of electrolyte diffusion

  17. The effect of elemental and hydrocarbon impurities on mercuric iodide gamma ray detector performance

    International Nuclear Information System (INIS)

    Mercuric iodide is a room temperature semiconductor material that is used for gamma ray and x-ray radiation detection. Mercuric iodide is synthesized from mercuric chloride and potassium iodide and is then purified by a series of melts and sublimation steps and by zone refining. The mercuric iodide is grown into crystals and platelets and then fabricated into detectors. Elemental contamination may be a determining factor in the performance of these detectors. These contaminates may be present in the starting material or may be introduced during, or be unaffected by, the purification, growth or fabrication steps. Methods have been developed for the analysis of trace levels of elemental contamination. Inductively coupled plasma/mass spectroscopy (ICP/MS), inductively coupled plasma/optical emission spectroscopy (ICP/OES) and gas chromatography/mass spectroscopy (GC/MS) are used to determine sub ppm levels of many trace elemental impurities. Trace levels of many elemental impurities in the raw mercuric iodide are significantly reduced during the purification and zone refining processes. Though the levels of impurities are reduced, poor performing mercuric iodide detectors have contamination levels remaining or reintroduced which are higher for Ag, Al, Ca, Cu, Mg, Mn, Na, Pb and Zn than detectors with good gamma ray response. This paper discusses the analytical methodology, the effects of purification on impurity levels, and the correlation between detector performance and impurity levels. (orig.)

  18. Modelling iodide – iodate speciation in atmospheric aerosol: Contributions of inorganic and organic iodine chemistry

    Directory of Open Access Journals (Sweden)

    S. Pechtl

    2007-01-01

    Full Text Available The speciation of iodine in atmospheric aerosol is currently poorly understood. Models predict negligible iodide concentrations but accumulation of iodate in aerosol, both of which is not confirmed by recent measurements. We present an updated aqueous phase iodine chemistry scheme for use in atmospheric chemistry models and discuss sensitivity studies with the marine boundary layer model MISTRA. These studies show that iodate can be reduced in acidic aerosol by inorganic reactions, i.e., iodate does not necessarily accumulate in particles. Furthermore, the transformation of particulate iodide to volatile iodine species likely has been overestimated in previous model studies due to negligence of collision-induced upper limits for the reaction rates. However, inorganic reaction cycles still do not seem to be sufficient to reproduce the observed range of iodide – iodate speciation in atmospheric aerosol. Therefore, we also investigate the effects of the recently suggested reaction of HOI with dissolved organic matter to produce iodide. If this reaction is fast enough to compete with the inorganic mechanism, it would not only directly lead to enhanced iodide concentrations but, indirectly via speed-up of the inorganic iodate reduction cycles, also to a decrease in iodate concentrations. Hence, according to our model studies, organic iodine chemistry, combined with inorganic reaction cycles, is able to reproduce observations. The presented chemistry cycles are highly dependent on pH and thus offer an explanation for the large observed variability of the iodide – iodate speciation in atmospheric aerosol.

  19. Experimental study of retinoic acid on improving iodide uptake in MCF-7 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    FU Hong-Liang; WU Jing-Chuan; DU Xue-Liang; LI Jia-Ning; WU Zhen; ZOU Ren-Jian

    2005-01-01

    The study aims to investigate the effect of retinoic acid on the iodide uptake of MCF-7 cells and its mechanism. The iodide uptake and expression of hNIS(human sodium/iodide symporter)mRNA in the breast cancer MCF-7 cells were compared individually before and after the intervention of all-trans retinoic acid (ATRA) with the iodide uptake assay and RT-PCR. The following results are obtained: (1) when treated with all-trans retinoic acid in the concentration of 1.0 μmol/L, the capacity of iodide uptake of MCF-7 cells reached about 1.5 times of the basal state; (2) 12 h after the intervention of 1.0 μmol/L ATRA, the hNISmRNA expression of the MCF-7 cells reached maximum. The study shows that all-trans retinoic acid has the effect to improve the iodide uptake of the MCF-7 cells and this effect may result from its up-regulation of the hNISmRNA expression.

  20. Molten-Phase Hydrolysis Stage Analysis and Experiments for the Calcium Bromine Thermochemical Cycle

    International Nuclear Information System (INIS)

    The goal of the United States Department of Energy Nuclear Hydrogen Initiative as linked with the Generation IV Nuclear Energy Systems Initiative for Gas Reactor Deployment is to develop a cost-effective, proliferation-resistant, low-greenhouse-gas emissions, and sustainable, nuclear-based energy supply system. The calcium-bromine cycle under development at Argonne National Laboratory combines both experimental and modeling studies of a novel continuous 'hybrid' cycle for hydrogen production, where 'hybrid' means that both nuclear heat and electricity are employed. Engineering the calcium-bromine cycle for continuous operation should facilitate its practical development since there will be an inherent advantage to using components and materials which will operate in a constant, non-cycling chemical and thermal environment. This paper focuses on the first and important calcium bromide hydrolysis stage to generate hydrogen bromide, which when split by electrolysis, produces hydrogen. (authors)

  1. Co-doping of Potassium and Bromine in Carbon Nanotubes: A Density Functional Theory Study

    Institute of Scientific and Technical Information of China (English)

    XIAO Yong; YAN xiao-Hong; DING Jian-Wen

    2007-01-01

    We investigate the co-doping of potassium and bromine in singlewalled carbon nanotubes (SWCNTs)and doublewalled carbon nanotubes(DWCNTs)based on density functional theory.In the co-doped(6,O)SWCNTs,the 4s electron of potassium is transferred to nanotube and Br,leading to the n-type feature of SWCNTs.When potassium is intercalated into inner tube and bromine is put on outer tube,the positive and negative charges reside on the outer and inner tubes of the(7.0)@(16,0)DWCNT,respectively.It is expected that DWCNTs would be an ideal candidate for p-n junction and diode applications.

  2. Stratospheric ozone depletion and future levels of atmospheric chlorine and bromine

    Science.gov (United States)

    Prather, Michael J.; Watson, Robert T.

    1990-01-01

    The rise in atmospheric chlorine levels caused by the emission of chlorofluorocarbons and other halocarbons is thought to be the main cause of the appearance of the Antarctic ozone 'hole' in the late 1970s, and the more modest ozone depletion observed over parts of the Northern Hemisphere. Atmospheric bromine, also associated with halocarbon emissions, is believed to contribute to ozone depletion. Over the next decade, further increases in these compounds are inevitable. Model calculations show that by the end of the next century, atmospheric chlorine and bromine levels may return to those prevalent before the onset of the ozone hole, but only if more stringent regulations are applied to halocarbon production than those currently proposed.

  3. First measurements of total chlorine and bromine in the lower stratosphere

    International Nuclear Information System (INIS)

    A total halogen collection system employing ultra-pure activated charcoal traps has been developed for use in the stratosphere aboard aircraft and balloon sampling platforms. Neutron activation techniques for low-level chlorine, bromine, and iodine analysis within the activated charcoal sampling matrix were developed. Initial results from six aircraft flights and one balloon mission in the lower stratosphere are presented for latitudes ranging from 160N to 670N. Little variability was observed in twelve total, gaseous and particulate chlorine (Cl/sub tot/) determinations as a function of latitude at 20 km with values ranging between 2.7 +- 9 ppbV and 3.2 +- .7 ppbV. Five total bromine (Br/sub tot/) values showed substantial variability ranging from 7 +- 4 pptV to 40 +- 11 pptV. No iodine was observed in any samples but a calculated I/sub tot/ upper limit of < 3 pptV was determined

  4. Polarization Effects in Methylammonium Lead Iodide Electronic Devices

    Science.gov (United States)

    Labram, John; Fabini, Douglas; Perry, Erin; Lehner, Anna; Wang, Hengbin; Glaudell, Anne; Wu, Guang; Evans, Hayden; Buck, David; Cotta, Robert; Echegoyen, Luis; Wudl, Fred; Seshadri, Ram; Chabinyc, Michael

    The immense success of group IV and III-V semiconductors has resulted in disruptive new photovoltaic (PV) cell technologies emerging extremely infrequently. For this reason, the recent progress in Methylammonium Lead Iodide (MAPbI3) solar cells can be viewed as a highly significant historic event. Despite the staggering recent progress made in reported power conversion efficiency (PCE), debate remains intense on the nature of the various instabilities synonymous with these devices. Using various electronic device measurements, we here present a body of experimental evidence consistent with the existence of a mobile ionic species within the MAPbI3 perovskite. Temperature-dependent transistor measurements reveal operating FET devices only below approximately 210K. This is attributed to ionic screening of the (otherwise charge-neutral) semiconductor-dielectric interface. Temperature-dependent pulsed-gate and impedance spectroscopy experiments also reveal behavior consistent with this interpretation. MAPbI3 PV cells were found to possess a PCE which decreases significantly below 210K. Combined, these set of measurements provide an interesting and consistent description of the internal processes at play within the MAPbI3 perovskite structure.

  5. Thermopower and activation energy of silver iodide based superionic materials

    International Nuclear Information System (INIS)

    Silver iodide based glasses, 60Agl-20Ag sub 2 O-20B sub 2O sub 3, 6 Agl-20Ag sub 2 O-20 MoO sub 3 and 60Agl-20Ag sub 2O-20WO sub 3, all in the mol % ratio, were prepared by rapidly quenching the melts of the chemicals in a stainless steel container; kept in a liquid nitrogen bath. The glassy nature of the as-quenched materials was confirmed by X-ray diffraction (XRD). The electrical conductivity of the glasses was measured at various temperatures ranging from 30 to 70 degree C using an impedance bridge operating in the frequency range between 40 Hz to 100 kHz. The plot of In σT versus 1000/T for each glassy material obeys Arrhenius law and the activation energy obtained is between 0.2 to 0.3 eV. Thermopower measurement was also carried out in the same temperature range as the conductivity measurement to obtain the heat of transport

  6. Chloride, bromide and iodide scintillators with europium doping

    Science.gov (United States)

    Zhuravleva, Mariya; Yang, Kan

    2014-08-26

    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 been 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.

  7. Preparation and evaluation of mercuric iodide for crystal growth

    Science.gov (United States)

    Skinner, N. L.; Ortale, C.; Schieber, M. M.; van den Berg, L.

    1989-11-01

    Large quantities (on the order of several hundred kilograms) of consistent, high-quality mercuric iodide (HgI2) for crystal growth have not been commercially available. The hydrocarbon, anion and cation impurity levels varied considerably, occasionally preventing crystal growth. This occurred even though the starting material was from the same vendor and was subjected to the same purification treatment. This paper will describe an aqueous precipitation process of HgI2 preparation in batches of 3 kg using Hg(NO3)2, or HgCl2 and KI. Since these salts are produced in much larger quantities than HgI2, more consistent quality is available. The impurity content of these batches and single crystals grown from them have been evaluated. These results and those from several commercially available starting materials and their grown single crystals are compared. Some of the single crystals grown using the in-house prepared HgI2 have yielded a large number of spectroscopy-grade nuclear detectors. The influence of the major impurities will be discussed.

  8. Correlation between mercuric iodide detector performance and crystalline perfection

    International Nuclear Information System (INIS)

    X-ray, neutron and gamma ray diffraction rocking curves; X-ray topography; microhardness; and optical microscopic measurements have been performed directly on several mercuric iodide (HgI2) nuclear radiation detectors fabricated from single crystals grown from the vapor phase. Two types of detectors were measured: Spectrometer types (grades A and B), which had resolutions of 5-10% for the 662 keV photopeak of 137Cs, or radiation counters (grades C and D), where the spectral resolution ranged from 11% to no resolution. A good correlation has been found between the detector grade and the full width at half maximum (FWHM) of both the X- and gamma ray rocking curves (i.e., the higher the detector grade (A or B), the narrower the FWHM of the diffraction peak). X-ray topography also correlated with well both the FWHM of the diffraction X-ray rocking curve and the detector grade. The uniformity of the microhardness of the HgI2 detectors was found to be proportional to the nuclear performance of the detector. The better spectrometer-grade detectors were softer and much more uniform in microhardness than the most inferior detectors. The better detectors were also found to have much smoother surfaces than the poorer detectors, as observed by optical microscopy studies. (orig.)

  9. Correlation between mercuric iodide detector performance and crystalline perfection

    Science.gov (United States)

    Schieber, M.; Ortale, C.; van den Berg, L.; Schnepple, W.; Keller, L.; Wagner, C. N. J.; Yelon, W.; Ross, F.; Georgeson, G.; Milstein, F.

    1989-11-01

    X-ray, neutron and gamma ray diffraction rocking curves; X-ray topography; microhardness; and optical microscopic measurements have been performed directly on several mercuric iodide (Hgl2) nuclear radiation detectors fabricated from single crystals grown from the vapor phase. Two types of detectors were measured: spectrometer types (grades A and B), which had resolutions of 5-10% for the 662 keV photopeak of 137Cs, or radiation counters (grades C and D), where the spectral resolution ranged from 11% to no resolution. A good correlation has been found between the detector grade and the full width at half maximum (FWHM) of both the X- and gamma ray rocking curves (i.e., the higher the detector grade (A or B), the narrower the FWHM of the diffraction peak). X-ray topography also correlated with well both the FWHM of the diffraction X-ray rocking curve and the detector grade. The uniformity of the microhardness of the HgI2 detectors was found to be proportional to the nuclear performance of the detector. The better spectrometer-grade detectors were softer and much more uniform in microhardness than the most inferior detectors. The better detectors were also found to have much smoother surfaces than the poorer detectors, as observed by optical microscopy studies.

  10. Correlation between mercuric iodide detector performance and crystalline perfection

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M.; Ortale, C.; Van den Berg, L.; Schnepple, W. (EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations); Keller, L.; Wagner, C.N.J. (California Univ., Los Angeles (USA). Dept. of Materials Science and Engineering); Yelon, W.; Ross, F. (Missouri Univ., Columbia (USA). Research Reactor Facility); Georgeson, G.; Milstein, F. (California Univ., Santa Barbara (USA). Dept. of Mechanical and Environmental Engineering)

    1989-11-01

    X-ray, neutron and gamma ray diffraction rocking curves; X-ray topography; microhardness; and optical microscopic measurements have been performed directly on several mercuric iodide (HgI{sub 2}) nuclear radiation detectors fabricated from single crystals grown from the vapor phase. Two types of detectors were measured: Spectrometer types (grades A and B), which had resolutions of 5-10% for the 662 keV photopeak of {sup 137}Cs, or radiation counters (grades C and D), where the spectral resolution ranged from 11% to no resolution. A good correlation has been found between the detector grade and the full width at half maximum (FWHM) of both the X- and gamma ray rocking curves (i.e., the higher the detector grade (A or B), the narrower the FWHM of the diffraction peak). X-ray topography also correlated with well both the FWHM of the diffraction X-ray rocking curve and the detector grade. The uniformity of the microhardness of the HgI{sub 2} detectors was found to be proportional to the nuclear performance of the detector. The better spectrometer-grade detectors were softer and much more uniform in microhardness than the most inferior detectors. The better detectors were also found to have much smoother surfaces than the poorer detectors, as observed by optical microscopy studies. (orig.).

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

    Science.gov (United States)

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

    2015-06-01

    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.

  12. Digermylene Oxide Stabilized Group 11 Metal Iodide Complexes.

    Science.gov (United States)

    Yadav, Dhirendra; Siwatch, Rahul Kumar; Sinhababu, Soumen; Karwasara, Surendar; Singh, Dharmendra; Rajaraman, Gopalan; Nagendran, Selvarajan

    2015-12-01

    Use of a substituted digermylene oxide as a ligand has been demonstrated through the isolation of a series of group 11 metal(I) iodide complexes. Accordingly, the reactions of digermylene oxide [{(i-Bu)2ATIGe}2O] (ATI = aminotroponiminate) (1) with CuI under different conditions afforded [({(i-Bu)2ATIGe}2O)2(Cu4I4)] (2) with a Cu4I4 octahedral core, [({(i-Bu)2ATIGe}2O)2(Cu3I3)] (3) with a Cu3I3 core, and [{(i-Bu)2ATIGe}2O(Cu2I2)(C5H5N)2] (4) with a butterfly-type Cu2I2 core. The reactions of compound 1 with AgI and AuI produced [({(i-Bu)2ATIGe}2O)2(Ag4I4)] (5) with a Ag4I4 octahedral core and [{(i-Bu)2ATIGe}2O(Au2I2)] (6) with a Au2I2 core, respectively. The presence of metallophilic interactions in these compounds is shown through the single-crystal X-ray diffraction and atom-in-molecule (AIM) studies. Preliminary photophysical studies on compound 6 are also carried out. PMID:26558406

  13. Persistent photovoltage in methylammonium lead iodide perovskite solar cells

    Directory of Open Access Journals (Sweden)

    A. Baumann

    2014-08-01

    Full Text Available We herein perform open circuit voltage decay (OCVD measurements on methylammonium lead iodide (CH3NH3PbI3 perovskite solar cells to increase the understanding of the charge carrier recombination dynamics in this emerging technology. Optically pulsed OCVD measurements are conducted on CH3NH3PbI3 solar cells and compared to results from another type of thin-film photovoltaics, namely, the two reference polymer–fullerene bulk heterojunction solar cell devices based on P3HT:PC60BM and PTB7:PC70BM blends. We observe two very different time domains of the voltage transient in the perovskite solar cell with a first drop on a short time scale that is similar to the decay in the studied organic solar cells. However, 65%–70% of the maximum photovoltage persists on much longer timescales in the perovskite solar cell than in the organic devices. In addition, we find that the recombination dynamics in all time regimes are dependent on the starting illumination intensity, which is also not observed in the organic devices. We then discuss the potential origins of these unique behaviors.

  14. Occupational exposure to brominated flame retardants : With emphasis on polybrominated diphenyl ethers

    OpenAIRE

    Thuresson, Kaj

    2004-01-01

    Brominated flame retardants (BFRs) are a diverse group of chemicals, which are used to slow down or inhibit the development of fires. BFRs are incorporated into a wide range of consumer products that are considered as potential fire hazards, such as TV-sets, household appliances, computers, and textiles. The production and use of BFRs is extensive and consists of mainly tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecan (HBCD). BFRs in general, but...

  15. Assessing oestrogenic effects of brominated flame retardants Hexabromocyclododecane and Tetrabromobisphenol A on MCF-7 cells

    Czech Academy of Sciences Publication Activity Database

    Dorosh, Andriy; Děd, Lukáš; Elzeinová, Fatima; Pěknicová, Jana

    2010-01-01

    Roč. 56, - (2010), s. 35-39. ISSN 0015-5500 R&D Projects: GA MŠk(CZ) 1M06011; GA MŠk(CZ) 2B06151 Institutional research plan: CEZ:AV0Z50520701 Keywords : endocrine disruptors * BRF - brominated flame retardant * MCF-7 cells * TFF1 - trefoil factor Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.729, year: 2010

  16. Brominated Skeletal Components of the Marine Demosponges, Aplysina cavernicola and Ianthella basta: Analytical and Biochemical Investigations

    OpenAIRE

    Eike Brunner; Peter Proksch; Hermann Ehrlich; Renate Schulze; Susanne Ueberlein; Hendrik Niemann; Kurt Kunze; Karl-Heinz van Pée

    2013-01-01

    Demosponges possess a skeleton made of a composite material with various organic constituents and/or siliceous spicules. Chitin is an integral part of the skeleton of different sponges of the order Verongida. Moreover, sponges of the order Verongida, such as Aplysina cavernicola or Ianthella basta, are well-known for the biosynthesis of brominated tyrosine derivates, characteristic bioactive natural products. It has been unknown so far whether these compounds are exclusively present in the ce...

  17. Reductive Dehalogenation of Brominated Phenolic Compounds by Microorganisms Associated with the Marine Sponge Aplysina aerophoba

    OpenAIRE

    Ahn, Young-Beom; Rhee, Sung-Keun; Fennell, Donna E.; Kerkhof, Lee J.; Hentschel, Ute; Häggblom, Max M.

    2003-01-01

    Marine sponges are natural sources of brominated organic compounds, including bromoindoles, bromophenols, and bromopyrroles, that may comprise up to 12% of the sponge dry weight. Aplysina aerophoba sponges harbor large numbers of bacteria that can amount to 40% of the biomass of the animal. We postulated that there might be mechanisms for microbially mediated degradation of these halogenated chemicals within the sponges. The capability of anaerobic microorganisms associated with the marine sp...

  18. Ship-source pollution by polychlorinated biphenyls and brominated flame retardants

    OpenAIRE

    ČULIN, Jelena; Bielić, Toni

    2015-01-01

    Polychlorinated biphenyls (PCBs) and brominated flame retardants (BFRs) are groups of anthropogenic contaminants that have been routinely used in many applications for several decades. Prior to the discovery of their detrimental health effects and subsequent implementation of regulatory measures they were widely applied in shipbuilding. They are still found onboard active and inactive ships and pose a risk to human and environment. Therefore, it is important to continue to carry out preven...

  19. Tropospheric bromine chemistry: implications for present and pre-industrial ozone and mercury

    Directory of Open Access Journals (Sweden)

    J. P. Parrella

    2012-04-01

    Full Text Available We present a new model for the global tropospheric chemistry of inorganic bromine (Bry coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM. Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone concentrations by <1−8 nmol mol−1 (6.5% globally, with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4%. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  20. Tropospheric bromine chemistry: implications for present and pre-industrial ozone and mercury

    Directory of Open Access Journals (Sweden)

    J. P. Parrella

    2012-08-01

    Full Text Available We present a new model for the global tropospheric chemistry of inorganic bromine (Bry coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM. Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by <1–8 nmol mol−1 (6.5% globally, with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4%. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  1. A comparison of the virucidal properties of chlorine, chlorine dioxide, bromine chloride and iodine.

    OpenAIRE

    Taylor, G R; Butler, M

    1982-01-01

    Chlorine dioxide, bromine chloride and iodine were compared with chlorine as virucidal agents. Under optimal conditions all disinfectants were effective at low concentrations, but each disinfectant responded differently to acidity and alkalinity. Disinfection by chlorine was impaired by the presence of ammonia, but the other disinfectants retained much of their potency. Disinfection of poliovirus by iodine resulted in structural changes in the virions as seen by electron micrroscopy, but the ...

  2. Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006–2009

    OpenAIRE

    N. Bobrowski; Giuffrida, G

    2012-01-01

    Over a 3-yr period, from 2006 to 2009, frequent scattered sunlight DOAS measurements were conducted at Mt. Etna at a distance of around 6 km downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna. Here, results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO ...

  3. Mercury oxidation from bromine chemistry in the free troposphere over the southeastern US

    OpenAIRE

    S. Coburn; Dix, B.; Edgerton, E.; Holmes, C. D; Kinnison, D.; Liang, Q; A. ter Schure; Wang, S.; R. Volkamer

    2015-01-01

    The elevated deposition of atmospheric mercury over the Southeastern United States is currently not well understood. Here we measure partial columns and vertical profiles of bromine monoxide (BrO) radicals, a key component of mercury oxidation chemistry, to better understand the processes and altitudes at which mercury is being oxidized in the atmosphere. We use the data from a ground-based MAX-DOAS instrument located at a coastal site ~ 1 km from the Gulf o...

  4. Toxicity of brominated flame retardants with focus on retinoid system disturbances

    OpenAIRE

    Litens Karlsson, Sabina

    2015-01-01

    Background: Brominated flame retardants (BFR) are detected in the environment and biota all over the world. They contribute to the human body burden of industrial chemicals and exposure is mainly via food. Indoor dust contributes substantially in some exposure situations, which involve small children. Regulatory restrictions and bans have been introduced as some BFRs can impact proper development, potentially via the endocrine system. Objectives: The study aim was to clarify the role of...

  5. Volcanic plumes: Evaluation of spectroscopic measurements, early detection, and bromine chemistry

    OpenAIRE

    Vogel, Leif

    2011-01-01

    Volcanos emit inter alia highly reactive chemical compounds, which influence the atmosphere on a local, regional and global scale. Subject of this study are measurements of volcanic plumes via differential optical absorption spectroscopy (DOAS). A new tool for analysis and optimisation of evaluation schemes was developed, which is applicable to any DOAS measurement. Measurements of bromine monoxide (BrO) and sulphur dioxide (SO2 ) are presented, which were gathered at Mt. Etna (Italy) and Pac...

  6. Thermal Recycling of Brominated Flame Retardants with Fe2O3.

    Science.gov (United States)

    Altarawneh, Mohammednoor; Ahmed, Oday H; Jiang, Zhong-Tao; Dlugogorski, Bogdan Z

    2016-08-01

    Plastics containing brominated flame retardants (BFRs) constitute the major fraction of nonmetallic content in e-waste. Co-pyrolysis of BFRs with hematite (Fe2O3) represents a viable option for the thermal recycling of BFRs. Consensus of experimental findings confirms the excellent bromine fixation ability of Fe2O3 and the subsequent formation of iron bromides. This contribution provides a comprehensive mechanistic account of the primary reactions between a cluster model of Fe2O3 and major bromine-bearing products from the decomposition of tetrabromobisphenol A (TBBA), the most commonly deployed BFR. We estimate the thermo-kinetic parameters for interactions of Fe2O3 with HBr, brominated alkanes and alkenes, bromobenzene, and bromophenol. Dissociative addition of HBr at a Fe-O bond proceeds through a trivial barrier of 8.2 kcal/mol with fitted parameters in the Arrhenius equation of k(T) = 7.96 × 10(11) exp(-6400/RT) s(-1). The facile and irreversible nature for HBr addition to Fe2O3 accords with the experimentally reported 90% reduction in HBr emission when Fe2O3 interacts with TBBA pyrolysates. A detailed kinetic analysis indicates that, transformation of Fe2O3 into iron bromides and oxybromides occurs via successive addition of HBr to Fe(Br)-O(H) entities. Elimination of a water molecule proceeds through an intramolecular H transfer. A direct elimination one-step mechanism operates in the dehydrohalogenation of bromoethane into ethene over Fe2O3. Dissociative decomposition and direct elimination channels assume comparable reaction rates in formation of acetylene from vinyl bromide. Results from this study provide an atomic-based insight into a promising thermal recycling route of e-waste. PMID:27366936

  7. Brominated Biphenyls Prime Extensive Microbial Reductive Dehalogenation of Aroclor 1260 in Housatonic River Sediment

    OpenAIRE

    Bedard, Donna L.; Van Dort, Heidi; DeWeerd, Kim A.

    1998-01-01

    The upper Housatonic River and Woods Pond (Lenox, Mass.), a shallow impoundment on the river, are contaminated with polychlorinated biphenyls (PCBs), the residue of partially dechlorinated Aroclor 1260. Certain PCB congeners have the ability to activate or “prime” anaerobic microorganisms in Woods Pond sediment to reductively dehalogenate the Aroclor 1260 residue. We proposed that brominated biphenyls might have the same effect and tested the priming activities of 14 mono-, di-, and tribromin...

  8. The bromination Hypocrellin A and the spectra character of the reaction of gelatin with the derivative

    International Nuclear Information System (INIS)

    The bromination derivates of hypocrellin A (Br-HA) was prepared in this paper, and the photodynamic activity also was appraised. UV-Vis spectroscopy and Fluorescence spectrophotometer were employed to detect the reaction of Br-HA with gelatin. The result shown the Br-HA can react with gelatin, and the HA-Br also photodegraded the pyridinoline cross-link formation in gelatin.

  9. Reactive airways dysfunction and systemic complaints after mass exposure to bromine.

    OpenAIRE

    Woolf, A; Shannon, M.

    1999-01-01

    Occasionally children are the victims of mass poisoning from an environmental contaminant that occurs due to an unexpected common point source of exposure. In many cases the contaminant is a widely used chemical generally considered to be safe. In the following case, members of a sports team visiting a community for an athletic event were exposed to chemicals while staying at a local motel. Bromine-based sanitizing agents and other chemicals such as hydrochloric acid, which were used in exces...

  10. On bromine, nitrogen oxides and ozone depletion in the tropospheric plume of Erebus volcano (Antarctica)

    OpenAIRE

    Boichu, Marie; Oppenheimer, Clive; Roberts, Tjarda J.; V. I. Tsanev; Kyle, Philip R

    2011-01-01

    International audience Since the discovery of bromine oxide (BrO) in volcanic emissions, there has been speculation concerning its role in chemical evolution and notably ozone depletion in volcanic plumes. We report the first measurements using Differential Optical Absorption Spectroscopy (DOAS) of BrO in the tropospheric plume of the persistently degassing Erebus volcano (Antarctica). These are the first observations pertaining to emissions from an alkaline phonolitic magma. The observed ...

  11. Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska

    OpenAIRE

    Thompson, C. R.; P. B. Shepson; Liao, J.; Huey, L.G.; E. C. Apel; Cantrell, C. A.; Flocke, F.; Orlando, J.; Fried, A.; Hall, S. R; R. S. Hornbrook; D. J. Knapp; Mauldin III, R. L; Montzka, D. D.; B. C. Sive

    2014-01-01

    The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there ha...

  12. Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska

    OpenAIRE

    Thompson, C. R.; P. B. Shepson; Liao, J.; Huey, L.G.; E. C. Apel; Cantrell, C. A.; Flocke, F.; Orlando, J.; Fried, A.; Hall, S. R; R. S. Hornbrook; D. J. Knapp; Mauldin III, R. L; Montzka, D. D.; B. C. Sive

    2015-01-01

    The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indicatio...

  13. Brominated and organophosphate flame retardants in selected consumer products on the Japanese market in 2008

    International Nuclear Information System (INIS)

    Highlights: → We examined the flame retardants in electronics, curtains, wallpaper and insulator. → Use of alternative brominated and organophosphate flame retardants was suggested. → All the products investigated also contained PBDEs, TBBPA and polybromophenols. → Incorporation of recycled materials containing hazardous substance was suggested. - Abstract: The concentrations of traditional brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) in new consumer products, including electronic equipment, curtains, wallpaper, and building materials, on the Japanese market in 2008 were investigated. Although some components of the electronic equipment contained bromine at concentrations on the order of percent by weight, as indicated by X-ray fluorescence analysis, the bromine content could not be fully accounted for by the BFRs analyzed in this study, which included polybrominated diphenylethers, decabromodiphenyl ethane, tetrabromobisphenol A, polybromophenols, and hexabromocyclododecanes. These results suggest the use of alternative BFRs such as newly developed formulations derived from tribromophenol, tetrabromobisphenol A, or both. Among the 11 OPFRs analyzed, triphenylphosphate was present at the highest concentrations in all the products investigated, which suggests the use of condensed-type OPFRs as alternative flame retardants, because they contain triphenylphosphate as an impurity. Tripropylphosphate was not detected in any samples; and trimethylphosphate, tributyl tris(2-butoxyethyl)phosphate, and tris(1,3-dichloro-2-propyl)phosphate were detected in only some components and at low concentrations. Note that all the consumer products evaluated in this study also contained traditional BFRs in amounts that were inadequate to impart flame retardancy, which implies the incorporation of recycled plastic materials containing BFRs that are of global concern.

  14. Simultaneous determination of bromine and iodine in the rat thyroid by short-term INAA

    Czech Academy of Sciences Publication Activity Database

    Pavelka, Stanislav; Vobecký, Miloslav; Babický, Arnošt

    Tokyo: Tokyo Metropolitan University, 2007. s. 118-118. [International Conference on Modern Trends in Activation Analysis /12./. 16.09.2007-21.09.2007, Hachioji] R&D Projects: GA AV ČR(CZ) KJB401630701 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40310501 Keywords : spo2 * bromine * iodine * thyroid gland Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  15. Detailed modeling of the atmospheric degradation mechanism of very-short lived brominated species

    OpenAIRE

    G. Krysztofiak; Catoire, Valéry; Poulet, G.; Marécal, V.; Pirre, Michel; Louis, F.; Canneaux, S.; B. Josse

    2012-01-01

    International audience Detailed chemical reaction schemes for the atmospheric degradations of the very short-lived species (VSLS) bromoform (CHBr3) and dibromomethane (CH2Br2) have been established. These degradation schemes have been implemented in the meteorological/tracer transport model CATT-BRAMS used in the present case as pseudo one-dimensional model with chemistry of CH4, CO, HOx, NOx, NOy and Ox. They include the main possible reactions of the intermediate brominated peroxy radica...

  16. Meteorological controls on the vertical distribution of bromine monoxide in the lower troposphere

    OpenAIRE

    Peterson, P K; Simpson, W. R.; K. A. Pratt; P. B. Shepson; U. Frieß; J. Zielcke; Platt, U.; Walsh, S J; S. V. Nghiem

    2014-01-01

    Multiple axis differential absorption spectroscopy (MAX-DOAS) measurements of bromine monoxide (BrO) probed the vertical structure of halogen activation events during March–May 2012 at Barrow, Alaska. An analysis of the BrO averaging kernels and degrees of freedom obtained by optimal-estimation-based inversions from raw MAX-DOAS measurements reveals the information is best represented by reducing the retrieved BrO profile to two ...

  17. MISCIBILITY AND MORPHOLOGY OF THIN FILMS OF BLENDS OF POLYSTYRENE WITH BROMINATED POLYSTYRENES: EFFECTS OF VARYING THE MOLECULAR WEIGHT,BROMINATION DEGREE AND ANNEALING

    Institute of Scientific and Technical Information of China (English)

    Rui Song; De-bin Yang; Ling-hao He; Guang-tao Yao

    2006-01-01

    Thin films of incompatible polymer blends can form a variety of structures during preparation and subsequent annealing process. For the polymer blend system consisting of polystyrene and poly(styrene-co-p-bromo-styrene), I.e.,PS/PBrxS, its compatibility could be adjusted by varying the degree of bromination and the molecular weight of both components comprised. In this paper, surface chemical compositions of the cast and the annealing films were investigated by X-ray photoelectron spectroscopy (XPS) and contact angle measurement; meanwhile, surface topographical changes are followed by atomic force microscopy (AFM). In addition, substantial attention was paid to the effect of annealing on the morphologic variations induced by phase separation and/or dewetting of the thin film. Moreover, the influences of the molecular weight, Mw, as well as the brominated degree, x%, on the sample surface are explored systematically, and the corresponding observations are explained in virtue of the Flory-Huggins theory, along with the dewetting of the polymer thin film.

  18. Effect of Bromine Substitution on Human Dermal Absorption of Polybrominated Diphenyl Ethers.

    Science.gov (United States)

    Abdallah, Mohamed Abou-Elwafa; Pawar, Gopal; Harrad, Stuart

    2015-09-15

    Human dermal absorption of eight mono- to deca-brominated diphenyl ethers (PBDEs) was investigated for the first time using EPISKIN human skin equivalent tissue. Using a standard in vitro protocol, EPISKIN tissues mounted in specially designed diffusion cells were exposed to the target PBDEs for 24 h. Estimated steady-state flux (Jss) and permeation coefficients (Papp) across the skin increased with decreasing bromine substitution from BDE-153 (Papp = 4.0 × 10(-4) cm/h) to BDE-1 (Papp = 1.1 × 10(-2) cm/h). This was accompanied by an increase in the time required to traverse the skin tissue into the receptor fluid (lag time) from 0.25 h for BDE-1 to 1.26 h for BDE-153. Papp values for the studied PBDEs were correlated significantly (P water solubility and log KOW. While less brominated congeners achieved faster dermal penetration, higher PBDEs displayed greater accumulation within the skin tissue. The PBDEs thus accumulated represent a contaminant depot from which they may be slowly released to the systemic circulation over a prolonged period. Maximal percutaneous penetration was observed for BDE-1 (∼ 30% of the applied 500 ng/cm(2) dose). Interestingly, BDE-183 and BDE-209 showed very low dermal absorption, exemplified by a failure to reach the steady state within the 24 h exposure period that was studied. PMID:26301594

  19. Effects of Assistant Solvents and Mixing Intensity on the Bromination Process of Butyl Rubber

    Institute of Scientific and Technical Information of China (English)

    王伟; 邹海魁; 初广文; 向阳; 彭晗; 陈建峰

    2014-01-01

    A slow bromination process of butyl rubber (IIR) suffers from low efficiency and low selectivity (S) of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%(by volume) dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product (xA1s) of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r·min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed (RPB) reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.

  20. Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF.

    Science.gov (United States)

    Aldrian, Alexia; Ledersteger, Alfred; Pomberger, Roland

    2015-02-01

    This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television sets (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC-MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements. PMID:25464945

  1. Computer simulation of the cluster destruction of stratospheric ozone by bromine

    Institute of Scientific and Technical Information of China (English)

    A.E.Galashev; O.R.Rakhmanova

    2012-01-01

    The interaction of (Br-)i(H2O)50-i,0≤i≤6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation.The ozone molecules as well as the bromine ions do not leave the cluster during the calculation of 25 ps.The ability of the cluster containing molecular oxygen to absorb the infrared (IR)radiation is reduced in the frequency range of 0 ≤ ω ≤ 3500 cm-1 when the number of the bromine ions in the cluster grows.The intensity of the Raman spectrum is not changed significantly when the Br-ions are added to the ozonecontaining system.The power of the emitted IR radiation is increased when the number of bromine ions grows in the oxygen-containing system.The data obtained in this study on the IR and the Raman spectra of the water clusters that contain ozone,oxygen,and Br-can be used to develop an investigation of the mechanisms of ozone depletion.

  2. Measurement and human exposure assessment of brominated flame retardants in household products from South China

    International Nuclear Information System (INIS)

    Brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs), and decabromodiphenyl ethane (DBDPE) were examined in household products in the Pearl River Delta, South China, including electronic appliances, furniture and upholstery, car interiors, and raw materials for electronics. The concentrations of PBDEs derived from penta-BDE mixture were much lower (<111 ng/g) than those for octa- and deca-BDE commercially derived PBDEs, with maximum values of 15,107 and 1,603,343 ng/g, respectively, in all the household products. Our findings suggest the recycling of old electronic products and their reuse might be also a potential important source of discontinued PBDEs to the environment. DBDPE was found in 20.0% of all the samples, ranging from 311 to 268,230 ng/g. PBDE congener profiles in both the household products and raw materials suggest that some less brominated BDEs in the environment may be derived from the decomposition of higher brominated PBDEs in PBDE-containing products in process of the manufacturing, use and/or recycling. Human exposure to PBDEs from household products via inhalation ranged from 175 to 612 pg/kg bw day, accounting for a small proportion of the total daily exposure via indoor inhalation. Despite the low deleterious risk associated with household products with regard to PBDEs, they are of special concern because of the relatively higher exposures observed for young children and further work is required.

  3. Computer simulation of the cluster destruction of stratospheric ozone by bromine

    International Nuclear Information System (INIS)

    The interaction of (Br−)i(H2O)50−i, 0 ≤ i ≤ 6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation. The ozone molecules as well as the bromine ions do not leave the cluster during the calculation of 25 ps. The ability of the cluster containing molecular oxygen to absorb the infrared (IR) radiation is reduced in the frequency range of 0 ≤ ω ≤ 3500 cm−1 when the number of the bromine ions in the cluster grows. The intensity of the Raman spectrum is not changed significantly when the Br− ions are added to the ozone-containing system. The power of the emitted IR radiation is increased when the number of bromine ions grows in the oxygen-containing system. The data obtained in this study on the IR and the Raman spectra of the water clusters that contain ozone, oxygen, and Br− can be used to develop an investigation of the mechanisms of ozone depletion

  4. Bromine recovery in residual solutions generated in the 15 N isotopic determination methodology (Rittenberg, 1946)

    International Nuclear Information System (INIS)

    The isotopic determination of 15 N (Rittenberg, 1946) is a methodology used in the Laboratory of Isotope Stable (CENA/USP). In this procedure, in the oxidation of nitrogen species for N2, solution of Li Br O is used, generating as residue 50 L y-1 of solution contends Li Br and Li Br O. Seeking to recover the bromine contained in that residue, very toxic substance, a special line was built composed by reaction balloons (1 and 2 liters), addition funnel, gas flow regulator and connections in glass. In the system proposed, after the acidification (sulfuric acid) of the alkaline residual solution, the liberated bromine (Br2) it was then dragged by flow of nitrogen and reacted with solution of LiOH. That reaction facilitated the production of Li Br O in solution (Efficiency = 82±2%), that was reused later on same analytic procedure. The high cost of the liquid bromine is another attractiveness that corroborates the employment of the developed procedure. They took place isotopic determinations using the recovered solutions and prepared, and the observed values didn't show statistical difference (T test of Student). The presented procedure is part of the Management Program of Chemical Residues of CENA/USP, which seeks to destine the residues of responsibility of the institution appropriately, forming professionals to the practices of environmental management. (author)

  5. A satellite based study of tropospheric bromine explosion events and their linkages to polar cyclone development

    Science.gov (United States)

    Blechschmidt, Anne-Marlene; Richter, Andreas; Burrows, John P.; Kaleschke, Lars; Strong, Kimberly; Theys, Nicolas; Weber, Mark; Zhao, Xiaoyi; Zien, Achim; Hodges, Kevin I.

    2016-04-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by the UV-vis satellite instruments GOME-2/MetOp-A and SCIAMACHY/Envisat over Arctic and Antarctic sea ice in polar spring. The plumes are associated with an autocatalytic chemical chain reaction involving tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. This influences atmospheric chemistry as it affects the oxidising capacity of the troposphere through OH production and may also influence the local weather/temperature of the polar atmosphere, as ozone is a major greenhouse gas. Here, we make combined use of satellite retrievals and numerical model simulations to study individual BrO plume cases in the polar atmosphere. In agreement with previous studies, our analysis shows that the plumes are often transported by high latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. Moreover, general characteristics of bromine explosion events linked to transport by polar weather systems, such as frequency, spatial distribution and favourable weather conditions are derived based on a new detection method. Our results show that BrO cyclone transport events are by far more common in the Antarctic than in the Arctic.

  6. Development of crystals based in cesium iodide for application as radiation detectors; Desenvolvimento de cristais baseados em iodeto de cesio para aplicacao como detectores de radiacao

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Maria da Conceicao Costa

    2006-07-01

    Inorganic scintillators with fast luminescence decay time, high density and high light output have been the object of studies for application in nuclear physics, high energy physics, nuclear tomography and other fields of science and engineering. Scintillation crystals based on cesium iodide (CsI) are matters with relatively low higroscopy, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, the growth of pure CsI crystals, CsI:Br and CsI:Pb, using the Bridgman technique, is described. The concentration of the bromine doping element (Br) was studied in the range of 1,5x10{sup -1} M to 10{sup -2} M and the lead (Pb) in the range of 10{sup -2} M to 5x10{sup -4} M. To evaluate the scintillators developed, systematic measurements were carried out for luminescence emission and luminescence decay time for gamma radiation, optical transmittance assays, Vickers micro-hardness assays, determination of the doping elements distribution along the grown crystals and analysis of crystals response to the gamma radiation in the energy range of 350 keV to 1330 keV and alpha particles from a {sup 241}Am source, with energy of 5.54 MeV. It was obtained 13 ns to 19 ns for luminescence decay time for CsI:Br and CsI:Pb crystals. These results were very promising. The results obtained for micro-hardness showed a significant increase in function of the doping elements concentration, when compared to the pure CsI crystal, increasing consequently the mechanical resistance of the grown crystals. The validity of using these crystals as radiation sensors may be seen from the results of their response to gamma radiation and alpha particles. (author)

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

    Science.gov (United States)

    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. PMID:22541949

  8. Surface Snowpack Key to Bromine Activation in a Changing Arctic Environment

    Science.gov (United States)

    Pratt, Kerri; Custard, Kyle; Shepson, Paul; Douglas, Thomas; Pöhler, Denis; Stephan, General; Zielcke, Johannes; Simpson, William; Platt, Ulrich; von Glasow, Roland; Tanner, David; Huey, L. Gregory; Carlsen, Mark; Stirm, Brian

    2013-04-01

    Arctic sea ice is rapidly declining and transforming from a multiyear ice pack to thinner, more saline, seasonal ice, which has important implications for Arctic atmospheric composition. Following springtime polar sunrise, "ozone depletion events", attributed to bromine chemistry, lead to episodic decreases in lower tropospheric ozone concentrations to near zero, concurrent with mercury depletion and deposition. Despite our increasing understanding of the spatial variability of BrO and possible reaction pathways based on laboratory studies, important questions remain regarding the most efficient sources of and mechanisms for Arctic halogen activation. During the March-April 2012 BRomine, Ozone, and Mercury EXperiment (BROMEX) in Barrow, Alaska, outdoor chamber experiments with snow and ice samples were conducted. Ozone was added as the precursor oxidant, and the samples were investigated with and without ambient sunlight. Samples included first-year sea ice, brine icicles, several layers of snow above first-year sea ice, and seasonal snow above the tundra. Chemical ionization mass spectrometry was utilized to monitor Br2 production. Tundra snow and surface snow above sea ice produced the most Br2, with no production resulting from sea ice and basal snow directly above sea ice. Overall, the most efficient Br2 production was observed from snow samples characterized by lower pH and higher bromide/chloride ratios. Br2 was only observed in the presence of sunlight, indicating the role of snowpack photochemical reactions and the hydroxyl radical in its production. Br2 production via the surface snowpack explains previously-observed BrO enhancements above sea ice, as well as observations of inland tundra hotspots in measured BrO by aircraft-based nadir MAX-DOAS (Multi Axis-Differential Optical Absorption Spectroscopy) measurements, conducted during BROMEX. The findings indicate that atmospherically processed snow is likely a major source of Arctic bromine release, which

  9. Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006–2009

    Directory of Open Access Journals (Sweden)

    G. Giuffrida

    2012-12-01

    Full Text Available Over a 3-yr period, from 2006 to 2009, frequent scattered sunlight DOAS measurements were conducted at Mt. Etna at a distance of around 6 km downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna. Here, results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO / SO2 ratio, and its variability in relation to volcanic processes. That the halogen/sulphur ratio can serve as a precursor or indicator for the onset of eruptive activity was already proposed by earlier works (e.g. Noguchi and Kamiya 1963; Menyailov, 1975; Pennisi and Cloarec, 1998; Aiuppa et al., 2002. However, there is still a limited understanding today because of the complexity with which halogens are released, depending on magma composition and degassing conditions. Our understanding of these processes is far from complete, for example of the rate and mechanism of bubble nucleation, growth and ascent in silicate melts (Carroll and Holloway, 1994, the halogen vapour-melt partitioning and the volatile diffusivity in the melt (Aiuppa et al., 2009. With this study we aim to add one more piece to the puzzle of what halogen/sulphur ratios might tell about volcanic activities. Our data set shows an increase of the BrO / SO2 ratio several weeks prior to an eruption, followed by a decline before and during the initial phase of eruptive activities. Towards the end of activity or shortly thereafter, the ratio increases to baseline values again and remains more or less constant during quiet phases. To explain the observed evolution of the BrO / SO2 ratio, a first empirical model is proposed. This model suggests that bromine, unlike chlorine and fluorine, is less soluble in the magmatic melt than sulphur. By using the DOAS method to determine SO2, we actually

  10. Selective sorption of iodide onto organo-MnO2 film and its electrochemical desorption and detection

    International Nuclear Information System (INIS)

    Highlights: • HDPy/MnO2 film can selectively sorb iodide with expansion of interlayer spaces. • The sorbed iodide ions are oxidized anodically and expelled as I2 molecules. • The iodide concentration can be determined by anodic current during desorption. - Abstract: This paper reports an electrochemically grown film consisting of layered MnO2 intercalated with hexadecylpyridinium cations (HDPy+), which can selectively sorb and detect iodide anions in aqueous solution amperometrically. Sorption of iodide by the HDPy/MnO2 film did not occur via ion exchange, but through hydrophobic interactions between the interlayer organic phase of the film and iodide ions in solution. The sorption rate increased with the deposited amount of MnO2. During the sorption process, the interlayer spaces expanded, and new diffraction peaks appeared that were attributed to the incorporated species. Anodic polarization of the iodide-sorbed HDPy/MnO2 film led to electron transfer from the incorporated iodide to the underlying substrate through the MnO2 sheets. The oxidized iodide was expelled from the film as molecular I2, while the expanded interlayer spaces were restored to their original state. Thus, the MnO2 layers and the incorporated HDPy can synergistically sorb/desorb iodide anions, resulting in a unique “self-cleaning” function that can operate electrochemically. This property allowed amperometric detection of iodide at a concentration as low as 0.0186 μM, which was below the detection limits reported for previous iodide sensors

  11. Selective sorption of iodide onto organo-MnO{sub 2} film and its electrochemical desorption and detection

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Masaharu, E-mail: nkymm@yamaguchi-u.ac.jp; Sato, Ayu; Nakagawa, Kimiko

    2015-06-02

    Highlights: • HDPy/MnO{sub 2} film can selectively sorb iodide with expansion of interlayer spaces. • The sorbed iodide ions are oxidized anodically and expelled as I{sub 2} molecules. • The iodide concentration can be determined by anodic current during desorption. - Abstract: This paper reports an electrochemically grown film consisting of layered MnO{sub 2} intercalated with hexadecylpyridinium cations (HDPy{sup +}), which can selectively sorb and detect iodide anions in aqueous solution amperometrically. Sorption of iodide by the HDPy/MnO{sub 2} film did not occur via ion exchange, but through hydrophobic interactions between the interlayer organic phase of the film and iodide ions in solution. The sorption rate increased with the deposited amount of MnO{sub 2}. During the sorption process, the interlayer spaces expanded, and new diffraction peaks appeared that were attributed to the incorporated species. Anodic polarization of the iodide-sorbed HDPy/MnO{sub 2} film led to electron transfer from the incorporated iodide to the underlying substrate through the MnO{sub 2} sheets. The oxidized iodide was expelled from the film as molecular I{sub 2}, while the expanded interlayer spaces were restored to their original state. Thus, the MnO{sub 2} layers and the incorporated HDPy can synergistically sorb/desorb iodide anions, resulting in a unique “self-cleaning” function that can operate electrochemically. This property allowed amperometric detection of iodide at a concentration as low as 0.0186 μM, which was below the detection limits reported for previous iodide sensors.

  12. Characterization of strontium iodide scintillators with silicon photomultipliers

    Science.gov (United States)

    Mitchell, Lee J.; Phlips, Bernard

    2016-06-01

    This work characterizes a commercially available europium-doped strontium iodide detector recently developed by Radiation Monitoring Devices (RMD). The detector has been chosen for a space-based mission scheduled to launch in early 2017. The primary goal of this work was to characterize the detector's response over the expected operational range of -10 °C to 30 °C as well as the expected operational voltage range of +26.5-+28.5 V and identify background interferences that may develop due to neutron activation produced by cosmic-ray interactions. The 8 mm×8 mm×20 mm detectors use KETEK silicon photomultipliers (SiPM), with an active area of 6 mmx6 mm (KETEK PM6660). Our results show substantial integral nonlinearity due to the SiPM ranging from 0% to 25% at room temperature over the energy range of 80-2614 keV. The nonlinearity, a function of temperature and overvoltage, leads to an underestimate of the full width at half max (FWHM), which is 2.6% uncorrected at 662 keV and 3.8% corrected at 662 keV. The temperature dependence of the detector results in a noise threshold that increases substantially above 30 °C due to the SiPM dark rate. In an effort to simulate the harsh environment of space, neutron activation of the detector was also explored. Gamma-ray lines at 127 keV and 164 keV were observed in the detector along with Kα x-rays associated with europium. Beta decay from europium- and iodine-activation products were also observed within the detector.

  13. THERAPY OF GRAVES’ DISEASE WITH SODIUM IODIDE-131

    Directory of Open Access Journals (Sweden)

    I Wayan Hartadi Noor

    2013-11-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Graves’ disease is the most common form of thyrotoxicosis, with a peak incidence in the 20-40 year of age group. Females are involved about five times more commonly than male. The easiest sign to recognize patients with Graves’ disease is the present of Graves’ ophthalmopathy. The diagnosis of Graves’ disease may sometimes base only on a physical examination and a medical history. Diffuse thyroid enlargement and sign of thyrotoxicosis, mainly ophthalmopathy and to lesser extent dermopathy, usually adequate for diagnosis. TSH test combined with FT4 test is usually the first laboratory test performs in these patients. The patients suffered Graves’ disease can be treated with antithyroid drug therapy or undergo subtotal Thyroidectomy. Another therapy is by using sodium iodide-131, where this therapy has advantages including easy administration, effectiveness, low expense, and absence of pain. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  14. Rutherford Backsattering and Auger spectroscopy of mercuric iodide detectors

    International Nuclear Information System (INIS)

    The electrical properties of metallic contacts on solid state x-ray detectors can play an important role in determining the overall response and sensitivity of these devices. Rutherford Backscattering (RBS) and Auger electron spectroscopies have been utilized to characterize thin palladium contacts on mercuric iodide (HgI2) detectors. The RBS measurements were performed at room temperature with the metal contact preventing evaporate loss of the HgI2 and reducing contamination to the vacuum chamber. Computer simulations of the RBS results indicate that the interface region of a sample with a palladium contact had approximately the ideal stoichiometry but that the palladium film thickness (350 /angstrom/) was less than expected from the deposition conditions. Auger sputter profiling which removes the metal contact ''cap'' was performed with a rapid transfer system equipped with liquid nitrogen cooling to avoid evaporative loss of the sample and reduce vacuum system contamination. This technique indicated significant penetration of Hg and I into the Pd contact for a variety of samples. In many cases, the penetration extended all the way to the surface. For a 600 /angstrom/ contact, approximately two thirds or 400 /angstrom/ of the contact is part of a ''reaction zone'' in which there is strong intermixing of the palladium, mercury, and iodine. In one case, where copper was tried as an electrode, the ''reaction zone'' extended all the way to the surface, and the device failed as a detector. The relationship of the contact stoichiometry to the deposition process and device performance will be discussed. 5 refs., 4 figs

  15. Rutherford Backsattering and Auger spectroscopy of mercuric iodide detectors

    Energy Technology Data Exchange (ETDEWEB)

    Felter, T. E.; Stulen, R. H.; Schnepple, W. F.; Ortale, C.; van den Berg, L.

    1987-01-01

    The electrical properties of metallic contacts on solid state x-ray detectors can play an important role in determining the overall response and sensitivity of these devices. Rutherford Backscattering (RBS) and Auger electron spectroscopies have been utilized to characterize thin palladium contacts on mercuric iodide (HgI/sub 2/) detectors. The RBS measurements were performed at room temperature with the metal contact preventing evaporate loss of the HgI/sub 2/ and reducing contamination to the vacuum chamber. Computer simulations of the RBS results indicate that the interface region of a sample with a palladium contact had approximately the ideal stoichiometry but that the palladium film thickness (350 /angstrom/) was less than expected from the deposition conditions. Auger sputter profiling which removes the metal contact ''cap'' was performed with a rapid transfer system equipped with liquid nitrogen cooling to avoid evaporative loss of the sample and reduce vacuum system contamination. This technique indicated significant penetration of Hg and I into the Pd contact for a variety of samples. In many cases, the penetration extended all the way to the surface. For a 600 /angstrom/ contact, approximately two thirds or 400 /angstrom/ of the contact is part of a ''reaction zone'' in which there is strong intermixing of the palladium, mercury, and iodine. In one case, where copper was tried as an electrode, the ''reaction zone'' extended all the way to the surface, and the device failed as a detector. The relationship of the contact stoichiometry to the deposition process and device performance will be discussed. 5 refs., 4 figs.

  16. Structure and scintillation of Eu2+-activated calcium bromide iodide

    International Nuclear Information System (INIS)

    We report the structure and scintillation properties of Eu2+-activated calcium bromide iodide. CaBr0.7I1.3 was the only composition that could be synthesized in the CaBr2–CaI2 system. The compound has an effective atomic number of 47 and crystallizes in a trigonal crystal system with the R-3 space group and a density of 3.93 g/cc. The structure is layered and contains Ca in an octahedral environment with the Br/I anions jointly occupying a single site. Eu2+-activated samples show an intense narrow emission, characteristic of the 5d–4f transition of Eu2+, when excited with UV or X-rays. The sample with 0.5% Eu shows a light output of 63,000 ph/MeV at 662 keV with 96% of the light emitted with a monoexponential decay time of 1332 ns. An energy resolution of 10.4% full width at half maximum (FWHM) has been achieved for 662 keV gamma rays at room temperature. - Highlights: • CaBr0.7I1.3 is the only composition that formed in the CaBr2–CaI2 system. • Crystallizes in a trigonal crystal system with the R-3 space group. • Eu2+-activation yields scintillator with bright blue emission centered at 465 nm. • Light output is 63,000 ph/MeV with 10.4% energy resolution at 662 keV. • Monoexponential decay time of 1332 ns

  17. Endothelium modulates anion channel-dependent aortic contractions to iodide.

    Science.gov (United States)

    Lamb, F S; Barna, T J

    2000-05-01

    Anion currents contribute to vascular smooth muscle (VSM) membrane potential. The substitution of extracellular chloride (Cl) with iodide (I) or bromide (Br) initially inhibited and then potentiated isometric contractile responses of rat aortic rings to norepinephrine. Anion substitution alone produced a small relaxation, which occurred despite a lack of active tone and minimal subsequent contraction of endothelium-intact rings (4.2 +/- 1.2% of the response to 90 mM KCl). Endothelium-denuded rings underwent a similar initial relaxation but then contracted vigorously (I > Br). Responses to 130 mM I (93.7 +/- 1.9% of 90 mM KCl) were inhibited by nifedipine (10(-6) M), niflumic acid (10(-5) M), tamoxifen (10(-5) M), DIDS (10(-4) M), and HCO(-)(3)-free buffer (HEPES 10 mM) but not by bumetanide (10(-5) M). Intact rings treated with N(omega)-nitro-L-arginine (10(-4) M) responded weakly to I (15.5 +/- 2.1% of 90 mM KCl), whereas hemoglobin (10(-5) M), indomethacin (10(-6) M), 17-octadecynoic acid (10(-5) M), and 1H-[1,2, 4]oxadiazole[4,3-a]quinoxalin-1-one (10(-6) M) all failed to augment the response of intact rings to I. We hypothesize that VSM takes up I primarily via an anion exchanger. Subsequent I efflux through anion channels having a selectivity of I > Br > Cl produces depolarization. In endothelium-denuded or agonist-stimulated vessels, this current is sufficient to activate voltage-dependent calcium channels and cause contraction. Neither nitric oxide nor prostaglandins are the primary endothelial modulator of these anion channels. If they are regulated by an endothelium-dependent hyperpolarizing factor it is not a cytochrome P-450 metabolite. PMID:10775130

  18. Retinoic acid induces sodium/iodide symporter gene expression and radioiodide uptake in the MCF-7 breast cancer cell line

    OpenAIRE

    Kogai, Takahiko; Schultz, James J.; Johnson, Laura S.; Huang, Min; Brent, Gregory A.

    2000-01-01

    The sodium/iodide symporter (NIS) stimulates iodide uptake in normal lactating breast, but is not known to be active in nonlactating breast or breast cancer. We studied NIS gene regulation and iodide uptake in MCF-7 cells, an estrogen receptor (ER)-positive human breast cancer cell line. All-trans retinoic acid (tRA) treatment stimulated iodide uptake in a time- and dose-dependent fashion up to ≈9.4-fold above baseline. Stimulation with selective retinoid compounds indicated that the inductio...

  19. Processes of adsorption/desorption of iodides and cadmium cations onto/from Ag(111

    Directory of Open Access Journals (Sweden)

    VLADIMIR D. JOVIĆ

    2011-02-01

    Full Text Available In this work, the adsorption/desorption processes of iodides and cadmium cations in the presence of iodides onto/from Ag(111 were investigated. It was shown that both processes were complex, characterized by several peaks on the cyclic voltammograms (CVs. By PeakFit analysis of the recorded CVs and subsequent fitting of the obtained peaks by the Frumkin adsorption isotherm, the interaction parameter (f and the Gibbs energy of adsorption (DGads for each adsorbed phase were determined. In the case of iodide adsorption, four peaks were characterized by negative values of f, indicating attractive lateral interaction between the adsorbed anions, while two of them possessed value of f < –4, indicating phase transition processes. The adsorption/desorption processes of cadmium cations (underpotential deposition – UPD of cadmium in the presence of iodide anions was characterized by two main peaks, each of them being composed of two or three peaks with negative values of f. By the analysis of charge vs. potential dependences obtained either from the CVs or current transients on potentiostatic pulses, it was concluded that adsorbed iodides did not undergo desorption during the process of Cd UPD, but became replaced by Cd ad-atoms and remained adsorbed on top of a Cd layer and/or in between Cd the ad-atoms.

  20. Evaluation of the reversibility of iodide uptake by argillaceous rocks by the radial diffusion method

    International Nuclear Information System (INIS)

    Laboratory radial in- and out-diffusion experiments were performed to investigate the reversibility of the iodide (I-) uptake by argillaceous rocks from the Tournemire site (France). At first, the suitability of the method was demonstrated by means of deuterium depleted water (DDW) diffusion experiments. The values for the DDW effective diffusion coefficient (1.7 to 2.7 x 10-11 m2 s-1) are indeed very close to those obtained from previous through-diffusion experiments carried out on Tournemire samples with tritiated water. The diffusion of chloride and bromide led to the determination of halide-accessible porosities, which are necessary to calculate the retardation factor (R) and the distribution ratio (RD). The calculated values for the halide-accessible porosity (2 to 5%) clearly indicated the effect of anionic exclusion and are consistent with previous data. On the contrary, the in-diffusion experiments performed with iodide clearly showed its uptake by argillite, with rock capacity factor values ranging from 14% to 25%. The corresponding values of RD (0.035 to 0.08 L kg-1) are one order of magnitude lower than those previously derived from batch methods. At last, the experiments of iodide out-diffusion revealed that only iodide located in the halide-accessible porosity diffused out of the rock samples, suggesting that the uptake of iodide by argillite would not be reversible or that the kinetics of desorption would be low (> 70 days). (orig.)

  1. Functional activity of human sodium/iodide symporter in tumor cell lines

    International Nuclear Information System (INIS)

    Aim: The sodium/iodide symporter (NIS) actively transports iodide into thyrocytes. Thus, NIS represents a key protein for diagnosis and radioiodine therapy of differentiated thyroid cancer. Additionally, in the future the NIS gene may be used for cancer gene therapy of non-thyroid-derived malignancies. In this study we evaluated the functionality of NIS with respect to iodide uptake in a panel of tumor cell lines and compared this to gene transfer efficiency. Methods: A human NIS-containing expression vector and reporter-gene vectors encoding and beta;-Galactosidase- or EGFP were used for transient transfection of 13 tumor cell lines. Following transfection measurements of NIS-mediated radioiodide uptake using Na125I and of transfection efficiency were performed. The latter included β;-Galactosidase activity measurements using a commercial kit and observation by fluorescence microscopy for EGFP expression. Results: In contrast to respective parental cells, most NIS-transfected cell lines displayed high, perchlorate-sensitive radioiodide uptake. Differences in radioiodide uptake between cell lines apparently corresponded to transfection efficiencies, as judged from reporter-gene assays. Conclusion: With respect to iodide uptake we provide evidence that NIS is functional in different cellular context. As iodide uptake capacity appears to be well correlated to gene transfer efficiency, cell type-specific actions on NIS (e. g. post-translational modification such as glycosylation) are not inhibitory to NIS function. Our data support the promising role of NIS in cancer gene therapy strategies. (orig.)

  2. Estradiol decreases iodide uptake by rat thyroid follicular FRTL-5 cells

    Directory of Open Access Journals (Sweden)

    Furlanetto T.W.

    2001-01-01

    Full Text Available Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 ± 0.370 to 2.085 ± 0.364 pmol I-/µg DNA at 1 ng/ml (P<0.02, to 1.970 ± 0.302 pmol I-/µg DNA at 10 ng/ml (P<0.003, and to 2.038 ± 0.389 pmol I-/µg DNA at 100 ng/ml (P<0.02. In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 ± 0.408 to 7.312 ± 0.506 pmol I-/µg DNA (P<0.02. A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.

  3. An investigation of sodium iodide solubility in sodium-stainless steel systems

    International Nuclear Information System (INIS)

    Sodium iodide and major constituents of stainless steel in sodium are determined by using the steel capsules to obtain a better understanding on contribution of the constituents to the apparent iodide solubility in sodium. The capsule loaded with 20 g sodium and 0.1 - 0.3 g powder of sodium iodide is heated at its upper part in a furnace and cooled at its bottom on brass plates to establish a large temperature gradient along the capsule tube. After a given period of equilibration, the iodide and constituents are fixed in solidified sodium by quick quenching of the capsules. Sodium samples are taken from the sectioned capsule tube and submitted to sodium dissolution by vaporized water for determination of the iodine and to vacuum distillation for determination of the metal elements. Iron and nickel concentrations are observed to be lower in the samples at higher iodine concentrations. Chromium and manganese concentrations are seen to be insensitive to the iodine concentrations. The observations can be interpreted by a model that sodium oxide combines with metal iodide in sodium to form a complex compound and with consideration that the compound will fall and deposit onto the bottom of the capsule by thermal diffusion. (author)

  4. Alpha-lipoic acid induces sodium iodide symporter expression in TPC-1 thyroid cancer cell line

    International Nuclear Information System (INIS)

    Introduction: Patients with metastatic thyroid cancers that do not uptake iodine need effective therapeutic option. Differentiation-inducing agents have been tried to restore functional expression of sodium iodide symporter (NIS) without success. Our objective was to assess the effect of alpha-lipoic acid (ALA), known as potential antioxidant, on expression of sodium iodide symporter in thyroid cancer cells. Methods: Human thyroid cancer-derived cell lines, TPC-1, were treated with ALA, and changes in NIS mRNA and protein expression were measured. ALA's effect on NIS gene promoter was evaluated, and functional NIS expression was assessed by iodide uptake assay. Results: Treatment with ALA increased NIS mRNA expression up to ten folds of control dose-dependently after 24 h of exposure. ALA increased NIS promoter activity, and increased iodide uptake by 1.6 fold. ALA induced expression of NIS protein, but had no significant effect on the plasma membrane trafficking. ALA increased phosphorylation of CREB and nuclear translocation of pCREB, and co-treatment of ALA and trichostatin A increased iodide uptake by three folds in TPC-1 cells. Conclusions: ALA is a potential agent to increase NIS transcription in TPC-1. It could be used as an adjunctive agent to increase efficacy of radioiodine therapy if combined with a strategy to increase NIS protein trafficking to cell membrane.

  5. Functional activity of human sodium/iodide symporter in tumor cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Petrich, T.; Knapp, W.H.; Poetter, E. [Dept. of Nuclear Medicine, Medizinische Hochschule Hannover, Hannover (Germany)

    2003-02-01

    Aim: The sodium/iodide symporter (NIS) actively transports iodide into thyrocytes. Thus, NIS represents a key protein for diagnosis and radioiodine therapy of differentiated thyroid cancer. Additionally, in the future the NIS gene may be used for cancer gene therapy of non-thyroid-derived malignancies. In this study we evaluated the functionality of NIS with respect to iodide uptake in a panel of tumor cell lines and compared this to gene transfer efficiency. Methods: A human NIS-containing expression vector and reporter-gene vectors encoding β-Galactosidase- or EGFP were used for transient transfection of 13 tumor cell lines. Following transfection measurements of NIS-mediated radioiodide uptake using Na{sup 125}I and of transfection efficiency were performed. The latter included β-Galactosidase activity measurements using a commercial kit and observation by fluorescence microscopy for EGFP expression. Results: In contrast to respective parental cells, most NIS-transfected cell lines displayed high, perchlorate-sensitive radioiodide uptake. Differences in radioiodide uptake between cell lines apparently corresponded to transfection efficiencies, as judged from reporter-gene assays. Conclusion: With respect to iodide uptake we provide evidence that NIS is functional in different cellular context. As iodide uptake capacity appears to be well correlated to gene transfer efficiency, cell type-specific actions on NIS (e. g. post-translational modification such as glycosylation) are not inhibitory to NIS function. Our data support the promising role of NIS in cancer gene therapy strategies. (orig.)

  6. Trapping radiodine, in the form of methyl iodide, on nuclear carbon

    Energy Technology Data Exchange (ETDEWEB)

    Nacapricha, D. [Mahidol Univ., Bangkok (Thailand); Taylor, C. [John Moores Univ., Liverpool (United Kingdom)

    1996-12-31

    Studies have been performed on potassium-iodide-impregnated charcoals of the type used in the nuclear industry for trapping radioiodine released during nuclear fission. The effects of various parameters on the trapping efficiency of methyl iodide have been investigated. A variation in particle size within a bulk charcoal caused poor precision in K value measurements because of differences in surface area, pore volume, and bed density, leading to differences in the deposition of the impregnant. Precision is improved by sieving the charcoal to a narrower size because smaller particles have a higher porosity. This finding is supported by surface area and pore measurements. Two methods of impregnation are compared by measuring K values and the deposition of potassium iodide. Charcoal impregnated by rotary evaporation exhibits both higher K values and higher potassium iodide contents than sprayed charcoal. Two designs of spraying drum are compared: a drum with helical vanes allows more efficient deposition and more uniform distribution of impregnant than a drum with axial vanes. A decrease in the K value with increasing humidity correlates with the available surface area. A similar correlation exists between water content and available pore volume. Aging of potassium-iodide-impregnated charcoal, caused by the formation of oxygen complexes on the surface, is associated with significant falls in K value. K values of charcoals also can be restored to at least their original values by heat treatment in the absence of air. 12 refs., 6 figs., 1 tab.

  7. X-ray imaging performance of structured cesium iodide scintillators.

    Science.gov (United States)

    Zhao, Wei; Ristic, Goran; Rowlands, J A

    2004-09-01

    Columnar structured cesium iodide (CsI) scintillators doped with Thallium (Tl) have been used extensively for indirect x-ray imaging detectors. The purpose of this paper is to develop a methodology for systematic investigation of the inherent imaging performance of CsI as a function of thickness and design type. The results will facilitate the optimization of CsI layer design for different x-ray imaging applications, and allow validation of physical models developed for the light channeling process in columnar CsI layers. CsI samples of different types and thicknesses were obtained from the same manufacturer. They were optimized either for light output (HL) or image resolution (HR), and the thickness ranged between 150 and 600 microns. During experimental measurements, the CsI samples were placed in direct contact with a high resolution CMOS optical sensor with a pixel pitch of 48 microns. The modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) of the detector with different CsI configurations were measured experimentally. The aperture function of the CMOS sensor was determined separately in order to estimate the MTF of CsI alone. We also measured the pulse height distribution of the light output from both the HL and HR CsI at different x-ray energies, from which the x-ray quantum efficiency, Swank factor and x-ray conversion gain were determined. Our results showed that the MTF at 5 cycles/mm for the HR type was 50% higher than for the HL. However, the HR layer produces approximately 36% less light output. The Swank factor below K-edge was 0.91 and 0.93 for the HR and HL types, respectively, thus their DQE(0) were essentially identical. The presampling MTF decreased as a function of thickness L. The universal MTF, i.e., MTF plotted as a function of the product of spatial frequency f and CsI thickness L, increased as a function of L. This indicates that the light channeling process in CsI improved the MTF of

  8. Bromide and iodide removal from waters under dynamic conditions by Ag-doped aerogels.

    Science.gov (United States)

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

    2007-02-01

    The objective of this study was to analyze the efficiency of Ag-doped aerogels in the removal of bromide and iodide from water. To test the applicability of these aerogels in water treatment, adsorption of bromide and iodide was studied under dynamic conditions using waters from Lake Zurich and a mineral water. The results obtained by using these waters showed a high breakthrough volume (V(0.02)=0.4 L) of the columns, while the height of the mass transfer zone (H(MTZ)=6.8 cm) was low, regardless of the anion under study. Bromide- and iodide-saturated columns were regenerated with NH4OH. No change in the column characteristics was observed after two regeneration treatments, regardless of the type of water considered. PMID:17109877

  9. Doping in mercuric iodide crystals and its influence on electronic properties and material structure

    International Nuclear Information System (INIS)

    Doping of mercuric iodide single crystals with SbI3 was studied. Three major aspects of the influence of doping were investigated: the α to β solid phase transition, the crystal structure and the semiconducting properties. A controlled doping method and a new growth technique from the melt were developed. A quantitative correlation between the antimony concentration and the charge carrier transport properties as well as the nuclear detector characteristics of HgI2 were established for the first time. In the present work the influence of various impurities (Sb, Cu, Ag, Bi) on the solid state phase transformation of mercuric iodide has been investigated. In the second part of the work a new growth method for mercuric iodide single crystals containing a controlled amount of SbI3, has been developed. In the last part of this work the influence of the presence of impurities in the crystal on the charge carrier transport properties has been investigated. (author)

  10. Study on methyl iodide prepared without acute toxicant and its trial application in iodine adsorber test

    International Nuclear Information System (INIS)

    This paper studied a method of substitution, which substituted the non-toxic chlorotrimethylsilane (Me3SiCl) /sodium iodide (NaI) for the acutely toxic dimethyl sulphate (DMS) as a dealkylating agent for the first time to react with phosphate methylesters in preparing the gaseous radioactive methyl iodide. Comparative tests were carried out between substitution method and DMS method to measure respective cleaning efficiencies of iodine absorber both in lab and in the ventilation system of nuclear power plant. The impact of the substitutes on the organic material components of methyl iodide generator was also evaluated. The results showed that the substitution method was comparable to the former DMS method, and the substitutes was also compatible with the generator. Therefore, the substitution method can be preliminary judged applicable to both workshop and in-place tests of iodine adsorber in nuclear power plants. (authors)

  11. Quantification of propidium iodide delivery with millisecond electric pulses: A model study

    CERN Document Server

    Yu, Miao

    2014-01-01

    A model study of propidium iodide delivery with millisecond electric pulses is presented; this work is a companion of the experimental efforts by Sadik et al. [1]. Both membrane permeabilization and delivery are examined with respect to six extra-cellular conductivities. The transmembrane potential of the permeabilized regions exhibits a consistent value, which corresponds to a bifurcation point in the pore-radius-potential relation. Both the pore area density and membrane conductance increase with an increasing extra-cellular conductivity. On the other hand, the inverse correlation between propidium iodide delivery and extra-cellular conductivity as observed in the experiments is quantitatively captured by the model. This agreement confirms that this behavior is primarily mediated by electrophoretic transport during the pulse. The results suggest that electrophoresis is important even for the delivery of small molecules such as propidium iodide. The direct comparison between model prediction and experimental...

  12. Optimization of mercuric iodide platelets growth by the polymer controlled vapor transport method

    Directory of Open Access Journals (Sweden)

    Fornaro L.

    1999-01-01

    Full Text Available Mercuric iodide crystals in their platelet habit were grown by the polymer controlled vapor transport method. Mercuric iodide 99% in purity was sublimated at temperatures about 122 - 126 °C and vacuum conditions (10-5 mmHg, after selecting an appropriate polymer. Temperature profiles and experimental heat transfer models were determined for two growth furnaces using different insulator configurations for the cold extreme (air, ceramic wool, grilon, copper and ceramic wool. Growth conditions for few and separate nucleation points and large crystals were determined. Representative samples were characterized by optical microscopy and by measuring the current density and apparent resistivity of the material. Future optimization and comparisons with others mercuric iodide crystal growth methods are included.

  13. Iodide retention by cinnabar (HgS) and chalcocite (Cu{sub 2}S)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.L.; Balsley, S.D.; Brady, P.V.

    1995-07-01

    Sorption of iodide (I{sup {minus}}) on cinnabar (HgS) and chalcocite (Cu{sub 2}S) was examined as a function of pH at 25{degrees}C in a series of batch experiments. Calculated distribution ratios (K{sub d}) far exceed those reported for other minerals; maximal K{sub d}`s of 1375 cc/g (Cu{sub 2}S) and 3080 c/g (HgS) were observed between pH 4-5, but wre substantial at all pH`s measured (4 < pH < 10). Iodide sorption apparently occurs by the formation of an insoluble surface solid solution with exposed Hg and Cu sites. Surface solid solution formation is favored at low pH due to the lessened electrostatic repulsion of the iodide ion by the sulfide surfaces.

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

    International Nuclear Information System (INIS)

    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 the 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

  15. Production of HBR from bromine and steam for off-peak electrolytic hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Schlief, R.E.; Hanrahan, R.J.; Stoy, M.A. [Univ. of Florida, Gainesville, FL (United States)] [and others

    1995-09-01

    Progress is reported on the development of a renewable energy source based solar-electrolytic system for production of hydrogen and oxygen. It employs water, bromine, solar energy and supplemental electrical power. The concept is being developed by Solar Reactor Technologies, Inc., (SRT), with the U.S. Department of Energy (DOE). An overview of the nature and objectives of this program is provided here, and technical progress made during the first (three-month) performance period of the Phase I work effort is reported. The SRT concept entails (1) absorption of concentrated solar radiation by bromine vapor Br{sub 2(g)} in a high-temperature reactor producing Br{sub (g)} atoms, (2) reaction of Br{sub (g)} with water yielding hydrogen bromide (HBr), and (3) electrolysis of stored hydrogen bromide for production of H{sub 2(g)} and recovery of Br{sub 2(I)}. Incorporation of solar radiation in the primary photochemical step (1) reduces by 50 - 70% the electrical power required to split water. The SRT concept is very attractive from an economic viewpoint as well. The reversible fuel cell, employed in the SRT electrolysis concept is capitalized via its use in load leveling by the utility. A 1 kW solar reactor was designed and constructed during the first three-month performance period by SRT personnel at the University of Florida, Gainesville. It was employed in taking survey data of the reaction between bromine and steam at temperatures between 900 and 1300 K. This reaction was run under purely thermal conditions, i.e. in the absence of solar photons. The experimental data are reported and interpreted employing concomitant thermodynamic calculations. The anticipated improvement is discussed briefly as well as the effect of a photochemical boost to the reaction. The amount of this enhancement will be studied in the next three month performance period.

  16. Molecular simulations and density functional theory calculations of bromine in clathrate hydrate phases

    International Nuclear Information System (INIS)

    Bromine forms a tetragonal clathrate hydrate structure (TS-I) very rarely observed in clathrate hydrates of other guest substances. The detailed structure, energetics, and dynamics of Br2 and Cl2 in TS-I and cubic structure I (CS-I) clathrate hydrates are studied in this work using molecular dynamics and quantum chemical calculations. X-ray diffraction studies show that the halogen-water–oxygen distances in the cages of these structures are shorter than the sum of the van der Waals radii of halogen and oxygen atoms. This suggests that the stabilizing effects of halogen bonding or other non-covalent interactions (NCIs) may contribute to the formation of the unique tetragonal bromine hydrate structure. We performed molecular dynamics simulations of Br2 and Cl2 clathrate hydrates using our previously developed five-site charge models for the dihalogen molecules [Dureckova et al. Can. J. Chem. 93, 864 (2015)] which reproduce the computed electrostatic potentials of the dihalogens and account for the electropositive σ-hole of the halogen bond donor (the dihalogen). Analysis of the radial distribution functions, enthalpies of encapsulation, velocity and orientation autocorrelation functions, and polar angle distributions are carried out for Br2 and Cl2 guests in various cages to contrast the properties of these guests in the TS-I and CS-I phases. Quantum chemical partial geometry optimizations of Br2 and Cl2 guests in the hydrate cages using the M06-2X functional give short halogen-water distances compatible with values observed in X-ray diffraction experiments. NCI plots of guest-cage structures are generated to qualitatively show the relative strength of the non-bonding interactions between dihalogens and water molecules. The differences between behaviors of Br2 and Cl2 guests in the hydrate cages may explain why bromine forms the unique TS-I phase

  17. Trophic transfer of naturally produced brominated aromatic compounds in a Baltic Sea food chain.

    Science.gov (United States)

    Dahlgren, Elin; Lindqvist, Dennis; Dahlgren, Henrik; Asplund, Lillemor; Lehtilä, Kari

    2016-02-01

    Brominated aromatic compounds (BACs) are widely distributed in the marine environment. Some of these compounds are highly toxic, such as certain hydroxylated polybrominated diphenyl ethers (OH-PBDEs). In addition to anthropogenic emissions through use of BACs as e.g. flame retardants, BACs are natural products formed by marine organisms such as algae, sponges, and cyanobacteria. Little is known of the transfer of BACs from natural producers and further up in the trophic food chain. In this study it was observed that total sum of methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and OH-PBDEs increased in concentration from the filamentous red alga Ceramium tenuicorne, via Gammarus sp. and three-spined stickleback (Gasterosteus aculeatus) to perch (Perca fluviatilis). The MeO-PBDEs, which were expected to bioaccumulate, increased in concentration accordingly up to perch, where the levels suddenly dropped dramatically. The opposite pattern was observed for OH-PBDEs, where the concentration exhibited a general trend of decline up the food web, but increased in perch, indicating metabolic demethylation of MeO-PBDEs. Debromination was also indicated to occur when progressing through the food chain resulting in high levels of tetra-brominated MeO-PBDE and OH-PBDE congeners in fish, while some penta- and hexa-brominated congeners were observed to be the dominant products in the alga. As it has been shown that OH-PBDEs are potent disruptors of oxidative phosphorylation and that mixtures of different congener may act synergistically in terms of this toxic mode of action, the high levels of OH-PBDEs detected in perch in this study warrants further investigation into potential effects of these compounds on Baltic wildlife, and monitoring of their levels. PMID:26517387

  18. The measurement of bromine monoxide from Fairbanks, AK and comparison with OMI/AURA

    Science.gov (United States)

    Mount, G. H.; Spinei, E.; Herman, J. R.; Cede, A.; Abuhassan, N.; Simpson, W. R.; McPeters, R. D.; Bhartia, P. K.; Johnson, B. J.; Salawitch, R. J.; Canty, T. P.; Chance, K.; Kurosu, T. P.; Suleiman, R. M.

    2011-12-01

    Enhanced column bromine monoxide in the Arctic has been observed by satellites for some time and is related to bromine "hotspots" that result in nearly complete removal of surface ozone in springtime. Salawitch et al. (2010) have demonstrated that these enhancements show little relation, at times, to satellite-enhanced column BrO. Several recent studies have shown that closure of the budget for total column BrO is achieved by summing observed tropospheric partial column BrO with a calculated stratospheric partial column that accounts for the supply of 7 ppt of Bry from natural, short-lived biogenic bromocarbons to the lowermost stratosphere. However, the burden of Bry in the upper stratosphere in these studies, 26 ppt, is at the upper limit of Bry levels inferred from upper stratospheric BrO. A ground-based NASA-sponsored field campaign was held in Fairbanks, AK in March and April 2011 to measure bromine monoxide and other trace gases by direct sun and multi-axis scattered skylight in combination with daily ozonesondes and OMI/AURA satellite data of BrO. The tropospheric contribution to column BrO should be near zero at this time/location. The campaign was therefore focused on defining the stratospheric BrO burden and evaluating the accuracy of total column BrO reported by OMI. The comparison of the ground-based BrO data with the OMI data is reported. Additionally, the DOAS derivation of BrO is explored using various spectral fitting windows and an error budget compiled showing the sensitivity of the deduced BrO vertical column with instrument-dependent spectral window.

  19. Thermodynamic properties of bromine fluorene derivatives: An experimental and computational study

    International Nuclear Information System (INIS)

    Highlights: • Vapour pressures of two bromine derivatives of fluorene were measured. • Combustion energies of two bromine derivatives of fluorene were determined. • Standard molar ΔH, ΔS and ΔG of sublimation and vapourisation were derived. • Standard molar ΔH, ΔS and ΔG of formation in crystal and gas phases were calculated. • Gas phase ΔH of formation was also estimated by quantum chemical calculations. - Abstract: This report presents a comprehensive experimental and computational study of the thermodynamic properties of two bromine fluorene derivatives: 2-bromofluorene and 2,7-dibromofluorene. The standard (p° = 0.1 MPa) molar enthalpies of formation in the crystalline phase of these compounds were derived from the standard molar energies of combustion, in oxygen, at T = 298.15 K, measured by rotating bomb combustion calorimetry. The vapour pressures of the crystalline phase of the two compounds were measured using the Knudsen effusion method and a static method that has also been used to measure the liquid vapour pressures of 2-bromofluorene. From these results the standard molar enthalpies, entropies and Gibbs energies of sublimation of the two compounds studied and of vapourisation of 2-bromofluorene were derived. The enthalpies and temperatures of fusion were determined from DSC experiments. Derived results of standard enthalpies and Gibbs energies of formation, in both gaseous and crystalline phases, were compared with the ones reported in the literature for fluorene. The experimental values of the gas-phase enthalpies of formation of each compound were compared with estimates based on density functional theory calculations using the B3LYP hybrid exchange–correlation energy functional with the 6-311++G(d,p) basis set

  20. With bromine against mercury. Reduction of emission of mercury from combustion gases by 90 % minimally; Mit Brom gegen Quecksilber. Hg-Emissionen aus Verbrennungsabgasen um mindestens 90 % senken

    Energy Technology Data Exchange (ETDEWEB)

    Kanefke, Rico [Currenta GmbH und Co. OHG, Leverkusen (Germany)

    2009-01-15

    Emission of mercury is a global problem. If mercury once arrived into the environment, it remains there for a long period of time and increasingly becomes a strain for humans. In particular, the combustion of coal releases mercury. Under this aspect, the author of the contribution under consideration reports on a new procedure to an almost complete separation of mercury from exhaust gases. The complete oxidation of mercury in the flue gas is the basis to the improved separation of mercury. During bromination of mercury in the cooling down flue gas of boilers, mercury bromide is developed. Bromine is given as a bromine compound such as calcium bromide to the fuel such as coal. At temperatures greater than 1,000 Celsius, at first hydrogen bromide is developed which is converted to bromine by means of the bromine-Deacon-process during cooling. At temperatures below 100 Celsius, the formed bromine reacts with sulphur dioxide so that bromine is available in the entire reaction vessel for the oxidation of mercury. With comparable amount of SO{sub 2}, the oxidation of mercury with bromine is at least 25 times more efficient than the oxidation with chlorine. After this, mercury bromide is separated in the wet scrubber and precipitated during the treatment of rinsing water. Then the resulting mercury sulphide is separated as a filter cake from the water and spent on the dump. Thus, mercury is withdrawn from the atmospheric mercury cycle.

  1. Assessment of PCDD/F and PBDD/F Emissions from Coal-fired Power Plants during Injection of Brominated Activated Carbon for Mercury Control

    Science.gov (United States)

    The effect of the injection of brominated powdered activated carbon (Br-PAC) on the emission of brominated and chlorinated dioxins and furans in coal combustion flue gas has been evaluated. The tests were performed at two U.S. Department of Energy (DOE) demonstration sites where ...

  2. Reaction modelling of Iron Oxide Bromination in the UT-3 thermochemical cycle for Hydrogen production from water

    International Nuclear Information System (INIS)

    Analysis modelling of the iron oxide bromination had been carried out using experiment data from the iron oxide bromination in the UT-3 thermochemical cycle. Iron oxide in the form of pellets were made of the calcination of the mixture of iron oxide, silica, graphite and cellulose at 1473 K. Thermobalance reactor was used to study the kinetic reactions of the iron oxide bromination at a temperature of 473 K for 2 - 6 hours. The data collected from the experiments were used as input for the common models. However, none of these models could not explain the result of the experiments. A new model, a combination of two kinetic reactions : exposed particle and coated particle was created and worked successfully

  3. Origin of bromine in ancient sutras of the Otani collection. PIXE application to preservation of cultural assets

    International Nuclear Information System (INIS)

    Some small fragments of rag paper - made more than a thousand and a few hundred years ago, and excavated at Turfan, west of China by the Otani-expedition dispatched there during the late Meiji and the Taisho eras - were measured by PIXE. Bromine was highly detected in all of these ancient fragments and modern paper samples that had been placed together with these Turfan manuscripts. In other paper samples, bromine could not be detected (H+, 4 MeV, 50 μC and H+, 2 MeV, 100 μC) and their average concentration was about 1.1 ppm (S.D. = 1.11 ppm, N = 15, 0.3 - 3.4 ppm). The bromine contamination of ancient sutras is mainly caused by larvicide of methyl bromide, and the observation suggests that the ancient manuscripts might be spoiled gradually by agricultural chemicals for protecting them from vermin. (author)

  4. Enriched concentrations of bromine, chlorine, and iodine in urban rainfall as determined by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Concentrations of bromine, chlorine and iodine were determined in bulk rain as part of a detailed urban monitoring program. Instrumental neutron activation gives simultaneous non-destructive analysis of these halogens with detection limits of 2, 30 and 1 ng/g for bromine, chlorine, and iodine, respectively. Results for enrichment factor calculations based on crustal, seawater and lake water reference elements were somewhat contradictory. Elemental ratios of Br/Cl, I/Cl, Br/Pb, and Cl/Pb, together with an analysis of chlorine in urban surface materials, support the suggestions that local anthropogenic sources may cause the high bromine and chlorine concentrations observed in urban precipitation while fractionation from an oceanic source is likely responsible for high iodine concentrations. (author)

  5. Tris(1,2-dimethoxyethane-κ2O,O′iodidocalcium iodide

    Directory of Open Access Journals (Sweden)

    Siou-Wei Ou

    2012-02-01

    Full Text Available In the title complex, [CaI(C4H10O23]I, the CaII atom is seven-coordinated by six O atoms from three 1,2-dimethoxyethane (DME ligands and one iodide anion in a distorted pentagonal–bipyramidal geometry. The I atom and one of the O atoms from a DME ligand lie in the axial positions while the other O atoms lie in the basal plane. The other iodide anion is outside the complex cation.

  6. Thyroid hormones and iodide in the near-term pregnant rat.

    OpenAIRE

    Versloot, P.M.

    1998-01-01

    Thyroid hormones, thyroxine (T4) and 3,5,3'-triiodothyronine (T3), are produced by the thyroid gland. To synthesize thyroid hormones the thyroid needs iodide. The uptake of iodide as well as the production and secretion of T4 and T3 by the thyroid gland is regulated by thyrotropin (TSH), which is produced by the pituitary. However, most of the biologically active form, T3, is produced from T4 via monodeiodination in peripheral tissues.This reaction is catalyzed by the deiodinases, type I (ID-...

  7. Iodide uptake in human anaplastic thyroid carcinoma cells after transfer of the human thyroid peroxidase gene

    International Nuclear Information System (INIS)

    Human thyroperoxidase (hTPO) is critical for the accumulation of iodide in thyroid tissues. Poorly differentiated and anaplastic thyroid tumours which lack thyroid-specific gene expression fail to accumulate iodide and, therefore, do not respond to iodine-131 therapy. We consequently investigated whether transfer of the hTPO gene is sufficient to restore the iodide-trapping capacity in undifferentiated thyroid and non-thyroid tumour cells. The human anaplastic thyroid carcinoma cell lines C643 and SW1736, the rat Morris hepatoma cell line MH3924A and the rat papillary thyroid carcinoma cell line L2 were used as in vitro model systems. Employing a bicistronic retroviral vector based on the myeloproliferative sarcoma virus for the transfer of the hTPO and the neomycin resistance gene, the C643 cells and SW1736 cells were transfected while the L2 cells and MH3924A cells were infected with retroviral particles. Seven recombinant C643 and seven SW1736 cell lines as well as four recombinant L2 and four MH3924A cell lines were established by neomycin selection. They were studied for hTPO expression using an antibody-based luminescence kit, followed by determination of the enzyme activity in the guaiacol assay and of the iodide uptake capacity in the presence of Na125I. Genetically modified cell lines expressed up to 1,800 times more hTPO as compared to wild type tumour cells. The level of hTPO expression varied significantly between individual neomycin-resistant cell lines, suggesting that the recombinant retroviral DNA was integrated at different sites of the cellular genome. The accumulation of iodide, however, was not significantly enhanced in individual recombinant cell lines, irrespective of low or high hTPO expression. Moreover, there was no correlation between hTPO expression and enzyme activity in individual cell lines. The transduction of the hTPO gene per se is not sufficient to restore iodide trapping in non-iodide-concentrating tumour cells. Future studies

  8. Study of semitransparent palladium contacts on mercuric iodide by photoluminescence spectroscopy and thermally stimulated current measurements

    Science.gov (United States)

    Bao, X. J.; Schlesinger, T. E.; James, R. B.; Gentry, G. L.; Cheng, A. Y.; Ortale, C.

    1991-04-01

    Semitransparent palladium contacts on mercuric iodide were studied by low temperature photoluminescence spectroscopy and thermally stimulated conductivity. These contacts were deposited either by thermal evaporation or by plasma sputtering. Changes due to palladium deposition were found in the photoluminescence spectra and were attributed to modifications in the stoichiometry within the palladium/mercuric iodide interfacial region. Thermally stimulated conductivity measurements revealed two dominant traps with activation energies of 0.010 and 0.54 eV. The importance of these traps in the application of nuclear detection is discussed.

  9. Study of semitransparent palladium contacts on mercuric iodide by photoluminescence spectroscopy and thermally stimulated current measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bao, X.J.; Schlesinger, T.E. (Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (US)); James, R.B.; Gentry, G.L. (Advanced Materials Research Division, Sandia National Laboratories, Livermore, California 94550 (US)); Cheng, A.Y.; Ortale, C. (EG G Energy Measurements, Inc., Goleta, California 93116 (US))

    1991-04-15

    Semitransparent palladium contacts on mercuric iodide were studied by low temperature photoluminescence spectroscopy and thermally stimulated conductivity. These contacts were deposited either by thermal evaporation or by plasma sputtering. Changes due to palladium deposition were found in the photoluminescence spectra and were attributed to modifications in the stoichiometry within the palladium/mercuric iodide interfacial region. Thermally stimulated conductivity measurements revealed two dominant traps with activation energies of 0.010 and 0.54 eV. The importance of these traps in the application of nuclear detection is discussed.

  10. Photoemission and optical constant measurements of a Cesium Iodide thin film photocathode

    International Nuclear Information System (INIS)

    The performance of cesium iodide as a reflective photocathode is presented. The absolute quantum efficiency of a 500 nm thick film of cesium iodide has been measured in the wavelength range 150 nm–200 nm. The optical absorbance has been analyzed in the wavelength range 190 nm–900 nm and the optical band gap energy has been calculated. The dispersion properties were determined from the refractive index using an envelope plot of the transmittance data. The morphological and elemental film composition have been investigated by atomic force microscopy and X-ray photo-electron spectroscopy techniques

  11. Hydrogen atom position in hydrated iodide anion from x-ray absorption near edge structure

    International Nuclear Information System (INIS)

    Hydrogen atom position in the hydrated iodide anion complex is determined from X-ray Absorption Near Edge Structure (XANES) of an aqueous iodide solution at both the K- and L-edges. The spectra are compared with the theoretical ones calculated by using the FEFF method for several model geometries having hydrogen atoms at different positions. Satisfactory agreements are obtained from models with an almost linear alignment of iodine-hydrogen-oxygen atoms, indicating the capability of the XANES analysis when it is combined with the multiple scattering calculations as a method to detect the positions of hydrogen atoms in the first coordination sphere. (author)

  12. Quick analytical method for the determination of iodide and iodate ions in aqueous solutions

    International Nuclear Information System (INIS)

    An analytical quick-test method was developed to determine iodide and iodate ions in aqueous solutions using solid phase extraction cartridges for sample preparation. Work was focussed on finding simple, but efficient conditions for quantitative separation of iodate and iodide. Iodine amounts were then determined by standard methods. Ion-exchange absorbers in cartridge form were used. Selectivity and yield of the species separation were studied at pH value of 5-10 and various solution compositions using 131I radioactive tracer. The electrolytes used were diluted alkaline, nitrate and boric acid-borate solutions. Application to nuclear reactor cooling water analysis or environmental investigations and monitoring is proposed. (author)

  13. Nitrosyl iodide, INO: A combined ab initio and high-resolution spectroscopic study

    Science.gov (United States)

    Bailleux, S.; Duflot, D.; Aiba, S.; Nakahama, S.; Ozeki, H.

    2016-04-01

    In the nitrosyl halides series (XNO, where X = F, Cl, Br, I), INO is the only chemical species whose rotational spectrum has not been reported. Nitrosyl iodide, together with the nitryl (INO2), nitrite (IONO) and nitrate (IONO2) iodides, is believed to impact tropospheric ozone levels. Guided by our quantum chemical calculations, we report the detection of INO in the gas phase by high-resolution spectroscopy for the first time. INO was generated by mixing continuously I2 and NO. The measurement and least-squares analysis of 173 a-type rotational transitions resulted in the accurate determination of molecular parameters.

  14. Studying the iodine leaching from the compositions based on epoxide resin and lead iodide

    International Nuclear Information System (INIS)

    When studying iodine leaching, the possibility to use solid compositions, produced by incorporation of dry powdered lead iodide and its aqueous suspension into epoxide resin for long-term immobilization of iodine-129 under conditions of monitored storage, is evaluated. Analysis of the results obtained has shown that leaching rate in the first 4 days has the maximum value and constitutes (4.2 - 2700.0) x 10-6 cm/day. Then the process of leaching is determined by diffusion mechanism. For samples, prepared by wet lead iodide incorporation the rate of leaching is higher than that of the corresponding samples prepared by dry compound incorporation

  15. Magnetically enhanced triode etching of large area silicon membranes in a molecular bromine plasma

    International Nuclear Information System (INIS)

    The optimization of a process for etching 125 mm silicon membranes formed on 150 mm wafers and bonded to Pyrex rings is discussed. A magnetically enhanced triode etching system was designed to provide an intense, remote plasma surrounding the membrane while, at the same time, suppressing the discharge over the membrane itself. For the optimized molecular bromine process, the silicon etch rate is 40 nm/min and the selectivity relative to SiO2 is 160:1. 14 refs., 6 figs

  16. Neutron Activation Analysis of Vanadium, Copper, Zinc, Bromine and Iodine in Pyura Microcosmus

    International Nuclear Information System (INIS)

    Most of the tunicates seem to accumulate vanadium more energetically than other marine organisms. However, there is a very great variation within the group. Maximum amounts of vanadium were found in the Ascididae family whereas in some species of the Pyuridae family vanadium was apparently absent. This paper describes the simple and rapid determination by activation analysis of vanadium, copper, zinc, bromine and iodine in Pyura microcosmus, a species of the Pyuridae family. The same elements were also investigated in the environmental sea-water. Samples of P. microcosmus and sea-water were collected from a point about 15 m below the surface in the Saronic Gulf near Athens. All irradiations of samples and standards were carried out with the DEMOCRITUS Reactor of the Nuclear Research Centre of Greece, at a neutron flux of 2 x 1011 n/cm2s. The time of irradiation with the pneumatic transfer system ranged from 1 to 25 min, depending on the element being determined. After irradiation and addition of inactive carriers, the radioisotopes of interest were isolated by fast radiochemical procedures based on solvent extraction techniques. Vanadium and copper were extracted as cupferrates into chloroform, and zinc was extracted with 8% methyldioctylamine into trichloroethylene. Bromine and iodine were distilled first and then separated from each other by selective redox and extraction procedures. The photopeak areas of 52V, 64Cu, 69mZn, 82Br and 128I were measured by means of a multichannel analyser and compared with those of standards of the above radionuclides processed in the same manner. After irradiation the time to complete the analysis ranged from 5 to 35 min depending on the element being determined. The quantities of the elements determined in P. microcosmus, expressed in micrograms per gram of dry matter, were: vanadium 1.0, copper 7.5, iodine 14.1, bromine 406 and zinc 702. The per cent concentration of the same elements found in the sea-water was as follows

  17. SYNTHESIS AND GREEN BROMINATION OF SOME CHALCONES AND THEIR ANTIMICROBIAL SCREENING

    Directory of Open Access Journals (Sweden)

    Mayur R. Adokar

    2013-04-01

    Full Text Available Chalcones are the versatile molecules having the structural flexibility which permits structural transformations into flavonoids, flavanones, pyrazoles, oxazoles, pyrimidines etc. Changes in their structure have offered the development of new medicinal agents having improved pharmacological potency. Their derivatives have attracts increasing attention due to numerous pharmacological potential. In the present communication we report the synthesis of chalcones from various acetophenone derivatives with different aromatic aldehydes and green chemistry approach to their bromination with the help of Tetrabutylammonium Tribromide (TBATB. All the synthesized chalcone dibromides were screened for their antimicrobial activity against Aspergillus flavus, Rhizopus sp., Fusarium solani and Aspergillus niger.

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

    Science.gov (United States)

    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…

  19. Synthesis of a Stable Primary-Alkyl-Substituted Selenenyl Iodide and Its Hydrolytic Conversion to the Corresponding Selenenic Acid.

    Science.gov (United States)

    Sase, Shohei; Kakimoto, Ryo; Kimura, Ryutaro; Goto, Kei

    2015-01-01

    A primary-alkyl-substituted selenenyl iodide was successfully synthesized through oxidative iodination of a selenol with N-iodosuccinimide by taking advantage of a cavity-shaped steric protection group. The selenenyl iodide exhibited high thermal stability and remained unchanged upon heating at 100 °C for 3 h in [D₈]toluene. The selenenyl iodide was reduced to the corresponding selenol by treatment with dithiothreitol. Hydrolysis of the selenenyl iodide under alkaline conditions afforded the corresponding selenenic acid almost quantitatively, corroborating the chemical validity of the recent proposal that hydrolysis of a selenenyl iodide to a selenenic acid is potentially involved in the catalytic mechanism of an iodothyronine deiodinase. PMID:26633336

  20. Synthesis of a Stable Primary-Alkyl-Substituted Selenenyl Iodide and Its Hydrolytic Conversion to the Corresponding Selenenic Acid

    Directory of Open Access Journals (Sweden)

    Shohei Sase

    2015-12-01

    Full Text Available A primary-alkyl-substituted selenenyl iodide was successfully synthesized through oxidative iodination of a selenol with N-iodosuccinimide by taking advantage of a cavity-shaped steric protection group. The selenenyl iodide exhibited high thermal stability and remained unchanged upon heating at 100 °C for 3 h in [D8]toluene. The selenenyl iodide was reduced to the corresponding selenol by treatment with dithiothreitol. Hydrolysis of the selenenyl iodide under alkaline conditions afforded the corresponding selenenic acid almost quantitatively, corroborating the chemical validity of the recent proposal that hydrolysis of a selenenyl iodide to a selenenic acid is potentially involved in the catalytic mechanism of an iodothyronine deiodinase.

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

    Science.gov (United States)

    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. PMID:19184627

  2. The sodium iodide symporter: its implications for imaging and therapy; Der Natrium-Iodid-Symporter (NIS): Bedeutung fuer die Bildgebung und therapeutische Optionen

    Energy Technology Data Exchange (ETDEWEB)

    Spitzweg, C. [Medizinische Klinik und Poliklinik fuer Nuklearmedizin der Ludwig-Maximilians-Univ. Muenchen, Klinikum Grosshadern, Muenchen (Germany)

    2007-03-15

    The sodium iodide symporter (NIS) is an intrinsic plasma membrane glycoprotein that mediates the active transport of iodide in the thyroid gland and a number of extrathyroidal tissues, in particular lactating mammary gland. In addition to its key function in thyroid physiology, NIS-mediated iodide accumulation allows diagnostic thyroid scintigraphy as well as therapeutic radioiodine application in benign and malignant thyroid disease. NIS therefore represents one of the oldest targets for molecular imaging and therapy. Based on the effective administration of radioiodine that has been used for over 60 years in the management of follicular cell-derived thyroid cancer, cloning and characterization of the NIS gene has paved the way for the development of a novel cytoreductive gene therapy strategy based on targeted NIS expression in thyroidal and nonthyroidal cancer cells followed by therapeutic application of {sup 131}I or alternative radionuclides, including {sup 188}Re and {sup 211}At. In addition, the possibility of direct and non-invasive imaging of functional NIS expression by {sup 123}I- and {sup 99m}Tc-scintigraphy or {sup 124}I-PET-imaging allows the application of NIS as a novel reporter gene. In conclusion, the dual role of NIS as diagnostic and therapeutic gene and the detection of extra-thyroidal endogenous NIS expression in breast cancer open promising perspectives in nuclear medicine and molecular oncology for diagnostic and therapeutic application of NIS outside the thyroid gland. (orig.)

  3. Levels of persistent fluorinated, chlorinated and brominated compounds in human blood collected in Sweden in 1997-2000

    Energy Technology Data Exchange (ETDEWEB)

    Lindstroem, G.; Kaerrman, A.; Bavel, B. van [MTM Research Centre, Oerebro Univ. (Sweden); Hardell, L. [Dept. of Oncology, Univ. Hospital, Oerebro (Sweden); Hedlund, B. [Environmental Monitoring Section, Swedish EPA, Stockholm (Sweden)

    2004-09-15

    Levels of persistent fluorinated, chlorinated and brominated compounds in blood collected from the Swedish population have been determined in connection with several exposure and monitoring studies at the MTM Research Centre. A data base with 631 individual congener specific measurements on halogenated POPs such as dioxins, PCBs, HCB, DDE, chlordanes, PBDEs and PFAs including information on residency, age, BMI, diet, occupation, number of children, smoking habits, immunological status etc. has been compiled from samples collected between 1994 and 2004. A brief overview focusing on levels of some persistent chlorinated, brominated and fluorinated, compounds in blood collected in a background population group (n=83) in 1997-2000 is given here.

  4. Price Wars and the Stability of Collusion: A Study of the Pre-World War I Bromine Industry

    OpenAIRE

    Margaret Levenstein

    1993-01-01

    Bromine producers colluded to raise prices and profits during most of the period between 1885 and 1914. Collusion was punctuated by price wars in which prices fell sharply. The characteristics of these price wars are compared with those in the Green-Porter and Abreu- Pearce-Stachetti models. Some of the bromine price wars resulted from the imperfect monitoring problems in these models. Those price wars were short and mild. More severe price wars were part of a bargaining process, in which fir...

  5. Synchrotron X-ray fluorescence studies of a bromine-labelled cyclic RGD peptide interacting with individual tumor cells

    International Nuclear Information System (INIS)

    The first example of synchrotron X-ray fluorescence imaging of cultured mammalian cells in cyclic peptide research is reported. The study reports the first quantitative analysis of the incorporation of a bromine-labelled cyclic RGD peptide and its effects on the biodistribution of endogenous elements (for example, K and Cl) within individual tumor cells. The first example of synchrotron X-ray fluorescence imaging of cultured mammalian cells in cyclic peptide research is reported. The study reports the first quantitative analysis of the incorporation of a bromine-labelled cyclic RGD peptide and its effects on the biodistribution of endogenous elements (for example, K and Cl) within individual tumor cells

  6. Occurrence and risk assessment of organophosphorus and brominated flame retardants in the River Aire (UK)

    International Nuclear Information System (INIS)

    This study presents the occurrence and risk of PBDEs, new brominated and organophosphorus flame retardants along a river affected by urban and industrial pressures (River Aire, UK). Tris(2-choroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris[2-chloro-1-(chloromethyl)ethyl] phosphate (TDCP) and triphenyl phosphate (TPhP) were detected in all samples, with TCPP present at the highest concentrations, ranging from 113 to 26 050 ng L-1. BDE-209 was detected in most of the sampled sites, ranging from 17 to 295 ng L−1, while hexabromobenzene (HBB) and pentabromoethyl benzene (PBEB) were seldom detected. A risk quotients based on predicted no effect concentrations (PNEC) and flame retardants water concentration proved significant risk for adverse effects for algae, Daphnia and fish in sites close to industrial and urban sewage discharges. This study provides a protocol for the risk estimation of priority and new generation flame retardants based on river concentrations and toxicological values. -- Highlights: •Brominated and organophosphorus flame retardants were monitored in River Aire (UK). •BDE-209 and organophosphorus flame retardants were detected at high concentrations. •A risk assessment was performed based on water concentration and acute toxicity data. •Low to significant risk for adverse effects was observed for algae, fish and Daphnia. -- Organophosphorus flame retardants and BDE-209 were detected at high concentrations along River Aire (UK) and a risk assessment indicated significant risk for adverse effects to aquatic organisms

  7. Iodine-123 and bromine-75 production and development program at Juelich

    International Nuclear Information System (INIS)

    The iodine-123 and bromine-75 production and development program at the Nuclear Research Center in Juelich as of 1982 is described, and examples of recent 123I- and 75Br-analogue tracers that have been developed to the level of clinical trial are given. Iodine-123 is produced via the 127I(d,6n)123Xe → 123I process and by the 124Te(p,2n)123I and 122Te(d,n)123I reactions. These production methods are critically reviewed. Bromine-75-labeled benzodiazenes have been prepared for in vivo mapping of benzodiazepine receptor sites. The 7-(75Br)-5-(2-fluorophenyl)-1-methyl-1,3-dihydro-2H-1,4-benzodiazepine-2-one (BFB) was prepared with a specific activity of > 104 Ci/mmole. Finally, preparation and applications of the halogenated amino acid L-3-(123I)-iodo-α-methyltyrosine (IMT) and the analogous 75Br compound (BMT) are reported. Both IMT and BMT have been successfully applied for pancreas imaging and tomography, and IMT has been used for imaging both melanotic and amelanotic malignant melanoma of the eye

  8. Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

    2004-09-15

    Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

  9. Levelized cost of energy and sensitivity analysis for the hydrogen-bromine flow battery

    Science.gov (United States)

    Singh, Nirala; McFarland, Eric W.

    2015-08-01

    The technoeconomics of the hydrogen-bromine flow battery are investigated. Using existing performance data the operating conditions were optimized to minimize the levelized cost of electricity using individual component costs for the flow battery stack and other system units. Several different configurations were evaluated including use of a bromine complexing agent to reduce membrane requirements. Sensitivity analysis of cost is used to identify the system elements most strongly influencing the economics. The stack lifetime and round-trip efficiency of the cell are identified as major factors on the levelized cost of electricity, along with capital components related to hydrogen storage, the bipolar plate, and the membrane. Assuming that an electrocatalyst and membrane with a lifetime of 2000 cycles can be identified, the lowest cost market entry system capital is 220 kWh-1 for a 4 h discharge system and for a charging energy cost of 0.04 kWh-1 the levelized cost of the electricity delivered is 0.40 kWh-1. With systems manufactured at large scales these costs are expected to be lower.

  10. Dissolution of brominated epoxy resins by dimethyl sulfoxide to separate waste printed circuit boards.

    Science.gov (United States)

    Zhu, Ping; Chen, Yan; Wang, Liangyou; Qian, Guangren; Zhang, Wei Jie; Zhou, Ming; Zhou, Jin

    2013-03-19

    Improved methods are required for the recycling of waste printed circuit boards (WPCBs). In this study, WPCBs (1-1.5 cm(2)) were separated into their components using dimethyl sulfoxide (DMSO) at 60 °C for 45 min and a metallographic microscope was used to verify their delamination. An increased incubation time of 210 min yielded a complete separation of WPCBs into their components, and copper foils and glass fibers were obtained. The separation time decreased with increasing temperature. When the WPCB size was increased to 2-3 cm(2), the temperature required for complete separation increased to 90 °C. When the temperature was increased to 135 °C, liquid photo solder resists could be removed from the copper foil surfaces. The DMSO was regenerated by rotary decompression evaporation, and residues were obtained. Fourier transform infrared spectroscopy (FT-IR), thermal analysis, nuclear magnetic resonance, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to verify that these residues were brominated epoxy resins. From FT-IR analysis after the dissolution of brominated epoxy resins in DMSO it was deduced that hydrogen bonding may play an important role in the dissolution mechanism. This novel technology offers a method for separating valuable materials and preventing environmental pollution from WPCBs. PMID:23398278

  11. Stable bromine isotopic composition of methyl bromide released from plant matter

    Science.gov (United States)

    Horst, Axel; Holmstrand, Henry; Andersson, Per; Thornton, Brett F.; Wishkerman, Asher; Keppler, Frank; Gustafsson, Örjan

    2014-01-01

    Methyl bromide (CH3Br) emitted from plants constitutes a natural source of bromine to the atmosphere, and is a component in the currently unbalanced global CH3Br budget. In the stratosphere, CH3Br contributes to ozone loss processes. Studies of stable isotope composition may reduce uncertainties in the atmospheric CH3Br budget, but require well-constrained isotope fingerprints of the source end members. Here we report the first measurements of stable bromine isotopes (δ81Br) in CH3Br from abiotic plant emissions. Incubations of both KBr-fortified pectin, a ubiquitous cell-stabilizing macromolecule, and of a natural halophyte (Salicornia fruticosa), yielded an enrichment factor (ε) of -2.00 ± 0.23‰ (1σ, n = 8) for pectin and -1.82 ± 0.02‰ (1σ, n = 4) for Salicornia (the relative amount of the heavier 81Br was decreased in CH3Br compared to the substrate salt). For short incubations, and up to 10% consumption of the salt substrate, this isotope effect was similar for temperatures from 30 up to 300 °C. For longer incubations of up to 90 h at 180 °C the δ81Br values increased from -2‰ to 0‰ for pectin and to -1‰ for Salicornia. These δ81Br source signatures of CH3Br formation from plant matter combine with similar data for carbon isotopes to facilitate multidimensional isotope diagnostics of the CH3Br budget.

  12. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  13. Ultrafast optical limiting properties and transient dynamics of symmetrical phenoxazinium bromine salt

    Science.gov (United States)

    Xiao, Zhengguo; Ge, Jianfeng; Li, Zhongguo; Wu, Xingzhi; Fang, Yu; Shi, Guang; Zhang, Xueru; Wang, Yuxiao; Song, Yinglin

    2015-12-01

    A symmetrical phenoxazinium bromine salt with resonant D-π-D structure was prepared and spectroscopically characterized. The ultrafast nonlinear optical (NLO) response of the compound dissolved in DMF was investigated using open aperture Z-scan method with 190 fs laser pulses at 515 nm. And the photo-physical dynamics of the compound was studied using transient absorption spectra at femtosecond time regime. The titled sample showed strong reverse saturable absorption (RSA) at 515 nm. Transient absorption results demonstrated that the compound exhibited RSA signals at 478-580 nm and SA signals at 600-780 nm. A simplified three-energy-level model was used to determine the photo-physical parameters. And the excited-state lifetime was evaluated to be around one nanosecond. Our results show that the phenoxazinium bromine salt has a large ratio of singlet excited-state absorption cross-section to that of ground state cross-section (18.7), indicating it is a candidate material for future ultrafast optical limiters.

  14. Natural solar photolysis of total organic chlorine, bromine and iodine in water.

    Science.gov (United States)

    Abusallout, Ibrahim; Hua, Guanghui

    2016-04-01

    Municipal wastewater has been increasingly used to augment drinking water supplies due to the growing water scarcity. Wastewater-derived disinfection byproducts (DBPs) may negatively affect the aquatic ecosystems and human health of downstream communities during water reuse. The objective of this research was to determine the degradation kinetics of total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI) in water by natural sunlight irradiation. Outdoor solar photolysis experiments were performed to investigate photolytic degradation of the total organic halogen (TOX) formed by fulvic acid and real water and wastewater samples. The results showed that TOX degradation by sunlight irradiation followed the first-order kinetics with half-lives in the range of 2.6-10.7 h for different TOX compounds produced by fulvic acid. The TOX degradation rates were generally in the order of TOI > TOBr ≅ TOCl(NH2Cl) > TOCl(Cl2). High molecular weight TOX was more susceptible to solar photolysis than corresponding low molecular weight halogenated compounds. The nitrate and sulfite induced indirect TOX photolysis rates were less than 50% of the direct photolysis rates under the conditions of this study. Fulvic acid and turbidity in water reduced TOX photodegradation. These results contribute to a better understanding of the fate of chlorinated, brominated and iodinated DBPs in surface waters. PMID:26841230

  15. Novel Spectrophotometric Method for Determination of Macro-paracetamol via Reaction with Bromine

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The reaction between Br2 and paracetamol(p-AAP) leads to the formation of a coloured product, which can be used for spectrophotometric determination of the p-AAP content in its pure form and in different pharmaceutical preparations with p-AAP. The stoichiometric composition of the reaction was found to be n(p-AAP)∶n(bromine)=1∶3. The effects of pH and time on the spectra of p-AAP-bromine redox reaction product were studied. The interference of different additives on the measured spectra of the obtained product was also studied. The results obtained by the present method were compared with those obtained by the standard method. The F- and t- test values were calculated for both of the applied procedures and they met a confidence level of 99%. The proposed procedure actually needs no separation of these drugs from their sources before analysis and was unaffected by interference of other phenolic compounds. The proposed method is simpler and faster than the repoeted ones.

  16. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    International Nuclear Information System (INIS)

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjornoya (Bear Island). Elevated levels of chlorobornanes (CHBs) (up to 46.7 ng/g wet weight=ww), polybrominated diphenyl ethers (PBDEs) (up to 27.2 ng/g ww), polybrominated biphenyls (PBBs) (up to 1.1 ng/g ww) and polychlorinated naphthalenes (PCNs, only 4 congeners) (up to 62.7 pg/g ww), were measured in biota from Lake Ellasjoen. In Lake Oyangen, located only 5 km north of Ellasjoen, levels of these contaminants were significantly lower. δ15N-values were 7-10%o higher in organisms from Ellasjoen as compared to Oyangen. This is attributed to biological inputs related to seabird activities. The present study illustrates that contaminants such as CHBs, brominated flame retardants and PCNs accumulate in the Ellasjoen food web in a manner similar to PCBs and conventional organochlorine pesticides. Transport mechanisms that control PCB and DDT distributions, i.e. atmospheric long-range transport and biotransport by seabirds, are also relevant for the contaminants investigated in the present study. - Elevate levels of chlorobornanes, polychlorinated naphthalenes and brominated flame retardants have been measured in biota from a Norwegian Arctic lake

  17. Development of Zinc/Bromine Batteries for Load-Leveling Applications: Phase 2 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    CLARK,NANCY H.; EIDLER,PHILLIP

    1999-10-01

    This report documents Phase 2 of a project to design, develop, and test a zinc/bromine battery technology for use in utility energy storage applications. The project was co-funded by the U.S. Department of Energy Office of Power Technologies through Sandia National Laboratories. The viability of the zinc/bromine technology was demonstrated in Phase 1. In Phase 2, the technology developed during Phase 1 was scaled up to a size appropriate for the application. Batteries were increased in size from 8-cell, 1170-cm{sup 2} cell stacks (Phase 1) to 8- and then 60-cell, 2500-cm{sup 2} cell stacks in this phase. The 2500-cm{sup 2} series battery stacks were developed as the building block for large utility battery systems. Core technology research on electrolyte and separator materials and on manufacturing techniques, which began in Phase 1, continued to be investigated during Phase 2. Finally, the end product of this project was a 100-kWh prototype battery system to be installed and tested at an electric utility.

  18. Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

    Science.gov (United States)

    Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.; VanRoozendael, M.

    2012-01-01

    We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  19. Small mammal populations in Maryland meadows during four years of herbicide (Brominal? ) applications

    Science.gov (United States)

    Clark, D.R., Jr.; Moulton, C.A.; Hines, J.E.; Hoffman, D.J.

    1996-01-01

    The herbicide Brominal? was applied at the recommended rate to one plot in each of three paired 0.6-ha plots; the other three plots were used as controls. Plots were sprayed once in the fall of 1988 and 1989 and twice in the spring of 1990 and 1991. Small mammals were trapped three times during each activity season (April?October) to obtain population estimates before and after spraying and in the spring preceding fall spraying or the fall following spring spraying. Population estimates immediately after spraying gave no evidence of direct mortality. By 1991, dicot vegetation on treated plots was suppressed and mean numbers of meadow voles (Microtus pennsylvanicus) were less than on control plots. Because meadow voles favor dicots over monocots in their diet, reduced availability of dicots may have been related to the smaller vole population estimates. Species diversity of small mammals was negatively correlated with size of vole populations, but was not different between treated and control plots. Brominal apparently induced opaque corneas in nine voles. The condition was found in two voles too small to have been conceived at the time of the last previous spray nearly 8 months earlier, suggesting exposure to residue alone.

  20. Relaxation of the Silver/Silver Iodide Electrode in Aqueous Solution

    NARCIS (Netherlands)

    Peverelli, K.J.

    1979-01-01

    The aim of this study is to detect and characterize relaxation processes on silver/silver iodide electrodes in aqueous electrolyte solution. The information obtained is to be used for an estimation of the consequences of similar processes on colloidal AgI particles during encounter.In chapter 1 a ge

  1. Effect of hot-pressing conditions on the properties of iodide sodalite

    International Nuclear Information System (INIS)

    Higher hot-pressing temperatures and pressures increase density and reduce porosity and leachability of the iodide sodalite products. The effect of temperature is more significant than pressure with a significantly superior waste form being produced at 10600C compared to 8200C. Products prepared at 10600C and 5000 to 7000 psi pressure have apparent densities of 2.60 g/cm3 (99.5% of theoretical), porosities -6 g/cm2/d. Iodine concentration in the products is 15 to 20 wt %. These tests further substantiate the viability of using hot-pressed iodide sodalites as long-term waste forms for isolating long-lived 129I from the environment. The products produced at high temperatures are extremely hard, mechanically stable, capable of incorporating large amounts of iodine in a small volume, and have excellent leaching characteristics. In this study, sodalite formed at high temperatures containing 20 wt % iodine, had cumulative fraction leach values of approx. 2.6 x 10-6 cm for 96 h, and incremental leach rates of approx. 3.2 x 10-7 cm/d. Even though initial results look promising, work should continue in the following areas: (1) long-term leaching of products; (2) determine optimum conditions and effect of process variables on hydrothermal reaction; (3) characterize structural, crystal, and mechanical properties of iodide sodalite product; and (4) develop better methods of measuring iodide losses during the process

  2. Solution enthalpy of potassium iodide in furfural and its mixtures with dimethylsulfoxide

    International Nuclear Information System (INIS)

    Solution enthalpy of potassium iodide in furfural-dimethylsulfoxide mixtures at 298.15 K and furfural concentration 17.3-100% are determined experimentally. K+ and I- ion solvate shell composition, which in the general case doesn't correspond to the mixed solvent composition, is calculated

  3. The sodium iodide symporter (NIS) and potential regulators in normal, benign and malignant human breast tissue.

    LENUS (Irish Health Repository)

    Ryan, James

    2011-01-01

    The presence, relevance and regulation of the Sodium Iodide Symporter (NIS) in human mammary tissue remains poorly understood. This study aimed to quantify relative expression of NIS and putative regulators in human breast tissue, with relationships observed further investigated in vitro.

  4. Investigations related to the chemical behaviour of methyl iodide at severe PWR-accidents

    International Nuclear Information System (INIS)

    The decomposition velocity of methyl iodide in aqueous solutions of boric acid has been measured at temperatures up to 423 K and at chemical conditions which are expected to exist in the sumpwater pool during a severe reactor accident. The decomposition was due only to hydrolysis which increased by the expected amount at high temperature. No influence of the cooling water additives was observed. Treatment of the available kinetic data indicated that the influence of polluting material expectedly present in the sump is likely to be negligible too. A possible exception may be the enhancement of the decomposition rate by particulate and dissolved silver. The resistance of methyl iodide to gas phase decomposition by steam and oxygen at 423 K was investigated and only slow decomposition in the order of 10-7/s observed which is explained by reaction with steel surfaces. Neither gas phase oxidation nor hydrolysis occur at this temperature. The resistance to oxidation is of kinetic nature. Gas phase hydrolysis is not possible due to thermodynamics. This was confirmed by the observed gas phase formation of methyl iodide from hydrogen iodide and methanol at 423 K. The kinetics of this reaction are best explained by two parallel reactions, one of second order with a kinetic constant of 1.25 x 10-5/kPa s, and one of third order under action of steam with a constant of 2 x 10-6/kPa2 s. (orig./HP)

  5. Monochloramine determination using NN diethyl-p-phenylene-diamine. Influence of iodide traces

    International Nuclear Information System (INIS)

    When determining ''D.P.D.'' free oxidizers, the monochloramine interfers in particular for iodide levels analogous to those likely to be found in sea water. This is not so for iodate. The zero time extrapolation of the change in colour curve is one method that enables the method to be made more selective

  6. Photodissociation of sodium iodide and resonant ionization of sodium atom produced

    Institute of Scientific and Technical Information of China (English)

    HUO Bing-hai; Z.T.Salim; A.H.Bakery

    2004-01-01

    Resonant ionization spectroscopy (RIS) and resonant ionization mass spectroscopy (RIMS) are employed to detect the photodissociation product of sodium iodide molecules in a molecular beam in an intense laser field in the absence of the buffer gases. Time of flight mass spectra is recorded. In particular, the appearances of multiphoton ionization are discussed.

  7. Reductive degradation of perfluoroalkyl compounds with aquated electrons generated from iodide photolysis at 254 nm

    OpenAIRE

    Park, Hyunwoong; vecitis, Chad D.; Cheng, Jie; Dalleska, Nathan F; Mader, Brian T.; Hoffmann, Michael R.

    2011-01-01

    The perfluoroalkyl compounds (PFCs), perfluoroalkyl sulfonates (PFXS) and perfluoroalkyl carboxylates (PFXA) are environmentally persistent and recalcitrant towards most conventional water treatment technologies. Here, we complete an in depth examination of the UV-254 nm production of aquated electrons during iodide photolysis for the reductive defluorination of six aquated perfluoroalkyl compounds (PFCs) of various headgroup and perfluorocarbon tail length. Cyclic voltammograms (CV) show tha...

  8. Leaching of iodide (I(-)) and iodate (IO3(-)) anions from synthetic layered double hydroxide materials.

    Science.gov (United States)

    Theiss, Frederick L; Ayoko, Godwin A; Frost, Ray L

    2016-09-15

    Several studies have previously demonstrated that layered double hydroxides (LDHs) show considerable potential for the adsorption of radioiodine from aqueous solution; however, few studies have demonstrated that these materials are able to store radioactive (131)I for an acceptable period. The leaching of iodide (I(-)) and iodate (IO3(-)) form Mg/Al LDHs has been carried out. Contact time appeared to be a more significant variable for the leaching of iodate (IO3(-)) compared to that of iodide (I(-)). Experimental results are fitted to the pseudo second order model, suggesting that diffusion is likely to be the rate-limiting step. The presence of carbonate in the leaching solution appeared to significantly increase the leaching of iodide (I(-)) as did the presence of chloride to a lesser extent. The maximum amount of iodate (IO3(-)) leached using ultrapure water as the leaching solution was 21% of the iodate (IO3(-)) originally present. The corresponding result for iodide (I(-)) was even lower at 3%. PMID:27309951

  9. Electron stimulated reactions of methyl iodide coadsorbed with amorphous solid water

    International Nuclear Information System (INIS)

    The electron stimulated reactions of methyl iodide (MeI) adsorbed on and suspended within amorphous solid water (ice) were studied using a combination of postirradiation temperature programmed desorption and reflection absorption infrared spectroscopy. For MeI adsorbed on top of amorphous solid water (ice), electron beam irradiation is responsible for both structural and chemical transformations within the overlayer. Electron stimulated reactions of MeI result principally in the formation of methyl radicals and solvated iodide anions. The cross section for electron stimulated decomposition of MeI is comparable to the gas phase value and is only weakly dependent upon the local environment. For both adsorbed MeI and suspended MeI, reactions of methyl radicals within MeI clusters lead to the formation of ethane, ethyl iodide, and diiodomethane. In contrast, reactions between the products of methyl iodide and water dissociation are responsible for the formation of methanol and carbon dioxide. Methane, formed as a result of reactions between methyl radicals and either parent MeI molecules or hydrogen atoms, is also observed. The product distribution is found to depend on the film's initial chemical composition as well as the electron fluence. Results from this study highlight the similarities in the carbon-containing products formed when monohalomethanes coadsorbed with amorphous solid water are irradiated by either electrons or photons

  10. LIQUID-CRYSTALLINE AND THERMOCHROMIC BEHAVIOR OF 4-SUBSTITUTED 1-METHYLPYRIDINIUM IODIDE SURFACTANTS

    NARCIS (Netherlands)

    NUSSELDER, JJH; ENGBERTS, JBFN; VANDOREN, HA

    1993-01-01

    The mesogenic behaviour of a series of thirty-one 1-alkyl-4-(or 2-)alkyl-pyridinium salts and of a homologous series of four 1-methyl-4-n-alkoxycarbonylpyridinium iodides is described. The occurrence and stability range of the thermotropic phases depend dramatically on the structure of the surfactan

  11. Phase partitioning, retention kinetics, and leaching of fumigant methyl iodide in agricultural soils

    Science.gov (United States)

    Although it is not currently being sold in the USA, the recent US registration of the fumigant methyl iodide has led to an increased interest in its environmental fate and transport. Although some work has now considered its volatile emissions from soil, there remains a lack of experimental data reg...

  12. Mitigating 1,3-dichloropropene, chloropicrin, and methyl iodide emissions from fumigated soil with reactive film

    Science.gov (United States)

    Implicated as a stratospheric ozone-depleting compound, methyl bromide (MeBr) is being phased out despite being considered to be the most effective soil fumigant. Its alternatives, i.e., 1,3-dichloropropene (1,3-D, which includes cis- and trans- isomers), chloropicrin (CP) and methyl iodide (MeI), h...

  13. Expedient Method for Samarium(II) Iodide Preparation Utilizing a Flow Approach

    Czech Academy of Sciences Publication Activity Database

    Voltrová, Svatava; Šrogl, Jiří

    2013-01-01

    Roč. 24, č. 3 (2013), s. 394-396. ISSN 0936-5214 R&D Projects: GA MŠk LH12013 Institutional support: RVO:61388963 Keywords : flow * samarium * iodide * reduction Subject RIV: CC - Organic Chemistry Impact factor: 2.463, year: 2013

  14. Surface treatments of silver rods with enhanced iodide adsorption for I-125 brachytherapy seeds

    International Nuclear Information System (INIS)

    This study described an effective method to load 125I on silver rods for the preparation of a brachytherapy source. We tested various ligands on the silver rod surface to screen the one with the highest adsorption and specific radioactivity. In addition, we investigated the effect of surface etching to increase the adsorption capability followed by the extended surface area. We also found that the use of an oxidant during iodide adsorption can increase the loading significantly. The maximum activity of 137.90 MBq/rod (3.7269 mCi/rod) was achieved on the etched silver rods with phosphate ligand and hydrogen peroxide as an oxidant. In addition, this is 4.5-fold higher than that of the conventional chloride treatment method. - Highlights: • Surface treatment of silver rods with several ligands was investigated to find optimum ligand for production of I-125 seeds. • Activity of adsorbed iodide was increased up to 499% on HNO3-etched rods compared to H2O-washed rods. • When H2O2 was used as an oxidant for surface-modification, the amount of adsorbed iodide was increased up to 589%. • Activity of adsorbed iodide exhibited the highest value (137.90 MBq/rod) on rods etched and treated with PO43− and H2O2

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

    Science.gov (United States)

    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…

  16. Diffusion coefficient determination of sodium iodide vapor in rare gases with use of ionization sensor

    International Nuclear Information System (INIS)

    The diffusion coefficients of sodium iodide vapor in the rare gases, argon, krypton and xenon, are determined by a method combining the analysis of measured diffusing mass with continuous monitoring of the sodium iodide vapor concentration in a flowing stream of sodium iodide-rare gas mixture. The flowing sodium iodide vapor is ionized upon its passage over a heated filament, and the generated ions are collected by a negatively-charged arched plate saddling the filament. The resulting ion current, measured by digital current meter, is integrated in time to obtain cumulative values from outset of run. The curve of the integrated values plotted against time approaches linearity with progress of run. The asymptote of the curve intersects the time axis at a point whose position serves to determine the diffusion coefficient, by applying an equation derived from the formula given by Carslaw and Jaeger. The coefficients thus determined for the three rare gases in runs at temperatures between 660degC and 710degC have proved to agree well with the values estimated using the semi-empirical correlation presented by Wilke and Lee. (author)

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

    Science.gov (United States)

    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…

  18. Heat and Radiation Effects on Iodide Sorption by Surfactant Modified Bentonite (SMB)

    International Nuclear Information System (INIS)

    Radioactive waste repository is designed using multiple barriers to prevent the release of radionuclides to environments. Bentonite has been used as engineering barrier in many countries. Although the bentonite is an effective sorbent for cationic radionuclides, it is not good for anions such as 129-I and 99-Tc because of negative surface charges over the pH. Radioactive iodine exists usually as anions such as iodate (IO3-) and iodide (I-) as stable iodine species in groundwater environments. Therefore, the iodine is one of the most difficult elements for its transport through engineering barrier (i. e., bentonite) to be controlled by sorption processes in the geological repository. We modified the bentonite using a cationic surfactant to enhance iodine sorption capability. The goal of this study is addressed to evaluate the effects of sorption of high heat and radiation on iodide sorption to surfactant modified bentonite (SMB) which can be used as engineering barrier in the repository. The iodide sorption on the SMBs was significantly affected by temperature conditions rather than radiation. As temperature increases, the iodide sorption decreases. Considering the similar sorption abilities between 100 and 200% SMBs, the 100% SMB is economical sorbent to apply for engineering barrier in a geological repository

  19. Theoretical calculations of primary particle condensation for cadmium and caesium iodide vapours

    International Nuclear Information System (INIS)

    This report considers a model of aerosol nucleation from the vapour phase which has been developed by Buckle. The applicability of the model has been tested by considering the condensation of caesium iodide and cadmium vapours under a wide variety of pre-mixed flow conditions of interest to PWR severe accident studies. (U.K.)

  20. Electrical properties of silver iodide nanoparticles system embedded into opal porous matrix

    International Nuclear Information System (INIS)

    Opal-based composite with silver iodide nanoparticles (AgI/opal) has been prepared by host-guest technology. Temperature and frequency dependences of electrical conductivity and those of dielectric permittivity of AgI/opal samples were measured. Size effects in this opal-based nanocomposite have been discussed

  1. Solvation thermodynamics of ammonium iodide ions in 2-propanol and its mixtures with water

    International Nuclear Information System (INIS)

    The electrometric method using chains without transfer has been applied to determine total thermodynamic characteristics of ammonium iodide ions salvation in 2-propanol and its mixtures with water at 278.15-308.15 K.Regularities of their changes with temperature and composition of a mixed solvent are considered

  2. Reversible stimulus-responsive Cu(I) iodide pyridine coordination polymer.

    Science.gov (United States)

    Amo-Ochoa, P; Hassanein, K; Gómez-García, C J; Benmansour, S; Perles, J; Castillo, O; Martínez, J I; Ocón, P; Zamora, F

    2015-10-01

    We present a structurally flexible copper-iodide-pyridine-based coordination polymer showing drastic variations in its electrical conductivity driven by temperature and sorption of acetic acid molecules. The dramatic effect on the electrical conductivity enables the fabrication of a simple and robust device for gas detection. X-ray diffraction studies and DFT calculations allow the rationalisation of these observations. PMID:26264525

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

    Science.gov (United States)

    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…

  4. Kinetic modeling of the purging of activated carbon after short term methyl iodide loading

    International Nuclear Information System (INIS)

    A bimolecular reaction model containing the physico-chemical parameters of the adsorption and desorption was developed earlier to describe the kinetics of methyl iodide retention by activated carbon adsorber. Both theoretical model and experimental investigations postulated constant upstream methyl iodide concentration till the maximum break-through. The work reported here includes the extension of the theoretical model to the general case when the concentration of the challenging gas may change in time. The effect of short term loading followed by purging with air, and an impulse-like increase in upstream gas concentration has been simulated. The case of short term loading and subsequent purging has been experimentally studied to validate the model. The investigations were carried out on non-impregnated activated carbon. A 4 cm deep carbon bed had been challenged by methyl iodide for 30, 90, 120 and 180 min and then purged with air, downstream methyl iodide concentration had been measured continuously. The main characteristics of the observed downstream concentration curves (time and slope of break-through, time and amplitude of maximum values) showed acceptable agreement with those predicted by the model

  5. The preparation and structural properties of trivalent lanthanide and actinide oxide iodides

    International Nuclear Information System (INIS)

    A report is presented on the preparation of NpOI, LaOI and ErOI by reacting the appropriate tri-iodide and antimony sesquioxide at moderate temperatures. Positional parameters for the atoms in NpOI, derived from X-ray powder diffraction intensity data, are also reported. (U.K.)

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

    Science.gov (United States)

    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

  7. Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

    Energy Technology Data Exchange (ETDEWEB)

    Holm, J.; Ekberg, C. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT, Espoo (Finland)); Glaenneskog, H. (Vattenfall Power Consultant, Goeteborg (Sweden))

    2011-05-15

    An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment, was started. During year 2008 (NROI-1) the radiolytic oxidation of elemental iodine was investigated and during 2009 (NROI-2), the radiolytic oxidation of organic iodine was studied. This project (NROI-3) is a continuation of the investigation of the oxidation of organic iodine. The project has been divided into two parts. 1. The aims of the first part were to investigate the effect of ozone and UV-radiation, in dry and humid conditions, on methyl iodide. 2. The second project was about gamma radiation (approx20 kGy/h) and methyl iodide in dry and humid conditions. 1. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UV-radiation intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. The particle formation was instant and extensive when methyl iodide was exposed to ozone and/or radiation at all temperatures. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-200 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine oxides (I{sub xO{sub y}). However, the correct speciation of the formed particles was difficult to obtain because the particles melted and fused together under the electron beam. 2. The results from this sub-project are more inconsistent and hard to interpret. The particle formation was significant lesser than corresponding experiments when ozone/UV-radiation was used instead of gamma radiation. The transport of gaseous methyl iodide through the facility was

  8. Conversion of Iodide to Hypoiodous Acid and Molecular Iodine at the Air-Water Interface

    Science.gov (United States)

    Pillar, E. A.; Guzman, M. I.

    2013-12-01

    Sea spray aerosols continuously transfer a significant amount of halides to the marine boundary layer, where they play a major role in the depletion of tropospheric ozone. The reactivity of iodide is of special interest in sea spray aerosols, where this species is enriched relative to chloride and bromide in surface seawater. This work presents laboratory experiments that provide mechanistic information to understand the reactivity of halides in atmospheric aerosols. Pneumatically assisted electrospray is used to aerosolize solutions of sodium iodide (0.01-100 μM), which are rapidly (~3 μs) oxidized by ozone at 25 °C. Reaction products include HIO, IO2-, IO3-, I2, HI2O-, and I3-, all identified by mass spectrometry. The distribution of products varies along two different reaction pathways, one favoring the production of I2 and HIO for typical tropospheric ozone levels (~50 ppbv), and another one directed to the production of IO3- at higher oxidizer concentrations. The formation of products increases exponentially with rising concentrations of initial sodium iodide, [NaI]0. The process is determined to be pH independent for the pH range 6-8 representative of surface waters. The substitution of aqueous solutions by organic solvents, such as methanol or acetonitrile, causes a decrease in the surface tension and lifetime of the droplets, leading to larger I2 production. The presence of surface active organic compounds, which alter the structure of the interfacial region, promote the pathway of I2 formation over IO3-. In conclusion, this presentation will show how the oxidation of iodide in aqueous microdroplets can release reactive gas-phase species, such as I2 and HIO, capable to affect tropospheric ozone globally. Normalized intensity of products observed during the ozonolysis of iodide solutions at 130 ppbv ozone. Cone voltage = 70 V, needle voltage = 2.5 kV.

  9. The use of mercuric iodide in instruments for safeguards and non-proliferation applications

    International Nuclear Information System (INIS)

    Mercuric Iodide is a material exceptionally suited for solid state detectors operating at room temperature. The high density and the high atomic numbers of the constituent elements provide a large absorption factor and a high full-energy-peak efficiency at gamma ray energies. The large electronic bandgap results in a very high resistivity and therefore a low leakage current at temperatures within and outside the personal comfort range. Constellation Technology has developed the technology to grow large, high quality crystals from mercuric iodide. Spectrometry grade detectors with dimensions of 25 mm x 25 mm x 3 mm and with an energy resolution of approximately 3% FWHM at 662 keV can be fabricated from these mercuric iodide crystals. The spectral resolution is primarily determined by the transport properties of the holes that at present still have relatively low values. When radiation of lower energy needs to be measured, it is possible to reduce the thickness of the detector and still maintain an acceptable detection efficiency. The spectrum of a 1.5 mm thick detector is shown. The resolution of this detector approximately 1.8% FWHM and the peak-to-valley ratio is larger than twelve. Standard semi-Gaussian processing and no pulse-shape discrimination was used. These detectors can be conveniently incorporated into hand-held instruments to detect weak sources or heavily shielded sources. Previous measurements have shown that the Minimum Detectable Activity (MDA) of a 3 mm thick mercuric iodide detector with dimensions as given above is about 10% less than the MDA of a 50 mm x 50 mm sodium iodide detector, due to the superior energy resolution. Software methods are being developed to improve the identification of weak sources against a large background. Results of these measurements will be presented

  10. Accumulation of organochlorines and brominated flame retardants in estuarine and marine food chains: Field measurements and model calculations

    NARCIS (Netherlands)

    Veltman, K.; Hendriks, J.; Huijbregts, M.; Leonards, P.E.G.; Heuvel-Greve, van den M.J.; Vethaak, D.

    2005-01-01

    Food chain accumulation of organochlorines and brominated flame retardants in estuarine and marine environments is compared to model estimations and fresh water field data. The food chain consists of herbivores, detritivores and primary and secondary carnivores i.e. fish, fish-eating birds and marin

  11. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    International Nuclear Information System (INIS)

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH− ligand generates and adsorbs in a certain scale because of abundant OH− on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs

  12. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Xu, Lining, E-mail: xulining@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Minxu [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Meng, Yao [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Zhu, Jinyang; Zhang, Lei [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-09-30

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH{sup −} ligand generates and adsorbs in a certain scale because of abundant OH{sup −} on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs.

  13. Exposure to brominated trihalomethanes in water during pregnancy and micronuclei frequency in maternal and cord blood lymphocytes

    DEFF Research Database (Denmark)

    Stayner, Leslie Thomas; Pedersen, Marie; Patelarou, Evridiki;

    2014-01-01

    BACKGROUND: Water disinfection by-products have been associated with an increased cancer risk. Micronuclei (MN) frequency in lymphocytes is a marker of genomic damage and can predict adult cancer risk. OBJECTIVE: We evaluated maternal exposure to drinking water brominated trihalomethanes (BTHM) i...

  14. Preparation of bromine-77 labelled monoclonal anti-hPLAP [human placental alkaline phosphatase] antibody using chloramine-T

    International Nuclear Information System (INIS)

    A tumor-associated monoclonal antibody, named 7E8 and raised against human placental alkaline phosphatase (hPLAP), is labelled with bromine-77 by means of chloramine-T. The paper describes optimum radiobromination conditions resulting in 34 % radiochemical yield of labelled antibody with more than 90 % immunoreactivity. (author)

  15. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    NARCIS (Netherlands)

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N. J. A.; Sauer, Pieter J. J.; Bos, Arend F.

    2009-01-01

    BACKGROUND: Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. OBJECTIVE: We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age. METHOD

  16. Synergistic Effect of Azadirachta Indica Extract and Iodide Ions on the Corrosion Inhibition of Aluminium in Acid Media

    International Nuclear Information System (INIS)

    The synergistic action caused by iodide ions on the corrosion inhibition of aluminium (Al) in 0.5 M HCl in the presence of Azadirachta Indica (AZI) plant extract has been investigated using potintiodynamic polarization and impedance techniques. It is found that AZI extract inhibits the corrosion of aluminium in 0.5 M HCl. The inhibition efficiency increases with the increase in AZI extract concentration, until 24% v/v of AZI extract, then Inh.% is decreased with father increase in AZI extract concentration. The adsorption of this extract in the studied concentration is found to obey Frewendlish adsorption isotherm. The addition of iodide ions enhances the inhibition efficiency to a considerable extent. The increase in Inh.% values in presence of fixed concentration of iodide ions indicates that AZI extract forms an insoluble complex at lower AZI extract concentrations by undergoing a joint adsorption. But at higher concentrations of AZI extract, competitive adsorption is found between iodide ions and the formed complex leading to less Inh.%. The Inh.% decreased in presence of iodide ions with AZI extract than in presence of AZI extract alone at all studied iodide concentrations. The synergism parameter S θ is defined and calculated from surface coverage values. This parameter in the case of AZI extract is found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of iodide ions

  17. Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

    International Nuclear Information System (INIS)

    Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

  18. Contrasting the surface ocean distribution of bromoform and methyl iodide; implications for boundary layer physics, chemistry and climate

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, C J, E-mail: carl.j.palmer@gmail.co [Department of Oceanography, University of Cape Town, 7701 (South Africa)

    2010-08-15

    Bromoform and methyl iodide are both methane-like hydrocarbons with a halogen atom replacing one or more of the hydrogen atoms. Both of these compounds occur naturally in the environment as a result of their production from seaweed and kelp. They are of interest to climate science as a result of their catalytic destruction of boundary layer ozone (a potent greenhouse gas) and, specifically for methyl iodide, the proposed role in the formation of new cloud condensation nuclei with implications for climate. In this paper, the currently available data on the distribution of bromoform and methyl iodide are analysed and contrasted to show that the concentrations of bromoform and methyl iodide do not correlate, that, in contrast to bromoform, the parameterization of sea surface methyl iodide concentrations demands only the sea surface temperature, and that the pelagic distribution of methyl iodide appears to follow the solar zenith angle. These three observations together suggest that, while the pelagic source of bromoform is mostly biogenic, the source of methyl iodide is photochemical. This has implications for the understanding of planetary boundary layer chemistry and potential organohalogen mediated feedbacks to climate.

  19. Synthesis of cholesteryl-α-D-lactoside via generation and trapping of a stable β-lactosyl iodide

    Science.gov (United States)

    Davis, Ryan A.; Fettinger, James C.; Gervay-Hague, Jacquelyn

    2015-01-01

    The generation of β-lactosyl iodide was carried out under non-in situ-anomerization, metal free conditions by reacting commercially available β-per-O-acetylated lactose with trimethylsilyl iodide (TMSI). The β-iodide was surprisingly stable as evidenced by NMR spectroscopy. Introduction of octanol or cholesterol under microwave conditions gave high yields of α-linked glycoconjugates. Careful analysis of the reaction products and mechanistic considerations suggest an acid catalyzed rearrangement that provides α-linked glycosylation products with a free C2-hydroxyl. Accessibility to these compounds may further advance glycolipidomic profiling of immune modulating bacterial derived-glycans. PMID:26543257

  20. Investigating the lifetime of bromine-quenched G.M. Counters with temperature

    International Nuclear Information System (INIS)

    The amount of halogen quench gas as a percentage of the total fill gas contained within a gas-filled Geiger–Müller detector is directly linked to its operational characteristics. Preserving this halogen gas will help maintain the operating lifetime of the detectors. Such halogen gases are highly corrosive and the small quantities within a gas-filled detector can deplete rapidly via interactions with surrounding materials. The rate of interactions is thought to be proportional to not only temperature, but also to the current initiated by ionisation events associated with the formation of each signal pulse. As all pulses are of similar magnitudes, GM detector operational lifetimes are quantified in accumulated counts rather than a given operating time. We have studied three different types of corrosion-resistant mechanisms to protect the bromine halogen gas from any interactions with 446 stainless steel detector components of ZP1200 Geiger–Müller tubes at temperatures up to 125 °C. Three types of surface treatments for these detectors used were labelled as “raw” using only an oxygen-plasma-bombardment process, “passivated” using a combination of nitric acid passivation followed by an oxygen plasma-bombardment process, and thirdly plating with a few micron thickness of chromium followed by an oxygen plasma-bombardment process. 32 detector samples were irradiated at room temperature with a Caesium-137 source at dose rates of approximately 1.3 mSv/hr up to 5.7×1010 accumulated counts; another 32 detector samples were aged to 3.3×1010 counts at 125 °C. At room temperature, the chromium-plated samples exhibited an initial rise in their starting voltage readings. All other detector performance characteristics, for all detector types, did not change significantly during the ageing process, and the surface morphology of the detector cathodes was unaffected. At 125 °C, the chromium-based plating produced the most stable long-term response. These chromium